WO2013008455A1 - Solar cell backside protective sheet and solar cell - Google Patents

Solar cell backside protective sheet and solar cell Download PDF

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Publication number
WO2013008455A1
WO2013008455A1 PCT/JP2012/004458 JP2012004458W WO2013008455A1 WO 2013008455 A1 WO2013008455 A1 WO 2013008455A1 JP 2012004458 W JP2012004458 W JP 2012004458W WO 2013008455 A1 WO2013008455 A1 WO 2013008455A1
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WIPO (PCT)
Prior art keywords
solar cell
adhesive
base material
parts
mol
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Application number
PCT/JP2012/004458
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French (fr)
Japanese (ja)
Inventor
猿渡　昌隆
安川　秀範
裕紀 杉
島田　健志郎
Original Assignee
東洋アルミニウム株式会社
東洋インキＳｃホールディングス株式会社
トーヨーケム株式会社
東洋モートン株式会社
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Publication date
Application filed by 東洋アルミニウム株式会社, 東洋インキＳｃホールディングス株式会社, トーヨーケム株式会社, 東洋モートン株式会社 filed Critical 東洋アルミニウム株式会社
Priority to KR1020137034436A priority Critical patent/KR101871293B1/en
Priority to JP2013523831A priority patent/JP6046620B2/en
Priority to CN201280033885.4A priority patent/CN103650156B/en
Publication of WO2013008455A1 publication Critical patent/WO2013008455A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/04—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices
    • H01L31/042—PV modules or arrays of single PV cells
    • H01L31/048—Encapsulation of modules
    • H01L31/049—Protective back sheets
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J175/00—Adhesives based on polyureas or polyurethanes; Adhesives based on derivatives of such polymers
    • C09J175/04—Polyurethanes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
    • B32B27/08—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/40—Layered products comprising a layer of synthetic resin comprising polyurethanes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
    • B32B7/04—Interconnection of layers
    • B32B7/12—Interconnection of layers using interposed adhesives or interposed materials with bonding properties
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G18/00—Polymeric products of isocyanates or isothiocyanates
    • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
    • C08G18/08—Processes
    • C08G18/10—Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G18/00—Polymeric products of isocyanates or isothiocyanates
    • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
    • C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
    • C08G18/40—High-molecular-weight compounds
    • C08G18/42—Polycondensates having carboxylic or carbonic ester groups in the main chain
    • C08G18/4202—Two or more polyesters of different physical or chemical nature
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G18/00—Polymeric products of isocyanates or isothiocyanates
    • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
    • C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
    • C08G18/40—High-molecular-weight compounds
    • C08G18/42—Polycondensates having carboxylic or carbonic ester groups in the main chain
    • C08G18/4205—Polycondensates having carboxylic or carbonic ester groups in the main chain containing cyclic groups
    • C08G18/4208—Polycondensates having carboxylic or carbonic ester groups in the main chain containing cyclic groups containing aromatic groups
    • C08G18/4225—Polycondensates having carboxylic or carbonic ester groups in the main chain containing cyclic groups containing aromatic groups derived from residues obtained from the manufacture of dimethylterephthalate and from polyhydroxy compounds
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G18/00—Polymeric products of isocyanates or isothiocyanates
    • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
    • C08G18/70—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the isocyanates or isothiocyanates used
    • C08G18/72—Polyisocyanates or polyisothiocyanates
    • C08G18/74—Polyisocyanates or polyisothiocyanates cyclic
    • C08G18/75—Polyisocyanates or polyisothiocyanates cyclic cycloaliphatic
    • C08G18/751—Polyisocyanates or polyisothiocyanates cyclic cycloaliphatic containing only one cycloaliphatic ring
    • C08G18/752—Polyisocyanates or polyisothiocyanates cyclic cycloaliphatic containing only one cycloaliphatic ring containing at least one isocyanate or isothiocyanate group linked to the cycloaliphatic ring by means of an aliphatic group
    • C08G18/753—Polyisocyanates or polyisothiocyanates cyclic cycloaliphatic containing only one cycloaliphatic ring containing at least one isocyanate or isothiocyanate group linked to the cycloaliphatic ring by means of an aliphatic group containing one isocyanate or isothiocyanate group linked to the cycloaliphatic ring by means of an aliphatic group having a primary carbon atom next to the isocyanate or isothiocyanate group
    • C08G18/755—Polyisocyanates or polyisothiocyanates cyclic cycloaliphatic containing only one cycloaliphatic ring containing at least one isocyanate or isothiocyanate group linked to the cycloaliphatic ring by means of an aliphatic group containing one isocyanate or isothiocyanate group linked to the cycloaliphatic ring by means of an aliphatic group having a primary carbon atom next to the isocyanate or isothiocyanate group and at least one isocyanate or isothiocyanate group linked to a secondary carbon atom of the cycloaliphatic ring, e.g. isophorone diisocyanate
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G18/00—Polymeric products of isocyanates or isothiocyanates
    • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
    • C08G18/70—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the isocyanates or isothiocyanates used
    • C08G18/72—Polyisocyanates or polyisothiocyanates
    • C08G18/77—Polyisocyanates or polyisothiocyanates having heteroatoms in addition to the isocyanate or isothiocyanate nitrogen and oxygen or sulfur
    • C08G18/78—Nitrogen
    • C08G18/79—Nitrogen characterised by the polyisocyanates used, these having groups formed by oligomerisation of isocyanates or isothiocyanates
    • C08G18/791—Nitrogen characterised by the polyisocyanates used, these having groups formed by oligomerisation of isocyanates or isothiocyanates containing isocyanurate groups
    • C08G18/792—Nitrogen characterised by the polyisocyanates used, these having groups formed by oligomerisation of isocyanates or isothiocyanates containing isocyanurate groups formed by oligomerisation of aliphatic and/or cycloaliphatic isocyanates or isothiocyanates
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L63/00—Compositions of epoxy resins; Compositions of derivatives of epoxy resins
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J163/00—Adhesives based on epoxy resins; Adhesives based on derivatives of epoxy resins
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J175/00—Adhesives based on polyureas or polyurethanes; Adhesives based on derivatives of such polymers
    • C09J175/04—Polyurethanes
    • C09J175/06—Polyurethanes from polyesters
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/04—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices
    • H01L31/042—PV modules or arrays of single PV cells
    • H01L31/048—Encapsulation of modules
    • H01L31/0481—Encapsulation of modules characterised by the composition of the encapsulation material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2457/00—Electrical equipment
    • B32B2457/12—Photovoltaic modules
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/50—Photovoltaic [PV] energy
    • Y02E10/52—PV systems with concentrators

Definitions

  • the present invention relates to a solar cell back surface protection sheet used on the back surface of a solar cell module, and a solar cell module including the solar cell back surface protection sheet.
  • a solar cell module is used for photovoltaic power generation, and a solar cell back surface protection sheet (so-called back sheet) is provided for the purpose of protection and insulation from the back surface.
  • the solar cell module is required to have a service life of a long period of more than ten years, and the long-term reliability is also required for the backsheet that protects it.
  • the backsheet is required to have insulation against electricity generated from a power generation element called a cell and good adhesion to a sealing material for sealing the cell.
  • Patent Documents 1 and 2 back sheets obtained by laminating various resin films and metal foils via an adhesive have been proposed.
  • Patent Document 3 an outdoor polyurethane adhesive containing a polyester polyol or a polyester polyurethane polyol has been proposed (Patent Document 3).
  • the adhesive used for the backsheet is required to have good adhesion and weather resistance that can withstand long-term use. Further, it is required that the adhesive is inexpensive and can be easily applied by a general coating method such as gravure coating or comma coating. Furthermore, it is required to be excellent in wet heat resistance and exhibit an excellent adhesive force even in an environment lower than normal temperature.
  • the conventional backsheet has room for further improvement in these respects.
  • the present invention has been made in view of the above background, and is excellent in long-term reliability, wet heat resistance, excellent adhesiveness in a low-temperature environment, and further excellent in cost and coating properties.
  • the main object is to provide a sheet and a solar cell module.
  • the present inventor used an adhesive containing a main agent and a curing agent having a specific composition, and a specific amount of the specific curing agent with respect to the main agent. The inventors have found that the above object can be achieved and have completed the present invention.
  • the solar cell back surface protective sheet according to the present invention includes at least 1) an outer layer base material having weather resistance, 2) an intermediate layer base material, and 3) a seal for sealing a power generation element used in the solar cell module.
  • An adhesive layer composed of a stopper and an inner layer base material having good adhesiveness and joining at least one side of the thickest base material among the outer layer base material, the intermediate layer base material, and the inner layer base material is the following (1) Formed of a main agent containing (3) and an adhesive containing a curing agent of (4) below, The adhesive has a solid content of 4 to 12 parts by weight based on 100 parts by weight of the main component solids.
  • a dibasic acid component containing 40 to 70 mol% of an aromatic dibasic acid and 30 to 60 mol% of an aliphatic dibasic acid having 9 to 10 carbon atoms, and an aliphatic dihydric alcohol 30 having 5 or more carbon atoms A linear polyester polyol having a weight average molecular weight of 70,000 to 80,000 obtained by reacting with a dihydric alcohol component containing ⁇ 40 mol%.
  • a dibasic acid component containing 60 to 80 mol% of an aromatic dibasic acid and 20 to 40 mol% of an aliphatic dibasic acid having 9 to 10 carbon atoms, and an aliphatic dihydric alcohol 70 having 5 or more carbon atoms A polyester polyurethane polyol having a weight average molecular weight of 30,000 to 40,000, which is obtained by reacting a polyester polyol obtained by reacting with a dihydric alcohol component containing ⁇ 80 mol% with an organic diisocyanate.
  • the thickness of the thickest substrate is preferably 125 to 350 ⁇ m, and the adhesive amount of the adhesive layer in contact with the thickest substrate is in the range of more than 5 g / m 2 and 30 g / m 2 or less. Is preferred. Moreover, it is preferable that there are a plurality of the intermediate layer base materials, and at least a part thereof is bonded to each other via the adhesive layer.
  • the linear polyester polyol is preferably 60 to 80% by weight in a total of 100% by weight of the linear polyester polyol and the polyester polyurethane polyol.
  • the solar cell module according to the present invention includes the solar cell back surface protective sheet of the above aspect.
  • the solar cell back surface protective sheet of the present invention is excellent in long-term reliability and wet heat resistance, and is excellent in adhesiveness in a low-temperature environment, and is excellent in cost and coating properties. And the outstanding effect that a solar cell module can be provided is produced.
  • any number A to any number B means a range larger than the numbers A and A but smaller than the numbers B and B.
  • the solar cell back surface protective sheet of the present invention includes at least 1) an outer layer base material having weather resistance, 2) an intermediate layer base material, and 3) a sealing material for sealing a power generation element used in a solar cell module; It is comprised from the inner-layer base material which has favorable adhesiveness.
  • the adhesive layer for bonding at least one surface of the thickest base material among the outer layer base material, the intermediate layer base material, and the inner layer base material has the following (1) to (3). It is formed with the main ingredient containing this and the adhesive agent containing the hardening
  • the solar cell back surface protective sheet of the present invention can also bond the substrates to each other with another adhesive.
  • An inner layer base material is arrange
  • the intermediate layer base material may be singular or plural.
  • the solar cell back surface protection sheet is required to have voltage resistance. It is preferable to provide the voltage resistance mainly to the intermediate layer base material. However, when a plurality of intermediate layer base materials are provided, all of the intermediate layer base materials may not have voltage resistance.
  • the term “adhesive” refers to the adhesive of the present invention containing the main agent containing the following (1) to (3) and the curing agent (4) below.
  • the thickness of the thickest substrate among the outer layer substrate, the intermediate layer substrate, and the inner layer substrate is preferably 125 to 350 ⁇ m.
  • the adhesive amount after drying of the adhesive layer in contact with the thickest substrate is in the range of more than 5 g / m 2 and 30 g / m 2 or less. The reason will be described later.
  • the thickest substrate may be any of an outer layer substrate, an intermediate layer substrate, and an inner layer substrate, but the intermediate layer substrate is preferably the thickest substrate.
  • the application surface of the above-mentioned adhesive amount is one surface, but when the intermediate layer base material is the thickest base material, the intermediate layer base material It is preferable that at least one of the two joint surfaces of the material satisfies the above coating conditions.
  • the adhesive layer of the present invention has a range of more than 5 g / m 2 and 30 g / m 2 or less at the two joining surfaces. .
  • the said adhesive agent can be applied suitably also to joining of base materials other than the thickest base material. That is, the adhesive of the present invention can be suitably used for all the joining of each base material (for example, plastic film, metal foil, etc.) constituting the solar cell back surface protective sheet.
  • the adhesive of the present invention is a polyurethane adhesive containing a main agent and a curing agent.
  • the adhesive may be a two-component mixed adhesive that mixes the main agent and the curing agent at the time of use, or may be a one-component adhesive in which the main agent and the curing agent are mixed in advance. .
  • curing agent at the time of use may be sufficient.
  • the main component of the adhesive is (1) a dibasic acid component containing 40 to 70 mol% of an aromatic dibasic acid and 30 to 60 mol% of an aliphatic dibasic acid having 9 to 10 carbon atoms, and 5 or more carbon atoms.
  • the curing agent for the adhesive contains (4) a polyisocyanate having an isocyanurate of isophorone diisocyanate.
  • the adhesive of the present invention contains 4 to 12 parts by weight of the solid content of the curing agent with respect to 100 parts by weight of the solid content of the main agent. More preferably, it is 6 to 12 parts by weight, and still more preferably 8 to 10 parts by weight.
  • the linear polyester polyol (hereinafter also simply referred to as “polyester polyol”) used in the present invention comprises 40 to 70 mol% of an aromatic dibasic acid and 30 to 60 mol% of an aliphatic dibasic acid having 9 to 10 carbon atoms.
  • the dibasic acid component contained is reacted with a dihydric alcohol component containing 30 to 40 mol% of an aliphatic dihydric alcohol having 5 or more carbon atoms.
  • a dibasic acid or a polyhydric alcohol component having another structure may be included.
  • dibasic acid and its ester compound examples include isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, phthalic anhydride, adipic acid, azelaic acid, sebacic acid, succinic acid, glutaric acid, tetrahydrophthalic anhydride, hexahydrophthalic anhydride Examples thereof include acid, maleic anhydride, itaconic anhydride and ester compounds thereof.
  • the aromatic dibasic acid is 40 to 70 mol% (preferably 50 to 60 mol%) and the aliphatic dibasic having 9 to 10 carbon atoms based on the total amount of the dibasic acid.
  • the acids are combined so as to be 30 to 60 mol% (preferably 40 to 50 mol%).
  • the amount of aromatic dibasic acid used is less than 40 mol%, sufficient heat resistance and viscoelasticity may not be obtained. Moreover, by setting it as 70 mol% or less, adhesive force can be exhibited more effectively. Further, by setting the aliphatic dibasic acid having 9 to 10 carbon atoms to 30 mol% or more, the ester bond degree of the polyester polyol is made appropriate, the hydrolysis base point is suppressed, and long-term wet heat resistance is more effectively brought out. be able to. Further, by setting the aliphatic dibasic acid having 9 to 10 carbon atoms to 60 mol% or less, it is possible to appropriately adjust the heat resistance and viscoelasticity and to more effectively express the adhesive force.
  • the aromatic dibasic acid is preferably terephthalic acid, dimethyl terephthalate, isophthalic acid, or phthalic anhydride from the viewpoint of reactivity in the transesterification reaction.
  • azelaic acid having 9 carbon atoms and sebacic acid having 10 carbon atoms are preferable from the viewpoint of high lipophilicity, hydrophobicity, and suppression of water absorption into the polymer. .
  • the dihydric alcohol component by controlling the proportion of aliphatic dihydric alcohol having 5 or more carbon atoms to 30 mol% or more, it is possible to suppress the increase in hydrolysis base point by making the ester bond degree of the polyester polyol appropriate, and long-term moisture resistance Thermal properties can be extracted more effectively. Moreover, the solubility to the organic solvent of a product becomes favorable by making the ratio of an aliphatic dihydric alcohol 40 mol% or less, and the applicability
  • aliphatic dihydric alcohols having 5 or more carbon atoms as aliphatic dihydric alcohols having 5 or more carbon atoms, neopentyl glycol having 5 carbon atoms and having improved side chain stability and 3-methyl-1,5-pentane having 6 carbon atoms Diol, 1,6-hexanediol and the like that are highly lipophilic and hydrophobic and suppress water absorption into the polymer are preferred.
  • the weight average molecular weight of the polyester polyol is 70,000 to 80,000 from the viewpoint of ensuring cohesive strength, stretchability and adhesive strength. Among these, from the viewpoint of the solubility of the resin, the viscosity, and the coating property (handleability) of the adhesive, it is more preferably 72,000-78,000.
  • the number average molecular weight was measured using GPC (gel permeation chromatography) “HPC-8020” manufactured by Tosoh Corporation. GPC is liquid chromatography that separates and quantifies substances dissolved in a solvent (THF; tetrahydrofuran) based on the difference in molecular size.
  • LF-604 manufactured by Showa Denko KK: GPC column for rapid analysis: 6MMID ⁇ 150MM size
  • the flow rate is 0.6 ML / MIN
  • the column temperature is 40. It carried out on the conditions of (degreeC) and the determination of the weight average molecular weight (Mw) was performed in polystyrene conversion.
  • polyester polyurethane polyol used in the present invention comprises 60 to 80 mol% (preferably 65 to 75 mol%) of an aromatic dibasic acid and 20 to 40 mol% (preferably 25 to 40 mol%) of an aliphatic dibasic acid having 9 to 10 carbon atoms. 35 mol%) and a dihydric alcohol component containing 70 to 80 mol% (preferably 72 to 78 mol%) of an aliphatic dihydric alcohol having 5 or more carbon atoms.
  • the polyester polyol obtained is reacted with an organic diisocyanate.
  • the amount of aromatic dibasic acid used 60 mol% or more heat resistance and viscoelasticity can be obtained effectively.
  • the adhesive force can be more effectively exhibited by setting it to 80 mol% or less.
  • the ester bond degree of the polyester polyol is made appropriate, the hydrolysis base point is suppressed, and long-term wet heat resistance is more effectively brought out. be able to.
  • the aliphatic dibasic acid having 9 to 10 carbon atoms 40 mol% or less it is possible to appropriately adjust the heat resistance and viscoelasticity and to exhibit the adhesive force more effectively. It is done.
  • Organic diisocyanate is not particularly limited. Specific examples include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, 1,5-naphthalene diisocyanate, hexamethylene diisocyanate, hydrogenated diphenylmethane diisocyanate, and the like. It is done. These can be used alone or in combination of two or more. From the viewpoint of reducing yellowing of the adhesive over time, it is preferable to use an aliphatic or alicyclic isocyanate compound for the urethane cross-linking part.
  • the weight average molecular weight of the polyester polyurethane polyol is 30,000 to 40,000 in view of adjusting the viscosity as an adhesive in consideration of the large weight average molecular weight of the polyester polyol and the high viscosity. Among these, 32,000 to 38,000 is more preferable.
  • the bisphenol type epoxy resin used in the present invention preferably has a number average molecular weight of 1,000 to 2,000 and an epoxy equivalent of 500 to 1,000 g / eq.
  • the epoxy group reacts with the carboxyl group generated by hydrolysis of the ester bond to suppress the decrease in molecular weight due to the hydrophobicity of the bisphenol skeleton.
  • bisphenol-type epoxy resins bisphenol A-type epoxy resins and bisphenol F-type epoxy resins are preferable from the viewpoint of maintaining shear strength, and these can be used alone or in combination of two or more.
  • the number average molecular weight of the bisphenol type epoxy resin may be 1,000 to 2,000 from the viewpoints of adjusting the heat resistance and viscoelasticity of the cured adhesive film and adjusting the solution viscosity. If the number average molecular weight of the bisphenol-type epoxy resin is less than 1,000, sufficient heat resistance may not be obtained. Moreover, adhesive force can be more effectively exhibited by a number average molecular weight being 2,000 or less. In the present invention, the use of a high molecular weight polyol is expected to reduce the viscosity of the adhesive solution by using a low molecular weight epoxy resin, thereby improving the coating property. However, the number average molecular weight is 2,000. By making it below, the solution viscosity can be effectively reduced.
  • the number average molecular weight of the bisphenol type epoxy resin is preferably 1,200 to 1,800 from the balance between wet heat resistance and low temperature adhesive strength.
  • the composition ratio of the polyester polyol and the polyester polyurethane polyol (hereinafter collectively referred to as “polyol component”) is not particularly limited, but the polyester polyol is used in an amount of 60 to 80% by weight in a total of 100% by weight of the polyol component. It is preferable to use 65 to 75% by weight.
  • the ratio of the polyester polyol in the polyol component is preferably in the range of 60 to 80% by weight from the balance between wet heat resistance and low temperature adhesive force.
  • the ratio of ester bond by reaction of carboxyl group and hydroxyl group in the polyol component (reaction ratio of carboxyl group and hydroxyl group is 1: 1) is expressed as the degree of ester bond (mol / 100 g) in the molecule. It is desirable to design to be less than 1. That is, by setting the degree of ester bond to less than 1, the ratio of ester bonds can be reduced to increase hydrolysis resistance, and deterioration of adhesive strength over time can be further suppressed to improve long-term wet heat resistance.
  • the present invention uses a dibasic acid having a large molecular weight of 9 to 10 and a polyhydric alcohol having a large molecular weight of 5 or more as a dibasic acid, so in unit weight (in 100 g).
  • the ester bond degree of the polyol component is preferably in the range of 0.75 to 0.99.
  • Such an ester bond degree can be achieved within the range of the ratio of the aromatic dibasic acid in the dibasic acid component and the carbon number of the polyhydric alcohol in the adhesive used in the present invention.
  • the acid value (mgKOH / g) of the polyol component is preferably 5 or less, and more preferably 2 or less.
  • the main component of the adhesive can contain any additive as long as the effects of the present invention are not impaired.
  • the additive include a silane coupling agent, a reaction accelerator, a leveling agent, and an antifoaming agent.
  • silane coupling agent examples include trialkoxysilanes having a vinyl group such as vinyltrimethoxysilane and vinyltriethoxysilane, 3-aminopropyltriethoxysilane, and N- (2-aminoethyl) 3-aminopropyltrimethoxy.
  • Trialkoxysilanes having amino groups such as silane; glycidyl groups such as 3-glycidoxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and 3-glycidoxypropyltriethoxysilane; The trialkoxysilane which has is mentioned.
  • These silane coupling agents can be used alone or in combination of two or more.
  • the amount of the silane coupling agent added is preferably 0.5 to 5% by weight, more preferably 1 to 3% by weight, based on the total amount of the main agent. If it is less than 0.5% by weight, the effect of improving the adhesive strength by adding the silane coupling agent is poor, and even if it exceeds 5% by weight, no further improvement in performance is observed.
  • reaction accelerator examples include metal catalysts such as dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate, and dibutyltin dimaleate; 1,8-diaza-bicyclo (5,4,0) undecene-7,1,5 -Tertiary amines such as diazabicyclo (4,3,0) nonene-5,6-dibutylamino-1,8-diazabicyclo (5,4,0) undecene-7; reactive tertiary amines such as triethanolamine 1 type, or 2 or more types of reaction accelerators selected from these groups can be used.
  • metal catalysts such as dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate, and dibutyltin dimaleate
  • leveling agents include polyether-modified polydimethylsiloxane, polyester-modified polydimethylsiloxane, aralkyl-modified polymethylalkylsiloxane, polyester-modified hydroxyl group-containing polydimethylsiloxane, polyetherester-modified hydroxyl group-containing polydimethylsiloxane, and acrylic copolymers.
  • antifoaming agent examples include silicone resins, silicone solutions, copolymers of alkyl vinyl ethers, acrylic acid alkyl esters, and methacrylic acid alkyl esters.
  • the curing agent used in the present invention includes a polyisocyanate having an isocyanurate of isophorone diisocyanate.
  • This isocyanurate has a long pot life after mixing with the main agent, good solution stability, and long-term wet heat resistance of the adhesive.
  • the isocyanurate content is 50 to 100% by weight in the polyisocyanate.
  • isocyanurate means the trimer of diisocyanate.
  • the curing agent can contain any polyisocyanate in an amount of less than 50% by weight in addition to the above polyisocyanate.
  • it is preferably a low yellowing type aliphatic or alicyclic polyisocyanate.
  • Examples of the low molecular weight polyisocyanate include hexamethylene diisocyanate, phenylene diisocyanate, 2,4- or 2,6-tolylene diisocyanate, diphenylmethane-4,4-diisocyanate, 3,3-dimethyl-4,4-biphenylene diisocyanate, Examples include dicyclohexylmethane-4,4-diisocyanate, isophorone diisocyanate, and mixtures thereof.
  • Examples of the polyhydric alcohol to be reacted with these low molecular weight polyisocyanates include those described above as raw materials for the polyester polyol in the previous stage for producing the polyester polyurethane polyol.
  • the main agent and the curing agent have a hardener solid content of 4 to 12 parts by weight with respect to 100 parts by weight of the main agent solid content.
  • the amount of the curing agent By setting the amount of the curing agent to 4 parts by weight or more, the wet heat resistance can be improved more effectively.
  • the adhesive force in low temperature can be more effectively exhibited by making a hardening
  • the isocyanate group in the curing agent is blended so that the equivalent ratio is 1.0 to 10.0 with respect to the total of the hydroxyl groups of the polyester polyol and the polyester polyurethane polyol in the main agent. Considering the disappearance of isocyanate groups due to the reaction with water and the aging time after lamination, it is preferably 3.0 to 7.0.
  • weather resistant outer layer base material 1 examples include polyolefin resins such as polyethylene (PE) (high density polyethylene, low density polyethylene, linear low density polyethylene), polypropylene (PP), polybutene, and (meth) acrylic.
  • PE polyethylene
  • PP polypropylene
  • acrylic polybutene
  • polyvinyl chloride resin polystyrene resin, polyvinylidene chloride resin, saponified ethylene-vinyl acetate copolymer, polyvinyl alcohol, polycarbonate resin, fluororesin, polyvinylidene fluoride resin, polyvinyl fluoride resin
  • Polyvinyl acetate resins, acetal resins, polyester resins (polyethylene terephthalate (PET), polybutylene terephthalate, polyethylene naphthalate), polyamide resins, and other various resin films or sheets can be used. These resin films or sheets may be stretched in a uniaxial or biaxial direction.
  • a white pigment such as titanium oxide or barium sulfate or a black pigment such as carbon may be mixed for the purpose of absorbing or reflecting ultraviolet rays.
  • the thickness of the outer layer base material 1) is not limited, but can be, for example, about 10 to 350 ⁇ m, preferably about 10 to 100 ⁇ m.
  • the intermediate layer base material 2 for example, polyethylene terephthalate resin, ethylene trifluoroethylene film, and other various resin films or sheets can be used. These resin films or sheets may be stretched in a uniaxial or biaxial direction.
  • the thickness of the intermediate layer substrate 2) is not limited, but is preferably 30 to 350 ⁇ m, more preferably 100 to 350 ⁇ m, still more preferably 125 to 350 ⁇ m, and particularly preferably 150 to 300 ⁇ m. preferable.
  • the solar cell back surface protection sheet may be required to have a partial discharge voltage of 600 V or 1,000 V depending on the power generation capacity of the solar cell. . Since the partial discharge voltage depends on the thickness of the solar cell back surface protection sheet, the base material constituting the solar cell back surface protection sheet is required to be thicker than the base material constituting the food packaging laminate.
  • the intermediate layer base material 2) responsible for voltage resistance mainly bears “thickness”.
  • the thickness of the intermediate layer base material 2) is preferably 100 to 350 ⁇ m as described above.
  • the thickness of the intermediate layer base material 2) is preferably 125 to 350 ⁇ m.
  • PE polyethylene
  • high-density polyethylene low-density polyethylene, linear low-density polyethylene
  • an inner layer base material having good adhesiveness
  • Polyolefin resin such as polypropylene (PP), polybutene, (meth) acrylic resin, polyvinyl chloride resin, polystyrene resin, polyvinylidene chloride resin, saponified ethylene-vinyl acetate copolymer, polyvinyl alcohol, Polycarbonate resin, fluororesin, polyvinyl fluoride resin, polyvinyl acetate resin, acetal resin, polyester resin (polyethylene terephthalate (PET), polybutylene terephthalate, polyethylene naphthalate), polyamide resin, and other various types Resin film It is possible to use a solid or sheet. These resin films or sheets may be stretched in a uniaxial or biaxial direction.
  • the thickness of the inner layer base material is not limited, but is, for example, 10 to 350 ⁇ m, preferably about 30 to 250 ⁇ m, more preferably 30 to 100 ⁇ m.
  • the thickest substrate among the outer layer base material 1), the intermediate layer base material 2), and the inner layer base material 3) is joined by the adhesive.
  • the bonding method is not particularly limited, but an adhesive is applied to one side of one laminated base material by gravure printing, comma coating, dry laminating, etc., and the solvent is stripped, and then bonded to the other laminated base material, Alternatively, it may be cured under heating.
  • the thickness of the thickest base material among the outer layer base material, the intermediate layer base material, and the inner layer base material and the amount of the adhesive layer after drying can be appropriately designed.
  • the thickness of the thickest base material is 125 to 350 ⁇ m.
  • the amount of the adhesive layer after drying applied to at least one surface of the laminate substrate is preferably more than 5 g / m 2 and not more than 30 g / m 2 as described above. More preferably, by more than 5 g / m 2, and at 25 g / m 2 or less, more preferably, 6 g / m 2 or more and 20 g / m 2 or less. Since the specific gravity of the adhesive excluding the organic solvent is about 1.1 g / cm 3 , 1.1 g / m 2 can be converted to about 1 ⁇ m / m 2 . Therefore, the amount of the adhesive layer is about 4.5 to 27.3 ⁇ m in terms of thickness.
  • the amount of the adhesive layer after drying exceed 5 g / m 2 , it is possible to more effectively reduce the influence of hydrolysis on the adhesive layer.
  • the amount of the adhesive layer is set to 30 g / m 2 or less, the organic solvent in the adhesive can be easily volatilized at the time of drying before being bonded to the base material.
  • the solar cell back surface protective sheet of the present invention is manufactured by industrially laminating a plurality of base materials and then completing the curing of the adhesive layer in a state of being wound in a roll shape
  • the present inventors have conducted intensive studies. As a result, it was found that industrial productivity can be further improved in the following embodiments. That is, the thickness of the thickest substrate among the outer layer substrate, the intermediate layer substrate, and the inner layer substrate is 125 to 350 ⁇ m, and the amount of the adhesive layer is more than 5 g / m 2 and not more than 30 g / m 2
  • the laminate is wound into a roll in the adhesive development process after applying the adhesive while effectively satisfying the electrical insulation with respect to the light emitting elements disposed in the solar cell module.
  • tunneling floating (hereinafter referred to as tunneling) in the roll-shaped laminate can be more effectively suppressed.
  • tunneling floating
  • the solar cell back surface protective sheet of the present invention is installed in a solar cell module by adhering the inner layer base material side with a sealing material for sealing the power generation element of the solar cell module.
  • the configuration of the solar cell module of the present invention is not particularly limited, and a known solar cell module can be used.
  • the solar cell back surface protective sheet of the present invention at least one surface of the thickest base material among the outer layer base material, the intermediate layer base material, and the interior base material is bonded by the specific adhesive described above. Adhesives with good agent performance and weather resistance that can withstand long-term use are obtained. As a result, a solar cell back surface protective sheet with high long-term reliability can be provided.
  • the adhesive used in the present invention is inexpensive and has a characteristic that it can be easily applied by a general coating method such as gravure coating or comma coating.
  • the solar cell back surface protective sheet of the present invention is resistant to moist heat by using an adhesive in which the ratio of the main agent and the curing agent is 4 to 12 parts by weight of the curing agent solid content with respect to 100 parts by weight of the main agent solid content. Excellent adhesion at low temperatures. That is, it is possible to provide a solar cell back surface protective sheet that is excellent in long-term reliability and wet heat resistance, is excellent in adhesiveness in a low temperature environment, and is excellent in cost and coating properties.
  • Example 1 25 kg of titanium oxide particles were added to 100 kg of low density polyethylene resin (LDPE) having a density of 0.91 g / cm 3 and kneaded sufficiently to prepare an LDPE resin composition. Subsequently, it was extruded with an extruder to produce a first film having a thickness of 50 ⁇ m.
  • LDPE low density polyethylene resin
  • a 250 ⁇ m thick polyethylene terephthalate film (manufactured by Toyobo Co., Ltd .: Toyobo Ester Film E5102) was prepared as a second film having excellent electrical insulation. Further, a PVF film (manufactured by DuPont, 38 ⁇ m) was prepared as the third film. These films were bonded by a dry laminating method using an adhesive for dry laminating. The adhesive for dry lamination is as follows.
  • the reaction vessel was gradually depressurized to 1 to 2 Torr, and when the acid value became 0.8 mgKOH / g or less, the reaction under reduced pressure was stopped to obtain a polyester polyol having a weight average molecular weight of 75,000.
  • a resin solution in which the concentration of the polyester polyol obtained by dilution with ethyl acetate was 50% was designated as polyol A.
  • a reactor was charged with 94.2 parts of neopentyl glycol, 91.7 parts of 1,6-hexanediol, 37.6 parts of ethylene glycol, 211.5 parts of isophthalic acid, and 122.9 parts of sebacic acid.
  • the esterification reaction was carried out by heating to 160 to 250 ° C. with stirring.
  • the reaction vessel was gradually depressurized to 1 to 2 Torr, and when the acid value became 1 mgKOH / g or less, the reaction under reduced pressure was stopped to obtain a polyester polyol in the previous stage having a weight average molecular weight of 6,000.
  • 22.9 parts of isophorone diisocyanate was gradually added and reacted by heating at 100 to 150 ° C.
  • Polyol B was a resin solution in which the concentration of the polyester polyurethane polyol obtained by dilution with ethyl acetate was 50%.
  • Polyol A 100 parts (solid content 50 parts), polyol B 40 parts (solid content 20 parts), number average molecular weight 1,200 and epoxy equivalent 600 g / eq of bisphenol A type epoxy resin 30 parts and epoxy group-containing organosilane coupling agent 3
  • a resin solution with a solid content of 50% obtained by heating, dissolving and mixing the parts at 70 ° C. and diluting with ethyl acetate was used as the main agent 1.
  • the total ester bond degree of polyol A and polyol B in the main agent 1 is 0.89 when determined as follows.
  • the number of ester bonds is set to 1.
  • the average molecular weight (equivalent) of the dibasic acid and dihydric alcohol in the polyol is calculated.
  • the ester bond degree is defined as the number of ester bonds (subtracting dehydration during the reaction) divided by the molecular weight.
  • Curing agent 1 was obtained by diluting a trimer of isophorone diisocyanate with ethyl acetate to give a resin solution having a solid content of 50%.
  • the adhesive solution was adjusted so that the amount of the adhesive layer after drying was 10 g / m 2, and the first to third films were laminated to obtain a laminate of 210 mm ⁇ 295 mm (A4 size). .
  • aging was performed at 60 ° C. for 7 days to cure the adhesive, thereby producing a back protective sheet for solar cells.
  • the adhesive strength 25 ° C., 15 ° C.
  • the adhesive strength after the weather resistance test (25 ° C.) were evaluated by the methods described later.
  • Examples 2-4 The solar system is the same as in Example 1 except that 100 parts of the main agent 1 is 10 parts (Example 2), 6 parts (Example 3), and 4 parts (Example 4) of the curing agent 1, respectively. A battery back protection sheet was prepared and evaluated.
  • Comparative Example 1 A solar cell back surface protective sheet was prepared and evaluated in the same manner as in Example 1 except that the solid content of the curing agent 1 was changed to 14 parts with respect to the main component 1 having a solid content of 100 parts.
  • Example 5 Using the adhesive solution of Example 2, the amount of the adhesive layer after drying was 3 g / m 2 (Example 5), 5 g / m 2 (Example 6), 15 g / m 2 (Example 7), and 20 g. / M 2 (Example 8), 25 g / m 2 (Example 9), 30 g / m 2 (Example 10), 35 g / m 2 (Comparative Example 11)
  • the back surface protection sheet for solar cells was produced and evaluated in the same manner as described above.
  • Example 12 A 100 ⁇ m thick polyethylene terephthalate film (manufactured by Toyobo Co., Ltd .: Toyobo Ester Film E5100) was used in place of the 250 ⁇ m thick polyethylene terephthalate film as the second film, and the same adhesive solution as in Example 2 was used. And the solar cell back surface protection sheet was produced and evaluated like Example 1 except having adjusted so that the hardening
  • curing agent 1 is 14 parts (Comparative Example 2), 12 parts (Example 13), 10 parts (Example 14), 6 parts (Example 15), 4 parts (implemented). Except for Example 16), a back protective sheet for solar cell was prepared and evaluated in the same manner as in Example 1.
  • Examples 17 and 18 Instead of an epoxy resin having a number average molecular weight of 1,200, a bisphenol A type epoxy resin having a number average molecular weight of 1,400 and an epoxy equivalent of 700 g / eq (Example 17), a number average molecular weight of 1,000 and an epoxy equivalent of 500 g / eq A back protective sheet for solar cell was prepared and evaluated in the same manner as in Example 2 except that 30 parts of each of bisphenol A type epoxy resins (Example 18) were used.
  • Comparative Example 3 A resin solution having a solid content of 50% was used as the main agent 3 in the same manner as in Comparative Example 1, except that the polyol A was 120 parts (solid content 60 parts) and the polyol B was 20 parts (solid content 10 parts). Except that the base material 3 and the curing agent 1 were blended at a ratio of 100: 14 (weight ratio), diluted with ethyl acetate and adjusted to a solid content of 30%, and used as an adhesive solution, the sun was applied as in Example 1. A battery back protection sheet was prepared and evaluated.
  • Comparative Example 4 (Polyol B not used) A solar cell back surface protective sheet was prepared and evaluated in the same manner as in Comparative Example 1 except that polyol B was not used and polyol A was changed to 140 parts (solid content: 70 parts).
  • Comparative Example 5 (no use of polyol A) A solar cell back surface protective sheet was prepared and evaluated in the same manner as in Comparative Example 1 except that polyol A was not used and polyol B was changed to 140 parts (solid content: 70 parts).
  • Comparative Example 6 Dilute isophorone diisocyanate trimer with ethyl acetate to cure 50% solids resin solution instead of tolylene diisocyanate TMP adduct with ethyl acetate to cure 50% solids resin solution Agent 2 was obtained. Moreover, 14 parts of solid content of the hardening
  • Comparative Examples 7 and 8 (polyol A is not used) Charge 99.6 parts of dimethyl terephthalate, 92.2 parts of ethylene glycol, 72.2 parts of neopentyl glycol, 0.02 part of zinc acetate and heat to 160-210 ° C with stirring under a nitrogen stream. After transesterification, 97% of the theoretical amount of methanol was distilled off, and then 77.5 parts of isophthalic acid and 129.6 parts of adipic acid were charged and heated to 160 to 240 ° C. to carry out the esterification reaction. The reaction can was gradually depressurized to 1-2 torr.
  • the reaction under reduced pressure was stopped when the acid value was 0.8 mgKOH / g or less to obtain a polyester polyol (degree of ester bond 0.90 mol / 100 g) having a weight average molecular weight of 60,000.
  • a resin solution having a solid content of 50% obtained by dilution with ethyl acetate was designated as polyol C.
  • 100 parts polyol C was used.
  • curing agent 1 were used with respect to the main ingredient 1 of solid content 100 parts. Except this, it carried out similarly to Example 1, and produced and evaluated the back surface protection sheet for solar cells.
  • the polyol C has a weight average molecular weight of 60,000 and does not contain an aliphatic dibasic acid having 9 to 10 carbon atoms, and therefore does not correspond to the polyester polyol A in the present invention.
  • Comparative Example 9 (does not contain bisphenol type epoxy resin) 40 parts of polyol A (20 parts of solid content), 100 parts of polyol B (50 parts of solid content) and 3 parts of an epoxy group-containing organosilane coupling agent were heated, dissolved and mixed at 70 ° C., and diluted with ethyl acetate. A resin solution having a solid content of 50% was used as the main agent 4. Further, 14 parts of the curing agent 1 was used with respect to 100 parts of the main agent 4. Except this, it carried out similarly to Example 1, and produced and evaluated the back surface protection sheet for solar cells.
  • Comparative Example 10 A back protective sheet for solar cells in the same manner as in Example 2 except that 30 parts of bisphenol A type epoxy resin having a number average molecular weight of 800 and an epoxy equivalent of 400 g / eq was used instead of the epoxy resin having a number average molecular weight of 1,200. Were made and evaluated.
  • ⁇ Partial discharge> The measurement was performed in air and in oil by a method based on the IEC partial discharge test (IEC61730-2, IEC606664-1). ⁇ : 1,000 V or more measured in air and in oil ⁇ : 1,000 V or more measured only in oil ⁇ : Less than 1,000 V in any measuring method Partial discharge evaluation is Although it is not necessarily an essential property for the solar cell back surface protective sheet, it is good in any sample except Example 12 using a 100 ⁇ m thick polyethylene terephthalate film instead of a 250 ⁇ m polyethylene terephthalate film as the second film. Results were obtained.

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Abstract

Provided is a solar cell backside protective sheet which has excellent long-term reliability and moist heat resistance, and has excellent adhesiveness in low-temperature environments, and also has low cost and excellent coating properties; also provided is a solar cell module. In this solar cell backside protective sheet, an adhesive layer which bonds to at least one surface of the thickest of an outer layer substrate, a middle layer substrate and an inner layer substrate is adhered by means of an adhesive containing: a main component containing linear polyester polyols of a specific configuration, polyester polyurethane polyols and a bisphenol type epoxy resin; and a curing agent containing isocyanurate. The aforementioned adhesive contains 4-12 parts by weight of the solids content of the curing agent per 100 parts by weight of the solids content of the main component.

Description

太陽電池裏面保護シート及び太陽電池モジュールSolar cell back surface protection sheet and solar cell module
　本発明は、太陽電池モジュールの背面に用いられる太陽電池裏面保護シート、及びこの太陽電池裏面保護シートを具備する太陽電池モジュールに関する。 The present invention relates to a solar cell back surface protection sheet used on the back surface of a solar cell module, and a solar cell module including the solar cell back surface protection sheet.
　近年、クリーンなエネルギーの筆頭として、半導体特有の量子効果を利用して光エネルギーを電気エネルギーに変換する太陽光発電が注目されている。太陽光発電には太陽電池モジュールが用いられるが、その裏面からの保護及び絶縁を目的として太陽電池裏面保護シート（いわゆるバックシート）が設けられている。 In recent years, photovoltaic power generation that converts light energy into electrical energy by utilizing a quantum effect peculiar to semiconductors has been attracting attention as the head of clean energy. A solar cell module is used for photovoltaic power generation, and a solar cell back surface protection sheet (so-called back sheet) is provided for the purpose of protection and insulation from the back surface.
　太陽電池モジュールは、十数年もの長期に亘る耐用年数が求められており、それを保護するバックシートにも同じく長期信頼性が求められている。また、バックシートには、セルと称される発電素子から発生する電気に対する絶縁性や、セルを封止するための封止材との良好な密着性が求められている。これらの要求に応えるために、従来さまざまな樹脂フィルムや金属箔を、接着剤を介して積層して得られるバックシートが提案されている（例えば、特許文献１、２等）。
　また、ポリエステルポリオールやポリエステルポリウレタンポリオールを含有する屋外用ポリウレタン系接着剤が提案されている（特許文献３）。 The solar cell module is required to have a service life of a long period of more than ten years, and the long-term reliability is also required for the backsheet that protects it. In addition, the backsheet is required to have insulation against electricity generated from a power generation element called a cell and good adhesion to a sealing material for sealing the cell. In order to meet these demands, conventionally, back sheets obtained by laminating various resin films and metal foils via an adhesive have been proposed (for example, Patent Documents 1 and 2).
Further, an outdoor polyurethane adhesive containing a polyester polyol or a polyester polyurethane polyol has been proposed (Patent Document 3).
特開２０１０－２７８３７５号公報JP 2010-278375 A 特開２００９－２９０２０１号公報JP 2009-290201 A 特開２０１０－０４３２３８号公報JP 2010-043238 A
　バックシートは、長期信頼性が高いことが強く求められている。これを実現するために、バックシートに用いられる接着剤について、良好な接着性、及び長期の使用に耐え得る耐候性が求められる。また、接着剤がコスト的に安価で、しかもグラビア塗工、コンマコート等の一般的な塗工方法で容易に塗工できることが要求される。さらに、湿熱耐性に優れ、常温よりも低温の環境下においても優れた接着力を発揮できることが求められる。従来のバックシートにはこれらの点で更なる改善の余地があった。 バ ッ ク Backsheets are strongly required to have long-term reliability. In order to realize this, the adhesive used for the backsheet is required to have good adhesion and weather resistance that can withstand long-term use. Further, it is required that the adhesive is inexpensive and can be easily applied by a general coating method such as gravure coating or comma coating. Furthermore, it is required to be excellent in wet heat resistance and exhibit an excellent adhesive force even in an environment lower than normal temperature. The conventional backsheet has room for further improvement in these respects.
　本発明は上記背景に鑑みてなされたものであり、長期信頼性、及び湿熱耐性に優れ、かつ、低温環境下における接着性に優れ、さらに、コスト性、及び塗工性に優れる太陽電池裏面保護シート、及び太陽電池モジュールを提供することを主な目的とする。 The present invention has been made in view of the above background, and is excellent in long-term reliability, wet heat resistance, excellent adhesiveness in a low-temperature environment, and further excellent in cost and coating properties. The main object is to provide a sheet and a solar cell module.
　本発明者は上記目的を達成すべく鋭意研究を重ねた結果、特定組成の主剤及び硬化剤を含有する接着剤を用い、かつ、主剤に対して特定の硬化剤を特定の量とすることにより上記目的を達成できることを見出し、本発明を完成するに至った。 As a result of intensive studies to achieve the above object, the present inventor used an adhesive containing a main agent and a curing agent having a specific composition, and a specific amount of the specific curing agent with respect to the main agent. The inventors have found that the above object can be achieved and have completed the present invention.
　即ち、本発明に係る太陽電池裏面保護シートは、少なくとも、１）耐候性を有する外層基材、２）中間層基材、及び３）太陽電池モジュールに用いられる発電素子を封止するための封止材と良好な接着性を有する内層基材から構成され、外層基材、中間層基材、及び内層基材のうちの最も厚い基材の少なくとも片面を接合する接着剤層が下記（１）～（３）を含有する主剤と、下記（４）の硬化剤を含有する接着剤により形成され、
　前記接着剤は、主剤固形分１００重量部に対し、硬化剤の固形分を４～１２重量部とするものである。
（１）芳香族二塩基酸４０～７０モル％と炭素数９～１０の脂肪族二塩基酸３０～６０モル％とを含む二塩基酸成分と、炭素数５以上の脂肪族２価アルコール３０～４０モル％を含む２価アルコール成分とを反応させてなる、重量平均分子量が７０，０００～８０，０００の直鎖ポリエステルポリオール。
（２）芳香族二塩基酸６０～８０モル％と炭素数９～１０の脂肪族二塩基酸２０～４０モル％とを含む二塩基酸成分と、炭素数５以上の脂肪族２価アルコール７０～８０モル％を含む２価アルコール成分とを反応させることにより得られるポリエステルポリオールに有機ジイソシアネートを反応させてなる、重量平均分子量が３０，０００～４０，０００のポリエステルポリウレタンポリオール。
（３）数平均分子量が１，０００～２，０００のビスフェノール型エポキシ樹脂。
（４）イソホロンジイソシアネートのイソシアヌレートを有するポリイソシアネート。
　前記最も厚い基材の厚みは１２５～３５０μｍとすることが好ましく、前記最も厚い基材と接する前記接着剤層の接着剤量は５ｇ／ｍ２を超えて３０ｇ／ｍ２以下の範囲とすることが好ましい。
　また、前記中間層基材は、複数あり、少なくとも一部において互いに前記接着剤層を介して接着されていることが好ましい。
　また、前記直鎖ポリエステルポリオールと、前記ポリエステルポリウレタンポリオールとの合計１００重量％中、前記直鎖ポリエステルポリオールが６０～８０重量％であることが好ましい。 That is, the solar cell back surface protective sheet according to the present invention includes at least 1) an outer layer base material having weather resistance, 2) an intermediate layer base material, and 3) a seal for sealing a power generation element used in the solar cell module. An adhesive layer composed of a stopper and an inner layer base material having good adhesiveness and joining at least one side of the thickest base material among the outer layer base material, the intermediate layer base material, and the inner layer base material is the following (1) Formed of a main agent containing (3) and an adhesive containing a curing agent of (4) below,
The adhesive has a solid content of 4 to 12 parts by weight based on 100 parts by weight of the main component solids.
(1) a dibasic acid component containing 40 to 70 mol% of an aromatic dibasic acid and 30 to 60 mol% of an aliphatic dibasic acid having 9 to 10 carbon atoms, and an aliphatic dihydric alcohol 30 having 5 or more carbon atoms A linear polyester polyol having a weight average molecular weight of 70,000 to 80,000 obtained by reacting with a dihydric alcohol component containing ˜40 mol%.
(2) a dibasic acid component containing 60 to 80 mol% of an aromatic dibasic acid and 20 to 40 mol% of an aliphatic dibasic acid having 9 to 10 carbon atoms, and an aliphatic dihydric alcohol 70 having 5 or more carbon atoms A polyester polyurethane polyol having a weight average molecular weight of 30,000 to 40,000, which is obtained by reacting a polyester polyol obtained by reacting with a dihydric alcohol component containing ˜80 mol% with an organic diisocyanate.
(3) A bisphenol type epoxy resin having a number average molecular weight of 1,000 to 2,000.
(4) A polyisocyanate having an isocyanurate of isophorone diisocyanate.
The thickness of the thickest substrate is preferably 125 to 350 μm, and the adhesive amount of the adhesive layer in contact with the thickest substrate is in the range of more than 5 g / m 2 and 30 g / m 2 or less. Is preferred.
Moreover, it is preferable that there are a plurality of the intermediate layer base materials, and at least a part thereof is bonded to each other via the adhesive layer.
The linear polyester polyol is preferably 60 to 80% by weight in a total of 100% by weight of the linear polyester polyol and the polyester polyurethane polyol.
　本発明に係る太陽電池モジュールは、上記態様の太陽電池裏面保護シートを備えるものである。 The solar cell module according to the present invention includes the solar cell back surface protective sheet of the above aspect.
　本発明の太陽電池裏面保護シートによれば、長期信頼性、及び湿熱耐性に優れ、かつ、低温環境下における接着性に優れ、さらに、コスト性、及び塗工性に優れる太陽電池裏面保護シート、及び太陽電池モジュールを提供することができるという優れた効果を奏する。 According to the solar cell back surface protective sheet of the present invention, the solar cell back surface protective sheet is excellent in long-term reliability and wet heat resistance, and is excellent in adhesiveness in a low-temperature environment, and is excellent in cost and coating properties. And the outstanding effect that a solar cell module can be provided is produced.
実施例で作製した太陽電池裏面保護シートの層構成を示す図である。It is a figure which shows the layer structure of the solar cell back surface protection sheet produced in the Example. 比較例で作製した太陽電池裏面保護シートの層構成を示す図である。It is a figure which shows the layer structure of the solar cell back surface protection sheet produced by the comparative example.
　以下、本発明について詳細に説明する。なお、本発明の趣旨に合致する限り、他の実施形態も本発明の範疇に属し得ることは言うまでもない。また、本明細書において「任意の数Ａ～任意の数Ｂ」なる記載は、数Ａ及び数Ａより大きい範囲であって、数Ｂ及び数Ｂより小さい範囲を意味する。 Hereinafter, the present invention will be described in detail. It goes without saying that other embodiments may also belong to the category of the present invention as long as they match the gist of the present invention. In the present specification, the description “any number A to any number B” means a range larger than the numbers A and A but smaller than the numbers B and B.
　本発明の太陽電池裏面保護シートは、少なくとも、１）耐候性を有する外層基材、２）中間層基材、及び３）太陽電池モジュールに用いられる発電素子を封止するための封止材と良好な接着性を有する内層基材から構成されるものである。そして、本発明の太陽電池裏面保護シートは、外層基材、中間層基材、及び内層基材のうちの最も厚い基材の少なくとも片面を接合する接着剤層が下記（１）～（３）を含有する主剤と、下記（４）の硬化剤を含有する接着剤により形成されるものである。従って、上記条件を満たす範囲において、本発明の太陽電池裏面保護シートは、他の接着剤により基材同士を接合することも可能である。内層基材は、太陽電池裏面保護シートのうち発光素子側の表層に配設されるものであり、外層基材は、発光素子から最も離間した位置に配設されるものである。中間層基材は、単数であってもよいが、複数有していてもよい。太陽電池裏面保護シートは、耐電圧性を有することが求められる。耐電圧性は、主として中間層基材に持たせることが好ましい。但し、中間層基材を複数設ける場合には、すべての中間層基材が耐電圧性を有していなくてもよい。なお、以降において特に断りなく「接着剤」というときには、下記（１）～（３）を含有する主剤と、下記（４）の硬化剤を含有する本発明の接着剤をいうものとする。 The solar cell back surface protective sheet of the present invention includes at least 1) an outer layer base material having weather resistance, 2) an intermediate layer base material, and 3) a sealing material for sealing a power generation element used in a solar cell module; It is comprised from the inner-layer base material which has favorable adhesiveness. In the solar cell back surface protective sheet of the present invention, the adhesive layer for bonding at least one surface of the thickest base material among the outer layer base material, the intermediate layer base material, and the inner layer base material has the following (1) to (3). It is formed with the main ingredient containing this and the adhesive agent containing the hardening | curing agent of following (4). Therefore, within the range that satisfies the above conditions, the solar cell back surface protective sheet of the present invention can also bond the substrates to each other with another adhesive. An inner layer base material is arrange | positioned in the surface layer by the side of a light emitting element among solar cell back surface protection sheets, and an outer layer base material is arrange | positioned in the position most spaced apart from the light emitting element. The intermediate layer base material may be singular or plural. The solar cell back surface protection sheet is required to have voltage resistance. It is preferable to provide the voltage resistance mainly to the intermediate layer base material. However, when a plurality of intermediate layer base materials are provided, all of the intermediate layer base materials may not have voltage resistance. In the following description, the term “adhesive” refers to the adhesive of the present invention containing the main agent containing the following (1) to (3) and the curing agent (4) below.
　本発明の太陽電池裏面保護シートは、外層基材、中間層基材、及び内層基材のうちの最も厚い基材の厚みを１２５～３５０μｍとすることが好ましい。また、最も厚い基材と接する接着剤層の乾燥後の接着剤量が５ｇ／ｍ２を超えて３０ｇ／ｍ２以下の範囲にあることが好ましい。その理由については後述する。最も厚い基材は、外層基材、中間層基材、及び内層基材のいずれでもよいが、中間層基材が最も厚い基材であることが好ましい。なお、外層基材、又は内層基材が最も厚い基材の場合には、上記接着材量の塗布面は一面となるが、中間層基材が最も厚い基材の場合には、中間層基材の２つの接合面の少なくとも一面において、上記塗布条件を満足することが好ましい。中間層基材が最も厚い基材の場合には、２つの接合面において、本発明の接着剤層が５ｇ／ｍ２を超えて３０ｇ／ｍ２以下の範囲となるようにすることがより好ましい。また、最も厚い基材以外の基材同士の接合にも上記接着剤を好適に適用できる。即ち、本発明の接着剤は、太陽電池裏面保護シートを構成する各基材（例えば、プラスチックフィルム、金属箔等）の接合すべてに好適に用いることができる。 In the solar cell back surface protective sheet of the present invention, the thickness of the thickest substrate among the outer layer substrate, the intermediate layer substrate, and the inner layer substrate is preferably 125 to 350 μm. Moreover, it is preferable that the adhesive amount after drying of the adhesive layer in contact with the thickest substrate is in the range of more than 5 g / m 2 and 30 g / m 2 or less. The reason will be described later. The thickest substrate may be any of an outer layer substrate, an intermediate layer substrate, and an inner layer substrate, but the intermediate layer substrate is preferably the thickest substrate. In addition, when the outer layer base material or the inner layer base material is the thickest base material, the application surface of the above-mentioned adhesive amount is one surface, but when the intermediate layer base material is the thickest base material, the intermediate layer base material It is preferable that at least one of the two joint surfaces of the material satisfies the above coating conditions. In the case where the intermediate layer base material is the thickest base material, it is more preferable that the adhesive layer of the present invention has a range of more than 5 g / m 2 and 30 g / m 2 or less at the two joining surfaces. . Moreover, the said adhesive agent can be applied suitably also to joining of base materials other than the thickest base material. That is, the adhesive of the present invention can be suitably used for all the joining of each base material (for example, plastic film, metal foil, etc.) constituting the solar cell back surface protective sheet.
　本発明の接着剤は、主剤及び硬化剤を含有するポリウレタン系接着剤である。上記接着剤は、主剤と硬化剤とを使用時に混合する２液混合タイプの接着剤であってもよいし、主剤と硬化剤とが予め混合された１液タイプの接着剤であってもよい。また、複数の主剤及び／又は複数の硬化剤を使用時に混合するタイプであってもよい。 The adhesive of the present invention is a polyurethane adhesive containing a main agent and a curing agent. The adhesive may be a two-component mixed adhesive that mixes the main agent and the curing agent at the time of use, or may be a one-component adhesive in which the main agent and the curing agent are mixed in advance. . Moreover, the type which mixes a several main ingredient and / or several hardening | curing agent at the time of use may be sufficient.
　上記接着剤の主剤は、（１）芳香族二塩基酸４０～７０モル％と炭素数９～１０の脂肪族二塩基酸３０～６０モル％とを含む二塩基酸成分と、炭素数５以上の脂肪族２価アルコール３０～４０モル％を含む２価アルコール成分とを反応させてなる、重量平均分子量が７０，０００～８０，０００の直鎖ポリエステルポリオールと、（２）芳香族二塩基酸６０～８０モル％と炭素数９～１０の脂肪族二塩基酸２０～４０モル％とを含む二塩基酸成分と、炭素数５以上の脂肪族２価アルコール７０～８０モル％を含む２価アルコール成分とを反応させることにより得られるポリエステルポリオールに有機ジイソシアネートを反応させてなる、重量平均分子量が３０，０００～４０，０００のポリエステルポリウレタンポリオールと、（３）数平均分子量が１，０００～２，０００のビスフェノール型エポキシ樹脂を含有する。
　上記接着剤の硬化剤は、（４）イソホロンジイソシアネートのイソシアヌレートを有するポリイソシアネートを含有する。本発明の接着剤は、主剤の固形分１００重量部に対し、前記硬化剤の固形分を４～１２重量部含有する。より好ましくは、６～１２重量部であり、さらに好ましくは８～１０重量部である。 The main component of the adhesive is (1) a dibasic acid component containing 40 to 70 mol% of an aromatic dibasic acid and 30 to 60 mol% of an aliphatic dibasic acid having 9 to 10 carbon atoms, and 5 or more carbon atoms. A linear polyester polyol having a weight average molecular weight of 70,000 to 80,000 obtained by reacting with a dihydric alcohol component containing 30 to 40 mol% of an aliphatic dihydric alcohol, and (2) an aromatic dibasic acid A dibasic acid component containing 60 to 80 mol% and an aliphatic dibasic acid having 9 to 10 carbon atoms and 20 to 40 mol%, and a divalent compound containing 70 to 80 mol% of an aliphatic dihydric alcohol having 5 or more carbon atoms A polyester polyurethane polyol having a weight average molecular weight of 30,000 to 40,000 obtained by reacting an organic diisocyanate with a polyester polyol obtained by reacting with an alcohol component, and (3) a number average Molecular weight contains bisphenol type epoxy resin of 1,000-2,000.
The curing agent for the adhesive contains (4) a polyisocyanate having an isocyanurate of isophorone diisocyanate. The adhesive of the present invention contains 4 to 12 parts by weight of the solid content of the curing agent with respect to 100 parts by weight of the solid content of the main agent. More preferably, it is 6 to 12 parts by weight, and still more preferably 8 to 10 parts by weight.
［（１）直鎖ポリエステルポリオール］
　本発明で用いる直鎖ポリエステルポリオール（以下、単に「ポリエステルポリオール」とも言う）は、芳香族二塩基酸４０～７０モル％と炭素数９～１０の脂肪族二塩基酸３０～６０モル％とを含む二塩基酸成分と、炭素数５以上の脂肪族２価アルコール３０～４０モル％を含む２価アルコール成分とを反応させてなる。上記条件を満たす範囲であれば、他の構造の二塩基酸や多価アルコール成分を含んでいてもよい。 [(1) Linear polyester polyol]
The linear polyester polyol (hereinafter also simply referred to as “polyester polyol”) used in the present invention comprises 40 to 70 mol% of an aromatic dibasic acid and 30 to 60 mol% of an aliphatic dibasic acid having 9 to 10 carbon atoms. The dibasic acid component contained is reacted with a dihydric alcohol component containing 30 to 40 mol% of an aliphatic dihydric alcohol having 5 or more carbon atoms. As long as the above conditions are satisfied, a dibasic acid or a polyhydric alcohol component having another structure may be included.
　二塩基酸及びそのエステル化合物としては、例えば、イソフタル酸、テレフタル酸、ナフタレンジカルボン酸、無水フタル酸、アジピン酸、アゼライン酸、セバシン酸、コハク酸、グルタル酸、無水テトラヒドロフタル酸、無水ヘキサヒドロフタル酸、無水マレイン酸、無水イタコン酸及びそのエステル化合物を例示できる。 Examples of the dibasic acid and its ester compound include isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, phthalic anhydride, adipic acid, azelaic acid, sebacic acid, succinic acid, glutaric acid, tetrahydrophthalic anhydride, hexahydrophthalic anhydride Examples thereof include acid, maleic anhydride, itaconic anhydride and ester compounds thereof.
　本発明ではこれらを適宜組み合わせて使用できるが、二塩基酸全量に対し、芳香族二塩基酸が４０～７０モル％（好ましくは５０～６０モル％）、炭素数９～１０の脂肪族二塩基酸が３０～６０モル％（好ましくは４０～５０モル％）となるように組み合わせる。 In the present invention, these can be used in appropriate combinations, but the aromatic dibasic acid is 40 to 70 mol% (preferably 50 to 60 mol%) and the aliphatic dibasic having 9 to 10 carbon atoms based on the total amount of the dibasic acid. The acids are combined so as to be 30 to 60 mol% (preferably 40 to 50 mol%).
　芳香族二塩基酸の使用量が４０モル％未満であると、充分な耐熱性及び粘弾性が得られないおそれがある。また、７０モル％以下とすることにより、接着力をより効果的に発揮させることができる。また、炭素数９～１０の脂肪族二塩基酸を３０モル％以上とすることにより、ポリエステルポリオールのエステル結合度を適切なものとして加水分解基点を抑制し、長期耐湿熱性をより効果的に引き出すことができる。また、炭素数９～１０の脂肪族二塩基酸を６０モル％以下とすることにより、耐熱性と粘弾性を適切に調整し、接着力をより効果的に発現させることができる。 If the amount of aromatic dibasic acid used is less than 40 mol%, sufficient heat resistance and viscoelasticity may not be obtained. Moreover, by setting it as 70 mol% or less, adhesive force can be exhibited more effectively. Further, by setting the aliphatic dibasic acid having 9 to 10 carbon atoms to 30 mol% or more, the ester bond degree of the polyester polyol is made appropriate, the hydrolysis base point is suppressed, and long-term wet heat resistance is more effectively brought out. be able to. Further, by setting the aliphatic dibasic acid having 9 to 10 carbon atoms to 60 mol% or less, it is possible to appropriately adjust the heat resistance and viscoelasticity and to more effectively express the adhesive force.
　上記例示化合物の中でも、芳香族二塩基酸としては、エステル交換反応における反応性の観点から、テレフタル酸、テレフタル酸ジメチル、イソフタル酸、無水フタル酸が好ましい。炭素数９～１０の脂肪族二塩基酸としては、親油性が高く、疎水性を有し、ポリマーへの吸水を抑制する観点から、炭素数９のアゼライン酸及び炭素数１０のセバシン酸が好ましい。 Among the above exemplified compounds, the aromatic dibasic acid is preferably terephthalic acid, dimethyl terephthalate, isophthalic acid, or phthalic anhydride from the viewpoint of reactivity in the transesterification reaction. As the aliphatic dibasic acid having 9 to 10 carbon atoms, azelaic acid having 9 carbon atoms and sebacic acid having 10 carbon atoms are preferable from the viewpoint of high lipophilicity, hydrophobicity, and suppression of water absorption into the polymer. .
　多価アルコールの具体例としては、例えば、エチレングリコール、ジエチレングリコール、トリエチレングリコール、プロピレングリコール、ジプロピレングリコール、１，６－ヘキサンジオール、ネオペンチルグリコール、１，４－ブチレングリコール、１，４－シクロヘキサンジメタノール、１，９－ナノンジオール、３－メチル－１，５－ペンタンジオール等が挙げられる。これらは単独又は２種以上で使用できるが、多価アルコール全量に対し、炭素数５以上の脂肪族２価アルコールを３０～４０モル％（好ましくは３２～３８モル％）の割合で使用する。 Specific examples of the polyhydric alcohol include, for example, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1,6-hexanediol, neopentyl glycol, 1,4-butylene glycol, 1,4-cyclohexane. Examples include dimethanol, 1,9-nanonediol, and 3-methyl-1,5-pentanediol. These may be used singly or in combination of two or more, but an aliphatic dihydric alcohol having 5 or more carbon atoms is used in a proportion of 30 to 40 mol% (preferably 32 to 38 mol%) based on the total amount of polyhydric alcohol.
　２価アルコール成分において、炭素数５以上の脂肪族２価アルコールの割合を３０モル％以上とすることによりポリエステルポリオールのエステル結合度を適切にして加水分解基点が増加するのを抑制し、長期耐湿熱性をより効果的に引き出すことができる。また、脂肪族２価アルコールの割合を４０モル％以下とすることにより生成物の有機溶剤への溶解性が良好となり、接着剤の塗工性が良好となる。 In the dihydric alcohol component, by controlling the proportion of aliphatic dihydric alcohol having 5 or more carbon atoms to 30 mol% or more, it is possible to suppress the increase in hydrolysis base point by making the ester bond degree of the polyester polyol appropriate, and long-term moisture resistance Thermal properties can be extracted more effectively. Moreover, the solubility to the organic solvent of a product becomes favorable by making the ratio of an aliphatic dihydric alcohol 40 mol% or less, and the applicability | paintability of an adhesive agent becomes favorable.
　上記例示化合物の中でも、炭素数５以上の脂肪族２価アルコールとして、側鎖を有し溶解安定性を向上させる炭素数５のネオペンチルグリコール、炭素数６の３－メチル－１，５－ペンタンジオール、親油性が高く疎水性を有しポリマーへの吸水を抑制する１，６－ヘキサンジオール等が好ましい。 Among the above exemplified compounds, as aliphatic dihydric alcohols having 5 or more carbon atoms, neopentyl glycol having 5 carbon atoms and having improved side chain stability and 3-methyl-1,5-pentane having 6 carbon atoms Diol, 1,6-hexanediol and the like that are highly lipophilic and hydrophobic and suppress water absorption into the polymer are preferred.
　ポリエステルポリオールの重量平均分子量は、凝集力、延伸性及び接着強度を確保する観点から７０，０００～８０，０００とする。この中でも、樹脂の溶解性、粘度及び接着剤の塗工性（取り扱い性）の観点から、７２，０００～７８，０００であることが一層好ましい。
　なお、本発明における数平均分子量測定は東ソー社製ＧＰＣ（ゲルパーミエーションクロマトグラフィー）「ＨＰＣ－８０２０」を用いた。ＧＰＣは溶媒（ＴＨＦ；テトラヒドロフラン）に溶解した物質をその分子サイズの差によって分離定量する液体クロマトグラフィーである。本発明における測定は、カラムに「ＬＦ－６０４」（昭和電工社製：迅速分析用ＧＰＣカラム：６ＭＭＩＤ×１５０ＭＭサイズ）を直列に２本接続して用い、流量０．６ＭＬ／ＭＩＮ、カラム温度４０℃の条件で行い、重量平均分子量（Ｍｗ）の決定はポリスチレン換算で行った。 The weight average molecular weight of the polyester polyol is 70,000 to 80,000 from the viewpoint of ensuring cohesive strength, stretchability and adhesive strength. Among these, from the viewpoint of the solubility of the resin, the viscosity, and the coating property (handleability) of the adhesive, it is more preferably 72,000-78,000.
In the present invention, the number average molecular weight was measured using GPC (gel permeation chromatography) “HPC-8020” manufactured by Tosoh Corporation. GPC is liquid chromatography that separates and quantifies substances dissolved in a solvent (THF; tetrahydrofuran) based on the difference in molecular size. In the measurement of the present invention, “LF-604” (manufactured by Showa Denko KK: GPC column for rapid analysis: 6MMID × 150MM size) is connected in series to the column, the flow rate is 0.6 ML / MIN, and the column temperature is 40. It carried out on the conditions of (degreeC) and the determination of the weight average molecular weight (Mw) was performed in polystyrene conversion.
［（２）ポリエステルポリウレタンポリオール］
　本発明で用いるポリエステルポリウレタンポリオールは、芳香族二塩基酸６０～８０モル％（好ましくは６５～７５モル％）と炭素数９～１０の脂肪族二塩基酸２０～４０モル％（好ましくは２５～３５モル％）とを含む二塩基酸成分と、炭素数５以上の脂肪族２価アルコール７０～８０モル％（好ましくは７２～７８モル％）を含む２価アルコール成分とを反応させることにより得られるポリエステルポリオールに、有機ジイソシアネートを反応させてなる。 [(2) Polyester polyurethane polyol]
The polyester polyurethane polyol used in the present invention comprises 60 to 80 mol% (preferably 65 to 75 mol%) of an aromatic dibasic acid and 20 to 40 mol% (preferably 25 to 40 mol%) of an aliphatic dibasic acid having 9 to 10 carbon atoms. 35 mol%) and a dihydric alcohol component containing 70 to 80 mol% (preferably 72 to 78 mol%) of an aliphatic dihydric alcohol having 5 or more carbon atoms. The polyester polyol obtained is reacted with an organic diisocyanate.
　芳香族二塩基酸の使用量を６０モル％以上とすることにより、効果的に耐熱性及び粘弾性を得ることができる。一方、８０モル％以下とすることにより、接着力をより効果的に発揮させることができる。また、炭素数９～１０の脂肪族二塩基酸を２０モル％以上とすることにより、ポリエステルポリオールのエステル結合度を適切なものとして加水分解基点を抑制し、長期耐湿熱性をより効果的に引き出すことができる。また、炭素数９～１０の脂肪族二塩基酸を４０モル％以下とすることにより、耐熱性と粘弾性を適切に調整し、接着力をより効果的に発現させることができるという効果が得られる。さらに、炭素数５以上の脂肪族２価アルコールの割合を７０モル％以上とすることによりポリエステルポリオールのエステル結合度を適切にして加水分解基点が増加するのを抑制し、長期耐湿熱性をより効果的に引き出すことができる。また、脂肪族２価アルコールの割合を８０モル％以下とすることにより生成物の有機溶剤への溶解性が良好となり、接着剤の塗工性が良好となる。 By making the amount of aromatic dibasic acid used 60 mol% or more, heat resistance and viscoelasticity can be obtained effectively. On the other hand, the adhesive force can be more effectively exhibited by setting it to 80 mol% or less. Further, by setting the aliphatic dibasic acid having 9 to 10 carbon atoms to 20 mol% or more, the ester bond degree of the polyester polyol is made appropriate, the hydrolysis base point is suppressed, and long-term wet heat resistance is more effectively brought out. be able to. Further, by making the aliphatic dibasic acid having 9 to 10 carbon atoms 40 mol% or less, it is possible to appropriately adjust the heat resistance and viscoelasticity and to exhibit the adhesive force more effectively. It is done. Furthermore, by controlling the proportion of aliphatic dihydric alcohols having 5 or more carbon atoms to 70 mol% or more, the ester bond degree of the polyester polyol is appropriately controlled to prevent the hydrolysis base point from increasing, and the long-term moist heat resistance is more effective. Can be withdrawn. Moreover, the solubility to the organic solvent of a product becomes favorable by making the ratio of aliphatic dihydric alcohol 80 mol% or less, and the applicability | paintability of an adhesive agent becomes favorable.
　ここで、芳香族二塩基酸、脂肪族二塩基酸及び炭素数５以上の脂肪族２価アルコールの説明については前記と同じである。 Here, the explanation of the aromatic dibasic acid, the aliphatic dibasic acid and the aliphatic dihydric alcohol having 5 or more carbon atoms is the same as described above.
　有機ジイソシアネートとしては特に限定されない。具体的には、２，４－トリレンジイソシアネート、２，６－トリレンジイソシアネート、キシリレンジイソシアネート、ジフェニルメタンジイソシアネート、イソホロンジイソシアネート、１，５－ナフタレンジイソシアネート、ヘキサメチレンジイソシアネート、水添化ジフェニルメタンジイソシアネート等が挙げられる。これらは単独又は２種以上で使用できる。なお、接着剤の経時的な黄変を低減させる観点では、ウレタン架橋部には、脂肪族又は脂環族のイソシアネート化合物を用いることが好ましい。 Organic diisocyanate is not particularly limited. Specific examples include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, 1,5-naphthalene diisocyanate, hexamethylene diisocyanate, hydrogenated diphenylmethane diisocyanate, and the like. It is done. These can be used alone or in combination of two or more. From the viewpoint of reducing yellowing of the adhesive over time, it is preferable to use an aliphatic or alicyclic isocyanate compound for the urethane cross-linking part.
　ポリエステルポリウレタンポリオールとポリエステルポリオールを併用することにより、ポリオール成分全体としてのエステル結合度（後述する）を下げることができ、その結果、加水分解起点を減らして耐湿熱性を高めることができる。 By using the polyester polyurethane polyol and the polyester polyol in combination, the degree of ester bond (described later) as the whole polyol component can be lowered, and as a result, the hydrolysis starting point can be reduced and the heat and moisture resistance can be increased.
　ポリエステルポリウレタンポリオールの重量平均分子量は、ポリエステルポリオールの重量平均分子量が大きく粘度が高いことを考慮し、接着剤としての粘度を調整する点で３０，０００～４０，０００とする。この中でも、３２，０００～３８，０００であることが一層好ましい。 The weight average molecular weight of the polyester polyurethane polyol is 30,000 to 40,000 in view of adjusting the viscosity as an adhesive in consideration of the large weight average molecular weight of the polyester polyol and the high viscosity. Among these, 32,000 to 38,000 is more preferable.
［（３）ビスフェノール型エポキシ樹脂］
　本発明で用いるビスフェノール型エポキシ樹脂は、数平均分子量が１，０００～２，０００であり、更にエポキシ当量が５００～１，０００ｇ／ｅｑであることが好ましい。ビスフェノール型エポキシ樹脂を含むことにより、ビスフェノール骨格の疎水性によって、エポキシ基がエステル結合の加水分解により発生したカルボキシル基と反応して分子量低下を抑制することが期待される。 [(3) Bisphenol type epoxy resin]
The bisphenol type epoxy resin used in the present invention preferably has a number average molecular weight of 1,000 to 2,000 and an epoxy equivalent of 500 to 1,000 g / eq. By including the bisphenol type epoxy resin, it is expected that the epoxy group reacts with the carboxyl group generated by hydrolysis of the ester bond to suppress the decrease in molecular weight due to the hydrophobicity of the bisphenol skeleton.
　ビスフェノール型エポキシ樹脂の中でも、せん断強度保持の観点から、ビスフェノールＡ型エポキシ樹脂、ビスフェノールＦ型エポキシ樹脂等が好ましく、これらは単独又は２種以上を混合して使用できる。 Among the bisphenol-type epoxy resins, bisphenol A-type epoxy resins and bisphenol F-type epoxy resins are preferable from the viewpoint of maintaining shear strength, and these can be used alone or in combination of two or more.
　ビスフェノール型エポキシ樹脂の数平均分子量は、接着剤硬化膜の耐熱性・粘弾性調整と溶液粘度の調整の観点から、１，０００～２，０００であればよい。ビスフェノール型エポキシ樹脂の数平均分子量が１，０００未満であると、十分な耐熱性が得られないおそれがある。また、数平均分子量を２，０００以下とすることにより、接着力をより効果的に発揮させることができる。また、本発明では高分子量のポリオールを使用する点で、低分子量のエポキシ樹脂により接着剤溶液の粘度を低下させて塗工性を向上させる効果が期待されるが、数平均分子量を２，０００以下とすることにより、溶液粘度を効果的に低下させることができる。湿熱耐性と低温での接着力のバランスから、ビスフェノール型エポキシ樹脂の数平均分子量は１，２００～１，８００であることが好ましい。 The number average molecular weight of the bisphenol type epoxy resin may be 1,000 to 2,000 from the viewpoints of adjusting the heat resistance and viscoelasticity of the cured adhesive film and adjusting the solution viscosity. If the number average molecular weight of the bisphenol-type epoxy resin is less than 1,000, sufficient heat resistance may not be obtained. Moreover, adhesive force can be more effectively exhibited by a number average molecular weight being 2,000 or less. In the present invention, the use of a high molecular weight polyol is expected to reduce the viscosity of the adhesive solution by using a low molecular weight epoxy resin, thereby improving the coating property. However, the number average molecular weight is 2,000. By making it below, the solution viscosity can be effectively reduced. The number average molecular weight of the bisphenol type epoxy resin is preferably 1,200 to 1,800 from the balance between wet heat resistance and low temperature adhesive strength.
　ビスフェノール型エポキシ樹脂の含有量は、接着剤硬化皮膜の粘弾性調整の観点から、主剤固形分１００重量％中、５０重量％以下が好ましく、接着力を考慮して２０～４０重量％がより好ましい。 The content of the bisphenol-type epoxy resin is preferably 50% by weight or less in 100% by weight of the main agent solid content from the viewpoint of adjusting the viscoelasticity of the cured adhesive film, and more preferably 20 to 40% by weight in consideration of adhesive strength. .
［上記成分を含有する主剤］
　上記ポリエステルポリオールとポリエステルポリウレタンポリオール（以下、これらをまとめて「ポリオール成分」とも称する）の組成比は、特に限定されないが、ポリエステルポリオールを、ポリオール成分の合計１００重量％中、６０～８０重量％使用することが好ましく、６５～７５重量％使用することがより好ましい。ポリオール成分中のポリエステルポリオールの割合を、８０重量％以下とすることにより耐湿熱性をより効果的に引き出すことができる。一方、ポリエステルポリオールの割合を６０重量％以上にすることにより低温での接着力をより良好にできる。従って、湿熱耐性と低温での接着力のバランスから、ポリオール成分中のポリエステルポリオールの割合は、６０～８０重量％の範囲であることが好ましい。 [Main agent containing the above components]
The composition ratio of the polyester polyol and the polyester polyurethane polyol (hereinafter collectively referred to as “polyol component”) is not particularly limited, but the polyester polyol is used in an amount of 60 to 80% by weight in a total of 100% by weight of the polyol component. It is preferable to use 65 to 75% by weight. By setting the ratio of the polyester polyol in the polyol component to 80% by weight or less, the heat and humidity resistance can be more effectively brought out. On the other hand, when the proportion of the polyester polyol is 60% by weight or more, the adhesive strength at low temperatures can be improved. Accordingly, the ratio of the polyester polyol in the polyol component is preferably in the range of 60 to 80% by weight from the balance between wet heat resistance and low temperature adhesive force.
　本発明では、ポリオール成分におけるカルボキシル基と水酸基の反応（カルボキシル基と水酸基の反応比を１対１とする）によるエステル結合の割合を、分子中のエステル結合度（モル／１００ｇ）として表した際、１未満になるように設計することが望ましい。即ち、エステル結合度を１未満とすることでエステル結合の割合を小さくして耐加水分解性を高め、経時的な接着強度劣化を更に抑制して長期の耐湿熱性を向上させることができる。この点、本発明では二塩基酸として分子量の大きい炭素数が９～１０の二塩基酸、及び分子量の大きい炭素数５以上の多価アルコールを使用しているため、単位重量中（１００ｇ中）のエステル結合度が小さくなる。 In the present invention, when the ratio of ester bond by reaction of carboxyl group and hydroxyl group in the polyol component (reaction ratio of carboxyl group and hydroxyl group is 1: 1) is expressed as the degree of ester bond (mol / 100 g) in the molecule. It is desirable to design to be less than 1. That is, by setting the degree of ester bond to less than 1, the ratio of ester bonds can be reduced to increase hydrolysis resistance, and deterioration of adhesive strength over time can be further suppressed to improve long-term wet heat resistance. In this respect, the present invention uses a dibasic acid having a large molecular weight of 9 to 10 and a polyhydric alcohol having a large molecular weight of 5 or more as a dibasic acid, so in unit weight (in 100 g). The ester bond degree of becomes small.
　特に、室温での接着強度及び高温（８０～１５０℃など）下での接着強度の両立を考慮すると、ポリオール成分のエステル結合度は０．７５～０．９９の範囲が好ましい。このようなエステル結合度は、本発明で用いる接着剤における二塩基酸成分中の芳香族二塩基酸の割合及び多価アルコールの炭素数の範囲内で達成することができる。また、ポリオール成分の酸価（ｍｇＫＯＨ／ｇ）は５以下であることが好ましく、２以下であることがより好ましい。 In particular, considering the compatibility of the adhesive strength at room temperature and the adhesive strength at high temperatures (80 to 150 ° C., etc.), the ester bond degree of the polyol component is preferably in the range of 0.75 to 0.99. Such an ester bond degree can be achieved within the range of the ratio of the aromatic dibasic acid in the dibasic acid component and the carbon number of the polyhydric alcohol in the adhesive used in the present invention. Further, the acid value (mgKOH / g) of the polyol component is preferably 5 or less, and more preferably 2 or less.
　接着剤の主剤は、前記ポリオール成分、及びビスフェノール型エポキシ樹脂に加えて、本発明の効果を阻害しない範囲で、任意の添加剤を含むことができる。添加剤としては、例えば、シランカップリング剤、反応促進剤、レベリング剤、消泡剤等が挙げられる。 In addition to the polyol component and the bisphenol-type epoxy resin, the main component of the adhesive can contain any additive as long as the effects of the present invention are not impaired. Examples of the additive include a silane coupling agent, a reaction accelerator, a leveling agent, and an antifoaming agent.
　シランカップリング剤としては、例えば、ビニルトリメトキシシラン、ビニルトリエトキシシラン等のビニル基を有するトリアルコキシシラン、３－アミノプロピルトリエトキシシラン、Ｎ－（２－アミノエチル）３－アミノプロピルトリメトキシシランなどのアミノ基を有するトリアルコキシシラン；３－グリシドキシプロピルトリメトキシシラン、２－（３，４－エポキシシクロヘキシル）エチルトリメトキシシラン、３－グリシドキシプロピルトリエトキシシランなどのグリシジル基を有するトリアルコキシシランが挙げられる。これらのシランカップリング剤は、単独又は２種以上で使用できる。 Examples of the silane coupling agent include trialkoxysilanes having a vinyl group such as vinyltrimethoxysilane and vinyltriethoxysilane, 3-aminopropyltriethoxysilane, and N- (2-aminoethyl) 3-aminopropyltrimethoxy. Trialkoxysilanes having amino groups such as silane; glycidyl groups such as 3-glycidoxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and 3-glycidoxypropyltriethoxysilane; The trialkoxysilane which has is mentioned. These silane coupling agents can be used alone or in combination of two or more.
　シランカップリング剤の添加量は、主剤全量に対し、０．５～５重量％であることが好ましく、１～３重量％であることがより好ましい。０．５重量％未満では、シランカップリング剤を添加することによる接着強度向上効果に乏しく、５重量％を超えて添加してもそれ以上の性能の向上は認められない。 The amount of the silane coupling agent added is preferably 0.5 to 5% by weight, more preferably 1 to 3% by weight, based on the total amount of the main agent. If it is less than 0.5% by weight, the effect of improving the adhesive strength by adding the silane coupling agent is poor, and even if it exceeds 5% by weight, no further improvement in performance is observed.
　反応促進剤としては、例えば、ジブチルチンジアセテート、ジブチルチンジラウレート、ジオクチルチンジラウレート、ジブチルチンジマレート等金属系触媒；１，８－ジアザ－ビシクロ（５，４，０）ウンデセン－７、１，５－ジアザビシクロ（４，３，０）ノネン－５、６－ジブチルアミノ－１，８－ジアザビシクロ（５，４，０）ウンデセン－７等の３級アミン；トリエタノールアミンのような反応性３級アミン等が挙げられ、これらの群から選ばれた１種または２種以上の反応促進剤を使用できる。 Examples of the reaction accelerator include metal catalysts such as dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate, and dibutyltin dimaleate; 1,8-diaza-bicyclo (5,4,0) undecene-7,1,5 -Tertiary amines such as diazabicyclo (4,3,0) nonene-5,6-dibutylamino-1,8-diazabicyclo (5,4,0) undecene-7; reactive tertiary amines such as triethanolamine 1 type, or 2 or more types of reaction accelerators selected from these groups can be used.
　レベリング剤としては、例えば、ポリエーテル変性ポリジメチルシロキサン、ポリエステル変性ポリジメチルシロキサン、アラルキル変性ポリメチルアルキルシロキサン、ポリエステル変性水酸基含有ポリジメチルシロキサン、ポリエーテルエステル変性水酸基含有ポリジメチルシロキサン、アクリル系共重合物、メタクリル系共重合物、ポリエーテル変性ポリメチルアルキルシロキサン、アクリル酸アルキルエステル共重合物、メタクリル酸アルキルエステル共重合物、レシチンなどが挙げられる。 Examples of leveling agents include polyether-modified polydimethylsiloxane, polyester-modified polydimethylsiloxane, aralkyl-modified polymethylalkylsiloxane, polyester-modified hydroxyl group-containing polydimethylsiloxane, polyetherester-modified hydroxyl group-containing polydimethylsiloxane, and acrylic copolymers. Methacrylic copolymer, polyether-modified polymethylalkylsiloxane, acrylic acid alkyl ester copolymer, methacrylic acid alkyl ester copolymer, lecithin and the like.
　消泡剤としては、例えば、シリコーン樹脂、シリコーン溶液、アルキルビニルエーテルとアクリル酸アルキルエステルとメタクリル酸アルキルエステルとの共重合物などが挙げられる。 Examples of the antifoaming agent include silicone resins, silicone solutions, copolymers of alkyl vinyl ethers, acrylic acid alkyl esters, and methacrylic acid alkyl esters.
［硬化剤］
　本発明で用いる硬化剤は、イソホロンジイソシアネートのイソシアヌレートを有するポリイソシアネートを含む。このイソシアヌレートは、主剤と混合した後のポットライフが長く、溶液安定性が良好である上、接着剤の長期に亘る耐湿熱性が得られる。このイソシアヌレートの含有量はポリイソシアネート中に５０～１００重量％である。なお、イソシアヌレートとは、ジイソシアネートの三量体の意である。 [Curing agent]
The curing agent used in the present invention includes a polyisocyanate having an isocyanurate of isophorone diisocyanate. This isocyanurate has a long pot life after mixing with the main agent, good solution stability, and long-term wet heat resistance of the adhesive. The isocyanurate content is 50 to 100% by weight in the polyisocyanate. In addition, isocyanurate means the trimer of diisocyanate.
　本発明では、硬化剤は、上記ポリイソシアネート以外に任意のポリイソシアネートを５０重量％未満の量で含むことができる。但し、接着剤の黄変を抑制する点では低黄変型の脂肪族又は脂環族のポリイソシアネートであることが好ましい。 In the present invention, the curing agent can contain any polyisocyanate in an amount of less than 50% by weight in addition to the above polyisocyanate. However, in terms of suppressing yellowing of the adhesive, it is preferably a low yellowing type aliphatic or alicyclic polyisocyanate.
　具体的には、低分子量ポリイソシアネート、低分子量ポリイソシアネートと水又は多価アルコールとを反応させて得られるポリウレタンイソシアネート、及び低分子量イソシアネートの二量体等から選ばれる１種以上を併用することができる。 Specifically, one or more selected from low molecular weight polyisocyanate, polyurethane isocyanate obtained by reacting low molecular weight polyisocyanate with water or polyhydric alcohol, dimer of low molecular weight isocyanate, etc. may be used in combination. it can.
　低分子量ポリイソシアネートとしては、例えば、ヘキサメチレンジイソシアネート、フェニレンジイソシアネート、２，４－又は２，６－トリレンジイソシアネート、ジフェニルメタン－４，４－ジイソシアネート、３，３－ジメチル－４，４－ビフェニレンジイソシアネート、ジシクロヘキシルメタン－４，４－ジイソシアネート、イソホロンジイソシアネート及びこれらの混合物が挙げられる。これらの低分子量ポリイソシアネートと反応させる多価アルコールとしては、例えば、上記ポリエステルポリウレタンポリオールを製造する前段階のポリエステルポリオールの原料として前記したものが挙げられる。 Examples of the low molecular weight polyisocyanate include hexamethylene diisocyanate, phenylene diisocyanate, 2,4- or 2,6-tolylene diisocyanate, diphenylmethane-4,4-diisocyanate, 3,3-dimethyl-4,4-biphenylene diisocyanate, Examples include dicyclohexylmethane-4,4-diisocyanate, isophorone diisocyanate, and mixtures thereof. Examples of the polyhydric alcohol to be reacted with these low molecular weight polyisocyanates include those described above as raw materials for the polyester polyol in the previous stage for producing the polyester polyurethane polyol.
　硬化剤は、本発明の効果を阻害しない範囲内で、任意に、周知のオキサゾリン化合物、例えば、２，５－ジメチル－２－オキサゾリン、２，２－（１，４－ブチレン）－ビス（２－オキサゾリン）又はヒドラジド化合物、例えば、イソフタル酸ジヒドラジド、セバシン酸ジヒドラジド、アジピン酸ジヒドラジド等を含むことができる。 The curing agent may optionally be a known oxazoline compound, for example, 2,5-dimethyl-2-oxazoline, 2,2- (1,4-butylene) -bis (2), as long as the effects of the present invention are not impaired. -Oxazoline) or hydrazide compounds such as isophthalic acid dihydrazide, sebacic acid dihydrazide, adipic acid dihydrazide and the like.
　主剤と硬化剤は、前述したように、主剤固形分１００重量部に対して硬化剤固形分を４～１２重量部とする。硬化剤の量を４重量部以上とすることにより耐湿熱性をより効果的に改善することができる。また、硬化剤を１２重量部以下とすることにより、低温での接着力をより効果的に発揮させることができる。従って、湿熱耐性と低温での接着力とのバランスから、硬化剤の量は４～１２重量部とする。
　また、主剤中のポリエステルポリオール及びポリエステルポリウレタンポリオールの水酸基の合計に対して、硬化剤中のイソシアネート基が当量比にして１．０～１０．０になるように配合されることが好ましく、空気中の水分との反応によるイソシアネート基の消失や、ラミネート後のエージング時間を考慮すると３．０～７．０であることが好ましい。 As described above, the main agent and the curing agent have a hardener solid content of 4 to 12 parts by weight with respect to 100 parts by weight of the main agent solid content. By setting the amount of the curing agent to 4 parts by weight or more, the wet heat resistance can be improved more effectively. Moreover, the adhesive force in low temperature can be more effectively exhibited by making a hardening | curing agent into 12 weight part or less. Therefore, the amount of the curing agent is 4 to 12 parts by weight from the balance between wet heat resistance and adhesive strength at low temperature.
Further, it is preferable that the isocyanate group in the curing agent is blended so that the equivalent ratio is 1.0 to 10.0 with respect to the total of the hydroxyl groups of the polyester polyol and the polyester polyurethane polyol in the main agent. Considering the disappearance of isocyanate groups due to the reaction with water and the aging time after lamination, it is preferably 3.0 to 7.0.
［太陽電池裏面保護シート］
　耐候性を有する外層基材１）としては、例えば、ポリエチレン（ＰＥ）（高密度ポリエチレン、低密度ポリエチレン、線状低密度ポリエチレン）、ポリプロピレン（ＰＰ）、ポリブテン等のポリオレフィン系樹脂、（メタ）アクリル系樹脂、ポリ塩化ビニル系樹脂、ポリスチレン系樹脂、ポリ塩化ビニリデン系樹脂、エチレン－酢酸ビニル共重合体ケン化物、ポリビニルアルコール、ポリカーボネート系樹脂、フッ素樹脂、ポリフッ化ビニリデン系樹脂、ポリフッ化ビニル系樹脂、ポリ酢酸ビニル系樹脂、アセタール系樹脂、ポリエステル系樹脂（ポリエチレンテレフタレート（ＰＥＴ）、ポリブチレンテレフタレート、ポリエチレンナフタレート）、ポリアミド系樹脂、その他の各種の樹脂のフィルム又はシートを使用することができる。これらの樹脂のフィルムまたはシートは、一軸又は二軸方向に延伸されているものでもよい。 [Solar cell back surface protection sheet]
Examples of the weather resistant outer layer base material 1) include polyolefin resins such as polyethylene (PE) (high density polyethylene, low density polyethylene, linear low density polyethylene), polypropylene (PP), polybutene, and (meth) acrylic. Resin, polyvinyl chloride resin, polystyrene resin, polyvinylidene chloride resin, saponified ethylene-vinyl acetate copolymer, polyvinyl alcohol, polycarbonate resin, fluororesin, polyvinylidene fluoride resin, polyvinyl fluoride resin Polyvinyl acetate resins, acetal resins, polyester resins (polyethylene terephthalate (PET), polybutylene terephthalate, polyethylene naphthalate), polyamide resins, and other various resin films or sheets can be used. These resin films or sheets may be stretched in a uniaxial or biaxial direction.
　外層基材１）には、紫外線を吸収又は反射する目的で、酸化チタン、硫酸バリウム等の白色顔料、カーボン等の黒色顔料を混入してもよい。また、着色顔料以外の公知の紫外線吸収剤、水分吸収剤（乾燥剤）、酸素吸収剤、酸化防止剤等公知の添加剤を混入してもよい。 In the outer layer base material 1), a white pigment such as titanium oxide or barium sulfate or a black pigment such as carbon may be mixed for the purpose of absorbing or reflecting ultraviolet rays. Moreover, you may mix well-known additives, such as well-known ultraviolet absorbers other than a coloring pigment, a moisture absorber (drying agent), an oxygen absorber, and antioxidant.
　外層基材１）の厚さは限定的ではないが、例えば、１０～３５０μm、好ましくは、１０～１００μｍ程度とすることができる。 The thickness of the outer layer base material 1) is not limited, but can be, for example, about 10 to 350 μm, preferably about 10 to 100 μm.
　中間層基材２）としては、例えば、ポリエチレンテレフタレート樹脂、エチレントリフルオロエチレンフィルム、その他の各種の樹脂のフィルム又はシートを使用することができる。これらの樹脂のフィルムまたはシートは、一軸又は二軸方向に延伸されているものでもよい。 As the intermediate layer base material 2), for example, polyethylene terephthalate resin, ethylene trifluoroethylene film, and other various resin films or sheets can be used. These resin films or sheets may be stretched in a uniaxial or biaxial direction.
　中間層基材２）の厚さは限定的ではないが、３０～３５０μｍが好ましく、１００～３５０μｍであることがより好ましく、１２５～３５０μｍであることが一層好ましく、特に１５０～３００μｍであることが好ましい。
　太陽電池用裏面保護シートには、太陽電池モジュールを電圧印加による破損から保護する為に、太陽電池セルの発電容量に応じ、部分放電電圧６００Ｖ、若しくは１，０００Ｖの耐性が要求されることがある。部分放電電圧は、太陽電池裏面保護シートの厚みに依存するので、太陽電池裏面保護シートを構成する基材は、食品包装用積層体を構成する基材よりも厚いことが求められる。太陽電池裏面保護シートを構成する基材のうち、耐電圧性を担う中間層基材２）が、主として「厚さ」を担う。そこで、中間層基材２）の厚みは前記の通り、１００～３５０μｍであることが好ましい。一方、太陽電池裏面保護シートを構成する基材が厚くなると、価格が高くなる。そこで、中間層基材２）の厚みは１２５～３５０μｍであることが好ましい。 The thickness of the intermediate layer substrate 2) is not limited, but is preferably 30 to 350 μm, more preferably 100 to 350 μm, still more preferably 125 to 350 μm, and particularly preferably 150 to 300 μm. preferable.
In order to protect the solar cell module from damage due to voltage application, the solar cell back surface protection sheet may be required to have a partial discharge voltage of 600 V or 1,000 V depending on the power generation capacity of the solar cell. . Since the partial discharge voltage depends on the thickness of the solar cell back surface protection sheet, the base material constituting the solar cell back surface protection sheet is required to be thicker than the base material constituting the food packaging laminate. Among the base materials constituting the solar cell back surface protection sheet, the intermediate layer base material 2) responsible for voltage resistance mainly bears “thickness”. Therefore, the thickness of the intermediate layer base material 2) is preferably 100 to 350 μm as described above. On the other hand, when the base material which comprises a solar cell back surface protection sheet becomes thick, a price will become high. Therefore, the thickness of the intermediate layer base material 2) is preferably 125 to 350 μm.
　太陽電池モジュールに用いられる発電素子を封止するための封止材と良好な接着性を有する内層基材としては、例えば、ポリエチレン（ＰＥ）（高密度ポリエチレン、低密度ポリエチレン、線状低密度ポリエチレン）、ポリプロピレン（ＰＰ）、ポリブテン等のポリオレフィン系樹脂、（メタ）アクリル系樹脂、ポリ塩化ビニル系樹脂、ポリスチレン系樹脂、ポリ塩化ビニリデン系樹脂、エチレン－酢酸ビニル共重合体ケン化物、ポリビニルアルコール、ポリカーボネート系樹脂、フッ素樹脂、ポリフッ化ビニル系樹脂、ポリ酢酸ビニル系樹脂、アセタール系樹脂、ポリエステル系樹脂（ポリエチレンテレフタレート（ＰＥＴ）、ポリブチレンテレフタレート、ポリエチレンナフタレート）、ポリアミド系樹脂、その他の各種の樹脂のフィルム又はシートを使用することができる。これらの樹脂のフィルム又はシートは、一軸又は二軸方向に延伸されているものでもよい。 For example, polyethylene (PE) (high-density polyethylene, low-density polyethylene, linear low-density polyethylene) is used as a sealing material for sealing a power generating element used in a solar cell module and an inner layer base material having good adhesiveness. ), Polyolefin resin such as polypropylene (PP), polybutene, (meth) acrylic resin, polyvinyl chloride resin, polystyrene resin, polyvinylidene chloride resin, saponified ethylene-vinyl acetate copolymer, polyvinyl alcohol, Polycarbonate resin, fluororesin, polyvinyl fluoride resin, polyvinyl acetate resin, acetal resin, polyester resin (polyethylene terephthalate (PET), polybutylene terephthalate, polyethylene naphthalate), polyamide resin, and other various types Resin film It is possible to use a solid or sheet. These resin films or sheets may be stretched in a uniaxial or biaxial direction.
　内層基材の厚さは限定的ではないが、例えば１０～３５０μmであり、３０～２５０μｍ程度が好ましく、３０～１００μｍがより好ましい。 The thickness of the inner layer base material is not limited, but is, for example, 10 to 350 μm, preferably about 30 to 250 μm, more preferably 30 to 100 μm.
　また、本発明では、少なくとも上記３層を用いればよく、その他、太陽電池裏面保護シートの構成として公知の任意層を更に積層してもよい。例えば、内層基材として１２５～３５０μmのオレフィン層を、中間層基材として１２５～３５０μmのポリエチレンテレフタレートフィルム層を、外層基材として１０～１００μmのフッ素層からなる太陽電池裏面保護シートを例示できる。 Further, in the present invention, at least the above three layers may be used, and other arbitrary layers known as the constitution of the solar cell back surface protective sheet may be further laminated. For example, a solar cell back surface protective sheet comprising an olefin layer of 125 to 350 μm as an inner layer substrate, a polyethylene terephthalate film layer of 125 to 350 μm as an intermediate layer substrate, and a fluorine layer of 10 to 100 μm as an outer layer substrate can be exemplified.
　上述したように、上記接着剤により外層基材１）、中間層基材２）、内層基材３）のうちの最も厚い基材の少なくとも片面を接合する。接着方法は特に限定されないが、一方のラミネート基材の片面に、グラビア印刷、コンマコート、ドライラミネート等によって接着剤を塗布し、溶剤を揮散させた後、他方のラミネート基材と貼り合わせ、常温もしくは加温下で硬化させれば良い。外層基材、中間層基材、及び内層基材のうちの最も厚い基材の厚み及び乾燥後の接着剤層の量は、適宜設計し得るが、最も厚い基材の厚みを１２５～３５０μｍとし、そのラミネート基材の少なくとも片面に塗布される乾燥後の接着剤層の量は、前述したように５ｇ／ｍ２を超えて３０ｇ／ｍ２以下とすることが好ましい。より好ましくは、５ｇ／ｍ２を超えて、２５ｇ／ｍ２以下であり、さらに好ましくは、６ｇ／ｍ２以上、２０ｇ／ｍ２以下である。有機溶剤を除く接着剤の比重は、約１．１ｇ／ｃｍ３なので、１．１ｇ／ｍ２は約１μｍ／ｍ２と換算できる。従って、前記接着剤層の量は、厚みに換算すると約４．５～２７．３μｍとなる。乾燥後の接着剤層の量を５ｇ／ｍ２超えとすることにより、接着剤層が受ける加水分解の影響をより効果的に低減できる。また、接着剤層の量を３０ｇ／ｍ２以下とすることにより、基材と貼り合せる前の乾燥時に接着剤中の有機溶剤を十分揮発させやすくできる。 As described above, at least one side of the thickest substrate among the outer layer base material 1), the intermediate layer base material 2), and the inner layer base material 3) is joined by the adhesive. The bonding method is not particularly limited, but an adhesive is applied to one side of one laminated base material by gravure printing, comma coating, dry laminating, etc., and the solvent is stripped, and then bonded to the other laminated base material, Alternatively, it may be cured under heating. The thickness of the thickest base material among the outer layer base material, the intermediate layer base material, and the inner layer base material and the amount of the adhesive layer after drying can be appropriately designed. The thickness of the thickest base material is 125 to 350 μm. The amount of the adhesive layer after drying applied to at least one surface of the laminate substrate is preferably more than 5 g / m 2 and not more than 30 g / m 2 as described above. More preferably, by more than 5 g / m 2, and at 25 g / m 2 or less, more preferably, 6 g / m 2 or more and 20 g / m 2 or less. Since the specific gravity of the adhesive excluding the organic solvent is about 1.1 g / cm 3 , 1.1 g / m 2 can be converted to about 1 μm / m 2 . Therefore, the amount of the adhesive layer is about 4.5 to 27.3 μm in terms of thickness. By making the amount of the adhesive layer after drying exceed 5 g / m 2 , it is possible to more effectively reduce the influence of hydrolysis on the adhesive layer. In addition, by setting the amount of the adhesive layer to 30 g / m 2 or less, the organic solvent in the adhesive can be easily volatilized at the time of drying before being bonded to the base material.
　本発明の太陽電池裏面保護シートは、工業的に複数の基材を貼り合せた後、ロール状に巻いた状態で接着剤層の硬化を完了させて製造する場合、本発明者らが鋭意検討を重ねたところ、以下の態様において工業的生産性をより改善できることがわかった。即ち、外層基材、中間層基材、及び内層基材のうちの最も厚い基材の厚みを１２５～３５０μｍとし、かつ、接着剤層の量を５ｇ／ｍ２を超えて３０ｇ／ｍ２以下とすることにより、太陽電池モジュール内に配設された発光素子に対して効果的に電気的な絶縁を満たしつつ、接着剤を塗工した後の接着性発現プロセスにおいて積層体をロール状に巻いても、ロール状積層体に浮き（以下、トンネリングという）が生じるのをより効果的に抑制できることがわかった。その結果、接着剤の塗工後の接着性発現プロセスにおいて工業的生産性が高い太陽電池裏面保護シートを提供することができる。 When the solar cell back surface protective sheet of the present invention is manufactured by industrially laminating a plurality of base materials and then completing the curing of the adhesive layer in a state of being wound in a roll shape, the present inventors have conducted intensive studies. As a result, it was found that industrial productivity can be further improved in the following embodiments. That is, the thickness of the thickest substrate among the outer layer substrate, the intermediate layer substrate, and the inner layer substrate is 125 to 350 μm, and the amount of the adhesive layer is more than 5 g / m 2 and not more than 30 g / m 2 Thus, the laminate is wound into a roll in the adhesive development process after applying the adhesive while effectively satisfying the electrical insulation with respect to the light emitting elements disposed in the solar cell module. However, it has been found that floating (hereinafter referred to as tunneling) in the roll-shaped laminate can be more effectively suppressed. As a result, it is possible to provide a solar cell back surface protective sheet with high industrial productivity in the adhesiveness development process after the application of the adhesive.
　本発明の太陽電池裏面保護シートは、内層基材側を太陽電池モジュールの発電素子を封止するための封止材と接着することにより太陽電池モジュールに設置される。本発明の太陽電池モジュールの構成は特に限定されず、公知の太陽電池モジュールが使用できる。 The solar cell back surface protective sheet of the present invention is installed in a solar cell module by adhering the inner layer base material side with a sealing material for sealing the power generation element of the solar cell module. The configuration of the solar cell module of the present invention is not particularly limited, and a known solar cell module can be used.
　本発明の太陽電池裏面保護シートによれば、上述した特定の接着剤により外層基材、中間層基材、及び内装基材のうち最も厚い基材の少なくとも片面が接着されていることにより、接着剤性能として良好な接着剤、及び長期の使用に耐え得る耐候性が得られる。その結果、長期信頼性の高い太陽電池裏面保護シートを提供することができる。また、本発明で用いる接着剤はコスト的に安価であり、しかもグラビア塗工、コンマコート等の一般的な塗工方法で容易に塗工できるという特性も有する。さらに、本発明の太陽電池裏面保護シートは、主剤と硬化剤の割合が主剤固形分１００重量部に対して、硬化剤固形分が４～１２重量部である接着剤を用いることにより、湿熱耐性と低温での接着力に優れる。即ち、長期信頼性、及び湿熱耐性に優れ、かつ、低温環境下における接着性に優れ、さらに、コスト性、及び塗工性に優れる太陽電池裏面保護シートを提供できる。 According to the solar cell back surface protective sheet of the present invention, at least one surface of the thickest base material among the outer layer base material, the intermediate layer base material, and the interior base material is bonded by the specific adhesive described above. Adhesives with good agent performance and weather resistance that can withstand long-term use are obtained. As a result, a solar cell back surface protective sheet with high long-term reliability can be provided. In addition, the adhesive used in the present invention is inexpensive and has a characteristic that it can be easily applied by a general coating method such as gravure coating or comma coating. Furthermore, the solar cell back surface protective sheet of the present invention is resistant to moist heat by using an adhesive in which the ratio of the main agent and the curing agent is 4 to 12 parts by weight of the curing agent solid content with respect to 100 parts by weight of the main agent solid content. Excellent adhesion at low temperatures. That is, it is possible to provide a solar cell back surface protective sheet that is excellent in long-term reliability and wet heat resistance, is excellent in adhesiveness in a low temperature environment, and is excellent in cost and coating properties.
　以下に実施例及び比較例を示して本発明を具体的に説明する。但し、本発明は実施例に限定されない。実施例中、部は重量部を示す。 Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples. However, the present invention is not limited to the examples. In the examples, parts refer to parts by weight.
　実施例１
　密度０．９１ｇ／ｃｍ３の低密度ポリエチレン樹脂（ＬＤＰＥ）１００ｋｇに酸化チタン粒子２５ｋｇを添加し、十分に混練してＬＤＰＥ樹脂組成物を調製した。次いで押出機で押出して厚み５０μｍの第１フィルムを作製した。 Example 1
25 kg of titanium oxide particles were added to 100 kg of low density polyethylene resin (LDPE) having a density of 0.91 g / cm 3 and kneaded sufficiently to prepare an LDPE resin composition. Subsequently, it was extruded with an extruder to produce a first film having a thickness of 50 μm.
　次に、電気絶縁性に優れる第２フィルムとして厚さ２５０μｍのポリエチレンテレフタレートフィルム（東洋紡績社製：東洋紡エステルフィルムＥ５１０２）を用意した。また、第３フィルムとしてＰＶＦフィルム（デュポン社製、３８μｍ）を用意した。これらのフィルムを、ドライラミネート用接着剤を用いたドライラミネート法で接着した。
　なお、ドライラミネート用接着剤は次の通りである。 Next, a 250 μm thick polyethylene terephthalate film (manufactured by Toyobo Co., Ltd .: Toyobo Ester Film E5102) was prepared as a second film having excellent electrical insulation. Further, a PVF film (manufactured by DuPont, 38 μm) was prepared as the third film. These films were bonded by a dry laminating method using an adhesive for dry laminating.
The adhesive for dry lamination is as follows.
　テレフタル酸ジメチル１１９．５部、エチレングリコール９２．２部、ネオペンチルグリコール７２．２部及び酢酸亜鉛０．０２部を反応缶に仕込み、窒素気流下で攪拌しながら１６０～２１０℃に加熱してエステル交換反応を行った。理論量の９７％のメタノールが留出した後、イソフタル酸９３．０部、アゼライン酸１３０．０部を仕込み、１６０～２７０℃に加熱してエステル化反応を行った。反応缶を徐々に１～２トールまで減圧し、酸価が０．８ｍｇＫＯＨ／ｇ以下となったところで減圧下での反応を停止し、重量平均分子量が７５，０００のポリエステルポリオールを得た。酢酸エチルで希釈して得られたポリエステルポリオールの濃度を５０％とする樹脂溶液をポリオールＡとした。 Charge 119.5 parts of dimethyl terephthalate, 92.2 parts of ethylene glycol, 72.2 parts of neopentyl glycol and 0.02 part of zinc acetate to a reactor, and heat to 160-210 ° C. with stirring under a nitrogen stream. A transesterification reaction was performed. After distillation of 97% of the theoretical amount of methanol, 93.0 parts of isophthalic acid and 130.0 parts of azelaic acid were charged and heated to 160 to 270 ° C. for esterification reaction. The reaction vessel was gradually depressurized to 1 to 2 Torr, and when the acid value became 0.8 mgKOH / g or less, the reaction under reduced pressure was stopped to obtain a polyester polyol having a weight average molecular weight of 75,000. A resin solution in which the concentration of the polyester polyol obtained by dilution with ethyl acetate was 50% was designated as polyol A.
　ネオペンチルグリコール９４．２部、１，６－ヘキサンジオール９１．７部、エチレングリコール３７．６部、イソフタル酸２１１．５部、及びセバシン酸１２２．９部を反応缶に仕込み、窒素気流下で攪拌しながら１６０～２５０℃に加熱してエステル化反応を行なった。反応缶を徐々に１～２トールまで減圧し、酸価が１ｍｇＫＯＨ／ｇ以下となったところで減圧下での反応を停止し、重量平均分子量が６，０００の前段階のポリエステルポリオールを得た。得られたポリエステルポリオールにイソホロンジイソシアネート２２．９部を徐々に加えて１００～１５０℃で加熱反応させた。６時間反応後に、重量平均分子量３５，０００のポリエステルポリウレタンポリオールを得た。酢酸エチルで希釈して得られたポリエステルポリウレタンポリオールの濃度を５０％とする樹脂溶液をポリオールＢとした。 A reactor was charged with 94.2 parts of neopentyl glycol, 91.7 parts of 1,6-hexanediol, 37.6 parts of ethylene glycol, 211.5 parts of isophthalic acid, and 122.9 parts of sebacic acid. The esterification reaction was carried out by heating to 160 to 250 ° C. with stirring. The reaction vessel was gradually depressurized to 1 to 2 Torr, and when the acid value became 1 mgKOH / g or less, the reaction under reduced pressure was stopped to obtain a polyester polyol in the previous stage having a weight average molecular weight of 6,000. To the obtained polyester polyol, 22.9 parts of isophorone diisocyanate was gradually added and reacted by heating at 100 to 150 ° C. After reacting for 6 hours, a polyester polyurethane polyol having a weight average molecular weight of 35,000 was obtained. Polyol B was a resin solution in which the concentration of the polyester polyurethane polyol obtained by dilution with ethyl acetate was 50%.
　ポリオールＡ１００部（固形分５０部）、ポリオールＢ４０部（固形分２０部）、数平均分子量１，２００でエポキシ当量６００ｇ／ｅｑのビスフェノールＡ型エポキシ樹脂３０部及びエポキシ基含有オルガノシランカップリング剤３部を７０℃で加熱・溶解・混合し、酢酸エチルで希釈して得られた固形分５０％の樹脂溶液を主剤１とした。
　なお、主剤１中のポリオールＡとポリオールＢとの合計のエステル結合度は、以下のようにして求めると０．８９である。
　即ち、各ポリオールの原料である二塩基酸：２価アルコール＝１：１ (モル比)で反応したとして、そのエステル結合数を１とする。そのポリオール中の二塩基酸と２価アルコールの平均分子量(当量)を算出する。(反応時の脱水などを差し引いた)エステル結合数をその分子量で割り算したものを、エステル結合度と規定する。
式）エステル結合度＝１/分子量値　(単位 /g)＝１００/分子量値　(単位 /１００ｇ)
ポリオールＡのエステル結合度が０．９３であり、ポリオールＢのエステル結合が０．７９であるので、主剤１のエステル結合度は、
（０．９３×１００＋０．７９×４０）／（１００＋４０）＝０．８９
となる。 Polyol A 100 parts (solid content 50 parts), polyol B 40 parts (solid content 20 parts), number average molecular weight 1,200 and epoxy equivalent 600 g / eq of bisphenol A type epoxy resin 30 parts and epoxy group-containing organosilane coupling agent 3 A resin solution with a solid content of 50% obtained by heating, dissolving and mixing the parts at 70 ° C. and diluting with ethyl acetate was used as the main agent 1.
The total ester bond degree of polyol A and polyol B in the main agent 1 is 0.89 when determined as follows.
That is, assuming that the reaction is performed with dibasic acid: dihydric alcohol = 1: 1 (molar ratio) which is a raw material of each polyol, the number of ester bonds is set to 1. The average molecular weight (equivalent) of the dibasic acid and dihydric alcohol in the polyol is calculated. The ester bond degree is defined as the number of ester bonds (subtracting dehydration during the reaction) divided by the molecular weight.
Formula) Degree of ester bond = 1 / molecular weight value (unit / g) = 100 / molecular weight value (unit / 100g)
Since the ester bond degree of polyol A is 0.93 and the ester bond of polyol B is 0.79, the ester bond degree of main agent 1 is
(0.93 × 100 + 0.79 × 40) / (100 + 40) = 0.89
It becomes.
　イソホロンジイソシアネートの三量体を酢酸エチルで希釈して固形分５０％の樹脂溶液としたものを硬化剤１とした。 Curing agent 1 was obtained by diluting a trimer of isophorone diisocyanate with ethyl acetate to give a resin solution having a solid content of 50%.
　主剤１と硬化剤１を固形分において１００：１２（重量比）で配合し、酢酸エチルで希釈して固形分３０％に調整した溶液を接着剤溶液とした。 A solution in which the main agent 1 and the curing agent 1 were blended at a solid content of 100: 12 (weight ratio) and diluted with ethyl acetate to a solid content of 30% was used as an adhesive solution.
　上記接着剤溶液を乾燥後の接着剤層の量が１０ｇ／ｍ２となるように調整し、第１フィルム～第３フィルムのラミネートを行い、２１０ｍｍ×２９５ｍｍ（Ａ４サイズ）の積層体を得た。ラミネート後、前記の２１０ｍｍ×２９５ｍｍ（Ａ４サイズ）の積層体をほぼ水平に置いた状態で、６０℃で７日間エージングを行い、接着剤を硬化させて太陽電池用裏面保護シートを作製した。
　後述する方法にて、接着力（２５℃、１５℃）、耐候性試験後の接着力（２５℃）、トンネリングを評価した。 The adhesive solution was adjusted so that the amount of the adhesive layer after drying was 10 g / m 2, and the first to third films were laminated to obtain a laminate of 210 mm × 295 mm (A4 size). . After the lamination, with the 210 mm × 295 mm (A4 size) laminate being placed almost horizontally, aging was performed at 60 ° C. for 7 days to cure the adhesive, thereby producing a back protective sheet for solar cells.
The adhesive strength (25 ° C., 15 ° C.), the adhesive strength after the weather resistance test (25 ° C.), and tunneling were evaluated by the methods described later.
実施例２～４
　１００部の主剤１に対して、硬化剤１をそれぞれ１０部（実施例２）、６部（実施例３）、４部（実施例４）とした以外は、実施例１と同様にして太陽電池用裏面保護シートを作製し、評価した。 Examples 2-4
The solar system is the same as in Example 1 except that 100 parts of the main agent 1 is 10 parts (Example 2), 6 parts (Example 3), and 4 parts (Example 4) of the curing agent 1, respectively. A battery back protection sheet was prepared and evaluated.
比較例１
　固形分１００部の主剤１に対して、硬化剤１の固形分を１４部とした以外は、実施例１と同様にして太陽電池用裏面保護シートを作製し、評価した。 Comparative Example 1
A solar cell back surface protective sheet was prepared and evaluated in the same manner as in Example 1 except that the solid content of the curing agent 1 was changed to 14 parts with respect to the main component 1 having a solid content of 100 parts.
　実施例５～１１
　実施例２の接着剤溶液を用い、乾燥後の接着剤層の量が３ｇ／ｍ２（実施例５）、５ｇ／ｍ２（実施例６）、１５ｇ／ｍ２（実施例７）、２０ｇ／ｍ２（実施例８）、２５ｇ／ｍ２（実施例９）、３０ｇ／ｍ２（実施例１０）、３５ｇ／ｍ２（比較例１１）となるように調整した以外は、実施例２と同様にして太陽電池用裏面保護シートを作製し、評価した。 Examples 5 to 11
Using the adhesive solution of Example 2, the amount of the adhesive layer after drying was 3 g / m 2 (Example 5), 5 g / m 2 (Example 6), 15 g / m 2 (Example 7), and 20 g. / M 2 (Example 8), 25 g / m 2 (Example 9), 30 g / m 2 (Example 10), 35 g / m 2 (Comparative Example 11) The back surface protection sheet for solar cells was produced and evaluated in the same manner as described above.
　実施例１２
　第２フィルムとして厚さ２５０μｍのポリエチレンテレフタレートフィルムの代わりに厚さ１００μｍのポリエチレンテレフタレートフィルム（東洋紡績社製：東洋紡エステルフィルムＥ５１００）を用い、実施例２と同様の接着剤溶液を用いた。そして、硬化剤１を１０重量部となるように調整した以外は、実施例１と同様にして太陽電池用裏面保護シートを作製し、評価した。 Example 12
A 100 μm thick polyethylene terephthalate film (manufactured by Toyobo Co., Ltd .: Toyobo Ester Film E5100) was used in place of the 250 μm thick polyethylene terephthalate film as the second film, and the same adhesive solution as in Example 2 was used. And the solar cell back surface protection sheet was produced and evaluated like Example 1 except having adjusted so that the hardening | curing agent 1 might be 10 weight part.
　比較例２、実施例１３～１６
　使用する樹脂製フィルムの種類は実施例１と同様とし、使用する接着剤を変更した。
　ポリオールＡ４０部（固形分２０部）、ポリオールＢ１００部（固形分５０部）、数平均分子量１，２００でエポキシ当量６００ｇ／ｅｑのビスフェノールＡ型エポキシ樹脂３０部及びエポキシ基含有オルガノシランカップリング剤３部を７０℃で加熱・溶解・混合し、酢酸エチルで希釈して得られた固形分５０％の樹脂溶液を主剤２とした。 Comparative Example 2, Examples 13-16
The type of resin film used was the same as in Example 1, and the adhesive used was changed.
Polyol A 40 parts (solid content 20 parts), polyol B 100 parts (solid content 50 parts), number average molecular weight 1,200 and epoxy equivalent 600 g / eq of bisphenol A type epoxy resin 30 parts and epoxy group-containing organosilane coupling agent 3 A resin solution having a solid content of 50% obtained by heating, dissolving and mixing the parts at 70 ° C. and diluting with ethyl acetate was used as the main agent 2.
　１００部の主剤２に対して、硬化剤１をそれぞれ１４部（比較例２）、１２部（実施例１３）、１０部（実施例１４）、６部（実施例１５）、４部（実施例１６）とした以外は、実施例１と同様にして太陽電池用裏面保護シートを作製し、評価した。 For 100 parts of main agent 2, curing agent 1 is 14 parts (Comparative Example 2), 12 parts (Example 13), 10 parts (Example 14), 6 parts (Example 15), 4 parts (implemented). Except for Example 16), a back protective sheet for solar cell was prepared and evaluated in the same manner as in Example 1.
　実施例１７、１８
　数平均分子量１，２００のエポキシ樹脂の代わりに、数平均分子量１，４００、エポキシ当量７００ｇ／ｅｑのビスフェノールＡ型エポキシ樹脂（実施例１７）、数平均分子量１，０００、エポキシ当量５００ｇ／ｅｑのビスフェノールＡ型エポキシ樹脂（実施例１８）をそれぞれ３０部用いた以外は、実施例２と同様にして太陽電池用裏面保護シートを作製し、評価した。 Examples 17 and 18
Instead of an epoxy resin having a number average molecular weight of 1,200, a bisphenol A type epoxy resin having a number average molecular weight of 1,400 and an epoxy equivalent of 700 g / eq (Example 17), a number average molecular weight of 1,000 and an epoxy equivalent of 500 g / eq A back protective sheet for solar cell was prepared and evaluated in the same manner as in Example 2 except that 30 parts of each of bisphenol A type epoxy resins (Example 18) were used.
　比較例３
　ポリオールＡを１２０部（固形分６０部）、ポリオールＢを２０部（固形分１０部）とした以外は比較例１と同様にして固形分５０％の樹脂溶液を主剤３とした。
　主剤３と硬化剤１を１００：１４（重量比）で配合し、酢酸エチルで希釈して固形分３０％に調整した溶液を接着剤溶液として用いた以外は、実施例１と同様にして太陽電池用裏面保護シートを作製し、評価した。 Comparative Example 3
A resin solution having a solid content of 50% was used as the main agent 3 in the same manner as in Comparative Example 1, except that the polyol A was 120 parts (solid content 60 parts) and the polyol B was 20 parts (solid content 10 parts).
Except that the base material 3 and the curing agent 1 were blended at a ratio of 100: 14 (weight ratio), diluted with ethyl acetate and adjusted to a solid content of 30%, and used as an adhesive solution, the sun was applied as in Example 1. A battery back protection sheet was prepared and evaluated.
　比較例４（ポリオールＢを使用しない）
　ポリオールＢを使用せず、ポリオールＡを１４０部（固形分７０部）とした以外は、比較例１と同様にして太陽電池用裏面保護シートを作製し、評価した。 Comparative Example 4 (Polyol B not used)
A solar cell back surface protective sheet was prepared and evaluated in the same manner as in Comparative Example 1 except that polyol B was not used and polyol A was changed to 140 parts (solid content: 70 parts).
　比較例５（ポリオールＡを使用しない）
　ポリオールＡを使用せず、ポリオールＢを１４０部（固形分７０部）とした以外は、比較例１と同様にして太陽電池用裏面保護シートを作製し、評価した。 Comparative Example 5 (no use of polyol A)
A solar cell back surface protective sheet was prepared and evaluated in the same manner as in Comparative Example 1 except that polyol A was not used and polyol B was changed to 140 parts (solid content: 70 parts).
　比較例６（硬化剤が異なる）
　イソホロンジイソシアネートの三量体を酢酸エチルで希釈して固形分５０％の樹脂溶液の代わりに、トリレンジイソシアネートのＴＭＰアダクト体を酢酸エチルで希釈して固形分５０％の樹脂溶液としたものを硬化剤２とした。また、固形分１００部の主剤１に対して硬化剤２の固形分を１４部用いた。これ以外は実施例１と同様にして太陽電池用裏面保護シートを作製し、評価した。 Comparative Example 6 (Different curing agents)
Dilute isophorone diisocyanate trimer with ethyl acetate to cure 50% solids resin solution instead of tolylene diisocyanate TMP adduct with ethyl acetate to cure 50% solids resin solution Agent 2 was obtained. Moreover, 14 parts of solid content of the hardening | curing agent 2 was used with respect to the main ingredient 1 of solid content 100 parts. Except this, it carried out similarly to Example 1, and produced and evaluated the back surface protection sheet for solar cells.
　比較例７、８（ポリオールＡを使用しない）
　テレフタル酸ジメチル９９．６部、エチレングリコール９２．２部、ネオペンチルグリコール７２．２部、酢酸亜鉛０．０２部を反応缶に仕込み、窒素気流下で攪拌しながら１６０～２１０℃に加熱してエステル交換反応を行い、理論量の９７％のメタノールが留出した後、イソフタル酸７７．５部、アジピン酸１２９．６部を仕込み、１６０～２４０℃に加熱してエステル化反応を行った。反応缶を徐々に１～２トールまで減圧した。酸価が０．８ｍｇＫＯＨ／ｇ以下で減圧反応を停止し、重量平均分子量が６０，０００のポリエステルポリオール（エステル結合度０．９０モル／１００ｇ）を得た。酢酸エチルで希釈して得られた固形分５０％の樹脂溶液を、ポリオールＣとした。
　１００部のポリオールＡの代わりに１００部のポリオールＣを用いた。また、固形分１００部の主剤１に対して硬化剤１の固形分を１４部（比較例７）、または１０部（比較例８）用いた。これ以外は実施例１と同様にして太陽電池用裏面保護シートを作製し、評価した。
　なお、前記ポリオールＣは、重量平均分子量が６０，０００であり、炭素数９～１０の脂肪族二塩基酸を含まないので、本願発明におけるポリエステルポリオールＡには該当しない。 Comparative Examples 7 and 8 (polyol A is not used)
Charge 99.6 parts of dimethyl terephthalate, 92.2 parts of ethylene glycol, 72.2 parts of neopentyl glycol, 0.02 part of zinc acetate and heat to 160-210 ° C with stirring under a nitrogen stream. After transesterification, 97% of the theoretical amount of methanol was distilled off, and then 77.5 parts of isophthalic acid and 129.6 parts of adipic acid were charged and heated to 160 to 240 ° C. to carry out the esterification reaction. The reaction can was gradually depressurized to 1-2 torr. The reaction under reduced pressure was stopped when the acid value was 0.8 mgKOH / g or less to obtain a polyester polyol (degree of ester bond 0.90 mol / 100 g) having a weight average molecular weight of 60,000. A resin solution having a solid content of 50% obtained by dilution with ethyl acetate was designated as polyol C.
Instead of 100 parts polyol A, 100 parts polyol C was used. Moreover, 14 parts (comparative example 7) or 10 parts (comparative example 8) of solid content of the hardening | curing agent 1 were used with respect to the main ingredient 1 of solid content 100 parts. Except this, it carried out similarly to Example 1, and produced and evaluated the back surface protection sheet for solar cells.
The polyol C has a weight average molecular weight of 60,000 and does not contain an aliphatic dibasic acid having 9 to 10 carbon atoms, and therefore does not correspond to the polyester polyol A in the present invention.
　比較例９（ビスフェノール型エポキシ樹脂を含有しない）
　ポリオールＡ４０部（固形分２０部）、ポリオールＢ１００部（固形分５０部）及びエポキシ基含有オルガノシランカップリング剤３部を７０℃で加熱・溶解・混合し、酢酸エチルで希釈して得られた固形分５０％の樹脂溶液を主剤４とした。また、１００部の主剤４に対して硬化剤１を１４部用いた。これ以外は、実施例１と同様にして太陽電池用裏面保護シートを作製し、評価した。 Comparative Example 9 (does not contain bisphenol type epoxy resin)
40 parts of polyol A (20 parts of solid content), 100 parts of polyol B (50 parts of solid content) and 3 parts of an epoxy group-containing organosilane coupling agent were heated, dissolved and mixed at 70 ° C., and diluted with ethyl acetate. A resin solution having a solid content of 50% was used as the main agent 4. Further, 14 parts of the curing agent 1 was used with respect to 100 parts of the main agent 4. Except this, it carried out similarly to Example 1, and produced and evaluated the back surface protection sheet for solar cells.
　比較例１０
　数平均分子量１，２００のエポキシ樹脂の代わりに、数平均分子量８００、エポキシ当量４００ｇ／ｅｑのビスフェノールＡ型エポキシ樹脂を３０部用いた以外は、実施例２と同様にして太陽電池用裏面保護シートを作製し、評価した。 Comparative Example 10
A back protective sheet for solar cells in the same manner as in Example 2 except that 30 parts of bisphenol A type epoxy resin having a number average molecular weight of 800 and an epoxy equivalent of 400 g / eq was used instead of the epoxy resin having a number average molecular weight of 1,200. Were made and evaluated.
　以下、評価方法について説明する。
＜２５℃初期接着力、１５℃接着力＞
　実施例及び比較例で作製した太陽電池裏面保護シート（試料）を１５ｍｍ幅・約１５０ｍｍ長さに切り出し、ＪＩＳ Ｋ６８５４Ｔ型剥離試験に準拠し、接着力（＝剥離強度）を測定した。試験機を用いて、２５℃、１５℃の雰囲気下にて、引張速度１００ｍｍ／ｍｉｎで各樹脂フィルム層を１８０°剥離することで剥離強度を測定し、以下の基準にて評価した。
　◎：１２Ｎ／１５ｍｍ以上
　○：９Ｎ／１５ｍｍ以上１２Ｎ未満
　△：６Ｎ／１５ｍｍ以上９Ｎ未満
　×：６Ｎ／１５ｍｍ未満 Hereinafter, the evaluation method will be described.
<25 ° C initial adhesive strength, 15 ° C adhesive strength>
The solar cell back surface protective sheet (sample) produced in Examples and Comparative Examples was cut into a width of 15 mm and a length of about 150 mm, and the adhesive strength (= peel strength) was measured according to a JIS K6854T type peel test. The peeling strength was measured by peeling each resin film layer 180 ° at a tensile rate of 100 mm / min in an atmosphere of 25 ° C. and 15 ° C. using a testing machine, and evaluated according to the following criteria.
◎: 12N / 15mm or more ○: 9N / 15mm or more and less than 12N △: 6N / 15mm or more and less than 9N ×: Less than 6N / 15mm
＜耐候性試験後の接着力＞
　ダンプヒート（試験条件８５℃、８５％）、１，０００時間後、２，０００時間後（屋外実曝露状態１０年以上に相当）の接着力を試験前と同様にして２５℃の雰囲気下にて測定し、初期を１００％として剥離強度の保持率（％）を算出し、以下の基準にて評価した。
　◎：２，０００時間後に９５％以上強度保持
　○：２，０００時間後に８５％以上９５％未満強度保持
　△：２，０００時間後に６０％以上８５％未満強度保持
　×：２，０００時間後に６０％未満強度保持 <Adhesive strength after weather resistance test>
Dump heat (test conditions 85 ° C., 85%), 1,000 hours later, 2,000 hours later (corresponding to an actual outdoor exposure state of 10 years or more) in an atmosphere of 25 ° C. in the same manner as before the test. The peel strength retention rate (%) was calculated with the initial value being 100%, and evaluated according to the following criteria.
◎: Strength retention of 95% or more after 2,000 hours ○: Strength retention of 85% or more and less than 95% after 2,000 hours Δ: Strength retention of 60% or more and less than 85% after 2,000 hours ×: 60 after 2,000 hours Less than% strength retention
＜トンネリング（ロール状の太陽電池裏面保護シートの浮き）＞
　実施例及び比較例で第１フィルム～第３フィルムのラミネートを行い、１ｍ幅の長尺の積層体を、外径（直径）１７０ｍｍの紙製の筒の外周に長さ１０ｍ分、巻き付け、ロール状積層体を得た。巻芯を天地方向にした状態で前記ロール状積層体を立て、６０℃で７日間エージングし、太陽電池裏面保護シートを得た。ロール状の太陽電池裏面保護シートの浮きの有無を観察した。浮きの生じた箇所の数で以下の基準にて評価した。「浮き」とは、接着剤層と基材との間に隙間が生じることをいう。
　○：浮き無し
　△：浮き５箇所以内
　×：浮き５箇所以上 <Tunneling (floating of roll-shaped solar cell back surface protection sheet)>
In Examples and Comparative Examples, the first film to the third film are laminated, and a 1 m wide long laminate is wound around the outer periphery of a paper tube having an outer diameter (diameter) of 170 mm for a length of 10 m, and rolled. A layered laminate was obtained. The roll-shaped laminate was erected with the winding core in the vertical direction, and aged at 60 ° C. for 7 days to obtain a solar cell back surface protective sheet. The presence or absence of lifting of the roll-shaped solar cell back surface protective sheet was observed. Evaluation was made based on the following criteria by the number of places where the float occurred. “Floating” means that a gap is formed between the adhesive layer and the substrate.
○: No floating △: Within 5 floating points ×: 5 or more floating points
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
＜部分放電＞
　ＩＥＣ部分放電試験（ＩＥＣ６１７３０－２，ＩＥＣ６０６６４－１)に準拠した方法によって、気中および油中にて測定を行った。
　○：気中及び油中測定方法で１，０００Ｖ以上であるもの
　△：油中測定方法のみで１，０００Ｖ以上であるもの
　×：どの測定方法でも１，０００Ｖに満たないもの
　部分放電評価は、必ずしも太陽電池裏面保護シートに必須の特性ではないが、第２のフィルムとして２５０μｍのポリエチレンテレフタレートフィルムの代わりに厚さ１００μｍのポリエチレンテレフタレートフィルムを用いた実施例１２以外は、いずれのサンプルにおいても良好な結果が得られた。 <Partial discharge>
The measurement was performed in air and in oil by a method based on the IEC partial discharge test (IEC61730-2, IEC606664-1).
○: 1,000 V or more measured in air and in oil △: 1,000 V or more measured only in oil ×: Less than 1,000 V in any measuring method Partial discharge evaluation is Although it is not necessarily an essential property for the solar cell back surface protective sheet, it is good in any sample except Example 12 using a 100 μm thick polyethylene terephthalate film instead of a 250 μm polyethylene terephthalate film as the second film. Results were obtained.
　この出願は、２０１１年７月１１日に出願された日本出願特願２０１１－１５３０６６を基礎とする優先権を主張し、その開示の全てをここに取り込む。 This application claims priority based on Japanese Patent Application No. 2011-153066 filed on July 11, 2011, the entire disclosure of which is incorporated herein.

Claims (5)

  1. 　少なくとも、１）耐候性を有する外層基材、２）中間層基材、及び３）太陽電池モジュールに用いられる発電素子を封止するための封止材と良好な接着性を有する内層基材から構成され、
    　前記外層基材、前記中間層基材、及び前記内層基材のうちの最も厚い基材の少なくとも片面を接合する接着剤層が下記（１）～（３）を含有する主剤と、下記（４）の硬化剤を含有する接着剤により形成され、
    　前記接着剤は、主剤の固形分１００重量部に対し、前記硬化剤の固形分を４～１２重量部含有する太陽電池裏面保護シート。
    （１）芳香族二塩基酸４０～７０モル％と炭素数９～１０の脂肪族二塩基酸３０～６０モル％とを含む二塩基酸成分と、炭素数５以上の脂肪族２価アルコール３０～４０モル％を含む２価アルコール成分とを反応させてなる、重量平均分子量が７０，０００～８０，０００の直鎖ポリエステルポリオール。
    （２）芳香族二塩基酸６０～８０モル％と炭素数９～１０の脂肪族二塩基酸２０～４０モル％とを含む二塩基酸成分と、炭素数５以上の脂肪族２価アルコール７０～８０モル％を含む２価アルコール成分とを反応させることにより得られるポリエステルポリオールに有機ジイソシアネートを反応させてなる、重量平均分子量が３０，０００～４０，０００のポリエステルポリウレタンポリオール。
    （３）数平均分子量が１，０００～２，０００のビスフェノール型エポキシ樹脂。
    （４）イソホロンジイソシアネートのイソシアヌレートを有するポリイソシアネート。     At least 1) an outer layer base material having weather resistance, 2) an intermediate layer base material, and 3) an encapsulant for sealing a power generation element used in a solar cell module and an inner layer base material having good adhesiveness Configured,
    An adhesive layer that joins at least one surface of the thickest base material among the outer layer base material, the intermediate layer base material, and the inner layer base material contains a main agent containing the following (1) to (3); ) Of an adhesive containing a curing agent,
    The solar cell back surface protective sheet, wherein the adhesive contains 4 to 12 parts by weight of the solid content of the curing agent with respect to 100 parts by weight of the solid content of the main agent.
    (1) a dibasic acid component containing 40 to 70 mol% of an aromatic dibasic acid and 30 to 60 mol% of an aliphatic dibasic acid having 9 to 10 carbon atoms, and an aliphatic dihydric alcohol 30 having 5 or more carbon atoms A linear polyester polyol having a weight average molecular weight of 70,000 to 80,000 obtained by reacting with a dihydric alcohol component containing ˜40 mol%.
    (2) a dibasic acid component containing 60 to 80 mol% of an aromatic dibasic acid and 20 to 40 mol% of an aliphatic dibasic acid having 9 to 10 carbon atoms, and an aliphatic dihydric alcohol 70 having 5 or more carbon atoms A polyester polyurethane polyol having a weight average molecular weight of 30,000 to 40,000, which is obtained by reacting a polyester polyol obtained by reacting with a dihydric alcohol component containing ˜80 mol% with an organic diisocyanate.
    (3) A bisphenol type epoxy resin having a number average molecular weight of 1,000 to 2,000.
    (4) A polyisocyanate having an isocyanurate of isophorone diisocyanate.
  2. 　前記最も厚い基材の厚みが１２５～３５０μｍであり、前記最も厚い基材と接する前記接着剤層の接着剤量が５ｇ／ｍ２を超えて３０ｇ／ｍ２以下の範囲である請求項１記載の太陽電池裏面保護シート。 2. The thickness of the thickest substrate is 125 to 350 μm, and the adhesive amount of the adhesive layer in contact with the thickest substrate is in the range of more than 5 g / m 2 and 30 g / m 2 or less. Solar cell back surface protection sheet.
  3. 　前記中間層基材は、複数あり、少なくとも一部において互いに前記接着剤層を介して接着されている請求項１又は２に記載の太陽電池裏面保護シート。 The solar cell back surface protective sheet according to claim 1 or 2, wherein there are a plurality of the intermediate layer base materials, and at least some of them are adhered to each other via the adhesive layer.
  4. 　前記直鎖ポリエステルポリオールと、前記ポリエステルポリウレタンポリオールとの合計１００重量％中、前記直鎖ポリエステルポリオールが６０～８０重量％である、請求項１～３のいずれか１項に記載の太陽電池裏面保護シート。 The solar cell back surface protection according to any one of claims 1 to 3, wherein the linear polyester polyol is 60 to 80 wt% in a total of 100 wt% of the linear polyester polyol and the polyester polyurethane polyol. Sheet.
  5. 　請求項１～４のいずれか１項に記載の太陽電池裏面保護シートを備えた太陽電池モジュール。 A solar cell module comprising the solar cell back surface protective sheet according to any one of claims 1 to 4.
PCT/JP2012/004458 2011-07-11 2012-07-10 Solar cell backside protective sheet and solar cell WO2013008455A1 (en)

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