JP2021042313A - Adhesive sheet - Google Patents

Abstract

To provide an adhesive sheet having heat resistance sufficient to withstand a solder reflow process and excellent in re-peelability.SOLUTION: This invention relates to an adhesive sheet that uses a polyamide film as a support, and has an adhesive layer at least containing an acryl adhesive and an amine antioxidant on the support. Particularly, this invention relates to an adhesive sheet that can be used as a process film with re-peelability to be used for the production of electronics industrial materials such as printed wiring boards.SELECTED DRAWING: None

Description

The present invention relates to an adhesive sheet, and more particularly to an adhesive sheet that can be used as a process film having removability used in the production of electronic industrial materials such as printed wiring boards.

The printed wiring board is a wiring board in which the circuit pattern of the conductor required for connecting the electric / electronic components mounted on the printed wiring board is formed on the surface or surface of the insulating substrate and the inside thereof by printing or the like. Such a printed wiring board can be roughly classified into a rigid printed wiring board and a flexible printed wiring board from the viewpoint of shape, and structurally, it is divided into a single layer and two or more layers. Among these printed wiring boards, the flexible printed wiring board is a flexible printed wiring board in which a conductor circuit pattern is formed on a highly flexible insulating base sheet, and is a space having a narrow and complicated structure inside an electronic device. It is an indispensable substrate for three-dimensional high-density mounting inside. Such flexible printed wiring boards are one of the most promising electronic device components that can meet the demands of recent years for smaller size, lighter weight, higher density, and higher accuracy, and their demand is rapidly increasing. It's growing.

Since the flexible printed wiring board is required to be flexible, a plastic sheet as an insulating base sheet, particularly a plastic sheet having excellent heat resistance and insulating properties such as a polyimide sheet and a polyphenylene sulfide sheet, is used. It is used, and a circuit pattern is formed on the surface or the surface of the base material sheet and the inside thereof by a metal material such as copper. As a method for forming a circuit pattern, for example, an additive method is known as well as a constructive method in which only a necessary portion of a copper foil of a copper-clad laminate is left and the other portion is dissolved and removed by an etching process. This additive method is a method of forming a circuit pattern by plating only a necessary part of a substrate, and there are a semi-additive method and a full additive method. The performance required for such a flexible printed wiring board includes, for example, dimensional accuracy, low warpage / twist rate, heat resistance, peeling strength, bending strength, high volume resistivity, chemical resistance, and heat bending strength. In addition to the above, the processing suitability of the printed wiring board is also important.

In such a flexible printed wiring board, in the process of forming the above-mentioned circuit and mounting the electric / electronic components, in order to suppress solvent contamination, foreign matter contamination, generation of defects, etc. on the wiring board, those treatments are generally performed. A process film having removability (hereinafter, referred to as “removable process film”) is attached to the base material sheet to be used in advance. This re-peeling step film is provided with an adhesive layer that can be re-peeled on one surface of the base film, and is attached to a base sheet for a flexible printed wiring board, and then punched and subjected to a solvent. After undergoing various steps such as immersion in a film and hot pressing, the film is peeled off from the produced flexible printed wiring board. Therefore, in addition to not causing floating or peeling during the process, there is no adhesive residue on the adherend (base sheet) after peeling, and the adherend does not curl. It is important to have peelability.

Furthermore, in recent years, in the component mounting process on a flexible printed wiring board, a method of collectively connecting and mounting (solder reflow process) by putting the component and the substrate into a solder reflow furnace in a aligned state has been widely adopted. ing. In this case, since operations in a high temperature region such as soldering are included, heat resistance is required for the base film and the adhesive layer of the re-peeling step film. At present, when a solder reflow furnace having a temperature of about 200 ° C. or higher is used, it is the mainstream to use a polyimide film having high heat resistance as a base film (support) for the re-peeling process film. Alternatively, a method of using a polyetheretherketone film as a base film has also been proposed.

Further, in recent years, an adhesive sheet using a fully aromatic polyamide film having high heat resistance as a base film has been proposed (for example, Patent Documents 1 and 2). Although the heat resistance of the polyamide film is inferior to that of the polyimide film, it can be said to be a preferable base film because it is colorless, inexpensive, and has heat resistance sufficient to withstand the solder reflow process.

When the adhesive is placed in a high temperature region, it has problems such as carbonization, loss of adhesive strength, strong adhesive strength, and coloring. Conventionally, for this reason, a pressure-sensitive adhesive made of a silicone resin has often been used, but the silicone resin may release a silicone oligomer, which causes a problem of causing defects in the electrical contacts of electronic devices. In recent years, acrylic pressure-sensitive adhesives having heat resistance sufficient to withstand the solder reflow process have been proposed (for example, Patent Document 3 and Patent Document 4). Further, a method of adding an antioxidant to an acrylic pressure-sensitive adhesive is also known in Patent Document 5 and the like.

Japanese Unexamined Patent Publication No. 2003-105275 Japanese Unexamined Patent Publication No. 2004-95461 Japanese Patent No. 6562131 Japanese Unexamined Patent Publication No. 2010-116532 Japanese Unexamined Patent Publication No. 2006-96957

As described above, the polyamide film has heat resistance sufficient to withstand the solder reflow process, and is used in applications requiring various heat resistances. However, from careful examination by the present inventor, an adhesive sheet prepared by using a polyamide film as a base film has an increased adhesive strength when exposed to a high temperature, and is particularly used as a process film requiring re-peeling. Adhesive sheets can be a fatal problem. Therefore, when trying to produce an pressure-sensitive adhesive sheet using a polyamide film, it is necessary to provide a heat-resistant pressure-sensitive adhesive layer. However, although Patent Document 1 suggests that a heat-resistant adhesive layer is preferable, no specific solution is presented, and Patent Document 2 describes an adhesive sheet for a tact switch that does not require re-peeling. It is a suggestion.

In Patent Document 3, in order to provide a pressure-resistant adhesive that reduces contamination when re-peeled, a specific acrylic resin and an epoxy curing agent are contained, and a semi-hindered phenol-based antioxidant is further provided. Adhesives containing antioxidants such as agents have been proposed. However, although vinyl chloride and other various plastic films have been described as the base film of the pressure-sensitive adhesive sheet, no solution has been presented for the problem peculiar to the polyamide film. Further, Patent Document 4 also does not mention the problem peculiar to the polyamide film.

Patent Document 5 proposes that an acrylic pressure-sensitive adhesive contains an antioxidant for the purpose of preventing yellowing of the pressure-sensitive adhesive, but there is no mention of removability. Further, although known antioxidants have been proposed as antioxidants, there is no description of particularly preferable antioxidants. It is generally said that antioxidants are divided into two types, one is a type that captures radicals to prevent oxidation and the other is a type that decomposes peroxides. The former is a phenolic antioxidant or amine-based oxidation. It is said that an inhibitor is equivalent. However, according to the careful examination of the present inventor, phenolic antioxidants and amine-based antioxidants, which are said to prevent oxidation by the same mechanism of action, are used as adhesives for pressure-sensitive adhesive sheets using a polyamide film as a support. The present invention was conceived with the results of exhibiting completely different actions and effects.

Therefore, an object of the present invention is to provide an adhesive sheet having heat resistance that can withstand a solder reflow step and having excellent removability.

As a result of diligent studies to solve the above problems, the present inventor has found that the problem can be solved by an adhesive sheet having the following configuration.

A pressure-sensitive adhesive sheet using a polyamide film as a support and having an pressure-sensitive adhesive layer containing at least an acrylic pressure-sensitive adhesive and an amine-based antioxidant on the support.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide an adhesive sheet having heat resistance that can withstand a solder reflow process and having excellent removability.

The pressure-sensitive adhesive sheet of the present invention uses a polyamide film as a support, and has a pressure-sensitive adhesive layer containing at least an acrylic pressure-sensitive adhesive and an amine-based antioxidant on the support.

<Adhesive layer>
The acrylic pressure-sensitive adhesive contained in the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet of the present invention is preferably a pressure-resistant adhesive that can withstand the solder reflow process, and therefore the 5% weight loss temperature of the dried product is 200 ° C. The above is preferable, and the one at 250 ° C. or higher is more preferable. The 5% weight loss temperature of the dried product can be measured by a thermogravimetric differential thermal analyzer (TG-DTA).

As the acrylic pressure-sensitive adhesive contained in the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet of the present invention, an acrylic copolymer obtained by polymerizing a plurality of monomer components including an acrylic monomer can be used. Examples of the monomer components that can be used including the acrylic monomer include carboxyl group-containing monomers such as (meth) acrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, and isocrotonic acid, or anhydrides thereof (for example, maleic anhydride). , (Meta) methyl acrylate, (meth) ethyl acrylate, (meth) propyl acrylate, (meth) isopropyl acrylate, (meth) butyl acrylate, (meth) isobutyl acrylate, (meth) acrylate s- Butyl, t-butyl (meth) acrylate, pentyl (meth) acrylate, isopentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, (meth) acrylic 2-Ethylhexyl acid, isooctyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, (meth) Dodecyl acrylate, Tridecyl (meth) acrylate, Tetradecyl (meth) acrylate, Pentadecyl (meth) acrylate, Hexadecyl (meth) acrylate, Heptadecyl (meth) acrylate, Octadecil (meth) acrylate, (meth) acrylic (Meta) acrylic acid alkyl ester having a linear or branched alkyl group having 1 to 20 carbon atoms, such as isostearyl acid, nonadecil (meth) acrylic acid, and eicosyl (meth) acrylic acid, (meth) acrylic acid. 2-methoxyethyl, 2-ethoxyethyl (meth) acrylate, methoxytriethylene glycol (meth) acrylate, 3-methoxypropyl (meth) acrylate, 3-ethoxypropyl (meth) acrylate, (meth) acrylate (Meta) acrylic acid alkoxyalkyl ester such as 4-methoxybutyl, 4-ethoxybutyl (meth) acrylic acid, 2-hydroxyethyl (meth) acrylic acid, 3-hydroxypropyl (meth) acrylic acid, (meth) acrylic acid 4-Hydroxybutyl, hydroxyalkyl (meth) acrylate such as 6-hydroxyhexyl (meth) acrylate, hydroxy group (hydroxyl) -containing monomer such as allyl alcohol, (meth) acrylamide, N, N-dimethyl (meth) acrylamide , N-methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N-hydroxyethi Amid group-containing monomers such as luacrylamide, amino group-containing monomers such as aminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, t-butylaminoethyl (meth) acrylate, glycidyl (meth) acrylate, In addition to glycidyl group-containing monomers such as methylglycidyl (meth) acrylate, cyano group-containing monomers such as acrylonitrile and methacrylonitrile, N-vinyl-2-pyrrolidone, and (meth) acryloylmorpholin, N-vinylpyridine and N-vinylpiperidone. , N-vinylpyrimidine, N-vinylpiperazin, N-vinylpyrrole, N-vinylimidazole, N-vinyloxazole and other heterocyclic monomer, sulfonic acid group-containing monomer such as sodium vinylsulfonate, 2-hydroxyethyl Examples thereof include a phosphate group-containing monomer such as acryloyl phosphate, an imide group-containing monomer such as cyclohexyl maleimide and isopropyl maleimide, and an isocyanate group-containing monomer such as 2-methacryloyloxyethyl isocyanate.

The acrylic pressure-sensitive adhesive used in the present invention may also contain a thermoplastic resin. Thermoplastic resins include polyamide, polyurethane resin, polyvinyl acetate, polyvinyl acetal, polystyrene, fluororesin, polycarbonate, polyether, polyisobutylene, petroleum resin, rosin, nitrocellulose, sucrose ester, vinyl chloride / vinyl acetate copolymer. Examples thereof include coalescence, ethylene / vinyl acetate-based copolymer, α-olefin / maleic anhydride-based copolymer, and styrene / maleic anhydride-based copolymer. The thermoplastic resin is preferably used in the range of 10 to 80% by mass with respect to the acrylic copolymer.

The acrylic pressure-sensitive adhesive used in the present invention may contain a pressure-sensitive adhesive. As the tackifier, gum rosin, tall oil rosin, rosin ester obtained by esterifying unmodified rosin of wood rosin with alcohol, disproportionated rosin modified from unmodified rosin, polymerized rosin, modified rosin such as hydrogenated rosin, etc. Disproportionate rosin ester obtained by further esterifying these modified rosins with alcohol or the like, polymerized rosin ester, modified rosin ester such as hydrogenated rosin ester, rosin phenol obtained by adding phenol to unmodified rosin, terpenphenol resin, dipentene resin, aromatic Examples thereof include group-modified terpene resin, hydrogenated terpene resin, acid-modified terpene resin, terpene-based resin such as styrene terpene resin, and petroleum resin. The tackifier may be used alone or in combination of two or more, and it is particularly preferable to use a rosin-based tackifier and a terpene-based tackifier in combination. The amount of the tackifier is preferably used in the range of 5 to 100% by mass with respect to the acrylic copolymer.

Examples of commercially available acrylic pressure-sensitive adhesives described above include Oliveine (registered trademark) BPS6430OP, Oliveine BPS5978, and Oliveine BPS5227-1 manufactured by Toyochem Co., Ltd.

In the present invention, in order to further improve the cohesive force of the acrylic pressure-sensitive adhesive and obtain stable adhesiveness, it is preferable that the pressure-sensitive adhesive layer contains a cross-linking agent together with the acrylic pressure-sensitive adhesive. As the cross-linking agent, an isocyanate-based cross-linking agent, an epoxy-based cross-linking agent, a metal chelate-based cross-linking agent, an aziridine-based cross-linking agent and the like can be used. Above all, it is preferable to use an aziridine-based cross-linking agent. Preferred aziridine-based cross-linking agents include N, N'-hexamethylene-1,6-bis (1-aziridinecarboxyamide), trimethylolpropane-tri-β-aziridinyl propionate, and bisisophthaloyl-1. -(2-Methylaziridine), tri-1-aziridinylphosphonoxide, N, N'-diphenylethane-4,4'-bis (1-aziridinecarboxyamide) and the like. The amount of the cross-linking agent is preferably in the range of 0.01 to 10% by mass, more preferably 0, of the solid content of the acrylic pressure-sensitive adhesive (total amount of acrylic copolymer, tackifier, and thermoplastic resin). It is in the range of 1 to 5% by mass.

In the present invention, the adhesive layer contains an amine-based antioxidant. Examples of the amine-based antioxidant include a hindered amine-based antioxidant, an aromatic amine-based antioxidant, an amine ketone-based antioxidant, and the like, and an aromatic amine-based antioxidant is preferable. Examples of the hindered amine-based antioxidant include ADEKA STAB (registered trademark) LA series manufactured by ADEKA Corporation, TINUVIN (registered trademark) series manufactured by BASF, and the like. As the aromatic amine-based antioxidant, an aromatic secondary amine-based antioxidant is particularly preferable. Examples of the aromatic secondary amine-based antioxidant include diphenylamine, N-phenyl-o-toluidine, N-phenyl-m-toluidine, N-phenyl-p-toluidine, bis (2-methylphenyl) amine, and bis ( 3-Methylphenyl) amine, bis (4-methylphenyl) amine, p, p'-dioctyldiphenylamine, N-phenyl-1-naphthylamine, 4,4'-bis (α, α-dimethylbenzyl) diphenylamine, p- (P-Toluenesulfonylamide) Diphenylamine, N, N'-di-2-naphthyl-p-phenylenediamine, N-phenyl-N'-isopropyl-p-phenylenediamine, phenothiazine and the like can be mentioned. As the amine ketone type antioxidant, 2,2,4-trimethyl-1,2-dihydroquinoline polymer, 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, a reaction product of diphenylamine and acetone, etc. Can be mentioned.

The amine-based antioxidant may be used alone or in combination of two or more. The amount of the amine-based antioxidant used is preferably in the range of 0.1 to 30% by mass of the solid content of the acrylic pressure-sensitive adhesive (total amount of acrylic copolymer, thermoplastic resin, and pressure-sensitive adhesive). It is preferably in the range of 1 to 20% by mass.

Further, in addition to the amine-based antioxidant, other known antioxidants can also be used in combination with the amine-based antioxidant. Examples of other antioxidants include phenolic antioxidants, sulfur-based antioxidants, phosphorus-based antioxidants and the like.

Phenolic antioxidants include, for example, 2,6-di-t-butyl-p-cresol, butylated hydroxyanisol, 2,6-di-t-butyl-4-ethylphenol and stea-β- (3,5). Monophenolic antioxidants such as -di-t-butyl-4-hydroxyphenyl) propionate, 2,2'-methylenebis (4-methyl-6-t-butylphenol), 2,2'-methylenebis (4-ethyl) -6-t-butylphenol), 4,4'-thiobis (3-methyl-6-t-butylphenol), 4,4'-butylidenebis (3-methyl-6-t-butylphenol) and 3,9-bis [ 1,1-dimethyl-2- [β- (3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxy] ethyl] 2,4,8,10-tetraoxaspiro [5,5] undecane, etc. Bisphenol antioxidant, 1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3, 5-di-t-butyl-4-hydroxybenzyl) benzene, tetrakis- [methylene-3- (3', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane, bis [3,3 ′ -Bis- (4'-hydroxy-3'-t-butylphenyl) butyl acid] glycol ester, 1,3,5-tris (3', 5'-di-t-butyl-4'-hydroxybenzyl ) -S-Triazine-2,4,6- (1H, 3H, 5H) High molecular weight phenolic antioxidants such as trione and tocopherol can be mentioned.

Examples of the sulfur-based antioxidant include dilauryl 3,3'-thiodipropionate, dimyristyl 3,3'-thiodipropionate and disstearyl 3,3'-thiodipropionate.

Examples of the phosphorus-based antioxidant include triphenylphosphine, diphenylisodecylphosphine, phenyldiisodecylphosphine and the like.

As the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet of the present invention, known substances such as plasticizers, matting agents, surfactants, metal soaps, and flame retardants can be further used.

The thickness of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet of the present invention is preferably 5 to 100 μm, more preferably 10 to 50 μm.

<Support>
The pressure-sensitive adhesive sheet of the present invention uses a polyamide film as a support. Polyamides constituting the polyamide film include aliphatic polyamides and aromatic polyamides. Examples of the aliphatic polyamide include polyamide 6 and polyamide 66. The aromatic polyamide includes a semi-aromatic polyamide and a total aromatic polyamide, and examples of the semi-aromatic polyamide include polyamide 6T, polyamide 9T, and polyamide 10T. Total aromatic polyamides are obtained from aromatic dicarboxylic acids and aromatic diamines. In the present invention, aromatic polyamides having low water absorption and high heat resistance are preferable. The aromatic polyamide may have an aromatic group in the main chain, and in addition to so-called para-type aramid and meta-type aramid, a part of the skeleton may be diphenyl ether, diphenyl propane, diphenyl methane, diphenyl ketone, diphenyl sulfoxide, or biphenyl. Examples thereof include those substituted with, etc., and those in which the hydrogen group of the aromatic ring is substituted with a methyl group, a halogen atom, or the like. The polyamide may have an aliphatic group or an alicyclic group in addition to the aromatic group.

The thickness of the polyamide film used in the present invention is preferably 15 to 100 μm, more preferably 25 to 50 μm.

In addition to the support and the pressure-sensitive adhesive layer, the pressure-sensitive adhesive sheet of the present invention may be provided with known layers such as an antistatic layer, a hard coat layer, and a release layer.

Hereinafter, the present invention will be described in more detail with reference to Examples, and the present invention will be specifically described, but the present invention is not limited to the following Examples. In the following, the concentration will be collectively referred to as "solid content concentration" regardless of whether the substantial component is a solid substance or a liquid substance.

"Measurement of 5% weight loss temperature of adhesive"
The following coating liquid for measuring physical properties was prepared and coated on a release film (RF-CS001 manufactured by Aim Co., Ltd., thickness 75 μm) so as to have a dry film thickness of 20 μm. The obtained adhesive film was attached to an aluminum pan, the release film was peeled off, and then 130 ° C. (residual) at a temperature rise rate of 10 ° C./min using a DTG-60 thermogravimetric differential thermal analyzer manufactured by Shimadzu Corporation. The 5% weight loss temperature with respect to the state (which is considered to be a dried product in which all the solvent content was evaporated) was measured and found to be 256 ° C. Therefore, the pressure-sensitive adhesive sheet using the acrylic pressure-sensitive adhesive contained in the following coating liquid for measuring physical properties has heat resistance that can withstand the solder reflow process.

<Coating liquid for measuring physical properties>
Oliveine BPS5978 (Acrylic adhesive manufactured by Toyochem Co., Ltd. Solid content concentration 35% by mass)
100g
Oliveine BXX5134 (Aziridine-based cross-linking agent manufactured by Toyochem Co., Ltd. Solid content concentration 5% by mass) 9 g
Ethyl acetate was added to bring the total amount to 350 g.

"Preparation of adhesive sheet 1"
The following adhesive layer coating liquid 1 was prepared, applied on a release film (RF-CS001 manufactured by Aim Co., Ltd.) so as to have a dry film thickness of 30 μm, and dried. Subsequently, an aromatic polyamide film (Uniamide (registered trademark) EX manufactured by Unitika Ltd., thickness 25 μm) was laminated to prepare an adhesive sheet 1. The amount of the antioxidant in the pressure-sensitive adhesive layer coating liquid 1 is 5% by mass with respect to the solid content of the acrylic pressure-sensitive adhesive.

<Adhesive layer coating liquid 1>
Oliveine BPS5978 100g
Oliveine BXX5134 9.0g
Nocrack (registered trademark) CD (Aromatic secondary amine-based antioxidant manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd. Solid content concentration 100% by mass) 1.750 g
Ethyl acetate was added to bring the total amount to 150 g.

"Preparation of adhesive sheet 2"
The pressure-sensitive adhesive sheet 2 was produced in the same manner as the pressure-sensitive adhesive sheet 1 except that the pressure-sensitive adhesive layer coating liquid 2 having the following formulation was applied instead of the pressure-sensitive adhesive layer coating liquid 1. The amount of the antioxidant in the pressure-sensitive adhesive layer coating liquid 2 is 5% by mass with respect to the solid content of the acrylic pressure-sensitive adhesive.

<Adhesive layer coating liquid 2>
Oliveine BPS5978 100g
Oliveine BXX5134 9.0g
Nocrack PA (Aromatic secondary amine-based antioxidant manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd. Solid content concentration 100% by mass) 1.750 g
Ethyl acetate was added to bring the total amount to 150 g.

"Preparation of adhesive sheet 3"
The pressure-sensitive adhesive sheet 3 was produced in the same manner as the pressure-sensitive adhesive sheet 1 except that the pressure-sensitive adhesive layer coating liquid 3 having the following formulation was applied instead of the pressure-sensitive adhesive layer coating liquid 1. The amount of the antioxidant in the pressure-sensitive adhesive layer coating liquid 3 is 5% by mass with respect to the solid content of the acrylic pressure-sensitive adhesive.

<Adhesive layer coating liquid 3>
Oliveine BPS5978 100g
Oliveine BXX5134 9.0g
Nocrack TD (Aromatic secondary amine-based antioxidant manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd. Solid content concentration 100% by mass) 1.750 g
Ethyl acetate was added to bring the total amount to 150 g.

"Preparation of adhesive sheet 4"
The pressure-sensitive adhesive sheet 4 was produced in the same manner as the pressure-sensitive adhesive sheet 1 except that the pressure-sensitive adhesive layer coating liquid 4 having the following formulation was applied instead of the pressure-sensitive adhesive layer coating liquid 1. The amount of the antioxidant in the pressure-sensitive adhesive layer coating liquid 4 is 5% by mass with respect to the solid content of the acrylic pressure-sensitive adhesive.

<Adhesive layer coating liquid 4>
Oliveine BPS5978 100g
Oliveine BXX5134 9.0g
Nocrack 6C (Aromatic secondary amine-based antioxidant manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd. Solid content concentration 100% by mass) 1.750 g
Ethyl acetate was added to bring the total amount to 150 g.

"Preparation of adhesive sheet 5"
The pressure-sensitive adhesive sheet 5 was produced in the same manner as the pressure-sensitive adhesive sheet 1 except that the pressure-sensitive adhesive layer coating liquid 5 having the following formulation was applied instead of the pressure-sensitive adhesive layer coating liquid 1. The amount of the antioxidant in the pressure-sensitive adhesive layer coating liquid 5 is 5% by mass with respect to the solid content of the acrylic pressure-sensitive adhesive.

<Adhesive layer coating liquid 5>
Oliveine BPS5978 100g
Oliveine BXX5134 9.0g
Nocrack 224 (Aminketone-based antioxidant manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd. Solid content concentration 100% by mass) 1.750 g
Ethyl acetate was added to bring the total amount to 150 g.

"Preparation of adhesive sheet 6"
The pressure-sensitive adhesive sheet 6 was produced in the same manner as the pressure-sensitive adhesive sheet 1 except that the pressure-sensitive adhesive layer coating liquid 6 having the following formulation was applied instead of the pressure-sensitive adhesive layer coating liquid 1. The amount of the antioxidant in the pressure-sensitive adhesive layer coating liquid 6 is 5% by mass with respect to the solid content of the acrylic pressure-sensitive adhesive.

<Adhesive layer coating liquid 6>
Oliveine BPS5978 100g
Oliveine BXX5134 9.0g
Nocrack NS-5 (Phenolic antioxidant manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd. Solid content concentration 100% by mass) 1.750g
Ethyl acetate was added to bring the total amount to 150 g.

"Preparation of adhesive sheet 7"
The pressure-sensitive adhesive sheet 7 was produced in the same manner as the pressure-sensitive adhesive sheet 1 except that the pressure-sensitive adhesive layer coating liquid 7 having the following formulation was applied instead of the pressure-sensitive adhesive layer coating liquid 1. The amount of the antioxidant in the pressure-sensitive adhesive layer coating liquid 7 is 5% by mass with respect to the solid content of the acrylic pressure-sensitive adhesive.

<Adhesive layer coating liquid 7>
Oliveine BPS5978 100g
Oliveine BXX5134 9.0g
Nocrack MB (Sulfur-based antioxidant manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd. Solid content concentration 100% by mass) 1.750g
Ethyl acetate was added to bring the total amount to 150 g.

"Preparation of adhesive sheet 8"
The pressure-sensitive adhesive sheet 8 was produced in the same manner as the pressure-sensitive adhesive sheet 1 except that the pressure-sensitive adhesive layer coating liquid 8 having the following formulation was applied instead of the pressure-sensitive adhesive layer coating liquid 1. The amount of the antioxidant in the pressure-sensitive adhesive layer coating liquid 8 is 5% by mass with respect to the solid content of the acrylic pressure-sensitive adhesive.

<Adhesive layer coating liquid 8>
Oliveine BPS5978 100g
Oliveine BXX5134 9.0g
Nocrack TNP (Phosphorus-based antioxidant manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd. Solid content concentration 100% by mass) 1.750g
Ethyl acetate was added to bring the total amount to 150 g.

"Preparation of adhesive sheet 9"
The pressure-sensitive adhesive sheet 9 was produced in the same manner as the pressure-sensitive adhesive sheet 1 except that the pressure-sensitive adhesive layer coating liquid 9 having the following formulation was applied instead of the pressure-sensitive adhesive layer coating liquid 1. The amount of the antioxidant in the pressure-sensitive adhesive layer coating liquid 9 is 5% by mass with respect to the solid content of the acrylic pressure-sensitive adhesive.

<Adhesive layer coating liquid 9>
Oliveine BPS5978 100g
Oliveine BXX5134 9.0g
Nocrack 400 (Sulfur-based antioxidant manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd. Solid content concentration 100% by mass) 1.750g
Ethyl acetate was added to bring the total amount to 150 g.

"Preparation of adhesive sheet 10"
The pressure-sensitive adhesive sheet 10 was produced in the same manner as the pressure-sensitive adhesive sheet 1 except that the pressure-sensitive adhesive layer coating liquid 10 having the following formulation was applied instead of the pressure-sensitive adhesive layer coating liquid 1. The amount of the antioxidant in the pressure-sensitive adhesive layer coating liquid 10 is 5% by mass with respect to the solid content of the acrylic pressure-sensitive adhesive.

<Adhesive layer coating liquid 10>
Oliveine BPS5978 100g
Oliveine BXX5134 9.0g
ADEKA STAB AO40 (Phenolic antioxidant manufactured by ADEKA Corporation. Solid content concentration 100% by mass) 1.750 g
Ethyl acetate was added to bring the total amount to 150 g.

"Preparation of adhesive sheet 11"
The pressure-sensitive adhesive sheet 11 was produced in the same manner as the pressure-sensitive adhesive sheet 1 except that the pressure-sensitive adhesive layer coating liquid 11 having the following formulation was applied instead of the pressure-sensitive adhesive layer coating liquid 1. The amount of the antioxidant in the pressure-sensitive adhesive layer coating liquid 11 is 0.05% by mass with respect to the solid content of the acrylic pressure-sensitive adhesive.

<Adhesive layer coating liquid 11>
Oliveine BPS5978 100g
Oliveine BXX5134 9.0g
Nocrack CD 0.0175g
Ethyl acetate was added to bring the total amount to 150 g.

"Preparation of adhesive sheet 12"
The pressure-sensitive adhesive sheet 12 was produced in the same manner as the pressure-sensitive adhesive sheet 1 except that the pressure-sensitive adhesive layer coating liquid 12 having the following formulation was applied instead of the pressure-sensitive adhesive layer coating liquid 1. The amount of the antioxidant in the pressure-sensitive adhesive layer coating liquid 12 is 0.2% by mass with respect to the solid content of the acrylic pressure-sensitive adhesive.

<Adhesive layer coating liquid 12>
Oliveine BPS5978 100g
Oliveine BXX5134 9.0g
Nocrack CD 0.070g
Ethyl acetate was added to bring the total amount to 150 g.

"Preparation of adhesive sheet 13"
The pressure-sensitive adhesive sheet 13 was produced in the same manner as the pressure-sensitive adhesive sheet 1 except that the pressure-sensitive adhesive layer coating liquid 13 having the following formulation was applied instead of the pressure-sensitive adhesive layer coating liquid 1. The amount of the antioxidant in the pressure-sensitive adhesive layer coating liquid 13 is 0.8% by mass with respect to the solid content of the acrylic pressure-sensitive adhesive.

<Adhesive layer coating liquid 13>
Oliveine BPS5978 100g
Oliveine BXX5134 9.0g
Nocrack CD 0.280g
Ethyl acetate was added to bring the total amount to 150 g.

"Preparation of adhesive sheet 14"
The pressure-sensitive adhesive sheet 14 was produced in the same manner as the pressure-sensitive adhesive sheet 1 except that the pressure-sensitive adhesive layer coating liquid 14 having the following formulation was applied instead of the pressure-sensitive adhesive layer coating liquid 1. The amount of the antioxidant in the pressure-sensitive adhesive layer coating liquid 14 is 1.2% by mass with respect to the solid content of the acrylic pressure-sensitive adhesive.

<Adhesive layer coating liquid 14>
Oliveine BPS5978 100g
Oliveine BXX5134 9.0g
Nocrack CD 0.420g
Ethyl acetate was added to bring the total amount to 150 g.

"Preparation of adhesive sheet 15"
The pressure-sensitive adhesive sheet 15 was produced in the same manner as the pressure-sensitive adhesive sheet 1 except that the pressure-sensitive adhesive layer coating liquid 15 having the following formulation was applied instead of the pressure-sensitive adhesive layer coating liquid 1. The amount of the antioxidant in the pressure-sensitive adhesive layer coating liquid 15 is 17.5% by mass with respect to the solid content of the acrylic pressure-sensitive adhesive.

<Adhesive layer coating liquid 15>
Oliveine BPS5978 100g
Oliveine BXX5134 9.0g
Nocrack CD 6.125g
Ethyl acetate was added to bring the total amount to 150 g.

"Preparation of adhesive sheet 16"
The pressure-sensitive adhesive sheet 16 was produced in the same manner as the pressure-sensitive adhesive sheet 1 except that the pressure-sensitive adhesive layer coating liquid 16 having the following formulation was applied instead of the pressure-sensitive adhesive layer coating liquid 1. The amount of the antioxidant in the pressure-sensitive adhesive layer coating liquid 16 is 22.5% by mass with respect to the solid content of the acrylic pressure-sensitive adhesive.

<Adhesive layer coating liquid 16>
Oliveine BPS5978 100g
Oliveine BXX5134 9.0g
Nocrack CD 7.875g
Ethyl acetate was added to bring the total amount to 150 g.

"Preparation of adhesive sheet 17"
The pressure-sensitive adhesive sheet 17 was produced in the same manner as the pressure-sensitive adhesive sheet 1 except that the pressure-sensitive adhesive layer coating liquid 17 having the following formulation was applied instead of the pressure-sensitive adhesive layer coating liquid 1. The amount of the antioxidant in the pressure-sensitive adhesive layer coating liquid 17 is 27.5% by mass with respect to the solid content of the acrylic pressure-sensitive adhesive.

<Adhesive layer coating liquid 17>
Oliveine BPS5978 100g
Oliveine BXX5134 9.0g
Nocrack CD 9.625g
Ethyl acetate was added to bring the total amount to 150 g.

"Preparation of adhesive sheet 18"
The pressure-sensitive adhesive sheet 18 was produced in the same manner as the pressure-sensitive adhesive sheet 1 except that the pressure-sensitive adhesive layer coating liquid 18 having the following formulation was applied instead of the pressure-sensitive adhesive layer coating liquid 1. The amount of the antioxidant in the pressure-sensitive adhesive layer coating liquid 18 is 32.5% by mass with respect to the solid content of the acrylic pressure-sensitive adhesive.

<Adhesive layer coating liquid 18>
Oliveine BPS5978 100g
Oliveine BXX5134 9.0g
Nocrack CD 11.375g
Ethyl acetate was added to bring the total amount to 150 g.

"Preparation of adhesive sheet 19"
The pressure-sensitive adhesive sheet 19 was produced in the same manner as the pressure-sensitive adhesive sheet 1 except that the pressure-sensitive adhesive layer coating liquid 19 having the following formulation was applied instead of the pressure-sensitive adhesive layer coating liquid 1. The amount of the antioxidant in the pressure-sensitive adhesive layer coating liquid 19 is 5% by mass with respect to the solid content of the acrylic pressure-sensitive adhesive.

<Adhesive layer coating liquid 19>
Oliveine BPS5978 100g
Organics (registered trademark) TC-100 (Metal chelate cross-linking agent manufactured by Matsumoto Fine Chemicals Co., Ltd. Solid content concentration 75% by mass) 0.15 g
Nocrack CD 1.750g
Ethyl acetate was added to bring the total amount to 150 g.

"Preparation of adhesive sheet 20"
The pressure-sensitive adhesive sheet 20 was produced in the same manner as the pressure-sensitive adhesive sheet 1 except that the pressure-sensitive adhesive layer coating liquid 20 having the following formulation was applied instead of the pressure-sensitive adhesive layer coating liquid 1. The amount of the antioxidant in the pressure-sensitive adhesive layer coating liquid 20 is 1.2% by mass with respect to the solid content of the acrylic pressure-sensitive adhesive.

<Adhesive layer coating liquid 20>
Oliveine BPS5978 100g
Nocrack CD 0.420g
Ethyl acetate was added to bring the total amount to 150 g.

"Preparation of adhesive sheet 21"
The pressure-sensitive adhesive sheet 21 was produced in the same manner as the pressure-sensitive adhesive sheet 1 except that an aluminum sheet having a thickness of 0.1 mm was used as the support instead of the aromatic polyamide film.

The adhesive strength of the obtained adhesive sheets 1 to 21 immediately after preparation, the adhesive strength after heating at 260 ° C. for 20 minutes, and the adhesive residue were measured according to the following method. Table 1 shows the results together with the multiples of the change in the adhesive force after heating with respect to the adhesive force when not heated (adhesive force after heating / adhesive force when not heated).

<Evaluation of adhesive strength when not heated>
The release film (RF-CS001) of the adhesive sheet was peeled off, attached to an aluminum plate having a thickness of 0.1 mm, and then cut to a width of 25 mm. The adhesion strength of the obtained test piece was measured with a peeling machine (combination of a T-shaped peeling method attachment manufactured by Imada Co., Ltd. and a force gauge DST).

<Evaluation of adhesive strength after heating at 260 ° C for 20 minutes>
The release film (RF-CS001) of the adhesive sheet was peeled off, attached to an aluminum plate having a thickness of 0.1 mm, left at 260 ° C. for 20 minutes, and then cut to a width of 25 mm. The adhesion strength of the obtained test piece was measured with a peeling machine (combination of a T-shaped peeling method attachment manufactured by Imada Co., Ltd. and a force gauge DST). The adhesive strength after heating is close to the adhesive strength without heating, and the smaller the multiple of change in the adhesive strength after heating with respect to the adhesive strength without heating, the better the removability.

<Remaining glue>
After heating at 260 ° C for 20 minutes, observe the surface of the aluminum plate of the sample whose adhesive strength has been evaluated, and if the adhesive sheet cannot be peeled off or if the adhesive layer component is attached to the entire surface, x, some adhesive layer components Those with a mark are marked with △, and those without a mark are marked with ○.

From the above results, the effect of the present invention can be clearly seen.

Claims (1)

A pressure-sensitive adhesive sheet using a polyamide film as a support and having an pressure-sensitive adhesive layer containing at least an acrylic pressure-sensitive adhesive and an amine-based antioxidant on the support.