TWI746812B - Polyester adhesive composition containing carboxylic acid group - Google Patents

Abstract

The subject of the present invention is to provide a polyester-based adhesive composition containing carboxylic acid groups, which maintains good adhesion to various plastic films, metals such as copper, aluminum, stainless steel, and glass epoxy resin, while also being able to Corresponding to lead-free solder under high humidity, it has excellent moisture and heat resistance and excellent sheet life. The solution to this problem is: an adhesive composition comprising a polyester resin (A) containing a carboxylic acid group and a compound (B) having two or more glycidyl groups in the molecule, which is characterized by: containing a carboxyl group The glass transition temperature (Tg) of the acid-based polyester resin (A) is 40~90℃, the acid value is 1~30mgKOH/g, and it contains polymer polyol (A1) and polymer polyol (A1) Different polymer polyols (A2) and tetracarboxylic dianhydride are used as copolymerization components.

Description

Polyester adhesive composition containing carboxylic acid group

The present invention relates to an adhesive composition, an adhesive sheet, and an adhesive composition having excellent adhesion, solder resistance, and sheet life to various plastic films, metals such as copper, aluminum, stainless steel, and glass epoxy resins. The adhesive sheet is a printed wiring board as a component.

In recent years, adhesives have been used in various fields. Due to the diversification of the purpose of use, it is required to compare the adhesives used in the past to various plastic films, metals, glass epoxy resins, etc., for adhesion, humidity and heat resistance, etc. Higher performance. For example, adhesives for circuit boards, including flexible printed wiring boards (hereinafter sometimes referred to as FPCs), require adhesiveness, processability, electrical properties, and storage properties. Conventionally, epoxy/acrylic butadiene-based adhesives, epoxy/polyvinyl butyral-based adhesives, etc. have been used for this application.

Especially in recent years, considering the use environment of lead-free solder and FPC, adhesives with a higher degree of heat resistance are required. In addition, considering the high density of wiring, the multilayering of FPC wiring boards, and the workability, there is a strong demand for solder resistance under high humidity. In response to these issues, some people have disclosed a resin composition for an adhesive that uses a specific polyester or polyester-polyurethane and epoxy resin as the main components. However, the pot life of these compositions after blending and the sheet life after coating and drying are short, and it may be difficult to circulate at room temperature (for example, Patent Documents 1 to 2). [Prior Art Document] [Patent Document]

[Patent Document 1] Japanese Patent Application Publication No. 2010-84005 [Patent Document 2] Japanese Patent Application Publication No. 2009-096939

[The problem to be solved by the invention]

The subject of the present invention is to improve the various problems of the conventional adhesives, and to provide a polyester-based adhesive composition containing carboxylic acid groups, which maintains resistance to various plastic films, copper, aluminum, and stainless steel It has good adhesion to other metals and glass epoxy resins, and also corresponds to the high degree of heat and humidity resistance (solder resistance) of lead-free solder under high humidity, and excellent sheet life. [Means to solve the problem]

As a result of diligent research by the inventors of the present invention, they found that the above-mentioned problems can be solved by the means shown below, and completed the present invention. That is, the present invention is constituted as follows.

An adhesive composition comprising a polyester resin (A) containing a carboxylic acid group and a compound (B) having two or more glycidyl groups in the molecule, and is characterized by: a polyester resin containing a carboxylic acid group ( A) The glass transition temperature (T g) is 40~90℃, the acid value is 1~30mgKOH/g, and it contains polymer polyol (A1) and polymer polyol different from polymer polyol (A1) (A2) and tetracarboxylic dianhydride as copolymerization components.

The polymer polyol (A1) and/or the polymer polyol (A2) are preferably polyester polyols.

An adhesive sheet containing the hardened substance of the aforementioned adhesive composition. A printed wiring board includes the adhesive sheet as a constituent element. [Effects of the invention]

The polyester-based adhesive composition containing carboxylic acid groups of the present invention maintains good adhesion to various plastic films, metals such as copper, aluminum, stainless steel, and glass epoxy resins, and can also correspond to high humidity conditions. Lead-free solder has a high degree of heat and humidity resistance (solder resistance) and excellent sheet life.

<Polymer polyol (A1)> The glass transition temperature of the polymer polyol (A1) is not particularly limited, but it is preferably 0°C or higher, and more preferably 5°C or higher. If the glass transition temperature is too low, the adhesive composition becomes more viscous, and bubbles are likely to be trapped during bonding and become defective. Furthermore, it is preferably 90°C or less, more preferably 80°C or less, and particularly preferably 75°C. If the glass transition temperature is too high, the coating film will become brittle, embrittlement will become a problem, or there will be concerns about insufficient adhesion to the substrate.

The acid value (mgKOH/g) of the polymer polyol (A1) is not particularly limited, but is preferably 0.1 or more, more preferably 0.3 or more, and particularly preferably 1 or more. If it is too small, crosslinking may become insufficient and the heat and humidity resistance may decrease. Moreover, it is preferably 10 or less, more preferably 8 or less, and particularly preferably 6 or less. If it is too large, the acid addition chain extension caused by tetracarboxylic dianhydride may become impossible. Therefore, as the crosslinking density becomes higher, the coating film obtained from the adhesive composition becomes hard, and there is a tendency for the adhesive force to decrease.

The number average molecular weight (Mn1) of the polymer polyol (A1) is not particularly limited, but is preferably 10,000 or more, more preferably 11,000 or more, and particularly preferably 12,000 or more. If Mn1 is less than 10,000, the cross-linking density becomes higher, and the coating film obtained from the adhesive composition becomes hard, and the adhesive force tends to decrease. In addition, since it becomes difficult to alleviate the stress of water vapor generated when the solder is humidified, the solder resistance tends to deteriorate. In addition, Mn1 is preferably 50,000 or less, more preferably 40,000 or less, and particularly preferably 30,000 or less. If it is too large, crosslinking may become insufficient and heat resistance may decrease. The number average molecular weight (Mn1) of the polymer polyol (A1) is preferably greater than the number average molecular weight (Mn2) of the polymer polyol (A2), the molecular weight of the tetracarboxylic dianhydride, and the largest among the copolymer components is more preferred.

<Polymer polyol (A2)> The polymer polyol (A2) is a polyol different from the polymer polyol (A1). Different from the polymer polyol (A 1), it means that at least one of the composition or the physical properties is different. The number average molecular weight (Mn2) of the polymer polyol (A2) is preferably 1,000 or more, more preferably 1,500 or more. If it is less than 1,000, the polymer polyol (A2) is likely to form bonds with each other, and is likely to have a low molecular weight and a high acid value, and the coating film may become brittle and embrittlement may become a problem. Also, it is preferably less than 10,000, more preferably 8,000 or less, particularly preferably 7,000 or less, and particularly preferably 5,000 or less. When it is 10,000 or more, the acid addition chain extension of tetracarboxylic dianhydride may become impossible.

The difference between the number average molecular weight (Mn1) of the polymer polyol (A1) and the number average molecular weight (Mn2) of the polymer polyol (A2) is not particularly limited, and it is preferably 2,000 or more, more preferably 3,000 or more, and particularly preferably Above 4,000. By setting the aforementioned difference in molecular weight, the compatibility and solder resistance of the carboxylic acid group-containing polyester resin (A) can be improved. That is, by using one of the polymer polyol (A1) or (A2) as a long-chain block and making it high molecular weight, the stress generated during solder resistance evaluation can be alleviated. In addition, by using the other as a short-chain block, the amount of carboxylic acid groups can be adjusted, so solder resistance can be imparted. In this way, the solder resistance can be improved. The upper limit of the difference in molecular weight is not particularly limited, but is preferably 40,000 or less, more preferably 30,000 or less, and particularly preferably 20,000 or less.

The acid value (mgKOH/g) of the polymer polyol (A2) is not particularly limited, and is preferably 0.1 or more, more preferably 0.3 or more, and particularly preferably 1 or more. If it is too small, solder resistance may be poor. Moreover, it is preferably 10 or less, more preferably 8 or less, and particularly preferably 6 or less. If it is too high, the acid addition chain extension caused by tetracarboxylic dianhydride may become impossible.

The glass transition temperature of the polymer polyol (A2) is not particularly limited. It is preferably -20°C or higher, more preferably -10°C or higher, particularly preferably 0°C or higher, still more preferably 10°C or higher, and particularly preferably 20°C or higher. Above ℃, preferably above 30℃. If the glass transition temperature is too low, the adhesive composition tends to become more viscous, and bubbles tend to be trapped during bonding and become defective. Moreover, it is preferably 80°C or lower, and more preferably 70°C or lower. If the glass transition temperature is too high, the coating film will become brittle and embrittlement will become a problem.

The polymer polyol (A1) and/or the polymer polyol (A2) are not particularly limited, but a polyester polyol is preferable.

<Polyester polyol> The polyester polyol is preferably composed of a polyvalent carboxylic acid component and a polyol component. Regarding the polycarboxylic acid components constituting the polyester polyol, when the total polycarboxylic acid is 100 mol%, it is preferable to contain 60 mol% or more of the aromatic dicarboxylic acid. It is more preferably 70 mol% or more, particularly preferably 80 mol% or more, and may also be 100 mol%. If it is too small, the cohesive force of the coating film may become weak, and the bonding strength to various substrates may decrease.

The aromatic dicarboxylic acid is not particularly limited, and examples thereof include terephthalic acid, isophthalic acid, phthalic acid, naphthalene dicarboxylic acid, biphenyl dicarboxylic acid, and 2,2'-diphthalic acid. In addition, examples include: sulfoterephthalic acid, 5-sulfoisophthalic acid, 4-sulfophthalic acid, 4-sulfonaphthalene-2,7-dicarboxylic acid, 5-(4-sulfo (Phenoxy) isophthalic acid and other aromatic dicarboxylic acids having sulfonic acid groups, and aromatic dicarboxylic acids having sulfonate groups such as metal salts and ammonium salts. These can be used alone or in combination of two or more kinds. Among them, terephthalic acid, isophthalic acid, and mixtures thereof are particularly preferable from the viewpoint of enhancing the cohesive force of the coating film.

Examples of other polycarboxylic acid components include: 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid and its anhydrides, and other alicyclic dicarboxylic acids ; Succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, dimer acid and other aliphatic dicarboxylic acids. In addition, 5-hydroxyisophthalic acid, p-hydroxybenzoic acid, p-hydroxyphenethyl alcohol, p-hydroxyphenylpropionic acid, p-hydroxyphenylacetic acid, 6-hydroxy-2-naphthoic acid, 4,4-bis(p-hydroxyphenethyl) Hydroxyphenyl) valeric acid is equivalent to an oxycarboxylic acid compound with a hydroxyl group and a carboxyl group in the molecular structure.

Regarding the polyol components constituting the polyester polyol, when the total polyol is 100 mol%, the diol component is preferably 90 mol% or more, more preferably 95 mol% or more, or 100 mol% %.

The diol component is preferably an aliphatic diol, an alicyclic diol, an aromatic diol, or an ether bond-containing diol. Examples of aliphatic diols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 2-methyl-1,3-propanediol, 1, 5-pentanediol, 2,2-dimethyl-1,3-propanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,9-nonanediol, 2 -Ethyl-2-butylpropanediol (DMH), neopentyl glycol hydroxytrimethylacetate, dimethylolheptane, 2,2,4-trimethyl-1,3-pentanediol, etc. Examples of alicyclic diols include: 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, tricyclodecanediol, dimethyloltricyclodecane, Spirodiol, hydrogenated bisphenol A, hydrogenated bisphenol A's ethylene oxide adduct and propylene oxide adduct, etc. Examples of glycols containing ether bonds include: diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, neopentyl glycol epoxy Ethane adduct, neopentyl glycol propylene oxide adduct. Examples of aromatic-containing diols include para-xylene glycol, meta-xylene glycol, o-xylene glycol, 1,4-phenylene glycol, and 1,4-phenylene glycol. Ethylene oxide adducts of glycols; bisphenol A, ethylene oxide adducts of bisphenol A, and propylene oxide adducts, etc. Add 1 to the two phenolic hydroxyl groups of bisphenols respectively Diols derived from several moles of ethylene oxide or propylene oxide, etc. These can be used alone or in combination of two or more kinds. Among them, aliphatic diols are preferred, such as ethylene glycol, 2-methyl-1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 2,2-dimethyl-1 ,3-propanediol or 1,6-hexanediol is more preferred.

In order to introduce the branch skeleton into the polyester polyol as necessary, the polycarboxylic acid component and/or the polyol component may be copolymerized with a trifunctional or higher component. During the copolymerization, when all the polycarboxylic acid components and all the polyol components are each 100 mol%, the trifunctional or more components should preferably be 0.1 mol% or more, more preferably 0.5 mol% or more, and more preferably 5 mol% Ear% or less, preferably 3 mol% or less. By being within the above range, especially when making a hardened coating film by reacting with a hardener, the branch skeleton can be introduced, and the terminal group concentration (reaction site) of the resin can be increased, and high crosslinking density can be obtained. Strong coating film. In addition, if it exceeds 5 mol%, mechanical properties such as elongation at the breaking point of the coating film may decrease, and gelation may occur during polymerization.

Examples of polycarboxylic acid components with more than three functions include: trimellitic acid, trimellitic acid, ethylene glycol bis(dehydrated trimellitic acid) ester, and glycerin (dehydrated trimellitic acid) ester , Trimellitic anhydride, pyromellitic anhydride (PMDA), oxydiphthalic dianhydride (ODPA), 3,3',4,4'-benzophenone tetracarboxylic dianhydride (BTDA), 3 ,3',4,4'-Diphenyltetracarboxylic dianhydride (BPDA), 3,3',4,4'-Diphenyl tetracarboxylic dianhydride (DS DA), 4,4'-( Compounds such as hexafluoroisopropylidene)diphthalic dianhydride (6FDA), 2,2'-bis((dicarboxyphenoxy)phenyl)propane dianhydride (BSAA), etc. On the other hand, as examples of polyhydric alcohols with more than three functions, glycerin, trimethylolethane, trimethylolpropane, neopentylerythritol, and the like can be cited.

The acid value can also be introduced into the polyester polyol. The acid value of the polyester polyol is preferably 10 mgKOH/g or less, more preferably 8 mgKOH/g or less. If it is too high, the acid addition chain extension caused by tetracarboxylic dianhydride may become impossible. Furthermore, it is preferably 0.1 mgKOH/g or more, and more preferably 0.3 mgKOH/g or more. If it is too low, crosslinking may become insufficient and the heat and humidity resistance may decrease.

The method of introducing the acid value includes a method of introducing carboxylic acid into the polyester polyol by acid addition after polymerization. If monocarboxylic acid, dicarboxylic acid, or trifunctional or higher polycarboxylic acid compound is used for acid addition, the molecular weight may decrease due to transesterification. Therefore, it is preferable to use a compound having at least one carboxylic anhydride group. Carboxylic anhydrides include: succinic anhydride, maleic anhydride, phthalic anhydride, 2,5-norbornene dicarboxylic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride (PMDA), Oxydiphthalic dianhydride (ODP A), 3,3',4,4'-benzophenone tetracarboxylic dianhydride (BTDA), 3,3',4,4'-diphenyltetracarboxylic acid Acid dianhydride (BPDA), 3,3',4,4'-diphenyl tetracarboxylic dianhydride (DSDA), 4,4'-(hexafluoroisopropylene) diphthalic dianhydride (6FD A), 2,2'-bis((dicarboxyphenoxy)phenyl)propane dianhydride (BSAA), etc.

<Tetracarboxylic dianhydride> Examples of the tetracarboxylic dianhydride include aromatic tetracarboxylic dianhydride, aliphatic tetracarboxylic dianhydride, or alicyclic tetracarboxylic dianhydride, and aromatic tetracarboxylic dianhydride is preferable. Specifically, for example, pyromellitic anhydride (PMD A), oxydiphthalic dianhydride (ODPA), 3,3',4,4'-benzophenone tetracarboxylic dianhydride (BTDA ), 3,3',4,4'-diphenyltetracarboxylic dianhydride (BPDA), 3,3',4,4'-diphenyltetracarboxylic dianhydride (DSDA), 4,4' -(Hexafluoroisopropylidene)diphthalic dianhydride (6FDA), 2,2'-bis[(dicarboxyphenoxy)phenyl]propane dianhydride (BSAA), these can be used alone, or Can use more than 2 kinds. Among them, pyromellitic anhydride is preferable.

<Carboxylic acid group-containing polyester resin (A)> The glass transition temperature of the carboxylic acid group-containing polyester resin (A) of the present invention must be 40°C or higher. It is preferably 45°C or higher, more preferably 50°C or higher. If the glass transition temperature is too low, the adhesive composition becomes more viscous, bubbles are likely to be trapped during bonding, and the sheet life becomes insufficient. In addition, it must be below 90°C. It is preferably 85°C or less, more preferably 80°C or less. If the glass transition temperature is too high, the coating film will become brittle and embrittlement will become a problem.

The acid value of the carboxylic acid group-containing polyester resin (A) of the present invention must be 1 mgKOH/g or more. It is preferably 5 mgKOH/g or more, more preferably 10 mgKOH/g or more. In addition, it needs to be 30 mgKOH/g or less. It is preferably 28 mgKOH/g or less, more preferably 25 mgKOH/g or less. If the acid value is too low, there may be insufficient cross-linking and insufficient solder resistance may be obtained. If the acid value is too high, the cross-linking density may become too high, which may result in hardening of the cured coating film and adhesion. Reduced situation. In addition, there may be cases where the storage stability of the varnish obtained by dissolving the carboxylic acid group-containing polyester resin (A) in a solvent is reduced, and the crosslinking reaction is likely to proceed at room temperature, and a stable sheet cannot be obtained life.

The carboxylic acid group-containing polyester resin (A) is a resin containing the aforementioned polymer polyol (A1), polymer polyol (A2), and tetracarboxylic dianhydride as copolymer components. Preferably, the number average molecular weight (Mn3) of the carboxylic acid group-containing polyester resin (A) is 1.7 times or less the number average molecular weight (Mn1) of the polymer polyol (A1). That is, Mn3/Mn1≦1.7. More preferably, it is 1.6 times or less. It is considered that when it exceeds 1.7 times, the difference in molecular weight is small, or the amount of tetracarboxylic dianhydride is excessive. Therefore, the carboxylic acid group-containing polyester resin (A) has an insufficient carboxylic acid group content, resulting in a decrease in solder resistance, or the elastic modulus of the cured coating film becomes too high, and adhesiveness tends to decrease. The lower limit of Mn3/Mn1 is preferably 0.8 times or more, more preferably 0.9 times or more, and particularly preferably 1.0 times or more. If it is too small, the polymer polyol (A2) may react with the chain extender (tetracarboxylic dianhydride) more often, and the block of the polymer polyol (A1) may not react with the carboxylic dianhydride It reacts sufficiently, resulting in insufficient solder resistance. In addition, if the carboxylic acid group-containing polyester resin (A) is within the range of the above-mentioned number average molecular weight (Mn3/Mn 1), it may also contain only polymer polyol (A1) and carboxylic dianhydride resin, only Polymer polyol (A2) and carboxylic dianhydride resin.

The copolymerization ratio of the polymer polyol (A1) and the polymer polyol (A2) in the carboxylic acid group-containing polyester resin (A), relative to 100 parts by mass of the polymer polyol (A1), the polymer polyol ( A2) Preferably it is 5 parts by mass or more, more preferably 10 parts by mass or more, and particularly preferably 20 parts by mass or more. In addition, it is preferably 50 parts by mass or less, more preferably 40 parts by mass or less, and particularly preferably 30 parts by mass or less. When the number of terminals that can react with tetracarboxylic anhydride is reduced, and the heat resistance becomes insufficient.

The copolymerization ratio of the polymer polyol (A1) and tetracarboxylic dianhydride in the carboxylic acid group-containing polyester resin (A), relative to 100 parts by mass of the polymer polyol (A1), the tetracarboxylic dianhydride is preferably 0.5 part by mass or more, more preferably 1 part by mass or more, and particularly preferably 2 parts by mass or more. In addition, it is preferably 10 parts by mass or less, more preferably 8 parts by mass or less, and particularly preferably 5 parts by mass or less. There are cases where the coating film becomes hard and sufficient adhesiveness cannot be obtained.

The copolymerization amount of the polymer polyol (A1) in the carboxylic acid group-containing polyester resin (A) is preferably 30% by mass or more, more preferably 40% by mass or more, and particularly preferably 50% by mass or more. By increasing the copolymerization amount of the polymer polyol (A1), an improvement in the resistance to humidified solder can be expected. Moreover, it is preferably 90% by weight or less, more preferably 85% by weight or less, and particularly preferably 80% by weight or less. If it is too much, the copolymerization amount of the polymer polyol (A2) and tetracarboxylic dianhydride may decrease, and the solder resistance and adhesiveness may decrease. The method for producing the carboxylic acid group-containing polyester resin (A) is not particularly limited, but solution polymerization or melt polymerization is preferred, and solution polymerization is particularly preferred.

<Epoxy resin (B)> The epoxy resin (B) is not particularly limited as long as it hardens and crosslinks the carboxyl group of the polyester resin (A) containing a carboxylic acid group, but it is preferably one molecule Multifunctional epoxy resin with multiple epoxy groups in it. By using a multifunctional epoxy resin, the hardened coating film obtained from the adhesive composition can easily form three-dimensional crosslinks, which can improve heat resistance. Examples of polyfunctional epoxy resins include cresol novolac type epoxy resins, epoxy resins having a dicyclopentadiene skeleton, and phenol novolac type epoxy resins. If it is a cresol novolac type epoxy resin or a phenol novolac type epoxy resin, the crosslink density of the hardened coating film can be reduced, and the stress during peeling can be relieved, thereby improving the solder resistance. Examples of commercially available products of cresol novolac type epoxy resins include YDCN-700 manufactured by DIC Corporation. On the other hand, if it is an epoxy resin with a dicyclopentadiene skeleton, because the dicyclopentadiene skeleton is rigid, the moisture absorption of the cured coating film can be extremely small, and the cured coating film can be cross-linked The density is reduced and the stress during peeling is alleviated. Therefore, solder resistance is improved. Examples of commercially available products of epoxy resins having a dicyclopentadiene skeleton include HP7200 series manufactured by DIC Corporation. These can be used alone or in combination of two or more kinds.

Furthermore, in addition to using the above-mentioned polyfunctional epoxy resin, an epoxy resin containing a nitrogen atom can also be used. If the epoxy resin containing nitrogen atoms is used in combination, the coating film of the adhesive composition can be heated at a relatively low temperature to become a semi-cured state (hereinafter sometimes referred to as B-stage), and the B-stage film can be suppressed. Liquidity, and improve the tendency of workability in bonding operations. In addition, the effect of suppressing the blistering of the B-stage film can be expected, which is preferable. Examples of epoxy resins containing nitrogen atoms include: tetraglycidyl diamino diphenylmethane, triglycidyl p-aminophenol, tetraglycidyl diamino methyl cyclohexanone, N, Glycidamine series such as N,N',N'-tetraglycidyl-m-xylenediamine, etc. The blending amount of the epoxy resin containing nitrogen atoms is preferably 20% by mass or less of the total epoxy resin (B). If the blending amount is more than 20% by mass, the rigidity tends to be too high and the adhesiveness tends to decrease. In addition, the crosslinking reaction tends to proceed easily when the adhesive sheet is stored, and the sheet life tends to decrease. The upper limit of the blending amount is more preferably 10% by mass, and particularly preferably 5% by mass.

It is also possible to use other epoxy resins as the epoxy resin (B) used in the present invention. Examples include: glycidyl ether type such as bisphenol A diglycidyl ether, bisphenol S diglycidyl ether, and brominated bisphenol A diglycidyl ether; glycidyl hexahydrophthalate, two Glycidyl ester type such as polyglycidyl ester; triglycidyl isocyanurate, 3,4-epoxycyclohexyl methyl formate, epoxidized polybutadiene, epoxidized soybean oil and other alicyclic Or aliphatic epoxides, etc., one kind may be used alone, or two or more kinds may be used.

The epoxy resin (B) is preferably 2 parts by mass or more, and more preferably 5 parts by mass or more with respect to 100 parts by mass of the carboxylic acid group-containing polyester resin (A). Moreover, it is preferably 50 parts by mass or less, more preferably 40 parts by mass or less, and particularly preferably 30 parts by mass or less. If the amount is too small, the curing may be insufficient, and the adhesiveness and heat and humidity resistance may decrease. If the amount is too large, the uncrosslinked epoxy resin may increase and the solder resistance may decrease. In addition, the water absorption rate may increase due to the hydroxyl group generated when the carboxylic acid reacts with the epoxy group, and the humidity and heat resistance may deteriorate.

、1,8-二氮雜雙環(5,4,0)-十一烯-7、1,5-二氮雜雙環(4,3,0)-壬烯-5、或6-二丁基胺基-1,8-二氮雜雙環(5,4,0)-十一烯-7等三級胺類、及將該等三級胺類以苯酚、辛酸、或四級化四苯基硼酸鹽等製成胺鹽之化合物；三烯丙基鋶六氟銻酸鹽或二烯丙基錪六氟銻酸鹽等陽離子觸媒；三苯基膦等。該等中，考量熱硬化性、耐熱性、對於金屬之黏接性、及摻合後之保存穩定性的觀點，宜為1,8-二氮雜雙環(5,4,0)-十一烯-7、1,5-二氮雜雙環(4,3,0)-壬烯-5、或6-二丁基胺基-1,8-二氮雜雙環(5,4,0)-十一烯-7等三級胺類、及將該等三級胺類以苯酚、辛酸、或四級化四苯基硼酸鹽等製成胺鹽之化合物。硬化觸媒之摻合量相對於含有羧酸基之聚酯樹脂(A)100質量份，宜為0.01~1.0質量份。若為此範圍內，可進一步增加對於含有羧酸基之聚酯樹脂(A)與環氧樹脂(B)之反應的觸媒效果，獲得牢固的黏接性能。In the present invention, a curing catalyst can be used for the curing reaction of the epoxy resin (B). Examples include: 2-methylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenyl-4-methylimidazole, or 1-cyanoethyl-2- Ethyl-4-methylimidazole and other imidazole compounds; triethylamine, triethylenediamine, N'-methyl-N-(2-dimethylaminoethyl)piper

, 1,8-diazabicyclo(5,4,0)-undecene-7, 1,5-diazabicyclo(4,3,0)-nonene-5, or 6-dibutyl Amino-1,8-diazabicyclo(5,4,0)-undecene-7 and other tertiary amines, and these tertiary amines are phenol, caprylic acid, or quaternary tetraphenyl Compounds made into amine salts such as borate; cationic catalysts such as triallyl hexafluoroantimonate or diallyl hexafluoroantimonate; triphenyl phosphine, etc. Among them, considering the thermal hardenability, heat resistance, adhesion to metals, and storage stability after blending, 1,8-diazabicyclo(5,4,0)-eleven Ene-7, 1,5-diazabicyclo(4,3,0)-nonene-5, or 6-dibutylamino-1,8-diazabicyclo(5,4,0)- Tertiary amines such as undecene-7, and compounds in which these tertiary amines are made into amine salts with phenol, caprylic acid, or quaternary tetraphenyl borate. The blending amount of the hardening catalyst is preferably 0.01 to 1.0 parts by mass relative to 100 parts by mass of the carboxylic acid group-containing polyester resin (A). If it is within this range, the catalyst effect for the reaction between the carboxylic acid group-containing polyester resin (A) and the epoxy resin (B) can be further increased, and firm adhesion performance can be obtained.

<Organic solvent> The adhesive composition of the present invention can be dissolved in an organic solvent to prepare a resin solution. The organic solvent is not particularly limited as long as it dissolves the carboxylic acid group-containing polyester resin (A), and it is more preferable to also dissolve the epoxy resin (B). Organic solvents can be used: aromatic hydrocarbons such as benzene, toluene, and xylene; alicyclic hydrocarbons such as cyclohexane, cyclohexene, methylcyclohexane, and ethylcyclohexane; methanol, ethanol, isopropanol, Alcohol solvents such as butanol, pentanol, hexanol, propylene glycol, and phenol; ketone solvents such as acetone, methyl isobutyl ketone, methyl ethyl ketone, pentanone, hexanone, cyclohexanone, isophorone, and acetophenone; Cyrosu, Ethyl Cyrosu, etc.; ester solvents such as methyl acetate, ethyl acetate, butyl acetate, methyl propionate, butyl formate, etc.; trichloroethylene, dichloroethylene, chlorine Halogenated hydrocarbons such as benzene and chloroform can be used alone or in combination of two or more. Among them, a mixed solvent of aromatic hydrocarbons and ketone solvents is preferable, and a mixed solvent of toluene and methyl ethyl ketone is more preferable.

The amount of the organic solvent is preferably 50 parts by mass or more, more preferably 70 parts by mass or more, and particularly preferably 100 parts by mass or more relative to 100 parts by mass of the carboxylic acid group-containing polyester resin (A). Furthermore, it is preferably 700 parts by mass or less, more preferably 600 parts by mass or less, and particularly preferably 500 parts by mass or less. If the amount is too small, the storage stability of the adhesive composition may decrease, and if the amount is too large, it may become industrially disadvantageous.

<Other additives> In the adhesive composition of the present invention, various curable resins and additives can be further blended within a range that does not impair the effects of the present invention. Examples of the curable resin include phenol resins, amino resins, isocyanate compounds, and silane coupling agents.

Examples of phenol resins include alkylated phenols and formaldehyde condensates of cresols. Specifically, examples include: alkylated (for example, methyl, ethyl, propyl, isopropyl, butyl) phenol, p-tertyl phenol, 4,4'-second butylene phenol, p-tert-butyl Phenol, o-cresol, m-cresol, p-cresol, p-cyclohexanol, 4,4'-isopropylidene, p-nonanol, p-octanol, 3-pentadecylphenol, phenol, phenyl o Formaldehyde condensates of cresol, p-phenylphenol, xylenol, etc. These can be used alone or in combination of two or more kinds.

The amino resin includes, for example, formaldehyde adducts such as urea, melamine, and benzoguanamine, and further examples thereof include alkyl ether compounds obtained by using alcohols having 1 to 6 carbon atoms. Specifically, it can include: methoxylated hydroxymethyl urea, methoxylated hydroxymethyl N,N-ethylene urea, methoxylated hydroxymethyl dicyandiamide, methoxylated hydroxymethyl Melamine, methoxylated methylol benzoguanamine, butoxylated methylol melamine, butoxylated methylol benzoguanamine, etc. Preferably, they are methoxylated methylol melamine, butoxylated methylol melamine, and methylolated benzoguanamine, which can be used individually or independently.

The isocyanate compound includes aromatic or aliphatic diisocyanate, trivalent or higher polyisocyanate, and can be either a low molecular compound or a high molecular compound. Examples include: tetramethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, xylene diisocyanate, hydrogenated xylene diisocyanate, isophor Ketone diisocyanate or 3-mer of these isocyanate compounds. Further examples include compounds containing terminal isocyanate groups obtained by reacting excess of these isocyanate compounds with low molecular active hydrogen compounds or high molecular active hydrogen compounds. The low molecular active hydrogen compounds are, for example, ethylene glycol, propylene glycol, tris Methylolpropane, glycerin, sorbitol, ethylenediamine, monoethanolamine, diethanolamine, or triethanolamine, etc.; the polymer active hydrogen compound is, for example, various polyester polyols, polyether polyols, and polyols Amines and so on.

The isocyanate compound may also be a blocked isocyanate. Examples of isocyanate blocking agents include phenols such as phenol, thiophenol, methyl thiophenol, cresol, xylenol, resorcinol, nitrophenol, and chlorophenol; acetoxime, Methyl ethyl ketoxime, cyclohexanone oxime and other oximes; methanol, ethanol, propanol, butanol and other alcohols; 2-chloroethanol, 1,3-dichloro-2-propanol and other halogen-substituted alcohols; third Tertiary alcohols such as butanol and tertiary amyl alcohol; internal amines such as ε-caprolactam, δ-valerolactam, γ-butyrolactam, and β-propiolactin. Other examples include: aromatic amines, imines, acetone, acetone, ethyl malonate and other active methylene compounds; mercaptans, imines, ureas, diaromatics Base compounds such as sodium bisulfite, etc. The blocked isocyanate can be obtained by an addition reaction of the above-mentioned isocyanate compound, an isocyanate compound, and an isocyanate blocking agent by a conventionally known appropriate method.

The adhesive composition of the present invention may also be blended with a silane coupling agent as needed. By blending the silane coupling agent, the adhesion to metals and the characteristics of heat resistance are improved, so it is very ideal. The silane coupling agent is not particularly limited, and examples thereof include those having an unsaturated group, those having a glycidyl group, and those having an amine group. Examples of the silane coupling agent having an unsaturated group include vinyl ginseng (β-methoxyethoxy) silane, vinyl triethoxy silane, vinyl trimethoxy silane, and the like. Silane coupling agents with glycidyl groups include: γ-glycidoxypropyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, β-(3 , 4-epoxycyclohexyl) ethyl triethoxy silane, etc. Silane coupling agents with amino groups include: N-β-(aminoethyl)-γ-aminopropyl trimethoxysilane, N-β-(aminoethyl)-γ-aminopropyl Methyldimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, etc. Among them, in consideration of heat resistance, γ-glycidoxypropyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, or β-(3 , 4-epoxycyclohexyl) ethyl triethoxy silane and other silane coupling agents with glycidyl groups. The blending amount of the silane coupling agent is preferably 0.5-20 parts by mass relative to 100 parts by mass of the carboxylic acid group-containing polyester resin (A). If the blending amount of the silane coupling agent is less than 0.5 parts by mass, the heat resistance of the obtained adhesive composition may become poor. If it exceeds 20 parts by mass, the heat resistance and adhesion may be poor. Case.

In the adhesive composition of the present invention, additives such as bromine-based, phosphorus-based, nitrogen-based, and metal hydroxide compounds, such as flame retardants, leveling agents, pigments, and dyes, can be appropriately blended as needed.

<Adhesive sheet> In the present invention, an adhesive sheet refers to a coating film (hereinafter also referred to as an adhesive layer) of an adhesive composition obtained by curing the adhesive composition of the present invention. The adhesive sheet has the function of bonding the base material to the material to be bonded through the adhesive layer. The base material of the adhesive sheet functions as a protective layer of the material to be bonded after bonding. In addition, if a release substrate is used, the release substrate can be released, and then the adhesive layer can be transferred to another material to be bonded. The adhesive sheet can be obtained by coating the adhesive composition on the base material or the release base material, and drying and hardening. Specific constitutions include: base material/adhesive layer, release base material/adhesive layer, release base material/adhesive layer/substrate, release base material/adhesive layer/release base Materials and so on. Moreover, it may be the adhesive layer itself after peeling off the mold release base material as appropriate. In addition, a trace or a small amount of organic solvent may be contained in the adhesive sheet.

As for the adhesive sheet, it can be obtained by applying the adhesive composition of the present invention to various substrates in a usual manner, removing at least a part of the solvent, and drying it. In addition, after removing at least a part of the solvent and drying it, the release base material is attached to the adhesive layer, it can be wound without causing transfer to the base material, and the handling is excellent, and the adhesive layer It is also protected, so it has excellent storage properties and is easy to use. In addition, after coating on a release substrate and drying, if another release substrate is attached as necessary, the adhesive layer itself may be transferred to another substrate.

The base material is not particularly limited, and examples thereof include film-like resins, metal plates, metal foils, papers, and the like. Examples of film-like resins include polyester resins, polyamide resins, polyimide resins, polyimide resins, and olefin resins. Examples of materials for metal plates and metal foils include various metals such as SUS, copper, aluminum, iron, zinc, and their respective alloys, plating products, etc. Examples of paper include high-quality paper, kraft paper, roll paper, cellophane, etc. In addition, as a composite material, glass epoxy resin and the like can be exemplified. Considering the adhesion and durability of the substrate and the adhesive composition, polyester resin, polyamide resin, polyimide resin, polyimide resin, SUS steel plate, copper foil, aluminum foil, and glass are suitable Epoxy resin.

The mold release substrate is not particularly limited. For example, it can be exemplified: coating layers of clay, polyethylene, polypropylene and other fillers are provided on both sides of paper such as high-quality paper, kraft paper, roll paper, cellophane, etc., and further on each of the coating layers Coated with silicone-based, fluorine-based, and alkyd-based release agents. In addition, various olefin films themselves such as polyethylene, polypropylene, ethylene-α-olefin copolymer, propylene-α-olefin copolymer, etc., and application of the above-mentioned mold release agent to polyethylene terephthalate, etc. Those made on the film. Considering the demolding force of the mold release substrate and the adhesive layer, and the adverse effects of polysiloxane on the electrical characteristics, it is appropriate to use polypropylene filling treatment on both sides of high-quality paper and use alkyd on it. Those made from a molding agent, or those made by using an alkyd-based mold release agent on polyethylene terephthalate.

The method of applying the adhesive composition to the substrate or the release substrate is not particularly limited, and examples include chipped wheel coating, reverse roll coating, and the like. Or, if necessary, the adhesive layer can be directly or by a transfer method to be placed on the rolled copper foil or the polyimide film which is the constituent material of the printed wiring board. The thickness of the adhesive layer after drying can be appropriately changed as needed, and should be within the range of 5~200μm. When the thickness of the adhesive layer is less than 5μm, the adhesive strength may become insufficient. When the thickness exceeds 200 μm, the residual solvent increases due to insufficient drying, and the problem of swelling during the pressing of the printed wiring board manufacturing can be cited. The drying conditions are not particularly limited, and the residual solvent ratio after drying is preferably 4% by mass or less, and more preferably 1% by mass or less. If it is more than 4% by mass, the following problem may occur: When the printed wiring board is pressed, the residual solvent may foam and swell.

<Printed Wiring Board> The printed wiring board in the present invention includes adhesive sheets as constituent elements, and more specifically, includes a laminate (metal foil/adhesive (Agent layer/resin base material) as a constituent element. The printed wiring board uses, for example, a metal-clad laminate and is manufactured by a conventionally known method such as a subtraction method. If necessary, the conductor circuit formed by the metal foil may be partially or entirely covered with a cover film, screen printing ink, etc., to be collectively referred to as a so-called flexible circuit board (FPC), flat cable, and tape-type automatic bonding ( TAB) used circuit boards, etc.

The printed wiring board of the present invention can be made into any laminated structure that can be used as a printed wiring board. For example, it can be made into a printed wiring board composed of four layers of a base film layer, a metal foil layer, an adhesive layer, and a cover film layer. In addition, for example, a printed wiring board composed of five layers of a base film layer, an adhesive layer, a metal foil layer, an adhesive layer, and a cover film layer can be produced. The printed wiring board may be reinforced with a reinforcing material as necessary. In this case, the reinforcing material and the adhesive layer are arranged under the base film layer.

Furthermore, it can also be made into the structure which laminated|stacked 2 or 3 or more of the said printed wiring boards as needed.

The adhesive composition of the present invention can be ideally used in each adhesive layer of a printed wiring board. In particular, when the adhesive composition of the present invention is used as an adhesive, it has high adhesiveness to a substrate constituting a printed wiring board, and can impart a high degree of heat resistance that can be compatible with lead-free solder. Especially in the high temperature area where solder resistance is evaluated, due to the good balance of chemical cross-linking between resin and resin and physical cross-linking between resin and inorganic filler, stress can be relieved without the solder resistance in humidified state The impact caused by the evaporation of water in the test results in swelling and deformation. Therefore, it is suitable for the adhesive between the metal foil layer and the cover film layer, and the adhesion between the base film layer and the reinforcing material layer. Especially when using metal reinforcing materials such as SUS plates and aluminum plates, when welding is carried out in a humidified state, the moisture cannot evaporate from the reinforcing material side, which impacts the adhesive layer between the base film layer and the reinforcing material layer. Particularly strong, suitable as an adhesive composition for bonding in this case.

The inorganic filler used in the present invention is not particularly limited. For example, aluminum oxide, silicon dioxide, titanium oxide, tantalum oxide, zirconium oxide, silicon nitride, barium titanate, barium carbonate, lead titanate, zirconium titanium can be used. Lead acid, lead lanthanum zirconate titanate, gallium oxide, spinel, mullite, cordierite, talc, aluminum hydroxide, magnesium hydroxide, aluminum titanate, yttria-containing zirconia, barium silicate, nitride Boron, calcium carbonate, calcium sulfate, zinc oxide, zinc borate, magnesium titanate, magnesium borate, barium sulfate, organic bentonite, carbon, etc., can be used alone or in combination of two or more. Considering the transparency, mechanical properties, and heat resistance of the adhesive composition, silica is preferred, and aerosol-like silica with a three-dimensional network structure is particularly preferred. In addition, in terms of imparting hydrophobicity, hydrophobic silica treated with monomethyltrichlorosilane, dimethyldichlorosilane, hexamethyldisilazane, octylsilane, silicone oil, etc., is preferable. When aerosol silica is used as the inorganic filler, the average particle size of the primary particles is preferably 30nm or less, more preferably 25nm or less. If the average particle size of the primary particles exceeds 30 nm, the interaction between the particles and the resin will decrease, and the heat resistance will tend to decrease. In addition, the average particle diameter of the primary particles referred to herein refers to the average value of the diameter of a circle of 100 particles randomly selected from the image of the primary particles obtained by using a scanning electron microscope.

The blending amount of the inorganic filler relative to 100 parts by mass of the carboxylic acid group-containing polyester resin (A) is preferably 10 parts by mass or more, more preferably 13 parts by mass or more, and particularly preferably 15 parts by mass or more. If it is less than 10 parts by mass, the effect of improving heat resistance may not be exhibited. Furthermore, it is preferably 50 parts by mass or less, more preferably 45 parts by mass or less, and particularly preferably 40 parts by mass or less. If it exceeds 50 parts by mass, poor dispersion of the inorganic filler may occur, or the viscosity of the solution may become too high, which may cause inconvenience to workability, or may decrease the adhesiveness.

In the printed wiring board of the present invention, as the base film, any resin film that has been conventionally used as a base material of a printed wiring board can be used. The resin of the base film can be a halogen-containing resin or a halogen-free resin. From the viewpoint of environmental issues, halogen-free resins are preferable, but from the viewpoint of flame retardancy, halogen-containing resins can also be used. The substrate film is preferably a polyimide film or a polyimide film.

As for the metal foil used in the present invention, any conventionally known conductive material that can be used for circuit substrates can be used. As the material, for example, copper foil, aluminum foil, steel foil, nickel foil, etc. can be used, and composite metal foils obtained by combining these, and metal foils treated with other metals such as zinc and chromium compounds can also be used. Preferably it is copper foil.

The thickness of the metal foil is not particularly limited, and is preferably 1 μm or more, more preferably 3 μm or more, and particularly preferably 10 μm or more. Moreover, it is preferably 50 μm or less, more preferably 30 μm or less, and particularly preferably 20 μm or less. When the thickness is too thin, it may be difficult for the circuit to obtain sufficient electrical performance. On the other hand, when the thickness is too thick, the processing efficiency when making the circuit may be reduced.

Metal foil is usually provided in the form of a roll. The form of the metal foil used when manufacturing the printed wiring board of this invention is not specifically limited. When the metal foil in the form of a roll is used, its length is not particularly limited. Also, the width is not particularly limited, but it is preferably about 250 to 1000 mm.

As the cover film, any insulating film known as an insulating film for printed wiring boards can be used. For example, it can be used: from polyimide, polyester, polyphenylene sulfide, polyether ether, polyether ether ketone, polyaramide, polycarbonate, polyarylate, polyimide, polyimide Films made of various polymers such as amines. It is more preferably a polyimide film or a polyimide film, and particularly preferably a polyimide film.

The material resin of the cover film can be a halogen-containing resin or a halogen-free resin. From the viewpoint of environmental issues, halogen-free resins are preferable, but from the viewpoint of flame retardancy, halogen-containing resins can also be used.

The printed wiring board of the present invention can be manufactured using any conventionally known process in addition to using the materials of the above-mentioned layers.

In a preferred embodiment, a semi-finished product (hereinafter referred to as "cover-film-side semi-finished product") in which an adhesive layer is laminated on the cover film layer is manufactured. On the other hand, it manufactures a semi-finished product in which a metal foil is laminated on a base film layer and a desired circuit pattern is formed (hereinafter referred to as a "base film side two-layer semi-finished product") or an adhesive is laminated on the base film Layer, a semi-finished product made by laminating a metal foil layer on it and forming a desired circuit pattern (hereinafter referred to as "3-layer semi-finished product on the base film side"; hereinafter the two-layer semi-finished product on the substrate film side and the 3-layer semi-finished product on the substrate film side The semi-finished products are collectively referred to as "substrate film side semi-finished products"). By bonding the semi-finished product on the cover film side and the semi-finished product on the base film side obtained in this way, a 4-layer or 5-layer printed wiring board can be obtained.

The semi-finished product on the substrate film side can be obtained by, for example, a manufacturing method including the following steps: (A) apply a solution of the resin to be the substrate film on the aforementioned metal foil, and perform preliminary drying of the coating film; (B) (A) The laminate of the metal foil and the preliminarily dried coating film obtained in the process is heat-treated and dried (hereinafter referred to as "heat treatment and solvent removal step").

The formation of the circuit in the metal foil layer can use conventionally known methods. Additive or subtractive methods can be used. The subtraction method is preferred.

The obtained semi-finished product on the substrate film side can be used directly for bonding with the semi-finished product on the cover film side, or it can be used for bonding with the semi-finished product on the cover film side after bonding the release film and storing it.

The semi-finished product on the cover film side is manufactured by applying an adhesive to the cover film, for example. The cross-linking reaction in the coated adhesive can be implemented as needed. In a preferred embodiment, the adhesive layer is semi-hardened.

The obtained cover film side semi-finished product can be directly used for bonding with the base film side semi-finished product, or after the release film is bonded and stored, it can be used for bonding with the base film side semi-finished product.

The semi-finished product on the base film side and the semi-finished product on the cover film side are stored in the form of a roll, for example, and then laminated to manufacture a printed wiring board. As for the bonding method, any method can be used, and for example, pressing or a roll can be used for bonding. In addition, it is also possible to bond the two together while heating by a method such as heating and pressing, or using a heating roller device.

The semi-finished product on the base film side, the semi-finished product on the cover film side, and the semi-finished product on the reinforcing material side all belong to the laminate for printed wiring boards in the present invention.

The adhesive composition of the present invention can be ideally used in each adhesive layer of a printed wiring board. It has excellent adhesion to various substrates and excellent humidity and heat resistance. Therefore, it can be used in addition to printed wiring boards, but also by It contains conductive powders such as metal powder, and can be used in: electromagnetic wave shielding purposes; circuit formation purposes for touch panels and electronic parts; conductive adhesives for terminals and wires. [Example]

In order to describe the present invention in more detail, examples and comparative examples are listed below, but the present invention is not limited by the examples at all. In addition, each measured value described in the Examples and Comparative Examples was measured by the following method. Also, unless otherwise specified, "parts" means "parts by mass", and "%" means "mass%".

[Polymerization example of polymer polyol (A1-1)] Add 90 parts of terephthalic acid, 358 parts of isophthalic acid, and trimellitic anhydride to a reaction tank equipped with a stirrer, a thermometer, and a cooler for distillation 5 parts, 319 parts of 2-methyl-1,3-propanediol, 172 parts of 1,4-cyclohexanediol, 0.2 parts of tetrabutyl titanate, slowly increase the temperature to 250°C, and drain the distilled water to Outside the system, the esterification reaction is carried out. After the esterification reaction is completed, the initial polymerization is performed while gradually reducing the pressure to 10 mmHg, and the temperature is raised to 250° C., and the subsequent polymerization is further performed below 1 mmHg until the predetermined torque is reached. After that, the pressure was returned to normal pressure with nitrogen, 5 parts of trimellitic anhydride was added, and reacted at 220° C. for 30 minutes, thereby obtaining a polymer polyol (A1-1). The composition and characteristic values of the polymer polyol (A1-1) obtained in this way are shown in Table 1. Each measurement evaluation item is in accordance with the aforementioned method.

[Polymerization example of polymer polyol (A2-1)] Add 390 parts of terephthalic acid, 390 parts of isophthalic acid, and 367 parts of ethylene glycol to a reaction tank equipped with a stirrer, a thermometer, and a cooler for distillation Part, 362 parts of 2,2-dimethyl-1,3-propanediol, 0.2 part of tetrabutyl titanate, slowly increase the temperature to 250°C, and proceed the esterification reaction while draining the distilled water out of the system. After the esterification reaction is completed, the initial polymerization is performed while slowly reducing the pressure to 10mmHg, and the temperature is raised to 250°C, and the subsequent polymerization is further performed below 1mmHg until the predetermined torque is reached, thereby obtaining a polymer polyol (A2-1) . The composition and characteristic values of the polymer polyol (A2-1) obtained in this way are shown in Table 1. Each measurement evaluation item is in accordance with the aforementioned method.

The polymer polyol (A1-2~A1-5) is obtained by the same method as the polymer polyol (A1-1). In addition, the polymer polyol (A2-2) was obtained by the same method as the polymer polyol (A2-1). The characteristic values of these are shown in Table 1.

【Table 1】

(1) Composition of carboxylic acid group-containing polyester resin (A) The carboxylic acid group-containing polyester resin (A) was dissolved in deuterated chloroform, and the molar ratio of each component was determined ^{by 1 H-NMR analysis.}

(2) Number average molecular weight (Mn) Dissolve the sample (polyester resin (A) containing carboxylic acid group, polymer polyol (A1) or polymer polyol (A2)) in tetrahydrofuran or dilute with tetrahydrofuran to make The sample concentration was about 0.5% by mass, and the sample was filtered with a membrane filter made of polytetrafluoroethylene with a pore size of 0.5 μm as a sample for measurement. The number average molecular weight is measured by a gel permeation chromatograph with tetrahydrofuran as the mobile phase and a differential refractometer as the detector. The flow rate is set to 1 mL/min, and the column temperature is set to 30°C. The column uses Showa Denko KF-802, 804L, 806L. The molecular weight standard uses monodisperse polystyrene. However, when the sample does not dissolve in tetrahydrofuran, use N,N-dimethylformamide instead of tetrahydrofuran. Low-molecular compounds (oligomers, etc.) whose number average molecular weight is less than 1,000 are not included in the count and omitted.

(3) The glass transition temperature uses a differential scanning calorimeter "DSC220" manufactured by Seiko Electronics Co., Ltd., put 5 mg of the measurement sample into the aluminum pan, press the lid and seal it, and keep it at 250°C for 5 minutes once. , Use liquid nitrogen for rapid cooling, and then increase the temperature from -150°C to 250°C at a temperature increase rate of 20°C/min and perform the measurement. The inflection point of the obtained curve is regarded as the glass transition temperature. In addition, when there are two or more inflection points, it is regarded as a block copolymerization, and each inflection point is read, and it is regarded as having a plurality of glass transition temperatures.

(4) Acid value Dissolve 0.2 g of the sample (polyester resin containing carboxylic acid group (A), polymer polyol (A1) or polymer polyol (A2)) in 20 ml of chloroform, and use phenolphthalein as an indicator , Titrate with 0.1N potassium hydroxide ethanol solution. From this titration amount, the mg number of KOH consumed for neutralization was converted into the amount per 1 g of resin, and the acid value (mgKOH/g) was calculated.

<Synthesis example of carboxylic acid group-containing polyester resin (A-1)> Add 160 parts of polymer polyol (A1) and polymer polyol (A2) to a reaction tank equipped with a stirrer, thermometer, and reflux tube 40 parts, 5.2 parts of pyromellitic anhydride, and 200 parts of toluene were dissolved in toluene while slowly raising the temperature to 80°C. After the dissolution was completed, 0.1 part of triethylamine was added as a reaction catalyst, and the temperature was gradually raised to 105° C. and allowed to react for 24 hours. After confirming the completion of the reaction by IR, it was diluted with 108 parts of toluene to obtain a solution with a solid content of 40% of the carboxylic acid group-containing polyester resin (A-1). The composition and characteristic values of the carboxylic acid group-containing polyester resin (A-1) obtained in this way are shown in Table 2. Each measurement evaluation item is in accordance with the aforementioned method.

<Synthesis examples of carboxylic acid group-containing polyester resin (A-2)~(A-13)> The same as the synthesis example (A-1) of carboxylic acid group-containing polyester resin to obtain carboxylic acid group-containing polyester Resin (A-2)~(A-13).

【Table 2】

<Example 1> To 100 parts of solid content of carboxylic acid group-containing polyester resin (A-1), Nippon Steel & Sumikin Chemical Co., Ltd. product YDCN-700-10 (novolac type) was added as an epoxy resin Epoxy resin) 9 parts and Mitsubishi Gas Chemical Co., Ltd. TETRAD (registered trademark)-X (N,N,N',N'-tetraepoxypropyl-m-xylene diamine) 0.1 part, with methyl ethyl ketone The solid content concentration was adjusted to 35% to obtain an adhesive composition. The adhesive composition obtained was evaluated by the method shown below.

<Examples 2 to 12, Comparative Examples 1 to 6> The carboxylic acid group-containing polyester resin and epoxy resin were changed to those shown in Table 3, and the same method as in Example 1 was used to change them to those shown in Table 3. For each blending amount, Examples 2 to 12 and Comparative Examples 1 to 6 were performed. The results are shown in Table 3.

(5) Peel strength, solder resistance, and sheet life (5)-1 Peel strength (adhesion) The adhesive composition obtained in the examples or comparative examples is applied to a polyimide film with a thickness of 12.5 μm (Kaneka Co., Ltd., APICAL (registered trademark)), the thickness after drying becomes 25 μm, and it is dried at 130°C for 5 minutes to obtain an adhesive film (B-stage product). The adhesive layer of the adhesive film is bonded with the glossy surface of the 20μm rolled copper foil, and pressed at 160°C under a ^{pressure of 30kgf/cm 2} for 30 seconds to bond. Then, it was heat-treated at 140°C for 4 hours to harden, and a sample for evaluation was obtained.

Peel strength: The sample for evaluation was pulled at 25°C at a tensile speed of 50 mm/min to perform a 180° peel test to measure the peel strength. This test shows the peel strength at room temperature. In consideration of practical performance, it is preferably 3.5 N/cm or more, and more preferably 5 N/cm or more. -Evaluation criteria- ◎: 10N/cm or more ○: 5N/cm or more, less than 10N/cm △: 3.5N/cm or more, less than 5N/cm ×: less than 3.5N/cm

(5)-2 Solder resistance Solder resistance (drying): After placing the sample for evaluation in an environment of 120°C for 30 minutes, let it float in the heated solder bath for 1 minute, and measure it at intervals of 10°C. The upper limit temperature of bulging. In this test, the higher the measured value, the better the heat resistance. In consideration of practical performance, it is preferably 350°C or higher, and more preferably 360°C or higher. -Evaluation Criteria- ◎: No swelling even at 360°C or higher. ○: No swelling above 350°C but below 360°C. △: No swelling above 340°C and below 350°C. ×: There is swelling below 340°C.

Solder resistance (humidification): After leaving the sample for evaluation at 40°C and 80% humidification for 3 days, let it float in the heated solder bath for 1 minute, and measure the upper limit of no swelling at 10°C intervals temperature. In this test, although the higher the measured value, the better the heat resistance, but the impact caused by the evaporation of water vapor contained in each substrate and adhesive layer must also be suppressed, and more stringent heat resistance is required than in the dry state. sex. In consideration of practical performance, it is preferably 260°C or higher, and more preferably 270°C or higher. -Evaluation Criteria- ◎: No swelling even at 270°C or higher. ○: No swelling above 260°C and below 270°C. △: No swelling above 250°C and below 260°C. ×: There is swelling below 250°C.

(5)-3 Evaluation of sheet life. Preparation of samples for sheet life measurement: The adhesive composition obtained in the examples or comparative examples was applied to a polyimide film with a thickness of 12.5 μm (Kaneka Co., Ltd.) Made, APICAL (registered trademark)), the thickness after drying becomes 25μm, and it is dried at 130°C for 5 minutes to obtain an adhesive film (B-stage product). Place the B-stage product in an environment of 40°C×80% for 2 weeks. Laminate the B-stage product so that the adhesive layer of the adhesive film is in contact with the glossy surface of the 20μm rolled copper foil, ^{and press it at 160°C under a pressure of 30kgf/cm 2} for 30 seconds to bond . Then, it was heat-treated at 140°C for 4 hours to harden, and a sample for evaluation was obtained. The evaluation samples of peel strength and solder resistance were similarly produced by the above method.

【table 3】

According to the examples in Table 3, the adhesive composition of the present invention has excellent initial peel strength, solder resistance, and sheet life.

In the case of the adhesive composition of Comparative Examples 1 to 6, the properties such as peel strength, solder resistance, and sheet life are insufficient. [Industrial Utilization]

The adhesive composition of the present invention has excellent adhesiveness, solder resistance and sheet life to various plastic films, metals such as copper, aluminum, stainless steel, and glass epoxy resin. Therefore, it is particularly useful as an adhesive system for circuit boards such as FPC.

Claims (4)

An adhesive composition comprising a polyester resin (A) containing a carboxylic acid group and an epoxy resin (B), characterized in that the glass transition temperature (Tg) of the polyester resin (A) containing a carboxylic acid group is 40~90℃, acid value 1~30mgKOH/g, and contains polymer polyol (A1), polymer polyol (A2) which is different from polymer polyol (A1) and tetracarboxylic dianhydride as copolymer Ingredients, the copolymerization amount of the polymer polyol (A1) in the carboxylic acid group-containing polyester resin (A) is 30% by mass or more and 90% by weight or less, which is higher than that in the carboxylic acid group-containing polyester resin (A) The copolymerization ratio of molecular polyol (A1) and polymer polyol (A2), relative to 100 parts by mass of polymer polyol (A1), polymer polyol (A2) is 5 parts by mass or more and 50 parts by mass or less, containing The copolymerization ratio of the polymer polyol (A1) and the tetracarboxylic dianhydride in the carboxylic polyester resin (A) is 0.5 mass parts of the tetracarboxylic dianhydride relative to 100 parts by mass of the polymer polyol (A1) Part or more and 10 parts by mass or less, the epoxy resin (B) is 2 parts by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the carboxylic acid group-containing polyester resin (A). For example, the adhesive composition of item 1 in the scope of patent application, wherein the polymer polyol (A1) and/or the polymer polyol (A2) are polyester polyols. An adhesive sheet, which contains the hardened material of the adhesive composition as described in item 1 or 2 of the scope of patent application. A printed wiring board that includes the adhesive sheet as described in item 3 of the scope of patent application as a constituent element.