JPWO2018105543A1 - Carboxylic acid group-containing polymer compound and adhesive composition containing the same - Google Patents

Abstract

Adhesive composition with excellent moisture and heat resistance that can be used for lead-free soldering under high humidity while maintaining good adhesion to various plastic films, metals such as copper, aluminum, and stainless steel, and glass epoxy. To provide. A polymer polyol (A) having a number average molecular weight (Mn1) of 7,000 or more as a copolymer component and a polymer polyol having a number average molecular weight (Mn2) different from the polymer polyol (A) of 1,000 or more A carboxylic acid group-containing polymer compound containing at least (B) and tetracarboxylic dianhydride and satisfying the following (1) to (2). (1) The number average molecular weight (Mn1) of the polymer polyol (A) is the largest in the copolymer component (2) The number average molecular weight (Mn3) of the carboxylic acid group-containing polymer compound is the polymer polyol (A) The number average molecular weight (Mn1) is 1.7 times or less.

Description

  The present invention relates to various plastic films, metals such as copper, aluminum, and stainless steel, a carboxylic acid group-containing polymer compound excellent in adhesiveness to glass epoxy and wet heat resistance, and an adhesive composition and adhesive containing the same. The present invention relates to a sheet and a printed wiring board including the sheet as a component.

  In recent years, adhesives have been used in various fields, but due to diversification of purposes of use, various plastic films, adhesiveness to metal, glass epoxy, etc., moisture and heat resistance, etc., compared to conventionally used adhesives, There is a need for higher performance. For example, adhesives for circuit boards including flexible printed wiring boards (hereinafter sometimes abbreviated as FPC) are required to have adhesiveness, workability, electrical characteristics, and storage stability. Conventionally, epoxy / acryl butadiene adhesives, epoxy / polyvinyl butyral adhesives, and the like are used for this application.

  In particular, in recent years, adhesives having higher heat resistance are required from the viewpoint of compatibility with lead-free solder and the usage environment of FPC. In addition, solder resistance under high humidity is strongly demanded from the high density of wiring, the multi-layered FPC wiring board, and workability. Responding to these problems, a resin composition for an adhesive mainly comprising a specific polyester or polyester / polyurethane and an epoxy resin is disclosed (for example, Patent Documents 1 and 2).

JP-A-11-116930 JP 2008-205370 A

  However, the composition described in Patent Document 1 has not always obtained satisfactory results from the viewpoint of lead-free solder heat resistance. Moreover, even the composition shown by patent document 2 was not fully satisfied regarding the lead-free solder heat resistance depending on the base material type.

  The problem of the present invention is to improve each of the problems of these conventional adhesives, and to maintain good adhesion to various plastic films, metals such as copper, aluminum and stainless steel, and glass epoxy. Another object of the present invention is to provide a carboxylic acid group-containing polymer compound that is capable of dealing with lead-free solder under high humidity and has a high degree of moisture and heat resistance, and an adhesive composition containing the carboxylic acid group-containing polymer compound. .

  As a result of intensive studies, the present inventors have found that the above problems can be solved by the following means, and have reached the present invention. That is, the present invention has the following configuration.

A polymer polyol (A) having a number average molecular weight (Mn1) of 7,000 or more as a copolymerization component;
A polymer polyol (B) having a number average molecular weight (Mn2) different from that of the polymer polyol (A) of 1,000 or more;
A carboxylic acid group-containing polymer compound comprising at least tetracarboxylic dianhydride and satisfying the following (1) to (2).
(1) The number average molecular weight (Mn1) of the polymer polyol (A) is the largest in the copolymer component (2) The number average molecular weight (Mn3) of the carboxylic acid group-containing polymer compound is the polymer polyol (A) The number average molecular weight (Mn1) is 1.7 times or less

  The polymer polyol (A) and / or polymer polyol (B) is preferably a polyester polyol or a polycarbonate polyol.

  An adhesive composition containing the carboxylic acid group-containing polymer compound. An adhesive sheet containing a cured product of the adhesive composition. A printed wiring board comprising the adhesive sheet as a constituent element.

  The carboxylic acid group-containing polymer compound of the present invention and the adhesive composition containing the carboxylic acid group-containing polymer compound are excellent in adhesion to various plastic films, metals such as copper, aluminum, stainless steel, and glass epoxy. Highly moist and heat-resistant (solder resistance) that can be used for lead-free soldering under high humidity while maintaining its properties.

<Polymer polyol (A)>
The polymer polyol (A) needs to have a number average molecular weight (Mn1) of 7,000 or more. Preferably it is 7,000 or more, More preferably, it is 8,000 or more, More preferably, it is 10,000 or more, Especially preferably, it is 12,000 or more. When Mn1 is less than 7,000, the crosslinking density increases, and the coating film obtained from the adhesive composition becomes hard, so the adhesion tends to decrease. In addition, since it becomes difficult to relieve the water vapor stress generated during humidification soldering, the resistance to humidification soldering tends to deteriorate. Further, Mn1 is preferably 50,000 or less, more preferably 40,000 or less, and further preferably 30,000 or less. If it is too large, crosslinking may be insufficient and heat resistance may be reduced.

  The acid value (mgKOH / g) of the polymer polyol (A) is not particularly limited, but is preferably 10 or less, more preferably 8 or less, and further preferably 6 or less. If it is low, there is no problem, but if it is too large, acid addition chain extension by tetracarboxylic dianhydride may not be possible. Therefore, since the reaction between the polymer polyols (B) proceeds, the crosslink density increases, and the coating film obtained from the adhesive composition becomes hard, so that the adhesion tends to decrease.

  The hydroxyl value (mgKOH / g) of the polymer polyol (A) is not particularly limited, but the maximum value is preferably 24 mgKOH / g or less, more preferably 21 mgKOH / g or less, and further preferably 16 mgKOH / g or less. Especially preferably, it is 14 mgKOH / g or less. If it is too large, the reaction becomes insufficient and heat resistance may not be exhibited. The minimum value is preferably 2 mgKOH / g or more, more preferably 3 mgKOH / g or more, and still more preferably 3.5 mgKOH / g or more. If it is too small, the crosslinking density is lowered, and heat resistance may not be exhibited.

  Although the glass transition temperature of a high molecular polyol (A) is not specifically limited, It is preferable that it is 0 degreeC or more, More preferably, it is 5 degreeC or more. If the glass transition temperature is too low, the tackiness of the adhesive composition becomes strong, and bubbles are likely to be caught and poorly bonded. Moreover, it is preferable that it is 60 degrees C or less, More preferably, it is 50 degrees C or less, More preferably, it is 40 degrees C or less, Most preferably, it is 30 degrees C or less. If the glass transition temperature is too high, the coating film becomes brittle and there is a concern that embrittlement becomes a problem.

<Polymer polyol (B)>
The polymer polyol (B) is a polyol different from the polymer polyol (A), and the number average molecular weight (Mn2) needs to be 1,000 or more. The difference from the polymer polyol (A) means that at least either the composition or the physical properties are different. The number average molecular weight (Mn2) is preferably 1,200 or more, more preferably 1,500 or more. If it is less than 1,000, the polymer polyol (B) can easily form a bond, so that it tends to have a low molecular weight and a high acid value, and a gel-like substance is likely to be generated in the crosslinked coating film. Further, it is preferably 10,000 or less, more preferably 8,000 or less, and further preferably 6,000 or less. If it is too large, the amount of carboxylic acid groups that can be imparted decreases, and the resulting coating film may have insufficient crosslinking density, resulting in insufficient heat resistance.

  The acid value (mgKOH / g) of the polymer polyol (B) is not particularly limited, but is preferably 10 or less, more preferably 8 or less, and further preferably 6 or less. If it is too high, it may become impossible to extend the acid addition chain with tetracarboxylic dianhydride.

  The hydroxyl value (mgKOH / g) of the polymer polyol (B) is not particularly limited, but the maximum value is preferably 120 mgKOH / g or less, more preferably 100 mgKOH / g or less, and still more preferably 80 mgKOH / g or less. is there. If the hydroxyl value is too high, the polymer polyols (B) are likely to be bonded to each other, so that a low molecular weight and a high acid value are obtained, and a gel-like product is likely to be generated in the coating film after crosslinking. The minimum value is preferably 11 mgKOH / g or more, more preferably 14 mgKOH / g or more, and still more preferably 18 mgKOH / g or more. If it is too low, acid addition chain extension by tetracarboxylic dianhydride may not be possible.

  The glass transition temperature of the polymer polyol (B) is not particularly limited, but in the case of a polyester polyol, it is preferably −20 ° C. or higher, more preferably −10 ° C. or higher, and further preferably 0 ° C. or higher. Yes, more preferably 10 ° C. or higher, particularly preferably 20 ° C. or higher, and most preferably 30 ° C. or higher. In the case of polycarbonate polyol, it is preferably −100 ° C. or higher, more preferably −90 ° C. or higher, still more preferably −80 ° C. or higher, and particularly preferably −70 ° C. or higher. If the glass transition temperature is too low, the tackiness of the adhesive composition tends to be strong, and bubbles are likely to bite and become defective during bonding. In the case of a polyester polyol, the temperature is preferably 80 ° C. or lower, more preferably 70 ° C. or lower, and further preferably 60 ° C. or lower. In the case of polycarbonate polyol, the temperature is preferably 0 ° C. or lower, more preferably −10 ° C. or lower, and further preferably −20 ° C. or lower. If the glass transition temperature is too high, the coating film becomes brittle and there is a concern that embrittlement becomes a problem.

  The number average molecular weight (Mn1) of the polymer polyol (A) needs to be larger than the number average molecular weight (Mn2) of the polymer polyol (B), and the difference in molecular weight is not particularly limited, but is 6,000 or more. It is preferable that there is, more preferably 8,000 or more, and still more preferably 10,000 or more. By providing the difference in molecular weight, it is possible to achieve improvement in the compatibility, heat resistance and humidification solder resistance of the carboxylic acid group-containing polymer compound. That is, the polymer polyol (A) can relieve the stress caused by water vapor generated during the evaluation of the humidification solder resistance by introducing a long chain block to increase the molecular weight. Moreover, since the amount of carboxylic acid groups can be adjusted by the short chain block of the polymer polyol (B), heat resistance can be imparted. Thereby, the improvement of heat resistance and humidification soldering resistance can be achieved. The upper limit of the difference in molecular weight is not particularly limited, but is preferably 50,000 or less, more preferably 40,000 or less, and still more preferably 30,000 or less.

  The polymer polyol (A) and / or polymer polyol (B) is not particularly limited, but is preferably a polyester polyol or a polycarbonate polyol. These can be used alone or in combination of two or more. When the same kind of polyol is used for both the polymer polyol (A) and the polymer polyol (B), phase separation is relatively difficult to occur, which is advantageous in that the reaction proceeds efficiently. On the other hand, by using a plurality of different types of polyols in combination, it becomes possible to impart characteristics that cannot be obtained when used alone. For example, improvement of hydrolysis resistance can be expected by using a polyester polyol for the polymer polyol (A) and a polycarbonate polyol for the polymer polyol (B). Preferably, both the polymer polyol (A) and the polymer polyol (B) are polyester polyols.

<Polyester polyol>
The polyester polyol is preferably composed of a polycarboxylic acid component and a polyol component. As the polycarboxylic acid component constituting the polyester polyol, when the total polycarboxylic acid is 100 mol%, the aromatic dicarboxylic acid is preferably contained in an amount of 60 mol% or more. More preferably, it is 70 mol% or more, More preferably, it is 80 mol% or more, and it may be 100 mol%. If the amount is too small, the cohesive force of the coating film is weak, and the adhesive strength to various substrates may be reduced.

  The aromatic dicarboxylic acid is not particularly limited, and examples thereof include terephthalic acid, isophthalic acid, orthophthalic acid, naphthalenedicarboxylic acid, biphenyldicarboxylic acid, and diphenic acid. Also, aromatic dicarboxylic acids having a sulfonic acid group such as sulfoterephthalic acid, 5-sulfoisophthalic acid, 4-sulfophthalic acid, 4-sulfonaphthalene-2,7-dicarboxylic acid, 5 (4-sulfophenoxy) isophthalic acid, And aromatic dicarboxylic acids having a sulfonate group such as metal salts and ammonium salts thereof. These can be used alone or in combination of two or more. Among these, terephthalic acid, isophthalic acid, and a mixture thereof are particularly preferable from the viewpoint of increasing the cohesive strength of the coating film.

  Other polycarboxylic acid components include 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, and alicyclic dicarboxylic acids such as acid anhydrides thereof, succinic acid, and adipic acid. And aliphatic dicarboxylic acids such as azelaic acid, sebacic acid, dodecanedioic acid and dimer acid. Further, 5-hydroxyisophthalic acid, p-hydroxybenzoic acid, p-hydroxyphenethyl alcohol, p-hydroxyphenylpropionic acid, p-hydroxyphenylacetic acid, 6-hydroxy-2-naphthoic acid, 4,4-bis (p An oxycarboxylic acid compound having a hydroxyl group and a carboxyl group in the molecular structure such as -hydroxyphenyl) valeric acid can also be used.

  As the polyol component constituting the polyester polyol, when the total polyol is 100 mol%, the glycol component is preferably 90 mol% or more, more preferably 95 mol% or more, and 100 mol%. There is no problem.

  The glycol component is preferably an aliphatic glycol, an alicyclic glycol, an aromatic-containing glycol, or an ether bond-containing glycol. Examples of aliphatic glycols include ethylene glycol, 1,2-propylene glycol, 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), hydroxypivalic acid neopentyl glycol ester, dimethylol heptane, 2,2,4-trimethyl-1,3-pentanediol and the like. Examples of alicyclic glycols include 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, tricyclodecanediol, tricyclodecane dimethylol, spiroglycol, hydrogenated bisphenol A, and hydrogenated bisphenol A. Examples thereof include an ethylene oxide adduct and a propylene oxide adduct. Examples of ether bond-containing glycols include diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, neopentyl glycol ethylene oxide adduct, and neopentyl glycol propylene oxide adduct. Can be mentioned. Examples of aromatic-containing glycols include para-xylene glycol, meta-xylene glycol, ortho-xylene glycol, 1,4-phenylene glycol, ethylene oxide adduct of 1,4-phenylene glycol, bisphenol A, ethylene oxide addition of bisphenol A Examples include glycols obtained by adding 1 to several moles of ethylene oxide or propylene oxide to two phenolic hydroxyl groups of bisphenols, such as a product and a propylene oxide adduct. These can be used alone or in combination of two or more. Of these, aliphatic glycols are preferred, 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 preferable.

  The polyester polyol may be copolymerized with a tri- or higher functional component in the polycarboxylic acid component and / or the polyol component for the purpose of introducing a branched skeleton if necessary. In the case of copolymerization, the total polycarboxylic acid component and the total polyol component are each 100 mol%, preferably 0.1 mol% or more, more preferably 0.5 mol% or more, and preferably 5 mol% or less. The mol% or less is more preferable. By making it within the above-mentioned range, particularly when a cured coating film is produced by reacting with a curing agent, a branched skeleton can be introduced, the terminal group concentration (reaction point) of the resin is increased, the crosslinking density is high, and the strength Can be obtained. On the other hand, if it exceeds 5 mol%, mechanical properties such as elongation at break of the coating film may be lowered, and gelation may occur during polymerization.

  Examples of tri- or higher functional polycarboxylic acid components include trimellitic acid, trimesic acid, ethylene glycol bis (anhydro trimellitate), glycerol tris (anhydro trimellitate), trimellitic anhydride, pyromellitic anhydride (PMDA), oxydiphthalic dianhydride (ODPA), 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride (BTDA), 3,3 ′, 4,4′-diphenyltetracarboxylic dianhydride Product (BPDA), 3,3 ′, 4,4′-diphenylsulfonetetracarboxylic dianhydride (DSDA), 4,4 ′-(hexafluoroisopropylidene) diphthalic dianhydride (6FDA), 2,2 Examples thereof include compounds such as' -bis [(dicarboxyphenoxy) phenyl] propane dianhydride (BSAA). On the other hand, examples of the trifunctional or higher polyol include glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol.

  An acid value may be introduced into the polyester polyol. The acid value of the polyester polyol is preferably 10 mgKOH / g or less, and more preferably 8 mgKOH / g or less. If it is low, there is no particular problem, but if it is too high, it may not be possible to extend the acid addition chain with tetracarboxylic dianhydride.

  Examples of the method for introducing the acid value include a method of introducing a carboxylic acid into a polyester polyol by acid addition after polymerization. If a monocarboxylic acid, dicarboxylic acid, or trifunctional or higher polycarboxylic acid compound is used for acid addition, the molecular weight may be reduced by transesterification. Therefore, a compound having at least one carboxylic anhydride group should be used. preferable. Carboxylic anhydrides include succinic anhydride, maleic anhydride, orthophthalic acid, 2,5-norbornene dicarboxylic acid anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride (PMDA), oxydiphthalic dianhydride Product (ODPA), 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride (BTDA), 3,3 ′, 4,4′-diphenyltetracarboxylic dianhydride (BPDA), 3,3 ', 4,4'-Diphenylsulfonetetracarboxylic dianhydride (DSDA), 4,4'-(hexafluoroisopropylidene) diphthalic dianhydride (6FDA), 2,2'-bis [(dicarboxyphenoxy ) Phenyl] propane dianhydride (BSAA) and the like.

<Polycarbonate polyol>
The polycarbonate polyol is a polyol having a carbonate bond, and is preferably a polycarbonate diol. A commercially available product can be used as the polycarbonate diol. Examples of the commercially available polycarbonate diol include trade names Duranol (registered trademark) T-4692 (number average molecular weight 2000), T-5562 (number average molecular weight 2000), T-5651 (number average molecular weight 1000) manufactured by Asahi Kasei Chemicals Corporation. , T-6002 (number average molecular weight 2000), CD-220 (number average molecular weight 2000), CD-220PL (number average molecular weight 2000), CD-220HL (number average molecular weight 2000), trade name Kuraray Polyol C manufactured by Kuraray Co., Ltd. -2050 (number average molecular weight 2000), C-2090 (number average molecular weight 2000), C-3090 (number average molecular weight 3000), trade name ETERNACOLL (registered trademark) UH-100 (number average molecular weight 1000) manufactured by Ube Industries, Ltd. , UH-200 (number average molecular weight 2000), PH-100 (number average The amount 1000), PH-200 (average molecular weight 2000), and the like. When a polyester polyol having a low glass transition temperature is used as the polymer polyol (B), it is disadvantageous in terms of hydrolyzability, but since an ester bond having poor hydrolyzability can be eliminated by using a polycarbonate polyol, It is considered possible to improve the hydrolyzability. The polycarbonate polyol is preferably a liquid from the viewpoint of workability, and the DURANOL (registered trademark) series is particularly preferable.

<Tetracarboxylic dianhydride>
Examples of the tetracarboxylic dianhydride include an aromatic tetracarboxylic dianhydride, an aliphatic tetracarboxylic dianhydride, and an alicyclic tetracarboxylic dianhydride, and an aromatic tetracarboxylic dianhydride is preferable. Specifically, for example, pyromellitic anhydride (PMDA), oxydiphthalic dianhydride (ODPA), 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride (BTDA), 3,3 ′, 4,4′-diphenyltetracarboxylic dianhydride (BPDA), 3,3 ′, 4,4′-diphenylsulfonetetracarboxylic dianhydride (DSDA), 4,4 ′-(hexafluoroisopropylidene) diphthalate Examples include acid dianhydride (6FDA) and 2,2′-bis [(dicarboxyphenoxy) phenyl] propane dianhydride (BSAA). These may be used alone or in combination of two or more. Of these, pyromellitic anhydride is preferable.

<Carboxylic acid group-containing polymer compound>
The carboxylic acid group-containing polymer compound of the present invention contains at least the polymer polyol (A), the polymer polyol (B) and tetracarboxylic dianhydride as a copolymer component, and (1) in the copolymer component, The number average molecular weight (Mn1) of the polymer polyol (A) is the largest, and (2) the number average molecular weight (Mn3) of the carboxylic acid group-containing polymer compound is the number average molecular weight (Mn1) of the polymer polyol (A). 1.7 times or less.

  In the present invention, a polymer polyol having two or more components including a polymer polyol (A) having a number average molecular weight of 7,000 or more and a polymer polyol (B) having a number average molecular weight of 1,000 or more is used as a copolymerization component, Furthermore, it is possible to improve heat resistance and humidification solder resistance by extending the chain using tetracarboxylic dianhydride. In other words, the short-chain polymer polyol (B) block is introduced while improving the resistance to humidification by relieving the stress of water vapor generated when evaluating the resistance to humidification soldering with the long-chain polymer polyol (A) block. By doing so, a sufficient amount of carboxylic acid for imparting heat resistance can be introduced. When the polymer polyol (A) alone is chain-extended with tetracarboxylic dianhydride, the molecular weight becomes long, and there are cases where the crosslinking necessary to withstand solder cannot be obtained. In addition, if a chain extender is used at that time, a reaction product between the chain extenders is easily generated due to the molar balance, and thus a gel-like product is likely to be generated in the cured coating film.

  The glass transition temperature of the carboxylic acid group-containing polymer compound is not particularly limited, and is preferably 0 ° C. or higher, more preferably 5 ° C. or higher, and further preferably 10 ° C. or higher. If the glass transition temperature is too low, the tackiness of the adhesive composition becomes strong, and bubbles are likely to be bitten and become defective during bonding. Moreover, it is preferable that it is 80 degrees C or less, More preferably, it is 70 degrees C or less, More preferably, it is 60 degrees C or less. If the glass transition temperature is too high, the coating film becomes brittle and there is a concern that embrittlement becomes a problem.

<Requirement (1)>
The requirement (1) will be described. Among the copolymer components of the carboxylic acid group-containing polymer compound, the number average molecular weight (Mn1) of the polymer polyol (A) needs to be maximum. As the copolymer component, in addition to the polymer polyol (A), the polymer polyol (B), and the tetracarboxylic dianhydride, for example, other polyol components and a chain extender described later can be arbitrarily used. However, it is necessary that the number average molecular weight (Mn1) of the polymer polyol (A) is the largest among the number average molecular weights of all copolymerization components including these. Since the number average molecular weight (Mn1) of the polymer polyol (A) is the maximum, the carboxylic acid group-containing polymer is copolymerized with the carboxylic acid group-containing polymer compound. The compound can exhibit excellent humidification soldering resistance.

<Requirement (2)>
The requirement (2) will be described. It is necessary that the number average molecular weight (Mn3) of the carboxylic acid group-containing polymer compound is 1.7 times or less than the number average molecular weight (Mn1) of the polymer polyol (A). That is, Mn3 / Mn1 ≦ 1.7. Preferably it is 1.6 times or less. When it exceeds 1.7 times, it is considered that the difference in molecular weight is small or the amount of tetracarboxylic dianhydride is excessive. Therefore, the carboxylic acid group content of the carboxylic acid group-containing polymer compound is insufficient and heat resistance is lowered, or the elastic modulus of the cured coating film is too high, and the adhesiveness is likely to be lowered. The lower limit of Mn3 / Mn1 is preferably 0.8 times or more, more preferably 0.9 times or more, and further preferably 1.0 times or more. If it is too small, there is a possibility that the reaction of only the polymer polyol (B) and the chain extender (tetracarboxylic dianhydride) has occurred, so the block of the polymer polyol (A) is sufficiently carboxylic dianhydride. There is a possibility that it will not react with the product, resulting in insufficient resistance to humidification soldering. As long as the carboxylic acid group-containing polymer compound is within the range of the number average molecular weight (Mn3 / Mn1), the polymer polyol (A) and the resin containing only the carboxylic dianhydride, or the polymer polyol (B) And a resin containing only carboxylic acid dianhydride.

  The acid value of the carboxylic acid group-containing polymer compound of the present invention is preferably 5 mgKOH / g or more, more preferably 10 mgKOH / g or more, and further preferably 15 mgKOH / g or more. Moreover, it is preferable that it is 100 mgKOH / g or less, More preferably, it is 60 mgKOH / g or less, More preferably, it is 40 mgKOH / g or less. If the acid value is too small, sufficient heat resistance may not be obtained due to insufficient crosslinking, and if the acid value is too high, the crosslinking density becomes too high, the cured coating film becomes hard, and adhesiveness may decrease. Moreover, the storage stability of the varnish which melt | dissolved the carboxylic acid group containing high molecular compound in the solvent falls, and a crosslinking reaction advances easily at normal temperature, and the stable sheet life may not be obtained.

  The carboxylic acid group-containing polymer compound of the present invention is not necessarily limited to the three components of the polymer polyol (A), the polymer polyol (B) and the tetracarboxylic dianhydride, and the fourth copolymer component. Other high molecular weight components can be used. Examples of the fourth copolymer component include a polymer polyol different from the polymer polyol (A) and the polymer polyol (B). When the fourth copolymer component is used, the number average molecular weight of the fourth copolymer component is preferably Mn1 or less of the polymer polyol (A) and Mn2 or more of the polymer polyol (B).

  The copolymerization ratio of the polymer polyol (A) and the polymer polyol (B) in the carboxylic acid group-containing polymer compound is 5 masses for 100 mass parts of the polymer polyol (A). It is preferably at least 10 parts by mass, more preferably at least 10 parts by mass, and even more preferably at least 20 parts by mass. Further, it is preferably 50 parts by mass or less, more preferably 40 parts by mass or less, and even more preferably 30 parts by mass or less. If the amount is too large, the moisture resistance solder resistance may be insufficient. The terminal which can react with a thing decreases, and heat resistance may become insufficient.

  In the carboxylic acid group-containing polymer compound, the copolymerization ratio of the polymer polyol (A) and tetracarboxylic dianhydride is 0.5% of tetracarboxylic dianhydride with respect to 100 parts by mass of the polymer polyol (A). The amount is preferably at least 1 part by mass, more preferably at least 1 part by mass, and even more preferably at least 2 parts by mass. Moreover, 10 mass parts or less are preferable, More preferably, it is 8 mass parts or less, More preferably, it is 5 mass parts or less. When too small, bridge | crosslinking may be insufficient and heat resistance may become insufficient, and when too large, it is a coating film. May become hard and sufficient adhesion may not be obtained.

  The copolymerization amount of the polymer polyol (A) in the carboxylic acid group-containing polymer compound is preferably 50% by mass or more, more preferably 60% by mass or more, and further preferably 70% by mass or more. By increasing the copolymerization amount of the polymer polyol (A), it is possible to expect improvement in humidification solder resistance. Moreover, it is preferable that it is 90 weight% or less, More preferably, it is 85 mass% or less, More preferably, it is 80 mass% or less. If the amount is too large, the copolymerization amount of the polymer polyol (B) or tetracarboxylic dianhydride may decrease, and the heat resistance and adhesion may decrease.

<Chain extender>
The carboxylic acid group-containing polymer compound has a chain in addition to the polymer polyol (A), polymer polyol (B), and tetracarboxylic dianhydride as a copolymerization component as long as the effects of the present invention are not impaired. An extender can optionally be used. An acid value can be efficiently provided by using a chain extender. When the chain extender is used, the amount of copolymerization is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, based on 100 parts by mass of the polymer polyol (A). Preferably it is 1 part by mass or more. Moreover, it is preferable that it is 5 mass parts or less, More preferably, it is 4 mass parts or less, More preferably, it is 3 mass parts or less. If the amount of copolymerization is too large, the molecular weight may be difficult to increase, the reaction between chain extenders may progress, and the varnish may become cloudy.

  The chain extender is preferably a low molecular diol having a molecular weight of 1000 or less, and examples thereof include 2,2-dimethyl-1,3-propanediol and dimethylolbutanoic acid. These can be used alone or in combination of two or more. Of these, 2,2-dimethyl-1,3-propanediol is preferred from the viewpoint of solubility and compatibility.

  The carboxylic acid group-containing polymer compound may use a quaternary ammonium salt or a tertiary amine as a reaction catalyst as long as the effects of the present invention are not impaired. For example, imidazole compounds such as 2-methylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenyl-4-methylimidazole, or 1-cyanoethyl-2-ethyl-4-methylimidazole; Triethylamine, triethylenediamine, N′-methyl-N- (2-dimethylaminoethyl) piperazine, N, N-diisopropylethylamine, N, N-dimethylaminopyridine, 1,8-diazabicyclo (5,4,0) -undecene Tertiary amines such as -7,1,5-diazabicyclo (4,3,0) -nonene-5, or 6-dibutylamino-1,8-diazabicyclo (5,4,0) -undecene-7, and the like Tertiary amines of phenol, octylic acid, or quaternized tetraphenylborate salts Compounds made into amine salts with: tetramethylammonium bromide, tetraethylammonium bromide, tetra-n-butylammonium bromide, tetramethylammonium chloride, trimethylbenzylammonium chloride, triethylbenzylammonium chloride, tetramethylammonium hydroxide, water And quaternary ammonium salts such as trimethylbenzylammonium oxide and tetra-n-butylammonium hydroxide.

<Adhesive composition>
The adhesive composition of the present invention contains at least the carboxylic acid group-containing polymer compound, and preferably contains an organic solvent or an epoxy resin (D).

  The adhesive composition preferably contains 20% by mass or more of the carboxylic acid group-containing polymer compound, more preferably 30% by mass or more, and still more preferably 40% by mass or more. Moreover, it is preferable that it is 90 mass% or less, More preferably, it is 85 mass% or less, More preferably, it is 80 mass% or less. If the amount is too small, the adhesiveness and heat-and-moisture resistance may decrease. If the amount is too large, the storage stability of the adhesive composition may decrease.

<Organic solvent>
The organic solvent is not particularly limited as long as it dissolves the carboxylic acid group-containing polymer compound, and more preferably dissolves the epoxy resin (D). Examples of the organic solvent include aromatic hydrocarbons such as benzene, toluene, and xylene, cycloaliphatic hydrocarbons such as cyclohexane, cyclohexene, methylcyclohexane, and ethylcyclohexane, methanol, ethanol, isopropyl alcohol, butanol, pentanol, hexanol, Alcohol solvents such as propanediol and phenol, acetone solvents such as methyl isobutyl ketone, methyl ethyl ketone, pentanone, hexanone, cyclohexanone, isophorone, and acetophenone, cell solvents such as methyl cellosolve and ethyl cellosolve, methyl acetate, ethyl acetate , Ester solvents such as butyl acetate, methyl propionate and butyl formate, and halogenated hydrocarbons such as trichloroethylene, dichloroethylene, chlorobenzene and chloroform Can be used, it can be used in combination of these one or more. Of these, a mixed solvent of an aromatic hydrocarbon and a ketone solvent 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 still more preferably 100 parts by mass or more with respect to 100 parts by mass of the carboxylic acid group-containing polymer compound. Moreover, it is preferable that it is 500 mass parts or less, More preferably, it is 400 mass parts or less, More preferably, it is 300 mass parts or less. If the amount is too small, the storage stability of the adhesive composition may be lowered. If the amount is too large, it may be industrially disadvantageous.

<Epoxy resin (D)>
The epoxy resin (D) is not particularly limited as long as it cures and crosslinks with the carboxyl group of the carboxylic acid group-containing polymer compound, but is a polyfunctional epoxy resin having a plurality of epoxy groups in one molecule. Is preferred. By using a polyfunctional epoxy resin, a cured coating film obtained from the adhesive composition can easily form a three-dimensional cross-link and improve heat resistance.
Examples of the polyfunctional epoxy resin include a cresol novolac type epoxy resin, an epoxy resin having a dicyclopentadiene skeleton, and a phenol novolac type epoxy resin. When it is a cresol novolac type epoxy resin or a phenol novolac type epoxy resin, the crosslink density of the cured coating film can be lowered to relieve the stress at the time of peeling, so that the moisture resistance soldering property is improved. Examples of commercially available products of cresol novolac type epoxy resin include YDCN-700 manufactured by DIC. On the other hand, an epoxy resin having a dicyclopentadiene skeleton has a rigid dicyclopentadiene skeleton, so the hygroscopic property of the cured coating becomes extremely small, the crosslinking density of the cured coating is lowered, and the stress at the time of peeling is reduced. Can be relaxed. Therefore, humidification solder resistance improves. As a commercially available product of an epoxy resin having a dicyclopentadiene skeleton, HP7200 series manufactured by DIC can be mentioned. These can be used alone or in combination of two or more.

  Furthermore, in addition to the polyfunctional epoxy resin, an epoxy resin containing a nitrogen atom can also be used. When an epoxy resin containing a nitrogen atom is used in combination, the coating film of the adhesive composition can be brought into a semi-cured state (hereinafter sometimes referred to as B stage) by heating at a relatively low temperature, and the B stage. There is a tendency that the workability in the bonding operation can be improved by suppressing the fluidity of the film. Moreover, since the effect which suppresses foaming of a B stage film can be anticipated, it is preferable. Examples of the epoxy resin containing a nitrogen atom include glycidylamines such as tetraglycidyldiaminodiphenylmethane, triglycidylparaaminophenol, tetraglycidylbisaminomethylcyclohexanone, N, N, N ′, N′-tetraglycidyl-m-xylenediamine, and the like. The system etc. are mentioned. It is preferable that the compounding quantity of the epoxy resin containing these nitrogen atoms is 20 mass% or less of the whole epoxy resin (D). When the blending amount is more than 20% by mass, the rigidity becomes excessively high and the adhesiveness tends to be lowered, and the crosslinking reaction tends to proceed during storage of the adhesive sheet, and the sheet life tends to be lowered. The upper limit of the more preferable amount is 10 mass%, More preferably, it is 5 mass%.

  Other epoxy resins can also be used in combination as the epoxy resin (D) used in the present invention. For example, glycidyl ether type such as bisphenol A diglycidyl ether, bisphenol S diglycidyl ether, brominated bisphenol A diglycidyl ether, glycidyl ester type such as hexahydrophthalic acid glycidyl ester, dimer acid glycidyl ester, triglycidyl isocyanurate, 3 , 4-epoxycyclohexylmethyl carboxylate, epoxidized polybutadiene, alicyclic or epoxides such as epoxidized soybean oil, and the like. These may be used alone or in combination of two or more.

  It is preferable that an epoxy resin (D) is 2 mass parts or more with respect to 100 mass parts of carboxylic acid group containing polymer compounds, More preferably, it is 5 mass parts or more. Moreover, it is preferable that it is 50 mass parts or less, More preferably, it is 30 mass parts or less, More preferably, it is 20 mass parts or less. If the amount is too small, curing may be insufficient, and adhesiveness and heat-and-moisture resistance may decrease. If the amount is too large, uncrosslinked epoxy resin may increase and heat resistance may decrease.

  In the present invention, a curing catalyst can be used for the curing reaction of the epoxy resin (D). For example, imidazole compounds such as 2-methylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenyl-4-methylimidazole, or 1-cyanoethyl-2-ethyl-4-methylimidazole; Triethylamine, triethylenediamine, N′-methyl-N- (2-dimethylaminoethyl) piperazine, 1,8-diazabicyclo (5,4,0) -undecene-7, 1,5-diazabicyclo (4,3,0) -Tertiary amines such as nonene-5 or 6-dibutylamino-1,8-diazabicyclo (5,4,0) -undecene-7 and these tertiary amines to phenol, octylic acid or quaternized Compounds converted to amine salts with tetraphenylborate salts, etc .; triallylsulfonium hexafluoroan Cationic catalysts such as timonate or diallyl iodonium hexafluoroantimonate; and triphenylphosphine. Of these, 1,8-diazabicyclo (5,4,0) -undecene-7, 1,5-diazabicyclo (4,3,0) -nonene-5, or 6-dibutylamino-1,8-diazabicyclo (5 , 4,0) -undecene-7 and the like, and compounds obtained by converting these tertiary amines into amine salts with phenol, octylic acid or quaternized tetraphenylborate salts are thermosetting and heat resistant. From the viewpoint of adhesion to metal and storage stability after blending. It is preferable that the compounding quantity of a curing catalyst is 0.01-1.0 mass part with respect to 100 mass parts of carboxylic acid group containing polymer compounds. If it is this range, the catalytic effect with respect to reaction of a carboxylic acid group containing high molecular compound and an epoxy resin (D) will increase further, and firm adhesive performance can be obtained.

<Other additives>
The adhesive composition of the present invention can further contain various curable resins and additives as long as the effects of the present invention are not impaired. Examples of the curable resin include phenolic resins, amino resins, isocyanate compounds, and silicone resins.

  Examples of the phenolic resin include formaldehyde condensates of alkylated phenols and cresols. Specifically, alkylated (eg, methyl, ethyl, propyl, isopropyl, butyl) phenol, p-tert-amylphenol, 4,4′-sec-butylidenephenol, p-tert-butylphenol, o-cresol, m -Cresol, p-cresol, p-cyclohexylphenol, 4,4'-isopropylidenephenol, p-nonylphenol, p-octylphenol, 3-pentadecylphenol, phenol, phenyl-o-cresol, p-phenylphenol, xylenol, etc. Formaldehyde condensates. These can be used alone or in combination of two or more.

  Examples of amino resins include formaldehyde adducts such as urea, melamine, and benzoguanamine, and alkyl ether compounds based on alcohols having 1 to 6 carbon atoms. Specific examples include methoxylated methylol urea, methoxylated methylol N, N-ethyleneurea, methoxylated methylol dicyandiamide, methoxylated methylol melamine, methoxylated methylol benzoguanamine, butoxylated methylol melamine, butoxylated methylol benzoguanamine and the like. Preferred are methoxylated methylol melamine, butoxylated methylol melamine, and methylolated benzoguanamine, each of which can be used alone or in combination.

  Isocyanate compounds include aromatic or aliphatic diisocyanates and trivalent or higher polyisocyanates, which may be either low molecular compounds or high molecular compounds. Examples thereof include tetramethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, and trimers of these isocyanate compounds. Further, an excess amount of these isocyanate compounds, for example, low molecular active hydrogen compounds such as ethylene glycol, propylene glycol, trimethylolpropane, glycerin, sorbitol, ethylenediamine, monoethanolamine, diethanolamine, or triethanolamine, or various polyester polyols, Examples thereof include terminal isocyanate group-containing compounds obtained by reacting polyether polyols, polyamides and other polymer active hydrogen compounds.

  The isocyanate compound may be a blocked isocyanate. Examples of the isocyanate blocking agent include phenols such as phenol, thiophenol, methylthiophenol, cresol, xylenol, resorcinol, nitrophenol, and chlorophenol; oximes such as acetoxime, methylethyl ketoxime, and cyclohexanone oxime; methanol, ethanol, propanol, Alcohols such as butanol; halogen-substituted alcohols such as ethylene chlorohydrin and 1,3-dichloro-2-propanol; tertiary alcohols such as t-butanol and t-pentanol; ε-caprolactam, δ-valero Examples include lactams such as lactam, γ-butyrolactam, and β-propyllactam. Other examples include aromatic amines, imides, active methylene compounds such as acetylacetone, acetoacetate ester, and malonic acid ethyl ester, mercaptans, imines, ureas, diaryl compounds, and sodium bisulfite. The blocked isocyanate is obtained by subjecting the above isocyanate compound, isocyanate compound and isocyanate blocking agent to an addition reaction by a conventionally known appropriate method.

  You may mix | blend a silane coupling agent with the adhesive composition of this invention as needed. It is very preferable to add a silane coupling agent because adhesion to metal and heat resistance are improved. Although it does not specifically limit as a silane coupling agent, What has an unsaturated group, What has a glycidyl group, What has an amino group, etc. are mentioned. Examples of the silane coupling agent having an unsaturated group include vinyltris (β-methoxyethoxy) silane, vinyltriethoxysilane, and vinyltrimethoxysilane. Examples of silane coupling agents having a glycidyl group include γ-glycidoxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and β- (3,4-epoxycyclohexyl) ethyltriethoxysilane. Etc. Examples of the silane coupling agent having an amino group include N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane, N-phenyl-γ. -Aminopropyltrimethoxysilane etc. can be mentioned. Among these, from the viewpoint of heat resistance, γ-glycidoxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysilane, etc. A silane coupling agent having a glycidyl group is preferred. It is preferable that the compounding quantity of a silane coupling agent is 0.5-20 mass parts with respect to 100 mass parts of carboxylic acid group containing high molecular compounds. When the blending amount of the silane coupling agent is less than 0.5 parts by mass, the resulting adhesive composition may have poor heat resistance, and when it exceeds 20 parts by mass, heat resistance or adhesion may be poor. There is.

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

<Adhesive sheet>
In this invention, an adhesive sheet contains the coating film (henceforth an adhesive bond layer) of the adhesive composition obtained by hardening the adhesive composition of this invention. The adhesive sheet has a function of adhering a base material to an adherend by an adhesive layer. The base material of the adhesive sheet functions as a protective layer for the adherend after adhesion. When a release substrate is used, the release substrate can be released and the adhesive layer can be transferred to another adherend. The adhesive sheet is obtained by applying the adhesive composition to a substrate or a release substrate, drying, and curing. Specific configurations include a base material / adhesive layer, a release base material / adhesive layer, a release base material / adhesive layer / base material, a release base material / adhesive layer / release base material, etc. Is mentioned. Moreover, depending on the case, the adhesive agent layer which peeled the mold release base material independently may be sufficient. The adhesive sheet may contain a trace amount or a small amount of an organic solvent.

  The adhesive sheet can be obtained by applying the adhesive composition of the present invention to various substrates according to a conventional method, removing at least a part of the solvent, and drying. In addition, after removing at least a part of the solvent and drying, pasting the release substrate to the adhesive layer makes it possible to roll up without causing the substrate to be transferred to the substrate, and is excellent in operability and adhesion. Since the agent layer is protected, it is excellent in storage stability and easy to use. In addition, after applying and drying on the release substrate, if another release substrate is attached as necessary, the adhesive layer itself can be transferred to another substrate.

  The substrate is not particularly limited, and examples thereof include a film-like resin, a metal plate, a metal foil, and papers. Examples of the film-like resin include polyester resin, polyamide resin, polyimide resin, polyamideimide resin, and olefin resin. Examples of metal plate and metal foil materials include various metals such as SUS, copper, aluminum, iron, and zinc, and alloys and plated products thereof. Glassine paper etc. can be illustrated. Moreover, glass epoxy etc. can be illustrated as a composite material. Polyester resin, polyamide resin, polyimide resin, polyamideimide resin, SUS steel plate, copper foil, aluminum foil, and glass epoxy are preferable from the viewpoint of adhesive strength between the substrate and the adhesive composition and durability.

  The release substrate is not particularly limited. For example, a coating layer of a sealant such as clay, polyethylene, or polypropylene is provided on both surfaces of paper such as fine paper, kraft paper, roll paper, and glassine paper. Furthermore, those in which a silicone-type, fluorine-type, or alkyd-type release agent is applied on each of the coating layers. In addition, various olefin films such as polyethylene, polypropylene, ethylene-α-olefin copolymer, propylene-α-olefin copolymer, and those obtained by applying the release agent on a film such as polyethylene terephthalate can be used. For the reasons such as the release force between the release substrate and the adhesive layer, and the adverse effect of silicone on the electrical characteristics, polypropylene seal treatment is applied to both sides of the fine paper and an alkyd release agent is used on it. Or what uses an alkyd type mold release agent on polyethylene terephthalate is preferred.

  It does not specifically limit as a method of coating an adhesive composition on a base material or a mold release base material, A comma coater, a reverse roll coater, etc. are mentioned. Alternatively, if necessary, an adhesive layer can be provided directly or by a transfer method on a rolled copper foil, which is a printed wiring board constituent material, or a polyimide film. Although the thickness of the adhesive bond layer after drying is changed suitably as needed, Preferably it is the range of 5-200 micrometers. If the thickness of the adhesive layer is less than 5 μm, the adhesive strength may be insufficient. If it exceeds 200 μm, the drying is insufficient, the residual solvent is increased, and there is a problem that blisters are generated at the time of printing printed circuit board production. The drying conditions are not particularly limited, but the residual solvent ratio after drying is preferably 4% by mass or less, and more preferably 1% by mass or less. If it exceeds 4% by mass, there may be a problem that the residual solvent is foamed when the printed wiring board is pressed to cause swelling.

<Printed wiring board>
The printed wiring board in the present invention includes an adhesive sheet as a constituent element, and more specifically, a laminate (metal foil / adhesive layer / resin base) formed of a metal foil and a resin base material forming a conductor circuit. Material) as a component. A printed wiring board is manufactured by conventionally well-known methods, such as a subtractive method, using a metal-clad laminated body, for example. If necessary, a so-called flexible circuit board (FPC), flat cable, tape automated bonding (covered by using a cover film or screen printing ink, etc., partially or entirely covered with a conductor circuit formed of metal foil (tape automated bonding) TAB) circuit board and the like.

  The printed wiring board of the present invention can have any laminated structure that can be employed as a printed wiring board. For example, it can be set as the printed wiring board comprised from four layers, a base film layer, a metal foil layer, an adhesive bond layer, and a cover film layer. For example, it can be set as the printed wiring board comprised from five layers, a base film layer, an adhesive bond layer, a metal foil layer, an adhesive bond layer, and a cover film layer. The printed wiring board may be reinforced with a reinforcing material as necessary. In that case, the reinforcing material and the adhesive layer are provided under the base film layer.

  Furthermore, if necessary, a configuration in which two or three or more of the above-described printed wiring boards are stacked may be employed.

  The adhesive composition of the present invention can be suitably used for 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 the base material constituting the printed wiring board and can impart high heat resistance that can also be used for lead-free solder. Is possible. In particular, in the high-temperature range where solder resistance is evaluated, the chemical cross-linking between the resin and the resin and the physical cross-linking between the resin and the inorganic filler are provided in a well-balanced manner. It is possible to relieve stress without swelling or deformation. Therefore, it is suitable for bonding between the metal foil layer and the cover film layer, and bonding between the base film layer and the reinforcing material layer. In particular, when a metal reinforcing material such as a SUS plate or an aluminum plate is used, moisture cannot evaporate from the reinforcing material side when soldering in a humidified state, so the adhesive layer between the base film layer and the reinforcing material layer is used. The impact exerted is particularly strong and is suitable as an adhesive composition used for adhesion in such a case.

  The inorganic filler used in the present invention is not particularly limited. For example, alumina, silica, titania, tantalum oxide, zirconia, silicon nitride, barium titanate, barium carbonate, lead titanate, lead zirconate titanate, titanium Lead lanthanum zirconate, gallium oxide, spinel, mullite, cordierite, talc, aluminum hydroxide, magnesium hydroxide, aluminum titanate, yttria-containing zirconia, barium silicate, boron nitride, calcium carbonate, calcium sulfate, zinc oxide Zinc borate, magnesium titanate, magnesium borate, barium sulfate, organic bentonite, carbon, and the like can be used, and these may be used alone or in combination of two or more. Silica is preferable from the viewpoint of transparency, mechanical properties, and heat resistance of the adhesive composition, and fumed silica having a three-dimensional network structure is particularly preferable. In addition, hydrophobic silica treated with monomethyltrichlorosilane, dimethyldichlorosilane, hexamethyldisilazane, octylsilane, silicone oil or the like is more preferable for imparting hydrophobicity. When using fumed silica as the inorganic filler, the average diameter of the primary particles is preferably 30 nm or less, more preferably 25 nm or less. When the average diameter of the primary particles exceeds 30 nm, the interaction between the particles and the resin tends to decrease, and the heat resistance tends to decrease. In addition, the average diameter of a primary particle said here is an average value of the circle equivalent diameter of 100 particle | grains extracted randomly from the primary particle image obtained using the scanning electron microscope.

  As for the compounding quantity of an inorganic filler, 10 mass parts or more are preferable with respect to 100 mass parts of carboxylic acid group containing polymer compounds, More preferably, it is 13 mass parts or more, More preferably, it is 15 mass parts or more. If it is less than 10 parts by mass, the effect of improving heat resistance may not be exhibited. Moreover, it is preferable that it is 50 mass parts or less, More preferably, it is 45 mass parts or less, More preferably, it is 40 mass parts or less. If it exceeds 50 parts by mass, the inorganic filler may be poorly dispersed, the solution viscosity may become too high, resulting in problems in workability, or the adhesiveness may be lowered.

  In the printed wiring board of the present invention, as the substrate film, any resin film conventionally used as a substrate for printed wiring boards can be used. As the resin for the base film, a resin containing halogen may be used, or a resin not containing halogen may be used. From the viewpoint of environmental problems, a resin containing no halogen is preferable. However, from the viewpoint of flame retardancy, a resin containing halogen can also be used. The base film is preferably a polyimide film or a polyamideimide film.

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

  Although there is no limitation in particular about the thickness of metal foil, Preferably it is 1 micrometer or more, More preferably, it is 3 micrometers or more, More preferably, it is 10 micrometers or more. Moreover, it is preferably 50 μm or less, more preferably 30 μm or less, and still more preferably 20 μm or less. If the thickness is too thin, it may be difficult to obtain sufficient electrical performance of the circuit. On the other hand, if the thickness is too thick, the processing efficiency at the time of circuit fabrication may be reduced.

  The 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 a roll-shaped metal foil is used, its length is not particularly limited. The width is not particularly limited, but is preferably about 250 to 1000 mm.

  As the cover film, any conventionally known insulating film can be used as an insulating film for a printed wiring board. For example, films produced from various polymers such as polyimide, polyester, polyphenylene sulfide, polyethersulfone, polyetheretherketone, aramid, polycarbonate, polyarylate, polyimide, and polyamideimide can be used. More preferably, it is a polyimide film or a polyamidoimide film, More preferably, it is a polyimide film.

  As the material resin for the cover film, a resin containing halogen may be used, or a resin not containing halogen may be used. From the viewpoint of environmental problems, a resin containing no halogen is preferable. However, from the viewpoint of flame retardancy, a resin containing halogen can also be used.

  The printed wiring board of the present invention can be produced using any conventionally known process except that the material of each layer described above is used.

  In a preferred embodiment, a semi-finished product in which an adhesive layer is laminated on a cover film layer (hereinafter referred to as “cover film-side semi-finished product”) is produced. On the other hand, an adhesive layer is laminated on a semi-finished product (hereinafter referred to as “base film side two-layer semi-product”) or a base film layer in which a desired circuit pattern is formed by laminating a metal foil layer on the base film layer. And a semi-finished product (hereinafter referred to as “base film side three-layer semi-product”) having a desired circuit pattern formed by laminating a metal foil layer thereon (hereinafter referred to as base film side two-layer semi-product) The base film side three-layer semi-finished product is collectively referred to as “base film side semi-finished product”). A four-layer or five-layer printed wiring board can be obtained by laminating the cover film side semi-finished product and the base film side semi-finished product thus obtained.

  The base film side semi-finished product includes, for example, (A) a step of applying a solution of a resin to be a base film to the metal foil, and initial drying of the coating film, and (B) the metal foil obtained in (A) It can be obtained by a production method including a step of heat-treating and drying the laminate with the initial dry coating film (hereinafter referred to as “heat treatment / solvent removal step”).

  A conventionally known method can be used to form a circuit in the metal foil layer. An active method may be used and a subtractive method may be used. The subtractive method is preferable.

  The obtained base film side semi-finished product may be used as it is for pasting with the cover film side semi-finished product. May be used.

  The cover film side semi-finished product is manufactured, for example, by applying an adhesive to the cover film. If necessary, a crosslinking reaction in the applied adhesive can be performed. In a preferred embodiment, the adhesive layer is semi-cured.

  The obtained cover film-side semi-finished product may be used as it is for pasting with the base-side semi-finished product, or after being laminated and stored with the release film for pasting with the base-film-side semi-finished product. May be used.

  The base film-side semi-finished product and the cover film-side semi-finished product are each stored, for example, in the form of a roll and then bonded to produce a printed wiring board. Arbitrary methods can be used as a method of bonding, for example, it can bond using a press or a roll. Moreover, both can also be bonded together, heating by the method of using a heating press or a heating roll apparatus.

  The base film side semi-finished product, the cover film side semi-finished product, and the reinforcing agent side semi-finished product are all laminated bodies for printed wiring boards in the present invention.

  Although the adhesive composition of the present invention is suitably used for each adhesive layer of a printed wiring board, it is excellent in adhesion to various base materials and moisture and heat resistance. By containing conductive powder, it can be used for electromagnetic shielding applications, touch panel and electronic component circuit forming applications, terminals and lead wire conductive adhesives, and the like.

  In order to describe the present invention in more detail, examples and comparative examples are given below, but the present invention is not limited to the examples. In addition, each measured value described in the Example and the comparative example was measured by the following method. Unless otherwise specified, “part” means “part by mass” and “%” means “% by mass”.

(Physical property evaluation method)
(1) Composition of carboxylic acid group-containing polymer compound The carboxylic acid group-containing polymer compound was dissolved in deuterated chloroform, and the molar ratio of each component was determined by 1H-NMR analysis.

(2) Number average molecular weight (Mn)
A sample (carboxylic acid group-containing polymer compound, polymer polyol (A) or polymer polyol (B)) was dissolved or diluted in tetrahydrofuran so that the sample concentration was about 0.5% by mass, and the pore size was 0.5 μm. A sample for measurement was filtered through a polytetrafluoroethylene membrane filter. The number average molecular weight was measured by gel permeation chromatography using tetrahydrofuran as the mobile phase and a differential refractometer as the detector. The flow rate was 1 mL / min and the column temperature was 30 ° C. As the column, KF-802, 804L and 806L manufactured by Showa Denko were used. Monodisperse polystyrene was used as the molecular weight standard. However, when the sample did not dissolve in tetrahydrofuran, N, N-dimethylformamide was used instead of tetrahydrofuran. Low molecular compounds (oligomers and the like) having a number average molecular weight of less than 500 were omitted without counting.

(3) Glass transition temperature With a differential scanning calorimeter “DSC220 type” manufactured by Seiko Denshi Kogyo Co., Ltd., 5 mg of a measurement sample is put in an aluminum pan, sealed with a lid, and once held at 250 ° C. for 5 minutes. Then, it was rapidly cooled with liquid nitrogen, and then measured from −150 ° C. to 250 ° C. at a temperature rising rate of 20 ° C./min. The inflection point of the obtained curve was taken as the glass transition temperature. When there were two or more inflection points, it was considered that block copolymerization was performed, and each mutation point was read and handled as having a plurality of glass transition temperatures.
(4) Acid value 0.2 g of a sample (carboxylic acid group-containing polymer compound, polymer polyol (A) or polymer polyol (B)) is dissolved in 20 ml of chloroform, and phenolphthalein is used as an indicator. Titrated with 1N potassium hydroxide ethanol solution. From this titration amount, the acid number (mgKOH / g) was calculated by converting the number of mg of KOH consumed for neutralization into the amount per 1 g of resin.

(5) Solder resistance, peel strength (5) -1 Evaluation sample preparation method After drying an adhesive composition described later on a polyimide film having a thickness of 12.5 μm (manufactured by Kaneka Corporation, Apical (registered trademark)). The adhesive film (B stage product) was obtained by applying the coating material leaving a tensile allowance so that the thickness of the film became 25 μm and drying at 140 ° C. for 5 minutes. The adhesive film was bonded so that the glossy surface of 20 μm rolled copper foil was in contact with the adhesive layer surface of the adhesive film, and pressed and bonded at 160 ° C. under a pressure of 35 kgf / cm ² for 30 seconds. Subsequently, it was cured by heat treatment at 140 ° C. for 4 hours to obtain a sample for evaluation of solder resistance and peel strength.

(5) -2 Evaluation method of each characteristic Each characteristic was evaluated by the following method.
Dry solder resistance: The sample for evaluation was allowed to stand in an environment of 120 ° C. for 30 minutes, then floated in a heated solder bath for 1 minute, and the upper limit temperature at which swelling did not occur was measured at a pitch of 10 ° C. Specifically, starting from 260 ° C., the temperature was increased to 360 ° C. in steps of 270 ° C., 280 ° C. and 10 ° C.
In this test, a higher measured value indicates better heat resistance. In consideration of practical performance, 350 ° C. or higher is preferable, and 360 ° C. or higher is more preferable.
Evaluation criteria A: No swelling even at 360 ° C. or higher.
○: It does not swell at less than 340 ° C, but swells at 340 ° C or more and less than 360 ° C
(Triangle | delta): Although it does not swell at less than 330 degreeC, it swells at 330 degreeC or more and less than 340 degreeC.
×: Swelling occurs at less than 330 ° C.

Solder resistance (humidification): The sample for evaluation was allowed to stand at 40 ° C. and 80% humidification for 3 days, then floated in a heated solder bath for 1 minute, and the upper limit temperature at which swelling did not occur was measured at a pitch of 10 ° C. Specifically, starting from 220 ° C., the temperature was increased to 300 ° C. in steps of 230 ° C., 240 ° C. and 10 ° C. In this test, it shows that the higher the measured value has better heat resistance, but it is also necessary to suppress the impact due to evaporation of water vapor contained in each base material and adhesive layer, rather than the dry state, More severe heat resistance is required. In consideration of practical performance, 260 ° C. or higher is preferable, and 270 ° C. or higher is more preferable.
Evaluation criteria ○: No swelling even at 270 ° C or higher.
Δ: Swelling occurs at 260 ° C. or higher and lower than 270 ° C.
X: Swells at less than 260 ° C.

Peel strength: A sample for evaluation was drawn at 25 ° C., a polyimide film was drawn, a 90 ° peel test was conducted at a tensile speed of 50 mm / min, and the peel strength was measured. This test shows the adhesive strength at room temperature. In view of practical performance, it is preferably 7 N / cm or more, more preferably 10 N / cm or more.
Evaluation criteria A: 15 N / cm or more B: 10 N / cm or more, less than 15 N / cm Δ: 7 N / cm or more, less than 10 N / cm ×: less than 7 N / cm

Polymerization example of polymer polyol (A1) In a reaction can equipped with a stirrer, a thermometer, and a condenser for outflow, 189 parts of terephthalic acid, 435 parts of isophthalic acid, 7 parts of trimellitic anhydride, 2-methyl-1, Charge 110 parts of 3-propanediol, 483 parts of 1,6-hexanediol and 0.2 part of tetrabutyl titanate, gradually raise the temperature to 250 ° C., and perform the esterification reaction while removing the distilled water out of the system. It was. After completion of the esterification reaction, initial polymerization was carried out while gradually reducing the pressure to 10 mmHg, the temperature was raised to 250 ° C., and further, late polymerization was carried out at 1 mmHg or less until a predetermined stirring torque was reached. Thereafter, the pressure was returned to normal pressure with nitrogen, 28 parts of trimellitic anhydride was added, and the mixture was reacted at 220 ° C. for 30 minutes to obtain a polymer polyol (A1). The composition and characteristic values of the polymer polyol (A1) thus obtained are shown in Table 1. Each measurement evaluation item followed the above-mentioned method.

Polymerization example of polymer polyol (B1) In a reaction vessel equipped with a stirrer, a thermometer, and a condenser for outflow, 390 parts of terephthalic acid, 390 parts of isophthalic acid, 367 parts of ethylene glycol, 2,2-dimethyl-1, 362 parts of 3-propanediol and 0.2 part of tetrabutyl titanate were charged, the temperature was gradually raised to 250 ° C., and the esterification reaction was performed while removing distilled water out of the system. After completion of the esterification reaction, the polymer polyol (B1) is polymerized by performing initial polymerization under reduced pressure while gradually reducing the pressure to 10 mmHg, raising the temperature to 250 ° C., and further performing late polymerization until a predetermined stirring torque is reached at 1 mmHg or less. Got. Table 1 shows the composition and characteristic values of the polymer polyol (B1) thus obtained. Each measurement evaluation item followed the above-mentioned method.

  Polymer polyols (A2) and (B2) were obtained in the same manner as the polymer polyol (A1). The polymer polyol (A3) was obtained by the same method as the polymer polyol (B1). These characteristic values are shown in Table 1.

As the polymer polyols (B3) and (B4), those shown below were used.
Polymer polyol (B3): Polycarbonate diol T5652 (number average molecular weight 2000) manufactured by Asahi Kasei Corporation
Polymer polyol (B4): Kuraray Co., Ltd. polyester polyol P2010 (number average molecular weight 2000)
Polymer polyol (B5): Polycarbonate diol T5651 (number average molecular weight 1000) manufactured by Asahi Kasei Corporation

Synthesis Example of Carboxylic Acid Group-Containing Polymer Compound (C1) In a reaction can equipped with a stirrer, thermometer, and reflux tube, 160 parts of polymer polyol (A1), 40 parts of polymer polyol (B1), pyromellitic anhydride 5.2 parts of acid and 200 parts of toluene were charged and dissolved in toluene while gradually raising the temperature to 80 ° C. After the dissolution was completed, 0.1 part of triethylamine was added as a reaction catalyst, and then the temperature was gradually raised to 105 ° C. and reacted for 24 hours. After confirming the completion of the reaction by IR, a solution with a solid content concentration of 40% of the carboxylic acid group-containing polymer compound (C1) was obtained by diluting with 108 parts of toluene. The composition and characteristic values of the carboxylic acid group-containing polymer compound (C1) thus obtained are shown in Table 2. Each measurement evaluation item followed the above-mentioned method.

<Synthesis Examples of Carboxylic Acid Group-Containing Polymer Compound (C2) to (C10)>
The carboxylic acid group-containing polymer compounds (C2) to (C10) were obtained in the same manner as in Synthesis Example (C1) of the carboxylic acid group-containing polymer compound. However, for (C6), (C8), and (C9), 2,2-dimethylpropanediol was added at the preparation stage. Others are the same as the synthesis example (C1) of the carboxylic acid group-containing polymer compound.

<Example 1>
To 100 parts of the solid content of the carboxylic acid group-containing polymer compound (C1), 9 parts of YDCN-700-10 (Novolac type epoxy resin) manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. and TETRAD manufactured by Mitsubishi Gas Chemical Co., Ltd. are used as epoxy resins. Add 0.1 part of (registered trademark) -X (N, N, N ′, N′-tetraglycidyl-m-xylenediamine), adjust the solid content concentration to 35% using methyl ethyl ketone, and bond An agent composition was obtained. The obtained adhesive composition was evaluated by the method shown below. The results are shown in Table 3.

<Examples 2-8, Comparative Examples 1-6>
The carboxylic acid group-containing polymer compound and the epoxy resin were changed to those shown in Table 3, and were changed to the respective compounding amounts shown in Table 3 in the same manner as in Example 1. Examples 1-6 were performed. The results are shown in Table 3.

  According to the examples in Table 3, it can be seen that the resin of the present invention has a drying soldering resistance of 340 ° C. or higher and is excellent in the humidification soldering resistance.

  As in Comparative Examples 1 and 6, when the number average molecular weight of the polymer polyol is relatively small as 6000 and 2000, the distance between the cross-linking points is shortened, so that the coating film becomes hard and peel strength and moisture resistance solder resistance Decreases.

  As in Comparative Examples 2 and 3, when the polymer polyol (B) is not used, a gel-like material is generated, and the humidification solder resistance and peel strength are lowered.

As in Comparative Example 4, when the polymer polyol (A) was not used, a coating film could not be produced (film formation).
As in Comparative Example 5, when the molecular weight of the carboxylic acid group-containing polymer compound (C) was too large, the fluidity was lowered and a coating film could not be created.

  As in Example 6, there is no problem using a small amount of chain extender.

  The carboxylic acid group-containing polymer compound of the present invention and the adhesive composition containing the carboxylic acid group-containing polymer compound are excellent in adhesion to various plastic films, metals such as copper, aluminum, stainless steel, and glass epoxy. High degree of moisture and heat resistance that can be used for lead-free soldering under high humidity while maintaining its properties. Therefore, it is particularly useful as an adhesive for circuit boards including FPC.

Claims (6)

A polymer polyol (A) having a number average molecular weight (Mn1) of 7,000 or more as a copolymerization component;
A polymer polyol (B) having a number average molecular weight (Mn2) different from that of the polymer polyol (A) of 1,000 or more;
At least tetracarboxylic dianhydride,
Carboxylic acid group-containing polymer compound satisfying the following (1) to (2).
(1) The number average molecular weight (Mn1) of the polymer polyol (A) is the largest in the copolymer component (2) The number average molecular weight (Mn3) of the carboxylic acid group-containing polymer compound is the polymer polyol (A) The number average molecular weight (Mn1) is 1.7 times or less   The carboxylic acid group-containing polymer compound according to claim 1, wherein the polymer polyol (A) and / or the polymer polyol (B) is a polyester polyol or a polycarbonate polyol.   The carboxylic acid group-containing polymer compound according to claim 1 or 2, wherein the acid value is 5 to 100 mgKOH / g.   The adhesive composition containing the carboxylic acid group containing high molecular compound in any one of Claims 1-3.   An adhesive sheet containing a cured product of the adhesive composition according to claim 4.   A printed wiring board comprising the adhesive sheet according to claim 5 as a constituent element.