JP2010150463A - Curable urethane resin, curable resin composition including the resin and method of producing curable urethane resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a curable urethane resin used suitably as an adhesive and a coating agent excellent in adhering property, heat resistance, flexibility, bending property, adhesiveness, electrical insulation, moist thermal resistance or the like, in particular, extremely excellent in the uniting of adhering property and electrical insulation and the uniting of bending property and heat resistance. <P>SOLUTION: The curable urethane resin is made by reacting a terminal acid anhydride group-containing urethane prepolymer (C) with a hydroxide group-containing resin (D), wherein the terminal acid anhydride group-containing urethane prepolymer (C) is a prepolymer made by reacting a terminal isocyanate group-containing urethane prepolymer (A) prepared by reacting a polymer polyol (a1) with a diisocyanate compound (a2), with tetrabasic acid anhydride (B), and the hydroxide group-containing resin (D) is a resin made by reacting a compound (d1) having at least two epoxy groups with a bisphenol compound (d2). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a curable urethane resin useful as an adhesive and a coating agent, a curable resin composition containing the resin, and a method for producing the curable urethane resin. More specifically, adhesion, heat resistance, flexibility, flexibility, adhesion, electrical insulation, moisture and heat resistance are particularly useful as adhesives and coating agents used around electronic materials such as printed wiring boards. The present invention relates to a curable urethane resin, a curable resin composition containing the resin, and a method for producing the curable urethane resin.

  In recent years, the development of the electronics field has been remarkable, and in particular, electronic devices have become smaller, lighter, and higher in density, and demands for these performances have become increasingly sophisticated. In order to meet such demands, thinning, multilayering, and high definition of electronic materials including printed wiring boards are being actively studied. Adhesives and coating agents used in these materials , High flexibility, flexibility, adhesion, and high electrical insulation, adhesion, heat, etc. associated with the narrowing of space, which were not required for conventional rigid substrates such as glass epoxy Stability etc. are required. Specific examples of the adhesive / coating agent used around the electronic material include the following (1) to (5).

  (1) Interlayer adhesive: Used to bond circuit boards together and directly contacts a copper circuit. It is used between the layers of a multilayer substrate, and there are liquid and sheet-like ones.

  (2) Coverlay film adhesive: used to bond a coverlay film (such as a polyimide film used for the purpose of protecting the outermost surface of a circuit) and an underlying circuit board; In many cases, the adhesive layer is integrated.

  (3) Adhesive for copper-clad film (CCL): used to bond polyimide film and copper foil together. Processing such as etching is performed when the copper circuit is formed.

  (4) Coverlay: used for the purpose of protecting the outermost surface of the circuit, and is formed by applying or bonding to the circuit and then curing. Some are photosensitive and thermosetting.

  (5) Adhesive for reinforcing plate: For the purpose of complementing the mechanical strength of the wiring board, it is used to fix a part of the wiring board to a reinforcing plate made of metal, glass epoxy, polyimide or the like.

  These forms include liquid form and sheet form (previously formed into a film), and the form is appropriately selected according to the application.

  Various studies have been made in order to meet such high demands on electronic material peripheral members, but no material that sufficiently satisfies all the characteristics has been obtained.

  For example, an adhesive composition mainly comprising an acid value-containing polyester / polyurethane and an epoxy resin is disclosed (Patent Document 1). Although this shows good adhesiveness derived from urethane bonds, it has poor heat resistance because it is difficult to form sufficient crosslinks because the distance between the crosslinks is long, and the amount of epoxy resin is increased to supplement this. In such a case, there is a problem that wettability to the substrate is lowered and adhesive strength is lowered. Furthermore, since the polyester skeleton is used as the main chain, there is a problem that the insulation reliability at high temperature humidification is remarkably inferior.

  Moreover, the adhesive composition containing a urethane modified carboxyl group containing polyester resin, an epoxy resin, and a hardening | curing agent is disclosed (patent document 2). Although this shows good adhesiveness derived from urethane bonds, it has poor heat resistance, and due to the low molecular weight of the urethane resin, there is a poor workability that many protrusions occur when thermosetting with a press or the like. It was a problem. Further, as in Patent Document 1, since the polyester skeleton is used as the main chain, there is a problem that the insulation reliability at high temperature humidification is extremely inferior.

  Moreover, the resin composition containing a polyimide siloxane, a both-ends epoxy siloxane, and a hardening | curing agent is disclosed (patent document 3). Although this system has flexibility specific to siloxane resins and excellent heat resistance, the siloxane skeleton itself has poor adhesion to the substrate, so that sufficient adhesion can be obtained by curing with epoxysiloxane having a low crosslinking density. The problem is that it is not possible, and because the distance between the cross-linking points of the epoxy group is large, the problem of poor workability that many protrusions occur when thermosetting with a press or the like is a problem. Further, since the compatibility with other components is remarkably poor, there is a problem that the degree of freedom in designing the composition is poor and the coating film has insufficient resistance as a composition.

  Also disclosed is a thermosetting resin composition mainly composed of an epoxy resin, an NBR rubber containing as little ionic impurities as possible, and a nitrogen-containing phenol novolac resin (Patent Document 4). This adhesive composition has the disadvantages that many NBR rubber-derived protrusions occur when it is heat-cured with a press or the like, and the processability is poor. In addition, if a large amount of epoxy resin or phenol is added to compensate for this, There was a problem that decreased. Furthermore, NBR rubber with as little ionic impurities as possible is expensive and sometimes difficult to use industrially.

  Moreover, the resin composition containing an epoxy resin, a phenol resin, the hardening accelerator for epoxy resins, and an elastomer is disclosed (patent document 5). In this case as well, there is a problem that it is difficult to simultaneously improve the processability deterioration derived from the elastomer and the decrease in adhesive strength derived from the epoxy / phenol curing system.

In addition, proposals have been made focusing on polybutadiene, which is a flexible skeleton. For example, a polyimide resin having a polybutadiene skeleton is disclosed, and an example in which a resin composition containing the polyimide resin, a polybutadiene polyol, and a blocked isocyanate is used as an overcoat agent for a flexible circuit is disclosed (Patent Document 6). . In this case, since the distance between the cross-linking points with the blocked isocyanate is large, the problem of poor workability that a large amount of protrusion occurs during hot pressing is a problem. Moreover, a resin composition (Patent Document 7) in which a polyamidoimide resin having a polybutadiene skeleton and a polysiloxane skeleton and an epoxy resin are blended, or a resin composition (Patent Document 8) in which a polyimide resin having a polybutadiene skeleton and an epoxy resin are blended. It is disclosed. However, since these resins also have a large distance between cross-linking points with an epoxy group, there is a problem of poor workability that a lot of protrusion occurs during hot pressing.
JP-A-11-116930 JP 2007-51212 A JP 2004-91648 A JP 2003-165898 A JP 2007-161811 A JP-A-11-199669 JP 11-246760 A JP 2003-292575 A

  The present invention is extremely advantageous in terms of adhesiveness, heat resistance, flexibility, flexibility, adhesion, electrical insulation, moisture and heat resistance, etc., particularly compatibility between adhesiveness and electrical insulation, and compatibility between flexibility and heat resistance. Excellent curable urethane resin, curable resin composition containing the resin, and curable urethane resin that are suitably used as adhesives and coating agents used around electronic materials including printed wiring boards It aims at providing the manufacturing method of.

As a result of intensive studies, the present inventors have found that a specific curable urethane resin can solve the above problems, and have completed the present invention. That is, the first invention of the present invention is a curable urethane resin obtained by reacting a terminal acid anhydride group-containing urethane prepolymer (C) and a hydroxyl group-containing resin (D),
The terminal isocyanate group-containing urethane prepolymer (C) obtained by reacting the polymer polyol (a1) and the diisocyanate compound (a2) with the terminal acid anhydride group-containing urethane prepolymer (C), a tetrabasic acid anhydride ( B) is a prepolymer obtained by reacting with
The present invention relates to a curable urethane resin, wherein the hydroxyl group-containing resin (D) is a resin obtained by reacting a compound (d1) having two or more epoxy groups with a bisphenol compound (d2).

  The second invention relates to the curable urethane resin according to the first invention, wherein the polymer polyol (a1) is at least one compound selected from polycarbonate polyol, polyether polyol, polybutadiene polyol, and polysiloxane polyol.

  The third invention relates to the curable urethane resin of the first or second invention, wherein the terminal isocyanate group-containing urethane prepolymer (A) has a urea bond.

  The fourth invention relates to the curable urethane resin according to any one of the first to third inventions having an acid value of 1 to 150 mgKOH / g.

  The fifth invention relates to the curable urethane resin according to any one of the first to fourth inventions having a weight average molecular weight of 5,000 to 500,000.

  The sixth invention relates to a curable resin composition comprising the curable urethane resin of any one of the first to fifth inventions and the epoxy group-containing compound (E).

  The seventh invention further relates to the curable resin composition of the sixth invention, further comprising a thermosetting aid (F).

  The eighth invention further relates to the curable resin composition of the sixth or seventh invention, further comprising a thermosetting compound (G).

The ninth invention is a first step of obtaining a terminal isocyanate group-containing urethane prepolymer (A) by reacting the polymer polyol (a1) with the diisocyanate compound (a2),
Second step of obtaining terminal acid anhydride group-containing urethane prepolymer (C) by reacting terminal isocyanate group-containing urethane prepolymer (A) obtained in the first step with tetrabasic acid anhydride (B). ,
A third step of obtaining a hydroxyl group-containing resin (D) by reacting a compound (d1) having two or more epoxy groups with a bisphenol compound (d2);
In addition, the terminal acid anhydride group-containing urethane prepolymer (C) obtained in the second step and the hydroxyl group-containing resin (D) obtained in the third step are reacted to obtain a curable urethane resin. The present invention relates to a method for producing a curable urethane resin comprising four steps.

  According to the present invention, adhesion, heat resistance, flexibility, flexibility, adhesion, electrical insulation, moisture and heat resistance, etc., especially in terms of compatibility of adhesion and electrical insulation, compatibility of flexibility and heat resistance Excellent curable urethane resin, curable resin composition containing the resin, and curable urethane resin that are suitably used as adhesives and coating agents used around electronic materials including printed wiring boards We were able to provide a manufacturing method.

The curable urethane resin of the present invention reacts a terminal isocyanate group-containing urethane prepolymer (A) obtained by reacting a polymer polyol (a1) and a diisocyanate compound (a2) with a tetrabasic acid anhydride (B). A terminal acid anhydride group-containing urethane prepolymer (C), and
It is a curable urethane resin obtained by reacting a hydroxyl group-containing resin (D) obtained by reacting a compound (d1) having two or more epoxy groups with a bisphenol compound (d2).

  In particular, the compound to be reacted with the terminal acid anhydride group-containing urethane prepolymer (C) is obtained by reacting a compound (d1) having two or more epoxy groups with a bisphenol compound (d2) (D ), Physical properties that are very important as adhesives and coating agents used around printed circuit boards and other electronic materials, such as storage stability before curing, processing stability during curing, after curing Solder heat resistance, solder heat resistance after humidification, etc. can be remarkably improved. It is possible to increase the molecular weight by reacting the terminal acid anhydride group-containing urethane prepolymer (C) with the hydroxyl group-containing resin (D), and simultaneously introduce a carboxyl group into the main chain. Since this functions as a new thermal crosslinking point, the workability and the heat resistance of the cured coating film can be remarkably improved.

  For example, when the terminal acid anhydride group-containing urethane prepolymer (C) is used as it is as a curable urethane resin, it is generally adhered to a certain degree due to the adhesiveness derived from the urethane bond and the crosslinking of the terminal acid anhydride group. Strength and heat resistance can be obtained, but higher solder heat resistance such as high-temperature solder test and solder test in a humidified state cannot be satisfied. In order to solve these problems, generally, a resin having a high Tg (Tg: glass transition temperature) skeleton or a curing agent having a high Tg skeleton is added. In these cases, the entire adhesive layer has a high Tg, Adhesive strength is remarkably reduced due to a decrease in adhesion to the material.

  On the other hand, the curable urethane resin of the present invention contains a hydroxyl group containing a terminal acid anhydride group-containing urethane prepolymer (C) and a compound (d1) having two or more epoxies and a bisphenol compound (d2). By making it react with resin (D), high molecular weight and the carboxyl group which is a thermosetting functional group can be newly introduce | transduced in a hydroxyl-containing resin (D) unit. The hydroxyl group-containing resin (D) in which a thermosetting functional group is present due to the effect of such high molecular weight and new introduction of a carboxyl group which is a thermosetting functional group into the hydroxyl group-containing resin (D) unit. In the vicinity of the unit portion, the crosslink density is particularly high, and high heat resistance can be exhibited while maintaining good processing stability and high adhesive force.

  In addition, the curable urethane resin of the present invention has higher electrical insulation properties by using at least one compound selected from polycarbonate polyol, polyether polyol, polysiloxane polyol, and polybutadiene diol, particularly as the polymer polyol (a1). And heat resistance, and at the same time, due to the effects of the hydroxyl group-containing resin (D) used, it exhibits high adhesion even when using a polycarbonate skeleton or polysiloxane skeleton, which are generally considered difficult to adhere to a substrate. be able to.

  For example, in general, when a skeleton having excellent heat resistance such as polycarbonate or polysiloxane is used in order to ensure electrical insulation, adhesion to a base material is lowered, so that adhesive strength cannot be ensured. On the other hand, the present invention can solve the trade-off between high electrical insulation and adhesive strength for the above reasons.

  Moreover, the curable urethane resin of this invention can further improve adhesive force and heat resistance by introduce | transducing a urea bond suitably in a terminal acid anhydride group containing urethane prepolymer (C). Specifically, the introduction of a urea bond increases the cohesive strength of the resin layer, resulting in adhesion and heat resistance without any adverse effects on storage stability, processing stability, flexibility, and electrical insulation. Can be improved.

  Furthermore, since the curable urethane resin of the present invention has a hydroxyl group, it is newly introduced into the hydroxyl group-containing resin (D) unit in the curable urethane resin by suitably reacting the acid anhydride group-containing compound. Carboxyl groups can be introduced to adjust the acid value in the resin. Specifically, since the viscoelastic properties of the cured coating film can be controlled by arbitrarily adjusting the carboxyl group, which is a thermosetting functional group, both excellent adhesion and heat resistance must be achieved. Can do.

  Hereinafter, the curable urethane resin of the present invention, a curable resin composition containing the curable urethane resin, and a method for producing the curable urethane resin will be described in detail.

  First, the terminal acid anhydride group-containing urethane prepolymer (C) will be described. The terminal acid anhydride group-containing urethane prepolymer (C) includes a terminal isocyanate group-containing urethane prepolymer (A) obtained by reacting the polymer polyol (a1) and the diisocyanate compound (a2), a tetrabasic acid anhydride ( It is produced by reacting with B). Further, as a desired component, a hydroxyl group-containing compound (a3) [excluding those belonging to the “polymer polyol (a1)”], an isocyanate compound (a4) having one or more isocyanate groups in the molecule, an amine Compound (a5) can be used as appropriate.

  In the present invention, when the terminal isocyanate group-containing urethane prepolymer (A) is synthesized, the ratio of the reaction of the starting materials is the polymer polyol (a1), the hydroxyl group-containing compound (a3) optionally added, and the amine compound. With regard to (a5), when the total of the hydroxyl group and amino group contained therein is 1 mol, the diisocyanate compound (a2) and an isocyanate compound having one or more isocyanate groups in the molecule to be optionally added (a4) ) Is preferably reacted at a ratio of 1.00 mol to 2.00 mol, more preferably at a ratio of 1.00 mol to 1.95 mol.

  When the isocyanate group is less than 1.00 mol, the amount of the terminal isocyanate group of the terminal isocyanate group-containing urethane prepolymer (A) decreases, and the reaction with the next tetrabasic acid anhydride (B) is sufficient. Is difficult to occur and may cause gelation during the reaction. Moreover, when there are more isocyanate groups than 2.00 mol, the low isocyanate component (a2) produces | generates with an excess isocyanate compound (a2), and the problem may arise in the surface of workability that many protrusions generate | occur | produce at the time of hot press.

  The polymer polyol (a1) used in the present invention is a compound having a repeating unit having a degree of polymerization of 2 or more and containing two or more hydroxyl groups, and gel permeation chromatography (hereinafter also referred to as “GPC”). The weight average molecular weight in terms of polystyrene measured is preferably a compound having a molecular weight of 500 to 50,000. Examples of the polymer polyol (a1) include polyester polyols, polyether polyols, polycarbonate polyols, polysiloxane polyols, and polybutadiene diols. In the present application, unless otherwise specified, the weight average molecular weight means a polystyrene-reduced weight average molecular weight by GPC measurement.

  Known polyester polyols can be used as the polyester polyols used in the present invention. Examples of the polyester polyol include a polyester polyol obtained by condensation reaction of a polyfunctional alcohol component and a dibasic acid component. Among the polyfunctional alcohol components, diols include ethylene glycol, propylene glycol, dipropylene glycol, diethylene glycol, triethylene glycol, butylene glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 3,3 '-Dimethylol heptane, polyoxyethylene glycol, polyoxypropylene glycol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, octanediol, butylethylpentanediol, 2-ethyl-1,3- Hexanediol, cyclohexanediol, bisphenol A and the like are mentioned, and examples of the polyfunctional alcohol component having three or more hydroxyl groups include glycerin, trimethylolpropane, pentaerythritol and the like. It is.

  Examples of the dibasic acid component include aliphatic or aromatic dibasic acids such as terephthalic acid, adipic acid, azelaic acid, sebacic acid, phthalic anhydride, isophthalic acid, trimellitic acid, and anhydrides thereof.

  Β-butyrolactone, β-propiolactone, γ-butyrolactone, γ-valerolactone, δ-valerolactone, ε-caprolactone, γ-caprolactone, γ-heptanolactone, α-methyl-β-propiolactone, etc. Polyester polyols obtained by ring-opening polymerization of cyclic ester compounds such as lactones can also be used.

Known polyether polyols can be used as the polyether polyols used in the present invention. For example, polymers, copolymers, and graft copolymers of alkylene oxides such as tetrahydrofuran, ethylene oxide, propylene oxide, butylene oxide;
Polyether polyols obtained by condensation of hexanediol, methylhexanediol, heptanediol, octanediol or mixtures thereof;
Those having two or more hydroxyl groups can be used.

  The polycarbonate polyols used in the present invention have a structure represented by the following general formula (1) in the molecule, and known polycarbonate polyols can be used.

General formula (1)
− [— O—R ⁸ —O—CO—] _m —
(In the formula, R ⁸ represents a divalent organic residue, and m represents an integer of 1 or more.)

  The polycarbonate polyol can be obtained, for example, by (1) a reaction between glycol or bisphenol and a carbonate ester, or (2) a reaction in which phosgene is allowed to act on glycol or bisphenol in the presence of an alkali.

  Specific examples of the carbonic acid ester used in the production method (1) include dimethyl carbonate, diethyl carbonate, diphenyl carbonate, ethylene carbonate, and propylene carbonate.

  Specific examples of glycols or bisphenols used in the production methods (1) and (2) include ethylene glycol, propylene glycol, dipropylene glycol, diethylene glycol, triethylene glycol, butylene glycol, and 3-methyl-1,5-pentanediol. 2-methyl-1,8-octanediol, 3,3′-dimethylolheptane, polyoxyethylene glycol, polyoxypropylene glycol, propanediol, 1,3-butanediol, 1,4-butanediol, 1, 5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, neopentyl glycol, octanediol, butylethylpentanediol, 2-ethyl-1,3-hexanediol, cyclohexanediol It can be used bisphenols such as bisphenol A, bisphenol F, ethylene oxide to the bisphenols, also bisphenols obtained by adding an alkylene oxide such as propylene oxide. These compounds can be used as one kind or a mixture of two or more kinds.

  Specifically, the Kuraray polyol C series of Kuraray Co., Ltd. can be used in the polycarbonate polyol. Among these, PMHC-1050, PMHC-2050, C-1090, C-2090, C-1065N, C-2065N, C-1015N, and C-2015N are preferable because of their flexibility.

  Examples of the polysiloxane polyols used in the present invention include compounds represented by general formulas (2) and (3).

  General formula (2)

(X represents a hydroxyl group, R ¹ and R ² each represent an alkylene group having 1 to 6 carbon atoms, and n represents an integer of 5 or more.)

  General formula (3)

(Y represents a hydroxyl group, R ³ is an alkyl group having 1 to 6 carbon atoms, R ⁴ , R ⁵ and R ⁶ are each an alkylene group having 1 to 6 carbon atoms, and R ⁷ is a hydrogen atom or 1 to 1 carbon atoms. 6 represents an alkyl group, and n represents an integer of 5 or more.)

  As the polybutadiene polyols used in the present invention, known polybutadiene polyols can be used, and those containing hydrogenated unsaturated bonds in the molecule are also included. For example, polyethylene polyol, polypropylene polyol, polybutadiene polyol, hydrogenated polybutadiene polyol, polyisoprene polyol, hydrogenated polyisoprene polyol and the like can be mentioned.

Specifically, in polybutadiene polyol, liquid polybutadiene having hydroxyl groups at both ends, such as NISSSO PB (G series) manufactured by Nippon Soda Co., Ltd., Poly-Pd manufactured by Idemitsu Petrochemical Co., Ltd .;
Hydrogenated polybutadiene having hydroxyl groups at both ends, such as NISSSO PB (GI series) manufactured by Nippon Soda Co., Ltd., polytail H, polytail HA, etc. manufactured by Mitsubishi Chemical Corporation;
Liquid C5 polymer having hydroxyl groups at both ends, such as Poly-iP manufactured by Idemitsu Petrochemical Co., Ltd .;
Idemitsu Petrochemical Co., Ltd.'s Epaul, Kuraray Co., Ltd.'s TH-1, TH-2, TH-3, and the like include hydrogenated polyisoprene having hydroxyl groups at both ends, but are not limited thereto. Absent.

  Among these polymer polyols (a1), polycarbonate polyols using only 1,6-hexanediol as glycol, and 1,6-hexanediol and 3-methyl-1,5-pentanediol as glycol are used. Polycarbonate diol, polycarbonate diol, polytetramethylene glycol, polypropylene glycol, or tetramethylene glycol and neopentyl glycol using 1,9-nonanediol and 2-methyl-1,8-octanediol as glycol Copolyether polyols, polysiloxane polyols, polybutadiene polyols, etc. are excellent in flexibility of the skeleton, heat resistance, and hydrolysis resistance. Flexibility, heat resistance, excellent moisture resistance and the like, especially preferred.

  In the present invention, these polymer polyols (a1) may be used alone or in combination.

  As a diisocyanate compound (a2) used by this invention, C4-C50 aromatic diisocyanate, aliphatic diisocyanate, araliphatic diisocyanate, alicyclic diisocyanate etc. can be mentioned, for example.

  Examples of the aromatic diisocyanate include 1,3-phenylene diisocyanate, 4,4′-diphenyl diisocyanate, 1,4-phenylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6- Tolylene diisocyanate, 4,4'-toluidine diisocyanate, 2,4,6-triisocyanate toluene, 1,3,5-triisocyanate benzene, dianisidine diisocyanate, 4,4'-diphenyl ether diisocyanate, 4,4 ', 4 "-Triphenylmethane triisocyanate etc. can be mentioned.

  Examples of the aliphatic diisocyanate include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, 2 4,4-trimethylhexamethylene diisocyanate and the like.

  Examples of the araliphatic diisocyanate include ω, ω′-diisocyanate-1,3-dimethylbenzene, ω, ω′-diisocyanate-1,4-dimethylbenzene, ω, ω′-diisocyanate-1,4-diethylbenzene, Examples thereof include 1,4-tetramethylxylylene diisocyanate and 1,3-tetramethylxylylene diisocyanate.

  Examples of the alicyclic diisocyanate include 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate [alias: isophorone diisocyanate], 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane. Diisocyanate, methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 4,4′-methylenebis (cyclohexyl isocyanate), 1,3-bis (isocyanatemethyl) cyclohexane, 1,4-bis (isocyanate methyl) ) Cyclohexane and the like.

  In the present invention, aromatic diisocyanate or araliphatic diisocyanate is preferably used when the heat resistance of the target curable urethane resin is particularly improved, and the flexibility of the target curable urethane resin is particularly improved. It is preferable to use aliphatic diisocyanate or alicyclic diisocyanate. In the present invention, these diisocyanate compounds (a2) can be appropriately selected and used according to the purpose and application, or only one kind may be used alone or a plurality may be used in combination.

  The hydroxyl group-containing compound (a3) optionally used in the present invention is a compound having one or more hydroxyl groups, but is a compound excluding the compound belonging to the “polymer polyol (a1)”, and representative examples thereof include, for example, Monoalcohol compound (a3-1) having one hydroxyl group in the molecule, diol compound (a3-2) having two hydroxyl groups in the molecule, compound (a3-3) having three or more hydroxyl groups in the molecule ). These may have both a hydroxyl group and a functional group other than a hydroxyl group in the molecule. Moreover, you may use individually and may use it in combination of multiple.

Examples of the monoalcohol compound (a3-1) having one hydroxyl group in the molecule include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, tertiary butanol, lauryl alcohol, stearyl alcohol and the like. Aliphatic monoalcohols;
Alicyclic monoalcohols such as cyclohexanol;
Aromatic monoalcohols such as benzyl alcohol and fluorenol;
Phenols such as phenol and methoquinone;
Examples of monoalcohol compounds having functional groups other than hydroxyl groups include hydroxyl group-containing carboxylic acid compounds such as 12-hydroxystearic acid, 2-hydroxyethyl (meth) acrylate (“2-hydroxyethyl acrylate” and “2-hydroxyethyl methacrylate” And the like, the same shall apply hereinafter), a hydroxyl group-containing (meth) acrylate compound such as 4-hydroxybutyl (meth) acrylate, a hydroxyl group-containing epoxy compound such as glycidol, Examples include hydroxyl group-containing oxetane compounds such as oxetane alcohol. Other examples include oligomer-type monoalcohols such as one-end methoxylated polyethylene glycol, one-end methoxylated polypropylene glycol, and caprolactone addition polymer using monoalcohol as an initiator.

  In the present invention, when a monoalcohol compound (a3-1) having one hydroxyl group in these molecules is used, the polymerization terminal of the obtained terminal isocyanate group-containing urethane prepolymer (A) can be sealed, It can be suitably used when the molecular weight needs to be adjusted, for example, when a low molecular weight terminal isocyanate group-containing urethane prepolymer (A) is intentionally synthesized. Further, when a hydroxyl group-containing compound having a functional group other than a hydroxyl group is used, a functional group other than an isocyanate group can be introduced into the terminal of the terminal isocyanate group-containing urethane prepolymer (A). It can be suitably used when terminal modification of the prepolymer (A) is required. In the present invention, in consideration of hydroxyl reactivity and polymerization control, lauryl alcohol, stearyl alcohol, cyclohexanol, 12-hydroxystearic acid, glycidol, 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, etc. Is preferably used.

Examples of the diol compound (a3-2) having two hydroxyl groups in the molecule include ethylene glycol, propylene glycol, dipropylene glycol, diethylene glycol, triethylene glycol, 2-methyl-1,3-propanediol, 2-methyl-2-ethyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 2-methyl-2-propyl-1,3-propanediol, 2-butyl-2-methyl -1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, 2-methyl -2,4-pentanediol, 1,3,5-trimethyl-1,3-pentanediol, 2-methyl-1,8-o Tandiol, 3,3′-dimethylolheptane, polyoxyethylene glycol (addition mole number 10 or less), polyoxypropylene glycol (addition mole number 10 or less), propanediol, 1,3-butanediol, 1,4-butane Diol, 1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, neopentyl glycol, octanediol, 3-butyl-3-ethyl-1,5-pentanediol, 2-ethyl-1 Aliphatic or alicyclic diols such as 1,6-hexanediol, cyclohexanediol, cyclohexanedimethanol, tricyclodecanedimethanol, cyclopentadienedimethanol, dimer diol, hydrogenated bisphenol A, spiroglycol, etc .;
1,3-bis (2-hydroxyethoxy) benzene, 1,2-bis (2-hydroxyethoxy) benzene, 1,4-bis (2-hydroxyethoxy) benzene, 4,4′-methylenediphenol, 4, 4 ′-(2-norbornylidene) diphenol, 4,4′-dihydroxybiphenol, o-, m-, and p-dihydroxybenzene, 4,4′-isopropylidenephenol, 1,2-indanediol, 1,3 -Naphthalenediol, 1,5-naphthalenediol, 1,7-naphthalenediol, 9,9'-bis (4-hydroxyphenyl) fluorene, 9,9'-bis (3-methyl-4-hydroxyphenyl) fluorene or Alkylene oxides such as ethylene oxide and propylene oxide on bisphenol A and bisphenol F And aromatic diols such as bisphenols comprising by addition or the like. Other examples include sulfur atom-containing diols and bromine atom-containing diols.

  Moreover, the compound which has functional groups other than a hydroxyl group is also mentioned as a diol compound (a3-2) which has two hydroxyl groups in a molecule | numerator. In addition to the hydroxyl group, examples of the compound containing a tertiary amino group include N, N-bis (2-hydroxypropyl) aniline, N, N-bis (2-hydroxyethyl) aniline, N, N-bis (2 -Hydroxyethyl) methylamine, N, N-bis (2-hydroxyethyl) propylamine, N, N-bis (2-hydroxyethyl) butylamine, N, N-bis (2-hydroxyethyl) hexylamine, N, Tertiary amino group-containing diol compounds such as N-bis (2-hydroxyethyl) octylamine, N, N-bis (2-hydroxyethyl) benzylamine, and N, N-bis (2-hydroxyethyl) cyclohexylamine are listed. Examples of the compound containing a carboxyl group include dimethylolbutanoic acid and dimethylolpropionic acid. And derivatives thereof (caprolactone adduct, ethylene oxide adduct, propylene oxide adduct, etc.), 3-hydroxysalicylic acid, 4-hydroxysalicylic acid, 5-hydroxysalicylic acid, 2-carboxy-1,4-cyclohexanedimethanol, etc. It is done.

  Among these, dimethylolbutanoic acid and dimethylolpropionic acid are preferable in the present invention in that the concentration of carboxyl groups in the resin can be increased. Further, by using a tertiary amino group-containing diol compound such as N, N-bis (2-hydroxypropyl) aniline, the cohesive force of the coating film is increased, and the flexibility is further improved while maintaining flexibility. It is preferable because a tough coating film can be formed.

  Examples of the compound having three or more hydroxyl groups in the molecule (a3-3) include, for example, trimethylolethane, polytrimethylolethane, trimethylolpropane, polytrimethylolpropane, pentaerythritol, polypentaerythritol, sorbitol, Mannitol, arabitol, xylitol, galactitol, glycerin and the like can be mentioned.

  In this invention, when using the compound (a3-3) which has three or more hydroxyl groups in these molecules, since a part of terminal isocyanate group containing urethane prepolymer (A) obtained can be branched, hardened | cured material The crosslink density of can be increased, and the resistance of the cured coating film can be improved. Therefore, in the present invention, it may be used as necessary for the purpose of further improving the resistance of the cured coating film. Among these compounds (a3-3) having 3 or more hydroxyl groups in the molecule, it is preferable to use trimethylolpropane or pentaerythritol in terms of reaction control.

  As an isocyanate compound (a4) having one or more isocyanate groups in the molecule, which is optionally used in the present invention, monofunctional isocyanate having one isocyanate group in one molecule is, for example, (meth) acryloyl Examples thereof include oxyethyl isocyanate, 1,1-bis [(meth) acryloyloxymethyl] ethyl isocyanate, vinyl isocyanate, allyl isocyanate, (meth) acryloyl isocyanate, isopropenyl-α, α-dimethylbenzyl isocyanate. In addition, 1,6-diisocyanatohexane, isophorone diisocyanate, 4,4′-diphenylmethane diisocyanate, polymeric diphenylmethane diisocyanate, xylylene diisocyanate, tolylene 2,4-diisocyanate, toluene diisocyanate, 2,4-diisocyanic acid Toluene, hexamethylene diisocyanate, 4-methyl-m-phenylene diisocyanate, naphthylene diisocyanate, paraphenylene diisocyanate, tetramethylxylylene diisocyanate, cyclohexylmethane diisocyanate, hydrogenated xylylene diisocyanate, cyclohexyl diisocyanate, tolidine diisocyanate, 2,2 , 4-Trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate Nitrate, m-tetramethylxylylene diisocyanate, p-tetramethylxylylene diisocyanate, diisocyanate compounds such as diisocyanate diisocyanate and hydroxyl group, carboxyl group, or amide group-containing vinyl monomers are reacted in equimolar amounts. Can be mentioned.

  Examples of the polyfunctional isocyanate (a4) having 3 or more isocyanate groups in one molecule include aliphatic polyisocyanates such as aromatic polyisocyanates and lysine triisocyanates, araliphatic polyisocyanates, and alicyclic polyisocyanates. Isocyanate etc. are mentioned, The trimethylol propane adduct body of the diisocyanate compound (a2) mentioned above, the burette body which reacted with water, and the trimer which has an isocyanurate ring are mentioned.

  In the present invention, when it is desired to reduce the unreacted hydroxyl group remaining at the terminal of the terminal isocyanate group-containing urethane prepolymer (A), a monofunctional isocyanate having one isocyanate group in one molecule is used for the purpose of sealing the terminal. In the case where the terminal isocyanate group-containing urethane prepolymer (A) is branched for the purpose of improving the resistance of a coating film obtained by heat curing from the curable resin composition according to the present invention, 1 is preferable. It is preferable to use a polyfunctional isocyanate having three or more isocyanate groups in the molecule. In the present invention, these isocyanate compounds can be appropriately selected and used according to the purpose and application, and only one kind may be used alone or a plurality may be used in combination.

  Furthermore, in the present invention, when the terminal isocyanate group-containing urethane prepolymer (A) is synthesized, it is preferable to react the amine compound (a5) as a desired component. As a result, urea bonds can be introduced into the resulting curable urethane resin, and the cohesive force, adhesive force, and heat resistance of the cured coating film can be significantly improved. In the present invention, the amine compound (a5) is used. More preferably it is used. The amine compound (a5) in the present invention refers to a compound having at least one primary or secondary amino group in the molecule.

  As the amine compound (a5) of the present invention, for example, propylamine, hexylamine, cyclohexylamine, benzylamine, 2-ethylhexylamine, octylamine, dodecylamine, monoamine compounds such as aniline, ethylenediamine, propylenediamine, trimethylene Diamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, triethylenetetramine, diethylenetriamine, triaminopropane, 2,2,4-trimethylhexamethylenediamine, tolylenediamine, hydrazine, piperazine and other aliphatic polyamines, isophoronediamine , Cycloaliphatic polyamines such as dicyclohexylmethane-4,4′-diamine, and phenylenediamine, xylylenediamine, 4,4′-diaminodiphe An aromatic polyamine of ether, and the like.

  Also, diamine compounds such as both-end amino group-modified polyethylene oxide, both-end amino group-modified polypropylene oxide, polysilicone diamine, and polybutadiene diamine, one-end amino group-modified polyethylene oxide, one-end amino group-modified polypropylene oxide, polysilicon monoamine, Examples thereof include monoamine compounds such as polybutadiene monoamine, and polymer type polyamine compounds such as polyethyleneimine and polyallylamine.

  Further, as the amine compound (a5), the primary amino group in the compound having a primary amino group is modified to a secondary amino group by Michael addition reaction with the (meth) acryloyl group of the (meth) acryloyl group-containing compound. The amine compound obtained by doing this is mentioned. When such a compound is used, a polar functional group can be introduced into the terminal isocyanate group-containing urethane prepolymer (A) by appropriately selecting the (meth) acryloyl group-containing compound. For example, a diamine having a secondary amino group is synthesized by Michael addition of the acryloyl group of 4-hydroxybutyl acrylate to the primary amino group of isophorone diamine, and used as a raw material for the urethane resin of the present invention. Hydroxyl groups can be introduced therein.

  Moreover, the amine compound which has functional groups other than an amino group can also be used as the amine compound (a5) of this invention. For example, 2-hydroxyethylethylenediamine, N- (2-hydroxyethyl) propylenediamine, (2-hydroxyethylpropylene) diamine, (di-2-hydroxyethylethylene) diamine, (di-2-hydroxyethylpropylene) diamine, Diamines having a hydroxyl group such as (2-hydroxypropylethylene) diamine and (di-2-hydroxypropylethylene) diamine, dimeramine obtained by converting the carboxyl group of dimer acid to an amino group, and propoxyamino groups at both ends Examples include polyoxyalkylene glycol diamine.

  In the present invention, these amine compounds (a5) may be used alone or in combination, and a monoamine, a diamine, or a polyamine is appropriately selected or used depending on the purpose or application. be able to. For example, when the terminal isocyanate group-containing urethane prepolymer (A) is synthesized, by using a monoamine compound in combination, the amount of residual isocyanate groups can be reduced and the ends can be sealed, so that the molecular weight can be easily controlled. Moreover, by using a diamine compound, it becomes possible to extend a polymer chain, and a high molecular weight polymer can be obtained. Furthermore, by using a polyamine compound, the polymer chain can be branched and finally the cohesive strength and resistance of the coating film can be improved.

  In the present invention, the proportions of these amine compounds (a5) used are the polymer polyol (a1), the hydroxyl group-containing compound (a2) to be added as necessary, and the hydroxyl groups contained in the amine compound (a5). When the total of amino groups is 1 mol, the amino group is preferably used in a proportion of 0.05 mol to 0.90 mol, more preferably 0.10 mol to 0.80 mol.

  When the amino group is used at a ratio of less than 0.05 mol, the ratio of the urea bond introduced is small, and the effect of using the amine compound (a5) is difficult to obtain. When the amino group is used in a proportion of more than 0.90 mol, the amount of urea bonds introduced becomes too large, the polarity of the entire resin becomes high, and it may be difficult to dissolve in the solvent. At the same time, the cohesive force may become too strong and the adhesive force with the substrate may be reduced. Also, when the amino group is used at a ratio close to 0.05 mol within the range of 0.05 mol to 0.90 mol, the heat resistance is increased while maintaining the flexibility and high adhesion derived from the urethane bond. In addition, when it is used at a rate close to 0.90 mol, the solder heat resistance under severe conditions such as humidification and high temperature can be remarkably improved. Thus, in this invention, the usage-amount of an amine compound (a5) can be adjusted according to the objective within said range.

  As a method of reacting the amine compound (a5), a method of reacting with a diisocyanate compound (a2) [and optionally further an isocyanate compound (a4)] after charging simultaneously with other raw materials such as the polymer polyol (a1), An example is a method in which an isocyanate-terminated urethane chain is synthesized in advance, and an amine compound (a5) is dropped or added thereto to obtain a terminal isocyanate group-containing urethane prepolymer (A) containing a urea bond.

  In the present invention, the conditions for synthesizing the terminal isocyanate group-containing urethane prepolymer (A) are not particularly limited, and can be performed under known conditions. For example, a polymer polyol (a1) and a solvent [and optionally a hydroxyl group-containing compound (a3)] are charged into a flask and dissolved uniformly by heating and stirring at 20 to 120 ° C. in a nitrogen stream, and then the diisocyanate compound (a2 The terminal isocyanate group-containing urethane prepolymer (A) can be obtained by adding [and optionally the isocyanate compound (a4)] and heating at 50 to 150 ° C. with stirring. At this time, as described above, the amine compound (a5) can also be used.

  In the reaction, a urethanization catalyst such as an organotin compound or a tertiary amino group-containing compound may be used as necessary. In addition, before adding the diisocyanate compound (a2), the polymer polyol (a1) and solvent previously charged in the flask may be heated and stirred at 100 ° C. or higher to remove a part of the solvent. This operation is usually performed to remove water (dehydration treatment) in the system, and this operation can suppress the deactivation of isocyanate groups by water when the diisocyanate compound (a2) is reacted.

  Next, it is about the ratio of reacting the terminal isocyanate group-containing urethane prepolymer (A) and the tetrabasic acid anhydride (B), but the total of isocyanate groups contained in the terminal isocyanate group-containing urethane prepolymer (A). Is 1 mol, the acid anhydride group contained in the tetrabasic acid anhydride (B) is preferably reacted at a ratio of 1.00 mol to 2.00 mol, preferably 1.00 mol to 1. mol. It is more preferable to make it react in the ratio of 95 mol.

  When the acid anhydride group is less than 1.00 mol, the amount of the terminal acid anhydride group of the obtained terminal acid anhydride group-containing urethane prepolymer (C) decreases, and the reaction with the following hydroxyl group-containing resin (D) Since the amount of carboxyl groups generated during the process is also reduced, the desired heat resistance may not be obtained. Moreover, when there are more acid anhydride groups than 2.00 mol, the problem that it is easy to cause gelatinization at the time of the reaction process with the following hydroxyl-containing resin (D) with an excess tetrabasic acid anhydride (B). is there.

  Moreover, when it is made to react in the ratio close | similar to 1.00 mol in the range of 1.00 mol-2.00 mol, the weight average molecular weight of terminal isocyanate group containing urethane prepolymer (A) becomes large enough, and is final. The flexibility and adhesion of the coating film obtained are improved. Similarly, when the reaction is carried out at a ratio close to 2.00 mol, since many sites (that is, terminal acid anhydride groups) to be reacted with the hydroxyl group-containing resin (D) are obtained in the subsequent step, the carboxyl that can be introduced into the resin Since the amount of groups can be increased, the heat resistance of the finally obtained coating film can be improved. Thus, in this invention, these reaction ratios can be adjusted according to the objective within the range of 1.00 mol-2.00 mol.

  The tetrabasic acid anhydride (B) used in the present invention is preferably a compound having 2 or more carboxylic acid anhydride groups in the molecule and having 8 to 50 carbon atoms. For example, pyromellitic anhydride 3,4,3 ′, 4′-benzophenone tetracarboxylic dianhydride, 2,3,2 ′, 3′-benzophenone tetracarboxylic dianhydride, 2,3,3 ′, 4′-benzophenone tetracarboxylic Acid dianhydride, 3,3 ′, 4,4′-diphenyltetracarboxylic dianhydride, 2,2 ′, 3,3′-diphenyltetracarboxylic dianhydride, 4,4′-oxydiphthalic acid dianhydride 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, 2,2-bis (2,3-dicarboxyphenyl) propane dianhydride, 1,1-bis (2,3- Dicarboxyphenyl) ethane dianhydride 1,1-bis (3,4-dicarboxyphenyl) ethane dianhydride, bis (2,3-dicarboxyphenyl) methane dianhydride, bis (3,4-dicarboxyphenyl) methane dianhydride, Bis (3,4-dicarboxyphenyl) sulfone dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, 1,2, 5,6-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,2,4,5-naphthalenetetracarboxylic dianhydride, 1,4,5 8-naphthalenetetracarboxylic dianhydride, phenanthrene-1,8,9,10-tetracarboxylic dianhydride, pyrazine-2,3,5,6-tetracarboxylic dianhydride, thiophene-2,3 4,5-tetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) dimethylsilane dianhydride, bis (3,4-dicarboxyphenyl) diphenylsilane dianhydride, 1,4-bis (3 , 4-Dicarboxyphenyldimethylsilyl) benzene dianhydride, 1,3-bis (3,4-dicarboxyphenyl) -1,1,3,3-tetramethyldicyclohexane dianhydride, p-phenylbis ( Trimellitic acid monoester anhydride), ethylenetetracarboxylic dianhydride, 1,2,3,4-butanetetracarboxylic dianhydride, decahodronaphthalene-1,4,5,8-tetracarboxylic acid Dianhydride, 4,8-dimethyl-1,2,3,5,6,7-hexahydronaphthalene-1,2,5,6-tetracarboxylic dianhydride, cyclopentane-1,2, 3,4-tetracarboxylic dianhydride, pyrrolidine-2,3,4,5-tetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, bis (exo-bicyclo [ 2,2,1] heptane-2,3-dicarboxylic anhydride) sulfone, bicyclo- (2,2,2) -oct (7) -ene-2,3,5,6-tetracarboxylic dianhydride 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride, 2,2-bis [4- (3,4-dicarboxyphenoxy) phenyl] hexafluoropropane dianhydride, 4, 4′-bis (3,4-dicarboxyphenoxy) diphenyl sulfide dianhydride, 1,4-bis (2-hydroxyhexafluoroisopropyl) benzenebis (trimellitic anhydride), 1,3-bi (2-hydroxyhexafluoroisopropyl) benzenebis (trimellitic anhydride), 5- (2,5-dioxotetrahydrofuryl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, tetrahydrofuran- 2,3,4,5-Tetracarboxylic dianhydride, commercially available from Shin Nippon Rika Co., Ltd. “Ricacid TMTA-C”, “Ricacid MTA-10”, “Ricacid MTA-15”, “Ricacid TMEG series” , “Licacid TDA” and the like. In the present invention, these tetrabasic acid anhydrides (B) may be used alone or in combination.

  Among them, aromatic tetrabasic acid anhydrides such as pyromellitic anhydride and benzophenonetetracarboxylic dianhydride are particularly excellent in the present invention because of excellent reactivity with isocyanate groups and heat resistance of the finally obtained resin. preferable.

  Next, the hydroxyl group-containing resin (D) of the present invention will be described. The hydroxyl group-containing resin (D) of the present invention is produced by reacting a compound (d1) having two or more epoxy groups with a bisphenol compound (d2) as essential components.

  In the present invention, when synthesizing the hydroxyl group-containing resin (D), the starting material is reacted at a ratio of 1 mol of the epoxy group contained in the compound (d1) having two or more epoxy groups. In this case, the phenolic hydroxyl group contained in the bisphenol compound (d2) is preferably reacted at a rate of 0.4 mol to 1.00 mol, and reacted at a rate of 0.5 mol to 0.90 mol. More preferred. Further, when the phenolic hydroxyl group in the bisphenol compound (d2) is reacted at a ratio of less than 0.4 mol with respect to 1.0 mol of the epoxy group in the compound (d1) having two or more epoxy groups, it remains. There is a problem that excessive epoxy groups easily cause gelation of the resin in a later synthesis step. When the reaction is performed at a ratio of more than 1.0 mol, the amount of residual bisphenol compound increases, and a large amount of protrusion occurs during hot pressing. In some cases, the processability is deteriorated and the heat resistance is adversely affected.

  Next, the compound (d1) having two or more epoxy groups in the present invention will be described. The compound (d1) having two or more epoxy groups used in the present invention is not particularly limited as long as it is a compound containing two or more epoxy groups in the molecule. Specific examples of the compound having two epoxy groups include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, bisphenol A / epichlorohydrin type epoxy resin, and bisphenol F.・ Epichlorohydrin type epoxy resin, biphenol ・ epichlorohydrin type epoxy resin, glycerin ・ epichlorohydrin adduct polyglycidyl ether, resorcinol diglycidyl ether, polybutadiene diglycidyl ether, hydroquinone diglycidyl ether, dibromoneopentyl ether Glycol diglycidyl ether, neopentyl glycol diglycidyl ether, hexahydrophthalic acid diglycidyl ester, hydrogenated bisphenol A type jig Ricidyl ether, polypropylene glycol diglycidyl ether, diphenylsulfone diglycidyl ether, dihydroxybenzophenone diglycidyl ether, biphenol diglycidyl ether, diphenylmethane diglycidyl ether, bisphenol fluorenediglycidyl ether, biscresol fluorenediglycidyl ether, bisphenoxyethanol full orange glycidyl Ether, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N-diglycidylaniline, N, N-diglycidyltoluidine, JP2004-156024A, JP2004-315595A And epoxy compounds excellent in flexibility disclosed in JP-A No. 2004-323777, and the following formulas (4) to (6) An epoxy compound represented by the structure, and the like.

  Formula (4)

  Formula (5)

  Formula (6)

  Specific examples of the compound having three or more epoxy groups include, for example, trishydroxyethyl isocyanurate triglycidyl ether, triglycidyl isocyanurate, “Epicoat 1031S”, “Epicoat 1032H60” manufactured by Japan Epoxy Resin Co., Ltd. In addition to “Epicoat 604” and “Epicoat 630”, phenol novolac type epoxy resin, cresol novolac type epoxy resin, dicyclopentadiene type epoxy resin, naphthalene type epoxy resin disclosed in JP-A No. 2001-240654, ethylene glycol Epichlorohydrin adduct polyglycidyl ether, pentaerythritol polyglycidyl ether, trimethylolpropane polyglycidyl ether, N, N, N ′, N′-tetrag Glycidyl -m- xylene diamine, and the like. Moreover, the compound which has other thermosetting groups other than an epoxy group can also be used. For example, the silane modified epoxy resin currently disclosed by Unexamined-Japanese-Patent No. 2001-59011 and 2003-48953 is mentioned.

Next, the bisphenol compound (d2) in this invention is demonstrated. The bisphenol compound (d2) used in the present invention is not particularly limited as long as it is a compound containing two or more phenolic hydroxyl groups in the molecule. Specifically, for example, bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 1,1-bis (4-hydroxyphenyl) -n-propane, 1,1-bis (4-hydroxyphenyl) -n-butane, 1,1-bis (4-hydroxyphenyl) -n-pentane, 1,1-bis (4-hydroxyphenyl) -n-hexane, 1,1-bis (4 -Hydroxyphenyl) -n-heptane, 1,1-bis (4-hydroxyphenyl) -n-octane, 1,1-bis (4-hydroxyphenyl) -n-nonane, 1,1-bis (4-hydroxy) Phenyl) -n-decane, bis (4-hydroxyphenyl) phenylmethane, bis (4-hydroxyphenyl) naphthylmethane, bis (4-hydroxyphenyl) toluylmethane Bis (4-hydroxyphenyl)-(4-ethylphenyl) methane, bis (4-hydroxyphenyl)-(4-n-propylphenyl) methane, bis (4-hydroxyphenyl)-(4-isopropylphenyl) methane, Bis (4-hydroxyphenyl)-(4-n-butylphenyl) methane, bis (4-hydroxyphenyl)-(4-pentylphenyl) methane, bis (4-hydroxyphenyl)-(4-hexylphenyl) methane, Bis (4-hydroxyphenyl)-(4-fluorophenyl) methane, bis (4-hydroxyphenyl)-(4-chlorophenyl) methane, bis (4-hydroxyphenyl)-(2-fluorophenyl) methane, bis (4 -Hydroxyphenyl)-(2-chlorophenyl) methane, bis (4-hydroxy) Enyl) tetrafluorophenylmethane, bis (4-hydroxyphenyl) tetrachlorophenylmethane, bis (3-methyl-4-hydroxyphenyl) methane, bis (3,5-dimethyl-4-hydroxyphenyl) methane, bis (3- Ethyl-4-hydroxyphenyl) methane, bis (3-isobutyl-4-hydroxyphenyl) methane, bis (3-tert-butyl-4-hydroxyphenyl) -1-phenylmethane, bis (3-phenyl-4-hydroxy) Phenyl) -1-phenylmethane, bis (3-fluoro-4-hydroxyphenyl) methane, bis (3,5-difluoro-4-hydroxyphenyl) methane, bis (3-chloro-4-hydroxyphenyl) methane, bis (3,5-dichloro-4-hydroxyphenyl) methane, 1,1-bi (3-methyl-4-hydroxyphenyl) ethane, 1,1-bis (3,5-dimethyl-4-hydroxyphenyl) ethane, 1,1-bis (3-ethyl-4-hydroxyphenyl) ethane, , 1-bis (3-isobutyl-4-hydroxyphenyl) ethane, 1,1-bis (3-fluoro-4-hydroxyphenyl) ethane, 1,1-bis (3,5-difluoro-4-hydroxyphenyl) Bisphenol in which a hydrogen atom is bonded to a central carbon such as ethane, 1,1-bis (3-chloro-4-hydroxyphenyl) ethane, 1,1-bis (3,5-dichloro-4-hydroxyphenyl) ethane Kind;
2,2-bis (4-hydroxyphenyl) -n-butane, 2,2-bis (4-hydroxyphenyl) -n-pentane, 2,2-bis (4-hydroxyphenyl) -n-hexane, 2, 2-bis (4-hydroxyphenyl) -n-heptane, 2,2-bis (4-hydroxyphenyl) -n-octane, 2,2-bis (4-hydroxyphenyl) -n-nonane, 2,2- Bis (4-hydroxyphenyl) -n-decane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane (commonly called bisphenol P), 1,1-bis (4-hydroxyphenyl) -1-naphthylethane 1,1-bis (4-hydroxyphenyl) -1-toluylethane, 1,1-bis (4-hydroxyphenyl) -1- (4-ethylphenyl) ethane, 1,1-bis (4 Hydroxyphenyl) -1- (4-n-propylphenyl) ethane, 1,1-bis (4-hydroxyphenyl) -1- (4-isopropylphenyl) ethane, 1,1-bis (4-hydroxyphenyl)- 1- (4-n-butylphenyl) ethane, 1,1-bis (4-hydroxyphenyl) -1- (4-pentylphenyl) ethane, 1,1-bis (4-hydroxyphenyl) -1- (4 -Hexylphenyl) ethane, 1,1-bis (3-tert-butyl-4-hydroxyphenyl) -1-phenylethane, 1,1-bis (3-phenyl-4-hydroxyphenyl) -1-phenylethane, 1,1-bis (4-hydroxyphenyl) -1- (4-fluorophenyl) ethane, 1,1-bis (4-hydroxyphenyl) -1- (4-chlorophenyl) 1,1-bis (4-hydroxyphenyl) -1- (2-fluorophenyl) ethane, 1,1-bis (4-hydroxyphenyl) -1- (2-chlorophenyl) ethane, 1,1-bis Bisphenols in which one methyl group is bonded to the central carbon such as (4-hydroxyphenyl) -1-tetrafluorophenylethane, 1,1-bis (4-hydroxyphenyl) -1-tetrachlorophenylethane;
2,2-bis (4-hydroxyphenyl) propane (commonly known as bisphenol A), 2,2-bis (3-methyl-4-hydroxyphenyl) propane (commonly known as bisphenol C), 2,2-bis (3,5- Dimethyl-4-hydroxyphenyl) propane, 2,2-bis (3-ethyl-4-hydroxyphenyl) propane, 2,2-bis (3-isobutyl-4-hydroxyphenyl) propane, 2,2-bis (3 -Fluoro-4-hydroxyphenyl) propane, 2,2-bis (3,5-difluoro-4-hydroxyphenyl) propane, 2,2-bis (3-chloro-4-hydroxyphenyl) propane, 2,2- Bisphenols in which two methyl groups are bonded to a central carbon such as bis (3,5-dichloro-4-hydroxyphenyl) propane;
Bis (4-hydroxyphenyl) -1,1-diphenylmethane, bis (3-methyl-4-hydroxyphenyl) -1,1-diphenylmethane, bis (3-t-butyl-4-hydroxyphenyl) -1,1- Bisphenols which are diphenylmethane derivatives such as diphenylmethane, bis (3-phenyl-4-hydroxyphenyl) -1,1-diphenylmethane, bis (3-chloro-4-hydroxyphenyl) -1,1-diphenylmethane;
1,1-bis (4-hydroxyphenyl) cyclohexane (commonly called bisphenol Z), 1,1-bis (3-methyl-4-hydroxyphenyl) cyclohexane, 1,1-bis (3,5-dimethyl-4-hydroxy) Phenyl) cyclohexane, 1,1-bis (3-ethyl-4-hydroxyphenyl) cyclohexane, 1,1-bis (3-isobutyl-4-hydroxyphenyl) cyclohexane, 1,1-bis (3-fluoro-4-) Hydroxyphenyl) cyclohexane, 1,1-bis (3,5-difluoro-4-hydroxyphenyl) cyclohexane, 1,1-bis (3-chloro-4-hydroxyphenyl) cyclohexane, 1,1-bis (3,5 Bisph is a cyclohexane derivative such as -dichloro-4-hydroxyphenyl) cyclohexane Nord like;
1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 1,1-bis (3-methyl-4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 1,1- Bis (3,5-dimethyl-4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 1,1-bis (3-ethyl-4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 1, 1-bis (3-isobutyl-4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 1,1-bis (3-fluoro-4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 1, -3,3,5-trimethylsilane such as 1-bis (3,5-difluoro-4-hydroxyphenyl) -3,3,5-trimethylcyclohexane Bisphenols is Rohekisan derivatives;
9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bis (3-methyl-4-hydroxyphenyl) fluorene, 1,1-bis (3,5-dimethyl-4-hydroxyphenyl) fluorene, 9 , 9-bis (3-ethyl-4-hydroxyphenyl) fluorene, 9,9-bis (3-isobutyl-4-hydroxyphenyl) fluorene, 1,1-bis (3-fluoro-4-hydroxyphenyl) fluorene, Bisphenols which are fluorene derivatives such as 9,9-bis (3,5-difluoro-4-hydroxyphenyl) fluorene;
1,1-bis (4-hydroxyphenyl) -cyclopentane, 1,1-bis (4-hydroxyphenyl) cyclopentane, 1,1-bis (4-hydroxyphenyl) cyclooctane, 1,1-bis (4 Bisphenols which are cycloalkane derivatives such as -hydroxyphenyl) cyclononane, 1,1-bis (4-hydroxyphenyl) cyclodecane;
Biphenols directly linked with aromatic rings such as 4,4′-biphenol;
Bis (4-hydroxyphenyl) sulfone, bis (3-methyl-4-hydroxyphenyl) sulfone, bis (3,5-dimethyl-4-hydroxyphenyl) sulfone, bis (3-ethyl-4-hydroxyphenyl) sulfone, Bisphenols which are sulfone derivatives such as bis (3-isobutyl-4-hydroxyphenyl) sulfone, bis (3-fluoro-4-hydroxyphenyl) sulfone, bis (3,5-difluoro-4-hydroxyphenyl) sulfone;
Bis (4-hydroxyphenyl) ether, bis (3-methyl-4-hydroxyphenyl) ether, bis (3,5-dimethyl-4-hydroxyphenyl) ether, bis (3-ethyl-4-hydroxyphenyl) ether, Bisphenols having an ether bond such as bis (3-isobutyl-4-hydroxyphenyl) ether, bis (3-fluoro-4-hydroxyphenyl) ether, bis (3,5-difluoro-4-hydroxyphenyl) ether;
Bis (4-hydroxyphenyl) sulfide, bis (3-methyl-4-hydroxyphenyl) sulfide, bis (3,5-dimethyl-4-hydroxyphenyl) sulfide, bis (3-ethyl-4-hydroxyphenyl) sulfide, Bisphenols having sulfide bonds such as bis (3-isobutyl-4-hydroxyphenyl) sulfide, bis (3-fluoro-4-hydroxyphenyl) sulfide, bis (3,5-difluoro-4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) sulfoxide, bis (3-methyl-4-hydroxyphenyl) sulfoxide, bis (3,5-dimethyl-4-hydroxyphenyl) sulfoxide, bis (3-ethyl-4-hydroxyphenyl) sulfoxide, bis (3-isobutyl 4-hydroxyphenyl) sulfoxide, bis (3-fluoro-4-hydroxyphenyl) sulfoxide, bis (3,5-difluoro-4-hydroxyphenyl) bisphenol a sulfoxide derivative such as sulfoxides;
Bisphenols having a heteroatom-containing aliphatic ring such as phenolphthalein;
Dihydroxybenzenes such as hydroquinone, resorcinol and methylhydroquinone;
Dihydroxynaphthalenes such as 1,5-dihydroxynaphthalene and 2,6-dihydroxynaphthalene;
Bis (2,3,5,6-tetrafluoro-4-hydroxyphenyl) difluoromethane, 1,1-bis (2,3,5,6-tetrafluoro-4-hydroxyphenyl) perfluoroethane, 2,2 Examples thereof include bisphenols having no carbon-hydrogen bond such as -bis (2,3,5,6-tetrafluoro-4-hydroxyphenyl) perfluoropropane.

  In the present invention, the conditions for synthesizing the hydroxyl group-containing resin (D) are not particularly limited, and can be performed under known conditions. For example, a hydroxyl group-containing resin (D) can be obtained by charging a flask with a compound (d1) having two or more epoxy groups, a bisphenol compound (d2), and a solvent and heating at 100 to 150 ° C. with stirring. . At this time, a catalyst such as triphenylphosphine or a tertiary amino group-containing compound may be used as necessary.

  Next, the curable urethane resin of the present invention will be described. The curable urethane resin of the present invention can be produced by reacting the terminal acid anhydride group-containing urethane prepolymer (C) described so far with the hydroxyl group-containing resin (D). Here, the ratio in which the terminal acid anhydride group-containing urethane prepolymer (C) and the hydroxyl group-containing resin (D) are reacted is hydroxyl group-containing with respect to 100 parts by weight of the terminal acid anhydride group-containing urethane prepolymer (C). It is preferable to react 2 to 150 parts by weight of resin (D), more preferably 5 to 120 parts by weight. When reacting in the range of 2 to 50 parts by weight, in particular, the flexibility of the finally obtained curable urethane resin is improved and the adhesiveness tends to increase, whereby a strong adhesive force tends to be obtained. When making it react in the range of a weight part, it exists in the tendency for the heat resistance derived from a hydroxyl-containing resin (D) to be obtained more favorably. Thus, in this invention, these reaction ratios can be suitably changed according to the objective.

  On the other hand, when the amount is less than 2 parts by weight, in the curable urethane resin of the present invention finally obtained, the desired heat resistance may not be obtained. When the amount is more than 150 parts by weight, the urethane contributes to adhesion. If the amount of the group or imide group decreases, the desired adhesive force may not be obtained.

  Furthermore, in the present invention, for the purpose of adjusting the acid value of the curable urethane resin, the acid anhydride group in the acid anhydride group-containing compound (K) is added to 1.0 mol of the hydroxyl group in the curable urethane resin. The reaction can be carried out at a ratio of less than 1.0 mol. In addition, the acid anhydride group in the acid anhydride group-containing compound (K) cannot be reacted in an amount larger than 1.0 mol with respect to 1.0 mol of the hydroxyl group in the hydroxyl group-containing resin (D).

  As the acid anhydride group-containing compound (K) used in the present invention, compounds belonging to the tetrabasic acid anhydride (B) can be used, but compounds containing at least one acid anhydride group in the molecule There is no particular limitation as long as it is sufficient. Specifically, for example, phthalic anhydride, trimellitic anhydride, methyltetrahydrophthalic anhydride, methylpentahydrophthalic anhydride, methyltrihydrophthalic anhydride, trialkyltetrahydrophthalic anhydride, methylcyclohexene dicarboxylic acid anhydride, Examples thereof include compounds containing an acid anhydride group having an alicyclic structure or an aromatic ring structure, such as het anhydride, tetrabromophthalic anhydride. Other acid anhydride group-containing compounds (K) include succinic anhydride, maleic anhydride, glutaric anhydride, butyl succinic anhydride, hexyl succinic anhydride, octyl succinic anhydride, dodecyl succinic anhydride, butyl Maleic anhydride, pentyl maleic anhydride, hexyl maleic anhydride, octyl maleic anhydride, decyl maleic anhydride, dodecyl maleic anhydride, butyl glutamic anhydride, hexyl glutamic anhydride, heptyl glutamic anhydride, Examples include octyl glutamic anhydride, decyl glutamic anhydride, dodecyl glutamic anhydride, and the like. In the present invention, the acid anhydride group-containing compound (K) may be used alone or in combination.

  The greatest feature of the present invention is that the terminal acid anhydride group-containing urethane prepolymer (C) is reacted with the hydroxyl group-containing resin (D) to increase the molecular weight.

  The acid value of the curable urethane resin of the present invention is preferably 1 to 150 mgKOH / g, more preferably 5 to 100 mgKOH / g. When the acid value is less than 1 mg KOH / g, there are few carboxyl groups or acid anhydride groups that function as curable groups, and sufficient resistance may not be imparted to the cured coating film. On the other hand, when the acid value exceeds 150 mgKOH / g, the hardness of the coating film increases, and sufficient adhesive strength may not be obtained. In addition, when the acid value is designed in the range of 1 to 150 mgKOH / g and in the range close to 1 mgKOH / g, the flexibility and adhesion of the resulting coating are improved, while the design is made in the range close to 150 mgKOH / g. In that case, since the number of crosslinking points increases, the heat resistance of the finally obtained coating film is improved. Thus, in this invention, the acid value of curable urethane resin can be adjusted according to the objective within the range of 1-150 mgKOH / g.

  The weight average molecular weight of the curable urethane resin of the present invention is preferably 5,000 to 500,000, more preferably 10,000 to 300,000. If the weight average molecular weight is less than 5000, sufficient solder heat resistance and flexibility may not be obtained. Moreover, when the weight average molecular weight exceeds 500,000, the viscosity at the time of coating and handling may become a subject. In addition, when the weight average molecular weight is designed to be close to 5000 within the range of 5000 to 500000, the distance between the crosslinking points of the obtained resin is short, so that a resin rich in crosslinkability is obtained and finally obtained. The heat resistance of the coating film can be improved. On the other hand, when designing with a value close to 500,000, the finally obtained coating film is excellent in adhesion and flexibility. Thus, in this invention, the weight average molecular weight of curable urethane resin can be adjusted according to the objective within the range of 5000-500000.

The method for producing a curable urethane resin of the present invention is a first step in which a polymer polyol (a1) and a diisocyanate compound (a2) are reacted to obtain a terminal isocyanate group-containing urethane prepolymer (A);
A second step of obtaining a terminal acid anhydride group-containing urethane prepolymer (C) by reacting the terminal isocyanate group-containing urethane prepolymer (A) with the tetrabasic acid anhydride (B);
A third step of obtaining a hydroxyl group-containing resin (D) by reacting a compound (d1) having two or more epoxy groups with a bisphenol compound (d2);
In addition, the terminal acid anhydride group-containing urethane prepolymer (C) obtained in the second step and the hydroxyl group-containing resin (D) obtained in the third step are reacted to obtain a curable urethane resin. Includes four steps.

  Moreover, you may include the 5th process of making the curable urethane resin obtained at the 4th process react with an acid anhydride group containing compound (K) further.

  As reaction conditions of the first step, it is preferable to carry out the reaction by heating and stirring at a temperature of room temperature or higher and 180 ° C. or lower, and a reaction catalyst can be used as necessary. As reaction conditions for the second step, it is preferable to carry out the reaction by heating and stirring at a temperature of 50 to 200 ° C. in the presence of nitrogen, and a reaction catalyst and a dehydrating agent can be used as necessary. Moreover, as reaction conditions of a 3rd process, it is preferable to make it react by heating and stirring at the temperature of 100-150 degreeC above room temperature in nitrogen presence, and can use a catalyst as needed. As the reaction conditions in the fourth step, it is preferable to carry out the reaction by heating and stirring at a temperature of room temperature to 150 ° C.

  The catalyst used in the first step may be any catalyst used for general urethanization, for example, an amine catalyst such as triethylamine or dimethylbenzylamine, or a tin catalyst such as dibutyltin dilaurate. Can be used. As the catalyst used in the second step, water or alcohol can be used as a catalyst in addition to amine or metal, and a dehydrating agent can be used when imidization is promoted in the latter half of the reaction. As the catalyst used in the third step, a catalyst such as triphenylphosphine or a tertiary amino group-containing compound can be used.

  Moreover, the solvent used for the synthesis | combination of curable urethane resin can be suitably selected according to the end use and the solubility of a reaction material. For example, when a dry film type adhesive sheet is used as an end use, it is preferable to use a low boiling point solvent because it is necessary to quickly dry the solvent in the dry film preparation step. Examples of the low boiling point solvent in this case include methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, butyl acetate, tetrahydrofuran, toluene, isopropyl alcohol and the like. When the reaction is carried out at the boiling point or higher of these solvents, it is preferable to synthesize without solvent and dilute with an appropriate solvent after completion of the reaction. In addition, when liquid adhesive is used as the final application, it is necessary to suppress the volatilization of the solvent as much as possible in consideration of the process of kneading the filler with a roll in the adhesive preparation process and the storage stability as a solution. It is preferable to use a solvent having a high boiling point. Examples of the high boiling point solvent in this case include carbitol acetate, methoxypropyl acetate, cyclohexanone, diisobutyl ketone and the like. However, it is preferable to select a solvent that volatilizes at the temperature of heating in the adhesive curing step.

  In the present invention, these solvents may be used alone or in combination, if necessary, and may be used in combination. Or a solvent may be added.

The curable resin composition of the present invention comprises the curable urethane resin and the epoxy group-containing compound (E). The epoxy group-containing compound (E) of the present invention will be described. The curable resin composition of the present invention is characterized by using an epoxy group-containing compound (E) as a curing agent for the curable urethane resin described above. The epoxy group-containing compound (E) in the present invention is not particularly limited as long as it is a compound containing an epoxy group in the molecule.
As the epoxy group-containing compound (E) used in the present invention, the above-mentioned compound (d1) having two or more epoxy groups is included in this range, and in particular, Japan Epoxy Resin having three or more epoxy groups. “Epicoat 1031S”, “Epicoat 1032H60”, “Epicoat 604”, and “Epicoat 630” manufactured by Co., Ltd. are preferable in the present invention because of their excellent heat resistance. In addition, aliphatic epoxy compounds and epoxy compounds described in JP-A Nos. 2004-156024, 2004-315595, and 2004-323777 are preferable because they are excellent in flexibility of a cured coating film. . In addition, the dicyclopentadiene type epoxy compound, the phenol novolak type epoxy resin, the cresol novolak type epoxy resin, the biphenol / epichlorohydrin type epoxy resin, etc. described in JP-A No. 2001-240654 are thermally cured in the present invention. It is excellent in terms of durability of a cured coating film including properties, hygroscopicity and heat resistance, and is preferable.

  In the present invention, these epoxy group-containing compounds (E) may be used alone or in combination. The amount of the epoxy group-containing compound (E) used may be determined in consideration of the application of the curable resin composition of the present invention, and is not particularly limited, but with respect to 100 parts by weight of the curable urethane resin. Thus, it is preferably added at a ratio of 0.5 to 100 parts by weight, more preferably 1 to 80 parts by weight. By using the epoxy group-containing compound (E), the crosslinking density of the curable resin composition of the present invention can be adjusted to an appropriate value, so that various physical properties of the cured coating film can be further improved. Can do. If the amount of the epoxy group-containing compound (E) used is less than 0.5 parts by weight, the crosslinking density of the coating after heat curing becomes too low, and the desired adhesive strength and heat resistance may be insufficient. . Further, if the amount used is more than 100 parts by weight, the crosslinking density after heat curing becomes too high, and as a result, the flexibility and flexibility of the coating film may be lowered, and the adhesive force may be significantly deteriorated. is there.

  Next, the thermosetting aid (F) of the present invention will be described. The heat curing aid (F) of the present invention represents a compound that contributes directly or catalytically to the curing reaction when the epoxy group-containing compound (E) and the curable urethane resin are cured. It is preferably used in the curable resin composition.

Examples of the heat curing aid (F) include tertiary amines such as triethylamine, tributylamine, benzyldimethylamine, 2,4,6-tris (dimethylaminomethyl) phenol, N-methylpiperazine, and salts thereof;
2-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-methylimidazole, 2,4-dicyano-6- [2-methylimidazolyl-1] Imidazoles such as ethyl-S-triazine, 2-ethyl-4-methylimidazole tetraphenylborate, and salts thereof;
1,5-diazabicyclo [5,4,0] -7-undecane, 1,5-diazabicyclo [4,3,0] -5-nonene, 1,4-diabicyclo [2,2,2,] octane, , 8-diazabicyclo [5.4.0] undecene-7-tetraphenylborate and the like diazabicyclo compounds;
Phosphines such as tributylphosphine, triphenylphosphine, tris (dimethoxyphenyl) phosphine, tris (hydroxypropyl) phosphine, tris (cyanoethyl) phosphine;
Phosphonium salts such as tetraphenylphosphonium tetraphenylborate, methyltributylphosphonium tetraphenylborate, methyltricyanoethylphosphonium tetraphenylborate;
In addition, dicyandiamide, carboxylic acid hydrazide, and the like can be cited as compounds that are catalytic and that directly contribute to the curing reaction. Examples of the carboxylic acid hydrazide include succinic acid hydrazide and adipic acid hydrazide.

  In the present invention, it is preferable to use dicyandiamide, carboxylic acid hydrazide, imidazoles, and diazabicyclo compounds because the thermosetting reaction proceeds more efficiently and the coating film has excellent resistance.

  In the present invention, these thermosetting aids (F) may be used alone or in combination of two or more. The amount of the thermosetting aid (F) used may be determined in consideration of the cured product properties of the curable resin composition, and is not particularly limited, but is 100 parts by weight of the curable urethane resin of the present invention. In the range of 0.05 to 20 parts by weight, more preferably in the range of 0.1 to 10 parts by weight. Thereby, the crosslinking speed and crosslinking density of the curable resin composition of the present invention can be adjusted, and various physical properties can be further improved. When the use amount of the thermosetting aid (F) is less than 0.05 parts by weight, the effect of addition is difficult to obtain, and when the use amount is more than 20 parts by weight, an excess of the thermosetting aid ( F) tends to cause a decrease in electrical insulation, adhesive strength, and solder heat resistance.

  Next, the thermosetting compound (G) of the present invention will be described. The thermosetting compound (G) of the present invention is a compound having a functional group capable of reacting alone with heat or capable of reacting with a hydroxyl group, an amino group, an epoxy group, a carboxyl group, etc. Excluding those belonging to the containing compound (E). Specifically, for example, an isocyanate compound, a blocked isocyanate compound, a cyanate ester compound, an aziridine compound, an acid anhydride group-containing compound, a carboxyl group-containing compound, a carbodiimide group-containing compound, an oxetane group-containing compound, a benzoxazine compound, a maleimide compound, Citraconimide compound, nadiimide compound, allyl nadiimide compound, vinyl ether compound, vinyl benzyl ether resin, thiol compound, melamine compound, guanamine compound, amino resin, phenol resin, resol resin, alkyd resin, acrylic resin, unsaturated polyester resin, diallyl Phthalate resin, silicone resin, xylene resin, furan resin, ketone resin, triallyl cyanurate resin, tris (2-hydroxyethyl) isocyanura Resin containing bets, resins containing triallyl trimellitate, dicyclopentadiene resins, such as thermosetting resin by trimerization of aromatic dicyanamide and the like.

  The isocyanate compound is not particularly limited as long as it is a compound having a plurality of isocyanate groups in the molecule. Specifically, the polyisocyanate having 3 or more isocyanate groups in one molecule exemplified by the diisocyanate compound (a2) and the isocyanate compound (a4) having 1 or 3 or more isocyanate groups in the molecule is provided. Can be mentioned.

  The blocked isocyanate compound is not particularly limited as long as the isocyanate group is an isocyanate compound protected with ε-caprolactam, MEK oxime, or the like. Specific examples include those obtained by blocking the isocyanate group of the isocyanate compound with ε-caprolactam, MEK oxime, cyclohexanone oxime, pyrazole, phenol, and the like.

  Examples of cyanate ester compounds include bis (4-cyanatophenyl) ethane, 2,2-bis (4-cyanatophenyl) propane, 2,2-bis (3,5-dimethyl-4-cyanatophenyl) methane, 2,2-bis (4-cyanatophenyl) -1,1,1,3,3,3-hexafluoropropane, α, α'-bis (4-cyanatophenyl) -m-diisopropylbenzene, phenol addition Examples include cyanate ester compounds of dicyclopentadiene polymers, and prepolymers thereof are used alone or in combination. Among these, 2,2-bis (4-cyanatophenyl) propane, 2,2-bis (3,5-dimethyl-4-cyanatophenyl) and the like are preferable because the dielectric properties of the cured product are particularly good. Metal-based reaction catalysts are used as a curing agent for the cyanate ester compound, and metal catalysts such as manganese, iron, cobalt, nickel, copper, and zinc are used. Specifically, it is used as an organometallic complex such as an organometallic salt compound such as 2-ethylhexanoate or naphthenate and an acetylacetone complex. The compounding amount of the metal-based reaction catalyst is preferably 1 to 3000 ppm, more preferably 1 to 1000 ppm, and still more preferably 2 to 300 ppm with respect to the cyanate ester compound. If the compounding amount of the metal-based reaction catalyst is less than 1 ppm, the effect of addition is difficult to obtain, and if it exceeds 3000 ppm, control of the reaction becomes difficult and curing tends to be too fast, but this is not a limitation.

  Examples of the aziridine compound include N, N′-diphenylmethane-4,4′-bis (1-aziridinecarboxite), N, N′-toluene-2,4-bis (1-aziridinecarboxite), bisiso Phthaloyl-1- (2-methylaziridine), tri-1-aziridinylphosphine oxide, N, N′-hexamethylene-1,6-bis (1-aziridinecarboxite), trimethylolpropane-tri-β -Aziridinylpropionate, tetramethylolmethane-tri-β-aziridinylpropionate, tris-2,4,6- (1-aziridinyl) -1,3,5-triazine, trimethylolpropane tris [ 3- (1-aziridinyl) propionate], trimethylolpropane tris [3- (1-aziridinyl) butyrate ], Trimethylolpropane tris [3- (1- (2-methyl) aziridinyl) propionate], trimethylolpropane tris [3- (1-aziridinyl) -2-methylpropionate], 2,2′-bishydroxy Methylbutanol tris [3- (1-aziridinyl) propionate], pentaerythritol tetra [3- (1-aziridinyl) propionate], diphenylmethane-4,4-bis-N, N′-ethyleneurea, 1,6-hexamethylene Bis-N, N′-ethylene urea, 2,4,6- (triethyleneimino) -Syn-triazine, bis [1- (2-ethyl) aziridinyl] benzene-1,3-carboxylic acid amide and the like can be mentioned. .

  The acid anhydride group-containing compound is not particularly limited as long as it is a compound containing an acid anhydride group in the molecule like the above-mentioned acid anhydride group-containing compound (K). Examples thereof include polycarboxylic acid anhydrides such as dicarboxylic acid anhydride, hexacarboxylic acid dianhydride, hexacarboxylic acid dianhydride, and maleic anhydride copolymer resin. In more detail, the acid anhydride group-containing compound includes phthalic anhydride, tetrahydrophthalic anhydride, etc., and maleic anhydride copolymer resins include SMA resin series manufactured by Sartomer, GSM series manufactured by Gifu Shellac Manufacturing Co., Ltd. Styrene-maleic anhydride copolymer resin, p-phenylstyrene-maleic anhydride copolymer resin, α-olefin-maleic anhydride copolymer resin such as polyethylene-maleic anhydride, “VEMA” (manufactured by Daicel Chemical Industries, Ltd.) And a copolymer of methyl vinyl ether and maleic anhydride), acrylic anhydride-modified polyolefin ("Aurolen series": manufactured by Nippon Paper Chemical Co., Ltd.), maleic anhydride copolymer acrylic resin, and the like.

Examples of the carboxyl group-containing compound include o-phthalic acid, isophthalic acid, terephthalic acid, 1,4-dimethylterephthalic acid, 1,3-dimethylisophthalic acid, 5-sulfo-1,3-dimethylisophthalic acid, 4, Aromatic dicarboxylic acids such as 4-biphenyldicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, norbornene dicarboxylic acid, diphenylmethane-4,4′-dicarboxylic acid, and phenylindanedicarboxylic acid;
Alicyclic dicarboxylic acids such as hexahydroterephthalic acid, hexahydroisophthalic acid, hexahydrophthalic acid, tetrahydrophthalic acid;
Aliphatic acids such as oxalic acid, malonic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, suberic acid, maleic acid, chloromaleic acid, fumaric acid, dodecanedioic acid, pimelic acid, citraconic acid, glutaric acid, itaconic acid And dicarboxylic acids.

  Examples of the carbodiimide group-containing compound include the Carbodilite series of Nisshinbo Industries, Ltd. Among these, Carbodilite V-01, 03, 05, 07, and 09 are preferable because of excellent compatibility with organic solvents.

  Examples of the oxetane group-containing compound include 1,4-bis {[(3-ethyloxetane-3-yl) methoxy] methyl} benzene [manufactured by Toagosei Co., Ltd., trade name: Aron oxetane OXT-121, etc.], 3- Ethyl-3-{[(3-ethyloxetane-3-yl) methoxy] methyl} oxetane [manufactured by Toa Gosei Co., Ltd., trade name; Aron oxetane OXT-221 etc.], 1,3-bis [(3-ethyloxetane- 3-yl) methoxy] benzene, 4,4′-bis [(3-ethyl-3-oxetanyl) methoxymethyl] biphenyl, esterified product of (2-ethyl-2-oxetanyl) ethanol and terephthalic acid, (2- Ethyl-2-oxetanyl) ethanol and phenol novolac resin etherified product, (2-ethyl-2-oxetanyl) ethanol and Esterified products of valence carboxylic acid compounds.

  As the benzoxazine compound, described in Macromolecules, 36, 6010 (2003), “P-a”, “P-alp”, “P-ala”, “B-ala”, described in Macromolecules, 34, 7257 (2001). “P-appe”, “B-appe”, “Ba type benzoxazine”, “Fa type benzoxazine”, “Bm type benzoxazine” manufactured by Shikoku Kasei Co., Ltd. and the like can be mentioned.

  Examples of the vinyl benzyl ether resin include V-1000X (manufactured by Showa Polymer Co., Ltd.), U.S. Pat. No. 4,116,936, U.S. Pat. No. 4,170,711, U.S. Pat. No. 4,278,708, JP-A-9-31006, JP Examples thereof include vinyl benzyl ether resins described in JP 2001-181383 A, JP 2001-253992 A, JP 2003-277440 A, JP 2003-283076 A, and WO 02/083610 pamphlet.

  The maleimide compound has at least one maleimide group in the molecule. For example, phenylmaleimide, 1-methyl-2,4-bismaleimidebenzene, N, N′-m-phenylenebismaleimide, N , N′-p-phenylene bismaleimide, N, N′-4,4-biphenylene bismaleimide, N, N′-4,4- (3,3-dimethylbiphenylene) bismaleimide, N, N′-4, 4- (3,3-dimethyldiphenylmethane) bismaleimide, N, N′-4,4- (3,3-diethyldiphenylmethane) bismaleimide, N, N′-4,4-diphenylmethane bismaleimide, N, N ′ -4,4-diphenylpropane bismaleimide, N, N'-4,4-diphenyl ether bismaleimide, N, N'-4,4-diphenyl Rufone bismaleimide, 2,2-bis [4- (4-maleimidophenoxy) phenyl] propane, 2,2-bis [3-s-butyl-3,4- (4-maleimidophenoxy) phenyl] propane, 1, 1-bis [4- (4-maleimidophenoxy) phenyl] decane, 4,4′-cyclohexylidene-bis [1- (4-maleimidophenoxy) phenoxy] -2-cyclohexylbenzene, 2,2-bis [4 -(4-maleimidophenoxy) phenyl] hexafluoropropane and the like may be used alone or in admixture of two or more.

  The citraconimide compound is a compound having at least one citraconic imide group in the molecule or a polymer thereof, such as phenyl citraconic imide, 1-methyl-2,4-biscitraconimide benzene, N, N '-M-phenylene biscitraconimide, N, N'-p-phenylene biscitraconimide, N, N'-4,4-biphenylenebiscitraconimide, N, N'-4,4- (3,3-dimethyl Biphenylene) biscitraconimide, N, N′-4,4- (3,3-dimethyldiphenylmethane) biscitraconimide, N, N′-4,4- (3,3-diethyldiphenylmethane) biscitraconimide, N, N′-4,4-diphenylmethane biscitraconimide, N, N′-4,4-diphenylpropane bissite Conimide, N, N′-4,4-diphenyl ether biscitraconimide, N, N′-4,4-diphenylsulfone biscitraconimide, 2,2-bis [4- (4-citraconimidophenoxy) phenyl] propane, 2,2-bis [3-s-butyl-3,4- (4-citraconimidophenoxy) phenyl] propane, 1,1-bis [4- (4-citraconimidophenoxy) phenyl] decane, 4,4 ′ -Cyclohexylidene-bis [1- (4-citraconimidophenoxy) phenoxy] -2-cyclohexylbenzene, 2,2-bis [4- (4-citraconimidophenoxy) phenyl] hexafluoropropane, etc. Two or more types may be mixed and used.

  The nadiimide compound is a compound having at least one nadiimide group in the molecule or a polymer thereof, such as phenyl nadiimide, 1-methyl-2,4-bisnadiimidebenzene, N, N ′. -M-phenylenebisnadiimide, N, N'-p-phenylenebisnadiimide, N, N'-4,4-biphenylenebisnadiimide, N, N'-4,4- (3,3-dimethylbiphenylene) bisnadiimide, N, N′-4,4- (3,3-dimethyldiphenylmethane) bisnadiimide, N, N′-4,4-diphenylmethanebisnadiimide, N, N′-4,4-diphenylpropanebisnadiimide, N, N ′ -4,4-diphenyl ether bisnadiimide, N, N'-4,4-diphenylsulfone bisnadiimide, 2,2-bis [4- 4-Nadiimidophenoxy) phenyl] propane, 2,2-bis [3-s-butyl-3,4- (4-nadiimidophenoxy) phenyl] propane, 1,1-bis [4- (4-nadiimide) Phenoxy) phenyl] decane, 4,4′-cyclohexylidene-bis [1- (4-nadiimidophenoxy) phenoxy] -2-cyclohexylbenzene, 2,2-bis [4- (4-nadiimidophenoxy) phenyl There are hexafluoropropane, etc., and these may be used alone or in admixture of two or more.

  Examples of the allyl nadiimide compound include bis {4- (allylbicyclo [2.2.1] hept-5-ene-2,3-dicarboximide) phenyl} methane, 1,6-hexane-bis-allylnadiimide, meta Examples thereof include xylylene-bis-allylnadiimide, which may be used alone or in combination of two or more.

  Examples of the vinyl ether compound include 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, diethylene glycol monovinyl ether, cyclohexanedimethanol divinyl ether, cyclohexanedimethanol monovinyl ether, cyclohexyl vinyl ether, cyclohexane methanol vinyl ether, ethylcyclohexanol vinyl ether, methoxyethyl vinyl ether, ethoxy Ethyl vinyl ether, hydroxypropyl vinyl ether, hydroxypentyl vinyl ether, diethylaminoethyl vinyl ether, tricyclodecane epoxy vinyl ether, ethylene glycol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, tetra Tylene glycol divinyl ether, pentaerythritol divinyl ether, propylene glycol divinyl ether, dipropylene glycol divinyl ether, tripropylene glycol divinyl ether, neopentyl glycol divinyl ether, 1,4-butanediol divinyl ether, 1,6-hexanediol divinyl ether Glycerin divinyl ether, trimethylolpropane divinyl ether, 1,4-dihydroxylcyclohexane divinyl ether, 1,4-dihydroxymethylcyclohexane divinyl ether, hydroquinone divinyl ether, ethylene oxide modified hydroquinone divinyl ether, ethylene oxide modified resorcin divinyl ether, ethylene Oxide modified bisphenol A divinyl ether, ethylene oxide modified bisphenol S divinyl ether, glycerin trivinyl ether, sorbitol tetravinyl ether, trimethylolpropane trivinyl ether, pentaerythritol trivinyl ether, pentaerythritol tetravinyl ether, dipentaerythritol hexavinyl ether, dipentaerythritol polyvinyl ether, ditrimethylol There are propanetetravinylether, ditrimethylolpropanepolyvinylether, etc., and these may be used alone or in admixture of two or more.

  As thiol compounds, 2,4,6-trimercapto-s-triazole, 2-dibutylamino-4,6-dimercapto-s-triazine, 2-anilino-4,6-dimercapto-S-triazine, tetraethylene glycol Bis-3-mercaptopropionate, trimethylolpropane tris-3-mercaptopropionate, tris- (ethyl-3-mercaptopropionate) isocyanurate, pentaerythritol tetrakis-3-mercaptopropionate, dipentaerythritol There are hexa-3-mercaptopropionate and the like, or a mixture of two or more may be used.

  Examples of amino resins include addition compounds of urea, melamine, benzoguanamine, acetoguanamine, and the like with formaldehyde, or partial condensates thereof. Moreover, as a phenol resin, the addition compound of compounds, such as phenol, cresols, and bisphenol, and formaldehyde, or its partial condensate is mentioned. Specifically, phenol resin, cresol resin, t-butylphenol resin, dicyclopentadiene cresol resin, dicyclopentadiene phenol resin, xylylene-modified phenol resin, tetrakisphenol resin, bisphenol A resin, poly-p-vinylphenol resin resole Mold resin and novolac resin. Other examples include naphthol compounds, trisphenol compounds, phenol aralkyl resins, and the like. Among them, the resol type resin of phenol resin is very excellent in terms of heat resistance and curability and can be suitably used in the present invention.

  These thermosetting compounds (G) may use only 1 type and may use 2 or more types together. The amount of the thermosetting compound (G) used may be determined in consideration of the use of the curable resin composition and is not particularly limited, but is 100 parts by weight of the curable urethane resin of the present invention. In the range of 0.1 to 100 parts by weight, more preferably in the range of 0.5 to 80 parts by weight. Thereby, it is possible to adjust the crosslinking density and cohesion force of the curable resin composition of the present invention, and various physical properties can be further improved. If the use amount of the thermosetting compound (G) is less than 0.1 parts by weight, the effect of addition is difficult to obtain, and if the use amount is more than 100 parts by weight, the crosslinking density after heat curing is low. As a result, it becomes too high, and as a result, the flexibility, flexibility, adhesive strength, etc. of the coating film may be lowered.

  The present invention is excellent in adhesive strength, electrical insulation, heat resistance, flexibility, and workability, and particularly satisfies storage stability and processing stability at the same time, and has high heat resistance while maintaining high adhesive strength. Furthermore, a curable urethane resin and a curable resin composition comprising the same were obtained, which can achieve both adhesive strength and electrical insulation, heat resistance and flexibility. These include adhesives and adhesive sheets for electronic materials including the periphery of flexible printed wiring boards, coating agents, solder resists for circuit coating, coverlay films, plating resists, interlayer electrical insulation materials for printed wiring boards, optical waveguides, etc. It can be used suitably. The curable resin composition of the present invention is particularly suitably used for an adhesive composition.

  The present invention will be described more specifically with reference to the following examples. However, the following examples do not limit the scope of rights of the present invention. In the examples, “parts” and “%” represent “parts by weight” and “% by weight”, respectively, and Mw represents a weight average molecular weight.

<Measurement of weight average molecular weight (Mw)>
For measurement of Mw, GPC (gel permeation chromatography) “HPC-8020” manufactured by Tosoh Corporation was used. GPC is liquid chromatography that separates and quantifies substances dissolved in a solvent (THF; tetrahydrofuran) based on the difference in molecular size. For the measurement in the present invention, “LF-604” (manufactured by Showa Denko KK: GPC column for rapid analysis: 6 mm ID × 150 mm size) is connected in series to the column, the flow rate is 0.6 ml / min, the column temperature. It carried out on the conditions of 40 degreeC, and the determination of the weight average molecular weight (Mw) was performed in polystyrene conversion.

[Production Example 1]
<Production of terminal acid anhydride group-containing urethane prepolymer>
Polycarbonate diol (Kuraray polyol C-2090: Kuraray Co., Ltd .: 3-methyl-1,5-pentanediol / 1) was added to a four-necked flask equipped with a stirrer, reflux condenser, nitrogen inlet tube, inlet tube, and thermometer. , 6-hexanediol = 9/1 (molar ratio) copolymerized polycarbonate diol: hydroxyl value = 56 mg KOH / g, Mw = 2000) 136.1 parts, 70 parts of toluene as a solvent were charged with stirring under a nitrogen stream to 60 parts. The temperature was raised to 0 ° C. and dissolved uniformly. Subsequently, 25.5 parts of isophorone diisocyanate and 0.081 part of dibutyltin dilaurate as a catalyst were added to the flask and stirred at 100 ° C. for 3 hours to obtain a terminal isocyanate group-containing urethane prepolymer solution (Mw: 7600). .

Subsequently, after adding 205 parts of cyclohexanone and cooling to room temperature, 1.75 parts of dimethylbenzylamine was added as a catalyst. After adding 13.4 parts of pyromellitic anhydride to this solution, the temperature was raised to 90 ° C. while stirring under a nitrogen stream, and it was confirmed by IR that the isocyanate group-derived peak (near 2254 cm ⁻¹ ) had disappeared. The temperature was raised to ° C. and reacted for 4 hours to obtain a terminal acid anhydride group-containing urethane prepolymer solution. The terminal acid anhydride group-containing urethane prepolymer thus obtained had a weight average molecular weight of 45,000, and an actually measured acid value of the resin solids was 18.10 mgKOH / g.

<Production of hydroxyl group-containing resin>
In a reaction vessel equipped with a stirrer, thermometer, reflux condenser, and nitrogen introduction tube, 13.4 parts of bisphenol A, 15.2 parts of hexamethylene diglycidyl ether [manufactured by Nagase ChemteX Corp., EX-212L], 0.29 parts of triphenylphosphine and 32 parts of toluene were charged and reacted in a nitrogen atmosphere at 110 ° C. for 5 hours to obtain a hydroxyl group-containing resin solution (Mw: 18000).

<Manufacture of curable urethane resin>
The terminal acid anhydride group-containing urethane prepolymer solution and the hydroxyl group-containing resin solution were mixed and reacted at 100 ° C. for 3 hours. The reaction was stopped when a peak derived from an acid anhydride group (near 1793 cm ⁻¹ ) disappeared by IR to obtain a curable urethane resin solution. The obtained curable urethane resin had a weight average molecular weight of 269300 and an acid value of 13.33 mgKOH / g.

[Production Examples 2 to 10]
Except having replaced with the material shown in Table 1, it carried out similarly to manufacture example 1, and obtained the curable urethane resin solution of this invention.

[Production Example 11]
After obtaining a curable urethane resin solution by the same method as in Production Example 1, 0.62 part of succinic anhydride (manufactured by Shin Nippon Rika Co., Ltd., Ricacid SA) was charged into this solution, and 100% in a nitrogen atmosphere. The reaction was carried out at 2 ° C. for 2 hours. To obtain a reaction was stopped curable urethane resin solution at the time the peak derived from the acid anhydride group in IR (1793cm around ^-1) disappeared. The obtained curable urethane resin had a weight average molecular weight of 223600 and an acid value of 18.66 mgKOH / g.

[Production Example 12]
Except having replaced with the material shown in Table 1, it carried out similarly to manufacture example 11, and obtained the curable urethane resin solution of this invention.

[Production Example 13]
<Production of terminal acid anhydride group-containing urethane prepolymer>
Polycarbonate diol (Kuraray polyol C-2090: Kuraray Co., Ltd .: 3-methyl-1,5-pentanediol / 1) was added to a four-necked flask equipped with a stirrer, reflux condenser, nitrogen inlet tube, inlet tube, and thermometer. , 6-hexanediol = 9/1 (molar ratio) copolymer polycarbonate diol: hydroxyl value = 56 mg KOH / g, Mw = 2000) 147.6 parts, dimethylolbutanoic acid 2 parts, toluene 70 parts as a solvent, nitrogen The mixture was heated up to 60 ° C. with stirring under an air stream, and dissolved uniformly. Subsequently, 33 parts of isophorone diisocyanate and 0.091 part of dibutyltin dilaurate as a catalyst were added to this flask and stirred at 100 ° C. for 3 hours to obtain a terminal isocyanate group-containing urethane prepolymer solution (Mw: 6700).

Subsequently, 225 parts of cyclohexanone was charged and cooled to room temperature, and then 2 parts of dimethylbenzylamine was added as a catalyst. After adding 17.4 parts of pyromellitic anhydride to this solution, the temperature was raised to 90 ° C. with stirring under a nitrogen stream, and after confirming that the peak derived from the isocyanate group (near 2254 cm ⁻¹ ) disappeared by IR, 135 The temperature was raised to ° C. and reacted for 4 hours to obtain a terminal acid anhydride group-containing urethane prepolymer solution. The obtained terminal acid anhydride group-containing urethane prepolymer had a weight average molecular weight of 43200, and the actually measured acid value of the resin solid content was 23.42 mgKOH / g.

<Production of hydroxyl group-containing resin>
In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen introduction tube, 10.8 parts of bisphenol A, 12.3 parts of hexamethylene diglycidyl ether [manufactured by Nagase ChemteX Corporation, EX-212L], 0.23 parts of triphenylphosphine and 43 parts of toluene were charged and reacted in a nitrogen atmosphere at 110 ° C. for 5 hours to obtain a hydroxyl group-containing resin solution (Mw: 18000).

<Manufacture of curable urethane resin>
The terminal acid anhydride group-containing urethane prepolymer solution and the hydroxyl group-containing resin solution were mixed and reacted at 100 ° C. for 3 hours. The reaction was stopped when a peak derived from an acid anhydride group (near 1793 cm ⁻¹ ) disappeared by IR to obtain a curable urethane resin solution. The obtained curable urethane resin had a weight average molecular weight of 198700 and an acid value of 19.31 mgKOH / g.

[Production Example 14]
Except having replaced with the material shown in Table 1, it carried out similarly to manufacture example 13, and obtained the curable urethane resin solution of this invention.

[Production Example 15]
<Production of terminal acid anhydride group-containing urethane prepolymer>
Polycarbonate diol (Kuraray polyol C-2090: Kuraray Co., Ltd .: 3-methyl-1,5-pentanediol / 1) was added to a four-necked flask equipped with a stirrer, reflux condenser, nitrogen inlet tube, inlet tube, and thermometer. , 6-hexanediol = 9/1 (molar ratio) copolymerized polycarbonate diol: hydroxyl value = 56 mg KOH / g, Mw = 2000) 147.6 parts, 70 parts of toluene as a solvent were charged, and the mixture was stirred under a nitrogen stream while stirring. The temperature was raised to 0 ° C. and dissolved uniformly. Subsequently, 33 parts of isophorone diisocyanate and 0.091 part of dibutyltin dilaurate as a catalyst were added to the flask and stirred at 100 ° C. for 3 hours. Subsequently, 2 parts of 1,6-hexanediamine was added to this solution and stirred at 85 ° C. for 3 hours to obtain a terminal isocyanate group-containing urethane prepolymer solution (Mw: 8400).

Subsequently, 226 parts of cyclohexanone was charged and cooled to room temperature, and then 2 parts of dimethylbenzylamine was added as a catalyst. After adding 17.4 parts of pyromellitic anhydride to this solution, the temperature was raised to 90 ° C. while stirring under a nitrogen stream, and after confirming that the peak derived from the isocyanate group (near 2254 cm ⁻¹ ) disappeared by IR, 135 The temperature was raised to 0 ° C. and reacted for 4 hours to obtain a terminal acid anhydride group-containing urethane prepolymer solution. The obtained terminal acid anhydride group-containing urethane prepolymer had a weight average molecular weight of 50200, and the acid value of the resin solid content measured was 17.04 mgKOH / g.

<Production of hydroxyl group-containing resin>
In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen introduction tube, 10.8 parts of bisphenol A, hexamethylene diglycidyl ether [manufactured by Nagase ChemteX Corporation, EX-212L] 12.3 parts, 0.23 parts of triphenylphosphine and 43 parts of toluene were charged and reacted in a nitrogen atmosphere at 110 ° C. for 5 hours to obtain a hydroxyl group-containing resin solution (Mw: 18000).

<Manufacture of curable urethane resin>
The terminal acid anhydride group-containing urethane prepolymer solution and the hydroxyl group-containing resin solution were mixed and reacted at 100 ° C. for 3 hours. The reaction was stopped when a peak derived from an acid anhydride group (near 1793 cm ⁻¹ ) disappeared by IR to obtain a curable urethane resin solution. The obtained curable urethane resin had a weight average molecular weight of 224900 and an acid value of 12.22 mgKOH / g.

[Production Example 16]
Except having replaced with the material shown in Table 1, it carried out similarly to manufacture example 15, and obtained the curable urethane resin solution of this invention.

C-2090: manufactured by Kuraray Co., Ltd .: 3-methyl-1,5-pentanediol / 1,6-hexanediol = 9/1 (molar ratio) copolymerized polycarbonate diol PTG2000 sn: manufactured by Hodogaya Chemical Co., Ltd .: polytetramethylene glycol FM-4411: manufactured by Chisso Corporation, polydimethylsiloxanediol UM-90: manufactured by Ube Industries, Ltd .: 1,4-cyclohexanedimethanol / 1,6-hexanediol = 1/1 (molar ratio) copolymerized polycarbonate diol DMBA : Dimethylolbutanoic acid TMP: trimethylolpropane IPDI: isophorone diisocyanate XDI: metaxylylene diisocyanate 1,6-HDA: 1,6-hexanediamine DBTDL: dibutyltin dilaurate PMDA: pyromellitic anhydride BT A: 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride DMBAm: dimethylbenzylamine EX-212L: manufactured by Nagase ChemteX Corporation, hexamethylene diglycidyl ether YD-8125: manufactured by Tohto Kasei Co., Ltd .: Bisphenol A type high purity epoxy resin Bis-A: Bisphenol A
Rikacid SA: Shin Nippon Rika Co., Ltd .: Succinic anhydride Rikacid TH: Shin Nippon Rika Co., Ltd .: 1,2,3,6-tetrahydrophthalic anhydride

[Production Example 17]
Polycarbonate diol (Kuraray polyol C-2090: Kuraray Co., Ltd .: 3-methyl-1,5-pentanediol / 1) was added to a four-necked flask equipped with a stirrer, reflux condenser, nitrogen inlet tube, inlet tube, and thermometer. , 6-hexanediol = 9/1 (molar ratio) copolymerized polycarbonate diol: 270 parts of hydroxyl value = 56 mg KOH / g, Mw = 2000), 51 parts of isophorone diisocyanate, 220 parts of toluene as a solvent, and stirred under a nitrogen stream Then, the temperature was raised to 60 ° C. and dissolved uniformly. Subsequently, 0.16 part of dibutyltin dilaurate was added to the flask as a catalyst, and the mixture was stirred at 100 ° C. for 3 hours to carry out a urethanization reaction. Next, 380 parts of cyclohexanone and 29 parts of pyromellitic anhydride were added, stirred at 90 ° C. for 1 hour, then added with 3.5 parts of dimethylbenzylamine, heated to 135 ° C., and reacted for 4 hours. After cooling, the solid content was adjusted to 35% with cyclohexanone to obtain a curable urethane resin solution. The weight average molecular weight of the obtained curable urethane resin was 14,000, and the acid value of the resin solid content measured was 27 mgKOH / g.

[Production Examples 18 to 23]
A curable urethane resin solution was obtained in the same manner as in Production Example 17 except that the materials shown in Table 2 were used.

[Production Example 24]
Polycarbonate diol (Kuraray polyol C-2090: Kuraray Co., Ltd .: 3-methyl-1,5-pentanediol / 1) was added to a four-necked flask equipped with a stirrer, reflux condenser, nitrogen inlet tube, inlet tube, and thermometer. , 6-hexanediol = 9/1 (molar ratio) copolymerized polycarbonate diol: hydroxyl value = 56 mg KOH / g, Mw = 2000) 253 parts, isophorone diisocyanate 60 parts, toluene 220 parts as a solvent, stirred under a nitrogen stream Then, the temperature was raised to 60 ° C. and dissolved uniformly. Subsequently, 0.16 part of dibutyltin dilaurate was added to the flask as a catalyst, and the mixture was stirred at 100 ° C. for 3 hours to carry out a urethanization reaction. Next, 5.3 parts of isophorone diamine was added, and stirring was continued for 1 hour to carry out a urea reaction. Next, 380 parts of cyclohexanone and 34 parts of pyromellitic anhydride were added and stirred at 90 ° C. for 1 hour, and then 3.5 parts of dimethylbenzylamine was added and the temperature was raised to 135 ° C. and reacted for 4 hours. After cooling, the solid content was adjusted to 35% with cyclohexanone to obtain a curable urethane resin solution. The weight-average molecular weight of the obtained curable urethane resin was 27000, and the acid value of the resin solid content measured was 29 mgKOH / g.

[Production Example 25]
Polycarbonate diol (Kuraray polyol C-2090: Kuraray Co., Ltd .: 3-methyl-1,5-pentanediol / 1) was added to a four-necked flask equipped with a stirrer, reflux condenser, nitrogen inlet tube, inlet tube, and thermometer. , 6-hexanediol = 9/1 (molar ratio) copolymerized polycarbonate diol: hydroxyl value = 56 mg KOH / g, Mw = 2000) 295 parts, dimethylolbutanoic acid 9 parts, isophorone diisocyanate 45 parts, toluene 186 parts as a solvent The mixture was heated to 100 ° C. with stirring in a nitrogen stream and stirred for 6 hours to carry out a urethanization reaction. After cooling, the solid content was adjusted to 35% with cyclohexanone to obtain a curable urethane resin solution. The weight average molecular weight of the obtained curable urethane resin was 32000, and the acid value of the resin solid content measured was 11 mgKOH / g.

  The compositions of Production Examples 17 to 25 are shown in Table 2.

P-2011: Kuraray Co., Ltd .: Aromatic polyester polyol IPDA: Isophoronediamine

Example 1
20 parts of polyfunctional glycidyl ether type epoxy resin (“Epicoat 1031S” manufactured by Japan Epoxy Resin Co., Ltd.) as the epoxy group-containing compound (E) with respect to 100 parts of the solid content of the curable urethane resin solution obtained in Production Example 1. , And 1 part of dicyandiamide (“Epicure DICY7” manufactured by Japan Epoxy Resin Co., Ltd.) as a thermosetting aid (F) were mixed to obtain a curable resin composition. This curable resin composition was uniformly applied onto a polyester film subjected to a release treatment so that the film thickness after drying was 30 μm and dried to provide an adhesive layer. Next, another release-treated polyester film was laminated on the adhesive layer side to obtain an adhesive sheet with a double-sided protective film.

(Examples 2 to 16)
A double-sided protective film is provided in the same manner as in Example 1 except that the curable urethane resin solution of Production Example 1 used in Example 1 is replaced with the curable urethane resin solution obtained in Production Examples 2 to 16, respectively. An adhesive sheet was prepared.

(Comparative Examples 1-9)
An adhesive sheet with a double-sided protective film was prepared in the same manner as in Example 1 except that the curable urethane resin solution of Example 1 was replaced with the curable urethane resin solution obtained in Production Examples 17 to 25, respectively. .

(Examples 17 to 36)
Except having obtained the curable resin composition by the composition shown in Table 3, it carried out similarly to Example 1, and created the adhesive sheet with a double-sided protective film.

828: manufactured by Japan Epoxy Resin Co., Ltd., bisphenol A type epoxy compound EOCN-102S: manufactured by Nippon Kayaku Co., Ltd., cresol novolac type epoxy resin EPPN-201L: manufactured by Nippon Kayaku Co., Ltd., phenol novolac type epoxy resin YH434L: Tohto Kasei Tetrafunctional polyglycidylamine type epoxy resin manufactured by Co., Ltd. Oncoat 1040: Fluorene type polyfunctional epoxy resin manufactured by Nagase ChemteX Corporation DICY: Dicyandiamide DBU: 1,8-diazabicyclo- (5,4,0) -undecene 7
TPP: triphenylphosphine 2E4MeZ: 2-ethyl-4-methylimidazole TPA-B80E: manufactured by Asahi Kasei Corporation, isocyanurate type blocked isocyanate Ricacid TMTA-C: polyfunctional acid anhydride Aron oxetane OXT- 121: manufactured by Toagosei Co., Ltd., 1,4-bis {[(3-ethyloxetane-3-yl) methoxy] methyl} oxetane Ba: manufactured by Shikoku Kasei Co., Ltd., benzoxazine compound Carbodilite V-07: Nisshinbo Co., Ltd. Company-made, polycarbodiimide compound ZISNET DB: Sankyo Kasei Co., Ltd., 2-dibutylamino-4,6-dimercapto-s-triazine BAR: Toyo Ink Manufacturing Co., Ltd., bisphenol A type resol resin PQR: Toyo Ink Manufacturing Co., Ltd. Company made: p-cle Sol type resol resin

(Comparative Examples 10-21)
Except having obtained the curable resin composition by the composition shown in Table 4, it carried out similarly to Example 1, and created the adhesive sheet with a double-sided protective film.

(Comparative Example 22)
37.8 parts of bisphenol A type epoxy resin (manufactured by Japan Epoxy Resin, Epicoat 828EL) as the base resin, and (3- or 4-) methylhexahydrophthalic anhydride (HN-5500, manufactured by Hitachi Chemical Co., Ltd.) 34 as the curing agent 8 parts, 2,4,6-tris (dimethylaminomethyl) phenol (Japan Epoxy Resin, Epicure 3010) 0.4 part as a curing accelerator, carboxyl group-containing butadiene acrylonitrile rubber (Nippon Zeon, Nipol 1072) 27.0 parts was dissolved in MEK to obtain a curable resin composition having a solid content of 30%. Using this, an adhesive sheet with a double-sided protective film was prepared in the same manner as in Example 1.

(Comparative Example 23)
50 parts of carboxyl group-containing acrylonitrile butadiene rubber (Nippon Zeon, Nipol 1072), 34 parts of bisphenol A type epoxy resin (Japan Epoxy Resin, Epicoat 1001), phenol novolac resin (BPG-558, Showa Polymer Co., Ltd.) 7 parts, 0.2 part of imidazole (2-ethyl-4-methylimidazole), 0.5 part of phenolic anti-aging agent (manufactured by Sumitomo Chemical Co., Ltd., Sumilizer TP-D) is dissolved in MEK and the solid content is 30%. A curable resin composition was obtained. Using this, an adhesive sheet with a double-sided protective film was prepared in the same manner as in Example 1.

  With respect to the adhesive sheets obtained in Examples and Comparative Examples, storage stability, processing stability, adhesive strength, solder bath resistance, post-solder adhesive strength, humidified solder bath resistance, and electrical insulation were evaluated by the following methods.

(1) Processing stability An adhesive sheet having a size of 65 mm × 65 mm, from which the protective film has been removed, is a polyimide film with a thickness of 75 μm [“Kapton 300H” manufactured by Toray DuPont Co., Ltd.] and a copper with a thickness of 45 μm. It was sandwiched between stretched laminates, laminated at 80 ° C., and then subjected to a pressure bonding treatment at 160 ° C. and 1.0 MPa for 1 hour. Furthermore, this test piece was heat-cured at 160 ° C. for 2 hours to prepare an evaluation test piece. About this test piece, the difference of the area of the adhesive bond layer before a crimping | compression-bonding process and after thermosetting was measured, and processing stability was evaluated by making this into the protruding area. This processing stability is an evaluation of the degree to which the adhesive layer is softened by heat during the crimping process and causes the positional deviation of the circuit board and the contact between the wirings, and the result was judged according to the following criteria.
◎ ・ ・ ・ "Projection area ≤ 100mm ² "
○ “100 mm ² <overhang area ≦ 250 mm ² ”
Δ: “250 mm ² <overhang area ≦ 500 mm ² ”
× ... "500mm ² <overhang area"

(2) Adhesive strength A test piece prepared by evaluation of processing stability was cut out to a width of 10 mm and a length of 65 mm, and a T peel peel test was performed at an elongation of 300 mm / min in an atmosphere of 23 ° C. and a relative humidity of 50%. The strength (N / cm) was measured. This test evaluates the adhesive strength of the adhesive layer when used at room temperature, and the results were judged according to the following criteria.
◎ ・ ・ ・ “18 (N / cm) <Adhesive strength”
○ “12 (N / cm) <Adhesive strength ≦ 18 (N / cm)”
Δ: “8 (N / cm) <Adhesion strength ≦ 12 (N / cm)”
X ... "Adhesive strength ≤ 8 (N / cm)"

(3) Storage stability After the adhesive sheet with a double-sided protective film prepared in Examples and Comparative Examples was heated and stored at 40 ° C. for 3 months, lamination, pressure-bonding treatment and thermosetting were performed under the conditions of (1) above. The adhesive strength was evaluated by the same method as in (2) above, and compared with the adhesive strength obtained with an adhesive sheet that was not stored under heat. This test evaluates the temporal stability of an uncured adhesive layer by the difference in adhesive strength depending on the presence or absence of heat storage. The better the temporal stability, the more stable the uncured state, and the accelerated heating. Even if it is applied, the decrease in adhesive strength is small, the worse the stability over time, the more uncured state is unstable, the curing reaction proceeds due to accelerated heating, and compared to the case where no accelerated heating is applied Power is greatly reduced. These evaluation results were judged according to the following criteria.
◎ ・ ・ ・ "Adhesion strength does not change at all by heating"
○ ・ ・ ・ "Adhesion strength hardly changes by heating"
△ ... "Adhesion strength slightly decreased due to accelerated heating"
× ... “Adhesive strength has been significantly reduced by heating”

(4) Resistance to Solder Bath Similar to (2) above, a test piece cut out to a width of 10 mm and a length of 65 mm was floated for 1 minute by bringing the polyimide film surface into contact with 260 ° C. molten solder. Thereafter, the appearance of the test piece was visually observed, and the presence or absence of adhesion abnormality such as foaming, floating, and peeling of the adhesive layer was evaluated. This test evaluates the thermal stability of the adhesive layer at the time of solder contact with the appearance. Those with good heat resistance have poor heat resistance, whereas the appearance does not change before and after soldering. Things are subject to foaming and peeling after soldering. These evaluation results were judged according to the following criteria.
◎ ・ ・ ・ No change in appearance
○ ・ ・ ・ “Slight foaming is observed”
△ ... "Bubbling is observed"
× ・ ・ ・ "Strong foaming and peeling are observed"

(5) Adhesive strength after soldering For the test piece after the evaluation of solder bath resistance in (4) above, the adhesive strength is measured by the same method as in (2) above, and the adhesive strength before soldering and the adhesive strength after soldering. And compared. This test is to evaluate the thermal stability of the adhesive layer at the time of solder contact by the change in the adhesive strength before and after the soldering treatment, and the one having good heat resistance does not change the adhesive strength before and after the soldering treatment. On the other hand, those having poor heat resistance have a marked decrease in adhesive strength after soldering. These evaluation results were judged according to the following criteria.
◎ ・ ・ ・ "Adhesive strength does not change at all"
○ ・ ・ ・ “Adhesive strength hardly changes”
△ ... "Adhesion strength slightly decreased"
× ... "Adhesive strength has been significantly reduced"

(6) Humidity solder bath resistance In the same manner as in (2) above, a test piece cut into a width of 10 mm and a length of 65 mm was left to humidify in an atmosphere of 40 ° C. and relative humidity of 90% for 96 hours, and then 260 ° C. The polyimide film surface was brought into contact with the molten solder and floated for 1 minute. Thereafter, the appearance of the test piece was visually observed, and the presence or absence of adhesion abnormality such as foaming, floating, and peeling of the adhesive layer was evaluated. This test evaluates the thermal stability of the adhesive layer at the time of solder contact in a humidified state by appearance. In the case of a bad product, foaming or peeling occurs after soldering. These evaluation results were judged according to the following criteria.
◎ ・ ・ ・ “No change in appearance”
○ ・ ・ ・ “Almost no change in appearance”
△ ... "Bubbling is observed"
× ・ ・ ・ "Strong foaming and peeling are observed"

(7) Electrical insulation The 65 mm x 65 mm adhesive sheet, from which the protective film has been removed, is a 25 μm thick polyimide film ["Kapton 100H" manufactured by Toray DuPont Co., Ltd.] and a copper circuit on the polyimide. It is sandwiched between the formed comb pattern (conductor pattern width / space width = 50 μm / 50 μm) and printed circuit board, laminated at 80 ° C., and then subjected to pressure bonding treatment at 160 ° C. and 1.0 MPa for 1 hour. It was. Furthermore, this test piece was heat-cured at 160 ° C. for 2 hours to prepare an evaluation test piece. A DC voltage of 50 V was continuously applied to the conductor circuit of this test piece for 100 hours under an atmosphere of a temperature of 130 ° C. and a relative humidity of 85%, and the insulation resistance value between the conductors after 100 hours was measured. The evaluation criteria are as follows.
◎ ・ ・ ・ “Insulation resistance value of 10 ⁸ Ω or more”
○ “Insulation resistance value of 10 ⁷ or more and less than 10 ⁸ Ω”
△ “Insulation resistance value of 10 ⁶ or more and less than 10 ⁷ Ω”
× ・ ・ ・ “Insulation resistance less than 10 ⁶ Ω”

  The results of evaluation are shown in Tables 5 and 6 below.

  As can be seen from the examples and comparative examples in Table 5, the resins used in the comparative examples are the high molecular weight of the terminal acid anhydride group-containing urethane prepolymer (C) and the high molecular weight of the hydroxyl group-containing resin (D). Since the effect of introducing appropriate crosslinking points into the chain was not performed, storage stability, post-solder adhesive strength, and humidified solder bath resistance were significantly deteriorated. On the other hand, in the examples, these three physical properties were improved, and good results were obtained with good balance in all physical properties. These are considered to be influenced by the high molecular weight and the selective introduction of a carboxyl group, which is a thermosetting functional group, only into the hydroxyl group-containing resin (D). In other words, due to the effect of selective introduction of the functional group, the crosslink density is increased particularly around the (D) unit portion where the thermosetting functional group exists, and the high degree of processing stability and high adhesive force are maintained. It is considered that the heat resistance was excellent. Moreover, in Comparative Example 3 using the resin obtained from Production Example 19 using a polyester skeleton, the insulating property was remarkably deteriorated. This is considered to be an influence by hydrolysis derived from polyester. Further, in Comparative Example 8 using the resin obtained from Production Example 24 into which a urea bond was introduced, although the adhesive strength was improved by increasing the molecular weight, no crosslinkable functional group was introduced into the resin main chain. The physical properties deteriorated.

About Table 6, as can be seen from the examples and comparative examples, in the examples, the effect of increasing the molecular weight by the hydroxyl group-containing resin (D) and introducing appropriate crosslinking points into the main chain is achieved. Good results were shown. Furthermore, by adding the thermosetting compound (G), it was possible to improve the humidified solder resistance and the post-solder adhesive strength without reducing the adhesive strength and the like. These are considered to be a synergistic effect of the high molecular weight of the resin, introduction of a crosslinking point into the hydroxyl group-containing resin (D), and the thermosetting compound (G). On the other hand, in the comparative example, since the effect of increasing the molecular weight by the hydroxyl group-containing resin (D) and introducing an appropriate crosslinking point into the main chain was not performed, almost all physical properties including processing stability deteriorated. . In Comparative Examples 22 and 23 using a rubber-based resin, although the processing stability and solder heat resistance were somewhat excellent, the adhesive strength after soldering and the humidified solder bath resistance deteriorated. Thus, in the present invention, excellent heat resistance and electrical insulation can be expressed while maintaining adhesive strength, processing stability, and storage stability that could not be achieved with conventional resins and resin compositions. .

Claims (9)

A curable urethane resin obtained by reacting a terminal acid anhydride group-containing urethane prepolymer (C) and a hydroxyl group-containing resin (D),
The terminal isocyanate group-containing urethane prepolymer (C) obtained by reacting the polymer polyol (a1) and the diisocyanate compound (a2) with the terminal acid anhydride group-containing urethane prepolymer (C), a tetrabasic acid anhydride ( B) is a prepolymer obtained by reacting with
A curable urethane resin, wherein the hydroxyl group-containing resin (D) is a resin obtained by reacting a compound (d1) having two or more epoxy groups with a bisphenol compound (d2).   The curable urethane resin according to claim 1, wherein the polymer polyol (a1) is at least one compound selected from polycarbonate polyol, polyether polyol, polybutadiene polyol, and polysiloxane polyol.   The curable urethane resin according to claim 1 or 2, wherein the terminal isocyanate group-containing urethane prepolymer (A) has a urea bond.   The curable urethane resin according to any one of claims 1 to 3, which has an acid value of 1 to 150 mgKOH / g.   The curable urethane resin according to any one of claims 1 to 4, having a weight average molecular weight of 5,000 to 500,000.   A curable resin composition comprising the curable urethane resin according to claim 1 and an epoxy group-containing compound (E).   Furthermore, the curable resin composition of Claim 6 containing a thermosetting auxiliary agent (F).   Furthermore, the curable resin composition of Claim 6 or 7 containing a thermosetting compound (G). A first step of obtaining a terminal isocyanate group-containing urethane prepolymer (A) by reacting the polymer polyol (a1) with the diisocyanate compound (a2);
Second step of obtaining terminal acid anhydride group-containing urethane prepolymer (C) by reacting terminal isocyanate group-containing urethane prepolymer (A) obtained in the first step with tetrabasic acid anhydride (B). ,
A third step of obtaining a hydroxyl group-containing resin (D) by reacting a compound (d1) having two or more epoxy groups with a bisphenol compound (d2);
In addition, the terminal acid anhydride group-containing urethane prepolymer (C) obtained in the second step and the hydroxyl group-containing resin (D) obtained in the third step are reacted to obtain a curable urethane resin. A method for producing a curable urethane resin, comprising four steps.