JP2010132735A - Curable urethane resin and curable resin composition comprising the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a curable urethane resin which is excellent in adhesiveness, heat resistance, flexibility, bendability, adhesion property, electrical insulating property, resistance to moist heat, and the like, and is preferably used as an adhesive and a coating agent used in electronic materials and the like, including a printed circuit board. <P>SOLUTION: The curable urethane resin is prepared by reacting a terminal isocyanate group-containing urethane prepolymer (C) with a carboxyl group- and terminal acid anhydride group-containing prepolymer (F), wherein the terminal isocyanate group-containing urethane prepolymer (C) is prepared by reacting a polymer polyol (A) and a diisocyanate compound (B) and the carboxyl group- and terminal acid anhydride group-containing prepolymer (F) is prepared by reacting a compound (D), having a functional group which can be reacted with an acid anhydride group to generate a carboxyl group, with tetrabasic acid anhydride (E). <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. A curable urethane resin, a thermosetting resin composition containing the resin, and a curable urethane, which are preferably used as adhesives and coating agents used around electronic materials such as printed wiring boards. It aims at providing the manufacturing method of resin.

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 isocyanate group-containing urethane prepolymer (C) with a carboxyl group and a terminal acid anhydride group-containing prepolymer (F). ,
The terminal isocyanate group-containing urethane prepolymer (C) is a prepolymer obtained by reacting the polymer polyol (A) and the diisocyanate compound (B),
A compound (D) having a functional group capable of producing a carboxyl group by reacting a carboxyl group and a terminal acid anhydride group-containing prepolymer (F) with an acid anhydride group, and a tetrabasic acid anhydride (E) It is related with the curable urethane resin characterized by being the prepolymer formed by making it react.

  Moreover, 2nd invention is curable urethane of 1st invention whose polymer polyol (A) is at least 1 sort (s) of compounds chosen from the group which consists of polycarbonate polyol, polyether polyol, polybutadiene polyol, and polysiloxane polyol. It relates to resin.

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

  The fourth invention relates to the curable urethane resin according to any one of the first to third inventions, wherein the carboxyl group- and terminal acid anhydride group-containing prepolymer (F) has an amide bond.

  Moreover, 5th invention is related with the curable urethane resin of the invention in any one of 1st-4th whose acid value is 1-150 mgKOH / g.

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

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

  Moreover, 8th invention is related with the curable resin composition of 7th invention containing a thermosetting adjuvant (H).

  Moreover, 9th invention is related with the curable resin composition of 7th or 8th invention containing a thermosetting compound (J).

The tenth invention is a first step in which a polymer polyol (A) and a diisocyanate compound (B) are reacted to obtain a terminal isocyanate group-containing urethane prepolymer (C),
Prepolymer containing carboxyl group and terminal acid anhydride group by reacting compound (D) having a functional group capable of reacting with acid anhydride group to form carboxyl group and tetrabasic acid anhydride (E) A second step of obtaining (F),
And curing by reacting the terminal isocyanate group-containing urethane prepolymer (C) obtained in the first step with the carboxyl group and terminal acid anhydride group-containing prepolymer (F) obtained in the second step. The present invention relates to a method for producing a curable urethane resin, comprising a third step of obtaining a curable urethane resin.

  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 A curable urethane resin, a thermosetting resin composition containing the resin, and a curable urethane, which are preferably used as adhesives and coating agents used around electronic materials such as printed wiring boards. A method for producing a resin could be provided.

The curable urethane resin of the present invention is a terminal isocyanate group-containing urethane prepolymer (C) obtained by reacting a polymer polyol (A) and a diisocyanate compound (B),
And a compound (D) having a functional group capable of reacting with an acid anhydride group to form a carboxyl group [hereinafter sometimes referred to as a compound (D). ] And a tetrabasic acid anhydride (E) are reacted with a carboxyl group and a terminal acid anhydride group-containing prepolymer (F).

  In particular, the compound to be reacted with the terminal isocyanate group-containing urethane prepolymer (C) is a carboxyl group and terminal acid anhydride group-containing prepolymer obtained by reacting the compound (D) with a tetrabasic acid anhydride (E) ( F) are very important properties as adhesives and coating agents used around electronic materials such as printed wiring boards, such as storage stability before curing, processing stability during curing, and curing. The solder heat resistance after soldering, the solder heat resistance after humidification, etc. can be remarkably improved. This is because a high molecular weight can be achieved by reacting the terminal isocyanate group-containing urethane prepolymer (C) with the carboxyl group and terminal acid anhydride group-containing prepolymer (F), and at the same time in the main chain. A carboxyl group can be introduced, and this functions as a new thermal crosslinking point, so that the workability and the heat resistance of the cured coating film can be remarkably improved.

  For example, when a tetrabasic acid anhydride (E) is used instead of a carboxyl group and a terminal acid anhydride group-containing prepolymer (F), generally the adhesiveness derived from a urethane bond and the terminal acid anhydride group Adhesion and heat resistance can be obtained to a certain extent by cross-linking, but it is difficult to form sufficient cross-linking because of the distance between the cross-linking points, and more advanced tests such as high-temperature solder tests and solder tests in a humidified state. Solder heat resistance is not satisfactory. 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 has good storage stability due to the effects of high molecular weight by the carboxyl group and terminal acid anhydride group-containing prepolymer (F) and the introduction of appropriate crosslinking points into the main chain. High heat resistance can be exhibited while maintaining high adhesive force without increasing Tg and simultaneously satisfying the properties and processing stability.

  Moreover, the curable urethane resin of the present invention is higher by using at least one compound selected from the group consisting of polycarbonate polyol, polyether polyol, polysiloxane polyol, and polybutadiene diol, particularly as the polymer polyol (A). It exhibits electrical insulation and heat resistance, and at the same time has a polycarbonate skeleton and a polysiloxane skeleton, which are generally difficult to bond due to the effects of the carboxyl group and terminal acid anhydride group-containing prepolymer (F) used. High adhesion to the substrate.

  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, since the curable urethane resin of the present invention does not require the use of a high Tg raw material, it exhibits excellent flexibility. Resins with high flexibility generally tend to have poor heat resistance, but the resin of the present invention introduces an imide bond in the molecule, and thus exhibits high heat resistance compared to general urethane resins. Furthermore, the use of the carboxyl group- and terminal acid anhydride group-containing prepolymer (F) introduces a crosslinking point, that is, a carboxyl group, into the main chain, so that the heat resistance can be further improved by crosslinking. it can.

  For example, a low Tg skeleton or a urethane bond is usually introduced in order to ensure flexibility, but high heat resistance cannot be ensured due to poor heat resistance. Moreover, in order to ensure heat resistance, a high Tg skeleton and a high heat resistant bond are introduced. However, since these generally have poor flexibility, it is impossible to achieve both heat resistance and flexibility.

  On the other hand, the present invention can solve the trade-off between high flexibility and high heat resistance for the reasons described above. In the present invention, the flexibility is further improved by suitably using at least one compound selected from the group consisting of low-Tg polycarbonate polyol, polyether polyol, polysiloxane polyol, and polybutadiene polyol as the polymer polyol (A). can do.

  Moreover, the curable urethane resin of this invention can further improve these effects by introduce | transducing a urea bond and an amide bond suitably. Specifically, by introducing urea bonds and amide bonds, the cohesive strength of the resin layer increases, and as a result, the adhesive strength does not adversely affect storage stability, processing stability, flexibility, and electrical insulation. And heat resistance can be improved.

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

  The curable urethane resin of the present invention is prepared by reacting a polymer polyol (A) and a diisocyanate compound (B) as essential components to produce a terminal isocyanate group-containing urethane prepolymer (C), and the resulting terminal isocyanate group-containing urethane. A compound (D) having a functional group capable of reacting with an acid anhydride group to form a carboxyl group separately from 1.0 mol of the isocyanate group of the prepolymer (C), and a tetrabasic acid anhydride (E ) And the acid anhydride group in the terminal acid anhydride group-containing prepolymer (F) obtained by reacting with the above compound, preferably 1.0 to 4.0 mol, more preferably 1.05 to 3.50. It can be obtained by reacting at a molar ratio.

  Here, the ratio of the carboxyl group and the acid anhydride group in the terminal acid anhydride group-containing prepolymer (F) to react with 1.0 mol of the isocyanate group of the terminal isocyanate group-containing urethane prepolymer (C) is 1. When the amount is less than 0 mol, an isocyanate group may finally remain at the polymer terminal, and storage stability may deteriorate. The ratio of reacting the carboxyl group and the acid anhydride group in the terminal acid anhydride group-containing prepolymer (F) to 4.0 mol of the isocyanate group of the terminal isocyanate group-containing urethane prepolymer (C) is 4.0. When the amount exceeds mol, the amount of residual free carboxyl group and terminal acid anhydride group-containing prepolymer (F) increases, resulting in deterioration of workability such as occurrence of a large amount of protrusion during hot pressing, and high hygroscopicity and heat resistance. May adversely affect sex.

  The terminal isocyanate group-containing urethane prepolymer (C) is produced by reacting the polymer polyol (A) and the diisocyanate compound (B). Furthermore, as a desired component, a hydroxyl group-containing compound (a) [excluding those belonging to the aforementioned “polymer polyol (A)”], an isocyanate compound (b) having one or more isocyanate groups in the molecule, Amine compound (I) can be used as appropriate.

  In the present invention, when synthesizing the terminal isocyanate group-containing urethane prepolymer (C), the ratio of the reaction of the starting materials is the polymer polyol (A), the hydroxyl group-containing compound (a) optionally added, and the amine compound. Regarding (I), when the total of the hydroxyl group and amino group contained therein is 1 mole, the diisocyanate compound (B) and an isocyanate compound having one or more isocyanate groups in the molecule to be added (b) ) 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 (C) decreases, and the reaction with the following carboxyl group and terminal acid anhydride group-containing prepolymer (F) In the process, sufficient reaction is unlikely to occur, and gelation may occur during the reaction. Moreover, when there are more isocyanate groups than 2.00 mol, the molecular weight of terminal isocyanate group containing urethane prepolymer (C) becomes small, and it becomes difficult to obtain desired coating-film resistance and film formability.

  Moreover, when it is made to react in the ratio close | similar to 1.00 mol within the range of 1.00 mol-2.00 mol, the weight average molecular weight of terminal isocyanate group containing urethane prepolymer (C) becomes large enough, and is final. The flexibility and adhesion of the coating film obtained are improved. Similarly, when the reaction is performed at a ratio close to 2.00 mol, many sites (that is, terminal isocyanate groups) with which the carboxyl group and terminal acid anhydride group-containing prepolymer (F) are reacted in the subsequent step are obtained. Since the amount of imide bonds that can be introduced into the resin per unit weight 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 polymer polyol (A) used in the present invention is a compound having a repeating unit having a polymerization degree of 2 or more and containing two hydroxyl groups, and is measured by gel permeation chromatography (hereinafter also referred to as “GPC”). Preferably, it is a compound having a weight average molecular weight in terms of polystyrene of 500 to 50,000. Examples of the polymer polyol (A) 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 (A), 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 Since the copolymer polyether polyol, polysiloxane polyol, polybutadiene polyol, and the like are excellent in flexibility of the skeleton, heat resistance, and hydrolysis resistance, electrical insulation as the curable urethane resin of the present invention, Song resistance, heat resistance, excellent moisture resistance and the like, especially preferred.

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

  As a diisocyanate compound (B) 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, when the heat resistance of the target curable urethane resin is particularly improved, it is preferable to use an aromatic diisocyanate or an araliphatic diisocyanate, and the flexibility of the target curable urethane resin is particularly improved. In this case, it is preferable to use aliphatic diisocyanate or alicyclic diisocyanate. In the present invention, these diisocyanate compounds (B) 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 (a) 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 (A)”, and representative examples thereof include, for example, Monoalcohol compound (a-1) having one hydroxyl group in the molecule, diol compound (a-2) having two hydroxyl groups in the molecule, compound (a-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 (a-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 (a-1) having one hydroxyl group in these molecules is used, the polymerization terminal of the obtained terminal isocyanate group-containing urethane prepolymer (C) 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 (C) 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 (C). It can be suitably used when terminal modification of the prepolymer (C) 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 (a-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-oct Diol, 3,3'-dimethylol heptane, 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 (a-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 (a-3) having 3 or more hydroxyl groups in the molecule include trimethylol ethane, polytrimethylol ethane, trimethylol propane, polytrimethylol propane, pentaerythritol, polypentaerythritol, sorbitol, Mannitol, arabitol, xylitol, galactitol, glycerin and the like can be mentioned.

  In this invention, when using the compound (a-3) which has three or more hydroxyl groups in these molecules, since a part of terminal isocyanate group containing urethane prepolymer (C) 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 (a-3) having 3 or more hydroxyl groups in the molecule, it is preferable to use trimethylolpropane or pentaerythritol in terms of reaction control.

  As the isocyanate compound (b) having one or three or more isocyanate groups in the molecule, optionally used in the present invention, the monofunctional isocyanate having one isocyanate group in one molecule includes, 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 having 3 or more isocyanate groups in one molecule include aliphatic polyisocyanates such as aromatic polyisocyanates and lysine triisocyanates, araliphatic polyisocyanates, and alicyclic polyisocyanates. And a trimethylolpropane adduct of the diisocyanate compound (B) described above, a burette reacted with water, and a trimer having an isocyanurate ring.

  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 (C), 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 (C) 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 (C) is synthesized, it is preferable to react the amine compound (I) 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 remarkably improved. Therefore, in the present invention, the amine compound (I) is used. More preferably it is used. The amine compound (I) in the present invention refers to a compound having at least one primary or secondary amino group in the molecule.

  Examples of the amine compound (I) according to the present invention include monoamine compounds such as propylamine, hexylamine, cyclohexylamine, benzylamine, 2-ethylhexylamine, octylamine, dodecylamine, and aniline, ethylenediamine, propylenediamine, and 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′-diaminodiphenyl And aromatic polyamines such as ether.

  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.

  Also, as the amine compound (I), a primary amino group in a compound having a primary amino group is modified to a secondary amino group by Michael addition reaction with a (meth) acryloyl group of a (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 (C) 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 as amine compound (I) of this invention can also be used. 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 (I) may be used alone or in combination, and monoamines, diamines, and polyamines are appropriately selected or combined depending on the purpose and application. be able to. For example, when synthesizing the terminal isocyanate group-containing urethane prepolymer (C), by using a monoamine compound in combination, the amount of residual isocyanate groups can be reduced and the terminal 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 (I) used are the polymer polyol (A), the hydroxyl group-containing compound (a) to be added as necessary, and the hydroxyl groups contained in the amine compound (I). 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 (I) 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 amine compound (I) can be adjusted according to the objective within the said range.

  As a method of reacting the amine compound (I), a method of reacting with the diisocyanate compound (B) [and optionally further with the isocyanate compound (b)] after charging simultaneously with other raw materials such as the polymer polyol (A), Examples include a method of obtaining a terminal isocyanate group-containing urethane prepolymer (C) containing a urea bond by synthesizing an isocyanate-terminated urethane chain in advance and dropping or adding the amine compound (I) thereto.

  In the present invention, the conditions for synthesizing the terminal isocyanate group-containing urethane prepolymer (C) are not particularly limited, and can be performed under known conditions. For example, a polymer polyol (A) and a solvent [and optionally a hydroxyl group-containing compound (a)] 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 (B The terminal isocyanate group-containing urethane prepolymer (C) can be obtained by adding [and optionally the isocyanate compound (b)] and heating at 50 to 150 ° C. with stirring. At this time, the amine compound (I) can also be used as described above.

  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 introducing the diisocyanate compound (B), the polymer polyol (A) and solvent previously charged in the flask may be heated and stirred at 100 ° C. or higher to remove part of the solvent. This operation is usually performed to remove water in the system (dehydration treatment). By this operation, when the diisocyanate compound (B) is reacted, the deactivation of isocyanate groups by water can be suppressed.

  Next, the carboxyl group- and terminal acid anhydride group-containing prepolymer (F) will be described. The carboxyl group- and terminal acid anhydride group-containing prepolymer (F) includes a compound (D) having a functional group capable of reacting with an acid anhydride group to form a carboxyl group, and a tetrabasic acid anhydride (E). It is manufactured by reacting. Here, examples of the functional group capable of reacting with the acid anhydride group in the compound (D) to form a carboxyl group include a hydroxyl group and an amino group. Examples of the compound having a hydroxyl group as the compound (D) include the polymer polyol (A) and the hydroxyl group-containing compound (a), and examples of the compound having an amino group as the compound (D) include the above-described compounds. An amine compound (I) is mentioned.

  The tetrabasic acid anhydride (E) used here is preferably a compound having 2 or more carboxylic acid anhydride groups in the molecule and having 8 to 50 carbon atoms, such as pyromellitic anhydride, 3 , 4,3 ′, 4′-benzophenone tetracarboxylic dianhydride, 2,3,2 ′, 3′-benzophenone tetracarboxylic dianhydride, 2,3,3 ′, 4′-benzophenone tetracarboxylic dianhydride Anhydride, 3,3 ′, 4,4′-diphenyltetracarboxylic dianhydride, 2,2 ′, 3,3′-diphenyltetracarboxylic dianhydride, 4,4′-oxydiphthalic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, 2,2-bis (2,3-dicarboxyphenyl) propane dianhydride, 1,1-bis (2,3-dicarboxy) Phenyl) ethane dianhydride, 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-naphthalenetetra Carboxylic 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-di Carboxyphenyldimethylsilyl) benzene dianhydride, 1,3-bis (3,4-dicarboxyphenyl) -1,1,3,3-tetramethyldicyclohexane dianhydride, p-phenylbis (trimellitic acid mono Ester acid anhydride), ethylenetetracarboxylic dianhydride, 1,2,3,4-butanetetracarboxylic dianhydride, decahodronaphthalene-1,4,5,8-tetracarboxylic 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 acid 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-bis (2- Droxyhexafluoroisopropyl) 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. “Licacid TMTA-C”, “Licacid MTA-10”, “Licacid MTA-15”, “Licacid TMEG series”, “ Ricacid TDA "and the like. In the present invention, these tetrabasic acid anhydrides (E) 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.

  In the present invention, when synthesizing the carboxyl group- and terminal acid anhydride group-containing prepolymer (F), the ratio of the reaction of the starting material is a function that can react with the acid anhydride group to generate a carboxyl group. Of the acid anhydride group contained in the tetrabasic acid anhydride (E) with respect to 1 mol of the functional group capable of reacting with the acid anhydride group in the compound (D) having a group to form a carboxyl group. The total is preferably reacted at a rate of 1.00 mol to 4.00 mol, more preferably at a rate of 1.05 mol to 1.95 mol. When the acid anhydride group is less than 1.00 mol, the amount of the terminal acid anhydride group of the carboxyl group and the terminal acid anhydride group-containing prepolymer (F) decreases, and the terminal isocyanate group-containing urethane prepolymer (C) and In this reaction step, a sufficient reaction with the isocyanate group may be difficult to occur. Moreover, when there are more acid anhydride groups than 4.00 mol, the molecular weight of a carboxyl group and a terminal acid anhydride group containing prepolymer (F) will become small, and it will become difficult to obtain desired coating-film resistance and film formability.

  Further, when the reaction is carried out at a ratio close to 1.00 mol within the range of 1.00 mol to 4.00 mol, the weight average molecular weight of the carboxyl group- and terminal acid anhydride group-containing prepolymer (F) is sufficiently large. Thus, the flexibility and adhesion of the finally obtained coating film are improved. Similarly, when the reaction is carried out at a ratio close to 4.00 mol, many sites (that is, terminal acid anhydride groups) that react with the terminal isocyanate group-containing urethane prepolymer (C) are obtained in the subsequent step. The amount of imide bonds that can be introduced into the film increases, and 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-4.00 mol.

  Further, in the present invention, when synthesizing the carboxyl group- and terminal acid anhydride group-containing prepolymer (F), the compound (D) having a functional group capable of reacting with an acid anhydride group to form a carboxyl group. Of these, it is preferable to react the amine compound (I). Thereby, an amide bond 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 remarkably improved. Therefore, in the present invention, the amine compound (I) is used. More preferably it is used.

  The proportion of the amine compound (I) used when synthesizing the carboxyl group and terminal acid anhydride group-containing prepolymer (F) is to react with the acid anhydride group in the compound (D) to generate a carboxyl group. When the total number of functional groups that can be used 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 introduced amide bond is small, and the effect of using the amine compound (I) is difficult to obtain. In addition, when the amino group is used in a proportion higher than 0.90 mol, the amount of the amide bond 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 amine compound (I) can be adjusted according to the objective within the said range.

  In the present invention, the conditions for synthesizing the carboxyl group- and terminal acid anhydride group-containing prepolymer (F) are not particularly limited, and can be performed under known conditions. For example, a hydroxyl group-containing compound and / or an amino group-containing compound as a compound (D) and a solvent are charged in a flask, and dissolved uniformly by heating and stirring at 20 to 120 ° C. in a nitrogen stream, By adding the acid anhydride (E) and heating at 20 to 150 ° C. with stirring, the carboxyl group- and terminal acid anhydride group-containing prepolymer (F) can be obtained.

  Alternatively, a hydroxyl group-containing compound as a compound (D) and a solvent are charged in a flask, dissolved uniformly by heating and stirring at 20 to 120 ° C. in a nitrogen stream, and then a tetrabasic acid anhydride (E) is added. After heating at 20 to 150 ° C. with stirring, a predetermined amount of the compound having an amino group as the compound (D) is added dropwise, and reacted at 20 to 100 ° C. to react with the carboxyl group and terminal acid anhydride group-containing prepolymer. A polymer (F) can be obtained.

  In the reaction, a catalyst such as a tertiary amino group-containing compound may be used as necessary. In addition, before adding the tetrabasic acid anhydride (E), the hydroxyl group-containing compound and the solvent as the compound (D) previously charged in the flask are heated and stirred at 100 ° C. or higher to remove part of the solvent. May be. This operation is usually performed to remove water in the system (dehydration treatment), and this operation suppresses the deactivation of the acid anhydride group by water when reacting the tetrabasic acid anhydride (E). can do.

  The reaction conditions for reacting the isocyanate group in the terminal isocyanate group-containing urethane prepolymer (C) with the acid anhydride group in the carboxyl group and terminal acid anhydride group-containing prepolymer (F) are particularly limited. Instead, it can be performed under known conditions. For example, a reaction vessel containing a terminal isocyanate group-containing urethane prepolymer (C) that has been reacted is charged with a carboxyl group and a terminal acid anhydride group-containing prepolymer (F), and an additional solvent, and stirred under a nitrogen stream. While heating at 60-100 ° C. for 0.5-5 hours. Then, a catalyst is added, it heats up to 120-150 degreeC, and curable urethane resin is obtained by stirring for 2 to 6 hours. At this time, it is preferable to add a tertiary amino group-containing compound such as triethylamine or dimethylbenzylamine as a catalyst. In this case, the terminal isocyanate group-containing urethane prepolymer (C) and the carboxyl group and terminal acid anhydride group-containing prepolymer are included. It is preferable to add in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight in total with the polymer (F).

  The present invention is characterized in that the terminal isocyanate group-containing urethane prepolymer (C) is chain-extended using a carboxyl group and a terminal acid anhydride group-containing prepolymer (F).

  Furthermore, the curable urethane resin of the present invention is preferably made to have a high molecular weight by reacting with a chain extender (K) as necessary. Thereby, the curable urethane resin obtained further improves the cohesive force, adhesive force, and heat resistance of the cured coating film.

  The chain extender (K) referred to in the present invention is a compound capable of increasing the molecular weight of the resin by reacting with an acid anhydride group or a carboxyl group in the curable urethane resin. Examples of the functional group capable of reacting with the acid anhydride group in the curable urethane resin include a hydroxyl group, a primary or secondary amino group, a thiol group, an epoxy group, and an oxetane group. Moreover, since an aziridinyl group, a vinyl ether group, and a carbodiimide group can be made to react with the carboxyl group in curable urethane resin, the compound which has these functional groups can also be used as a chain extender (K). Among these functional groups, the hydroxyl group, primary or secondary amino group, thiol group, vinyl ether group, and carbodiimide group are required to have two or more in the chain extender (K). , And the oxetane group generates a hydroxyl group by reacting with an acid anhydride group, and this hydroxyl group further reacts with an acid anhydride group in the curable urethane resin, so that at least one oxetane group is present in the chain extender (K). Just have it. Moreover, since an aziridinyl group reacts with the carboxyl group which the acid anhydride group opened, an amino group is produced | generated, it is sufficient to have at least one in a chain extender (K) like the above. The chain extender (K) of the present invention also includes compounds having a combination of these functional groups.

  Specific examples of the chain extender (K) include epoxy group-containing compounds, oxetane group-containing compounds, compounds containing two or more hydroxyl groups, compounds containing two or more primary or secondary amino groups, aziridinyl Examples thereof include a group-containing compound, a compound containing two or more carbodiimide groups, a compound containing two or more vinyl ether groups, and a compound containing two or more thiol groups.

As an epoxy group containing compound, the epoxy group containing compound illustrated below is mentioned. For example, N-glycidyl phthalimide, methyl glycidyl ether, n-butyl glycidyl ether, t-butyl glycidyl ether, 2-ethylhexyl glycidyl ether, decyl glycidyl ether, stearyl glycidyl ether, allyl glycidyl ether, phenyl glycidyl ether, p-sec-butyl Phenyl glycidyl ether, p-tert-butylphenyl glycidyl ether, butoxypolyethylene glycidyl ether, glycidol, styrene oxide, diallyl monoglycidyl isocyanuric acid, glycidyl (meth) acrylate, 4-hydroxybutyl acrylate glycidyl ether, 3- (2-biphenyloxy ) -1,2-epoxypropane, o-cresyl glycidyl ether, m-cresyl glycy Ether, compounds having one epoxy group such as p- cresyl glycidyl ether;
Ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, monoallyl diglycidyl isocyanuric acid, bisphenol A / epichlorohydrin type epoxy resin, bisphenol F / epichlorohydrin type epoxy resin Polyglycidyl ether of biphenol / epichlorohydrin type epoxy resin, glycerin / epichlorohydrin adduct, phenol novolac type epoxy resin, cresol novolac type epoxy resin, dicyclopentadiene type epoxy resin, naphthalene type epoxy resin, ethylene glycol / epichlorohydrin addition Polyglycidyl ether, pentaerythritol polyglycidyl ether, resorcinol diglycidyl ether, Ributadiene diglycidyl ether, hydroquinone diglycidyl ether, dibromoneopentyl glycol diglycidyl ether, neopentyl glycol diglycidyl ether, trimethylolpropane polyglycidyl ether, hexahydrophthalic acid diglycidyl ester, hydrogenated bisphenol A diglycidyl ether, polypropylene Glycol diglycidyl ether, N, N, N ′, N′-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N-diglycidylaniline, N, Examples thereof include compounds having two or more epoxy groups such as N-diglycidyl toluidine.

As an oxetane group containing compound, the oxetane group containing compound illustrated below is mentioned. For example, a compound having one oxetane group such as oxetane alcohol and oxetane alcohol methacrylate;
1,4-bis {[(3-ethyloxetane-3-yl) methoxy] methyl} benzene [manufactured by Toa Gosei Co., Ltd., trade name; Aron oxetane OXT-121 etc.], 3-ethyl-3-{[(3- Ethyl oxetane-3-yl) methoxy] methyl} oxetane [manufactured by Toagosei 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 An etherified product with a novolak resin, an esterified product of (2-ethyl-2-oxetanyl) ethanol and a polyvalent carboxylic acid compound, etc. Examples include compounds having two or more xetane groups.

  Examples of the compound containing two or more hydroxyl groups include the diol compound (a-2) described above and the compound (a-3) having three or more hydroxyl groups in the molecule. Furthermore, compounds having two or more phenolic hydroxyl groups can also be used.

  Examples of the compound containing two or more primary or secondary amino groups include those exemplified as the amine compound (I) described above.

  Examples of the aziridinyl group-containing compound include aziridinyl group-containing compounds exemplified below. For example, N, N′-diphenylmethane-4,4′-bis (1-aziridinecarboxite), N, N′-toluene-2,4-bis (1-aziridinecarboxite), bisisophthaloyl-1- (2-methylaziridine), tri-1-aziridinylphosphine oxide, N, N′-hexamethylene-1,6-bis (1-aziridinecarboxite), trimethylolpropane-tri-β-aziridinylpro Pionate, 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′-bishydroxymethylbutanol tris [3 -(1-aziridinyl) propionate], pentaerythritol tetra [3- (1-aziridinyl) propionate], diphenylmethane-4,4-bis-N, N′-ethyleneurea, 1,6-hexamethylenebis-N, N Examples include '-ethyleneurea, 2,4,6- (triethyleneimino) -Syn-triazine, bis [1- (2-ethyl) aziridinyl] benzene-1,3-carboxylic acid amide, and the like.

  Examples of the compound containing two or more carbodiimide groups include carbodiimide group-containing compounds exemplified below. An example is the Carbodilite series from Nisshinbo Industries. Among these, Carbodilite V-01, 03, 05, 07, and 09 are preferable because of excellent compatibility with organic solvents.

Examples of the compound containing two or more vinyl ether groups include the vinyl ether group-containing compounds exemplified below. For example, ethylene glycol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, tetraethylene 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 Side 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 Examples thereof include tetravinyl ether, dipentaerythritol hexavinyl ether, dipentaerythritol polyvinyl ether, ditrimethylolpropane tetravinyl ether, and ditrimethylolpropane polyvinyl ether.
Examples of the compound containing two or more thiol groups include 1,3-propanedithiol, 1,2-ethanedithiol, 2,2′-oxydiethanethiol, 2,2′-thiodiethanethiol, 1,3- Propanedithiol, 1,4-butanedithiol, 1,5-pentanedithiol, 1,6-hexanedithiol, 1,9-nonanedithiol, polytetramethylenedithiol, ethylene glycol bisthioglycolate, butanediol bisthioglycolate, Examples include 2,5-dimercapto-1,3,4-thiadiazole, 1,4-bis (3-mercaptobutyryloxy) butane, thiodibenzenethiol, and the like.

  In the present invention, by chain extension using a chain extender (K), structural modification such as high molecular weight and branching of the curable urethane resin can be performed. These structural modifications improve storage stability and processing stability, and further improve the heat resistance of the cured coating film while maintaining high adhesive strength. As the chain extender (K), an epoxy group-containing compound, a compound containing two or more hydroxyl groups, and a compound containing two or more amino groups are preferable from the viewpoint that the molecular weight can be increased by adding a small amount. In addition, from the viewpoint that chain extension can be performed under relatively mild conditions (for example, low temperature and short time), compounds containing aziridinyl group, compounds containing two or more carbodiimide groups, and compounds containing two or more vinyl ether groups are preferred. In addition, from the viewpoint that many crosslinkable functional groups can be introduced into the chain extension site, a compound having both a hydroxyl group and a carboxyl group, a compound having both an amino group and a carboxyl group, and a compound having both an amino group and a phenolic hydroxyl group It is preferable to use a compound having both a thiol group and a carboxyl group. In the present invention, these chain extenders may be used alone or in combination.

  Examples of the compound having both a hydroxyl group and a carboxyl group include dimethylolbutanoic acid, dimethylolpropionic acid, and derivatives thereof (caprolactone adduct, ethylene oxide adduct, propylene oxide adduct, etc.), 3-hydroxysalicylic acid, Examples include 4-hydroxysalicylic acid, 5-hydroxysalicylic acid, 2-carboxy-1,4-cyclohexanedimethanol and the like.

  Examples of the compound having both an amino group and a carboxyl group include 3,3'-dicarboxy-4,4'-diaminobiphenyl.

  Examples of the compound having both an amino group and a phenolic hydroxyl group include 3,3'-dihydroxy-4,4'-diaminobiphenyl.

  Examples of the compound having both a thiol group and a carboxyl group include mercaptopropionic acid.

  The reaction conditions for reacting the acid anhydride group or carboxyl group in the curable urethane resin with the functional group in the chain extender (K) are not particularly limited, and can be performed under known conditions. . For example, the chain extender (K) was added to the curable urethane resin, and the chain was extended by the chain extender (K) by stirring for 0.5 to 10 hours while heating at 100 to 160 ° C. in a nitrogen atmosphere. A curable urethane resin can be obtained.

  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 5,000 to 500,000, since the terminal of the resulting resin (that is, acid anhydride group) is large, a resin having high crosslinkability is obtained. The heat resistance of the obtained 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 (A) and a diisocyanate compound (B) are reacted to obtain a terminal isocyanate group-containing urethane prepolymer (C);
Prepolymer containing carboxyl group and terminal acid anhydride group by reacting compound (D) having a functional group capable of reacting with acid anhydride group to form carboxyl group and tetrabasic acid anhydride (E) A second step of obtaining (F);
And curing by reacting the terminal isocyanate group-containing urethane prepolymer (C) obtained in the first step with the carboxyl group and terminal acid anhydride group-containing prepolymer (F) obtained in the second step. A third step of obtaining a conductive urethane resin.

  Moreover, you may include the 4th process of making the curable urethane resin obtained at the 3rd process react with a chain extension agent (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 the reaction conditions in the second step, the reaction is preferably performed by heating and stirring at a temperature of room temperature to 120 ° C., and a reaction catalyst can be used as necessary. As reaction conditions of the third 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. In addition, as the reaction conditions of the fourth step, it is preferable to carry out the reaction by heating and stirring at a temperature of room temperature to 180 ° C. in the presence of nitrogen, and it is suitable as necessary after the completion of the third step. A new reaction catalyst can also be added.

  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, an amine-based or metal-based catalyst can be used as in the first step. As a catalyst used in the third step, water and 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 fourth step, an amine-based or metal-based catalyst can be used as in the first step.

  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 (G). The epoxy group-containing compound (G) will be described. The curable resin composition of the present invention is characterized by using an epoxy group-containing compound (G) as a curing agent for the curable urethane resin described above. The epoxy compound (G) in the present invention is not particularly limited as long as it is a compound containing an epoxy group in the molecule.

  For example, examples of the compound having one epoxy group in the molecule include compounds exemplified as the chain extender (K), such as N-glycidylphthalimide, glycidol, and glycidyl (meth) acrylate. These can be suitably used for the purpose of controlling the crosslink density of the cured product by using together with a compound having two or more epoxy groups in the molecule exemplified below as needed.

  Examples of the compound containing two or more epoxy groups in the molecule include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, bisphenol A / epichlorohydrin type epoxy resin, Bisphenol F / epichlorohydrin type epoxy resin, bisphenol S / epichlorohydrin type epoxy resin, bisphenol AD / epichlorohydrin type epoxy resin, biphenol / epichlorohydrin type epoxy resin, ethylene oxide adduct of bisphenol A or Propylene oxide adduct epichlorohydrin type epoxy resin, glycerin / epichlorohydrin adduct polyglycidyl ether, naphthalenediol diglycidyl ether, resorcino Rudiglycidyl ether, polybutadiene diglycidyl ether, hydroquinone diglycidyl ether, dibromoneopentyl glycol diglycidyl ether, neopentyl glycol diglycidyl ether, hexahydrophthalic acid diglycidyl ester, hydrogenated bisphenol A type diglycidyl ether, polypropylene glycol diglycidyl Ether, diphenylsulfone diglycidyl ether, dihydroxybenzophenone diglycidyl ether, biphenol diglycidyl ether, diphenylmethane diglycidyl ether, bisphenol full orange glycidyl ether, biscresol full orange glycidyl ether, bisphenoxyethanol full orange glycidyl ether, 1,3-bis ( N, N-diglycidyl Minomethyl) cyclohexane, N, N-diglycidylaniline, N, N-diglycidyltoluidine, Japanese Patent Application Laid-Open Nos. 2004-156024, 2004-315595, and 2004-323777. And an epoxy compound having a structure represented by the following formulas (4) to (6).

  Formula (4)

  Formula (5)

  Formula (6)

  Further, trishydroxyethyl isocyanurate triglycidyl ether, triglycidyl isocyanurate, “Epicoat 1031S”, “Epicoat 1032H60”, “Epicoat 604”, “Epicoat 630” manufactured by Japan Epoxy Resins Co., Ltd. Cresol novolak type epoxy resin, dicyclopentadiene type epoxy resin, naphthalene type epoxy resin, polyglycidyl ether of ethylene glycol / epichlorohydrin adduct, pentaerythritol polyglycidyl ether, trimethylolpropane disclosed in JP-A-2001-240654 Examples thereof include polyglycidyl ether, N, N, N ′, N′-tetraglycidyl-m-xylenediamine, 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.

  In particular, an isocyanurate ring-containing epoxy compound such as trishydroxyethyl isocyanurate triglycidyl ether or triglycidyl isocyanurate is preferred because it tends to improve adhesion to polyimide and copper when used in the present invention. Further, “Epicoat 1031S”, “Epicoat 1032H60”, “Epicoat 604”, and “Epicoat 630” manufactured by Japan Epoxy Resin Co., Ltd. are very preferable in the present invention because they are multifunctional and have excellent heat resistance. 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. Further, 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 (G) may be used alone or in combination. The amount of the epoxy group-containing compound (G) used may be determined in consideration of the application of the curable resin composition of the present invention, and is not particularly limited, but relative 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. Since the crosslinking density of the curable resin composition of the present invention can be adjusted to an appropriate value by using the epoxy group-containing compound (G), various physical properties of the cured coating film are further improved. Can do. If the amount of the epoxy group-containing compound (G) used is less than 0.5 parts by weight, the crosslinking density of the coating film 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 (H) of the present invention will be described. The heat curing aid (H) of the present invention represents a compound that contributes directly or catalytically to the curing reaction when the epoxy group-containing compound (G) and the curable urethane resin are cured. It is preferably used in the thermosetting resin composition.

Examples of the heat curing aid (H) 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 (H) may be used alone or in combination of two or more. The amount of the thermosetting aid (H) 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. If the amount of the thermosetting aid (H) used is less than 0.05 parts by weight, the effect of addition is difficult to obtain, and if the amount used is more than 20 parts by weight, an excess of the thermosetting aid ( H) tends to cause a decrease in electrical insulation, adhesive strength, and solder heat resistance.

  Next, the thermosetting compound (J) of the present invention will be described. The thermosetting compound (J) 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, amino group, epoxy group, carboxyl group, etc. Excluding those belonging to the containing compound (G). 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 (B) and the isocyanate compound (b) having 1 or 3 or more isocyanate groups in the molecule is described above. 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. Specifically, in addition to the above-described tetrabasic acid anhydride (E), polycarboxylic acid such as dicarboxylic acid anhydride, hexacarboxylic acid dianhydride, hexacarboxylic acid dianhydride, and maleic anhydride copolymer resin. And anhydrides. 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, and polymers thereof These may be used alone or in combination of two or more.

  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 (J) may use only 1 type and may use 2 or more types together. The amount of the thermosetting compound (J) 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 (J) 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 thermosetting 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 thermosetting 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 isocyanate 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) 69.0 parts, 40 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, 13.3 parts of isophorone diisocyanate and 0.41 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: 8400). .

<Production of carboxyl group- and terminal acid anhydride group-containing 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 mgKOH / g, Mw = 2000) 63.6 parts, pyromellitic anhydride 14.0 parts, toluene 40 parts as a solvent The mixture was heated to 100 ° C. with stirring under a nitrogen stream, and then 0.39 part of dimethylbenzylamine was added to the flask as a catalyst and stirred for 3 hours, and the prepolymer solution containing carboxyl groups and terminal acid anhydride groups ( Mw: 3400).

<Manufacture of curable urethane resin>
The carboxyl group- and terminal acid anhydride group-containing prepolymer solution was added to the terminal isocyanate group-containing urethane prepolymer solution, and the solid content was adjusted to 40% with 160 parts of cyclohexanone. This solution was stirred at 90 ° C., and it was confirmed by IR that the peak derived from the isocyanate group (near 2254 cm ⁻¹ ) disappeared, and then the temperature was raised to 135 ° C. and reacted for 4 hours. After cooling to room temperature, the curable urethane resin solution of the present invention was obtained. The weight average molecular weight of the curable urethane resin obtained in this production example was 79500, and the acid value of the resin solid content measured was 26.8 mgKOH / g.

[Production Examples 2 to 25]
Except having replaced with the material shown in Table 1 and Table 2, it carried out similarly to manufacture example 1, and obtained the curable urethane resin solution of this invention.

C-2090: Kuraray Co., Ltd .: 3-methyl-1,5-pentanediol / 1,6-hexanediol = 9/1 (molar ratio) copolymerized polycarbonate diol FM-4411: manufactured by Chisso Corporation, polydimethylsiloxane Diol C-590: manufactured by Kuraray Co., Ltd .: 3-methyl-1,5-pentanediol / 1,6-hexanediol = 9/1 (molar ratio) copolymerized polycarbonate diol C-5090: manufactured by Kuraray Co., Ltd .: 3- Methyl-1,5-pentanediol / 1,6-hexanediol = 9/1 (molar ratio) copolymerized polycarbonate diol UM-90: Ube Industries, Ltd .: 1,4-cyclohexanedimethanol / 1,6-hexane Diol = 1/1 (molar ratio) copolymerized polycarbonate diol T-5562: manufactured by Asahi Kasei Corporation: PO Carbonate diol PTG2000 sn: manufactured by Hodogaya Chemical Co., Ltd .: polytetramethylene glycol IPDI: isophorone diisocyanate MDI: diphenylmethane-4,4′-diisocyanate XDI: metaxylylene diisocyanate DBTDL: dibutyltin dilaurate PMDA: pyromellitic anhydride BTDA: 3, 3 ', 4,4'-Benzophenonetetracarboxylic dianhydride DSDA: Ricacid DSDA [Bis (3,4-dicarboxyphenyl) sulfone dianhydride: manufactured by Shin Nippon Rika Co., Ltd.]
DMBA: Dimethylbenzylamine

[Production Example 26]
<Production of terminal isocyanate 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 mgKOH / g, Mw = 2000) 64.8 parts, dimethylolbutanoic acid 0.54 parts, toluene 40 parts as a solvent The mixture was heated to 60 ° C. with stirring in a nitrogen stream and dissolved uniformly. Subsequently, 13.8 parts of isophorone diisocyanate and 0.39 parts 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). .

<Production of carboxyl group- and terminal acid anhydride group-containing 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 group value = 56 mg KOH / g, Mw = 2000) 66.9 parts, pyromellitic anhydride 14.7 parts, toluene 40 parts as a solvent The mixture was heated to 100 ° C. with stirring under a nitrogen stream, and then 0.41 part of dimethylbenzylamine was added to the flask as a catalyst, followed by stirring for 3 hours, and a prepolymer (Mw) containing carboxyl groups and terminal acid anhydride groups. : 3300).

<Manufacture of curable urethane resin>
The carboxyl group- and terminal acid anhydride group-containing prepolymer solution was added to the terminal isocyanate group-containing urethane prepolymer solution, and the solid content was adjusted to 40% with 160 parts of cyclohexanone. This solution was stirred at 90 ° C., and it was confirmed by IR that the peak derived from the isocyanate group (near 2254 cm ⁻¹ ) disappeared, and then the temperature was raised to 135 ° C. and reacted for 4 hours. After cooling to room temperature, the curable urethane resin solution of the present invention was obtained. The weight average molecular weight of the curable urethane resin obtained by this production example was 73100, and the acid value of the resin solid content measured was 28.7 mgKOH / g.

[Production Examples 27 to 29]
A curable urethane resin solution of the present invention was obtained in the same manner as in Production Example 26 except that the materials shown in Table 2 were used.

[Production Example 30]
<Production of terminal isocyanate 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 group value = 56 mg KOH / g, Mw = 2000) 71.3 parts, toluene 40 parts as a solvent, and stirring under nitrogen stream 60 The temperature was raised to 0 ° C. and dissolved uniformly. Subsequently, 13.7 parts of isophorone diisocyanate and 0.42 parts 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: 7600). .

<Production of carboxyl group- and terminal acid anhydride group-containing 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) 60.0 parts, dimethylolbutanoic acid 0.50 part, toluene 40 parts as a solvent The mixture was heated to 60 ° C. with stirring in a nitrogen stream and dissolved uniformly, and then 14.6 parts of pyromellitic anhydride was charged, the temperature was raised to 100 ° C., and then dimethylbenzylamine 0 was added to the flask as a catalyst. 37 parts were added and stirred for 3 hours to obtain a carboxyl group- and terminal acid anhydride group-containing prepolymer solution (Mw: 3100).

<Manufacture of curable urethane resin>
The carboxyl group- and terminal acid anhydride group-containing prepolymer solution was added to the terminal isocyanate group-containing urethane prepolymer solution, and the solid content was adjusted to 40% with 160 parts of cyclohexanone. This solution was stirred at 90 ° C., and it was confirmed by IR that the peak derived from the isocyanate group (near 2254 cm ⁻¹ ) disappeared, and then the temperature was raised to 135 ° C. and reacted for 4 hours. After cooling to room temperature, the curable urethane resin solution of the present invention was obtained. The weight average molecular weight of the curable urethane resin obtained in this production example was 19000, and the acid value of the resin solid content measured was 31.5 mgKOH / g.

[Production Example 31]
Except having replaced with the material shown in Table 2, it carried out similarly to manufacture example 30, and obtained the curable urethane resin solution of this invention.

[Production Example 32]
<Production of terminal isocyanate 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) 110.7 parts, 40 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, 21.3 parts of isophorone diisocyanate and 0.66 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). .

<Production of carboxyl group- and terminal acid anhydride group-containing prepolymer>
A 4-necked flask equipped with a stirrer, reflux condenser, nitrogen inlet pipe, inlet pipe, and thermometer was charged with 7.5 parts of 1,6-hexamethylenediamine and 40 parts of toluene as a solvent, and stirred under a nitrogen stream. The mixture was heated to 60 ° C. and uniformly dissolved, and then 27.7 parts of pyromellitic anhydride was charged, 0.14 part of dimethylbenzylamine was added as a catalyst, and the mixture was stirred at 60 ° C. for 3 hours. A terminal acid anhydride group-containing prepolymer solution (Mw: 1200) was obtained.

<Manufacture of curable urethane resin>
The carboxyl group- and terminal acid anhydride group-containing prepolymer solution was added to the terminal isocyanate group-containing urethane prepolymer solution, and the solid content was adjusted to 40% with 160 parts of cyclohexanone. This solution was stirred at 90 ° C., and it was confirmed by IR that the peak derived from the isocyanate group (near 2254 cm ⁻¹ ) disappeared, and then the temperature was raised to 135 ° C. and reacted for 4 hours. After cooling to room temperature, the curable urethane resin solution of the present invention was obtained. The weight average molecular weight of the curable urethane resin obtained in this production example was 47600, and the acid value of the resin solid content measured was 36.5 mgKOH / g.

[Production Example 33]
Except having replaced with the material shown in Table 2, it carried out similarly to manufacture example 32, and obtained the curable urethane resin solution of this invention.

[Production Example 34]
<Production of terminal isocyanate 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) 69.0 parts, 40 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, 13.3 parts of isophorone diisocyanate and 0.41 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: 8400). .

<Production of carboxyl group- and terminal acid anhydride group-containing 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 mgKOH / g, Mw = 2000) 63.6 parts, pyromellitic anhydride 14.0 parts, toluene 40 parts as a solvent The mixture was heated to 100 ° C. with stirring under a nitrogen stream, and then 0.39 part of dimethylbenzylamine was added to the flask as a catalyst and stirred for 3 hours, and the prepolymer solution containing carboxyl groups and terminal acid anhydride groups ( Mw: 3400).

<Manufacture of curable urethane resin>
To the terminal isocyanate group-containing urethane prepolymer solution, the carboxyl group- and terminal acid anhydride group-containing prepolymer solution was added, and the solid content was adjusted to 40% with 160 parts of cyclohexanone. This solution was stirred at 90 ° C. and it was confirmed by IR that the peak derived from the isocyanate group (near 2254 cm ⁻¹ ) disappeared, and then the temperature was raised to 135 ° C. and reacted for 4 hours. Thereafter, the temperature was lowered to 120 ° C., EX-731 (Nagasedenacol “EX-731”, [N-glycidyl phthalimide]: manufactured by Nagase ChemteX Corporation) was added, and the mixture was stirred at 120 ° C. for 6 hours. . After cooling to room temperature, the curable urethane resin solution of the present invention was obtained. The weight average molecular weight of the curable urethane resin obtained in this production example was 105000, and the acid value of the resin solid content measured was 23.7 mgKOH / g.

[Production Example 35]
Except having replaced with the material shown in Table 2, it carried out similarly to manufacture example 34, and obtained the curable urethane resin solution of this invention.

BA: dimethylolbutanoic acid TMP: trimethylolpropane 1,6-HDA: 1,6-hexamethylenediamine EX731: Nagase Denacol "EX-731" manufactured by Nagase ChemteX Corporation

[Production Example 36]
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 curable urethane resin obtained in this production example was 14,000, and the acid value of the resin solid content measured was 27 mgKOH / g.

[Production Examples 37 to 42]
A curable urethane resin solution was obtained in the same manner as in Production Example 36 except that the materials shown in Table 3 were used.

[Production Example 43]
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 curable urethane resin obtained by this production example was 27000, and the acid value of the resin solid content measured was 29 mgKOH / g.
The compositions of Production Examples 36 to 43 are shown in Table 3.

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

[Production Example 44]
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 curable urethane resin obtained by this production example was 32000, and the acid value of the resin solid content measured was 11 mgKOH / g.

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 (G) 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 auxiliary (H) 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 2-35)
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 35, 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 36 to 44, respectively. .

(Examples 36 to 55)
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.

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, manufactured by Co., Ltd.
Oncoat 1040: Nagase ChemteX Corp., fluorene type polyfunctional epoxy resin 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 5, 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 thickness of 45 μm. It was sandwiched between the copper foil surfaces of the copper-clad laminate, laminated at 80 ° C., and then subjected to 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 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 heated and stored. 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 6 and 7 below.

  About Table 6, as can be seen from the examples and comparative examples, the resin used in the comparative example is a high molecular weight and a suitable crosslinking point into the main chain by the carboxyl group- and terminal acid anhydride group-containing prepolymer (F). Since no introduction was 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 largely influenced by the introduction of a crosslinkable functional group into the resin main chain and the high molecular weight. Further, in Comparative Example 3 made of a resin using a polyester skeleton in the production example, 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 43 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.

As can be seen from the examples and comparative examples in Table 7, in the examples, the effect of increasing the molecular weight by introducing a carboxyl group- and terminal acid anhydride group-containing prepolymer (F) and introducing an appropriate crosslinking point into the main chain was performed. And showed good results in all physical properties. Furthermore, by adding the thermosetting compound (J), 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 increasing the molecular weight of the resin, introducing an appropriate crosslinking point into the main chain, and the thermosetting compound (J). On the other hand, in the comparative example, since the high molecular weight by the carboxyl group- and terminal acid anhydride group-containing prepolymer (F) and the introduction of appropriate crosslinking points into the main chain are not carried out, All physical properties 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 (10)

A curable urethane resin obtained by reacting a terminal isocyanate group-containing urethane prepolymer (C) with a carboxyl group and a terminal acid anhydride group-containing prepolymer (F),
The terminal isocyanate group-containing urethane prepolymer (C) is a prepolymer obtained by reacting the polymer polyol (A) and the diisocyanate compound (B),
A compound (D) having a functional group capable of producing a carboxyl group by reacting a carboxyl group and a terminal acid anhydride group-containing prepolymer (F) with an acid anhydride group, and a tetrabasic acid anhydride (E) A curable urethane resin characterized by being a prepolymer obtained by reacting with.   The curable urethane resin according to claim 1, wherein the polymer polyol (A) is at least one compound selected from the group consisting of 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 (C) has a urea bond.   The curable urethane resin according to any one of claims 1 to 3, wherein the carboxyl group- and terminal acid anhydride group-containing prepolymer (F) has an amide bond.   Acid value is 1-150 mgKOH / g, The curable urethane resin in any one of Claims 1-4.   The curable urethane resin according to any one of claims 1 to 5, 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 (G).   Furthermore, the curable resin composition of Claim 7 containing a thermosetting auxiliary agent (H).   Furthermore, the curable resin composition of Claim 7 or 8 containing a thermosetting compound (J). A first step of obtaining a terminal isocyanate group-containing urethane prepolymer (C) by reacting a polymer polyol (A) with a diisocyanate compound (B);
Prepolymer containing carboxyl group and terminal acid anhydride group by reacting compound (D) having a functional group capable of reacting with acid anhydride group to form carboxyl group and tetrabasic acid anhydride (E) A second step of obtaining (F),
And curing by reacting the terminal isocyanate group-containing urethane prepolymer (C) obtained in the first step with the carboxyl group and terminal acid anhydride group-containing prepolymer (F) obtained in the second step. The manufacturing method of curable urethane resin characterized by including the 3rd process of obtaining curable urethane resin.