JP5108388B2 - Curable resin composition and cured product - Google Patents

Description

  The present invention relates to a heat and / or photocurable resin composition obtained by reacting a carboxyl group-containing urethane resin with a compound having both a (meth) acrylic double bond and an epoxy group. The present invention relates to a curable resin composition and a cured product that provide an overcoat agent, a surface protective film, and the like that are suitable for overcoating applications that provide a flexible circuit board with low warpage and excellent long-term reliability of electrical insulation.

  Conventionally, the surface protection film for flexible wiring circuits has been made by punching a polyimide film called a coverlay film with a mold made in accordance with the pattern, and then attaching it with an adhesive or giving it flexibility. An ultraviolet curing type or a thermosetting type overcoat agent is applied by a screen printing method, and the latter is particularly useful in terms of workability. As these curing type overcoat agents, resin compositions mainly composed of epoxy resin, acrylic resin, or composites thereof are known. These are often mainly composed of resins that have been modified, such as the introduction of a butadiene skeleton, a siloxane skeleton, a polycarbonate diol skeleton, a long-chain aliphatic skeleton, and the like. In addition, while suppressing the deterioration of chemical resistance and electrical insulation as much as possible, the improvement of flexibility and the occurrence of warpage due to curing shrinkage have been suppressed.

  However, in recent years, flexible substrates have become lighter and thinner as electronic devices become lighter and smaller, and accordingly, the effects of flexibility and curing shrinkage of the resin composition to be overcoated are becoming more prominent. . For this reason, in the present situation, the curing type overcoat agent cannot satisfy the required performance in terms of warpage due to flexibility and curing shrinkage.

  Japanese Patent Application Laid-Open No. 2004-137370 (Patent Document 1) reacts a di-isocyanate polyurethane obtained by reacting a polycarbonate diol using a diol having 6 or less carbon atoms with a diisocyanate compound and trimellitic acid. Although a polyamide-imide resin is disclosed, there is a drawback that the long-term reliability of the electrical properties of the cured product is not sufficient.

From the viewpoint of productivity, there is an advantage that molding by UV curing can be performed in a shorter time than thermosetting system that requires time for heating and cooling. There was a problem that flexibility and electrical insulation characteristics were inferior.
JP 2004-137370 A

  An object of the present invention is to provide a curable resin composition having a high long-term reliability of electrical insulation, flexible, small warpage due to curing shrinkage, and particularly capable of ultraviolet curing, and a cured product thereof.

As a result of intensive studies to solve the above problems, the present inventors have
(A) a carboxyl group-containing urethane resin obtained by reacting the following raw materials (a), (b) and (c);
(A) a polyisocyanate compound,
(B) a polyol compound,
(C) a dihydroxy compound having a carboxyl group,
(B) A curable resin composition obtained by reacting a compound having both a (meth) acrylic double bond and an epoxy group gives a cured film by ultraviolet irradiation or the like, and the cured film has good adhesion to the substrate. The results show that the long-term reliability of electrical insulation is high, and the present invention has been completed.

That is, the present invention relates to the following [1] to [20].
[1] (A) a carboxyl group-containing urethane resin using the following (a), (b) and (c) as raw materials;
(A) a polyisocyanate compound,
(B) a polyol compound,
(C) a dihydroxy compound having a carboxyl group,
(B) A curable resin composition comprising a curable resin obtained by reacting a compound having both a (meth) acrylic double bond and an epoxy group.
[2] The curable resin composition wherein the carboxyl group-containing urethane resin (A) is further made from (d) a monohydroxy compound as a raw material.
[3] The curable resin composition in which the carboxyl group-containing urethane resin (A) is further obtained from (e) a monoisocyanate compound.
[4] A curable resin composition in which the polyisocyanate compound (a) is a polyisocyanate compound having an alicyclic structure in which the number of carbon atoms other than carbon atoms in the isocyanate group is 6 to 30.
[5] A polyisocyanate compound having an alicyclic structure having 6 to 30 carbon atoms other than carbon atoms in the isocyanate group is 1,4-cyclohexane diisocyanate, isophorone diisocyanate, methylene bis (4-cyclohexyl isocyanate). A curable resin composition which is at least one compound selected from the group consisting of hydrogenated 1,3-xylylene diisocyanate and hydrogenated 1,4-xylylene diisocyanate.
[6] The polyol compound (b) is a polycarbonate polyol, a polyether polyol, a polyester polyol, a polylactone polyol, a polybutadiene polyol, a hydroxylated polysilicon at both ends, and an oxygen atom only in the hydroxyl group and has 18 to 18 carbon atoms. A curable resin composition which is at least one compound selected from the group consisting of 72 polyols.
[7] The curable resin composition wherein the dihydroxy compound (c) having a carboxyl group is 2,2-dimethylolpropionic acid and / or 2,2-dimethylolbutanoic acid.
[8] The monohydroxy compound (d) is methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol and t-butanol, 2-hydroxyethyl (meth) acrylic acid, and 4- A curable resin composition which is at least one compound selected from the group consisting of hydroxybutyl (meth) acrylic acid.
[9] A curable resin composition in which the carboxyl group-containing urethane resin (A) has a number average molecular weight of 1,000 to 100,000 and an acid value of 5 to 120 mg-KOH / g.
[10] The curable resin composition having a number average molecular weight of 3,000 to 50,000 and an acid value of 10 to 100 mg-KOH / g of the carboxyl group-containing urethane resin (A).
[11] The compound (B) having both the (meth) acrylic double bond and the epoxy group is glycidyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate glycidyl ether, and 3,4-epoxycyclohexylmethyl. A curable resin composition which is at least one compound selected from the group consisting of (meth) acrylates.
[12] The ratio of the carboxyl group-containing urethane resin (A) and the compound (B) having both the (meth) acrylic double bond and the epoxy group is in (A) to the epoxy group in (B). A curable resin composition having a ratio such that the molar ratio of carboxyl groups ((Acid) / (Epoxy)) is 0.5 to 1.25.
[13] A curable resin composition containing a solvent (C).
[14] The solvent (C) is toluene, xylene, ethylbenzene, nitrobenzene, isophorone, diethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol monomethyl ether acetate, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, dipropylene glycol methyl. Ether acetate, diethylene glycol ethyl ether acetate, methyl methoxypropionate, ethyl methoxypropionate, methyl ethoxypropionate, ethyl ethoxypropionate, n-butyl acetate, isoamyl acetate, ethyl lactate, cyclohexanone, N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, γ-butyro Ton and a curable resin composition is at least one selected from the group consisting of dimethyl sulfoxide.
[15] A curable resin composition in which the carboxyl group-containing urethane resin (A) is produced in the presence of a solvent (C).
[16] The curable resin is obtained by mixing the carboxyl group-containing urethane resin (A) with a compound (B) having both a (meth) acrylic double bond and an epoxy group in a solvent (C). Resin, a curable resin composition produced by reacting in the presence of a phosphine catalyst.
[17] A curable resin composition containing a polymerization initiator (D).
[18] A curable resin composition in which the polymerization initiator (D) is a photopolymerization initiator.
[19] A curable resin composition containing inorganic and / or organic fine particles (E).
[20] A cured product obtained by curing the curable resin composition.

  The curable resin composition of the present invention can be cured by ultraviolet rays, and the cured product has high long-term reliability of electrical insulation, is flexible, and has little warpage due to curing shrinkage. Therefore, the curable resin composition of the present invention can be used as a film forming material (overcoat agent) and the like, and can be used particularly for forming a protective film for a flexible wiring circuit having a low tack property.

Hereinafter, the curable resin composition and the cured product of the present invention will be described in more detail.
[Curable resin composition]
The curable resin composition of the present invention contains a curable resin obtained by reacting (A) a carboxyl group-containing urethane resin, (B) a compound having both a (meth) acrylic double bond and an epoxy group. To do.

(A) Carboxyl group-containing urethane resin:
The carboxyl group-containing polyurethane (A)
(A) a polyisocyanate compound,
(B) a polyol compound (c) a dihydroxy compound having a carboxyl group,
If necessary, it is further synthesized by reacting (d) a monohydroxy compound and, if necessary, (e) a monoisocyanate compound.

(A) Polyisocyanate compound:
Specific examples of the polyisocyanate compound (a) used in the present invention include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, isophorone diisocyanate, 1,6-hexamethylene diisocyanate, 1,3-trine. Methylene diisocyanate, 1,4-tetramethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, 1,9-nonamethylene diisocyanate, 1,10-decamethylene diisocyanate, 1 , 4-cyclohexane diisocyanate, 2,2′-diethyl ether diisocyanate, diphenylmethane-4,4′-diisocyanate, (o, m, or p) -xylene diisocyanate, methylene bis (4-cycl Hexyl isocyanate), cyclohexane-1,3-diisocyanate, cyclohexane-1,4-dimethylene diisocyanate, 1,5-naphthalene diisocyanate, p- phenylene diisocyanate, 3,3 '
-Diisocyanates such as methylene ditolylene-4,4'-diisocyanate, 4,4'-diphenyl ether diisocyanate, tetrachlorophenylene diisocyanate, norbornane diisocyanate, hydrogenated (1,3- or 1,4-) xylylene diisocyanate . These diisocyanates can be used alone or in combination of two or more.

  As the polyisocyanate compound (a), a diisocyanate having two isocyanate groups per molecule is usually used, but the carboxyl group-containing urethane resin (A) used in the present invention does not gel. A small amount of polyisocyanate having three or more isocyanate groups such as triphenylmethane triisocyanate can also be used.

  When the alicyclic compound having 6 to 30 carbon atoms other than carbon atoms in the isocyanate group (NCO group) is used as the polyisocyanate compound (a), the curable resin composition of the present invention. The cured product formed from is excellent in long-term insulation reliability especially at high temperature and high humidity.

  These alicyclic compounds are contained in the polyisocyanate compound (a) in an amount of 10 mol% or more, preferably 20 mol%, more preferably 30 mol%, based on the total amount (100 mol%) of the polyisocyanate compound (a). It is desirable to include the above.

  These alicyclic compounds include 1,4-cyclohexane diisocyanate, isophorone diisocyanate, methylene bis (4-cyclohexyl isocyanate), hydrogenated 1,3-xylylene diisocyanate and hydrogenated 1,4-xylylene diisocyanate.

(B) Polyol compound:
The number average molecular weight of the polyol compound (b) used in the present invention (however, the polyol compound (b) does not include the dihydroxy compound (c) having a carboxyl group described later) is usually 250 to 50,000. The molecular weight is a value in terms of polystyrene measured by GPC under the conditions described later.

  The polyol compound (b) preferably used in the present invention is a polycarbonate polyol, polyether polyol, polyester polyol, polylactone polyol, polybutadiene polyol, both-end hydroxylated polysilicone, and a hydroxyl group containing only an oxygen atom and a carbon atom number. It is a polyol compound which is 18-72.

  The polycarbonate polyol can be obtained by reacting a diol having 4 to 18 carbon atoms with a carbonate or phosgene as a raw material, and is represented, for example, by the following structural formula (1).

・・・（１）
式（１）において、Ｒは対応するジオール（ＨＯ−Ｒ−ＯＨ）から水酸基を除いた残基であり、ｎは正の整数、好ましくは２〜５０である。

... (1)
In the formula (1), R is a residue obtained by removing a hydroxyl group from the corresponding diol (HO-R-OH), and n is a positive integer, preferably 2-50.

Specifically, the polycarbonate polyol represented by the formula (1) includes 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl- 1,5-pentanediol, 1,8-octanediol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 1,9-nonanediol, 2-methyl-1,8-octanediol, 1, It can be produced by using 10-decamethylene glycol or 1,2-tetradecanediol as a raw material.

  The polycarbonate polyol may be a polycarbonate polyol having a plurality of types of alkylene groups in its skeleton (copolymerized polycarbonate polyol), and the use of the copolymerized polycarbonate polyol prevents crystallization of the carboxyl group-containing polyurethane (A). Often advantageous from a viewpoint. In consideration of solubility in a solvent, it is preferable to use a polycarbonate polyol having a branched skeleton and having a hydroxyl group at the end of the branched chain.

  The polyether polyol is obtained by dehydration condensation of a diol having 2 to 12 carbon atoms or ring-opening polymerization of an oxirane compound, oxetane compound or tetrahydrofuran compound having 2 to 12 carbon atoms. It is represented by the structural formula (2).

・・・（２）
式（２）において、Ｒは対応するジオール（ＨＯ−Ｒ−ＯＨ）から水酸基を除いた残基であり、ｎは正の整数、好ましくは４〜５０である。

... (2)
In the formula (2), R is a residue obtained by removing a hydroxyl group from the corresponding diol (HO—R—OH), and n is a positive integer, preferably 4 to 50.

  Specific examples of the polyether polyol represented by the formula (2) include polyethylene glycol, polypropylene glycol, poly-1,2-butylene glycol, polytetremethylene glycol, and poly-3-methyltetramethylene glycol. Can be mentioned. Moreover, these copolymers can also be used in order to improve the compatibility of (polyether polyol) and the hydrophobicity of (polyether polyol).

  The polyester polyol is obtained by dehydration condensation of a dicarboxylic acid and a diol or an ester exchange reaction between an esterified product of a lower alcohol of a dicarboxylic acid and a diol, and is represented by the following structural formula (3), for example. .

・・・（３）
式（３）において、Ｒ¹は対応するジオール（ＨＯ−Ｒ¹−ＯＨ）から水酸基を除いた残基であり、Ｒ²は対応するジカルボン酸（ＨＯＣＯ−Ｒ²−ＣＯＯＨ）から２つのカルボキシル基を除いた残基であり、ｎは正の整数、好ましくは２〜５０である。

... (3)
In the formula (3), R ¹ is a residue obtained by removing a hydroxyl group from the corresponding diol (HO—R ¹ —OH), and R ² is a group of two carboxyl groups from the corresponding dicarboxylic acid (HOCO—R ² —COOH). And n is a positive integer, preferably 2-50.

Specific examples of the diol (HO—R ¹ —OH) include ethylene glycol, 1,
2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl -1,5-pentanediol, 1,8-octanediol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 1,9-nonanediol, 2-methyl-1,8-octanediol, , 10-Decamethylene glycol or 1,2-tetradecanediol, 2,4-diethyl-1,5-pentanediol, butylethylpropanediol, 1,3-cyclohexanedimethanol, 3-xylylene glycol, 1,4- Xylylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol And the like.

Examples of the dicarboxylic acid (HOCO-R ² -COOH), specifically, succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, decane dicarboxylic acid, brassylic acid, 1,4-cyclohexanedicarboxylic acid, hexa Hydrophthalic acid, methyltetrahydrophthalic acid, endomethylenetetrahydrophthalic acid, methylendomethylenetetrahydrophthalic acid, chlorendic acid, fumaric acid, maleic acid, itaconic acid, citraconic acid, phthalic acid, isophthalic acid, terephthalic acid, 1,4- Naphthalenedicarboxylic acid and 2,6-naphthalenedicarboxylic acid are mentioned.

  The polylactone polyol is obtained by ring-opening polymerization of a diol and a lactone compound or a condensation reaction of a diol and a hydroxyalkanoic acid, and is represented, for example, by the following structural formula (4).

・・・（４）
式（４）において、Ｒ¹は対応するヒドロキシアルカン酸（ＨＯ−Ｒ¹−ＣＯＯＨ）から水酸基およびカルボキシル基を除いた残基であり、Ｒ²は対応するジオール（ＨＯ−Ｒ²−ＯＨ）から水酸基を除いた残基であり、ｎは正の整数、好ましくは２〜５０である。

... (4)
In the formula (4), R ¹ is a residue obtained by removing a hydroxyl group and a carboxyl group from the corresponding hydroxyalkanoic acid (HO—R ¹ —COOH), and R ² is derived from the corresponding diol (HO—R ² —OH). It is a residue excluding a hydroxyl group, and n is a positive integer, preferably 2-50.

Specific examples of the hydroxyalkanoic acid (HO—R ¹ —COOH) include 3-hydroxybutanoic acid, 4-hydroxypentanoic acid, and 5-hydroxyhexanoic acid (ε-caprolactone).

  The polybutadiene polyol is, for example, a diol obtained by polymerizing butadiene or isoprene by anionic polymerization and introducing hydroxyl groups at both ends by terminal treatment, and a diol obtained by hydrogen reduction of these double bonds.

Specific examples of the polybutadiene polyol include hydroxylated polybutadiene mainly having 1,4-repeating units (for example, Poly bd R-45HT, Poly bd R-15HT (manufactured by Idemitsu Kosan Co., Ltd.)), hydroxylated hydrogen Polybutadiene (for example, polytail H, polytail HA (manufactured by Mitsubishi Chemical Corporation)), hydroxylated polybutadiene having mainly 1,2-repeating units (for example, G
-1000, G-2000, G-3000 (manufactured by Nippon Soda Co., Ltd.)), hydroxylated hydrogenated polybutadiene (for example, GI-1000, GI-2000, GI-3000 (manufactured by Nippon Soda Co., Ltd.)), hydroxyl group Polyisoprene (for example, Poly IP (made by Idemitsu Kosan Co., Ltd.)) and hydroxylated hydrogenated polyisoprene (for example, Epol (made by Idemitsu Kosan Co., Ltd.)).

  The both-terminal hydroxylated polysilicone is represented by the following structural formula (5), for example.

・・・（５）
式（１）において、Ｒ¹は独立に炭素数２〜５０の脂肪族炭化水素基または芳香族炭化
水素基であり、これらはエーテル基を含んでいてもよく、複数個あるＲ²は、それぞれ独
立に、炭素数１〜１２の脂肪族炭化水素基または芳香族炭化水素基である。

... (5)
In Formula (1), R ¹ is independently an aliphatic hydrocarbon group having 2 to 50 carbon atoms or an aromatic hydrocarbon group, which may contain an ether group, and a plurality of R ² are each Independently, it is a C1-C12 aliphatic hydrocarbon group or an aromatic hydrocarbon group.

Examples of the commercial products of the both-end hydroxylated polysilicone include “X-22-160AS, KF6001, KF6002, KF-6003” manufactured by Shin-Etsu Chemical Co., Ltd., and the like.
Specific examples of the “polyol compound having an oxygen atom only in the hydroxyl group and having 18 to 72 carbon atoms” include a diol compound having a skeleton obtained by hydrogenating dimer acid. And “Sovermol908” manufactured by Cognis.

In addition, a diol having a molecular weight of 300 or less can be used as long as the physical properties of the cured product are not impaired.
Specific examples of such low molecular weight diols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, and 1,4-butane. Diol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,8-octanediol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 1,9-nonanediol, 2-methyl-1,8-octanediol, 1,10-decamethylene glycol, 1
, 2-tetradecanediol, 2,4-diethyl-1,5-pentanediol, butylethylpropanediol, 1,3-cyclohexanedimethanol, 1,3-xylylene glycol, 1,4-xylylene glycol, diethylene glycol, Examples include triethylene glycol or dipropylene glycol.

(C) a dihydroxy compound containing a carboxyl group;
Specific examples of the dihydroxy compound (c) containing a carboxyl group used in the present invention include 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid, N, N-bishydroxyethylglycine, N , N-bishydroxyethylalanine and the like. Among them, 2,2-dimethylolpropionic acid and 2,2-dimethylolbutanoic acid are particularly preferable from the viewpoint of solubility in a solvent. These dihydroxy compounds (c) containing a carboxyl group can be used singly or in combination of two or more.

(D) a monohydroxy compound, (e) a monoisocyanate compound;
The carboxyl group-containing polyurethane (A) used in the present invention can be synthesized only from the above three components ((a), (b) and (c)). For the purpose of imparting properties, or for the purpose of eliminating the influence of the isocyanate group and hydroxyl group residue at the end of the polyurethane, it can be synthesized by further reacting the monohydroxy compound (d) and / or the monoisocyanate compound (e). .

The monohydroxy compound (d) used for the purpose of further imparting radical polymerizability and cationic polymerizability to the polyurethane of the present invention is 2-hydroxyethyl (meth) acrylate as long as it is a compound having a radical polymerizable double bond. , Hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, cyclohexanedimethanol mono (meth) acrylate, caprolactone or alkylene oxide adduct of each of the above (meth) acrylates, glycerin di (meth) acrylate, trimethylol di (meth) ) Acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, ditrimethylolpropane tri (meth) acrylate, allyl alcohol, allyloxyethanol, etc. It is below. Moreover, if it is a compound which has carboxylic acid, glycolic acid, hydroxypivalic acid, etc. will be mentioned.

  These monohydroxy compounds can be used alone or in combination of two or more. Among these compounds, 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, allyl alcohol, glycolic acid and hydroxypivalic acid are preferable, and 2-hydroxyethyl (meth) ) Acrylate and 4-hydroxybutyl (meth) acrylate are more preferred.

  Moreover, as a monohydroxy compound (d) used for the purpose of eliminating the influence of the isocyanate residue at the terminal of the polyurethane of the present invention, in addition to the above monohydroxy compound, methanol, ethanol, n-propanol, isopropanol, n- Examples include butanol, isobutanol, sec-butanol, t-butanol, amyl alcohol, hexyl alcohol, octyl alcohol, and the like.

As the monoisocyanate compound (e), those having a radical double bond include (meth) acryloyloxyethyl isocyanate, 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl to a diisocyanate compound. (Meth) acrylate, cyclohexanedimethanol mono (meth) acrylate, caprolactone or alkylene oxide adduct of each (meth) acrylate, glycerin di (meth) acrylate, trimethylol di (meth) acrylate, pentaerythritol tri (meth) acrylate , Dipentaerythritol penta (meth) acrylate, ditrimethylolpropane tri (meth) acrylate, allyl alcohol, mono-adducts of allyloxyethanol, etc. And the like.

  Examples of the monoisocyanate hydroxy compound used for the purpose of eliminating the influence of the terminal hydroxyl residue include phenyl isocyanate, hexyl isocyanate, and dodecyl isocyanate.

<Carboxyl group-containing polyurethane (A)>
The number average molecular weight of the carboxyl group-containing polyurethane (A) used in the present invention is preferably 1,000 to 100,000, and more preferably 3,000 to 50,000. Here, the molecular weight is a value in terms of polystyrene measured by gel permeation chromatography. If the molecular weight is less than 1,000, the elongation, flexibility and strength of the cured film may be impaired. If the molecular weight exceeds 100,000, the solubility of the polyurethane in the solvent becomes low and the viscosity even if dissolved. Since it becomes too high, restrictions may be increased in terms of use.

In this specification, unless otherwise specified, the GPC measurement conditions are as follows.
Device name: JASCO Corporation HPLC unit HSS-2000
Column: Shodex column LF-804
Mobile phase: Tetrahydrofuran Flow rate: 1.0 mL / min
Detector: RI-2031Plus manufactured by JASCO Corporation
Temperature: 40.0 ° C
Sample volume: Sample loop 100 μl Sample concentration: Prepared around 0.1 wt%.

  The acid value of the carboxyl group-containing polyurethane (A) is preferably 5 to 120 mgKOH / g, and more preferably 10 to 100 mgKOH / g. When the acid value is less than 5 mgKOH / g, there are few reaction points with the compound having both the (B) (meth) acrylic double bond and the epoxy group, and the heat resistance may be impaired. When it exceeds 120 mgKOH / g, there are too many reaction points, and the cured film may be too hard and brittle.

In the present specification, the acid value of the resin is a value measured by the following method.
About 0.2 g of a sample is precisely weighed in a 100 ml Erlenmeyer flask with a precision balance, and 10 ml of a mixed solvent of ethanol / toluene = 1/2 (weight ratio) is added and dissolved therein. Further, 1 to 3 drops of phenolphthalein ethanol solution is added to this container as an indicator, and the mixture is sufficiently stirred until the sample becomes uniform. This is titrated with a 0.1N potassium hydroxide-ethanol solution, and the end point of neutralization is taken when the indicator is slightly red for 30 seconds. The value obtained from the result using the following calculation formula is defined as the acid value of the resin.

Acid value (mgKOH / g) = [B × f × 5.611] / S
B: Amount of 0.05N potassium hydroxide-ethanol solution used (ml)
f: Factor of 0.05N potassium hydroxide-ethanol solution S: Amount of sample collected (g).

The carboxyl group-containing polyurethane (A) used in the present invention is prepared by using the above-mentioned polyisocyanate (a), the above-mentioned polyisocyanate (a), and a suitable organic solvent in the presence or absence of a known urethanization catalyst such as dibutyltin dilaurate. Can be synthesized by reacting the polycarbonate diol (b), the dihydroxy compound (c), and, if necessary, the monohydroxy compound (d) or the monoisocyanate compound (e). However, the physical property value at the time of actual use as a cured film is finally improved.

  As the organic solvent, those having low reactivity with isocyanate can be used, and a solvent having no basic functional group such as amine and having a boiling point of 110 ° C. or higher, preferably 200 ° C. or higher is preferable. Examples of such solvents include toluene, xylene, ethylbenzene, nitrobenzene, cyclohexane, isophorone, diethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol monomethyl ether acetate, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, dipropylene glycol methyl. Ether acetate, diethylene glycol ethyl ether acetate, methyl methoxypropionate, ethyl methoxypropionate, methyl ethoxypropionate, ethyl ethoxypropionate, ethyl acetate, n-butyl acetate, isoamyl acetate, ethyl lactate, acetone, methyl ethyl ketone, cyclohexanone, N, N-dimethylformamide, N N- dimethylacetamide, N- methylpyrrolidone, .gamma.-butyrolactone, dimethyl sulfoxide, it can be mentioned chloroform and methylene chloride.

  In view of the fact that the organic solvent having low solubility of the resulting carboxyl group-containing polyurethane (A) is not preferable, and considering that polyurethane is used as a raw material for inks in electronic material applications, among these, in particular, propylene glycol methyl ether Acetate, propylene glycol ethyl ether acetate, dipropylene glycol methyl ether acetate, diethylene glycol ethyl ether acetate, γ-butyrolactone and the like are preferable.

Although there is no restriction | limiting in particular about the order which performs the preparation of a raw material, Usually, after the said dihydroxy compound (c) which has the said polyol compound (b) and the said carboxyl group is first charged and dissolved in a solvent, 20-150 degreeC, Preferably, the diisocyanate compound (a) is added dropwise at 60 to 120 ° C, and then 30 to 160 ° C, more preferably 50 to 1 ° C.
These are reacted at 30 ° C.

  The feed molar ratio of the raw material is adjusted according to the molecular weight and acid value of the target polyurethane, but when the monohydroxy compound (d) is introduced into the polyurethane, the end of the polyretane molecule is an isocyanate group. It is necessary to use the polyisocyanate compound (a) in excess of the polyol compound (b) and the dihydroxy compound (c) having a carboxyl group (so that the isocyanate groups are in excess of the total of hydroxyl groups).

  Specifically, the charged molar ratio of polyisocyanate compound (a) :( polyol compound (b) + dihydroxy compound having a carboxyl group (c)) is 0.5 to 1.5: 1, preferably 0.8-1.2: 1.

Moreover, the dihydroxy compound (c) which has a polyol compound (b): carboxyl group is 1: 0.1-30, Preferably it is 1: 0.3-10.
When the monohydroxy compound (d) is used, the number of moles of the polyisocyanate compound (a) is made larger than the number of moles of (polyol compound (b) + dihydroxy compound (c) having a carboxyl group), and the monohydroxy compound It is preferable to use (d) in an amount of 0.5 to 1.5 times mol, preferably 0.8 to 1.2 times mol, based on the excess number of moles of NCO groups.

When the monoisocyanate compound (e) is used, the polyisocyanate compound (a)
The number of moles of (polyol compound (b) + carboxyl group-containing dihydroxy compound (c)) is more than the number of moles, and 0.5 to 1.5 times the amount of moles of hydroxyl groups, preferably Is preferably used in a molar amount of 0.8 to 1.2 times.

  In order to introduce the monohydroxy compound (d) into the polyurethane, the reaction between the polycarbonate diol (b) and the dihydroxy compound (c) and the diisocyanate (a) is almost completed at both ends of the polyurethane. In order to react the remaining isocyanate group with the monohydroxy compound (d), the monohydroxy compound (d) is dropped into the polyurethane solution at 20 to 150 ° C., more preferably at 70 to 120 ° C., and then Hold at the same temperature to complete the reaction.

  In order to introduce the monoisocyanate compound (e) into the polyurethane, at the time when the reaction between the polycarbonate diol (b) and the dihydroxy compound (c) and the diisocyanate (a) is almost completed, both ends of the polyurethane are introduced. In order to react the remaining hydroxyl group with the monoisocyanate compound (e), the monoisocyanate compound (e) is dropped into the polyurethane solution at 20 to 150 ° C., more preferably at 50 to 120 ° C., and then the same. Hold at temperature to complete reaction.

(B) Compound having both (meth) acrylic double bond and epoxy group:
The compound (B) having both a (meth) acrylic double bond and an epoxy group is selected for the purpose of reacting with the carboxyl group-containing polyurethane (A).

That is, —COOH of the carboxyl group-containing polyurethane (A) reacts with an epoxy group of the compound (B) having both a (meth) acrylic double bond and an epoxy group, and —COO—CH ₂ CH ( OH) CH ₂ — is formed, and (A) and (B) are combined.

Such compounds include glycidyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate glycidyl ether, 3,4-epoxycyclohexylmethyl (meth)
An acrylate etc. are mentioned.

  As a condition for reacting (A) and (B), a catalyst that promotes the reaction of an epoxy group and a carboxylic acid is added to the solution obtained by synthesizing (A), and 50 to 160 ° C, more preferably 80 to 140 ° C. Heat to react. If the reaction temperature is too low, the speed is too slow, and if the reaction temperature is too high, gelation may occur.

The amount of (A) and (B) used is preferably such that the epoxy group is 0.5 to 1.25 equivalents relative to the carboxylic acid group of (A), more preferably 0.5 to 1.1, 0.5-1
. 0 is most preferred. When it is lower than 0.5 equivalent, the heat resistance is impaired, and when it is higher than 1.25 equivalent, the component (B) that cannot be reacted is produced, which adversely affects electrical insulation.

  The reaction can be performed in an inert gas or air atmosphere as the reaction atmosphere. Considering the polymerization preventing effect in particular, it is preferable that a small amount of oxygen is present, and it is preferable to carry out the reaction in an atmosphere having an oxygen concentration of 5 to 10% by mixing an inert gas such as nitrogen and air.

Examples of the reaction catalyst include tertiary amines and phosphine compounds, and examples of the tertiary amine include triethylamine, tributylamine, trioctylamine, DBU, DBN, 2,4,6-trisdimethylaminomethylphenol, and the like. Examples of the phosphine compound include triphenyl phosphine, triphenyl phosphite, trimethyl phosphine, and trimethyl phosphite. As for the amount used, if the amount used is too small, there is no effect of addition, and if the amount used is too large, the electrical insulation is reduced, so 0.1 to 5 weight with respect to the total weight of (A) and (B) %, More preferably 0.5 to 3% by weight.

In addition, a polymerization inhibitor can be added if necessary. Examples of the polymerization inhibitor that can be used here include hydroquinone, p-methoxyphenol, 2,6-di-t-butyl-p-cresol, butyl. Monophenolic compounds such as hydroxyanisole, 2,6-di-t-butyl-4-ethylphenolstearyl-β- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, 2,2 ′ -Methylenebis (4-methyl-6-t-butylphenol), 4,4'-thiobis (3-methyl-6-t-butylphenol), 4,4'-butylidenebis (3-methyl-6-t-butylphenol), etc. 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4
-Hydroxybenzyl) benzene, tetrakis- [methylene-3- (3 ', 5'-di-t-
Butyl-4′-hydroxyphenyl) propionate] methane, tris (3 ′, 5′-di-t-butyl-4′-hydroxybenzyl) -s-triazine-2,4,6- (1H, 3H,
5H) polymer phenolic compounds such as trione and tocopherol, phenothiazine, dilauryl 3,3′-thiodipropionate, dimyristyl 3,3′-thiodipropionate, distearyl 3,3′-thiodipropionate, etc. Phosphorus compounds such as sulfur compounds, triphenyl phosphite, diphenylisodecyl phosphite, and phenyl diisodecyl phosphite can be mentioned. These can be used alone or in combination of two or more, and it is preferable to use 5 parts by mass or less with respect to 100 parts by mass in total of the component (A) and the component (B). If it exceeds 5 parts by mass, the heat resistance of the cured product of the curable resin composition of the present invention may be impaired.

The curable resin composition of the present invention can contain (C) a solvent.
(C) Solvent:
In the present invention, it is preferable to use a solvent (C). The curable resin composition of the present invention preferably takes a form dissolved in the solvent (C), and the curable resin composition of the present invention is contained in the solvent used for the synthesis of the carboxyl group-containing urethane resin (A). It is particularly preferable that it is in a dissolved state.

  As the reason, when trying to obtain the curable resin composition of the present invention, a compound having both a carboxyl group-containing polyurethane (A), a (meth) acrylic double bond and an epoxy group unless a solvent is used ( It may be difficult to react B).

  Moreover, if the solvent (C) is the solvent used for the synthesis of the carboxyl group-containing polyurethane (A), a step of dissolving the carboxyl group-containing polyurethane (A) again is unnecessary, which is preferable in terms of economy.

  The solvent (C) is not particularly limited as long as it can dissolve the carboxyl group-containing polyurethane (A). A solvent having a boiling point of 30 ° C to 300 ° C is preferable, and a solvent having a boiling point of 80 ° C to 250 ° C is preferable. Further preferred.

Solvents (C) include toluene, xylene, ethylbenzene, nitrobenzene, cyclohexane, isophorone, diethylene glycol dimethyl ether, ethylene glycol diethyl ether, carbitol acetate, ethylene glycol monomethyl ether acetate, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, diethylene glycol Propylene glycol methyl ether acetate, diethylene glycol ethyl ether acetate, methyl methoxypropionate, ethyl methoxypropionate, methyl ethoxypropionate, ethyl ethoxypropionate, ethyl acetate, n-butyl acetate, isoamyl acetate, ethyl lactate, acetone, methyl ethyl ketone, cyclohexanone N, N-dimethylfo Muamido, N, N- dimethylacetamide, N- methylpyrrolidone, .gamma.-butyrolactone, dimethyl sulfoxide, and the like can be exemplified chloroform and methylene chloride.

If this solvent (C) is used, the amount thereof is a carboxyl group-containing polyurethane (A).
And the concentration (solid content concentration) of the compound (B) having both (meth) acrylic double bond and epoxy group is preferably 10 to 90% by mass, and 30 to 80% by mass Is more preferable.

The curable resin composition of the present invention can further contain a polymerization initiator such as a photopolymerization initiator or a thermal radical polymerization initiator.
4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, 4-t-butyl-trichloroacetophenone, diethoxyacetophenone, 2-hydroxy-2-phenyl-1-phenylpropan-1-one as a photopolymerization initiator, 1- (4-dodecylphenyl) -2-hydroxy-2-methylpropan-1-one, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 4- (2-hydroxy Acetophenone-based light such as ethoxy) -phenyl- (2-hydroxy-2-propyl) ketone, 1-hydroxycyclohexyl phenylketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1 Radical polymerization initiators, benzoin, benzoin methyl ether, Benzoin photoradical polymerization initiators such as benzoin isopropyl ether, benzoin isobutyl ether, benzyl methyl ketal, benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, acrylated benzophenone, 4- Benzoyl-4 '
-Methyldiphenyl sulfide, 3,3'-dimethyl-4-methoxybenzophenone,
Benzophenone photoradical polymerization initiators such as 4,4′-dimethylaminobenzophenone, 4,4′-diethylaminobenzophenone, 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, isopropylthioxanthone, 1-chloro-4-propoxythioxanthone, 2,4-dichlorothioxanthone, etc. Thioxanthone photoradical polymerization initiator, α-acyloxime ester, methylphenylglyoxylate, benzyl, 9,10-phenanthrenequinone, camphorquinone, dibenzosuberone, 2-ethylanthraquino Ketone radical photopolymerization initiators such as 2,4 ′, 4 ″ -diethylisophthalophenone, 2,2′-bis (2-chlorophenyl) -4,4 ′, 5,5′-tetraphenyl-1, Imidazole photo radical polymerization initiators such as 2'-imidazole, acyl phosphine oxide photo radical polymerization initiators such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide, carbazole photo radical polymerization initiators, triphenylphosphonium hexafluoro Antimonate, triphenylphosphonium hexafluorophosphate, p- (phenylthio) phenyldiphenylsulfonium hexafluoroantimonate, 4-chlorophenyldiphenylsulfonium hexafluorophosphate, (2,4-cyclopentadien-1-yl) [(1-me Examples include Lewis acid onium salts such as (tilethyl) benzene] -iron-hexafluorophosphate.

As thermal radical polymerization initiators, methyl ethyl ketone peroxide, cyclohexanone peroxide, methylcyclohexanone peroxide, methyl acetate peroxide, acetyl acetate peroxide, 1,1-bis (t-butylperoxy) butane, 1,1-bis ( t-butylperoxy) -cyclohexane, 1,1-bis (t-butylperoxy) -2-methylcyclohexane, 1,1-bis (t-butylperoxy) -3
, 3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) cyclododecane, 1,1-bis (t-hexylperoxy) -cyclohexane, 1,1-bis (t-
(Hexylperoxy) -3,3,5-trimethylcyclohexane, 2,2-bis (4,4-di-t-butylperoxycyclohexyl) propane, t-butyl hydroperoxide, t-hexyl hydroperoxide, 1 , 1,3,3-Tetramethylbutyl hydroperoxide, cumene hydroperoxide, p-methyl hydroperoxide, diisopropylbenzene hydroperoxide, di-t-butyl peroxide, dicumyl peroxide, t-butyl cumylper Oxide, α, α′-bis (t-butylperoxy) diisopropylbenzene, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane, 2,5-dimethyl-2,5-bis ( t-butylperoxy) hexyne-3, isobutyryl peroxide, , 3,5-trimethylhexanoyl peroxide, octanoyl peroxide, lauroyl peroxide, stearoyl peroxide, succinic acid peroxide, m-toluoyl benzoyl peroxide, benzoyl peroxide, di-n-propyl peroxydicarbonate , Diisopropyl peroxydicarbonate, bis (4-t-butylcyclohexyl) peroxydicarbonate, di-2-ethoxyethyl peroxydicarbonate, di-2-ethoxyhexyl peroxydicarbonate, di-3-methoxybutylper Oxydicarbonate, di-S-butylperoxydicarbonate, di (3-methyl-3-methoxybutyl) peroxydicarbonate, α, α'-bis (neodecanoylperoxy) diisopropyl Benzene, t-butylperoxyneodecanoate, t-hexylperoxyneodecanoate, 1,1,
3,3-tetramethylbutylperoxyneodecanoate, 1-cyclohexyl-1-methylethylperoxyneodecanoate, cumylperoxyneodecanoate, t-butylperoxypivalate, t-hexylperoxy Pivalate, t-butylperoxy-2-ethylhexanoate, t-hexylperoxy-2-ethylhexanoate, 1,1
, 3,3-tetramethylbutylperoxy-2-ethylhexanoate, 2,5-dimethyl-2,5-bis (2-ethylhexanoylperoxy) hexane, 1-cyclohexyl-1-methylethylperoxy 2-ethylhexanoate, t-butylperoxy-3
, 5,5-trimethylhexanoate, t-butylperoxyisopropyl monocarbonate, t-hexylperoxyisopropyl monocarbonate, t-butylperoxy-2-ethylhexyl monocarbonate, t-butylperoxyallyl monocarbonate, t -Butyl peroxyisobutyrate, t-butyl peroxymalate, t-butyl peroxybenzoate, t-hexyl peroxybenzoate, t-butyl peroxy-m-toluyl benzoate, t-butyl peroxylaurate, t -Butyl peroxyacetate, bis (t-butylperoxy) isophthalate, 2,5-dimethyl-2,5-bis (m-toluylperoxy) hexane, 2,5-dimethyl-2,5-bis (benzoyl) Peroxy) hexane, t-butyltrimethyl Organic peroxides such as ril peroxide, 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone, 2,3-dimethyl-2,3-diphenylbutane, or 1-[( 1-cyano-1-methylethyl) azo] formamide, 1,1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis (2-methylbutyronitrile), 2,2′-azobis Isobutyronitrile, 2
, 2′-azobis (2,4-dimethyl-4-methoxyvaleronitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), 2-phenylazo-4-methoxy-2,4-dimethylvaleronitrile 2,2′-azobis (2-methylpropionamidine) dihydrochloride, 2,2-azobis (2-methyl-N-phenylpropionamidine) dihydrochloride, 2,2′-azobis [N- (4-chlorophenyl) -2-methylpropionamidine] dihydrochloride, 2,2′-azobis [N- (4-hydrophenyl) -2-methylpropionamidine] dihydrochloride, 2,2′-azobis [2-methyl-N- (
2-propenyl) propionamidine] dihydrochloride, 2,2′-azobis [N- (
2-hydroxyethyl) -2-methylpropionamidine] dihydrochloride, 2,2 ′
-Azobis [2-methyl-N- (phenylmethyl) propionamidine] dihydrochloride, 2,2'-azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride, 2,2'-azobis [2 -(2-imidazolin-2-yl) propane] dihydrochloride, 2,2'-azobis [2- (5-methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2,2'-azobis {2 -[1- (2-hydroxyethyl) -2
-Imidazolin-2-yl] propane} dihydrochloride, 2,2′-azobis [2- (
4,5,6,7-tetrahydro-1H-1,3-diazepin-2-yl) propane] dihydrochloride, 2,2′-azobis [2- (3,4,5,6-tetrahydropyrimidine-2- Yl) propane] dihydrochloride, 2,2′-azobis [2- (5-hydroxy-)
3,4,5,6-tetrahydropyrimidin-2-yl) propane] dihydrochloride, 2,2'-azobis (2-methylpropionamide), 2,2'-azobis [2-methyl-N- (2- Hydroxyethyl) propionamide], 2,2′-azobis {2-methyl-N
-[1,1-bis (hydroxymethyl) -2-hydroxyethyl] propionamide}, 2,2′-azobis {2-methyl-N- [1,1-bis (hydroxymethyl) ethyl] propionamide}, 2,2′-azobis (2-methylpropane), 2,2′-azobis (
2,4,4-trimethylpentane), dimethyl 2,2′-azobis (2-methylpropionate), 4,4′-azobis (4-cyanopentanoic acid), 2,2′-azobis [2- ( Azo compounds such as hydroxymethyl) propionitrile].

  These polymerization initiators can be used alone or in combination of two or more, and the amount used thereof is (A) component 100 from the viewpoint of the curability of the curable resin composition and the heat resistance of the resulting cured product. It is preferable to set it as 0.01 mass part-10 mass parts with respect to a mass part. In particular, when curing with ultraviolet rays, a photopolymerization initiator must be present.

Other compounds having a polymerizable double bond can be added to the curable resin composition of the present invention for the purpose of promoting photopolymerization and the like.
Other compounds having a polymerizable double bond that can be used in the present invention include methyl (meth) acrylate, ethyl (meth) acrylate, (n-propyl) (meth) acrylate, isopropyl (meth) acrylate, (Meth) acrylic acid-n-butyl, (meth) acrylic acid isobutyl, (meth) acrylic acid-sec-butyl, (meth) acrylic acid hexyl, (meth) acrylic acid octyl, (meth) acrylic acid-2-ethylhexyl , Decyl (meth) acrylate, isobornyl (meth) acrylate, cyclohexyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate, (meth) acrylate-2-hydroxyethyl, (meth) Acrylic acid-2-hydroxypropyl, (meth) acrylic acid-3-hydroxypropyl, (meth) acrylic acid Mono (meth) acrylates such as 2-hydroxybutyl and 2-hydroxyphenylethyl (meth) acrylate, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N-acryloylmorpholine (Meth) acrylamides such as compounds having two or more (meth) acryloyl groups include ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate , Diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, trimethylolpropane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol penta (meth) acrylate, etc. Functional (meth) acrylates, bisphenol A type epoxy resin, hydrogenated bisphenol A type epoxy resin, brominated bisphenol A type epoxy resin, bisphenol F type epoxy resin, novolac type epoxy resin, phenol novolac type epoxy resin, cresol novolak type Epoxy resin, alicyclic epoxy resin, N-glycidyl type epoxy resin, bisphenol A novolac type epoxy resin, chelate type epoxy resin, glyoxal type epoxy resin, amino group-containing epoxy resin, rubber-modified epoxy resin, dicyclopentadiene phenolic type Examples include so-called epoxy (meth) acrylates obtained by adding (meth) acrylic acid to epoxy resins such as epoxy resins, silicone-modified epoxy resins, and ε-caprolactone-modified epoxy resins. It is possible.

  Examples of compounds having one vinyl group include monovinyl ethers such as n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, 2-ethylhexyl vinyl ether, octadecyl vinyl ether, cyclohexyl vinyl ether, vinyl acetate, and vinyl propionate. Monovinyl esters such as vinyl butyrate and vinyl benzoate, divinyl esters such as divinyl adipate, N-vinyl amides such as N-vinylpyrrolidone and N-methyl-N-vinylacetamide, styrene, 2,4-dimethyl- α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, 2,5-dimethylstyrene, 2,6-dimethylstyrene, , 4-dimethylstyrene, 3,5-dimethylstyrene, 2,4,6-trimethylstyrene, 2,4,5-trimethylstyrene, pentamethylstyrene, o-ethylstyrene, m-ethylstyrene, p-ethylstyrene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, o-bromostyrene, m-bromostyrene, p-bromostyrene, o-methoxystyrene, m-methoxystyrene, p-methoxystyrene, o-hydroxystyrene, m-hydroxystyrene, p-hydroxystyrene, 2-vinylbiphenyl, 3-vinylbiphenyl, 4-vinylbiphenyl, 1-vinylnaphthalene, 2-vinylnaphthalene, 4-vinyl-p-terphenyl, 1-vinylanthracene, α -Methylstyrene, o-isopropenyltoluene, -Isopropenyltoluene, p-isopropenyltoluene, 2,4-dimethyl-α-methylstyrene, 2,3-dimethyl-α-methylstyrene, 3,5-dimethyl-α-methylstyrene, p-isopropyl-α- Mention may be made of styrene derivatives such as methylstyrene, α-ethylstyrene and α-chlorostyrene. Examples of the compound having two or more vinyl groups include ethylene glycol divinyl ether, 1,4-butanediol divinyl ether, 1,6-hexanediol divinyl ether, 1,9-nonanediol divinyl ether, cyclohexane dimethanol divinyl ether, Examples thereof include polyfunctional vinyl ethers such as diethylene glycol divinyl ether, triethylene glycol divinyl ether, trimethylolpropane trivinyl ether, pentaerythritol tetravinyl ether, divinylbenzene, and divinylbiphenyl.

  As an example of a compound having an allyl group, examples of a compound having one allyl group include allyl alcohol, ethylene glycol monoallyl ether, allylamine, allyl glycidyl ether, and allyl esters such as allyl acetate and allyl benzoate. Examples of the compound having one or more allyl groups include diallylamine, diallyl 1,4-cyclohexanedicarboxylate, diallyl phthalate, diallyl terephthalate, and diallyl isophthalate.

  These other compounds having a polymerizable double bond can be used alone or in combination of two or more, and (meth) acrylic acid esters are particularly preferred. The amount used is preferably 200 parts by mass or less with respect to 100 parts by mass of the components (A) and (B) of the present invention from the viewpoint of the heat resistance of the cured product of the resulting curable resin composition.

The curable resin composition of the present invention can contain inorganic and / or organic fine particles (E).
Known inorganic and / or organic fine particles (E) can be used.

  The blending amount varies depending on the selected carboxyl group-containing polyurethane (A) and the compound (B) having both the (meth) acrylic double bond and the epoxy group, and is 5 to 5 with respect to the entire resin composition. It is preferably within the range of 40% by weight.

As organic fine particles (organic filler), epoxy resin powder, melamine resin powder, urea resin powder, guanamine resin powder, polyester resin powder, silicone powder, etc.
Examples of the inorganic fine particles (inorganic filler) include inorganic fillers such as silica, alumina, titanium oxide, barium sulfate, talc, calcium carbonate, glass powder, and quartz powder.

  The curable resin composition of the present invention further includes various known additives, for example, fiber reinforcing materials such as glass fiber, carbon fiber, boron nitride fiber, titanium oxide, zinc oxide, carbon black, iron black, organic pigment, organic pigment Colorants such as dyes, antioxidants such as hindered phenol compounds, phosphorus compounds and hindered amine compounds, ultraviolet absorbers such as benzotriazole compounds and benzophenone compounds can be blended.

Moreover, a viscosity modifier, a flame retardant, an antibacterial agent, an antifungal agent, an antiaging agent, an antistatic agent, a plasticizer, a lubricant, a foaming agent, and the like can be added and mixed depending on the application.
Each component can be dissolved or dispersed using a mixer such as a disper, a kneader, a three-roll mill, a bead mill, a homogenizer and the like.

[Cured product]
The cured product of the present invention is obtained by curing the curable resin composition. The cured product of the present invention is used as a film such as a surface protective film of a wiring circuit. When used as such a film, the cured product of the present invention is applied, for example, to the surface of the object to be protected by applying the curable resin composition of the present invention using a bar coater or the like, dried and then cured. To be created.

  Examples of the method for curing the curable resin composition include thermal curing and / or curing with active energy rays. Examples of the active energy rays include near infrared rays, visible rays, ultraviolet rays and electron beams, and visible rays and ultraviolet rays are particularly preferable.

  Among the active energy rays, the light source for curing by visible light or ultraviolet light is, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a deuterium lamp, a metal halide lamp, a halogen lamp, a xenon lamp, a tungsten lamp, a gallium lamp, or a carbon arc. A lamp, an incandescent bulb, a fluorescent lamp, an excimer lamp, a laser, or the like can be used. Of these light sources, a high-pressure mercury lamp and a metal halide lamp are particularly preferable.

The wavelength of the light source for visible light or ultraviolet curing is usually 200 nm to 750 nm. The irradiation amount is usually 5 mJ / cm ^{2 to} 1000 mJ / cm ² .
In curing using an electron beam, examples of the irradiation method include a scanning method, a broad beam method, a curtain beam method, an ion plasma method, and the irradiation amount is usually 1 Gy to 500 kGy, preferably 10 Gy to 200 kGy.

Examples The present invention will be described below with reference to examples, but the present invention is not limited to these examples.
Synthesis example of carboxyl group-containing urethane (A) [Synthesis Example 1]
In a 1 L three-necked flask equipped with a stirrer, a thermometer, and a condenser, C-1015N (manufactured by Kuraray Co., Ltd., polycarbonate diol, raw material diol molar ratio: 1,9-nonanediol: 2-methyl-1,8-octane was added as a polyol compound. Diol = 15: 85, molecular weight 964) 101 g, 2,2-dimethylolbutanoic acid (manufactured by Nippon Kasei Co., Ltd.) 26 g as a dihydroxyl compound having a carboxyl group, and ethylene glycol monomethyl ether acetate (Daicel Chemical Industries, Ltd.) as a solvent (Trade name, methyl glycol acetate) 275 g was charged, and the 2,2-dimethylolbutanoic acid was dissolved at 90 ° C.

  The temperature of the reaction solution was lowered to 70 ° C., and 73 g of Desmodur-W (hydrogenated diphenylmethane diisocyanate, manufactured by Sumika Bayer Urethane Co., Ltd.) was added dropwise as a polyisocyanate over 30 minutes with a dropping funnel. After completion of dropping, the reaction was carried out at 80 ° C. for 1 hour, then at 100 ° C. for 1 hour, then at 120 ° C. for 2 hours. After confirming that the isocyanate had almost disappeared, further reacted at 120 ° C. for 1.5 hours. Went.

The number average molecular weight of the obtained carboxyl group-containing polyurethane was 7430, and the acid value of the solid content was 21 mgKOH / g.
[Example 1]
In a 100 mL three-necked flask equipped with a thermometer, a stirrer, and a condenser, 61 g of the carboxyl group-containing polyurethane solution obtained in Synthesis Example 1 (solid content concentration 42 mass%, acid value 21 mg-KOH / g), p-methoxyphenol ( 0.24 g, manufactured by Wako Pure Chemical Industries, Ltd.
Triphenylphosphine (manufactured by Tokyo Chemical Industry Co., Ltd.) (0.29 g) and glycidyl methacrylate (manufactured by Mitsubishi Chemical Co., Ltd. (3.4 g)) were charged and reacted in an air stream at 120 ° C. for 3 hours. The molar ratio ((Acid) / (Epoxy)) of the carboxyl group in (A) to the epoxy group in it was 1.

The number average molecular weight of the solid content of the obtained curable resin composition (hereinafter referred to as curable resin composition 1) was 5922.
[Example 2]
Into the curable resin composition 1 prepared in Example 1, 1-hydroxy-cyclohexyl phenyl ketone as a photopolymerization initiator is mixed with a planetary mixer under the blending conditions shown in Table 1 to obtain a curable resin composition. 2 was adjusted.

<Evaluation of cured product>
Using a bar coater, apply the curable resin composition 2 to the substrate so that the thickness of the coating after drying is 25 μm, and evaluate the warpage, flexibility and long-term reliability under the following conditions. It was.

[Low warpage]
As a base material, a 25 μm-thick polyimide film [Kapton (registered trademark) 300H, manufactured by Toray DuPont Co., Ltd.] was used. After drying the curable resin composition 2 applied to this film at 80 ° C. for 30 minutes, nitrogen was used. The curable resin composition 2 was cured by exposure with a high-pressure mercury lamp (illuminance: 18 mW / cm 2 at a wavelength of 365 nm) in an atmosphere for 120 seconds to form a cured film as a cured product on the film. The film coated with the cured film was cut into a circle having a diameter of 50 mm, placed with the printed surface facing upward, and evaluated according to the following criteria.

○: The maximum warp height is less than 5 mm,
X: The maximum warp height is 5 mm or more.
[Flexibility]
As a base material, a 25 μm-thick polyimide film [Kapton (registered trademark) 100H, manufactured by Toray DuPont Co., Ltd.] was used. After drying the curable resin composition 2 applied to this film at 80 ° C. for 30 minutes, nitrogen was used. The curable resin composition 2 was cured by exposure with a high-pressure mercury lamp (illuminance: 18 mW / cm 2 at a wavelength of 365 nm) in an atmosphere for 120 seconds to form a cured film as a cured product on the film. The polyimide film coated with the cured film was bent 180 ° outward to check for whitening of the cured film. The flexibility was evaluated according to the following criteria.

○: No whitening of the cured film ×: Whitening or cracking of the cured film occurs.
[Long-term reliability of electrical insulation]
As the base material, a commercially available substrate (IPC standard) IPC-C (comb pattern) was used. After drying the curable resin composition 2 applied to this film at 80 ° C. for 30 minutes, high-pressure mercury in a nitrogen atmosphere. The curable resin composition 2 was cured by exposure with a lamp (illuminance of 18 mW / cm 2 at a wavelength of 365 nm) for 120 seconds, and a cured film as a cured product was formed on the film. The substrate was left to stand for 1000 hours with a bias voltage of 100 V applied in an atmosphere of 85 ° C. and 85% relative humidity, and the electrical insulation was evaluated according to the following criteria.

○: Neither migration nor decrease in insulation resistance value ×: Migration or decrease in insulation resistance value occurred in 1000 hours or less.

1) 1-hydroxy-cyclohexyl phenyl ketone, trade name manufactured by Ciba Specialty Chemicals As described above, the cured product formed on the film by the curable resin composition of the present invention has high long-term reliability of electrical insulation, Flexible and less warping due to cure shrinkage. Therefore, the curable resin composition of this invention can be utilized suitably for the surface protective film etc. of a flexible wiring circuit.

Claims (13)

(A) a carboxyl group-containing urethane resin using the following (a), (b) and (c) as raw materials;
(A) a polyisocyanate compound,
(B) a polyol compound,
(C) a dihydroxy compound having a carboxyl group,
(B) containing a curable resin and a polymerization initiator (D) obtained by reacting a compound having both a (meth) acrylic double bond and an epoxy group,
The polyol compound (b) is a polycarbonate polyol,
The curable resin composition, wherein the carboxyl group-containing urethane resin (A) has a number average molecular weight of 3,000 to 50,000 and an acid value of 10 to 100 mg-KOH / g. The curable resin composition according to claim 1 , wherein the polyisocyanate compound (a) is a polyisocyanate compound having an alicyclic structure in which the number of carbon atoms other than carbon atoms in the isocyanate group is 6 to 30. A polyisocyanate compound having an alicyclic structure having 6 to 30 carbon atoms other than carbon atoms in the isocyanate group is 1,4-cyclohexane diisocyanate, isophorone diisocyanate, methylene bis (4-cyclohexyl isocyanate), hydrogenated The curable resin composition according to claim 2 , which is at least one compound selected from the group consisting of 1,3-xylylene diisocyanate and hydrogenated 1,4-xylylene diisocyanate. The curable resin composition according to any one of claims 1 to 3 , wherein the dihydroxy compound (c) having a carboxyl group is 2,2-dimethylolpropionic acid and / or 2,2-dimethylolbutanoic acid. object. The compound (B) having both the (meth) acrylic double bond and the epoxy group is glycidyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate glycidyl ether, and 3,4-epoxycyclohexylmethyl (meth). the curable resin composition according to any one of claims 1 to 4, at least one compound selected from the group consisting of acrylate. The use ratio of the carboxyl group-containing urethane resin (A) and the compound (B) having both the (meth) acrylic double bond and the epoxy group is the carboxyl group in (A) to the epoxy group in (B). the molar ratio ((Acid) / (Epoxy) ) curable resin composition according to any one of claims 1 to 5, which is a ratio such that 0.5 to 1.25 of. The curable resin composition of any one of Claims 1-6 containing a solvent (C). The solvent (C) is toluene, xylene, ethylbenzene, nitrobenzene, isophorone, diethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol monomethyl ether acetate, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, dipropylene glycol methyl ether acetate, Diethylene glycol ethyl ether acetate, methyl methoxypropionate, ethyl methoxypropionate, methyl ethoxypropionate, ethyl ethoxypropionate, n-butyl acetate, isoamyl acetate, ethyl lactate, cyclohexanone, N, N-dimethylformamide, N, N-dimethyl Acetamide, N-methylpyrrolidone, γ-butyrolactone The curable resin composition according to claim 7 is at least one selected from the group consisting of finely dimethyl sulfoxide. The curable resin composition according to claim 7 or 8 , wherein the carboxyl group-containing urethane resin (A) is produced in the presence of a solvent (C). The curable resin comprises a carboxyl group-containing urethane resin (A) and a compound (B) having both a (meth) acrylic double bond and an epoxy group in an amine system, phosphine, in a solvent (C). the curable resin composition according to any one of claims 7-9, which is prepared by reacting in the presence of a system catalyst. The curable resin composition according to any one of claims 1 to 10 , wherein the polymerization initiator (D) is a photopolymerization initiator. The curable resin composition according to any one of claims 1 to 11 , comprising inorganic and / or organic fine particles (E). Cured product obtained by curing the curable resin composition according to any one of claims 1 to 12.