JPH11158252A - Thermosetting resin composition, protective film comprising the same and its forming - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a thermosetting resin composition suitable for forming a flexible film which produces no warpage after thermosetting and shows excellence in flex resistance, bending resistance, flexibility, plating resistance, thermal resistance, PCT resistance, resistance to soldering heat, electric insulation and adhesion to a substrate, required for a solder resist used in manufacturing a flexible printed wiring board and a tape carrier package or a protective film used in manufacturing an electroluminescent panel or the like, a protective film comprising the hardened resin and its formation. SOLUTION: A thermosetting resin contains (A) a polycarboxylic acid having not less than 2 carboxylic acid groups, an acid number of 20-120 mgKOH/g, a glass transition temperature of -60 to 40 deg.C and weight average molecular weight of 5,000-100,000, (B) a resin having not less than 2 epoxy groups in a molecule, (C) an organic solvent and, in a preferable embodiment, (D) a mercapto compound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solder resist ink used for manufacturing a printed wiring board, particularly for manufacturing a flexible printed wiring board or a tape carrier package, or a backlight for a liquid crystal display or a display for displaying information. For a protective film for a back electrode of an electroluminescent panel used for, and a thermosetting resin composition useful for a protective film of a display panel such as a mobile phone, a watch, and a car stereo, etc., more specifically, after thermosetting. No warpage, adhesion to substrate required for solder resist ink for flexible printed wiring boards and tape carrier packages or protective film for electroluminescent panels, bending resistance, folding resistance, flexibility Resistance, plating resistance, heat resistance, PCT resistance, solder heat resistance,
The present invention relates to a thermosetting resin composition suitable for forming a flexible film having excellent electrical insulation, a protective film made of the cured product, and a method for forming the same.

[0002]

2. Description of the Related Art As a solder resist used in the manufacture of a flexible printed wiring board or a tape carrier package, a polyimide film called a coverlay film is punched out by a mold corresponding to a pattern. Adhesive type and ultraviolet curing type to form a flexible film,
There are a type of applying a thermosetting solder resist ink or a liquid polyimide ink by screen printing, and a type of a liquid photo solder resist ink for forming a flexible film.

However, in coverlay film,
Since there is a problem in followability with the copper foil, a highly accurate pattern cannot be formed. On the other hand, the UV-curable solder resist ink and the liquid photo-solder resist ink have poor adhesion to the polyimide of the base material, so that sufficient flexibility cannot be obtained. Further, since the curing shrinkage of the solder resist ink and the cooling shrinkage after the curing are large, warpage occurs, which is a problem. In liquid polyimide ink,
A soluble aromatic polyimide as disclosed in Japanese Patent Application Laid-Open No. 1-121364 is used, but it is expensive and bleeding occurs at the time of printing, so that sufficient workability cannot be obtained.

Further, as a conventional thermosetting solder resist ink, an epoxy resin-based resist ink composition containing an epoxy resin and a dibasic anhydride as essential components as disclosed in Japanese Patent Publication No. 5-75032 is used. However, when the film formed is adjusted so as to have flexibility, the adhesion to the polyimide of the substrate is deteriorated, and the plating resistance and P
There is a problem that CT resistance and solder heat resistance decrease.

On the other hand, as an ink used for a protective film for an electroluminescent panel, a gravure ink, a vinyl chloride-based heat-drying ink, a melamine resin-based thermosetting ink, or a flexible coating film is used. Is applied by screen printing. However, the gravure ink has a problem in practical use because it does not have an insulating property, so that the electric capacity is reduced, and sufficient luminance of light emission cannot be obtained. Also,
In the case of the ultraviolet curable ink, since the electroluminescent panel is warped after curing, acoustic noise is generated when electrons collide with and excite the phosphor to emit light, which is a problem.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of a solder resist ink or a protective film for forming a flexible film.
As a first embodiment, (A) one molecule has two or more carboxyl groups and an acid value of 20 to 120 mgKOH /
g, a polycarboxylic acid resin having a glass transition temperature of −60 to 40 ° C. and a weight average molecular weight of 5,000 to 100,000, (B) a resin having two or more epoxy groups in one molecule, And (C) a thermosetting resin composition containing an organic solvent. Further, as a second embodiment, (A) one molecule has two or more carboxyl groups, an acid value of 20 to 120 mgKOH / g, a glass transition temperature of -60 to 40 ° C, and a weight average molecular weight. 5,000 to 100,000, (B) a resin having two or more epoxy groups in one molecule, (C) an organic solvent, and (D) a mercapto compound. Is provided.

Further, according to the present invention, there is provided a protective film made of a cured product of the thermosetting resin composition formed on the surface of a protected portion of a product or a component. A method for forming a protective film, which comprises applying a conductive resin composition and then curing the composition by heating it to a predetermined temperature. Examples of the application of the protective film include a printed wiring board, a tape carrier package, a back electrode of an electroluminescent panel, or a product or component such as a mobile phone, a watch or a car stereo display panel. As a method for applying the thermosetting resin composition, a screen printing method, a slit coating method, a roll coating method, a spray coating method, a curtain coating method, or the like is used.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to a composition for forming a solder resist used for manufacturing a flexible printed wiring board or a tape carrier package or a protective film used for manufacturing an electroluminescent panel or the like. A thermosetting reaction system consisting of an acid resin and a polyfunctional epoxy resin is adopted, but the crosslink density of these components is suppressed to an appropriate range for obtaining a film having sufficient flexibility, and after thermosetting. The acid value and the glass transition temperature of the polycarboxylic acid resin used are regulated to specific ranges so as not to cause the warpage. The lower the crosslink density of the reaction product, the greater the flexibility of the formed film, and the lower the crosslink density and glass transition temperature, the less the warpage of the film after thermosetting. However, when the crosslink density is low, the properties of the obtained film, such as heat resistance, plating resistance, and chemical resistance, are also likely to deteriorate. Therefore, it is necessary to design the composition system such that the crosslink density is in an appropriate range in which these contradictory properties are balanced,
According to the study of the present inventors, the measured value of the glass transition temperature of the product obtained after heating and curing the thermosetting resin composition is higher than the calculated value. Also,
The higher the acid value of the polycarboxylic acid resin used, the higher the crosslink density and the higher the glass transition temperature. However, there is no necessarily a proportional relationship between these, and if the glass transition temperature of the polycarboxylic acid resin is too low, the acid value will increase. , The crosslink density does not increase. Therefore, it is necessary to regulate the polycarboxylic acid resin to be used from both the acid value and the glass transition temperature.

The present inventors have conducted intensive studies on these phenomena, and as a result, have adopted a thermosetting reaction system composed of a polycarboxylic acid resin and a polyfunctional epoxy resin, and set the acid value of the polycarboxylic acid resin to 20 to 120 mg KOH. / G and the glass transition temperature within the range of -60 to 40 ° C, without causing warpage after thermosetting, having sufficient flexibility, bending resistance and folding resistance. That a film having excellent flexibility, plating resistance, PCT resistance, solder heat resistance, chemical resistance, adhesion to a base, etc. can be obtained, and the weight average molecular weight of the polycarboxylic acid resin is 5,000. It has been found that the printability is improved by setting the range to 100,000, and the present invention has been completed. Further, according to the study of the present inventors, the presence of a mercapto compound in addition to the above components,
It has been found that the adhesion of the substrate to polyimide or copper is improved, and the plating resistance can be further improved. Hereinafter, each component of the thermosetting resin composition of the present invention will be described in detail.

First, as the polycarboxylic acid resin (A) used in the composition of the present invention, a known and commonly used polycarboxylic acid resin is used as long as the acid value, glass transition temperature and weight average molecular weight are within the above ranges. However, it is particularly preferable that one polymerizable unsaturated bond and one
There is a copolymer resin containing a compound having two carboxyl groups as an essential monomer component. Examples of the compound having one polymerizable unsaturated bond and one carboxyl group in one molecule include acrylic acid, methacrylic acid, and hydroxyl group-containing (meth) acrylate to which a polybasic acid anhydride is added. 2-acryloyloxyethyl) succinic acid, mono (2-acryloyloxyethyl) phthalic acid,
Mono (2-acryloyloxyethyl) hexahydrophthalic acid, mono (2-acryloyloxypropyl) succinic acid, mono (2-acryloyloxypropyl) phthalic acid, mono (2-acryloyloxypropyl) hexahydrophthalic acid, mono ( 2- (methacryloyloxyethyl) succinic acid, mono (2-methacryloyloxyethyl) phthalic acid, mono (2-methacryloyloxyethyl) hexahydrophthalic acid, mono (2-methacryloyloxypropyl) succinic acid, mono (2-methacryloyl oil) (Oxypropyl) phthalic acid, mono (2-methacryloyloxypropyl) hexahydrophthalic acid, and the like, and these can be used alone or in combination of two or more. The content ratio of the compound having one polymerizable unsaturated bond and one carboxyl group in one molecule in the polycarboxylic acid resin is determined by copolymerizing the acid value with the (meth) acrylic ester described below. Is 20-120m
It is necessary to be gKOH / g. Acid value is 20mg
If it is less than KOH / g, the crosslinking density will be low, and the heat resistance, solvent resistance, etc. will be reduced. Conversely, acid value is 120mg
If it exceeds KOH / g, problems such as an increase in warpage due to curing shrinkage during thermal curing and an increase in repulsion force when bent are caused.

Further, as the polymerizable monomer which is copolymerized with the compound having one polymerizable unsaturated bond and one carboxyl group in one molecule, a known and commonly used polymerizable monomer can be used. For the purpose of lowering the glass transition point and increasing the plating resistance, a (meth) acrylate having 6 to 21 carbon atoms is preferable. Specific examples include n-propyl acrylate, i-propyl acrylate, n-butyl acrylate, i-butyl acrylate, t-butyl acrylate, i-amyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, benzyl acrylate, and i-propyl acrylate. Examples include boronyl acrylate, i-decyl acrylate, n-lauryl acrylate, n-stearyl acrylate, and methacrylates thereof. Among these,
From the viewpoint of imparting hydrophobicity, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, n-lauryl acrylate, and n-lauryl methacrylate are particularly preferable, and by using these, prevention of penetration of a plating solution into a formed film and washing with hot water. The effect of preventing floating and peeling is obtained, and plating resistance is improved.

A compound having one polymerizable unsaturated bond and one carboxyl group in one molecule; and a compound having 6 to 2 carbon atoms.
Glass transition point (Tg) of copolymer resin (polycarboxylic acid resin) containing (meth) acrylic acid ester as an essential component
Can be approximately determined by the following formula (1) from the Tg of the polymer of each monomer alone and the weight fraction of each component, and this Tg is −60 to 40 ° C., particularly preferably −40.
The monomer composition is determined so as to reach -20 ° C. 1 / Tg = W ₁ / Tg ₁ + W ₂ / Tg ₂ +... + W _n / Tg _n (1) In the formula, Tg indicates a glass transition point (° K) of the copolymer, and Tg _{1, Tg 2, ···, Tg} n represents a glass transition point (° K) of each component alone of the polymer. W ₁ ,
W ₂ ,..., W _n are weight fractions of each component (W ₁ + W _2).
+ ... + W _n = 1). The glass transition point of the copolymer resin (polycarboxylic acid resin) thus obtained is
If it exceeds 40 ° C., the warpage during cooling after thermosetting increases, while if it is lower than −60 ° C., the hardness of the coating film after thermosetting decreases.

The polycarboxylic acid resin (copolymer resin) has a weight average molecular weight of 5,000 to 100,000.
Is preferably within the range. Weight average molecular weight of 5,
When the molecular weight is less than 000, it is difficult to produce a copolymer resin, and a stable supply of the resin cannot be obtained. Also, 1
Since the concentration of carboxyl groups per molecule is low, good coating properties cannot be obtained after thermosetting. On the other hand, 10
If it exceeds 000, bleeding or plate separation occurs when the resin composition is printed on a substrate, transfer is deteriorated, and workability and properties of a heat-cured coating film are deteriorated.

As the resin (B) having two or more epoxy groups in one molecule, bisphenol A type, hydrogenated bisphenol A type, bisphenol F type, bisphenol S type, phenol novolak type, cresol novolak type, bisphenol Known and commonly used epoxies such as glycidyl ethers such as novolak type, biphenol type, bixylenol type and trisphenol methane type of A, glycidyl esters such as diglycidyl phthalate, glycidyl amines such as triglycidyl isocyanurate and tetraglycidyl meta-xylylenediamine. Resins can be used alone or in combination of two or more. Among them, particularly preferred are epoxy resins which are hardly soluble in organic solvents and the like, for example, triglycidyl isocyanurate (structural isomers include α-form and β-form, but α-form is particularly preferred). Can be The mixing ratio of these epoxy resins is preferably 0.6 to 2.0 equivalents to 1 equivalent of the carboxyl group of the polycarboxylic acid resin (A).
It is preferable from the viewpoint of properties such as plating resistance, PCT resistance and solder heat resistance of the cured coating film.

As the organic solvent (C), ketones,
Cellosolves, carbitols, cellosolve acetates, carbitol acetates, propylene glycol ethers, dipropylene glycol ethers, propylene glycol ether acetates, dipropylene glycol acetates, aromatic hydrocarbons and the like, These may be used alone or in combination of two or more. Furthermore, the boiling point of these organic solvents is 140-
A temperature of 180 ° C. is preferable in consideration of printability of the composition, and screen printing can be performed without causing bleeding.

As the (D) mercapto compound, known and commonly used mercapto compounds can be used. Particularly preferred are 2-mercaptopropionic acid, trimethylolpropane tris (2-thiopropionate),
-Mercaptoethanol, 2-aminothiophenol,
Mercapto group-containing silane coupling agents such as 3-mercapto-1,2,4-triazole and 3-mercapto-propyltrimethoxysilane. These may be used alone or in combination of two or more. The compounding amount is suitably in the range of 1 to 10 parts by weight per 100 parts by weight of the polycarboxylic acid resin (A). If the amount of the mercapto compound is less than the above range, adhesion to the polyimide of the substrate may not be obtained, which is not preferable. Conversely, when the ratio exceeds the above range, the epoxy group of the epoxy resin required for the crosslinking reaction is consumed (reacts with the epoxy group), and the crosslinking density is undesirably reduced.

The thermosetting resin composition of the present invention may further contain, if necessary, a known / common epoxy resin curing accelerator for accelerating the curing reaction of the epoxy resin. Imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole, 1- (2-cyanoethyl) -2- Ethyl-
Imidazole derivatives such as 4-methylimidazole, guanamines such as acetoguanamine and benzoguanamine, benzyldimethylamine, 4- (dimethylamino) -N,
N-dimethylbenzylamine, 4-methoxy-N, N-
Examples include amine compounds such as dimethylbenzylamine, 4-methyl-N, N-dimethylbenzylamine, dicyandiamide, and melamine. Examples of commercially available products include 2MZ-A and 2MZ manufactured by Shikoku Chemical Industry Co., Ltd.
-OK, 2PHZ, 2P4BHZ, 2P4MHZ (all are trade names of imidazole compounds), U-CAT3503N and U-CAT3502T (all are trade names of blocked isocyanate compounds blocked with dimethylamine) manufactured by San-Apro.

The thermosetting resin composition of the present invention may contain, if necessary, known inorganic materials such as barium sulfate, talc, silica and clay for the purpose of improving the properties such as adhesion, hardness and heat resistance. A filler can be compounded, and the compounding amount is as described in (A) above.
The amount is suitably 100 parts by weight or less per 100 parts by weight of the polycarboxylic acid resin, and preferably 5 to 65 parts by weight. If the blending amount of the inorganic filler exceeds the above ratio, the flex resistance and the folding resistance of the cured coating film decrease, which is not preferable. Further, if necessary, known and commonly used coloring pigments, thermal polymerization inhibitors,
Thickeners, defoamers, leveling agents, silane coupling agents, and the like can be added.

The thermosetting resin composition having the above composition is applied to a circuit-formed flexible printed wiring board, a tape carrier package or an electroluminescent panel by a screen printing method.
By heating to a temperature of 0 to 180 ° C. and thermally curing, there is no warping due to curing shrinkage and cooling shrinkage, adhesion to the substrate, bending resistance, folding resistance, flexibility, plating resistance,
A solder resist film or a protective film excellent in PCT resistance, solder heat resistance, electric insulation and the like is formed.

An example of a mode in which the thermosetting resin composition of the present invention is applied to an electroluminescent panel will be described with reference to the drawings. FIG. 1 shows a schematic configuration of an example of an electroluminescent element, and is a transparent substrate (front plate) such as a PET (polyethylene terephthalate) film.
1 is covered with a transparent electrode 2 in the form of a conductive film such as an ITO film or the like or a pattern. On the transparent electrode 2, a first insulating film 3 and a second insulating film 5 made of a dielectric are coated. The light emitting layer 4 in a pattern sandwiched between the light emitting layers 4 is formed. Further, a pattern-shaped back electrode 6 made of a carbon electrode or the like is formed on these, and is entirely covered with a protective film 7 made of a cured product of the thermosetting resin composition of the present invention. In FIG. 1, the lower side shows the front side. The present invention is, of course, not limited to the embodiment shown in FIG. 1, and can be applied as a protective film for the back electrode of various forms of electroluminescent panel. Further, the cured product of the thermosetting resin composition of the present invention exhibits excellent properties as described above, so that a mobile phone,
It is also useful as a protective film for display panels such as watches and car stereos.

[0021]

The present invention will be specifically described below with reference to examples and comparative examples. In the following, “parts” and “%” are all based on weight unless otherwise specified.

Synthesis Example 1 In a flask equipped with a thermometer, a stirrer, a dropping funnel, and a reflux condenser, 214.3 parts of carbitol acetate and 24.0 parts of azobisisobutyronitrile were put, and placed under a nitrogen atmosphere. Heated to 70 ° C. There, acrylic acid 1
A mixed monomer of 8.0 parts, 162.5 parts of i-butyl methacrylate, and 319.5 parts of 2-ethylhexyl methacrylate was added dropwise over 3 hours. Thereafter, the mixture was further stirred and reacted for 4 hours, and the nonvolatile content was 70% and the solid content was 28.
1 mg KOH / g, weight average molecular weight 16,000, Tg
= 9.7 ° C to obtain a polycarboxylic acid resin solution.
Hereinafter, this polycarboxylic acid resin solution is referred to as A varnish.

Synthesis Example 2 A flask equipped with a thermometer, a stirrer, a dropping funnel, and a reflux condenser was charged with 214.3 parts of dipropylene glycol monomethyl ether and 20.0 parts of azobisisobutyronitrile.
Was heated to 70 ° C. under a nitrogen atmosphere. There, 36.0 parts of acrylic acid, 189.0 parts of n-butyl methacrylate, and n-lauryl methacrylate 27
5.0 parts of the mixed monomer was added dropwise over 3 hours. Thereafter, the mixture was further stirred and reacted for 4 hours, and the solid content was 70%, the acid value of the solid content was 56.1 mgKOH / g, the weight average molecular weight was 25
000, calculated value of Tg = -30.5 ° C. to obtain a polycarboxylic acid resin solution. Hereinafter, this polycarboxylic acid resin solution is referred to as B varnish.

Comparative Synthesis Example 1 A flask equipped with a thermometer, a stirrer, a dropping funnel, and a reflux condenser was charged with 300.0 parts of dipropylene glycol monomethyl ether and 12.0 parts of azobisisobutyronitrile.
Was heated to 70 ° C. under a nitrogen atmosphere. Thereto, a mixed monomer of 72.0 parts of acrylic acid, 428.0 parts of i-butyl methacrylate, and 200.0 parts of 2-hydroxyethyl methacrylate was dropped over 3 hours. Then, the mixture was further stirred and reacted for 4 hours,
%, A solid content acid value of 80.1 mg KOH / g, a weight average molecular weight of 45,000, and a calculated value of Tg = 55.2 ° C., to obtain a polycarboxylic acid resin solution. Hereinafter, this polycarboxylic acid resin solution is referred to as C varnish.

Example 1 The following components using the A varnish obtained in Synthesis Example 1 were kneaded with a three-roll mill to obtain a thermosetting resin composition. A varnish 100 parts Phthalocyanine green 2 parts DICY-7A 1 part (Dicyandiamide manufactured by Yuka Shell Epoxy Co., Ltd.) TEPIC-H 10 parts (α-triglycidyl isocyanurate manufactured by Nissan Chemical Industries, Ltd.) Silicone KS-66 1 part (Silicone antifoaming agent manufactured by Shin-Etsu Silicone Co., Ltd.) Barium sulfate 20 parts Crystalline silica 5 parts Propylene glycol monobutyl ether 10 parts 149 copies in total

Example 2 The following components using the B varnish obtained in Synthesis Example 2 were kneaded with a three-roll mill to obtain a thermosetting resin composition. B varnish 100 parts Phthalocyanine green 2 parts DICY-7A 1 part TEPIC-H 10 parts Silicone KS-66 1 part Barium sulfate 20 parts Crystalline silica 5 parts Propylene glycol monobutyl ether 10 parts 149 copies in total

Example 3 The following components using the B varnish obtained in Synthesis Example 2 were kneaded with a three-roll mill to obtain a thermosetting resin composition. B varnish 100 parts Phthalocyanine green 2 parts DICY-7A 1 part TEPIC-H 10 parts Silicone KS-66 1 part Crystalline silica 40 parts Propylene glycol monobutyl ether 10 parts A-189 3 parts (3-mercapto manufactured by Nippon Yunika Co., Ltd.) -Propyltrimethoxysilane) ──────────────────────────────── 167 parts in total

Example 4 The following components using the B varnish obtained in Synthesis Example 2 were kneaded with a three-roll mill to obtain a thermosetting resin composition. B Varnish 100 parts Phthalocyanine green 2 parts 2PHZ 1 part Epicoat 828 20 parts (Bisphenol A type epoxy resin manufactured by Yuka Shell Epoxy Co., Ltd.) Silicone KS-66 1 part Barium sulfate 30 parts Talc 10 parts Dipropylene glycol monomethyl ether 10 parts A-189 3 parts ──────────────────────────────── Total 177 parts

Example 5 The following components using the B varnish obtained in Synthesis Example 2 were kneaded with a three-roll mill to obtain a thermosetting resin composition. B varnish 100 parts Phthalocyanine green 2 parts 2PHZ 1 part Melamine 1 part DEN 431 20 parts (Phenol novolac type epoxy resin manufactured by Dow Chemicals) Silicone KS-66 1 part Crystalline silica 30 parts Clay 20 parts Dipropylene glycol monomethyl ether 10 parts A-189 3 parts ──────────────────────────────── Total 188 parts

Comparative Example 1 The following components using the C varnish obtained in Comparative Synthesis Example 1 were kneaded with a three-roll mill to obtain a thermosetting resin composition. C varnish 100 parts Phthalocyanine green 2 parts DICY-7A 1 part TEPIC-H 10 parts Silicone KS-66 1 part Barium sulfate 20 parts Crystalline silica 5 parts Diethylene glycol monoethyl ether acetate 10 parts 149 copies in total

Comparative Example 2 The following components using the A varnish obtained in Synthesis Example 1 were kneaded with a three-roll mill to obtain a thermosetting resin composition. A varnish 100 parts Phthalocyanine green 2 parts DICY-7A 1 part Epicoat 828 4 parts Silicone KS-66 1 part Barium sulfate 20 parts Crystalline silica 5 parts Diethylene glycol monoethyl ether acetate 10 parts Total 143 copies

Comparative Example 3 Styrene-acrylic acid resin (Johncryl 68, weight average molecular weight 10,000, T
g = 70 ° C., solid content acid value 195 mg KOH / g)
The mixture was weighed and dissolved in 40 parts of carbitol acetate by heating. Hereinafter, this varnish is referred to as D varnish. The following components using the D varnish were kneaded with a three-roll mill to obtain a thermosetting resin composition. D varnish 100 parts Phthalocyanine green 2 parts DICY-7A 1 part Epicoat 828 60 parts Silicone KS-66 1 part Barium sulfate 20 parts Crystalline silica 5 parts Diethylene glycol monoethyl ether acetate 20 parts 209 copies in total

Performance Evaluation: (1) Adhesion Each of the thermosetting resin compositions of Examples 1 to 5 and Comparative Examples 1 to 3 was prepared by using a Kapton material with an adhesive (thickness: 50 μm).
m) and the whole surface was printed by screen printing on a PET film, and cured at 150 ° C. for 30 minutes (dry film thickness: 20 μm).
m). The adhesion of the cured coating film was evaluated according to the following criteria in accordance with JIS D0202. ：: When the number of grids remains completely △: When the number of grids is less than 100, and when 60 or more remain ×: When the number of grids is less than 60

(2) Flex resistance The thermosetting resin compositions of Examples 1 to 5 and Comparative Examples 1 to 3 were all printed on a Kapton material (thickness: 50 μm) by screen printing at 150 ° C. For 30 minutes (dry film thickness: 20 μm). The flex resistance of the cured coating film is I
According to PC-SM-840B TM2.4.29, the evaluation was performed based on the following criteria under the condition of 1/8 inch in diameter and 10 cycles. ：: The cured coating film has no cracks Δ: The cured coating film has some cracks X: The cured coating film has cracks

(3) Folding Resistance The thermosetting resin compositions of Examples 1 to 5 and Comparative Examples 1 to 3 were all printed on a Kapton material (thickness: 25 μm) by screen printing at 150 ° C For 30 minutes (dry film thickness: 20 μm). The cured coating film obtained was bent at 180 ° and evaluated according to the following criteria. ：: The cured coating film has no cracks Δ: The cured coating film has some cracks X: The cured coating film has cracks

(4) Flexibility The thermosetting resin compositions of Examples 1 to 5 and Comparative Examples 1 to 3 were all printed on a Kapton material (50 μm in thickness) by screen printing. It was cured for 30 minutes (dry film thickness 20 μm). The obtained cured coating film is 10m wide.
m and a length of about 90 mm, and the repulsive force when bent to 3 mm on an electronic balance was evaluated according to the following criteria. ○: less than 10 g (equivalent to 50 μm of Kapton material) △: less than 10 to 30 g ×: 30 g or more

(5) Warpage The thermosetting resin compositions of Examples 1 to 5 and Comparative Examples 1 to 3 were all printed on a Kapton material (150 × 110 mm, thickness 25 μm) by screen printing. 150
Cured at 30 ° C. for 30 minutes (dry film thickness 20 μm). After cooling, the warpage of the obtained cured coating film was evaluated according to the following criteria. ○: no warpage △: slightly warped ×: warped

(6) Plating Resistance Each of the thermosetting resin compositions of Examples 1 to 5 and Comparative Examples 1 to 3 was applied to a printed circuit board (1.6 mm thick).
A pattern was printed thereon and cured at 150 ° C. for 30 minutes (dry film thickness: 20 μm). The plating resistance of the obtained cured coating film was evaluated according to the following criteria. Plating bath: LT-34 manufactured by Shipley Far East;
70 ° C. × 10 minutes Hot water washing: 80 ° C. × 10 minutes ○: The cured coating has no blistering, peeling, or discoloration △: The cured coating has slight blistering, peeling, or discoloration ×: The cured coating has blistering, Those with peeling or discoloration

(7) PCT Resistance Each of the thermosetting resin compositions of Examples 1 to 5 and Comparative Examples 1 to 3 was applied to a printed circuit board (1.6 mm thick).
A pattern was printed thereon and cured at 150 ° C. for 30 minutes (dry film thickness: 20 μm). The PCT resistance of the obtained cured coating film was evaluated under the following criteria under conditions of 121 ° C. and 50 hours of saturation. ：: The cured coating has no blistering, peeling or discoloration △: The cured coating has slight blistering, peeling or discoloring ×: The cured coating has blistering, peeling or discoloration

(8) Heat Resistance to Solder Each of the thermosetting resin compositions of Examples 1 to 5 and Comparative Examples 1 to 3 was applied to a printed circuit board (1.6 mm thick).
A pattern was printed thereon and cured at 150 ° C. for 30 minutes (dry film thickness: 20 μm). A rosin-based flux was applied to the obtained cured coating film, immersed in a solder bath at 260 ° C. for 10 seconds, and the state of the cured coating film was evaluated according to the following criteria. ：: The cured coating has no blistering, peeling or discoloration △: The cured coating has slight blistering, peeling or discoloring ×: The cured coating has blistering, peeling or discoloration

(9) Electrical Insulation Each of the thermosetting resin compositions of Examples 1 to 5 and Comparative Examples 1 to 3 was applied to a B pattern of a printed circuit board (1.6 mm thick) determined by IPC. Print the pattern on top,
It was cured at 150 ° C. for 30 minutes (dry film thickness: 20 μm).
The electrical insulation of the obtained cured coating film was evaluated according to the following criteria. Humidification conditions: temperature 85 ° C, humidity 85% RH, applied voltage 10
0V, 500 hours Measurement conditions: Measurement time 60 seconds, applied voltage 500V ○: insulation resistance 10 ⁹ Omega or after humidification, copper without migration △: insulation resistance 10 ⁹ Omega or after humidification, there copper migration × : Insulation resistance after humidification 10 ⁸ Ω or less, copper migration

Table 1 shows the results of the above test. As is clear from the results shown in Table 1, the cured coating film formed from the thermosetting resin composition of the present invention has no warpage, adhesion to the substrate, bending resistance, folding resistance, flexibility, Excellent in plating resistance, PCT resistance and solder heat resistance. In addition, good results were also obtained in terms of electrical insulation.

[Table 1]

[0043]

As described above, according to the present invention, a solder resist ink used for manufacturing a flexible printed wiring board and a tape carrier package excellent in flexibility, or an electroluminescent panel is manufactured. The present invention provides a thermosetting resin composition useful as a protective film to be obtained. Since such a solder resist ink does not warp after thermosetting, it is easy to mount components or chips on a flexible printed wiring board or a tape carrier package. Further, the thermosetting resin composition of the present invention can be produced at a lower cost as compared with a conventionally used liquid polyimide ink. On the other hand, when used as a protective film, similarly, there is no warping after thermosetting, so that acoustic noise when the electroluminescent element emits light can be reduced. In addition, since the insulating property is better than that of the conventionally used gravure ink, the dissipation of the charge amount is effectively prevented, and the luminance of light emission can be improved. Therefore, the thermosetting resin composition of the present invention is useful as a solder resist ink used for manufacturing a flexible printed wiring board or a tape carrier package, or as a protective film used for manufacturing an electroluminescent panel, and has flexibility. A protective film with excellent properties such as bending resistance, bending resistance, flexibility, plating resistance, PCT resistance, solder heat resistance, electrical insulation, and adhesion to a base can be formed at low cost and with high productivity. .

[Brief description of the drawings]

FIG. 1 is a schematic partial cross-sectional view of an example of an electroluminescent device having a protective film formed on the surface of a back electrode according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transparent base material 2 Transparent electrode 3 First insulating film 4 Light emitting layer 5 Second insulating film 6 Back electrode 7 Protective film

Claims (11)

[Claims] (A) A compound having two or more carboxyl groups in one molecule, having an acid value of 20 to 120 mgKOH / g, a glass transition temperature of -60 to 40 ° C, and a weight average molecular weight of 5,000. A thermosetting resin composition comprising: a polycarboxylic acid resin having a molecular weight of about 100,000, (B) a resin having two or more epoxy groups in one molecule, and (C) an organic solvent. (A) having two or more carboxyl groups in one molecule, having an acid value of 20 to 120 mgKOH / g, a glass transition temperature of -60 to 40 ° C, and a weight average molecular weight of 5, (B) a resin having two or more epoxy groups in one molecule, (C) an organic solvent, and (D) a mercapto compound. Curable resin composition. 3. The thermosetting resin composition according to claim 2, wherein the (D) mercapto compound is 3-mercapto-propyltrimethoxysilane. 4. The polycarboxylic acid resin (A) is a copolymer resin containing a compound having one polymerizable unsaturated bond and one carboxyl group in one molecule as an essential monomer component. The thermosetting resin composition according to any one of claims 1 to 3. 5. The method according to claim 1, wherein the polycarboxylic acid resin (A) is a copolymer resin containing a (meth) acrylic acid ester having 6 to 21 carbon atoms as an essential monomer component. The thermosetting resin composition according to claim 1. 6. The compounding amount of the resin having an epoxy group (B) is the same as that of the carboxyl group 1 of the polycarboxylic acid resin (A).
The thermosetting resin composition according to any one of claims 1 to 5, wherein the amount is 0.6 to 2.0 equivalents per equivalent. 7. The compounding amount of the mercapto compound (D) is 1 to 100 parts by weight of the polycarboxylic acid resin (A).
The thermosetting resin composition according to any one of claims 2 to 6, wherein the amount is from 10 to 10 parts by weight. 8. A protective film comprising a cured product of the thermosetting resin composition according to claim 1, formed on a surface of a protected portion of a product or a part. 9. The protective film according to claim 8, wherein the product or component is a printed wiring board, a tape carrier package, a back electrode of an electroluminescent panel, or a display panel of a mobile phone, a clock or a car stereo. . 10. A protective film, characterized in that the thermosetting resin composition according to any one of claims 1 to 7 is applied to the surface of a protected portion and then heated to a predetermined temperature to be cured. Forming method. 11. The method according to claim 10, wherein the application is performed by a screen printing method, a slit coating method, a roll coating method, a spray coating method, or a curtain coating method.