JPH05156190A - Solder-resist ink composition and its cured product - Google Patents

Abstract

PURPOSE:To obtain an ink which can be washed with water and has a high heat distortion temperature and excellent heat resistance, adhesion, hardness, chemical resistance, etc., by adding a specified epoxy resin to a solder-resist ink. CONSTITUTION:The objective solder-resist ink composition contains an epoxy resin of formula I. This resin can be obtained by reacting the alcoholic hydroxyl groups of a compound of formula II with epichlorohydrin. In the formulas, R1 and R2 are independent of each other and are H or 1-4 C alkyl; n>=1; M is H or glycidyl, provided that M is necessarily glycidyl when (n)=1, and at least one of Ms is glycidyl when n>=2. Examples of the curing agents to be used include dicyandiamide and 2,4-diamino-6-[2'-methylimidazolyl-(1)']-ethyl-s- triazine.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a solder resist ink composition which can be washed with water and has a cured product which is excellent in heat resistance, adhesion, chemical resistance, high heat distortion temperature hardness, and has little bleeding. Regarding cured products.

[0002]

BACKGROUND OF THE INVENTION Solder resist inks are commonly used on circuit boards (eg paper-phenol, paper-epoxy, glass-
By etching a copper clad laminate using an organic material such as epoxy as a base material, a printed circuit board obtained by forming a desired circuit, or an inorganic material such as ceramics as a base material,
A protective coating is formed by screen printing or roll coating on the surface of a circuit board, etc. obtained by forming a desired circuit by a screen printing method using a conductor or a resistor. Used for protection, circuit protection during soldering, board protection during plating, etc.
6408, JP-A-51-87028, JP-A-54-
156167, JP-A-55-12175, JP-A-5
5-53478, JP-A-55-46165, JP-A-61-12772 and JP-A-63-30578). As the solder resist, conventionally, a bisphenol A type epoxy resin, a phenol novolac type epoxy resin, or a cresol novolac type epoxy resin mixed with a curing agent has been used.

[0003]

In recent years, there has been a strong demand for a water-based ink cleaning device that can clean the ink due to environmental problems.
In addition, the miniaturization and high density of circuit boards are progressing, and the required characteristics for solder resists are becoming more sophisticated accordingly, and those with superior heat distortion temperature, dimensional stability, heat resistance, chemical resistance, etc. Has been requested.

[0004]

The present invention allows the composition to be washed with water, has a high heat distortion temperature, is excellent in heat resistance, adhesion, hardness, chemical resistance, etc. The present invention provides a small amount of solder resist ink composition and a cured product thereof. That is, the present invention is: Formula (1)

[0005]

[Chemical 4]

(Wherein R ₁ and R ₂ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, n is an integer of 1 or more, and M is a hydrogen atom or a glycidyl group. However, when n is 1, M is always a glycidyl group, and when n is 2 or more, at least one M is a glycidyl group.) A solder resist ink composition containing an epoxy resin (A) .. 2. Epoxy resin (A) and curing agent (B) according to item 1
2. A solder resist ink composition comprising: and a solvent (C). 3. The solder resist ink composition according to item 2, wherein the curing agent (B) is one or more selected from the group consisting of dicyandiamide, an imidazole compound, a triazine compound, a urea compound and an aromatic amine compound. Solvent (C) is formula (2)

[0007]

[Chemical 5]

(In the formula, R ₃ is a hydrogen atom or a carbon number of 1 to
8 is an alkyl group, R ₄ is an ethylene group optionally substituted by a methyl group, R ₅ is a hydrogen atom or

[0009]

[Chemical 6]

And R ₆ represents an alkyl group having 1 to 8 carbon atoms. However, R ₃ and R ₅ are not hydrogen atoms at the same time. n shows the integer of 1-4. 1) or 2 selected from the group consisting of a compound represented by the formula) and solvent naphtha
4. The solder resist ink composition according to claim 2 or 3, which is one or more kinds. 5. A cured product of the solder resist ink composition according to item 1, 2, or 3. A cured product of the solder resist ink composition according to item 4.

The epoxy resin (A) represented by the formula (1) is a compound represented by the formula (3).

[0012]

[Chemical 7]

It can be obtained by reacting an alcoholic hydroxyl group of the formula (wherein R ₁ , R ₂ and n have the same meanings as in formula (1)) with epichlorohydrin.
The compound represented by the formula (3) is a hydantoin compound represented by the formula (4).

[0014]

[Chemical 8]

(In the formula, R ₁ and R ₂ have the same meanings as in formula (1).) For example, hydantoin, 5,5-dimethylhydantoin, 5,5-diethylhydantoin, 5
-Ethyl-5-methylhydantoin, 5,5-dipropylhydantoin and the like and compounds represented by the formula (5)

[0016]

[Chemical 9]

(Wherein R ₁ and R ₂ have the same meanings as those in formula (1)), and 1 mol of the hydantoin compound represented by formula (4) is represented by formula (5). Compound 1.2
It can be obtained by reacting at 130 to 160 ° C. for usually 5 to 10 hours at a ratio of ˜2 mol.

Next, the amount of epichlorohydrin used is preferably 1 equivalent or more per 1 equivalent of the alcoholic hydroxyl group in the formula (3). However, hydroxyl group 1
When the amount is more than 15 times the equivalent, the effect of increasing the amount is almost lost, while the volume efficiency is deteriorated, which is not preferable.
A quaternary ammonium salt such as tetramethylammonium chloride or benzyltrimethylammonium chloride is preferably used as a catalyst when the compound represented by the formula (3) is reacted with epichlorohydrin.
The amount used is preferably 0.3 to 50 g per 1 equivalent of the alcoholic hydroxyl group in the formula (3).

During the reaction, alkali metal hydroxides (eg,
It is preferable to use caustic soda, caustic potash, lithium hydroxide, calcium hydroxide, etc.). The amount of the alkali metal hydroxide used is preferably approximately equivalent to 1 equivalent of the epoxidized alcoholic hydroxyl group of the compound represented by the formula (3). The alkali metal hydroxide may be solid or aqueous solution. When using an aqueous solution, during the reaction,
The water in the reaction system can be reacted under atmospheric pressure or reduced pressure while being distilled out of the reaction system.

The reaction temperature is preferably 30 to 100 ° C. When the reaction temperature is lower than 30 ° C., the reaction becomes slow and a long reaction time is required. When the reaction temperature exceeds 100 ° C., many side reactions occur, which is not preferable. After completion of the reaction, excess epichlorohydrin can be distilled off under reduced pressure, and then the resin can be dissolved in an organic solvent to carry out a dehydrohalogenation reaction with an alkali metal hydroxide. As the organic solvent, methyl isobutyl ketone, toluene, xylene and the like can be used, but methyl isobutyl ketone is preferably used.

The cured product (B) used in the present invention is, for example, dicyandiamide or an imidazole compound (for example,
2-Ethyl-4-methylimidazole, 1-Cyanoethyl-2-ethyl-4-methylimidazole, 2,4-diamino-6- (2-methylimidazolyl- (1))-ethyl-S-triazine, 2,4 -Diamino-6- (2-
Ethyl-4-methylimidazolyl- (1))-ethyl-
S-triazine / isocyanuric acid adduct, 2-methyl-
Imidazole, 1-phenyl-2-methyl-imidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, etc., triazine compounds (eg 2,4
-Diamino-6-vinyl-S-triazine-isocyanuric acid adduct, 2-vinyl-4,6-diamino-S-triazine, 2-methoxyethyl-4,6-diamino-S-
Triazine, 2-0-cyanophenyl-4,6-diamino-S-triazine and the like, urea compounds (for example, 3-
(3,4-Dichlorophenyl) -1,1′-dimethylurea, 1,1′-isophorone-dis (3-methyl-3-)
Hydroxyethylurea), 1,1′-tolylene-bis (3,3-dimethylurea), etc.), aromatic amine compounds (eg, 4,4′-diamino-diphenylmethane, etc.)
Can be mentioned.

Among the curing agents (B), dicyandiamide and 2,4-diamino-6- [2 'are particularly preferable.
-Methylimidazolyl- (1) ']-ethyl-S-triazine, 2-ethyl-4-methylimidazole, 1,1
′ -Isophorone-bis (3-methyl-3-hydroxyethylurea), 1,1′-tolylene-bis (3,3-dimethylurea) 3- (3,4-dichlorophenyl)-
1,1′-dimethylurea and the like.

Specific examples of the solvent (C) used in the present invention include ethyl cellosolve, isopropyl cellosolve, butyl cellosolve, diethylene glycol monoacetate, ethyl carbitol, butyl carbitol, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, diester. Examples include propylene glycol monomethyl ether and solvent naphtha. The ratio of each of the components (A) to (C) contained in the solder resist ink composition of the present invention is preferably 0.5 to 60 parts by weight of the component (B) when the amount of the component (A) is 100 parts by weight,
It is particularly preferably 1 to 30 parts by weight, and the component (C) is 2
0 to 60 parts by weight is preferable, and 30 to 50 is particularly preferable.
Parts by weight.

The composition of the present invention may further include various additives such as talc, silica, alumina, barium sulfate,
An extender pigment such as magnesium oxide, a thixotropic agent such as Aerosil, a leveling agent such as silicone or an acrylate copolymer, a defoaming agent, a flame retardant and a coloring agent can be added. These various additives can be added to the composition in any amount. Further, a novolac type epoxy resin, a bisphenol type epoxy resin and the like can be added. The composition of the present invention can be produced by uniformly mixing the components. The composition of the present invention is cured by heating to 130 ° C. or higher by a conventional method to obtain the cured product of the present invention. In general use of the composition of the present invention, the composition of the present invention is printed on a substrate by screen printing or the like, and then heat cured (130 to 1).
A protective film (usually 10 to 10
A cured film having a thickness of 0 μm) can be produced.

[0025]

EXAMPLES The present invention will be described in more detail below with reference to examples. The parts in the synthesis examples and examples are parts by weight. Synthesis Example of Epoxy Resin Represented by Formula (1) Synthesis Example 1 2,4-Diglycidyl-5,5-dimethylhydantoin (epoxy equivalent 137) 548 parts, 5,5-dimethylhydantoin 128 parts, triethanolamine 2 parts Was added and the reaction product 67 was obtained by stirring at 140 ° C. for 5 hours.
6 parts (epoxy equivalent: 360, softening point: 76 ° C., average value of n in formula (2): 2.1) was added to epichlorohydrin 20.
After dissolving in 00 parts, 13 parts of tetramethylammonium chloride was added, and 98.5% Na was added at 70 ° C. with stirring.
104 parts of OH were added over 100 minutes. After the addition, the reaction was further performed at 70 ° C. for 3 hours. Then, most of the excess unreacted epichlorohydrin was distilled off under reduced pressure, the reaction product containing the by-product salt was dissolved in 1500 parts of methyl isobutyl ketone, the by-product salt was filtered and removed, and then methyl isobutyl ketone was distilled. Then, 722 parts of an epoxy resin (a) having an epoxy equivalent of 216 and a softening point of 65 ° C. was obtained. When the obtained epoxy resin (a) is calculated from the epoxy equivalent, about 1.8 of 2.1 alcoholic hydroxyl groups in the formula (2) are epoxidized.

Synthesis Example 2 822 parts of 2,4-diglycidyl-5,5-dimethylhydantoin (epoxy equivalent 137), 256 parts of 5,5-dimethylhydantoin and 3.5 parts of triethanolamine were added, and the mixture was heated at 140 ° C. for 7 hours. Reaction product 1 obtained by stirring
After dissolving 078 parts (epoxy equivalent 577, softening point 90 ° C., average value of n in formula (2) is 4.3) in 4070 parts epichlorohydrin, 26 parts tetramethylammonium chloride are added, and the mixture is stirred at 70 ° C. At 98.
211 parts of 5% NaOH was added over 100 minutes. After the addition, the reaction was further performed at 70 ° C. for 3 hours. Then, most of the excess unreacted epichlorohydrin was distilled off under reduced pressure, and the reaction product containing a by-product salt was removed with methyl isobutyl ketone 2500.
Part was dissolved, the by-product salt was filtered off, and then methyl isobutyl ketone was distilled to obtain 1221 parts of epoxy resin (b) having an epoxy equivalent of 239 and a softening point of 81 ° C. The epoxy resin (b) thus obtained was calculated from the epoxy equivalents to give about 3.1 of the 4.1 alcoholic hydroxyl groups in the formula (2).
Seven are epoxidized.

Synthesis Example 3 612 parts of 2,4-diglycidyl-5,5-diethylhydantoin (epoxy equivalent 153), 156 parts of 5,5-diethylhydantoin and 2.5 parts of triethanolamine were added, and the mixture was heated at 140 ° C. for 5 hours. Reaction product 7 obtained by stirring
68 parts (epoxy equivalent 410, softening point 73 ° C., formula (2)
The average value of n in 2.1 is epichlorohydrin 2
After being dissolved in 000 parts, 14 parts of tetramethylammonium chloride was added and stirred at 70 ° C. for 98.5%.
104 parts of NaOH were added over 100 minutes. After the addition, the reaction was further performed at 70 ° C. for 3 hours. Then, most of the excess unreacted epichlorohydrin was distilled off under reduced pressure, the reaction product containing a by-product salt was dissolved in 1600 parts of methyl isobutyl ketone, and the by-product salt was removed by filtration, and then methyl isobutyl ketone was distilled. Epoxy equivalent 238, softening point 64
833 parts of epoxy resin (c) at 0 ° C. was obtained. The epoxy resin (c) thus obtained was calculated from the epoxy equivalent to give approximately 1. 1 of 2.1 alcoholic hydroxyl groups in the general formula (2).
Nine are epoxidized.

Examples 1 to 3 and Comparative Examples 1 to 4 Each component was blended according to the blending composition shown in Table 1 (numerical values are parts by weight) and kneaded using a three-roll to obtain a solder resist ink composition. It was This ink composition was applied to a printed wiring board by screen printing so that the film thickness was about 25 μm, and heated at 150 ° C. for 30 minutes for curing to obtain a printed wiring board having a protective film. Regarding the protective film and the ink composition of the obtained printed wiring board,
Various performance tests were conducted. The results are shown in Table 2.

(Water solubility of ink composition): 5 g of the ink composition is dissolved in 50 g of water. ○ ・ ・ ・ Soluble △ ・ ・ ・ ・ Semi-dissolved × ・ ・ ・ ・ Insoluble (Evaluation of physical properties of protective film) (Pencil hardness): Measured according to JIS-K-5400 (Adhesion): JIS-D-0202 In accordance with the above, the cross-cut test (the number of pieces that did not come off in 100 cross-cuts) (heat resistance): The state of the coating film after immersion in molten solder at 260 ° C. for 180 seconds was determined. ○ ・ ・ ・ ・ No abnormality at all × ・ ・ ・ ・ ・ ・ Discoloration, peeling, blistering (gold plating resistance): Uemura Kogyo KK, Orna 533
Conditions: 1 A / dm ² , 15 minutes, plating thickness, 2 μm ○ ・ ・ ・ ・ No abnormality at all × ・ ・ ・ ・ Discoloration, peeling, blister

(Acid resistance): The state of the coating film after being immersed in a 10 Vol% H ₂ SO ₄ aqueous solution at room temperature was evaluated. ◎ ・ ・ ・ No abnormality for 48 hours ○ ・ ・ ・ ・ No abnormality for 24 hours △ ・ ・ ・ ・ No abnormality for 8 hours × ・ ・ ・ ・ ・ ・ Peeling and blistering in 1 hour (alkali resistance): 10 wt% NaOH The state of the coating film after being immersed in the aqueous solution at room temperature was evaluated. ○ ・ ・ ・ ・ No abnormalities for 30 days △ ・ ・ ・ ・ No abnormalities for 15 days × ・ ・ ・ ・ Peeling and blistering within 7 days (heat deformation temperature): TMA method, Shimadzu Thermal Analyzer TMA-4
0

(Electrical insulation resistance): JIS-Z-3197
Measured according to (bleed): width of bleed of ink composition (μ
m) (Discoloration of protective film during heat curing of ink composition) ("Discoloration of protective film" in the table): About discoloration state of the protective film during heat curing (150 ° C, 60 minutes) It was judged. ○ ・ ・ ・ ・ No abnormalities △ ・ ・ ・ ・ Discoloration × ・ ・ ・ ・ Severe discoloration

Table 1 (1) Example 1 2 3 Epoxy resin (A) obtained in Synthesis Example 1 (A) 100 〃 2 〃 (A) 100 combined 〃 3 〃 (A) 100 sets Epicoat 828 * 1 Composition Epicoat 1001 * 2 YDN-180 * 3 EOCN-102 * 4 Table 1 (1) continued Example 1 2 3 EPPN-201 * 5 Curing agent (B) Dicyandiamide 8.0 8.0 8.0 2-Ethyl-4-methylimidazole 7.0 combined Triazine compound * 6 6.0 6.0 Solvent (C) group Carbitol acetate 40 40 40 Extender pigment, talc 10 10 10 Barium sulfate 50 50 50 Aerosil 1.0 1.0 1.0 Coloring pigment, phthalocyanine green 6 6 6 Defoamer TSF401 * 7 2.0 2.0 2.0

Table 1 (2) Comparative Example 1 2 3 4 Epoxy resin (A) 〃 2 〃 (A) 〃 3 〃 (A) composition obtained in Synthesis Example 1 Epicoat 828 * 1 70 combination Epicoat 1001 * 2 30 40 sets YDN-180 * 3 60 composition EOCN-102 * 4 100 EPPN-201 * 5 100 Curing agent (B) Dicyandiamide 2.4 6.0 6.9 8.0 Table 1 (2) Continuing Example 1 2 3 4 2-Ethyl-4-methyl Imidazole 7.0 Triazine compound * 6 6.0 6.0 6.0 Solvent (C) combined Carbitol acetate 17 45 40 45 Body pigment, talc 10 14 10 10 pairs Barium sulfate 100 50 50 50 Aerosil 3.0 2.0 1.0 1.0 Color pigment, phthalocyanine green 6 6 6 6 Defoamer TSF401 * 7 2.4 2.0 2.0 2.0

Note * 1 Epicoat 828 …… Yuka Shell Epoxy Co., Ltd., bisphenol A type epoxy resin * 2 Epicoat 1001 〃 * 3 YDN-180 …… Toto Kasei Co., Ltd., phenol novolac epoxy resin * 4 EOCN-102 ...... Nippon Kayaku Co., Ltd., cresol novolak type epoxy resin * 5 EPPN-201 ...... Nippon Kayaku Co., Ltd., phenol novolak type epoxy resin * 6 2,4-diamino-6- [ 2'-Methylimidazole- (1) ']-Ethyl-S-triazine * 7 Defoamer manufactured by Toshiba Silicon Co., Ltd.

Table 2 (1) Example 1 2 3 Water solubility of ink composition ○ ○ ○ Pencil hardness 7H 7H 7H Adhesion 100 100 100 Heat resistance ○ ○ ○ Gold plating resistance ○ ○ ○ Acid resistance ◎ ◎ ◎ Resistance Alkaline ○ ○ ○ Heat distortion temperature (℃) 180 176 175 Electric insulation resistance (Ω) × 10 ¹¹ 0.2 0.1 0.1 Bleed (μm) Within 25 Within 25 Within 25 Discoloration of protective film ○ ○ ○

Table 2 (2) Comparative Example 1 2 3 4 Water solubility of ink composition × × × × Pencil hardness 6H 6H 6H 6H Adhesion 100/100 100/100 100/100 100/100 Heat resistance × × ○ ○ Gold plating resistance × × ○ ○ Acid resistance × △ ○ ◎ Alkali resistance × − − ○ Heat distortion temperature (℃) 159 144 146 159 Electric insulation resistance (Ω) × 10 ¹¹ 0.9 − 2.0 1.9 Bleed (μm) 150 150 25 Within 25 Within Discoloration of protective film × × × △

Example 4 Instead of using dicyandiamide and 2,4-diamino-6- [2'-methylimidazolyl- (1) ']-ethyl-S-triazine as the curing agent (B) in Example 1, dicyandiamide 8 was used. A solder resist ink composition was prepared using 0.5 parts of 3- (3,4-dichlorophenyl) -1,1'-dimethylurea and 6.0 parts, and the same experiment was performed. Results were obtained.

Example 5 Instead of using dicyandiamide and 2,4-diamino-6- [2'-methylimidazolyl- (1) ']-ethyl-S-triazine as the curing agent (B) in Example 1, KAYAHARD AS (manufactured by Nippon Kayaku Co., Ltd.,
A solder resist ink composition was prepared by using 30 parts of (aromatic amine-based epoxy curing agent), and the same experiment was conducted, and the same result as in Example 1 was obtained.

As is clear from the results shown in Table 2, the solder resist ink composition of the present invention can be washed with water and has little bleeding, and the cured product thereof has a high heat distortion temperature,
It has excellent heat resistance, high hardness, gold plating resistance, and chemical resistance.

[0040]

EFFECT OF THE INVENTION The solder resist ink composition of the present invention can be washed with water, and its cured film has a high heat distortion temperature, and also has heat resistance, moisture resistance, high hardness, plating resistance,
It has excellent chemical resistance and electrical insulation properties, and has little bleeding.

Claims (6)

[Claims] 1. A formula (1): (In the formula, R ₁ and R ₂ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, n is an integer of 1 or more, and M is a hydrogen atom or a glycidyl group.
When n is 1, M is always a glycidyl group, and when n is 2 or more, at least one M is a glycidyl group. ) A solder resist ink composition containing an epoxy resin (A) represented by 2. A solder resist ink composition comprising the epoxy resin (A) according to claim 1, a curing agent (B) and a solvent (C). 3. The solder resist ink composition according to claim 2, wherein the curing agent (B) is one or more selected from the group consisting of dicyandiamide, imidazole compound, triazine compound, urea compound and aromatic amine compound. .. 4. The solvent (C) has the formula (2): (In the formula, R ₃ is a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, R ₄ is an ethylene group which may be substituted by a methyl group, R ₅ is a hydrogen atom or And R ₆ represents an alkyl group having 1 to 8 carbon atoms. However, R ₃ and R ₅ are not hydrogen atoms at the same time. n is 1
Indicates an integer of ˜4. 4. The solder resist ink composition according to claim 2 or 3, which is one kind or two or more kinds selected from the group consisting of the compound represented by (4) and solvent naphtha. 5. A cured product of the solder resist ink composition according to claim 1, claim 2, or claim 3. 6. A cured product of the solder resist ink composition according to claim 4.