JPH06208223A - Photosensitive resin composition - Google Patents

Abstract

PURPOSE:To provide a photosensitive resin compsn. which is cured by irradiation with UV, can be washed with water and is useful as a solder resist for a printed circuit board and as marking ink. CONSTITUTION:This photosensitive resin compsn. contains: (A) a prepolymer obtd. by introducing onium-contg. groups into the residual epoxy groups of a compd. obtd. by adding unsatd. monocarboxylic acid to part of an oligomer or a polymer having epoxy groups, (B) a reactive diluent and (C) a photopolymn. initiator as essential components.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel photosensitive resin composition, and more specifically, as a solder resist for printed wiring boards, which is curable by ultraviolet irradiation and can be washed with water.
It also relates to a photosensitive resin composition useful as a marking ink or the like.

[0002]

2. Description of the Related Art In recent years, a curing method by ultraviolet irradiation has been widely used as a resin curing method in the fields of printing plates, paints and adhesives from the viewpoint of resource saving and energy saving. This curing means is also used in the field of electronics such as printed wiring boards and the like, and the photosensitive resin composition is used as a protective film forming material for circuits.

By the way, the resist ink is usually applied to the substrate by a screen method, a curtain coater method, a dipping method or the like and then cured by a means such as heating or ultraviolet irradiation to achieve the initial purpose. However, if the uncured ink attached to the coating machine is left to stand, it will be cured over time and the coating machine will become unusable, which is an undesirable situation. Therefore, in screen printing etc.,
The screen must be cleaned and ink removed after each interruption of printing. Further, when the product becomes defective due to a coating error, it is necessary to remove the ink from the substrate and regenerate it.

On the other hand, conventional resist inks include, for example, a photosensitive resin obtained by adding an acryloyl group or a methacryloyl group to an epoxy resin, a urethane resin, a polyester resin, a polybutadiene resin or a copolymer resin, and a polyol (meth) acrylate. A photosensitive resin composition composed of a reactive diluent such as polyester, (meth) acrylate, and polyether (meth) acrylate and a photopolymerization initiator, which is usually washed with 1,1,1-trichloroethane or Organic solvents such as glycol ethers are used. However, such organic solvents have a problem of danger such as environmental pollution and fire, and in particular, the problem of environmental pollution is a natural damage, and the influence on the human body has recently been greatly emphasized. It is the current situation.

[0005]

Under these circumstances, the present invention provides a solder resist for a printed wiring board which is hardened by ultraviolet irradiation and can be washed with water.
Moreover, it was made for the purpose of providing a photosensitive resin composition useful as a marking ink or the like.

[0006]

Means for Solving the Problems As a result of intensive studies to develop a photosensitive resin composition having the above-mentioned preferable properties, the present inventors have found that a specific water-soluble prepolymer has a photopolymerization initiation property. It has been found that the object can be achieved by a composition in which a reactive diluent is combined, and the present invention has been completed based on this finding.

That is, the present invention relates to (A) a prepolymer in which an onium-containing group is introduced into a residual epoxy group of a compound obtained by adding an unsaturated monocarboxylic acid to a part of an oligomer or polymer having an epoxy group, The present invention provides a photosensitive resin composition comprising a reactive diluent (B) and a photopolymerizable initiator (C) as essential components.

In the composition of the present invention, as the component (A), an onium-containing group is added to the residual epoxy group of the compound obtained by adding an unsaturated monocarboxylic acid to a part of the epoxy group of the oligomer or polymer having an epoxy group. The introduced water-soluble prepolymer is used. The epoxy group-containing oligomer or polymer has an epoxy equivalent of usually 1,000 or less, preferably 100 to 500.
Epoxy resin such as bisphenol A type epoxy resin, bisphenol S type, biphenyl type epoxy resin, bisphenol F type epoxy resin, brominated epoxy resin, alicyclic epoxy resin, heterocyclic epoxy resin,
Aliphatic epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, naphthalene novolac type epoxy resin, glycidyl amine type epoxy resin, bisphenol S modified novolac type polyfunctional epoxy resin, polyfunctional modified novolac type epoxy resin, phenols Condensation product with aromatic aldehyde having phenolic hydroxyl group Epoxy resin, at least one monomer selected from alkyl acrylate and alkyl methacrylate, and at least one selected from epoxy group-containing (meth) acrylate Examples thereof include a copolymer with the epoxy group-containing monomer.

As the unsaturated monocarboxylic acid to be added to a part of the epoxy group of the oligomer or polymer having these epoxy groups, acrylic acid, methacrylic acid, crotonic acid, cinnamic acid, etc. are used. The amount of this unsaturated monocarboxylic acid added to the epoxy resin is
0.2 to 0.2 equivalent to 1.0 equivalent of the epoxy group of the epoxy resin
It is preferably in the range of 0.9 equivalent. If the addition amount is less than 0.2 equivalent, the ultraviolet curability is insufficient,
When it exceeds 0.9 equivalent, the residual epoxy group becomes small, the introduction of the onium-containing group is limited, and the water-solubilization becomes difficult.

Thus, a compound in which an unsaturated monocarboxylic acid is added to a part of the epoxy group of an oligomer or polymer having an epoxy group can be obtained. In the present invention, the compound is water-solubilized. It is necessary to introduce an onium-containing group composed of a nitrogen atom, a phosphorus atom or a sulfur atom having a secondary hydroxyl group of carbon atoms into the residual epoxy group, and at this time, an organic acid is simultaneously reacted as a counter anion. The onium salts produced by this reaction are quaternary ammonium salts, quaternary phosphonium salts and tertiary sulfonium salts. Further, the organic acid is not particularly limited, for example, formic acid, acetic acid, acrylic acid,
Examples thereof include lactic acid, crotonic acid, maleic acid, fumaric acid and itaconic acid.

In the present invention, a resin composition is prepared by adding a reactive diluent of the component (B) and a photopolymerization initiator of the component (C) to the onium-containing prepolymer thus obtained. To prepare. The reactive diluent of the component (B) is used for further sufficiently photocuring the prepolymer of the component (A) to obtain a coating film having acid resistance, heat resistance, alkali resistance and the like. is there. Examples of such a reactive diluent include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate.
Acrylate, 2-ethylhexyl (meth) acrylate, hydroxy (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, polyethylene Glycol di (meth) acrylate, neopentyl glycol adipate di (meth) acrylate, hydroxypivalic acid neopentyl glycol di (meth) acrylate, dicyclopentanyl di (meth) acrylate, caprolactane-modified dicyclopentenyl di (meth) acrylate, EO
Modified phosphoric acid di (meth) acrylate, allylated cyclohexyl di (meth) acrylate, isocyanurate di (meth) acrylate, trimethylolpropane tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, propionic acid modified dipentaerythritol Tri (meth) acrylate, pentaerythritol tri (meth) acrylate, PO-modified trimethylolpropane tri (meth) acrylate, tris (acryloxyethyl) isocyanurate, propionic acid-modified dipentaerythritol penta (meth) acrylate,
Dipentaerythritol hexa (meth) acrylate,
Examples thereof include caprolactone-modified dipentaerythritol hexa (meth) acrylate.

These reactive diluents may be used alone or in combination of two or more, and the compounding amount thereof is 5 parts with respect to 100 parts by weight of the prepolymer of the component (A). It is selected in the range of 0.0 to 400 parts by weight, preferably 50 to 150 parts by weight. If this amount is less than 5.0 parts by weight, the photocurability is insufficient and the effect of improving the acid resistance and heat resistance of the cured coating film is not sufficiently exhibited, and if it exceeds 400 parts by weight, the surface curing is too good. Therefore, the internal curing is insufficient, and it becomes difficult to obtain the adhesion of the cured coating film, and the detergency to water is adversely affected.

On the other hand, the photopolymerization initiator as the component (C) is not particularly limited, and generally used photopolymerization initiators can be used. Examples of the photopolymerization initiator include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1- [4- (methylthio) phenyl]- 2-morpholino-propan-1-one, 4-
(2-hydroxyethoxy) phenyl-2 (hydroxy-2-propyl) ketone, benzophenone, p-phenylbenzophenone, 4,4'-diethylaminobenzophenone, dicyclobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tertiary Libutyl anthraquinone, 2-amino anthraquinone, 2
-Methylthioxanthone, 2-ethylthioxanthone,
2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyl dimethyl ketal, acetophenone dimethyl ketal, p
-Dimethylamine benzoate and the like can be mentioned.
These may be used alone or in combination of two or more, and the compounding amount thereof is usually 0.5 to 50 parts by weight with respect to 100 parts by weight of the prepolymer as the component (A), It is preferably selected in the range of 2 to 30 parts by weight.

The photosensitive resin composition of the present invention contains a prepolymer, a reactive diluent and a photopolymerization initiator as essential components, and if necessary, various additive components such as silica, alumina and talc. , Inorganic pigments such as calcium carbonate and barium sulfate, organic pigments such as phthalocyanine and azo, antifoaming agents, paint additives such as leveling agents, adhesion promoters such as phosphorus-containing unsaturated carboxylic acid derivatives, urea derivatives, imidazole A curing accelerator such as a derivative, or an organic solvent may be contained.

[0015]

EFFECT OF THE INVENTION The photosensitive resin composition of the present invention gives a cured coating film which is excellent in heat resistance and adhesion to a substrate and which has good electric insulation, chemical resistance and hardness when exposed to ultraviolet rays. It is preferably used as a solder resist or a marking ink for wiring boards. In addition to this, including etching resist and plating resist,
It can be used for a wide range of applications such as paints, photosensitive adhesives, plastic relief materials, printing plate materials and the like. Furthermore, since water can be used for cleaning, it is industrially extremely valuable without the problem of environmental pollution.

[0016]

EXAMPLES Next, the present invention will be described in more detail by way of examples. The water washability of the photosensitive resin composition and the performance of the cured coating film were evaluated according to the following methods.

Next, the solution of the photosensitive resin composition was applied to the copper clad laminate by screen printing to a thickness of 15 to 20 μm. Then 80W / cm, 3 lights, 3m / min UV
It was passed through a furnace to obtain a cured coating film. Table 1 shows the evaluation results of the water washability and the cured coating film.

(1) Washability with water A test piece obtained by applying a solution of the photosensitive resin composition to a copper clad laminate by screen printing so as to have a thickness of 15 to 20 μm is 30 mm.
A test piece was cut by × 50 mm. After shaking this test piece in an aqueous solution, the presence or absence of ink on the test piece was determined according to the following criteria. ○: Almost completely removed, △: Half removed, ×: Not removed

(2) Adhesion test According to the test method of JIS D-0202, a cross-cut was put on a test piece in a grid pattern, and then the state of peeling after a peeling test with cellophane tape was visually judged according to the following criteria. . ◯: No peeling on the grid, Δ: partial peeling, ×: peeling on the entire surface

(3) Solder heat resistance According to the test method of JIS C-6481, the test piece was floated for 10 seconds in a solder bath at 260 ° C. for 10 seconds. The evaluation was made according to. ◯: No change was observed, Δ: Part of the coating film was peeled off, ×: Film was completely peeled off

(4) Pencil hardness Evaluation was carried out according to the test method of JIS K-5400.

Production Example 1 Phenol novolac type epoxy resin (epoxy equivalent 1
79) 187.5 parts by weight of acrylic acid 52.8 parts by weight, trimethylolpropane triacrylate 133.
The reaction was carried out in 4 parts by weight under reflux at 110 ° C. for 7 hours to obtain a phenol novolac type epoxy acrylate. Thereafter, the mixture was cooled to 70 ° C., 18.9 parts by weight of acetic acid and 28.0 parts by weight of dimethylaminoethanol were added, and the mixture was reacted for 4 hours to obtain a photosensitive resin solution.

Production Example 2 In place of 18.9 parts by weight of acetic acid and 28.0 parts by weight of dimethylaminoethanol in Production Example 1, 18.0 parts of acetic acid was used.
A resin solution was obtained in the same manner as in Production Example 1 except that 9 parts by weight and 23.6 parts by weight of trimethylphosphine were used.

Production Example 3 Instead of 18.9 parts by weight of acetic acid and 28.0 parts by weight of dimethylaminoethanol in Production Example 1, 18.0 parts of acetic acid was used.
A resin solution was obtained in the same manner as in Production Example 1 except that 9 parts by weight and 19.6 parts by weight of methyl sulfide were used.

Production Example 4 A mixture of 200 parts by weight of methyl methacrylate, 78 parts by weight of hydroxyethyl methacrylate, 284 parts by weight of glycidyl methacrylate and 17 parts by weight of azobisisobutyronitrile was added to 350 parts of ethylene glycol dimethyl ether.
The reaction was carried out in a part by weight under reflux at 60 ° C. under a nitrogen gas atmosphere for 10 hours. Thereafter, 72 parts by weight of acrylic acid was added and reacted at 110 ° C. until the acid value became 0, then 60 parts by weight of acetic acid and 89 parts by weight of dimethylaminoethanol were added to the reaction product, and the mixture was reacted at 70 ° C. for 4 hours. Further, this resin solution was volatilized with ethylene glycol dimethyl ether under reduced pressure heating and drying, and then 978 parts by weight of hydroxyethyl methacrylate was added to obtain a photosensitive resin solution.

Production Example 5 A resin solution was prepared in the same manner as in Production Example 4, except that 60 parts by weight of acetic acid and 89 parts by weight of dimethylaminoethanol in Production Example 4 were replaced with 60 parts by weight of acetic acid and 76 parts by weight of trimethylphosphine. Obtained.

Production Example 6 A resin solution was prepared in the same manner as in Production Example 4 except that 60 parts by weight of acetic acid and 89 parts by weight of dimethylaminoethanol in Production Example 4 were replaced with 60 parts by weight of acetic acid and 47 parts by weight of methyl sulfide. Obtained.

Example 1 100 parts by weight of the photosensitive resin solution obtained in Production Example 1 was added with 3.0 parts by weight of benzyl dimethyl ketal, 1.5 parts by weight of phthalocyanine green, 50 parts by weight of hydroxyethyl methacrylate, and monoacryloyloxy. Propyl phosphate 3.0 parts by weight, talc 100 parts by weight, silica 2
A photosensitive resin composition was prepared by mixing and dispersing 0 part by weight with a triple roll.

Example 2 100 parts by weight of the photosensitive resin solution obtained in Preparation Example 2 was added with 3.0 parts by weight of benzyl dimethyl ketal, 1.5 parts by weight of phthalocyanine green, 50 parts by weight of hydroxyethyl methacrylate, and monoacryloyloxy. Propyl phosphate 3.0 parts by weight, talc 100 parts by weight, silica 2
A photosensitive resin composition was prepared by mixing and dispersing 0 part by weight with a triple roll. Then, a cured coating film was obtained in the same manner as in Example 1. The water washability and the performance of the cured coating film are shown in Table 1.

Example 3 100 parts by weight of the photosensitive resin solution obtained in Production Example 3 was added with 3.0 parts by weight of benzyl dimethyl ketal, 1.5 parts by weight of phthalocyanine green, 50 parts by weight of hydroxyethyl methacrylate, and monoacryloyloxy. Propyl phosphate 3.0 parts by weight, talc 100 parts by weight, silica 2
A photosensitive resin composition was prepared by mixing and dispersing 0 part by weight with a triple roll. Then, a cured coating film was obtained in the same manner as in Example 1. The water washability and the performance of the cured coating film are shown in Table 1.

Example 4 To 100 parts by weight of the photosensitive resin solution obtained in Preparation Example 4, 3.0 parts by weight of benzyl methyl ketal, 1.5 parts by weight of phthalocyanine green, 17.5 parts by weight of hydroxyethyl methacrylate, monoacryloyl were used. Oxypropyl phosphate 3.0 parts by weight, talc 35 parts by weight, silica 10
The photosensitive resin composition was prepared by mixing and dispersing parts by weight with a three-roll mill.

Example 5 100 parts by weight of the photosensitive resin solution obtained in Production Example 5 was added with 3.0 parts by weight of benzyl methyl ketal, 1.5 parts by weight of phthalocyanine green, 17.5 parts by weight of hydroxyethyl methacrylate, and monoacryloyl. Oxypropyl phosphate 3.0 parts by weight, talc 35 parts by weight, silica 10
The photosensitive resin composition was prepared by mixing and dispersing parts by weight with a three-roll mill.

Example 6 100 parts by weight of the photosensitive resin solution obtained in Preparation Example 6 was added with 3.0 parts by weight of benzyl methyl ketal, 1.5 parts by weight of phthalocyanine green, 17.5 parts by weight of hydroxyethyl methacrylate, and monoacryloyl. Oxypropyl phosphate 3.0 parts by weight, talc 35 parts by weight, silica 10
The photosensitive resin composition was prepared by mixing and dispersing parts by weight with a three-roll mill.

[0034]

[Table 1]

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Claims (4)

[Claims] 1. A prepolymer in which an onium-containing group is introduced into a residual epoxy group of a compound obtained by adding an unsaturated monocarboxylic acid to a part of an oligomer or polymer having an epoxy group, and (B) reactivity. Diluent, (C)
A photosensitive resin composition comprising a photopolymerizable initiator as an essential component. 2. The amount of the unsaturated monocarboxylic acid added to the epoxy resin in the component (A) is 0.2 to 0.9 equivalent with respect to 1.0 equivalent of the epoxy group of the oligomer or polymer having an epoxy group. The photosensitive resin composition according to claim 1. 3. The component (B) has a double bond, and the content thereof is 5.0 to 400 per 100 parts by weight of the component (A).
The photosensitive resin composition according to claim 1, which is part by weight. 4. The content of the component (C) is the same as that of the component (A) 10.
0.5 to 50 parts by weight per 0 parts by weight.
Or the photosensitive resin composition according to item 3.