JP2001264977A - Photosensitive resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive resin composition which can be exposed with UV and can be developed with a dilute aqueous alkali solution, has sensitivity, good thermal stability and good development latitude, gives a coating film excellent in performance and is suitable for use as a soldering resist ink for the production of a printed wiring board. SOLUTION: The photosensitive resin composition contains (A) a photosensitive resin obtained by reacting a polyfunctional epoxy compound with an unsaturated monobasic acid, reacting the resulting product with a saturated or unsaturated polybasic acid anhydride and reacting the resulting monoepoxy compound having an unsaturated double bond in a carboxyl group with a water-soluble monoepoxy compound (B) an epoxy resin (C) a photopolymerization initiator ad (D) a photopolymerizable unsaturated compound and/or a solvent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive resin composition, and more particularly, to a photosensitive resin composition having high sensitivity to ultraviolet light exposure,
The present invention relates to a photosensitive resin composition in which the obtained coating film has good physical properties and can be developed with a dilute alkali.

[0002]

2. Description of the Related Art In recent years, a dilute alkali development type liquid solder photoresist ink has been widely used as a solder resist ink for various printed wiring boards. As the photosensitive resin of the dilute alkali developing type, for example,
Novolak-type epoxy (meth) acrylates having a carboxyl group in the side chain as disclosed in JP-B-4390 have been studied, but the photocurability is sufficient for recent demands for higher sensitivity of solder resist inks. It cannot be said that. JP-A-11-24254, JP-A-9-80749, and JP-A-10-282665 disclose a method in which glycidyl (meth) acrylate or the like is reacted with a carboxyl group of an acid acrylate-added epoxy acrylate. A highly sensitive photosensitive resin composition has been proposed. However, such a resin composition has low thermal stability as compared with the conventional one, and has a time (development control width) for which development with a dilute alkali after applying a solder resist ink and drying is only about one day. The development control width of the conventional novolak type epoxy (meth) acrylate having a carboxyl group in the side chain is insufficient compared with about 3 days, and those which could not be developed in one day in the actual process are discarded. And the workability is poor, such that work cannot be performed before the holidays.

[0003]

DISCLOSURE OF THE INVENTION The present invention is capable of performing exposure with ultraviolet light and developing with a dilute aqueous alkaline solution, has high sensitivity, has good thermal stability and development control width, and has excellent coating performance. The purpose of the present invention is to provide a photosensitive resin composition suitable as a solder resist ink for producing a printed wiring board, which shows the following.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies in order to solve the above-mentioned problems, and as a result, have found that a photosensitive resin composition having a specific component composition meets the above-mentioned object. The invention has been completed. That is, the present invention provides (A) a method of reacting a polyfunctional epoxy compound with an unsaturated monobasic acid and further reacting a saturated or unsaturated polybasic acid anhydride with a carboxyl group having an unsaturated double bond. A photosensitive resin obtained by reacting a monoepoxy compound and a water-soluble monoepoxy compound, (B) an epoxy resin, (C) a photopolymerization initiator, and (D) a photosensitive resin containing a polymerizable unsaturated compound and / or a solvent. The present invention provides a resin composition.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The component (A) in the photosensitive resin composition of the present invention is obtained by reacting a polyfunctional epoxy compound with an unsaturated monobasic acid, and further reacting a saturated or unsaturated polybasic acid anhydride. It is a photosensitive resin obtained by reacting a monoepoxy compound having an unsaturated double bond with a water-soluble monoepoxy compound. Since the monoepoxy compound having an unsaturated double bond bonded to a carboxyl group derived from a saturated or unsaturated polybasic acid anhydride is bonded to the outermost part of the resin, the reactivity at the time of ultraviolet irradiation is three-dimensional. High and has high light sensitivity to ultraviolet irradiation. Similarly, the water-soluble monoepoxy compound improves the affinity of the resin for alkali, furthermore moderately suppresses the motility of the unsaturated double bond of the monoepoxy compound having an unsaturated double bond. Imparts resin stability.

The polyfunctional epoxy compound used here is not particularly limited, but for example, bisphenol A
Epoxy resins such as epoxy resin, bisphenol F type, phenol novolak type, cresol novolak type, bisphenol A novolak type, cycloaliphatic epoxy resin, and heterocyclic type, and those obtained by introducing halogen atoms such as bromine atom and chlorine atom into these. No. Among these, a cresol novolak type epoxy resin is particularly preferable.

As the unsaturated monobasic acid to be reacted with the polyfunctional epoxy compound, acrylic acid or methacrylic acid is suitable, and in particular, acrylic acid is preferably used in order to obtain high active energy photocurability. Other examples include crotonic acid, cinnamic acid, sorbitanic acid, and acrylic acid dimer. Two or more of these unsaturated monobasic acids may be used in combination. It is preferable to react 0.8 to 1.1 equivalents of these unsaturated monobasic acids with respect to 1.0 equivalent of the epoxy group of the polyfunctional epoxy compound. When the proportion of the unsaturated monobasic acid is less than 0.8 equivalent, storage stability is deteriorated, and
There is a problem such as gelation at the time of synthesis, and when it exceeds 1.1 equivalents, odor is generated or heat resistance is reduced.

The above-mentioned saturated or unsaturated polybasic anhydrides include maleic anhydride, succinic anhydride, itaconic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride. And dibasic acid anhydrides such as methyltetrahydrophthalic anhydride and chlorendic anhydride; and polybasic acid anhydrides such as trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic anhydride and biphenyltetracarboxylic anhydride. In particular, it is preferable to use tetrahydrophthalic anhydride and hexahydrophthalic anhydride which are excellent in electrolytic corrosion. The amount of these saturated or unsaturated polybasic acid anhydrides used is 0.4 mol to 0.9 mol per 1.0 mol of hydroxyl groups obtained by reacting the epoxy compound with the unsaturated monobasic acid.
Although it is a molar ratio, the reaction is preferably performed at a ratio of 0.6 mol to 0.9 mol. If the amount is less than 0.4 mol, sufficient alkali developability cannot be obtained, and if it exceeds 0.9 mol, the electrical properties and the like of the cured coating film deteriorate.

Examples of the monoepoxy compound having an unsaturated double bond include glycidyl methacrylate, glycidyl acrylate, and cyclomer A manufactured by Daicel Chemical Industries, Ltd.
(Meth) acrylates having an alicyclic epoxy group such as 200 and M100. As the water-soluble monoepoxy compound, a compound represented by the formula (I)

[0010]

Embedded image

[In the formula, R ¹ represents an alkyl group or an aryl group, and R ² represents a polyethylene oxide or a polypropylene oxide having three or more repeating units. (For example, Denacol E manufactured by Nagase Kasei Co., Ltd.)
X-145, EX-171, etc.) or formula (II)

[0012]

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(For example, Sakamoto Pharmaceutical Co., Ltd.)
SY-GTA80).

The amounts of the monoepoxy compound having an unsaturated double bond and the water-soluble monoepoxy compound to be reacted with the carboxyl group formed by the reaction of the above polybasic acid anhydride are determined by the sensitivity, developability and electrical properties of the resulting composition. In consideration of the properties and the like, it is usually preferable to react in a ratio of 0.1 to 0.4 mol in total with respect to 1.0 mol of the generated carboxyl group. On the other hand, if it exceeds 0.4 mol, the cured coating film, electrical properties and the like will be reduced.

The ratio of the amount of the water-soluble monoepoxy compound to be reacted with the carboxyl group generated by the reaction of the polybasic acid anhydride is 0.05 to 0.2 with respect to 1.0 mol of the generated carboxyl group. It is a mole ratio. If the amount of the water-soluble monoepoxy compound is less than 0.05 mol, good development control width cannot be obtained, and if it exceeds 0.2 mol, a highly sensitive resin cannot be obtained.

The epoxy resin of component (B) includes bisphenol A type epoxy resin, bisphenol F type epoxy resin, hydrogenated bisphenol A type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, dicyclopentadiene-phenol. Novolak type epoxy resin, phenol-cresol novolak co-condensation type epoxy resin, bisphenol A novolak type epoxy resin, bisphenol F novolak type epoxy resin or their halogenated epoxy compounds, triphenylolmethane type epoxy resin, alkyl-substituted triphenylolmethane Resin obtained by reacting epichlorohydrin with polyfunctional phenols such as epoxy resin, tetraphenylolethane epoxy resin, etc. Complexes such as epoxy resins obtained by reacting sinaphthalenes epichlorohydrin, silicone-modified epoxy resins, ε-caprolactone-modified epoxy resins, glycidylamine-type epoxy resins obtained by reacting epichlorohydrin with primary or secondary amines, and triglycidyl isocyanates. Cyclic epoxy resin and the like. These epoxy resins (B) can be used alone or in combination of two or more.

The amount of the epoxy resin (B) used is 3 to 100 parts by weight, preferably 6 to 75 parts by weight, based on 100 parts by weight of the photosensitive resin (A). If the amount of the epoxy resin (B) is less than 3 parts by weight, the amount of carboxyl groups in the photosensitive resin (A) is less than the amount that substantially reacts, so that the water resistance, alkali resistance, and electrical properties are undesirably reduced. On the other hand, when the amount exceeds 100 parts by weight, a linear polymer having an unreacted epoxy group is generated, so that heat resistance and solvent resistance become insufficient, and neither is preferable.

Examples of the photopolymerization initiator (C) include benzoin and its derivatives such as benzoin, benzoin methyl ether, benzoin isopropyl ether and benzoin isobutyl ether; benzyl and its derivatives such as benzyl and benzyl dimethyl ketal; Acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1-
Acetophenone and its derivatives such as (4-methylthiophyl) -2-morpholinopropan-1-one, 2-methylanthraquinone, 2-chloroanthraquinone,
Anthraquinone and its derivatives such as ethylanthraquinone and 2-t-butylanthraquinone, thioxanthone,
Thioxanthone and its derivatives such as 2,4-dimethylthioxanthone and 2-chlorothioxanthone, and benzophenone and its derivatives such as benzophenone and N, N-dimethylaminobenzophenone, and the like. It can be used in combination of more than one species. It is known that the use of various amine compounds in combination with these photopolymerization initiators, if necessary, promotes the photopolymerization initiation effect, and can be used in combination in the present invention.

The amount of the photopolymerization initiator (C) used is 0.1 to 20 parts by weight, preferably 1 to 10 parts by weight, based on 100 parts by weight of the photosensitive resin (A). If the amount is less than 0.1 part by weight, the effect as a photopolymerization initiator cannot be sufficiently obtained. On the other hand, if the amount exceeds 20 parts by weight, the effect is not improved, and economically. Disadvantageous.

Further, the polymerizable unsaturated compound and / or the solvent used as the component (D) improve curability to active energy rays and / or coatability when the photosensitive resin composition is used as a resist ink. It is used for the purpose. As the polymerizable unsaturated compound, a monomer having an active energy ray-curable property is preferable, and 2
-Hydroxyethyl acrylate, 2-hydroxypropyl acrylate, N-pyrrolidone, N-acryloylmorpholine, N, N-dimethylacrylamide, N,
N-diethylacrylamide, N, N-dimethylaminoethyl acrylate, N, N-dimethylaminopropyl acrylate, methoxy polyethylene glycol acrylate, ethoxy polyethylene glycol acrylate, melamine acrylate, phenoxyethyl acrylate, phenoxypropyl acrylate, ethylene glycol diacrylate, diglycol Propylene glycol diacrylate, polydipropylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, glycerin diacrylate, isobornyl acrylate, dicyclopentenyloxyethyl acrylate, and these To Various corresponding methacrylates may be mentioned. These polymerizable unsaturated compounds (D) can be used alone or in combination of two or more.

On the other hand, examples of the solvent include ketones such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, aromatic hydrocarbons such as toluene and xylene, carbitols such as ethyl cellosolve, butyl cellosolve, carbitol and butyl carbitol, and ethyl acetate. Butyl acetate, cellosolve acetate, butyl cellosolve acetate, ethyl carbitol acetate and the like. These solvents can be used alone or in combination of two or more.

Polymerizable unsaturated compound and / or solvent (D)
Are used alone or as a mixture of two or more. The amount of the polymerizable unsaturated compound and / or the solvent (D) is 1 to 100 parts by weight of the photosensitive resin (A).
0 to 200 parts by weight, preferably 20 to 150 parts by weight. Above all, when the amount of the polymerizable unsaturated compound is less than 10 parts by weight, the photosensitivity is too low. On the other hand, when the amount is more than 200 parts by weight, the viscosity becomes too low when the photosensitive resin composition is used as a resist ink. The resistance as a coating film becomes insufficient. The solvent is used in the above range mainly in consideration of coatability.

When the photosensitive resin composition of the present invention is used as a liquid resist ink, the above (A) to (D)
In addition to the components, if necessary, inorganic fillers such as silica, calcium carbonate, barium sulfate, clay and talc,
Coloring pigments such as phthalocyanine green, phthalocyanine blue, titanium oxide, and carbon black; various additives such as antifoaming agents and leveling agents; Agents can be added.

[0024]

The present invention will be specifically described below with reference to examples and comparative examples. All parts and percentages are by weight unless otherwise specified.

Synthesis Example 1 A cresol novolak type epoxy resin having an epoxy equivalent of 206, "Epototo YDCN704" (manufactured by Toto Kasei Co., Ltd.) was reacted with 206 parts and 72 parts (1 mol) of acrylic acid in 192 parts of carbitol acetate. The obtained epoxy acrylate is added to tetrahydrophthalic anhydride 12
After adding and reacting 1.6 parts (0.8 mol), 5.7 parts (0.04 mol) of glycidyl methacrylate and "Denacol EX-145" [manufactured by Nagase Kasei Co., Ltd.,
Epoxy equivalent 416] 16.6 parts (0.04 mol) were added and reacted to obtain photosensitive resin A having an acid value of solids of 95.7 mgKOH / g.

Synthesis Example 2 A cresol novolac type epoxy resin having an epoxy equivalent of 213 "Epiclon N-695" (manufactured by Dainippon Ink and Chemicals, Inc.) 213 parts and acrylic acid 72 parts (1 mol)
Was reacted in 192 parts of carbitol acetate, and 121.6 parts (0.8 mol) of tetrahydrophthalic anhydride was added to the epoxy acrylate, followed by reaction, and 39.8 parts (0.28 part) of glycidyl methacrylate. Mol) and "Denacol EX-145" [Epoxy equivalent 416, manufactured by Nagase Kasei Co., Ltd.] 16.6 parts (0.0
4 mol), and the mixture was reacted.
OH / g of photosensitive resin B was obtained.

Synthesis Example 3 A cresol novolak type epoxy resin having an epoxy equivalent of 215, "Sumi Epoxy ESCN220HH" (manufactured by Sumitomo Chemical Co., Ltd.) 215 parts and acrylic acid 72 parts (1 mol)
Was reacted in 192 parts of carbitol acetate, and 121.6 parts (0.8 mol) of tetrahydrophthalic anhydride was added to the epoxy acrylate and reacted.
5.7 parts (0.04 mol) of glycidyl methacrylate and 66.6 parts (0.16 mol) of "Denacol EX-145" [Nippon Kasei Co., Ltd., epoxy equivalent 416]
And the solid content acid value is 70.0 mgKOH / g
Of photosensitive resin C was obtained.

Synthesis Example 4 A phenol novolak type epoxy resin “DEN438” having an epoxy equivalent of 180 [manufactured by Dow Chemical Co., Ltd.] 18
0 parts and acrylic acid 72 parts (1 mol) were reacted in 192 parts of carbitol acetate, and 121.6 parts (0.8 mol) of tetrahydrophthalic anhydride were added to the epoxy acrylate, followed by reaction. 22.7 parts (0.16 mol) of glycidyl methacrylate and 66.6 parts (0.16 mol) of "Denacol EX-145" (Epoxy equivalent 416, manufactured by Nagase Kasei Co., Ltd.) were added and reacted to obtain a solid acid. A photosensitive resin D having a value of 58.2 mgKOH / g was obtained.

Synthesis Example 5 A cresol novolak type epoxy resin having an epoxy equivalent of 206 "Epototo YDCN704" (manufactured by Toto Kasei Co., Ltd.) was reacted with 206 parts of acrylic acid in 72 parts (1 mol) of carbitol acetate in 192 parts of carbitol acetate. The obtained epoxy acrylate was added to tetrahydrophthalic anhydride.
After adding and reacting 2 parts (0.6 mol), 28.4 parts (0.1 mol) of glycidyl methacrylate and "Denacol EX-171" [Negase Kasei Co., Ltd., epoxy equivalent 862] 25.9 Then, a photosensitive resin E having an acid value of 62.3 mgKOH / g was obtained.

Synthesis Example 6 A cresol novolak type epoxy resin having an epoxy equivalent of 206 "Epototo YDCN704" (manufactured by Toto Kasei Co., Ltd.) was reacted with 206 parts of acrylic acid in 72 parts (1 mol) of carbitol acetate in 192 parts of carbitol acetate. The obtained epoxy acrylate is added to tetrahydrophthalic anhydride 12
After adding 1.6 parts (0.8 mol) and reacting, 14.2 parts (0.1 mol) of glycidyl methacrylate and "Denacol EX-145" [epoxy equivalent 416, manufactured by Nagase Kasei Co., Ltd.] 41 Then, 6.6 parts (0.1 mol) were added and reacted to obtain a photosensitive resin F having an acid value of 73.9 mgKOH / g in solid content.

Comparative Synthesis Example 1 A cresol novolak type epoxy resin having an epoxy equivalent of 206 "Epototo YDCN704" (manufactured by Toto Kasei Co., Ltd.) was reacted with 206 parts of acrylic acid and 72 parts (1 mol) of acrylic acid in 192 parts of carbitol acetate. The resulting epoxy acrylate is added to tetrahydrophthalic anhydride 12
After adding 1.6 parts (0.8 mol) and reacting, 28.4 parts (0.2 mol) of glycidyl methacrylate was added and reacted to obtain a photosensitive resin G having an acid value of 78.7 mgKOH / g of solid content. Obtained.

Comparative Synthesis Example 2 A cresol novolak type epoxy resin having an epoxy equivalent of 206, "Epototo YDCN704" (manufactured by Toto Kasei Co., Ltd.) was reacted with 206 parts of acrylic acid in 72 parts (1 mol) of carbitol acetate in 192 parts of carbitol acetate. The resulting epoxy acrylate is added to tetrahydrophthalic anhydride 12
After adding 1.6 parts (0.8 mol) and reacting, 83.2 parts (0.2 mol) of Denacol EX-145 "(Epoxy equivalent 416, manufactured by Nagase Kasei Co., Ltd.) was added and reacted. Photosensitive resin H having a solid content acid value of 69.7 mgKOH / g was obtained.

Comparative Synthesis Example 3 A cresol novolak type epoxy resin having an epoxy equivalent of 206, "Epototo YDCN704" (manufactured by Toto Kasei Co., Ltd.) is reacted with 206 parts of acrylic acid and 72 parts (1 mol) of acrylic acid in 192 parts of carbitol acetate. The epoxy acrylate obtained above was added to tetrahydrophthalic anhydride
0 parts (0.5 mol) were added and reacted to obtain an acid value of 7 for solid content.
9.3 mg KOH / g of photosensitive resin I was obtained.

Examples 1 to 6 and Comparative Examples 1 to 3 Each component was blended according to the blending ratios shown in Table 1 and kneaded well with a three-roll mill to obtain the photosensitive resin composition of the present invention. Was.

Next, the photosensitive resin composition prepared in each of the above Examples and Comparative Examples was applied to a surface-treated printed wiring board by screen printing so as to have a thickness of 30 to 40 μm. After preliminarily drying for minutes, the mixture was cooled to room temperature to obtain a dried coating film. This coating film was exposed for 60 seconds using a parallel ultra-high pressure mercury lamp exposure device manufactured by Oak Manufacturing Co., Ltd., and then heated at 150 ° C. for 30 minutes using a hot air drier to obtain a cured coating film. Various physical properties of the obtained coating film were evaluated in accordance with the following evaluation test methods. Table 2 shows the results.

Sensitivity A step tablet for sensitivity measurement (Kodak 14-stage) was set on the pre-dried coating film, and exposed for 60 seconds using a parallel ultra-high pressure mercury lamp exposure device manufactured by Oak Manufacturing Co., Ltd., and a 1% aqueous solution of sodium carbonate was used. After development at a spray pressure of 2.0 kgf / mm ² for 60 seconds, the number of steps of the unremoved portion of the exposed portion was measured.

Development control width The dried coating film after pre-drying and the dried coating film with the pre-drying time extended to 70 minutes are developed using a 1% aqueous sodium carbonate solution at a spray pressure of 2.0 kgf / mm ² , followed by development. Was observed and evaluated according to the following criteria. ：: No coating film was visually observed after a development time of 60 seconds. Δ: No coating film was visually observed after a developing time of 120 seconds. C: After 120 seconds of development time, there is a residual film visually.

Solder heat resistance A cured coating film is floated so that the entire surface is immersed in solder according to JIS C6481, and placed in a 260 ° C. solder bath for 10 seconds.
After being floated three times and taken out, the state of the coating film such as swelling or peeling was observed and evaluated according to the following criteria. ：: No change in appearance. X: Appearance change.

Solvent Resistance The state of the cured coating film after immersion in methylene chloride for 30 minutes was evaluated. ○: No change in appearance △: Slight change in appearance ×: Film peeled

The insulation resistance was evaluated according to JIS Z3197. Thermal stability 10 parts of trimethylolpropane triacrylate are sufficiently mixed with resin E, resin F and resin G, put in a test tube, and the time at which fluidity is lost at 120 ° C. is evaluated as the gelation time. The results are shown in Table 3.

[0041]

[Table 1]

[0042]

[Table 2]

[0043]

[Table 3]

[0044]

The photosensitive resin composition of the present invention has high sensitivity, good thermal stability and good development control, and can provide a pattern excellent in heat resistance, electrical insulation and chemical resistance. It is suitably used as a solder resist ink for printed wiring boards.

 ────────────────────────────────────────────────── ─── Continued on front page F term (reference) 2H025 AA01 AA04 AA11 AB15 AB20 AC01 AD01 BC13 BC42 BC49 BC74 BC83 BC86 BJ10 CA00 CC03 FA17 5E314 AA27 AA32 AA41 AA47 CC07 GG14 GG08 GG14

Claims (3)

[Claims] 1. A monofunctional compound having an unsaturated double bond in a carboxyl group formed by reacting (A) a polyfunctional epoxy compound with an unsaturated monobasic acid and further reacting a saturated or unsaturated polybasic acid anhydride. A photosensitive resin obtained by reacting an epoxy compound and a water-soluble monoepoxy compound,
(B) epoxy resin, (C) photopolymerization initiator and (D)
A photosensitive resin composition comprising a polymerizable unsaturated compound and / or a solvent. 2. The photosensitive resin of the component (A) comprises a polyfunctional epoxy compound, an unsaturated monobasic acid, and a saturated or unsaturated polybasic acid anhydride. The photosensitive composition according to claim 1, which is obtained by reacting a monoepoxy compound having an unsaturated double bond with a water-soluble monoepoxy compound in a total amount of 0.1 to 0.4 mol. Resin composition. 3. The photosensitive resin of the component (A) comprises a polyfunctional epoxy compound, an unsaturated monobasic acid, and a saturated or unsaturated polybasic acid anhydride. 3. The photosensitive resin composition according to claim 1, wherein the photosensitive resin composition is obtained by reacting a water-soluble monoepoxy compound at a ratio of 0.05 to 0.2 mol.