JP2756623B2 - Photopolymerizable composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a photopolymerizable composition containing a novel binder. More specifically, the present invention relates to a photopolymerizable composition which is suitable for use as a dry film photoresist or photomask for preparing a printed circuit board, a lithographic printing plate, a resin relief printing plate, has a fine strip, has excellent storage stability, and is alkali developable. .

[0002]

2. Description of the Related Art In recent years, dry film resists have been widely used in the field of making printed circuit boards. There are two methods for producing a printed circuit board, a tenting method and a plating method. In either method, a resist that is no longer required in a circuit forming step is removed. In this case, when the peeling piece is large, not only the peeling piece is entangled with the roll of the peeling machine and not only significantly reduces the workability, but also the peeling piece may be re-attached to a clean substrate, so that the peeling piece is preferably fine. . Further, in the development and peeling steps, it is preferable that the treatment can be performed with an aqueous alkaline solution rather than an organic solvent in terms of effects on the human body and environmental pollution. For this purpose, it is widely known to use a binder having a carboxyl group as a composition of a dry film resist.

In order to satisfy the above requirements, Japanese Patent Application Laid-Open
As described in 4-55550, a method of “mixing high and low molecular weight methacrylic acid / (meth) acrylate copolymer” as a binder,
As described in JP-A-64-55551 and JP-A-64-55551, as a binder, a terpolymer of methacrylic acid / styrene / (meth) acrylate having a low molecular weight and a methacrylic acid / (meth) having a high molecular weight are used. ) Method of mixing acrylate copolymer ”, and JP-A-2-22-2
A method using a monofunctional monomer described in Japanese Patent No. 21960 has been proposed, but the size of the peeled piece was not yet sufficient. Furthermore, when stored for a long period of time in a state where the dry film is wound up in a roll shape, the so-called edge fusion in which the photosensitive layer exudes from the edge of the film and the adjacent films are fused to each other is likely to occur. Did not.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a photopolymerizable composition which can be treated with an alkaline aqueous solution and which has a fine strip and hardly generates edge fusion.

[0005]

As a result of various studies, the present inventors have found a photopolymerizable composition which can achieve the above object. That is, an object of the present invention is to provide (1) a carboxyl group-containing binder, (2) a photopolymerizable monomer,
And (3) a photopolymerizable composition which can be developed with an aqueous alkali solution containing a photopolymerization initiator system, wherein the carboxyl group-containing binder comprises methacrylic acid / methyl methacrylate / benzyl methacrylate / acrylic acid-2- A photopolymerizable composition comprising an ethylhexyl copolymer and a copolymer of styrene (meth) acrylic acid (weight average molecular weight: 1,000 to 100,000) in an amount of 5 to 50% by weight of a total binder. Achieved.

[0006] If the molecular weight of the styrene / (meth) acrylic acid copolymer is less than 1,000, the resist becomes too soft, and edge fusion is likely to occur. 10
If it exceeds 000, the peeled piece does not become fine and is not suitable for the composition of the present invention. If the content of the styrene / (meth) acrylic acid copolymer is less than 5% by weight, the peeled pieces will not be sufficiently fine. On the other hand, if it exceeds 50% by weight, the film becomes brittle and is not suitable for the composition of the present invention. Specific examples of the copolymer include a styrene / methacrylic acid copolymer, a styrene / acrylic acid copolymer, and a styrene / methacrylic acid / acrylic acid copolymer. The copolymerization ratio is styrene / acid group (total of contained monomers) = 5: 95 to 9
5: 5 (molar ratio) is preferable, and particularly preferable is 15/5.
85 to 60/40.

As the binder other than the above-mentioned styrene / (meth) acrylic acid copolymer, a binder selected from the following wide variety of polymer substances can be used in combination. Binders that can be combined have good compatibility with photopolymerizable monomers and photopolymerization initiator systems, and can be removed during the production process from coating liquid preparation to coating and drying, and during storage of the resulting mixture. No mixing occurs, properties according to the method of use of the present invention, for example, when used for a photoresist for tenting, strength, stretchability, abrasion resistance, chemical resistance and the like are appropriate, and further, a binder The molecular weight, the intermolecular force, the hardness, the softening temperature, the crystallinity, the elongation at break, and the like are appropriate.

Specific examples of the binder preferably used in the present invention include a styrene / maleic anhydride copolymer and methyl methacrylate / methacrylic acid / methacrylic acid 2- described in JP-A-60-258439. Ethylhexyl / benzyl methacrylate quaternary copolymer; styrene / maleic acid mono-n-butyl ester copolymer described in JP-B-55-38961;
A styrene / methyl methacrylate / ethyl acrylate / methacrylic acid quaternary copolymer described in US Pat.
Benzyl methacrylate / methacrylic acid copolymer described in JP-A-52-99810, JP-B-58-1257.
No. 7 acrylonitrile / methacrylic acid 2-
Ethylhexyl / methacrylic acid terpolymer, and methyl methacrylate / ethyl acrylate / acrylic acid terpolymer described in JP-B-55-6210 and styrene / maleic anhydride partially esterified with isopropanol And two types of copolymers. Particularly preferred are methyl methacrylate / methacrylic acid / 2-ethylhexyl methacrylate / benzyl methacrylate quaternary copolymer. These molecular weights can take a wide range of values depending on the type of binder, but are generally 5,000.
~ 2,000,000, preferably 10,000 ~ 2
It is in the range of 00,000. When the molecular weight is less than 5,000, the mechanical strength of the resist obtained by photopolymerization becomes insufficient, and when the molecular weight is more than 2,000,000, the developability deteriorates, which is not suitable for the purpose of the present invention. The total amount of the binder is preferably from 40 to the solid content of the photopolymerizable composition.
90 wt%, more preferably 50 to 70 wt%.
If the content is less than 40 wt%, the flowability of the photopolymerizable composition is too high, so that edge fusion easily occurs.
%, The difference in solubility between the exposed part and the unexposed part becomes too small to obtain good image quality, and none of them is suitable for the purpose of the present invention.

The photopolymerizable monomers that can be used in the present invention include the following. For example, JP
Publicly known (meth) acrylic acid esters as described in JP-A-258538 and JP-A-2-269721. Specifically, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, nonaethylene glycol di (meth) acrylate, tetradecaethylene glycol di (meth) acrylate, nona Propylene glycol di (meth) acrylate, dodecapropylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane ethylene oxide adduct tri (meth) acrylate, pentaerythritol di (meth) acrylate, penta Erythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, glycerol Di (meth) acrylate, (meth) acrylic acid esters of 1,3-propanediol di (meth) polyols such acrylate.

(Meth) acrylamides include methylenebis (meth) acrylamide, ethylenediamine, diaminopropane, diaminobutane, pentamethylenediamine, bis (2-aminopropyl) amine, diethylenetriaminediamine, phenylenediamine, diaminobenzoic acid and the like. There are poly (meth) acrylamides derived from

Examples of the allyl compound include diallyl esters such as phthalic acid and malonic acid, and diallyl esters such as benzenedisulfonic acid and 2,5-dihydroxydisulfonic acid.

As the vinyl ether compound, for example,
Examples include ethylene glycol divinyl ether and 1,3,5-tri-β-vinyloxyethoxybenzene.

The vinyl esters include divinyl succinate and divinyl adipate.

Examples of the styrene compound include divinylbenzene and p-allylstyrene.

Further, a reaction product obtained by reacting a polyol compound having at least two hydroxyl groups with a slightly excessive polyisocyanate compound having at least two isocyanate groups is added to at least one hydroxyl group and at least one ethylene compound. A polyfunctional urethane compound having at least two ethylenically unsaturated groups, which is obtained by reacting with a compound having an ethylenically unsaturated group, can also be suitably used in the present invention.

The amount of the photopolymerizable monomer is from 10 to 60% by weight of the solid content of the photopolymerizable composition, preferably from 25 to 50% by weight.
%. If the amount is less than 10% by weight, the difference in solubility between the exposed and unexposed parts is too small, so that good image quality cannot be obtained. If the amount exceeds 60% by weight, the flowability of the photopolymerizable composition is too high, resulting in edge fusion. This is not suitable for the purpose of the present invention.

Suitable photopolymerization initiators that can be used in the present invention include about 300 to 800 nm, more preferably 330 nm.
It preferably contains at least one component having a molecular extinction coefficient of at least about 50 in the range of -500 nm. Examples include aromatic ketones, lophine dimers, benzoin and benzoin ethers, polyhalogens, and combinations of two or more of these.

The following compounds can be mentioned as specific examples. As aromatic ketones, for example,
Benzophenone, 4,4'-bis (dimethylamino) benzophenone, 4,4'-bis (diethylamino) benzophenone, 4-methoxy-4'-dimethylaminobenzophenone, 4,4'-dimethoxybenzophenone,
-Dimethylaminobenzophenone, 4-dimethylaminoacetophenone, benzyl, anthraquinone, 2-te
Examples thereof include rt-butylanthraquinone, 2-methylanthraquinone, xanthone, thioxanthone, 2-chlorothioxanthone, 2,4-diethylthioxanthone, fluorenone, and acridone.

The preferred examples of the rofin dimer are described in JP-B-45-37377, JP-B-48-38403, JP-A-56-35134, and JP-A-63-200605. And the like. For example, 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer,
(O-chlorophenyl) -4,5-di (m-methoxyphenyl) imidazole dimer, 2- (o-fluorophenyl) -4,5-diphenylimidazole dimer, 2-
(O-methoxyphenyl) -4,5-diphenylimidazole dimer, 2- (p-methoxyphenyl) -4,5
-Diphenylimidazole dimer and the like.

Examples of benzoin and benzoin ethers include benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether and benzoin phenyl ether.

Examples of the polyhalogen compound include carbon tetrabromide, phenyltribromomethylphenylsulfone, phenyltrichloromethylketone, and JP-A-53-133428, JP-B-57-1819, and JP-B-57-6096. And U.S. Pat. No. 3,615,455.

Particularly preferred examples include 4,4'-bis (dimethylamino) benzophenone, 4,4'-bis (diethylamino) benzophenone, 2,4-diethylthioxanthone, 4,4'-bis (diethylamino) benzophenone and Combination with benzophenone, 4,4'-
Combinations of bis (diethylamino) benzophenone and 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, combinations of 4,4′-bis (diethylamino) benzophenone and phenyltribromomethylphenylsulfone, and the like. Can be

The content of the photopolymerization initiator system is preferably 0.1 to 20% by weight based on the solid content of the photopolymerizable composition.
More preferably, it is 0.2 to 10% by weight. 0.1wt
When the amount is less than 20% by weight, the sensitivity is insufficient, and when the amount exceeds 20% by weight, the film properties of the photopolymerizable composition are adversely affected.

As described above, the photopolymerizable composition of the present invention comprises a carboxyl group-containing binder, a photopolymerization initiator (system) and a photopolymerizable monomer. If necessary, a thermal polymerization inhibitor, a plasticizer , A dye, a color changing agent, an adhesion promoter, and the like may be used in combination, so that a desired photoresist, resin relief printing plate, planographic printing plate, photomask, and the like can be prepared in a wide range.

The thermal polymerization inhibitor is added to prevent thermal polymerization of the photopolymerizable composition or polymerization with time.
Thereby, the chemical stability at the time of preparation of the photopolymerizable composition or at the time of storage until it is used after being laminated on a metal plate can be enhanced. Examples of the thermal polymerization inhibitor include p-methoxyphenol, hydroquinone, benzoquinone, o-toluquinone, p-toluquinone, t-butylcatechol, pyrogallol, 2-hydroxybenzophenone, and 4-methoxy-
2-hydroxybenzophenone, cuprous chloride, phenothiazine, phenidone, floranyl, chloranil, naphthylamine, pyridine, p-toluidine, β-naphthol, 2,6-di-t-butyl-p-cresol, nitrobenzene, dinitrobenzene, picrine Acids, aluminum salts or ammonium salts of N-nitrosophenylhydroxylamine, methylene blue organic copper, methyl salicylate, aryl phosphite and the like. A preferable addition amount of the thermal polymerization inhibitor is 0.001 to 10% by weight, more preferably, a solid content of the photopolymerizable composition.
0.01 to 3 wt%. If it is less than 0.001 wt%, the thermal stability is poor, and if it exceeds 10 wt%, the sensitivity decreases.

The plasticizer is added to adjust the film quality of the photopolymerizable composition before and after photocuring, other physical properties, photosensitivity and the like. Examples of the plasticizer include phthalic esters such as dibutyl phthalate, diheptyl phthalate, dioctyl phthalate, and diallyl phthalate; glycol esters such as triethylene glycol diacetate and tetraethylene glycol diacetate; and p-toluene sulfone Acid amides such as amide, benzenesulfonamide and Nn-butylbenzenesulfonamide; aliphatic dibasic acid esters such as diisobutyl adipate, dioctyl azelate and dibutyl maleate; tributyl citrate; glycerin triacetate; lauric acid Butyl 4,5-diepoxycyclohexane-1,2-dicarboxylate dioctyl and the like. The preferable addition amount of the plasticizer is 0.001 to 50% by weight, more preferably 0.01 to 20% by weight of the solid content of the photopolymerizable composition. If it exceeds 50% by weight, the developability and the image quality are adversely affected.

Dyes are added for coloring the photopolymerizable composition. Examples of dyes include malachite green, methyl green, brillat green, methyl violet, crystal violet, ethyl violet, Victoria Pure Blue BOH, and oil blue # 603.
(Manufactured by Orient Chemical Co., Ltd.), eosin, erythrosin B, rose bengal, rhodamine B, rhodamine 6G, 2,7-dichlorofluorescein, phenolphthalein, alizarin red S, thymolphthalein,
Quinaldine red, methanil yellow, thymol sulfophthalein, diphenyltriazene, xylenol blue, methyl congo red, diphenylthiocarbazone,
Examples include paramethyl red, congo red, benzobulbulin 4B, α-naphthyl red, nile blue A, phenacetaline, parafuchsin, and basic fuchsin. The preferred amount of the dye added is 0.001 to 10 wt%, more preferably 0.1 to 5 wt%, of the solid content of the photopolymerizable composition. If it exceeds 10% by weight, the sensitivity is adversely affected.

The color change agent is added so that a visible image can be obtained when the photopolymerizable composition is irradiated with light through a photomask. Examples of the color changing agent include diphenylamine, dibenzylaniline, triphenylamine, diethylaniline, diphenyl-p-phenylenediamine, p-toluidine, 4,4′-biphenyldiamine, o-chloroaniline, p, p ', p "-hexamethyltriaminotriphenylmethane, p, p'-tetramethyldiaminotriphenylmethane, p, p', p"-
And triaminotriphenylcarbinol.
The preferable amount of the color changing agent is 0.001 to 10% by weight, more preferably 0.01 to 5% by weight of the solid content of the photopolymerizable composition.
wt%. If it exceeds 10% by weight, sensitivity reduction and fogging are likely to occur.

The adhesion promoter is added in order to increase the adhesion of the photopolymerizable composition to the surface of a metal plate such as copper, stainless steel, anodized aluminum and silicon. Examples of the adhesion promoter include benzimidazole and benzthiazole described in JP-B-50-9177.
Benztriazole, 2-mercaptobenzthiazole and 2-mercaptobenzimidazole described in JP-A-53-702, and JP-A-59-11
3432, JP-A-59-16501, JP-A-60-160
12543, JP-A-60-12544, JP-A-61
And the compounds described in the respective specifications. The preferable addition amount of the adhesion promoter is 0.001 to 10% by weight, more preferably 0.01 to 5% by weight of the solid content of the photopolymerizable composition. If it exceeds 10% by weight, it may cause development residue.

The photopolymerizable composition of the present invention forms a resist image by laminating and image-exposing a substrate to a substrate by a known method, and then dissolving and removing (developing) an unexposed portion.

The photopolymerizable composition of the present invention can be developed with an aqueous alkali solution. As the developer, for example, an aqueous solution of 0.1 to 10% by weight of sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, potassium carbonate, lithium carbonate, ammonia or the like can be used. Amines, for example, primary amines such as butylamine, hexylamine, benzylamine and allylamine, secondary amines such as diethylamine and benzylethylamine, tertiary amines such as triethylamine, ethanolamine, diethanolamine, triethanolamine and 2-amino-1 Hydroxylamines such as 1,3-propanediol, cyclic amines such as morpholine, pyridine, piperazine and piperidine; basic salts such as sulfates, carbonates, bicarbonates, alkali metal phosphates and pyrophosphates of the amines; Tetramethyl ammonium hydride Kishido, it is also possible to use hydroxy salts choline and the like. Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto. In addition, "part" means "part by weight".

[0032]

【Example】

 Examples 1 and 2, Comparative Examples 1 to 5 The following materials were mixed to prepare a uniform solution. Dodecapropylene glycol diacrylate 15.0 parts Tetraethylene glycol dimethacrylate 3.5 parts p-toluenesulfonamide 1.2 parts 4,4'-bis (diethylamino) benzophenone 0.12 parts Benzophenone 2.3 parts 2- (2 '-Chlorophenyl) -4,5-diphenyl imidazole dimer (25 wt% dichloromethane solution) 4.5 parts Tribromomethylphenyl sulfone 0.25 parts Leuco crystal violet 0.25 parts Malachite green 0.02 parts

To 27.14 parts of the solution thus obtained, 35% solutions of various binders in the amounts shown in Table 1 were added.

Table 1: Binder type and performance of composition Binder type ABCD Peeled piece size Edge fusion Example 1 90 10 3 cm No fusion Example 2 80 20 1 cm No fusion Comparative example 1 100 5 cm Fusion None Comparative Example 2 80 203 cm fused With Comparative Example 3 80 205 cm not fused Comparative Example 4 70 30 3 cm fused Comparative Example 5 60 40 2 cm fused Binder A: methyl methacrylate / methacrylic acid / acrylic acid 2 -Ethylhexyl / benzyl methacrylate copolymer (molar ratio = 55/28/12/5, weight average molecular weight = 80,000, 35 wt% solution, solvent is methyl ethyl ketone / 1-methoxy-2-propanol = 2/1) binder B: Same as Binder A except that the weight average molecular weight is 150,000 Vine Der C: Same as Binder A except that the weight average molecular weight is 10,000 Binder D: Styrene / acrylic acid copolymer (molar ratio = 63/37, weight average molecular weight 10,000)

After further stirring, each solution was brought to a thickness of 20 μm.
m on a polyethylene terephthalate temporary support,
After drying at 100 ° C. for 2 minutes, a dry film having a photosensitive resin coating film having a thickness of about 40 μm was prepared.

<Evaluation of Peeling Piece> The dry film prepared above was put on a cleaned copper-clad laminate (copper thickness: 35 μm).
Laminated at ℃. After 15 minutes, 70 mj / c using a 5 kW ultra-high pressure mercury lamp (HMW-532D manufactured by Oak Co., Ltd.)
m ^{2 The} entire surface was exposed. After 15 minutes of exposure, spray development was performed for 40 seconds with a 1% aqueous solution of sodium carbonate (30 ° C.).
Washed with water at 0 ° C. for 40 seconds. The resist thus obtained was stripped with a 3% NaOH aqueous solution at 50 ° C., and the size of the strip was evaluated.

<Evaluation of Edge Fusion> The dry film was cut into 5 cm squares exactly, and 10 sheets were superposed.
A weight of kg was placed. The samples were stored in an atmosphere of 30 ° C. and 80%, and after one week, it was checked whether the ends of the ten samples were fused.

[0038]

As shown in Table 1, it is clear that the photopolymerizable composition of the present invention is superior to the conventionally known compositions in that the size of the strip is small and edge fusion hardly occurs. It is.

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁶ Identification code FI G03F 7/028 G03F 7/028 H05K 3/06 H05K 3/06 J (56) References JP-A-64-55551 (JP, A JP-A-2-191955 (JP, A) JP-A-4-122937 (JP, A) JP-A-3-205404 (JP, A) JP-A-61-134756 (JP, A) 6210 (JP, B2) (58) Fields investigated (Int. Cl. ⁶ , DB name) G03F 7/033 G03F 7/004 G03F 7/027 G03F 7/028 C08F 2/50 G03F 7/00 H05K 3/06

Claims (2)

(57) [Claims] (1) a carboxyl group-containing binder,
(2) A photopolymerizable composition which can be developed with an aqueous alkali solution containing a photopolymerizable monomer and (3) a photopolymerization initiator system, wherein the carboxyl group-containing binder contains methacrylic acid / methyl methacrylate / Copolymer of benzyl methacrylate / -2-ethylhexyl acrylate and styrene (meth) acrylic acid at 5 to 50% by weight of the total binder (weight average molecular weight 1,000 to 100,00
0) A photopolymerizable composition comprising: 2. The photopolymerizable composition according to claim 1, wherein the photopolymerization initiator system contains a lophine dimer.