JPH0421183B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a photoinsoluble resin composition exhibiting excellent photosensitivity, and more specifically, a polymer containing a photosensitive group in its side chain that can generate radicals upon irradiation with light. The present invention relates to a characteristic photopolymerizable resin composition.

Many studies have been conducted to increase the photosensitivity speed of photoinsoluble resins based on the principle of photopolymerization, and most of them are related to photopolymerization sensitizers (initiators) that are active to ultraviolet light. On the other hand, photosensitive resins are attracting attention not only as photoresist materials, inks, paints, varnishes, and printing plate materials, but also as image-forming materials that use laser light and photosensitive materials that replace silver salts. The photosensitivity of conventional materials is extremely inadequate. Therefore, it is necessary to expand the photosensitive wavelength range and dramatically increase the photosensitive speed.

In this case, it goes without saying that the photosensitive resin must have both high resolution, which is an excellent characteristic, and various physical properties suitable for the purpose.

Several proposals have been made for photopolymerizable resins that are sensitive to visible light. In JP-A-48-36281, S having at least one trihalomethyl group conjugated to a triazine ring through ethylenically unsaturation and at least one chromophore moiety is disclosed.
- A method using triazine as a polymerization initiator has been proposed. Furthermore, Japanese Patent Application Laid-Open No. 15529/1984 proposes a composition using an unsaturated ketone conjugated with p-dialkylaminoallylidene as a photopolymerization initiator. Alternatively, JP-A-52-134692 proposes a composition using a polycyclic quinone and a tertiary amine as a photopolymerization initiation system.

All of these can provide materials that are sensitive to longer wavelengths than conventional photopolymerizable resins, but they require even higher photosensitive speeds to be used as photosensitive materials for lasers or silver salt substitute materials. is desired.

The photosensitivity of a photoinsolubilized resin depends on the molecular weight of the polymer to be insolubilized, the efficiency of the crosslinking reaction necessary for photoinsolubilization,
and the absorbance of the photosensitive group. Since the above-mentioned polymer composition sensitive to visible light is characterized by a low-molecular photopolymerization initiator that absorbs visible light, it can be said that high sensitivity was achieved by focusing on the absorbance of the photosensitive group. I can do it.

As a result of careful consideration of the above points, the present inventor has found that it is possible to achieve even higher sensitivity by polymerizing a photopolymerization initiator that absorbs visible light.
The present invention was developed based on the idea that high resolution can be expected since the resin is homogeneous.

That is, the present invention provides (A) general formula () (In the formula, R ₁ is a hydrogen atom or a methyl group,
R ₂ is a divalent organic residue, R ₃ is a hydrogen atom or a cyano group, R ₄ is a hydrogen atom or a lower alkoxy group, R ₅ is a lower alkyl group,
n is 0 or 1. ) One part of a photosensitized vinyl polymeric polymer substance having a molecular weight in the range of 5,000 to 1,000,000 and having at least one structural unit represented by (B) a compound that generates radical species by one-electron reduction. 0.01 to 0.5 parts of at least one compound selected from the group; and (C) 0.05 to 5 parts of at least one compound selected from the group of compounds having at least one ethylenically unsaturated bond having polymerizability. The present invention provides a photoinsoluble photosensitive material characterized by the following.

According to the present invention, by bonding a photosensitive residue having the ability to initiate photopolymerization to a polymer, the initiation site itself directly participates in the insolubilization of the polymer by radical polymerization, thereby achieving even higher sensitivity. is achieved.

Since the structure represented by the general formula () causes a dimerization reaction when irradiated with light, the polymer having this residue in its side chain already has photoinsolubilization ability. However, its photosensitivity is not sufficiently high, and by using it together with other auxiliary substances and a substance capable of vinyl polymerization according to the present invention, it exhibits a photoinsolubilizing ability with extremely high sensitivity.

In order to produce the photosensitizing substance (A) constituting the photoinsoluble resin composition of the present invention having such characteristics, it is necessary to efficiently polymerize this relatively large molecular weight structural unit. The structural unit of the general formula () is a substituted cinnamic acid or substituted cinnamylidene acetic acid residue, and therefore, the components necessary for the photosensitive material of the present invention can be easily obtained by known methods for introducing these photosensitive residues. (A) can be manufactured. (See Nagamatsu and Inui, "Photosensitive Polymers," Kodansha (1976)).

On the other hand, cinnamic acid-based photosensitive materials that utilize photodimerization reaction for crosslinking not only require a sensitizer to exhibit practical sensitivity, but also require the introduction of a large amount of cinnamic acid residues into the basic polymer. It was hot. On the other hand, in order for component (A) to achieve sufficient practical sensitivity in the presence of components (B) and (C), as described below,
Requires a much lower adoption rate. This not only effectively prevents the undesirable gelation that often occurs when introducing photosensitive residues into polymers, but also
This provides a highly economical photosensitive material.

Considering the above points, we believe that polymers with epoxy groups, such as polymers and copolymers of glycidyl (meth)acrylate, have the general formula () (In the formula, R ₁ , R ₂ , R ₃ , R ₄ and n have the same meanings as above.) A method of reacting a carboxylic acid represented by the following is desirable. The compound represented by the general formula () has a dialkylamino group and is difunctional, so it was thought that gelation would occur during the reaction, but in reality, a soluble substance is easily obtained. .
This is considered to be because the nucleophilic reactivity of the amino group is reduced by the conjugated carboxyl group.

The vinyl comonomers used in the copolymer of glycidyl (meth)acrylate used in this reaction include acrylonitrile, methacrylonitrile, methyl acrylate, ethyl acrylate, 2-ethylhexyl acrylate, benzyl acrylate, Acrylic acid, ethyl methacrylate, propyl methacrylate, butyl methacrylate, benzyl methacrylate, 2-ethylhexyl methacrylate,
N,N-dimethylacrylamide, N,N-dimethylmethacrylamide, N-vinylpyrrolidone,
Styrene, 2-vinylpyridine, 4-vinylpyridine, etc. can be mentioned. Only one type of these vinyl comonomers may be used, and
Needless to say, there is no problem in using multiple types. In this case, the copolymerization ratio of these vinyl copolymerization monomer pairs and glycidyl (meth)acrylate is
Anything in the range from 20:80 to 98:2 is acceptable. If the ratio of copolymerized monomers is smaller than this, the storage stability of the resulting photosensitizing polymer will be poor, and conversely, if it is larger than this range, the rate of introduction of residues with photosensitizing ability will be low. , its photosensitivity becomes extremely low.

Examples of the carboxylic acid represented by the general formula () used in this reaction include, but are not limited to, the following.

Any substance having a structural unit represented by the general formula () produced by the above method has a good shelf life. Moreover, by selecting any of these copolymerization components, physical properties depending on the purpose can be imparted to the polymer.

The polymer having a photosensitizing residue in its side chain used in the present invention has a low rate of insolubilization by light irradiation when it is used alone, but it can transfer one electron when it is combined with the photosensitive group represented by the general formula () by light irradiation. By coexisting with a compound that generates radical species, a highly efficient photopolymerization initiation system can be obtained. The one-electron reduced compounds used for this purpose are electron-accepting and include, for example, onium salts such as diphenyliodonium, ditolyliodonium, di(m-nitrophenyl)iodonium, 2,4,6-tris( chloromethyl)-S-triazine, 2-phenyl-
S-triazine derivatives such as 4,6-bis(trichloromethyl)-S-triazine, p-nitro-
α,α,α-tribromoacetophenone, O-nitro-α,α,α-tribromoacetophenone,
Trihaloacetylated benzene derivatives such as α, α, α-tribromoacetophenone, triphenylimidazole dimer, 2-(O-chlorophenyl)
-4,5-diphenylimidazole dimer, 2-
(O-methoxyphenyl)-4,5-diphenylimidazole dimer, 2-(α-naphthyl)-4,5
- triarylimidazole dimers such as diphenylimidazole dimers, benzophenones, benzophenone derivatives such as Michler's ketone, benzoquinones, naphthoquinones, anthraquinones, 2-
Quinones such as methylacetraquinone and phenanthrenequinone, organic peroxides such as benzoyl peroxide, di-t-butyl peroxide, cumene hydroperoxide, and perisophthalic acid di-t-butyl ester, etc. I can do it.

These electron-accepting compounds are used in an amount of 0.5 to 10 molar equivalents to the photosensitive residue represented by the general formula (),
More preferably, a highly efficient photopolymerization initiation system is obtained by mixing 1 to 5 molar equivalents.

Furthermore, a chain transfer agent may be added as desired in order to increase the efficiency of the polymerization reaction by light irradiation. Examples include 2-mercaptobenzthiazole and 2-mercaptobenzoxazole.

The compound having at least one ethylenically unsaturated bond having polymerization ability as the third component constituting the photoinsoluble resin composition of the present invention includes oligomers in addition to vinyl monomers, and further includes:
It may also be a high molecular weight compound. Specifically, acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, acrylamide, methacrylamide,
There are high-boiling monomers such as diacetone acrylamide and N-vinylcarbazole, as well as ethylene glycol, diethylene glycol, 1,
Di or poly(meth) such as 3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,10-decanediol, trimethylolethane, pentaerythritol, sorbitol, mannitol, etc. ) Acrylic esters, further examples include (meth)acrylated epoxy resins, polyester acrylate oligomers, (meth)acrylated urethane oligomers, and acroleinated polyvinyl alcohols.

The amount of these polymerizable compounds is preferably 0.1 to 5 parts based on 1 part of the photosensitizing polymer compound (A) having a photosensitive group represented by the general formula (). Furthermore, it goes without saying that these polymerizable compounds do not have to be used alone, and may be a mixture of two or more.

The photoinsoluble resin composition of the present invention has the general formula ()
It becomes insolubilized at a very high rate against light at a wavelength that is absorbed by the photosensitive group represented by . This is because this photosensitive group absorbs light energy and transfers electrons to the electron-accepting compound (B), resulting in a radical cation represented by the following partial structure. This is thought to be because ton is eliminated from the alkyl group (R ₃ ), and the radicals generated thereby initiate polymerization and cause graft polymerization. Furthermore, the fact that the electron-accepting compound itself generates a radical after transferring one electron and becomes an initiator is considered to be one reason why the resin composition of the present invention exhibits high sensitivity.

A pigment or dye may be added to the photoinsoluble resin composition of the present invention as a coloring agent, if desired. Furthermore, leuco dyes such as leucomalachite green, leuco crystal violet, etc. may be added to develop color using generated radicals. In this case, the visible coloring produced by light irradiation is particularly convenient for plate-making work.

As light sources suitable for the composition of the present invention, in addition to high-pressure mercury lamps, ultra-high-pressure mercury lamps, high-pressure xenon lamps, halogen lamps, and fluorescent lamps, He-Cd lasers and Ar lasers can be used.

The photoinsolubilized resin composition of the present invention has superior characteristics in sensitivity and resolution than conventional photopolymerizable compositions, so it can be used as a plate-making material for planography or letterpress, for the creation of reliefs, and for non-silver salt images. It can be applied to a wide range of fields such as manufacturing and printed wiring boards, and is also effective for negativeless plate making because it is sensitive to laser light.

This will be explained in more detail with reference to Examples below.

Example 1 5 g of polyglycidyl methacrylate was dissolved in 100 ml of N,N-dimethylacetamide, and p-
0.5 g of dimethylamino-α-cyanocinnamic acid and 0.32 g of tetrabutylammonium chloride were added and dissolved, and the mixture was stirred at 70°C for 1 hour. The reaction product was allowed to cool and then poured into methanol 1, and the precipitated resin was collected, thoroughly washed with methanol, and vacuum-dried.
The ultraviolet-visible absorption spectrum confirmed that 1.7 mol% of dimethylaminocyanocinnamic acid residues had been introduced. Dissolve this resin in dioxane and
A photosensitive solution was prepared by adding 10 ml of diphenyliodonium hexafluorophosphate and 0.7 g of pentaerythritol triacrylate to 1 g of this solution, and further diluting with 1.5 ml of dioxane. This was spin-coated on an aluminum plate at 1000 rpm, and then a 10% polyvinyl alcohol aqueous solution was spin-coated thereon. This photosensitive layer was applied to a step tablet manufactured by Eastman Kodak.
Irradiated with a xenon lamp through No. 1A. After washing with water to remove the polyvinyl alcohol layer, the film was developed with dioxane, and it was found that the film had a sensitivity approximately five times that of a commercially available polyvinyl cinnamate sensitive material.

Example 2 5 g of an 8:2 copolymer of n-butyl methacrylate and glycidyl methacrylate was dissolved in 100 ml of dimethylacetamide, and p-dimethylamino-
2.2 g of α-cyanocinnamic acid and 0.32 g of tetrabutylammonium chloride were added, and the mixture was stirred and reacted at 70° C. for 21 hours. The reaction product was separated and dried in the same manner as in Example 1. It contained 10.2 mol% dimethylaminocyanocinnamic acid residues. Dissolve this resin in dioxane to make a 10 weight solution, and 1 g of this solution.
10 mg of diphenyliodonium hexafluorophosphate, 0.7 g of pentaerythritol triacrylate and 1.5 ml of dioxane as diluent.
was added to make a homogeneous solution. This was made into a photosensitive layer coated with a polyvinyl alcohol film in the same manner as in Example 1, and when irradiated with a xenon lamp, the sensitivity was about 128 times that of a commercially available polyvinyl cinnamate-based sensitive material. Furthermore, when we measured the sensitivity to light with an oscillation wavelength of 488 nm using an argon ion laser as a light source, we found a sensitivity of approximately 1 mJ/cm ² .

Substantially similar results were obtained when bis(p-tolyl)iodonium hexafluorophosphate and bis(p-anisyl)iodonium tetrafluoroborate were used instead of diphenyliodonium hexafluorophosphate.

Example 3 1 g of a 10% dioxane solution of the resin obtained in Example 2
To this, 10 mg of 2-methyl-4,6-bis(trichloromethyl)-S-triazine, 70 mg of pentaerythritol triacrylate, and 1.5 ml of dioxane were added to make a homogeneous solution, and the sensitivity to xenon lamp was determined in the same manner as in Example 1. When measured, the sensitivity was approximately 16 times that of commercially available polyvinyl cinnamate-based sensitive materials.

Example 4 1 g of a 10% dioxane solution of the resin obtained in Example 2
To this, 10 mg of bis(2,4,5-triphenylimidazolyl) and 80 mg of pentaerythritol triacrylate were added, and the sensitivity was determined in the same manner as in Example 1. showed sensitivity.

Example 5 5 g of a 9:1 copolymer of n-butyl methacrylate and glycidyl methacrylate was dissolved in 100 ml of dimethylacetamide, and 1.3 g of p-dimethylaminocinnamylidene-α-cyanoacetic acid and tetrabutylammonium chloride were dissolved therein. Add 0.32g and heat at 70℃ for 10
The reaction was stirred for hours. The reaction product was poured into methanol, and the separated resin was thoroughly washed with methanol and dried. 1g of 10% dioxane solution of this resin
A photosensitive solution was prepared by adding 10 mg of diphenyliodonium hexafluorophosphate and 0.7 g of pentaerythritol triacrylate. This composition exhibited a sensitivity approximately 36 times that of commercially available polyvinyl cinnamate-based sensitive materials.

Example 6 Methyl methacrylate and chloromethylstyrene
10g of 93:7 copolymer and 90g of dimethylacetamide
3.2 g of p-dimethylamino-α-cyanocinnamic acid potassium salt was added thereto, and the reaction was carried out at 60°C for 4 hours. The reaction solution was poured into methanol to separate the product, which was thoroughly washed with methanol. To the thus obtained solution of the polymer in ethyl cellosolve acetate, 10% by weight of 2-methyl-4,6-bis(trichloromethyl)-S-triazine based on the polymer was added, and the same amount of tetraethylene glycol as the polymer was added. A photosensitive solution was prepared by adding diacrylate. When this was coated on an aluminum plate and then covered with a polyvinyl alcohol film, it showed approximately 16 times the sensitivity of polycinnamic acid-based sensitive materials. Here, when a triphenylimidazole dimer was used instead of the S-triazine derivative, about twice the sensitivity was obtained.

Claims (1)

[Claims] 1 (A) General formula (In the formula, R ₁ is a hydrogen atom or a methyl group,
R ₂ is a divalent organic residue, R ₃ is a hydrogen atom or a cyano group, R ₄ is a hydrogen atom or a lower alkoxy group, R ₅ is a lower alkyl group,
n is 0 or 1. ) One part of a photosensitized vinyl polymeric polymer substance having a molecular weight in the range of 5,000 to 1,000,000 and having at least one structural unit represented by (B) a compound that generates radical species by one-electron reduction. 0.01 to 0.5 parts of at least one compound selected from the group; and (C) 0.05 to 5 parts of at least one compound selected from the group of compounds having at least one ethylenically unsaturated bond having polymerizability. A photo-insoluble photosensitive material comprising: 2 The compound that generates a radical species by one-electron reduction is a diaryliodonium salt, at least one
S-triazine compounds substituted with two mono-, di-, or trihalomethyl groups, triarylimidazole dimers, benzophenones and their nuclear substitutes, quinones, benzyl and their nuclear substitutes, and organic peroxides. The photoinsoluble resin composition according to scope 1.