JPS6343411B2 - - Google Patents

Description

Detailed Description of the Invention [Industrial Application Field] The present invention provides a photocurable resin composition that exhibits excellent photosensitivity, and more specifically, a photocurable resin composition that has a photosensitive group in its side chain that can generate radicals when irradiated with light. The present invention relates to a photocurable resin composition characterized by containing a polymer having the following properties.

[Conventional technology]

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. JP-A-48-36281 proposes a method in which a halomethylated s-triazine having a chromophore is used as a polymerization initiator. Furthermore, JP-A-54-15529 proposes a composition using an unsaturated ketone conjugated with p-dialkylaminoallylidene as a photopolymerization initiator. Or again, JP-A-52-
No. 134692 proposes a composition containing a polycyclic quinone and a tertiary amine as a photopolymerization initiation system.

[Purpose of the invention]

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, silver salt substitute materials, etc. 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 polymer composition sensitive to visible light is characterized by a low-molecular photopolymerization initiator that absorbs visible light, it can be said that it is designed to achieve high sensitivity by focusing on the absorbance of the photosensitive group. .

[Structure of the invention]

As a result of careful consideration of the above points, the inventors of the present invention 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 because the resin is homogeneous.

That is, the present invention provides (A) general formula () (In the formula, R is a hydrogen atom or a methyl group,
1 part of a _vinyl polymeric polymer substance having a molecular weight in the range of 1,000 to _1,000,000 and having at least one structural unit represented by (B) 0.01 to 0.5 parts of thioxanthone which may have a substituent, 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 resin composition comprising:

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.

[Effect]

In order to produce the polymer compound (A) constituting the photocurable resin composition of the present invention having such characteristics, it is necessary to efficiently polymerize this relatively large molecular weight residue. The following three methods are particularly effective for this purpose, and will be explained below.

The first method focuses on the reactivity of the epoxy group of glycidyl (meth)acrylate, which is easily available, and involves copolymerizing this reactive vinyl monomer with other copolymerizable vinyl monomers. Polymer is the raw material.

The reaction between dialkylaminobenzoic acid and glycidyl (meth)acrylate copolymer is carried out in a polar solvent. As a solvent, a solvent that does not have active hydrogen,
For example, tetrahydrofuran, acetonitrile, acetone, chloroform, trichlene, O-
Dichlorobenzene, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, and dimethylsulfoxide are preferred. In order to accelerate this reaction, it is effective to add halogen ions, and for this purpose, halogen ions such as lithium chloride, lithium bromide, tetraethylammonium chloride, tetraethylammonium bromide, tetrabutylammonium chloride, triethylbenzylammonium chloride, etc. Among them, organic ammonium chloride is preferred.

Through this reaction, the general formula () (In the formula, R, R ₁ and R ₂ have the same meanings as above)
A polymer substance having a structural unit represented by is obtained.

Vinyl monomers used in the copolymer of glycidyl (meth)acrylate that reacts with p-dialkylaminobenzoic acid include acrylonitrile, methacrylonitrile, methyl acrylate, ethyl acrylate, 2-ethylhexyl acrylate, and acrylic acid. benzyl, acrylic acid, ethyl methacrylate,
Propyl methacrylate, butyl methacrylate, benzyl methacrylate, 2-ethylhexyl methacrylate, N,N-dimethylacrylamide, N,
Examples include N-dimethylmethacrylamide, N-vinylpyrrolidone, styrene, 2-vinylpyridine, and 4-vinylpyridine. It goes without saying that only one type of these vinyl comonomers may be used, or a plurality of types may be used.

A second method for producing a polymeric substance having a structural unit represented by the general formula () will be described next.

In this method, a polymer compound having an active halogen atom is reacted with p-dialkylaminobenzoic acid. Examples of the polymer compound having an active halogen atom used in this reaction include a polymer or copolymer of chloromethylstyrene or vinyl chloroacetate. p
-Dialkylaminobenzoic acid may be converted into an alkali metal salt or ammonium salt in advance, and this may be reacted with the above-mentioned polymer compound. This reaction gives the general formula () (In the formula, R ₁ and R ₂ have the same meanings as above, and Y
(represents CH ₂ -- or --OCOCH ₂ --) is obtained. Further, as the vinyl monomer necessary to provide a copolymer of chloromethylstyrene or vinyl chloroacetate, the same vinyl monomers as in the case of glycidyl methacrylate can be mentioned.

A third method for producing a polymeric substance having a structural unit represented by the general formula () will be explained. In this method, a vinyl monomer containing a p-dialkylaminobenzoic acid ester residue is prepared in advance, and other vinyl monomers are copolymerized therewith.

Examples of the vinyl monomer having a p-dialkylaminobenzoic acid ester residue used here include the following.

These monomers can be easily produced from glycidyl (meth)acrylate and p-dialkylaminobenzoic acid.

Vinyl monomers copolymerized with these monomers include acrylonitrile, methacrylonitrile,
Ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, benzyl acrylate, tetrahydrofurfuryl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, benzyl methacrylate, methacrylic acid Examples include 2-ethylhexyl, N,N-dimethylacrylamide, N,N-dimethylmethacrylamide, N-vinylpyrrolidone, styrene, 2-vinylpyridine, and 4-vinylpyridine. These vinyl monomers can be used alone or in combination.

Although a commonly used copolymerization method can be used as is, a solution polymerization method is convenient in order to reliably produce a soluble polymer.

All of the vinyl polymers containing the structural unit represented by the general formula () produced by the above three methods have good storage stability. Moreover, since the copolymerization component forming the vinyl unit other than the vinyl constituent unit having photosensitizing ability can be arbitrarily selected, the polymer is characterized in that it can impart arbitrary physical properties to the polymer depending on the purpose.

Although the vinyl polymeric polymer substance having the structural unit represented by the general formula () used in the present invention cannot be photoinsoluble alone, the addition of thioxanthone, which may have a substituent, increases the ability to initiate photopolymerization with high efficiency. shows. In addition to thioxanthone, the thioxanthone derivatives used here include 2-chlorothioxanthone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2-phenylthioxanthone, 4-isopropylthioxanthone, 2,4-
Examples include diethylthioxanthone.

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 point 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.

Although it is known that a dialkylaminobenzoic acid ester and a thioxanthone derivative constitute a photopolymerization initiation system, the photocurable resin composition of the present invention is insolubilized at a very high rate. This is thought to be because a radical cation is generated in the dialkylaminobenzoic acid residue by light irradiation, and this site serves as a polymerization initiation point for efficient crosslinking.

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.

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 board creation.

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

Example 1 5 g of a 9:1 copolymer of n-butyl methacrylate and glycidyl methacrylate was dissolved in 100 ml of N,N-dimethylacetamide, and 0.77 g of p-dimethylaminobenzoic acid and 0.32 g of tetrabutylammonium chloride were added thereto. The mixture was stirred and reacted at 70°C for 17 hours. The reaction product was poured into about 1 liter of methanol, and the precipitate was collected, thoroughly washed with methanol, and dried under vacuum to obtain 5.3 g of a colorless resin. The p-dimethylaminobenzoic acid residue is 6.9 from the ultraviolet absorption spectrum.
It became clear that mol% was introduced. This resin was dissolved in dioxane to make a 10% solution by weight, and 1 g of this solution contained 10 mg of 2- or 4-chlorothioxanthone, 70 mg of pentaerythritol triacrylate, and 1.5 mg of dioxane as a diluting solvent.
ml was added to prepare a photosensitive resin solution. This solution was spin-coated onto an aluminum plate at 1000 rpm, and a 10% by weight aqueous solution of polyvinyl alcohol was further spin-coated thereon. The photosensitive layer was irradiated for 20 seconds with a xenon lamp (0.9 mW/cm ² ) through a Step Tablet No. 1A manufactured by Eastman Kodak.
After washing with water to remove the PVA film and developing it with dioxane, it showed approximately 32 times the sensitivity of commercially available polyvinyl cinnamate-based photosensitive materials. Moreover, even after the photosensitive layer used here was stored in a dark place at room temperature for 4 months, it showed exactly the same sensitivity.

Example 2 2,4-diethylthioxanthone was used instead of chlorothioxanthone used in Example 1,
When evaluating photosensitivity with other conditions being the same,
The sensitivity was about 16 times that of commercially available polyvinyl cinnamate-based photosensitive materials.

Example 3 3.0 g of an 8:2 copolymer of n-butyl methacrylate and glycidyl methacrylate was dissolved, and p
-0.9 g of dimethylaminobenzoic acid and 0.32 g of tetrabutylammonium chloride were added, and the mixture was stirred and reacted at 70°C for 15 hours. Hereinafter, by the same method as in Example 1, 13.1 mol% of p-dimethylaminobenzoic acid group was added.
3.05 g of the introduced photosensitive resin was obtained. The photosensitivity of this resin was evaluated in the same manner as in Example 1.
Approximately 32 times the sensitivity of polyvinyl cinnamate-based photosensitive materials was obtained.

Example 4 Methyl methacrylate-chloromethylstyrene
80:20 copolymer 10g to dimethylacetamide 190%
5.50 g of p-dimethylaminobenzoic acid sodium salt was added thereto, and the mixture was reacted at 65° C. for 5 hours. The reaction solution was poured into 1.8 methanol to precipitate the polymer, washed with methanol, and then vacuum dried. The obtained resin was dissolved in tetrahydrofuran, and this solution was filtered to remove insoluble materials, and then reprecipitated into methanol. This was washed with methanol and vacuum dried to obtain 11.3 g of a colorless polymer. It was revealed from the ultraviolet absorption spectrum that it contained 13.1 mol% of aminobenzoic acid residues. This polymer was dissolved in ethyl cellosolve acetate to make a 10% solution by weight, and this solution
3.00g of pentaerythritol triacrylate
0.3g and 2- or 4-chlorothioxanthone
0.03 g was added, and this was spin-coated onto an aluminum plate, and further a 10% by weight aqueous solution of polyvinyl alcohol was spin-coated thereon. The sensitivity of this photosensitive layer was evaluated in the same manner as in Example 1, and the sensitivity was approximately 32 times that of the polyvinyl cinnamate type sensitive material.

〔Effect of the invention〕

The photocurable resin composition of the present invention exhibits high photosensitivity and has excellent storage stability. Therefore, it is excellent as a plate-making material for photosensitive planography, letterpress, etc. Furthermore, it is effective as a dry film resist for producing printed wiring boards and as a resist for microfabrication.

Claims (1)

[Claims] 1 (A) General formula (In the formula, R is a hydrogen atom or a methyl group, R ₁ ,
(R ₂ is an alkyl group and X is a divalent organic residue) 1 part of a vinyl polymeric polymer substance having a molecular weight in the range of 1,000 to 1,000,000 and having at least one structural unit represented by (B) 0.01 to 0.5 parts of thioxanthone, which may have a substituent, 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 polymerization ability.
A photocurable resin composition comprising: