JPH08297367A - Photopolymerizable composition - Google Patents

Abstract

PURPOSE: To ensure high sensitivity especially to light in a visible region by using a photopolymn. initiating system contg. a biimidazole compd. and a specified coumarin compd. CONSTITUTION: A photopolymn. initiating system contg. a biimidazole compd. and at least one kind of coumarin compd. represented by the formula is used. In the formula, each of R<1> , R<2> and R<5> is H, halogen, alkyl, etc., each of R<3> and R<4> is optionally substd. alkyl, at least one of pairs R<2> -R<3> and R<4> -R<5> may form optionally substd. alkylene by mutual combination, R<6> is H, alkyl, acyl, cyano, carboxyl or its ester or amide deriv. and R<7> is a 3-15C residue of a hetero ring. The objective photopolymerizable compsn. having high sensitivity and satisfactory dissolution stability is obtd.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a photopolymerizable composition. In particular, the present invention relates to a photopolymerizable composition having high sensitivity to light rays in the visible region.

[0002]

2. Description of the Related Art Conventionally, many image forming methods utilizing a photopolymerization system are known. For example, a photopolymerizable composition comprising a compound containing an addition-polymerizable ethylenic double bond, a photopolymerization initiator, and an organic polymer binder optionally used is prepared, and the photopolymerizable composition is supported. A photosensitive material having a layer of the photopolymerizable composition applied on the body is prepared, and the desired image is imagewise exposed to polymerize and cure the exposed portion, and the unexposed portion is dissolved and removed to form a cured relief image. And a layer of a photopolymerizable composition is provided between two supports in which at least one of the above-mentioned light-sensitive materials is transparent, and the transparent support side is imagewise exposed to cause a change in adhesive strength due to light. After that, there is a method of forming an image by peeling the support, and an image forming method utilizing the change of toner adherability of the photopolymerizable composition layer due to light. Conventionally, benzoin, benzoin alkyl ether, benzyl ketal, benzophenone, anthraquinone, benzyl, or Michler's ketone has been used as the photopolymerization initiator of the photopolymerizable composition applied to these methods.

However, these photopolymerization initiators are
Compared with the ability to initiate photopolymerization for light in the ultraviolet region below 00 nm, it is significantly lower than that for light in the visible light region above 400 nm, thus limiting the range of application of photopolymerizable compositions containing them.

In recent years, with the development of image forming technology, there has been a strong demand for photopolymers having a high sensitivity to light rays in the visible region. For example, it is a light-sensitive material suitable for non-contact type projection exposure plate making, laser plate making by visible light laser, and the like. Among these techniques, the plate making method using an 488 nm oscillation beam of an argon ion laser is considered to be one of the most promising techniques in the future.

Several proposals have hitherto been made regarding a photopolymerization composition containing a photopolymerization initiation system which is sensitive to light rays in the visible light region. For example, a system of hexaarylbiimidazole and (p-dialkylaminobenzylidene) ketone (JP-A-47-2528, JP-A-54-155).
292, JP-A-56-166154), a system of ketocoumarin and an activator (JP-A-52-112681,
JP-A-58-15503, JP-A-60-88005), a system of a substituted triazine and a sensitizer (JP-A-54-54).
151024, JP-A-58-29803, JP-A-5-
8-40302), biimidazole, styrene derivative, thiol system (JP-A-59-56403), organic peroxide and dye system (JP-A-59-1402).
03, JP-A-59-189340)
A system of a titanocene compound and a sensitizer (JP-A-63-2211).
No. 10, JP-A-4-26154, JP-A-4-2197.
No. 56). These are certainly effective to some extent, but from a practical point of view, characteristics such as sensitivity are still insufficient, and an improved technique has been desired.

The present invention meets these requirements, that is, the first object of the present invention is to provide a photopolymerizable composition having sufficient sensitivity, and the second object is storage stability. Another object of the present invention is to provide the same composition suitable for laser plate making. The authors have found that the above-mentioned object is achieved by the following specific composition.

That is, the present invention provides a photopolymerizable composition comprising a compound having at least one ethylenically unsaturated double bond capable of addition polymerization and a photopolymerization initiation system, wherein the photopolymerization initiation system is (a) ) Biimidazole compound, (b) at least one coumarin compound represented by the following general formula [I]

[0008]

Embedded image

[0009] wherein, R ^1, R ² and R ⁵ are each a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group, R ² and R ³ and R ⁴ each represent a substituted or unsubstituted alkyl group R ³ and R ⁴ and R ⁵
At least one pair may be linked to each other to form a substituted or unsubstituted alkylene group, R ⁶ is a hydrogen atom,
It represents an alkyl group, an acyl group, a cyano group, a carboxyl group or an ester derivative or amide derivative group thereof, and R ⁷ represents a heterocyclic residue having 3 to 15 carbon atoms. ] The photopolymerizable composition characterized by containing
Easily achieved by. Hereinafter, the present invention will be described in detail.

The compound having at least one addition-polymerizable ethylenically unsaturated double bond contained as the first essential component in the photopolymerizable composition of the present invention (hereinafter abbreviated as "ethylenic compound") is When the photopolymerizable composition is irradiated with actinic rays, it is a compound having an ethylenically unsaturated double bond that undergoes addition polymerization by the action of the photopolymerization initiation system that is the second essential component and cures. For example, it is a monomer having the above double bond or a polymer having an ethylenically unsaturated double bond in the side chain or main chain. Incidentally, the meaning of the monomer in the present invention is a concept corresponding to a so-called polymer substance, and therefore includes not only a narrowly defined monomer but also a dimer, a trimer and an oligomer. .

Examples of the monomer having an ethylenically unsaturated bond include unsaturated carboxylic acid, ester of aliphatic polyhydroxy compound and unsaturated carboxylic acid; ester of aromatic polyhydroxy compound and unsaturated carboxylic acid; Examples thereof include esters obtained by an esterification reaction of a saturated carboxylic acid with a polyvalent carboxylic acid and the above-mentioned aliphatic polyhydroxy compound, polyvalent hydroxy compound such as aromatic polyhydroxy compound, and the like.

The ester of the aliphatic polyhydroxy compound and the unsaturated carboxylic acid is not limited, but specific examples thereof include ethylene glycol diacrylate, triethylene glycol diacrylate, trimethylolpropane triacrylate, trimethylolethane triacrylate. Acrylic esters such as pentaerythritol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, glycerol acrylate, etc. Methacrylic acid ester replaced, Itaconic acid ester similarly replaced with itaconate Crotonate is maleic acid ester, and was replaced with crotonic acid ester or maleate was replaced.

Examples of the ester of an aromatic polyhydroxy compound and an unsaturated carboxylic acid include hydroquinone diacrylate, hydroquinone dimethacrylate, resorcin diacrylate, resorcin dimethacrylate and pyrogallol triacrylate.

The ester obtained by the esterification reaction of an unsaturated carboxylic acid with a polyvalent carboxylic acid and a polyvalent hydroxy compound is not necessarily a single substance, but typical examples include acrylic acid, phthalic acid and Examples thereof include condensates of ethylene glycol, condensates of acrylic acid, maleic acid and diethylene glycol, condensates of methacrylic acid, terephthalic acid and pentaerythritol, condensates of acrylic acid, adipic acid, butanediol and glycerin.

In addition to the above ester (meth) acrylates, there are so-called urethane (meth) acrylates and epoxy (meth) acrylates. The former can be prepared by an addition reaction between a polyvalent isocyanate and hydroxyacrylic esters, and the latter can be prepared by an addition reaction between a polyvalent epoxy compound and hydroxyacrylic esters.

Other examples of the ethylenic compound used in the present invention include acrylamides such as ethylenebisacrylamide; allyl esters such as diallyl phthalate;
Vinyl group-containing compounds such as divinyl phthalate are useful.

The above-mentioned polymer having an ethylenically unsaturated bond in the main chain is, for example, a polyester obtained by a polycondensation reaction of an unsaturated divalent carboxylic acid and a dihydroxy compound, or an unsaturated divalent carboxylic acid and a diamine. There are polyamides and the like obtained by polycondensation reaction. The polymer having an ethylenically unsaturated bond in the side chain is a divalent carboxylic acid having an unsaturated bond in the side chain, for example itaconic acid, propylidene succinic acid,
There is a condensation polymer of ethylidene malonic acid and the like and a dihydroxy or diamine compound. Further, a polymer having a functional group having a reactive activity such as a hydroxy group or a methyl halide group in its side chain, for example, polyvinyl alcohol, poly (2-hydroxyethyl methacrylate), polyepichlorohydrin, etc. and acrylic acid, methacrylic acid, crotonic acid, etc. Polymers obtained by the macromolecular reaction with the unsaturated carboxylic acid can also be suitably used.

Of the above-mentioned ethylenic compounds, acrylic acid ester or methacrylic acid ester monomers are particularly preferably used. Next, the photopolymerization initiation system, which is the second essential component of the photopolymerization composition of the present invention, will be described.
The photopolymerization initiation system of the present invention is composed of a combination of two kinds of components, and the first component thereof is a biimidazole compound represented by (a) in the present invention.

In the present invention, the biimidazole compound is a compound having two imidazole skeletons in its structure and is not particularly limited, but specific examples of suitable biimidazole include 2,2 '-Bis (o-chlorophenyl) -4,4', 5,5'-tetraphenylbiimidazole (hereinafter abbreviated as A-1), 2,2'-bis (o-bromophenyl) -4,4 ′, 5,5′-Tetraphenylbiimidazole, 2,2′-bis (o, p-dichlorophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, 2,2′-bis ( o-chlorophenyl) -4,4 ', 5,5'-tetra (m-methoxyphenyl) biimidazole, 2,2'-bis (o-chlorophenyl) -4,4', 5,5'-tetra (P-Carboethoxyphenyl) bi Imidazole (hereinafter, abbreviated as A-2), 2,2'-bis (o-bromophenyl) -4,
4 ', 5,5'-tetra (p-carboethoxyphenyl) biimidazole, 2,2'-bis (o, p-dichlorophenyl) -4,4', 5,5'-tetra (p-carbo) Benzyloxyphenyl) biimidazole, 2,2 '
-Bis (o-chlorophenyl) -4,4 ', 5,5'-
Tetra (p-carbo-n-propyloxyphenyl) biimidazole, 2,2'-bis (o-chlorophenyl)
-4,4 ', 5,5'-Tetra (p-carbophenoxyphenyl) biimidazole, 2,2'-bis (o-chlorophenyl) -4,4', 5,5'-tetra (p-chloro) Phenyl) biimidazole, 2,2'-bis (o-chlorophenyl) -4,4 ', 5,5'-tetra (o, p
-Dichlorophenyl) biimidazole (hereinafter abbreviated as A-3), 2,2'-bis (o-bromophenyl) -4,
4 ', 5,5'-tetra (o, p-dichlorophenyl)
Examples thereof include biimidazole and 2,2'-bis (o-chlorophenyl) -4,4 ', 5,5'-tetra (p-bromophenyl) biimidazole. Among these, a biimidazole compound having a structure represented by the following general formula [II] is preferable.

[0020]

[Chemical 4]

[Wherein Ar ¹ , Ar ² and Ar ³ each represent a phenyl group which may have a substituent,
Ar ¹ has a halogen atom at the ortho position. Among them, in the formula, a phenyl group having a halogen atom at the ortho position is provided as Ar ^{1 at the} 2,2 ′ position,
It is preferable that at least one of the phenyl groups Ar ² and Ar ^{3 at} the 4 ′, 5,5 ′ position has a halogen atom or an alkoxycarbonyl group as a substituent. Examples of the halogen atom include chlorine atom and bromine atom, and the carbon number of the alkyl of the carboalkoxy group is
It is preferably about 1 to 10.

These biimidazole compounds are, for example,
Bull. Chem. Soc. Japan,33, 56
5 (1960) and J. Org. Chem. ,36
[16] to the method disclosed in 2262 (1971).
According to the method, it can be easily synthesized. Next, the light of the present invention
The second component (b) constituting the initiation system will be described. This
Is a specific amino group having a heterocyclic residue at the 3-position.
A marine compound represented by the above general formula [I]
is there.

When R ¹ , R ² and R ⁵ represent a halogen atom, it is generally a chlorine atom, a bromine atom or an iodine atom, and R ¹ , R ² , R ⁵ and R ⁶ are an alkyl group or an alkoxy group. When the group is represented, it is preferably a lower alkyl group or a lower alkoxy group, particularly preferably an alkyl group or an alkoxy group having 1 to 4 carbon atoms, for synthetic reasons.

The alkyl group represented by R ³ and R ⁴ may have a substituent, and the substituent includes a phenyl group, a halogen atom, an alkoxy group, an acyl group, a carboxyl group, a hydroxyl group and the like. Can be mentioned. Also, R
^{When 2} and R ³ and R ⁴ and R ⁵ are linked to each other to form an alkylene group, the alkylene group may be a linear alkylene group or a branched alkylene, and the carbon number thereof is usually 2 to 8, preferably 3 to 6. . Above all, it is preferable that the main chain has 3 carbon atoms from the viewpoint of synthesis.

The heterocyclic residue represented by R ⁷ is an aromatic heterocyclic residue having at least one nitrogen atom, oxygen atom or sulfur atom, such as benzoxazolyl group, benzothiazolyl group and benzimidazolyl group. Groups. Examples of the suitable coumarin compound include the following compounds.

[0026]

Embedded image

[0027]

[Chemical 6]

[0028]

[Chemical 7]

Of these, those having a structure in which a combination of both R ² and R ³ and R ⁴ and R ⁵ in the general formula [I] are linked to each other to form a substituted or unsubstituted alkylene group preferable. These coumarin compounds can be prepared according to known methods such as German Published Patent No. 2,011,500 and US Pat. No. 3,338,784.

Next, the heterocyclic thiol compound as the component (c) optionally used in the photopolymerization initiation system of the present invention will be explained. This thiol compound is useful for improving various characteristics such as sensitivity and storability. The heterocyclic thiol compound in the present invention is a heterocyclic compound having a mercapto group, and specific examples thereof include, for example, 2
-Mercaptobenzothiazole (hereinafter abbreviated as C-1), 2-mercaptobenzoxazole, 2-mercaptobenzimidazole and the like having at least one nitrogen atom, oxygen atom, and sulfur atom, and having a mercapto group-containing carbon number Examples thereof include aromatic heterocyclic compounds.

The amount of each of the components (a), (b) and optionally (c) in the photopolymerization initiation system of the present invention described above is 0.1 to 0.1 for the ethylenic compound. 60% by weight, component (b) 0.1-20% by weight
It is preferable that the content of the component (c) is 50% by weight or less.
Particularly preferable amount of the component (a) is 1 to 40% by weight and (b) is 0.5 to 15% by weight based on the ethylenic compound.
And component (c) is in the range of 40% by weight or less.

In the photopolymerizable composition of the present invention, in addition to the above-mentioned constituents, an organic polymer substance may be further added as a binder for the purpose of modifying the composition and improving the physical properties after photocuring. it can. The binder may be appropriately selected depending on the improvement purpose such as compatibility, film forming property, developability, and adhesiveness. Specifically, for example, to improve the water-based developability, acrylic acid copolymer, methacrylic acid copolymer, itaconic acid copolymer, partially esterified maleic acid copolymer, acidic cellulose modified product having a carboxyl group in the side chain, Examples include polyethylene oxide and polyvinylpyrrolidone. To improve film strength and adhesion, a polyether of epichlorohydrin and bisphenol A; soluble nylon; alkyl polymethacrylate such as polymethylmethacrylate or alkyl polyacrylate; alkyl methacrylate and acrylonitrile, acrylic acid, methacrylic acid , Copolymers with vinyl chloride, vinylidene chloride, styrene, etc .; copolymers with acrylonitrile and vinyl chloride, vinylidene chloride; vinylidene chloride, chlorinated polyolefins, copolymers with vinyl chloride and vinyl acetate; polyvinyl acetate; Acrylonitrile / styrene copolymer; Acrylonitrile / butadiene / styrene copolymer; Polyvinyl alkyl ether; Polyvinyl alkyl ketone; Polystyrene; Polyamide; Polyurethane; Polyethylene terephthalate isophthalate Mention may be made of acetyl cellulose and polyvinyl butyral. These binders can be added and mixed in a weight ratio of generally 500% or less, preferably 200% or less with respect to the ethylenic compound.

The photopolymerizable composition of the present invention may further contain a thermal polymerization inhibitor, a coloring agent, a plasticizer, a surface protective agent, a smoothing agent, if necessary.
Coating aids and other additives can be added. Examples of the thermal polymerization inhibitor include hydroquinone, p-methoxyphenol, pyrogallol, catechol, 2,6-di-
There are t-butyl-p-cresol, β-naphthol, and the like. Examples of the colorant include phthalocyanine pigments, azo pigments, carbon black, pigments such as titanium oxide, ethyl violet, crystal violet, azo dyes, anthraquinone dyes. , There are cyanine dyes. When the binder is used, the thermal polymerization inhibitor and the colorant are added in an amount of 0.01 to 5% of the thermal polymerization inhibitor and 0.1% of the colorant with respect to the total weight of the ethylenic compound and the binder. ~ 4
0% is preferable.

Examples of the plasticizer include dioctyl phthalate, didodecyl phthalate, triethylene glycol dicaprylate, dimethyl glycol phthalate, tricresyl phosphate, dioctyl adipate, dibutyl sebacate, triacetyl glycerin, and the like. When used, 30% or less is generally added to the total weight of the ethylenic compound and the binder.

When using the photopolymerizable composition of the present invention,
The light-sensitive material can be prepared by forming the light-sensitive material without a solvent or dissolving it in a suitable solvent to form a solution, which is coated on a support and dried. Examples of the solvent include methyl ethyl ketone, cyclohexanone, butyl acetate, amyl acetate, methyl lactate, toluene, xylene, monochlorobenzene, carbon tetrachloride, trichloroethylene, trichloroethane, dimethylformamide, methyl cellosolve, ethyl cellosolve, tetrahydrofuran, pentoxone, propylene glycol methyl ether acetate. Etc., and one kind or two or more kinds can be used in combination.

The support applied when preparing a light-sensitive material using the photopolymerizable composition of the present invention may be any of those usually used. For example, a sheet of metal such as aluminum, magnesium, copper, zinc, chromium, nickel, iron or an alloy containing them as a main component; high-quality paper, art paper,
Papers such as release paper; inorganic sheets such as glass and ceramics; polyethylene terephthalate, polyethylene, polymethylmethacrylate, vinyl chloride, vinyl chloride-vinylidene chloride copolymer, polystyrene, 6-nylon, cellulose triacetate, cellulose acetate butyrate, etc. Polymer sheets, etc.

Further, the photopolymerizable composition of the present invention is further provided with a known technique for preventing adverse effects such as sensitivity deterioration and storage stability deterioration due to oxygen, for example, providing a peelable transparent cover sheet on the photosensitive layer. Wax-like substance with low oxygen permeability,
It is also possible to provide a coating layer made of a water-soluble polymer or the like.

The exposure light source applicable to the composition of the present invention is not particularly limited, but carbon arc, high pressure mercury lamp, xenon lamp, metal halide lamp, fluorescent lamp, tungsten lamp, helium cadmium laser, argon ion laser, YAG laser, etc. 400
A general-purpose light source containing visible light of nm or more can be used more suitably.

[0039]

EXAMPLES The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples as long as the gist thereof is not exceeded. Examples 1 to 20, Comparative Examples 1 to 4 Methyl methacrylate / methacrylic acid copolymer (weight average molecular weight 45,000, polymerization ratio 85/15) 1.8 g and trimethylolpropane triacrylate 2.2 g were added to methyl ethyl ketone 36 g. Dissolved in. A predetermined amount of the starting system components (a) and (b) shown in Table 1 and optionally (c) were added and dissolved therein to obtain a sample photosensitive solution. On a grained and anodized aluminum sheet,
Using a whirler, apply a dry film thickness of 2 μm,
Further, a polyvinyl alcohol aqueous solution was applied on the surface so that the dry film thickness was 3 μm to prepare a photosensitive material sample.

<Sensitivity> A xenon lamp; UI-501C manufactured by USHIO INC. Was used as a sample of this light-sensitive material, and a spectral sensitivity measuring device manufactured by Narumi Co., Ltd. was used so that the abscissa axis represents wavelength and the ordinate axis represents logarithmically weak light intensity. For 10 seconds. The exposed sample was developed with an aqueous solution containing 6% by weight of butyl cellosolve and 1% by weight of sodium silicate, and the minimum amount of exposure energy required for photocured image formation was determined from the height of the cured image corresponding to each wavelength obtained. The sensitivity was calculated and used as the sensitivity of the photosensitive composition at each wavelength. The results are shown in Table 1. Here, all the sensitivities are shown as values corresponding to the light of 488 nm. In addition,
In the table,% indicates the weight% added to the total amount of the binder polymer and the acrylate monomer.

[0041]

[Table 1]

Example 20 In the photosensitive layer composition of Example 13, the addition amount of the component C-1 was changed.
A photosensitive material sample was prepared in the same manner as the conditions of the example except that 10% was used.
I made it. The sensitivity measured in the same way is 65 μJ / cm ²So
However, as a result of re-evaluating this sample after storing it at room temperature for 8 months,
No change in sensitivity or other characteristics was observed.

[0043]

The photopolymerizable composition of the present invention has extremely high sensitivity and excellent dissolution stability. Therefore, the composition is useful in a wide range of applications, such as lithographic, intaglio,
It can be used industrially because it can be used for making printing plates such as letterpress, photoresist for making printed wiring and IC, dry film, image formation such as relief image and image duplication, photocurable ink, paint, adhesive, etc. Extremely useful.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location H01L 21/027 H01L 21/30 502R

Claims (5)

[Claims] 1. A photopolymerizable composition comprising a compound having at least one ethylenically unsaturated double bond capable of addition polymerization and a photopolymerization initiation system, wherein the photopolymerization initiation system is (a) a biimidazole compound, (B) The following general formula [I]
At least one coumarin compound represented by: [In the formula, R ¹ , R ² and R ⁵ each represent a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group, and R 1
³ and R ⁴ each represent a substituted or unsubstituted alkyl group, or at least one pair of R ² and R ³ and R ⁴ and R ⁵ may be linked to each other to form a substituted or unsubstituted alkylene group. , R ⁶ is a hydrogen atom, an alkyl group,
It represents an acyl group, a cyano group, a carboxyl group or an ester derivative or amide derivative group thereof, and R ⁷ represents a heterocyclic residue having 3 to 15 carbon atoms. ] The photopolymerizable composition characterized by containing these. 2. The photopolymerizable composition according to claim 1, wherein the photopolymerization initiation system further contains (c) at least one kind of a heterocyclic thiol compound. 3. The photopolymerizable composition according to claim 1, wherein the biimidazole compound is represented by the following general formula [II]. Embedded image [In the formula, Ar ¹ , Ar ² and Ar ³ each represent a phenyl group which may have a substituent, and Ar ¹ has a halogen atom at the ortho position. ] 4. In the general formula [II], Ar ² and A
At least one of r ³ is a phenyl group having a halogen atom or an alkoxycarbonyl group.
The photopolymerizable composition described. 5. The coumarin compound is R ^{2 of the} general formula [I].
The photopolymerizable composition according to any one of claims 1 to 4, wherein R ³ and R ³ and R ⁴ and R ⁵ are linked to each other to form a substituted or unsubstituted alkylene group.