JPH095996A - Photopolymerizable composition - Google Patents

Abstract

(57) Summary: A photopolymerizable composition containing a compound having at least one ethylenically unsaturated double bond capable of addition polymerization, a titanocene compound as a photopolymerization initiation system, and a sensitizer, and It is characterized by containing a heterocyclic thiol compound. [Effect] The photopolymerizable composition of the present invention has extremely high sensitivity and excellent stability.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a photopolymerizable composition. The present invention relates to a photopolymerizable composition having particularly high sensitivity and excellent stability.

[0002]

2. Description of the Related Art Conventionally, many image forming methods using 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 initiators are not always sufficient in terms of sensitivity, and the sensitive wavelength range has been limited to the short wavelength range.

On the other hand, in recent years, with the development of image forming technology, there has been a strong demand for a photopolymer having a high sensitivity to light rays in the visible region. It is a photosensitive material suitable for, for example, non-contact type projection exposure plate making or laser plate making using a visible light laser. 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.

[0004] Several proposals have heretofore been made for a photopolymerization composition containing a photopolymerization initiation system capable of responding to light in the visible light region. For example, a system of hexaarylbiimidazole and (p-dialkylaminobenzylidene) ketone (JP-A-47-2528, JP-A-54-155)
No. 292, JP-A-56-166154), a system of ketocoumarin and an activator (JP-A-52-112681,
JP-A-58-15503 and JP-A-60-88005), and a system of a substituted triazine and a sensitizer (JP-A-54-15803).
No. 15,1024, JP-A-58-29803, JP-A-58-29803
Nos. 8-40302), a system of biimidazole, a styrene derivative, and a thiol (JP-A-59-56403), and a system of an organic peroxide and a dye (JP-A-59-1402).
03, JP-A-59-189340) and others,
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). Although these are certainly effective to some extent, even higher sensitivity is required, and improved techniques for stability have been desired.

In addition to this, as a visible sensitizing system using a titanocene compound, for example, a combination system with a coumarin compound having a specific structure having a heterocycle has been proposed, and a certain level of effect is expected (Japanese Patent Application Laid-Open No. HEI 3). No. 239703, JP-A-5-289335). However, even in the case of this system, for example, when it is applied to laser plate making, it has been demanded to cope with some difficulties, that is, a system having higher sensitivity and good dissolution stability.

[0006]

The present invention meets these needs, that is, the first object of the present invention is to provide a photopolymerizable composition having excellent stability, and the second object thereof.
The purpose of is to provide the composition having sufficient sensitivity in a wide wavelength range, and yet another object is to provide the composition having properties suitable for laser plate making and the like. The authors have found that the above-mentioned object is achieved by the following specific composition.

That is, the gist of the present invention is to provide a compound having at least one ethylenically unsaturated double bond capable of addition polymerization, a titanocene compound as a photopolymerization initiation system, and a sensitizer capable of sensitizing the titanocene compound. In the photopolymerizable composition containing, the said composition further contains a heterocyclic thiol compound, The photopolymerizable composition characterized by the above-mentioned. 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 include ethylene glycol diacrylate, triethylene glycol diacrylate, trimethylolpropane triacrylate, and trimethylolethane triacrylate. Acrylates such as pentaerythritol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, glycerol acrylate, and the acrylates of these exemplified compounds as methacrylates Methacrylic acid ester replaced with 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 the aromatic polyhydroxy compound and the 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 representative specific examples include acrylic acid, phthalic acid and Examples 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.

Among the above-mentioned ethylenic compounds, acrylic acid ester or methacrylic acid ester monomers can be particularly preferably used. Next, the photopolymerization initiation system which is the second essential component of the photopolymerizable 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 titanocene compound (component (a)). The titanocene compound is not particularly limited, but can be appropriately selected and used from various titanocene compounds described in, for example, JP-A-59-152396 and JP-A-61-151197. More specifically, di-cyclopentadienyl-Ti-di-chloride, di-cyclopentadienyl-Ti-bis-phenyl, di-cyclopentadienyl-Ti-bis-
2,3,4,5,6-pentafluorophen-1-yl, dicyclopentadienyl-Ti-bis-2,3
5,6-tetrafluorophenyl-1-yl, di-cyclopentadienyl-Ti-bis-2,4,6-trifluorophenyl-1-yl, di-cyclopentadienyl-Ti
-Bis-2,6-di-fluorophenyl-1-yl, di-
Cyclopentadienyl-Ti-bis-2,4-di-fluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,3,4,5,6-pentafluorophen-1- Il, di-methylcyclopentadienyl-
Ti-bis-2,3,5,6-tetrafluorophenyl
1-yl, di-methylcyclopentadienyl-Ti-bis-2,6-difluorophenyl-1-yl, di-cyclopentadienyl-Ti-bis-2,6-difluoro-
3- (pyr-1-yl) -phen-1-yl (hereinafter abbreviated as titanocene compound A-1) and the like can be mentioned.

As the second component constituting the photopolymerization initiation system of the present invention, any sensitizer (component (b)) having a sensitizing effect on the titanocene compound can be used. Examples of suitable sensitizers include, for example, JP-A-63 / 1988.
-221110, JP-A-3-239703, and other aminocoumarins, JP-A-6-29506
1, tetrahydroquinoline derivatives, the pyrromethene compounds described in Japanese Patent Application No. 5-83587, and JP-A-4-26154 and 4-2.
Examples thereof include xanthene-based dyes as described in each publication of 19756. Further, a part of a more specific example is described in Japanese Patent Application No. 6-12 filed by the present inventors earlier.
No. 949 is also disclosed. More specific examples of the sensitizer include compounds represented by the following formula.

[0018]

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(In the formula, R ¹ represents a C _{1 to} C ₄ alkyl group, and R ² and R ³ represent the same or different C _{1 to} C ₁₀ alkyl groups.)

[0020]

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(In the formula, R ⁵ and R ⁶ represent the same or different C _{1 to} C ₁₀ alkyl groups)

[0022]

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(In the formula, R ⁶ represents a C ₁ -C ₄ alkyl group)

[0024]

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(In the formula, R ⁷ represents a C ₁ -C ₁₀ alkyl group) In the present invention, a sensitizer containing a coumarin ring is particularly effective. The present invention relates to a compound having at least one ethylenically unsaturated double bond capable of addition polymerization and a photopolymerization initiation system comprising components (a) and (b), and then a heterocyclic thiol having a different role from these. It is characterized by containing a compound (component (c)).

The heterocyclic thiol compound is a compound having a structure in which a mercapto group is substituted on the heterocyclic compound. Examples of preferable heterocyclic thiol compounds include 2-mercaptobenzothiazole (hereinafter, heterocyclic thiol compound). (Abbreviated as C-1), 2-mercaptobenzoxazole and 2-mercaptobenzimidazole. By containing the heterocyclic thiol compound, the composition of the present invention has good stability of the photopolymerization system, particularly sensitivity stability and antifogging effect. As described above, the components (a) and (b) used in the photopolymerizable composition of the present invention
The suitable amount of the additive (c) used is 0.1 to 30% by weight of the component (a), 0.1 to 20% by weight of the component (b), and 100% by weight of the ethylenic compound. (C) is in the range of 0.1 to 40% by weight.

The composition of the present invention may further contain p-dialkylaminobenzoic acid ester (component (d)). This ester is effective in improving sensitivity. Specifically, for example, p-dimethylaminobenzoic acid ethyl ester (hereinafter abbreviated as benzoic acid ester D-1), p-diethylaminobenzoic acid ethyl ester, p
-Dimethylaminobenzoic acid isopropyl ester, p-
Dimethylaminobenzoic acid-n-butyl ester, p-dimethylaminobenzoic acid-n-octyl ester or p
C such as ethyl di-n-butylaminobenzoate
₁ -C ₁₀ p-dialkylamino benzoic acid esters substituted with alkyl. The alkyl group preferably has 1 to 6 carbon atoms, and the two alkyls may be the same or different, but are preferably the same. The alkyl group constituting the ester has about 1 to 12 carbon atoms, preferably 1 to 10 carbon atoms. The preferred amount of the ester used is 60% by weight or less based on 100% by weight of the ethylenic compound.

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 in order to modify the composition and improve the physical properties after photocuring. it can. The binder may be appropriately selected according to the purpose of improving compatibility, film forming property, developability, adhesiveness and the like. Specifically, for example, for improving aqueous developability, acrylic acid copolymer, methacrylic acid copolymer, itaconic acid copolymer, partially esterified maleic acid copolymer, modified acidic cellulose having a carboxyl group in a side chain, Examples include polyethylene oxide and polyvinylpyrrolidone. Polyether of epichlorohydrin and bisphenol A to improve film strength and adhesion; soluble nylon; polyalkyl methacrylate and polyalkyl acrylate such as polymethyl methacrylate; alkyl methacrylate and acrylonitrile, acrylic acid, methacrylic acid Copolymers of acrylonitrile with vinyl chloride, vinylidene chloride; vinylidene chloride, chlorinated polyolefin, copolymers of vinyl chloride and vinyl acetate; polyvinyl acetate; Copolymer of acrylonitrile and styrene; copolymer of acrylonitrile and butadiene, styrene; 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 colorant, 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, and 2,6-di-
There are t-butyl-p-cresol, β-naphthol, and the like. Examples of the coloring agent include phthalocyanine pigments, azo pigments, pigments such as carbon black and titanium oxide, ethyl violet, crystal violet, azo dyes, and anthraquinone dyes. And 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, sheets of metals such as aluminum, magnesium, copper, zinc, chromium, nickel, iron or alloys containing these as main components; fine 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,
A coating layer of a water-soluble polymer or the like may be provided.

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 more preferably used.

[0035]

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. In addition,
Abbreviations used as the sensitizer of the component (b) are as follows.

[0036]

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Example 1 1.8 g of a methyl methacrylate / methacrylic acid copolymer (weight average molecular weight 45,000, polymerization ratio 85/15) and trimethylolpropane triacrylate 2.2 g were dissolved in 36 g of methyl ethyl ketone. To this, 80 mg of the titanocene compound A-1, 80 mg of the sensitizer B-2 and 200 mg of the heterocyclic thiol C-1 were added and dissolved to obtain a sample photosensitive solution. On a grained and anodized aluminum sheet, using a whiler, dry film thickness 2μ
Then, 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.

As a photosensitive material sample, a xenon lamp; UI-501C manufactured by USHIO INC. Was used, and a spectral sensitivity measuring device manufactured by Narumi Co., Ltd. was used for 10 seconds so that the horizontal axis represents wavelength and the vertical axis logarithmically decreases the light intensity. Irradiated. 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 required for photocured image formation was calculated from the height of the cured image corresponding to each wavelength obtained. Then, the sensitivity of each wavelength of the photosensitive composition was used. The initial sensitivity of this sample for light of 488 nm is 110 μJ /
cm ² . When another stability test was carried out by leaving another same sample piece in an oven at 55 ° C. for 100 hours, the sensitivity did not change and no fog was observed.

Comparative Example 1 A sample prepared in the same manner as in Example 1 except that the heterocyclic thiol C-1 in the photosensitive solution was excluded was evaluated by the same method. As a result, the initial sensitivity was 150 μJ / cm ² , and partial fog occurred as a result of the stability acceleration test.

Example 2 In place of the sensitizer B-2 in Example 1, B-3 was added in an amount of 80 m.
After adding g, a photosensitive solution was prepared and evaluated by the same method. The initial sensitivity was 150 μJ / cm ² , and as a result of the stability acceleration test, the sensitivity was slightly lowered to 220 μJ / cm ² , but fog did not occur.

Comparative Example 2 A sample prepared in the same manner as in Example 2 except that the heterocyclic thiol C-1 was excluded was evaluated in the same manner. The initial sensitivity was 280 μJ / cm ² , and as a result of the stability acceleration test, the sensitivity was greatly reduced to 1500 μJ / cm ² and fogging occurred.

Example 3 In Example 1, benzoic acid ester D- was further added to the photosensitive solution.
400 mg of No. 1 was added to prepare a photosensitive solution, and the same method as described below was evaluated. The initial sensitivity was 60 μJ / cm ² , and as a result of the stability acceleration test, there was no change in sensitivity and no fog occurred.

Comparative Example 3 A sample prepared in the same manner as in Example 3 except that the heterocyclic thiol C-1 was omitted was evaluated by the same method. The initial sensitivity was 68 μJ / cm ² , and as a result of the stability acceleration test, the sensitivity was slightly lowered to 95 μJ / cm ² and fog was observed.

Example 4 In place of the sensitizer B-2 in Example 3, B-1 of 80 m was used.
g to prepare a photosensitive solution. For the sensitivity measurement, a value corresponding to a light ray having a wavelength of 400 nm that B-1 can absorb was determined. The initial sensitivity was 120 μJ / cm ² , and as a result of the stability acceleration test, the sensitivity did not change and no fog was observed.

Comparative Example 4 A sample prepared in the same manner as in Example 4 except that the heterocyclic thiol C-1 was excluded was evaluated by the same method. The initial sensitivity was 190 μJ / cm ² , and as a result of the stability acceleration test, the sensitivity was greatly reduced to 690 μJ / cm ² and fog was observed.

Example 5 B-3 was replaced by 80 m in place of the sensitizer B-2 in Example 3.
Evaluation was made in the same manner except that g was used. Initial sensitivity is 110
μJ / cm ² and the sensitivity of the stability acceleration test is 16
Fog was not observed although it was slightly lowered to 0 μJ / cm ² .

Comparative Example 5 A sample prepared in the same manner as in Example 5 except that the heterocyclic thiol C-1 was excluded was evaluated in the same manner. The initial sensitivity was 190 μJ / cm ² , and as a result of the stability acceleration test, the sensitivity was greatly reduced to 910 μJ / cm ^2, and fog was also observed.

Example 6 B-4 was replaced by 80 m in place of the sensitizer B-2 in Example 3.
Evaluation was made in the same manner except that g was used. Initial sensitivity is 100
It is μJ / cm ² and the sensitivity of the stability acceleration test is 11
It was 0 μJ / cm ² and no fog was observed.

Comparative Example 6 A sample prepared in the same manner as in Example 6 except that the heterocyclic thiol C-1 was excluded was evaluated in the same manner. Initial sensitivity is 1
Results Sensitivity of is accelerated stability testing at 30μJ / cm ² was reduced by a large margin to 480μJ / cm ^2.

The photopolymerizable composition of the present invention has excellent stability and high sensitivity. Therefore, the composition is useful in a wide range of application fields, for example, printing plates such as planographic printing, intaglio printing, letterpress printing, photoresists for printed wiring and IC, dry film, images such as relief images and image duplication. It is industrially very useful because it can be used for forming, photocurable ink, paint, adhesive and the like.

──────────────────────────────────────────────────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 (2)

[Claims] 1. A photopolymerizable composition comprising a compound having at least one ethylenically unsaturated double bond capable of addition polymerization, a titanocene compound as a photopolymerization initiation system, and a sensitizer capable of sensitizing the titanocene compound. 2. The photopolymerizable composition according to the item 1, further comprising a heterocyclic thiol compound. 2. The photopolymerizable composition according to claim 1, further comprising a p-dialkylaminobenzoic acid ester.