JPH08146605A - Photopolymerizable composition - Google Patents

Abstract

PURPOSE: To provide the photopolymerizable composition high in sensitivity and superior in lipophilicness and dissolution stability by incorporating a titanocene compound and a specified coumarin compound in a photopolymerization initiation system. CONSTITUTION: The photopolymerizable composition contains the compound having at least one additionally polymerizable ethylenically unsaturated double bond and the photopolymerization initiation system comprising the titanocene compound and at least one kind of coumarin compound represented by the formula in which each of R<1> and R<2> and R<5> is an H or halogen atom or an alkyl or alkoxy group; each of R<3> and R<4> is an alkyl group and at least one of them is 4-16 C an alkyl group; R<6> is an H atom or an alkyl, alkoxy, acyl, cyano, or carboxylic group or its ester derivative group; and R<7> is a 3-17 C heterocyclic group.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD 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 and having excellent dissolution stability and good oil sensitivity.

[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. 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.

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)
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).
151024, JP-A-58-29803, JP-A-5-
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)
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, the sensitivity is not sufficient from a practical point of view, and an improved technique has 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 heterocyclic ring has been proposed, and a certain level of effect is expected (Japanese Patent Laid-Open No. HEI 3). No. 239703, JP-A-5-289335).

[0007]

However, even in the case of the present system, when it is applied to, for example, laser plate making, some problems are solved, namely, higher sensitivity and good dissolution stability and oil sensitivity are required. A system equipped with was also required.

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

[0009]

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

[0010]

Embedded image

[Wherein R ¹ , R ² and R ⁵ each represent a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group, and R ³ and R ⁴ each represent an alkyl group, but at least one of them has 4 carbon atoms. Represents 16 to 16 alkyl groups, R ⁶ represents a hydrogen atom, an alkyl group, an alkoxy group, an acyl group, a cyano group, a carboxyl group or an ester derivative or amide derivative group thereof;
⁷ represents a heterocyclic residue having a total of 3 to 17 carbon atoms. ] It is easily achieved by the photopolymerizable composition characterized by containing.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. 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”) means photopolymerization. When the photosensitive composition is irradiated with actinic rays, it is a compound having an ethylenically unsaturated double bond that undergoes addition polymerization by the action of a photopolymerization initiation system that is a second essential component and is cured, 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 acids, esters of aliphatic polyhydroxy compounds with unsaturated carboxylic acids; esters of aromatic polyhydroxy compounds with unsaturated carboxylic acids; 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 and trimethylolethane triacrylate. Acrylic acid esters of polyhydroxy compounds such as pentaerythritol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, and glycerol acrylate, and these exemplified compounds. Methacrylic acid ester in which acrylate was replaced with methacrylate, similarly replaced with itaconate Itaconic acid esters, maleic acid esters in which instead of the crotonic acid ester or maleate was replaced crotonate.

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.

Among the ethylenic compounds described above, the acrylic acid ester or methacrylic acid ester monomer can be particularly preferably used, and among these, the acrylic acid ester or methacrylic acid ester of the aliphatic polyhydroxy compound is preferable. 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 titanocene compound represented by (a) in the present invention. Although the titanocene compound is not particularly limited, for example, JP-A-59-152396,
It can be appropriately selected and used from various titanocene compounds described in JP-A-61-151197. More specifically, di-cyclopentadienyl-T
i-di-chloride, di-cyclopentadienyl-Ti
-Bis-phenyl, di-cyclopentadienyl-Ti-
Bis-2,3,4,5,6-pentafluorophenyl-1
-Yl, dicyclopentadienyl-Ti-bis-2,
3,5,6-Tetrafluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,4,6-trifluorophen-1-yl, di-cyclopentadienyl-
Ti-bis-2,6-di-fluorophen-1-yl,
Di-cyclopentadienyl-Ti-bis-2,4-di-
Fluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,3,4,5,6-pentafluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2 , 3,5,6-Tetrafluorophen-1-yl, di-methylcyclopentadienyl-Ti
-Bis-2,6-difluorophenyl-1-yl, di-
Examples thereof include cyclopentadienyl-Ti-bis-2,6-difluoro-3- (pyr-1-yl) -phen-1-yl (hereinafter abbreviated as A-1).

Next, the second component (b) of the photopolymerization initiation system of the present invention will be described. This compound is a coumarin compound having a heterocyclic residue at the 3-position and a specific dialkylamino group at the 7-position. As a related technique of this compound, it has been reported that a compound having a lower dialkylamino group at the 7-position is preferable (Japanese Patent Laid-Open No. 3-23).
9703). The same specification discloses that the most preferred of the lower dialkylamino groups is a diethylamino group. However, as a result of various studies, we have found that the above-mentioned diethylamino group derivative has a property of easily crystallizing during storage, whereas the dialkylamino group derivative having an alkyl group having 4 to 16 carbon atoms has the drawback. I found a solution. Further, it was also found that the adoption of the derivative increases the oil sensitivity of the photosensitive layer and imparts an advantageous property to the ink receptivity, which is important in the laser plate making technique.

In the above general formula [I], R ¹ , R ² and R ⁵ each represent a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group, and R ³ and R ⁴ each represent an alkyl group, but at least one of them Has 4 carbon atoms
And R ⁶ represents a hydrogen atom, an alkyl group, an alkoxy group, an acyl group, a cyano group, a carboxyl group or an ester derivative or amide derivative group thereof. R ⁷ represents a heterocyclic residue having a total of 3 to 17 carbon atoms.

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. Each of R ¹ , R ² , R ⁵ and R ⁶ is preferably a hydrogen atom or a lower alkyl group.

2 of R ³ and R ⁴ in the above general formula [I]
At least one of the four alkyl groups is an alkyl group having 4 to 16 carbon atoms, more preferably an alkyl group having 5 to 12 carbon atoms, which may be linear or branched. If the number of carbon atoms of the alkyl group is out of this range and is too small or too large, the solubility may be lowered and precipitation may be more likely to occur in the photosensitive layer. It is more preferable that both R ³ and R ⁴ are alkyl having 4 to 16 carbon atoms. The alkyl group may have a substituent, and examples of the substituent include a phenyl group, a halogen atom, an alkoxy group, an acyl group, a carboxyl group and a hydroxyl group. As R ⁷ , a nitrogen-containing aromatic heterocyclic residue is preferable, and the total number of carbon atoms is 3 to 1.
The fused ring system nitrogen-containing aromatic heterocyclic residue of 1 is preferable. Specific examples thereof include a benzothiazolyl group, a benzoxazolyl group, and a benzimidazolyl group.

Hereinafter, the coumarin compound of the component (b) in the present invention will be specifically exemplified by using the general formula [I].
These are to be understood as examples until now. Unless otherwise specified, the substituents R ¹ , R ² , R ⁵ and R ⁶ all represent a hydrogen atom, and R ⁷ represents a 2-benzothiazolyl group.

[0026]

TABLE 1 ^{B-1: R 3 = R} 4 = n- amyl ^{B-2: R 3 = R} 4 = n- hexyl ^{B-3: R 3 = R} 4 = n- heptyl B-4: R ³ = R ⁴ = n-octyl ^{B-5: R 3 = R} 4 = n- decyl ^{B-6: R 3 = R} 4 = n- dodecyl ^{B-7: R 3 = R} 4 = 2- ethylhexyl B-8: R ³ = n-hexyl, R ⁴ = ethyl ^{B-9: R 3 = R} 4 = 4- hydroxybutyl B-10: R ³ = n- amyl, R ⁴ = 4-methoxybutyl B-11: R ³ = R ⁴ = n-heptyl; R ⁶ = carboethoxy ^{B-12: R 3 = R} 4 = n- octyl; R ⁷ = 2-benzoxazolyl ^{B-13: R 3 = R} 4 = n- hexyl; R ⁷ 2- naphtho (1,2-d) oxazolyl ^{B-14: R 3 = R} 4 = n- hexyl; R ⁷ = 2- naphtho (2,1-d) oxazolyl B-15 R ³ = R ⁴ = n- octyl; R ⁷ = 2-benzimidazolyl

These compounds can be easily prepared according to a conventional method. More preferred substituents in formula [I] are
This is a case where both R ³ and R ⁴ are alkyl groups having 5 to 12 carbon atoms and R ⁷ is a 2-benzothiazolyl group.

Next, the compound of the third component (c) optionally used in the photopolymerization initiation system of the present invention will be described. This brings about an improvement in sensitivity characteristics and the like, and one or two or more kinds are used from the compounds represented by the above general formula [II], [III] or [IV]. In the general formulas [II] to [IV], R ^{8 to} R ¹⁸ each represent an alkyl group, preferably an alkyl group having 1 to 4 carbon atoms, and R ⁸ more specifically has 1 to 20 carbon atoms. Alkyl group, preferably 1 to 10 carbon atoms, more preferably 1 to 4 carbon atoms
The following alkyl groups may be linear or may have a branched structure. The alkyl group of R ⁸ may be further substituted with a substituent such as a halogen atom, an aryl group, an acyl group, a carboxyl group or an alkoxy group.

Specific examples of the compounds represented by the general formulas [II] to [IV] include, for example, p-dimethylaminobenzoic acid ethyl ester, p-diethylaminobenzoic acid ethyl ester and p-dimethylaminobenzoic acid. Dialkylaminobenzoic acid alkyl ester such as isopropyl ester, p-dimethylaminobenzoic acid-n-butyl ester, p-dimethylaminobenzoic acid-n-octyl ester or p-di-n-butylaminobenzoic acid ethyl ester; Bisaminobenzophenone such as 4'-bis (dimethylamino) benzophenone, 4,4'-bis (diethylamino) benzophenone or 4,4'-bis (diisopropylamino) benzophenone; 4,4'-
Examples thereof include bis (dimethylamino) benzyl and bisaminobenzyl such as 4,4′-bis (diethylamino) benzyl. Among these, dialkylaminobenzoic acid alkyl ester is particularly preferable.

The amount of each component (a), (b) and optionally (c) used in the photopolymerization initiation system of the present invention described above is 0.2 to 0.2 for the component (a) with respect to the ethylenic compound. 40% by weight, component (b) 0.1-20% by weight
And the range of 0.1 to 40% by weight of the component (c) is preferable. Particularly preferable amount of the component (a) is 1 to 30% by weight and (b) is 0.5 to 15% by weight based on the ethylenic compound.
And the component (c) is in the range of 1 to 30% by weight.

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. 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 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 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, etc. 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 more preferably used.

[0038]

EXAMPLES The present invention will be described in more detail below with reference to Reference Examples, Examples and Comparative Examples, but the present invention is not limited to these Examples unless it exceeds the gist. Reference Example Preparation of Coumarin Compound B-1 3-aminophenol 6.6 g, n-amyl bromide 19.8 g, calcium carbonate 3.5 g and dimethylformamide 20 g were stirred at 80 ° C. for 12 hours, and then 3-
(N, N-di-n-amylamino) -phenol was obtained. Next, 16 g of dimethylformamide at 10 ° C or lower
After adding 18 g of phosphorus oxychloride to the inside and stirring for 1 hour, the above aminophenol derivative was added dropwise and mixed at 70 ° C. for 1 hour.
Warmed for hours. The reaction mixture was discharged into water to obtain the corresponding salicylaldehyde derivative.

Next, in 50 cc of ethanol, 5.5 g of 2-benzothiazolylacetic acid ethyl ester and 2 piperidine were added.
g and the above aldehyde derivative were mixed and dissolved, and reacted at 80 ° C. for 1 hour to give yellow-orange crystals (melting point: 108).
C.) as 3- (2-benzothiazolyl) -7-
(N, N-di-n-amylamino) -coumarin was obtained.
Next, the methods used in the following examples for evaluating sensitivity, dissolution stability in the photosensitive layer, and contact angle will be described.

<Sensitivity> Using a xenon lamp (UI-501C manufactured by Ushio Denki Co., Ltd.) as a photosensitive material sample, a spectral sensitivity measuring device manufactured by Narumi Co., Ltd. was used so that the horizontal axis represents wavelength and the vertical axis represents logarithmically weak light intensity. Irradiate 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 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. Here, all the sensitivities are shown by energy values corresponding to a light beam of 488 nm.

<Dissolution stability> The photosensitive material sample was kept at room temperature (22
After standing for 2 months at (~ 25 ° C), the state of precipitation of the starting system components is visually observed. If no precipitation is observed at all, it is "good", if some precipitation is observed, it is "poor", overall The case where precipitation was observed was defined as "notably poor".

<Contact Angle> The ink receptivity or oil sensitivity was evaluated by measuring the contact angle with water. That is,
A solid image sample piece was obtained by irradiating the entire surface of the photosensitive material sample with an exposure amount giving 6 solids, developing and drying. This was set in a contact angle meter (CA-D type Kyowa Interface Science Co., Ltd.) to measure the contact angle θ with water. The larger this θ is, the higher the oil sensitivity is.

The coumarin compounds R-1 and R-2 used in the comparative examples represent the following compounds in the general formula [I]. ^{R-1: R 3 = R} 4 = ethyl; R ⁷ = 2-benzothiazolyl ^{group; R 1 = R 2 = R} 5 = R 6 = hydrogen atom. ^{R-2: R 3 = R} 4 = n- octadecyl group; R ^1,
R ² , R ⁵ , R ⁶ , and R ⁷ are all the same as R-1.

Example 1 1.8 g of a methyl methacrylate / methacrylic acid copolymer (weight average molecular weight 45,000, polymerization ratio 85/15) and 2.2 g of trimethylolpropane triacrylate were dissolved in 36 g of methyl ethyl ketone. 80 mg of titanocene compound A-1 and coumarin compound B-
80 mg of 1 was added and dissolved 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. The initial sensitivity of this sample was 90 μJ / cm ² , the same sensitivity was maintained even after 2 months at room temperature, and the dissolution stability was also good. At the same time, the image obtained by imagewise exposure showed no abnormalities and showed good image characteristics.

Comparative Example 1 Evaluation was made in the same manner as in Example 1 except that R-1 was used instead of the coumarin compound B-1. Initial sensitivity is 95 μJ / cm ²
However, after 2 months at room temperature, the dissolution stability became poor and the sensitivity also decreased in a mottled manner, so a poor image was obtained.

Examples 2 to 6 and Comparative Examples 2 and 3 As Example 1 except that the coumarin compound in Example 1 was changed to the compound shown in Table 1 and 400 mg of p-dimethylbenzoic acid ethyl ester was further added and mixed. Similarly, a photosensitive material sample was prepared, and the items shown in Table 1 were evaluated. The results are shown in the table.

[0047]

[Table 2]

Example 7 B having a benzoxazolyl group as a coumarin compound
Evaluation was performed in the same manner as in Example 2 except that -12 was used.
The initial sensitivity was 55 μJ / cm ² . The same sensitivity was maintained even after 2 months at room temperature, and precipitation of the starting system components was not observed.

Example 8 B having a benzimidazolyl group as a coumarin compound
Evaluation was performed in the same manner as in Example 2 except that -15 was used.
The initial sensitivity was 89 μm / cm ² . The same sensitivity was maintained even after 2 months at room temperature, and precipitation of the starting system components was not observed.

Examples 9 to 13 and Comparative Examples 4 and 5 The coumarin compound was added in an amount of 2 × 10 ^-4 mol.
Evaluation was performed in the same manner as in Examples 2 to 6 and Comparative Examples 2 and 3. The results are shown in Table-2.

[0051]

[Table 3]

Example 14 B having a benzoxazolyl group as a coumarin compound
Evaluation was performed in the same manner as in Example 9 except that -12 was used.
The initial sensitivity was 55 μJ / cm ² . The same sensitivity was maintained even after 2 months at room temperature, and precipitation of the starting system components was not observed.

Example 15 B having a benzimidazolyl group as a coumarin compound
Evaluation was performed in the same manner as in Example 9 except that -15 was used.
The initial sensitivity was 89 μm / cm ² . The same sensitivity was maintained even after 2 months at room temperature, and precipitation of the starting system components was not observed.

[0054]

The photopolymerizable composition of the present invention has extremely high sensitivity, and is excellent in oil sensitivity and dissolution stability. Therefore, the composition is useful in a wide range of application fields, for example, making printing plates such as planographic, intaglio, letterpress, printed wiring and IC.
It is very useful industrially because it can be used for photoresists, dry films, image formation such as relief images and image reproduction, photocurable inks, paints, adhesives and the like.

Claims (2)

[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 titanocene compound, b) at least one coumarin compound represented by the following general formula [I]: [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 an alkyl group, at least one of which represents an alkyl group having 4 to 16 carbon atoms, and R
⁶ is a hydrogen atom, an alkyl group, an alkoxy group, an acyl group,
It represents a cyano group, a carboxyl group or a group of an ester derivative or an amide derivative thereof; R ⁷ represents a heterocyclic residue having 3 to 17 carbon atoms in total. ] The photopolymerizable composition characterized by containing these. 2. The photopolymerization initiation system further comprises (c) at least one compound represented by the following general formula [II], [III] or [IV]: [In the formula, R ^{8 to} R ¹⁸ each represent an alkyl group. ]
The photopolymerizable composition according to claim 1, further comprising: