JPH11160872A - Photopolymerizable composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the photopolymerizable composition high in sensitivity to light in the wavelength region of >600 nm by incorporating a specified dye and a radical generator in a photopolymerization initiation system. SOLUTION: The photopolymerizable composition comprises an additionally polymerizable ethylenically unsaturated compound and the photopolymerization initiation system and thus system contains the radical generator and the dye represented by the formula in which each of R1 and R2 is, independently, an optionally substituted alkyl group; each of R3 -R6 is, independently, an H atom of an optionally substituted alkyl group; each of R7 and R8 is, independently, an H atom or optionally substituted alkyl or cycloalkyl group or 6-15 C aromatic hydrocarbon group or the like; each of (m) and (n) is 0 or 1; each of Z1 and Z2 is, independently, a heterocyclic group; and X is a counter anion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a photopolymerizable composition. In particular, the present invention relates to a photopolymerizable composition exhibiting high sensitivity to light in a long wavelength region. The composition of the present invention is used for various photosensitive materials.

[0002]

2. Description of the Related Art Conventionally, many image forming methods using a photopolymerization system are known. For example, a photopolymerizable composition comprising an addition-polymerizable compound containing an ethylenic double bond, a photopolymerization initiator, and an organic polymer binder (binder resin) used as desired is prepared, and the photopolymerization is performed. A photosensitive material provided with a layer of a photopolymerizable composition by applying a hydrophilic composition on a support, and polymerizing and curing the exposed portion by image exposure of a desired image,
A method of forming a cured relief image by dissolving and removing an unexposed portion, a method of forming an image by peeling a support after causing a change in adhesive strength by light,
In addition, there is an image forming method utilizing a change in toner adhesion due to light of the photopolymerizable composition layer. As the photopolymerization initiator of the photopolymerizable composition applied to these methods, conventionally,
Benzoin, benzoin alkyl ether, benzyl ketal, benzophenone, anthraquinone, benzyl,
Alternatively, Michler's ketone and the like have been used, but these photopolymerization initiators have a function of responding to short-wavelength light mainly in the ultraviolet region of 400 nm or less.

In recent years, with the development of image forming technology, there has been a strong demand for photopolymers having high sensitivity to light rays in the visible region. For example, a laser plate making method using an 488 nm oscillation beam of an argon ion laser is considered to be one of the promising techniques, and in response to this, there are many photopolymerization initiation systems whose sensitivity range has been extended to about 500 nm. Proposed. Furthermore, recently, research on a photopolymerization initiation system corresponding to a long-wavelength light exceeding 600 nm has been activated. One of those applied technologies is laser plate making using a He-Ne laser or a semiconductor laser, and the other is a full-color image duplication technology using a photopolymerization system.

[0004] As for the latter, a long time ago was the Japanese Patent Publication No. 46-41.
346. The specification states that blue,
A three-layered dispersion of a droplet-shaped photopolymerizable composition containing each photopolymerization initiator corresponding to green and red light and a color coupler in a gelatin film is applied to form a photosensitive layer. Then, a technique is disclosed in which, when a color image beam is irradiated and processed with a color developing solution, an uncured portion is colored to obtain a full-color image. Further, an application technique in which this idea is combined with a pressure-sensitive coloring technique using microcapsules has been proposed. For example, the description is found in JP-A-62-143044. According to the specification, a photopolymerizable composition containing a photopolymerization initiator and each leuco dye sensitive to each of the three color light rays is filled in microcapsules and applied on a sheet, and this is exposed to a color image light ray. After that, the capsule in the uncured portion is pressed, broken, and transferred onto a color-developing sheet, and the yellow, magenta, and cyan colors are developed to obtain a full-color image.

The biggest problem in the above-described laser plate making using a long-wavelength laser or a full-color image duplication technique using a panchromatic color light-sensitive material is a long-wavelength laser, particularly about 600 nm.
This is an improvement in the sensitivity of the light-sensitive material to light in a region exceeding m.
Usually, the photopolymerization initiation system has an active radical generation capacity of 500 n.
It is well known that the sensitivity rapidly decreases for light having a wavelength of m or more, particularly, a wavelength exceeding 600 nm.
It is believed that this is basically due to the fact that active radicals are unlikely to be generated due to a decrease or disappearance of the molecule's cleavage ability with a decrease in photoexcitation energy. Heretofore, some photopolymerization initiators corresponding to such long-wavelength light have been proposed, but they are not sufficiently sensitive.

For example, some of the present inventors have previously reported that a photoinitiating system comprising a combination of a specific cyanine dye and a triazine derivative exhibits high sensitivity, particularly in the visible region of 400 to 500 nm. (JP-A-58-298
03 specification).

[0007]

However, in particular, 6
Obtaining good sensitivity in the region exceeding 00 nm and further in the near infrared region has been considered difficult from the viewpoint of the photoexcitation energy. The present invention has been made in view of such circumstances, and has as its object to provide a photopolymerizable composition that exhibits high sensitivity to light in a long wavelength region exceeding 600 nm.

[0008]

Means for Solving the Problems The inventors of the present invention have made intensive studies to overcome such difficulties, and have found that a system in which a cyanine dye having certain characteristics and a radical generator are combined has the above-mentioned characteristics. The present inventors have found that this can be a very effective photoinitiating system in the wavelength region, and have reached the present invention. That is, the gist of the present invention is to provide a photopolymerizable composition comprising an addition-polymerizable ethylenically unsaturated compound and a photopolymerization initiation system, wherein the photopolymerization initiation system is represented by the following general formula (I): ).

[0009]

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(Wherein, R ₁ and R ₂ each independently represent an alkyl group which may have a substituent;
₃ , R ₄ , R ₅ and R ₆ each independently represent a hydrogen atom or an alkyl group which may have a substituent. Also,

[0011]

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May be independently linked via a divalent linking group to form a cyclic structure. Y represents an oxygen atom or a sulfur atom; R ₇ and R ₈ each independently represent a hydrogen atom, an alkyl group or a cycloalkyl group which may have a substituent, an aromatic carbon atom having 6 to 15 carbon atoms; It represents a hydrogen group or an aromatic heterocyclic group having 4 to 15 carbon atoms which may have a substituent. m and n each represent 0 or 1,
Z ₁ and Z ₂ each independently represent a heterocyclic residue. X
^- represents a counter anion. ) And (b) a radical polymerizing agent.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION In the photopolymerizable composition of the present invention, an addition-polymerizable compound having at least one ethylenically unsaturated double bond contained as a first essential component (hereinafter referred to as "ethylenic compound") The abbreviation) means that when the photopolymerizable composition is irradiated with actinic rays, it undergoes addition polymerization by the action of the photopolymerization initiation system, which is the second essential component, to form an ethylenically unsaturated double bond that cures. A compound having
For example, the above-mentioned monomer having a double bond or a polymer having an ethylenically unsaturated double bond in a side chain or a main chain. Incidentally, the meaning of the monomer in the present invention is a concept relative to a so-called polymer substance, and therefore,
It includes dimers, trimers and oligomers in addition to monomers in a narrow sense.

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

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 between the unsaturated carboxylic acid and the polyhydric carboxylic acid and the polyhydric hydroxy compound is not necessarily a single substance, but typical examples include acrylic acid, phthalic acid and ethylene glycol. Condensates, 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, and the like.

Other examples of the ethylenic compound used in the present invention include acrylamides such as ethylenebisacrylamide; allyl esters such as diallyl phthalate;
A vinyl group-containing compound such as divinyl phthalate is useful. The polymer having an ethylenically unsaturated bond in the main chain is, for example, a polyester obtained by a polycondensation reaction between an unsaturated divalent carboxylic acid and a dihydroxy compound,
There is a polyamide obtained by a polycondensation reaction between an unsaturated divalent carboxylic acid and a diamine. The polymer having an ethylenically unsaturated bond in the side chain is a condensation polymer of a divalent carboxylic acid having an unsaturated bond in the side chain such as itaconic acid, propylidene succinic acid, ethylidene malonic acid and a dihydroxy compound or a diamine compound. is there. Polymers having a reactive group such as a hydroxy group or a methyl halide group on the side chain, such as polyvinyl alcohol, poly (2-hydroxyethyl methacrylate), polyepichlorohydrin, etc., and acrylic acid, methacrylic acid, crotonic acid, etc. A polymer obtained by a polymer reaction with an unsaturated carboxylic acid can also be suitably used.

Of the ethylenic compounds described above, acrylate or methacrylate 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 (a) is a dye represented by the above general formula [I], preferably in a polar organic solvent, For example, the maximum absorption wavelength in methanol is 58
It has absorption at a wavelength longer than 0 nm. The dye of the general formula (I) is a cationic cyanine dye in which two nitrogen-containing heterocycles are linked by a polymethine chain.

Each of the nitrogen-containing heterocycles including Z ₁ and Z ₂ may be the same or different. Specifically, for example, thiazole, benzothiazole, naphthothiazole, thiazoline, quinoline, pyrroline, tetrazole, indole, Derivatives such as pyridine, oxazole, benzoxazole, naphthoxazole, imidazole, benzimidazole, benzoselenazole or naphthoselenazole.

When R _{1 to} R ₈ represent an alkyl group, it is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms. Iodine atom, bromine atom, chlorine atom, acyl group, aryl group, alkoxy group, hydroxy group, cyano group, more preferably alkyl group having 1 to 5 carbon atoms, alkoxy group having 1 to 5 carbon atoms, 6 to 6 carbon atoms 15 aryl groups. Preferred aromatic hydrocarbon ring groups for R ₈ and R ₇ are a phenyl group and a naphthyl group, and preferred cycloalkyl groups include a cyclohexyl group.

[0021]

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When forming a cyclic structure, the following groups are preferably formed.

[0023]

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[0024] The pair of the general formula (I) anion X ^-
Examples thereof include halogen anions such as Cl ⁻ , Br ⁻ and I ⁻ , inorganic anions such as ClO ₄ ⁻ , BF ₄ ⁻ and PF ₆ ⁻ , or CH ₃ SO ₄ ⁻ and CH ₃ CO _3.
O ^-,

[0025]

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Organic anions such as the above can be mentioned, and all of them can be suitably used. The cyanine dye used in the present invention can be prepared according to a conventional method.
en Bach, Chem. Ber. , 89,136
3, (1956).
Next, specific examples of the cyanine dye represented by the general formula [I] are illustrated, but the present invention is not limited to these specific examples.

[0027]

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[0028]

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[0029]

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[0030]

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[0031]

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[0032]

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The component (b) constituting the photopolymerization initiation system of the present invention is a radical generator which generates an active radical when irradiated with light in the presence of the above-mentioned sensitizer. Examples of the radical generator include halogenated hydrocarbon derivatives, diaryliodonium salts, organic peroxides, various titanocene compounds as described in JP-A-59-152396, JP-A-61-151197, Various hexaarylbiimidazole compounds described in JP-B-6-29285, JP-A-62-1430
44, etc. can be used.

The radical generator (b) is preferably an s-triazine derivative having at least one mono-, di-, or trihalogen-substituted methyl group bonded to an s-triazine ring. These are described, for example, in Wakabayashi et al., Bull. Che
m. Soc. Japan, 42 , 2924, (196)
9), U.S. Pat. No. 3,987,037; C.
Schaefer et al, J. Mol. Org. Che
m. , 29 , 1527, (1964).

Hereinafter, these compounds will be specifically exemplified. The symbols in brackets [] are the abbreviations of the compounds used in the examples described below. For example, 2,4,6-tris (trichloromethyl) -s-triazine [tt-1], 2-methyl-4,6-bis (trichloromethyl) -s-triazine, 2-phenyl-4,6-bis (Trichloromethyl)
-S-triazine, 2- (p-chlorophenyl) -4,
6-bis (trichloromethyl) -s-triazine, 2-
Phenylthio-4,6-bis (trichloromethyl) -s
-Triazine, 2-benzylthio-4,6-bis (trichloromethyl) -s-triazine, 2- (p-tolyl)
-4,6-bis (trichloromethyl) -s-triazine, 2- (p-methoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine, 2-n-propyl-4,6-bis ( Trichloromethyl) -s-triazine, 2- (α, α, β-trichloroethyl) -4,6-
Bis (trichloromethyl) -s-triazine, 2-styryl-4,6-bis (trichloromethyl) -s-triazine, 2,4,6-tris (dichloromethyl) -s-triazine, 2,4,6-tris (Monochloromethyl)-
s-triazine, 2- (p-methoxystyryl) -4,
6-bis (trichloromethyl) -s-triazine [tt
-2], 2,4,6-tris (tribromomethyl) -s
-Triazine, 2-methyl-4,6-bis (tribromomethyl) -s-triazine, 2,4,6-tris (dibromomethyl) -s-triazine, 2-methoxy-4,6
-Bis (tribromomethyl) -s-triazine, 2-
(4-methoxynaphthyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (3,4-epoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine, 2- {1 -(P-methoxyphenyl) -2,
4-butadienyl} -4,6-bis (trichloromethyl) -s-triazine (tt-3) and the like.

Of these, particularly preferred are, for example,
2,4,6-tris (trichloromethyl) -s-triazine, 2-phenyl-4,6-bis (trichloromethyl) -s-triazine, 2-methyl-4,6-bis (trichloromethyl) -s- Triazine, 2- (p-methoxyphenyl) -4,6-bis (trichloromethyl) -s
-Triazine, 2- (p-methoxystyryl) -4,6
-Bis (trichloromethyl) -s-triazine, 2-
(3,4-epoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine, 2- {1- (p-methoxyphenyl) -2,4-butadienyl} -4,6-bis (trichloromethyl And s-triazines containing two or more trichloro or tribromomethyl groups such as -s-triazine. These s-triazines are
According to the above references, the corresponding nitrile compound can be reacted with aluminum bromide in the presence of hydrogen chloride or can be synthesized via the corresponding imidate.

The photopolymerization initiation system of the present invention comprises the aforementioned (a)
(B) A remarkable effect can be exerted for the first time by a combination of the two components, but the use ratio is (a) :( b) by weight,
It is preferably in the range 1:20 to 10: 1, particularly preferably in the range 1: 8 to 4: 1. Further, the photopolymerization initiation system contained in the photopolymerizable composition of the present invention is preferably in a weight ratio to the ethylenic compound, more preferably 0.1%.
It is between 1% and 30%, particularly preferably between 0.5% and 20%.

The photopolymerizable composition of the present invention may further contain other substances in addition to the above-mentioned components, depending on the purpose of use. For example, when a film-forming ability or a viscosity adjusting ability is required, an organic polymer substance may be added as a binder. Specific examples thereof include, for example, (meth) acrylic acid, their esterified products, maleic acid,
Examples thereof include homo- or copolymers such as acrylonitrile, styrene, vinyl acetate, and vinylidene chloride; and polyethylene oxide, polyvinylpyrrolidone, polyamide, polyurethane, polyethylene terephthalate isophthalate, acetylcellulose, and polyvinyl butyral. These binders can be added and mixed in a weight ratio of not more than 500%, preferably not more than 200% with respect to the ethylenic compound.

In addition, thermal polymerization inhibitors such as hydroquinone, p-methoxyphenol, 2,6-di-tert-butyl-p-cresol; coloring agents comprising organic or inorganic dyes and pigments; dioctyl phthalate, didodecyl phthalate,
Additives such as plasticizers such as tricresyl phosphate, dioctyl adipate, and triethylene glycol dicabrylate, and other additives such as sensitizers such as tertiary amines and thiols can also be added.

When the composition of the present invention is applied to a color image reproduction technique, a dye precursor such as JP-B-46-41 is used.
No. 346, color developing materials used in conventional color photographic films and dye leuco bodies well known in the technical field of pressure sensitive dyes can be added. As the dye leuco, for example, triarylmethane, bisarylmethane, xanthene compound,
Examples include fluoran and thiazine compounds and compounds having a lactone, lactam, sultone, or spiropyran structure as a partial skeleton thereof.

The preferred amounts of the various additives described above are 2% or less of a thermal polymerization inhibitor, 10% or less of a colorant, 40% or less of a plasticizer, and 40% or less of a dye precursor in terms of a weight ratio to the solid content of the photopolymerizable composition. % Or less. The form of the photosensitive material produced by using the present composition can be appropriately selected according to the purpose of use. For example, a form in which a non-solvent or diluted with an appropriate solvent is applied to a sheet, for example, a polymer sheet, paper, or a metal sheet, dried and, if necessary, an overcoat layer for oxygen shielding is further provided in an upper layer, Various selections are possible, such as a form in which a plurality of types of photosensitive materials dispersed in small droplets in a medium are coated in multiple layers, and a form in which the composition is encapsulated in microcapsules and coated on a sheet.

The exposure light source applicable to the composition of the present invention is not particularly limited. Examples thereof include a carbon arc, a high-pressure mercury lamp, a xenon lamp, a metal halide lamp, a fluorescent lamp, a tungsten lamp, a helium neon laser, a semiconductor laser and the like. Light sources containing visible light can be used particularly preferably.

[0043]

The present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to these examples unless it exceeds the gist.

EXAMPLES 1-5, COMPARATIVE EXAMPLES 1-2 On a grained and anodized aluminum sheet, a photosensitive composition coating solution having the following composition was applied to a dry film thickness of 2 μm by using a whirler. And apply at 80 ° C for 2
Dried for minutes. Next, a polyvinyl alcohol aqueous solution is applied to the surface so that the dry film thickness is 3 μm,
After drying at 80 ° C. for 2 minutes, an overcoat layer was formed to prepare a sample.

[Composition of photosensitive composition coating solution]

[0046]

TABLE 1 Methyl methacrylate / methacrylic acid copolymer 50 parts by weight (weight average molecular weight 450,000, copolymerization molar ratio 90:10) Trimethylolpropane triacrylate 50 parts by weight Sensitizing dye (described in Table 1) Compound) 2 parts by weight Radical generator (compound shown in Table 1) 10 parts by weight Coating solvent cyclohexanone 600 parts by weight N-methylpyrrolidone 300 parts by weight

This sample was fixed on an aluminum rotating drum having a diameter of 7 cm so that the photosensitive layer was on the outside, and then 83
A beam of a semiconductor laser (manufactured by Applied Techno Co., Ltd.) of 0 nm and 30 mW was subjected to scanning exposure at various drum rotation speeds using a beam spot condensed to 20 μm. Soda, 0.5% by weight of Perex NBL (anionic surfactant, manufactured by Kao Corporation)
To form a scanning line image. The sensitivity of the sample was evaluated based on the maximum number of rotations of the image forming drum on which a line image was formed. The higher the rotation number of the image forming drum, the higher the sensitivity. The results are shown in Table 1.

[0048]

[Table 2] * 1: Shown by the above-mentioned exemplified dye numbers. * 2: A dye having the following structure was used.

[0049]

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* 3: Corresponds to the aforementioned symbol. * 4: Indicates that no image was formed.

[0051]

According to the present invention, by using a photopolymerization initiation system in which a cyanine dye having a specific structure is selected from triazine derivatives and combined with a radical generator, for example, the long wavelength of 830 nm used in the examples can be obtained. It is possible to form an image with good sensitivity to the above light rays.

Claims (3)

[Claims] 1. A photopolymerization composition comprising an addition-polymerizable ethylenically unsaturated compound and a photopolymerization initiation system, wherein the photopolymerization initiation system contains the following (a) and (b): (A) A dye represented by the following general formula (I). Embedded image (Wherein, R ₁ and R ₂ each independently represent an alkyl group which may have a substituent, and R ₃ , R ₄ , R
₅ and R ₆ each independently represent a hydrogen atom or an alkyl group which may have a substituent. Also, May be independently bonded via a divalent bonding group to form a cyclic structure. Y represents an oxygen atom or a sulfur atom; R ₇ and R ₈ each independently represent a hydrogen atom, an alkyl group or a cycloalkyl group which may have a substituent, an aromatic carbon atom having 6 to 15 carbon atoms; It represents a hydrogen group or an aromatic heterocyclic group having 4 to 15 carbon atoms which may have a substituent. m and n each represent 0 or 1, and Z ₁ and Z ₂
Each independently represents a heterocyclic residue. X ^- is a counter anion. ). (B) a radical generator. 2. The photopolymerizable composition according to claim 1, wherein the radical generator contains an s-triazine compound having at least one halomethyl group. 3. The photopolymerization according to claim 1, wherein the s-triazine compound having at least one halomethyl group is a compound having two or more trichloromethyl groups or tribromomethyl groups. Composition.