JP3010880B2 - Photopolymerizable composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a photopolymerizable composition. In particular, the present invention relates to a photopolymerizable composition exhibiting extremely high sensitivity to light in the visible region.

[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. Create a light-sensitive material with a layer of photopolymerizable composition applied to the body, image-expose the desired image, polymerize and cure the exposed part, and dissolve and remove the unexposed part to form a cured relief image A method in which a layer of a photopolymerizable composition is provided between two supports in which at least one of the above-mentioned photosensitive materials is transparent, and image exposure is performed from the transparent support side to cause a change in adhesive strength due to light. After that, there is a method of forming an image by peeling the support, an image forming method utilizing a change in toner adhesion of the photopolymerizable composition layer due to light, and the like. Conventionally, benzoyl, benzoin alkyl ether, benzyl ketal, benzophenone, anthraquinone, benzyl, or Michler's ketone has been used as a photopolymerization initiator of the photopolymerizable composition applied to these methods. However, these photopolymerization initiators have a 4
It is significantly lower for light in the visible light range above 00 nm, thus limiting the 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 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, a plate making method using an oscillating beam of visible light of an argon ion laser is considered to be one of the most promising techniques in the future.

Several proposals have been made for a photopolymerizable composition containing a photopolymerization initiation system that can respond to light in the visible light range. For example, a system of hexaarylbiimidazole, a radical generator and a dye (Japanese Patent Publication No. Sho 4
No. 5-37377), a system of hexaarylbiimidazole and (p-dialkylaminobenzylidene) ketone (JP-A-47-2528, JP-A-54-1552).
No. 92), a system of a cyclic cis-α-dicarbonyl compound and a dye (JP-A-48-84183), a system of a substituted triazine and a merocyanine dye (JP-A-54-15102).
No. 4), a system of ketocoumarin and an activator (Japanese Unexamined Patent Publication No.
112681, JP-A-58-15503,
JP-A-60-88005), a system of a substituted triazine and a sensitizer (JP-A-58-29803, JP-A-4030)
No. 2), 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-59-140203, 1).
89340) and the like.

[0005]

However, these prior arts are certainly effective for visible light, but have the drawback of the prior art that the sensitivity is not so high and still insufficient from a practical point of view. Was.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to overcome such difficulties and obtain an excellent photopolymerizable composition. In a photopolymerizable composition, wherein the addition-polymerizable compound has one or more ethylenically unsaturated double bonds, the photopolymerization initiation system has a sensitizer having a specific skeleton and The present inventors have found that by containing at least one activator capable of generating an active radical upon irradiation with light in the presence of the sensitizer, high sensitivity and high practicability are achieved, and the present invention has been achieved.

[0007] In other words, an object of the present invention is to provide a photopolymerizable composition having higher sensitivity to long wavelength light such as visible light. Another object of the present invention is to provide a photopolymerizable composition that enables a higher-speed plate-making operation using a lower-power laser, for example, an air-cooled argon laser, for example, in the case of laser plate making with an argon ion laser. It is in.

[0008] Another object of the present invention is to provide a photopolymerizable composition which enables a plate-making operation which is extremely advantageous in terms of cost and time. Thus, the object of the present invention is to
A photopolymerizable composition comprising at least an addition-polymerizable compound and a photopolymerization initiation system, wherein the addition-polymerizable compound has one or more ethylenically unsaturated double bonds,
And the photopolymerization initiation system comprises: (a) a sensitizer represented by the following general formula [I];

[0009]

Embedded image

[Wherein, R¹~ R⁶Is a hydrogen atom,
Halogen atom, alkyl group, aryl group, arylal
A kill group, an acyl group, an alkoxycarbonyl group,
An unsubstituted hydrocarbon ring group, a substituted or unsubstituted heterocyclic group or
Is -SO_Three-R⁸And R ⁸Is hydrogen atom, alkyl
Group, aryl group, arylalkyl group or alkali gold
Represents a genus atom. R⁷Is hydrogen atom, alkyl group, aryl
X represents an aryl group or an arylalkyl group;¹, X^TwoIs
Halogen, alkyl, aryl, ant
Alkyl group, substituted or unsubstituted hydrocarbon ring group, or
Represents a substituted or unsubstituted heterocyclic group. ]
Achieved easily.

Hereinafter, the present invention will be described in detail. The addition-polymerizable compound having at least one ethylenically unsaturated double bond (hereinafter abbreviated as “ethylenic compound”), which is contained as the first essential component in the photopolymerizable composition of the present invention, refers to light When the polymerizable composition is irradiated with an actinic ray, it is a compound having an ethylenically unsaturated double bond, which is addition-polymerized and cured by the action of a photopolymerization initiation system as a second essential component, 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. In the present invention, the meaning of the monomer is a concept corresponding to a so-called polymer substance, and therefore includes not only monomers in a narrow sense but also dimers, trimers, and oligomers. is there.

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; Esters obtained by an esterification reaction of a saturated carboxylic acid with a polyvalent carboxylic acid and a polyvalent hydroxy compound such as the above-mentioned aliphatic polyhydroxy compound and aromatic polyhydroxy compound are exemplified.

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 includes 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 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 a side chain, for example, 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 of formula (I) 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 photopolymerization composition of the present invention, will be described. The photopolymerization initiation system of the present invention is composed of a combination of two components, and the first component is a compound represented by the aforementioned general formula [I] represented as (a) in the present invention.

These sensitizers include, but are not limited to, for example, US Pat. H. Boger et
al, Hetroatom Chemistry, V
ol. 1, 5, 389 (1990). When each of R ^{1 to} R ⁸ represents an alkyl group, it preferably has 1 to 6 carbon atoms,
Particularly preferably, it may be 3 or may have a straight chain or a side chain. When R ^{1 to} R ⁸ each represent an arylalkyl group, an acyl group, or an alkoxycarbonyl group, the number of carbon atoms on the carbon chain side is particularly preferably 1 to 3, respectively. When each of R ^{1 to} R ⁸ represents a halogen atom, it is generally preferred that it is a bromine atom or a chlorine atom, and when R ⁸ represents an alkali metal atom, it is generally a lithium atom, a sodium atom or a potassium atom. Is preferred. When R ^{1 to} R ⁶ , X ¹ and X ² each represent a hydrocarbon ring group, the hydrocarbon ring is preferably mononuclear or dinuclear, and the substituent is an alkyl group having 1 to 3 carbon atoms. Is particularly preferred. Further, it is generally preferable that the hetero atom contained in the heterocyclic group is a nitrogen atom, an oxygen atom or a sulfur atom.

Hereinafter, typical examples of the sensitizer represented by the general formula [I] will be given. However, the sensitizer represented by the general formula [I] used in the present invention is not limited to these specific examples. Absent. In the following examples, unless otherwise specified, R ¹ , R ³ , R ⁴ and R ⁶ represent a methyl group,
X ¹ and X ² represent a fluorine atom.

Compound examples [I-1] R ² and R ⁵ ; hydrogen atom, R ⁷ ; hydrogen atom [I-2] R ² and R ⁵ ; hydrogen atom, R ⁷ ; methyl group [I-3] R ² And R ⁵ ; hydrogen atom, R ⁷ ; ethyl group [II-1] R ² and R ⁵ ; methyl group, R ⁷ ; hydrogen atom [II-2] R ² and R ⁵ ; methyl group, R ⁷ ; methyl group [II-3] R ² and R ⁵ ; methyl group, R ⁷ ; ethyl group [III-1] R ² and R ⁵ ; ethyl group, R ⁷ ; hydrogen atom [III-2] R ² and R ⁵ ; ethyl Group, R ⁷ ; methyl group [III-3] R ² and R ⁵ ; ethyl group, R ⁷ ; ethyl group [IV-1] R ² and R ⁵ ; ethoxycarbonyl group, R ⁷ ; hydrogen atom [IV-2 ] R ² and R ^5; ethoxycarbonyl group, R ^7; methyl [V-1] R ² and R ^5; a hydrogen atom, R ^7; hydrogen atom, X ¹ and X ² Ethyl [V-2] R ² and R ^5; methyl, R ^7; selected and used at least one kind of the above-described sensitizers are ethyl groups present invention; hydrogen atom, X ¹ and X ² Offer.

The second component constituting the photoinitiating system of the present invention is an activator capable of generating an active radical when irradiated with light in the presence of the above-mentioned sensitizer represented by (b) in the present invention. It is. Any of these activators can be used as long as they have a property of generating an active radical by causing some action with the photoexcited sensitizer. Examples thereof include hexaarylbiimidazole, halogenated hydrocarbon derivatives, organic thiol compounds, diaryliodonium salts, and organic peroxides. Preferred activators include 3,3 ', 4,4'-tetra (t
-Butylperoxycarbonyl) benzophenone (hereinafter, referred to as B-1), organic peroxides such as 1,3-di (t-butyldioxycarbonyl) benzene, benzoyl peroxide, and t-butyl perbenzoate. be able to.

Suitable amounts of the sensitizer and activator constituting the photopolymerization initiation system used in the above-described photopolymerizable composition of the present invention are not particularly limited.
The sensitizer is preferably 0.05 to 20 parts by weight based on 00 parts by weight.
Parts by weight, more preferably 0.2 to 10 parts by weight, the activator is preferably 0.5 to 100 parts by weight, more preferably 1 to 100 parts by weight.
It is suitable to use 50 parts by weight.

In the photopolymerizable composition of the present invention, it is preferable to further add an organic polymer substance as a binder for modifying the present composition and improving physical properties after photocuring, in addition to the above-mentioned respective components. . 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 for improving film strength and adhesion; soluble nylon; polyalkyl methacrylate and polyalkyl acrylate such as polymethyl methacrylate; alkyl methacrylate and acrylonitrile, acrylic acid, methacrylic acid Copolymer of acrylonitrile with vinyl chloride and vinylidene chloride; copolymer of vinylidene chloride, chlorinated polyolefin, copolymer 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 are preferably not more than 500% by weight based on the ethylenic compound, more preferably not more than 200%.
% Can be added and mixed.

The photopolymerizable composition of the present invention may further contain, if necessary, a thermal polymerization inhibitor, a coloring agent, a plasticizer, a surface protective agent, a leveling agent,
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, carbon black, pigments such as titanium oxide, ethyl violet, crystal violet, azo dyes, and anthraquinone dyes. And cyanine dyes. When the binder is used, the amount of the thermal polymerization inhibitor and the coloring agent is 0.01% to 3% and the amount of the coloring agent is 0.1% to 3% based on the total weight of the ethylenic compound and the binder.
1% to 20% is preferred.

Examples of the plasticizer include dioctyl phthalate, didodecyl phthalate, triethylene glycol dicaprylate, dimethyl glycol phthalate, tricresyl phosphate, dioctyl adipate, dibutyl sebacate, and triacetyl glycerin. When is used, 10% or less can be 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 a light-sensitive material without a solvent or dissolving it in a suitable solvent to form a solution, coating the solution on a support and drying. Examples of the solvent include methyl ethyl ketone, cyclohexanone, butyl acetate, amyl acetate, ethyl propionate, toluene, xylene, monochlorobenzene, carbon tetrachloride, trichloroethylene,
There are trichloroethane, dimethylformamide, methyl cellosolve, ethyl cellosolve, tetrahydrofuran, bentoxone and the like, and one kind or two or more kinds can be used in combination.

The support applied when preparing a photosensitive material using the photopolymerizable composition of the present invention may be any of those commonly 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, polymethyl methacrylate, vinyl chloride, vinyl chloride-vinylidene chloride copolymer, polystyrene, 6-nylon, cellulose triacetate, cellulose acetate butyrate, etc. Polymer sheet.

Further, the photopolymerizable composition of the present invention may further be a known technique for preventing adverse effects such as a decrease in sensitivity and a deterioration in storage stability due to oxygen, for example, providing a peelable transparent cover sheet on a photosensitive layer. A low oxygen permeable waxy substance,
A coating layer of a water-soluble polymer or the like may be provided.
The exposure light source which can be applied to the composition of the present invention is not particularly limited. A general-purpose light source including the above can be more preferably used.

[0028]

EXAMPLES Hereinafter, 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 of the present invention.

Examples 1 to 6 and Comparative Examples 1 to 2 A coating solution of a photosensitive composition having the following composition was applied on a grained and anodized aluminum sheet using a wheeler to a dry film thickness of 2 μm. Further, an aqueous solution of polyvinyl alcohol was applied on the surface so that the dry film thickness became 3 μm to prepare a photosensitive material sample.

Next, a xenon lamp (UXL-1000-DO, manufactured by Ushio Electric Co., Ltd.) was used as the photosensitive material sample. Irradiated for 10 seconds. The exposed sample is developed with an aqueous solution containing 2% by weight of butyl cellosolve and 1% by weight of sodium silicate, and the minimum exposure required for photocured image formation is calculated from the height of the obtained cured image. Sensitivity. Table 1 shows the results.

[0031]

[Table 1] [Coating solution of photosensitive composition] Methyl methacrylate / methacrylic acid copolymer: 50 parts (weight average molecular weight: 45,000, copolymerization ratio: 85/15) Trimethylolpropane triacrylate: 50 parts Victoria Pure Blue BOH 0.1 parts Methyl cellosolve 800 parts Tetrahydrofuran 50 parts Sensitizers (described in Table 1) Activators ...

[0032]

[Table 2]

In Table 1, sensitizers [S-1] and [S-2] are respectively

[0034]

Embedded image

[0035]

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Represents

[0037]

The photopolymerizable composition of the present invention has a visible light,
In particular, it is extremely sensitive to long wavelength light. Therefore, the composition is useful for a wide range of application fields, for example, making printing plates such as flat plates, intaglio, letterpress, printed wiring and I.
Photoresist for forming C, dry film, image formation such as relief image and image duplication, photo-curable ink,
Since it can be used for paints, adhesives, etc., it is extremely useful industrially.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G03F 7/027 C08F 2/50 G03F 7/004 G03F 7/028

Claims (2)

(57) [Claims] 1. A photopolymerizable composition comprising at least an addition-polymerizable compound and a photopolymerization initiation system, wherein the addition-polymerizable compound has at least one ethylenically unsaturated double bond. And the photopolymerization initiation system comprises: (a) a sensitizer represented by the following general formula [I]: Wherein R ^{1 to} R ⁶ are each a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an arylalkyl group, an acyl group, an alkoxycarbonyl group, a substituted or unsubstituted hydrocarbon ring group, a substituted or unsubstituted heterocyclic group. Ring group, or -SO
It represents ₃ -R ^8, R ⁸ represents a hydrogen atom, an alkyl group, an aryl group, an arylalkyl group, an alkali metal atom or a quaternary ammonium. R ⁷ represents a hydrogen atom, an alkyl group, an aryl group or an arylalkyl group;
¹ and X ² each represent a halogen atom, an alkyl group, an aryl group, an arylalkyl group, a substituted or unsubstituted hydrocarbon ring group or a substituted or unsubstituted heterocyclic group. (B) A photopolymerizable composition comprising at least one activator capable of generating an active radical upon irradiation with light in the presence of the sensitizer. 2. The photopolymerizable composition according to claim 1, which contains an organic peroxide as an activator.