JPH05323592A - Manufacture of lithographic printing plate - Google Patents

Abstract

PURPOSE:To provide a manufacturing method for a high-resolution lithographic printing plate not requiring solution development which is highly sensitive to near infrared rays and is excellent in printability and visibility, and also in which the miniaturization of equipment and the cost reduction of material is provided. CONSTITUTION:As the process for manufacturing a lithographic printing plate out of a photosensitive material in which a photosensitive layer containing a borate complex consisting of at least a polymerizable compound and a cationic dye having near-infrared-ray absorbing power is provided on a base material, a lithographic printing plate manufacturing method comprises a process in which rays including near infrared rays are applied in a picture shape, and a process in which the unexposed parts of the photosensitive layer are transferred on another base material by means of heating and/or pressurization. If necessary, a process in which the picture images after the transfer formation are polymerized and hardened by exposure and/or heating is included.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for preparing a lithographic printing plate using a photosensitive material, and more specifically, it is capable of writing with light in the near infrared region and forms a high resolution lithographic printing plate by a complete dry process. On how to do.

[0002]

2. Description of the Related Art Conventionally, a large number of photosensitive lithographic printing plate materials using a photopolymerization system and methods for preparing lithographic printing plates using the same have been known. For example, a photosensitive composition comprising a compound capable of addition polymerization or crosslinking, a photopolymerization initiator, and optionally a binder component such as an organic polymer compound is coated on a hydrophilic support to form a photosensitive lithographic printing plate material. , A desired image is imagewise exposed to the photosensitive composition layer (photosensitive layer) to cure the exposed portion, and the unexposed portion is dissolved and removed to form an oleophilic image portion to obtain a lithographic printing plate. A commonly used liquid development type method; JP-A Nos. 52-9501 and 52-1501.
No. 04, No. 53-40537, No. 53-53404, etc., the above-mentioned photosensitive layer is formed between two transparent supports, at least one of which is transparent. A desired image is imagewise exposed, and a change in the adhesive force of the photosensitive composition to the support caused by the exposure is utilized to form a lipophilic image part on the hydrophilic support by peeling development to form a lithographic printing plate. A photopolymerizable composition as disclosed in JP-A-62-125358, which is provided in a microcapsule on a substrate to form a photosensitive layer on the substrate, and the photosensitive composition in the microcapsule is imagewisely formed. After exposure and curing, the photosensitive layer surface is superposed on the printing plate substrate and pressed to destroy the unexposed microcapsules and at the same time transfer the photosensitive composition in the microcapsules onto the printing plate substrate. And a method for forming a lithographic printing plate.

In particular, the latter two methods are preferable methods in terms of environmental pollution, worker safety, and downsizing of the apparatus, since no liquid developer is used.

However, although the peeling development is a dry development, it essentially utilizes the difference in the adhesive force (adhesive force) between the exposed and unexposed portions of the photosensitive layer for the printing plate support and the peeling base material. Since it is for forming an image, it is difficult to completely remove the unexposed portion, and high resolution cannot be obtained, which is not suitable for the field of high-grade printing.

Further, in the method of encapsulating the photosensitive composition in the microcapsules, it is necessary to reduce the particle size of the microcapsules in order to obtain high resolution, but if the particle size of the microcapsules is reduced, the microcapsules are added. Since a very large force is required for pressure crushing, a large-scale device is required, which is not preferable.

Conventionally, as the photopolymerization initiator for the photosensitive composition used in these lithographic printing plate forming methods, aromatic ketones such as benzophenone, thioxanthone, quinone and thioacridone, benzoin, benzyl, benzyl ketal and the like are used. It is used.

Since these photopolymerization initiators have a photosensitive wavelength in the ultraviolet region, a lithographic printing plate is prepared using a photosensitive lithographic printing plate material having a photosensitive composition containing these photopolymerization initiators. The general method to do is to adhere a mask material having a negative pattern of a desired image formed with a light-shielding material (for example, a silver salt film) on the surface of the photosensitive composition or the transparent oversheet provided thereon, After exposure with an ultraviolet light source such as a mercury lamp, dissolution development or peeling development is performed.

With the recent advances in image processing, light sources, and image forming techniques, there has been a demand for a photosensitive material having sensitivity to light having a longer wavelength than before. One example is a system in which a light source is modulated by an image signal transmitted through a communication line and an output signal from an electronic plate making system or an image processing system, and a photosensitive material is directly scanned and exposed to form a printing plate. A laser is suitable as a light source at this time. In particular, there has been a demand for the development of a photosensitive lithographic printing plate material which is small in size and low in cost and capable of directly forming a high resolution lithographic printing plate by scanning exposure with a semiconductor laser.

Regarding the photosensitive composition containing a photopolymerization initiator having sensitivity in the visible light region, several techniques have been proposed in the past. For example, JP-A-47-2528 and 54-15
No. 5292, No. 48-84183, No. 54-151024, No. 58-40302
No. 59-56403, No. 59-189340, No. 60-88005, JP-A-2-69, No. 2-189548 and the like.

Although these have visible light sensitivity, they cannot be said to have sufficient practical sensitivity yet, and a long exposure time is required to directly form a printing plate by laser scanning exposure, which is not efficient. Also, the laser light source that can be used is limited to those that have an oscillation wavelength in the visible light range such as He-Ne gas laser and Ar gas laser, and it is not possible to use the semiconductor laser which is currently the smallest and cheapest laser light source. ,
I needed a large device.

Further, in the lithographic printing plate, the visibility property of exposure is an important property. When performing so-called "multi-sided printing" in which a plurality of exposures are performed while changing the position on one printing plate, it is possible to distinguish the exposed portion from the unexposed portion, which shortens the working time,
It is extremely important from the viewpoint of reducing exposure errors. Conventionally, in order to impart an exposure visible image property, a compound called an exposure visible image agent that selectively develops a color in an exposed portion has been added to a light-sensitive material. However, the conventional visible image agent is to match the absorption wavelength of the visible image agent and the photosensitive material, and it is an essential requirement that it does not adversely affect the plate making performance, therefore it is necessary to use a very expensive material, This caused an increase in the cost of the printing plate.

[0012]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to enable recording with high sensitivity and high resolution for near infrared light, printability and visible image quality. Excellent in size, downsizing of the device and cost reduction of materials,
The purpose is to provide a method for preparing a lithographic printing plate that does not require liquid development.

[0013]

SUMMARY OF THE INVENTION As a result of intensive efforts by the inventors to achieve the above object, a photosensitive material containing a borate complex of a cationic dye having a specific near-infrared absorbing ability as a photopolymerization initiator on a substrate. After imagewise exposure of the photosensitive material provided with the braided layer, the unexposed portion of the photosensitive composition layer is transferred onto another substrate under heating and / or pressure to obtain a near-infrared region. The inventors have found that a lithographic printing plate having extremely high photosensitivity to light and having a high resolution can be obtained by a complete dry process, and completed the present invention. That is, the object of the present invention was achieved by the following configurations. (1) A lithographic printing plate is prepared from a photosensitive material in which a photosensitive layer containing at least a compound capable of addition polymerization or crosslinking and a borate complex of a cationic dye having a near-infrared absorbing ability is provided on a sheet-shaped substrate. As a step, a step of irradiating imagewise light including near-infrared light, a photosensitive layer surface irradiated with the imagewise light is superposed on a support having a hydrophilic surface, and heated and / or pressurized to be exposed. A step of transferring only the unexposed portion of the layer onto the support, a step of peeling the sheet-like substrate together with the exposed portion of the photosensitive layer, and an image formed of the unexposed photosensitive layer formed on the support. A method for producing a lithographic printing plate comprising a step of polymerizing and curing by exposing and / or heating.

(2) A photosensitive material comprising a support having a hydrophilic surface and a photosensitive layer containing at least an addition-polymerizable or crosslinkable compound and a borate complex of a cationic dye having near-infrared absorbing ability. A step of irradiating an image-wise light including near-infrared light, the photosensitive layer surface irradiated with the image-wise light,
A step of transferring the unexposed portion of the photosensitive layer onto the surface of the substrate by heating and / or applying pressure on another substrate surface, and peeling and supporting the substrate together with the unexposed portion of the photosensitive layer. A method for producing a lithographic printing plate, which comprises a step of forming an image consisting of an exposed portion of the photosensitive layer on a body.

(3) The photosensitive layer contains at least one organic boron salt as one of its constituent components.
The method for preparing a lithographic printing plate as described in (1) or (2).

(4) The method of preparing a lithographic printing plate as described in (1) or (2), wherein imagewise exposure is performed by scanning exposure with a laser having an oscillation wavelength in the near infrared region.

The present invention will be described in detail below.

The first constitution of the present invention comprises a photosensitive composition comprising at least a compound capable of addition polymerization or crosslinking and a borate complex of a cationic dye capable of absorbing near infrared rays on a sheet-shaped substrate. A method for producing a lithographic printing plate comprising a photosensitive material provided with a photosensitive layer and a support having a hydrophilic surface.

The sheet-shaped substrate used in the present invention is required to have sufficient mechanical strength and high dimensional stability, and to have further heat resistance when heating is required. is necessary. Specifically, polyesters such as polyethylene terephthalate, polyethylene naphthalate, and aramid resin; celluloses such as cellulose triacetate and cellulose diacetate; polyvinyl chloride, polyethylene, polypropylene, polystyrene, polyvinyl alcohol, cellophane, polysulfone, polyimide, and others.
In addition to plastic films such as polycarbonate, polyamide, polyethylene ether ketone, polyarylate, and ABS, thin paper such as condenser paper and glassine paper, various coated papers, synthetic papers, metals, metal foils, various ceramics films, etc., alone or It can be used as a composite of two or more kinds. Furthermore, it is optional to add a filler, a stabilizer, an additive and the like to these base materials, if necessary.

The substrate having a thickness of 1 to 500 μm can be used, and preferably 5 to 200 μm.

An antistatic layer, a heat resistant layer, a slipping layer and the like may be provided on the surface of the substrate opposite to the surface on which the photosensitive layer is provided in order to improve transportability and heat resistance.

The photosensitive composition of the photosensitive layer of the present invention comprises the first
A compound capable of addition polymerization or crosslinking is included as an essential constituent component of.

The compound capable of addition polymerization or crosslinking includes
Known compounds can be used without particular limitation,
A compound having at least one ethylenically unsaturated double bond in the molecule is preferably used. Specific compounds include 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate,
Glycerol acrylate, tetrahydrofurfuryl acrylate, phenoxyethyl acrylate, nonylphenoxyethyl acrylate, tetrahydrofurfuryloxyethyl acrylate, tetrahydrofurfuryloxyhexanolide acrylate, acrylate of ε-caprolactone adduct of 1,3-dioxane alcohol, 1, 3-
Monofunctional acrylic acid esters such as dioxolane acrylate; or methacrylic acid, itaconic acid, crotonic acid, maleic acid ester obtained by replacing these acrylates with methacrylate, itaconate, crotonate, maleate; ethylene glycol diacrylate, triethylene glycol diacrylate , Pentaerythritol diacrylate, hydroquinone diacrylate, resorcin diacrylate, hexanediol diacrylate, neopentyl glycol diacrylate, tripropylene glycol diacrylate, hydroxypivalate neopentyl glycol diacrylate, neopentyl glycol adipate diacrylate, hydroxy Diacrylation of ε-caprolactone adduct of neopentyl glycol pivalate -, 2- (2-hydroxy 1,1-dimethylethyl) -5-hydroxymethyl-5-ethyl-1,3-dioxane diacrylate, tricyclodecane dimethylol acrylate, ε-of tricyclodecane dimethylol acrylate Bifunctional acrylic acid esters such as caprolactone adduct, diacrylate of diglycidyl ether of 1,6-hexanediol; or methacrylic acid, itaconic acid, crotonic acid, in which these acrylates are replaced by methacrylate, itaconate, crotonate, maleate, Maleic acid ester; trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, trimethylolethane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol tet Acrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate,
Ε-caprolactone adduct of dipentaerythritol hexaacrylate, pyrogallol triacrylate, propionic acid / dipentaerythritol triacrylate, propionic acid / dipentaerythritol tetraacrylate, polyfunctional acrylic acid such as hydroxypivalylaldehyde modified dimethylolpropane triacrylate Esters; or methacrylic acid obtained by replacing these acrylates with methacrylate, itaconate, crotonate, maleate, itaconic acid, crotonic acid, maleic acid ester and the like can be mentioned. Of these, acrylic acid ester and methacrylic acid ester compounds can be particularly preferably used. These compounds can be used alone or in combination of two or more.

In addition, as a compound capable of addition polymerization or crosslinking, a so-called prepolymer obtained by introducing acrylic acid or methacrylic acid into an oligomer having an appropriate molecular weight to impart photopolymerization property can be preferably used. These prepolymers may be used alone or in admixture of two or more, or may be used in admixture with the above-mentioned monomers. As the prepolymer, for example, adipic acid, trimellitic acid, maleic acid, phthalic acid, terephthalic acid, hymic acid, malonic acid, succinic acid, glutaric acid, itaconic acid, pyromellitic acid, fumaric acid, glutaric acid, pimelic acid,
Polybasic acids such as sebacic acid, dodecanoic acid, tetrahydrophthalic acid, ethylene glycol, propylene glycol, diethylene glycol, propylene oxide, 1,
4-butanediol, triethylene glycol, tetraethylene glycol, polyethylene glycol, glycerin, trimethylolpropane, pentaerythritol,
Polyester acrylates obtained by introducing (meth) acrylic acid into a polyester obtained by binding a polyhydric alcohol such as sorbitol, 1,6-hexanediol, 1,2,6-hexanetriol; bisphenol A, epichlorohydrin, (meth) acrylic Acid, epoxy acrylates such as phenol novolac, epichlorohydrin, and (meth) acrylic acid that have (meth) acrylic acid introduced into epoxy resin; ethylene glycol, adipic acid, tolylene diisocyanate, 2-hydroxyethyl acrylate, polyethylene glycol, Tolylene diisocyanate 2-hydroxyethyl acrylate, hydroxyethyl phthalyl methacrylate xylene diisocyanate, 1,2-polybutadiene glycol tolylene diisocyanate
Urethane acrylates such as 2-hydroxyethyl acrylate, trimethylolpropane, propylene glycol, tolylene diisocyanate, and 2-hydroxyethyl acrylate, in which (meth) acrylic acid is introduced into urethane resin; polysiloxane acrylate, polysiloxane
Silicone resin acrylates such as diisocyanate and 2-hydroxyethyl acrylate; alkyd-modified acrylates obtained by introducing a (meth) acryloyl group into an oil-modified alkyd resin, and spirane resin acrylates.

The second essential constituent component of the photosensitive composition of the photosensitive layer of the present invention is a borate complex of a cationic dye having a near-infrared absorbing ability, which is contained as a photopolymerization initiator.

The borate anion of the dye salt formed from the cation type dye part and the borate anion (hereinafter referred to as the dye of the present invention) is preferably the one represented by the following general formula (1).

[0027]

[Chemical 1]

In the formula, R ₁ , R ₂ , R ₃ and R ₄ may be the same or different and each is an alkyl group (eg ethyl, butyl), an aryl group (eg phenyl, naphthyl), an aralkyl group (eg benzyl, Phenethyl), alkenyl groups (eg vinyl, allyl), alkynyl groups (eg propenyl), cycloalkyl groups (eg cyclopentyl, cyclohexyl), heterocyclic groups (eg thienyl,
Pyridyl), and each group may further have a substituent.
Particularly preferably, at least one of R _{1 to} R ₄ is an aryl group and at least one is an alkyl group.

The aryl group is preferably a phenyl or naphthyl group, and may be substituted with an alkyl group or an alkoxy group. The alkyl group is preferably an alkyl group having 1 to 12 carbon atoms, and examples thereof include methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl and decyl groups. These alkyl groups may be substituted with a halogen atom, an alkoxy group, a hydroxyl group, a cyano group, a phenyl group or the like. As the cationic dye portion, cationic cyanine, merocyanine, carbocyanine, rhodamine, azomethine, indoaniline, azurenium, polymethine, triarylmethane, indoline, thiazine, xanthine, acridine and oxazine dyes having absorption in the near infrared region are available. Can be mentioned.

In order to write an image by scanning exposure using a semiconductor laser as a light source, a cation type infrared dye is preferable, and a cyanine type dye, an azurenium type dye and an indoaniline type dye are particularly preferable. In particular, when a cyanine dye is used in this borate complex of a cationic dye having a near-infrared absorbing ability, it has the property of fading when exposed to light in the absorption wavelength range (photobleaching), and photopolymerization. It is particularly preferable because it has both functions of an initiator and a visible light exposure agent.

Examples of these pigments include coloring materials, 61
[4] Although described on pages 215 to 226, typical examples will be given below.

[0032]

[Chemical 2]

[0033]

[Chemical 3]

[0034]

[Chemical 4]

[0035]

[Chemical 5]

In the present invention, it is preferable to add a salt compound of borate anion as a sensitizer. Preferred salt compounds include quaternary ammonium cations or 4
It is a salt composed of a primary phosphonium cation and a borate anion represented by the general formula (1).

The ammonium cation and phosphonium cation are preferably tetraalkylammonium [(R) ₄ N ⁺ ] and tetraalkylphosphonium [(R) ₄ P ⁺ ], respectively, and the alkyl group (R) has a carbon atom number of 1 to
There are 12 alkyl groups (eg, methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl, decyl, dodecyl, etc.). These alkyl groups may be substituted with a halogen atom, an alkoxy group, a hydroxyl group, a cyano group, a phenyl group or the like.

The amount of the above-mentioned essential components constituting the photosensitive composition is not particularly limited, but preferably, a cationic dye having a near infrared absorbing ability is added to 100 parts by weight of a compound capable of addition polymerization or crosslinking. The borate complex is 0.01 to 20 parts by weight, more preferably 0.05 to 10 parts by weight, and the sensitizer is 0 to 50 parts by weight, more preferably 0 to 20 parts by weight.

The photosensitive composition used in the present invention is for the purpose of, in addition to the above-mentioned constituents, a polymerization initiator other than the above photopolymerization initiator, modification of the photosensitive composition and improvement of physical properties after curing. As the above, a binder component can be contained.

The polymerization initiator is capable of exposing the formed image of the unexposed area and the image of the exposed area containing unreacted monomer to light and / or light.
Alternatively, it is for curing by applying heat, and a known photopolymerization initiator or thermal polymerization initiator can be used. As the photopolymerization initiator, one or a combination of two or more compounds described in “Photopolymer Handbook”, edited by Photopolymer Society, published by Kogyo Kogyokai (1989), pages 39 to 48 is preferably used. it can.

Examples of the thermal polymerization initiator include organic peroxides such as cumene hydroperoxide, t-butyl hydroperoxide, dicumyl peroxide, di-t-butyl peroxide, benzoyl peroxide, acetyl peroxide and lauroyl peroxide. For example, azo compounds such as azobisisobutyronitrile; hydrogen peroxide and a divalent iron salt, persulfate and sodium hydrogen sulfate, cumene hydroperoxide and a divalent iron salt,
In addition to redox-based polymerization initiators such as benzoyl peroxide and dimethylaniline, disulfide compounds and organometallic complexes such as manganese triacetylacetonate and pentacyanobenzyl cobaltate can be used.

The blending amount of these polymerization initiators is not particularly limited, but it is preferable that the compound 100 capable of addition polymerization or crosslinking is used.
The amount is 0 to 20 parts by weight, and more preferably 0 to 10 parts by weight.

The binder component is preferably an organic polymer compound, which can be appropriately selected according to the purposes such as compatibility with other components, tackiness, adhesiveness, film forming property, developability, printability, and improvement. Good. Specific compounds include, for example, polymethacrylic acid, polymethylmethacrylate, polyacrylic acid, polyacrylic acid alkyl ester (alkyl group is methyl, ethyl, butyl, etc.), acrylic acid alkyl ester (alkyl group is methyl, (Ethyl, butyl, etc.) with acrylonitrile, vinyl chloride, vinylidene chloride, styrene, butadiene, acrylic acid, methacrylic acid, etc .; polyvinyl chloride, vinyl chloride, polyvinylidene chloride, vinylidene chloride, styrene, styrene-butadiene And acrylonitrile copolymers; polyacrylonitrile, polyvinyl alcohol, polyvinyl alkyl ether (where alkyl is methyl, ethyl, propyl, butyl, etc.), polyvinyl alkyl ketone, polystyrene, polybutadiene, poly Plane, polyamide, polyurethane, polyethylene terephthalate, polyethylene isophthalate; chlorinated polyolefin such as chlorinated polyethylene, chlorinated polypropylene; chlorinated rubber, cyclized rubber, ethyl cellulose, acetyl cellulose, polyvinyl butyral, polyvinyl formal; various other itacone Acid copolymers,
Examples thereof include maleic acid copolymers, partially esterified maleic acid copolymers, and the like, and these compounds may be used alone or in combination of two or more. Further, a multi-component copolymer containing the above compound as a main component in an amount of 30 mol% or more can also be preferably used.

These binder components may be added and mixed in an amount of 500 parts by weight or less, more preferably 200 parts by weight or less, based on 100 parts by weight of the compound capable of addition polymerization or crosslinking.

In the photosensitive composition of the present invention, if necessary, a thermal polymerization inhibitor, a colorant, a plasticizer, a resin, a surface protective agent, a smoothing agent, a coating aid, an autoxidizer, an oxygen barrier layer. Various additives such as a forming agent can be contained.

As the thermal polymerization inhibitor, compounds such as quinone type and phenol type can be used. Examples thereof include hydroquinone, pyrogallol, p-methoxyphenol, catechol, β-naphthol, 2,6-di-t-butyl-p-cresol and the like. The thermal polymerization inhibitor is 1 per 100 parts by weight of the total amount of the compound capable of addition polymerization or crosslinking and the binder.
It is added in an amount of 0 parts by weight or less, preferably about 0.001 to 5 parts by weight.

As the colorant, carbon black, titanium oxide, iron oxide, phthalocyanine pigment, azo pigment,
Examples thereof include pigments such as anthraquinone pigments, crystal violet, methylene blue, azo dyes, anthraquinone dyes, cyanine dyes and the like. It is preferable to use the coloring agent in an addition amount range that does not absorb the light having the absorption wavelength of the photopolymerization initiator or inhibits the polymerization.

Since the photopolymerization initiator of the present invention is infrared-sensitive, it is one of the major features of the present invention that it is hardly affected by the colorant having absorption in the visible region. The colorant is a total amount of addition-polymerizable or crosslinkable compound and binder of 100.
40 parts by weight or less, preferably 0.01 to 20 parts by weight, is added to the parts by weight.

Examples of the plasticizer include phthalic acid esters such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diheptyl phthalate, dioctyl phthalate, diisobutyl phthalate, dicyclohexyl phthalate, ditridecyl phthalate, isononyl phthalate, dibutyl benzyl phthalate and diaryl phthalate. Kinds; Glycol esters such as dimethyl glycol phthalate, methyl phthalyl ethyl glycolate, methyl phthalyl ethyl glucolate, etc .; Phosphate esters such as tricresyl phosphate, triphenyl phosphate, tributyl phosphate, tri-2-ethylhexyl phosphate; butyl Aliphatic monobasic acid esters such as oleate and glycerin monooleate; dibutyl adipate, diisobutyl adipate Chromatography, dioctyl adipate,
Aliphatic dibasic acid esters such as dioctyl azelate, dibutyl sebacate, dimethyl sebacate, dioctyl sebacate, dibutyl maleate; dihydric alcohol esters such as diethylene glycol dibenzoate and triethylene glycol di-2-ethylbutyrate Kind; Other,
Triethyl citrate, glycerin triacetyl ester, butyl laurate and the like can be used. The plasticizer is preferably used in an amount of 20 parts by weight or less based on 100 parts by weight of the total amount of the compound capable of addition polymerization or crosslinking and the binder.

Examples of the autoxidizer include phosphines, phosphonates, phosphites, stannous salt compounds, sulfides, disulfides, thiols, thioketones and the like, as well as compounds which are easily oxidized by oxygen, for example, N, N-
N, N-dialkylanilines such as dimethyl-2,6-diisopropylaniline and N, N, 2,4,6-pentamethylaniline, and N-
Examples thereof include phenylglycine. The autoxidizer is a total amount of addition-polymerizable or crosslinkable compound and binder of 10
It is preferably used in an amount of 0.1 to 20 parts by weight based on 0 parts by weight.

As the material for forming the oxygen barrier layer, higher fatty acids such as stearic acid, behenic acid and behenic acid amide, or higher fatty acid derivatives can be added to the photosensitive layer and oriented on the surface for use.

The oxygen barrier layer forming material is 0.1 per 100 parts by weight of the total amount of the addition-polymerizable or crosslinkable compound and the binder.
It is preferable to use it in an addition amount in the range of 20 parts by weight.

The thickness of the photosensitive composition layer is usually 0.1 to 100 μm.
And preferably in the range of 0.5 to 20 μm.

The photosensitive composition of the present invention is coated and formed on a sheet-shaped substrate without using a solvent, or is dissolved in an appropriate solvent and applied on a sheet-shaped substrate and dried to form a photosensitive composition. The organic composition layer can be formed.

As the solvent of the coating liquid, for example, acetone,
Ketones such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, diisobutyl ketone; esters such as ethyl acetate, butyl acetate, amyl acetate, ethyl propionate, dimethyl phthalate, ethyl benzoate; such as toluene, xylene, benzene, ethylbenzene, etc. Aromatic hydrocarbons such as carbon tetrachloride, trichloroethylene, chloroform, 1,1,1-trichloroethane,
Halogenated hydrocarbons such as monochlorobenzene, chloronaphthalene and dichloroethane; ethers such as tetrahydrofuran, diethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoethyl ether acetate; and others, dimethylformamide, dimethylsulfoxide, Bentoxon etc. can be used.

In addition to the above-mentioned constitution, the photosensitive lithographic printing plate material of the present invention may be provided with other layers, if necessary, within a range not departing from the object of the present invention. For example, it is optional to provide a layer for controlling the adhesive force between the support and the photosensitive composition layer, a gas barrier layer or a peelable cover sheet on the photosensitive layer.

As the support having a hydrophilic surface (hereinafter, simply referred to as support) used in the present invention, all known materials for lithographic printing plates are preferably used. In particular,
Metals such as aluminum, zinc, chromium, copper, magnesium, nickel and iron and alloy plates and sheets mainly containing them, inorganic plates and sheets such as paper, glass and ceramics, and polyethylene terephthalate whose surface is mattized to make it hydrophilic. Such a plastic plate or sheet, a plate or sheet in which a metal layer such as aluminum, zinc, or chromium is laminated on the plastic plate or sheet, a hydrophilic polymer compound layer provided on an arbitrary support, and the like. As examples of hydrophilic polymer compounds, cellulose derivatives, polyvinyl alcohol, polyvinylpyrrolidone, polyacrylamide, polyethylene glycol, gelatin, gum arabic and the like are preferably used. For printing plate materials, an aluminum plate that has been grained in the above support is particularly preferably used. As the graining method, any known method such as glass bead graining, sandblast graining, electrolytic graining, brush graining and ball graining can be preferably used. When the support material is aluminum, a grained surface further subjected to anodization is also preferably used.

The thickness of the support is usually in the range of 12 to 2000 μm, preferably 20 to 500 μm. To make a lithographic printing plate using the photosensitive material described above, first,
Imagewise exposure is carried out using a light source containing near infrared rays as a photosensitive material. Next, the exposed light-sensitive material and the support are superposed so that the exposed surface of the light-sensitive material is in contact with the support, and both are heated and / or pressed to expose only the unexposed portion of the photosensitive layer on the support. To adhere to. Then, the exposed portion of the photosensitive layer is peeled off from the support together with the sheet-shaped substrate, whereby an image composed of the unexposed portion of the photosensitive layer can be formed on the support. Furthermore, a lithographic printing plate suitable for printing can be prepared by applying light and / or heat to the formed image to cure the addition-polymerizable or crosslinkable compound of the photosensitive composition layer.

The second constitution of the present invention comprises a photosensitive layer containing at least a compound capable of addition polymerization or crosslinking and a borate complex of a cationic dye having a near-infrared absorbing ability on a support having a hydrophilic surface. A method for producing a lithographic printing plate comprising a photosensitive material provided and a substrate for transferring and removing an unexposed portion of the photosensitive layer from a support.

In this structure, the support and the photosensitive layer are preferably those described above.

The photosensitive layer can be formed by coating on a support without solvent or by dissolving in a suitable solvent and coating and drying it on the support. In this case,
The coating liquid solvent described above can be preferably used.

As a substrate for transferring and removing the unexposed portion of the photosensitive layer from the support, papers, plastics, etc. processed into any shape such as sheet, plate, roll and the like,
Metals and ceramics can be used. Specifically, for example, thin paper such as condenser paper, glassine paper, various coated paper, paper such as synthetic paper (those obtained by laminating foamed plastic on a substrate), polyethylene terephthalate, polyethylene naphthalate, polyester such as aramid resin, etc. Resins such as cellulose triacetate and cellulose diacetate, and other polyvinyl chloride, polyethylene, polypropylene, polystyrene, polyvinyl alcohol, cellophane, polysulfone, polyimide, polycarbonate, polyamide, polyethylene ether ketone, polyarylate, ABS In addition to plastics such as the above, metals such as aluminum, zinc, and copper and metal foils, various ceramics can be used alone or as a composite of two or more kinds.

Further, if necessary, a filler, a stabilizer, an additive and the like are added to the base material for transferring and removing the unexposed portions of these photosensitive layers from the support, and the photosensitive layers in the unexposed portions are blended. It is optional to apply a surface treatment to control the adhesive force under heating and / or pressure.

To prepare a lithographic printing plate using the photosensitive material having the above-mentioned second structure, first, the photosensitive material is exposed imagewise by using a light source containing near infrared rays. Next, the exposed photosensitive material and a base material for transferring and removing the unexposed portion of the photosensitive layer from the support on the exposed surface of the photosensitive material are superposed, and both are heated and / or pressurized to form a photosensitive layer. Only the unexposed part of is adhered onto the substrate. Then, by peeling the unexposed portion of the photosensitive material together with the substrate from the lithographic printing plate support, an image composed of the exposed portion of the photosensitive layer can be formed on the lithographic printing plate support. In this case, since the formed image is the photosensitive layer which has already been polymerized and cured, it can be used as it is as a lithographic printing plate. Of course,
It is also preferable to apply light and / or heat to the formed image to completely react a small amount of unreacted addition-polymerizable or crosslinkable compound before use.

As the light source for imagewise exposure, any light source having a wavelength in the near infrared region (for example, a range of 700 to 2000 nm) and generating an electromagnetic wave active with respect to the photopolymerization initiator can be used. Lasers, light emitting diodes,
Xenon lamp, halogen lamp, carbon arc lamp,
Examples thereof include metal halide lamps and tungsten lamps.

When performing batch exposure using a xenon lamp, a halogen lamp, a carbon arc lamp, a metal halide lamp, a tungsten lamp, etc., a negative pattern of a desired exposure image is formed on the cover film side of a photosensitive material with a light shielding material. The mask materials may be superposed and exposed.

When an array type light source such as a light emitting diode array is used, or when a light source such as a halogen lamp, a metal halide lamp or a tungsten lamp is exposed and controlled by an optical shutter material such as liquid crystal or PLZT, an image signal is used. It is possible to carry out digital exposure according to the conditions. In this case, so-called direct plate making can be performed in which direct writing is performed without using a mask material.

The laser is suitable for so-called direct plate making, in which direct writing is performed without using a mask material, because light can be focused into a beam and scanning exposure can be performed according to image data. When a laser is used as a light source, it is easy to reduce the exposure area to a minute size, and high-resolution image formation is possible.

The laser light source used in the present invention is a well-known solid laser such as a YAG laser or a glass laser, a He-Ne laser, a carbon dioxide laser, as long as it has an oscillation wavelength in the near infrared region. A carbon monoxide laser, other discharge excitation molecular laser, gas laser such as excimer laser, chemical laser, dye laser, semiconductor laser and the like can be used. Among them, YAG laser, He-Ne laser, and semiconductor lasers are preferable, and especially semiconductor lasers are small in size and inexpensive, since the oscillation wavelength can be changed by their composition,
It is also possible and preferable to select appropriately according to the photosensitive wavelength range of the photosensitive composition used.

The composition of the semiconductor laser which is preferably used and the oscillation wavelength range thereof are as follows.

InGaP laser (0.65 to 1.0 μm), AlGaAs
Laser (0.7 to 1.0 μm), GaAsP laser (0.7 to 1.0 μm
m), InGaAs laser (1.0 to 3.5 μm), InAsP laser (1.0 to 3.5 μm), CdSnP2 laser (1.01 μm), GaSb
Laser (1.53μm) etc.

As a method for transferring the unexposed portion of the photosensitive layer onto a support or a base material, the photosensitive layer surface and the support or base material to be transferred are placed in contact with each other so that heating and / or pressurization is possible. A method of bringing the roller-shaped or plate-shaped member into contact, a method of irradiating an electromagnetic wave containing a heat ray, and the like can be arbitrarily selected. The transfer conditions such as transfer temperature and pressure may be set as appropriate so that only the unexposed portion of the exposed photosensitive layer is transferred. In addition to heating and / or pressure during transfer,
It is also preferable to apply vibration to accelerate transfer.

The light applied to the image after formation is added to the photosensitive layer by a laser, a xenon lamp, a halogen lamp, a carbon arc lamp, a metal halide lamp, a tungsten lamp, an infrared lamp, a high pressure mercury lamp, a fluorescent lamp, sunlight or the like. Any known light source can be used as long as it acts on the existing photopolymerization initiator. The exposure intensity and the exposure time may be appropriately set depending on the composition of the photosensitive composition of the photosensitive layer and the conditions of the exposure device, as long as they can be cured to such an extent that there is no practical problem as a lithographic printing plate. In this case, the same effect can be obtained with either batch exposure or scanning exposure.

Any known heating method can be used as the method for heat-curing the image after formation. As long as the heating temperature and heating time can be cured to such an extent that there is no practical problem as a lithographic printing plate, the photosensitive composition It may be appropriately set depending on the composition and the conditions of the heating device.

[0075]

EXAMPLES The present invention will be described below based on examples, but the embodiments of the present invention are not limited thereto.

Example 1 A transparent polyethylene phthalate film having a thickness of 25 μm was coated with a photosensitive composition having the following composition by a wire bar coating method so as to have a dry film thickness of 3 μm.

Photosensitive composition 100 parts by weight of dipentaerythritol hexaacrylate Acrylic resin 30 parts by weight (butyl acrylate / styrene / acrylic acid copolymer) 70 parts by weight of chlorinated polyethylene (Sanyo Kokusaku Pulp: Super Clone 907LTA) Cationic dye Borate complex (Compound IR-1) 3 parts by weight Methyl ethyl ketone 800 parts by weight A negative mask with a negative pattern of a desired image formed of a light-shielding material is overlaid on the photosensitive layer surface, and a xenon flash lamp (ideal science Company:
Using Zenofax FX180), the exposure time is 1 ms, the exposure energy is 100 mJ / cm ² , and the photosensitive layer surface is anodized. The aluminum surface is a sand plate (thickness: 0.3 mm).
And a heated roll was passed under the following conditions and heated and pressed to transfer the unexposed portion of the photosensitive layer onto the aluminum support.

(Heating / pressurizing conditions) Temperature: 110 ° C. Pressure: 3 kg / cm ² Speed: 5 cm / sec After cooling the sample to room temperature, the polyethylene terephthalate film was peeled off, and the exposed portion of the photosensitive layer was a polyethylene terephthalate film. At the same time, it was peeled off, and an image composed of an unexposed portion of the photosensitive layer was formed on the aluminum support.

The thus formed image was collectively exposed by the above-mentioned xenon flash lamp in exactly the same manner to obtain a lithographic printing plate.

When this lithographic printing plate was used in a commercially available offset printing machine, a non-image area was free from stains and a printed matter with high sharpness was obtained. Printing durability was 50,000 sheets or more.

Next, a mask of a resolution chart was masked on this light-sensitive material, and after exposure, a lithographic printing plate was prepared by the above-mentioned processing. A resolution of 60 lines / mm or more was obtained.

Example 2 A lithographic printing plate was prepared and evaluated in the same manner as in Example 1 except that the composition of the photosensitive composition was changed to the following composition.
A printed matter with high sharpness was obtained without stains on non-image areas.
Printing durability was 50,000 sheets or more and a resolution of 60 lines / mm or more was obtained.

Photosensitive composition 100 parts by weight of dipentaerythritol hexaacrylate Acrylic resin 30 parts by weight (butyl acrylate / styrene / acrylic acid copolymer) 70 parts by weight of chlorinated polyethylene (Supercron 907LTA: supra) Cationic dye borate Complex (Compound IR-1) 3 parts by weight Organic boron salt compound BTPB.TBA 5 parts by weight (Tetrabutylammonium salt of butyltriphenylboron) Methyl ethyl ketone 800 parts by weight Example 3 After anodizing a grained aluminum plate, The surface is degreased by immersing it in a 3% aqueous solution of sodium metasilicate at 25 ° C for 5 minutes, and the dried product is used as a support. A photosensitive composition layer having the following composition is wire-bar coated on the surface. It was applied by the method so that the dry film thickness was 4 μm.

Photosensitive composition 100 parts by weight dipentaerythritol hexaacrylate 100 parts by weight diallyl phthalate prepolymer 30 parts by weight (Dupotote DT170 manufactured by Toto Kasei Co., Ltd.) 70 parts by weight chlorinated polyethylene (Supercron 907LTA: supra) Cationic dye borate complex (Compound IR-16) 3 parts by weight Organic boron salt compound BTPB / TBP 5 parts by weight (Tetrabutylphosphonium salt of butyltriphenylboron) Methyl ethyl ketone 800 parts by weight Negative mask in which a negative pattern of a desired image is formed on the photosensitive layer surface with a light-shielding material Xenon flash lamps (Xenofax FX
180: as described above, after performing a batch exposure with an exposure time of 1 msec and an exposure energy of 30 mJ / cm ² , a polyethylene terephthalate film (thickness 50 μm) provided with the following heat-bonding layer on the surface of the photosensitive layer was 1 μm. The layers were superposed, passed through a hot roll under the following conditions, heated and pressed to transfer the unexposed portion of the photosensitive layer onto the polyethylene terephthalate film.

Heat-bonding layer Linear saturated polyester resin (manufactured by Toyobo: Byron 200) 20 parts by weight Methyl ethyl ketone 50 parts by weight Toluene 30 parts by weight (heating and pressurizing conditions) Temperature: 140 ° C. Pressure: 1.5 kg / cm ² Speed: 5 cm After cooling the sample to room temperature, the polyethylene terephthalate film was peeled off. The unexposed part of the photosensitive layer was peeled off together with the polyethylene terephthalate film, and an image consisting of the exposed part of the photosensitive layer was formed on the aluminum support. A lithographic printing plate was obtained.

When this lithographic printing plate was used in a commercial offset printing machine, a non-image area was free from stains and a printed matter with high sharpness was obtained. Printing durability was 50,000 sheets or more.

Then, a resolution chart was masked on this light-sensitive material, and after exposure, a lithographic printing plate was prepared by the above-mentioned treatment. A resolution of 80 lines / mm or more was obtained.

Example 4 A transparent polyethylene phthalate film having a thickness of 25 μm was coated with a photosensitive composition having the following composition by a wire bar coating method so as to have a dry film thickness of 3 μm.

Photosensitive composition Dipentaerythritol hexaacrylate 100 parts by weight Acrylic resin 30 parts by weight (butyl acrylate / styrene / acrylic acid copolymer) Chlorinated polyethylene 70 parts by weight (Supercron 907LTA: supra) Cationic dye borate Complex (Compound IR-8) 3 parts by weight Organic boron salt compound BTAB / TBA 5 parts by weight (Tetrabutylammonium salt of butyltrianisylboron) Benzophenone 3 parts by weight Michler's ketone 3 parts by weight Methyl ethyl ketone 800 parts by weight Negative of desired image on photosensitive layer surface A xenon flash lamp (Zenofax FX) in which a negative mask whose pattern is made of light-shielding material is layered and light of 720 nm or less is cut by a filter.
(180: above), after performing one-time exposure with an exposure time of 1 msec and an exposure energy of 10 mJ / cm ² , the photosensitive layer surface was overlaid on an anodized sand surface aluminum plate (thickness 0.3 mm), and An unexposed portion of the photosensitive layer was transferred onto the aluminum support by passing through a hot roll under the conditions and heating and pressurizing.

(Heating / pressurizing conditions) Temperature: 110 ° C. Pressure: 3 kg / cm ² Speed: 5 cm / sec After cooling the sample to room temperature, the polyethylene terephthalate film was peeled off, and the exposed part of the photosensitive layer was a polyethylene terephthalate film. At the same time, it was peeled off, and an image composed of an unexposed portion of the photosensitive layer was formed on the aluminum support.

The formed image was collectively exposed with a high pressure mercury lamp to obtain a lithographic printing plate.

When this lithographic printing plate was used in a commercially available offset printing machine, a non-image area was free from stains and a printed matter with high sharpness was obtained. Printing durability was 50,000 sheets or more.

Next, when a resolution chart was masked on this light-sensitive material and exposed to light, a lithographic printing plate was prepared by the above-mentioned treatment. A resolution of 60 lines / mm or more was obtained.

Examples 5 to 8 Lithographic printing plates were prepared in the same manner as in Examples 1 to 4, except that the imagewise exposure was replaced with laser scanning exposure under the following conditions. (Exposure condition) Light source: Semiconductor laser (Sharp Corporation: LT090M
D, output 100mW) Main wavelength: 830nm Beam diameter: 15μm Scanning pitch: 10
μm Average energy density of light irradiated on photosensitive surface: 5 mJ / cm
² Each sample was evaluated by the method described in Examples 1 to 4,
In each case, a printing plate having good printing durability and sharpness in which a non-image area was not stained was obtained. All the light-sensitive materials had a resolution of 100 lines / mm or more in scanning exposure with a laser.

Comparative Examples 1 to 11 After graining an aluminum plate was anodized, it was immersed in a 3% aqueous solution of sodium metasilicate at 25 ° C. for 5 minutes to degrease its surface, and then dried. Then, the photosensitive composition used in Examples 1 to 11 was applied thereon by a wire bar coating method so as to have a dry film thickness of 3 μm. Furthermore, on the photosensitive composition layer, a thickness of 25 μm
The transparent polyethylene terephthalate film of 1 was pressure-laminated to obtain a photosensitive material.

A xenon flash lamp (Zenofax FX180: supra) in which a negative mask in which a negative pattern of a desired image is formed on a transparent cover film made of a photosensitive material is overlaid and a light of 720 nm or less is cut by a filter.
Exposure time is about 1 msec, exposure energy is 100 mJ /
After the batch exposure at cm ² , the cover film was peeled off, and a positive pattern of the cured resin was formed on the support. When this was subjected to a printing test using an ordinary offset printing machine, printing durability of 50,000 sheets or more was obtained, but there was partial peeling residue in the non-image area, and stains were produced on the white background of the printed matter.

Comparative Examples 12 to 15 Photosensitive materials were formed in the same manner as in Example 2 except that the borate complex of the cationic dye and the organic boron salt of the photosensitive composition were replaced with the compounds shown below. Evaluation is the same as in Example 6,
The energy required for making a lithographic printing plate was examined by scanning recording with a semiconductor laser, but no polymerization was observed even at an exposure amount of 500 mJ / cm ² .

Next, the same material was used to perform batch exposure with ultraviolet light and visible light to determine the exposure energy required for image formation, and the following results were obtained, which were compared with the constitution of the present invention. Required a remarkably large exposure amount.

Initiator composition Comparative Example 12: No initiator 13: TBA / BTPB 3 parts by weight 14: Diphenyliodonium hexafluorophosphate 3 parts by weight Michler's ketone 3 parts by weight 15: Benzophenone 1 part by weight Michler's ketone methyl ether 1 Parts by weight triethylamine 1 part by weight exposure light source semiconductor laser visible light ultraviolet light (830 nm) (400 to 700 nm) (350 nm or less) Comparative Example 12 No polymerization No polymerization No polymerization 〃 13 No polymerization No polymerization No polymerization 〃 14 polymerized without 300mJ / cm ² 250mJ / cm ² 〃 15 without polymerization was not polymerized 200 mJ / cm ²

[0100]

EFFECTS OF THE INVENTION According to the present invention, a high resolution which is highly sensitive to near infrared light, excellent in printability and visible image quality, and which realizes downsizing of an apparatus and cost reduction of a material without liquid development. It is possible to provide a method for producing a planographic printing plate.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor, Otowa Komamura, Konica Stocks Company, 1 Sakura-cho, Hino City, Tokyo (72) Inventor, Katsunori Kato, 1 Sakura-cho, Hino City, Tokyo, Konica Stock Company

Claims (4)

[Claims] 1. A lithographic printing plate comprising a photosensitive material comprising a sheet-shaped substrate and a photosensitive layer containing at least a compound capable of addition polymerization or crosslinking and a borate complex of a cationic dye having near-infrared absorbing ability. As a step of producing, a step of irradiating light containing near infrared light imagewise, the photosensitive layer surface irradiated with the imagewise light is superposed on a support having a hydrophilic surface and heated and / or pressurized. An image formed by a step of transferring only the unexposed portion of the photosensitive layer onto the support, a step of peeling the sheet-shaped substrate together with the exposed portion of the photosensitive layer, and an unexposed photosensitive layer formed on the support. A method for producing a lithographic printing plate, comprising the step of exposing and / or heating the above to polymerize and cure. 2. A lithographic printing plate comprising a photosensitive material having a hydrophilic surface and provided with a photosensitive layer containing at least a compound capable of addition polymerization or crosslinking and a borate complex of a cationic dye having a near-infrared absorbing ability. As the process of creating
The step of irradiating light including image-wise near-infrared light, the photosensitive layer surface irradiated with the imagewise light is superposed on the surface of another substrate and heated and / or pressurized to expose only the unexposed portion of the photosensitive layer. A planographic printing plate characterized by comprising a step of transferring onto the surface of the base material, and a step of peeling the base material together with an unexposed portion of the photosensitive layer to form an image on the support, which is composed of the exposed portion of the photosensitive layer. How to make a print version. 3. The method of preparing a lithographic printing plate as claimed in claim 1, wherein the photosensitive layer contains at least one organic boron salt as one of its constituent components. 4. The method for producing a lithographic printing plate according to claim 1, wherein imagewise exposure is performed by scanning exposure with a laser having an oscillation wavelength in the near infrared region.