JPH0854729A - Production of planographic printing plate - Google Patents

Abstract

PURPOSE:To obtain a printing plate excellent in storage property and dimensional stability, able to freely select its base body, and further, able to be produced by a small-size equipment from a low cost material by performing sticking of the photosensitive layer formed on a transparent supporting body to a hydrophilic base material and exposing of it to light in successive process. CONSTITUTION:The image recording material consists of a transparent supporting body 1, photosensitive layer 2 and cover sheet which can be removed. The photosensitive layer 2 contains a photopolymn. initiator and a compd. having polymerizable or crosslinkable ethylene-type unsatd. double bonds. The photosensitive layer 2 and a base material are laminated, if necessary, after the cover sheet 3 is peeled, just before exposure for an image, and then after exposure for the image, the supporting body 1 for the image forming material is removed to obtain the image. Then the image part is irradiated with active rays and hardened to obtain the printing plate. To stick the layer 2 just before exposure, means that sticking and exposure are substantially performed in serial process in one device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming method using a photosensitive material, and more specifically, a method for producing a lithographic printing plate having high resolution, stability over time, and printability by a complete dry process at low cost. Regarding

[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 containing a compound capable of addition polymerization or crosslinking, a photopolymerization initiator, and optionally a binder component composed of an organic polymer compound, etc. is coated on a hydrophilic support to form a photosensitive lithographic plate. As a printing material, a desired image is imagewise exposed to the photosensitive composition to cure the exposed portion, and the lithographic printing plate is formed by forming an oleophilic image portion by dissolving and removing the unexposed portion, which is usually used. Liquid developing method, and Japanese Patent Laid-Open Nos. 52-9501 and 52-1501
No. 04, No. 53-40537, No. 53-53404, Japanese Patent Application No. 4-87182, etc., the above-mentioned photosensitive composition is formed between at least one transparent support. The desired image is imagewise exposed from the transparent support side, and the change in the adhesive strength of the photosensitive composition to the support is caused by the exposure,
A lithographic printing plate formed by forming a lipophilic image portion on a hydrophilic support by peeling development, a photopolymerizable composition, as disclosed in JP-A-62-125358, encapsulated in microcapsules. After the photosensitive layer is provided on the substrate and the photosensitive composition in the microcapsules is imagewise exposed and cured, the surface of the photosensitive layer is superposed on the printing plate substrate and pressed to form microcapsules in the unexposed area. The method of forming a lithographic printing plate by transferring the photosensitive composition in the microcapsules to the printing plate substrate at the same time as destroying, as disclosed in Japanese Patent Application No. 4-124939 etc., on a support. After imagewise exposing the provided photosensitive layer, the photosensitive layer is brought into close contact with the hydrophilic support and heated and / or
Alternatively, the unexposed portion of the photosensitive layer is transferred and formed on a hydrophilic support by pressurization and post-exposure cured to obtain a lithographic printing plate, as disclosed in JP-A-4-94937, a curing component. A method of preparing a lithographic printing plate in which an image is formed by thermal transfer on a hydrophilic support with a heat-fusible ink layer containing, and a formed image is formed by irradiation with actinic rays, and the like.

Particularly, the latter four methods are preferable methods from the viewpoints of environmental pollution, worker safety, and downsizing of the apparatus, since no liquid developer is used. Conventional peeling developing materials are dry developing, but since the photosensitive layer and the cover sheet for peeling development are distributed in the form of being laminated on the printing plate substrate, the laminating state changes with time and the image There was a problem with stability and reproducibility. Furthermore, in the conventional peeling development material, the type of printing machine,
Alternatively, it was completely impossible to select a printing plate substrate according to the printing application.

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. However, if the particle size is reduced, it is very difficult to destroy the microcapsules under pressure. Since a large amount of force is required, a large-sized device is required, which is not preferable in terms of device cost and device size.

After the photosensitive layer provided on the support is imagewise exposed, the photosensitive layer is brought into close contact with the hydrophilic support, and the unexposed portion of the photosensitive layer is made hydrophilic by heating and / or pressing. Since a lithographic printing plate is formed by transferring and forming on a transparent support after exposure and curing, the difference in transferability between the exposed portion and the unexposed portion is utilized.
Relatively high temperatures and / or high pressures are required to obtain uniform image transfer and sufficient resolution. When an ordinary resin film is used as the support, the support is deformed by the temperature and pressure at the time of transfer, resulting in poor dimensional stability. or,
Using a support material having high heat resistance and high mechanical strength causes an increase in material cost.

In the method of directly forming the lipophilic layer on the hydrophilic support by thermal transfer, the heat diffusion to the side of the hydrophilic support is large, and in particular, an aluminum substrate used in a usual printing plate as the hydrophilic support. Requires excessive energy for image formation. In addition, direct transfer to an ordinary aluminum substrate for printing plates, which has a grained surface, makes it difficult to evenly adhere the image forming material to the surface of the aluminum substrate, and easily causes transfer omissions, resulting in a large size and high resolution. It was not suitable for commercial printing, which requires high quality.

Conventionally, as the photopolymerization initiator of 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. The photosensitive wavelengths of these photopolymerization initiators are in the ultraviolet region. Therefore, a general method for producing a lithographic printing plate using a photosensitive lithographic printing plate material having a photosensitive composition containing a photopolymerization initiator is a photosensitive composition surface or a transparent layer provided thereon. A mask material having a negative pattern of a desired image formed of a light-shielding material (for example, a silver salt film) is brought into close contact with the oversheet surface, exposed to an ultraviolet light source such as a mercury lamp, and then melt-developed or peel-developed.

In recent years, with advances in image processing, light sources, and image forming techniques, there has been a demand for a photosensitive material that is more sensitive to long-wave light than before. An example is a system that forms a printing plate by directly scanning and exposing a photosensitive material by modulating a light source with an image signal transmitted through a communication line and an output signal from an electronic plate making system or an image processing system. A laser is suitable as a light source at this time. In particular, it has been desired to develop a photosensitive lithographic printing plate material capable of directly forming a printing plate with a high resolution by scanning exposure of a small-sized and low-cost semiconductor laser.

Several techniques have been conventionally proposed for a photosensitive composition containing a photopolymerization initiator having sensitivity in the visible light region. For example, JP-A-47-2528 and 54-155292
No. 48, No. 48183, No. 54-151024, No. 60-88005, No. 5
8-40302, 59-56403, 59-189340, JP-A-2-69
No. 2-189548 and the like. Although these techniques have visible light sensitivity, they are not yet sufficiently practical in sensitivity and require a long exposure time to directly form a printing plate by laser scanning exposure, and are not efficient. Also, since the usable laser light source is limited to those having an oscillation wavelength in the visible light range such as He-Ne gas laser and Ar gas laser, it is not possible to use the semiconductor laser which is currently the smallest and cheapest laser light source. I couldn't, and needed a large device.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and its object is to have excellent storage stability and dimensional stability, and a printing plate substrate can be arbitrarily selected. Another object of the present invention is to provide a method for preparing a lithographic printing plate that does not require liquid development and that realizes further downsizing of the apparatus and cost reduction of materials.

[0011]

Means for Solving the Problems As a result of earnest studies, the inventors have found that a photosensitive layer provided on a transparent support is bonded to a hydrophilic substrate and exposed in a series of steps. It has been found that the above objective can be achieved. That is, (1) using an image recording material having a photosensitive layer containing a compound having a polymerizable or crosslinkable ethylenic double bond and a photopolymerization initiator on a transparent support, 1) a hydrophilic surface 2) step of attaching a substrate having a to the exposed portion 2) a step of laminating a photosensitive layer of an image recording material on the hydrophilic surface on the exposed portion 3) a step of imagewise exposing from the support side of the image recording material 4 ) Step of peeling / removing the support of the image recording material together with the exposed or unexposed portion of the photosensitive layer 5) Actinic rays on the image formed of the exposed or unexposed portion of the photosensitive layer formed on the hydrophilic surface A method for producing a lithographic printing plate, which comprises a series of steps including a step of irradiating and / or heating and post-curing.

(2) Using an image recording material having a photosensitive layer containing a compound having a polymerizable or crosslinkable ethylenic double bond and a photopolymerization initiator on a transparent support, 1) hydrophilic Step 2 of laminating the photosensitive layer of the image recording material to the base material having a surface 2) Step of mounting the above-mentioned laminated base material and the image recording material on the exposed portion 3) Imagewise from the support side of the image recording material 4) Step of peeling and removing the support of the image recording material together with the exposed or unexposed portion of the photosensitive layer 5) From the exposed or unexposed portion of the photosensitive layer formed on the hydrophilic surface A method for producing a lithographic printing plate, which comprises performing a series of steps of irradiating and / or heating an image with actinic rays to post-cure the image.

(3) A transparent support having a photosensitive layer containing a compound having a polymerizable or crosslinkable ethylenic double bond and a photopolymerization initiator, and a peelable cover sheet if necessary. The image recording material is stored in the unwinding portion of a length capable of producing a plurality of printing plates, and one end of the image recording material is connected to the winding member. Step of laminating a photosensitive layer of an image recording material on a substrate having a hydrophilic surface without cutting the image recording material 2) Step of imagewise exposing from the support side of the image recording material 3) Step of peeling and removing the support together with the exposed or unexposed portion of the photosensitive layer while winding the image recording material on the winding member without cutting the image recording material 4) Exposed portion of the photosensitive layer formed on the hydrophilic surface Alternatively, a step of irradiating an image composed of an unexposed area with an actinic ray to post-cure it. The lithographic printing plate creation method of performing Ranaru series of steps.

(4) The photopolymerization initiator is sensitive to near infrared rays, and image exposure is performed by scanning exposure with a semiconductor laser.
The method for preparing a lithographic printing plate as described in (1), (2) or (3).

(5) The image recording material comprises a transparent support, a photosensitive layer containing a compound having a polymerizable or crosslinkable ethylenic double bond and a photopolymerization initiator, and a peelable cover sheet. A lithographic printing plate according to (1), (2), (3) or (4), which is formed by stacking in this order and has a step of peeling off the cover sheet before bonding to a substrate having a hydrophilic surface. How to make.

The image recording materials used in the present invention are as follows:
The printing plate creation method will be described in detail in order.

(Image Recording Material) The image recording material of the present invention comprises a transparent support 1 and a photosensitive layer 2 containing a compound having a polymerizable or crosslinkable ethylenically unsaturated double bond and a photopolymerization initiator. 1), or a photosensitive layer 2 containing a compound having a polymerizable or crosslinkable ethylenically unsaturated double bond and a photopolymerization initiator on the transparent support 1 and a peelable cover sheet 3 The structure (FIG. 1b) is formed by stacking the layers in this order.

The image recording material having the above-mentioned structure is housed in the unwinding portion having a length capable of producing a plurality of printing plates, and one end of the image forming material is connected to the winding member (FIG. 2). )
It is within the scope of the invention.

The support used in the present invention has a light transmittance in a wavelength range capable of activating the photopolymerization initiator contained in the photosensitive layer (preferably a transmittance of 40% or more, more preferably Any known material can be used as long as it has good dimensional stability and can withstand mechanical strength at the time of peeling. Specific examples thereof include heat-resistant plastic films such as polyethylene terephthalate, polyethylene naphthalate, polyamide, polyimide, polycarbonate, polysulfone, polyvinyl alcohol cellophane, and polystyrene. The thickness of the support is usually preferably 5 to 500 μm, more preferably
5 to 200 μm.

The surface of the support is preferably surface-treated for the purpose of controlling the adhesive force with the photosensitive layer.
Specifically, corona discharge treatment, flame treatment, ozone treatment,
UV treatment, radiation treatment, roughening treatment, chemical treatment,
There are plasma treatment, low temperature plasma treatment, primer treatment, grafting treatment and the like. In particular, corona discharge treatment and primer treatment with an acrylic compound are preferable because they can increase the difference in adhesiveness between the exposed and unexposed portions of the photosensitive layer and the cover sheet.

Further, a backing layer may be provided on the surface of the support opposite to the side on which the photosensitive layer is provided for the purpose of imparting running stability, heat resistance, antistatic properties, antireflection properties and the like.

The photosensitive layer contains a compound having a polymerizable or crosslinkable ethylenically unsaturated double bond and a photopolymerization initiator as essential components.

As the compound capable of being polymerized or crosslinked, known compounds can be used without particular limitation, but compounds having at least one ethylenically unsaturated double bond in the molecule are preferable. Specific compounds include 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate,
2-hydroxypropyl acrylate, glycerol acrylate, tetrahydrofurfuryl acrylate, phenoxyethyl acrylate, nonylphenoxyethyl acrylate, tetrahydrofurfuryloxyethyl acrylate, tetrahydrofurfuryloxyhexanolide acrylate, addition of ε-caprolactone to 1,3-dioxane alcohol Acrylates, monofunctional acrylic acid esters such as 1,3-dioxolane acrylate, or these acrylates methacrylate, itaconate,
Crotonate, methacrylic acid substituted for maleate, itaconic acid, crotonic acid, maleic acid ester; ethylene glycol diacrylate, triethylene glycol diacrylate, pentaerythritol diacrylate, hydroquinone diacrylate, resorcin diacrylate, hexanediol diacrylate, neopentyl Glycol diacrylate, tripropylene glycol diacrylate, hydroxy pivalate neopentyl glycol diacrylate, neopentyl glycol adipate diacrylate, hydroxypivalate neopentyl glycol diacrylate of ε-caprolactone adduct, 2- (2-hydroxy -1,1-Dimethylethyl) -5-hydroxymethyl-5-ethyl-1,3-dioxane diacrylate, tricyclodecane dimethyl Bifunctional acrylic acid esters such as roll acrylate, ε-caprolactone adduct of tricyclodecane dimethylol acrylate, diacrylate of diglycidyl ether of 1,6-hexanediol, diacrylate of bisphenol A or bisphenol A derivative, or the like Of methacrylic acid, itaconate, crotonate, maleate, methacrylic acid, crotonic acid, maleic acid ester; trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, trimethylolethane triacrylate, pentaerythritol triacrylate, penta Erythritol tetraacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate , Dipentaerythritol hexaacrylate, ε-caprolactone adduct of dipentaerythritol hexaacrylate, pyrogallol triacrylate, propionic acid / dipentaerythritol triacrylate, propionic acid / dipentaerythritol tetraacrylate, hydroxypivalylaldehyde modified dimethylolpropane triacrylate Acrylics, polyfunctional acrylic acid esters such as isocyanuric acid or modified isocyanuric acid triacrylate, or methacrylates of these acrylates,
Examples thereof include itaconate, crotonate, methacrylic acid substituted for maleate, itaconic acid, crotonic acid, and maleic acid ester. Among these, acrylic acid ester and methacrylic acid ester compounds are particularly preferable. Of these compounds, one kind or a mixture of two or more kinds can be used.

In addition, as a compound capable of addition polymerization or crosslinking, a so-called prepolymer obtained by introducing photopolymerizability by introducing acrylic acid or methacrylic acid into an oligomer having an appropriate molecular weight 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, adipic acid, trimellitic acid, maleic acid, phthalic acid, terephthalic acid, hymic acid, malonic acid, succinic acid, glutaric acid, itaconic acid, pyromellitic acid, fumaric acid, pimelic acid, sebacine Acid, dodecanoic acid, polybasic acid such as tetrahydrophthalic acid, ethylene glycol, propylene glycol, diethylene glycol, propylene oxide, 1,4-butanediol, triethylene glycol, tetraethylene glycol, polyethylene glycol, glycerin, trimethylolpropane, Polyester acrylates obtained by introducing (meth) acrylic acid into a polyester obtained by binding a polyhydric alcohol such as pentaerythritol, sorbitol, 1,6-hexanediol, and 1,2,6-hexanetriol; bisphenol -Epoxy chlorohydrin- (meth) acrylic acid, phenol novolac-epoxy chlorohydrin- (meth) acrylic acid-containing epoxy acrylates with (meth) acrylic acid introduced into them; ethylene glycol, adipic acid, tolylene diisocyanate-2 Hydroxyethyl acrylate, polyethylene glycol / tolylene diisocyanate / 2-hydroxyethyl acrylate, hydroxyethylphthalyl methacrylate / xylene diisocyanate, 1,2-polybutadiene glycol / tolylene diisocyanate / 2
Urethane acrylates such as 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; and alkyd-modified acrylates obtained by introducing a (meth) acryloyl group into an oil-modified alkyd resin and spirane resin acrylates.

As the photopolymerization initiator, for example, any of known photopolymerization initiators described on pages 39 to 56 of Photopolymer Handbook (edited by Photopolymer Society, published by Industrial Research Institute, 1989) can be arbitrarily used. However, spectral sensitization of the photosensitive layer can be easily performed by using the compound represented by the following general formula (1) or (2), and thus image formation can be performed with any light source in the ultraviolet to near infrared region. It can be carried out. In particular, by imparting sensitivity to red to near infrared, scanning exposure with a semiconductor laser, which has made remarkable progress in recent years, becomes possible, and it can be used as a highly sensitive digital image forming material.

[0027]

Embedded image

In the formula, Dye ⁺ represents a cationic dye and M ^{k +} represents a transition metal coordination complex cation.

R ₁ , R ₂ , R ₃ and R _{4, which} may be the same or different, each represents an alkyl group, an aryl group, an alkenyl group, an alkynyl group, a heterocyclic group or a cyano group, and these alkyl groups, The aryl group, alkenyl group, alkynyl group and heterocyclic group may further have a substituent. However,
At least one of R ₁ , R ₂ , R ₃ and R ₄ is an optionally substituted alkyl group. Also, R ₁ , R ₂ , R ₃ and R ₄ are 2
One or more may combine with each other to form a ring.

R ₅ and R ₆ each represent a hydrogen atom, a halogen atom or a monovalent substituent.

X is a hydroxyl group or --N (R ₇ ) (R ₈ ) group (R ₇ and R ₈ each represent a hydrogen atom or an optionally substituted alkyl group, and R ₅ , R ₆ or R ₇ are M may represent a transition metal atom.

K is 1 to 3, j is 2 or 3, m is 1 to 5,
n represents an integer of 1 to 4, respectively.

Specific examples of the cationic dye represented by Dye ⁺ include JP-A Nos. 62-143044, 63-208036 and 64-842.
Nos. 45, 64-88444, JP-A 1-152108, and 3-202609 can be used. Specific examples of preferable compounds are shown in the compound group A.

<< Compound Group A >>

[0035]

Embedded image

[0036]

[Chemical 3]

[0037]

[Chemical 4]

[0038]

[Chemical 5]

Specific examples of the transition metal coordination complex cation represented by M ^{k +} include those described in JP-A-4-261405, in addition to those listed in the following compound group B.

<< Compound Group B >>

[0041]

[Chemical 6]

M ^{k +} jk X R ₉ R ₁₀ R ₁ R ₂ R ₃ R ₄ Co ²⁺ 2 2 N (C ₂ H ₅ ) ₂ NHCOC ₃ H ₇ (i) CH ₃ Ph Ph Ph Bu Ru ²⁺ 2 2 N (C ₂ H ₅ ) ₂ NHCOC ₃ H ₇ (i) CH ₃ Ph Ph Ph Bu Ru ²⁺ 2 2 N (C ₂ H ₅ ) (C ₂ H ₄ NHSO ₂ CH ₃ ) Cl CH ₃ Ph Ph Ph Bu Ru ²⁺ 2 2 N (C ₂ H ₅ ) (C ₂ H ₄ NHCOCH ₃ ) H CH ₃ Ph Ph Ph Bu Fe ²⁺ 2 2 N (C ₂ H ₅ ) (C ₂ H ₄ OH) CH ₃ CH ₃ Ph Ph Ph Bu Ir ³⁺ 2 3 N (C ₂ H ₅ ) ₂ NHCOC ₃ H ₇ (i) CH ₃ Ph Ph Ph Bu Ru ²⁺ 2 2 N (C ₂ H ₅ ) ₂ CONHC ₄ H ₉ CH ₃ Ph Ph Ph Bu Ru ²⁺ 2 2 N (C ₂ H ₅ ) ₂ CONHC ₄ H ₉ CH ₃ Ph Ph Ph iPr Co ²⁺ 2 2 N (C ₂ H ₅ ) ₂ NHCOC ₃ H ₇ (i) H Ph Ph Ph Bu Ru ²⁺ 2 2 N (C ₂ H ₅ ) ₂ NHSO ₂ CH ₃ CH ₃ Ph Ph Ph Bu Ru ²⁺ 3 3 N (C ₂ H ₅ ) ₂ NHCOC ₃ H ₇ (i) CH ₃ Ph Ph Ph Bu Ru ²⁺ 2 2 N (C ₂ H ₅ ) ₂ NHCOC ₃ H ₇ (i) CH ₂ NHSO ₂ CH ₃ Ph Ph Ph Bu Co ²⁺ 2 2 N (C ₂ H ₅ ) ₂ SO ₂ N (C ₂ H ₅ ) ₂ CH ₃ Ph Ph Ph Bu Ru ²⁺ 2 2 N (C ₂ H ₅ ) ₂ NHCOC ₃ H ₇ (i) NHCOCH ₃ Ph Ph Ph Bu Ru ²⁺ 2 2 N (C ₂ H ₅ ) (C ₂ H ₄ NHSO ₂ CH ₃ ) Cl CH ₃ Ph Ph Ph Bu Fe ²⁺ 2 2 N (C ₂ H ₅ ) ₂ NHCONHC ₃ H ₇ (i) CH ₃ Ph Ph Ph Bu Ru ²⁺ 2 2 N (C ₂ H ₅ ) ₂ NHCOC ₃ H ₇ (i) CH ₃ Bu Bu Bu Bu Ru ²⁺ 2 2 N (C ₂ H ₅ ) ₂ NHCOC ₃ H ₇ (i) CH ₃ Ph Ph Ph Bz

[0043]

[Chemical 7]

Where Ph: phenyl Bu: buthyl iPr: i-pr
opyl Bz: represents benzyl.

[0045]

Embedded image

M ²⁺ R ₁₁ Ru ²⁺ Cl Ru ²⁺ NHCOC ₃ H ₇ (i) Co ²⁺ Cl The photopolymerization initiator represented by the general formula (1) or (2) is a dye anion moiety. In this example, even if this compound is added, a dye having an anion moiety and a borate compound represented by the following general formula (3) are allowed to coexist. The same function can be exhibited even when the compound represented by the general formula (1) is produced by ion exchange in the photosensitive layer or in the coating liquid for the photosensitive layer.
Further, when using the photopolymerization initiator of the general formula (1) or (2), it is preferable to add the borate represented by the general formula (3) for the purpose of improving the sensitivity.

[0047]

[Chemical 9]

In the formula, R ₁ , R ₂ , R ₃ and R ₄ have the same meanings as defined in the general formula (1) or (2), and X ⁺
Is a counter cation (eg, an alkali metal cation,
Periodic table group 5A onium compounds such as ammonium cations and phosphonium cations, and group 6A group onium compounds such as sulfonium and telluronium). Specific examples of the compound are described in JP-A-64-13142 and JP-A-2-4804.

The polymerization initiator for post-curing may be the same as or different from the photopolymerization initiator for image exposure. A thermal polymerization initiator can also be used as the polymerization initiator for post-curing.

Examples of thermal polymerization initiators include organic peroxides such as cumene hydroperoxide, t-butyl hydroperoxide, dicumyl peroxide, di-t-butyl peroxide, benzoyl peroxide, acetyl peroxide and lauroyl peroxide. Azo compounds such as azobisisobutyronitrile, hydrogen peroxide and divalent iron salts, persulfate and sodium hydrogen sulfate, cumene hydroperoxide and divalent iron salts, redox-based polymerization of benzoyl peroxide and dimethylaniline, etc. In addition to the initiator, a disulfide compound, manganese triacetylacetonate, an organometallic complex such as pentacyanobenzyl cobaltate, or the like can be used.

The blending amount of these polymerization initiators is not particularly limited, but preferably, the compound 10 capable of addition polymerization or crosslinking is used.
It is 0.1 to 20 parts by weight with respect to 0 parts by weight.

A binder resin is used in the photosensitive layer if necessary. As the binder resin, polyester resin, polyvinyl acetal resin, polyurethane resin, polyamide resin, cellulose resin, olefin resin, vinyl chloride resin, (meth) acrylic resin, styrene resin, polycarbonate resin, polysulfone Resin, polycaprolactone resin, polyacrylonitrile resin, urea resin, epoxy resin, phenoxy resin,
Examples include rubber-based resins. Particularly in the case of a printing plate, an olefin resin, an acrylic resin and a styrene resin having high lipophilicity are preferable. Further, a resin having an unsaturated bond in the resin, for example, a diallyl phthalate resin and its derivative,
Since chlorinated polypropylene and the like can be polymerized with the above-mentioned compound having an ethylenically unsaturated bond, they can be preferably used depending on the application. As the binder resin, it is preferable to use one kind or a mixture of two or more kinds of the above resins, or a monomer of the above resins is copolymerized and used.

These binder resins are used by adding and mixing in an amount of 500 parts by weight or less, more preferably 200 parts by weight or less, relative to 100 parts by weight of the polymerizable compound having an ethylenically unsaturated bond. Is preferred.

Various additives can be further added to the photosensitive layer of the present invention as long as the effects are not impaired. For example, alkyl ethers, fluorine-based surfactants, nonionic surfactants for the purpose of improving coating properties, long-chain alkyl esters for the purpose of improving the oil sensitivity and water repellency of the image area,
Fluorine-based surfactants, other known stabilizers, plasticizers and the like.

The amount of these additives added varies depending on the intended use, but is generally 0.01 to 30% by weight based on the total solid content of the photosensitive composition.

The releasable cover sheet is preferably one having a high releasability from the photosensitive layer, little change due to temperature and humidity, and a high surface smoothness.

Resins preferably used for the cover sheet include polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polyethylene,
Examples include polyolefin resins such as polypropylene. It is also preferable that the surface of the cover sheet is subjected to a known release treatment and placed.

The thickness of the cover sheet is usually preferably 1 to 200 μm, more preferably 5 to 125 μm.

In the present invention, an intermediate layer having a cushioning property is provided for the purpose of ensuring uniform adhesion when transferring an image onto an image-forming substrate and enabling bonding under more mild conditions. Providing layers is within the scope of the invention.

The cushioning intermediate layer may be one that can be deformed by the temperature and / or pressure when transferring the photosensitive layer. The cushioning intermediate layer is preferably formed by providing a porous resin layer, a thermoplastic compound layer, a heat-melting compound layer, or the like on the support material.

In the second aspect of the present invention, it is necessary that the cushioning intermediate layer is also substantially transparent to actinic rays. As an aspect of claim 2, it is more preferable to form an intermediate layer having a cushioning property with a thermoplastic compound layer or a thermofusible compound layer.

In order to form the porous resin layer, the coating solution for forming a layer is mechanically agitated to apply a coating solution in which bubbles are generated, which is applied onto a base material and dried. A foaming agent is mixed and applied to form a foam by heating, and a layer-forming resin is dissolved in a mixed solvent of a good solvent and a poor solvent to be applied and dried to form microvoids in the layer. Etc. are preferably applied.

Specific examples of the thermoplastic compound include:
For example, polyethylene resin, polypropylene resin, polyisobutylene resin, polystyrene-butadiene copolymer resin, polystyrene resin, polychloroprene resin, acrylic copolymer resin, ethylene-vinyl acetate copolymer resin, polyvinyl chloride resin, vinylidene chloride resin , Polyacrylonitrile-butadiene copolymer resin, polyurethane resin, natural rubber, neoprene resin, polybutadiene resin, vinyl chloride-vinyl acetate copolymer resin, gelatin,
Thermoplastic resins such as polyester resin, polycarbonate resin, epoxy resin, phenoxy resin, polyvinyl acetate resin, and polyamide resin are preferable. Particularly preferably, polyisobutylene resin, polystyrene-butadiene copolymer resin, polychloroprene resin, acrylic copolymer resin, ethylene-vinyl acetate copolymer resin, polyacrylonitrile-butadiene copolymer resin, polyurethane resin, natural rubber , Neoprene resin, polybutadiene resin,
It is a polyester resin.

One or two selected from these compound groups
It is preferred to include one or more compounds as part of the composition. Particularly preferably, a thermoplastic elastomer selected from ethylene-based copolymers, acrylic-based copolymers, styrene-based copolymers, urethane-based resins and the like is contained.

The heat-fusible compound is a solid at room temperature,
It is a compound that becomes a liquid that is melted by heating, and is generally called higher fatty acid, higher alcohol, wax, fat or oil. Specifically, it is described in JP-A-61-179787.
The compounds described on page (2) can be mentioned.

It is particularly preferable that the intermediate layer of the present invention has a softening temperature lower than the softening temperature of the exposed portion of the photosensitive layer laminated on the intermediate layer. The preferred softening temperature varies depending on the composition of the photosensitive layer, but in general, the thermal deformation starting temperature is
It is 150 ° C or lower, and more preferably 100 ° C or lower. Particularly preferably, the Vicat softening temperature specified by JIS K 6730 is 60.
C. or lower, more preferably 40.degree. C. or lower.

The intermediate layer is prepared by dispersing or dissolving the components for forming the intermediate layer in a solvent to prepare a coating liquid for forming the intermediate layer, coating on the surface of the support, and drying, or the components for forming the intermediate layer. It can be formed by a laminating method or the like in which a mixture having is melt-extruded and laminated on the surface of a support. The preferable thickness of the intermediate layer is in the range of 1 to 50 μm, more preferably 3 to 30 μm.

Further, an adhesiveness control layer for improving peel developability may be provided between the intermediate layer and the photopolymerizable layer. As the adhesion control layer, for example, a layer containing a release agent such as a silicone resin or a fluorine resin, or a layer made of a polyvinyl alcohol resin, a cellulose resin or an acrylic resin is preferably used. It is also a preferred embodiment to bond the surface-treated resin film described above in the section of the support on the intermediate layer. The thickness of the adhesion control layer is 0.05 to 25 μm, more preferably 0.1 to 15 μm.
It is in the range of m.

As the substrate having a hydrophilic surface (hereinafter referred to as substrate) used in the present invention, all known materials for lithographic printing plates are preferably used. Specifically, aluminum, zinc, chromium, copper, magnesium, nickel,
Metals such as iron and alloy plates and sheets mainly composed of them, inorganic plates and sheets such as paper, glass and ceramics,
A plastic plate or sheet such as polyethylene terephthalate whose surface is matted to make it hydrophilic, a plate or sheet in which a metal layer such as aluminum, zinc or chromium is laminated on the plastic plate or sheet, and a hydrophilic polymer on any support. For example, a compound layer is provided.

Examples of the hydrophilic polymer compound include cellulose derivatives, polyvinyl alcohol, polyvinylpyrrolidone, polyacrylamide, polyethylene glycol, gelatin, gum arabic and the like. As the printing plate material, an aluminum plate subjected to a graining treatment is particularly preferably used among the above-mentioned base materials. After degreasing the surface of the aluminum plate (including the alumina laminate), those treated by known methods such as glass bead graining, sandblast graining, electrolytic graining, brush graining, ball graining, and chemical polishing Can be used. Particularly preferred is an electrolytic etching method using hydrochloric acid or nitric acid, which gives deep and uniform grain.

When the support material is aluminum, a grained surface further subjected to anodization is also preferably used. The anodizing treatment is performed using, for example, phosphoric acid, sulfuric acid or the like.

The thickness of the substrate is usually in the range of 12 to 2000 μm, preferably 20 to 500 μm.

(Method for preparing printing plate) In the present invention,
The photosensitive layer and the base material of the above-mentioned image recording material are laminated immediately before image exposure after peeling the cover sheet as necessary,
After imagewise exposure, the image recording material support is peeled off to form an image (peeling development), and the obtained image area is further irradiated with actinic rays to be post-cured to prepare a printing plate.

As the base material, a resin film having a hydrophilic surface may be used if printing durability is not required, and an aluminum base material may be used if printing durability is required. As described above, in the present invention, it is possible to use any base material depending on the application, which is extremely rational.

The bonding just before the exposure means that the bonding and the exposure are substantially performed in a series of steps, preferably in the same apparatus as shown in the apparatus example diagram (FIG. 3). For example, the substrate is conveyed to the exposure unit or the exposure cylinder in the apparatus and fixed, and then the image recording material is bonded, or the substrate and the image recording material are bonded to each other on the exposure unit or the exposure cylinder. It is preferable to carry out the process and fix it.

The image recording material is supplied in the form of a sheet and attached to a base material, or is supplied in the form of a roll and cut before or after the attachment, or used to prepare a printing plate having a plurality of image recording materials. It is possible to supply the image-forming material in a shape in which it is housed in the unwinding part and has one end of the image-forming material connected to the take-up member, and to perform the bonding, exposure and peeling without cutting the image-forming material. it can. In particular, by supplying and using the image recording material in a shape in which the image recording material is accommodated in the unwinding portion having a length capable of producing a plurality of printing plates, and one end of the image forming material is connected to the winding member, The supply of the image recording material and the collection of the used image recording material can be performed at the same time, and the workability becomes extremely high.

When the image recording material is supplied in the form of a sheet, exposure can be performed by scanning the outer surface of the cylinder, scanning the inner surface of the cylinder, or scanning the surface. When the image recording material is accommodated in the unwinding portion having a length capable of producing a plurality of printing plates, and when the image forming material is provided in a shape in which one end of the image forming material is connected to the winding member, the exposure is a plane scan. Is preferred.

The development is carried out by peeling the image-exposed image recording material from the substrate to remove the image-exposed portion or the unexposed portion together with the support. The peeling method is not particularly limited, but it is necessary to adopt a peeling method in which the peeling angle and the peeling speed are constant in order to obtain a uniform image.

The method of irradiating the image area with actinic rays and / or post-curing by heating is not limited as long as it can give the image area a strength sufficient to withstand printing. For example, the image after the peeling and development may be collectively exposed or scanned with a light source such as a fluorescent lamp, a mercury lamp, a halogen lamp, and a laser, or may be heated with a heat source such as a heater and an infrared lamp.

[0080]

EXAMPLES The present invention will be described below based on examples, but the embodiments of the present invention are not limited thereto. In addition, "part" in an Example represents a "weight part" unless there is particular notice.

Example 1 A 25 μm-thick polyethylene terephthalate (PET) film (T-100, manufactured by Diafoil Hoechst) subjected to corona discharge treatment (80 W / m ² / min) was used as a support for an image recording material. . On this support, a photosensitive layer composition having the following composition was applied by wire bar coating so that the dry film thickness was 2.5 μm to form a photosensitive layer.

Photosensitive layer composition isocyanuric acid EO-modified (n = 3) triacrylate 30.0 parts (Toagosei Kagaku Kogyo: M-315) Brominated bisphenol A-EO modified dimethacrylate 10.0 parts (Daiichi Kogyo Seiyaku Co., Ltd .: GX-6094) Polymethylmethacrylate resin 30.0 parts (Mitsubishi Rayon: Dyanal BR-83) Cyanine dye (Nippon Kayaku: Kayasorb CY-10) 0.6 parts Lithium butyltriphenylborate 1.7 parts 1-Phenyl-5-mercaptotetrazole 0.9 parts Methyl ethyl ketone 400 parts Thickness as a peelable cover sheet on the photosensitive layer
An image recording material was prepared by laminating a 25 μm polyethylene sheet.

The prepared image recording material was divided into two equal parts, and one of them was stored as it was in a refrigerator (4 ° C.) (Example 1). On the other hand, after peeling off the cover sheet, a printing plate support (after anodizing a grained aluminum plate, immersing it in a 3% aqueous solution of sodium metasilicate at 25 ° C for 5 minutes to degrease the surface) A lithographic printing plate was prepared by adhering it on a processed and dried product by passing it through a pair of hot-press rolls under the following conditions and storing it in a refrigerator (4 ° C.) (Comparative Example 1).

Temperature: 100 ° C., Pressure: 2.0 kg / cm ² , Transport speed: 10 mm / sec Example 2 An intermediate layer composition having the following composition was wire-coated on a PET film (T-100) having a thickness of 25 μm. An intermediate layer was provided by coating by bar coating so that the dry film thickness was 5 μm.

Intermediate layer composition Ethylene / vinyl acetate copolymer 15 parts (Mitsui DuPont Polychemical Co .: Evaflex EV-210) Toluene 85 parts Corona discharge treatment (80 W / m ² / min) on the above intermediate layer. A 5.7 μm-thick PET film (T-100 described above) was attached to obtain a support for an image recording material.

On this support, a photosensitive layer composition having the following composition was applied by wire bar coating to a dry film thickness of 2.5 μm to form a photosensitive layer.

Photosensitive Layer Composition Isocyanuric Acid EO Modified (n = 3) Triacrylate 30.0 parts (M-315 above) Brominated Bisphenol A-EO Modified Dimethacrylate 10.0 parts (GX-6094 above) Polymethylmethacrylate resin 30.0 parts (Dianal BR-83 above) Near infrared dye (IR-1) 0.6 parts Lithium butyl triphenylborate 1.7 parts 1-Phenyl-5-mercaptotetrazole 0.9 parts Methyl ethyl ketone 400 parts Releasable on the photosensitive layer 25μ thick as cover sheet
An image recording material was prepared by laminating m polyethylene sheets.

The image recording material thus prepared was divided into two equal parts and stored in the same manner as in Example 1 to obtain Example 2 and Comparative Example 2.

Example 3 Example 2 except that the photosensitive composition layer was changed to the following
An image recording material was prepared in the same manner as in.

Photosensitive Layer Composition Dipentaerythritol Hexaacrylate 40.0 parts (Nippon Kayaku Co., Ltd .: KAYARAD DPHA) Polymethylmethacrylate resin 40.0 parts (said Dyanal BR-3) Cyanine dye (Kayasorb CY-10) 0.6 Parts lithium butyltriphenylborate 1.7 parts 1-phenyl-5-mercaptotetrazole 0.9 parts benzoyl peroxide 2.0 parts methyl ethyl ketone 400 parts The image recording material thus prepared was divided into two equal parts and stored in the same manner as in Example 1 and Example 3 and It was set as Comparative Example 3.

(Performance Evaluation) Six kinds of image recording materials (Examples 1 to 3 and Comparative Examples 1 to 3) stored at 4 ° C. for 7 days were taken out and left at room temperature (20 ° C.) for 2 hours. Next, Examples 1 to 1
After removing the cover sheet of the image recording material of 3 and anodizing the support for the printing plate (the grained aluminum plate was treated with a 3% aqueous solution of sodium metasilicate at 25 ° C. for 5 minutes).
It was dipped for a minute to degrease the surface, dried, and passed over a pair of hot-press rolls under the following conditions to bond them to prepare a lithographic printing plate.

Temperature: 100 ° C., pressure: 2.0 kg / cm ² , transport speed: 10 mm / sec Six types of lithographic printing plate samples were mounted on the outer surface of the exposure cylinder having a diameter of 300 mm, and the exposure cylinder was rotated at a constant speed. However, image exposure was performed under the following conditions.

Light source: LT090MD (manufactured by Sharp Corporation, output 100 m
W, main wavelength 830 nm) Optical efficiency: 67%, exposure beam diameter: 10 μm, exposure pitch:
After exposure to 6 μm, the base material and the support of the image recording material were heated at a temperature of 25 ° C / 80 ° C.
When peeled at cm / sec, the exposed portion of the photosensitive layer was peeled off together with the support, and an image composed of an unexposed portion was formed on the substrate.

The exposure energy required for image formation was 1.5 mJ / cm ² in all the samples.

The images on the substrate are shown in Examples 1 and 2 and Comparative Example 1
And 2 were post-cured by exposing them to 150 mJ / cm ² using a halogen lamp. In Example 3 and Comparative Example 3, the substrate was post-cured by heating the substrate at 150 ° C. for 1 minute.

Example 4 The image recording apparatus shown in FIG. 3 was loaded with the image recording material and the printing plate support used in Example 2.

The printing plate support was conveyed from the aluminum plate replenishing section onto the exposure cylinder and wound, and then the cover sheet of the image recording material was peeled off and bonded to the support on the exposure cylinder while pressing the support roller with a contact roller. did.

Scanning exposure was performed with a semiconductor laser from the exposure section while rotating the exposure cylinder. The exposure conditions were the same as in Example 1.

After exposure, the printing plate support and the image recording material were peeled off at a peeling portion at a speed of 30 cm / sec to form an image.
The printing plate after peeling is an ultraviolet lamp (200 mJ / cm at 350 nm light)
After irradiating with the intensity of ² ), the printing plate was carried out.

Example 5 As shown in FIG. 4, the image recording material (without a cover sheet) loaded in the cartridge shown in FIG. 2 was pressed by a pressure roller while the printing plate support was conveyed to the flat plate exposure section. Then, they were laminated and fixed to the exposed part.

Using an optical system having an fθ lens and a polygon mirror, scanning exposure was performed with a semiconductor laser beam from the support side of the recording material.

After the exposure, the printing plate support was moved in the transport direction, and the image recording material adhered was peeled at a speed of 30 cm / sec while being wound around the winding portion to form an image. The printing plate after peeling off is a UV lamp (200 mJ with 350 nm light).
/ Cm ² intensity) to obtain a printing plate.

The 8 types of printing plates thus obtained were evaluated for reproducibility of halftone dots and lack of image area (uniformity) by a microscope, and stains for non-image area and printing durability by a printing test. The results are shown below.

Halftone dots (175 lines) Image deficiency Non-image area stains Printing durability (sheets) Example 1 4-95% △ None 50000 Example 2 2-98% ○ None 70000 or more Example 3 2-98% ○ None 100000 or more Example 4 2 to 98% ○ None 70000 or more Example 5 2 to 98% ○ None 70000 or more Comparative Example 1 10 to 90% × Yes 20000 Comparative Example 2 10 to 95% × Yes 35000 Comparative Example 3 10 ~ 95% × Yes 40000

[0105]

According to the present invention, high resolution and stability over time,
A lithographic printing plate excellent in printability could be produced at a low cost by a complete dry process.

[Brief description of drawings]

FIG. 1 is a sectional view showing the structure of an image recording material used in the invention for both a and b.

FIG. 2 is a cartridge in which the image recording material of the present invention is stored in such a length that a plurality of printing plates can be prepared.

FIG. 3 is a schematic view showing an example of an apparatus having an exposure cylinder used for making a printing plate of the present invention.

FIG. 4 is a time-series process chart in the case of producing the printing plate of the present invention by another device having a flat plate exposure section.

[Explanation of symbols]

 1 Support 2 Photosensitive Layer 3 Cover Sheet 11 Image Recording Material 12 Unwinding Member 13 Winding Member 20 Exposure Cylinder 21 Image Recording Material Replenishing Section 22 Aluminum Plate Replenishing Section 23 Contact Roll 24 Light Source Unit 25 Ultraviolet Lamp 26 Aluminum Plate 27 Cover Sheet peeling section 28 Recording material peeling section 29 Aluminum plate peeling section 30 Plate material unloading section 31 Waste material discharging section 41 Cartridge 42 Support 43 Crimping roll 44 Exposure section 45 Light source unit 46 Printing plate

Claims (5)

[Claims] 1. An image recording material having a photosensitive layer containing a compound having a polymerizable or crosslinkable ethylenic double bond and a photopolymerization initiator on a transparent support. 1) Hydrophilic surface 2) step of attaching a substrate having a to the exposed portion 2) a step of laminating a photosensitive layer of an image recording material on the hydrophilic surface on the exposed portion 3) a step of imagewise exposing from the support side of the image recording material 4 ) Step of peeling / removing the support of the image recording material together with the exposed or unexposed portion of the photosensitive layer 5) Actinic rays on the image formed of the exposed or unexposed portion of the photosensitive layer formed on the hydrophilic surface A method of preparing a lithographic printing plate, which comprises performing a series of steps including a step of irradiating and / or heating and post-curing. 2. An image recording material having a photosensitive layer containing, on a transparent support, a compound having a polymerizable or crosslinkable ethylenic double bond and a photopolymerization initiator, 1) a hydrophilic surface Step 2 of laminating the photosensitive layer of the image recording material to the base material having 2) step of mounting the above-mentioned laminated base material and image recording material on the exposed portion 3) imagewise from the support side of the image recording material Step of exposing 4) Step of peeling and removing the support of the image recording material together with the exposed or unexposed portion of the photosensitive layer 5) Consist of the exposed or unexposed portion of the photosensitive layer formed on the hydrophilic surface A method for producing a lithographic printing plate, which comprises performing a series of steps of irradiating an image with actinic rays and / or heating to post-cure the image. 3. An image having, on a transparent support, a photosensitive layer containing a compound having a polymerizable or crosslinkable ethylenic double bond and a photopolymerization initiator, and optionally a peelable cover sheet. The recording material is stored in the unwinding portion of a length capable of producing a plurality of printing plates, and one end of the image recording material is connected to the winding member. Of a photosensitive layer of an image recording material on a substrate having a transparent surface without cutting the image recording material 2) Imagewise exposing from the support side of the image recording material 3) Supporting the image recording material The step of peeling and removing the body while winding the image recording material on the winding member without cutting the image recording material together with the exposed or unexposed portion of the photosensitive layer 4) the exposed portion of the photosensitive layer formed on the hydrophilic surface or Is it a process of irradiating the image consisting of unexposed areas with actinic rays to post-cure it? The lithographic printing plate creation method characterized by performing a series of steps consisting. 4. The method for producing a lithographic printing plate as claimed in claim 1, 2 or 3, wherein the photopolymerization initiator is sensitive to near infrared rays and the image exposure is carried out by scanning exposure of a semiconductor laser. 5. The image recording material comprises a transparent support,
A photosensitive layer containing a compound having a polymerizable or crosslinkable ethylenic double bond and a photopolymerization initiator, and a peelable cover sheet are laminated in this order and bonded to a substrate having a hydrophilic surface. The method for producing a lithographic printing plate according to claim 1, 2, 3 or 4, further comprising a step of peeling off the cover sheet.