JPH0667414A - Image forming material and image forming method - Google Patents

Abstract

PURPOSE:To provide an image forming material and image forming method which imparts high sensitivity and high image quality with a small-size mechanism using a semiconductor laser in a longer wavelength than visible light, especially in a near infrared region. CONSTITUTION:The image forming material is produced by depositing at least a cushion layer, peeling layer, photosensitive ink layer and peelable cover sheet on a substrate. The photosensitive ink layer contains an addition-polymerizable or crosslinkable compd. and a borate complex of cationic dye. By using this image forming material, images are formed in such processes of carrying and winding, exposure, peeling, sticking, image transfer, image retransfer, post exposure, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive image-forming material and an image-forming method using the same, and more specifically to a photosensitive composition layer provided on a support and having an adhesive force which is changed by exposure. The present invention relates to an image-forming material capable of forming an image by peeling development or image transfer after exposing a light-sensitive material having the same, and having high sensitivity to light in the visible or near-infrared region, and an image forming method using the same.

[0002]

2. Description of the Related Art Conventionally, an image forming material using a photosensitive material such as a photopolymer and an image forming method using the same have been known and used for producing a color proof for color proofing in color printing. ing. For example, a photosensitive composition comprising a compound capable of addition polymerization or crosslinking, a photopolymerization initiator, and optionally a binder component composed of a coloring material, an organic polymer compound or the like is applied on a support to form an image. A method is known in which an image is formed by exposing a photosensitive composition layer as a material to cure the exposed portion and dissolving and removing the unexposed portion. However, the conventional method using a liquid developing solution has problems of environmental pollution, safety of workers, and large size of the apparatus.

On the other hand, as a method of forming an image by a so-called dry process which does not require liquid treatment using a photosensitive material,
A method using peeling development and a method using transfer development have been known for a long time. As a method applying peeling development,
As disclosed in JP-B-43-22901 and the like, after peeling off the transparent support and the second support after exposing an image on a material comprising a transparent support, a photopolymerizable composition layer and a second support. Accordingly, an image forming method is known in which a positive image is formed on one support and a negative image is formed on the other support. As an image forming method using transfer development, an image is exposed to an image forming material having at least a photopolymerizable composition layer on a support through a color separation negative or a mask, and the photopolymerizable after exposure is used. The method of forming an image by transferring the composition layer surface to the image receptor by applying pressure while applying heat to the image receptor and transferring the unexposed portion onto the image receptor, U.S. Patents 3,060,023, 3,060,024, and the same. 3,
No. 060,025 and JP-A No. 63-147154. The image forming method by such a dry process is a preferable method in terms of environmental pollution, safety, and downsizing of the apparatus.

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. However, the photosensitive composition used in the conventional image forming method as described above, as a photopolymerization initiator, benzophenone, thioxanthone, quinone, aromatic ketones such as thioacridone, benzoin, benzyl,
Those having a photosensitive wavelength in the ultraviolet region, such as benzyl ketal, have been used.

Attempts to lengthen the photosensitive wavelength of a photosensitive composition to a wavelength longer than visible light have been proposed so far, and a photosensitive composition having a photosensitivity in the visible light region is disclosed in, for example, Japanese Patent Laid-Open No. 47-47. -2528, 54-155292, 48-84183, 54-1
51024, 60-88005, 58-40302, 59-56403
No. 59-189340, JP-A No. 2-69, No. 2-189548 and the like. Although these photosensitive compositions have sensitivity to visible light, they are still not sufficiently practical in sensitivity, and a long exposure time is required to form an image by laser scanning exposure, which is not efficient. Absent. Further, in the prior art, the semiconductor laser cannot be used because it has no sensitivity in the near infrared region, which is the oscillation wavelength of the semiconductor laser, which is currently the smallest and cheapest laser light source.

As a photosensitive composition sensitive to long wavelengths in the near-infrared region or more, JP-A-62-143044 discloses a system containing a novel photopolymerization initiator using a borate complex of a cationic dye. Disclosed and further proposed is an image forming method using the initiator system. However, in the above publication, there is no description about a photopolymerization initiator having a photosensitivity to a wavelength of 780 nm or more that can be applied to a semiconductor laser, and there is a drawback that the image forming method also requires a complicated structure such as a microcapsule. It was Further, Japanese Patent Application Laid-Open No. 2-4804 discloses a photosensitive material having a photosensitivity at a wavelength of 600 to 900 nm which can be applied to a semiconductor laser by combining a cationic dye and a borate compound as a photopolymerization initiator. However, conventionally, a simple color image forming method of dry treatment using a semiconductor laser and a photopolymerizable composition has not been known.

[0007]

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 use a laser having a long wavelength longer than visible light, particularly a semiconductor laser having a wavelength in near infrared light, It is an object of the present invention to provide a novel image forming method that has high sensitivity and excellent image quality, does not require liquid development, and can form an image with a simple and small mechanism.

[0008]

The present inventors have made diligent efforts to achieve the above object, and as a result, have developed an image forming material having a photosensitive composition containing a borate complex of a specific cationic dye as a photopolymerization initiator. It was clarified that when used, it exhibits extremely high photosensitivity to light in the visible to near-infrared region and can form a good image, and completed the present invention. That is, the above object of the present invention is achieved by the following configurations.

(1) At least a cushion layer on the support,
An image forming material in which a release layer, a photosensitive ink layer, and a releasable cover sheet are sequentially laminated, wherein the photosensitive ink layer contains at least an addition-polymerizable or crosslinkable compound and a borate complex of a cationic dye. material.

(2) Conveying and winding step of winding the image forming material described in (1) around an exposure drum, and an image obtained by scanning and exposing the image forming material wound around the exposure drum with laser light modulated according to image information. Exposure step, peeling step of peeling the cover sheet from the image-forming material after image exposure, adhesion step of pressing / pressurizing the image-forming material from which the cover sheet is peeled off and the image-receiving sheet, and peeling of the support of the image-forming material An image forming method comprising an image transfer step of transferring a photosensitive ink layer in an exposed portion onto an image receiving sheet, and a post-exposure step of irradiating the transferred uncured image with light.

(3) Conveying and winding step of winding the image forming material described in (1) around an exposure drum, and an image obtained by scanning and exposing the image forming material wound around the exposure drum with laser light modulated according to image information. Exposure step, peeling step of peeling the cover sheet from the image-forming material after image exposure, adhesion step of pressurizing / pressurizing the image-forming material from which the cover sheet has been peeled off and the image-receiving sheet, laminate of the image-forming material and the image-receiving sheet An image forming method comprising a post-exposure step of irradiating light on the surface and an image transfer step of peeling the support of the image-forming material to transfer the unexposed portion of the photosensitive ink layer onto the image receiving sheet.

(4) Conveying and winding step of winding the image forming material described in (1) around the exposure drum, and image of scanning and exposing the image forming material wound around the exposure drum with laser light modulated according to image information. Exposure step, peeling step of peeling the cover sheet from the image-forming material after image exposure, adhesion step of pressing / pressurizing the image-forming material from which the cover sheet is peeled off and the image-receiving sheet, and peeling of the support of the image-forming material Image transfer process of transferring the photosensitive ink layer of the exposed part onto the intermediate transfer medium, image retransfer process of retransferring the image on the intermediate transfer recording medium to the image receiving sheet, and post-exposure by irradiating the transferred uncured image with light. An image forming method comprising steps.

(5) The exposure drum in the image exposure process
The image forming method according to any one of (2) to (6), which is controlled to a constant temperature of 40 ° C. or higher.

(6) A photosensitive ink image containing yellow, magenta and cyan, or yellow, magenta, cyan and black coloring materials is transferred onto the same image receptor to form a full color image (2). The image forming method according to any one of (5) to (5).

The present invention will be described in detail below.

The image-forming material of the present invention comprises a support, at least a cushion layer, a peeling layer, a photosensitive ink layer containing a compound capable of addition polymerization or crosslinking and a borate complex of a cationic dye, and a peelable cover. The sheets are sequentially stacked.

Any support may be used as long as it has good dimensional stability. Specific examples thereof include polyethylene films, polypropylene films, polyethylene terephthalate films, polyethylene naphthalate films, acetate films, polyimide films and other resin films. Is used. The thickness of the support is not particularly limited,
Usually, a film having a thickness of 2 to 300 μm, preferably 5 to 200 μm is used. A backing layer may be provided on the back surface of the support in order to impart functions such as running stability and antistatic property.

The cushion layer is provided for the purpose of increasing the adhesion between the ink sheet and the image receiving sheet, but the support itself may be provided with cushioning properties. In order to impart cushioning properties, a material having a low elastic modulus, a material having rubber elasticity, or a thermoplastic material that is easily softened by heating to improve adhesiveness may be used. Specifically, natural rubber, acrylate rubber, butyl rubber, nitrile rubber, butadiene rubber, isoprene rubber, styrene-butadiene rubber, chloroprene rubber, urethane rubber, silicone rubber, acrylic rubber, fluorine rubber, neoprene rubber, chlorosulfonated polyethylene, Epichlorohydrin, EPD
M (ethylene / propylene / diene rubber), elastomer such as urethane elastomer, polyethylene, polypropylene, polybutene, impact resistant ABS resin, polyurethane, ABS resin, acetate, cellulose acetate,
Amide resin, polytetrafluoroethylene, nitrocellulose, polystyrene, epoxy resin, phenol-formaldehyde resin, polyester, impact-resistant acrylic resin, ethylene-vinyl acetate copolymer, acrylonitrile-butadiene copolymer, vinyl chloride-vinyl acetate copolymer Among the polymers, polyvinyl acetate, vinyl chloride resin containing a plasticizer, vinylidene chloride resin, polyvinyl chloride, polyvinylidene chloride and the like, resins having a low elastic modulus can be mentioned. Also, these materials can be applied to the support to give the support itself cushioning properties.

The thickness of the cushion layer varies depending on various factors such as the type of resin used, the type of photosensitive ink, the surface smoothness of the image receiving sheet, etc., but is usually in the range of 10 to 100 μm. The cushion layer can be formed by a conventionally known method such as a coating method, a laminating method or a hot melt extrusion method.

The release layer used in the present invention controls the transferability of the exposed area and the unexposed area after image recording of the photosensitive ink layer described below formed on the release layer to improve the S / N ratio. To do. Specific compounds include, for example, mold-releasing compounds such as silicone resins, fluorine resins, fluorine-based surfactants, resins such as alcohol-soluble polyamide, alcohol-soluble nylon, polyvinyl acetate, polyvinyl chloride, polyvinyl alcohol, etc. The compounds exemplified in JP-A 3-154057, page 3, upper left column, line 11 to upper right column, line 13 can be used. Further, the thickness of the peeling layer may be 0.05 to 5 μm,
It is preferably 0.1 to 2 μm.

The photosensitive ink layer contains a compound capable of addition polymerization or crosslinking as the first essential constituent component. The compound capable of addition polymerization or crosslinking is preferably a compound having at least one ethylenically unsaturated double bond in the molecule, specifically, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate. , Glycerol acrylate, Tetrahydrofurfuryl acrylate, Phenoxyethyl acrylate, Nonylphenoxyethyl acrylate, Tetrahydrofurfuryloxyethyl acrylate, Tetrahydrofurfuryloxyhexanolide acrylate, ε-Caprolactone adduct of 1,3-dioxane alcohol, acrylate, 1 Monofunctional acrylic acid esters such as 3,3-dioxolane acrylate, or methacrylic acid obtained by replacing these acrylates with methacrylate, itaconate, crotonate, maleate Itaconic acid, crotonic acid, maleic acid esters, 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,
Diacrylate of ε-caprolactone adduct of neopentyl glycol hydroxypivalate, 2- (2-hydroxy-1,1-dimethylethyl) -5-hydroxymethyl-5-ethyl-
Bifunctional acrylic ester such as 1,3-dioxane diacrylate, tricyclodecane dimethylol acrylate, ε-caprolactone adduct of tricyclodecane dimethylol acrylate, diacrylate of diglycidyl ether of 1,6-hexanediol, or the like, or Methacrylic acid obtained by replacing these acrylates with methacrylate, itaconate, crotonate, maleate, itaconic acid, crotonic acid, maleic acid ester; trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, trimethylolethane triacrylate, pentaerythritol triacrylate, Pentaerythritol tetraacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipenta Lithritol hexaacrylate, ε-caprolactone adduct of dipentaerythritol hexaacrylate, pyrogallol triacrylate, propionic acid / dipentaerythritol triacrylate, propionic acid / dipentaerythritol tetraacrylate, hydroxypivalaldehyde modified dimethylolpropane triacrylate, etc. Examples thereof include polyfunctional acrylic acid esters, or methacrylic acid, itaconic acid, crotonic acid, and maleic acid ester in which these acrylates are replaced with methacrylate, itaconate, crotonate, and maleate. Among them, acrylic acid ester and methacrylic acid ester compounds can be particularly preferably used. It is preferable to use one kind or a mixture of two or more kinds of these compounds.

The second essential constituent component of the photosensitive ink layer of the present invention is a borate complex of a cationic dye contained as a photopolymerization initiator. As the borate anion of the dye salt formed from the cationic dye part and the borate anion (hereinafter referred to as the dye of the present invention), those represented by the following general formula (1) are preferable.

The general formula _{^{(1) B - (R 1}} ) (R 2) (R 3) in (R ₄₎ formula, R _1, each R _2, R ₃ and R ₄ may be the same or different alkyl Groups (eg ethyl, butyl etc.), aryl groups (eg phenyl, naphthyl etc.), aralkyl groups (eg benzyl, phenethyl etc.), alkenyl groups (eg vinyl, allyl etc.), alkynyl groups (eg propenyl, butynyl etc.), cyclo It represents an alkyl group (eg, cyclohexyl, cyclopentyl, etc.) or a heterocyclic group (eg, thienyl, pyridyl, etc.), 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, which has absorption in the visible region to the infrared region, Examples include acridine and oxazine dyes.

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 indoalinine type dye are particularly preferable. These dyes are described, for example, in Coloring Materials, 61 [4], pages 215 to 226, and typical examples are given below.

[0026]

[Chemical 1]

[0027]

[Chemical 2]

[0028]

[Chemical 3]

[0029]

[Chemical 4]

In the present invention, it is preferable to add an ammonium salt of borate anion (hereinafter referred to as ammonium salt) as a sensitizer. A preferable ammonium salt is a salt composed of a quaternary ammonium cation and a borate anion represented by the general formula (1).
The ammonium cation is preferably tetraalkylammonium [(R) ₄ N] ⁺ , and the alkyl group (R) is an alkyl group having 1 to 12 carbon atoms (eg, methyl, ethyl, propyl, butyl, pentyl, hexyl). , Octyl, decyl, dodecyl and the like). 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 ink layer of the present invention is not particularly limited, but preferably, the dye of the present invention is 0.01 to 100 parts by weight of the addition-polymerizable or crosslinkable compound. -20 parts by weight, more preferably 0.
The amount of the sensitizer is 0 to 50 parts by weight, more preferably 0 to 20 parts by weight.

The photosensitive ink layer of the present invention preferably contains a binder component and a heat-fusible substance in addition to the above-mentioned components for the purpose of modifying the composition and improving the physical properties after curing.

As the heat-fusible compound, a compound which is solid at room temperature and reversibly becomes liquid when heated is used. As specific examples, carnauba wax, candelilla wax,
Vegetable waxes such as wood wax, auricurie wax and rice wax; animal waxes such as beeswax, insect wax, shellac wax and whale wax, lanolin; petroleum-based waxes such as paraffin wax, microcrystalline wax, petrolatum, ester wax and oxidized wax Waxes; and mineral waxes such as montan wax, ozokerite and ceresin;
Examples of so-called waxes such as Fischer-Tropsch wax, polyethylene wax, montan wax derivative, paraffin wax derivative, microcrystalline wax derivative, hardened castor oil, hardened castor oil derivative, and other so-called waxes, and other waxes Higher fatty acids such as palmitic acid, stearic acid, margaric acid and behenic acid; higher alcohols such as palmityl alcohol, stearyl alcohol, behenyl alcohol, marganyl alcohol, eicosanol; cetyl palmitate, myricyl palmitate, cetyl stearate. Higher fatty acid esters such as; amides such as acetamide, propionic acid amide, palmitic acid amide, stearic acid amide, behenic acid amide and amide wax;
Also, higher amines such as stearylamine, behenylamine and palmitylamine are preferably used.
In addition, low melting point thermoplastic resins such as low molecular weight polyethylene, polypropylene, polystyrene, polyester, polyamide, and polycaprolactone may be used.

As the heat-meltable material, it is preferable to use a compound having a melting point of 40 to 150 ° C. The heat-meltable material may be dissolved or dispersed in another compound in the photopolymerizable composition, or the heat-meltable material dissolved or dispersed in a solvent or a dispersion medium may be used as a photopolymerizable material. You may add and mix in the other compound in a composition.

The blending amount of the heat-fusible material is not particularly limited, but is 0.1 to 60% by weight, preferably 0.2 to 40% by weight of the photosensitive ink.
Used by weight percent.

The binder component is preferably an organic polymer compound, which is appropriately selected according to the purposes such as compatibility with other components, tackiness, adhesiveness, film forming property, developability, printability, and improvement. do it. Specific compounds include 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,
Copolymers of styrene / butadiene and the like and acrylonitrile; polyacrylonitrile, polyvinyl alcohol, polyvinyl allylic ether (where the alkyl group is methyl, ethyl, propyl, butyl, etc.), polyvinyl alkyl ketone, polystyrene, polybutadiene, polyisoprene,
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; and other various itaconic acid copolymers, maleic acid copolymers, partially esterified maleic acid copolymers, and the like. Among these, one kind or a combination of two or more kinds can be used. 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, relative to 100 parts by weight of the compound capable of addition polymerization or crosslinking.

The photosensitive ink layer of the present invention may further contain various additives such as a thermal polymerization inhibitor, a coloring agent, a plasticizer, a resin, a surface protective agent, a smoothing agent and a coating aid, if necessary. Can be made.

As the thermal polymerization inhibitor, compounds such as quinone type and phenol type are preferably used. Examples thereof include hydroquinone, pyrogallol, p-methoxyphenol, catechol, β-naphthol, 2,6-di-t-butyl-p-cresol and the like.

As the colorant, carbon black, titanium oxide, iron oxide, phthalocyanine pigment, azo pigment,
Pigments such as anthraquinone pigments and known pigments and / or dyes such as crystal violet, methylene blue, azo dyes, anthraquinone dyes and cyanine dyes can be used.

When the present invention is applied to a color proof used for a color composition for printing, etc., as a colorant, a color tone corresponding to a normal color required for color proofing, that is, each color of yellow, magenta, cyan and black is used. It is preferable to use the pigments and / or dyes mentioned above, and it is particularly preferable to use the pigments of the respective colors used in the printing ink in order to obtain a color image similar to a printed matter.

The following are some examples of pigments and dyes known in the art (CI stands for Color Index).

Pictorial Pure Blue (CI 42595),
Auramine (CI 41000), Catillon Brilliant Flavin (CI Basic 13), Rhodamine 6GCP (CI 4516
0), Rhodamine B (CI 45170), Safranine OK 70: 100
(CI 50240), Erioglaucin X (CI 42080), First Black HB (CI 26150), No.1201 Lyonol Yellow (CI 21090), Lionol Yellow GRO (CI 2109
0), Shimura First Yellow 8GF (CI 21105), Benzidine Yellow 84T-564D (CI 21095), Shimura First Red 4015 (CI 12355), Lionol Red 7B4401.
(CI 15830), Fast Gen Blue TGR-L (CI 7416
0), Lionol Blue SM (CI 26150), carbon black.

The content of the colorant in the photosensitive ink layer is appropriately determined according to the target optical density and the like, but is preferably 5 to 50% by weight, more preferably the total amount of the photosensitive ink layer.
10-35% by weight is used.

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. Dimethyl glycol phthalate, methyl phthalyl ethyl glycolate, methyl phthalyl ethyl glucolate, and other glycol esters; tricresyl phosphate, triphenyl phosphate, tributyl phosphate, tri-2-ethylhexyl phosphate, and other phosphate esters; butyl ole Monobasic acid esters such as oleate and glycerin monooleate; dibutyl adipate,
Aliphatic dibasic acid esters such as diisobutyl adipate, dioctyl adipate, dioctyl azelate, dibutyl sebacate, dimethyl sebacate, dioctyl sebacate, dibutyl maleate; diethylene glycol dibenzoate, triethylene glycol di-2-ethyl butyrate And other dihydric alcohol esters; triethyl oxalate, glycerin triacetyl ester, butyl laurate and the like can be used.

The photosensitive ink layer of the present invention is formed by coating on a support without using a solvent, or by dissolving or dispersing in a suitable solvent, coating and drying on a support to form a photosensitive composition layer. Can be formed. The film thickness of the photosensitive composition layer can be appropriately determined depending on the target optical density and the like, but within the allowable range, the thinner the film, the higher the resolution and the better the image quality. Therefore, the film thickness is preferably in the range of 0.1 to 20 μm, particularly preferably 0.1 to 6 μm.

In the image forming material of the present invention, a cover sheet is provided on the photosensitive ink layer. As a cover sheet,
Good mechanical strength to withstand peeling, good visible to near-infrared transmittance (40% or more, preferably 60% or more at a wavelength of about 300 to 2000 nm), high surface smoothness, etc. is necessary. Specifically, plastic films such as polyethylene terephthalate, cellulose triacetate, cellulose diacetate, polyvinyl chloride, polyvinyl alcohol, polycarbonate, polystyrene, polyethylene, polypropylene, cellophane, polysulfone, polyamide and polyimide are used alone or in combination of two or more. Can be used as a complex.

The thickness of the cover sheet is usually 3 to 200 μm,
It is preferably used in the range of 5 to 50 μm.

The cover sheet is formed by laminating the cover sheet on the photosensitive ink layer by heating and / or pressurizing, or by using a resin for the cover sheet in an appropriate solvent or water.
Apply the dissolved or dispersed coating liquid on the photosensitive ink layer.
It may be dried. Alternatively, it may be formed by coating and drying a photosensitive ink layer on a cover sheet, and then laminating it on a laminate having a cushion layer on a support and a release layer.

In addition to the above-mentioned constitution, the image forming 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, between the support and the cushion layer, between the cushion layer and the release layer,
Alternatively, a layer for controlling the adhesive force between the photosensitive ink layer and the cover sheet, an oxygen barrier layer on the photosensitive layer, a transport improving layer provided on the side of the support opposite to the surface provided with the photosensitive layer, and antistatic. Provision of layers and the like is also optional.

Next, the image forming method of the present invention will be described.

In the image forming method of the present invention, the image forming material is first wound around the exposure drum (conveying and winding step).

Next, the image forming material wound around the exposure drum is scanned with laser light modulated according to image information to perform image exposure (image exposure step).

By using this laser light source, light can be focused into a beam shape and scanning exposure can be performed in accordance with image data, so that direct writing can be performed without using a mask material, and a photosensitive ink can be used. Since the optical system can be easily set so as to focus the laser beam on the layer, high-resolution image formation becomes possible.

The laser light source used in the present invention is a well-known solid-state laser such as YAG laser; He-
Gas lasers such as Ne laser, argon laser, carbon dioxide laser, other discharge excitation molecular lasers and excimer lasers; chemical lasers, dye lasers, semiconductor lasers and the like can be used. Of these, an argon laser, a He-Ne laser, a semiconductor laser and the like are preferably used. In particular, semiconductor lasers are not only compact and lightweight and have relatively high output, but also the oscillation wavelength can be changed by their composition, so they can be selected appropriately according to the photosensitive wavelength range of the image-forming material used, and also directly. It is a very preferable light source because it has the advantage that it can be modulated.

The composition of a semiconductor laser that is preferably used and its oscillation wavelength range are shown by way of example. InGaP laser (0.6
5 to 1.0 μm), AlGaAs laser (0.7 to 1.0 μm), GaAsP
Laser (0.7 to 1.0 μm), InGaAs laser (1.0 to 3.5 μm)
μm), InAsP laser (1.0 to 3.5 μm), CdSnP ₂ laser (1.01 μm), GaSb laser (1.53 μm) and the like. The laser can form a beam by using a single light source or a plurality of light sources, and may simultaneously expose with a plurality of beams.

If the temperature of the image forming material is controlled to a constant temperature during image exposure, it is possible to form an image with good reproducibility regardless of the temperature of the environment. The temperature of the image forming material is not particularly limited, but it is preferable to control the temperature to 40 ° C. or higher. If the temperature is constantly controlled to be lower than 40 ° C., the temperature of the apparatus may reach the temperature of the image forming material or higher depending on the environment, and the apparatus becomes large due to installation of a cooling device or the like. When the temperature is controlled to 40 ° C or higher, there is an advantage that the temperature can be controlled only by the heating device in a normal use environment. Further, if the temperature of the image forming material during image exposure is high, the energy required for recording can be reduced because the rate of photopolymerization or photocrosslinking reaction of the photosensitive ink layer during image exposure is increased, that is, the recording sensitivity is increased. can do.
The upper limit of the temperature of the image forming material varies depending on the material of the image forming material and the heat resistance of the apparatus, but is usually 180 ° C. or lower, preferably 120 ° C. or lower. Further, the temperature control may be performed by controlling the temperature of the entire image forming material to a constant temperature, or by locally controlling only the vicinity of the portion irradiated with the laser beam during image exposure. The local control has the advantage that the heating device can be made compact.

The temperature can be controlled by a known method such as a method of incorporating a heater in the exposure drum or a method of irradiating with an infrared lamp from the surroundings, or the method described in Japanese Patent Application No. 4-99436. It can be performed by a method or the like.

Next, the cover sheet is peeled off from the image forming material after the image exposure to expose the photosensitive ink layer (peeling step).

The transfer of the colored image onto the image receiving member can be carried out after forming the colored image by bringing the image surface on the support and the image receiving surface of the image receiving member into close contact with each other and applying pressure. The pressurization can be performed by a known method such as passing a nip roll.

The surface of the image forming material on the side of the photosensitive ink layer from which the cover sheet has been peeled off and the image receiving sheet are pressed and pressure-bonded to bring the unexposed portion of the photosensitive ink layer into close contact with the image-receiving paper (adhesion). Process).

In this step, if necessary, heating may be carried out simultaneously with the pressurization. The temperature when heating is 40 to 15
0 ° C is preferred. As a pressurizing and / or heating means in the contacting step, a known method such as a heat roller or a heat press can be used.

Further, the support of the image forming material is peeled off and the uncured portion of the photosensitive ink layer that is brought into close contact with the image receiving paper is transferred onto the image receiving sheet to form an image by the uncured material of the photosensitive ink (transfer). Process).

The uncured image transferred onto the image-receiving sheet is cured by further irradiation with light in the post-exposure step, and the photopolymerization initiator contained in the uncured image is erased (post-exposure step). .

This post-exposure step stabilizes the image and provides a clear color image with good color reproducibility. The post-exposure step is not after the transfer step, but after the adhesion step.
It may be performed before the transfer step of peeling the support. By post-exposure before the transfer step, the image forming portion can be cured before the transfer, so that the transfer amount of the photosensitive ink layer at the time of transfer can be made constant and high density can be obtained. it can.

The image-receiving sheet used in the present invention is not particularly limited, and coated paper, art paper, high-quality paper, synthetic paper and the like, vinyl chloride resin sheet, ABS resin sheet,
Single layer of polyethylene terephthalate film, polyethylene naphthalate film, polyimide film, polyetherimide film, polycarbonate film, polyetherketone film, polyarylate film, polysulfone film, polyethersulfone film, etc., or various laminated layers of them Examples include plastic films, films formed of various metals, films formed of various ceramics, and the like. When an image is recorded on an image receiving material having a hydrophilic surface (for example, a hydrophilically treated aluminum plate or a hydrophilically treated plastic film), it can be used as a plate for lithographic printing.

Further, instead of an image receiving sheet for obtaining a final image, after an image is once formed on the intermediate transfer medium,
It may be transferred to another image receiving sheet. When an intermediate transfer medium is used, the post-exposure step may be performed after the transfer to the intermediate transfer material or after the final transfer to the image receiving sheet. The intermediate transfer medium usually has a support and an image-receiving layer, and may be formed of only the support. It is desirable that the intermediate transfer medium has excellent dimensional stability so that an image can be properly formed, and that it has appropriate heat resistance when heated in the contact step.

The image-receiving layer can be formed of a binder, various additives added as necessary, and a substance for imparting the cushioning property. Examples of the image-receiving layer include polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer,
Resins with relatively small polarity (small SP value) such as vinyl chloride resins and various modified olefin resins, and styrene-based, 1,2-polybutadiene-based, olefin-based, urethanes with a glass transition point (Tg) of 30 ° C or less. Thermoplastic elastomers such as series, polyester series and polyamide series are preferred. These resins are advantageous not only because they have good ink retransfer properties, but also because they do not peel off the image receiving sheet even when they come into close contact with the final image receiving sheet such as paper.

Further, it is effective to provide a cushion layer between the support and the support for the purpose of improving the retransfer property to the final image receiving sheet. The cushion layer interposed between the support and the image receiving layer is the same as the cushion layer described in the image forming material.

The thickness of the support in the intermediate transfer medium having the support, the cushion layer and the image receiving layer, and the thickness of the support in the intermediate transfer medium formed of only the support are not particularly limited. The thickness of the cushion layer is the same as the thickness of the cushion layer in the image forming material. The thickness of the image receiving layer is usually 0.1 to 20 μm, but this is not the case when the cushion layer is used as the image receiving layer.

By combining image exposure by laser scanning on an image forming material having a photosensitive composition layer and dry treatment by peeling development or image transfer, environmental problems and waste liquid treatment are required, and It is possible to easily perform high-definition image formation without performing liquid processing that requires a large processing device. Further, when a semiconductor laser is used as a light source and an image is formed in combination with a photosensitive composition having sensitivity to the wavelength of the semiconductor laser, not only is the device miniaturized due to the small semiconductor laser, but also the photosensitive composition As a cationic dye to be contained as a photopolymerization initiator, a dye having no or little absorption of visible light can be used, so that a good color without turbidity can be obtained particularly when a color image is formed. It has the advantage of being reproducible.

In the present invention, after a monochromatic image is formed on the image receiving sheet or the intermediate transfer medium, images of different tones are sequentially transferred onto the same image receiving sheet, whereby images having a plurality of tones are formed on the image receiving sheet. Can be formed. In particular, a full-color image can be formed on the image receiving sheet by sequentially transferring monochromatic images of yellow, magenta, cyan or yellow, magenta, cyan and black onto the same image receiving sheet. As the image forming material for forming a full color image, a plurality of image forming materials having different colors can be used to form a single color image having a plurality of different color tones, but preferably yellow, magenta and cyan. , Or yellow, magenta,
A so-called frame-sequential image-forming material having a photosensitive ink layer formed by coating a plurality of photosensitive inks containing cyan and black colorants in different colors on different regions of the same support is used. be able to. By using such a frame-sequential type image forming material, it is possible to simplify the transport system of the image forming material in the image forming apparatus and further downsize the image forming apparatus.

As the image forming material for forming a full color image, a material provided with a detection mark for identifying a color may be used. The transfer of the colored image onto the image receiving member can be performed by forming the colored image and then bringing the image surface on the support and the image receiving surface of the image receiving member into close contact with each other and applying pressure. Moreover, you may heat simultaneously at the time of pressurization as needed. Pressurization can be performed by a known method such as passing through a nip roll.

[0074]

EXAMPLES The present invention will be described below based on examples, but the present invention is not limited to these examples.

Example 1 An ethylene-vinyl acetate copolymer (EV-250 manufactured by Mitsui DuPont Polychemical Co., Ltd.) was used as a cushion layer as a 20 μm thick layer on a 100 μm thick polyethylene terephthalate film. 0.2 μm of polyvinyl alcohol (Nippon Gosei Kagaku KK: Gohsenol GL-05) was applied on the cushion layer.
And the thickness was set as the release layer. A photosensitive ink layer composition having the following composition was applied on the above-mentioned release layer by a wire bar coating method so as to have a dry film thickness of 1.0 μm.

Photosensitive ink composition Dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd.) 100 parts by weight Chlorinated polyethylene 50 parts by weight (Sanyo Kokusaku Pulp Co., Ltd .: Supercron 907LTA) Carnauba wax 50 parts by weight Borate complex of cationic dye (Compound IR-1) 3 parts by weight Organic boron compound 6 parts by weight (Tetrabutylammonium salt of butyltriphenylboron) Toluene 300 parts by weight Methyl ethyl ketone 300 parts by weight Magenta pigment 25 parts by weight (Toyo Ink Co., Ltd .: Lionol Red 6BFG- 4219X) Further, a transparent polyethylene terephthalate film having a thickness of 25 μm was pressure-laminated on the photosensitive ink layer to form a cover sheet, and an image forming material sample A was obtained.

The image forming material sample A is attached to the outer surface of the exposure drum including the heater with the cover sheet facing outward. Next, while rotating the exposure drum at a constant speed without heating it, a semiconductor laser modulated by image information from the outer peripheral direction of the exposure drum (LT090MD manufactured by Sharp Corporation, output 100 m
Image exposure is performed by scanning the entire surface of the image forming material while irradiating the laser beam from W). The laser was focused through the optical system so that the beam diameter was 8 μm on the surface of the image forming material, and the average energy density on the surface of the image forming material was 50 mJ / cm ² . The temperature of the exposure drum was 50 ° C. during image exposure. The temperature of the exposure drum at the end of image exposure was 26 ° C.

After the image exposure is completed, the cover sheet is peeled off from the image forming material while the image forming material is attached to the exposure drum to expose the surface of the photosensitive ink layer. The exposed photosensitive ink layer surface and the image receiving sheet, art paper (62.5 kg of Mitsubishi Toku Ryokan Art, manufactured by Mitsubishi Paper Mills Co., Ltd.), are brought into close contact with each other with a nip roll heated to 85 ° C. Next, the image forming material is peeled off from the image receiving sheet, and the unexposed portion of the photosensitive ink is imagewise transferred onto the image receiving sheet. The image-receiving sheet on which the image was formed was irradiated with light from a xenon lamp to cure the image. The obtained magenta image was excellent in fixability without color turbidity because the borate complex of the cationic dye as the photopolymerization initiator was decolored, and had a resolution of 100 lines / mm or more.

The same operation was carried out while the exposure drum was heated to 50 ° C. by the built-in heater, and the average energy density on the surface of the image forming material during exposure was 35 mJ / cm ²
The same good image was obtained.

Example 2 Example 1 was repeated except that the image receiving sheet was replaced with a white PET film (W410, manufactured by Dia foil Hoechst Co., Ltd., thickness: 100 μm) as an intermediate transfer medium from the art paper as the image receiving sheet, and no post-exposure was performed. Similarly, an uncured image was obtained on the white PET film.

This image is a plain paper (Beck smoothness of 200 seconds)
After passing through a laminator heated to 100 ° C., the white PET film was peeled off and the image was retransferred onto plain paper. Further, when the image was post-exposed and cured in the same manner as in Example 1, a magenta image having no color turbidity and excellent fixability and resolution (60 lines / mm or more) was obtained as in Example 1. It was

Example 3 Image forming material samples Y3, M3, C3 and K3 were prepared in the same manner as in Example 1 except that the pigment was changed to the following.

Samples Facial Y3 Cyan: Cyanimble-4920 (manufactured by Dainichiseika) M3 Magenta: Seika Fast Carmine 1483 (manufactured by Dainichiseika) C3 Yellow: Seika First Yellow H-7 (manufactured by Dainichiseika) K3 black: carbon black A color image was formed using the obtained four color image forming material samples Y3, M3, C3 and K3. That is, first, the image forming material Y3 was attached to the outer surface of the exposure drum including the heater with the cover sheet facing outside. Then, while rotating the exposure drum at a constant speed, scanning exposure is performed over the entire surface of the image forming material while irradiating the laser beam from the semiconductor laser modulated corresponding to the yellow image information from the outer peripheral direction of the exposure drum. went. The type of laser used, the beam diameter, and the energy density were the same as in Example 1, and the temperature of the exposure drum was 45 ° C. After the image exposure, the cover sheet is peeled off from the image forming material while the image forming material is attached to the exposure drum to expose the surface of the photosensitive ink layer, and then the surface of the photosensitive ink layer and the art paper ( (The same as in Example 1) was adhered while being pressed with a nip roll heated to 85 ° C. Next, the image-forming material is peeled off from the image-receiving sheet, the unexposed portion of the photosensitive ink is transferred onto the image-receiving sheet in an imagewise manner, and then light is irradiated by a xenon lamp to cure the image and decolorize the photopolymerization initiator. And a yellow image was obtained.

After removing the image forming material Y3 from the exposure drum, the image forming material sample M3 was attached to the exposure drum,
Scanning exposure is performed with a laser beam from a semiconductor laser that is modulated according to magenta image information. After the cover sheet was peeled off, the magenta image was brought into close contact with art paper on which a yellow image had been formed, transferred, and then post-exposed with a xenon lamp to cure the image and decolorize the photopolymerization initiator.

Image forming material sample C3 was prepared in exactly the same manner.
Using K3, cyan and black images were sequentially transferred and transferred onto art paper to obtain a full-color image. The obtained full-color image had good image transfer without image loss, and had excellent image adhesion to the art paper as an image receiving sheet. In addition, a transferred image of only the image portion can be obtained, and an image having a similar appearance and quality to the printed matter was obtained.

Example 4 An image forming material sample K4 was prepared in the same manner as in Example 1 except that the photosensitive ink layer having the following composition was used so that the dry film thickness of the photosensitive ink layer was 2.5 μm.

Photosensitive Ink Composition Dipentaerythritol Hexaacrylate (manufactured by Nippon Kayaku Co., Ltd.) 100 parts by weight Chlorinated polyethylene (supra: Supercron 907LTA) 50 parts by weight Carnauba wax 50 parts by weight Borate complex of cationic dye (compound IR -1) 3 parts by weight Organic boron compound 6 parts by weight (butyl triphenylboron tetrabutylammonium salt) Toluene 300 parts by weight Methyl ethyl ketone 300 parts by weight Yellow pigment (Mikuni dye company: MHI-534) 9 parts by weight Magenta pigment (Mikuni Dyeability: MHI-527) 9 parts by weight Cyan pigment (Mikuni Dyeability: MHI-454) 9 parts by weight Using image forming material sample K4, a thickness of 10
An image was formed in exactly the same manner as in Example 1 except that a polyethylene terephthalate film of 0 μm was used. The black image obtained had a high transmission density of 3.2, and
A high resolution of more than books / mm was obtained.

Example 5 Using the same image forming material sample K4 as in Example 4 and a polyethylene terephthalate film image-receiving sheet (thickness 100 μm), as in Example 1, a conveying and winding step, an image exposure step, a peeling step, and an adhesion step After the steps, the laminated body of the image-forming material and the image-receiving sheet which were in close contact with each other was irradiated with light with a xenon lamp, and then the support of the image-forming material was peeled off to form an image on the image-receiving sheet. The obtained black image had a high transmission density of 3.2 as in Example 4 and a high resolution of 100 lines / mm or more.

[0089]

According to the image forming method of the present invention, a laser having a long wavelength longer than visible light, particularly a semiconductor laser having a wavelength in the near infrared light region is used without using environmentally problematic liquid development. Due to the small size of the mechanism, it is possible to form images suitable for high-sensitivity and high-quality color proofing.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical indication location G03F 7/029 (72) Inventor Otomo Komamura 1 Sakura-cho, Hino-shi, Tokyo Konica Stock Association In-house

Claims (6)

[Claims] 1. An image-forming material in which at least a cushion layer, a release layer, a photosensitive ink layer and a releasable cover sheet are sequentially laminated on a support, wherein the photosensitive ink layer is at least a compound capable of addition polymerization or crosslinking. An image-forming material containing a borate complex of a cationic dye. 2. A conveying and winding step of winding the image forming material according to claim 1 on an exposure drum, and an image exposure for scanning and exposing the image forming material wound on the exposure drum with laser light modulated according to image information. Process, peeling process of peeling the cover sheet from the image forming material after image exposure, adhesion process of pressing and pressing the image forming material and the image receiving sheet after peeling the cover sheet, peeling the support of the image forming material and unexposing An image forming method comprising: an image transfer step of transferring a part of the photosensitive ink layer onto an image receiving sheet; and a post-exposure step of irradiating the transferred uncured image with light. 3. A conveying and winding step of winding the image forming material according to claim 1 on an exposure drum, and an image exposure for scanning and exposing the image forming material wound on the exposure drum with laser light modulated according to image information. Step, peeling step of peeling the cover sheet from the image-forming material after image exposure, adhesion step of pressing / pressurizing the image-forming material from which the cover sheet is peeled off and the image-receiving sheet, and a laminated body of the image-forming material and image-receiving sheet An image forming method comprising: a post-exposure step of irradiating light, and an image transfer step of peeling the support of the image forming material to transfer the photosensitive ink layer of the unexposed portion onto the image receiving sheet. 4. A conveying and winding step of winding the image forming material according to claim 1 on an exposure drum, and an image exposure for scanning and exposing the image forming material wound on the exposure drum with laser light modulated according to image information. Process, peeling process of peeling the cover sheet from the image forming material after image exposure, adhesion process of pressing and pressing the image forming material and the image receiving sheet after peeling the cover sheet, peeling the support of the image forming material and unexposing Image transfer step of transferring a part of the photosensitive ink layer onto an intermediate transfer medium, an image retransfer step of retransferring the image on the intermediate transfer recording medium to an image receiving sheet, and a post-exposure step of irradiating the transferred uncured image with light. An image forming method comprising: 5. The exposure drum in the image exposure process is 40
The image forming method according to claim 2, wherein the image forming method is controlled at a constant temperature of not less than 0 ° C. 6. A full-color image is formed by superimposing and transferring a photosensitive ink image containing yellow, magenta and cyan or yellow, magenta, cyan and black colorants on the same image receptor. Claim 2
6. The image forming method according to any one of 5 to 5.