JPH0961994A - Production of planographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a machine plate having excellent plate inspectability by having a stage for dyeing the original plate of the photosensitive planographic printing plate which has a photosensitive hydrophilic swelling layer after the exposure thereof. SOLUTION: The photosensitive planographic printing plate having the photosensitive hydrophilic swelling layer formed to have a water swelling property by laminating a hydrophilic polymer by application or transfer thereof on a substrate and crosslinking or pseudo crosslinking this polymer to make the polymer insoluble in water is subjected to image exposure, then to dyeing simultaneously or after development. The dyeing is usually executed by using a dyeing liquid. This dyeing liquid is required to selectively dye either of line drawing parts or non-line drawing parts and substantially not to dye the other parts. The dyeing liquid which does not pace such sludge as to contaminate the planographic printing plate and is less foamed and less degraded in dyeing density is preferable. One or >=2 kinds among basic dyes, acidic dyes, direct dyes, disperse dyes and reactive dyes are usable as the dye. The dyeing temp. is preferably 10 to 50 deg.C and more preferably 20 to 40 deg.C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement of practical characteristics of a novel photosensitive lithographic printing plate, and more particularly to a method for producing a lithographic printing plate excellent in plate inspection property.

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a lithographic printing plate using a novel photosensitive lithographic printing plate having at least a photosensitive hydrophilic swelling layer on a substrate.

This novel photosensitive lithographic printing plate is usually exposed and developed to form a printing plate. This printing plate has an image area which is an ink inking portion and a non-image area which is an ink repelling area. There is a problem that it is difficult to distinguish the image, it is difficult to confirm whether the original image is reproduced, it is difficult to confirm the end point of development, the correction work is difficult, the so-called plate inspection property is poor. It was Further, there is a problem that it is difficult to check an appropriate ink supply amount at the time of printing using a plate image area reader.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide plate inspection property when making a photosensitive lithographic printing plate precursor having at least a photosensitive hydrophilic swelling layer on a substrate. To do.

[0005]

That is, the present invention has the following configuration.

(1) A method for producing a lithographic printing plate using a photosensitive lithographic printing plate precursor having at least a photosensitive hydrophilic swelling layer on a substrate, characterized by comprising a step of dyeing the plate. Method of manufacturing a lithographic printing plate.

(2) The method for producing a lithographic printing plate as described in (1), wherein the non-image area is dyed after the exposure of the photosensitive lithographic printing plate precursor.

(3) The method for producing a lithographic printing plate as described in (1), wherein the image area is dyed after the exposure of the photosensitive lithographic printing plate precursor.

(4) At least λmax (water) is 50
The method for producing a lithographic printing plate as described in (1), which comprises dyeing with a dye having an absorption wavelength of 0 to 700 nm.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A photosensitive lithographic printing plate precursor according to the present invention having at least a photosensitive hydrophilic swelling layer on a substrate will be described.

The hydrophilic swelling layer will be described.

The term "hydrophilic" as used in the present invention means the property of being substantially insoluble in water and exhibiting water swelling property, and a known hydrophilic polymer is laminated on a substrate by coating or transfer to form a known hydrophilic polymer. A hydrophilic swelling layer which is cross-linked or pseudo-cross-linked by the method described above and made water-swellable by making it insoluble in water is preferably used.

The hydrophilic polymer referred to here is a known water-soluble polymer (meaning that it is completely soluble in water) or pseudo-water-soluble polymer (meaning that it is amphipathic). Means a polymer containing a non-dissolved portion) and a water-swellable polymer (meaning a polymer that swells in water but does not dissolve). That is, it means a polymer that adsorbs or absorbs water under normal use conditions, and a polymer that dissolves in water or swells in water.

Known hydrophilic polymers can be used in the present invention, and include animal polymers, plant polymers and synthetic polymers. For example, "Function
al Monomers ”(Y. Nyquist, De
Kker), "Water-soluble polymer" (Nakamura, Chemical Industry Co., Ltd.), "The latest processing and modification technology of water-soluble polymer water-dispersible resin and application development comprehensive technical data collection" (Business Development Center Publishing Department), Hydrophilic polymers described in "Applications and markets of new water-soluble polymers" (CMC) and the like can be mentioned.

Examples of hydrophilic polymers that effectively exhibit the effects of the present invention include carboxylate-based copolymers.

The carboxylic acid salt-based copolymer preferably used in the present invention is, from the viewpoint of water absorption and durability,
Α, β-unsaturated compounds having one or two carboxyl groups or carboxyl group-derived groups such as carboxyl groups, carboxylate salts, carboxylic acid amides, carboxylic acid imides, carboxylic anhydrides, etc. A saponification reaction product of a carboxylic acid copolymer contained as a component is exemplified.

Specific examples of the α, β-unsaturated compound include:
Acrylic acid, methacrylic acid, acrylamide, methacrylamide, maleic anhydride, maleic acid, maleic amide, maleic imide, itaconic acid, crotonic acid, fumaric acid, mesaconic acid, and the like, which are necessary for the present invention. It is possible to combine with another monomer component copolymerizable within a range showing hydrophilicity.

Examples of other copolymerizable monomer components include ethylene, propylene, isobutylene, 1-butylene, diisobutylene, methyl vinyl ether, styrene, vinyl acetate, acrylic acid ester, methacrylic acid ester, and acrylonitrile. Examples thereof include olefins, vinyl compounds and vinylidene compounds.

When combined with another monomer, the α, β-unsaturated compound containing a carboxyl group or a group convertible to this is usually 10 mol% or more in all the monomer components,
More preferably, it is at least 40 mol%.

The polymer containing, as a monomer, an α, β-unsaturated compound containing a carboxyl group or a group capable of being converted into a carboxyl group is usually prepared by radical polymerization. The degree of polymerization is not particularly limited.

Among the polymers thus prepared, preferred are polymers or copolymers of acrylic acid or methacrylic acid, α-olefins, copolymers of vinyl compounds and maleic anhydride.

These polymers or copolymers are prepared by using compounds such as hydroxides, oxides or carbonates of alkali metals or alkaline earth metals such as sodium, potassium, magnesium and barium, ammonia, amines and the like. Hydrophilicity is preferably imparted by carrying out a saponification reaction. In these reactions, the polymer or the copolymer is dissolved or dispersed in various organic solvents or water, and the above-mentioned alkali metal compound, alkaline earth metal compound, ammonia, amine, etc. are added thereto with stirring. It is carried out by

Among such carboxylic acid salt type copolymers, particularly vinyl ester / (meth) acrylic acid ester copolymers, in which the hydrophilic swelling layer exhibits appropriate water swelling property, printing durability and ink It is preferable in that both of the resilience are satisfied.

Further, as a hydrophilic polymer effectively exhibiting the effect of the present invention, an N-vinylcarboxylic acid amide copolymer can be mentioned.

The N-vinylcarboxylic acid amide-based copolymer is a copolymer (hereinafter, referred to as N-vinylcarboxylic acid amide-based copolymer) containing N-vinylcarboxylic acid amide (hereinafter abbreviated as NVA) represented by the following general formula (I) as an essential repeating unit. , And NVA-based copolymer).

[0026]

Embedded image (Where R ₁ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R ₂ is a hydrogen atom or a methyl group, a phenyl group, a R
₃ represents a hydrogen atom or a linear or branched alkyl group having 1 to 8 carbon atoms. ) Specific examples of NVA include N-vinylformamide, N
-Vinylpropionic acid amide, N-vinylbenzoic acid amide, N-methyl-N-vinylbenzoic acid amide, N-phenyl-N-vinylacetamide, N-phenyl-N-vinylbenzoic acid amide, etc. The invention is not limited to these examples.

From the viewpoint of water absorption and durability, the NVA copolymer preferably used in the present invention is a carboxyl group such as a carboxyl group, a carboxylate, a carboxylic acid amide, a carboxylic acid imide or a carboxylic anhydride, or a carboxyl group. It is preferable to contain, as a copolymerized unit, an α, β-unsaturated compound having one or two groups capable of being derived into

Specific examples of the α, β-unsaturated compound include:
Acrylic acid, methacrylic acid, acrylamide, methacrylamide, maleic anhydride, maleic acid, maleic amide, maleic imide, itaconic acid, crotonic acid, fumaric acid, mesaconic acid, and the like, which are necessary for the present invention. It is possible to combine with another monomer component copolymerizable within a range showing hydrophilicity.

Examples of other monomer components which can be copolymerized include ethylene, propylene, isobutylene, 1-butylene, diisobutylene, methyl vinyl ether, styrene, vinyl acetate, acrylic acid ester, methacrylic acid ester and acrylonitrile. Examples thereof include olefins, vinyl compounds and vinylidene compounds.

When combined with other monomers, the NVA unit is usually 10 mol% or more and 40 mol% or more in all the monomer components.
More preferably, it is the above.

Polymers containing NVA are usually prepared by radical polymerization. The degree of polymerization is not particularly limited.

Among the polymers thus prepared, particularly NVA and carboxylic acid salt-based copolymers such as acrylic acid, methacrylic acid and maleic anhydride, the hydrophilic swelling layer exhibits a suitable water swelling property. In addition, it is preferable from the viewpoint of satisfying both printing durability and ink resilience.

A known hydrophilic polymer can be added to the hydrophilic swelling layer of the present invention within a range that does not impair the effects of the invention. The following examples can be given as known hydrophilic polymers.

(A) Natural polymers Starch-acrylonitrile-based graft polymer hydrolyzate, starch-acrylic acid-based graft polymer, starch-styrene sulfonic acid-based graft polymer, starch-
Vinyl sulfonic acid type graft polymer, starch-acrylamide type graft polymer, carboxylated methyl cellulose, methyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl cellulose, cellulose xanthate, cellulose-acrylonitrile type graft polymer, cellulose-styrene sulfonic acid type graft polymer , Carboxymethyl cellulose cross-linked product,
Hyaluronic acid, agarose, collagen, milk casein, acid casein, rennet casein, ammonia casein, potash casein, borax casein, glue, gelatin, gluten, soy protein, alginate, ammonium alginate, potassium alginate, sodium alginate arabia gum , Tragacanth gum, karaya gum, guar gum, locust bean gum, Irish moss,
Soy lecithin, pectic acid, starch, carboxylated starch, agar, dextrin, mannan, etc.

(B) Synthetic Polymers Polyvinyl alcohol, polyethylene oxide, poly (ethylene oxide-co-propylene oxide), aqueous urethane resin, water-soluble polyester, ammonium polyacrylate, sodium polyacrylate, ammonium polymethacrylate, Acrylic copolymer, acrylic emulsion copolymer, polyvinyl alcohol cross-linked polymer, sodium polyacrylate cross-linked product, polyacrylonitrylyl saponified polymer, hydroxyethyl (meth) acrylate-based polymer ((meth) □ □
□□ stands for □□□□ or meta □□□□. ), Poly (vinyl methyl ether-co-maleic anhydride), maleic anhydride copolymer, vinylpyrrolidone copolymer, polyethylene glycol di (meth)
Acrylate-based crosslinked polymers, polypropylene glycol di (meth) acrylate-based crosslinked polymers and the like.

The above-mentioned hydrophilic compound may contain a monomer or a copolymerization component having different substituents for the purpose of imparting flexibility or controlling the hydrophilicity, as long as the effects of the invention are not changed. is there.

Next, the method of crosslinking the hydrophilic polymer will be described.

The hydrophilic swelling layer is obtained by cross-linking or pseudo-cross-linking at least one kind of the above-mentioned hydrophilic polymer, if necessary.
A layer is formed on the substrate by making it insoluble in water. Usually, the cross-linking reaction is performed by three-dimensional cross-linking reaction utilizing the reactive functional group of the hydrophilic polymer.

The cross-linking reaction may be either covalent cross-linking or ionic cross-linking.

Examples of the compound used in the crosslinking reaction include known polyfunctional compounds having a crosslinking property, such as polyepoxy compounds, polyisocyanate compounds, poly (meth) acrylic compounds, polymercapto compounds, polyalkoxysilyl compounds, Examples thereof include polyvalent metal salt compounds, polyamine compounds, aldehyde compounds, polyvinyl compounds and the like. The crosslinking reaction is carried out by adding a known catalyst to accelerate the reaction.

These hydrophilic polymers can be used alone or as a mixture of two or more kinds for the purpose of maintaining the shape of the hydrophilic swelling layer and adjusting the water swelling property, and a non-hydrophilic polymer is blended. It is also possible.

Further, for the purpose of improving the adhesiveness with the lower layer, it is possible to add a known silane coupling agent, isocyanate compound, catalyst or the like, or to provide it as an intermediate layer.

The hydrophilic swelling layer of the present invention may contain a hydrophobic polymer.

The hydrophobic polymer used in the present invention is preferably one mainly composed of an aqueous emulsion.

The aqueous emulsion referred to in the present invention means a hydrophobic polymer suspension aqueous solution in which fine polymer particles and, if necessary, particles comprising a protective layer surrounding the particles are dispersed in water.

That is, it means a self-emulsifying or forced emulsifying aqueous solution which is basically composed of emulsion particles composed of polymer particles as a dispersoid and a protective layer formed as necessary, and a dilute aqueous solution as a dispersion medium. Specific examples of the aqueous emulsion used in the present invention include vinyl polymer latex, conjugated diene polymer latex and aqueous or water dispersed polyurethane resin.

The hydrophilic swelling layer of the present invention is laminated on the substrate by mixing the above-mentioned hydrophilic polymer and hydrophobic polymer, cross-linking or similar cross-linking if necessary, and insolubilizing them in water.

For cross-linking, it is preferable to carry out the cross-linking reaction by using the reactive functional groups of the hydrophilic polymer and the hydrophobic polymer.

The cross-linking reaction may be a covalent bond or an ionic bond.

As a method for mixing the hydrophilic polymer and the hydrophobic polymer of the hydrophilic swelling layer of the present invention, a roll mixer such as a three-roll mill, a kneading method using a mixer such as a kneader, a homogenizer, a ball mill, etc. The mixing is preferably carried out by a known method used for producing a paint or putty, such as a method of wet mixing and dispersing using a disperser.

As a method for forming the hydrophilic swelling layer of the present invention, since an aqueous emulsion is preferably used as the hydrophobic polymer, each component (hydrophilic polymer, hydrophobic polymer, etc.) is mixed in an aqueous solution system, A method in which a crosslinking agent is added as necessary is preferable from the viewpoint of realizing a uniform phase-separated structure and improving ink repulsion.

Therefore, it is particularly preferable to use a water-soluble polyfunctional compound as the crosslinking agent. That is, it is preferable to use a water-soluble polyepoxy compound, polyamine compound, melamine compound, or the like.

In the hydrophilic swelling layer used in the present invention, in addition to the above-mentioned hydrophilic polymer, hydrophobic polymer and crosslinking agent optionally added, known anti-aging agents usually added in rubber compositions. It is possible to add an antioxidant, an antiozonant, an ultraviolet absorber, a dye, a pigment, a plasticizer and the like.

For the purpose of improving the adhesiveness with the lower layer,
Known silane coupling agents and isocyanate compounds,
It is also possible to add a catalyst or the like or to provide an intermediate layer between the substrate and the substrate.

It is also possible to add a small amount of various additives such as dyes and pigments, pH indicators, leuco dyes, surfactants and organic acids to the hydrophilic swelling layer used in the present invention.

In the present invention, the hydrophilic swelling layer preferably has a phase separation structure.

Next, the phase separation structure in the hydrophilic swelling layer according to the present invention will be described.

By providing a phase-separated structure composed of a phase containing a hydrophilic polymer as a main component and a phase containing a hydrophobic polymer as a main component, both ink repulsion and printing durability are realized in a wide composition range. It becomes possible.

The composition ratio of the hydrophilic polymer phase and the hydrophobic polymer phase constituting the phase-separated structure is arbitrary, and (1) either one is a continuous phase and the other is a dispersed phase, (2) hydrophilic A form in which the hydrophilic and hydrophobic polymer phases have a continuous phase and a dispersed phase, respectively (3) A form in which the hydrophilic and hydrophobic polymer phases are both continuous phases can be freely selected.

The hydrophilic swelling layer preferably has rubber elasticity. That is, the initial elastic modulus of the hydrophilic swelling layer measured by the following method is preferably within a specific range. [Measurement Method of Initial Elastic Modulus of Hydrophilic Swelling Layer] A solution having the same composition as the hydrophilic swelling layer of the lithographic printing plate to be measured is spread on a Teflon dish and dried and cured at 60 ° C. for 24 hours. The obtained dried and cured film is 40 mm long, 1.95 mm wide, and about 0.2 mm thick using a razor blade.
Cut into strip-shaped test pieces. When the non-image area is to be processed after applying the solution and before the printing plate is made, the test piece is also processed in the same manner.

The test piece obtained was measured at 25 ° C. before measurement.
After being left to stand in an environment of 50% RH for 24 hours or more to adjust the humidity, the thickness was measured with a micro gauge, and the initial elastic modulus was measured under the following tensile conditions. Data processing is JIS K6
It was carried out according to 301.

Tensile speed 200 mm / min Distance between chucks 20 mm Number of repetitions 4 times Measuring machine "RTM-100" manufactured by Orientec Co., Ltd. The initial elastic modulus of the hydrophilic swelling layer used in the present invention is 0.
It is preferably in the range of 01 to 10 kgf / mm ² from the viewpoints of ink repellency and form retention. Preferably, it is in the range of 0.01 to 5 kgf / mm ² , and 0.0
The range of 1 to ² kgf / mm ² is more preferable.

That is, the initial elastic modulus is 0.01 kgf /
If it is less than mm ² , the shape retention of the hydrophilic swelling layer tends to be extremely lowered, and the durability during printing tends to be extremely lowered.
When the initial elastic modulus is more than 10 kgf / mm ² , rubber elasticity is insufficient and ink repulsion tends to be extremely reduced.

On the other hand, the initial elastic modulus of the image area (ink inking portion) after image formation needs to be higher than the initial elastic modulus of the hydrophilic swelling layer in the non-image area. Is 2 times or more, preferably 3 times or more.

The swelling ratio of the hydrophilic swelling layer of the present invention to water can be measured according to the following definition.

[0066]

[Equation 1] However, the water absorption amount means a value measured according to the following definition.

Water absorption (g / m ² ) = W _WET −W _DRY (I) W _DRY : Weight in dry state (g / m ² ) W _WET : Weight after immersion in water at 25 ° C. for 10 minutes (g)
/ M ² ) [Measurement method of water absorption amount] The portions of the lithographic printing plate to be measured, which are formed only from the non-image areas and the image areas, are cut into predetermined areas and immersed in purified water at 25 ° C. After soaking for 10 minutes, excess water adhering to the front and back surfaces of the lithographic printing plate was quickly wiped off with "Hize Gauze" (cotton cloth: manufactured by Asahi Kasei Kogyo Co., Ltd.), and the swelling weight of the lithographic printing plate W _WET Is weighed. Then, the lithographic printing plate is
Dry in an oven at ℃ for about 30 minutes, and weigh the dry weight W _DRY .

The hydrophilic swelling layer thickness is measured by a gravimetric method after peeling off the coating layer of the hydrophilic swelling layer at a portion corresponding to the non-image area of the dried lithographic printing plate coated on the substrate. Means a value. The thickness of the hydrophilic swelling layer was measured according to the following formula.

Hydrophilic swelling layer thickness (g / m ² ) = (W−W ₀ ) / α W: Dry weight (g) W of the lithographic printing plate, which was cut at a portion formed only from non-image areas ₀ : Dry weight after peeling off the hydrophilic swelling layer from the W (g) α: Measurement area of lithographic printing plate (m ² ) [Measurement method of hydrophilic swelling layer thickness] Planographic printing plate to be measured The area formed only from the non-image area of
After cutting into pieces, the pieces are dried in an oven at 60 ° C. for about 30 minutes, and the dry weight W is weighed. Then, the lithographic printing plate is immersed in purified water to swell the hydrophilic swelling layer, and the swelling layer is peeled off using a scraper or the like.

The lithographic printing plate from which the hydrophilic swelling layer has been peeled off is dried again in an oven at 60 ° C. for about 30 minutes, and the dry weight W ₀ is weighed.

The thickness of the hydrophilic swelling layer used in the present invention may be 0.1 to 100 g / m ² , and is preferably 0.3 from the viewpoint of ink repulsion and shape retention. 10 to 10 g / m ² . The thickness is 0.3g
If it is less than / m ² , the ink repellency tends to be extremely reduced, and defects such as pinholes are likely to occur during coating. Further, when it is 10 g / m ² or more, the shape retention property when swollen with water tends to deteriorate, which is economically disadvantageous.

The swelling ratio of the hydrophilic swelling layer of the present invention with respect to water is preferably 10 to 1000%. From the viewpoint of ink repellency and shape retention, 50 to 500% is more preferable. When the swelling ratio in water is less than 10%,
Ink repellency decreases, and defects such as pinholes tend to occur during coating. On the other hand, the swelling ratio in water is 10
When it is more than 00%, the shape retention property is significantly reduced.

Next, an image forming method using the photosensitive lithographic printing plate precursor according to the invention will be described, but the invention is not limited thereto.

The image of the lithographic printing plate of the present invention can be formed, for example, by irradiating the plate surface of a photosensitive lithographic printing plate precursor having a hydrophilic swelling layer on a substrate with an actinic ray. That is, the difference between the image area and the non-image area is caused by the irradiation of the actinic ray.

Preferably, the lithographic printing plate of the present invention is prepared by negative working image formation. That is, the initial elastic modulus of a portion of the hydrophilic swelling layer (hereinafter referred to as an unexposed portion) that is not exposed to the actinic ray (hereinafter referred to as an unexposed portion) is increased. As a result, it becomes an ink-receptive image area, and the unexposed area becomes an ink repellent non-image area.

Known photosensitive compounds are used for such image formation.

That is, a known photocrosslinking or photocurable photosensitive compound is contained in the hydrophilic swelling layer of the original plate, and the exposed area is selectively crosslinked and / or cured to increase the initial elastic modulus. Formation is achieved.

Examples of known photocrosslinking or photocurable photosensitive compounds include the following specific examples (1) to (6).

(1) Photopolymerizable Monomer or Oligomer (2) Photodimerization Type Photosensitive Resin Composition (3) Composition Composed of Monomer, Oligomer or Polymer Having Epoxy Group and Known Photoacid Generator (4) Composition of monomer, oligomer or polymer having allyl group and / or vinyl group and monomer, oligomer or polymer having mercapto group (5) Composition of diazonium salt compound and hydroxyl group-containing compound (6) Bisazide Polyisoprene rubber or polybutadiene rubber cyclized with a compound, or a photosensitive composition containing cresol novolac resin as a main component.

These photosensitive compounds are added to the composition when the hydrophilic swelling layer is formed on the substrate so as to be present in the composition, or after the hydrophilic swelling layer is formed, the photosensitive composition is added to the composition. It is added using a method of coating on the layer and impregnating the layer.

In the case of a photosensitive composition using a polymer or oligomer having a relatively high molecular weight, the former method of simultaneous addition at the time of forming the hydrophilic swelling layer is advantageously carried out, and a monomer or an oligomer having a relatively low molecular weight is used. The latter impregnation method is advantageous in the case of a photosensitive composition using, for example,

Further, a known photosensitizer may be added to the hydrophilic swelling layer of the original plate for the purpose of sensitizing these photosensitive compounds. As the known photosensitizer, a known photosensitizer can be freely selected, and various substituted benzophenone-based compounds, substituted thioxanthone-based compounds, and substituted acridone-based compounds are preferably used. In addition, it is substituted with a vicinal polyketaldonyl compound described in U.S. Pat.No. 236766, an .alpha.-carbonyl compound disclosed in U.S. Pat.No. 2,376,670, an U.S. Pat. Aromatic acyloin compounds, U.S. Pat. No. 3,046,127, polynuclear quinone compounds disclosed in U.S. Pat. Benzothiazole compounds, US Pat. No. 4,239
Benzothiazole compounds / trihalomethyl-s-triazine compounds disclosed in U.S. Pat.
Acridine and phenazine compounds disclosed in 51259, oxadiazole compounds disclosed in US Pat. No. 4212970, trihalomethyl-s having a chromophore group disclosed in US Pat. No. 3,954,475, US Pat.
Specific examples thereof include triazine-based compounds, and benzophenone group-containing peroxyester compounds disclosed in JP-A-59-197401 and JP-A-60-76503.

The substrate of the lithographic printing plate used in the present invention is not limited at all except that it must be flexible enough to be attached to an ordinary lithographic printing machine and capable of withstanding the load applied during printing.

Typical materials are aluminum, copper, iron,
Examples thereof include a metal plate, a plastic film such as a polyester film and a polypropylene film, coated paper, and a rubber sheet. Further, the substrate may be a composite of the above materials.

Further, the surface of the substrate may be subjected to various surface treatments such as electrochemical treatment, acid-base treatment and corona discharge treatment for the purpose of improving plate inspection property and adhesiveness.

It is also possible to form a primer layer by coating on these substrates for the purpose of improving the adhesiveness and preventing halation, to obtain substrates.

Next, the protective layer will be described.

On the surface of the photosensitive hydrophilic swelling layer of the photosensitive lithographic printing plate precursor of the present invention, a protective layer which is removable for the purpose of protecting the hydrophilic swelling layer is coated on the hydrophilic swelling layer. It is preferably formed or laminated with a protective film.

Specific examples of the protective film include polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyethylene terephthalate and cellophane. In order to improve vacuum adhesion during image exposure, these protective films are subjected to uneven processing, surface matte treatment, or coating and laminating a plastic layer containing silica particles on the surface of the protective film. This is also preferably done.

Next, the method of exposing the photosensitive lithographic printing plate precursor according to the invention will be described.

The photosensitive lithographic printing plate of the present invention preferably becomes a printing plate through a plate making process for negative working.
That is, image exposure is performed through a negative original image film by a normal exposure light source.

As the light source used in this exposure step,
For example, a high-pressure mercury lamp, a carbon arc lamp, a xenon lamp, a metal halide lamp, a fluorescent lamp and the like can be mentioned.

Next, a method for producing a lithographic printing plate using the photosensitive lithographic printing plate of the present invention will be described.

In the plate-making process, when the protective layer is the laminated film mentioned in the above example, peeling and removal can be easily carried out by a mechanical means such as a film peeling device or a manual means for peeling by hand. In this developing step, when rinsed with water or a developing solution, the photosensitive compound existing in the hydrophilic swelling layer in the unexposed area is dissolved and desensitized, and the dispersion structure and water swelling property suitable for repelling the ink are obtained. And the exposed area becomes an imaged area in which the water swelling property is lower than that of the unexposed area due to photocrosslinking curing of the photosensitive compound.

The dyeing of the present invention is carried out after image-wise exposing the photosensitive lithographic printing plate, simultaneously with development, or after development. Staining is usually carried out using a staining solution, but it is necessary that this staining solution selectively stains one of the image area and the non-image area and hardly stains the other area. In addition, even when a large amount of a photosensitive lithographic printing plate is processed by using an automatic development dyeing machine or by hand-developing and dyeing with a dyeing solution contained in a pad or the like, the photosensitive lithographic printing plate is contaminated. It does not generate sludge like
It is necessary that the dyeing liquid has less decrease in dyeing density and less bleeding of color such as dye migration of the printing plate after dyeing. Examples of such a dyeing solution include those having the following compositions.

1) Dye 2) Water The dye used in the present invention is selected from basic dyes, acid dyes, direct dyes, disperse dyes and reactive dyes.
One kind or two or more kinds can be used, but particularly water-soluble basic dyes and acid dyes are advantageously used.

Specific examples of the acid dye include the following.

Nitro dyes such as naphthol yellow (CI Asid Yellow 1), monoazo dyes such as Fast Red A (CI Asid Red 88), disazo dyes such as Naphthol Blue Black (C) .I Acid Black 1), nitroso dyes such as Naphthol Green B (CI Acid Green 1), triphenylmethane dyes such as Patent Blue (CI Acid Blue 3), Brilliant. Milling Green B (CI Acid Green 9), xanthene dyes such as Sulfo-Rhodamine B ((CI Acid Red 52), anthraquinone dyes such as Alizarin Direct Blue A2.
G (C.I. Acid Blue 40), azine dye such as Wool First Blue GL (C.I. Acid Blue 102), quinoline dye such as quinoline.
Yellow (CI Acid Yellow 3).

Specific examples of the basic dye include the following.

Diphenylmethane dyes such as auramine O (CI Basic Yellow 2), triphenylmethane dyes such as magenta (CI Basic Violet 14), methyl violet (CI Basic Violet 1) ), Malachite green (CI basic green 4), thiazole dyes such as thioflavin T (CI basic yellow 1), xanthene dyes such as rhodamine B (C.I.
I. Basic Violet 10), Oxazine dyes such as Neal Blue (CI Basic Blue 12), Thiazine dyes such as Methylene Blue B
(CI Basic Blue 9), azine dyes such as Safranine T (CI Basic Red 2), azo dyes such as Bismark Brown G (CI Basic Brown 1), indocyanine dyes , For example, Astraflaxin FF (CI Basic Red 1
2).

In consideration of the suitability of the plate image area reader, a dye having an absorption wavelength of λmax (water) of 500 to 700 nm can be preferably used. Specifically, the following are mentioned.

Acid dyes include C.I. I. Acid Red 51 (λmax = 526 nm), C.I. I. Acid Black 2 (λmax = 580 nm), C.I. I. Acid Red 92 (λmax = 586, 497 nm),
C. I. Acid Blue 74 (λmax = 611.5
nm), C.I. I. Acid Blue 9 (λmax = 63
1 nm).

Examples of the basic dye include C.I. I. Basic Red 13 (λmax = 523 nm), C.I. I. Basic Red 1 (λmax = 525, 491nm),
C. I. Basic Violet 7 (λmax = 53
8 nm), C.I. I. Basic Violet 10 (λ
max = 555, 517 nm), C.I. I. basic·
Violet 1 (λmax = 585 nm), C.I. I. Basic Violet 3 (λmax = 592nm),
C. I. Basic Blue 5 (λmax = 612n
m), C.I. I. Basic Blue 26 (λmax = 6
15 nm), C.I. I. Basic Blue 7 (λmax
= 617 nm), C.I. I. Basic Green 1 (λ
max = 627 nm), C.I. I. Basic blue 3
(Λmax = 655 nm), C.I. I. Basic Blue 9 (λmax = 668nm).

The content of these dyes is 0.0 in the dyeing solution.
1 to 10% by weight is preferable, more preferably 0.05
~ 5% by weight.

In addition to the above, solvents of hydrocarbons, alcohols, ketones, ethers and esters can be added, and further, anionic surfactants, cationic surfactants, nonionic surfactants, Amphoteric surfactants, dyeing aids, defoamers, carboxylic acids and amines can also be added.

The temperature of the dyeing solution may be arbitrary, but is preferably 1
The temperature is 0 to 50 ° C, and more preferably 20 to 40 ° C.

After the dyeing treatment, the plate may be washed with water and dried with hot air. The optimum temperature of hot air is 50 to 150 ° C.

When the printing plates thus treated are stacked and stored, a protective liquid may be applied to the plate surface to protect the plate surface, or a paper or film may be inserted and sandwiched.

Next, a printing method using the lithographic printing plate obtained from the photosensitive lithographic printing plate precursor according to the invention will be described.

A known lithographic printing machine is used for the lithographic printing of the present invention. That is, sheet-fed and rotary printing machines of the offset and direct printing type are used.

After image formation of the lithographic printing plate of the present invention,
Ink is attached to the plate cylinder of these planographic printing machines, and ink is supplied to the plate surface from an inking roller in contact therewith.

The non-image area having the hydrophilic swelling layer on the plate surface swells with the dampening water supplied from the dampening water supply device to repel the ink. On the other hand, the image area receives the ink and supplies the ink to the surface of the offset blanket cylinder or the surface of the printing medium to form a printed image.

The fountain solution used when printing the lithographic printing plate of the present invention may be the etchant used in the PS plate with water, but it is pure water containing no additives. Can be used.

When printing using the lithographic printing plate obtained from the photosensitive lithographic printing plate precursor according to the invention, it is preferable to use pure water containing no additives.

Hereinafter, the present invention will be described in more detail with reference to examples.

[0116]

【Example】

Example 1 On an aluminum plate (made by Sumitomo Light Metal Co., Ltd.) having a thickness of 0.3 mm,
Sodium acrylate-n-butyl methacrylate copolymer (composition ratio 40/60 mol%) was used as the hydrophilic polymer, and the following composition was applied and heat-treated at 150 ° C. for 60 minutes to obtain 2 g / m ² A hydrophilic swelling layer having a thickness was applied.

(1) Hydrophilic polymer 28 parts by weight (2) Tetraethylene glycol diglycidyl ether 5 parts by weight (3) Aqueous latex "JSR0596" (carboxy modified styrene-butadiene copolymer latex: Dainippon Ink and Chemicals, Inc.) )) 65 parts by weight (4) 2-aminopropyltrimethoxysilane 2 parts by weight (5) Purified water 900 parts by weight On the hydrophilic swelling layer coated as described above, a photosensitive composition having the following composition is applied. The composition was applied and heat-treated at 100 ° C. for 3 minutes to impregnate the hydrophilic swelling layer with 0.5 g / m ² of the photosensitive composition.

Thereafter, a 12-micron-thick single-sided matt biaxially oriented polypropylene film was laminated using a calendar roller so that the non-matted surface was in contact with the hydrophilic swelling layer, and a negative lithographic printing plate precursor was laminated. Got

The lithographic printing plate obtained was a PCW (PLATE CONTOROL WEDGE: manufactured by KALLE) using a high pressure mercury lamp "Jetlight 3303kW: manufactured by Oak Manufacturing Co., Ltd."
For 90 seconds through a negative film with
After 6 mW / cm ² ), the laminate film was peeled off.
Then, the entire surface of the plate was rinsed with tap water to wash the unexposed area of the photosensitive composition, and the development step was completed.

(1) CH ₂ = CHCOO- (CH ₂ ) ₉ -OCOCH = CH ₂ 20 parts by weight (2) Michler's ketone 2 parts by weight (3) 2,4-diethylthioxanthone 2 parts by weight (4) "isopar E "(isoparaffin hydrocarbon: manufactured by Esso Kagaku Co., Ltd.) 76 parts by weight The plate after the development process had poor plate inspection property, and the density difference between the image area and the non-image area was not clear. Therefore, the plate was dyed with the following dyeing solution. In the dyeing method, the plate was dipped in a vat containing a dyeing solution at 25 ° C. for 10 seconds, washed with water and dried. As a result of measuring the dyeing density with a Macbeth reflection densitometer RD514, the density difference between the image area and the non-image area is 1.1, and a printing plate with excellent plate inspection property can be obtained, and the original negative film is reliably reproduced. I was able to confirm that it is doing.

Example 1 Composition of Staining Liquid Crystal Violet (CI Basic Violet 3, Hodogaya Chemical Co., Ltd., λmax = 592 nm) 0.1 parts by weight Pure water 99.9 parts by weight Example 2 A plate was prepared in the same manner as in Example 1 except that the dyeing solution of Example 1 was changed to the following dyeing solution. As a result, it was confirmed that the density difference between the image area and the non-image area was 1.0, a printing plate having excellent plate inspection property was obtained, and the original image film was reliably reproduced.

Example 2 Composition of Dyeing Solution Aizen Victoria pure Blue BOH (CI Basic Blue 7, Hodogaya Chemical Co., Ltd., λmax = 617 nm) 0.1 part by weight Sodium dodecylbenzenesulfonate 0. 2 parts by weight KS-502 (manufactured by Shin-Etsu Chemical Co., Ltd., defoamer) 0.01 parts by weight Pure water 99.69 parts by weight Example 3 Implemented except that the dyeing solution of Example 1 was changed to the following dyeing solution A plate was prepared in the same manner as in Example 1. As a result, it was confirmed that the density difference between the image area and the non-image area was 1.15, a printing plate excellent in plate inspection property was obtained, and the original image film was reliably reproduced.

Example 3 Composition of Dyeing Solution Aizen Methyl Violet pure special (CI Basic Violet 1, Hodogaya Chemical Co., Ltd., λmax = 585 nm) 0.1 part by weight 2 Ethylhexyl sulfate sodium salt 0 0.2 parts by weight Butyl carbitol 5 parts by weight KS-502 (manufactured by Shin-Etsu Chemical Co., Ltd., defoaming agent) 0.01 parts by weight Pure water 99.7 parts by weight Example 4 The dyeing solution of Example 1 was dyed below. A plate was prepared in the same manner as in Example 1 except that the liquid was changed. As a result, it was confirmed that the plate inspection property was improved by the dyeing treatment, and the original film was reliably reproduced.

Example 4 Composition of Dyeing Solution Aizen Victoria pure Blue BOH (CI Basic Blue 7, Hodogaya Chemical Co., Ltd., λmax = 617 nm) 0.1 part by weight Neugen EA112 (Daiichi Kogyo Seiyaku Co., Ltd.) Co., Ltd., nonionic surfactant) 1.0 part by weight Butyl carbitol 5 parts by weight KS-502 (Shin-Etsu Chemical Co., Ltd., defoamer) 0.01 parts by weight Pure water 93.89 parts by weight Example 5 The lithographic printing plate precursor of Example 1 was used as a PC using a high pressure mercury lamp "Jetlight 3303 kW: manufactured by Oak Manufacturing Co., Ltd."
90 seconds contact exposure (3.6mW / c) through negative film with W (PLATE CONTOROL WEDGE: KALLE)
m ² ) Then, the entire surface of the plate was dyed with the dyeing solution (25
It was dipped in the solution at a temperature of 10 seconds for development and dyeing. As a result of measuring the dyeing density with a Macbeth reflection densitometer RD514, the density difference between the image area and the non-image area is 1.1, and a printing plate with excellent plate inspection property can be obtained, and the original negative film is reliably reproduced. I was able to confirm that it is doing.

[0125]

INDUSTRIAL APPLICABILITY The novel photosensitive lithographic printing plate of the present invention can obtain a printing plate excellent in plate inspection property by the dyeing step.

Claims (4)

[Claims] 1. A method for producing a lithographic printing plate using a photosensitive lithographic printing plate precursor having at least a photosensitive hydrophilic swelling layer on a substrate, which comprises a step of dyeing the plate. Printing plate manufacturing method. 2. The method for producing a lithographic printing plate according to claim 1, wherein the non-image area is dyed after the exposure of the photosensitive lithographic printing plate precursor. 3. The method for producing a lithographic printing plate according to claim 1, wherein the image area is dyed after the exposure of the photosensitive lithographic printing plate precursor. 4. At least λmax (water) of 500 to 7
The method for producing a lithographic printing plate according to claim 1, which comprises dyeing with a dye having an absorption wavelength of 00 nm.