JPH11227353A - Manufacture of direct drawing type waterless lithographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the discriminability of an image area from non-image area by method wherein a dyeing liquid which selectively dyes image area and hardly dyes non-image area, is used. SOLUTION: When this direct drawing type waterless lithographic printing plate which can perform a printing without using wetting water is manufactured by using an original plate wherein on a base plate, at least a heat-sensitive layer and a silicone rubber layer are laminated in order, a process to dye the plate is added. That is a dyeing process is performed at the same time when a lithographic printing plate original plate is image-exposed and developed by laser, or after the development is performed. This dyeing is normally performed by using a dyeing liquid, and for the dyeing liquid, one which selectively dyes image area, and hardly dyes non-image area is used, and a density difference between the image area and the non-image area is set at 0.5 or higher. Also, the dyeing is performed by using a dye having an absorption wavelength wherein at least λmax is 500-700 nm, and this dyeing is performed by using a dye of which the solubility for water is 0.01% or higher.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a waterless lithographic printing plate capable of printing without using a fountain solution, and more particularly to a direct drawing type waterless lithographic printing plate capable of directly making a plate with a laser beam. The present invention relates to a plate manufacturing method.

[0002]

2. Description of the Related Art Direct plate making, in which an offset printing plate is produced directly from an original without using a plate making film, is simple, does not require skill, is quick in obtaining a printing plate in a short time, Utilizing features such as rationality that can be selected according to quality and cost from the system,
In addition to the light printing industry, it has begun to enter the general offset printing and gravure printing fields.

[0003] In recent years, new types of various lithographic printing materials have been developed with the rapid progress of output systems such as prepress systems, imagesetters, and laser printers.

[0004] These lithographic printing plates can be classified according to plate-making methods, such as a method of irradiating a laser beam, a method of writing with a thermal head, a method of partially applying a voltage with a pin electrode, an ink repelling layer or an ink coating with an ink jet. Examples include a method of forming a layer. Above all, the method using laser light is superior to other methods in terms of resolution and plate making speed, and there are many types.

[0005] Lithographic printing plates using this laser beam are further classified into two types: a photon mode type by photoreaction and a heat mode type by which photothermal conversion is performed to cause a thermal reaction.

The photon mode type includes (1) a high-sensitivity PS plate using a photopolymer, (2) an electrophotographic lithographic plate using an organic photoconductor and zinc oxide, (3) a silver salt lithographic plate, and (4) a silver salt composite. Method lithography (5) Direct drawing master and the like, and the heat mode type includes (6) Thermal destruction method lithography.

However, the method (1) uses an argon ion laser mainly as a laser light source, so that the apparatus becomes large, and the printing plate uses a high-sensitivity photopolymer. There is a drawback that care must be taken and the storage stability tends to decrease.

The electrophotographic lithographic plate (2) has the advantage that it can be handled in a bright room, but the dark decay becomes large between 2 and 5 minutes after charging of the photosensitive layer, so that the exposure and development treatment is performed in a short time after charging. Therefore, it is difficult to output a large format with high resolution.

In the silver salt method (3), printing plates corresponding to lasers of various wavelengths have been developed. However, there is a problem that silver waste liquid comes out, and the sensitivity is high. There is also a problem that requires attention.

In the silver halide composite lithographic plate (4), a high-sensitivity silver halide emulsion layer is exposed on a photosensitive layer with an argon ion laser, developed, and then exposed and developed with ultraviolet rays using the exposed layer as a mask. . However, since this printing plate has two exposure and development steps, there is a problem that the processing of the printing plate becomes complicated.

The direct drawing master of (5) does not directly write on a printing plate with a laser, but transfers a toner image formed by a laser printer onto a printing plate as an ink-coated portion. However, the resolution of the printing plate is inferior to other methods.

For the above photon mode type,
The thermal destruction method (6) has the advantage that it can be handled in a bright room, and its usefulness has recently been reviewed due to the rapid progress of the output of a semiconductor laser as a light source.

For example, US Pat. No. 5,379,698 describes a direct-drawing waterless planographic printing plate using a metal thin film as a heat-sensitive layer. However, since the metal thin film itself reflects laser light, the sensitivity of the printing plate is reduced. There was a problem that was bad. Therefore, in order to increase the absorptivity of laser light,
An anti-reflection layer must be provided, which further increases the coating process, resulting in cost.

Further, JP-A-9-146264, JP-A-6-199064, US Pat. No. 5,339,737, EP0580393, and JP-A-6-5572.
No. 3, EP0573091, USP 5378
580, JP-A-7-164773, USP
No. 5,333,705 and EP 0644647 also describe a direct drawing type waterless planographic printing plate precursor using laser light as a light source and using carbon black or a dye corresponding to the wavelength of laser light as a light-to-heat conversion material of a heat-sensitive layer. Have been.

In this printing plate, it is difficult to discriminate an image between an image area which is an ink-coated area and a non-image area which is an ink repelling area, and it is difficult to confirm whether or not the original image is reproduced. In addition, there is a problem that it is difficult to confirm the end point of the development, that the correction operation is difficult, and that the so-called plate inspection is poor. 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.

In particular, the above-mentioned problem has been remarkable when carbon black is used as the light-to-heat conversion material and the heat-sensitive layer in the image area remains after development.

[0017]

SUMMARY OF THE INVENTION An object of the present invention is to provide a direct drawing type waterless planographic printing plate excellent in plate inspection.

[0018]

To achieve the above object, the present invention comprises the following constitution.

(1) In a method of manufacturing a lithographic printing plate using a direct-drawing waterless lithographic printing plate precursor obtained by sequentially laminating at least a heat-sensitive layer and a silicone rubber layer on a substrate, a step of dyeing the plate is performed. A method for producing a direct-drawing waterless lithographic printing plate, comprising:

[0020]

DETAILED DESCRIPTION OF THE INVENTION The dyeing of the present invention is carried out after imagewise exposing a direct-drawing waterless planographic printing plate precursor with a laser, 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 the image area and hardly stains the non-image area.
The image portion here refers to a portion where the silicone rubber layer has been removed and exposed, and refers to the surface of the heat-sensitive layer or the surface of the primer layer or the surface of the substrate which is a lower layer thereof, and any portion may be dyed. However, it is preferable to dye the heat-sensitive layer or the primer layer.

The dyeing solution is prepared by using an automatic developing dyeing machine, or by adding a dyeing solution to a pad or the like and manually developing and dyeing the same to directly process a waterless planographic printing plate in a large amount.
It is necessary that the dyeing liquid does not generate sludge that contaminates the lithographic printing plate, has little bubbling, has a small decrease in dyeing density, and has little color bleeding such as dye transfer of the printing plate after dyeing. is there. Examples of such a staining solution include those having the following composition.

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.
Species or two or more species can be used, and particularly, a water-soluble basic dye and an acid dye are advantageously used.

Specific examples of the acidic dye include the following.

Nitro dyes such as naphthol yellow (CI acid yellow 1), monoazo dyes such as fast red A (CI acid red 88), disazo dyes such as naphthol blue black (C 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 Rhodamina B (CI Acid Red 52), anthraquinone dyes such as Alizarin Direct Blue A2G
(CI Acid Blue 40), azine dyes such as Wool First Blue GL (CI Acid Blue 102), quinoline dyes such as quinoline yellow (CI Acid Yellow 3).

Specific examples of the basic dye include the following.

A diphenylmethane dye such as auramine O (CI basic yellow 2), a triphenylmethane dye 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 Neil Blue (CI Basic Blue 12), thiazine dyes such as methylene blue B
(CI Basic Blue 9), azine dyes such as Safranin T (CI Basic Red 2), azo dyes such as Bismarck Brown G (CI Basic Brown 1), indocyanine dyes For example, Astra Flaxin FF (CI Basic Red 1)
2).

Considering the compatibility of a plate image area reader, a dye having an absorption wavelength of λmax of 500 to 700 nm can be preferably used. λmax is measured from the spectral specific reflectance and spectral specific transmittance of a solid or solution dye using a spectrophotometer or the like. Further, the dye preferably has a solubility in water of 0.01% or more. If the content is 0.01% or less, the stability and the dyeability of the dye solution will be reduced. The dyes satisfying such conditions include the following.

Examples of the acid dye 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, 491 nm),
C. I. Basic Violet 7 (λmax = 53
8 nm), C.I. I. Basic Violet 1 (λm
ax = 585 nm), C.I. I. Basic Violet 3 (λmax = 592 nm), C.I. I. basic·
Blue 5 (λmax = 612 nm), C.I. I. Basic Blue 26 (λmax = 615 nm), C.I. I. Basic Blue 7 (λmax = 617 nm), C.I.
I. Basic Green 1 (λmax = 627n
m), C.I. I. Basic Blue 3 (λmax = 65
5 nm), C.I. I. Basic Blue 9 (λmax =
668 nm).

The content of these dyes is 0.01
Preferably from 10 to 10% by weight, more preferably from 0.05 to 10% by weight.
5% by weight.

In addition to the above, solvents such as hydrocarbons, alcohols, ketones, ethers and esters can be added. Anionic surfactants, cationic surfactants, nonionic surfactants Activators, amphoteric surfactants, dyeing aids, defoamers, carboxylic acids and amines can also be added.

The temperature of the dyeing solution may be arbitrarily selected, but is preferably 1
It is 0-50 degreeC, More preferably, it is used at 20-40 degreeC.

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

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

Next, the substrate used in the direct-drawing type waterless planographic printing plate precursor will be described.

As the substrate, any known metal, film, etc. can be used as long as it is a dimensionally stable plate. As such a dimensionally stable plate-like material, those conventionally used as a substrate of a printing plate are preferably exemplified. Examples of such a substrate include paper, paper on which plastics (polyethylene, polypropylene, polystyrene, etc.) are laminated, metal plates such as aluminum (including aluminum alloys), zinc, copper, iron, cellulose acetate, polyethylene terephthalate. G, polyethylene, polyester, polyamide, polyimide, polystyrene,
Examples of the film include plastic films such as polypropylene, polycarbonate, and polyvinyl acetal, and paper or plastic films on which the above-described metals are laminated or vapor-deposited.

Of these, the aluminum plate is particularly preferable because it is extremely stable in dimensions and inexpensive. A polyethylene terephthalate film used as a substrate for light printing is also preferably used.

In order to strengthen the adhesion between the substrate and the heat-sensitive layer, it is preferable to perform a surface treatment such as an etching treatment, a corona treatment, and a plasma treatment. In particular, when a plastic film such as polyethylene terephthalate or polyethylene naphthalate is used for the substrate, the substrate itself plays a role of a heat insulating layer. Therefore, it is particularly preferable to enhance the adhesiveness by such a surface treatment.

When the substrate is made of a material having relatively high heat conductivity such as a metal, it is preferable to provide a heat insulating layer between the substrate and the heat-sensitive layer for the purpose of improving adhesiveness and heat insulating effect. . With such a heat insulating layer, it is possible to prevent heat when the heat-sensitive layer causes a thermal reaction from diffusing to the substrate.

When the heat insulating layer is provided, in the present invention,
The following conditions must be satisfied. That is, the substrate and the heat-sensitive layer adhere well, and are stable over time,
Further, it has high solvent resistance to a developing solution and a solvent used at the time of printing.

Those satisfying such conditions include those containing epoxy resin, polyurethane resin, phenol resin, acrylic resin, alkyd resin, polyester resin, polyamide resin, urea resin, polyvinyl butyral resin, casein, gelatin and the like. No. These resins can be used alone or in combination of two or more. Further, those obtained by curing a composition similar to these resins may be used.

Of these, it is preferable to use a polyurethane resin, a polyester resin, an acrylic resin, an epoxy resin, a urea resin, or the like alone or as a mixture of two or more.

It is preferable that the heat insulating layer contains an additive such as a pigment or a dye to improve the plate inspection.

The thickness of the heat insulating layer is 0.5 to 50 in terms of the coating layer.
g / m2 is preferred from the viewpoint of the effect of preventing morphological defects on the substrate surface and blocking the adverse chemical effect and economic efficiency, and more preferably 1 to 10 g / m2.

Next, the heat-sensitive layer will be described.

In the present invention, the heat-sensitive layer comprises at least (a) a light-to-heat conversion material, (b) a binder, and (c) a crosslinking agent.

First, (a) the photothermal conversion material will be described.

The direct-drawing waterless planographic printing plate precursor of the present invention comprises:
In order to form an image by irradiating a laser beam, it is necessary to contain a photothermal conversion substance. The photothermal conversion material is not particularly limited as long as it absorbs laser light. At this time, the wavelength of the laser light may be any wavelength in the ultraviolet, visible, and infrared regions, and a photothermal conversion material having an absorption region according to the wavelength of the laser light to be used is appropriately selected. Good to use.

For example, black pigments such as carbon black, aniline black and cyanine black, phthalocyanine and naphthalocyanine-based green pigments, carbon graphite, diamine-based metal complexes, dithiol-based metal complexes, phenolthiol-based metal complexes, and mercaptophenol-based metal complexes , Water-containing inorganic compounds, copper sulfate, chromium sulfide, silicate compounds, metal oxides such as titanium oxide, vanadium oxide, manganese oxide, iron oxide, cobalt oxide, tungsten oxide, hydroxides of these metals, sulfuric acid salt,
Further, additives such as metal powders of bismuth, iron, magnesium and aluminum can be used.

In addition to the above substances, dyes that absorb infrared or near-infrared rays are also preferably used as photothermal conversion substances.

As these dyes, 400 nm to 1200
Any dye having a maximum absorption wavelength in the range of nm can be used. Preferred dyes include those for electronics,
Recording dyes cyanine, phthalocyanine, phthalocyanine metal complex, naphthalocyanine, naphthalocyanine metal complex, dithiol metal complex, naphthoquinone, anthraquinone, indophenol, indoaniline, pyrylium, thiopyrylium , Squarylium, croconium, diphenylmethane,
Triphenylmethane, triphenylmethanephthalide, triallylmethane, phenothiazine, phenoxazine, fluoran, thiofluorane, xanthene, indolylphthalide, spiropyran, azaphthalide, chromenopyrazole, Leuco auramine, rhodamine lactam, quinazoline, diazaxanthene, bislactone, fluorenone, monoazo, ketone imine, diazo, polymethine, oxazine, nigrosine, bisazo, bisazostilbene, bis Azooxadiazole, bisazofluorenone, bisazohydroxyperinone, azochrome complex, trisazotriphenylamine, thioindigo, perylene, nitroso, 1: 2 type metal complex,
Intermolecular CT system, quinoline system, quinophthalone system, fluid acid system basic dye, pigment, oil-soluble dye, triphenylmethane leuco dye, cationic dye, azo disperse dye, benzothiopyran spiropyran, 3, 9-
Examples include dibromoanthanthrone, indanthrone, phenolphthalein, sulfophthalein, ethyl violet, methyl orange, fluorescein, methyl viologen, methylene blue, dimrosbetaine and the like.

Among these, dyes for electronics and recording, having a maximum absorption wavelength of 700 nm to 900 n
m, cyanine-based dye, azurenium-based dye, squarylium-based dye, croconium-based dye, azo-based disperse dye, bisazostilbene-based dye, naphthoquinone-based dye, anthraquinone-based dye, perylene-based dye, phthalocyanine-based dye, na Phthalocyanine metal complex dyes,
Polymethine dyes, dithiol nickel complex dyes, indoaniline metal complex dyes, intermolecular CT dyes, benzothiopyran spiropyrans, nigrosine dyes and the like are preferably used.

Further, among these dyes, those having a large molar absorbance coefficient are preferably used. Specifically, ε = 1 × 10 ⁴ or more is preferable, and more preferably 1 × 1 4
Is 0 ⁵ or more. This is because if ε is smaller than 1 × 10 ⁴ , the effect of improving sensitivity is unlikely to be exhibited.

These light-to-heat converting substances alone have an effect of improving sensitivity, but the sensitivity can be further improved by using two or more kinds in combination.

The content of these light-to-heat converting substances is preferably from 0.1 to 40% by weight, more preferably from 0.5 to 25% by weight, based on the whole heat-sensitive layer composition.

Next, the binder (b) will be described. The binder polymer is not particularly limited as long as it is soluble in an organic solvent and has a film forming ability. From the viewpoint of the printing durability of a printing plate, the glass transition temperature (Tg) of the polymer is 20 ° C. or lower. Polymers, copolymers,
More preferably, a polymer or copolymer having a glass transition temperature of 0 ° C. or lower is preferably used.

Specific examples of the binder polymer include known vinyl polymers, unvulcanized rubber, polyoxides (polyethers), polyesters, polyurethanes, polyamides, and cellulose resins.

The content of these binders is preferably from 5 to 70% by weight, more preferably from 10 to 50% by weight, based on the total heat-sensitive layer composition.

The above various binder polymers may be used alone, or a mixture of several kinds of polymers may be used. Further, a crosslinking agent mentioned in (c) and a binder having a functional group having reactivity with the crosslinking agent of the silicone rubber layer are preferably used.

Among the above polymers, polyurethane, polyester and vinyl polymers are particularly preferred as the binder polymer.

Next, the crosslinking agent (c) will be described. The heat-sensitive layer preferably contains a cross-linking agent for the purpose of improving form retention, improving solvent resistance, and improving adhesion to the upper silicone rubber layer. When a polymer or oligomer is contained in the heat-sensitive layer, the crosslinking agent may be reacted with the compound or both.

As such a crosslinking agent, any of those described in Handbook of Crosslinking Agents (1981, Taiseisha Publishing Co., Ltd., written by Shinzo Yamashita and Tosuke Kaneko) can be used. The selection of these crosslinking agents is preferably selected depending on the object to be crosslinked. Specific examples of the reaction that can be used to form a crosslinked structure include, for example, hydroxyl groups and polyisocyanates in the heat-sensitive layer, epoxy resins, polyamines and amine derivatives, carboxylic acid derivatives such as polycarboxylic acids and carboxylic acid chlorides, metal chelate compounds and the like. Reaction, ene / thiol addition by an unsaturated group and a polythiol compound, thermal or photoradical polymerization of an unsaturated group, and the like.

The amount added to the heat-sensitive layer is preferably 3 to 50% by weight, more preferably 10 to 30% by weight, of the solid content forming the heat-sensitive layer. When the amount is less than 3% by weight, the effect, that is, the effect of improving the image reproducibility is lowered, while when it is more than 30% by weight, the physical properties of the heat-sensitive layer are liable to be reduced. This is because the problem of printability is likely to occur.

Further, in the present invention, a dye,
An acid, a leveling agent, a surfactant, a coloring agent, a plasticizer, and the like may be optionally added as needed.

The thickness of the heat-sensitive layer is 0.1 to 1 as a coating layer.
When it is 0 g / m 2, it is preferable in terms of printing durability of the printing plate and excellent in productivity because the diluting solvent is easily volatilized, and more preferably 1 to 7 g / m 2.

Next, the silicone rubber layer will be described.
In the present invention, examples of the silicone rubber layer include those made of a silicone rubber composition used in a conventional waterless lithographic printing plate.

Specific examples include those obtained by sparsely cross-linking a linear organopolysiloxane (preferably dimethylpolysiloxane).

The crosslinking method may be a condensation type or an addition type.

When performing condensation type crosslinking, tin, zinc,
It is preferable to add a metal carboxylate such as lead, calcium or manganese, for example, dibutyltin laurate, tin (II) octoate, naphthenate, or a catalyst such as chloroplatinic acid.

The addition type silicone rubber layer is formed, for example, by mixing a polyorganosiloxane having at least two vinyl groups in a molecule, a polyorganosiloxane having at least three SiH groups in a molecule and a platinum compound with an appropriate solvent. It can be formed from dilutions.

The platinum compound preferably used for the addition type silicone rubber layer is not particularly limited.
Platinum alone, platinum chloride, chloroplatinic acid, olefin-coordinated platinum and the like can be mentioned. Among these, olefin-coordinated platinum is preferable.

For the purpose of controlling the curing rate of the addition type silicone rubber layer, a vinyl group-containing organopolysiloxane such as tetracyclo (methylvinyl) siloxane,
It is preferable to add a reaction inhibitor such as a carbon-carbon triple bond-containing alcohol, acetone, methyl ethyl ketone, methanol, ethanol, and propylene glycol monomethyl ether.

In addition to these compositions, a hydroxyl group-containing organopolysiloxane or a hydrolyzable functional group-containing silane (or siloxane), which is a composition of the condensation type silicone rubber layer, may be added to improve the rubber strength. For this purpose, a known filler such as silica may be added.

Further, in the present invention, the silicone rubber layer preferably contains a silane coupling agent in addition to the above composition.

These silane coupling agents are preferably used in a ratio of 0.1 to 5% by weight, more preferably 0.5 to 5% by weight, based on the solid content of the silicone rubber layer composition.
3% by weight.

The thickness of these silicone rubber layers is 0.5 to
20 g / m2 is preferred, and more preferably 0.5 to 5 g / m2.
g / m2. If the film thickness is less than 0.5 g / m2, the ink repellency of the printing plate tends to decrease,
When it is larger than 0 g / m 2, it is disadvantageous not only from an economic viewpoint, but also has a problem that the ink mileage is deteriorated.

Next, a method for producing a direct drawing type waterless planographic printing plate precursor and a plate making method in the present invention will be described.

On a substrate which has been subjected to various treatments as required, a heat-insulating layer composition is applied as necessary using a conventional coater or a spin coater such as a wheyer, and the solvent is volatilized by heating. After curing by the action of heat or light, the heat-sensitive layer composition is applied, and the solvent is volatilized by heating and, if necessary, cured by the action of heat or light. Thereafter, the silicone rubber composition is applied and heat-treated at a temperature of 50 to 150 ° C. for several minutes to obtain a silicone rubber layer.

The plate thus obtained may be laminated with a protective film or formed with a protective layer for the purpose of protecting the silicone rubber layer.

Therefore, it is preferable that the protective film does not hinder the irradiation of the laser beam. Examples of such a cover film include a polyester film, a polypropylene film, a polyvinyl alcohol film, a saponified ethylene vinyl acetate copolymer film, and a polyvinylidene chloride film.

The thus obtained direct drawing type waterless planographic printing plate precursor is exposed imagewise with a laser beam from the protective film after the protective film is peeled off or, preferably, over the protective film.

The laser light source used in the plate making exposure step of the present invention has an emission wavelength range of 300 nm to 1500.
Those in the range of nm are used. That is, various lasers such as argon ion, krypton ion, helium-neon, helium-cadmium, ruby, glass, YAG, titanium sapphire, dye, nitrogen, metal vapor, excimer, free electron, and semiconductor are used.

Among these, for the purpose of making the printing plate precursor of the present invention, a semiconductor laser having an emission wavelength region near the near infrared region is preferable, and a high-power semiconductor laser is particularly preferably used.

The development is carried out by friction treatment in the presence or absence of water or an organic solvent. Alternatively, it is also possible to form a printing plate by so-called peeling development in which a pattern is formed on the printing plate by peeling off the protective film. The development is performed by using an automatic developing machine as described in JP-A-63-163357. After pre-processing the plate surface with the above-mentioned developer, the plate surface is rubbed with a rotating brush while showering with tap water or the like. It is also preferable to perform this.

Development is also possible by injecting hot water or steam onto the plate instead of the above-mentioned developer.

[0086]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto.

Example 1 A primer solution having the following composition was applied on a degreased aluminum plate having a thickness of 0.15 mm using a bar coater.
After drying at 80 ° C. for 2 minutes, a primer layer having a thickness of 4 g / m ² was applied.

Primer layer composition (a) Polyurethane resin (Samprene LQ-T1331, manufactured by Sanyo Chemical Industries, Ltd.) 90 parts by weight (b) Blocked isocyanate (Takenate B830, manufactured by Takeda Pharmaceutical Co., Ltd.) 35 parts by weight (c ) Epoxy / phenol / urea resin (SJ9372, manufactured by Kansai Paint Co., Ltd.) 8 parts by weight (d) Titanium oxide 10 parts by weight (e) Dimethylformamide. 900 parts by weight Subsequently, the following heat-sensitive layer composition was applied thereon using a bar coater, dried at 110 ° C. for 2 minutes, and the film thickness was 1 g / m ^2.
Was provided. Thermosensitive layer composition (a) IR-820 (B) (manufactured by Nippon Kayaku Co., Ltd., polymethine dye) 5 parts by weight (b) Aluminum acetylacetonate 30 parts by weight (c) Phenol novolak resin 60 parts by weight (d) Polyurethane resin 20 parts by weight (e) Denacol EX512 (polyglycerol polyglycidyl ether, manufactured by Nagase Kasei Kogyo Co., Ltd.) 5 parts by weight (f) Tetrahydrofuran 60 parts by weight (g) Dimethylformamide 20 parts by weight (h) Methyl isobutyl ketone 20 parts by weight Subsequently, a silicone rubber layer composition having the following composition was applied thereon using a bar coater, and a dew point of 30 ° C.
The film was cured by drying with heat and moisture at 5 ° C. for 2 minutes to provide a silicone rubber layer having a thickness of 2 g / m ² .

Silicone Rubber Layer Composition (a) 100 parts by weight of polydimethylsiloxane (molecular weight: about 25,000, terminal hydroxyl group) (b) 10 parts by weight of vinyltri (methylethylketoxime) silane (c) “Isoper E” (Exxon Chemical Co., Ltd.) 900 parts by weight) A polyester film “Lumirror” (manufactured by Toray Industries, Inc.) having a thickness of 8 μm is laminated on the laminated plate obtained as described above using a calendar roller, and is subjected to direct drawing type waterless lithographic printing. The original plate was obtained.

Thereafter, the "Lumirror" of the printing plate precursor was peeled off, and the semiconductor laser (O) mounted on the XY table was removed.
PC-A001-mmm-FC, output 0.75W, wavelength 780nm, OPTO POWER CORPORATE
ION), beam diameter 20 μm, exposure time 1
Pulse exposure was performed at a laser output of 250 mW for 0 μs.

Subsequently, the exposed plate was immersed (40 ° C., 60 seconds) in a pretreatment liquid having the following composition, and then rubbed with a wet cotton cloth to remove the silicone rubber layer in the exposed area. Development was completed.

Composition of pretreatment liquid (a) 95 parts by weight of polypropylene glycol (molecular weight: 200) (b) 5 parts by weight of water The plate after the development step has poor plate inspection properties, and the density difference between the image area and the non-image area. Was not clear. Then, the plate was stained with the following staining solution. In the dyeing method, the plate was immersed in a vat containing a dye solution at 25 ° C. for 10 seconds, washed with water and dried. As a result of measuring the staining density with a Macbeth reflection densitometer RD514,
The density difference between the image area and the non-image area was 1.1, and it was confirmed that a printing plate excellent in plate inspection properties was obtained and development was surely performed.

Composition of Staining Solution (a) 0.1 parts by weight of crystal violet (CI basic violet 3, manufactured by Hodogaya Chemical Industry Co., Ltd., λmax = 592 nm) (b) 99.9 parts by weight of pure water Part Example 2 The plate after laser irradiation of Example 1 was used in TWL-1160
(Toray Co., Ltd., automatic developing and dyeing machine for waterless lithographic printing plates)
Was developed at a speed of 60 cm / min. Here, as the pretreatment liquid, a liquid having a temperature of 40 ° C. and the following composition was used.

(A) 95 parts by weight of polypropylene glycol (molecular weight: 200) (b) 5 parts by weight of water Further, water was used as a developing solution, and the liquid temperature was 25 ° C. As the staining solution, the same as the staining solution of Example 1 was used,
The liquid temperature was 25 ° C.

As a result of measuring the dyeing density of the printing plate dyed by the automatic developing and dyeing machine with a Macbeth reflection densitometer RD514, the density difference between the image area and the non-image area was 1.1, and the plate inspection was excellent. A printing plate was obtained, and it was confirmed that the development was surely performed.

Example 3 A plate was made in the same manner as in Example 1 except that the dyeing solution of Example 2 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 excellent in plate inspection properties was obtained, and development was surely performed.

Staining Solution Composition (a) Aizen Victoria Pure Blue BOH (CI Basic Blue 7, manufactured by Hodogaya Chemical Industry Co., Ltd., λmax = 617 nm) 0.1 part by weight (b) Dodecylbenzene sulfone 0.2 parts by weight of sodium acid salt (c) KS-502 (manufactured by Shin-Etsu Chemical Co., Ltd., antifoaming agent) 0.01 parts by weight (d) 99.69 parts by weight of pure water Example 4 Staining solution of Example 2 Was made in the same manner as in Example 1 except that the following dyeing solution was used. As a result, the density difference between the image area and the non-image area was 1.15, and a printing plate excellent in plate inspection properties was obtained, and it was confirmed that development was surely performed.

Composition of Staining Solution (a) Aizen Methyl Violet Pure Special (CI Basic Violet 1, manufactured by Hodogaya Chemical Industry Co., Ltd., λmax = 585 nm) 0.1 part by weight (b) Sodium 2-ethylhexyl sulfate 0 0.2 parts by weight (c) Butyl carbitol 5 parts by weight (d) KS-502 (manufactured by Shin-Etsu Chemical Co., Ltd., antifoaming agent) 0.01 part by weight (e) Pure water 95.69 parts by weight Example 5 Plate making was performed in the same manner as in Example 1 except that the dyeing solution of Example 2 was changed to the following dyeing solution. As a result, the density difference between the image area and the non-image area was 0.9, and a printing plate excellent in plate inspection was obtained, and it was confirmed that development was surely performed.

Staining solution composition (a) 0.1 parts by weight of Aizen Victoria Pure Blue BOH (CI basic blue 7, manufactured by Hodogaya Chemical Industry Co., Ltd., λmax = 617 nm) (b) Neugen EA112 ( 1.0 part by weight (c) Butyl carbitol 5 parts by weight (d) KS-502 (manufactured by Shin-Etsu Chemical Co., Ltd., antifoaming agent) 01 parts by weight (e) Pure water 93.89 parts by weight Example 6 A plate was made in the same manner as in Example 1 except that the dyeing solution of Example 2 was changed to the following dyeing solution. As a result, the density difference between the image area and the non-image area was 0.9, and a printing plate excellent in plate inspection was obtained, and it was confirmed that development was surely performed.

Composition of Staining Solution (a) C.I. I. Acid Red 51 (λmax = 526 nm) 0.1 part by weight (b) Neugen EA112 (a nonionic surfactant manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 1.0 part by weight (c) Butyl carbitol 5 parts by weight ( d) KS-502 (manufactured by Shin-Etsu Chemical Co., Ltd., defoaming agent) 0.01 part by weight (e) Pure water 93.89 parts by weight Example 7 The plate after the laser irradiation of Example 1 was made to have the following composition. The plate was rubbed with a moist cotton cloth with the developing and dyeing solution, and the developing and dyeing treatments were performed simultaneously. Stain density by Macbeth reflection densitometer RD5
As a result of the measurement at 14, the density difference between the image area and the non-image area was 1.
1 and a printing plate excellent in plate inspection property was obtained, and it was confirmed that development was surely performed.

Composition of Developing / Dyeing Solution (a) 0.1 parts by weight of Aizen Victoria Pure Blue BOH (CI basic blue 7, manufactured by Hodogaya Chemical Industry Co., Ltd., λmax = 617 nm) (b) Neugen EA112 (Nonionic surfactant manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 1.0 part by weight (c) 5 parts by weight of butyl carbitol (d) 20 parts by weight of diethylene glycol mono-2-ethylhexyl ether (d) KS-502 (Shin-Etsu (Defoaming agent, manufactured by Chemical Industry Co., Ltd.) 0.01 parts by weight (e) 75 parts by weight of pure water

[0102]

According to the present invention, a direct drawing type waterless lithographic printing plate excellent in plate inspection properties can be obtained by obtaining a dyeing step.

Claims (5)

[Claims] 1. A method for producing a lithographic printing plate using a direct-drawing waterless lithographic printing plate precursor obtained by sequentially laminating at least a heat-sensitive layer and a silicone rubber layer on a substrate, comprising a step of dyeing the plate. A method for producing a direct-drawing waterless lithographic printing plate, characterized in that: 2. The method for producing a direct-drawing waterless lithographic printing plate according to claim 1, wherein the image portion is dyed after development of the direct-drawing waterless lithographic printing plate precursor. 3. The method for producing a direct drawing type waterless lithographic printing plate according to claim 1, wherein the density difference between the image area and the comparative image area is 0.5 or more. 4. At least λmax is 500 to 700 nm.
The method for producing a direct-drawing waterless planographic printing plate according to any one of claims 1 to 3, wherein the dye is dyed using a dye having an absorption wavelength of: 5. The method for producing a direct drawing type waterless lithographic printing plate according to claim 1, wherein the dyeing is carried out with a dye having a solubility in water of 0.01% or more.