JP2014180845A - Straight-drawing type water less lithographic printing plate original plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a straight-drawing type water less lithographic printing plate original plate having improved inferior quality in a production process, having printing plate readability by high aluminum concealment properties, image reproducibility and plate durability, and having excellent quality and production efficiency.SOLUTION: Provided is a straight-drawing type water less lithographic printing plate original plate using a pre-molded synthetic resin film or sheet as a supporting substrate.

Description

The present invention relates to a heat mode direct-drawing waterless lithographic printing plate precursor that can be directly made with a laser beam.

  Conventionally, a waterless planographic printing plate for performing planographic printing without using dampening water has been proposed. Recently, a direct-drawing waterless lithographic printing plate precursor has been disclosed that draws directly on the plate surface with laser light and converts the laser light into heat to reduce the adhesion between the heat-sensitive layer and the ink repellent layer, thereby forming an image. (For example, see Patent Documents 1 and 2).

  These direct-drawing waterless lithographic printing plate precursors have a laminated structure in which a primer layer, a heat-sensitive layer, and an ink repellent layer are applied and dried in this order on a support substrate, and these are formed in the same process. Manufactured continuously.

  In such a direct-drawing waterless planographic printing plate precursor, the primer layer plays the role of concealing the rolling marks of the metal substrate, improving the adhesion between the metal substrate and the heat-sensitive layer, and improving the printing durability by absorbing the impact during printing. . The thermosensitive layer has a role of photothermal conversion at the time of laser drawing, and the ink repellent layer has a role of ink repulsion at the time of printing.

However, in these conventional direct-drawing waterless lithographic printing plates, it is difficult to optimize the balance between the substrate transport speed, the coating conditions of each layer, and the drying conditions in the manufacturing process, and it is particularly necessary to make the coating thicker. As for a certain layer, due to insufficient temperature and drying time in the drying process, the resin of the layer component, the metal chelate compound and the like are separated from the surface layer as a sublimate, and are scattered and deposited in the dry atmosphere. When it re-adheres to the surface of the layer as a foreign substance, formation of the heat-sensitive layer and the ink repellent layer at that location is inhibited, and print quality and yield may be reduced.
In addition, since the primer layer needs to be thicker than other layers in order to provide cushioning properties and improve printing durability, drying equipment is required to apply and dry more resin solutions. It is necessary to lengthen the length of the substrate and to apply a higher amount of heat, which has been a cause of increased thermal distortion and energy cost of the support substrate.

Japanese Patent No. 4356505 Japanese Patent No. 4182775

  The present invention was devised in view of the various drawbacks of the prior art, and its object is to solve the above-mentioned problems. That is, an object of the present invention is to provide a waterless lithographic printing plate having high aluminum concealability, image reproducibility and printing durability, and excellent in quality and production efficiency.

  As a result of intensive studies in view of the above problems, the above-mentioned problem of the present invention is that a waterless lithographic printing plate precursor obtained by laminating at least a heat-sensitive layer and an ink repellent layer in this order on a substrate, It has been found that this can be achieved by providing a direct-drawing waterless lithographic printing plate precursor characterized by using a sheet as a supporting substrate.

  In particular, the direct-drawing waterless lithographic printing plate precursor, wherein the transmittance of the synthetic resin film or sheet constituting the support substrate is 15% or less at all wavelengths in the range of 300 to 900 nm, The thickness of the entire support substrate is 0.10 to 0.45 mm, the direct drawing type waterless lithographic printing plate precursor, and further, the material of the metal plate constituting the support substrate is aluminum It was found that this can be achieved by providing a direct-drawing waterless lithographic printing plate precursor.

  According to the present invention, quality defects in the production process are improved, and a direct-drawing waterless lithographic printing plate precursor having high aluminum concealment, image reproducibility, and printing durability and excellent in quality and production efficiency is obtained. It is possible.

  The present invention is described in further detail below.

  The direct-drawing waterless lithographic printing plate precursor of the present invention supports a pre-formed synthetic resin film or sheet in a waterless lithographic printing plate precursor obtained by laminating at least a heat-sensitive layer and an ink repellent layer in this order on a substrate. A direct-drawing waterless planographic printing plate precursor characterized by being used as a substrate. The waterless lithographic printing plate precursor is subjected to an exposure step and a development step, and a part of the ink repellent layer is removed to form a printing plate on which a desired image is formed. The portion where the ink repellent layer has been removed becomes the image portion, and the portion where the ink repellent layer remains becomes the non-image portion. The thermosensitive layer has a role of absorbing laser light in the exposure process.

  In the present invention, a pre-molded synthetic resin film or sheet is used as the support substrate. Here, “preliminarily” indicates that the film or sheet forming the support substrate is formed independently from the forming step of the heat-sensitive layer and the ink repellent layer that are sequentially formed on the support substrate.

  For the synthetic resin film and sheet used in the present invention, the type of synthetic resin is preferably polyester, polyolefin, polyamide, polyurethane, epoxy resin, etc. from the viewpoint of impact resistance, heat resistance, cost, etc. In particular, a synthetic resin that can hold a plate-like structure stably and can withstand the load applied during printing and the flexibility that can be set in a normal lithographic printing press is not limited thereto.

  In the present invention, a support substrate in which the above synthetic resin film or sheet is previously laid on a metal plate may be used. “Preliminary” as used herein means that the molding of the support substrate in which a synthetic resin film or sheet is laid on a metal plate and the molding process of the heat-sensitive layer and the ink repellent layer constituting the waterless lithographic plate are performed independently. Point to. However, the film and sheet forming process and the laying and bonding process on the metal plate may be the same or separate.

  The supporting substrate used in the present invention is sufficient if it can withstand the flexibility that can be set in a normal lithographic printing machine and the load applied during printing.

  As the metal plate used in the present invention, for example, aluminum, copper, zinc, steel, stainless steel and the like are preferably used. Of these substrates, an aluminum plate is particularly preferable because it is excellent in dimensional stability and inexpensive.

  The aluminum plate used in the present invention is a plate-like body such as pure aluminum or an aluminum alloy containing aluminum as a main component and containing a small amount of foreign atoms. Examples of the hetero atom include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, and titanium. Although aluminum suitable for the present invention is pure aluminum, it is difficult to produce completely pure aluminum in terms of refining technology. Therefore, it is preferable that the content of foreign atoms is as low as possible. The content of these different atoms is preferably 10% by weight or less. In addition, any aluminum alloy having a different atomic content as described above can be used in the present invention. The composition of the aluminum plate applied to the present invention is not specified, and conventionally known and publicly available materials can be used as appropriate.

  A plate reader that is a device for reading a halftone dot of a printing plate if the transmittance in the wavelength region of 300 to 900 nm of the synthetic resin film and sheet constituting the supporting substrate used in the present invention is 15% or less. (For example, iCPlate II (manufactured by X-Rite)) can be used stably. On the other hand, if the transmittance exceeds 15%, it is easily affected by the transmitted light from the back side of the film and the sheet and the pattern of the base such as a metal substrate, and the reading error increases. The conversion dye is exposed to light, causing problems such as a decrease in image reproducibility.

  The measuring method of the transmittance | permeability of the synthetic resin film and sheet | seat which comprises a support substrate can be measured, for example using a visible spectrophotometer. Although the measurement can be performed by a transmission method, when the support substrate is opaque, it can be converted after measurement by the reflection method. As such a visible spectrophotometer, U-3210 self-recording spectrophotometer manufactured by Hitachi, Ltd. may be mentioned. The reflection density can be measured with Macbeth RD-918 manufactured by Macbeth.

  In order to make the transmittance at 300 to 900 nm of the support substrate within the scope of the present invention, it is effective to include a pigment in the synthetic resin film and sheet constituting the support substrate. Examples of pigments include inorganic white pigments such as titanium oxide, zinc white, and lithopone, inorganic yellow pigments such as yellow lead, cadmium yellow, yellow iron oxide, ocher, and titanium yellow, and organic yellow pigments such as acetoacetic allyl monoazo pigments. Azo pigments such as acetoacetic allyl disazo pigments, condensed azo pigments, benzimidazolone monoazo pigments, isoindolinone pigments, isoindoline pigments, selenium pigments, perinone pigments, metal complex pigments, anthrapyrimidine pigments Polycyclic pigments such as acylamino yellow pigments, quinophthalone pigments, and flavantron pigments are preferably used. Among these white and yellow pigments, titanium oxide is particularly preferable in terms of hiding power and coloring power.

  Titanium oxide includes anatase type, rutile type, and brookite type, but from the standpoint of stability, rutile type and anatase type are preferred. Further, a titanium oxide surface treated with aluminum, silicon, titanium, zinc, zirconium or the like may be used. Specific examples of such titanium oxide include “Typaque (registered trademark)” R-820, R-830, R-930, R-550, R-630, and R-680 manufactured by Ishihara Sangyo Co., Ltd. , R-670, R-580, R-780, R-780-2, R-850, R-855, A-100, A-220, W-10, CR-50, CR-50-2, CR57 , CR-80, CR-90, CR-93, CR-95, CR953, CR-97, CR-60, CR-60-2, CR-63, CR-67, CR-58, CR-58-2 , CR-85, JR-301, JR-40, JR-405, JR-600A, JR-605, JR-600E, JR-603, JR-805, JR-806, JR-701, manufactured by Teika Co., Ltd. , JRNC, JR-800, JR, JA-1 JA-C, JA-3, JA-4, although such EN-5 are exemplified, but the invention is not limited thereto.

  As a particle diameter of the titanium oxide used for this invention, the range whose primary particle diameter is 0.2-0.3 micrometer is preferable. If the primary particle size is 0.2 μm or more, the desired concealing performance can be obtained, and if it is 0.3 μm or less, it is difficult to spontaneously settle and a composition liquid with stable dispersion can be obtained, and glossy and good Films and sheet coatings can be obtained.

  The addition amount of titanium oxide is preferably 2% by volume or more in the synthetic resin film and sheet. Furthermore, 3 volume% or more and 30 volume% or less are preferable. If it is 2 volume% or more, favorable concealment performance will be obtained, and if it is 30 volume% or less, favorable coating performance will be shown.

  Moreover, in this invention, you may use what processed the titanium oxide particle surface with the titanate coupling agent. By treating the surface of the titanium oxide particles with a titanate coupling agent, the dispersibility of the titanium oxide particles can be improved and a large amount of the titanium oxide particles can be added. Furthermore, the dispersion stability of the coating liquid to which titanium oxide particles are added is improved.

Specific examples of titanate coupling agents include isopropyl triisostearoyl titanate, isopropyl tri-n-stearoyl titanate, isopropyl trioctanoyl titanate, isopropyl tridodecylbenzenesulfonyl titanate, isopropyl tris (dioctyl pyrophosphite) titanate, tetraisopropyl bis (Dioctyl phosphite) titanate, tetraoctyl bis (ditridecyl phosphite) titanate, tetra (2,2-diallyloxymethyl-1-butyl) bis (di-tridecyl) phosphite titanate, bis (dioctyl pyrophosphate) oxyacetate Titanate, bis (dioctyl pyrophosphate) ethylene titanate, tris (dioctyl pyrophosphate) ethyl Titanate, isopropyl dimethacrylisostearoyl titanate, isopropyl isostearoyl diacryl titanate, isopropyl tri (dioctyl phosphate) titanate, isopropyl tricumylphenyl titanate, isopropyl tri (N-aminoethylaminoethyl) titanate, dicumylphenyloxyacetate titanate Isostearoyl ethylene titanate, isopropyl diisostearoyl cumylphenyl titanate, isopropyl distearoyl methacryl titanate, isopropyl diisostearoyl acryl titanate, isopropyl 4-aminobenzenesulfonyldi (dodecylbenzenesulfonyl) titanate, isopropyltrimethacryl titanate, isopropyldi (4 -Aminobenzoyl Isostearoyl titanate, isopropyl tri (dioctyl pyrophosphate) titanate, isopropyl triacryl titanate, isopropyl tri (N, N-dimethylethylamino) titanate, isopropyl trianthranyl titanate, isopropyl octyl, butyl pyrophosphate titanate, isopropyl di (butyl, methyl Pyrophosphate) titanate, tetraisopropyl di (dilauroyl phosphite) titanate, diisopropyloxyacetate titanate, isostearoyl methacryloxyacetate titanate, isostearoyl acryloxyacetate titanate, di (dioctyl phosphate) oxyacetate titanate, 4-aminobenzenesulfonyldodecyl Benzenesulfonyloxy Siacetate titanate, dimethacryloxyacetate titanate, dicumylphenolate oxyacetate titanate, 4-aminobenzoylisostearoyloxyacetate titanate, diacryloxyacetate titanate, di (octyl, butylpyrophosphate) oxyacetate titanate, isostearoyl methacrylethylene Titanate, di (dioctyl phosphate) ethylene titanate, 4-aminobenzenesulfonyldodecylbenzenesulfonylethylene titanate, dimethacrylethylene titanate, 4-aminobenzoylisostearoyl ethylene titanate, diacrylethylene titanate, dianthranylethylene titanate, di (butyl, methyl) Pyrophosphate) ethylene titanate, titanium Lylacetoacetate triisopropoxide, titanium bis (triethanolamine) diisopropoxide, titanium di-n-butoxide (bis-2,4-pentanedionate), titanium diisopropoxide bis (tetramethylheptanedionate), Titanium diisopropoxide bis (ethyl acetoacetate), titanium methacryloxyethyl acetoacetate triisopropoxide, titanium methylphenoxide, titanium oxide bis (pentanedionate), and “KR TTS” from Ajinomoto Co., Inc. KR 46B "," KR 55 "," KR 41B "," KR 138S "," KR 238S "," 338X "," KR 44 "," KR 9SA ", etc. Absent.
Titanium oxide titanate coupling agents can be roughly classified into two methods, a wet method and a dry method. As an example of the wet method, titanium oxide is added to a solution diluted with a solvent in which the titanate coupling agent dissolves, and the titanate coupling agent-treated titanium oxide dispersion is added by stirring with a homogenizer or the like. A liquid can be obtained. In addition, after adding glass beads etc., stirring vigorously with a paint shaker etc., filtering with a filter that can filter out glass beads etc., and removing the glass beads etc. can also obtain a titanate coupling agent treated titanium oxide dispersion. Can do. These steps can also be heated. As an example of the dry method, titanium oxide is added in a Henschel mixer, preliminarily dried at 95 ° C. for 20 minutes, and then a titanate coupling agent is added, and rotated at 1200 rpm while maintaining at 60 to 80 ° C. A titanate coupling agent-treated titanium oxide can be obtained.
The treatment amount of the titanate coupling agent with respect to titanium oxide is preferably 0.001 to 1 part by weight with respect to 100 parts by weight of titanium oxide. If it is the range of 0.001-1 weight part, the improvement effect of a dispersibility will be acquired. More preferably, it is 0.05-0.5 weight part.
The synthetic resin film and sheet constituting the support substrate in the present invention preferably contain an epoxy resin and a metal chelate compound. The epoxy resin and the metal chelate compound because the secondary hydroxyl group in the epoxy resin molecule easily causes an exchange reaction with the ligand in the metal chelate compound and the metal chelate compound acts catalytically in the polymerization of the epoxy resin. Synthetic resin films and sheets using the material have high-speed curability.
Further, since the hydroxyl group or glycidyl group in the epoxy resin molecule forms a hydrogen bond or a covalent bond with the hydroxyl group, carboxyl group or the like on the substrate surface, the adhesion to the substrate is enhanced. In addition, the metal chelate compound also forms a chemical bond with the hydroxyl group, carboxyl group, and the like on the substrate surface, which contributes to improvement in adhesion to the substrate. Therefore, a synthetic resin film and a sheet obtained by using an epoxy resin containing two or more hydroxyl groups in the molecule and a metal chelate compound are firmly bonded to the metal substrate.
In addition, the secondary hydroxyl group derived from the epoxy resin present on the surface of the synthetic resin film and the sheet, and the unreacted portion of the metal chelate compound form a chemical bond with the crosslinking agent, active hydrogen-containing compound, etc. in the heat sensitive layer. Adhesiveness between the resin film or sheet and the heat sensitive layer is also increased. As the epoxy resin, an epoxy resin containing two or more hydroxyl groups in the molecule is particularly preferable.
The epoxy resin used in the present invention can contain a phenoxy resin (polymer epoxy resin).
The epoxy resin used in the present invention is preferably a bisphenol type epoxy resin represented by the following general formula (I).

(In the formula, R ₁ , R ₂ and R ₃ are each one kind selected from the following formulas, and may be the same or different. M and n are each a positive integer of 0 or more, m + n ≧ 2.)

A brominated bisphenol type epoxy resin can also be used for the purpose of imparting flame retardancy. As such resin, specifically, “Epicoat (registered trademark)” 1001, 1002, 1003, 1055, 1004, 1004AF, 1007, 1009, 1010, 1003F, 1004F, 1005F, manufactured by Japan Epoxy Resin Co., Ltd. 1006F, 1100L, 4004P, 4007P, 4010P, 5051, 5054, 5057, 5203, 5354, 1256, 4250, 4275, “Epototo (registered trademark)” YD-011, YD-012, YD-01, manufactured by Tohto Kasei Co., Ltd. 013, YD-014, YD-017, YD-019, YD-020N, YD-020H, YD-7011R, YD-7017, YD-7019, YD-901, YD-902, YD-903N, YD-904, YD-907, YD-909, YD-9 7H, YD-6020, YDF-2001, YDF-2004, YDB-405, ST-5080, ST-5100, phenotote YP-50, YP-50S, YPB-40AM40, etc. is not. Among such epoxy resins, those having an epoxy equivalent of 600 or more are preferable. If the epoxy equivalent is 600 or more, good curability is exhibited. Here, the epoxy equivalent is the number of grams of resin containing 1 gram equivalent of an epoxy group.

  Examples of the metal chelate compound referred to in the present invention include an organic complex salt in which an organic ligand is coordinated to a metal, an organic inorganic complex salt in which an organic ligand and an inorganic ligand are coordinated to a metal, and a metal and an organic molecule. Mention may be made of metal alkoxides covalently bonded through oxygen.

  The main metals forming the organic complex compound include Cu (I), Ag (I), Hg (I), Hg (II), Li, Na, K, Be (II), B (III), Zn ( II), Cd (II), Al (III), Co (II), Ni (II), Cu (II), Ag (II), Au (III), Pd (II), Pt (II), Ca ( II), Sr (II), Ba (II), Ti (IV), V (III), V (IV), Cr (III), Mn (II), Mn (III), Fe (II), Fe ( III), Co (III), Pd (IV), Pt (IV), Sc (III), Y (III), Si (IV), Sn (II), Sn (IV), Pb (IV), Ru ( III), Rh (III), Os (III), Ir (III), Rb, Cs, Mg, Ni (IV), Ra Zr (IV), Hf (IV), Mo (IV), W (IV), Ge, In, lanthanides, actinides, and the like. Among these, Al, Ti, Mn, Fe, Co, Ni, Cu, Zn, Ge, In, Sn, Zr, and Hf are preferable. Among these, Al and Zr are preferable from the viewpoint of little coloring, and Al is particularly preferable from the viewpoint of reactivity.

  Examples of the ligand include compounds having the following coordination groups having O (oxygen atom), N (nitrogen atom), S (sulfur atom) and the like as donor atoms.

  Specific examples of the coordinating group include oxygen atoms as donor atoms: -OH (alcohol, enol and phenol), -COOH (carboxylic acid),> C = O (aldehyde, ketone, quinone), -O -(Ether), -COOR (ester), -N = O (nitroso compound, N-nitroso compound), -NO2 (nitro compound),> N-O (N-oxide), -SO3H (sulfonic acid),- As a thing using a nitrogen atom as a donor atom, such as PO3H2 (phosphorous acid), -NH2 (primary amine, amide, hydrazine),> NH (secondary amine, hydrazine),> N- (tertiary amine), -N = N- (azo compound, heterocyclic compound), = N-OH (oxime), -NO2 (nitro compound), -N = O (nitroso compound),> C = N- (Schiff base, heterocyclic compound) ),> C = NH (aldehyde, ketone imine, enamines), etc., with a sulfur atom as a donor atom, -SH (thiol), -S- (thioether),> C = S (thioketone, thioamide) , = S- (heterocyclic compound), -C (= O) -SH, -C (= S) -OH and -C (= S) -SH (thiocarboxylic acid), -SCN (thiocyanate, isothiocyanate) Etc. In the present invention, a ligand containing two or more such coordination groups in the ligand and forming one or more cyclic structures with the metal, specifically, β- Diketones, ketoesters, diesters, hydroxycarboxylic acids or esters or salts thereof, ketoalcohols, aminoalcohols, enolic active hydrogen compounds and the like are used.

Specific examples of such a ligand include the following.
(1) β-diketones: 2,4-pentanedione, 2,4-heptanedione, trifluoroacetylacetone, hexafluoroacetylacetone, dibenzoylmethane, benzoylacetone, benzoyltrifluoroacetone, and the like.
(2) Ketoesters: methyl acetoacetate, ethyl acetoacetate, butyl acetoacetate, octyl acetoacetate and the like.
(3) Diesters: malonic acid dimethyl ester, malonic acid diethyl ester, and the like.
(4) Hydroxycarboxylic acid or esters and salts thereof: lactic acid, methyl lactate, ethyl lactate, ammonium lactate, salicylic acid, methyl salicylate, ethyl salicylate, phenyl salicylate, malic acid, methyl malate, ethyl malate, tartaric acid, methyl tartrate , Ethyl tartrate, etc.
(5) Keto alcohols: 4-hydroxy-4-methyl-2-pentanone, 4-hydroxy-2-pentanone, 4-hydroxy-2-heptanone, 4-hydroxy-4-methyl-2-heptanone and the like.
(6) Amino alcohols: monoethanolamine, diethanolamine, triethanolamine, N-methyl-monoethanolamine, N-ethyl-monoethanolamine, N-dimethylethanolamine, N-diethylethanolamine and the like.
(7) Enolic active hydrogen compounds: methylol melamine, methylol urea, methylol acrylamide and the like.

  The metal chelate compound used in the present invention can have the above-mentioned ligand. Among them, an aluminum chelate compound in which one or more ligands selected from enols, diesters, and ketoesters are coordinated is used. preferable. Since these aluminum chelate compounds easily cause an exchange reaction with the active hydrogen-containing compound, the aluminum chelate compound itself can be prevented from sublimating or evaporating during heating.

  Moreover, it is particularly preferable to use an aluminum chelate compound in which two or more ketoesters are coordinated. By using such an aluminum chelate compound, it becomes less susceptible to moisture, and the storage stability of the synthetic resin solution is dramatically improved.

  As an addition ratio of the epoxy resin and the metal chelate compound, it is preferable to add them in such a ratio that both compounds react completely and become insoluble. If either an unreacted epoxy resin or a metal chelate compound remains, when the heat-sensitive layer composition is applied on the synthetic resin film and sheet, the components of the epoxy resin and the chelate compound are contained in the heat-sensitive layer composition. May be adversely affected on the performance of the printing plate.

  When specific examples of the addition ratio are given, when bisphenol A type epoxy resin (molecular weight 5,500) and aluminum-tris-acetylacetonate (molecular weight 324.3) are used, bisphenol A type epoxy resin vs. aluminum-tris. -The addition ratio of acetylacetonate is preferably in the range of 95 parts by weight to 5 parts by weight to 60 parts by weight to 40 parts by weight. Within this range, both compounds can sufficiently react and insolubilize, so that the performance of the printing plate is not adversely affected.

  Synthetic resin films and sheets used in the present invention include, in addition to epoxy resin, metal chelate compound, titanium oxide, phenol resin, acrylic resin, alkyd resin, polyester resin, polyamide resin, urea resin, polyvinyl butyral resin, casein, It may contain gelatin or the like.

  In addition, for the purpose of improving coating properties, alkyl ethers (for example, ethyl cellulose, methyl cellulose, etc.), fluorine-based surfactants, silicon-based surfactants, or nonionic surfactants may be added.

  Furthermore, for the purpose of improving the flexibility of the synthetic resin film and sheet, a flexibility-imparting agent such as natural rubber, synthetic rubber and polyurethane may be added. The addition amount of these flexibility-imparting agents is preferably 10 to 70% by weight, and more preferably 20 to 60% by weight. If it is 10% by weight or more, the flexibility is improved, and if it is 70% by weight or less, the inhibition of the curing reaction between the epoxy resin and the metal chelate compound is slight and can be substantially ignored.

  The components of the synthetic resin film and the sheet constituting the support substrate are preferably dissolved using a solvent. It is preferable that the solvent used for the resin solution has a property of sufficiently dissolving the metal chelate compound, the epoxy resin, and other additives. A solvent can also be used independently and can also be used in mixture of 2 or more types. In addition, when adding a pigment, it is preferable to select a solvent that wets the pigment surface well and provides good pigment dispersibility.

  As a method for preparing the resin composition, for example, a titanium oxide dispersion is put into a container, stirring is started, and an epoxy resin, a metal chelate compound, and other additives are sequentially added thereto, and further up to an arbitrary concentration with a solvent. The resin composition can be obtained by dilution.

  The titanium oxide dispersion can be obtained, for example, by adding titanium oxide in a solvent and dispersing with a paint shaker, a ball mill or the like.

  The support substrate in the present invention may be formed into a film or sheet by stretching the resin composition prepared as described above while heating and drying, or on another resin, metal film or sheet. You may shape | mold into a layer form by apply | coating, heating, and drying a resin composition.

  As for the application of the resin composition, for example, a normal coater such as a reverse roll coater, an air knife coater, a gravure coater, a die coater, a Meyer bar coater, or a spin coater such as a whaler, a desired film thickness, This does not apply as long as the appearance is obtained.

Heating at the time of molding the resin composition is preferably performed at a temperature equal to or higher than the boiling point of the solvent of the resin composition, and it is more preferable that the temperature gradient until reaching the maximum temperature is as gentle as possible. By doing so, drying unevenness due to bumping, precipitation of the composition, and sublimation can be suppressed, and the yield is further improved. When a general solvent is used, it is preferable that the drying temperature is 100 to 300 ° C. and the drying time is several minutes to several tens of minutes.
The synthetic resin film and sheet constituting the support substrate in the present invention include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, and those with isophthalic acid, dimer acid, etc., in addition to those containing the above-described epoxy resin and metal chelate compound. Thermoplastic resins such as copolymerized polyester, polyolefins such as polyethylene and polypropylene, and polyamides such as nylon 6, and those resins and titanium oxide may be included. The resin composition containing these thermoplastic resins may be processed into a single synthetic resin film or sheet, or may be laminated on a metal plate such as an aluminum plate.

  In the present invention, there is no particular limitation depending on the thickness of the entire support substrate, but it is preferably in the range of 0.10 to 0.45 mm in view of adaptation to a general printing press. In particular, when the thickness of the film and sheet portion made of the above resin composition is 1 μm or more, concealment can be obtained. However, when a metal plate is used for the base, the thickness of the metal portion is within the range where concealment can be obtained. And the thickness of the synthetic resin film or sheet portion may be arbitrarily changed.

Here, the measurement of the content of aluminum atoms in the synthetic resin film and the sheet can be performed by measuring the Al-Kα intensity by fluorescent X-rays. The details of the measurement method are summarized below.
Measuring device: Automatic fluorescent X-ray analyzer RIX3000 manufactured by Rigaku Electric Industry Co., Ltd.
Measurement conditions: X-ray tube: Rh
Tube voltage / current: 50 kV / 50 mA
Analysis line: Al-Kα
Analytical crystal: PET,
Detector: Gas flow proportional counter
Measurement atmosphere: in vacuum
Measuring surface: 30mmφ
Sample preparation and measurement: A sample piece cut to about 35 mm square was fixed to a measurement sample cell, and each sample was repeatedly measured twice (constant clock method: counting time 40 seconds).

  Next, the heat-sensitive layer used in the direct-drawing waterless planographic printing plate precursor of the present invention will be described.

  Although the material which comprises a thermosensitive layer is not specifically limited, It is preferable to contain (a) the compound which can decompose | disassemble by the effect | action of laser irradiation, and (b) a thermosetting compound.

  (A) As a compound that can be decomposed by the action of laser irradiation, (1) the compound itself does not absorb laser light, but the compound decomposes by the action of another compound that absorbs laser light, and (2) The compound itself absorbs laser light and decomposes.

  (1) Although the compound itself does not absorb laser light, examples of the compound that decomposes by the action of another compound that absorbs laser light include nitro compounds such as ammonium nitrate, potassium nitrate, sodium nitrate, carbonate compounds, and nitrocellulose. And organic peroxides such as benzoyl peroxide and perbenzoic acid esters, inorganic peroxides, azo compounds such as polyvinylpyrrolidone, azodicarbonamide, azobisisobutyronitrile, N, N′-dinitropentamethylenetetramine, etc. Nitroso compounds, azide compounds, diazo compounds or sulfonylhydrazide compounds such as p-toluenesulfonylhydrazine, p, p'-oxybis (benzenesulfohydrazine), and other low-molecular and high-molecular hydrazine derivatives. so That. Furthermore, a compound that generates an acid or an amine by the action of laser light, a compound that decomposes by the action of the generated acid or an amine, and the like can also be used in the present invention. Such a compound can be added in an amount of preferably 0.1 to 70% by weight, more preferably 1 to 50% by weight, still more preferably 5 to 30% by weight, based on the total solid content in the heat-sensitive layer.

  Moreover, as another compound which absorbs a laser beam, a well-known photothermal conversion substance can be mentioned. Specific examples of photothermal conversion materials include black pigments such as carbon black, titanium black, aniline black, and cyanine black, phthalocyanine, naphthalocyanine-based green pigments, carbon graphite, diamine-based metal complexes, dithiol-based metal complexes, and phenolthiol-based materials. Metal complexes, mercaptophenol-based metal complexes, crystal water-containing inorganic compounds, copper sulfate, chromium sulfide, silicate compounds, metal oxides such as titanium oxide, vanadium oxide, manganese oxide, iron oxide, cobalt oxide, and tungsten oxide, these And metal hydroxides and sulfates. Among these, carbon black is preferable from the viewpoints of photothermal conversion, economic efficiency, and handleability.

  Further, pigments that absorb infrared rays or near infrared rays, particularly dyes, are preferably used as the photothermal conversion substance. Particularly preferred dyes include cyanine, phthalocyanine, naphthalocyanine, dithiol metal complex, azurenium, squarylium, croconium, azo dispersion dye, bisazo, bisazostilbene, naphthoquinone, anthraquinone, perylene. Type, polymethine type, indoaniline metal complex dye, intermolecular CT type, benzothiopyran type, spiropyran type, nigrosine type, thioindigo type, nitroso type, quinoline type, fulgide type dye, particularly dyes are preferably used .

  The content of these photothermal conversion substances is preferably 1 to 40% by weight, more preferably 5 to 25% by weight, based on the total heat-sensitive layer composition. When the amount is less than 1% by weight, the effect of improving the sensitivity to laser light is not observed, and when the amount is more than 40% by weight, the printing durability of the printing plate tends to be lowered.

  (2) Examples of the compound that the compound itself absorbs and decomposes by laser light include the above-described dyes and pigments that exhibit a photothermal conversion action, which are relatively easily decomposed. Particularly preferred compounds include cyanine, phthalocyanine, naphthalocyanine, dithiol metal complex, azulenium, squarylium, croconium, azo disperse dye, bisazo, bisazostilbene, naphthoquinone, anthraquinone, perylene. Type, polymethine type, indoaniline metal complex dye, intermolecular CT type, benzothiopyran type, spiropyran type, nigrosine type, thioindigo type, nitroso type, quinoline type, fulgide type dye, particularly dyes are preferably used . The content of these compounds is preferably 1 to 40% by weight, more preferably 5 to 25% by weight, based on the total thermosensitive layer composition. When the amount is less than 1% by weight, the effect of improving the sensitivity to laser light is not observed, and when the amount is more than 40% by weight, the printing durability of the printing plate tends to be lowered.

  Examples of such compounds that can be decomposed by the action of laser irradiation include polymethine-based near infrared absorbing dyes, phthalocyanine-based near infrared absorbing dyes, cyanine-based near infrared absorbing dyes, dithiol metal complex-based near red Outer absorbing dyes and the like are preferable, and further, a combination of these near infrared absorbing dyes and at least one selected from organic peroxides, azo compounds, azide compounds, diazo compounds, and hydrazine derivatives is preferable.

  In the present invention, the thermosensitive layer preferably contains (b) a thermosetting compound. Conventionally, in direct-drawing lithographic printing plates that have a heat-sensitive layer and an ink repellent layer in this order, a type of printing plate that improves the adhesion between the heat-sensitive layer and the ink repellent layer by laser irradiation by applying techniques such as polymerization and crosslinking. Several attempts have been made to make it. On the other hand, an example of using a thermosetting compound in a so-called negative type printing plate precursor in which the adhesion between the heat sensitive layer and the ink repellent layer is reduced by laser irradiation is to introduce a cross-linked structure into the heat sensitive layer during the production of the original plate. There are only examples used for.

  The (b) thermosetting compound in the present invention refers to a group of compounds that are in the heat-sensitive layer of the printing plate precursor and have the ability to be directly or indirectly thermoset by the action of laser irradiation. say. Examples of such (b) thermosetting compounds include novolak resins and resol resins obtained by the condensation reaction of phenols such as phenol, cresol and xylenol with formaldehyde, phenol-furfural resins, furan resins, unsaturated polyesters, alkyds. Examples thereof include, but are not limited to, resins, urea resins, melamine resins, guanamine resins, epoxy resins, diallyl phthalate resins, unsaturated polyurethane resins, and polyimide precursors.

  In addition to the above-described reaction of the resin itself, a composition obtained by adding a heat-reactive crosslinking agent to a compound having a reactive functional group is also used in the present invention as a (b) thermosetting compound. be able to. Examples of the crosslinking agent include known polyfunctional compounds having crosslinking properties, such as polyfunctional blocked isocyanates, polyfunctional epoxy compounds, polyfunctional acrylate compounds, metal chelate compounds, polyfunctional aldehydes, polyfunctional mercapto compounds, polyfunctional alkoxys. Examples include silyl compounds, polyfunctional amine compounds, polyfunctional carboxylic acids, polyfunctional vinyl compounds, polyfunctional diazonium salts, polyfunctional azide compounds, and hydrazine. In addition, a known catalyst may be added to accelerate the reaction of the crosslinking agent. These crosslinking agents can be used alone or in admixture of two or more.

  Furthermore, in the present invention, (b) a compound that generates an acid or an amine by the action of heat and a compound that cures by the action of the generated acid or amine can be used as the thermosetting compound. Among such thermosetting compounds, a combination of a phenol resin and a metal chelate compound is particularly preferable.

  The proportion of the thermosetting compound (b) in the heat-sensitive layer is preferably 10 to 95% by weight, more preferably 30 to 70% by weight, based on the total solid content of the heat-sensitive layer composition. preferable. When the amount of the thermosetting compound is less than 10% by weight, the effect of improving the solvent resistance of the image area heat-sensitive layer by heat-curing the heat-sensitive layer may be poor. On the other hand, when the amount is more than 95% by weight, the heat decomposable compound and the photothermal conversion substance are relatively reduced, which may cause a problem in image formability by laser irradiation.

  In addition, the heat-sensitive layer composition may contain a binder polymer, a surfactant, and various additives. Specific examples of the binder polymer include acrylic acid esters such as polymethyl methacrylate and polybutyl methacrylate, homopolymers and copolymers of methacrylic acid esters, homopolymers of styrene monomers such as polystyrene, α-methylstyrene, and hydroxystyrene. Polymers and copolymers, various synthetic rubbers such as isoprene and styrene-butadiene, homopolymers and copolymers of vinyl esters such as polyvinyl acetate and vinyl chloride, and polyoxides such as polyethylene oxide and polypropylene oxide (polyethers) ), Polyesters, polyurethanes, polyamides, cellulose derivatives such as ethyl cellulose and cellulose acetate, phenoxy resins, methylpentene resins, polyparaxylylene resins, polyphenylenes Such as Fido resin and the like.

  The content of these binder polymers is preferably 5 to 70% by weight, more preferably 10 to 50% by weight, based on the total heat-sensitive layer composition. If the content is less than 5% by weight, problems occur in printing durability and coating properties of the coating liquid, and if it is more than 70% by weight, image reproducibility tends to be adversely affected.

The thickness of the heat-sensitive layer is preferably 0.1 to 10 g / m ² in terms of weight in terms of printing durability of the printing plate and the ability to easily dilute the diluting solvent and is excellent in productivity, and more preferably 0.5. it is a ~7g / ^{m 2.}

  When a direct-drawing waterless lithographic printing plate precursor having such a heat-sensitive layer is irradiated with laser, the surface of the heat-sensitive layer, that is, the surface in contact with the ink repellent layer, acts as a function of the laser light by the action of the photothermal conversion substance. The compound (a), which can be decomposed by, is decomposed. Moreover, the photothermal conversion substance itself may be decomposed by the action of laser light. At that time, it is preferable to generate a gas such as nitrogen or oxygen. Such decomposition of the compound and the action of the gas effectively weaken the adhesive force between the ink repellent layer and the heat-sensitive layer. On the other hand, curing of the thermosetting compound (b) proceeds inside the heat-sensitive layer of the laser irradiation part. As a result, the solvent resistance of the heat sensitive layer of the laser irradiation part is enhanced. As a result, in the subsequent development step, only the extreme surface of the heat-sensitive layer (the surface on the side in contact with the ink repellent layer) and the ink repellent layer are removed in the laser irradiation portion, and most of the heat-sensitive layer remains.

  In the printing plate thus obtained, the laser irradiation part becomes the image line part, and the laser non-irradiation part becomes the non-image line part. Since the heat-sensitive layer in the image area is cross-linked, the solvent resistance is high. Further, since the heat-sensitive layer remains, the cell depth is shallow. For these reasons, this printing plate has the advantage that fine dot reproducibility and ink mileage are good.

  Examples of the ink repellent layer used in the direct-drawing waterless lithographic printing plate precursor according to the present invention include a hydrophilic layer made of vinyl alcohols and the like, a hydrophilic layer including acrylic acid, acrylate, sulfonic acid, sulfonate, and the like. A hydrophilic swelling layer proposed in JP-A-8-282142, JP-A-8-282144, JP-A-8-292558, JP-A-9-54425, etc., an ink repellent layer, Although a layer containing a fluorine compound can be used, an ink repellent layer is preferable. As the ink repellent layer, either an addition polymerization type or a condensation polymerization type can be used.

  The components constituting the addition polymerization type ink repellent layer preferably include a vinyl group-containing polydimethylsiloxane, a SiH group-containing polysiloxane, and a reaction inhibitor and a curing catalyst for the purpose of controlling the curing rate.

  The vinyl group-containing polydimethylsiloxane has a structure represented by the following general formula (II) and has a vinyl group in the molecular terminal and / or main chain.

(In the formula, n represents an integer of 2 or more, and R ₄ and R ₅ are each a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 50 carbon atoms, and the number of carbon atoms. At least one group selected from the group of 4 to 50 substituted or unsubstituted aryl groups, which may be the same or different.

From the viewpoint of ink repellency of the printing plate, it is preferable that 50% or more of R ₄ and R ₅ in the above formula are methyl groups. The molecular weight of the vinyl group-containing polydimethylsiloxane can be from several thousands to several hundreds of thousands, but the weight average molecular weight is 10,000 to 10,000 from the viewpoints of handleability, ink repellency and scratch resistance of the resulting printing plate. It is preferable to use 1 million, more preferably 50,000 to 600,000.

  Examples of the SiH group-containing polysiloxane include compounds having SiH groups in the molecular chain or at the terminal, such as those represented by the following general formulas (III) to (VI).

(In the general formulas (III) to (VI), n represents an integer of 2 or more, and m represents an integer of 1 or more).

  The amount of SiH groups in the SiH group-containing polysiloxane is preferably 2 or more, more preferably 3 or more. The addition amount of the SiH group-containing polysiloxane is preferably 0.1 to 20% by weight, more preferably 1 to 15% by weight in the ink repellent layer. Speaking of the quantitative ratio with polydimethylsiloxane, the molar ratio of SiH group / vinyl group of polydimethylsiloxane is preferably 1.5 to 30, and more preferably 10 to 20. When this molar ratio is less than 1.5, the ink repellent layer may be insufficiently cured. Conversely, when it is greater than 30, the physical properties of the rubber become brittle and adversely affect the scratch resistance of the printing plate. It is because it becomes easy to give.

  Examples of the reaction inhibitor that can be used in the ink repellent layer include nitrogen-containing compounds, phosphorus compounds, unsaturated alcohols, and the like, and acetylene group-containing alcohols are preferably used. A preferable addition amount of the reaction inhibitor is 0.01 to 10% by weight, more preferably 0.1 to 5% by weight in the ink repellent layer.

Examples of the curing catalyst that can be used in the ink repellent layer include organic carboxylic acids such as acetic acid, propionic acid and maleic acid, acids such as toluenesulfonic acid and boric acid, and alkalis such as potassium hydroxide, sodium hydroxide and lithium hydroxide. , Amines, metal alkoxides such as titanium tetrapropoxide and titanium tetrabutoxide, metal diketenates such as iron acetylacetonate and titanium acetylacetonate dipropoxide, and metal organic acid salts. Among these, it is preferable to add a metal organic acid salt, and particularly a metal organic acid salt selected from tin, lead, zinc, iron, cobalt, calcium, and manganese. Specific examples of such compounds include dibutyltin diacetate, dibutyltin dioctate, dibutyltin dilaurate, zinc octylate, and iron octylate.
In addition to the above, a third transition element metal compound is preferable, and a platinum compound is more preferable. Specific examples include platinum alone, platinum chloride, chloroplatinic acid, olefin coordination platinum, alcohol-modified complexes of platinum, methylvinylpolysiloxane complexes of platinum, and the like. The amount of such a curing catalyst is preferably 0.01 to 20% by weight, more preferably 0.1 to 10% by weight as a solid content in the ink repellent layer. When the amount of the catalyst to be added is less than 0.01% by weight, the ink repellent layer is not sufficiently cured, and there may be a problem in adhesion to the heat sensitive layer. When the amount of the catalyst added is more than 20% by weight, the pot life of the ink repellent layer composition is adversely affected. In terms of the amount of metal such as platinum in the ink repellent layer composition, it is preferably 10 to 1000 ppm, more preferably 100 to 500 ppm.

  In addition to the above-mentioned compounds, the ink-repelling layer improves the adhesion with hydroxyl group-containing organopolysiloxane, hydrolyzable functional group-containing silane or siloxane, and known fillers such as silica for the purpose of improving rubber strength. For the purpose, a known silane coupling agent, titanate coupling agent, aluminum coupling agent and the like may be contained. As the silane coupling agent, alkoxysilanes, acetoxysilanes, ketoximine silanes and the like are preferable, and those having a vinyl group and ketoximine silanes are particularly preferable.

  The ink repellent layer contains a hydroxyl group-containing polydimethylsiloxane, a crosslinking agent (deacetic acid type, deoxime type, dealcohol type, deamine type, deacetone type, deamid type, deamidoxy type, etc.). Can do. Here, the hydroxyl group-containing polydimethylsiloxane has a structure represented by the following general formula (II).

(In the formula, n represents an integer of 2 or more, and R ₄ and R ₅ are each a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 50 carbon atoms, and the number of carbon atoms. At least one group selected from the group of 4 to 50 substituted or unsubstituted aryl groups, which may be the same or different.

As for R ₄ and R ₅ , 50% or more of the whole is preferably a methyl group from the viewpoint of ink repellency of the printing plate. The hydroxyl group can be located at the molecular end and / or in the main chain, but those having a hydroxyl group at the molecular chain end are preferably used. Further, molecular weights of several thousands to several hundred thousand can be used, but weight average molecular weights of 10,000 to 200,000, and further 3 from the viewpoints of handling properties, ink repellency and scratch resistance of the obtained printing plate, and the like. It is preferable to use one having 10,000 to 150,000.

Examples of the crosslinking agent preferably used in the ink repellent layer include acetoxysilanes, alkoxysilanes, ketoximine silanes, and allyloxysilanes represented by the following general formula (VII).
(R ₆ ) _4-n SiX _n (VII)
(In the formula, n represents an integer of 2 to 4, and R ₆ represents a substituted or unsubstituted alkyl group, alkenyl group, aryl group, or a combination thereof having 1 or more carbon atoms. A functional group selected from a halogen atom, an alkoxy group, an acyloxy group, a ketoximine group, an aminooxy group, an amide group, and an alkenyloxy group.
In the above formula, the number n of hydrolyzable groups is preferably 3 or 4.

  Specific compounds represented by the general formula (VII) include methyltriacetoxysilane, ethyltriacetoxysilane, vinyltriacetoxysilane, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane. , Tetraethoxysilane, tetrapropoxysilane, vinyltrimethoxysilane, vinyltriphenoxysilane, vinyltriethoxysilane, allyltriethoxysilane, vinyltriisopropoxysilane, vinyltrisisopropenoxysilane, vinylmethylbis (methylethylketoximine) Silane, methyltri (methylethylketoximine) silane, vinyltri (methylethylketoximine) silane, tetra (methylethylketoximine) silane, diisopropenoxydimethyl Orchids, bird isopropenoxysilane carboxymethyl silane, but like tetra allyloxy silanes, but it is not limited thereto. Among these, acetoxysilanes and ketoximinesilanes are preferable from the viewpoints of the curing speed of the ink repellent layer, handling properties, and the like.

  The addition amount of the crosslinking agent represented by the general formula (VII) is preferably 1.5 to 20% by weight, more preferably 3 to 10% by weight of the ink repellent layer composition. Speaking of the quantitative ratio with polydimethylsiloxane, the molar ratio of the functional group X / the hydroxyl group of polydimethylsiloxane is preferably 1.5 to 10.0. If this molar ratio is less than 1.5, gelation of the ink repellent layer composition is likely to occur, and conversely if it is greater than 10.0, the physical properties of the rubber become brittle, and the scratch resistance of the printing plate, etc. It is because it becomes easy to give a bad influence to.

  The ink repellent layer may contain a known filler such as silica and further a known silane coupling agent for the purpose of improving rubber strength.

The film thickness of the ink repellent layer used in the present invention is preferably 0.5 to 20 g / m ^{2 in} terms of weight, more preferably 1 to 4 g / m ² . When the film thickness is smaller than 0.5 g / m ^2, the ink repellency, scratch resistance, and printing durability of the printing plate tend to be lowered. When the film thickness is larger than 20 g / m ² , it is disadvantageous from an economic viewpoint. In addition to this, developability and ink mileage deteriorate.

  A preferred method for producing the direct-drawing waterless planographic printing plate precursor of the present invention will be described below.

  A heat-sensitive layer composition is applied on the support substrate prepared as described above, dried by heating at 50 to 180 ° C. for several tens of seconds to several minutes, and cured as necessary to obtain a heat-sensitive layer.

  Furthermore, an ink repellent layer composition is applied thereon and heat-treated at a temperature of 50 to 200 ° C. for several minutes to obtain an ink repellent layer.

  Examples of the coating method of each composition include a normal coater such as a reverse roll coater, an air knife coater, a gravure coater, a die coater, and a Meyer bar coater, or a spin coater such as a whaler. This is not limited as long as the thickness and appearance can be obtained.

  Thereafter, a protective film may be laminated or a protective layer may be formed for the purpose of protecting the ink repellent layer as necessary. Examples of the protective film include polyester film, polypropylene film, polyvinyl alcohol film, saponified ethylene vinyl acetate copolymer film, and polyvinylidene chloride film.

  Next, a plate making method for producing a printing plate from the directly drawn waterless lithographic printing plate precursor thus obtained will be described. The plate making method usually comprises at least (1) an exposure step, (2) a “pretreatment step” for reducing the adhesion between the ink repellent layer and the heat-sensitive layer in the laser-irradiated portion, and (3) an ink-repellent layer in the laser-irradiated portion. It consists of a “development process” for peeling. In addition, (4) a “post-treatment step” for dyeing the heat-sensitive layer in the image area with a staining solution (post-treatment solution), and (5) a “water-washing step” for completely washing off the pre-treatment solution and the staining solution. Good. Each step will be described in detail.

(1) Exposure process The direct drawing type waterless lithographic printing plate precursor is exposed to a desired image with a laser beam after peeling off the protective film or on the protective film.

As the laser light source used in the exposure process, one having an emission wavelength region in the range of 300 to 1500 nm is usually used. Among these, a semiconductor laser or a YAG laser having an emission wavelength region near the near infrared region is used. Preferably used. Specifically, from the viewpoint of handling of the plate material in a bright room, laser beams having wavelengths of 780 nm, 808 nm, 830 nm, and 1064 nm are preferably used for plate making.
Decomposition is generated on the surface of the heat-sensitive layer by laser irradiation, and further curing of the inside of the heat-sensitive layer is advanced by laser irradiation.

(2) Pretreatment step The pretreatment step is a step of immersing the plate in a pretreatment liquid maintained at a predetermined temperature for a predetermined time.

  If the irradiation energy of the laser in the exposure step is large, the ink repellent layer in the laser irradiation portion can be peeled off without going through the pretreatment step and proceeding directly to the development step. However, when the irradiation energy is small, since the thermal layer is less modified, it is difficult to detect ON / OFF of laser irradiation only by the development process, and development is likely to be impossible. When the laser irradiation energy is increased, the energy required for pattern formation of the printing plate can be large. Further, when a laser with too much energy is irradiated, the heat-sensitive layer is destroyed, and it becomes difficult for the heat-sensitive layer to remain after development, thus suffering from the disadvantages in printing described above. Therefore, the plate is treated with a pretreatment liquid in order to amplify the ON / OFF difference of laser irradiation and develop the low-energy laser irradiation portion.

  In the pretreatment step, the plate is preferably immersed in a pretreatment liquid at a temperature of 30 to 60 ° C. for 10 to 100 seconds. When immersed in a pretreatment liquid at a temperature of less than 30 ° C., or when immersed in the pretreatment liquid for less than 10 seconds, the thermal layer is not sufficiently swelled or dissolved, and the adhesion between the ink repellent layer and the thermal layer is insufficient. The power cannot be reduced sufficiently. Moreover, when immersed in the pretreatment liquid at a temperature exceeding 60 ° C., or when the immersion time in the pretreatment liquid exceeds 100 seconds, there may be a problem that the heat-sensitive layer peels off from the substrate.

  When the plate is immersed in the pretreatment liquid, the pretreatment liquid penetrates into the ink repellent layer and eventually reaches the heat sensitive layer. The heat-sensitive layer of the irradiated part has a thermal decomposition product in the upper part, or the solubility in the pretreatment liquid is improved, so the upper part of the heat sensitive layer is swollen or partially dissolved by the pretreatment liquid. The adhesive force between the ink repellent layer and the heat-sensitive layer is reduced. When the printing plate surface is rubbed lightly in this state, the ink repellent layer in the irradiated area is peeled off, and the lower heat-sensitive layer is exposed to form an ink deposit layer. On the other hand, since the heat-sensitive layer in the unirradiated part is insoluble or hardly soluble in the pretreatment liquid, the ink repellent layer is strongly bonded to the heat-sensitive layer and does not peel off even when rubbed strongly. In this manner, the ink repellent layer in the non-irradiated portion is not developed, and this portion repels the ink, so that the waterless planographic printing plate is imaged.

  Since the sensitivity of the printing plate is increased by such a mechanism, the selection of the pretreatment liquid is important. When a pretreatment liquid having a high heat-sensitive layer dissolving ability is used, the ink repellent layer in the unirradiated part is peeled off, and depending on the degree, even the heat-sensitive layer is developed. As a result, the life of the pretreatment liquid is shortened by contaminating the pretreatment liquid and the like. On the other hand, if a pretreatment liquid having a low heat-sensitive layer solubility is used, even the ink repellent layer in the irradiated area cannot be developed, and the sensitivity of the printing plate cannot be increased.

  As such a pretreatment liquid, a solvent formed by adding a polar solvent such as alcohol, ketone, ester, carboxylic acid or amine to water, or a solvent comprising at least one kind such as aliphatic hydrocarbons and aromatic hydrocarbons. A polar solvent is used in which at least one kind of polar solvent is added. Furthermore, it is preferable to use a glycol compound or glycol ether compound represented by the following general formula (VIII) as a main component.

(Here, R ₇ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, R ₈ and R ₉ represent a hydrogen atom or an alkyl group having 1 to 15 carbon atoms, and k is an integer of 1 to 12). ).

In general, the glycol ether compound has a higher solubility in the heat-sensitive layer than the glycol compound. Therefore, by selecting an appropriate compound among them or mixing them, a pretreatment liquid having optimal selective solubility can be obtained with respect to plate materials having different heat-sensitive layer curing conditions. . The effect as the pretreatment liquid takes into account not only the selective solubility of the heat-sensitive layer but also the swelling ability of the ink repellent layer. When the ink repellent layer swells, it becomes easy to peel off the ink repellent layer, so that even a pretreatment liquid having a low heat-sensitive layer solubility can be easily developed. However, if the ink repellent layer swells too much, it becomes easy to be scratched during development, so it is necessary to keep it within an appropriate range. Specifically, the ink repellent layer preferably has a swelling ratio of 30% or less, more preferably 10% or less. For example, the swelling rate of the ink repellent layer using silicone rubber with a glycol compound is almost 0%, and the ink repellent layer hardly swells. Therefore, only the selective solubility of the heat-sensitive layer affects the suitability as a pretreatment liquid. . On the other hand, when a linear functional group having a small number of repeating units such as ethylene oxide and propylene oxide and having a relatively long linear function is introduced into R ₈ and R ₉ , the swelling ability of the ink repellent layer is increased. Among glycol monoethers and glycol diethers, diethers generally have a higher swelling capacity for silicone rubber. In such a case, the pretreatment liquid is designed in consideration of both the selective solubility of the heat sensitive layer and the swelling ability of the silicone rubber.

  Examples of the glycol compound include ethylene glycol, propylene glycol, butylene glycol (1,2-butanediol), 2,3-butanediol, polyethylene glycol having a repeating unit number k = 2 to 12 in the general formula (VIII), polypropylene glycol, and the like. Is mentioned. These glycol compounds can be used alone or in combination of two or more. Among these, from the viewpoint of selective solubility, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol having a repeating unit number k = 2 to 4 in formula (VIII) Is particularly preferably used as a pretreatment liquid.

Examples of the glycol ether compound include monoalkyl ethers and dialkyl ethers of the above glycol compounds. Examples of the alkyl group for R ₈ and R ₉ include methyl group, ethyl group, propyl group, iso-propyl group, butyl group, iso-butyl group, tert-butyl group, heptyl group, hexyl group, heptyl group, octyl group, 2 -Ethylhexyl group, nonyl group, decanyl group, undecanyl group, dodecanyl group may be mentioned. Preferred glycol ether compounds include diethylene glycol monomethyl ether (methyl carbitol), diethylene glycol monoethyl ether (ethyl carbitol), diethylene glycol monopropyl ether (propyl carbitol), diethylene glycol monobutyl ether (butyl carbitol), diethylene glycol monohexyl. Ether, diethylene glycol mono-2-ethylhexyl ether, diethylene glycol dimethyl ether (diglyme), diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monopropyl ether, trie Lenglycol monobutyl ether, triethylene glycol monohexyl ether, triethylene glycol mono-2-ethylhexyl ether, triethylene glycol dimethyl ether (triglyme), triethylene glycol methyl ethyl ether, triethylene glycol diethyl ether, tetraethylene glycol monomethyl ether, tetra Ethylene glycol monoethyl ether, tetraethylene glycol monopropyl ether, tetraethylene glycol monobutyl ether, tetraethylene glycol monohexyl ether, tetraethylene glycol-2-ethylhexyl ether, tetraethylene glycol dimethyl ether (tetraglyme), tetraethylene glycol methyl ethyl ether Tetra Tylene glycol diethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether, dipropylene glycol monohexyl ether, dipropylene glycol mono-2-ethylhexyl ether, tripropylene Glycol monomethyl ether, tripropylene glycol monoethyl ether, tripropylene glycol monopropyl ether, tripropylene glycol monobutyl ether, tripropylene glycol monohexyl ether, tripropylene glycol mono-2-ethylhexyl ether, tetrapropylene glycol monomethyl ether, tetrapropylene glycol Monoech Examples include ether, tetrapropylene glycol monopropyl ether, tetrapropylene glycol monobutyl ether, tetrapropylene glycol monohexyl ether, and tetrapropylene glycol mono-2-ethylhexyl ether.

  The content of the glycol compound or glycol ether compound represented by the general formula (VIII) in the pretreatment liquid is preferably 50 to 100% by weight, and more preferably 70 to 95% by weight. If it is less than 50% by weight, the selective solubility of the heat-sensitive layer is inferior, so that the image reproducibility is lowered.

  Moreover, it is also preferable to make an amine compound coexist in a pretreatment liquid. Although the amine compound is inferior in selective solubility, it may be added as a secondary component in the pretreatment liquid for the purpose of increasing the sensitivity because the heat-sensitive layer has high solubility.

  As amine compounds, glycol amine compounds such as ethylene glycol amine, diethylene glycol amine, triethylene glycol amine, tetraethylene glycol amine, propylene glycol amine, dipropylene glycol amine, tripropylene glycol amine, methylamine, ethylamine, dimethylamine, Diethylamine, trimethylamine, triethylamine, propylamine, butylamine, amylamine, dipropylamine, dibutylamine, diamylamine, tripropylamine, tributylamine, methyldiethylamine, ethylenediamine, trimethylenediamine, tetramethylenediamine, polyethyleneimine, benzylamine, N, N-dimethylbenzylamine, N, N-diethylbenzyl , N, N-dipropylbenzylamine, o-, or m-, p-methoxy, or methylbenzylamine, N, N-di (methoxybenzyl) amine, β-phenylethylamine, γ-phenylpropylamine, cyclohexylamine Aniline, monomethylaniline, dimethylaniline, toluidine, α or β naphthylamine, o- or m-, or p-phenylenediamine, aminobenzoic acid, 2- (2-aminoethyl) ethanol, 2-amino-2-methyl -1,3-propanediol, 2-amino-1,3-propanediol, 2-amino-2-hydroxymethyl-1,3-propanediol, and the like.

  The content of the amine compound in the pretreatment liquid is preferably 25% by weight or less, and more preferably 15% by weight or less. If the amount is more than 25% by weight, the dissolving power in the heat-sensitive layer becomes strong, and not only the ink repellent layer in the image area but also the non-image area is easily peeled off, making it difficult to reproduce the image.

  In the pretreatment liquid, water, alcohols, carboxylic acids, esters, aliphatic hydrocarbons (hexane, heptane, etc.), aliphatic hydrocarbons (toluene, xylene, etc.), halogenated as necessary Hydrocarbons (such as trichlene) may be added. Further, a surfactant such as sulfate, phosphate, carboxylate or sulfonate may be added to the pretreatment liquid in order to prevent scratches when rubbing the plate surface during development.

(3) Development process By the pre-treatment, the surface of the heat-sensitive layer is swollen or partially dissolved in the laser irradiation part, and therefore the ink repellent layer is easily selectively peeled off. Therefore, development is performed by rubbing the plate surface with water or another solvent. Development with water is most preferable from the viewpoint of waste liquid. The pretreatment liquid contains a hydrophilic compound as a main component. Therefore, development with water is also preferred in that the processing liquid penetrating the printing plate can be washed away with water. Development may also be performed by spraying warm water or water vapor onto the plate surface. In order to improve developability, water added with a pretreatment liquid may be used. Although the temperature of a developing solution may be arbitrary, 10-50 degreeC is preferable.

(4) Post-processing step In order to facilitate confirmation of the image area formed by development, a post-processing step of dyeing with a staining solution may be provided. As a dye used in the dyeing solution, a basic dye, an acid dye, a direct dye, a disperse dye, a reactive dye, or the like can be used alone or in admixture of two or more. Of these, water-soluble basic dyes and acid dyes are preferably used.

  Basic dyes include “Crystal Violet”, “Ethyl Violet”, “Victoria Pure Blue”, “Victoria Blue”, “Methyl Violet”, “DIABACIS MAGENTA” (Mitsubishi Chemical Corporation), “AIZEN BASIC CYANINE 6GH” "(Made by Hodogaya Chemical Co., Ltd.)," PRIMOCYANINE BX CONC. "(Made by Sumitomo Chemical Co., Ltd.)," ASTRAZON BLUE G "(made by FARBENFARRIKEN BAYER)," DIACRYL SUPRA BRILLIANT 2B "(made by Mitsubishi Chemical Corporation) ), “AIZEN CATHILON TURQUOISE BLUE LH” (made by Hodogaya Chemical Co., Ltd.), “AIZEN DIAMOND GREEN GH” (made by Hodogaya Chemical Co., Ltd.), “AIZEN MALACHITE GREEN” (made by Hodogaya Chemical Co., Ltd.), etc. Is used.

  Acid dyes include “ACID VIORET 5B” (Hodogaya Chemical Co., Ltd.), “KITON BLUE A” (CIBA), “PATENT BLUE AF” (BASF), “RAKUTO BRILLIANT BLUE FCF” (Saito Chemical) Kogyo Co., Ltd.), “BRILLIANT ACID BLUE R” (GEIGY), “KAYANOL CYANINE 6B” (Nippon Kayaku Co., Ltd.), “SUPRANOL CYANINE G” (FARBENFARRIKEN BAYER), “ORIENT SOLUBLE BLUE OBB” (Orient Chemical Industries, Ltd.), “ACID BRILLIANT BLUE 5G” (manufactured by Chugai Kasei Co., Ltd.), “ACID BRILLIANT BLUE FFR” (manufactured by Chugai Kasei Co., Ltd.), “ACID GREEN GBH” (Takaoka Chemical Industries, Ltd.) And ACID BRILLIANT MILLING GREEN B (Hodogaya Chemical Co., Ltd.) are used.

  The content of these dyes in the dyeing solution is preferably 0.01 to 10% by weight, more preferably 0.1 to 5% by weight.

  Water, alcohols, glycols, glycol monoalkyl ethers, glycol dialkyl ethers are used as the solvent for the dyeing solution. These solvents are used alone or in combination of two or more. Glycols, glycol monoalkyl ethers, and glycol dialkyl ethers also have an effect as a pretreatment liquid. Therefore, even if the ink repellent layer in the laser irradiated part cannot be developed in the development process and is attached, It can also be developed.

  In addition, a dyeing assistant, an organic acid, an inorganic acid, an antifoaming agent, a plasticizer, and a surfactant may be optionally added to the dyeing solution.

  The temperature of the staining solution may be arbitrary, but is preferably 10 to 50 ° C. It is also possible to dye the image area simultaneously with development by adding the above dye to the developer.

(5) Washing step If the pretreatment liquid or the dyeing solution is still infiltrated into the plate surface, the ink repellent layer in the non-image area may easily peel off over time. You may provide the water washing process which wash | cleans completely from a printing plate surface. The temperature of the rinsing water may be arbitrary, but is preferably 10 to 50 ° C.

  The development method according to the steps described so far may be either manual development or development by an automatic development apparatus. Development by hand can be carried out by wiping the plate surface by impregnating a nonwoven fabric, absorbent cotton, cloth, sponge or the like with these pretreatment liquid, developer and dyeing liquid in order. In the case of using an automatic developing device, it is preferable that a preprocessing unit, a developing unit, and a post-processing unit are provided in this order. In some cases, a water washing section may be further provided behind the post-processing section. Such automatic processors are disclosed in “TWL-1160” and “TWL-650” manufactured by Toray Industries, Inc., or in Japanese Patent Laid-Open Nos. 4-2265, 5-2272, and 5-6000. The developing device which has been used.

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

<Method of measuring transmittance of synthetic resin film and sheet constituting supporting substrate>
When the support substrate was transparent, it was set in a U-3210 self-recording spectrophotometer manufactured by Hitachi, Ltd., and the transmittance with respect to light having a wavelength of 300 to 900 nm was measured.

  When the support substrate was opaque, an integrating sphere was attached to the U-3210 self-recording spectrophotometer, and the reflectance at a wavelength of 300 to 900 nm was measured instead of the transmittance. When measured by the reflection method, the light reflected by the substrate surface passes through the film and sheet twice, so the transmittance measured by the reflection method is twice the film thickness when measured by the transmission method. The corresponding value is obtained. This value can be converted into a value measured by the transmission method by the well-known Lambert-Berr method.

<Method of judging plate surface readability>
A direct-drawing waterless lithographic printing plate precursor is exposed and developed at 2,400 dpi, 1, 2, 3, 4, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 95, respectively. Printing plates having 96, 97, 98, and 99% halftone dots were prepared.

  The obtained printing plate was measured for dot area ratio using a dot area ratio measuring device iCPlate II (manufactured by X-Rite). “◯” indicates that the predetermined halftone dot area is displayed, and “X” indicates that the predetermined halftone dot area is displayed with a deviation of 3% or more from the predetermined halftone dot area.

<Determination method for foreign matter defects>
For a direct-drawing waterless lithographic printing plate precursor of size 1030 × 800 mm, visually observe the surface of 10 sheets for each condition, count the number of foreign matter defects with a maximum side of 400 μm or more present on the plate surface, The case where there was no “◯” was marked as “x” when even one was found.

<Measurement method of image reproducibility>
A direct-drawing waterless lithographic printing plate precursor is exposed and developed at 2,400 dpi, 1, 2, 3, 4, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 95, respectively. Printing plates having 96, 97, 98, and 99% halftone dots were prepared.

  The obtained printing plate was observed with a magnifying glass, and the reproducibility of each halftone dot was examined. The case where all of the 1 to 99% halftone dots were reproducible was indicated as “◯”, and the halftone dots lacking or missing were indicated as “x”.

<Measurement method of printing durability>
A plate obtained by developing a direct-drawing waterless lithographic printing plate precursor without exposure to light is set in a printing machine (Lislon L-426, manufactured by Komori Corporation), and is run empty without ink or paper being supplied. For each contact between the blanket and the plate, the ink repellent layer on the plate surface was damaged and the plate was deformed or broken. “◎” if there is no problem such as damage, deformation or breakage even after contact 30,000 times or more “○” if there is no problem if it is 10,000 times or more and less than 30,000 times. Was marked “x”.

<Composition of resin composition for preparing support substrate>
(A) Titanium oxide dispersion: Titanium master (manufactured by Sumika Color Co., Ltd.): 21.1 wt%
(B) Polyurethane resin: Samprene LQ-T1331D (manufactured by Sanyo Chemical Co., Ltd.): 31.0 wt%
(C) Epoxy resin: Epoxy 1010 DMF (manufactured by Petrochemicals): 9.5 wt%
(D) Aluminum tris (acetylacetonate): TR-25D (manufactured by Kawaken Fine Chemical Co., Ltd.): 3.6 wt%
(E) Vinyl polymer: Disparon LC951 (manufactured by Enomoto Kasei Co., Ltd.): 0.2 wt%
(F) Dimethylformamide: 9.4 wt%
(G) Methyl ethyl ketone: 25.2 wt%
<Composition of heat-sensitive layer composition>
(A) Phenol novolac resin: Sumilite resin PR53195 (manufactured by Sumitomo Bakelite Co., Ltd.): 11.4 wt%
(B) Polyurethane resin: Samprene LQ-T1331D (manufactured by Sanyo Chemical Co., Ltd.): 9.5 wt%
(C) Crosslinking agent: SP-Y08 (manufactured by Toray Fine Chemical Co., Ltd.): 2.3 wt%
(D) Infrared absorbing dye: YKR-2016 (manufactured by Yamamoto Kasei Co., Ltd.): 1.2 wt%
(E) Titanium di-n-butoxide bis (2,4-pentanedionate): Nursem titanium (manufactured by Nippon Chemical Industry Co., Ltd.): 2.9 wt%
(F) Ethanol: 4.9 wt%
(G) Tertiary butanol: 20.3 wt%
(H) Tetrahydrofuran: 47.5 wt%
<Composition of ink repellent layer composition>
(A) CY54-51Base (manufactured by Dow Corning Toray): 9.8 wt%
(B) Vinyltri (methylethylketoximine) silane: 0.5 wt%
(C) OS3000 (Honeywell) 0.2 wt%
(D) Neostan U-200 (manufactured by Nitto Kasei Co., Ltd.): Trace amount (e) Isopar E (manufactured by ExxonMobil Co., Ltd.): 89.5 wt%
<Common manufacturing and printing plate conditions>
Heat sensitive layer: film thickness 1.4 g / m ² , drying time: 140 ° C., 80 seconds ink repellent layer: film thickness: 2.1 g / m ² : 135 ° C., 80 seconds plate setter: trend setter 800 quanta (Kodak Corporation ) Made) semiconductor laser (wavelength 830nm)
Automatic processor: TWL-1160F (manufactured by Toray Industries, Inc.)
Pretreatment liquid: CP-Y (manufactured by Toray Industries, Inc.)
Post-treatment liquid: NA-1 (manufactured by Toray Industries, Inc.)
Conveying speed: 80 cm / min (Example 1)
A synthetic resin sheet substrate having a thickness of 0.3 mm was prepared in advance by heating and drying the heat insulation layer solution. About this sheet | seat, when the transmittance | permeability of light with a wavelength of 300-900 nm was measured with the spectrophotometer, it was 1% or less in all the wavelengths.

  Next, a heat-sensitive layer and an ink repellent layer were sequentially formed on the sheet under the above conditions to prepare a direct-drawing waterless lithographic printing plate precursor.

  The obtained printing plate was checked for each plate performance evaluation item according to the above procedure. As a result, the plate surface readability, foreign object defect, image reproducibility was judged as “◯”, and printing durability was judged as “◎”, and a good plate was gotten.

(Example 2)
A resin sheet having a thickness of about 10 μm prepared by heating and drying the heat insulating layer solution having the same composition as in Example 1 is laminated on a 0.29 mm aluminum plate (manufactured by Furukawa Sky Co., Ltd.) to obtain the total thickness of the substrate. A support substrate having a thickness of 0.30 mm was prepared in advance. About this sheet | seat, when the transmittance | permeability of light with a wavelength of 300-900 nm was measured with the spectrophotometer, it was 2% or less in all the wavelengths.

  Next, a heat-sensitive layer and an ink repellent layer were sequentially formed on the sheet under the above conditions to prepare a direct-drawing waterless lithographic printing plate precursor.

  The obtained printing plate was checked for each plate performance evaluation item according to the above procedure. As a result, the plate surface readability, foreign object defect, image reproducibility was judged as “◯”, and printing durability was judged as “◎”, and a good plate was gotten.

(Example 3)
A resin sheet having a thickness of about 10 μm prepared by heating and drying the heat insulating layer solution having the same composition as in Example 1 is laminated on a 0.44 mm aluminum plate (Furukawa Sky Co., Ltd.), and the total thickness of the substrate is obtained. A support substrate having a thickness of 0.45 mm was prepared in advance. When the transmittance of light with a wavelength of 300 to 900 nm of this sheet was measured with a spectrophotometer, it was 2% or less at all wavelengths.

  Next, a heat-sensitive layer and an ink repellent layer were formed on the sheet under the above conditions to prepare a direct-drawing waterless lithographic printing plate precursor.

  The obtained printing plate was checked for each plate performance evaluation item according to the above procedure. As a result, the plate surface readability, foreign object defect, image reproducibility was judged as “◯”, and printing durability was judged as “◎”, and a good plate was gotten.

Example 4
A resin sheet having a thickness of about 6 μm prepared by heating and drying a heat insulating layer solution having the same composition as in Example 1 is laminated on a 0.09 mm thick aluminum plate (Furukawa Sky Co., Ltd.), and the total thickness of the substrate is obtained. A support substrate having a thickness of 0.10 mm was prepared in advance. When the transmittance of light with a wavelength of 300 to 900 nm of this sheet was measured with a spectrophotometer, it was 15% or less at all wavelengths.

  Next, a heat-sensitive layer and an ink repellent layer were sequentially formed on the sheet under the above conditions to prepare a direct-drawing waterless lithographic printing plate precursor.

  The obtained printing plate was checked for each plate performance evaluation item according to the above procedure. As a result, the plate surface readability, foreign object defect, image reproducibility was judged as “◯”, and printing durability was judged as “◎”, and a good plate was gotten.

(Example 5)
When the transmittance of light having a wavelength of 300 to 900 nm was measured with a spectrophotometer for a high pet (made by Toyo Kohan Co., Ltd.) having a plate thickness of 0.30 mm laminated with a white PET resin on an aluminum plate, The wavelength was 2% or less.

  Next, a heat-sensitive layer and an ink repellent layer were formed in this order on this Hypet under the above conditions to produce a direct-drawing waterless lithographic printing plate precursor.

  The obtained printing plate was checked for each plate performance evaluation item according to the above procedure. As a result, the plate surface readability, foreign object defect, image reproducibility was judged as “◯”, and printing durability was judged as “◎”, and a good plate was gotten.

(Example 6)
When the transmittance of light with a wavelength of 300 to 900 nm was measured with a spectrophotometer for a universal bright (manufactured by JFE Steel Co., Ltd.) having a thickness of 0.30 mm laminated with a white PET resin on an iron plate, It was 2% or less.

  Next, a heat-sensitive layer and an ink repellent layer were sequentially formed on the universal bright under the above conditions to prepare a direct-drawing waterless lithographic printing plate precursor.

  The obtained printing plate was checked for each plate performance evaluation item according to the above procedure. As a result, the plate surface readability, foreign object defect, image reproducibility was judged as “◯”, and printing durability was judged as “◎”, and a good plate was gotten.

(Example 7)
On the PET film (manufactured by Toray Industries, Inc.) having an average thickness of 50 μm, a heat insulating layer solution having the same composition as in Example 1 was applied and dried, and the average thickness of the heat insulating layer was set to 6 μm using an adhesive. A support substrate having a total thickness of 0.30 mm was prepared in advance by bonding to an aluminum substrate having a thickness of 0.24 mm. When the transmittance of light with a wavelength of 300 to 900 nm of this sheet was measured with a spectrophotometer, it was 2% or less at all wavelengths.

  Next, a heat-sensitive layer and an ink repellent layer were formed on the sheet substrate under the above conditions to prepare a direct-drawing waterless lithographic printing plate precursor.

  The obtained printing plate was checked for each plate performance evaluation item according to the above procedure. As a result, the plate surface readability, foreign object defect, image reproducibility was judged as “◯”, and printing durability was judged as “◎”, and a good plate was gotten.

(Example 8)
When the transmittance of light with a wavelength of 300 to 900 nm was measured with a spectrophotometer for HiPet (manufactured by Toyo Kohan Co., Ltd.) with a total thickness of 0.50 mm laminated with white PET resin on an aluminum plate, all The wavelength was 2% or less.

  Next, a heat-sensitive layer and an ink repellent layer were formed on the HiPet under the above conditions to produce a direct-drawing waterless lithographic printing plate precursor.

  The obtained printing plate was checked for each plate performance evaluation item according to the above procedure. As a result, the plate surface readability, foreign matter defect, image reproducibility, and printing durability were all judged as “◯”, and a good plate was obtained. It was.

Example 9
A heat insulating layer solution having the same composition as that of Example 1 was applied onto a PET film having an average thickness of 20 μm (manufactured by Toray Industries, Inc.), dried, and an average thickness of the heat insulating layer was set to 4 μm using an adhesive. A support substrate having a total thickness of 0.05 mm was prepared in advance by bonding to an aluminum substrate having a thickness of 0.03 mm. When the transmittance of light with a wavelength of 300 to 900 nm of this sheet was measured with a spectrophotometer, it was 10% or less at all wavelengths.

  Next, a heat-sensitive layer and an ink repellent layer were formed on the sheet under the above conditions to prepare a direct-drawing waterless lithographic printing plate precursor.

  The obtained printing plate was checked for each plate performance evaluation item according to the above procedure. As a result, the plate surface readability, foreign matter defect, image reproducibility, and printing durability were all judged as “◯”, and a good plate was obtained. It was.

(Comparative Example 1)
After coating and drying a heat insulating layer solution having the same composition as in Example 1 on an aluminum plate (made by Furukawa Sky Co., Ltd.) having a plate thickness of 0.29 mm, the heat-sensitive layer and the ink repellent layer are continuously formed. A direct-drawing waterless lithographic printing plate precursor was created in a batch.

  About the obtained printing plate, when each performance evaluation item was confirmed in said procedure, the foreign material of the heat insulation layer composition was detected by the item of a foreign material defect, and was set to "x". For items other than foreign matter defects, the judgment was “◯”.

(Comparative Example 2)
A heat insulation layer solution having the same composition as in Example 1 was applied on an aluminum plate (Furukawa Sky Co., Ltd.) having a thickness of 0.30 mm and dried. The average thickness of the heat insulation layer was 2 μm, and the total thickness of the substrate was 0.00. A support substrate having a thickness of 30 mm was prepared. When the transmittance of light with a wavelength of 300 to 900 nm of this sheet was measured with a spectrophotometer, it was 20% or more at all wavelengths.

  Next, a heat-sensitive layer and an ink repellent layer were formed on the sheet under the above conditions to prepare a direct-drawing waterless lithographic printing plate precursor.

  Regarding the obtained printing plate, each performance evaluation item was confirmed by the above procedure. As a result, the plate surface readability item was “x”. In all other items, the judgment was “◯”.

(Comparative Example 3)
A heat sensitive layer and an ink repellent layer were formed in this order on a 0.30 mm thick aluminum plate (Furukawa Sky Co., Ltd.) under the above conditions to produce a direct-drawing waterless lithographic printing plate precursor. When the transmittance of light with a wavelength of 300 to 900 nm of this sheet was measured with a spectrophotometer, it was 100% at all wavelengths.

  When the performance evaluation items of the obtained printing plate were confirmed by the above procedure, “x” was obtained for the two items of plate surface readability and printing durability. In all other items, the judgment was “◯”.

Claims (5)

In a waterless lithographic printing plate precursor in which at least a heat-sensitive layer and an ink repellent layer are laminated in this order on a substrate, a pre-shaped synthetic resin film or sheet is used as a supporting substrate, and there is no direct drawing type waterless A planographic printing plate precursor and a method for producing the same. A waterless lithographic printing plate precursor in which at least a heat-sensitive layer and an ink repellent layer are laminated in this order on a substrate is characterized by using a support substrate in which a synthetic resin film or sheet is previously laid on a metal plate. Drawing waterless lithographic printing plate precursor and method for producing the same. The direct-drawing waterless lithographic printing plate precursor according to claim 1 or 2, wherein the transmittance of the synthetic resin film and sheet is 15% or less at all wavelengths in the range of 300 to 900 nm. Its manufacturing method. The direct-drawing waterless lithographic printing plate precursor according to any one of claims 1 to 3, wherein the thickness of the entire support substrate is from 0.10 to 0.45 mm, and a method for producing the same. 3. The direct-drawing waterless lithographic printing plate precursor according to claim 2, wherein the metal plate constituting the support substrate is made of aluminum, and a method for producing the same.