Waterless planographic printing plate precursor, method for producing and sorting waterless planographic printing plates, and method for producing printed matter

Abstract

A waterless planographic printing original plate which sequentially comprises at least a base material, a heat-sensitive layer and an ink-repellent layer in this order, wherein: the base material has a white layer or a white surface; and the heat-sensitive layer contains at least (a) an infrared absorbing dye that has a maximum absorption wavelength of 700 to 1,000 nm, (b) a dye that develops a color by acceptance of a proton, and (c) a proton-donating compound. Consequently, the present invention provides a waterless planographic printing original plate which enables the achievement of a high contrast between an image part and a non-image part by means of light exposure without requiring a special layer.

Description

[Technical Field]

[0001] The present invention relates to a waterless lithographic printing plate precursor, a method for producing waterless lithographic printing plates using the same, a method for sorting the plates, and a method for producing printed matter. [Background technology]

[0002] Printing methods using lithographic printing plates include water printing, in which a thin layer of water containing chemicals (hereinafter sometimes referred to as "fountain solution") is formed on the surface of the lithographic printing plate before printing to form ink-repellent non-image areas, and waterless printing, in which an ink-repellent layer such as a silicone rubber layer is formed instead of fountain solution to form ink-repellent non-image areas.

[0003] In water-based printing, dampening water is continuously supplied during printing, resulting in the generation of waste liquid that is a mixture of dampening water and ink. In contrast, waterless printing does not use dampening water, making it a printing method with less impact on the environment.

[0004] Waterless lithographic printing plates used in waterless printing are conventionally produced through a platemaking process that includes a step of exposing a waterless lithographic printing plate precursor to light (exposure step), a step of immersing the exposed waterless lithographic printing plate precursor in a chemical to swell and dissolve the heat-sensitive layer and / or the surface of the photosensitive layer in the exposed area (pretreatment step), a step of removing the ink-repellent layer in the image area by rubbing the surface (development step), and a step of dyeing the image area with a solution containing a dye to improve visibility (dyeing step).

[0005] With the increasing environmental awareness in recent years, the printing industry has been moving toward chemical-free production, and there is a demand for chemical-free platemaking processes for waterless lithographic printing plates. To address this issue, proposed technologies for obtaining lithographic printing plates with good print-out properties and easy plate inspection during chemical-free development include a direct-imageable waterless lithographic printing plate precursor having, on a substrate, at least a heat-sensitive layer and an ink-repellent layer, in this order, wherein the heat-sensitive layer is made of a composition comprising a mixture of at least an acid and a dye that develops color under the action of acid (see, for example, Patent Document 1), and a direct-imageable waterless lithographic printing plate precursor having, on a substrate, at least a heat-sensitive layer containing an infrared-absorbing compound and an ink-repellent layer, in this order, wherein a colored layer that does not contain the infrared-absorbing compound but contains a dye compound is provided between the heat-sensitive layer and the ink-repellent layer (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-51409 [Patent Document 2] Japanese Patent Publication No. 2020-26136 Summary of the Invention [Problem to be solved by the invention]

[0007] Although the direct-imageable waterless lithographic printing plate precursor described in Patent Document 1 can increase the contrast between image and non-image areas, with the recent increase in speed of printing processes and platemaking processes, there is a demand for higher contrast between image and non-image areas. In particular, when image patterns are to be distinguished mechanically, a higher contrast than before is required. On the other hand, the lithographic printing plate precursor described in Patent Document 2 can obtain high contrast between image and non-image areas after exposure, but has the problem of reduced productivity due to the formation of a colored layer.

[0008] Therefore, an object of the present invention is to provide a waterless lithographic printing plate precursor that can provide high contrast between image and non-image areas upon exposure without requiring any special layer. [Means for solving the problem]

[0009] The present invention relates to a waterless lithographic printing plate precursor having at least a substrate, a heat-sensitive layer, and an ink-repellent layer in this order, wherein the substrate has a white layer or a white surface, and the heat-sensitive layer contains at least (a) an infrared-absorbing dye having a maximum absorption wavelength of 700 to 1,000 nm, (b) a dye that develops color upon accepting a proton, and (c) a proton-donating compound. [Effects of the Invention]

[0010] According to the present invention, it is possible to obtain a waterless lithographic printing plate precursor that provides high contrast between image areas and non-image areas upon exposure without requiring any special layer. DETAILED DESCRIPTION OF THE INVENTION

[0011] The waterless lithographic printing plate precursor of the present invention (hereinafter, sometimes referred to as "printing plate precursor") will be described below.

[0012] The printing plate precursor of the present invention has at least a substrate, a thermosensitive layer, and an ink-repellent layer, in this order. The substrate has the function of supporting the thermosensitive layer, the ink-repellent layer, etc. The thermosensitive layer generates heat and decomposes when irradiated (exposed) to infrared rays, and has the function of facilitating removal of the ink-repellent layer in the exposed areas. By removing the ink-repellent layer, the exposed thermosensitive layer becomes an image area that accepts ink. In other words, the exposed areas become image areas. Because the ink-repellent layer has the function of repelling printing ink, the unexposed areas where the ink-repellent layer is not removed become non-image areas. In this way, an image pattern is formed by the exposed areas (image areas) and the unexposed areas (non-image areas).

[0013] The first aspect of the present invention is characterized by combining a substrate having a white layer or white surface with a thermosensitive layer containing at least (a) an infrared-absorbing dye having a maximum absorption wavelength of 700 to 1,000 nm (hereinafter sometimes referred to as "(a) infrared-absorbing dye"), (b) a dye that develops color upon proton acceptance (hereinafter sometimes referred to as "(b) dye"), and (c) a proton-donating compound. The thermosensitive layer of the printing plate precursor of the first aspect of the present invention is colored due to the coexistence of (b) dye and (c) proton-donating compound. When exposed to light, the infrared-absorbing dye (a) generates heat, and the generated heat causes the interaction between the dye (b) and the proton-donating compound to be lost, resulting in fading and partial pyrolysis and gasification. By providing a substrate with a white layer or white surface under the thermosensitive layer, the color of the faded thermosensitive layer in the exposed area overlaps with the white color of the substrate, and the color of the image area (exposed area) of the printing plate precursor when observed from the ink-repellent layer side appears white. On the other hand, when the white layer or white surface of the substrate overlaps with the color of the heat-sensitive layer in the unexposed areas, the brightness of the non-image areas (unexposed areas) is improved, thereby increasing the contrast between the exposed and unexposed areas.

[0014] Next, the substrate and each layer will be described.

[0015] (base material) The substrate is preferably one that is conventionally used as a substrate for printing plates and that undergoes minimal dimensional change during the printing process. Examples include substrates made of paper, metal, glass, plastic, etc. More specific examples of substrate materials include paper or paper laminated with plastic (polyethylene, polypropylene, polystyrene, etc.); metal plates made of aluminum (including aluminum alloys), zinc, copper, etc.; glass plates made of soda lime, quartz, etc.; silicon wafers; plastic films made of cellulose acetate, polyethylene terephthalate, polyethylene, polyester, polyamide, polyimide, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc.; and paper or plastic films laminated or vapor-deposited with the above metals.

[0016] Among these substrates, aluminum plate is particularly preferred because it undergoes minimal dimensional change during the printing process, and polyethylene terephthalate film is particularly preferred for light printing applications because of its excellent flexibility.

[0017] The thickness of the substrate is not particularly limited, and may be selected to suit the printing machine used for lithographic printing.

[0018] As mentioned above, these substrates have a white layer or a white surface to improve the contrast between the image area and the non-image area.

[0019] Here, "white" refers to a reflectance of 50% or more across the entire wavelength range when the reflectance is measured in a spectral range of 450 to 700 nm with a spectral interval of 10 nm. The reflectance can be measured on the white layer side or white surface side of a substrate having a white layer or white surface using a spectrophotometer (for example, the reflectance graph mode of the "eXact" Advance (manufactured by X-rite)).

[0020] "The substrate has a white layer" means that at least one surface of the substrate has a white layer with a reflectance within the above range. "The substrate has a white surface" means that at least one surface of the substrate has a reflectance within the above range. From the viewpoint of further improving the contrast between the image area and the non-image area, the reflectance of the substrate is more preferably 70% or more, and even more preferably 75% or more.

[0021] Examples of methods for providing a white layer on a substrate include a method of coating a liquid organic layer composition having a pigment dispersed therein onto the substrate, and a method of laminating a white film or sheet onto the substrate.

[0022] Examples of pigments contained in the white layer include inorganic white pigments such as titanium oxide, zinc oxide, and lithopone, and inorganic yellow pigments such as yellow lead, cadmium yellow, yellow iron oxide, ochre, and titanium yellow. Two or more of these pigments may be used. Among these, titanium oxide is preferred in terms of coloring power. Furthermore, the surface of the pigment particles may be treated with a titanate coupling agent or the like. Such surface treatment improves the dispersibility of the pigment particles, thereby improving dispersion stability even when the organic layer composition liquid contains a large amount of pigment particles.

[0023] When the white layer contains titanium oxide, its content in the white layer is preferably 2% by volume or more and 30% by volume or less. If the titanium oxide content is 2% by volume or more, the reflectance can be easily increased to 50% or more over the entire wavelength range of 450 to 700 nm. On the other hand, if the titanium oxide content is 30% by volume or less, the coating performance of the organic layer composition liquid can be improved.

[0024] The white layer may contain an active hydrogen group-containing compound, which can improve adhesion to the substrate and / or the thermosensitive layer. Examples of active hydrogen group-containing compounds include hydroxyl group-containing compounds, amino group-containing compounds, carboxyl group-containing compounds, and thiol group-containing compounds. Two or more of these compounds may be contained. Among these, hydroxyl group-containing compounds are preferred. Examples of hydroxyl group-containing compounds include phenolic hydroxyl group-containing compounds and alcoholic hydroxyl group-containing compounds. Examples of phenolic hydroxyl group-containing compounds include novolac resins and resol resins. Examples of alcoholic hydroxyl group-containing compounds include epoxy acrylate, epoxy methacrylate, polyvinyl butyral resins, and epoxy resins. Other examples include polymers into which hydroxyl groups have been introduced by known methods. Among these active hydrogen group-containing compounds, epoxy resins are preferred in terms of adhesion to the substrate.

[0025] In addition, examples of a method for providing a white surface on a substrate include a method in which the substrate is subjected to a surface roughening treatment to physically provide minute irregularities.

[0026] (thermal layer) The heat-sensitive layer of the present invention contains at least (a) an infrared-absorbing dye having a maximum absorption wavelength of 700 to 1,000 nm ((a) infrared-absorbing dye), (b) a dye that develops color upon accepting a proton ((b) dye), and (c) a proton-donating compound.

[0027] (a) Examples of infrared absorbing dyes having a maximum absorption wavelength of 700 to 1,000 nm include cyanine dyes, azulenium dyes, squarylium dyes, croconium dyes, azo disperse dyes, bisazostilbene dyes, naphthoquinone dyes, anthraquinone dyes, perylene dyes, phthalocyanine dyes, naphthalocyanine metal complex dyes, polymethine dyes, dithiol nickel complex dyes, indoaniline metal complex dyes, intermolecular CT dyes, benzothiopyran spiropyrans, and nigrosine dyes. Two or more of these may be contained. By containing two or more infrared absorbing dyes with different absorption wavelengths, it is possible to accommodate two or more lasers with different emission wavelengths.

[0028] Here, (a) the maximum absorption wavelength of the infrared absorbing dye is the wavelength showing the maximum absorbance in the absorption spectrum obtained by wavelength scanning measurement using an ultraviolet-visible-near-infrared spectrophotometer under the conditions of a wavelength range of 400 to 1,100 nm and a sampling interval of 5 nm.

[0029] Among these dyes, dyes with a large molar absorption coefficient ε are preferably used. Specifically, ε is 1×10 4 L / (mol cm) or more is preferable, and 1×10 5 L / (mol cm) or more. ε is 1×10 4 If the ε is L / (mol·cm) or higher, the initial sensitivity can be further improved. Here, ε is the value for the actinic energy rays being irradiated. If we are referring to the specific wavelength of the actinic energy rays, it is best to focus on 780nm, 830nm, or 1064nm.

[0030] The content of the (a) infrared-absorbing dye in the thermosensitive layer is preferably 12% to 20% by mass. By setting the content of the (a) infrared-absorbing dye to 12% by mass or more, sensitivity to laser light is increased, improving image reproducibility. Furthermore, since the thermosensitive layer can be partially burned off and thinned, the color of the faded thermosensitive layer in the exposed areas becomes even lighter, and the color of the image areas becomes closer to white, thereby further improving the contrast between the image areas and non-image areas. The content of the (a) infrared-absorbing dye is more preferably 14% by mass or more. On the other hand, by setting the content of the (a) infrared-absorbing dye to 20% by mass or less, peeling of the ink-repellent layer in non-image areas due to heat leakage to the periphery of the exposed areas can be suppressed. The content of the (a) infrared-absorbing dye is more preferably 18% by mass or less.

[0031] (b) Examples of dyes include acid-base indicators such as metanil yellow, thymol blue, 4-phenylazodiphenylamine, methyl yellow, methyl red, and neutral red; 3-(N,N-diethylamino)-7-(N,N'-dibenzylamino)fluoran, 1-ethyl-8-[ethyl(p-tolyl)amino]-2,2,4-trimethyl-1,2-dihydro-3'H-spiro[chromeno[2,3-g]quinolin-11,1'-isobenzofuran]-3'-one, and 3,3-bis(p-dimethylaminophenyl)-6-dimethylaminofluorane. phthalide, 3-[4-(diethylamino)-2-hexyloxyphenyl]-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide, 3-(4-diethylamino-2-methylphenyl)-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide, 3-[(4-diethylamino)-o-tolyl]-6-(dimethylamino)-3-[(4-dimethylamino)phenyl]phthalide, 3',6'-bis(diphenylamino)spiro[phthalide-3,9'-xanthene], 9-(N-ethyl-N-isopentylamino) )spiro[benzo[a]xanthene-12,3'-phthalide], 2-methyl-6-(Np-tolyl-N-ethylamino)-fluoran, 6'-(dibutylamino)-2'-bromo-3'-methylspiro[phthalide-3,9'-xanthene], 2'-anilino-6'-(N-ethyl-N-isopentylamino)-3'-methylspiro[phthalide-3,9'-xanthene], 2'-anilino-6'-(N,N-dipentan-1-ylamino)-3'-methyl-3H-spiro[isobenzofuran-1,9'-xanthene]-3-one, 2'-anilino Leuco dyes such as 6'-(dibutylamino)-3'-methylspiro[phthalide-3,9'-xanthene], 2'-anilino-6'-[N-ethyl-N-(4-tolyl)amino]-3'-methyl-3H-spiro[isobenzofuran-1,9'-xanthene]-3-one, 6-(diethylamino)-2-[(3-trifluoromethyl)anilino]xanthene-9-spiro-3'-phthalide, and 3,3-bis[2-(4-dimethylaminophenyl)-2-(4-methoxyphenyl)vinyl]-4,5,6,7-tetrachlorophthalide may be used in combination with two or more of these.Among these, leuco dyes are preferred because they can be changed between colorless and colored depending on their chemical structure. Leuco dyes become colorless when the interaction with the (c) proton-donating compound is lost upon exposure of the heat-sensitive layer, thereby increasing the contrast between the image and non-image areas.

[0032] The maximum absorption wavelength of the (b) dye when it changes color upon proton acceptance is preferably within the range of 500 to 650 nm. Since the (a) infrared-absorbing dye exhibits a light green to greenish color, if the maximum absorption wavelength of the (b) dye when it accepts a proton is within the range of 500 to 650 nm, the color of the thermosensitive layer will be its complementary color, a purple to blueish color. When the interaction between the (b) dye and the (c) proton-donating compound is lost upon exposure, the purple to blueish color resulting from the (b) dye fades in the thermosensitive layer, leaving only the light green to greenish color resulting from the (a) infrared-absorbing dye. Therefore, the exposed area (image area) will be a light green to greenish color, and the unexposed area (non-image area) will be a purple to blueish color, further improving the contrast between the image area and the non-image area.

[0033] Here, (b) the maximum absorption wavelength when the dye accepts a proton is determined by wavelength scanning measurement using an ultraviolet-visible-near-infrared spectrophotometer under conditions of a wavelength range of 400 to 1,100 nm and a sampling interval of 5 nm, and the wavelength showing the maximum absorbance in the obtained absorption spectrum.

[0034] Examples of the (b) dye having a maximum absorption wavelength within a range of 500 to 650 nm upon accepting a proton include 3,3-bis(p-dimethylaminophenyl)-6-dimethylaminophthalide, 3-[4-(diethylamino)-2-hexyloxyphenyl]-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide, 3-(4-diethylamino-2-methylphenyl)-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide, 3-[(4-diethylamino)-o-tolyl]-6-(dimethylamino)-3-[(4-dimethylamino)phenyl]phthalide, and 3',6'-bis(diphenylamino)spiro[phthalide-3,9'-xanthene].

[0035] In addition, the dye (b) that assumes a blackish color upon accepting protons can also be preferably used. The blackish color of the heat-sensitive layer fades upon exposure, leaving the light green to greenish color of the infrared-absorbing dye (a), which further improves the contrast between the image area and the non-image area.

[0036] Examples of the dye (b) that exhibits a blackish color upon accepting a proton include 2'-anilino-6'-(N-ethyl-N-isopentylamino)-3'-methylspiro[phthalide-3,9'-xanthene], 2'-anilino-6'-(N,N-dipentan-1-ylamino)-3'-methyl-3H-spiro[isobenzofuran-1,9'-xanthene]-3-one, 2'-anilino-6'-(dibutylamino)-3'-methylspiro[phthalide-3,9'- xanthene], 2'-anilino-6'-[N-ethyl-N-(4-tolyl)amino]-3'-methyl-3H-spiro[isobenzofuran-1,9'-xanthene]-3-one, 6-(diethylamino)-2-[(3-trifluoromethyl)anilino]xanthene-9-spiro-3'-phthalide, 3,3-bis[2-(4-dimethylaminophenyl)-2-(4-methoxyphenyl)vinyl]-4,5,6,7-tetrachlorophthalide, and the like.

[0037] The content of the (b) dye in the thermosensitive layer is preferably 5% to 20% by mass. By making the content of the (b) dye 5% by mass or more, the contrast between the image area and the non-image area can be further improved. The content of the (b) dye is more preferably 7% by mass or more. On the other hand, by making the content of the (b) dye 15% by mass or less, it is possible to suppress ink repulsion peeling, in which the ink repellent layer in the non-image area peels off.

[0038] (c) Examples of the proton-donating compound include inorganic acids, organic acids, polymers having active hydrogen-containing structural units, etc. Two or more of these may be used.

[0039] Examples of inorganic acids include phosphoric acid and boric acid. Examples of organic acids include phenolic hydroxy groups, carboxy groups, and sulfo groups. Among these, organic acids having a sulfo group, such as toluenesulfonic acid, xylenesulfonic acid, cumenesulfonic acid, dodecylbenzenesulfonic acid, and dinonylnaphthalenesulfonic acid, are preferred because they have a strong proton-donating property to the (b) dye and therefore are effective even in small amounts. The content of inorganic acid and / or organic acid in the heat-sensitive layer is preferably 0.01 to 5% by mass, more preferably 0.1 to 2% by mass, and even more preferably 0.5 to 2% by mass.

[0040] When an inorganic acid and / or an organic acid is used as the (c) proton-donating compound, the composition may further contain a film-forming polymer that does not have an active hydrogen-containing structural unit.

[0041] Examples of such polymers include melamine resins. The content of such polymers in the thermosensitive layer is preferably 20% by mass or more, more preferably 30% by mass or more. The content is preferably 95% by mass or less, more preferably 80% by mass or less.

[0042] In addition, polymers having active hydrogen-containing structural units are preferably used because they can improve the adhesion between the ink-repellent layer and the thermosensitive layer by reacting with the adhesive component in the upper ink-repellent layer, thereby preventing the ink-repellent layer from peeling off, and can also serve as a binder polymer for the thermosensitive layer.

[0043] Examples of polymers having active hydrogen-containing structural units include monomers containing carboxyl groups such as (meth)acrylic acid; (meth)acrylic acid esters containing hydroxyl groups such as hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate; N-alkyl (meth)acrylamides, (meth)acrylamides; reaction products of amines with glycidyl (meth)acrylate or allyl glycidyl (meth)acrylate; homopolymers or copolymers of ethylenically unsaturated monomers having active hydrogen such as p-hydroxystyrene and vinyl alcohol; and polymers having structural units having active hydrogen in the main chain. The copolymerizable monomer component in the copolymer may be another ethylenically unsaturated monomer having active hydrogen, or an ethylenically unsaturated monomer not containing active hydrogen. Examples of polymers having structural units having active hydrogen in the main chain include polyurethanes, polyureas, polyamides, epoxy resins, polyalkyleneimines, novolac resins, resol resins, and cellulose derivatives. Two or more of these may be used.

[0044] Among these, polymers having an alcoholic hydroxyl group, a phenolic hydroxyl group, or a carboxyl group are preferred, polymers having a phenolic hydroxyl group (such as a homopolymer or copolymer of p-hydroxystyrene, a novolac resin, or a resol resin) are more preferred, and novolac resins are even more preferred. Examples of novolac resins include phenol novolac resins and cresol novolac resins.

[0045] The content of the polymer having an active hydrogen-containing structural unit in the thermosensitive layer is preferably 20% by mass or more, more preferably 30% by mass or more, from the viewpoint of decomposing the surface of the thermosensitive layer by heat and accelerating development, and is preferably 95% by mass or less, more preferably 80% by mass or less, from the viewpoint of toughness of the thermosensitive layer.

[0046] In addition to the polymer having an active hydrogen-containing structural unit, a polymer having film-forming ability but not having an active hydrogen-containing structural unit (hereinafter referred to as "another polymer X") may be contained.

[0047] Examples of other polymers X include homopolymers or copolymers of (meth)acrylic acid esters such as polymethyl(meth)acrylate and polybutyl(meth)acrylate, homopolymers or copolymers of styrene monomers such as polystyrene and α-methylstyrene, various synthetic rubbers such as isoprene and styrene-butadiene, homopolymers of vinyl esters such as polyvinyl acetate or copolymers of vinyl acetate-vinyl chloride, various condensation polymers such as polyester and polycarbonate, etc. Two or more of these may be contained.

[0048] When these other polymers X are contained, their total content is preferably 5% by mass or more, more preferably 10% by mass or more, of the total solid content of the thermosensitive layer composition solution (i.e., in the thermosensitive layer) to improve the coatability of the thermosensitive layer composition solution, and preferably 50% by mass or less, more preferably 30% by mass or less, of the total solid content of the thermosensitive layer composition solution to achieve high-definition image reproduction.

[0049] When a polymer having an active hydrogen-containing structural unit is used as the (c) proton-donating compound, the thermosensitive layer preferably further contains a crosslinking agent. Examples of crosslinking agents include polyfunctional compounds having multiple functional groups reactive with the active hydrogen contained in the polymer. Examples include polyfunctional isocyanates, polyfunctional blocked isocyanates, polyfunctional epoxy compounds, polyfunctional (meth)acrylate compounds, polyfunctional aldehydes, polyfunctional mercapto compounds, polyfunctional alkoxysilyl compounds, polyfunctional amine compounds, polyfunctional carboxylic acids, polyfunctional vinyl compounds, polyfunctional diazonium salts, polyfunctional azide compounds, hydrazine, and organic complex compounds composed of metals and organic compounds. Two or more of these may be included.

[0050] Examples of organic complex compounds include organic complex salts in which an organic ligand is coordinated to a metal, organic-inorganic complex salts in which an organic ligand and an inorganic ligand are coordinated to a metal, and metal alkoxides in which a metal and an organic molecule are covalently bonded via oxygen. Among these, metal chelate compounds in which the ligand has two or more donor atoms and forms a ring containing a metal atom are preferably used in terms of the stability of the organic complex compound itself and the stability of the thermosensitive layer composition solution.

[0051] The main metals forming the organic complex compound are preferably Al(III), Ti(IV), Mn(II), Mn(III), Fe(II), Fe(III), Co(II), Co(III), Ni(II), Ni(IV), Cu(I), Cu(II), Zn(II), Ge, In, Sn(II), Sn(IV), Zr(IV), and Hf(IV). Al(III) is particularly preferred because it is easy to obtain a sensitivity-enhancing effect, and Ti(IV) is particularly preferred because it is easy to develop resistance to printing inks and ink cleaners.

[0052] The ligand may be a compound having a coordinating group having oxygen, nitrogen, sulfur, or the like as a donor atom. Specific examples of the coordinating group include those having oxygen as a donor atom, such as -OH (alcohols, enols, and phenols), -COOH (carboxylic acids), >C=O (aldehydes, ketones, and quinones), -O- (ethers), -COOR (esters, where R represents an aliphatic or aromatic hydrocarbon), -N=O (nitroso compounds), -NO2 (nitro compounds), >NO (N-oxides), -SO3H (sulfonic acids), and -PO3H2 (phosphorous acids); and those having nitrogen as a donor atom, such as -NH2 (primary amines and hydrazines), >NH (secondary amines), and >N- (tertiary amines). Examples of sulfur donor atoms include -N=N- (azo compounds, heterocyclic compounds), =N-OH (oximes), -NO2 (nitro compounds), -N=O (nitroso compounds), >C=N- (Schiff bases, heterocyclic compounds), >C=NH (aldehydes, ketone imines, enamines), and -NCS (isothiocyanato). Examples of sulfur donor atoms include -SH (thiols), -S- (thioethers), >C=S (thioketones, thioamides), =S- (heterocyclic compounds), -C(=O)-SH, -C(=S)-OH, -C(=S)-SH (thiocarboxylic acids), and -SCN (thiocyanato).

[0053] Among the organic complex compounds formed from the above-mentioned metals and ligands, preferred compounds include complex compounds of metals such as Al(III), Ti(IV), Fe(II), Fe(III), Mn(III), Co(II), Co(III), Ni(II), Ni(IV), Cu(I), Cu(II), Zn(II), Ge, In, Sn(II), Sn(IV), Zr(IV), and Hf(IV) with β-diketones, amines, alcohols, and carboxylic acids. Furthermore, particularly preferred complex compounds include acetylacetone complexes and acetoacetate complexes of Al(III), Fe(II), Fe(III), Ti(IV), and Zr(IV).

[0054] Specific examples of such compounds include the following compounds:

[0055] Aluminum tris(acetylacetonate), aluminum tris(ethyl acetoacetate), aluminum tris(propyl acetoacetate), aluminum tris(butyl acetoacetate), aluminum tris(hexyl acetoacetate), aluminum tris(nonyl acetoacetate), aluminum tris(hexafluoropentadionate), aluminum tris(2,2,6,6-tetramethyl-3,5-heptanedionate), aluminum bis(ethyl acetoacetate) mono(acetylacetonate), aluminum bis(acetylacetonate) mono(ethyl acetoacetate), aluminum bis(propyl acetoacetate) mono(acetylacetonate), aluminum bis(butyl acetoacetate) mono(acetylacetonate), aluminum bis(hexyl acetoacetate) mono(acetylacetonate), aluminum bis(propyl acetoacetate) mono(ethyl acetoacetate), aluminum bis(butyl acetoacetate) mono(ethyl acetoacetate), aluminum bis(hexylacetoacetate) mono(ethyl acetoacetate), aluminum bis(nonylacetoacetate) mono(ethyl acetoacetate), aluminum dibutoxide mono(acetylacetonate), aluminum diisopropoxide mono(acetylacetonate), aluminum diisopropoxide mono(ethyl acetoacetate), aluminum-s-butoxide bis(ethyl acetoacetate), aluminum di-s-butoxide mono(ethyl acetoacetate aluminium diisopropoxide mono(-9-octadecenylacetoacetate), titanium triisopropoxide mono(allylacetoacetate), titanium diisopropoxide bis(triethanolamine), titanium di-n-butoxide bis(triethanolamine), titanium diisopropoxide bis(acetylacetonate), titanium di-n-butoxide bis(acetylacetonate), titanium diisopropoxide bis(2,2,6,6-tetramethyl-3,5-heptanedionate), titanium diisopropoxide bis(ethyl acetoacetate), titanium di-n-butoxide bis(ethyl acetoacetate), titanium tri-n-butoxide mono(ethyl acetoacetate), titanium triisopropoxide mono(methacryloxyethyl acetoacetate), titanium oxide bis(acetylacetonate), titanium tetra(2-ethyl-3-hydroxyhexyl oxide), titanium dihydroxybis(lactate), titanium (ethylene glycolate) bis(dioctyl phosphate), zirconium di-n-butoxide bis(acetylacetonate), zirconium tetrakis(hexafluoropentanedionate), zirconium tetrakis (trifluoropentanedionate), zirconium tri-n-propoxide mono(methacryloxyethyl acetoacetate), zirconium tetrakis(acetylacetonate), zirconium tetrakis(2,2,6,6-tetramethyl-3,5-heptanedionate), triglycolate zirconate, trilactate zirconate, iron(III) acetylacetonate, dibenzoylmethane iron(II), tropolone iron, tristropolone iron(III), hinokitiol iron, trishinokitiol iron(III), acetoacetate iron(III), iron(III) benzoylacetonate, iron(III) diphenylpropanedionate, iron(III) tetramethylheptanedionate, iron(III) trifluoropentanedionate. Two or more of these may be contained.

[0056] The content of the organic complex compound in the thermosensitive layer is preferably 0.5 to 50% by mass, more preferably 5 to 20% by mass, and even more preferably 10 to 20% by mass.

[0057] (ink-repellent layer) As the ink repellent layer, a silicone rubber layer which is a crosslinked product of polyorganosiloxane can be preferably used.

[0058] Examples of the silicone rubber layer include a layer obtained by applying an addition reaction type silicone rubber layer composition or a condensation reaction type silicone rubber layer composition, and a layer obtained by applying a solution of these compositions and drying them.

[0059] The addition reaction type silicone rubber layer composition preferably contains at least a vinyl group-containing organopolysiloxane, a SiH group-containing compound having multiple hydrosilyl groups, and a curing catalyst. The silicone rubber layer composition may further contain a reaction inhibitor.

[0060] The vinyl group-containing organopolysiloxane has a structure represented by the following general formula (I) and has a vinyl group at the terminal of the main chain or within the main chain. Of these, those having a vinyl group at the terminal of the main chain are preferred. Two or more of these may be contained. -(SiR 1 R 2 -O-) n - (I) In the general formula (I), n represents an integer of 2 or more. 1 and R 2 each independently represents a saturated or unsaturated hydrocarbon group having 1 to 50 carbon atoms. The hydrocarbon group may be linear, branched, or cyclic, and may contain an aromatic ring.

[0061] In general formula (I), R 1 and R 2 In terms of the ink repellency of the waterless lithographic printing plate, it is preferable that 50% or more of the total be methyl groups. Furthermore, from the viewpoints of image reproducibility and the ink repellency and scratch resistance of the waterless lithographic printing plate, the weight-average molecular weight of the vinyl group-containing organopolysiloxane is preferably 20,000 or more and 160,000 or less.

[0062] Examples of the SiH group-containing compound include organohydrogenpolysiloxane and organic polymers having diorganohydrogensilyl groups, and preferably organohydrogenpolysiloxane. Two or more of these may be contained.

[0063] The organohydrogenpolysiloxane may have a linear, cyclic, branched or network molecular structure. Examples include the following:

[0064] These include polymethylhydrogensiloxanes with both molecular chain terminals capped with trimethylsiloxy groups, dimethylsiloxane-methylhydrogensiloxane copolymers with both molecular chain terminals capped with trimethylsiloxy groups, dimethylsiloxane-methylhydrogensiloxane-methylphenylsiloxane copolymers with both molecular chain terminals capped with trimethylsiloxy groups, dimethylpolysiloxanes with both molecular chain terminals capped with dimethylhydrogensiloxy groups, dimethylsiloxane-methylphenylsiloxane copolymers with both molecular chain terminals capped with dimethylhydrogensiloxy groups, and methylphenylpolysiloxanes with both molecular chain terminals capped with dimethylhydrogensiloxy groups.

[0065] As the SiH group-containing compound, a homopolymer of a siloxane structural unit represented by the following general formula (II) or a copolymer of a siloxane structural unit represented by the general formula (II) and a siloxane structural unit represented by the general formula (III) is preferred from the viewpoint of ink repellency. -[SiH(CH3)-O-]- (II) -[Si(CH3)2-O-]- (III) The content ratio of the siloxane constituent units represented by general formula (II) in the SiH group-containing compound relative to the total of siloxane constituent units represented by general formula (II) and siloxane constituent units represented by general formula (III) ((II) / ((II)+(III))) is preferably 50 mol % or more, in view of the large amount of reactive functional groups per molecule and excellent reaction rate and curability.

[0066] Examples of reaction inhibitors include nitrogen-containing compounds, phosphorus-based compounds, and unsaturated alcohols, with acetylene group-containing alcohols being preferred. Two or more of these may be contained. The addition of these reaction inhibitors allows for adjustment of the curing rate of the silicone rubber layer. The content of the reaction inhibitor in the silicone rubber layer composition is preferably 0.01% by mass or more and 20% by mass or less, and more preferably 0.1% by mass or more and 15% by mass or less. When the content of the reaction inhibitor in the silicone rubber layer composition is 0.01% by mass or more, the stability of the silicone rubber layer composition and its solution can be ensured, and when the content is 20% by mass or less, the curing properties of the silicone rubber layer are not significantly reduced.

[0067] The curing catalyst can be selected from known compounds. Platinum compounds are preferred, including platinum alone, platinum chloride, chloroplatinic acid, olefin-coordinated platinum, platinum alcohol-modified complexes, and platinum methylvinylpolysiloxane complexes. Two or more of these may be used. The content of the curing catalyst in the silicone rubber layer composition is preferably 0.001% by mass or more and 20% by mass or less, and more preferably 0.01% by mass or more and 15% by mass or less. A curing catalyst content of 0.001% by mass or more can sufficiently cure the silicone rubber layer, while a content of 20% by mass or less can ensure the stability of the silicone rubber layer composition and its solution.

[0068] The ink repellent layer may contain a compound represented by the following general formula (IV) for the purpose of improving adhesion to other adjacent layers. R-Si-(X)3(IV) In the general formula (IV), R represents an alkyl group, an aryl group, or a vinyl group, and X represents an acetoxy group or a dialkyloxyimino group.

[0069] When an ink-repellent layer containing a compound represented by general formula (IV) comes into contact with a thermosensitive layer, the compound represented by general formula (IV) bonds with the hydroxyl and imino groups on the surface of the thermosensitive layer via a condensation reaction, strengthening the adhesion between the ink-repellent layer and the thermosensitive layer. This suppresses peeling from the interface between the ink-repellent layer and the thermosensitive layer and damage near the surface of the thermosensitive layer during printing, significantly improving printing durability.

[0070] The content of the compound represented by general formula (IV) in the silicone rubber layer composition is preferably 1% by mass or more and 20% by mass or less, more preferably 4% by mass or more and 10% by mass or less. If the content of the compound is 1% by mass or more, adhesion to adjacent layers can be improved, and if it is 20% by mass or less, deterioration of image reproducibility due to excessive adhesion of the ink-repellent layer can be suppressed.

[0071] The printing plate precursor of the first aspect of the present invention is at least partially exposed to 100 mJ / cm 2 When the ink-repellent layer is irradiated with infrared light, the reflection density difference between the exposed and unexposed areas is preferably 0.30 or more, as measured from the ink-repellent layer side using a spectrophotometer fitted with a cyan, yellow, magenta, or black filter. If the reflection density difference between the exposed and unexposed areas is 0.30 or more, the contrast between the image and non-image areas can be increased by infrared irradiation, improving the reading accuracy when the image patterns are mechanically discriminated, sorted, and / or classified. The reflection density difference is preferably 0.35 or more, more preferably 0.45 or more, and even more preferably 0.50 or more.

[0072] The difference in reflection density between the image area and the non-image area can be measured using a spectrophotometer (for example, "eXact" Advance (manufactured by X-Rite)). A sample taken from the waterless lithographic printing plate precursor is subjected to a spectrophotometer with a filter selected from cyan, magenta, yellow, and black filters applied, and the reflection densities of the non-image area and the image area are measured 10 times from the ink-repellent layer side. The average values ​​of the measurements are taken as the reflection densities of the image area and the non-image area when each filter is applied. The absolute value of (non-image area reflection density - image area reflection density) is taken as the reflection density difference, and the reflection density differences when each filter is applied are taken as ΔD C , ΔD M , ΔD Y and ΔD K Let ΔD C , ΔD Y , ΔD M and ΔD K The largest value among these is taken as the reflection density difference and the contrast is evaluated.

[0073] The printing plate precursor of the second aspect of the present invention is a waterless lithographic printing plate precursor that is exposed to 100 mJ / cm 2 at least in part. 2 When infrared light is irradiated, the reflection density difference ΔD between the exposed and unexposed areas measured from the ink repellent layer side using a spectrophotometer with a cyan filter is C The reflection density difference ΔD between the exposed and unexposed areas is 0.30 or more. C If the reflection density difference ΔD is 0.30 or more, the contrast between the image area and the non-image area can be increased by infrared irradiation, and the reading accuracy can be improved when the image patterns are mechanically discriminated, sorted, and / or classified. C is preferably 0.35 or more, more preferably 0.45 or more, and even more preferably 0.50 or more.

[0074] As a means for making the difference in reflection density between the exposed and unexposed areas 0.30 or more, for example, a method of combining the above-mentioned white layer or a substrate having a white surface with a heat-sensitive layer containing (a) an infrared absorbing dye, (b) a dye, and (c) a proton-donating compound can be mentioned.C In order to increase this, (b) a dye whose maximum absorption wavelength when colored by proton acceptance is in the range of 500 to 650 nm may be used.

[0075] (Method of manufacturing a waterless planographic printing plate) A method for producing a waterless lithographic printing plate from the printing plate precursor of the present invention will be described. The method for producing a waterless lithographic printing plate includes (1) a step of exposing the aforementioned printing plate precursor of the present invention according to a desired image to form image areas and non-image areas (hereinafter, sometimes referred to as "step (1)"). After step (1), it is preferable to further include (2) a step of removing the ink-repellent layer from the image area of ​​the exposed waterless lithographic printing plate precursor (hereinafter, sometimes referred to as "step (2)").

[0076] First, step (1) will be described. Examples of light sources used for exposure include those with an emission wavelength range of 300 nm to 1500 nm. Among these, semiconductor lasers and YAG lasers with an emission wavelength range near the near-infrared range are preferably used because these are widely used as absorption wavelengths for heat-sensitive layers. Specifically, laser light with a wavelength of 780 nm, 830 nm, or 1064 nm is preferably used from the viewpoint of heat conversion efficiency.

[0077] The exposure energy should be 70 to 200 mJ / cm from the viewpoints of image reproducibility, productivity, and prevention of ink repellent layer peeling. 2 is preferred, and 90 to 110 mJ / cm 2 is more preferred.

[0078] The contrast between the image area and the non-image area of ​​the waterless lithographic printing plate after step (1) can be evaluated by the reflection density as described above.

[0079] In the present invention, the reflection density difference ΔD between the image area and the non-image area of ​​the waterless lithographic printing plate measured from the ink repellent layer side after step (1) when a cyan filter is applied is CIt is preferable that the reflection density difference ΔD is 0.30 or more, and this can improve the reading accuracy in the method for sorting waterless planographic printing plates described later. C is more preferably 0.35 or more, even more preferably 0.45 or more, and even more preferably 0.50 or more.

[0080] Reflection density difference ΔD C As a means for making the value of the printing plate precursor of the present invention 0.30 or more, for example, the above-mentioned method may be used.

[0081] Next, step (2) will be described. The ink-repellent layer in the exposed area (image area) is removed by applying a physical stimulus to the exposed printing plate precursor. Methods for applying the physical stimulus include, for example, (i) rubbing the plate surface with nonwoven fabric, absorbent cotton, cloth, sponge, rubber, or the like in the absence of liquid, (ii) wiping the plate surface with water-impregnated nonwoven fabric, absorbent cotton, cloth, sponge, or the like, (iii) rubbing the reverse side with a rotating brush while showering with water, and (iv) spraying the plate surface with high-pressure water, hot water, or steam.

[0082] The waterless lithographic printing plate precursor of the present invention allows chemical-free development in step (2), which does not require the use of conventional chemicals containing organic solvents such as pre-treatment liquids, developers, and post-treatment liquids. Chemical-free development does not require the dissolution of the heat-sensitive layer with chemicals for development, and therefore can significantly suppress peeling of the ink-repellent layer.

[0083] A part or all of the developing process can be carried out automatically using an automatic developing machine. Specific examples of automatic developing machines include the TWP-680 series (manufactured by HEIGHTS), TWP-1250 series (manufactured by HEIGHTS), TWL-650 series (manufactured by Toray Industries, Inc.), TWL-860 series (manufactured by Toray Industries, Inc.), and TWL-1160 series (manufactured by Toray Industries, Inc.), as well as an automatic developing machine with a curved recessed receiving table to prevent scratches on the backside of the plate, as described in JP-A-5-6000. These may also be used in combination.

[0084] In preparation for the case where developed lithographic printing plates are stored in a stack, it is preferable to place slip sheets between the plates for the purpose of protecting the plate surfaces.

[0085] (How to sort waterless lithographic printing plates) In addition to the image for printing, the waterless lithographic printing plate of the present invention can form on its plate surface an image pattern that can be read by a machine, such as a control number for management purposes, a one-dimensional code (e.g., a barcode), or a two-dimensional code (e.g., "QR Code" (registered trademark), micro "QR Code" (registered trademark), DataMatrix, MaxiCode, PDF417, MicroPDF417, etc.). The control image pattern formed on such a waterless lithographic printing plate can be machine-read to automatically sort and / or classify the waterless lithographic printing plates. An example of a system capable of such sorting is the Plate Sorting system manufactured by NELA. The waterless lithographic printing plate of the present invention has a high contrast between exposed and unexposed areas, and when used in such a system, this improves the accuracy of machine reading.

[0086] (Manufacturing method for printed matter) A method for producing a printed matter from the waterless lithographic printing plate of the present invention will now be described. The method for producing a printed matter of the present invention includes the steps of applying ink to the surface of the waterless lithographic printing plate obtained by the above-described method for producing a lithographic printing plate of the present invention, and transferring the ink to a substrate, either directly or via a blanket. It is preferable to use waterless lithographic printing plates sorted by the above-described sorting method as the waterless lithographic printing plates.

[0087] A waterless lithographic printing plate is a lithographic printing plate that can be used for printing without using dampening water. The layer derived from the heat-sensitive layer becomes the ink-receptive layer, which becomes the image area. The ink-repellent layer becomes the non-image area. The ink-receptive layer and the ink-repellent layer are essentially flush with each other, with only a micron-order step. Taking advantage of the difference in ink adhesion, ink is applied only to the image area, and then the ink is transferred to the substrate for printing. Examples of substrates include thin paper, cardboard, film, and labels. Ink can be transferred directly from the waterless lithographic printing plate to the substrate, or via a blanket.

[0088] Inks that can be used in the method for producing printed matter of the present invention include oil-based inks used in newspaper and commercial printing, and inks that can be cured by actinic radiation. Inks that can be cured by ultraviolet radiation (hereinafter sometimes referred to as "UV inks") generally contain photosensitive components that can be polymerized by ultraviolet radiation, such as reactive monomers or reactive oligomers, photopolymerization initiators, and optionally sensitizers and photosensitive resins. Inks that can be cured by electron beam radiation (hereinafter sometimes referred to as "EB inks") generally contain photosensitive components that can be polymerized by electron beams, such as reactive monomers or reactive oligomers and photosensitive resins.

[0089] The printing press used to produce printed matter from the waterless lithographic printing plate of the present invention is preferably an offset printing press, and either a sheet-fed printing press or a rotary printing press can be used. [Example]

[0090] The present invention will be described in more detail below with reference to examples. Evaluations in each example and comparative example were carried out by the following methods. It should be noted that Examples 1-4, 8, 13, 14, and 17 are currently reference examples, and Examples 5-7, 9-12, 15-16, and 18-22 are examples of the present invention.

[0091] (I) Manufacture of waterless lithographic printing plates (1) A step of exposing a desired image to form image and non-image areas. A sample of 670 mm x 560 mm was taken from the waterless lithographic printing plate precursor obtained in each Example and Comparative Example and was mounted on an exposure machine "PlateRite" 8900E (manufactured by Screen Graphic Solutions Co., Ltd.). Irradiation energy: 100 mJ / cm 2 The image area was exposed to light at 100 dpi, forming an image area and a non-image area. In the image area, 10 sets of 100 dots each of 20 μm × 20 μm halftone dots and 10 μm × 20 μm halftone dots were formed at a resolution of 2400 dpi and intervals of 175 lpi, to serve as images for evaluating image reproduction rate.

[0092] (2) A step of removing the ink-repellent layer from the image area of ​​the exposed waterless planographic printing plate precursor. The waterless lithographic printing plate precursor exposed by method (1) above was passed through an automatic developing machine TWL-1160F (manufactured by Toray Industries, Inc.) at a conveying speed of 60 cm / min to remove the ink-repellent layer in the image area, producing a waterless lithographic printing plate. For the Examples and Comparative Examples 1 and 3, no organic solvent-containing pretreatment solution, developer, or posttreatment solution was used. Instead, the developing tank of the automatic developing machine was replenished with water only, and the plate surface was rubbed with a rotating brush while spraying water. For Comparative Example 2, the pretreatment tank of the automatic developing machine was replenished with "NP-1" (manufactured by Toray Industries, Inc., a pretreatment solution for waterless lithographic negative printing), and the developing tank was replenished with water. The resulting waterless lithographic printing plate precursor was then "chemically developed."

[0093] (II) Evaluation of image reproducibility 100 dots of each of the 20 μm x 20 μm halftone dots and 10 μm x 20 μm halftone dots on the waterless lithographic printing plate obtained by (I) above were observed under a 25x magnification loupe. For each halftone dot, if the ink-repellent layer in the image area was removed after development, the image was deemed to have been reproduced. Furthermore, if the ink-repellent layer in the image area was not removed after development, the image was deemed not to have been reproduced. For the plate with the lowest image reproducibility among the 10 sets, the number of minute halftone dots reproduced per 100 dots was used to evaluate image reproducibility, which was defined as the image reproduction rate (%).

[0094] For halftone dots measuring 20 μm x 20 μm, an image reproduction rate of 80% or higher was deemed acceptable for practical use, and 100% was deemed good. Furthermore, for halftone dots measuring 20 μm x 20 μm, an image reproduction rate of 100% and an image reproduction rate of 30% or higher for halftone dots measuring 10 μm x 20 μm were deemed very good.

[0095] (III) Evaluation of ink-repellent layer peeling resistance A sample of 670 mm × 560 mm was taken from the waterless lithographic printing plate precursor obtained in each Example and Comparative Example, and was mounted on an exposure machine "PlateRite" 8900E (manufactured by Screen Graphic Solutions Co., Ltd.) at an irradiation energy of 200 mJ / cm, which is the practically preferable upper limit of irradiation energy. 2 The plate was exposed to light at 1000 W at 1000 W, forming image and non-image areas. These harsh exposure conditions accelerated thermal decomposition near the boundary between the ink-repellent layer and the thermosensitive layer, weakening the adhesive strength between the two layers and making the ink-repellent layer more susceptible to peeling. A 100 mm x 100 mm solid image was formed in the image area. The exposed waterless lithographic printing plate precursor was then passed through an automatic developing machine, TWL-1160F (Toray Industries, Inc.), with the transport speed varying from 40 cm / min to 80 cm / min in 10 cm / min increments, to remove the ink-repellent layer from the image area. For each Example and Comparative Examples 1 and 3, the automatic developing machine's developing tank was replenished with water only. For Comparative Example 2, the developing tank was replenished with water and the pretreatment tank with "NP-1." By rubbing the plate surface with a rotating brush while spraying water, a shear stress was applied to the ink-repellent layer, making it more susceptible to peeling. The boundary between the solid image area and the non-image area was observed, and the resistance to peeling of the ink repellent layer was evaluated based on the fastest conveying speed at which peeling of the ink repellent layer was observed in the non-image area.

[0096] It is preferable that no peeling of the ink repellent layer is observed even at slow conveying speeds where the shear stress is applied for a longer period of time; if peeling of the ink repellent layer is not observed even at a conveying speed of 40 cm / min, the score is 5; if peeling is observed at 40 cm / min but not at 50 cm / min, the score is 4; if peeling is observed at 50 cm / min but not at 60 cm / min, the score is 3; if peeling is observed at 60 cm / min but not at 70 cm / min, the score is 2; if peeling is observed at 70 cm / min but not at 80 cm / min, the score is 1; and if peeling is observed at 80 cm / min, the score is 0.

[0097] From the viewpoint of the manufacturing latitude of waterless planographic printing plates, a score of 1 or more is practical, preferably 3 or more, and more preferably 5.

[0098] (IV) Evaluation of contrast between image and non-image areas The waterless lithographic printing plate precursor obtained by the above-mentioned "(1) step of exposing according to a desired image to form image areas and non-image areas" was measured for reflection density in the non-image areas and image areas using a spectrophotometer "eXact" Advance (manufactured by X-Rite), and the difference in reflection density between the non-image areas and image areas was calculated. Measurements were carried out with a cyan, yellow, magenta, or black filter applied, and the average values ​​of 10 measurements were taken for the image and non-image areas, and the reflection densities of the image and non-image areas were calculated. The absolute value ΔD of each (non-image area reflection density - image area reflection density) was C , ΔD Y , ΔD M and ΔD K The largest value among these was taken as the reflection density difference and the contrast was evaluated. A reflection density difference of 0.30 or more was judged to be acceptable for practical use, 0.35 or more to be generally good, 0.45 or more to be good, and 0.50 or more to be very good.

[0099] [Example 1] A waterless lithographic printing plate precursor was prepared in the following manner.

[0100] <Substrate with white surface> The surface of a 0.24 mm thick degreased aluminum substrate (manufactured by Mitsubishi Aluminum Co., Ltd.) was brushed with three bundled nylon brushes with a single thread diameter of 0.3 mm and a pumice-water suspension (specific gravity 1.1 g / cm) with a median diameter of 25 μm. 3 The substrate was etched by immersing it in a 25% by mass aqueous solution of sodium hydroxide at 45°C for 9 seconds, rinsed with water, and then immersed in a 20% by mass aqueous solution of nitric acid at 60°C for 20 seconds, followed by rinsing with water.

[0101] Next, the grained aluminum substrate was subjected to continuous electrochemical surface roughening treatment in an electrolyte using a 60 Hz AC voltage. The electrolyte used was a 1% by mass aqueous solution of nitric acid (containing 0.5% by mass of aluminum ions) at a temperature of 50°C. The AC power waveform was a trapezoidal square wave AC with a duty ratio of 1:1, with a current value from zero to its peak time TP of 0.8 msec. The electrochemical surface roughening treatment was performed using a carbon electrode as the counter electrode. Ferrite was used as the auxiliary anode. The current density was 30 A / dm at the peak current value. 2 The amount of electricity in nitric acid electrolysis was 175 C / dm when the aluminum plate was the anode, and 5% of the current flowing from the power source was diverted to the auxiliary anode. 2 After that, the surface was washed with water using a spray.

[0102] Next, using a 0.5 mass % aqueous solution of hydrochloric acid (containing 0.5 mass % aluminum ions) and an electrolyte at a liquid temperature of 50°C, the quantity of electricity when the aluminum substrate was used as the anode was 50 C / dm 2 The surface was subjected to electrochemical roughening treatment in the same manner as in the nitric acid electrolysis under the conditions of:

[0103] This substrate was electrolytically charged with 15% sulfuric acid (containing 0.5% by mass of aluminum ions) at a current density of 15 A / dm 2 2.5g / m 2After forming the DC anodized coating, the substrate was washed with water, dried, and then immersed in a 2.5% by mass aqueous solution of sodium silicate at 30°C for 10 seconds to obtain a substrate with a white surface. The center line average roughness (Ra) of the obtained substrate with a white surface was 0.51 μm, and the reflectance was 50% or more over the entire wavelength range of 450 to 700 nm.

[0104] Next, the following thermosensitive layer composition solution-1 was applied to the substrate having a white surface and dried by heating at 140°C for 90 seconds to form a thermosensitive layer having a thickness of 1.5 µm. The thermosensitive layer composition solution-1 was obtained by mixing the following components at room temperature with stirring.

[0105] <Thermosensitive layer composition solution-1> (i) Methylol group-type methylated melamine resin: “CYMEL” (registered trademark) 370 (manufactured by Allnex, viscosity: 5100 to 10200 mPa·s): 83.0 parts by mass (ii) Infrared absorbing dye (cyanine dye): NK5559 (manufactured by Hayashibara Co., Ltd., maximum absorption wavelength: 774 nm): 11.0 parts by mass (iii) Dye that develops color upon proton acceptance (azo compound having a maximum absorption wavelength of 420 nm upon proton acceptance): Metanil Yellow (manufactured by Tokyo Chemical Industry Co., Ltd.): 5.0 parts by mass (iv) Proton donating compound: p-toluenesulfonic acid: 1.0 parts by mass (v) Tetrahydrofuran: 900 parts by mass.

[0106] Next, the following ink-repellent layer (silicone rubber layer) composition solution, prepared just before coating, was coated on the heat-sensitive layer and heated at 140°C for 80 seconds to provide an ink-repellent layer with an average film thickness of 2.5µm, thereby obtaining a waterless lithographic printing plate precursor. The ink-repellent layer composition solution was obtained by mixing the following components with stirring at room temperature.

[0107] <Ink-repellent layer composition solution> (i) α,ω-divinylpolydimethylsiloxane: DMS-V35 (weight average molecular weight 49,500, manufactured by GELEST Inc.): 86.95 parts by mass (ii) Methylhydrogensiloxane-dimethylsiloxane copolymer RD-1 ((II) / ((II)+(III))=0.5, manufactured by Dow Corning Toray Co., Ltd.): 4.24 parts by mass (iii) vinyltris(methylethylketoxyimino)silane: 2.64 parts by mass (iv) Platinum catalyst SRX212 (manufactured by Dow Corning Toray Co., Ltd.): 6.17 parts by mass (v) "Isopar" (registered trademark) E (manufactured by Esso Chemical Co., Ltd.): 900 parts by mass.

[0108] The obtained waterless lithographic printing plate precursor was evaluated by the above method, and the image reproduction rate was 90% of the 20 μm × 20 μm halftone dots, which is practically acceptable. The ink repellent layer peel resistance was good, scoring 3 points. The reflection density difference ΔD measured using a yellow filter Y The result was 0.30, which is acceptable for practical use.

[0109] [Example 2] A waterless lithographic printing plate precursor was obtained in the same manner as in Example 1, except that "Lumirror" (registered trademark) #225-E6SR (white PET film, manufactured by Toray Industries, Inc.), which has a reflectance of 70% or more over the entire wavelength range of 450 to 700 nm, was used as the substrate having a white surface.

[0110] The obtained waterless lithographic printing plate precursor was evaluated by the above method, and the image reproduction rate was 90% of the 20 μm × 20 μm halftone dots, which is practically acceptable. The ink repellent layer peel resistance was good, scoring 3 points. The reflection density difference ΔD measured using a yellow filter Y The result was 0.31, which is acceptable for practical use.

[0111] [Example 3] The following organic layer composition liquid-1 was applied to a 0.24 mm thick degreased aluminum substrate (manufactured by Mitsubishi Aluminum Corporation) and dried at 200°C for 90 seconds to provide an organic layer with a thickness of 10.0 μm, thereby obtaining a substrate having a white layer. The obtained substrate having a white layer had a reflectance of 75% or more over the entire wavelength range of 450 to 700 nm. Organic layer composition liquid-1 was obtained by stirring and mixing the following components at room temperature. A waterless lithographic printing plate precursor was obtained in the same manner as in Example 1, except that the substrate having a white surface was changed to the substrate having the above white layer.

[0112] <Organic layer composition liquid-1> (i) Polymer having active hydrogen: Epoxy resin: “jER” (registered trademark) 1010 (manufactured by Mitsubishi Chemical Corporation): 29.2 parts by mass (ii) Polymer having active hydrogen: Polyurethane: "Sunprene" (registered trademark) LQ-T1331D (manufactured by Sanyo Chemical Industries, Ltd., solid content concentration: 20% by mass): 51.7 parts by mass (iii) Aluminum chelate: Aluminum chelate ALCH-TR (Kawaken Fine Chemicals Co., Ltd.): 4.5 parts by mass (iv) Leveling agent: “Disparlon” (registered trademark) LC951 (manufactured by Kusumoto Chemicals Co., Ltd., solid content: 10% by mass): 0.1 parts by mass (v) Titanium oxide: “Tipake” (registered trademark) CR-50 (manufactured by Ishihara Sangyo Kaisha, Ltd.) dispersion in N,N-dimethylformamide (titanium oxide 50% by mass): 14.5 parts by mass (vi) N,N-dimethylformamide: 450 parts by mass (vii) Methyl ethyl ketone: 150 parts by mass.

[0113] The obtained waterless lithographic printing plate precursor was evaluated by the above method, and the image reproduction rate was 90% of the 20 μm × 20 μm halftone dots, which is practically acceptable. The ink repellent layer peel resistance was good, scoring 3 points. The reflection density difference ΔD measured using a yellow filter Y The result was 0.33, which is acceptable for practical use.

[0114] [Example 4] A lithographic printing plate precursor was obtained in the same manner as in Example 3, except that the heat-sensitive layer composition solution-1 was changed to the following heat-sensitive layer composition solution-2.

[0115] <Thermosensitive layer composition solution-2> (i) Methylol group-type methylated melamine resin: “CYMEL” (registered trademark) 370 (manufactured by Allnex, viscosity: 5100 to 10200 mPa·s): 82.0 parts by mass (ii) Infrared absorbing dye (cyanine dye): NK5559 (manufactured by Hayashibara Co., Ltd., maximum absorption wavelength: 774 nm): 12.0 parts by mass (iii) Dye that develops color upon proton acceptance (azo compound having a maximum absorption wavelength of 420 nm upon proton acceptance): Metanil Yellow (manufactured by Tokyo Chemical Industry Co., Ltd.): 5.0 parts by mass (iv) Proton donating compound: p-toluenesulfonic acid: 1.0 parts by mass (v) Tetrahydrofuran: 900 parts by mass.

[0116] The obtained waterless lithographic printing plate precursor was evaluated by the above-mentioned method, and the image reproduction rate was good, with 100% reproduction of 20 μm × 20 μm halftone dots and 10% reproduction of 10 μm × 20 μm halftone dots. The ink repellent layer peeling resistance was good, with a score of 3. The reflection density difference ΔD measured using a yellow filter Y The result was 0.33, which is acceptable for practical use.

[0117] [Example 5] A lithographic printing plate precursor was obtained in the same manner as in Example 3, except that the heat-sensitive layer composition solution-1 was changed to the following heat-sensitive layer composition solution-3.

[0118] <Thermosensitive layer composition solution-3> (i) Methylol group-type methylated melamine resin: “CYMEL” (registered trademark) 370 (manufactured by Allnex, viscosity: 5100 to 10200 mPa·s): 80.0 parts by mass (ii) Infrared absorbing dye (cyanine dye): NK5559 (manufactured by Hayashibara Co., Ltd., maximum absorption wavelength: 774 nm): 14.0 parts by mass (iii) Dye that develops color upon proton acceptance (azo compound having a maximum absorption wavelength of 420 nm upon proton acceptance): Metanil Yellow (manufactured by Tokyo Chemical Industry Co., Ltd.): 5.0 parts by mass (iv) Proton donating compound: p-toluenesulfonic acid: 1.0 parts by mass (v) Tetrahydrofuran: 900 parts by mass.

[0119] The obtained waterless lithographic printing plate precursor was evaluated by the above-mentioned method, and the image reproduction rate was very good, with 100% reproduction of 20 μm × 20 μm halftone dots and 30% reproduction of 10 μm × 20 μm halftone dots. The ink repellent layer peeling resistance was good, with a score of 3. The reflection density difference ΔD measured using a yellow filter Y The result was generally good, with a value of 0.35.

[0120] [Example 6] A lithographic printing plate precursor was obtained in the same manner as in Example 3, except that the heat-sensitive layer composition solution-1 was changed to the following heat-sensitive layer composition solution-4.

[0121] <Thermosensitive layer composition solution-4> (i) Methylol group-type methylated melamine resin: “CYMEL” (registered trademark) 370 (manufactured by Allnex, viscosity: 5100 to 10200 mPa·s): 76.0 parts by mass (ii) Infrared absorbing dye (cyanine dye): NK5559 (manufactured by Hayashibara Co., Ltd., maximum absorption wavelength: 774 nm): 18.0 parts by mass (iii) Dye that develops color upon proton acceptance (azo compound having a maximum absorption wavelength of 420 nm upon proton acceptance): Metanil Yellow (manufactured by Tokyo Chemical Industry Co., Ltd.): 5.0 parts by mass (iv) Proton donating compound: p-toluenesulfonic acid: 1.0 parts by mass (v) Tetrahydrofuran: 900 parts by mass.

[0122] The obtained waterless lithographic printing plate precursor was evaluated by the above-mentioned method, and the image reproduction rate was very good, with 100% reproduction of 20 μm × 20 μm halftone dots and 55% reproduction of 10 μm × 20 μm halftone dots. The ink repellent layer peeling resistance was good, with a score of 3. The reflection density difference ΔD measured using a yellow filter Y The result was generally good, with a value of 0.40.

[0123] [Example 7] A lithographic printing plate precursor was obtained in the same manner as in Example 3, except that the heat-sensitive layer composition solution-1 was changed to the following heat-sensitive layer composition solution-5.

[0124] <Thermosensitive layer composition solution-5> (i) Methylol group-type methylated melamine resin: “CYMEL” (registered trademark) 370 (manufactured by Allnex, viscosity: 5100 to 10200 mPa·s): 74.0 parts by mass (ii) Infrared absorbing dye (cyanine dye): NK5559 (manufactured by Hayashibara Co., Ltd., maximum absorption wavelength: 774 nm): 20.0 parts by mass (iii) Dye that develops color upon proton acceptance (azo compound having a maximum absorption wavelength of 420 nm upon proton acceptance): Metanil Yellow (manufactured by Tokyo Chemical Industry Co., Ltd.): 5.0 parts by mass (iv) Proton donating compound: p-toluenesulfonic acid: 1.0 parts by mass (v) Tetrahydrofuran: 900 parts by mass.

[0125] The obtained waterless lithographic printing plate precursor was evaluated by the above-mentioned method, and the image reproduction rate was very good, with 100% reproduction of 20 μm × 20 μm halftone dots and 70% reproduction of 10 μm × 20 μm halftone dots. The ink repellent layer peeling resistance was rated at 2 points. The reflection density difference ΔD measured using a yellow filter Y The result was generally good, with a value of 0.42.

[0126] [Example 8] A lithographic printing plate precursor was obtained in the same manner as in Example 3, except that the heat-sensitive layer composition solution-1 was changed to the following heat-sensitive layer composition solution-6.

[0127] <Thermosensitive layer composition solution-6> (i) Methylol group-type methylated melamine resin: “CYMEL” (registered trademark) 370 (manufactured by Allnex, viscosity: 5100 to 10200 mPa·s): 69.0 parts by mass (ii) Infrared absorbing dye (cyanine dye): NK5559 (manufactured by Hayashibara Co., Ltd., maximum absorption wavelength: 774 nm): 25.0 parts by mass (iii) Dye that develops color upon proton acceptance (azo compound having a maximum absorption wavelength of 420 nm upon proton acceptance): Metanil Yellow (manufactured by Tokyo Chemical Industry Co., Ltd.): 5.0 parts by mass (iv) Proton donating compound: p-toluenesulfonic acid: 1.0 parts by mass (v) Tetrahydrofuran: 900 parts by mass.

[0128] The obtained waterless lithographic printing plate precursor was evaluated by the above-mentioned method, and the image reproduction rate was very good, with 100% reproduction of 20 μm × 20 μm halftone dots and 80% reproduction of 10 μm × 20 μm halftone dots. The ink repellent layer peeling resistance was rated at 1 point. The reflection density difference ΔD measured using a yellow filter Y The result was generally good, with a value of 0.42.

[0129] [Example 9] A lithographic printing plate precursor was obtained in the same manner as in Example 3, except that the heat-sensitive layer composition solution-1 was changed to the following heat-sensitive layer composition solution-7.

[0130] <Thermosensitive layer composition solution-7> (i) Methylol group-type methylated melamine resin: “CYMEL” (registered trademark) 370 (manufactured by Allnex, viscosity: 5100 to 10200 mPa·s): 80.0 parts by mass (ii) Infrared absorbing dye (cyanine dye): NK5559 (manufactured by Hayashibara Co., Ltd., maximum absorption wavelength: 774 nm): 14.0 parts by mass (iii) Dye that develops color upon proton acceptance (leuco dye with a maximum absorption wavelength of 480 nm upon proton acceptance): RED520 (2-methyl-6-(Np-tolyl-N-ethylamino)-fluoran, manufactured by Fukui Yamada Chemical Co., Ltd.): 5.0 parts by mass (iv) Proton donating compound: p-toluenesulfonic acid: 1.0 parts by mass (v) Tetrahydrofuran: 900 parts by mass.

[0131] The obtained waterless lithographic printing plate precursor was evaluated by the above-mentioned method, and the image reproduction rate was very good, with 100% reproduction of 20 μm × 20 μm halftone dots and 30% reproduction of 10 μm × 20 μm halftone dots. The ink repellent layer peeling resistance was good, with a score of 3. The reflection density difference ΔD measured using a yellow filter Y A good result of 0.45 was obtained.

[0132] [Example 10] A lithographic printing plate precursor was obtained in the same manner as in Example 3, except that the heat-sensitive layer composition solution-1 was changed to the following heat-sensitive layer composition solution-8.

[0133] <Thermosensitive layer composition solution-8> (i) Methylol group-type methylated melamine resin: “CYMEL” (registered trademark) 370 (manufactured by Allnex, viscosity: 5100 to 10200 mPa·s): 80.0 parts by mass (ii) Infrared absorbing dye (cyanine dye): NK5559 (manufactured by Hayashibara Co., Ltd., maximum absorption wavelength: 774 nm): 14.0 parts by mass (iii) Dye that develops color upon proton acceptance (leuco dye with a maximum absorption wavelength of 570 nm upon proton acceptance): Blue 203 (3-[4-(diethylamino)-2-hexyloxyphenyl]-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide, manufactured by Fukui Yamada Chemical Industry Co., Ltd.): 5.0 parts by mass (iv) Proton donating compound: p-toluenesulfonic acid: 1.0 parts by mass (v) Tetrahydrofuran: 900 parts by mass.

[0134] The obtained waterless lithographic printing plate precursor was evaluated by the above-mentioned method, and the image reproduction rate was very good, with 100% reproduction of 20 μm × 20 μm halftone dots and 30% reproduction of 10 μm × 20 μm halftone dots. The ink repellent layer peeling resistance was good, with a score of 3. The reflection density difference ΔD measured using a cyan filter C A good result of 0.48 was obtained.

[0135] [Example 11] A lithographic printing plate precursor was obtained in the same manner as in Example 3, except that the heat-sensitive layer composition solution-1 was changed to the following heat-sensitive layer composition solution-9.

[0136] <Thermosensitive layer composition solution-9> (i) Infrared absorbing dye (cyanine dye): NK5559 (manufactured by Hayashibara Co., Ltd., maximum absorption wavelength: 774 nm): 14.0 parts by mass (ii) Dye that develops color upon proton acceptance (leuco dye with a maximum absorption wavelength of 570 nm upon proton acceptance): Blue 203 (3-[4-(diethylamino)-2-hexyloxyphenyl]-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide, manufactured by Fukui Yamada Chemical Co., Ltd.): 5.0 parts by mass (iii) Proton-donating compound (polymer having an active hydrogen-containing structural unit): poly(methacrylic acid) (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.): 81.0 parts by mass (iv) Tetrahydrofuran: 900 parts by mass.

[0137] The obtained waterless lithographic printing plate precursor was evaluated by the above method, and the image reproduction rate was very good, with 100% reproduction of 20 μm × 20 μm halftone dots and 30% reproduction of 10 μm × 20 μm halftone dots. The ink repellent layer peeling resistance was good, with a score of 4. The reflection density difference ΔD measured using a cyan filter C A good result of 0.48 was obtained.

[0138] [Example 12] A lithographic printing plate precursor was obtained in the same manner as in Example 3, except that the heat-sensitive layer composition solution-1 was changed to the following heat-sensitive layer composition solution-10.

[0139] <Thermosensitive layer composition solution-10> (i) Infrared absorbing dye (cyanine dye): NK5559 (manufactured by Hayashibara Co., Ltd., maximum absorption wavelength: 774 nm): 14.0 parts by mass (ii) Dye that develops color upon proton acceptance (leuco dye with a maximum absorption wavelength of 570 nm upon proton acceptance): Blue 203 (3-[4-(diethylamino)-2-hexyloxyphenyl]-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide, manufactured by Fukui Yamada Chemical Co., Ltd.): 5.0 parts by mass (iii) Proton-donating compound (polymer having an active hydrogen-containing structural unit): phenol-formaldehyde novolak resin “Sumilite Resin” (registered trademark) PR53195 (manufactured by Sumitomo Bakelite Co., Ltd.): 64.8 parts by mass (iv) Organic complex compound: Titanium-n-butoxide bis(acetylacetonate): “Nacem” (registered trademark) Titanium (manufactured by Nippon Chemical Industry Co., Ltd., concentration: 73% by mass, containing 27% by mass of n-butanol as a solvent): 16.2 parts by mass (v) Tetrahydrofuran: 900 parts by mass.

[0140] The obtained waterless lithographic printing plate precursor was evaluated by the above-mentioned method, and the image reproduction rate was very good, with 100% reproduction of 20 μm × 20 μm halftone dots and 30% reproduction of 10 μm × 20 μm halftone dots. The ink repellent layer peeling resistance was also very good, with a score of 5. The reflection density difference ΔD measured using a cyan filter C A good result of 0.48 was obtained.

[0141] [Example 13] A lithographic printing plate precursor was obtained in the same manner as in Example 3, except that the heat-sensitive layer composition solution-1 was changed to the following heat-sensitive layer composition solution-11.

[0142] <Thermosensitive layer composition solution-11> (i) Infrared absorbing dye (cyanine dye): NK5559 (manufactured by Hayashibara Co., Ltd., maximum absorption wavelength: 774 nm): 11.0 parts by mass (ii) Dye that develops color upon proton acceptance (leuco dye with a maximum absorption wavelength of 580 nm upon proton acceptance): FB-1 (3',6'-bis(diphenylamino)spiro[phthalide-3,9'-xanthene], manufactured by Fukui Yamada Chemical Industry Co., Ltd.): 5.0 parts by mass (iii) Proton-donating compound (polymer having an active hydrogen-containing structural unit): phenol-formaldehyde novolak resin “Sumilite Resin” (registered trademark) PR53195 (manufactured by Sumitomo Bakelite Co., Ltd.): 67.2 parts by mass (iv) Organic complex compound: Titanium-n-butoxide bis(acetylacetonate): “Nacem” (registered trademark) Titanium (manufactured by Nippon Chemical Industry Co., Ltd., concentration: 73% by mass, containing 27% by mass of n-butanol as a solvent): 16.8 parts by mass (v) Tetrahydrofuran: 900 parts by mass.

[0143] When the obtained waterless planographic printing plate precursor was evaluated using the above method, the image reproduction rate was 90% for 20 μm × 20 μm halftone dots, which is practically acceptable. The ink repellent layer peel resistance was rated at 5 points, which was very good. The reflection density difference ΔD measured using a cyan filter C The result was generally good, at 0.43.

[0144] [Example 14] A lithographic printing plate precursor was obtained in the same manner as in Example 3, except that the heat-sensitive layer composition solution-1 was changed to the following heat-sensitive layer composition solution-12.

[0145] <Thermosensitive layer composition solution-12> (i) Infrared absorbing dye (cyanine dye): NK5559 (manufactured by Hayashibara Co., Ltd., maximum absorption wavelength: 774 nm): 12.0 parts by mass (ii) Dye that develops color upon proton acceptance (leuco dye with a maximum absorption wavelength of 580 nm upon proton acceptance): FB-1 (3',6'-bis(diphenylamino)spiro[phthalide-3,9'-xanthene], manufactured by Fukui Yamada Chemical Industry Co., Ltd.): 5.0 parts by mass (iii) Proton-donating compound (polymer having an active hydrogen-containing structural unit): phenol-formaldehyde novolak resin “Sumilite Resin” (registered trademark) PR53195 (manufactured by Sumitomo Bakelite Co., Ltd.): 66.4 parts by mass (iv) Organic complex compound: Titanium-n-butoxide bis(acetylacetonate): “Nacem” (registered trademark) titanium (manufactured by Nippon Chemical Industry Co., Ltd., concentration: 73% by mass, containing 27% by mass of n-butanol as a solvent): 16.6 parts by mass (v) Tetrahydrofuran: 900 parts by mass.

[0146] The obtained waterless lithographic printing plate precursor was evaluated by the above-mentioned method, and the image reproduction rate was good, with 100% reproduction of 20 μm × 20 μm dots and 10% reproduction of 10 μm × 20 μm dots. The ink repellent layer peeling resistance was very good, with a score of 5. The reflection density difference ΔD measured using a cyan filter C The result was generally good, at 0.43.

[0147] [Example 15] A lithographic printing plate precursor was obtained in the same manner as in Example 3, except that the heat-sensitive layer composition solution-1 was changed to the following heat-sensitive layer composition solution-13.

[0148] <Thermosensitive layer composition solution-13> (i) Infrared absorbing dye (cyanine dye): NK5559 (manufactured by Hayashibara Co., Ltd., maximum absorption wavelength: 774 nm): 18.0 parts by mass (ii) Dye that develops color upon proton acceptance (leuco dye with a maximum absorption wavelength of 580 nm upon proton acceptance): FB-1 (3',6'-bis(diphenylamino)spiro[phthalide-3,9'-xanthene], manufactured by Fukui Yamada Chemical Industry Co., Ltd.): 5.0 parts by mass (iii) Proton-donating compound (polymer having an active hydrogen-containing structural unit): phenol-formaldehyde novolak resin “Sumilite Resin” (registered trademark) PR53195 (manufactured by Sumitomo Bakelite Co., Ltd.): 61.6 parts by mass (iv) Organic complex compound: Titanium-n-butoxide bis(acetylacetonate): “Nacem” (registered trademark) Titanium (manufactured by Nippon Chemical Industry Co., Ltd., concentration: 73% by mass, containing 27% by mass of n-butanol as a solvent): 15.4 parts by mass (v) Tetrahydrofuran: 900 parts by mass.

[0149] The obtained waterless lithographic printing plate precursor was evaluated by the above-mentioned method, and the image reproduction rate was very good, with 100% reproduction of 20 μm × 20 μm halftone dots and 55% reproduction of 10 μm × 20 μm halftone dots. The ink repellent layer peeling resistance was also very good, with a score of 5. The reflection density difference ΔD measured using a cyan filter C The result was very good, 0.50.

[0150] [Example 16] A lithographic printing plate precursor was obtained in the same manner as in Example 3, except that the heat-sensitive layer composition solution-1 was changed to the following heat-sensitive layer composition solution-14.

[0151] <Thermosensitive layer composition solution-14> (i) Infrared absorbing dye (cyanine dye): NK5559 (manufactured by Hayashibara Co., Ltd., maximum absorption wavelength: 774 nm): 20.0 parts by mass (ii) Dye that develops color upon proton acceptance (leuco dye with a maximum absorption wavelength of 580 nm upon proton acceptance): FB-1 (3',6'-bis(diphenylamino)spiro[phthalide-3,9'-xanthene], manufactured by Fukui Yamada Chemical Industry Co., Ltd.): 5.0 parts by mass (iii) Proton-donating compound (polymer having an active hydrogen-containing structural unit): phenol-formaldehyde novolak resin “Sumilite Resin” (registered trademark) PR53195 (manufactured by Sumitomo Bakelite Co., Ltd.): 60.0 parts by mass (iv) Organic complex compound: Titanium-n-butoxide bis(acetylacetonate): “Nacem” (registered trademark) Titanium (manufactured by Nippon Chemical Industry Co., Ltd., concentration: 73% by mass, containing 27% by mass of n-butanol as a solvent): 15.0 parts by mass (v) Tetrahydrofuran: 900 parts by mass.

[0152] The obtained waterless lithographic printing plate precursor was evaluated by the above method, and the image reproduction rate was very good, with 100% reproduction of 20 μm × 20 μm halftone dots and 70% reproduction of 10 μm × 20 μm halftone dots. The ink repellent layer peeling resistance was good, with a score of 4. The reflection density difference ΔD measured using a cyan filter C The result was very good, 0.52.

[0153] [Example 17] A lithographic printing plate precursor was obtained in the same manner as in Example 3, except that the heat-sensitive layer composition solution-1 was changed to the following heat-sensitive layer composition solution-15.

[0154] <Thermosensitive layer composition solution-15> (i) Infrared absorbing dye (cyanine dye): NK5559 (manufactured by Hayashibara Co., Ltd., maximum absorption wavelength: 774 nm): 25.0 parts by mass (ii) Dye that develops color upon proton acceptance (leuco dye with a maximum absorption wavelength of 580 nm upon proton acceptance): FB-1 (3',6'-bis(diphenylamino)spiro[phthalide-3,9'-xanthene], manufactured by Fukui Yamada Chemical Industry Co., Ltd.): 5.0 parts by mass (iii) Proton-donating compound (polymer having an active hydrogen-containing structural unit): phenol-formaldehyde novolak resin “Sumilite Resin” (registered trademark) PR53195 (manufactured by Sumitomo Bakelite Co., Ltd.): 56.0 parts by mass (iv) Organic complex compound: Titanium-n-butoxide bis(acetylacetonate): “Nacem” (registered trademark) Titanium (manufactured by Nippon Chemical Industry Co., Ltd., concentration: 73% by mass, containing 27% by mass of n-butanol as a solvent): 14.0 parts by mass (v) Tetrahydrofuran: 900 parts by mass.

[0155] The obtained waterless lithographic printing plate precursor was evaluated by the above-mentioned method, and the image reproduction rate was very good, with 100% reproduction of 20 μm × 20 μm halftone dots and 80% reproduction of 10 μm × 20 μm halftone dots. The ink repellent layer peeling resistance was good, with a score of 3. The reflection density difference ΔD measured using a cyan filterC The result was very good, 0.52.

[0156] [Example 18] A lithographic printing plate precursor was obtained in the same manner as in Example 3, except that the heat-sensitive layer composition solution-1 was changed to the following heat-sensitive layer composition solution-16.

[0157] <Thermosensitive layer composition solution-16> (i) Infrared absorbing dye (cyanine dye): NK5559 (manufactured by Hayashibara Co., Ltd., maximum absorption wavelength: 774 nm): 14.0 parts by mass (ii) Dye that develops color upon proton acceptance (leuco dye with a maximum absorption wavelength of 580 nm upon proton acceptance): FB-1 (3',6'-bis(diphenylamino)spiro[phthalide-3,9'-xanthene], manufactured by Fukui Yamada Chemical Industry Co., Ltd.): 5.0 parts by mass (iii) Proton-donating compound (polymer having an active hydrogen-containing structural unit): phenol-formaldehyde novolak resin “Sumilite Resin” (registered trademark) PR53195 (manufactured by Sumitomo Bakelite Co., Ltd.): 64.8 parts by mass (iv) Organic complex compound: Titanium-n-butoxide bis(acetylacetonate): “Nacem” (registered trademark) Titanium (manufactured by Nippon Chemical Industry Co., Ltd., concentration: 73% by mass, containing 27% by mass of n-butanol as a solvent): 16.2 parts by mass (v) Tetrahydrofuran: 900 parts by mass.

[0158] The obtained waterless lithographic printing plate precursor was evaluated by the above-mentioned method, and the image reproduction rate was very good, with 100% reproduction of 20 μm × 20 μm halftone dots and 30% reproduction of 10 μm × 20 μm halftone dots. The ink repellent layer peeling resistance was also very good, with a score of 5. The reflection density difference ΔD measured using a cyan filter C A good result of 0.48 was obtained.

[0159] [Example 19] A lithographic printing plate precursor was obtained in the same manner as in Example 3, except that the heat-sensitive layer composition solution-1 was changed to the following heat-sensitive layer composition solution-17.

[0160] <Thermosensitive layer composition solution-17> (i) Infrared absorbing dye (cyanine dye): NK5559 (manufactured by Hayashibara Co., Ltd., maximum absorption wavelength: 774 nm): 14.0 parts by mass (ii) Dye that develops color upon proton acceptance (leuco dye with a maximum absorption wavelength of 580 nm upon proton acceptance): FB-1 (3',6'-bis(diphenylamino)spiro[phthalide-3,9'-xanthene], manufactured by Fukui Yamada Chemical Industry Co., Ltd.): 7.0 parts by mass (iii) Proton-donating compound (polymer having an active hydrogen-containing structural unit): phenol-formaldehyde novolak resin “Sumilite Resin” (registered trademark) PR53195 (manufactured by Sumitomo Bakelite Co., Ltd.): 63.2 parts by mass (iv) Organic complex compound: Titanium-n-butoxide bis(acetylacetonate): “Nacem” (registered trademark) Titanium (manufactured by Nippon Chemical Industry Co., Ltd., concentration: 73% by mass, containing 27% by mass of n-butanol as a solvent): 15.8 parts by mass (v) Tetrahydrofuran: 900 parts by mass.

[0161] The obtained waterless lithographic printing plate precursor was evaluated by the above-mentioned method, and the image reproduction rate was very good, with 100% reproduction of 20 μm × 20 μm halftone dots and 30% reproduction of 10 μm × 20 μm halftone dots. The ink repellent layer peeling resistance was also very good, with a score of 5. The reflection density difference ΔD measured using a cyan filter C The result was very good, 0.51.

[0162] [Example 20] A lithographic printing plate precursor was obtained in the same manner as in Example 3, except that the heat-sensitive layer composition solution-1 was changed to the following heat-sensitive layer composition solution-18.

[0163] <Thermosensitive layer composition solution-18> (i) Infrared absorbing dye (cyanine dye): NK5559 (manufactured by Hayashibara Co., Ltd., maximum absorption wavelength: 774 nm): 14.0 parts by mass (ii) Dye that develops color upon proton acceptance (leuco dye with a maximum absorption wavelength of 580 nm upon proton acceptance): FB-1 (3',6'-bis(diphenylamino)spiro[phthalide-3,9'-xanthene], manufactured by Fukui Yamada Chemical Industry Co., Ltd.): 11.0 parts by mass (iii) Proton-donating compound (polymer having an active hydrogen-containing structural unit): phenol-formaldehyde novolak resin “Sumilite Resin” (registered trademark) PR53195 (manufactured by Sumitomo Bakelite Co., Ltd.): 60.0 parts by mass (iv) Organic complex compound: Titanium-n-butoxide bis(acetylacetonate): “Nacem” (registered trademark) Titanium (manufactured by Nippon Chemical Industry Co., Ltd., concentration: 73% by mass, containing 27% by mass of n-butanol as a solvent): 15.0 parts by mass (v) Tetrahydrofuran: 900 parts by mass.

[0164] The obtained waterless lithographic printing plate precursor was evaluated by the above-mentioned method, and the image reproduction rate was very good, with 100% reproduction of 20 μm × 20 μm halftone dots and 30% reproduction of 10 μm × 20 μm halftone dots. The ink repellent layer peeling resistance was also very good, with a score of 5. The reflection density difference ΔD measured using a cyan filter C The result was very good, 0.55.

[0165] [Example 21] A lithographic printing plate precursor was obtained in the same manner as in Example 3, except that the heat-sensitive layer composition solution-1 was changed to the following heat-sensitive layer composition solution-19.

[0166] <Thermosensitive layer composition solution-19> (i) Infrared absorbing dye (cyanine dye): NK5559 (manufactured by Hayashibara Co., Ltd., maximum absorption wavelength: 774 nm): 14.0 parts by mass (ii) Dye that develops color upon proton acceptance (leuco dye with a maximum absorption wavelength of 580 nm upon proton acceptance): FB-1 (3',6'-bis(diphenylamino)spiro[phthalide-3,9'-xanthene], manufactured by Fukui Yamada Chemical Industry Co., Ltd.): 15.0 parts by mass (iii) Proton-donating compound (polymer having an active hydrogen-containing structural unit): phenol-formaldehyde novolak resin “Sumilite Resin” (registered trademark) PR53195 (manufactured by Sumitomo Bakelite Co., Ltd.): 56.8 parts by mass (iv) Organic complex compound: Titanium-n-butoxide bis(acetylacetonate): “Nacem” (registered trademark) titanium (manufactured by Nippon Chemical Industry Co., Ltd., concentration: 73% by mass, containing 27% by mass of n-butanol as a solvent): 14.2 parts by mass (v) Tetrahydrofuran: 900 parts by mass.

[0167] The obtained waterless lithographic printing plate precursor was evaluated by the above-mentioned method, and the image reproduction rate was very good, with 100% reproduction of 20 μm × 20 μm halftone dots and 30% reproduction of 10 μm × 20 μm halftone dots. The ink repellent layer peeling resistance was also very good, with a score of 5. The reflection density difference ΔD measured using a cyan filter C The result was very good, 0.59.

[0168] [Example 22] A lithographic printing plate precursor was obtained in the same manner as in Example 3, except that the heat-sensitive layer composition solution-1 was changed to the following heat-sensitive layer composition solution-20.

[0169] <Thermosensitive layer composition solution-20> (i) Infrared absorbing dye (cyanine dye): NK5559 (manufactured by Hayashibara Co., Ltd., maximum absorption wavelength: 774 nm): 14.0 parts by mass (ii) Dye that develops color upon proton acceptance (leuco dye with a maximum absorption wavelength of 580 nm upon proton acceptance): FB-1 (3',6'-bis(diphenylamino)spiro[phthalide-3,9'-xanthene], manufactured by Fukui Yamada Chemical Industry Co., Ltd.): 17.0 parts by mass (iii) Proton-donating compound (polymer having an active hydrogen-containing structural unit): phenol-formaldehyde novolak resin “Sumilite Resin” (registered trademark) PR53195 (manufactured by Sumitomo Bakelite Co., Ltd.): 55.2 parts by mass (iv) Organic complex compound: Titanium-n-butoxide bis(acetylacetonate): “Nacem” (registered trademark) Titanium (manufactured by Nippon Chemical Industry Co., Ltd., concentration: 73% by mass, containing 27% by mass of n-butanol as a solvent): 13.8 parts by mass (v) Tetrahydrofuran: 900 parts by mass.

[0170] The obtained waterless lithographic printing plate precursor was evaluated by the above-mentioned method, and the image reproduction rate was very good, with 100% reproduction of 20 μm × 20 μm halftone dots and 30% reproduction of 10 μm × 20 μm halftone dots. The ink repellent layer peeling resistance was good, with a score of 3. The reflection density difference ΔD measured using a cyan filter C The result was very good, 0.59.

[0171] [Comparative Example 1] The following organic layer composition liquid-2 was applied to a 0.24 mm thick degreased aluminum substrate (manufactured by Mitsubishi Aluminum Corporation) and dried at 200°C for 90 seconds to provide an organic layer with a thickness of 10.0 μm. The substrate with the obtained organic layer had a reflectance of less than 50% over the entire wavelength range of 450 to 700 nm. Organic layer composition liquid-2 was obtained by mixing the following components with stirring at room temperature.

[0172] <Organic layer composition liquid-2> (i) Epoxy-phenolic resin "Kancoat" 90T-25-3094 (Kansai Paint Co., Ltd.): 100 parts by mass (ii) Dimethylformamide: 900 parts by mass.

[0173] Next, the following thermosensitive layer composition solution-21 was applied onto the organic layer and dried by heating at 140°C for 90 seconds to form a thermosensitive layer having a thickness of 1.5µm. The thermosensitive layer composition solution-21 was prepared by mixing the following components at room temperature with stirring.

[0174] <Thermosensitive layer composition solution-21> (i) Infrared absorbing dye (cyanine dye): “PROJET” 825LDI (manufactured by Avecia Co., Ltd.): 11 parts by weight (ii) Dye that develops color upon proton acceptance (leuco dye): "Crystal Violet Lactone" (3,3-bis(p-dimethylaminophenyl)-6-dimethylaminophthalide, manufactured by Yamamoto Chemical Industries, Ltd.): 5 parts by mass (iii) Proton-donating compound (polymer having an active hydrogen-containing structural unit): phenol-formaldehyde novolak resin “Sumilite Resin” (registered trademark) PR53195 (manufactured by Sumitomo Bakelite Co., Ltd.): 67.2 parts by mass (iv) Organic complex compound: Titanium-n-butoxide bis(acetylacetonate): “Nacem” (registered trademark) Titanium (manufactured by Nippon Chemical Industry Co., Ltd., concentration: 73% by mass, containing 27% by mass of n-butanol as a solvent): 16.8 parts by mass (v) Tetrahydrofuran: 900 parts by mass Next, the ink repellent layer composition solution prepared just before coating was coated on the heat-sensitive layer and heated at 140°C for 80 seconds to provide an ink repellent layer with an average thickness of 2.5 µm, thereby obtaining a waterless lithographic printing plate precursor.

[0175] When the obtained waterless planographic printing plate precursor was evaluated by the above-mentioned method, the ink repellent layer peel resistance was very good with a score of 5, but the image reproduction rate was insufficient with only 60% reproduction of 20 μm × 20 μm halftone dots. C The accuracy was low at 0.15, making the information unreadable by machine and making it unusable.

[0176] Comparative Example 2 In the process of removing the ink-repellent layer from the image area of ​​the exposed waterless lithographic printing plate precursor (I-2), "NP-1" (pretreatment liquid for negative waterless lithographic printing, manufactured by Toray Industries, Inc.) was additionally added to the pretreatment tank of the automatic developing machine, and the obtained waterless lithographic printing plate precursor was subjected to "chemical development," but was evaluated in the same manner as in Comparative Example 1.

[0177] When the obtained waterless lithographic printing plate precursor was evaluated by the above method, the image reproduction rate was 90% of the 20 μm × 20 μm halftone dots, which is no problem for practical use. However, due to the chemical development that dissolved the heat-sensitive layer, the ink repellent layer peel resistance was a low result of 0 points. Furthermore, even after chemical development, the reflection density difference ΔD measured using a cyan filter C The accuracy was low at 0.20, making the information unreadable by machine and making it unusable.

[0178] Comparative Example 3 A lithographic printing plate precursor was obtained in the same manner as in Example 3, except that the heat-sensitive layer composition solution-3 was changed to the following heat-sensitive layer composition solution-22.

[0179] <Thermosensitive layer composition solution-22> (i) Infrared absorbing dye (cyanine dye): NK5559 (manufactured by Hayashibara Co., Ltd., maximum absorption wavelength: 774 nm): 12.0 parts by mass (ii) Proton-donating compound (polymer having an active hydrogen-containing structural unit): phenol-formaldehyde novolak resin “Sumilite Resin” (registered trademark) PR53195 (manufactured by Sumitomo Bakelite Co., Ltd.): 70.4 parts by mass (iii) Organic complex compound: Titanium-n-butoxide bis(acetylacetonate): “Nacem” (registered trademark) Titanium (manufactured by Nippon Chemical Industry Co., Ltd., concentration: 73% by mass, containing 27% by mass of n-butanol as a solvent): 17.6 parts by mass (iv) Tetrahydrofuran: 900 parts by mass.

[0180] When the obtained waterless lithographic printing plate precursor was evaluated by the above method, the image reproduction rate was good with 100% reproduction of 20 μm × 20 μm halftone dots and 10% reproduction of 10 μm × 20 μm halftone dots, and the ink repellent layer peeling resistance was very good with a score of 5. However, since it does not contain a dye that develops color by accepting protons, the reflection density difference ΔD measured through a cyan filter was C The result was 0.03, which was difficult to even see, making it unusable.

[0181] The main configurations and evaluation results of each of the examples and comparative examples are shown in Tables 1 and 2.

[0182] [Table 1]

[0183] [Table 2]

Claims

1. A waterless lithographic printing plate precursor having at least a substrate, a heat-sensitive layer, and an ink-repellent layer in this order, wherein the substrate has a white layer, and the heat-sensitive layer contains at least (a) an infrared-absorbing dye having a maximum absorption wavelength of 700 to 1,000 nm, (b) a dye that develops color upon proton acceptance, and (c) a proton-donating compound, and the heat-sensitive layer contains 14 to 20% by mass of the (a) infrared-absorbing dye having a maximum absorption wavelength of 700 to 1,000 nm.

2. The waterless lithographic printing plate precursor according to claim 1 , wherein the (b) dye that develops color upon accepting a proton comprises a leuco dye.

3. 2. The waterless lithographic printing plate precursor according to claim 1, wherein the dye (b) that develops color upon accepting a proton has a maximum absorption wavelength within the range of 500 to 650 nm upon accepting a proton.

4. The waterless lithographic printing plate precursor according to claim 1 , wherein the (c) proton-donating compound comprises a polymer having an active hydrogen-containing structural unit.

5. The waterless lithographic printing plate precursor according to claim 1 , wherein the proton-donating compound (c) comprises a novolak resin.

6. A method for producing a waterless lithographic printing plate, comprising: (1) imagewise exposing the waterless lithographic printing plate precursor according to any one of claims 1 to 5 to form an image area and a non-image area.

7. 7. The method for producing a waterless lithographic printing plate according to claim 6, further comprising, after the step (1) of imagewise exposing to form image areas and non-image areas, a step (2) of removing the ink repellent layer in the image areas of the exposed waterless lithographic printing plate precursor.

8. The method for producing a waterless lithographic printing plate according to claim 7, wherein no organic solvent is used in the step (2) of removing the ink repellent layer from the image area of ​​the exposed waterless lithographic printing plate precursor.

9. After the step (1) of imagewise exposure to form image and non-image areas, the reflection density difference ΔD between the exposed and unexposed areas of the image and non-image areas of the waterless lithographic printing plate is measured from the ink repellent layer side using a spectrophotometer with a cyan filter. Ｃ The method for producing a waterless lithographic printing plate according to claim 6, wherein the σ is 0.30 or more.

10. A method for sorting waterless lithographic printing plates, comprising mechanically determining, sorting and / or classifying image patterns formed on the waterless lithographic printing plates obtained by the method of claim 6.

11. A method for producing a printed matter, comprising the steps of: depositing ink on the surface of a waterless lithographic printing plate obtained by the method of claim 6; and transferring the ink directly or via a blanket to a substrate.

12. The method for producing a printed matter according to claim 11, wherein the waterless planographic printing plates are sorted by the method according to claim 10.

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