JP2000272262A - Direct drawing type lithographic printing plate original plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve an image reproducibility while keeping an ink mileage favorable by providing a heat-sensitive layer containing a compound which can be decomposed by the action of a laser radiation, and a thermo-setting compound, and an ink repelling layer in order on a base sheet, and making the heat-sensitive layer contain an organic complex compound. SOLUTION: A heat-sensitive layer in this direct drawing type lithographic printing plate original plate wherein on a board, the heatsensitive layer and an ink repelling layer are provided in this order, is formed of a substance containing (a) a compound which can be decomposed by the action of a laser radiation, and (b) a thermo-setting compound. As the compound (a), ammonium nitrate, potassium nitrate, sodium nitrate, a carbonic ester compound or the like can be counted, and as the compound (b), a novolac resin and a resol resin, a phenol-furfural resin or the like can be counted. In addition, such a heat- sensitive layer is made to contain an organic complex compound such as an organic complex salt wherein an organic ligand is coordinated in a metal. As the ink repelling layer, a silicone rubber layer is used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a direct drawing type lithographic printing plate precursor that can be directly made by laser light.
In particular, the present invention relates to a direct drawing type waterless planographic printing plate precursor capable of printing without using dampening solution.

[0002]

2. Description of the Related Art A so-called direct drawing type plate making, in which an offset printing plate is produced directly from an original without using a plate making film, is simple, which does not require skill, rapidity in which a printing plate can be obtained in a short time, Taking advantage of features such as rationality that can be selected from various systems according to quality and cost, the company has begun to enter not only the light printing industry but also the fields of general offset printing and flexographic printing. In particular, a new type of various direct-drawing lithographic printing plates has recently been developed with the rapid progress of output systems such as a prepress system, an image setter, and a laser printer. These direct-drawing lithographic printing plates can be classified according to plate-making methods, such as a method of irradiating a laser beam, a method of writing with a thermal head, a method of partially applying a voltage with a pin electrode, an ink repellent layer or an ink-coated layer by inkjet. And the like. Above all, the method using laser light is resolution,
It is superior to other methods in terms of plate making speed and there are many types.

[0003] The printing plate using the laser light further includes:
There are two types: a photon mode by photoreaction and a heat mode in which photothermal conversion is performed to cause a thermal reaction. In particular, the heat mode method has an advantage that it can be handled in a bright room, and its usefulness has recently been reviewed due to the rapid progress of a semiconductor laser as a light source.

For example, US Pat. No. 5,339,737, US Pat. No. 5,353,705, JP-A-6-5-5
No. 5723, U.S. Pat. No. 5,378,580,
JP-A-7-164773, JP-A-6-18675
0, JP-A-7-309001, JP-A-9-
104182, JP-A-9-146264,
JP-A-9-146265, JP-A-9-23692
No. 7, JP-A-9-244228, U.S. Pat. No. 5,487,338, U.S. Pat.
No., US Pat. No. 5,649,486, US Pat. No. 5,704,291, US Pat. No. 5,570,063
No. 6 describes a direct-drawing waterless planographic printing plate precursor using a laser beam as a light source, a plate making method thereof, and the like.

[0005] The heat-sensitive layer of the printing plate precursor of this thermal destruction method is
Carbon black is mainly used as a laser light absorbing compound, and nitrocellulose is used as a thermal decomposition compound. The carbon black is converted into thermal energy by absorbing laser light, and the heat destroys the heat-sensitive layer. Finally, by removing this portion by development, the silicone rubber layer on the surface is simultaneously peeled off to form an ink-coated portion. However, this printing plate has a problem in that since the image is formed by destroying the heat-sensitive layer, the depth of the cells in the image area becomes deep, the ink deposition property at fine halftone dots is poor, and the ink mileage is poor. there were. Furthermore, in order to make the heat-sensitive layer easier to thermally destroy,
There is also a problem that the printing plate has poor press life due to the formation of a crosslinked structure. Furthermore, this printing plate has a problem that the sensitivity is low and a high laser light intensity is required to destroy the heat-sensitive layer.

Japanese Patent Application Laid-Open No. 9-239943 discloses a layer in which the adhesion to a silicone rubber layer is reduced by converting laser light into heat and a solid content of 10 to 2%.
There has been proposed a heat mode fountain solution-free lithographic printing plate precursor having an addition type silicone rubber layer containing 0% by weight of an organohydrogensiloxane. However,
In this proposal, the heat-sensitive layer is basically composed of carbon black and nitrocellulose.
Since the ink-receiving layer is a primer layer below the heat-sensitive layer, it has a problem of ink mileage and a problem of the intensity of laser light required for plate-making. Japanese Patent Application Laid-Open No. Hei 9-244228 is a proposal which enables high sensitivity by including hollow polymer fine particles in a primer layer. However, the problem of ink mileage still remained.

Japanese Unexamined Patent Publication No. 9-239942 proposes a release development type printing plate containing a substance which generates an acid in a laser sensitive layer and a polymer compound which is decomposed by the action of an acid. Since two steps, a light irradiation step and a heating step, are required, the steps are complicated, and there is a problem inherent in peeling development that reproducibility of fine halftone dots is poor.

In addition, US Pat. No. 5,379,698, JP-A-7-314934, JP-A-9-236.
No. 927 discloses a direct-drawing waterless planographic printing plate using a metal thin film as a heat-sensitive layer. Since this printing plate material has a very thin heat-sensitive layer, a very sharp image can be obtained, which is advantageous in terms of the resolution of the printing plate.
Due to poor adhesion between the substrate and the heat-sensitive layer, the heat-sensitive layer in the non-image area was peeled off during printing, and there was a problem that ink adhered and became a defect on printed matter.

[0009] In addition to the lithographic printing plate using laser light as described above, a heat-bonding direct-drawing waterless lithographic printing plate can be considered as a direct drawing type waterless lithographic printing plate. In this type of plate material, the silicone rubber layer in the laser beam irradiating portion selectively remains, and functions as a non-image portion. As plate materials of this type, for example, JP-A-9-68794, JP-A-9-80745,
JP-A-9-120157 and JP-A-9-19765
No. 9 has been proposed. JP-A-9-122015
In the plate material proposed in Japanese Patent Publication No. 7-27, the reaction of the photosensitive layer is advanced by using an acid generated by laser light irradiation as a catalyst to reproduce an image. However, after acid generation,
In order to advance the reaction, a step of heat treatment was required. Further, since the time from the generation of the acid to the heat treatment affects the image reproducibility, there is a problem that the image reproducibility becomes unstable. Plate materials proposed in JP-A-9-80745 and JP-A-9-197659 are also described.
The photosensitive layer contains a compound capable of generating an acid upon irradiation with actinic rays and a compound having a bond capable of reacting in the presence of the acid.After irradiation with laser light, the reaction proceeds using the generated acid. For this reason, there was a problem similar to the above. Further, as a fundamental problem of the thermal bonding type, since the area of the non-image area occupies 60 to 70% in the printing plate, the laser irradiation time for producing one printing plate becomes longer. As a result, there is a problem that the life of the laser is shortened.

While the development of a direct-printing printing plate is in progress, the technology of on-press plate making, in which laser irradiation and development are performed on a printing machine and printing is performed as it is, is also progressing. Japanese Patent Application Laid-Open No. Hei 9-300837 is an example, and proposes a recording plate material for on-press plate making comprising a foam layer, a silicone resin layer, and a base film layer, which foam on receiving a laser beam on a film substrate. In this plate material, the silicone rubber layer which is distorted by foaming of the foam layer is to be developed by peeling the base film, but there is a problem inherent in peeling development that reproducibility of fine halftone dots is poor. I was

[0011]

SUMMARY OF THE INVENTION The present invention solves all of the drawbacks of the prior art and provides a negative direct drawing type waterless lithographic printing plate having good image reproducibility while maintaining good ink mileage. To provide.

[0012]

That is, the present invention provides a heat sensitive layer and an ink repellent layer containing at least (a) a compound decomposable by the action of laser irradiation and (b) a thermosetting compound on a substrate. A direct-drawing lithographic printing plate precursor having at least this order, wherein the heat-sensitive layer contains an organic complex compound.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The present invention provides a direct-drawing type having, on a substrate, at least a thermosensitive layer containing (a) a compound decomposable by the action of laser irradiation, and (b) a thermosetting compound, and an ink repellent layer. A lithographic printing plate precursor, wherein the heat-sensitive layer contains an organic complex compound.

First, it is necessary that the heat-sensitive layer of the present invention has (a) a compound which can be decomposed by the action of laser irradiation. The compound that can be decomposed by the action of laser irradiation here means (1) the compound itself does not absorb laser light, but the compound is decomposed by the action of another compound that absorbs laser light; ) The compound itself may absorb laser light and decompose.

(1) The compound itself does not absorb laser light, but as a compound decomposed by the action of another compound that absorbs laser light, nitro compounds such as ammonium nitrate, potassium nitrate, sodium nitrate, carbonate compound, nitrocellulose, etc. Compounds, organic peroxides such as benzoyl peroxide and perbenzoate, inorganic peroxides,
Azo compounds such as polyvinylpyrrolidone, azodicarbonamide, azobisisobutyronitrile, nitroso compounds such as N, N'-dinitropentamethylenetetramine, azide compounds, diazo compounds or p-toluenesulfonylhydrazine, p, p'-oxybis Sulfonyl hydrazide compounds such as (benzenesulfohydrazine), and other low molecular weight and high molecular weight hydrazine derivatives. Furthermore, compounds that generate an acid or an amine under the action of laser light and compounds that decompose under the action of the generated acid or amine can also be used in the present invention. Such a compound is used in an amount of 0.1 to 70% by weight, preferably 1 to 5% by weight, based on the total solid content in the thermosensitive layer.
0% by weight, more preferably 5 to 30% by weight can be added.

As another compound that absorbs laser light, a known photothermal conversion material can be used. Specific examples of the light-heat conversion material include black pigments such as carbon black, titanium black, aniline black, and cyanine black, phthalocyanine, naphthalocyanine-based green pigments, carbon graphite, and diamine-based metal complexes.
Dithiol-based metal complex, phenolthiol-based metal complex, mercaptophenol-based metal complex, water-containing inorganic compound, copper sulfate, chromium sulfide, silicate compound, titanium oxide, vanadium oxide, manganese oxide, iron oxide, cobalt oxide, oxidation Examples include metal oxides such as tungsten, hydroxides and sulfates of these metals. Among these, carbon black is preferred from the viewpoints of light-to-heat conversion rate, economy, and handleability.

In addition, a dye that absorbs infrared or near-infrared light, particularly a dye, is preferably used as a photothermal conversion material. Particularly preferred dyes are cyanine-based, phthalocyanine-based, naphthalocyanine-based, dithiol metal complex-based, piasurenium-based, squarylium-based, croconium-based, azo-based disperse dyes, bisazo-based, bisazostilbene-based, naphthoquinone-based, anthraquinone-based, Examples include perylene, polymethine, indoaniline metal complex dyes, intermolecular CT, benzothiopyran, spiropyran, nigrosine, thioindigo, nitroso, quinoline, and fulgide dyes, particularly dyes.

The content of these light-to-heat converting substances is preferably 1 to 40% by weight, more preferably 5 to 25% by weight, based on the whole heat-sensitive layer composition. When the amount is less than 1% by weight, the effect of improving sensitivity to laser light is not seen, and
If the amount is more than 0% by weight, the printing durability of the printing plate tends to decrease.

(2) Examples of the compound that absorbs laser light and decomposes itself include the dyes and pigments that exhibit the photothermal conversion effect and that are relatively easily decomposed. Particularly preferred dyes are cyanine-based, phthalocyanine-based, naphthalocyanine-based, dithiol metal complex-based, piasurenium-based, squarylium-based, croconium-based, azo-based disperse dyes, bisazo-based, bisazostilbene-based, naphthoquinone-based, anthraquinone-based, Perylene, polymethine, indoaniline metal complex dye, intermolecular CT, benzothiopyran, spiropyran,
Nigrosine-based, thioindigo-based, nitroso-based, quinoline-based, and fulgide-based pigments, particularly dyes, may be mentioned. The content of these compounds is 1 to 4 with respect to the total heat-sensitive layer composition.
It is preferably 0% by weight, more preferably 5 to 25% by weight. When the amount is less than 1% by weight, the effect of improving the sensitivity to laser light is not seen, and when it is more than 40% by weight, the printing durability of the printing plate tends to decrease.

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

Further, the heat-sensitive layer of the present invention needs to contain (b) a thermosetting compound. Conventionally, heat-sensitive layer,
Attempts to produce a type of printing plate in which the adhesiveness between the heat-sensitive layer and the ink repellent layer is improved by laser irradiation by applying techniques such as polymerization and cross-linking to a direct drawing type lithographic printing plate having an ink repellent layer in this order Some have been done. On the other hand, in the case of a so-called negative-type printing plate precursor, in which the adhesiveness between the heat-sensitive layer and the ink repellent layer is reduced by laser irradiation, an example using a thermosetting compound is to introduce a cross-linked structure into the heat-sensitive layer at the time of manufacturing the master plate. There is only an example used for

The (b) thermosetting compound in the present invention refers to a compound in the heat-sensitive layer of a printing plate precursor, which still has the ability to be directly or indirectly thermoset by the action of laser irradiation. Say a group. Such (b)
Thermosetting compounds include phenol, cresol,
Novolak resin and resol resin, phenol / furfural resin, furan resin, unsaturated polyester, alkyd resin, urea resin, melamine resin, guanamine resin, epoxy resin, diallyl phthalate resin obtained by condensation reaction of phenols such as xylenol and formaldehyde, Examples include, but are not limited to, unsaturated polyurethane resins and polyimide precursors.

In addition to the above-mentioned resins which react themselves, a composition comprising a compound having a reactive functional group and a heat-reactive cross-linking agent is also used as (b) a thermosetting compound of the present invention. Can be used for Examples of the crosslinking agent include known polyfunctional compounds having crosslinking properties, such as polyfunctional blocked isocyanate, polyfunctional epoxy compound, polyfunctional acrylate compound, polyfunctional aldehyde, polyfunctional mercapto compound, polyfunctional alkoxysilyl compound, Examples include a functional amine compound, a polyfunctional carboxylic acid, a polyfunctional vinyl compound, a polyfunctional diazonium salt, a polyfunctional azide compound, and hydrazine.

Further, a compound which generates an acid or an amine under the action of heat and a compound which cures under the action of the generated acid or amine can be used in the present invention.

The proportion of (b) the thermosetting compound in the thermosensitive layer is preferably 10 to 10% of the total solid content of the thermosensitive layer.
It is preferably 95% by weight, more preferably 30 to 70% by weight. When the amount of the thermosetting compound is less than 10% by weight, the effect of improving the solvent resistance of the image-forming heat-sensitive layer by the heat-curing of the heat-sensitive layer may be poor. On the other hand, 95% by weight
If the amount is larger, the amount of the heat-decomposable compound or the light-to-heat conversion material is relatively reduced, which may cause a problem in image forming properties by laser irradiation.

The most important feature of the present invention is that the above-mentioned thermosensitive layer contains an organic complex compound. The organic complex compound referred to in the present invention is an organic complex salt in which an organic ligand is coordinated with a metal, an organic-inorganic complex salt in which an organic ligand and an inorganic ligand are coordinated with a metal, and an organic complex salt in which a metal and an organic molecule are oxygen. And metal alkoxides covalently bonded through Among these, metal chelate compounds in which the ligand has two or more donor atoms and forms a ring containing a metal atom are considered to be important in terms of the stability of themselves and the stability of the thermosensitive layer solution. It is preferably used in the invention.

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

As the ligand, O (oxygen atom),
Compounds having the following coordination groups having N (nitrogen atom), S (sulfur atom), etc. as donor atoms are mentioned. As specific examples of the coordinating group, those having an oxygen atom as a donor atom include -OH (alcohol, enol and phenol), -COOH (carboxylic acid), and> C = O
(Aldehydes, ketones, quinones), - O-(ether), - COOR (ester), - N = O (nitroso compounds, N- nitroso compounds), - NO ₂ (nitro compound),> NO (N- oxide), - SO ₃ H (sulfonic acid), - PO ₃ like H ₂ (phosphorous acid), a nitrogen atom as a donor atom, -NH ₂ (1 amine, amide, hydrazine),> NH (Secondary amine, hydrazine),> N- (tertiary amine), -N = N- (azo compound, heterocyclic compound), = N-OH (oxime), -NO
₂ (nitro compound), -N = 0 (nitroso compound),>
C = N- (Schiff base, heterocyclic compound),> C = NH
(Aldehydes and ketone imines, enamines), those having a sulfur atom as a donor atom include -SH (thiol), -S- (thioether),> C = S (thioketone, thioamide), and = S- (heterocycle). Compound), -C (=
O) -SH or -C (= S) -OH and -C (=
S) -SH (thiocarboxylic acid), -SCN (thiocyanate, isothiocyanate, etc.) and the like.

Further, as a part of specific examples of the ligand,
Examples include the following: (1) As aliphatic carboxylic acids, formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, maleic acid, fumaric acid, citraconic acid, itacone Acid, tricarballylic acid, propane-1,1,2,3-tetracarboxylic acid, butane-1,2,3,4-tetracarboxylic acid, glycolic acid, thioglycolic acid, lactic acid, β-hydroxypropionic acid, apple Acid, tartaric acid, citric acid, isocitric acid, alloisocitric acid, gluconic acid, pyruvic acid, oxalic acid, diglycolic acid, thiodiglycolic acid, mercaptosuccinic acid, dimercaptosuccinic acid, and the like.

(2) As aromatic carboxylic acids, aldehydes and related compounds, benzoic acid, phthalic acid, mandelic acid, salicylaldehyde, salicylic acid, 5-sulfosalicylic acid, α-carboxy-O-anisic acid, O- (carboxymethylthio) ) Benzoic acid, tropolone, methyltropolone, tyrone, chromotropic acid, etc.

(3) As amines and derivatives thereof, ethylenediamine, N-methylethylenediamine, N-ethylethylenediamine, Nn-propylethylenediamine, N-isopropylethylenediamine, N- (2-
(Hydroxyethyl) ethylenediamine, N, N-dimethylethylenediamine, N, N-diethylethylenediamine, N, N′-diethylethylenediamine, N, N′-
Di-n-propylethylenediamine, N, N'-di (2
-Hydroxyethyl) ethylenediamine, N, N,
N ', N'-tetramethylethylenediamine, diaminopropane, diaminobutane, trimethylenediamine, tetramethylenediamine, pentamethylenediamine, diaminocyclohexane, diaminocycloheptane, triethylenediamine, triaminopropane, 1,3-diamino-2- Aminomethylpropane, diethylenetriamine, 3,3′-diaminodipropylamine, triethylenetetramine, 2,2 ′, 2 ″ -triaminotriethylamine, ethanolamine, 2-methoxyethylamine, diethanolamine, triethanolamine, 2-
Mercaptoethylamine, 2-aminoethylmethyl sulfide, di (2-aminoethyl) ether, 2-amino-2'-hydroxydiethylsulfide, bis (2-aminoethyl) sulfide, pyridine, aminomethylpyridine, pyridine-2-carboxylic acid Acids, pyridinedicarboxylic acid, nicotinic hydrazide, isonicotinic hydrazide, pyridoxamine, piperidine, piperidinedicarboxylic acid, imidazole, histamine, 3-methylhistamine, and the like.

(4) As aminopolycarboxylic acids, iminodiacetic acid, iminodipropionic acid, N-methyliminodiacetic acid, N- (3,3-dimethylbutyl) iminodiacetic acid,
Phenyliminodiacetic acid, hydroxyethyliminodiacetic acid, mercaptoethyliminodiacetic acid, hydroxyethyliminodipropionic acid, hydroxypropyliminodiacetic acid, 2-hydroxycyclohexyliminodiacetic acid, methoxyethyliminodiacetic acid, methylthioethyliminodiacetic acid, methylthioethyliminodiacetic acid, 2-hydroxybenzyliminodiacetic acid, N- (carboxyphenyl) iminodiacetic acid, N- (carbamoylmethyl) iminodiacetic acid, cyanomethyliminodiacetic acid, aminoethyliminodiacetic acid, phosphonomethyliminodiacetic acid,
Sulfoethyliminodiacetic acid, sulfophenyliminodiacetic acid, nitrilotriacetic acid, carboxyethyliminodiacetic acid, carboxymethyliminodipropionic acid, nitrilotripropionic acid, N, N'-ethylenediaminediacetic acid, ethylenediamine-N, N'-dipropion acid,
N, N'-di (hydroxyethyl) ethylenediaminediacetic acid, Nn-butylethylenediaminetriacetic acid, N-
Cyclohexylethylenediaminetriacetic acid, N′-hydroxyethyl-N, N, N′-triacetic acid, benzylethylenediaminetriacetic acid, ethylenediaminetetraacetic acid,
Ethylenediamine-N, N'-diacetic acid / N, N'-dipropionic acid, ethylenediaminetetrapropionic acid,
1,2-propylenediaminetetraacetic acid, trimethylenediaminetetraacetic acid, cyclohexane-1,2-diaminetetraacetic acid, 1,3,5-triaminocyclohexanehexaacetic acid, ethyletherdiaminetetraacetic acid, diethylenetriaminepentaacetic acid, glycol etherdiamine Tetraacetic acid, trimethylenetetraaminehexaacetic acid, and the like.

(5) Examples of β-diketone, oxine, etc. include acetylacetone, trifluoroacetylacetone, hexafluoroacetylacetone, ethyl acetoacetate, benzoylacetone, benzoyltrifluoroacetone, dibenzoylmethane, floylacetone, and trifluoroacetone. , Benzoylfuroylmethane,
Thenoylacetone, trifluorotenoylacetone, furoylthenoylmethane, oxine (alias: 8-hydroxyquinoline), methyloxin, oxine-5-sulfonic acid, quinolinecarboxylic acid, 8-hydroxysinoline,
Hydroxynaphthyridine, hydroxyquinoxaline, hydroxyquinazoline, 2,2′-bipyridine, 2-
(2′-Chenyl) pyridine, 1,10-phenanthroline, methyl-1,10-phenanthroline, dimethyl-1,10-phenanthroline, dimethylglyoxime, dimethyldithiocarbamic acid, nitrosonaphthol, hydroxyflavone, 1- (2-pyridylazo )-
2-naphthol, eriochrome black A and B, eriochrome blue black B and R, phthalein complexone, and the like.

(6) Glycine, sarcosine, alanine, α-aminobutyric acid, valine, leucine, phenylalanine, tyrosine, serine, threonine, cysteine, methionine, aspartic acid, asparagine, glutamic acid, 1,2-diaminopropionic acid, Amino acids, peptides, proteins and the like such as ornithine, lysine, arginine, proline, histidine, tryptophan, N, N-bis (2-hydroxyethyl) glycine, glucylglycine, albumin, casein, myosin A, and the like. Purine, adenine, hypoxanthine, inosine, xanthosine, guanosine, adenosine-5'-phosphate,
Pyrimidines such as adenosine-5'-diphosphate, adenosine-5'-triphosphate, purine bases, nucleosides,
Nucleotides and the like. Antibiotics such as penicillin G, tetracycline, oxytetracyclone, and chlortetracyclone.

Among the organic complex compounds formed from a metal and a ligand as described above, compounds preferably used are Al, Ti, Fe, Mn, Co, Ni, Cu, Z
Complexes of metals such as n, Ge, In, Sn, Zr, and Hf with β-diketones, amines, alcohols, and carboxylic acids can be given. Further, Al, Fe (III), Ti, Z
Particularly preferred compounds of r include acetylacetonate (pentanedionate), ethylacetoacetonate (hexanedionate), propylacetoacetonate (heptanedionate), tetramethylheptanedionate, and benzoylacetonate.

Specific examples of such compounds include, for example, the following compounds, but are not limited thereto. . Aluminum tris (ethyl acetoacetate), aluminum tris (propyl acetoacetate), aluminum tris (butyl acetoacetate), aluminum tris (hexyl acetoacetate), aluminum tris (nonyl acetoacetate), aluminum tris acetylacetonate,
Aluminum bisethyl acetoacetate monoacetylacetonate, aluminum diacetylacetonate ethylacetoacetate, aluminum monoacetylacetonate bispropylacetoacetate, aluminum monoacetylacetonate bisbutylacetoacetate, aluminum monoacetylacetonate bishexylacetoacetate, aluminum mono Ethyl acetoacetate bispropyl acetoacetonate, aluminum monoethyl acetoacetate bisbutyl acetoacetonate, aluminum monoethyl acetoacetate bishexyl acetoacetonate, aluminum monoethyl acetoacetate bisnonyl acetoacetonate, aluminum dibutoxide monoacetoacetate, aluminum Dipropoxide Acetoacetate, aluminum dibutoxide monoethyl acetoacetate, aluminum -s- Butokishidobisu (ethylacetoacetate),
Aluminum di-s-butoxide ethyl acetoacetate, aluminum-9-octadecenyl acetoacetate diisopropoxide, and the like. Titanium allyl acetoacetate triisopropoxide, titanium di-n-butoxide (bis-2,4-pentanedionate), titanium diisopropoxide (bis-2,4-pentanedionate), titanium diisopropoxide bis ( Tetramethylheptanedionate), titanium diisopropoxide bis (ethyl acetoacetate), titanium methacryloxyethyl acetoacetate triisopropoxide,
Titanium oxide bis (pentanedionate) and the like. Iron (III) acetylacetonate, dibenzoylmethaneiron (II), tropolone iron, tristropolonoiron (III),
Iron hinokitiol, iron tris hinokithiolo (III), iron (III) acetoacetate, iron (III) benzoylacetonate, iron (III) trifluoropentanedionate and the like.

Further, from the viewpoint of combination with the above-mentioned thermosetting compounds, novolak resins, resol resins, phenol / furfural resins, and furan resins obtained by the condensation reaction of phenols such as phenol, cresol and xylenol with formaldehyde. And the like and the above-mentioned organic complex compounds.

Such an organic complex compound can function as a decomposable compound, as a crosslinking agent, or as a catalyst for a thermosetting reaction. Even when the organic complex compound functions as a decomposable compound or functions as a cross-linking agent, the heat-sensitive layer may have another decomposable compound as described above or another cross-linking agent as described above. Or may not be possessed. Further, among such functions, it is preferable to perform a function as a cross-linking agent or a function as a catalyst in a thermosetting reaction.

The proportion of such an organic complex compound in the thermosensitive layer is preferably from 0.5 to 50% by weight, more preferably from 3 to 30% by weight of the total solids of the thermosensitive layer. When the amount of the organic complex compound is less than 0.5% by weight, the above effects cannot be expected. On the other hand, when the amount is more than 50% by weight, problems such as a decrease in printing durability of the printing plate occur. That's why.

In addition, the heat-sensitive layer may contain a binder polymer, a surfactant and various additives.

Specific examples of the binder polymer include acrylic acid esters such as polymethyl methacrylate and polybutyl methacrylate, homopolymers and copolymers of methacrylic acid esters, and styrene monomers such as polystyrene, α-methylstyrene and hydroxystyrene. Homopolymers and copolymers, various synthetic rubbers such as isoprene and styrene-butadiene, homopolymers and copolymers of vinyl esters such as polyvinyl acetate and vinyl chloride, and polyoxides such as polyethylene oxide and polypropylene oxide (Polyethers), polyesters, polyurethanes, polyamides, cellulose derivatives such as ethyl cellulose, cellulose acetate, phenoxy resin, methylpentene resin, polyparaxylylene resin, poly Such as E two-sulfide resin, and the like.

The content of these binders is preferably from 5 to 70% by weight, more preferably from 10 to 50% by weight, based on the total heat-sensitive layer composition. When the content is less than 5%, problems are likely to occur in printing durability and coating properties of the coating solution, and when the content is more than 70% by weight, image reproducibility tends to be adversely affected.

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

When a laser is applied to the direct-drawing lithographic printing plate precursor having such a heat-sensitive layer, on the surface of the heat-sensitive layer, (a) a compound decomposed by the action of laser light is decomposed by the action of a light-to-heat conversion substance. I do. The photothermal conversion substance itself may be decomposed by the action of the laser beam. At that time, nitrogen,
It is preferable to generate a gas such as oxygen. The decomposition of such a compound and the action of gas weaken the adhesive force between the silicone rubber layer and the heat-sensitive layer.

On the other hand, in the heat-sensitive layer in the laser-irradiated portion, the curing of the thermosetting compound (b) proceeds. As a result, the solvent resistance of the heat-sensitive layer at the laser-irradiated portion is improved. As a result, a printing plate is obtained in which only the silicone rubber layer and the very surface of the heat-sensitive layer at the laser-irradiated portion have been separated by the subsequent development treatment.

In the plate thus obtained, the heat-sensitive layer in the image area has a high solvent resistance and remains, and thus has the advantage that the reproducibility of fine halftone dots and the ink mileage are good.

As the ink repellent layer of the present invention, a hydrophilic layer composed of vinyl alcohols or the like, a hydrophilic layer containing acrylic acid or acrylate, sulfonic acid or sulfonic acid salt, and the like, JP-A-8-282142, JP-A-8-282
144, JP-A-8-292558, JP-A-9-54425, and the like, a hydrophilic swelling layer, a silicone rubber layer, a layer containing a fluorine compound, and the like can be used. Is a silicone rubber layer. As the silicone rubber layer, any of an addition polymerization type and a condensation polymerization type can be used.

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

The vinyl group-containing polydimethylsiloxane is
It has a structure represented by the following general formula (I) and has a vinyl group at a molecular terminal and / or in a main chain. — (SiR ¹ R ² —O—) n— (I) (wherein, n represents an integer of 2 or more, and R ¹ and R ^{2 each} have 1 carbon atom)
~ 50 substituted or unsubstituted alkyl groups, having 2 to 2 carbon atoms
50 substituted or unsubstituted alkenyl groups, having 4 to 4 carbon atoms
At least one group selected from the group consisting of 50 substituted or unsubstituted aryl groups, which may be the same or different; It is preferable that 50% or more of R ¹ and R ² in the above formula are methyl groups from the viewpoint of ink repellency of the printing plate. Further, the molecular weight may be in the range of thousands to hundreds of thousands, but from the viewpoint of handleability, ink repellency and scratch resistance of the obtained printing plate, the weight-average molecular weight is 10,000 to 200,000, and more preferably 3 to 100,000. It is preferable to use a material of 10,000 to 150,000.

Examples of the compound having a SiH group include polysiloxanes having a SiH group in a molecular chain or at a terminal, and include, for example, compounds represented by the following general formulas (II) to (V). be able to.

[0051]

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(In the formula, n is an integer of 1 or more, and m is an integer of 1 or more.) The amount of SiH groups in the compound having SiH groups is 2 or more, and more preferably 3 or more. Is preferred. The amount of the compound having a SiH group is preferably 3 to 20% by weight, more preferably 5 to 15% by weight of the total composition of the silicone rubber layer. In terms of the quantitative ratio with polydimethylsiloxane, SiH
The molar ratio of group / carbon double bond of polydimethylsiloxane is preferably from 1.5 to 30, and more preferably from 10 to 20. If the molar ratio is less than 1.5, the curing of the silicone rubber layer may be insufficient, and if it is greater than 30, the physical properties of the rubber become brittle and adversely affect the scratch resistance of the printing plate. It is because it becomes easy to give.

Examples of the reaction inhibitor include a nitrogen-containing compound, a phosphorus compound, and an unsaturated alcohol, and an alcohol having an acetylene group is preferably used.
The preferable addition amount of the reaction inhibitor is 0.01 to 10% by weight, more preferably 1 to 5% by weight in the silicone rubber composition.
%.

The curing catalyst is a Group III transition metal compound, preferably a platinum compound. Specifically, platinum alone, platinum chloride, chloroplatinic acid, olefin-coordinated platinum, an alcohol-modified platinum complex, platinum methyl A vinyl polysiloxane complex can be given as an example. The amount of such a curing catalyst is 0.01 to 20 wt%, preferably 0.1 to 10 wt%, as a solid content in the silicone rubber layer.
%. The amount of catalyst to be added is 0.01w
If the amount is less than t%, curing of the silicone rubber layer becomes insufficient, and further, a problem may occur in adhesion to the heat-sensitive layer. On the other hand, if it is more than 20 wt%, the pot life of the silicone rubber layer solution is adversely affected. In terms of the amount of metal such as platinum in the silicone rubber layer composition, it is preferably 10 to 1000 ppm, and more preferably 100 to 500 ppm.

In addition to these compositions, a condensation-type silicone rubber layer composition such as a hydroxyl group-containing organopolysiloxane or a hydrolyzable functional group-containing silane (or siloxane), and silica for the purpose of improving rubber strength. Or a known silane coupling agent, a titanate-based coupling agent, an aluminum-based coupling agent or the like for the purpose of improving adhesiveness. As the silane coupling agent, alkoxysilanes, acetoxysilanes, ketoximine silanes and the like are preferable, and those having a vinyl group and ketoximine silanes are particularly preferable.

The components constituting the condensation-polymerized silicone rubber layer include a hydroxyl group-containing polydimethylsiloxane, a crosslinking agent (deacetic acid type, deoxime type, dealcohol type, deamine type, deacetone type, deamido type). , Deaminoxy type, etc.), and a curing catalyst.

The hydroxyl group-containing polydimethylsiloxane also has a structure represented by the above general formula (I). The hydroxyl group can be located at the molecular terminal and / or in the main chain, but those preferably used are those having a hydroxyl group at the molecular weight terminal.

As for R ¹ and R ² in the general formula, it is similarly preferable that 50% or more of the whole is a methyl group from the viewpoint of the ink repellency of the printing plate. As the molecular weight, those having a molecular weight of several thousand to several hundred thousand can be used, and from the viewpoint of handleability, ink repellency and scratch resistance of the obtained printing plate, the weight average molecular weight is 10,000 to 200,000, and further 30,000 to It is preferable to use 150,000.

Examples of the crosslinking agent used in the condensation polymerization type silicone rubber layer include acetoxysilanes, alkoxysilanes, ketoximine silanes, and allyloxysilanes represented by the following general formula (II). Can be. (R ² ) _4-n SiX _n (VI) (wherein, n represents an integer of 2 to 4, and R ² represents a substituted or unsubstituted alkyl group, alkenyl group, aryl group having 1 or more carbon atoms, or X represents a combined group of
Is a functional group selected from a halogen atom, an alkoxy group, an acyloxy group, a ketoximine group, an aminooxy group, an amide group, and an alkenyloxy group. ) In the above formula,
The number n of the hydrolyzable groups is preferably 3 or 4.

Specific compounds include methyltriacetoxysilane, ethyltriacetoxysilane, vinyltriacetoxysilane, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, tetraethoxysilane, tetraethoxysilane Propoxysilane, vinyltrimethoxysilane, vinyltriphenoxysilane, vinyltriethoxysilane,
Allyltriethoxysilane, vinyltriisopropoxysilane, vinyltrisisopropenoxysilane, vinylmethylbis (methylethylketoximine) silane, methyltri (methylethylketoximine) silane, vinyltri (methylethylketoximine) silane, tetra (methylethylketoximine) Examples include, but are not limited to, silane, diisopropenoxydimethylsilane, triisopropenoxymethylsilane, and tetraallyloxysilane.

Among these, acetoxysilanes, from the viewpoints of the curing speed of the silicone rubber layer and the handling properties,
Ketoximine silanes are preferred.

The amount of the crosslinking agent represented by the general formula (VI) is 1.5 to 20 wt% of the total composition of the silicone rubber layer.
%, More preferably 3 to 10 w
t%. Speaking of the quantitative ratio with polydimethylsiloxane, the molar ratio of functional group X / hydroxyl group of polydimethylsiloxane is preferably 1.5 to 10.0.
If the molar ratio is less than 1.5, gelation of the silicone rubber layer solution is likely to occur. Conversely, if the molar ratio is greater than 10.0, the physical properties of the rubber become fragile and the printing plate has poor scratch resistance. This is because it is likely to have an adverse effect.

As curing catalysts, acetic acid, propionic acid,
Organic carboxylic acids such as maleic acid; acids such as toluenesulfonic acid and boric acid; alkalis such as potassium hydroxide, sodium hydroxide and lithium hydroxide; amines; metal alkoxides such as titanium tetrapropoxide and titanium tetrabutoxide; and iron Metal diketenates such as acetylacetonate and titanium acetylacetonate dipropoxide, and organic acid salts of metals can be given. Among them, it is preferable to add an organic acid salt of a metal, particularly preferably an organic acid salt of a metal selected from tin, lead, zinc, iron, cobalt, calcium, and manganese. Specific examples of such compounds include dibutyltin diacetate, dibutyltin dioctate, dibutyltin dilaurate, zinc octylate, and iron octylate. The amount of such a curing catalyst is 0.01 to 20 wt% as a solid content in the silicone rubber layer,
Preferably, it is 0.1 to 10 wt%.
If the amount of the catalyst to be added is less than 0.01% by weight, the curing of the silicone rubber layer becomes insufficient, and a problem may be caused in the adhesion to the heat-sensitive layer. The other 2
If the amount is more than 0 wt%, the pot life of the silicone rubber layer solution is adversely affected.

Further, in addition to these compositions, a known filler such as silica and a known silane coupling agent may be contained for the purpose of improving rubber strength. The thickness of these silicone rubber layers is preferably 0.5 to 20 g / m ² , more preferably 1 to 4 g / m ² . When the film thickness is smaller than 0.5 g / m ^2, the ink repellency, scratch resistance and printing durability of the printing plate tend to decrease, and
When it is larger than m ² , not only is it disadvantageous from an economic viewpoint, but also there is a problem that developability and ink mileage are deteriorated.

The direct drawing type lithographic printing plate precursor may be laminated with a protective film or formed with a protective layer for the purpose of protecting the ink repellent layer. Examples of the protective film include a polyester film, a polypropylene film, a polyvinyl alcohol film, a saponified ethylene vinyl acetate copolymer film, and a polyvinylidene chloride film. The thus obtained direct drawing type lithographic printing plate precursor is exposed imagewise with a laser beam after the protective film is peeled off or from above the protective film.

The laser light source used in the plate-making exposure step of the present invention has an emission wavelength range of 300 nm to 1500.
Among them, a semiconductor laser or a YAG laser having an emission wavelength region near the near infrared region is preferably used. Specifically, from the viewpoint of handleability of the plate material in the light room, 780 n
Laser beams having wavelengths of m, 830 nm, and 1064 nm are preferably used for plate making.

The original plate after laser irradiation is developed by a friction treatment in the presence or absence of water or an organic solvent. The rubbing treatment is performed by wiping the plate surface with a non-woven fabric, absorbent cotton, cloth, sponge, or the like impregnated with a developer, or by rubbing the plate surface with a rotating brush while showering with tap water after pre-treating the plate surface with the following developer. be able to.

Examples of the developing solution used in the development treatment include water and water obtained by adding a surfactant to water,
Further, a polar solvent such as alcohol, ketone, ester or carboxylic acid is added to water, or at least one polar solvent is added to a solvent composed of at least one kind of aliphatic hydrocarbons or aromatic hydrocarbons. Or a polar solvent is used. A known surfactant can be freely added to the above-mentioned developer composition. Further, an alkali agent such as sodium carbonate, monoethanolamine, diethanolamine, diglycolamine, monoglycolamine, sodium silicate, potassium hydroxide, sodium borate and the like can be added. Among these, water or a mixture of water and a surfactant is preferable.

[0069]

The present invention will be described in more detail with reference to the following examples. Example 1 A solution having the following composition was applied on a degreased aluminum plate having a thickness of 0.24 mm, dried at 200 ° C. for 2 minutes, and provided with a primer layer of 3 g / m ² . <Primer 1> (a) Epoxy / phenol resin “Cancoat” 90T
-25-3094 (manufactured by Kansai Paint Co., Ltd.): 15 parts by weight (b) Dimethylformamide: 85 parts by weight The following heat-sensitive layer was coated on this primer layer. The dry film thickness is 1.0 g / m ² and the heat treatment is 100 ° C. × 1 minute. <Thermal layer 1> (a) Carbon black (# 30 manufactured by Mitsubishi Chemical Corporation):
15 parts by weight (b) Nitrocellulose (viscosity 1/2 second, nitrogen content 1
1.0%, “Bergerac NC”) (manufactured by SNP Japan Ltd.): 15 parts by weight (c) Iron (III) acetylacetonate (manufactured by Hanoi Chemicals): 10 parts by weight Part (d) "Sumilac" PC-1 (resole resin, manufactured by Sumitomo Durres Co., Ltd.): 60 parts by weight (g) tetrahydrofuran: 100 parts by weight (h) dimethylformamide: 100 parts by weight (i) methyl ethyl ketone: 700 parts by weight Department.

Then, the following silicone rubber layer was dried at a thickness of 2.0 μm under the drying conditions of 120 ° C. × 1 minute (moist heat drying).
It was painted as. <Silicone Rubber Layer 1> (a) Polydimethylsiloxane (molecular weight of about 50,000
0, both terminal hydroxyl groups): 100 parts by weight (b) Vinyl tris (methylethyl ketoxime) silane: 8 parts by weight (c) Dibutyltin diacetate: 0.5 parts by weight (d) 3-aminopropyltriethoxysilane: 0. 5
Parts by weight (e) "Isopar-E" (isoparaffinic hydrocarbon,
Exxon Chemical Co., Ltd.): 1400 parts by weight.

An 8 μm thick polypropylene film “Trefane” BO was applied to the laminate obtained as described above.
(Manufactured by Toray Industries, Inc.) was laminated using a calendar roller to obtain a direct-drawing waterless planographic printing plate precursor.

Thereafter, this printing plate precursor was placed in FX400-A
P (plate making machine, manufactured by Toray Engineering Co., Ltd.) and a semiconductor laser (wavelength 830 nm, beam diameter 20)
μm) and an irradiation energy of 30 at an exposure time of 10 μs.
Exposure was performed at 0 mJ / cm ² . The printing plate after exposure is specifically gray only in the heat-sensitive layer of the laser irradiation part,
It was speculated that some change had occurred.

Subsequently, the product was immersed in “PP-F” (a pretreatment liquid for a lithographic positive mold without water, manufactured by Toray Industries, Inc.) for 1 minute, and then water-containing “Hize Gauze” (manufactured by Asahi Chemical Industry Co., Ltd.) ) To obtain a negative waterless planographic printing plate from which only the silicone rubber layer in the portion irradiated with the laser beam was removed. At that time, the presence of fine powder presumed to be a decomposition product by laser irradiation was observed on the surface of the heat-sensitive layer in the laser irradiation part.

Further, the obtained printing plate was attached to a sheet-fed offset printing machine “HAMADA RS34L” (manufactured by Hamada Printing Machinery Co., Ltd.), and waterless lithographic ink (Dryocolor NSI, Ai, Dainippon Ink and Chemicals, Ltd.) 22.5% when printed on high-quality paper (62.5 kg / chrysanthemum) using
Printed matter that faithfully reproduced the image up to 98% was obtained.

Comparative Example 1 A printing plate was prepared in the same manner as in Example 1, except that the heat-sensitive layer composition was changed as follows. When evaluated in the same manner as in Example 1, the silicone rubber layer was peeled off over the entire surface. Therefore,
When the development was carried out by carefully rubbing with "Heisegase", a negative waterless planographic printing plate was obtained in which the heat-sensitive layer was removed together with the silicone rubber layer at the portion irradiated with the laser beam. When printing was performed using the obtained printing plate,
5% to 9%
Only prints with a reproducibility of up to 7% were obtained. <Thermal layer 2> (a) Carbon black (# 30 manufactured by Mitsubishi Chemical Corporation):
15 parts by weight (b) Nitrocellulose (viscosity 1/2 second, nitrogen content 1
1.0%, "Bergerac NC") (manufactured by SNP Japan Ltd.): 15 parts by weight (c) "Sumilac" PC-1 (resole resin, manufactured by Sumitomo Durres): 60 parts by weight (d) "SAMPLEN" IB-114B (hydroxyl-containing polyurethane resin manufactured by Sanyo Chemical Industries, Ltd.): 10 parts by weight (e) Tetrahydrofuran: 100 parts by weight (f) Dimethylformamide: 100 parts by weight (g) Methyl ethyl ketone : 700 parts by weight The absence of the organic complex compound in the heat-sensitive layer caused insufficient curing inside the heat-sensitive layer of the laser-irradiated portion, resulting in a deep printing plate cell and poor highlight reproducibility. Conceivable.

Example 2 A solution having the following composition was applied on a degreased aluminum plate having a thickness of 0.24 mm,
After drying at 2 ° C. for 2 minutes, a heat-sensitive layer of 1 g / m ² was provided. <Thermal Sensitive Layer 2> (a) "KAYASORB" IR-820B (manufactured by Nippon Kayaku Co., Ltd.): 10 parts by weight (b) "Nasem Titanium" (manufactured by Nippon Chemical Industry Co., Ltd., titanium di-n-butoxide (bis- 2,4-pentanedionate)): 10 parts by weight (c) "Sumilite Resin" PR50622 (phenol novolak resin, manufactured by Sumitomo Durez Co., Ltd.): 70 parts by weight (d) Tetrahydrofuran: 550 parts by weight (e) dimethyl Formamide: 350 parts by weight.

Next, the following silicone rubber layer was applied at a dry film thickness of 2.0 μm under the drying conditions of 120 ° C. for 1 minute. <Silicone rubber layer 2> (a) α, ω-divinylpolydimethylsiloxane (molecular weight of about 60,000): 100 parts by weight (b) HMS-501 (manufactured by Chisso Corporation at both ends methyl (methyl hydrogen siloxane) ( Dimethylsiloxane) copolymer SiH group number / molecular weight = 0.69 mol /
g): 7 parts by weight (c) "BY24-808" (manufactured by Toray Dow Corning Silicone Co., Ltd., reaction inhibitor): 3 parts by weight (d) "SRX-212" (manufactured by Toray Dow Corning Silicone Co., Ltd.) Platinum catalyst): 5 parts by weight (e) Vinyl tri (methyl ethyl ketoxime) silane: 3 parts by weight (f) "ISOPAR" E (manufactured by Esso Chemical Co., Ltd.): 10
00 parts by weight.

The printing plate precursor obtained as described above was irradiated with laser in the same manner as in Example 1. The irradiation energy was 250 mJ / cm ² . The surface of the heat-sensitive layer in the laser-irradiated part was white, which suggested that the components of the heat-sensitive layer were decomposed by the action of the laser irradiation.

Subsequently, an automatic developing device TWL manufactured by Toray Industries, Inc.
When development was carried out according to -650, the heat-sensitive layer in the portion irradiated with the laser beam remained, and a negative waterless planographic plate from which the silicone rubber layer had been removed was obtained. At the time of development, "PP-F" manufactured by Toray Industries, Inc. was used as a pretreatment liquid, and water was used as a developer. Similarly, when printing was performed using the obtained printing plate, a printed matter in which an image was faithfully reproduced from 1% to 99% was obtained.

When the heat-sensitive layer before and after laser irradiation was analyzed using an infrared absorption spectrum, it was found that “KAYASOR” including 1080 cm ⁻¹ was detected by laser light irradiation.
B "Reduced absorption due to IR-820B, 1028c
m- ¹ and other constituents of "Nursem Titanium" 2,
4-pentanedionate ring (acetylacetonate ring)
A decrease in the absorption due to. From this analysis result, it was confirmed that a decomposition product was generated on the surface of the heat-sensitive layer by laser irradiation.

Further, as a result of thermal analysis of the printing plate precursor using TG-GC / MS, it was confirmed that acetylacetone emerged from the thermosensitive layer with a peak at 150 ° C. Is the absorption derived from the acetylacetonate ring inside the thermosensitive layer (1028
cm ^-1 ), an increase in absorption at 1117 cm ^-1 derived from -CH ₂ -O-CH _2-, such as a dehydration condensation reaction of a novolak resin, and an increase in absorption at 723 cm ^-1. (Ring: increase of 880 cm ^-1 ) was confirmed, and it was confirmed that the curing reaction proceeded.

From the results of these analyses, in this example, “Nasem titanium” and “Sumilite resin” PR5
It was confirmed that 0622 (phenol novolak resin) worked as a thermosetting compound.

[Examples 3 to 8] From the composition of the heat-sensitive layer in Example 2, a printing plate precursor was prepared using an organic complex compound shown in Table 1 in place of (b) "Nersem titanium".
The obtained printing plate precursor was subjected to laser irradiation and development in exactly the same manner as in Example 2, and a negative type waterless lithographic plate in which the silicone rubber layer was removed from the portion irradiated with the laser beam from any of the plate precursors A printing plate was obtained. Further, when the print evaluation was performed in the same manner as in Example 2, as shown in Table 1, good prints could be obtained from any of them.

[0084]

[Table 1]

[0085]

According to the present invention, a negative type direct drawing type lithographic printing plate having good image reproducibility can be obtained.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H096 AA13 BA01 BA20 EA04 EA23 GA43 2H114 AA05 AA22 AA24 AA27 AA28 BA05 DA03 DA04 DA26 DA33 DA43 DA47 DA59 DA62 DA73 DA78 EA05 FA16 GA32 GA34 GA38

Claims (2)

[Claims] 1. A direct drawing type lithographic printing plate having at least a (a) a thermosensitive layer containing a compound decomposable by the action of laser irradiation and (b) a thermosetting layer containing a thermosetting compound and an ink repellent layer on a substrate in this order. A lithographic printing plate precursor, comprising: a heat-sensitive layer containing an organic complex compound. 2. The lithographic printing plate precursor according to claim 1, wherein the ink repellent layer is a silicone rubber layer.