JP3533749B2 - Direct drawing type waterless planographic printing plate precursor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waterless planographic printing plate precursor which can be printed without using fountain solution, and more particularly to a direct drawing type waterless planographic printing plate precursor which can be directly plate-made by a laser beam. It is a thing.

[0002]

2. Description of the Related Art A lithographic printing plate is disclosed in JP-A-61-51.
No. 142, JP-A-61-267043 and the like are generally PS plates for printing using fountain solution. This PS plate is obtained by polishing or anodizing the surface of a metal plate (aluminum, zinc, etc.) of a support to impart hydrophilicity, and applying a photosensitive resin to the plate.
An image is formed by developing. That is, printing can be performed by holding the dampening water in the portion where the photosensitive resin is removed and repelling the oil-based ink.

However, printing with such a PS plate causes difficulty in adjusting the amount of dampening water, elongation of paper due to water, etc.
It has various problems.

As a solution to these various problems, a waterless planographic printing plate has been proposed in Japanese Patent Publication No. 54-26923. The waterless lithographic printing plate can perform lithographic printing without using dampening water by utilizing the ink resilience of the uppermost silicone rubber layer. The image formation of such a waterless planographic printing plate is carried out by exposing the printing plate precursor through a positive or negative film.

[0005]

However, when a film is used for image formation as described above, there is a problem that it takes time from the preparation of the original document to the plate making because of the step of producing the film.

Therefore, several methods have been proposed for obtaining a waterless planographic printing plate without using a film, that is, a so-called direct drawing type waterless planographic printing plate, by directly outputting image data on the printing plate.

For example, a waterless planographic printing plate is prepared by jetting an ink repellent substance with an ink jet described in JP-A-50-83104, JP-A-51-84303, and JP-A-56-113456 to heat-cur it. A method for obtaining a printing plate and a method for obtaining a waterless planographic printing plate by spraying an ink receptive substance onto a silicone rubber layer described in JP-A-60-192693 are known. But,
These plate materials have not been put into practical use yet because they have a problem of low printing durability due to poor adhesion of silicone rubber, which is an ink repellent material.

Further, there is known a method of obtaining a waterless planographic printing plate by removing the silicone layer on the surface by electric discharge breakdown as described in Japanese Patent Publication No. 57-58296 and Japanese Patent Application Laid-Open No. 4-313890. There is a problem in that the resolution cannot be improved due to the size of the electrodes.

Further, as a method for solving the above-mentioned problems, JP-A-50-158405 and JP-A-6-55523.
No. 6-199064, US Pat. No. 5,339,737.
No., USP5353705, EP0573091,
EP0580393 describes a direct drawing type waterless planographic printing plate precursor using a laser beam as a light source.

The laser-sensitive layer of these printing plate precursors uses carbon black as a laser light absorbing compound, and this absorbs the laser light to be converted into heat energy. That is, the laser-sensitive layer is a heat-sensitive layer, the heat destroys the laser-sensitive layer, and by removing this portion by development, the silicone layer on the surface is peeled off to form an ink inking portion.

By using this method, the resolution is certainly improved as compared with the discharge breakdown method, but since these plate making methods are methods of thermally destroying the heat sensitive layer, other photopolymers and silver salt type direct drawing type are used. There was a problem that the sensitivity was low as compared with the planographic material.

One of the causes is that the irradiated laser beam is not efficiently absorbed by the heat-sensitive destruction layer. This is because carbon black has a particle size of 10 to 100 nm.
Since the particles are in the form of particles, a gap is generated between the particles in the range of the desirable addition amount, and particularly when the heat-sensitive destruction layer is made thin, the irradiated laser light is not efficiently absorbed.

Therefore, in order to efficiently absorb the laser light, the present inventors include a dye having a maximum absorption in the vicinity of the oscillation wavelength of the laser light or a black dye in the heat-sensitive destruction layer. It was found that the dye disperses at the molecular level, and as a result, the laser light can be efficiently absorbed and the sensitivity of the printing plate can be improved.

At this time, it was also found that the heat-decomposable compound in the heat-sensitive destructive layer is more likely to exhibit the sensitivity improving effect if it is dyed with a dye in advance.

Here, the term "sensitivity" refers to the minimum exposure energy required to form dots, and the minimum exposure time is actually measured.

Accordingly, an object of the present invention is to provide a printing plate having improved sensitivity in the conventional direct-writing type waterless lithographic printing plate of the thermal destruction type.

[0017]

In order to achieve the above object, the present invention has the following constitution.

1. In a direct drawing type waterless lithographic printing plate precursor having at least a heat sensitive destruction layer on a substrate, the heat sensitive destruction layer contains a thermally decomposable compound dyed with a dye ,
The heat-decomposable compound is a dye before the preparation of the heat-sensitive destruction layer.
A direct drawing type waterless planographic printing plate precursor characterized by being dyed with .

2. The direct drawing type waterless lithographic printing plate precursor as described in 1 above, wherein the dye is an infrared or near infrared absorbing dye.

3. The direct-drawing waterless planographic printing plate precursor as described in 1 above, wherein the dye is a black dye.

4. The directly imageable waterless planographic printing plate precursor as described in 1 above, wherein the thermally decomposable compound is a cellulose derivative.

5. The directly imageable waterless planographic printing plate precursor as described in 1 above, wherein the thermally decomposable compound is nitrocellulose.

6. The direct drawing type waterless planographic printing plate precursor as described in 1 above, wherein a silicone rubber layer is laminated on the heat-sensitive destruction layer.

7. 7. A waterless planographic printing plate obtained by selectively exposing and developing the direct drawing type waterless planographic printing plate precursor described in any one of 1 to 6 above.

The direct drawing type waterless planographic printing plate precursor of the invention will be described.

The direct drawing type means that a negative or positive film is not used at the time of exposure, directly from a recording head on a printing plate,
It means that an image can be formed.

As the substrate of the direct drawing type waterless planographic printing plate precursor of the present invention, a dimensionally stable plate is used. Examples of such a dimensionally stable plate-like material include those conventionally used as a substrate for a printing plate, and they can be preferably used. Examples of such a substrate include paper, paper laminated with plastic (eg, polyethylene, polypropylene, polystyrene, etc.), metal plate such as aluminum (including aluminum alloy), zinc, copper, etc., such as cellulose, carboxy. Plastic films such as methyl cellulose, cellulose acetate, polyethylene terephthalate, polyethylene, polyester, polyamide, polyimide, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc., and the above-mentioned metals are laminated. Alternatively, it includes vapor-deposited paper or plastic film. Among these substrates, the aluminum plate is particularly preferable because it is remarkably dimensionally stable and inexpensive.
A polyethylene terephthalate film used as a substrate for light printing is also preferably used.

The direct drawing type waterless planographic printing plate precursor of the invention may be provided with a primer layer in order to strengthen the adhesion between the substrate and the heat-sensitive destruction layer. The primer layer must meet the following conditions. That is, the substrate and the heat-sensitive destructive layer are well adhered to each other, are stable over time, and have good solvent resistance to the solvent of the developing solution. Also,
The primer layer also has a role as an insulating layer when the thermal destruction layer causes a thermal destruction reaction. In order to satisfy such conditions, in addition to those containing an epoxy resin as shown in Japanese Patent Publication No. 61-54219, polyurethane resin, phenol resin, acrylic resin, alkyd resin,
Polyester resin, polyamide resin, melamine resin, urea resin, benzoguanamine resin, vinyl chloride-vinyl acetate copolymer, vinyl chloride resin, polyvinyl butyral resin, ethylene-vinyl acetate copolymer, polycarbonate resin, polyacrylonitrile-butadiene copolymer , Polyether resin, polyether sulfone resin, milk casein, gelatin and the like can be used. These resins may be used alone or in combination of two or more.

Further, a composition obtained by photo-curing a composition similar to the heat-sensitive destructive layer may be used.

Of these, polyurethane resins, polyester resins, acrylic resins, epoxy resins, urea resins and the like are preferably used alone or in admixture of two or more.

As the anchor agent constituting the primer layer, a known adhesive such as a silane coupling agent can be used, and organic titanate is also effective.

It is also optional to add a surfactant for the purpose of improving the coatability.

Further, in the exposed portion of the waterless planographic printing plate, the primer layer is exposed and becomes the image area. Therefore, additives such as dyes and pigments are contained in the primer layer to improve the plate inspection property. Preferably. In this case, any dyes and pigments can be used as long as they have a hue different from that of the photosensitive layer, but green, blue and violet dyes and pigments or white pigments are preferable.

The composition for forming the above-mentioned primer layer is prepared as a composition solution by dissolving it in a suitable organic solvent such as DMF, methyl ethyl ketone, methyl isobutyl ketone, dioxane or the like. A primer layer is formed by uniformly applying such a composition solution on a substrate and heating at a required temperature for a required time.

The thickness of the primer layer is 0.5 as a coating layer.
~ 50 g / m ² is preferred, more preferably 1-10 g
/ M ² . When the thickness is less than 0.5 g / m ² , the effect of blocking morphological defects and chemical adverse effects on the surface of the substrate is reduced, and when it is more than 50 g / m ^2, it is disadvantageous from the economical point of view, so the above range is preferable.

The heat-sensitive destruction layer of the direct drawing type waterless lithographic printing plate precursor according to the invention is a layer which is partially or wholly decomposed by heat. Laser light can be preferably used for the recording head, but at this time, it is necessary to contain a compound capable of efficiently converting the laser light into heat. The present invention is characterized by using a dye as such a compound. Preferably, it is a dye having a maximum absorption wavelength in the range of 400 nm to 1200 nm, and specifically, it is a dye for electronics, such as cyanine dye, phthalocyanine dye, phthalocyanine metal complex dye, naphthalocyanine dye, naphthalocyanine metal complex. System, dithiol metal complex system, naphthoquinone system, anthraquinone system, indophenol system, indoaniline system, pyrilium system, thiopyrylium system, squarylium system, croconium system, diphenylmethane system, triphenylmethane system, triphenylmethanephthalide system, triaryl Methane, phenothiazine, phenoxazine, fluorane, thiofluorane, xanthene, indolylphthalide, spiropyran, azaphthalide, chromenopyrazole, leuco auramine, loader Lactam, quinazoline, diazaxanthene, bislactone, fluorenone, monoazo, ketonimine, diazo, methine, oxazine, nigrosine, bisazo, bisazostilbene, bisazooxadiazole, Bisazofluorenone type, bisazohydroxyperinone type,
Azochrome complex salt type, trisazotriphenylamine type,
Thioindigo-based, perylene-based, nitroso-based, 1: 2 type metal complex salt-based, intermolecular CT-based, quinoline-based, quinophthalone-based, fulgide-based acid dyes, basic dyes, pigments, oil-soluble dyes, and triphenylmethane-based dyes Leuco dye, cationic dye, azo disperse dye, benzothiopyran spiropyran, 3,9-dibromoanthanthrone, indanthrone, phenolphthalein, sulfophthalein, ethyl violet, methyl orange, fluorescein, methyl viologen, methylene blue, Jim Ross betaine etc. are mentioned.

Further, couplers for color photography, azo dye developers, anthraquinone dye developers, dye releasing agents, bisazo dyes, erythrosine, rose bengal, eosin Y, rhodamine B, methylene blue and thionine can be used.

Further, food and cosmetic dyes can also be used. Specifically, Resol Rubin B, Lake Red C, Resol Red, Tetrachrome Tetrachrome Tetrabromo Fluorescein, Brilliant Requi Red R, Deep Maroon, Toluidine Red, Tetra Brom Fluorescein, Herringdon Pink CN, Fast Acid Magenta, Permanent Red, Zibrom. Cluorescein, permanent orange, diiodofluorescein, uranine, quinoline yellow WS, alizanin cyanine green F, quinizarin green SS, pyranine conc, light green SF yellow, patent blue NA, calbaslen blue, alphazurin FG, resorcin Brown, Alizurin Purple SS, Violamine R, Brilliant Fast Scarlet, Permanent Red F5R, Ponceau SX, Fast Red S, Il Orange SS, Pola Yellow 5G, Fast Light Yellow 3G, Naphthol Green B, Guinea Green B, Sudan Blue B, Alizulol Purple, Naphthol Blue Black, Crocin, Gardenia Blue Dye, Paprika Dye, Chlorophyll, Carthamin, Safflower Yellow Dye, Beet Red, laccaic acid, madder pigment, spirulina pigment, cocoa pigment and the like can be mentioned.

Acid First Black, Acid Black, Direct Black, Basic Black, Modant Black, Azoic Black, Bat Black, Disperse Black, Solvent Black, Reactive Black, Chrome Black, etc. The black dye of can also be used.

Here, the black dye includes all dyes named black in the color index name.

Direct dyes such as Direct First Yellow GC, Direct First Orange, Direct First Scarlet 4BS, Chloranthine First Red 6BLL, Direct Sky Blue 5B,
Serious Supra Blue BRR, Direct First Turquoise Blue GL, Direct Copper Blue 2
B, Coplantin Green G, Direct First Black D, Milling Yellow O, Acid Brilliant Scarlet 3R, Acid Violet 5B, Alizanin Direct Blue A2G, Acid Cyanine 6
B, Acid Cyanine 5R, Acid Cyanine Green G, Milling Brown 3G, Cation Yellow 3
G, Cation Golden Yellow GL, Cation Flavin 10G, Cation Yellow 5GL, Cation Orange R, Cation Brown 3GL, Cation Pink FG, Cation Brilliant Red 4G, Cation Red GT
L, cation red BLH, cation red 6B, cation red 5B, cation blue 5G, cation blue GRL, cation blue GLH, cation navy blue RLH, alizanin, chrome first blue MB,
Chrome First Brown KE, Fast Scarlet G, Variamine Blue B, Naphthol AS, Naphthol AS-G, Vat Yellow GCN, Vat Orange RR
TS, Indigo, Batblue RSN, Batblue B
C, Bat Brilliant FTB, Bat Olive Green B, Bat Olive T, Bat Brown R, Bat Gray M, Disperse Fast Yellow G, Disperse Pink RF, Disperse Blue FFR, Disperse Blue Green B, Disperse Yellow 5G, Disperse Golden Yellow GG, Disperse Yellow RL, Disperse Yellow 3G, Disperse Orange B, Disperse Yellow Brown 2R, Disperse Fast Rubin 3B, Disperse Red FB,
Disperse Red FL, Disperse Red GFL,
Disperse Brilliant Pink REL, Disperse Violet HFRL, Disperse Blue FB, Disperse Star Cois Blue GL, Disperse Navy Blue 2GL, Disperse Developer, Solvent Orange G, Solvent First Yellow 3RE,
Solvent First Red B, Solvent First Blue HFL, Reactive Yellow 3G, Reactive Orange 2R, Reactive Red 3B, Reactive Scarlet 2G, Reactive Blue 3G, Reactive Blue R, Reactive Blue BR, Reactive Turquoise GF, Reactive Brilliant Blue R
Etc. are also used.

Of these, dyes for electronics and recording, which have a maximum absorption wavelength of 700 nm to 90 nm
Cyanine dye, azurenium dye, squarylium dye, croconium dye, azo disperse dye, bisazostilbene dye, naphthoquinone dye, anthraquinone dye, perylene dye, phthalocyanine dye, na in the range of 0 nm. Infrared or near infrared absorbing dyes such as phthalocyanine metal complex dyes, dithiol nickel complex dyes, indoaniline metal complex dyes, intermolecular CT dyes, and benzothiopyran spiropyrans are more preferable.

Acid First Black, Acid Black, Direct Black, Basic Black, Modant Black, Azoic Black, Bat Black, Disperse Black, Solvent Black, Reactive Black, Chrome Black, etc. The black dye of is also more preferably used.

Among these dyes, those having a large molar extinction coefficient are more preferably used. Specifically, ε = 1
It is preferably 10 ⁴ or more, more preferably 1 10 ⁵ or more. This is because if ε is smaller than 1 × 10 ⁴ , the effect of improving the sensitivity is difficult to appear.

The amount of these laser light absorbing dyes added is preferably 0.2 to 20% by weight, more preferably 0.5 to 10% by weight, based on the total components of the heat sensitive destruction layer, and the amount used is 0. If it is less than 0.2% by weight, the sensitivity of the printing plate is lowered, and if it is more than 70% by weight, the printing durability of the printing plate tends to be lowered.

These dyes have the effect of improving the sensitivity even when used alone, but it is possible to further improve the sensitivity by using two or more kinds in combination.

Further, these dyes by using a mixture with a previously thermally decomposable compound to be described later prior to, prepare thermosensitive failure layer composition, thermally decomposable without being consumed in dyeing dye of the binder polymer It is easily consumed for dyeing only the compound, and thus the sensitivity improving effect is easily exhibited.

In order to further enhance the effect of adding these dyes, black pigments such as carbon black, aniline black and cyanine black, phthalocyanine and naphthalocyanine green pigments, titanium oxide, vanadium oxide, manganese oxide, iron oxide and oxides. Additives such as metal oxides such as cobalt and tungsten oxide, metal powders such as hydroxides, sulfates, bismuth, tin and tellurium of these metals are preferably added.

The amount of these additives added is preferably 2 to 70% by weight, more preferably 5 to 60% by weight, based on the total composition of the heat-sensitive destructive layer. If it is less than 2% by weight, the effect of improving the sensitivity is not observed, and if it is more than 70% by weight, the printing durability of the printing plate is likely to be lowered.

The present invention is characterized in that the heat-decomposable compound is dyed with these dyes before preparation of the heat-sensitive destructive layer .

Here, the term "dyeing" means that the dye and the molecule of the thermally decomposable compound are bound or associated with each other by a chemical bond or an intermolecular force.

As a result, when the dye molecule absorbs infrared rays or near infrared rays and generates heat, the heat-decomposition compound in the vicinity can efficiently perform the thermal decomposition reaction by the heat, and as a result, the printing plate The sensitivity is improved.

If this thermally decomposable compound is a thermosensitive destructive layer
If the dye is not previously dyed before production, the dye is also consumed for dyeing other components, for example, the binder polymer, and the heat decomposable compound cannot be dyed efficiently. Therefore, even when the same amount of dye is added, the sensitivity of the printing plate is higher when the heat decomposable compound is dyed in advance before the preparation of the heat destructive layer .

When the heat-sensitive destruction layer of this printing plate is observed with a microscope, it is found that when the binder polymer is added, it has a sea-island structure, and the portion of the thermally decomposable compound dyed with the dye is strongly dyed. .

Here, as a method for making the dyed state, a method of previously mixing the dye and the heat decomposable compound is preferable as described above, but in addition to this, a method of depositing the dye on the layer of the heat decomposable compound is also available. is there. Alternatively, it is also possible to mix the dye and the thermally decomposable compound and then to react them by means such as heating to chemically bond them.

The heat decomposable compound is preferably a compound which is easily decomposed by heat and has a silicone rubber layer as an upper layer, which changes the adhesive force with the silicone rubber layer.
Specifically, cellulose, carboxymethyl cellulose, nitrocellulose, cellulose acetate, cellulose propyl acetate, cellulose butyl acetate, cellulose triacetate, hydroxypropyl cellulose ether, ethyl cellulose ether, cellulose derivatives such as cellulose phosphate, gelatin, polyvinyl acetate, polystyrene, Polystyrene-acrylonitrile copolymer, polysulfone, polyphenylene oxide, polyethylene oxide, polyvinyl alcohol-acetal copolymer, polyvinyl acetal, polyvinyl alcohol-polyacetal copolymer, polyvinyl alcohol-polybutyral copolymer, polyvinyl benzal, polyvinyl alcohol , Casein, ethylene maleic anhydride copolymer Chlorinated polyolefin such as chlorinated polyethylene, chlorinated polypropylene, polymethylmethacrylate, polyacrylic acid, polymethacrylic acid, polyacrylic acid alkyl ester, polymethacrylic acid alkyl ester (as the alkyl group, methyl group, ethyl group, propyl group , A butyl group), a copolymer of an acrylic acid alkyl ester with at least one of monomers such as acrylonitrile, vinyl chloride, vinylidene chloride, styrene and butadiene, polyvinyl chloride, vinyl chloride, polyvinylidene chloride and vinylidene chloride. Acrylonitrile copolymer, polyvinyl acetate, vinyl acetate and vinyl chloride copolymer, polyvinyl alcohol, polyvinyl acetate, polyvinylpyrrolidone, polyacrylonitrile,
Copolymer of acrylonitrile and styrene, polyvinyl alkyl ether (as the alkyl group, methyl group, ethyl group, propyl group, isopropyl group, butyl group, etc.), polyethylene, polypropylene, polybutylene,
Polystyrene, poly-α-methylstyrene, polyamide (6-nylon, 6,6-nylon, 6,10-nylon, 1,12-nylon, 1,10-nylon, etc.), poly-1,2-butadiene, poly -1,4-butadiene,
Homopolymers such as polyisoprene, polyurethane, polyester, chlorinated rubber, polychloroprene, polyvinyl butyral, polyvinyl formal, styrene-butadiene rubber, poly (chlorosulfonated ethylene), or
Among these copolymers, nitrocellulose, cellulose derivatives such as cellulose acetate, chlorine-containing copolymers such as polyvinyl chloride-vinyl acetate copolymer, ethylene-vinyl acetate copolymer are preferably used, and among them, nitrocellulose. Are more preferably used.

The nitrogen content of nitrocellulose is defined by the degree of substitution of the nitro group, and the nitrogen content used in the present invention is preferably 6.8% to 13.5%, more preferably 10.3. % To 12.8%. When the nitrogen content is less than 6.8%, the sensitivity of the printing plate is lowered, and when it is more than 13.5%, the risk of explosion or the like is increased and the handling is required with caution.

Further, various molecular weights of nitrocellulose can be obtained depending on the average degree of polymerization, and all of them can be used, but those used in the present invention preferably have an average degree of polymerization of 35 to 480. , And more preferably 45 to 290. When the average degree of polymerization is less than 35, the printing durability of the printing plate tends to be lowered, and when it is more than 290, the viscosity becomes high and the handling becomes inconvenient.

In addition to the above-mentioned thermally decomposable compounds, polyacetylene, polyaniline and the like which are known as conductive polymers are also preferably used.

The amount of these thermally decomposable compounds used is preferably 10 to 80% by weight, based on the total heat-sensitive destruction layer composition.
It is more preferably 20 to 60% by weight. Usage is 10
If it is less than 80% by weight, the sensitivity of the printing plate is lowered, and if it is more than 80% by weight, the storage stability of the printing plate tends to be lowered.

For the purpose of improving the sensitivity of the heat-sensitive destruction layer, it is also effective to add a thermal decomposition aid such as urea and urea derivatives, zinc white, lead carbonate, lead stearate and glycolic acid.

The amount of the thermal decomposition aid added is preferably 0.02 to 10% by weight, more preferably 0.1 to 5% by weight, based on the total photosensitive layer composition.

It is preferable that these heat-sensitive destructive layers have a cross-linked structure in order to enhance solvent resistance to printing ink.

Examples of the polyfunctional crosslinking agent used for introducing the crosslinked structure include polyfunctional isocyanate compounds, polyfunctional epoxy compounds, urea compounds and photopolymerizable monomers.

Examples of polyfunctional isocyanates include hexamethylene diisocyanate, isophorone diisocyanate, paraphenylene diisocyanate, 2,4- or 2,6-toluene diisocyanate, 4 , 4-diphenylmethane diisocyanate, polymethylene polyphenyl isocyanate, or adducts thereof, and the like. Examples of polyfunctional epoxy compounds include polyethylene glycol diglycidyl ethers and polypropylene glycol diglycidyl. There are ethers, bisphenol A diglycidyl ether, trimethylolpropane triglycidyl ether, and the like, and examples of the urea-based compound include urea resin, melamine resin, benzoguanamine resin, and the like.

As the photopolymerizable monomer, a monofunctional acrylate such as polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, phenoxyethyl (meth) acrylate, etc.
And methacrylate, polyethylene glycol di (meth) acrylate, trimethylolethane tri (meth)
Acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol di (meth) acrylate
And pentaerythritol tetra (meth) acrylate
Dipentaerythritol hexa (meth) acrylate
, Trimethylolpropane tri (acryloyloxypropyl) ether, tri (acryloyloxyethyl) isocyanurate, calcium (meth) acrylate, sodium (meth) acrylate, polyfunctional alcohols such as glycerin and trimethylolethane After adding ethylene oxide or propylene oxide to (meth)
Acrylated, Japanese Patent Publication No. 48-41708,
Urethane acrylates as described in JP-B-51-37193, JP-B-48-64183
No. 4, Japanese Patent Publication No. 49-43191, Japanese Patent Publication No. 52-3049
US Pat. No. 4,540,549, polyfunctional acrylates and methacrylates such as polyester acrylates, epoxy acrylates obtained by reacting an epoxy resin with (meth) acrylic acid, and the like, which are described in Japanese Unexamined Patent Publication No. The N-methylol acrylamide derivative described in Japanese Patent Publication No. 1994-242242 can be mentioned.

Further, by introducing an organic silyl group into the molecular chain of the polyfunctional crosslinking agent described in JP-A-5-333535,
Those having higher adhesiveness to the upper silicone layer and the amino group-containing monomer described in JP-A-6-118629 can be preferably used.

The above polyfunctional cross-linking agent may be a polymer containing a hydroxyl group, a carboxyl group or an amino group, a known photopolymerization initiator,
When used in combination with a photosensitizer, crosslinking becomes possible.

The amount of these polyfunctional crosslinking agents used is preferably 1 to 50% by weight, more preferably 3 to 40% by weight, based on the total heat-sensitive destructive layer composition. When the amount is less than 1% by weight, the solvent resistance of the printing plate tends to decrease, and when the amount is more than 50% by weight, the printing plate becomes hard and the printing durability tends to decrease.

Further, the heat-sensitive destruction layer preferably contains a binder polymer for the purpose of improving printing durability and storage stability. The polymer used at this time is a polymer used in the primer, that is, an epoxy resin, Polyurethane resin, phenol resin, acrylic resin, alkyd resin, polyester resin, polyamide resin, melamine resin, urea resin, benzoguanamine resin,
Vinyl chloride-vinyl acetate copolymer, vinyl chloride resin, polyvinyl butyral resin, ethylene-vinyl acetate copolymer, polycarbonate resin, polyacrylonitrile-butadiene copolymer, polyether resin, polyether sulfone resin, milk casein, gelatin and , Cellulose used in the heat-disruptive layer, carboxymethyl cellulose, cellulose acetate, cellulose propyl acetate, cellulose butyl acetate, cellulose triacetate, hydroxypropyl cellulose ether, ethyl cellulose ether, cellulose derivatives such as cellulose phosphate, gelatin, polyvinyl acetate,
Polystyrene, polystyrene-acrylonitrile copolymer, polysulfone, polyphenylene oxide, polyethylene oxide, polyvinyl alcohol-acetal copolymer, polyvinyl acetal, polyvinyl alcohol-polyacetal copolymer, polyvinyl alcohol-polybutyral copolymer, polyvinyl benzal, Polyvinyl alcohol, ethylene maleic anhydride copolymer, chlorinated polyolefin such as chlorinated polyethylene, chlorinated polypropylene, polymethylmethacrylate, polyacrylic acid, polymethacrylic acid, polyacrylic acid alkyl ester, polymethacrylic acid alkyl ester (alkyl group As a methyl group, ethyl group, propyl group, butyl group, etc.), acrylic acid alkyl ester and acrylonitrile, vinylidene chloride Copolymers with at least one monomer such as styrene, styrene, butadiene, polyvinyl chloride, vinyl chloride, polyvinylidene chloride, copolymers of vinylidene chloride and acrylonitrile, polyvinyl acetate, vinyl acetate and vinyl chloride. Copolymers, polyvinyl alcohol, polyvinyl acetate, polyvinylpyrrolidone,
Polyacrylonitrile, copolymer of acrylonitrile and styrene, polyvinyl alkyl ether (as the alkyl group, methyl group, ethyl group, propyl group, isopropyl group, butyl group, etc.), polyethylene, polypropylene, polybutylene, polystyrene, poly-α -Methylstyrene, polyamide (6-nylon, 6,6-nylon, 6,10-nylon, 1,12-nylon, 1,1
0-nylon, etc.), poly-1,2-butadiene, poly-
1,4-butadiene, polyisoprene, polyurethane,
Homopolymers such as polyester, chlorinated rubber, polychloroprene, polyvinyl butyral, polyvinyl formal, styrene-butadiene rubber, poly (chlorosulfonated ethylene), and the like, and copolymers among them, among others,
Epoxy resin, polyurethane resin, phenol resin, acrylic resin, alkyd resin, polyester resin, polyamide resin, ethylene-vinyl acetate copolymer, polycarbonate resin, polyacrylonitrile-butadiene copolymer, polyether resin and the like are preferable, and more preferable. Epoxy resin, polyurethane resin and acrylic resin are preferred.

The content of these binder polymers is
It is preferably 10 to 60% by weight, more preferably 20 to 50% by weight, based on the total heat-sensitive destructive layer composition. If the content is less than 10% by weight, printing durability tends to decrease,
If it exceeds 60% by weight, the sensitivity tends to decrease.

In addition to the above, a primer is used for the heat-sensitive destruction layer.
A small amount of a photocurable diazo resin may be added to improve the adhesion with the layer. Examples of such a diazo resin include U.S. Pat. No. 3,867,147 and U.S. Pat.
Examples thereof include those described in No. 632.703, but diazo resins represented by a condensation product of an aromatic diazonium salt and an active carbonyl-containing compound (eg formaldehyde) are particularly useful. A preferred diazo resin is, for example, p-
Hexafluorophosphate, tetrafluoroborate and phosphate salts of condensates of diazodiphenylamine and formaldehyde or acetaldehyde are included. Also, p- as described in U.S. Pat. No. 3.300.309.
Sulfonates of condensates of diazodiphenylamine and formaldehyde (for example, p-toluenesulfonate, dodecylbenzenesulfonate, 2-methoxy-4-hydroxy-5-benzoylbenzenesulfonate, etc.), phosphinates, organic carboxylates. Acid salts and the like are also preferable. The preferred addition amount of the above diazo resin is 0.1 to 5% by weight based on the total heat-sensitive destructive layer composition.

Further, the heat-sensitive destructive layer may appropriately contain additives such as antiseptics, antihalation dyes, defoamers, antistatic agents, dispersants, emulsifiers and surfactants.

Particularly, it is preferable to add a fluorine-containing surfactant in order to improve the coating property. The amount of these additives added is usually 10% by weight or less based on the total composition of the heat-sensitive destructive layer.

Further, in some cases, in order to enhance the adhesiveness with the silicone rubber layer, silica powder or hydrophobic silica powder whose surface is treated with a silane coupling agent containing a (meth) acryloyl group or an allyl group is subjected to total heat-sensing. It may be added in an amount of 20% by weight or less based on the breakdown layer composition.

The composition for forming the heat-sensitive destructive layer is DMF, methyl ethyl ketone, methyl isobutyl ketone, dioxane, toluene, xylene, ethyl acetate,
Butyl acetate, isobutyl acetate, isoamyl acetate, methyl propionate, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, ethylene glycol monoethyl ether, ethylene glycol diethyl ether, acetone, methyl alcohol, ethyl alcohol, cyclopentanol, cyclohexanol,
It is prepared as a composition solution by dissolving it in an appropriate organic solvent such as diacetone alcohol, benzyl alcohol, butyl butyrate and ethyl lactate. A heat-sensitive destructive layer is formed by uniformly applying such a composition solution on a substrate and heating at a required temperature for a required time.

It is necessary to carry out the thermal curing of these at a temperature at which the thermally decomposable compound does not decompose, usually at 130 ° C. or lower. For this reason, it is preferable to use a catalyst together.

Alternatively, when a photopolymerizable monomer is used, it is necessary to carry out photocuring with a light source such as an ultrahigh pressure mercury lamp or a halogen lamp after coating and heating.

The thickness of these heat-sensitive destruction layers is preferably 0.1 μm to 20 μm, more preferably 0.3 μm to 10 μm. When the film thickness is less than 0.1 μm, the sensitivity of the heat-sensitive destructive layer decreases, and when it is more than 20 μm, the ink consumption increases, so the above range is preferable.

For the purpose of further improving the sensitivity of the heat-sensitive destruction layer, it is also effective to provide a metal vapor deposition film between the primer layer and the heat-sensitive destruction layer to form a laser reflection layer.
As the vapor deposition film at this time, a vapor deposition film of a metal such as aluminum, nickel or titanium is used, and among them, a vapor deposition film of aluminum is more preferably used. However, in the case of a vapor-deposited film of aluminum, the preferable film thickness is in the range of 50 to 700 angstroms, and when it is thinner than 50 angstroms, the sensitivity of the photosensitive layer tends to decrease, and when it is thicker than 700 angstroms. However, the sensitivity of the heat-sensitive destruction layer tends to decrease.

The direct drawing type waterless planographic printing plate precursor of the present invention comprises
There is no particular limitation as long as it has a heat-sensitive destruction layer on the substrate, but a silicone rubber layer is preferably laminated on the heat-sensitive destruction layer.

As the silicone rubber layer, all conventional silicone compositions for waterless lithographic printing plates can be used.

The silicone rubber layer used in the present invention must be transparent so that ultraviolet rays can pass through it.

The silicone rubber layer of the direct drawing type waterless planographic printing plate precursor used in the present invention is required to have transparency which allows a laser beam to pass therethrough. Like this
The rubber layer is obtained by sparsely cross-linking a linear organopolysiloxane (preferably dimethylpolysiloxane), and a typical silicone rubber layer has a repeating unit represented by the following formula (I). It is a thing.

[0085]

[Chemical 1] (Here, n is an integer of 2 or more. R has 1 to 10 carbon atoms.
Is an alkyl, aryl, or cyanoalkyl group. It is preferable that 40% or less of the total R is vinyl, phenyl, vinyl halide, or phenyl halide, and 60% or more of R is a methyl group. Further, it has at least one hydroxyl group in the molecular chain in the form of a chain end or a side chain. ) In the case of the silicone rubber layer applied to the printing plate of the present invention, silicone rubber (R
TV, LTV type silicone rubber) is used. As such a silicone rubber, R of an organopolysiloxane chain is used.
Although a part of H may be substituted with H, it is usually crosslinked by condensation of the terminal groups represented by the following formulas (II), (III) and (IV). In some cases, an excess amount of the cross-linking agent may be present.

[0086]

[Chemical 2]

[Chemical 3]

[Chemical 4] (Here, R is the same as R described above, and R ¹ , R ²
Is a monovalent lower alkyl group, and Ac is an acetyl group. ) Silicone rubber that performs such condensation-type crosslinking,
Metal carboxylates of tin, zinc, lead, calcium, manganese, etc., such as dibutyltin laurate, tin (II) octoate, naphthenates, etc., or catalysts such as chloroplatinic acid are added.

Further, the silicone rubber layer which is used in the present invention and which is crosslinked by the addition reaction of the following formulas (V) and (VI) includes a polyvalent hydrogenorganopolysiloxane and two or more units in one molecule. A composition obtained by the reaction with a polysiloxane having a bond of the formula (VI), preferably a composition comprising the following components, is crosslinked and cured.

[0088]

[Chemical 5]

[Chemical 6] (1) Organopolysiloxane having at least two alkenyl groups (preferably vinyl groups) directly bonded to silicon atoms in one molecule 100 parts by weight (2) Organo having at least two groups of formula (V) in one molecule Hydrogen polysiloxane 0.1 to 1000 parts by weight (3) Addition catalyst 0.00001 to 10 parts by weight The alkenyl group of the component (1) may be at the terminal or in the middle of the molecular chain, and is an organic group other than the alkenyl group. as,
It is a substituted or unsubstituted alkyl group or aryl group.
The component (1) may have a small amount of hydroxyl groups. The component (2) reacts with the component (1) to form a silicone rubber layer,
It plays a role of imparting adhesiveness to the photosensitive layer. The hydrogen group of the component (2) may be at the terminal or in the middle of the molecular chain, and the organic group other than hydrogen is selected from the same as the component (1). The organic groups of the components (1) and (2) preferably have a methyl group content of 60% or more of the total number of the groups from the viewpoint of improving the ink repellency. Component (1) and component (2)
The molecular structure of may be linear, cyclic, or branched, and it is preferable that at least one of them has a molecular weight of more than 1000 from the viewpoint of rubber physical properties, and further, the molecular weight of component (2) may exceed 1,000. preferable. Examples of the component (1) include α, ω-divinylpolydimethylsiloxane and a (methylvinylsiloxane) (dimethylsiloxane) copolymer having methyl groups at both terminals, and the component (2) has a hydrogen group at both terminals. Polydimethylsiloxane, α, ω-
Examples thereof include dimethyl polymethyl hydrogen siloxane, (methyl hydrogen siloxane) (dimethyl siloxane) copolymer having methyl groups at both ends, and cyclic polymethyl hydrogen siloxane. The addition catalyst of the component (3) is arbitrarily selected from known ones, but a platinum-based compound is particularly desirable, and platinum simple substance, platinum chloride, chloroplatinic acid, olefin coordinated platinum and the like are exemplified. For the purpose of controlling the curing rate of these compositions, vinyl group-containing organopolysiloxane such as tetracyclo (methylvinyl) siloxane and carbon-carbon triple bond-containing alcohol-
It is also possible to add a crosslinking inhibitor such as alcohol, acetone, methyl ethyl ketone, methanol, ethanol and propylene glycol monomethyl ether. These compositions are characterized in that an addition reaction occurs at the time when the three components are mixed and curing begins, but the curing rate rapidly increases as the reaction temperature increases. Therefore, for the purpose of prolonging the pot life of the composition until rubberization and shortening the curing time on the photosensitive layer, the curing conditions of the composition are a temperature condition in which the characteristics of the substrate and the photosensitive layer are not changed, Further, it is preferable to keep the temperature at a high temperature until it is completely cured, from the viewpoint of stability of the adhesive force with the photosensitive layer.

In addition to these compositions, a known adhesion-imparting agent such as alkenyltrialkoxysilane may be added, and a hydroxyl group-containing organopolysiloxane or a hydrolyzable functional group which is a composition of the condensation type silicone rubber layer may be added. It is optional to add a group-containing silane (or siloxane), and it is also optional to add a known filler such as silica for the purpose of improving rubber strength.

The film thickness of these silicone rubber layers is 0.5.
˜50 g / m ² is preferred, and more preferably 0.5˜.
It is 10 g / m ² . When the film thickness is less than 0.5 g / m ² , the printing durability of the printing plate is likely to decrease, and
If it is larger than ² , the sensitivity tends to decrease.

For the purpose of protecting the silicone rubber layer on the surface of the direct drawing type waterless lithographic printing plate precursor constructed as described above, the surface of the silicone rubber layer was subjected to a plane or uneven treatment. It is also possible to laminate a thin protective film or to form a polymer coating film which is soluble in the developing solvent described in JP-A-5-323588.

In particular, when a protective film is laminated, laser exposure is performed on the protective film, and then the protective film is peeled off to form a pattern on the printing plate. It is also possible to create.

Next, an example of the method for producing a waterless planographic printing plate precursor according to the invention will be described. An ordinary coater such as a reverse roll coater, an air knife coater, and a Mayer bar coater or a spin coater such as a whaler was applied on the substrate, and the primer layer composition was applied if necessary and cured at 100 to 300 ° C. for several minutes. After that, a laser light reflection layer is provided if necessary, a heat-sensitive destructive layer composition coating liquid is applied, dried at a temperature of 50 to 130 ° C. for several minutes, and optionally heat-cured or light-cured, and then silicone rubber is applied thereon. The composition is applied and heat-treated at a temperature of 50 to 150 ° C. for several minutes to cure the rubber, thereby forming the composition. Then, if necessary, a protective film is laminated or a protective layer is formed.

The directly imageable waterless planographic printing plate precursor thus obtained is imagewise exposed with a laser beam.

Laser light is usually used for exposure, and the light source at this time has an oscillation wavelength of 300 nm to 1500.
such as Ar ion laser, Kr ion laser, He-Ne laser, He-Cd laser, ruby laser, glass laser, semiconductor laser, YAG laser, titanium sapphire laser, dye laser, nitrogen laser, metal vapor laser in the range of nm. Various lasers can be used. Among them, the semiconductor laser is preferable because it is miniaturized due to the recent technical progress and is economically advantageous over other laser light sources.

The direct drawing type waterless planographic printing plate precursor exposed by the above-mentioned method is subjected to development treatment, if necessary.

The developing solution used in the present invention includes, for example, water, one obtained by adding the following polar solvent to water, and aliphatic hydrocarbons (hexane, heptane, “Isopar E,
G, H "(trade name of ESSO-made isoparaffinic hydrocarbon), gasoline, kerosene, etc., aromatic hydrocarbons (toluene, xylene, etc.), halogenated hydrocarbons (tricrene, etc.), etc. A mixed solvent containing at least one of the following polar solvents is preferably used.

Alcohols (methanol, ethanol,
Propanol, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol,
Tripropylene glycol, polypropylene glycol, 1,3-butylene glycol, 2,3-butylene glycol, hexylene glycol, 2-ethyl-1,3
-Hexanediol etc.) Ethers (ethylene glycol monoethyl ether,
Diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, diethylene glycol mono-2
-Ethylhexyl ether, triethylene glycol monoethyl ether, tetraethylene glycol monoethyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, dioxane, tetrahydrofuran, etc. Ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone) , Diacetone alcohol, etc.) Esters (ethyl acetate, butyl acetate, methyl lactate, ethyl lactate, butyl lactate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, etc.) Carvone Acid (2-ethylbutyric acid, Prong acid, caprylic acid, 2-ethylhexanoic acid, capric acid, oleic acid,
Lauric acid, etc.) Also, a known surfactant may be freely added to the above-mentioned developer composition. In addition, an alkaline agent,
For example, sodium carbonate, monoethanolamine, diethanolamine, diglycolamine, monoglycolamine, triethanolamine, sodium silicate, potassium silicate, potassium hydroxide, sodium borate and the like can be added.

Also, well-known basic dyes such as crystal violet, Victor Pure Blue, Astrazone Red, acid dyes and oil-soluble dyes may be added to these developers to dye the image area at the same time as development. You can

At the time of developing, the developing solution can be developed by impregnating a non-woven fabric, absorbent cotton, cloth, sponge or the like with these developing solutions and wiping the plate surface.

For development, Japanese Patent Laid-Open No. 63-163357.
It is possible to suitably develop by pretreatment of the plate surface with the above-mentioned developing solution using an automatic developing machine as described in 1) and then rubbing the plate surface with a rotating brush while showering with tap water or the like.

Development can also be performed by spraying hot water or steam onto the plate surface instead of the above developing solution.

[0103]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.

Examples 1 to 5 and Comparative Example 1 An aluminum plate (manufactured by Sumitomo Metal Co., Ltd.) having a thickness of 0.15 mm was coated with the following primer composition using a bar coater, and 2
It was heat-treated at 20 ° C. for 2 minutes to provide a primer layer of 5 g / m ² .

(A) Polyurethane resin (Samprene LQ-T1331, manufactured by Sanyo Kasei Co., Ltd.) 100 parts by weight (b) Block isocyanate (Takenate B830, manufactured by Takeda Pharmaceutical Co., Ltd.) 20 parts by weight ( c) Epoxy phenol urea resin (SJ9372, manufactured by Kansai Paint Co., Ltd.) 8 parts by weight (d) Titanium oxide 10 parts by weight (e) Tetraglycerol dimethacrylate 0.2 parts by weight (f) Dimethylform Ami 725 parts by weight Subsequently, the following heat-sensitive destructive layer composition was coated on this using a bar coater and dried in hot air at 110 ° C. for 1 minute to form a photosensitive layer having a thickness of 2 g / m ^2. It was

At this time, (a), (b) and (c) were used after being mixed and adjusted in advance. Therefore, in Examples 1 to 5, nitrocellulose was dyed with a laser light absorbing dye.

(A) Nitrocellulose (average degree of polymerization: 85, nitrogen content: 11.6% (manufactured by Nacalai Tesque, Inc.)) 50 parts by weight (b) Laser light absorbing dye (Table 1) 2 parts by weight (c) Methyl ethyl ketone 300 parts by weight (d) Carbon black 〓 30 (manufactured by Mitsubishi Kasei Co., Ltd.) 12 parts by weight (e) Tungsten oxide 9 parts by weight (f) Polyurethane resin "Miractran" P22S (manufactured by Nippon Miractolan Co.) 21 parts by weight g) Urea resin "Beckamine" P-138 10 parts by weight (h) Methyl ethyl ketone 200 parts by weight Then, a silicone rubber composition having the following composition was spin-coated on this photosensitive layer, and then 115 ° C and dew point 30 ° C. ．
It was heat-cured for 5 minutes to provide a 2 g / m ² silicone rubber layer.

(A) Polydimethylsiloxane (molecular weight of about 25,000, terminal hydroxyl group) 100 parts by weight (b) Vinyltri (methylethylketoxime) silane 8 parts by weight (c) “Isopa-E” (manufactured by Exxon Chemical Co., Ltd.) A semiconductor laser (OPC-A001-mmm-FC, output 0.75, in which an original printing plate of 1400 parts by weight was mounted on an XY table.
W, wavelength 780 nm, OPTO POWERCORPO
Pulse exposure with a beam diameter of 20 μm and an output of 50 mW on the surface of the printing plate. At this time, the pulse interval was arbitrarily changed by a pulse generator, and the exposure time was measured.

Then, the exposed plate was developed using TWL1160 (waterless lithographic printing plate development apparatus manufactured by Toray Industries, Inc., processing speed 100 cm / min) under conditions of room temperature of 25 ° C. and humidity of 80%. It was Here, water was used as the developing solution. A liquid having the following composition was used as the dyeing liquid.

(A) Ethyl carbitol 18 parts by weight (b) Water 79.9 parts by weight (c) Crystal Violet 0.1 parts by weight (d) 2-Ethylhexanoic acid 2 parts by weight The image reproducibility of this printing plate was evaluated. It was evaluated with a magnifying power of 50 and the minimum exposure time for forming dots was measured.

Examples 6 to 10, Comparative Examples 2 and 3 On a degreased aluminum plate having a thickness of 0.24 mm, a primer solution having the following composition was applied, dried at 230 ° C. for 1 minute, and dried at 3 g / m ^2. Was provided.

(A) Cancoat 90T-25-3094 (Kansai Paint Co., Ltd., epoxy phenolic resin) 15 parts by weight (b) Victoria Pure Blue BOH naphthalene sulfonic acid 0.1 part by weight (c) Dimethyl Formamide 85 parts by weight Metal aluminum was vapor-deposited on the above primer layer to a thickness of 600 liters to form a laser reflection layer.

A heat-sensitive destructive layer composition having the following composition was coated on the aluminum vapor-deposited layer, dried at 100 ° C. for 1 minute,
A photosensitive layer having a thickness of 3 g / m ² was provided.

At this time, (a), (b), and (c) were used after being mixed and adjusted in advance. Therefore, in Examples 6 to 10, the thermally decomposable compound is dyed with the black dye.

(A) Thermally decomposable compound Table 2 (b) Black dye Table 2 (c) Methyl isobutyl ketone 300 parts by weight (d) Polyester resin (Vylon 300, manufactured by Toyobo Co., Ltd.) 30 parts by weight (e) Carbon Black # 2200B (manufactured by Mitsubishi Kasei Co., Ltd.) 15 parts by weight (f) 4,4'-diphenylmethane diisocyanate 20 parts by weight (g) methyl isobutyl ketone 300 parts by weight Subsequently, the following composition is provided on this photosensitive layer. Apply silicone rubber solution, dry for 2 minutes at 120 ℃, thickness 2g
/ M ² of silicone rubber layer was provided.

(A) Both ends silanol polydimethylsiloxane (number average molecular weight 100,000) 100 parts by weight (b) ethyltriacetoxysilane 12 parts by weight (c) dibutyltin diacetate 0.1 parts by weight (d) ) ISOPA-E 750 parts by weight A semiconductor laser (SLD-304XT, output 1W, wavelength 809n) in which this printing plate precursor is mounted on an XY table.
m, manufactured by Sony Corporation, using a beam diameter of 20 μm,
Pulse exposure was performed at an output of 80 mW on the surface of the printing plate. At this time, the pulse interval was arbitrarily changed by the pulse generator.

Subsequently, rubbing with a cotton pad impregnated with a developing solution having the following composition was carried out to develop.

(A) 70 parts by weight of water (b) 20 parts by weight of diethylene glycol mono-2-ethylhexyl ether The image reproducibility of this printing plate was observed with a magnifying power of 50.
The minimum exposure time per dot was measured.

Comparative Examples 4 and 5 In Examples 6 and 7, a dye was added at the same time as the other composition when preparing the heat-sensitive destructive layer composition, and other printing masters were prepared in the same manner and the sensitivity was measured. did. Therefore, in Comparative Examples 4 and 5, the thermally decomposable compound was not sufficiently dyed with the black dye, and therefore it took a long time to form dots and the dots formed were small. Was there.

[0120]

[Table 1]

[Table 2]

[0121]

The direct drawing type waterless planographic printing plate precursor of the present invention has improved sensitivity as compared with the conventional heat-sensitive destruction type waterless planographic printing plate precursor.

Claims (7)

(57) [Claims] 1. A directly imageable waterless planographic printing plate precursor having at least a heat-sensitive breakdown layer on the substrate, heat-sensitive breakdown layer contains a thermally decomposable compound dyed with a dye, further, heat
Decomposable compounds are dyed with a dye in advance before preparing the heat-sensitive destruction layer.
A direct drawing type waterless planographic printing plate precursor characterized by being colored . 2. The direct drawing type waterless planographic printing plate precursor as claimed in claim 1, wherein the dye is an infrared or near infrared absorbing dye. 3. The dye is a black dye,
The direct drawing type waterless planographic printing plate precursor according to claim 1. 4. The directly imageable waterless planographic printing plate precursor according to claim 1, wherein the thermally decomposable compound is a cellulose derivative. 5. The directly imageable waterless planographic printing plate precursor according to claim 1, wherein the thermally decomposable compound is nitrocellulose. 6. The direct drawing type waterless lithographic printing plate precursor according to claim 1, wherein a silicone rubber layer is laminated on the heat-sensitive destruction layer. 7. A waterless lithographic printing plate obtained by selectively exposing and developing the direct drawing type waterless lithographic printing plate precursor as claimed in any one of claims 1 to 6.