JPH11115147A - Method for manufacturing direct drawing type waterless lithographic printing original plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a plate stably and improve tone reproducibility without occurrence of plate surface flaws and others in development by a method in which a direct drawing type waterless lithographic printing original plate which is made by laminating a thermosensible layer, a silicone rubber layer in sequence on a substrate, after drawing with laser beams, is developed with the use of an aqueous solution containing a surfactant. SOLUTION: A direct drawing type waterless lithographic printing original plate is made by a method in which a thermosensible layer composition is applied on a substrate and heat-cured, a silicone rubber composition is applied and heat-treated and rubber-cured. The prepared original plate, after being exposed in the shape of an image to laser beams, is developed with the use of an aqueous solution containing a surfactant. The surfactant is soluble in water and insoluble in liquid paraffin, and the content is 0.05-5 wt.%. The surfactant has an affinity with plastic, a raw material of a brush, adjusts the frictional resistance of the brush, and facilitates the prevention of flaw generation on the silicone rubber layer of the plate surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for making a lithographic printing plate precursor without water, which can be printed without using fountain solution. It relates to a method of making a plate master.

[0002]

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

In recent years, new types of various lithographic printing materials have been developed recently due to rapid progress in output systems such as prepress systems, imagesetters, and laser printers. Above all, the method using laser light is superior to other methods in terms of resolution and plate making speed, and there are many types. The lithographic printing plate using the laser light is further classified into a photon mode by a photoreaction and a heat mode type in which a photoreaction is performed to cause a thermal reaction.

The photon mode type includes: (1) a high-sensitivity PS plate using a photopolymer; (2) a silver salt type lithographic plate; (3) a silver salt composite type lithographic plate; Photographic lithography (5) There is a direct drawing master.

As the heat mode type, there is (6) a thermal destruction type planographic plate.

The photon mode type (1) (2)
(3) is inconvenient to handle due to insufficient storage stability and high sensitivity, and is a large-sized apparatus and expensive because mainly using an argon ion laser as a laser light source. The electrophotography method (4) has an advantage that it can be handled in a bright room, but since the dark decay becomes large within 2 to 5 minutes after charging of the photosensitive layer, it is necessary to perform exposure and development processing in a short time after charging. It is difficult to output the size with high resolution. The direct drawing master of (5) uses a toner image formed by a laser printer as
This is to be transferred onto a printing plate. However, the resolution of the printing plate is inferior to other methods.

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

For example, Japanese Patent Laid-Open Publication No. 50-83104,
JP-A-51-84303, JP-A-56-1134
No. 56, a method of obtaining a waterless planographic printing plate by jetting an ink repellent substance with an ink jet and heat-curing the ink, or a method of forming an ink on a silicone rubber layer described in JP-A-60-192693. It is known to obtain a waterless lithographic printing plate by injecting a substance. However, these plate materials have a problem that printing durability is low due to poor adhesion of silicone rubber, which is an ink repellent substance, and has not been put to practical use yet.

Further, a method of obtaining a waterless lithographic printing plate by removing the silicone layer on the surface by discharge breakdown described in JP-B-57-58296 and JP-A-4-313890 is known. Because the electrode to be used is large,
There was a problem that the resolution did not increase.

As a method for solving the above problems, Japanese Patent Application Laid-Open Nos. 50-158405, 6-55723, 6-199064, US Pat.
No. 37, US Pat. No. 5,353,705, EP057
No. 3091, EP0580393,
A direct-drawing waterless lithographic printing plate precursor using laser light as a light source is exemplified.

The laser-sensitive layer of these printing plate precursors is
A thin metal film such as titanium or bismuth or carbon black is used as the laser light absorbing compound, and this is converted into thermal energy by absorbing the laser light. That is, the laser photosensitive layer is a heat-sensitive layer,
This heat destroys the laser-sensitive layer, and the silicone rubber in this portion can be easily removed, and the ink-coated portion can be formed by wiping lightly. However, although the printed plate has an image formed thereon, silicone rubber is inherently excellent in heat resistance, so the heat-sensitive layer in the lower layer is not completely destroyed / removed, and the ink-coated portion of the image is removed. Is left at the edge of the halftone dot, and the printing plate has poor tone reproducibility.

As a countermeasure, US Pat. No. 5,339,737 proposes a method of rubbing a silicone rubber layer with a cloth containing a chemical solution such as isopropanol. In this method, the isopropanol chemical solution has high volatility and is not preferable in terms of environmental pollution and health. When a developing machine is used, volatilization is particularly severe and the flash point is low, so that it cannot be said that it is practical from the viewpoint of safety.

Therefore, EP 0 573 091 discloses that
It has been proposed to scrape the silicone rubber layer with a tool containing a solvent insoluble in silicone rubber. Furthermore, rub development with a cloth or the like that does not contain anything, that is, a dry development method has also been proposed.However, these methods have an excessively high frictional resistance to the silicone rubber layer and easily damage the silicone rubber layer. It turned out that it was not a stable plate making method.

In the case of using a large amount, an automatic developing machine or the like can reduce the burden on an operator and has a large processing capacity. Therefore, US Pat. No. 4,588,277 proposes a waterless planographic automatic developing machine. ing. However, the disadvantage is that the fringe tends to remain, that is, the silicone rubber layer is almost completely removed on the downstream side in the rubbing direction of the brush roll within the halftone dot, while the silicone is provided on the upstream side, especially on the edge of the halftone dot. The rubber layer tends to remain. As a result, serious defects such as a decrease in tone reproducibility during printing and a shift in color tone occur.

[0015]

SUMMARY OF THE INVENTION The present invention is to solve the above-mentioned drawbacks of the prior art, and it is possible to form a stable plate without developing scratches on the plate during development and to provide a waterless planographic printing plate excellent in tone reproducibility. The purpose is to provide.

[0016]

In order to achieve the above object, a plate making method of a direct-drawing waterless planographic printing plate precursor according to the present invention comprises the following constitution.

That is, a direct drawing type waterless planographic printing plate precursor comprising a heat sensitive layer and a silicone rubber layer sequentially laminated on a substrate is drawn by a laser beam, and then developed using an aqueous solution containing a surfactant. It is.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

The surfactant in the aqueous solution used for the development may be any of anionic, cationic, nonionic and amphoteric surfactants, and may be used alone or as a mixture of two or more. In particular, those which are soluble in water and insoluble in liquid paraffin are preferably mentioned, and are preferably contained in an aqueous solution in an amount of 0.05 to 5% by weight.

By using a surfactant that is soluble in water and insoluble in liquid paraffin, the surfactant has an affinity for the plastic that is the brush material and adheres very thinly to the surface layer of the brush material. By adjusting the frictional resistance of the brush, it is easy to prevent the silicone rubber layer on the plate surface from being damaged. If the surfactant is soluble in both water and liquid paraffin, it is not preferable in terms of friction coefficient and foaming.

Further, the amount of the surfactant to be added is 0.1 to water.
When the content is at least 05% by weight, the frictional resistance is small and the generation of scratches on the plate surface is suppressed, which is preferable. On the other hand, when the content is 5% by weight or less, foaming due to rubbing with a brush and frictional resistance are in a preferable range, and the developing property is excellent.

Specific examples of the surfactant used include:
These include:

That is, in the case of the anionic surfactants, sulfates of higher alcohols and olefins, alkyl ether sulfates, and sulfones include alkyl sulfonates, alkyl allyl sulfonates, sulfosuccinates, fatty acid amide sulfonates, and the like. Examples of the phosphate type include alkyl phosphates and alkyl ether phosphates.

Examples of the cationic surfactant include an alkylamine salt, an alkylammonium salt, an alkylpyridinium salt and the like.

The amphoteric surfactants include carboxylic acid type, alanine type and imidazoline type, and the nonionic surfactants include polyoxyethylene type (alkyl ether, alkyl phenyl ether, alkyl phenyl condensate ether, alkyl Ester, alkylamine, alkylamide, polyoxypropylene ether, allylphenyl ether), polyhydric alcohol type (glycerin fatty acid ester, sorbitan fatty acid ester,
Polyoxyethylene sorbitan fatty acid ester), and alkanolamides and polyether surfactants.

It is also effective to use an antifoaming agent in the aqueous solution for the purpose of suppressing foaming, whereby the practical range of the surfactant can be expanded.

Examples of the defoaming agent include silicone-based defoaming agents (oil compound type (antifoaming agent having a trifluoropropylmethylpolysiloxane structure), emulsion type), alcohols, and nonionic surfactants having a small HLB interface. Activators and the like.

HLB is Hydropile-Lipophile Bal
Abbreviation of ance, a ratio between hydrophilicity and lipophilicity is represented by a numerical value between 0 and 20, with smaller numerical values meaning lipophilicity and higher numerical values meaning hydrophilicity.

In the plate making method of the present invention, it is particularly preferred that the development is carried out by rubbing with a roll-shaped developing brush around which a plastic thread is wound, since a more excellent effect can be obtained. A developing method using the roll-shaped developing brush will be described with reference to the drawings.

FIG. 1 is a schematic structural view of an example of an automatic developing machine preferably used in this method. A printing plate precursor 1 on which an image is exposed on a carry-in table 2 is inserted into a developing machine main body 3 by a transport roll 5. After being subjected to development processing,
It is discharged to.

During the development, the developer is sent from the developer storage tank 13 through the developer shower pipe 7 by the developer circulation pump 6, and the plate surface of the printing plate precursor 1, the development first brush 8, and the development second brush 9 is sprayed. In the present invention, the developing solution needs to be the above-mentioned surfactant aqueous solution, and the surfactant aqueous solution is sprayed on the brush, so that the surfactant adheres extremely thinly to the surface of the brush single yarn, and the friction coefficient is reduced. At the same time, the silicone rubber pieces that have been developed and removed can be washed away.

The printing plate precursor 1 is rubbed by the first developing brush 8 and the second developing brush 9, and the silicone rubber on the edge of the image area is removed. At this time, the first developing brush 8 and the second developing brush 9 are arranged so as to uniformly contact the printing plate precursor 1, rotate in opposite directions to each other, and are configured to be swingable in the axial direction, respectively. preferable.

Further, for each developing brush, a support mechanism such as a brush receiving stand 10 is provided at a position opposed to the first developing brush 8 so that the printing plate precursor 1 does not escape. Since the brush receiving table 10 is liable to cause abrasion on the back surface of the printing plate precursor due to the application of the load of the developing roll and the rubbing force of conveyance, the brush receiving table 10 is processed to reduce the frictional resistance in order to prevent this. It is preferably composed of materials, regardless of metal or plastic,
It may be cylindrical or plate-shaped.

In particular, in order to reduce the frictional resistance, it is preferable that the surface has fine irregularities of about 10 μm to 2 mm. Of these, a matte finish is particularly preferred. When the surface roughness is 10 μm or more, the frictional resistance is small and the generation of scratches can be prevented, and when it is 2 mm or less, the printing plate is not bent by the brush pressure and the brush rubbing force is uniform and the image becomes uniform. It is preferable because it has excellent reproducibility. Especially when the substrate is thin 0.1
This tendency is strong in a plate using a 5 mm aluminum or plastic material as a substrate.

The first developing brush and the second developing brush are roll-shaped developing brushes around which a plastic thread is wound, and the brush material is nylon having a diameter of 20 to 300 μm.
It is preferable to use polyethylene terephthalate, polybutylene terephthalate, polyvinylidene chloride, polyethylene, polypropylene, or the like. A brush roll obtained by implanting these materials in a metal channel (channel) is wound around a metal or plastic core.

At this time, each developing brush has a bristle length of 10 to 2
Those having an outer diameter of 100 to 200 mm implanted at 0 mm are particularly preferable in consideration of handleability and the size of the developing machine.

In order to obtain a printing plate having particularly excellent tone reproducibility, the developing machine is provided with two or more developing brushes, at least one of which is rotated in the reverse direction to the other developing brushes, and further oscillated in the axial direction. Preferably. The rotation speed of the developing brush at this time is preferably 100 to 500 rpm,
It is preferable that the swing range be 5 to 50 mm.

Further, due to the influence of the thickness of the channel material (the thickness of the channel), the density of the bristle of the developing brush that comes into contact with the printing plate precursor is uneven, and the developing property tends to vary in a streak form. In particular, when the elasticity of the developing brush decreases, streak-like development variation appears even with the swing mechanism. As a countermeasure, by applying a crimping process to the plastic thread used as the brush material, the thread is entangled with each other,
The portion corresponding to the thickness of the channel material is also uniform, and at the same time, the force applied to the single yarn is uniform, the rubbing force is stabilized, and the generation of streaky development unevenness is eliminated.

Examples of the crimping method include twisting, heat setting, untwisting, temporary twisting, special twisting, indentation, rubbing, air ejection, shaping, structural crimping, and composite crimping. Any method may be used. Among them, the crimped yarn processed by the shaping method and the composite crimping method is preferable because it has a beautiful sine curve or coil shape and can be appropriately entangled.

When the development is completed, the surfactant aqueous solution used as the developer is collected in the developer storage tank 13, but a silicone scum removing device 11 and a filter 12 for removing the silicone scum generated during plate making may be provided. Also preferred for environmental protection. Silicone residue removal device 11
The filter is preferably provided between the developing machine main body 3 and the developer storage tank 13 from the viewpoint of extending the life of the filter 12. The automatic developing machine is provided with an easily removable frame on the developer storage tank 13, uses a coarse wire mesh or punched metal on the bottom surface, and uses a coarse material such as a nonwoven fabric thereon to overflow from the developing machine main body 3. It is preferably designed to receive incoming silicone slag, and a multi-stage type is more effective.

As the material of the coarse material, a lipophilic material is preferably used. For example, a nonwoven fabric, woven fabric, knitted woven fabric, or the like made of polypropylene, polyethylene, polyamide, polyester, or the like is preferable.

As the filter 12, a cartridge type filter in which viscose rayon or cotton is wound in a cylindrical shape, or a disk type pressure filter using a sintered metal such as bronze or stainless steel is preferably used.

Next, the direct drawing type waterless planographic printing plate precursor developed in the present invention will be described.

The direct-drawing waterless planographic printing plate precursor used in the present invention is obtained by sequentially laminating a heat-sensitive layer and a silicone layer on a substrate, and specifically, as disclosed in JP-A-6-19906.
No. 4, US Pat. No. 5,353,705, EP0580
393, JP-A-6-55723, EP05
No. 73091, and those described in US Pat. No. 5,378,580.

At this time, the substrate may be a plate-like material which is dimensionally stable, and a substrate conventionally used as a substrate for a printing plate can be suitably used. Such substrates include paper,
Plastics (eg polyethylene, polypropylene,
Paper, for example, aluminum (including aluminum alloy), zinc, copper, etc., a metal plate such as cellulose, cellulose acetate, polyethylene terephthalate, polyethylene, etc.
Examples include plastic films such as polyester, polyamide, polyimide, polystyrene, polypropylene, polycarbonate, and polyvinyl acetal, and paper or plastic films on which the above-mentioned metals are laminated or vapor-deposited. Among these substrates, the aluminum plate is particularly preferable because it is extremely stable in dimension and inexpensive. Further, a polyethylene terephthalate film used as a substrate for light printing is also preferably used.

The direct drawing type waterless planographic printing plate precursor used in the present invention may be provided with a primer layer in order to strengthen the adhesion between the substrate and the heat-sensitive layer. At this time, as the primer layer,
Those satisfying the following conditions are mentioned. That is, the substrate and the heat-sensitive layer are well bonded and stable over time, and furthermore, have a resistance to the solvent of the developing solution. For example, epoxy resin, polyurethane resin, phenol resin, acrylic resin, alkyd resin, polyester resin, polyamide resin, melamine resin, urea resin,
Benzoguanamine 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-sensitive layer,
Carboxymethylcellulose, 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, polymethyl methacrylate, polyacrylic acid , Polymethacrylic acid, alkyl polyacrylate, polymeth Alkyl acrylate (eg, methyl group, ethyl group, propyl group, butyl group, etc.), copolymer of alkyl acrylate with at least one kind of monomer such as acrylonitrile, styrene, butadiene, or polyvinyl alcohol , Polyvinyl acetate, polyvinylpyrrolidone, polyacrylonitrile, a copolymer of acrylonitrile and styrene,
Polyvinyl alkyl ether (alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, 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, polyisoprene, polyurethane, polyester, polychloroprene, polyvinyl butyral, polyvinyl formal, styrene Examples include homopolymers or copolymers such as butadiene rubber, among which epoxy resins, polyurethane resins, phenolic resins, acrylic resins, alkyd resins, polyester resins, polyamide resins, ethylene-vinyl acetate copolymers, polycarbonate resins, Polyacrylonitrile-butadiene copolymer,
Polyether resins and the like are preferred, and more preferred are epoxy resins, polyurethane resins and acrylic resins.

In the present invention, the heat-sensitive layer is a heat-sensitive layer which efficiently absorbs a laser beam, and a part or all of which burns, evaporates or melts instantaneously by the heat, and a heat-sensitive layer which efficiently absorbs a laser beam. Then, the heat-sensitive layer causes a polymerization reaction by the heat and, at the same time, firmly adheres to the upper silicone rubber layer.

First, the heat-sensitive layer destruction type will be described.

In the heat-sensitive destruction type, it is necessary to efficiently absorb laser light, and the absorptivity for the wavelength (around 800 nm) of a semiconductor laser used as a light source is important. Examples of such a heat-sensitive layer include a metal thin film and a composition comprising at least a light-to-heat conversion substance and a thermally decomposable compound.

When the heat-sensitive layer is a metal thin film, there is no particular limitation as long as it can be deposited or sputtered. The thickness of the metal is preferably 1000 Å or less, and if it is in the range of 20 to 200 Å, high sensitivity is obtained, and it is particularly preferable.

Specifically, preferred metals include titanium, aluminum, bismuth, nickel, chromium, tellurium, tin, tungsten, antimony, gallium, polonium, selenium, magnesium, zinc, iron and the like. Antimony, gallium, bismuth, titanium and zinc are more preferred. The use of alloys of these metals is also effective in lowering the melting point and improving the sensitivity as a printing plate.

The heat-sensitive layer comprises at least a light-to-heat conversion material,
In the case of a composition comprising a thermally decomposable compound, the light-to-heat conversion material is carbon black or a dye for electronics or recording, and has a maximum absorption wavelength of 700 nm to 900 nm.
In the range of, cyanine dyes, azurenium dyes,
Squarylium dye, croconium dye, azo disperse dye, bisazostilbene dye, naphthoquinone dye, anthraquinone dye, perylene dye, phthalocyanine dye, naphthalocyanine metal complex dye, dithiol nickel complex dye, indoaniline Infrared or near-infrared absorbing dyes such as metal complex dyes, intermolecular CT dyes, and benzothiopyran-based spiropyrans are preferred.

Also, black dyes such as Acid First Black, Acid Black, Direct Black, Azoic Black, Bat Black, Disperse Black, Solvent Black, Reactive Black, and Chrome Black as referred to by the color index name are preferably used. You.

Among the above dyes, those having a large molar extinction coefficient are most preferably used. Specifically, ε = 1 × 1
0 ⁴ or more, more preferably 1 × 10 ⁵ or more.

When ε is smaller than 1 × 10 ⁴ , the effect of improving sensitivity is small. Here, the molar extinction coefficient is a value obtained by the “Lambert-Beer rule” A = εcb (A: absorbance, ε: molar extinction coefficient, c: concentration, b: optical path length).

The amount of the dye added is preferably 0.2% by weight or more based on all the components of the heat-sensitive layer from the viewpoint of improving the sensitivity of the printing plate, and is preferably 20% by weight or less. It is preferable in that the printing property is improved. More preferably 0.5
-10% by weight.

Although the above dyes alone have an effect of improving sensitivity, it is preferable to use two or more dyes in combination because it is possible to further improve the sensitivity.

Further, the above dye may be added at the time of preparing the thermosensitive layer composition. However, when the dye is previously mixed with the heat decomposable compound, the heat decomposable compound is dyed and the effect of improving sensitivity is exhibited. It's easy to do.

In order to further enhance the effect of adding the above dye, 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 cobalt oxide It is preferable to add additives such as metal oxides such as tungsten oxide and hydroxides of these metals, metal salts such as sulfates, bismuth, tin and tellurium.

The addition amount of these additives is preferably 2% by weight or more based on the total heat-sensitive layer composition from the viewpoint of the effect of improving the sensitivity, and is preferably 70% by weight or less. It is preferable in terms of properties. More preferably, it is 5 to 60% by weight.

As the thermally decomposable compound, a compound which is easily decomposed by heat and changes the adhesive force between the upper silicone rubber layer and the heat-sensitive layer is preferable. 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, polymethylmethacrylate And at least one of monomers such as polyacrylic acid, polymethacrylic acid, alkyl polyacrylate, alkyl polymethacrylate (alkyl groups such as methyl, ethyl, propyl and butyl), styrene and butadiene. Copolymer with polyvinyl alcohol, polyvinyl acetate,
Polyvinyl pyrrolidone, polyvinyl alkyl ether (alkyl groups such as 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, polyisoprene, polyurethane, polyester, polyvinyl butyral, Examples include homopolymers or copolymers such as polyvinyl formal and styrene-butadiene rubber. Among them, nitrocellulose, cellulose derivatives such as cellulose acetate, and ethylene-vinyl acetate copolymer are preferable, and nitrocellulose is more preferable.

The nitrogen content of nitrocellulose is determined by the degree of substitution of the nitro group. In the present invention, the nitrogen content is preferably 6.8% or more in terms of excellent printing plate sensitivity. 0.5% or less is preferable in terms of handling safety because there is little danger of explosion and the like.
More preferably, it is 10.3% to 12.8%.

Further, nitrocellulose having various molecular weights depending on the degree of polymerization can be obtained. In the present invention, all of them can be used. It is preferable in terms of properties, and it is preferably 290 or less in terms of low viscosity and easy handling. More preferably, it is from 45 to 290.

As the thermally decomposable compound, in addition to those described above, polyacetylene, polyaniline, and the like, which are known as conductive polymers, are preferably used.

The amount of the thermal decomposable compound used is preferably 10% by weight or more based on the total heat-sensitive layer composition in terms of excellent printing plate sensitivity, and is preferably 80% by weight or less. It is preferable in terms of storage stability. More preferably 2
0 to 60% by weight.

The heat-sensitive layer preferably has a crosslinked structure in order to increase the solvent resistance to printing ink.

Examples of the polyfunctional crosslinking agent used for introducing a crosslinked structure include a polyfunctional isocyanate compound, a polyfunctional epoxy compound, a urea compound and a photopolymerizable monomer.

As the polyfunctional isocyanate, for example,
Hexamethylene diisocyanate, isophorone diisocyanate, paraphenylene diisocyanate, 2,4-
Also, there are 2,6-toluene diisocyanate, 4,4-diphenylmethane diisocyanate, polymethylene polyphenyl isocyanate and adducts thereof, and the polyfunctional epoxy compound is, for example, polyethylene glycol. -Rudiglycidyl ethers, polypropylene glycol-diglycidyl ethers, bisphenol-
And dimethylidyl ether and trimethylolpropane triglycidyl ether. Examples of the urea compound include a urea resin, a melamine resin, and a benzoguanamine resin.

Examples of the photopolymerizable monomer include monofunctional acrylates such as polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, and phenoxyethyl (meth) acrylate.
And methacrylate, polyethylene glycol di (meth) acrylate, trimethylethaneethane (meth)
Acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol di (meth) acrylate
G, pentaerythritol tetra (meth) acryle
G, dipentaerythritol hexa (meth) acryle
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 the (meth)
Acrylates, urethane acrylates described in JP-B-48-41708 and JP-B-51-37193, and JP-B-48-64183.
JP, JP-B-49-43191, JP-B-52-
No. 30,490, polyfunctional acrylates and methacrylates such as polyester acrylates, epoxy acrylates obtained by reacting an epoxy resin with (meth) acrylic acid, and US Pat. No. 4,540,549. The N-methylolacrylamide derivatives described above can be exemplified.

Further, those described in JP-A-4-271522, in which an organic silyl group is introduced into the molecular chain of a polyfunctional cross-linking agent to enhance the adhesion to the upper silicone layer, and JP-A-4-271522. Amino group-containing monomers described in JP-A-221743 can also be preferably used.

The heat-sensitive layer can be cross-linked by using the above-mentioned polyfunctional cross-linking agent in combination with a polymer containing a hydroxyl group, a carboxyl group, or an amino group, or a known photopolymerization initiator or photosensitizer.

The amount of the polyfunctional crosslinking agent used is preferably 1% by weight or more based on the total heat-sensitive layer composition from the viewpoint of the solvent resistance of the printing plate, and is preferably 50% by weight or less.
The printing plate is preferred because it is soft and has excellent printing durability. More preferably, it is 3 to 40% by weight.

For the purpose of improving printing durability and storage stability, it is preferable to include a binder polymer. Examples of the polymer used at this time include the polymer used for the primer layer. The content of the binder polymer is preferably 10% by weight or more based on the total heat-sensitive layer composition from the viewpoint of printing durability, and is preferably 60% by weight or less from the viewpoint of sensitivity. More preferably 20 to
50% by weight.

In addition to the above, a small amount of a photocurable diazo resin may be added to improve the adhesion to the primer layer. As such a diazo resin, US Pat.
No. 147 and US Pat. No. 2,632,703 are mentioned, and a diazo resin represented by a condensate of an aromatic diazonium salt and an active carbonyl-containing compound (for example, formaldehyde) is particularly useful. Preferred diazo resins include, for example, hexafluorophosphate, tetrafluoroborate, and phosphate of a condensate of p-diazodiphenylamine and formaldehyde or acetaldehyde. Further, a sulfonate of a condensate of p-diazodiphenylamine and formaldehyde (for example, p-toluenesulfonate, dodecylbenzenesulfonate,
2-methoxy-4-hydroxy-5-benzoylbenzenesulfonate, etc.), phosphinates, organic carboxylate and the like are also preferable. The preferable addition amount of the diazo resin is 0.1 to 5% by weight based on the total heat-sensitive layer composition.

Further, the heat-sensitive layer may appropriately contain additives such as a preservative, an antihalation dye, an antifoaming agent, an antistatic agent, a dispersant, an emulsifier, and a surfactant. In particular, it is preferable to contain a fluorine-based surfactant in order to improve coatability. The content of these additives is preferably 10% by weight or less based on the total heat-sensitive layer composition.

Further, in order to enhance the adhesiveness to the silicone rubber layer, a silica powder or a hydrophobic silica powder whose surface has been treated with a silane coupling agent containing a (meth) acryloyl group or an allyl group may be used as the whole heat-sensitive layer composition. May be added in an amount of not more than 20% by weight.

The composition for forming the heat-sensitive layer is as follows:
Dimethylformamide (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,
It is prepared as a composition solution by dissolving in a suitable organic solvent such as cyclohexanol, diacetone alcohol, benzyl alcohol, butyl butyrate, and ethyl lactate. Such a composition solution is uniformly applied on a substrate and heated at a required temperature for a required time to form a heat-sensitive layer.

These heat curing must be carried out at a temperature at which the thermally decomposable compound does not decompose, usually at 130 ° C. or lower. For this purpose, it is preferable to use a catalyst in combination.

In the case where a photopolymerizable monomer is used, it is necessary to apply and heat and then photo-cur with a light source such as an ultra-high pressure mercury lamp or a halogen lamp.

For the purpose of further improving the sensitivity of the heat-sensitive layer, it is also effective to provide a vapor-deposited metal film between the primer layer and the heat-sensitive layer to form a laser reflection layer. As the deposited film at this time, a deposited film of a metal such as aluminum, nickel, and titanium is used, and among them, an aluminum deposited film is more preferably used. However, in the case of an aluminum vapor deposition film, the preferable film thickness is in the range of 50 to 700 Å, and when the thickness is smaller than 50 Å, the sensitivity of the heat-sensitive layer is apt to be reduced. On the contrary, when the thickness is larger than 700 Å. However, the sensitivity of the heat-sensitive layer tends to decrease.

Next, the heat-sensitive layer remaining type will be described.

The heat-sensitive layer-remaining type needs to contain at least a photothermal conversion substance and a compound which is cured by heating.

As the light-to-heat conversion material, the same materials as those described in the above-mentioned thermosensitive layer destruction type can be used. Among these light-to-heat conversion materials, infrared or near-infrared absorbing dyes and black dyes can be preferably used.

The substance which is cured by heating includes (1)
A compound which is cured by heating is a combination of a compound having two or more ethylenically unsaturated groups in one molecule and a substance which generates a radical by heating, (2) two ethylenically unsaturated groups in one molecule A combination of a compound having the above, a compound having two or more thiol groups in a molecule, and a substance that generates a radical by heating;
(3) One of a combination of an epoxy compound and an amino resin is preferable.

Next, the substance which is cured by heating described in the above (1) will be described.

The substance which is cured by heating as described in (1) is composed of a compound having two or more ethylenically unsaturated groups in one molecule and a substance which generates a radical by heating.

The compound having two or more ethylenically unsaturated groups in one molecule is not particularly limited, but is preferably a compound in which the ethylenically unsaturated group is an acryloyl group or a methacryloyl group.

The following are specific examples of the compound having two or more acryloyl groups or methacryloyl groups in one molecule. In addition, (meth) acrylate shall mean an acrylate and a methacrylate.

(A) An ester of a compound having two or more hydroxyl groups in one molecule with acrylic acid or methacrylic acid.

Specific examples of the compound having two or more hydroxyl groups in one molecule include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, 1,3- Butanediol, 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 2-butene-1,4-diol, 5- Hexene
1,2-diol, 7-octene-1,2-diol,
3-mercapto-1,2-propanediol, hydroquinone, dihydroxyanthraquinone, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, bisphenol A, bisphenol S, phenol formaldehyde novolak resin, resole resin, resorcinbenzaldehyde resin,
Pyrogallol acetone resin, hydroxystyrene polymer and copolymer, glycerin, diglycerin, trimethylolpropane, 1,2,4-butanetriol, pentaerythritol, dipentaerythritol, sorbitol, sorbitan, polyvinyl alcohol, cellulose and derivatives thereof And hydroxyethyl (meth) acrylate polymers and copolymers.

The compound having two or more hydroxyl groups in one molecule and acrylic acid or methacrylic acid can be esterified by a known method to obtain the desired (meth) acrylate compound.

In the esterification reaction, the above compound is preferably charged in such a ratio that the (meth) acrylate compound has a hydroxyl group, from the viewpoint of the adhesion between the silicone rubber layer and the heat-sensitive layer, and more preferably. Is preferably such that two or more hydroxyl groups remain.

(B) A reaction product of an epoxy compound having two or more epoxy groups in one molecule with acrylic acid or methacrylic acid.

Epoxy compounds which can be preferably used in the present invention include epoxy compounds obtained by reacting epihalohydrin with the compound having two or more hydroxyl groups in one molecule described in the above item (a).

By reacting these epoxy compounds with acrylic acid or methacrylic acid by a known method, a (meth) acrylate compound can be used.

(C) A reaction product of a compound having two or more amino groups in one molecule and glycidyl (meth) acrylate.

The compound having two or more amino groups in one molecule includes a polyamine represented by the following general formula (I).

[0098]

Embedded image In the formula, R ¹ and R ² are a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted phenyl group, or a substituted or unsubstituted aralkyl group. It may be different. As the substituent,
Examples thereof include an alkyl group having 1 to 6 carbon atoms, a halogen atom, a hydroxyl group, and an aryl group. Preferably, a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group,
n-butyl group, sec-butyl group, hydroxymethyl group,
Examples include a hydroxypropyl group, a chloromethyl group, a bromomethyl group, a phenyl group, a p-hydroxyphenyl group, a p-bromophenyl group, a p-tolyl group, an o-tolyl group, and a benzyl group.

A represents a divalent linking group, specifically represented by the general formula-(A ¹ ) _p- (A ² ) _q- . Where A
¹ is a substituted or unsubstituted cyclic or acyclic alkylene having 1 to 20 carbon atoms, a substituted or unsubstituted phenylene, and the substituent is an alkyl group having 1 to 6 carbon atoms, a halogen atom, a hydroxyl group, And an aryl group. A ^{2
Is, -O-B 1 -, -} S-B 2 -, - NH-B 3 -, -
CO—O—B ⁴ —, —SO ₂ —NH—B ⁵ —, B ¹ ,
B ² , B ³ , B ⁴ and B ⁵ are the same as A ¹ described above. p represents an integer of 1 or more, and q represents 0 or an integer of 1 or more.

Specific examples of the compound represented by the general formula (I) having two or more amino groups in one molecule include dioxyethylenediamine, trioxyethylenediamine, tetraoxyethylenediamine, pentaoxyethylenediamine, hexaoxyethylenediamine, and pepoxyethylenediamine. Taoxyethylenediamine, octaoxyethylenediamine, nonaoxyethylenediamine, decaoxyethylenediamine, tritriacontaoxyethylenediamine, monooxypropylenediamine, dioxypropylenediamine, trioxypropylenediamine, tetraoxyethylenediamine, pentaoxypropylenediamine, hexaoxypropylenediamine , Heptaoxypropylenediamine, octaoxypropylenediamine, nonaoxypropylenediamine Decaoxypropylenediamine, tritriacontaoxypropylenediamine, polymethylenediamine, polyetherdiamine, diethylenetriamine, iminobispropylamine, bis (hexamethylene) triamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, dimethylaminopropyl Amines, diethylaminopropylamine, aliphatic polyamine compounds such as substituted polyamines, m-xylylenediamine, aliphatic polyamine compounds having an aromatic ring such as tetrachloro-p-xylylenediamine, menthanediamine, N-aminoethylpiperazine, Alicyclic polyamines such as 1,3-diaminocyclohexane and isophoronediamine, m-phenylenediamine,
Diaminodiphenyl ether, 4,4′-methylenedianiline, diaminodiphenylsulfone, benzidine,
4,4'-bis (o-toluidine), 4,4'-thiodianiline, o-phenylenediamine, dianisidine, methylenebis (o-chloroaniline), 2,4-toluenediamine, bis (3,4-diaminophenyl) Examples thereof include aromatic polyamine compounds such as sulfone, diaminoditrisulfone, 4-chloro-o-phenylenediamine, 4-methoxy-6-methyl-m-phenylenediamine, and m-aminobenzylamine, dicyandiamide, and adipic dihydrazide.

Also, 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-ethylimidazole, 2,4-dimethylimidazole and the like can be mentioned.

Further, polyamidoamine obtained by reacting the above-mentioned polyamine with carboxylic acid so that both terminals become amino groups can also be mentioned.

The compound having two or more amino groups in one molecule and glycidyl (meth) acrylate can be reacted by a known method to obtain a desired (meth) acrylate compound.

(D) A reaction product of a compound having two or more amino groups in one molecule with acrylic acid or methacrylic acid.

The compound having two or more amino groups in one molecule described in the above item (c) is reacted with acrylic acid or methacrylic acid by a known method to obtain a (meth) acrylate compound, which is used. Can be.

(E) A reaction product of a compound having two or more carboxyl groups in one molecule and glycidyl (meth) acrylate.

Specific examples of the compound having two or more carboxyl groups in one molecule include the following.

Malonic acid, succinic acid, malic acid, thiomalic acid, racemic acid, citric acid, glutaric acid, adipic acid,
Pimelic acid, spearic acid, azelaic acid, sebacic acid,
Divalent organic carboxylic acids such as maleic acid, fumaric acid, itaconic acid and dimer acid; trivalent organic carboxylic acids such as trimellitic acid; and 3,9-bis (2-carboxyalkyl)
2,4,8,10-tetraoxaspiroundoundane and the like.

Further, a carboxy-modified unvulcanized rubber can be used. Specifically, natural rubber, butadiene,
Isoprene, styrene, acrylonitrile, carboxy-modified homopolymer or copolymer selected from acrylates, such as carboxy-modified polybutadiene, carboxy-modified styrene-butadiene copolymer, carboxy-modified acrylonitrile-butadiene copolymer,
Examples include carboxy-modified methyl methacrylate-butadiene copolymer.

Further, a compound obtained by subjecting the above polyvalent carboxylic acid to an esterification reaction with polyethylene glycol or polypropylene glycol can also be used. The compound preferably has carboxyl groups at both ends.

By reacting a compound having two or more carboxyl groups in one molecule with glycidyl (meth) acrylate by a known method, a (meth) acrylate compound can be used.

(F) Esterified product of a compound having two or more carboxyl groups in one molecule and hydroxy (meth) acrylate.

Examples of the compound having two or more carboxyl groups in one molecule include those described in the above item (e). The compound having two or more carboxyl groups in one molecule can be reacted with hydroxy (meth) acrylate by a known method to obtain a (meth) acrylate compound, which can be used.

Among these, the (meth) acrylate compound preferably has a hydroxyl group from the viewpoint of the adhesiveness between the silicone rubber layer and the heat-sensitive layer.
The (meth) acrylate compounds described in the items (b), (c) and (e) are preferable.

Next, the substance which generates radicals by heating in (1), which is a compound which is cured by heating, will be described.

The substance which generates a radical by heating is not particularly limited, but specific examples include organic peroxides, azo compounds, sulfides and the like.

As the organic peroxide, those having a decomposition temperature of 120 ° C. or more for a half-life of 1 minute are preferable from the viewpoint of storage stability of the unexposed printing plate precursor. Specific examples of such an organic peroxide include 2,4-dichlorobenzoyl peroxide, cumyl peroxy octoate, acetyl peroxide, succinic peroxide, t
-Butylperoxy (2-ethylhexanoate), m
-Toluolyl peroxide, benzoyl peroxide, t-butylperoxysobutyrate, 1,1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxide) Oxy) cyclohexane, t-butylperoxymaleic acid, t-
Butylperoxylaurate, t-butylperoxy 3,5,5-trimethylhexanoate, cyclohexanone peroxide, t-butylperoxyallyl carbonate, t-butylperoxyisopropyl carbonate, 2,5-dimethyl-2, 5-di (benzoylperoxy) hexane, 2,2-bis (t-butylperoxy) octane, t-butylperoxyacetate,
2-bis (t-butylperoxy) butane, t-butylperoxybenzoate, n-butyl-4,4-bis (t-butylperoxy) valerate, di-t-butylperoxyisophthalate, methyl ethyl ketone peroxide, Dicumyl peroxide, 2,5-dimethyl-
2,5-di (t-butylperoxy) hexane, α,
α'-bis (t-butylperoxy-m-isopropyl) benzene, t-butylcumyl peroxide, diisopropylbenzene hydroperoxide, di-t-butyl peroxide, p-menthanehydroperoxide, 2,5-dimethyl- 2,5-di (t-butylperoxy) hexyne, 1,1,3,3-tetramethylbutyl hydroperoxide, 2,5-dimethylhexane-
Examples thereof include 2,5-dihydroperoxide, cumene hydroperoxide, t-butyl hydroperoxide and the like.

Specific examples of the azo compound include azobisisobutylnitrile, 2-phenylazo-2,4-dimethyl-4-methoxyvaleronitrile, 2-cyano-2-propylazoformamide, 1,1-azobiscyclohexane- Examples thereof include 1-carbonitrile, 1,1′-azobis (1-acetoxy-1-phenylene), and 2,2′-azobis (2-amidobutane) dihydrochloride.

Specific examples of the sulfides include known monosulfides, disulfides, tetramethylthiuram disulfide and the like.

Among the substances which generate radicals by heating, organic peroxides are preferred.

Next, combinations of the preferred item (2) as a compound which is cured by heating will be described.

The item (2) is a compound having two or more ethylenically unsaturated groups in one molecule, and having two or more thiol groups in one molecule.
It is a combination of a compound having at least one compound and a substance that generates a radical by heating.

The compound having two or more ethylenically unsaturated groups in one molecule is not particularly limited, but is preferably a compound in which the ethylenically unsaturated group is a (meth) acryloyl group, a vinyl group, or an allyl group. preferable. Specific examples include the following compounds in addition to the compounds described in the above (1).

(A) Allyl urethanes A polyvalent isocyanate and an allyl alcohol are substituted with one allyl group.
A product obtained by an addition reaction such that two or more molecules are present in a molecule is exemplified.

Examples of the polyvalent isocyanate include the following. Paraphenylene diisocyanate, 2,4- or 2,6-toluylene diisocyanate (TDI), 4,4-diphenylmethane diisocyanate (MDI), tolidine diisocyanate (TO
DI), xylylene diisocyanate (XDI), hydrogenated xylylene diisocyanate, cyclohexane diisocyanate, meta-xylylene diisocyanate (MXD
I), hexamethylene diisocyanate (HDI or HMDI), lysine diisocyanate (LDI) (alias 2,6-diisocyanatomethylcaproate), hydrogenated MDI (H12 MDI) (alias 4,4'-methylenebis (cyclohexyl isocyanate)), Hydrogenated TDI
(HTDI) (also known as methylcyclohexane 2,4 (2,
6) diisocyanate), hydrogenated XDI (H6XDI)
(Also known as 1,3- (isocyanatomethyl) cyclohexane), isophorone diisocyanate (IPDI), diphenyl ether isocyanate, trimethylhexamethylene diisocyanate (TMDI), tetramethyl xylylene diisocyanate, polymethylene polyphenyl isocyanate, dimer acid diisocyanate ( DD
I), triphenylmethane triisocyanate, tris (isocyanatephenyl) thiophosphate, tetramethylxylylene diisocyanate, lysine ester triisocyanate, 1,6,11-undecane triisocyanate, 1,8-diisocyanate-4-isocyanatomethyloctane, Examples thereof include 1,3,6-hexamethylene triisocyanate, bicycloheptane triisocyanate, and the like, and polymers of polyisocyanates.

Alternatively, a compound obtained by reacting the isocyanate compound and the polyol in such a ratio that the isocyanate group remains may be used as the isocyanate compound.

The polyols that can be used at this time include ethylene glycol, propylene glycol,
1,3-propanediol, 1,4-butanediol,
1,3-butylene glycol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, neopentyl glycol, triethylene glycol, p-xylylene glycol, hydrogenated bisphenol A, bisphenol dihydroxypropyl ether Glycerin, trimethylolethane, trimethylolpropane, trishydroxymethylaminomethane, pentaerythritol, dipentaerythritol, sorbitol and the like.

Further, polypropylene glycol, polyethylene glycol, polytetramethylene glycol,
Ethylene oxide-propylene oxide copolymer,
Tetrahydrofuran-ethylene oxide copolymer, tetrahydrofuran-propylene oxide copolymer, etc., and polyester diols such as polyethylene adipate, polypropylene adipate, polyhexamethylene adipate, polyneopentyl adipate, polyhexamethylene neopentyl adipate, polyethylene hexamethylene Examples of adipate and the like further include poly-ε-caprolactone diol, polyhexamethylene carbonate diol, polytetramethylene adipate, sorbitol, methylglucose, and shucrose.

Also, various phosphorus-containing polyols, halogen-containing polyols and the like can be used as the polyol.

(B) Allyl esters [0130] A product obtained by subjecting a polycarboxylic acid or an acid anhydride thereof to an allyl alcohol by an esterification reaction such that two or more allyl groups are present in one molecule. The polyvalent carboxylic acid and allyl alcohol can be esterified by a known method to form allyl esters.

In this case, specific examples of the polycarboxylic acid used include malonic acid, succinic acid, malic acid, racemic acid, citric acid, glutaric acid, adipic acid, pimelic acid,
Speric acid, azelaic acid, sebacic acid, maleic acid,
Divalent carboxylic acids such as fumaric acid, itaconic acid and dimer acid; trivalent carboxylic acids such as trimellitic acid;
Bis (2 carboxyalkyl) 2,4,8,10-tetraoxaspiroundecane and the like can be mentioned.

A carboxy-modified unvulcanized rubber can also be used. Specifically, it is a carboxy-modified product of a homopolymer or a copolymer selected from natural rubber, butadiene, isoprene, styrene, acrylonitrile, and acrylate, such as carboxy-modified polybutadiene and carboxy-modified styrene-butadiene copolymer. Carboxy-modified acrylonitrile-butadiene copolymer, carboxy-modified methyl methacrylate-butadiene copolymer, and the like.

Specific examples of the acid anhydride include acetic anhydride, propionic anhydride, butyric anhydride, maleic anhydride, citraconic anhydride, crotonic anhydride, phthalic anhydride and the like.

(C) Vinyl ethers Examples of the product include a product obtained by reacting a polyol with acetylene or an ether exchange reaction between polyol and vinyl ether so that two or more vinyl groups are present in one molecule. In this case, as the polyol, the polyol described in the section of (a) Allyl urethanes can be used. These polyols are subjected to an addition reaction with acetylene by a known method to obtain vinyl ethers, which can be used.

Further, vinyl ethers can also be obtained by subjecting the above polyol to methyl vinyl ether or ethyl vinyl ether to undergo a transesterification reaction by a known method.

Specific examples of vinyl ethers include dipropylene glycol divinyl ether, triethylene glycol divinyl ether, m-phenylene bis (ethylene glycol) divinyl ether and the like.

These compounds having two or more ethylenically unsaturated groups in one molecule may be used alone or in combination of two or more.

Among these compounds having two or more ethylenically unsaturated groups in one molecule, allyl urethanes and urethane acrylates are used for the purpose of imparting flexibility to the heat-sensitive layer and improving the printing durability of the printing plate. It is preferable to use epoxy acrylate in combination with the silicone rubber layer from the viewpoint of adhesion.

A compound having two or more thiol groups in one molecule will be described. As the compound having two or more thiol groups in one molecule, known dithiols and polythiols can be used, and specific examples of more preferable compounds include the following.

(A) Dithiols having an aliphatic hydrocarbon as a main chain: methanedithiol, ethanedithiol, propanedithiol, butanedithiol, heptanedithiol, hexanedithiol, octanedithiol, nonanedithiol, decanedithiol, undecanedithiol, dodecanedithiol, Tridecanedithiol, tetradecanedithiol, heptadecanedithiol, hexadecanedithiol, octadecanedithiol, 4,8-dithiaundecane-1,11-dithiol, bis (2-mercaptoethyl) sulfide, 1,3-dihydroxy-2-propyl- 2 ', 3'-dimercaptopropyl ether,
2,3-dihydroxypropyl-2 ', 3'-dimercaptopropyl ether, 2,6-dimethyloctane-
2,6-dithiol, 2,6-dimethyloctane-3,
7-dithiol, 3,3-dimethylbutane-2,2-
Dithiol, 2,2-dimethylpropane-1,3-dithiol, 3,4-dimethoxybutane-1,2-dithiol, 3,4-dimercaptobutanol, 2,3-dimercapto-1-propanol, 1,3- Dimercapto-2
-Propanol, 1,2-dimercapto-1,3-butanediol, 1,2-dimercaptopropyl methyl ether, 2,3-dimercaptopropyl methyl ether,
2,3-dimercaptopropyl-2 ', 3'-dimethoxypropyl ether, 3,5,5-trimethylhexane-1,1-dithiol, 3,4,5-trimethoxypentane-1,2-dithiol, neo Pentanetetrathiol, bis (11-mercaptoundecyl) sulfide,
Bis (2-mercaptoethyl) sulfide, bis (18
-Mercaptooctadecyl) sulfide, bis (8-mercaptooctyl) sulfide, bis (10-mercaptodecyl) sulfide, bis (12-mercaptodecyl) sulfide, bis (9-mercaptononyl) sulfide, bis (4-mercaptobutyl) sulfide Bis (3-mercaptopropyl) sulfide, bis (6-mercaptohexyl) sulfide, bis (7-mercaptoheptyl) sulfide, bis (5-mercaptopentyl) sulfide, 2,2-bis (mercaptomethyl)-
1,3-propanedithiol.

(B) Dithiols having an aromatic or heterocyclic ring as the main chain 9,10-anthracenedimethanethiol, 1,3-diphenylpropane-2,2-dithiol, 2,4-dimethylbenzene-1,3 -Dithiol, 4,5-dimethylbenzene-1,3-dithiol, 4,4'-dimercaptobiphenyl, 4,4'-dimercaptobibenzyl,
2,4-di (p-mercaptophenyl) pentane, 2,
5-toluenedithiol, 3,4-toluenedithiol, 1,4-naphthalenedithiol, 1,5-naphthalenedithiol, 2,6-naphthalenedithiol, 2,7-
Naphthalenedithiol, 1,1, -bis (mercaptomethyl) cyclohexane, phenylmethane-1,1-dithiol, 4-tert-butylcyclohexane-1,1
-Dithiol, 1,2-benzenedithiol, 1,3-
Benzenedithiol, 1,4-benzenedithiol,
1,3,5-benzenetrithiol.

(C) Esterified product of a polyol and a thiol compound having a carboxyl group Examples of the thiol having a carboxyl group include mercaptoacetic acid, thioglycolic acid, α-mercaptopropionic acid, β-mercaptopropionic acid, 4-mercaptobutyric acid, and mercaptobutyric acid. Examples include undecylic acid, o-mercaptobenzoic acid, and p-mercaptobenzoic acid.

Examples of the polyol include those described in the item (a) in the explanation of the item (2).

Among the above compounds having two or more thiol groups in one molecule, aliphatic hydrocarbons are used in the main chain for the purpose of imparting flexibility to the heat-sensitive layer and improving the printing durability of the printing plate. An esterified product of a dithiol and a polyol and a thiol compound having a carboxyl group is preferable, and an esterified product of a combination of trimethylolpropane or pentaerythritol with thioglycolic acid or β-mercaptopropionic acid or a mixture thereof is preferable.

Next, the combination of item (3), which is preferably mentioned as a substance which is cured by heating, will be described.

The item (3) is a combination of an epoxy compound and an amino compound. As the epoxy compound, the epoxy compound described in the item (b) in the explanation of the item (1) can be used.

As the amino compound, the polyamine compounds described in the section (c) in the description of the above section (1) can be used. Furthermore, amino group-containing resins such as urea resins and melamine resins can also be used.

These amino compounds may be used alone or in combination of two or more.

From the viewpoint of storage stability of the heat-sensitive layer solution, preferably, so-called amine adducts obtained by reacting the above-mentioned polyamine with an epoxy compound can be preferably used.

Further, the heat-sensitive layer-remaining type preferably contains, in addition to the light-to-heat conversion substance and the compound which is cured by heating, a substance which generates an acid by heating. The acid generated by heating accelerates the thermosetting reaction of the thermosensitive layer, and as a result, the sensitivity of the printing plate precursor can be improved. Specific examples of the substance that generates an acid upon heating include the following.

(1) Onium Salt Iodinium salt, sulfonium salt, phosphonium salt, pyridium salt, diazonium salt and the like.
Preferably, diphenyliodonium triflate, diphenyliodonium pyrene sulfonate, diphenyliodonium dodecylbenzenesulfonate, triphenylsulfonium triflate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium naphthalenesulfonate, (hydroxyphenyl) benzylmethylsulfonium toluenesulfonate and the like is there.

(2) Halogen-Containing Compounds Haloalkyl group-containing heterocyclic compounds, haloalkyl group-containing hydrocarbon compounds and the like can be mentioned. Specific examples include an acetophenone compound containing a halogen, a pyrone compound, a triazine compound, and an oxazole compound. Preferably, phenyl-bis (trichloromethyl) -s-triazine, methoxyphenyl-
Bis (trichloromethyl) -s-triazine, naphthyl-bis (trichloromethyl) -s-triazine, 1,1
-Bis (4-chlorophenyl) -2,2,2-trichloroethane, trichloroacetophenone, decyl chloride (2-chloro-2-phenylacetophenone) and the like.

(3) Sulfone compounds β-ketosulfone, β-sulfonylsulfone and their α-diazo compounds can be exemplified. Preferred are phenacylphenylsulfone, mesitylphenacylsulfone, triboromomethylphenylsulfone, bis (phenylsulfonyl) methane, bis (phenylsulfonyl) diazomethane and the like.

(4) Sulfonate Compound Alkyl sulfonic acid ester, haloalkyl sulfonic acid ester, aryl sulfonic acid ester, imino sulfonate and the like can be mentioned. Preferably, benzoin tosylate, tris triflate of pyrogallol, nitrobenzyl-9,10-diethoxyanthracene-2
-Sulfonate, 2,6-dinitrobenzylsulfonate ester, o-nitrobenzylsulfonate ester and the like.

Other examples include N-imidoyl ester, pyrogallol ester, nitrobenzyl ester, α-sulfonyloxyketone, tris (trichloromethyl) triazine and the like.

Among these substances that generate an acid by heating, there are substances that decompose even by visible light or ultraviolet light to generate an acid. In the case of such a substance that decomposes by light, a dye that absorbs a wavelength range felt by the substance can be added to the heat-sensitive layer, so that light exposure resistance in a bright room can be imparted. In addition, when a black dye is used as the light-to-heat conversion material, the black dye generally has an absorption range up to the visible light and ultraviolet regions, so that it can have light exposure resistance without using another dye.

It is also preferable that the residual thermosensitive layer type of the present invention contains a binder polymer, and the binder polymer described for the thermosensitive layer destruction type can be suitably used.

The destructible and residual heat-sensitive layers of the present invention may optionally contain a dye, an acid, a leveling agent, a surfactant, a plasticizer, and the like having an absorption in a region other than the wavelength of the laser beam, if necessary. Can be added.

It is preferable to dilute the above-mentioned composition constituting the heat-sensitive layer in a known organic solvent to prepare and use the solution as a heat-sensitive layer solution.

The thickness of the heat-sensitive layer is preferably 0.1 μm or more from the viewpoint of the sensitivity of the heat-sensitive layer, and is preferably 20 μm or less from the viewpoint of ink consumption. More preferably, it is 0.3 μm to 10 μm.

Next, the silicone rubber layer will be described. As the silicone rubber layer of the present invention, any silicone rubber composition conventionally used for a waterless lithographic printing plate can be used.

Specifically, it is obtained by sparsely cross-linking a linear organopolysiloxane (preferably dimethylpolysiloxane). Typically, a repeating unit represented by the following formula (II) is used. And a silicone composition having the same.

[0163]

Embedded image Here, n is an integer of 2 or more. R is an alkyl, aryl, or cyanoalkyl group having 1 to 10 carbon atoms. Preferably, 40% or less of the whole R is vinyl, phenyl, vinyl halide, or halogenated phenyl, and 60% or more of R is a methyl group. Further, it has at least one or more hydroxyl group in the molecular chain at the chain end or in the form of a side chain.

In the present invention, a silicone rubber (RT) which performs the following condensation type crosslinking on the silicone rubber layer is used.
V, LTV silicone rubber). As such a silicone rubber, those in which a part of R of the organopolysiloxane chain is substituted with H can be used, but usually, the end groups represented by the following formulas (II), (III) and (IV) are used. Are crosslinked by condensation of An excess of a crosslinking agent may be present in this.

[0165]

Embedded image Here, R is the same as R described in the formula (II).

[0166]

Embedded image Here, R is the same as R described in formula (II),
₁ , R ₂ is a monovalent lower alkyl group.

[0167]

Embedded image Here, R is the same as R described in formula (II),
Is an acetyl group.

Examples of the silicone rubber which undergoes such condensation type crosslinking include metal carboxylate salts such as tin, zinc, lead, calcium and manganese, such as dibutyltin laurate, tin (II) octoate, and naphthenic acid. A salt or the like or a catalyst such as chloroplatinic acid is added.

In addition, it is also possible to add a hydroxyl group-containing organopolysiloxane or a hydrolyzable functional group-containing silane (or siloxane) which is a composition of the condensation type silicone rubber layer, and to improve the rubber strength. It is optional to add a known filler such as silica for the purpose. Further, in the present invention, it is also possible to use an addition type silicone rubber in addition to the above condensation type silicone rubber.

The addition type silicone rubber layer used in the present invention comprises a polyorganosiloxane having two or more vinyl groups in the molecule, a polyorganosiloxane having three or more SiH groups in the molecule, and a platinum compound. It is formed by applying a solution diluted with a suitable solvent on the photosensitive layer, drying by heating and curing.

Examples of the organopolysiloxane having two or more vinyl groups in the molecule used for the addition type silicone rubber layer include those having a vinyl group at either the terminal or the middle of the molecular chain. Preferred as the organic group are a substituted or unsubstituted alkyl group and an aryl group. Further, it may contain a trace amount of hydroxyl group.

Specific examples of the polyorganosiloxane having two or more vinyl groups in the molecule include the following.

Polydimethylsiloxane having vinyl groups at both terminals, (methylvinylsiloxane) (dimethylsiloxane) copolymer having methyl groups at both terminals, (methylvinylsiloxane) (dimethylsiloxane) copolymer having vinyl groups at both terminals, A compound in which two or more molecules of a vinyl group polydimethylsiloxane are cross-linked by dimethylene, a (methyl 1-hexene siloxane) (dimethyl siloxane) copolymer having a methyl group at both terminals, and a (methyl 1-
Hexene siloxane) (dimethyl siloxane) copolymer and the like.

These vinyl group-containing polysiloxanes preferably have a molecular weight of 5,000 or more, more preferably 10,000 or more, in view of rubber physical properties after curing.

These vinyl group-containing polysiloxanes can be used singly or as a mixture of a plurality of kinds at an arbitrary ratio.

Examples of the polyorganosiloxane having three or more SiH groups in the molecule include those having a SiH group at either the terminal or the middle of the molecular chain. Preferred organic groups other than the SiH group are substituted. Alternatively, it is an unsubstituted alkyl group or aryl group.

Specific examples of the polyorganosiloxane having three or more SiH groups in the molecule include the following.

Polydimethylsiloxane having SiH groups at both terminals, polymethylhydrogensiloxane having methyl groups at both terminals, (methylhydrogensiloxane) (dimethylsiloxane) copolymer having methyl groups at both terminals, SiH groups at both terminals
(Methyl hydrogen siloxane) (dimethyl siloxane) copolymer, cyclic polymethyl hydrogen siloxane and the like.

Of these, those which can be preferably used in the present invention are those having a value obtained by dividing the number of SiH groups of a polyorganosiloxane having three or more SiH groups in a molecule by a molecular weight of 0.001 mol / g or more. And more preferably 0.002 mol / g or more. 0.
If it is less than 001 mol / g, the curing speed is undesirably reduced.

Further, these SiH group-containing polyorganosiloxanes can be used alone, or a plurality of kinds can be used as a mixture at an arbitrary ratio.

It is preferable that 60% or more of the organic groups of the vinyl group-containing polyorganosiloxane and the SiH group-containing polyorganosiloxane are methyl groups from the viewpoint of improving ink repellency.

The mixing ratio of the above vinyl group-containing polyorganosiloxane to the SiH group-containing polyorganosiloxane is such that when the number of vinyl groups in the silicone rubber composition is 1, the number of SiH groups is 1.5. Is preferable, and more preferably 1.5 to 1.5.
To 12 are preferred.

When the number of SiH groups relative to the number of vinyl groups is 1.5
If it is less than 1, the curability of the silicone rubber layer decreases, and
If it is larger than 5, the silicone rubber becomes brittle and the abrasion resistance tends to decrease, which is not preferable.

The platinum compound used in the addition type silicone rubber layer is not particularly limited, but includes platinum alone, platinum chloride, chloroplatinic acid, olefin-coordinated platinum and the like. Among these, olefin-coordinated platinum is preferable.

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

Examples of the addition type silicone rubber composition preferably used in the present invention include the following.

(1) 100 parts by weight of a polyorganosiloxane having two or more vinyl groups in one molecule (2) 0.1 to 10,000 parts by weight of a polyorganosiloxane having three or more SiH groups in one molecule (3) Platinum compound 0.00001 to 10 parts by weight (4) Reaction inhibitor 0.1 to 10 parts by weight (5) Solvent 100 to 4000 parts by weight In addition to these compositions, hydroxyl group which is a composition of the condensation type silicone rubber layer It is also possible to add organopolysiloxane containing, hydrolyzable functional group containing silane (or siloxane), and to improve rubber strength,
It is also possible to add known fillers such as silica.

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

As specific examples of the silane coupling agent,
Known materials such as vinyl silane, (meth) acryloyl silane, epoxy silane, amino silane, mercapto silane and chloro silane can all be used, and among them, (meth)
Acryloyl silane, epoxy silane, amino silane,
And mercaptosilane.

Among them, epoxysilane is particularly preferred. Specific examples of epoxysilane include 3-glycidoxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and the like.

These silane coupling agents are preferably used at a ratio of 0.1 to 5% by weight, more preferably 0.5% by weight, based on the solid content of the silicone rubber layer composition.
３3% by weight.

The thickness of the silicone rubber layer is 0.5
To 50 g / m ² , more preferably 0.5 to 50 g / m ^2.
10 g / m ² . When the film thickness is smaller than 0.5 g / m ^2, the ink repellency of the printing plate tends to decrease,
If it is larger than 50 g / m ² , it is disadvantageous from an economic point of view.

The silicone rubber layer on the surface of the direct drawing type waterless planographic printing plate precursor of the invention described above is protected,
In the case where the heat-sensitive layer is a heat-polymerizable composition, a thin protective film having a plane or uneven surface treated on the surface of the silicone rubber layer may be laminated for the purpose of blocking oxygen at the time of exposure or the like, as disclosed in JP-A-5-323588. It is also possible to form a polymer coating film that dissolves in the developing solvent described in the publication.

In particular, when a protective film is laminated, laser exposure is performed from above the protective film, and then the protective film is peeled off and developed by the above-described method. is important.
In addition, when a radical polymerization-reactive material is used as the heat-sensitive layer composition, it is preferable to use a protective film having low oxygen permeability in order to prevent polymerization inhibition by oxygen. As a type of such a protective film, a polyester film is exemplified.

Next, a method for producing a direct-drawing waterless planographic printing plate precursor will be described.

A reverse roll coater, air knife coater, gravure coater, die coater,
Using a normal coater such as a Meyer bar coater or a spin coater such as a whey coater, apply the primer layer composition as necessary, heat at 100 to 300 ° C. for several minutes and cure, then apply the heat sensitive layer composition After heating at 60 to 130 ° C. for several tens of seconds to several minutes, the silicone rubber composition is applied and heat-treated at a temperature of 50 to 150 ° C. for several minutes to cure the rubber.

Then, if necessary, a protective film is laminated or a protective layer is formed.

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

Laser light is used for the exposure, and the light source at this time has an oscillation wavelength of 300 nm to 1500 n.
Ar 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, etc. Various lasers can be used. Among them, a semiconductor laser is preferable because it is downsized due to recent technological advances and is economically more advantageous than other laser light sources.

The direct drawing type waterless planographic printing plate precursor exposed by the above method is developed by the above method to obtain a target printing plate.

Hereinafter, the present invention will be described in more detail with reference to Examples. In Table 1, the halftone dot reproducibility is a value determined by the ratio (%) at which the number of lines per square inch is 175 and the halftone dot can be reproduced in the line. It means good.

[0202]

【Example】

Example 1 The following primer composition was applied to a 0.15 mm-thick aluminum plate (manufactured by Sumitomo Metal Co., Ltd.) using a bar coater.
Heat treatment was performed at 220 ° C. for 2 minutes to provide a primer layer of 5 g / m ² .

(A) 100 parts by weight of polyurethane resin (Samprene LQ-T1331, manufactured by Sanyo Chemical Industries, Ltd.) (b) 20 parts by weight of block isocyanate (Takenate B830, manufactured by Takeda Pharmaceutical Co., Ltd.) c) Epoxy phenol urea resin (SJ9372, manufactured by Kansai Paint Co., Ltd.) 8 parts by weight (d) Dibutyltin diacetate 0.5 part by weight (e) Victoria pure blue BOH naphthalene sulfonic acid 0.1 part by weight (F) 720 parts by weight of dimethylformamide (DMF) Then, a heat-sensitive layer composition having the following composition was applied thereon using a bar coater, dried in hot air at 130 ° C for 1 minute, and dried. A heat sensitive layer of ² g / m ² was provided.

(A) Nitrocellulose (average degree of polymerization 85, nitrogen content 11.6% (manufactured by Nacalai Tesque, Inc.)) 50 parts by weight (b) Carbon black 2 parts by weight (c) Polyurethane (“SAMPLEN” LQ- T1331, manufactured by Sanyo Chemical Industries, Ltd.) 15 parts by weight (d) Modified epoxy resin (“Epokey” 803, manufactured by Mitsui Toatsu Chemicals, Inc.) 15 parts by weight (e) Epoxy acrylate (“Denacol acrylate” DA314, 15 parts by weight (f) 5 parts by weight of diethylene triamine (g) 200 parts by weight of methyl ethyl ketone Then, a silicone having the following composition was formed on the heat-sensitive layer.
After spin coating the rubber composition, dried at 120 ° C. for 2 minutes,
A silicone rubber layer of ² g / m ² was provided.

(A) 100 parts by weight of polydimethylsiloxane (molecular weight: about 35,000, terminal hydroxyl group) (b) 8 parts by weight of vinyltri (methylethylketoxime) silane (c) Isoparaffinic hydrocarbon (“Isopa-E”, Exxon Chemical) 1400 parts by weight A laminate of a polypropylene film having a thickness of 6.5 μm (“Trefane BO” manufactured by Toray Industries, Inc.) was laminated on a laminate obtained as described above using a calendar roller. A waterless planographic printing plate precursor was obtained.

The printing plate precursor was mounted on a rotating drum, and a semiconductor laser (OPC-A001-mmm-FC,
Output 0.75W, wavelength 830nm, OPTO POWER
R CORPORATION), and pulse exposure was performed at a beam diameter of 20 μm and 10 μs.

Next, the polypropylene cover film of the exposed plate was peeled off, and development processing was performed at a speed of 100 cm / min using an automatic developing machine having a first developing brush and a second developing brush. The developing solution contains water as a main component and a nonionic surfactant "Newcol" 180T (polyoxyethylene stearate, manufactured by Nippon Emulsifier Co., Ltd.)
A 0.5% aqueous solution was used.

At this time, as a developing first brush and a developing second brush, a single yarn of 150 μm in diameter obtained by subjecting a single yarn of polybutylene terephthalate (PBT) to a crimping process by a shaping method to a hair length of 15 mm. Outer diameter 13 implanted to become
Using a 0 mm roll-shaped material cut with a lathe to a length of 1160 mm, the developing first brush is rotated at 400 revolutions per minute in the same direction as the transport direction, and the width of 30 is reciprocated at 120 strokes per minute.
mm.

The second developing brush was rotated at a speed of 400 revolutions per minute in a direction opposite to the transport direction of the printing original plate, and was oscillated with a width of 30 mm at 120 reciprocations per minute. As a result of observing the printing plate with a stereoscopic microscope, the silicone rubber at the edge portion of the halftone dot was also finely removed, and a printing plate free of scratches on the surface of the silicone rubber layer by a brush could be obtained. In addition, the obtained printing plate
The printer was attached to a color printing machine KOMORI SPRINT 425BP (manufactured by Komori Corporation), printed on coated paper using lithographic ink without water, and observed. As a result, a high quality printed matter was obtained. The results are shown in Table 1.

Example 2 A primer solution having the following composition was applied on a degreased aluminum plate having a thickness of 0.24 mm, and dried at 230 ° C. for 1 minute to provide a 3 g / m ² primer layer. (A) Cancoat 90T-25-3094 (Epoxyphenol resin manufactured by Kansai Paint Co., Ltd.) 15 parts by weight (b) Victoria Pure Blue BOH naphthalene sulfonic acid 0.1 part by weight (c) Polyurethane (“SAMPLEN LQ-T1331”) (Manufactured by Sanyo Chemical Industry Co., Ltd.) 20 parts by weight (d) 85 parts by weight of dimethylformamide (DMF) Next, a heat-sensitive layer composition having the following composition was applied on this primer layer, and dried at 130 ° C. for 1 minute. And 2 g of film thickness
/ M ² .

(A) 20 parts by weight of nitrocellulose (viscosity 1/2 second, nitrogen content 11.0%, "Berge rac NC" manufactured by SNP Japan Ltd.) (b) Carbon black 23 parts by weight (c) 30 parts by weight of polyester resin ("Byron 300", manufactured by Toyobo Co., Ltd.) (d) 15 parts by weight of modified epoxy resin ("Epokey 803", manufactured by Mitsui Toatsu Chemicals, Inc.) (e) Diethylene triamine 5 parts by weight (f) Methyl isobutyl ketone 600 parts by weight Subsequently, a silicone rubber solution having the following composition was applied on the heat-sensitive layer, dried at 120 ° C. for 2 minutes, and dried at a thickness of 3 g / m 2.
^Two silicone rubber layers were provided.

(A) 100 parts by weight of vinylpolydimethylsiloxane (b) 12 parts by weight of hydrogensiloxane (c) 0.2 parts by weight of platinum catalyst (d) 2 parts by weight of reaction inhibitor (e) "Isopar E" (isoparaffin) 1200 parts by weight A laminate of the above-obtained laminate was laminated with a 6.0 μm-thick polyester film (“Lumirror” manufactured by Toray Industries, Inc.) using a calendar roller. Then, a direct drawing type waterless planographic printing plate precursor was obtained. This original plate was subjected to laser exposure in the same manner as in Example 1, a surfactant shown in Table 1 was added to the developer, and the swing of the first developing brush of the automatic developing machine was stopped, and the transport speed was 100 cm / min. The contact width (brush width) between the brush and the plate was 12 mm at the speed described above, and the second developing brush was developed by swinging in the same manner as in Example 1. As a result, it was possible to obtain a printing plate from which the silicone rubber at the halftone dot edges was also neatly removed, and it was possible to obtain a high quality printed matter without any scratches on the printing plate surface during printing. The results are shown in Table 1.

Example 3 A primer solution having the following composition was applied on degreased aluminum having a thickness of 0.15 mm, dried at 200 ° C. for 2 minutes, and a primer layer of 3 g / m ² was provided. (A) 15 parts by weight of Cancoat 90T-25-3094 (epoxyphenol resin manufactured by Kansai Paint Co., Ltd.) (b) 0.1 parts by weight of Victoria Pure Blue BOH naphthalene sulfonate (c) 85 parts by weight of dimethylformamide A thermosensitive polymer layer composition having the following composition was applied on this primer layer, dried at 130 ° C. for 1 minute, and
g / m ² of the thermosensitive polymerization layer was provided. (A) pentaoxypropylene diamine / glycidyl methacrylate / methyl glycidyl ether = 1/3/1 mol ratio addition reaction product 40 parts by weight (b) m-xylylenediamine / glycidyl methacrylate / methyl glycidyl ether = 1/2/2 mol ratio addition The reaction was 40 parts by weight _{(c) CH 2 = CHCOO- (} C 2 H 4 O) 14 -COCH = CH 2 10 parts by weight (d) m-xylylenediamine / glycidyl methacrylate / 3-glycidoxy propyl trimethoxy silane = 1 / 3/1 mol ratio addition reactant 2 parts by weight (e) PA-1005 (infrared absorbing dye manufactured by Mitsui Toatsu Chemicals, Inc.) 6 parts by weight (f) Benzoyl peroxide 2 parts by weight (g) Perhexa 3M (organic peroxide) (Nippon Yushi Co., Ltd.) 4 parts by weight (h) Victoria Pure Blue BOH Na 0.5 parts by weight of phthalene sulfonate (i) 0.5 parts by weight of maleic acid (j) 800 parts by weight of propylene glycol monomethyl ether Then, a silicone rubber composition having the following composition is applied on the heat-sensitive polymerized layer. And dried at 115 ° C. for 2 minutes,
A 2 g / m ² thick silicone rubber layer was provided. (A) 100 parts by weight of polydimethylsiloxane (molecular weight: about 35,000, terminal hydroxyl group) (b) 12 parts by weight of ethyltriacetoxysilane (c) 0.1 part by weight of dibutyltin diacetate (d) "Isopar E" (isoparaffin) 1200 parts by weight of a hydrocarbon film (Exxon Chemical Co., Ltd.) 1200 parts by weight A polypropylene film (“Trefane BO” manufactured by Toray Industries, Inc.) having a thickness of 6.5 μm was applied to the laminate obtained as described above using a calendar roller. Then, a direct drawing type waterless planographic printing plate precursor was obtained. This original plate was subjected to laser exposure in the same manner as in Example 1, a surfactant shown in Table 1 was added to a developer, and development was performed in the same manner as in Example 2. As a result, it was possible to obtain a printing plate from which the silicone rubber at the halftone dot edges was also neatly removed, and it was possible to obtain a high quality printed matter without any scratches on the printing plate surface during printing. The results are shown in Table 1.

Examples 4 to 12 The same direct drawing type waterless lithographic printing plate precursor as in Example 1 was exposed by the same method, and a surfactant shown in Table 1 was added to a developer. Exposure and development were performed under exposure and development conditions. It was possible to obtain a printing plate from which the silicone rubber at the halftone dot edge was also neatly removed, and it was possible to obtain a high-quality printed matter during printing. The results are shown in Table 1.

[0215]

[Table 1] Comparative Example 1 A direct-drawing waterless planographic printing plate precursor obtained in the same manner as in Example 1 was subjected to an exposure treatment by the same method, and in a similar automatic developing machine, as a developing solution, water without adding a surfactant was used. As a result of observing the printing plate obtained by carrying out the development processing alone with a stereoscopic microscope, countless plate surface scratches were generated and the dot reproducibility was 15.
It was a remarkably inferior version of 0-70%. Comparative Example 2 A direct drawing type waterless lithographic printing plate precursor obtained in the same manner as in Example 2 was subjected to an exposure treatment by the same method. As an automatic developing machine, a product obtained by winding a nonwoven fabric around a roll instead of a developing brush was used. The developing process was carried out using water to which no surfactant was added as a developer. As a result of observing the obtained printing plate with a stereoscopic microscope, the printing plate was remarkably inferior in dot reproducibility of 30 to 75%, although the plate surface flaw was eliminated.

[0216]

The plate making method of the direct-drawing waterless lithographic printing plate precursor according to the present invention is directed to a direct-drawing waterless lithographic printing plate precursor obtained by sequentially laminating a heat-sensitive layer and a silicone rubber layer on a substrate by using a laser beam. After drawing, development is carried out using an aqueous solution containing a surfactant, so that stable plate making can be performed without generation of scratches on the plate during development, and high-quality printed matter having excellent tone reproducibility can be obtained. When the method of the present invention is applied to an automatic developing machine, the burden on the operator can be reduced and the processing capacity can be increased.

In particular, the effects of the present invention can be further improved by rubbing and developing with a roll-shaped developing brush wound with a plastic thread.

[Brief description of the drawings]

FIG. 1 is a schematic structural view of an automatic developing machine preferably used in the present invention.

[Explanation of symbols]

 1; printing plate precursor 2; carry-in table 3; developing machine body 4; carry-out table 5; transport roll 6; developer circulation pump 7; developer shower pipe 8; development first brush 9; development second brush 10; Table 11; Silicone residue removal device 12; Filter 13; Developer storage tank

Claims (5)

[Claims] 1. A direct-drawing waterless lithographic printing plate precursor comprising a heat-sensitive layer and a silicone rubber layer sequentially laminated on a substrate, followed by drawing with a laser beam, followed by development using an aqueous solution containing a surfactant. A plate making method for a direct-drawing waterless planographic printing plate precursor characterized by the following. 2. The aqueous solution containing a surfactant contains 0.05 to 5% by weight of a surfactant which is soluble in water and insoluble in liquid paraffin. The plate making method of the described direct drawing type waterless planographic printing plate precursor. 3. The method for making a direct-drawing waterless planographic printing plate precursor according to claim 1, wherein the development is carried out by rubbing with a roll-shaped developing brush wound with a plastic thread. 4. The method according to claim 3, wherein two or more roll-shaped developing brushes are used, at least one of which rotates in a direction opposite to the rotation of the other brushes and has a swing mechanism. Plate making method of direct drawing type waterless planographic printing plate precursor. 5. A method for making a direct-drawing waterless planographic printing plate precursor according to claim 3, wherein the plastic thread-like material wound around the roll-like developing brush is subjected to a crimping process. .