JPH11129639A - Plate making method for directly plotting type water-less lithographic printing original plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the sensitivity and the plate inspecting property without generating a contamination or an odor of a radiation lens at the time of a laser radiation by a method wherein when as directly plotting type water-less lithographic printing original plate is made, a laser exposure is performed while a cover coating layer is being fitted, and an image development is performed. SOLUTION: First, a heat-insulating layer composition is applied on a base plate, and after hardening it at 100-300 deg.C for several minutes, a heat-sensitive layer composition coating liquid is applied, and the coating liquid is dried for several minutes at a temperature of 50-180 deg.C. Then, a silicone rubber layer composition is applied, and the rubber hardening-forming is performed by heat-treating for several minutes at a temperature of 50-150 deg.C, and in addition, a film is laminated, or a polymer solution is coated, and a cover coating layer is formed. This water-less lithographic printing original plate which is obtained by such a method is exposed on an image by a laser beam while the cover coating layer is being fitted, and an image development is performed, and thus, a water-less lithographic printing plate is obtained. By this method, a contamination of a lens or an odor are not generated at the time of the laser exposure, and the sensitivity and the plate inspecting property can be improved.

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 waterless lithographic printing plate precursor which can be printed without using dampening water. The present invention also relates to a method for making a direct-drawing waterless planographic printing plate precursor.

[0002]

2. Description of the Related Art A printing plate for performing lithographic printing without using dampening water, particularly using a silicone rubber or a fluorine resin as an ink repellent layer, in particular, producing an offset printing plate directly without using a plate making film. The so-called direct plate making makes use of features such as simplicity that does not require skill, quickness to obtain a printing plate in a short time, and rationality that can be selected according to quality and cost from various systems, and light printing. It has begun to enter into the fields of general offset printing and gravure printing as well as the industry.

[0003] In recent years, new types of various lithographic printing materials have been developed with the rapid progress of output systems such as prepress systems, imagesetters, and laser printers.

[0004] These lithographic printing plates can be classified by plate making method, such as a method of irradiating a laser beam, a method of writing with a thermal head, a method of partially applying a voltage with a pin electrode, an ink repelling layer or an ink coating with an ink jet. A method of forming a layer and the like are known.

[0005] Among them, the method of irradiating a laser beam is superior to other methods in resolution and plate making speed, and there are many types.

[0006] For example, a method using a direct-drawing type waterless planographic printing plate precursor is mentioned.
No. 79, US Pat. No. 451,940, USP 533
No. 9737, USP 125319, USP5
No. 9283, etc., a direct drawing type waterless lithographic printing plate precursor in which a heat-sensitive layer containing an infrared absorbing substance and a self-oxidizing substance and a silicone rubber layer as an ink repellent layer are laminated on a substrate, and US Pat. A direct-drawing waterless planographic printing plate precursor described in the publication, in which a heat-sensitive layer composed of a metal thin film and a silicone rubber layer as an ink repellent layer are laminated on a substrate, and the like.

However, when these plate materials are irradiated with an infrared laser beam, the heat-sensitive layer melts and burns explosively, so that the oxide or combustion gas of the material constituting the heat-sensitive layer and the upper layer are coated. The silicone rubber layer scatters,
There is a problem in that the laser condensing lens, which is the most important part of the plate making apparatus, is contaminated. Furthermore, depending on the composition of the heat-sensitive layer, there is also a problem that odor is generated.

As a countermeasure against this, Japanese Patent Application Laid-Open No. 6-186750
Japanese Patent Application Laid-Open Publication No. H11-163873 proposes providing an exhaust device near the plate mounting drum and the illumination lens. However, this method was sufficiently effective as a countermeasure against odor, but it was not a complete countermeasure although it was effective to some extent against contamination of the irradiation lens.

For this reason, the irradiation lens is contaminated and the laser power is reduced. In the worst case, plate making cannot be performed. In addition, misregistration, defocusing, and the like may occur during the operation of cleaning the contaminated lens. However, the problem of causing registration failure and plate making failure has not been solved yet. Especially when using multiple lenses to increase the speed of plate making,
This problem is serious, and misregistration not only causes a product defect but also requires several hours, and in some cases, tens of hours for preparation.

[0010]

SUMMARY OF THE INVENTION The present inventors have made intensive studies to solve the problems of the prior art as described above, and as a result, have reached the present invention.

That is, the present invention provides a direct-printing waterless planographic printing plate precursor without causing contamination or odor of an irradiation lens during laser irradiation, and provides a waterless planographic printing plate having high sensitivity and excellent plate inspection properties. Its purpose is to obtain.

[0012]

To achieve the above object, the present invention comprises the following constitution.

That is, when making a direct-drawing waterless planographic printing plate precursor in which a heat insulating layer, a heat-sensitive layer, a silicone rubber layer, and a cover coat layer are sequentially laminated on a substrate, laser exposure is performed with the cover coat layer attached. And a developing method for making a direct-drawing waterless planographic printing plate precursor.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS That is, the present invention irradiates a laser beam and performs plate making with a cover coat layer attached, thereby producing oxides, combustion gas and silicone rubber generated from the heat-sensitive layer when the laser beam is irradiated. And the like to prevent scattering and the generation of odor.

In the present invention, the material constituting the cover coat layer may be any material capable of forming a film, such as laminating a plastic film such as polyethylene terephthalate, polypropylene, polyethylene, polyamide, or the like. It is preferable to coat on the rubber layer to form a cover coat layer.

At this time, as the polymer, polystyrene,
Polymethyl methacrylate, rosin-modified phenol resin, cyclized rubber, polyvinyl butyral, polyvinyl pyrrolidone, furan resin, xylene resin and the like are used. Above all, rosin-modified phenolic resins, cyclized rubbers, xylene resins and the like which do not contaminate the silicone rubber layer as the ink repellent layer are particularly effective.

In particular, it is preferable that the cover coat layer transmit infrared rays. In particular, when the infrared ray transmittance is 75% or more, energy is not absorbed before reaching the heat-sensitive layer. Preferably, even if the melting point of the cover coat layer is low, there is no fear that the cover coat layer itself will be melted and damaged.

The thickness of the cover coat layer is 2
The range of 10 to 10 μm is the most preferable for performance, and if it is less than 2 μm, the protective property of the plate material tends to decrease.
If the ratio exceeds the above range, the oxygen permeability and the laser beam permeability tend to decrease, which is not preferable in that the cost increases.

Further, the oxygen permeability of the cover coat layer is 4
^{00~100,000cc / m 2 / 24hr (20} ℃)
Is preferable in that the burning state of the heat-sensitive layer is good and a printing plate having good plate inspection properties can be obtained.

[0020] The oxygen permeability of 400cc / m ² / 24hr
When the temperature is lower than (20 ° C.), particularly when the heat-sensitive layer is a combination of carbon, a dye and a self-oxidizing material such as nitrocellulose, nitrocellulose burns, but most of the carbon and dye do not burn due to lack of oxygen. It remains on the heat insulating layer and remains black even after plate making, which is not preferable in terms of plate making condition and inspection of defects, so-called plate checking properties. Also, 10
When 0,000cc / m ² / 24hr exceeding (20 ° C.), it is not preferred in view of gas barrier properties.

In the present invention, the direct drawing type waterless planographic printing plate precursor is obtained by laminating a heat insulating layer, a heat-sensitive layer, a silicone rubber layer, and a cover coat layer on a substrate in this order. A reflective layer may be provided on the substrate. Hereinafter, the substrate and each layer other than the cover coat layer will be specifically described.

As the substrate of the direct drawing type waterless planographic printing plate precursor, a dimensionally stable plate is used. Examples of such a dimensionally stable plate include those conventionally used as a substrate of a printing plate, and they can be suitably used. Examples of such a substrate include paper, paper on which plastics (eg, polyethylene, polypropylene, polystyrene, etc.) are laminated, plates of metals such as aluminum (including aluminum alloys), zinc, copper, etc., cellulose, carboxymethylcellulose, cellulose acetate, and the like. Polyethylene terephthalate, polyethylene, polyester, polyamide, polyimide, polystyrene, polypropylene, polycarbonate, polyvinyl acetate
For example, a plastic film such as a metal, a paper or a plastic film on which a metal is laminated or vapor-deposited as described above are included. Among these substrates, an 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.

Next, the heat insulating layer will be described. In the present invention, the heat insulating layer satisfies the following conditions. That is, the substrate and the heat-sensitive layer are well adhered to each other and stable over time, and have good solvent resistance to a developing solution and a solvent used for printing. Further, the heat-sensitive layer also has a role as a thermal insulating layer for preventing heat when the heat-sensitive layer causes a thermal reaction from diffusing to the substrate, and in order to improve printing durability, both the heat-sensitive layer and the heat-sensitive layer have flexibility. It is also important.

In order for the heat insulating layer to have the above characteristics, it is preferable that the heat insulating layer contains a binder polymer. At this time, the binder polymer is not particularly limited as long as it is soluble in an organic solvent and has a film forming ability, but the glass transition temperature (Tg) of the polymer is 20 ° C.
It is preferable to use the following polymers and copolymers,
Polymers and copolymers having a Tg of 0 ° C. or lower are more preferred.

The glass transition temperature Tg (glass transition
The term “temperature” refers to a transition point (temperature) at which the physical properties of the amorphous polymer material change from a glassy state to a rubbery state (or vice versa). In a relatively narrow temperature region around the transition point, not only the elastic modulus, but also the expansion rate,
Various physical properties such as heat content, refractive index, diffusion coefficient, and dielectric constant also change greatly. Therefore, the measurement of the glass transition temperature includes a volume (specific volume) -temperature curve, a measurement of heat content by thermal analysis (DSC, DTA, etc.), a measurement of properties of the whole substance such as a refractive index and stiffness, and a measurement of mechanical properties. Some measure quantities that reflect molecular motion (such as dynamic viscoelasticity), dielectric loss tangent, and NMR spectra. In the present invention, the volume of the sample is measured using a dilatometer while increasing the temperature, and the point at which the gradient of the volume (specific volume) -temperature curve changes rapidly is defined as the glass transition temperature Tg.

In the present invention, the following are specific examples of the binder polymer that performs the function of retaining the form, but are not limited to these examples.

(1) Vinyl polymers Polymers and copolymers obtained from the following monomers and derivatives thereof.

For example, ethylene, propylene, 1-butene, styrene, butadiene, isoprene, vinyl chloride,
Vinyl acetate, methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, N-hexyl methacrylate, lauryl methacrylate, acrylic acid,
Methacrylic acid, maleic acid, itaconic acid, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, polyethylene glycol mono (meth) acrylate, polypropylene Glycol mono (meth) acrylate, phenoxyethyl (meth) acrylate, 2- (meth) acryloxyethyl hydrogen naphthalate, 2- (meth) acryloxyethyl hydrogen succinate, acrylamide, N-methylolacrylamide, diacetone acrylamide, glycidyl methacrylate, Acrylonitrile, vinyl toluene, isobutene, 3-methyl-1-butene, butyl vinyl ether, N-vinyl carbazole, methyl vinyl ketone, nitroethylene, α Shianiakuriru methyl, vinylidene cyanide, polyethylene glycol di (meth) acrylate, trimethylolethane tri (meth) acrylate, neopentyl glycol di (meth) acrylate,
Pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, hexanediol di (meth) acrylate, trimethylolpropane tri (acryloyloxypropyl) ether,
Polymers and copolymers obtained by polymerizing and copolymerizing (meth) acrylates after adding ethylene oxide or propylene oxide to polyfunctional alcohols such as glycerin, trimethylolethane, and trimethylolpropane. It can be used as a binder polymer.

Specific examples of the vinyl polymer having a glass transition temperature of 20 ° C. or lower include, for example, the following polymers, but the present invention is not limited thereto.

(A) Polyolefins Specific examples include poly (1-butene), poly (5-cyclohexyl-1-pentene), poly (1-decene), poly (1,1-dichloroethylene), and poly (1,1). 1-dimethylbutane), poly (1,1-dimethylpropane), poly (1-dodecene), polyethylene, poly (1-heptene), poly (1-hexene), polymethylene, poly (6
-Methyl-1-heptene), poly (5-methyl-1-hexene), poly (2-methylpropane), poly (1-nomene), poly (1-octene), poly (1-pentene), poly (1-pentene) 5-phenyl-1-pentene), polypropylene, polyisobutylene, poly (vinyl butyl ether), poly (vinyl ethyl ether), poly (vinyl isobutyl ether), poly (vinyl methyl ether) and the like.

(B) Polystyrenes A specific example is poly (4-[(2-butoxyethoxy)
Methyl] styrene), poly (4-decylstyrene), poly (4-dodecylstyrene), poly [4- (2-ethoxyethoxymethyl) styrene], poly [4- (hexoxymethyl) styrene], poly (4-hexyl) Styrene), poly (4-nonylstyrene), poly [4- (octoxymethyl) styrene], poly (4-octylstyrene), poly (4-tetradecylstyrene) and the like.

(C) Acrylic acid ester polymer and methacrylic acid ester polymer Poly (decyl methacrylate), poly (dodecyl methacrylate), poly (2-ethylhexyl methacrylate), poly (octadecyl methacrylate), poly (octyl methacrylate), poly (tetramethyl methacrylate) Examples thereof include copolymers with monomers such as decyl methacrylate), poly (n-hexyl methacrylate), and poly (lauryl methacrylate) or acrylates.

(2) Unvulcanized rubber Homopolymer or copolymer selected from natural rubber, butadiene, isoprene, styrene, acrylonitrile, acrylate and methacrylate, for example, polybutadiene (BR), styrene- Butadiene copolymer (SBR), carboxy-modified styrene-butadiene copolymer, polyisoprene (NR), polyisobutylene,
Polychloroprene (CR), polyneoprene, acrylate-butadiene copolymer, methacrylate-butadiene copolymer, acrylate-acrylonitrile copolymer (ANM), isobutylene-isoprene copolymer (IIR), acrylonitrile -Butadiene copolymer (NBR), carboxy-modified acrylonitrile-butadiene copolymer, acrylonitrile-chloroprene copolymer, acrylonitrile-isoprene copolymer, ethylene-propylene copolymer (EPM, EPD)
M), unvulcanized rubbers such as vinylpyridine-styrene-butadiene copolymer and styrene-isoprene copolymer.

Also, poly (1,3-butadiene), poly (2-chloro-1,3-butadiene), poly (2-decyl-1,3-butadiene), poly (2,3-dimethyl-
1,3-butadiene), poly (2-ethyl-1,3-butadiene), poly (2-heptyl-1,3-butadiene), poly (2-isopropyl-1,3-butadiene), poly (2- Methyl-1,3-butadiene), chlorosulfonated polyethylene, and the like.

Also, modified products of these rubbers, for example, rubbers which have been subjected to a commonly used modification such as epoxidation, chlorination, carboxylation, etc., and blends with other polymers can be used as the binder polymer.

(3) Polyoxides (polyethers) Trioxane, ethylene oxide, propylene oxide, 2,3-epoxybutane, 3,4-epoxybutene, 2,3-epoxypentane, 1,2-epoxyhexane, epoxycyclohexane , Epoxycycloheptane, epoxycyclooctane, styrene oxide, 2-
Phenyl-1,2-epoxypropane, tetramethylethylene oxide, epichlorohydrin, epibromohydrin, allyl glycidyl ether, phenyl glycidyl ether, n-butyl glycidyl ether, 1,4-dichloro-2,3-epoxybutane, 2,3 Polymers and copolymers by ring-opening polymerization such as -epoxypropionaldehyde, 2,3-epoxy-2-methylpropionaldehyde, and 2,3-epoxydiethylacetal.

Specific examples of polyoxides having a glass transition temperature of 20 ° C. or lower include polyacetaldehyde, poly (butadiene oxide), poly (1-butene oxide), poly (dodecene oxide), poly (ethylene oxide),
Poly (isobutene oxide), polyformaldehyde,
Examples thereof include poly (propylene oxide), poly (tetramethylene oxide), and poly (trimethylene oxide).

(4) Polyesters Polyesters obtained by polycondensation of polyhydric alcohols and polycarboxylic acids as shown below, polyesters obtained by polymerization of polyhydric alcohols and polycarboxylic anhydrides, and ring opening of lactones Examples include polyester obtained by polymerization and the like, and polyester obtained from a mixture of these polyhydric alcohols, polycarboxylic acids, polycarboxylic anhydrides, and lactones.

Specific examples of the polyhydric alcohol 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-xylene glycol, hydrogenated bisphenol A, bisphenol hydroxypropyl ether,
Glycerin, trimethylolethane, trimethylolpropane, trishydroxymethylaminomethane, pentaerythritol, dipentaerythritol, sorbitol and the like can be mentioned.

Specific examples of polycarboxylic acids and polycarboxylic anhydrides include phthalic anhydride, isophthalic acid, terephthalic acid, succinic anhydride, adipic acid, azelaic acid, sebacic acid, tetrahydrophthalic anhydride, and hexahydroanhydride. Examples include phthalic acid, tetrabromophthalic anhydride, tetrachlorophthalic anhydride, hetic anhydride, hymic anhydride, maleic anhydride, fumaric acid, itaconic acid, trimellitic anhydride, methylcyclohexentricarboxylic anhydride, and pyromellitic anhydride. Can be

Examples of the lactone include β-propiolactone, γ-butyrolactone, δ-valerolactone, ε-caprolactone and the like.

Specific examples of the polyester having a glass transition temperature of 20 ° C. or lower include poly [1,4- (2-butene) sebacate], [1,4- (2-butyne) sebacate], and poly (decametylenadipate). ), Poly (ethylene adipate), poly (oxydiethylene adipate), poly (oxydiethylene azelate), poly (oxydiethylene dodecanediate), poly (oxydiethylene glutarate), poly (oxydiethylene heptyl malonate) ), Poly (oxydiethylenenonylmalonate), poly (oxydiethyleneoctadecanediate), poly (oxydiethyleneoxalate), poly (oxydiethylenepentylmalonate), poly (oxydiethylenepimelate), poly (oxydiethylenepimelate), poly (oxy Diethylenepropyl malonate), poly (oxy Ethylene sebacate), poly (oxydiethylene suberate), poly (oxyethylene succinate), poly (pentamethylene adipate), poly (tetramethylene adipate), poly (tetramethylene sebacate), poly (trimethylene) Adipate) and the like.

(5) Polyurethanes Polyurethanes obtained from polyisocyanates and polyhydric alcohols, polyester polyols obtained by polycondensation of polyhydric alcohols and polyhydric carboxylic acids, both ends of which are hydroxyl groups, and lactones are obtained. Polymerized polyester polyol, polycarbonate diol, polyether polyol obtained by ring-opening polymerization of propylene oxide or tetrahydrofuran or modification of epoxy resin, or copolymer of (meth) acrylic monomer having hydroxyl group and (meth) acrylate And acrylic butadiene polyol.

Examples of polyisocyanates include paraphenylene diisocyanate, 2,4- or 2,6-toluylene diisocyanate (TDI), 4,4-diphenylmethane diisocyanate (MDI), tolidine diisocyanate (TODI), and xylylene diisocyanate (XDI). Hydrogenated xylylene diisocyanate, cyclohexane diisocyanate, meta-xylylene diisocyanate (MXDI), hexamethylene diisocyanate (HDI or HMDI), lysine diisocyanate (LDI) (also known as 4,4'-methylenebis (cyclohexyl isocyanate)), hydrogenated TDI ( HTDI)
(Alias methylcyclohexane 2,4 (2,6) diisocyanate), hydrogenated XDI (H6XDI) (alias 1,3
-(Isocyanatomethyl) cyclohexane), isophorone diisocyanate (IPDI), diphenyl ether isocyanate, trimethylhexamethylene diisocyanate (TMDI), tetramethylxylylene diisocyanate, polymethylene polyphenyl isocyanate, dimer acid diisocyanate (DDI), triphenylmethane triisocyanate , Tris (isocyanatephenyl) thiophosphate, tetramethylxylylene diisocyanate, lysine ester triisocyanate, 1,6,11-undecane triisocyanate,
Examples thereof include 1,8-diisocyanate-4-isocyanatomethyloctane, 1,3,6-hexamethylenetriisocyanate, bicycloheptanetriisocyanate, polyisocyanate polyhydric alcohol adducts, and polyisocyanate polymers.

As the polyhydric alcohols, in addition to those mentioned in the above section (4) Polyester, polypropylene glycol, polyethylene glycol, polytetramethylene glycol, ethylene oxide-propylene oxide copolymer, tetrahydrofuran-propylene oxide copolymer Polyester polyols such as polyethylene adipate, polypropylene adipate,
Polyhexamethylene neopentyl adipate, polyneopentyl adipate, polyhexamethylene neopentyl adipate,
Examples thereof include polyethylene hexamethylene adipate and the like, and poly-ε-caprolactone diol, polyhexamethylene carbonate diol, polytetramethylene adipate, sorbitol, methyl glucosit, sucrose and the like.

Examples of the polyvalent carboxylic acids and lactones include those described in the above section (4) Polyester.

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

The above-mentioned isocyanates and polyhydric alcohols can be reacted to form polyurethanes by a known method. Since these polyurethanes generally have a glass transition temperature of 20 ° C. or lower, they can be preferably used in the present invention. it can.

(6) Polyamides Copolymers of the following monomers are listed. As monomers, ε-caprolactam, ω-laurolactam, ω-aminoundecanoic acid, hexamethylenediamine, 4,4-bis-aminocyclohexylmethane, 2,
4,4-trimethylhexamethylenediamine, isophoronediamine, glycols, isophthalic acid, adipic acid, sebacic acid, dodecanenilic acid and the like.

More specifically, polyamides are generally classified into water-soluble polyamides and alcohol-soluble polyamides. Examples of the water-soluble polyamide include, for example,
A polyamide containing a sulfonic acid group or a sulfonate group obtained by copolymerizing sodium 3,5-dicarboxybenzenesulfonate as disclosed in JP-A-8-72250, disclosed in JP-A-49-43465. Polyamides having an ether bond obtained by copolymerizing any one of dicarboxylic acids, diamines or cyclic amides having an ether bond in the molecule as described in JP-A-50-7605. Polyamides containing a basic nitrogen obtained by copolymerizing N, N'-di (γ-aminopropyl) piperazine and the like, and polyamides obtained by quaternizing these polyamides with acrylic acid or the like; Japanese Patent Application Laid-Open No. 55-74537 discloses a copolymer containing a polyether segment having a molecular weight of 150 to 1500. If polyamides, and alpha-(N,
Ring-opening polymerization of N′-dialkylamino) -ε-caprolactam or α- (N, N′-dialkylamino) -ε-
Examples include polyamides obtained by ring-opening copolymerization of caprolactam and ε-caprolactam.

Examples of the alcohol-soluble polyamide include linear polyamides synthesized by known methods from dibasic acid fatty acids and diamines, ω-amino acids, lactams or derivatives thereof, and include not only homopolymers but also copolymers and block copolymers. Polymers and the like can also be used. Typical examples include nylon 3, 4, 5, 6, 8, 1
1, 12, 13, 66, 610, 6/10, 13/1
3, polyamide from meta-xylylenediamine and adipic acid, polyamide from trimethylhexamethylenediamine or isophoronediamine and adipic acid, ε-caprolactam / adipic acid / hexamethylenediamine /
4,4′-diaminodicyclohexylmethane copolymerized polyamide, ε-caprolactam / adipic acid / hexamethylenediamine / 2,4,4′-trimethylhexamethylenediamine copolymerized polyamide, ε-caprolactam / adipic acid / hexamethylenediamine / isophorone Diamine copolymerized polyamides, polyamides containing these components, N-methylol and N-alkoxymethyl derivatives thereof can also be used.

The above polyamides can be used alone or in combination for the heat insulating layer.

As the polyamide having a glass transition temperature of 20 ° C. or lower, a copolymerized polyamide containing a polyether segment having a molecular weight of 150 to 1500, more specifically, a polyether segment having an amino group at a terminal and having a molecular weight of 150 to 1500 is preferred. Structural units comprising 1500 polyoxyethylene and aliphatic dicarboxylic acid or diamine
Copolymer polyamides containing up to 70% by weight are exemplified, but the present invention is not limited thereto.

The above-mentioned polymers which can be used as the binder polymer may be used alone or as a mixture of several kinds of polymers.

Particularly preferred binder polymers for the heat insulating layer of the present invention include polyurethanes, polyesters, vinyl polymers and unvulcanized rubbers.

The preferred amount of the binder polymer used is
It is preferably from 15 to 90 wt%, more preferably from 15 to 80 wt%, based on the components of the heat insulating layer.

Although the above-mentioned binder polymer can be used without being crosslinked, it is preferable to form a crosslinked structure with a crosslinker in order to obtain a solvent resistance which can be practically used in the printing step.

The following are examples of the crosslinking agent that can be used in the heat insulating layer in the present invention.

(1) Isocyanates The isocyanates described in (5) Polyurethane of the binder polymer can be mentioned.

(2) Polyfunctional epoxy compounds Polyethylene glycol diglycidyl ethers, polypropylene glycol diglycidyl ethers, bisphenol A diglycidyl ethers, trimethylolpropane triglycidyl ether, pentaerythritol tetraglycidyl ether and the like can be mentioned.

(3) Polyfunctional acrylate compounds and the like.

In addition, as the anchoring agent in the heat insulating layer, a known adhesive such as a silane coupling agent can be used, and organic titanates are also effective.

For the purpose of further improving coatability, a surfactant can be added.

Since the heat-insulating layer is exposed in the drawing portion of the printing plate to form an image portion, it is preferable to add an additive such as a dye to the heat-insulating layer to improve the plate inspection property.

The composition for forming the above-mentioned heat insulating layer is as follows:
Dimethylformamide (DMF), methyl ethyl ketone, methyl isobutyl ketone, dioxane, toluene,
It is prepared as a composition solution by dissolving in a suitable organic solvent such as xylene or tetrahydrofuran (THF). Such a composition solution is uniformly applied on a substrate and heated at a required temperature for a required time to form a heat insulating layer.

The thickness of the heat insulating layer is preferably from 0.5 to 50 g / m ² , more preferably from ² to 7 g / m ² . When the thickness is less than 0.5 g / m ² , the effect of blocking morphological defects and chemical effects on the substrate surface is inferior, and when the thickness is more than 50 g / m ^2, it is disadvantageous from an economic point of view. preferable.

Next, the heat sensitive layer will be described in detail.

It is important that the heat-sensitive layer absorbs the laser light efficiently and is partially or entirely decomposed instantaneously by the heat. In the present invention, such a heat-sensitive layer is preferably a heat-sensitive layer containing a light-to-heat conversion substance and a self-oxidizing substance, or a heat-sensitive layer formed of a metal thin film.

First, the heat-sensitive layer containing the photothermal conversion substance and the self-oxidizing substance will be described.

The photothermal conversion material is not particularly limited as long as it can absorb light and convert it into heat. For example, black pigments such as carbon black, aniline black and cyanine black, phthalocyanine and naphthalocyanine green Pigment, carbon graphite, iron powder, diamine-based metal complex, dithiol-based metal complex, phenolthiol-based metal complex, mercaptophenol-based metal complex, arylaluminum metal salts, inorganic water-containing inorganic compound, copper sulfate,
Metal oxides such as chromium sulfide, silicate compounds, titanium oxide, vanadium oxide, manganese oxide, iron oxide, cobalt oxide, and tungsten oxide; hydroxides and sulfates of these metals; and bismuth, tin, tellurium, and iron And additives such as aluminum metal powder.

Among them, carbon black is particularly preferred from the viewpoints of light-to-heat conversion rate, economy and handling.

The carbon black is classified into furnace black, channel black, thermal black, acetylene black, lamp black and the like according to the production method. Furnace black includes various types in terms of particle size and other aspects. Since it is commercially available and commercially inexpensive, it is preferably used.

Carbon blacks having various particle sizes are commercially available. Among them, those having an average primary particle size of 15 nm to 29 nm are preferable, and 17 nm to 26 nm are more preferable.

When the average particle size of the primary particles is smaller than 15 nm, the heat-sensitive layer itself becomes transparent, which is not preferable in terms of the absorption efficiency of laser light. Since it is not dispersed in the density and the blackness of the heat-sensitive layer does not increase, it is not preferable in terms of laser light absorption efficiency. This ultimately also affects the printing plate sensitivity.

The method for measuring the primary particle size of carbon black includes a sedimentation method, a microscopic method, a transmission method, an adsorption method, an X-ray method and the like. Among these, a method using an electron microscope and an X-ray method are preferable. As the X-ray method, an X-ray generator manufactured by Rigaku Corporation can be used. Also, when measuring in the state of the printing plate, the printing plate is cut into a thin film,
Transmission Electron Microscop
The primary particle size of carbon black can be measured using e), but in the present invention, the value is determined by an arithmetic measurement method from an electron micrograph.

Further, the oil absorption of carbon black also affects the sensitivity of the printing plate and the viscosity of the heat-sensitive layer solution. The oil absorption indicates the structure of carbon black, that is, the degree of particle aggregation. As the oil absorption increases, the particle aggregation increases, and as the oil absorption decreases, the particle aggregation decreases.

In the heat-sensitive layer of the present invention, the refueling amount is 50 ml /
It is preferably in the range of 100 g to 100 ml / 100 g, more preferably 60 ml / 100 g to 90 ml / 1.
00 g.

If the oil absorption is less than 50 ml / 100 g, the dispersibility of the carbon black is reduced and the sensitivity of the printing plate is apt to be reduced. If the oil supply is more than 100 ml / 100 g, the viscosity of the composition solution is high. It becomes thixotropy and difficult to handle.

In the present invention, the oil absorption means ASTM
D2414-70 means the oil absorption in DBP (dibutyl phthalate). Specifically, dibutyl phthalate is dropped into 100 g of powdered carbon black and kneaded with a spatula or the like. When the mixture of carbon black and dibutyl phthalate becomes a paste, the amount (ml) of dibutyl phthalate added is 100%. Oil absorption.

The use of conductive carbon black is also
It is effective for improving the sensitivity of the plate material. Electrical conductivity of this time, 0.01Ω- ¹ cm- ¹ ~100Ω- ¹ cm
^-1 is preferred, more preferably 0.1.
Is a ^{1Ω- 1 cm- 1 ~10Ω- 1 cm- 1} .

Further, in addition to the above-mentioned substances, dyes that absorb infrared rays or near infrared rays are also preferably used as photothermal conversion substances.

As these dyes, 400 nm to 1200
Any dye having a maximum absorption wavelength in the range of nm can be used. Preferred dyes include those for electronics,
Recording dyes cyanine, phthalocyanine, phthalocyanine metal complex, naphthalocyanine, naphthalocyanine metal complex, dithiol metal complex, naphthoquinone, anthraquinone, indophenol, indoaniline, pyrylium, thiopyrylium , Squarylium, croconium, diphenylmethane,
Triphenylmethane, triphenylmethanephthalide, triallylmethane, phenothiazine, phenoxazine, fluoran, thiofluorane, xanthene, indolylphthalide, spiropyran, azaphthalide, chromenopyrazole, Leuco auramine, rhodamine lactam, quinazoline, diazaxanthen, bislactone, fluorenone, monoazo, ketoneimine, diazo, methine, oxazine, nigrosine, bisazo, bisazostilbene, bis Azooxadiazole, bisazofluorenone, bisazohydroxyperinone, azochrome complex, trisazotriphenylamine, thioindigo, perylene, nitroso, 1: 2 type metal complex, intermolecular CT System, quinoline Quinophthalone-based, fluid-based acid dyes, basic dyes, pigments, oil-soluble dyes, triphenylmethane-based leuco dyes, cationic dyes, azo-based disperse dyes, benzothiopyran-based spiropyrans, 3,9-dibromoanthanthrone, indanth Ron, phenolphthalein, sulfophthalein, ethyl violet,
Methyl orange, fluorescein, methyl viologen, methylene blue, dimrosbetaine and the like can be mentioned.

Among these, dyes for electronics and recording, having a maximum absorption wavelength of 700 nm to 900 nm
m, cyanine-based dye, azurenium-based dye, squarylium-based dye, croconium-based dye, azo-based disperse dye, bisazostilbene-based dye, naphthoquinone-based dye, anthraquinone-based dye, perylene-based dye, phthalocyanine-based dye, na Phthalocyanine metal complex dyes,
Black dyes such as dithiol nickel complex dyes, indoaniline metal complex dyes, intermolecular CT dyes, benzothiopyran spiropyrans, and nigrosine dyes are preferably used.

Further, among these dyes, those having a large molar absorbance coefficient are preferably used. Specifically, ε = 1 × 10 ⁴ or more, more preferably 1 × 10 ⁵ or more, from the viewpoint of the effect of improving sensitivity.

It is important that the heat-sensitive layer is instantaneously partially or entirely decomposed by the heat generated by the light-to-heat conversion material. In order to satisfy this thermal decomposition property, it is necessary that the heat-sensitive layer simultaneously contains a self-oxidizing substance.

As the self-oxidizing substance, nitro compounds such as ammonium nitrate, potassium nitrate, sodium nitrate and nitrocellulose, organic peroxides, azo compounds, diazo compounds and hydrazine derivatives are preferably used. In particular, nitrocellulose is a polymer and therefore has an appropriate viscosity in a solution state, and has a hydroxyl group in the molecule, so that it is easy to form a crosslinked structure of the thermosensitive layer, which is preferable.

Nitrocellulose is also preferable in that it can be selected from various molecular weights depending on the purpose. In addition,
Nitrocellulose here is not for explosives,
Preferably, it is industrial nitrocellulose.

Further, the viscosity of nitrocellulose is 1/16
Seconds to 3 seconds, more preferably 1/8
Seconds to 1 second, more preferably 1/8 seconds to 1/2 seconds. If the viscosity is less than 1/16 second, the printing durability of the printing plate tends to decrease because the degree of polymerization of nitrocellulose is low, and if it is more than 3 seconds, the viscosity becomes high, handling becomes inconvenient, and Coatability is undesirably reduced. The viscosity of nitrocellulose can be measured by a method specified in ASTM D301-72.

The degree of nitration of nitrocellulose also greatly affects the performance of the printing plate. Nitrocellulose is a linear polymer, and D-glucose as a repeating unit has a structure containing at most three hydroxyl groups.
The nitrogen content is determined by the degree of substitution of the hydroxyl group with the nitro group. The nitrogen content is the ratio of the atomic weight of nitrogen to the molecular weight of nitrocellulose, and is an index indicating the degree of nitration. Therefore, the higher the nitrogen content, the higher the degree of nitration.

The nitrogen content can be determined by the following formula or by elemental analysis.

[0091]

(Equation 1) That is, when all three hydroxyl groups of D-glucose were substituted with nitro groups, the nitrogen content was 14.1%,
The nitrogen content is 6.8% when only one is nitrated.
Therefore, the higher the nitrogen content, the smaller the number of hydroxyl groups in the molecule, and the more difficult it is to form a crosslinked structure in the thermosensitive layer.

From this point, the nitrogen content of the nitrocellulose used in the present invention is preferably 11.5% or less, more preferably 6.8% to 11.5%. When the nitrogen content is less than 6.8%, the sensitivity of the printing plate decreases, and the solubility in a solvent tends to decrease.
If it exceeds 1.5%, the number of hydroxyl groups decreases, and it becomes difficult to form a crosslinked structure of the heat-sensitive layer. As a result, the printing durability decreases, which is not preferable.

In particular, nitrocellulose is preferably used in combination with carbon black, which is preferable as a light-to-heat conversion material. At this time, the ratio of the amount added is very important. That is, the amount of carbon black added to nitrocellulose greatly affects the performance of the printing plate.

The weight ratio of the added amount is preferably 1.1 or more of carbon black to 1 of nitrocellulose. When the weight ratio of carbon black is 1.
If it is less than 1, the sensitivity of the printing plate tends to decrease because the laser light is not efficiently absorbed.

The sum of the weights of carbon black and nitrocellulose is 30 to 90 w
t% is preferable, and more preferably 40 to 70 wt%. If the amount used is less than 30 wt%, the sensitivity of the printing plate tends to decrease, and if it exceeds 90 wt%, the solvent resistance of the printing plate tends to decrease.

It is also very effective to add thermal decomposition aids such as urea and urea derivatives, zinc white, lead carbonate, lead stearate and glycolic acid. The amount of addition of these thermal decomposition aids is 0.02 to 10 wt.
% Is preferable, and more preferably 0.1 to 5% by weight.

These heat-sensitive layers preferably have a crosslinked structure in order to increase the solvent resistance to printing ink. The crosslinking method includes a thermal crosslinking type and a photo-crosslinking type. In the present invention, the heat-sensitive layer is not suitable for photo-crosslinking because the light-transmitting property is poor, and the thermal crosslinking type is preferred.

The polyfunctional crosslinking agent used to introduce the crosslinking structure includes a polyfunctional isocyanate compound or a polyfunctional epoxy compound, a urea compound, an amine compound, a hydroxyl group-containing compound, a carboxylic acid compound, and a thiol compound. And a combination with

When a polyfunctional isocyanate compound is used, since the reaction is not completed in a short time, it is preferable to heat and dry at a high temperature. However, when nitrocellulose is used as the self-oxidizing substance, the decomposition temperature of nitrocellulose is reduced. Is 180 ° C., and cannot be heated and dried at a temperature higher than 180 ° C. For this reason, the reaction gradually proceeds even after the printing plate is prepared, which may adversely affect the developability of the printing plate. From this point, a combination of a polyfunctional epoxy compound, an amine compound, an amide compound, a hydroxyl group-containing compound, a carboxylic acid compound, and a thiol compound is preferable as the crosslinking agent.

Examples of the polyfunctional epoxy compound include bisphenol A type epoxy resin, bisphenol F type epoxy resin and glycidyl ether type epoxy resin.

Examples of the amine compounds include butylated urea resin, butylated melamine resin, butylated benzoguanamine resin, butylated urea melamine co-condensation resin, aminoalkyd resin, iso-butylated melamine resin, methylated melamine resin, and hexamethoxy. Methylol melamine, methylated benzoguanamine resin, butylated benzoguanamine resin, diethylenetriamine, triethylenetriamine, tetraethylenepentamine, diethylaminopropylamine, N-aminoethylpiperazine, metaxylylenediamine, metaphenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, And isophorone diamine.

Examples of the amide compound include a polyamide-based curing agent and dicyandiamide used as a curing agent for an epoxy resin. Examples of the hydroxyl group-containing compound include a phenol resin and a polyhydric alcohol, and examples of the thiol-based compound include a polyhydric alcohol. And thiols.

As the carboxylic acid compound, phthalic acid, hexahydrophthalic acid, tetrahydrophthalic acid, dodecynylsuccinic acid, pyromellitic acid, chlorenic acid, maleic acid, fumaric acid and anhydrides thereof are preferably used.

Among the above cross-linking agents, a combination of a polyfunctional epoxy compound and an amine compound is more preferable from the viewpoints of curing speed and handleability.

Further, a polyfunctional crosslinking agent having an organic silyl group or an amino group-containing monomer can be preferably used.

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

Further, a quaternary ammonium salt, KOH, SnCl ₄ , Zn
It is preferable to use a known catalyst such as (BF ₄ ) ₂ and an imidazole compound.

The heat-sensitive layer preferably contains a binder polymer for the purpose of improving printing durability and storage stability.
The polymers mentioned as the binder polymer of the heat insulating layer are exemplified. That is, polyurethane resin, phenol resin, acrylic resin, alkyd resin, polyester 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, carboxymethylcellulose, cellulose acetate, cellulose propyl acetate, cellulose butyl acetate, cellulose triacetate, hydroxypropyl cellulose ether, ethyl cellulose ether, cellulose phosphate, etc. Cellulose derivatives, polyvinyl acetate, polystyrene, polystyrene-acrylonitrile copolymer, polysulfone, poly Eniren'okishido,
Polyethylene oxide, polyvinyl alcohol-acetal copolymer, polyvinyl acetal, polyvinyl alcohol-polyacetal copolymer, polyvinyl alcohol-polybutyral copolymer, polyvinyl benzal,
Examples thereof include chlorinated polyolefins such as polyvinyl alcohol, ethylene maleic anhydride copolymer, chlorinated polyethylene, and chlorinated polypropylene, among which cellulose derivatives such as cellulose acetate, and chlorine-containing polyvinyl chloride-vinyl acetate copolymers and the like. Copolymers, ethylene-vinyl acetate copolymers, polyurethane resins and acrylic resins are preferably used.

In addition to the above, polyacetylene, polyaniline, and the like, which are known as conductive polymers, are also preferably used as the binder polymer.

The preferred amount of the binder polymer used is
It is preferably 20 to 70% by weight, more preferably 15 to 50% by weight, based on the components of the heat-sensitive layer.

In addition, a known adhesive such as a silane coupling agent can be used as an anchoring agent in the heat-sensitive layer, and an organic titanate is also effective.

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 add a fluorosurfactant to improve coatability.

The amount of these additives is 10% by weight or less based on the total heat-sensitive layer composition.

The thickness of the heat-sensitive layer is preferably from 0.2 to 3 g / m ² , more preferably from 0.5 to ² g / m ² . A coating technique is required to reduce the thickness to less than 0.2 g / m ² , and if the thickness is more than 3 g / m ² , the laser light is applied to draw the film, resulting in poor decomposability. Is preferred.

When an addition type silicone rubber is used as the silicone rubber layer, a compound having an ethylenically unsaturated double bond may be added for the purpose of improving the adhesion between the heat-sensitive layer and the silicone rubber layer. it can. Examples of the compound having an ethylenically unsaturated double bond include the following compounds (1) to (5), and among them, epoxy acrylates are particularly preferable. The amount of the compound having an ethylenically unsaturated double bond to be used is preferably 0.5 to 30% by weight based on the total heat-sensitive layer composition.

(1) Esterified products of a polyfunctional hydroxyl group-containing compound and acrylic acid or methacrylic acid.

Examples of the polyfunctional hydroxyl group-containing compound include ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, 1,3-butanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, hydroquinone, dihydroxyanthraquinone, bisphenol A, bisphenol S, resole resin, pyrogallol acetone resin,
Examples include hydroxystyrene copolymers, glycerin, pentaerythritol, dipentaerythritol, trimethylolpropane, polyvinyl alcohol, cellulose and derivatives thereof, and polymers and copolymers of hydroxyacrylate and hydroxymethacrylate. Compounds obtained by subjecting these polyfunctional hydroxyl group-containing compounds to acrylic acid and methacrylic acid by an esterification reaction by a known method can be used. At this time, the reaction is performed at a ratio containing two or more ethylenically unsaturated groups in one molecule.

(2) Epoxy acrylates obtained by reacting an epoxy compound with acrylic acid, methacrylic acid, glycidyl acrylate, or glycidyl methacrylate.

Specific examples of the epoxy compound include (1)
And the compounds obtained by reacting epihalohydrin with the polyfunctional hydroxyl group-containing compound described in the section.

Further, those obtained by adding ethylene oxide or propylene oxide to each of the hydroxyl groups of the above-mentioned polyfunctional hydroxyl group-containing compound can also be used.

Epoxy acrylates obtained by reacting these epoxy compounds with acrylic acid, methacrylic acid, glycidyl acrylate, or glycidyl methacrylate by a known method can be used.

(3) A compound obtained by reacting an amine compound with glycidyl acrylate, glycidyl methacrylate or acrylic acid chloride or methacrylic acid chloride.

As the amine compound, octylamine,
Monovalent amine compounds such as laurylamine, dioxyethylenediamine, trioxyethylenediamine, tetraoxyethylenediamine, pentaoxyethylenediamine, hexaoxyethylenediamine, heptaoxyethylenediamine, octaoxyethylenediamine, nonaoxyethylenediamine, monooxypropylenediamine, dioxypropylene Diamine, trioxypropylenediamine, tetraoxypropylenediamine, pentaoxypropylenediamine, hexaoxypropylenediamine, heptaoxypropylenediamine, okitaoxypropylenediamine, nonaoxypropylenediamine, polymethylenediamine, polyetherdiamine, diethylenetriamine, triethylenetetramine And fats such as tetraethylpentamine And family polyamine compound, m-
Xylylenediamine, p-xylylenediamine, m-phenylenediamine, diaminodiphenyl ether, benzidine, 4,4'-bis (o-toluidine), 4,4 '
And polyamine compounds such as -thiodianiline, o-phenylenediamine, dianisidine, 4-chloro-o-phenylenediamine, and 4-methoxy-6-methyl-m-phenylenediamine. Compounds obtained by reacting these amine compounds with glycidyl acrylate, glycidyl methacrylate or acrylic acid chloride or methacrylic acid chloride by a known method can be used.

(4) A compound obtained by reacting a compound having a carboxyl group with glycidyl acrylate and glycidyl methacrylate.

As the compound having a carboxyl group,
Malonic, succinic, malic, thiomalic, racemic, citric, glutaric, adipic, pimelic,
Speric acid, azelaic acid, sebacic acid, maleic acid,
Examples include fumaric acid, itaconic acid, dimer acid, trimellitic acid, and carboxy-modified unvulcanized rubber.

A compound obtained by reacting a compound having a carboxyl group with glycidyl acrylate or glycidyl methacrylate by a known method can be used.

(5) Urethane acrylates Examples include glycerin diacrylate isophorone diisocyanate urethane prepolymer and pentaerythritol triacrylate hexamethylene diisocyanate urethane prepolymer.

The above compounds having an ethylenically unsaturated double bond in one molecule can be used alone,
A mixture of more than one species can be used.

In addition, in order to further improve the adhesiveness with the additional silicone rubber layer as the upper layer, hydrophobic silica whose surface is treated with a silane coupling agent containing a (meth) acryloyl group or an allyl group is used. The powder may be added in an amount of 20 wt% or less based on the entire thermosensitive layer composition.

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 dissolved in a suitable organic solvent such as cyclohexanol, diacetone alcohol, benzyl alcohol, butyl butyrate, and ethyl lactate to prepare a composition solution. A heat-sensitive layer is formed by uniformly applying and heating such a composition solution on the heat-insulating layer of the substrate.

It is preferable that the heat curing is performed in a range where the self-oxidizing substance is not decomposed, usually at 180 ° C. or lower, in combination with the above-mentioned catalyst.

Further, in the present invention, the heat-sensitive layer and the silicone rubber layer of the laser-exposed portion are simultaneously peeled off from the direct-drawing waterless planographic printing plate precursor in the final development to form an ink-coated portion. The development can be performed with water or a liquid containing water as a main component. In this case, it is necessary to completely remove the heat-sensitive layer. Since the ink is also deposited on the heat-sensitive layer, there is no problem in the performance of the printing plate even if the heat-sensitive layer remains, but it is difficult to visually confirm the pattern formation, that is, there is a disadvantage that the plate inspection property is poor. Therefore, in the present invention, by including a substance that dissolves or swells in water in the heat-sensitive layer, the developability is improved and a direct-drawing waterless planographic printing plate precursor having excellent plate inspection properties can be obtained.

The substance that dissolves or swells in water is not particularly limited as long as it can be well dispersed in the composition of the heat-sensitive layer. Examples thereof include salts, monomers, oligomers, and resins. Specific examples include, but are not limited to, the following.

(1) Natural Proteins At least one kind of protein selected from casein, gelatin, soybean protein, albumin and the like can be mentioned. Specific examples include milk casein, acid casein, rennet casein, ammonia casein, caricasein, borax casein, glue, gelatin, gluten, soy lecithin, soy protein, collagen and the like.

(2) Alginates Ammonium alginate, potassium alginate, sodium alginate and the like can be mentioned.

(3) Starches Starch alone or one obtained by graft-polymerizing starch and a synthetic monomer such as acrylic acid.

(4) Cellulose Cellulose alone or grafted with a synthetic monomer such as acrylic acid. Specific examples include carboxylated methylcellulose, methylcellulose, hydroxypropylmethylcellulose, hydroxyethylcellulose, and xanthate cellulose.

(5) Hyaluronic acids JP-B-61-8083, JP-A-58-56692
And natural polysaccharide polymers as disclosed in JP-A No. 60-49797 and JP-A-60-49797.

(6) Polyvinyl alcohols Polyvinyl alcohol alone or methyl acrylate
Saponified vinyl acetate copolymers and vinylpyrrolidone copolymers are exemplified.

(7) Acrylates α, β-unsaturated compounds having one or more groups such as carboxyl group, carboxylic acid group, carboxylic acid salt, carboxylic acid amide, carboxylic acid imide, and carboxylic acid anhydride in the molecule Monomer, polymer or crosslinked product.

Specific examples of the α, β-unsaturated compound include acrylic acid, methacrylic acid, acrylamide, methacrylamide, maleic anhydride, maleic acid, maleic amide, maleic imide, itaconic acid, croton Acid, fumaric acid, mesaconic acid and the like. These monomers can be subjected to radical polymerization by a known method to obtain a desired polymer or copolymer. In addition, these polymers or copolymers can be made more hydrophilic by reacting with compounds such as alkali metal or alkaline earth metal hydroxides, oxides or carbonates, ammonia, and amines. it can.

(8) Hydrophilic epoxy compound sorbitol polyglycidyl ether, sorbitan polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, triglycidyl tris (2-hydroxyethyl) isocyanurate Glycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether, neopentyl glycol diglycidyl ether, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, glyceryl ether added with phenol ethylene oxide, lauryl alcohol ethylene oxide added Glycidyl ether, adipine Acid diglycidyl ester and the like.

(9) Water-soluble acrylates Ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, propylene glycol diacrylate, propylene glycol dimethacrylate, dipropylene glycol Examples thereof include diacrylate, dipropylene glycol dimethacrylate, polypropylene glycol diacrylate, polypropylene glycol dimethacrylate, and a reaction product of p-xylylenediamine and glycidyl methacrylate.

Among the above-mentioned substances which dissolve or swell in water, salts of the substances (2), (6) and (7)
A substance obtained by reacting the above substance with an alkaline earth metal. As the monomer and oligomer, (2), (7),
(8) and (9). Examples of the resin include the substances (1), (3), (4), (5), (6) and (7).

Among these substances that dissolve or swell in water, resins, crosslinkable monomers, oligomers, and resins also serve as binders, so that it is not necessary to include another binder polymer in the heat-sensitive layer. It is also preferable from an economic point of view.

The amount of the substance that dissolves or swells in water in the heat-sensitive layer is preferably 10 to 40% by weight. If the addition amount is less than 10 wt%, it is not preferable in view of the effect of improving the developing property, and if it exceeds 40 wt%, it is not preferable since the heat-sensitive layer of the unexposed portion which should remain after development swells and is easily peeled off.

Next, the case where the heat-sensitive layer is a metal thin film will be described.

As described above, in the present invention, the heat-sensitive layer is
It is important that the laser light is efficiently absorbed, and a part or the whole is instantaneously evaporated or melted by the heat. In order to efficiently absorb laser light, the absorptance for the wavelength (around 800 nm) of a semiconductor laser used as a light source becomes important.

As an index of the absorptance for the light near 800 nm, the optical density of the heat-sensitive layer can be mentioned, and the higher the optical density, the higher the absorptivity of the laser light. In the present invention, the optical density of the heat-sensitive layer is preferably from 0.6 to 2.3, and more preferably from 0.8 to 2.0. When the optical density is lower than 0.6, the sensitivity of the printing plate is apt to decrease because the laser light is not efficiently absorbed, and when the optical density is higher than 2.3, the film thickness is increased, so that energy for forming an image is increased. Is necessary, and the sensitivity tends to decrease.

Here, the optical density refers to the Ratten filter no. Using Macbeth densitometer RD-106
The numerical value when the measurement is performed at 514.

Further, from the viewpoint of the sensitivity of the printing plate, the melting point of the metal is very important. That is, if the melting point is too high,
This is because even if the laser beam is irradiated, the metal does not melt or change such as evaporation. In the present invention, any metal having a melting point of 930 (K) or less can be used.

Specific examples of such a metal include tellurium,
Tin, antimony, gallium, magnesium, polonium, selenium, thallium, zinc, bismuth and the like.

On the other hand, if the melting point is too low, the form retention of the printing plate tends to be reduced. A particularly preferred range of the melting point is 500 (K) to 930 (K).

From this viewpoint, particularly preferred are tellurium, tin, antimony, magnesium, polonium, thallium, zinc and bismuth.

[0155] The use of two or three kinds of these metals is particularly preferable because the melting point can be more easily adjusted and the sensitivity as a printing plate can be improved.

When an alloy is used, various alloys can be produced depending on the combination of metals.
(K) Combinations of all of the following metals can be used, and among these, two or three of the metals of tellurium, tin, antimony, gallium, bismuth, and zinc are preferred in terms of ease of handling. Combinations are preferred.

As a specific combination, tellurium / tin, tellurium / antimony, tellurium / gallium, tellurium / bismuth, tellurium / zinc, tin / tin
Antimony, tin / gallium, tin / bismuth, tin /
Zinc is preferred, more preferably tellurium / tin, tellurium / antimony, tellurium / zinc, tin / antimony, tin / zinc.

The three alloys include tellurium / tin / antimony, tellurium / tin / gallium, tellurium / tin / bismuth, tellurium / tin / zinc, tellurium / zinc / antimony, tellurium / zinc / gallium, and tellurium / zinc / bismuth. , Tin / zinc / antimony are preferred, more preferably tellurium / tin / antimony, tellurium / tin / zinc,
Tin / zinc / antimony.

These two or three alloys are:
Since the shape retention is good and the melting point is 930 (K) or less, the sensitivity is increased, which is particularly preferable.

In addition, as the heat-sensitive layer, a layer in which a carbon thin film is laminated on or below a metal thin film so as to fall within the optical density range is also very effective. At this time, it is more preferable to form the carbon thin film on the metal thin film because the effect of improving the sensitivity is large. The metal used at this time is preferably a metal having a melting point of 2000 (K) or less, more preferably 1000 (K) or less. Melting point 2000
If it is higher than (K), it is difficult to form an image even if a carbon thin film is formed at the same time.

Specifically, titanium is preferred as a metal,
Aluminum, nickel, iron, chromium, tellurium, tin,
There are antimony, gallium, magnesium, polonium, selenium, thallium, zinc and bismuth, with tellurium, tin, antimony, gallium, bismuth and zinc being more preferred. These metals are easily evaporated or melted by heat when the thin film is irradiated with laser light.

Further, by forming an alloy using two or more kinds of the above metals, the melting point can be further reduced and the sensitivity as a printing plate can be increased.

Specifically, alloys of tellurium and tin, tellurium and antimony, tellurium and gallium, tellurium and bismuth, tellurium and zinc are preferred, and more preferred are tellurium and zinc, and tellurium and tin.

Among the three alloys, alloys of tellurium, tin and zinc, tellurium, gallium and zinc, tin, antimony and zinc, tin, bismuth and zinc are preferred, and more preferably tellurium, tin and zinc, and tin and bismuth. And zinc alloy. These materials are particularly preferable because of their high optical density and low melting point.

The thickness of the metal thin film is preferably 50 to 500 Å, more preferably 100 to 30 Å.
0 Angstrom.

The carbon thin film only needs to be black enough to suppress the reflection of the metal thin film, and the thickness of the carbon thin film is preferably 50 to 500 angstroms, and more preferably 100 to 300 angstroms.

Further, the thickness ratio of the metal thin film to the carbon thin film also affects the sensitivity of the printing plate. Specifically, when the thickness of the metal thin film is 1, the carbon thin film is 1/4 to 6 Preferably, there is.

If the thickness ratio of the carbon thin film is smaller than 1/4, it is not preferable in terms of sensitivity, and if it is larger than 6, it becomes difficult to form the carbon thin film.

When a carbon thin film is provided, the thickness of the heat-sensitive layer as a whole has a great influence on the sensitivity of the printing plate. That is, if the film thickness is too large, the energy required for evaporating and melting the thin film is required extraly, so that the sensitivity of the printing plate is reduced. Therefore, the thickness is preferably 1,000 Å or less, more preferably 300 Å or less.

When the heat-sensitive layer is a metal thin film or a metal thin film and a carbon thin film as described above, the thin film is preferably formed by vacuum deposition or sputtering. Vacuum evaporation is a method in which a metal or each of a metal and carbon is heated and evaporated in a reduced-pressure container of 10 ⁻⁴ to 10 ⁻⁷ mmHg to form a thin film on the surface of a substrate.

Sputtering is performed at 10 ^-1 to 10 ^-3 mmHg
In this method, a DC or AC voltage is applied to a pair of electrodes in a reduced-pressure vessel to cause glow discharge, and a thin film is formed on a substrate by using a sputtering phenomenon of a cathode.

In the present invention, a vacuum deposition method is preferable because a pattern can be easily formed by laser light.

It is also preferable to provide a silane coupling agent layer on the heat-sensitive layer in order to increase the adhesion to the silicone rubber layer. Thereby, the printing durability and solvent resistance of the printing plate can be greatly improved.

Examples of the silane coupling agent include vinyl silane, (meth) acryloyl silane, epoxy silane,
All known compounds such as aminosilane, mercaptosilane, and chlorosilane can be used. Among them, (meth) acryloylsilane, epoxysilane, aminosilane, and mercaptosilane are preferably used.

Specifically, (meth) acryloylsilane is 3- (meth) acryloylpropyltrimethoxysilane, 3- (meth) acryloylpropyltriethoxysilane, and epoxysilane is 3-glycidoxy. Propyltrimethoxysilane, 2- (3,4
-Epoxycyclohexyl) ethyltrimethoxysilane, and as aminosilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, N-2
— (Aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-aminopropyltriethoxysilane, and examples of mercaptosilane include 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, and the like.

These silane coupling agents are dissolved in an appropriate solvent and applied on the heat-sensitive layer in the form of a dilute solution.
By performing heat drying, a silane coupling agent layer can be formed.

It is sufficient that the silane coupling agent layer has a thickness such that a monomolecular film of the silane coupling agent is formed. Specifically, the thickness is preferably 1,000 angstroms or less, more preferably. 500 angstrom or less. When the thickness is more than 1000 Å, the sensitivity, printing durability and solvent resistance of the printing plate tend to decrease.

Next, the silicone rubber layer will be described.
As the silicone rubber layer, any silicone composition used in conventional waterless lithographic printing plates can be used.

Examples of such a silicone rubber layer include those obtained by sparsely cross-linking a linear organopolysiloxane (preferably dimethylpolysiloxane). A typical silicone rubber layer has the following formula: (I)
It has a repeating unit as shown in the following.

[0180]

Embedded image (Here, n is an integer of 2 or more. R has 1 to 10 carbon atoms.)
Alkyl, aryl, or cyanoalkyl group. 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. Particularly, in the present invention, the silicone rubber layer (RTV, LT) in which the silicone rubber layer undergoes condensation type crosslinking as described below.
(V-type silicone rubber). That is, the organic polysiloxane chain is obtained by substituting a part of R in the organopolysiloxane chain with H, or cross-linked by condensation of terminal groups represented by the following formulas (II), (III) and (IV). An excess of a crosslinking agent may be present in this.

[0181]

Embedded image (Here, R means the same as R described in the formula (I).)

Embedded image (Here, R means the same as R explained in the formula (I), and R ₁ and R ₂ mean a monovalent lower alkyl group.)

Embedded image (Where R means the same as R described in the formula (I), and Ac is an acetyl group.) The silicone rubber layer for performing such condensation type crosslinking includes:
It is preferable to add a metal carboxylate such as tin, zinc, lead, calcium, or manganese, for example, dibutyltin laurate, tin (II) octoate, naphthenate, or a catalyst such as chloroplatinic acid. .

In addition to these compositions, a known adhesion-imparting agent such as alkenyl trialkoxysilane may be added, or a hydrolyzable functional group-containing silane (or siloxane) may be used as the composition of the condensation type silicone rubber layer. ) Can be added, and for the purpose of improving rubber strength,
It is also possible to add a known filler such as silica. In addition to these compositions, it is also effective to add the above-mentioned silane coupling agent for the purpose of improving the adhesion to the heat-sensitive layer.

When a silane coupling agent is added to the silicone rubber layer, it is not necessary to provide a silane coupling agent layer.

Further, in the present invention, it is also possible to use an addition type silicone rubber in addition to the condensation type silicone rubber described above.

Examples of the addition type silicone rubber include, for example,
It is preferable to use one obtained by crosslinking and curing a hydrogen polysiloxane having a Si—H bond and a vinyl polysiloxane having a CH ＝ CH bond as specifically shown below with an addition catalyst.

That is, (1) 100 parts by weight of an organopolysiloxane having at least two alkenyl groups (preferably vinyl groups) directly bonded to silicon atoms in one molecule. (2) At least one Si—H group in one molecule. And 0.1 to 1000 parts by weight of an organohydrogen polysiloxane having two (3) addition catalysts of 0.00001 to 10 parts by weight.

The alkenyl group of the component (1) is
The organic group other than the alkenyl group may be a substituted or unsubstituted alkyl group or an allyl group.
And it may be a hydroxyl group. Component (1) may have a small amount of hydroxyl groups.

The component (2) reacts with the component (1) to form a silicone rubber layer, but also plays a role of imparting adhesiveness to the heat-sensitive layer. The hydrogen group of the component (2) may be at the terminal of the molecular chain or at the middle, and the organic group other than hydrogen is selected from those similar to the component (1).

The organic groups of the components (1) and (2) are preferably methyl groups in which at least 60% of all the groups are methyl groups from the viewpoint of improving ink repellency. The molecular structure of the component (1) and the component (2) may be linear, cyclic, or branched, and it is preferable that at least one of the molecular weights exceeds 1,000 in terms of rubber physical properties. Preferably, the molecular weight exceeds 1000.

Specifically, the component (1) includes α, ω
-Divinylpolydimethylsiloxane, (methylvinylsiloxane) (dimethylsiloxane) copolymer having both terminal methyl groups, and the like. Component (2) includes polydimethylsiloxane having both terminal hydrogen groups, α, ω-dimethylpolysiloxane. Examples thereof include methyl hydrogen siloxane, (methyl hydrogen siloxane) (dimethyl siloxane) copolymer having methyl groups at both terminals, cyclic polymethyl hydrogen siloxane, and the like.

The addition catalyst of the component (3) is arbitrarily selected from known catalysts, and is particularly preferably a platinum compound, such as platinum alone, platinum chloride, chloroplatinic acid, and olefin-coordinated platinum. .

For the purpose of controlling the curing rate of these compositions, organopolysiloxanes containing a vinyl group such as tetracyclo (methylvinyl) siloxane, alcohols containing a carbon-carbon triple bond, acetone, methyl ethyl ketone, methanol It is also possible to add a crosslinking inhibitor such as ethanol, ethanol and propylene glycol monomethyl ether.

These compositions are characterized in that an addition reaction occurs when the three components are mixed, and curing starts, but the curing speed rapidly increases as the reaction temperature increases. Therefore, the pot life until rubberization of the composition is lengthened,
For the purpose of shortening the curing time on the heat-sensitive layer, the composition should be kept at a temperature within a range that does not change the properties of the substrate and the heat-sensitive layer, and at a high temperature until completely cured. This is preferable from the viewpoint of stability of adhesive strength to the heat-sensitive layer.

The thickness of these silicone rubber layers was 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 less than 0.5 g / m ² , the ink repellency of the printing plate tends to decrease, and
If it is larger than / m ² , it is disadvantageous from an economic point of view.

The above-mentioned heat insulating layer, heat-sensitive layer and silicone rubber layer can be coated on a substrate by a slit die coater, direct gravure coater, offset gravure coater, reverse roll coater, natural roll coater, air knife coater, roll blade. Coater, Bali bar roll blade coater, two stream coater, rod coater, dip coater,
It is preferable to use various devices such as a curtain coater, and it is particularly preferable to use a slit die coater, an offset gravure coater, and each roll coater in terms of coating film accuracy, productivity, and cost.

Next, an example of a method for producing the above-described direct drawing type waterless planographic printing plate precursor will be described.

Using the above-described apparatus, the heat insulating layer composition was applied on the substrate and cured at 100 to 300 ° C. for several minutes. Then, the heat sensitive layer composition coating liquid was applied, and dried at 50 to 180 ° C. for several minutes. If necessary, heat and dry, apply a silicone rubber composition, heat-treat at a temperature of 50 to 150 ° C. for several minutes to cure the rubber, form a film, laminate a film or coat a polymer solution, and form a cover coat layer. .

The thus obtained direct-drawing waterless planographic printing plate precursor is exposed imagewise with a laser beam while the cover coat layer is mounted, and then developed to obtain the water-free lithographic printing plate precursor of the present invention. No planographic printing plate is obtained.

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 waterless planographic printing plate precursor exposed by the above method is subjected to peeling development or ordinary solvent development if necessary. If the cover coat layer is a film, the film is peeled off, and if it is coated with a polymer solution, it is developed as it is.

Examples of the developing solution used for the solvent developing treatment include water, water obtained by adding the following polar solvent to water, and aliphatic hydrocarbons (hexane, heptane, isoparaffin hydrocarbon, gasoline, kerosene, etc.). Preferably, at least one of the following polar solvents is added to at least one or more mixed solvents of aromatic hydrocarbons (toluene, xylene and the like), halogenated hydrocarbons (tricrene and the like) and the like.

Examples of the polar solvent include the following. That is, alcohols (methanol, ethanol, propanol, isopropanol, 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 mono) Butyl 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, lactic acid) Butyl, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, etc.Carboxylic acid (2-ethylbutyric acid, caproic acid, caprylic acid, 2-ethylhexanoic acid, capric acid, oleic acid,
Lauric acid).

Further, a known surfactant can be added to the above-mentioned developer composition. Further alkaline agents such as sodium carbonate, monoethanolamine, diethanolamine, diglycolamine, monoglycolamine, triethanolamine, sodium silicate,
Potassium silicate, potassium hydroxide, sodium borate and the like can also be added.

To these developers, known basic dyes such as crystal violet, Victoria Pure Blue, and Astrazone Red, acid dyes and oil-soluble dyes can be added to simultaneously develop and dye the image area.

In the development, the developer can be developed by impregnating a nonwoven fabric, absorbent cotton, cloth, sponge, or the like with the developer and wiping the plate surface.

For development, see JP-A-63-163357.
After the plate surface is pre-treated with the above-mentioned developing solution using an automatic developing machine as described in Japanese Patent Application Laid-Open No. H10-209, the plate surface can be suitably developed by 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 instead of the above-mentioned developer.

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited thereto.

[0209]

【Example】

Example 1 A heat insulating liquid having the following composition was applied on a degreased aluminum plate having a thickness of 0.24 mm, dried at 230 ° C. for 2 minutes, and provided with a heat insulating layer of 5 g / m ² .

(A) 100 parts by weight of polyurethane resin “Milactran” P22S (manufactured by Nippon Milactran) (b) 20 parts by weight of blocked 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 parts by weight (e) Victoria pure blue BOH naphthalene sulfonic acid 0.1 parts by weight (f) Dimethylformamide 720 Parts by weight Next, a heat-sensitive layer composition having the following composition was applied on the heat-insulating layer, and dried at 130 ° C. for 1 minute to provide a heat-sensitive layer having a thickness of 1 g / m ² .

(A) Nitrocellulose Viscosity 1/2 second, nitrogen content 11.0% "Berge rac NC" (manufactured by SNP Japan Ltd.) 24 parts by weight (b) Carbon black 30 parts by weight Part (c) Polyurethane “SAMPLEN” LQ-T1331 (manufactured by Sanyo Chemical Industries, Ltd.) 30 parts by weight (d) Modified epoxy resin “EPOKEY” 803 (manufactured by Mitsui Toatsu Chemicals) 15 parts by weight (e) Epoxy Acrylate “Denacol Acrylate” DA-314 (manufactured by Nagase Kasei Kogyo Co., Ltd.) 15 parts by weight (f) 5 parts by weight of diethylenetriamine (g) 600 parts by weight of methyl isobutyl ketone Subsequently, the following composition is formed on the heat-sensitive layer. A silicone rubber solution is applied, dried at 120 ° C. for 2 minutes, and has a thickness of 2 g / m 2.
^{A second} silicone rubber layer was provided.

(A) 100 parts by weight of vinyl polydimethylsiloxane (b) 12 parts by weight of hydrogen siloxane (c) 0.2 parts by weight of platinum catalyst (d) 2 parts by weight of curing retarder (e) Isoparaffinic hydrocarbon isopar E (manufactured by Exxon Chemical Co., Ltd.) 1200 parts by weight A biaxially stretched polypropylene film “Trefane BO” having a thickness of 6.5 μm as shown in Table 1 (manufactured by Toray Industries, Inc.) was added to the laminate obtained as described above. ) Was laminated using a calendar roller to obtain a printing plate precursor.

Thereafter, this printing plate precursor was mounted on a drum, and a semiconductor laser (output 1 W, wavelength 830 nm, TE
Pulse exposure was performed with a beam diameter of 20 μm and an exposure time of 10 μs using K.K. At this time, the laser output was arbitrarily changed by an LD pulse modulation driving device, the laser power on the plate surface was measured, and the odor during drawing was observed.
Subsequently, it was rubbed with a cotton pad impregnated with a developer having the following composition, developed, and visually evaluated for image reproducibility with an optical microscope.

(A) Water 80 parts by weight (b) Diethylene glycol mono-2-ethylhexyl ether 20 parts by weight As can be seen from Table 1, laser drawing properties, plate inspection properties,
Excellent sensitivity, no odor during drawing, and no contamination of the laser focusing lens.

Comparative Example 1 A direct-drawing waterless planographic printing plate precursor was prepared in the same manner as in Example 1 except that the cover coat layer was not provided. When the odor during the drawing and the contamination of the laser condenser lens were examined, the odor was generated as shown in Table 1 and was not satisfactory.

Examples 2 to 4 A direct-drawing waterless planographic printing plate precursor was prepared in the same manner as in Example 1 except that the cover coat layer was a film shown in Table 1.
The laser drawing properties, plate inspection properties, sensitivity, and odor during drawing were examined in the same manner as in Example 1. As shown in Table 1, Examples 2 to 4 were all satisfactory.

Example 5 A polymer solution having the following composition was applied on the silicone rubber layer of Example 1, dried at 120 ° C. for 1 minute, and dried to a thickness of 3 g / g.
It provided with a cover coat layer of m ^2.

(A) 95 parts by weight of rosin-modified phenolic resin “Despol 1355” (manufactured by Hitachi Chemical Co., Ltd.) (b) 5 parts by weight of primer “DY39067” for addition type silicone (manufactured by Toray Dow Corning Co., Ltd.) c) 100 parts by weight of dimethylformamide The direct-drawing waterless lithographic printing plate precursor obtained as described above was subjected to laser drawing, plate inspection, sensitivity and sensitivity in the same manner as in Example 1.
When the odor during drawing was examined, as shown in Table 1,
Everything was satisfactory.

Example 6 Using the same substrate and heat-insulating layer as in Example 1, the following metals were successively vacuum-deposited on the heat-insulating layer in the following weight ratio to provide a heat-sensitive layer. .

(A) 25 parts by weight of carbon (b) 75 parts by weight of titanium Subsequently, the following silane coupling agent was applied on the heat-sensitive layer and dried at 120 ° C. for 2 minutes to form an adhesive layer.

(A) 1.5 parts by weight of 3-aminopropyltrimethoxysilane (b) 1000 parts by weight of ethanol Further, a silicone rubber layer and a cover coat layer similar to those in Example 1 were laminated on the adhesive layer and directly drawn. A lithographic printing plate precursor without mold water was obtained. Evaluation was performed in the same manner as in Example 1, and satisfactory results were obtained as shown in Table 1.

[0222]

[Table 1]

[0223]

The plate making method of the direct drawing type waterless planographic printing plate precursor according to the present invention is directed to a direct drawing type waterless planographic plate comprising a heat insulating layer, a heat sensitive layer, a silicone rubber layer and a cover coat layer sequentially laminated on a substrate. When making a printing plate precursor, it is laser exposed with the cover coat layer attached and then developed, so it does not cause lens contamination or unpleasant odor during laser exposure, high sensitivity, good plate inspection, and workability It will be excellent.

Claims (4)

[Claims] 1. A direct drawing type waterless lithographic printing plate precursor comprising a heat insulating layer, a heat sensitive layer, a silicone rubber layer, and a cover coat layer sequentially laminated on a substrate. A plate making method for a direct-drawing waterless lithographic printing plate precursor, comprising developing and developing. 2. The method according to claim 1, wherein the cover coat layer is made of a material that transmits infrared light. 3. A method for making a direct-drawing waterless planographic printing plate precursor according to claim 2, wherein the infrared transmittance of the cover coat layer is 75% or more. 4. A cover coat layer having a thickness of 2 to 10 μm and an oxygen permeability of 400 to 100,000 cc.
/ M < ² > / 24 hr (20 [deg.] C.), wherein the plate making method of a direct-drawing waterless lithographic printing plate precursor according to any one of claims 1 to 3.