JP2001281867A - Photomechanical process for planographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photomechanical process for a planographic printing plate capable of giving an image with high resolution, adaptable to a direct pattern forming method with a laser, capable of giving an image particularly even in a light room, producing no waste liquid and very excellent in ink/water responsiveness and printing durability. SOLUTION: In the photomechanical process in which a planographic printing original plate having at least a hydrophilic undercoat layer on the substrate and a thin silver film layer on the undercoat layer is subjected to laser exposure to heat the thin silver film layer and to expose the hydrophilic undercoat layer, at least titanium particles and a resin containing a siloxane bond comprising Si atoms connected by way of oxygen atoms are contained in the hydrophilic undercoat layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of making a lithographic printing plate which can be handled in a bright room and can perform laser drawing in a heat mode.

[0002]

2. Description of the Related Art A lithographic printing plate comprises an oleophilic image portion which receives oil-based ink and an oil-repellent non-image portion which does not receive ink. Generally, the non-image portion comprises a hydrophilic portion which receives water. Have been. In normal lithographic printing,
Both water and ink are supplied to the plate, and the image area
The non-image portion selectively receives water and performs printing by transferring the ink on the image portion to a printing medium such as paper.

At present, a lithographic printing plate is manufactured by providing a lipophilic ink-receiving layer on a base material such as an aluminum plate, a zinc plate, or paper having a hydrophilic surface. Among these, a PS plate, which is made of a photosensitive material such as a diazo compound or a photopolymer on an aluminum base having a hydrophilic surface, or a silver complex salt on a paper or plastic support using silver halide as a photosensitive material. An image forming apparatus using a diffusion transfer method (DTR method) is generally used.

A method of forming an ink receiving layer (hereinafter referred to as an image layer) by using a diazo compound or a photopolymer is as follows. First, a photosensitive material such as a diazo compound or a photopolymer is formed on a substrate such as a metal plate, paper, a laminate, or an insulating substrate. Apply material. Next, the photosensitive material is irradiated with light to cause a chemical change to change the solubility in a developing solution. Here, photosensitive materials are classified into two types according to the type of chemical change. That is, a negative type in which the light-irradiated portion is polymerized and cured to become insoluble in the developer, and conversely, the functional group of the light-irradiated portion changes to have a solubility in the developer. It is a positive type. In any case, the portion of the photosensitive layer insoluble in the developer remaining on the substrate after the treatment with the developer becomes the image layer.

On the other hand, a lithographic printing plate using the DTR method, particularly a lithographic printing plate having a physical development nucleus layer on a silver halide emulsion layer, is disclosed, for example, in US Pat. No. 134,769, No. 4,160,670,
Nos. 4,336,321 and 4,501,811
No. 4,510,228 and 4,621,04
The exposed silver halide crystal described in the specification of JP-A No. 1 and the like, undergoes chemical development by DTR development and becomes black silver to form a hydrophilic non-image portion. On the other hand, unexposed silver halide crystals are converted into a silver salt complex by the complexing agent in the developer and diffuse to the physical development nucleus layer on the surface. An image portion mainly composed of developed silver is formed. Also, on a grained and anodized aluminum-based support, a physical development nucleus layer,
A lithographic printing plate to which a silver halide emulsion layer is sequentially coated is described in, for example, JP-A-63-260491, JP-A-3-26049.
No. 116151, 4-282295 and the like. After the above lithographic printing plate is image-exposed and DTR-developed, the silver halide emulsion layer is washed with warm water to form an anodized aluminum base. An image portion mainly composed of physically developed silver is formed.

In the plate making process for making these printing plates, conventionally, an intermediate film or an underprint is prepared from characters, images and photographic originals, and these are collected to prepare an exposure film. Subsequently, a contact exposure method using ultraviolet light or white light was mainly used. Further, a method has also been used in which a complete composition is produced by laminating the composition, and photographing is performed with a plate making camera. However, with the progress of computers, digital signals from computer information were transmitted to the exposure equipment (computer-to-plate),
It has become possible to perform a laser direct writing method in which a photosensitive material is directly exposed using a laser. The laser direct writing method has advantages such as low cost, high speed, and high productivity in a wide variety of small lot products because a plate-making film used in the middle can be omitted.

CTP corresponding to this laser direct writing method
Various methods have been proposed as printing plates (computer-to-plate). High sensitivity C of several μJ / cm ²
As the TP printing plate, a silver salt DTR type and an organic semiconductor type have been proposed. The former had a problem in the stability of the plate making process, and had to be handled in a dark room or a dark box until the development process was completed, and the latter had an advantage that it could be handled in a bright room until before exposure. However, there was a problem in dot reproducibility. As a CTP printing plate having a relatively high sensitivity of several hundred μJ / cm ² , a high-sensitivity photopolymer system has been proposed. This method has problems such as the necessity of heating after exposure and / or development, and the occurrence of dot thickening after exposure. As a low-sensitivity CTP printing plate of several hundred mJ / cm ² , a cross-linking / de-cross-linking thermal plate has been proposed, which has advantages such as handling in a bright room and excellent dot image quality. However, low sensitivity requires a high-output laser light source, high cost of the light source, heating after exposure is necessary, or replenishment of the elution processing solution is increased. Had.

Further, in the above-described image forming method, liquid processing such as using a developing solution is generally performed, and there is a disadvantage that processing of waste liquid is an environmental problem. 1
Since 995, the dumping of wastewater into the ocean has been banned, and the need for non-waste liquefaction and dry treatment has become a requirement of the times.

In response to such a demand, a lipophilic metal thin film is provided on a support having a hydrophilic surface, and the lipophilic metal thin film is irradiated with a high-output heat mode laser to apply heat. A printing plate of a method of forming an image by removing the printing plate has been proposed. For example, JP-A-10-
JP-A-180976 and JP-A-11-216963, by subjecting a printing original plate having a silver thin layer formed on a support having a hydrophilic layer by DTR development to heat mode laser exposure, thereby performing a development process. Plate making can be performed without performing the above.

In order to produce such a printing original plate, a silver salt diffusion transfer method is effective as a method for forming a silver thin film layer on a support, and a method described in JP-A-11-216963 is effective. It is valid. However, the methods disclosed in these documents have a problem that the printing characteristics such as stains are not sufficient.

[0011]

SUMMARY OF THE INVENTION An object of the present invention is to provide a lithographic printing plate making technique which can be handled in a bright room, is compatible with a direct drawing method using a laser, and has an image having high resolution. A lithographic printing plate which is capable of producing a lithographic printing plate without any waste liquid during plate making, and has improved printing stains, ink / water responsiveness and printing durability. It is to provide a plate making method.

[0012]

Means for Solving the Problems As a result of intensive studies, the present inventors have solved the above-mentioned problems. That is, the present invention provides a lithographic printing plate precursor having at least a hydrophilic undercoat layer on a support, and a silver thin film layer provided on the hydrophilic undercoat layer, and heating the silver thin film layer by laser exposure. In the method of making a lithographic printing plate for exposing the hydrophilic undercoat layer,
A method of making a lithographic printing plate, characterized in that the titanium oxide particles and Si in the hydrophilic undercoat layer contain at least a siloxane bond-containing resin connected via an oxygen atom.

In the present invention, the silver thin film layer portion is hydrophobic, and the exposed portion of the hydrophilic undercoat layer is, of course, hydrophilic. For this reason, the difference between an ink receptive portion and an ink repellent (water receptive) portion occurs on a lithographic printing plate depending on the presence or absence of heat mode exposure. That is, when plate making is performed by the plate making method of the lithographic printing plate of the present invention, the silver thin film layer heated by laser exposure is melted by heat and turned into fine particles.
By removing the fine particles using a removing device as necessary), the underlying hydrophilic layer is exposed to become a non-image area for repelling ink and receiving water, and a silver thin film layer is formed in an unheated area. By remaining as it is, it becomes an image part that receives ink, and lithographic printing becomes possible.

In the present invention, titanium oxide particles and S
A hydrophilic undercoat layer made of a resin containing a siloxane bond in which i is connected via an oxygen atom is used. Such titanium oxide particles are known as a photocatalyst, and are photo-excited by irradiation of ultraviolet light, and the particle surface has a contact angle of 10 with water.
It is characterized in that it is hydrophilized to a degree or less. However, in the present invention, it was found that the hydrophilic undercoat layer exposed by laser exposure had high hydrophilicity and had excellent printability even without irradiation with ultraviolet light.

Further, since titanium oxide can be stabilized in a state of sol dispersed with very fine particles, a very thin thin film can be easily formed. It has been found that the thin film thus formed has an appropriate adhesion to the silver thin film, and provides the printing durability required for printing.

Further, a resin containing a siloxane bond in which titanium oxide particles and Si are connected via an oxygen atom is applied on a support of a film or a paper coated with polyethylene to form a hydrophilic undercoat layer. When a silver thin film is formed, the silver thin film is easily removed by laser exposure,
Since silver particles did not remain on the exposed hydrophilic undercoat layer, it was found that printing stains did not occur.

Further, in the present invention, the plate making method for a lithographic printing plate according to the second invention is characterized in that the siloxane bond-containing resin in which the titanium oxide particles and Si in the hydrophilic undercoat layer are connected via an oxygen atom is used. By providing a hydrophilic polymer layer containing a hydrophobic compound on the silver thin film, the silver thin film is removed by laser exposure, whereby the titanium oxide particles and the hydrophilic polymer interact with each other. , Stable hydrophilicity, and excellent ink / water responsiveness during printing.

In the plate making method of a lithographic printing plate according to a third aspect of the present invention, the titanium oxide has an anatase crystal structure. It has been found that by using anatase type titanium oxide having high photocatalytic activity, the hydrophilic undercoat layer exposed by laser exposure has higher hydrophilicity and better printability.

In the plate making method of a lithographic printing plate according to a fourth aspect of the present invention, the titanium oxide particles have a particle size of 0.0
It is characterized by being 0.1 to 0.1 μm.
When the particle diameter is larger than 0.1 μm, it is difficult to form a uniform coating in a portion adjacent to the silver thin film layer, and as a result, a portion that is easily removed or hardly removed in the silver thin film layer during laser exposure. This causes unevenness in the removability. On the other hand, if the particle diameter is smaller than 0.001 μm, the particles themselves tend to cause secondary aggregation, making it difficult to form a uniform film. 0.001-0.
By using titanium oxide particles having a particle diameter of 1 μm, a uniform and strong film is formed in the hydrophilic layer, and the removability of the silver thin film layer can be made uniform over the entire hydrophilic undercoat layer. . Thus, an image having high resolution can be obtained.

In the plate making method of a lithographic printing plate according to a fifth aspect of the present invention, the hydrophilic layer has a thickness of 0.01 to 0.01.
The thickness is 0.3 μm. It has been found that thinning the hydrophilic layer gives the silver thin film an appropriate adhesiveness and an appropriate printing durability.

According to a sixth aspect of the present invention, there is provided a method for making a lithographic printing plate, wherein the silver thin film layer of the lithographic printing plate precursor comprises:
It is characterized by being composed of physically developed silver generated by a silver complex salt diffusion transfer method. The silver thin film layer physically developed by the silver complex salt diffusion transfer method has a higher laser absorptivity and lipophilicity than a silver thin film layer formed by a vapor deposition method or the like, and the removal efficiency of the silver thin film layer by laser exposure is improved. In addition, since the ink receptivity of the image portion silver thin film is increased, the performance as a lithographic printing plate is improved.

According to a seventh aspect of the present invention, there is provided the plate making method for a lithographic printing plate according to the seventh aspect, wherein the silver thin film layer is formed on a support by at least one element selected from aluminum, silicon, zirconium, and titanium. A physical development nucleus layer containing an oxide of (in this case, also acting as a hydrophilic layer), a silver halide emulsion layer are provided in this order, and a development process by a silver complex salt diffusion transfer method is performed without exposure, The silver halide emulsion layer was washed off, and physical development silver was formed in layers on physical development nuclei. According to this method, the hydrophilicity of the exposed surface can be greatly improved, and excellent ink / water responsiveness can be obtained. Although the detailed mechanism is unknown, it is considered that thermal damage to the hydrophilic layer is reduced because the ratio of the silver thin film layer and the inorganic oxide extremely close to each other increases.

In the plate making method of a lithographic printing plate according to an eighth aspect of the present invention, the silver thin film layer is composed of granular silver particles having an average particle size of 0.005 to 0.2 μm. A silver thin film layer. Such a silver thin film layer made of silver particles is easily removed by heat mode laser exposure, and has excellent printability.

According to a ninth aspect of the present invention, in the method of making a lithographic printing plate, the support is a film or a paper coated with polyethylene. Film or paper coated with polyethylene is cheaper than aluminum base, but surface treatment is inferior to aluminum base which has been subjected to hydrophilic treatment,
It was inferior in various printability including ink / water responsiveness. However, even if a film or a paper coated with polyethylene is used for the support, it has a hydrophilic layer containing an inorganic oxide thereon, and the inorganic oxide is exposed after exposure, so Hydrophilicity is improved, and ink / water responsiveness comparable to that of a surface-treated and hydrophilic aluminum base can be obtained. Further, the inorganic oxide can improve the physical layer strength of the hydrophilic layer, thereby improving the printing durability.

In a tenth aspect of the present invention, in the method of making a lithographic printing plate, drawing is performed using a laser having an output of 0.1 to 10 W on the lithographic printing plate precursor, and The silver content in the thin film layer is 0.1 to 1.5 g / m ² . The amount of silver in the silver thin film layer greatly affects the characteristics of removing the silver thin film layer during laser writing and the printing characteristics during printing. The amount of silver in the silver thin film layer is 1.5 g / m ²
If the amount is larger than the above range, the removal characteristic at the time of drawing deteriorates, and silver remains on the hydrophilic surface. As a result, stains are induced at the time of printing. On the other hand, the amount of silver in the silver thin film layer was 0.1 g /
If it is less than m ² , the removal characteristics will be improved and the hydrophilic surface will be exposed, but the printing durability will deteriorate during printing. Therefore, by setting the amount of silver in the silver thin film layer to 0.1 to 1.5 g / m ² , it is possible to prepare a lithographic printing plate excellent in both the removal characteristics and the printing characteristics at the time of drawing and the printing characteristics are balanced. Become.

According to the present invention, a lithographic printing plate can be made without using a liquid developer or devices for processing the same by heating a non-image portion with a laser according to a desired image. Becomes possible. Further, it is possible to work in a bright room from the lithographic printing original plate to the plate making process and the printing process, and it is possible to perform long-term stable storage in a bright room or under oxygen.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION The lithographic printing plate precursor according to the present invention has, on a support, a hydrophilic undercoat layer containing at least titanium oxide particles and a siloxane bond-containing resin in which Si is connected via an oxygen atom. And a silver thin film layer is provided thereon. In the method of making a lithographic printing plate according to the invention, first, a lithographic printing plate precursor is irradiated with a laser so as to obtain a desired image (non-image portion exposure). Here, the silver thin film layer is removed (ablated) by laser irradiation, or after laser exposure, the residue remaining in the exposed portion on the printing original plate is removed by means such as vacuuming, or silver particles are granulated. As a result, plate making is completed by finally exposing the hydrophilic undercoat layer in a portion to be a non-image portion and exposing a resin containing a siloxane bond in which titanium oxide particles and Si are connected via an oxygen atom. I do. After this,
When installed in a lithographic printing press, ink is received in the remaining silver thin film layer, and water is received in the hydrophilic layer containing a siloxane bond-containing resin in which titanium oxide particles and Si are connected via oxygen atoms. And printing becomes possible.

The titanium oxide particles used in the present invention are characterized in that they are photoexcited by irradiation with ultraviolet light, and the surface of the particles is hydrophilized to a contact angle of 10 ° or less with water. For details of the phenomenon that the surface is converted to hydrophilic by light irradiation, see, for example, Toshiya Watanabe, Ceramics, 31 (No. 10), 837 (19)
66). The crystal structure of the titanium oxide particles according to the present invention is preferably an anatase type. The preferred particle size of the titanium oxide particles is 0.001 to 0.1 μm,
More preferably, it is 0.005 to 0.05 μm. The titanium oxide particles should have a crystal structure of at least 30% by weight or more in the crystal, and preferably 50% by weight or more.

The particles are commercially available as a powder or as a titania sol dispersion. For example, Ishihara Sangyo Co., Ltd., Titanium Industry Co., Ltd., Sakai Chemical Co., Ltd., Nippon Aerosil Co., Ltd., Nissan Chemical Industry Co., Ltd. and the like can be mentioned. Further, the titanium particles used in the present invention may contain another metal element or an oxide thereof. The inclusion includes coating, supporting, or doping on the surface and / or inside of the particles.

As the metal element contained, for example, S
i, Mg, V, Mn, Fe, Sn, Ni, Mo, Ru,
Re, Os, Cr, Sb, In, Ir, Ta, Nb, C
s, Pd, Pt, Au and the like. Specifically, JP-A-7-228738, JP-A-7-187677, and JP-A-7-187677
-81223, 8-257399, 8-283
No. 022, No. 9-25123, No. 9-71437,
No. 9-70532, and the like. The content of the anatase type titanium oxide used in the present invention is 90% by weight or more, preferably 95% by weight or more.

As other components, inorganic pigment particles other than the titanium oxide particles of the present invention may be contained. For example, silica, alumina, kaolin, clay, zinc oxide, calcium carbonate, barium carbonate, calcium sulfate, barium sulfate, magnesium carbonate, titanium oxide other than anatase type crystals and the like can be mentioned. These other inorganic pigments are used in an amount not exceeding 40% by weight based on the anatase type titanium oxide particles of the present invention. Preferably, it is within 30% by weight.

The resin used for the hydrophilic undercoat layer of the present invention is mainly composed of a polysiloxane resin containing a siloxane bond in which silicon atoms are connected via oxygen atoms. By using this polysiloxane resin, particularly by forming a film using a sol-gel method,
There is an advantage that the strength of the film as the hydrophilic undercoat layer and the uniform dispersibility of the titanium oxide particles are excellent. Examples of the polysiloxane resin include those having a siloxane component bond represented by the following general formula (I).

[0033]

Embedded image

In the general formula (I), R _{01 to} R ₀₃ represent an organic residue selected from the symbol R ₀ in the general formula (II).
More preferably, the hydrophilic undercoat layer of the present invention is formed from a dispersion containing anatase-type titanium oxide particles and at least one silyl compound represented by the general formula (II).
Formed by gel method.

[0035]

Embedded image

In the general formula (II), R ₀ represents a hydrocarbon group or a heterocyclic group. Y is a hydrogen atom, a halogen atom, -O
R ₁ , —OCOR ₂ , or —N (R ₃ ) (R ₄ ) (R ₁ and R ₂ each represent a hydrocarbon group; R ₃ and R ₄ may be the same or different; Represents an atom or a hydrocarbon group). n represents 0, 1, 2 or 3.

Preferably, R ₀ in the general formula (II) is a linear or branched alkyl group having 1 to 12 carbon atoms which may be substituted (for example, methyl group, ethyl group, propyl group, butyl group). Group, pentyl group, hexyl group, heptyl group,
Octyl group, nonyl group, decyl group, dodecyl group and the like; groups substituted by these groups include a halogen atom (a chlorine atom, a fluorine atom, a bromine atom), a hydroxy group, a thiol group, a carboxy group, a sulfo group, and a cyano group. Group, epoxy group,
—OR _A group (R _A is a methyl group, an ethyl group, a propyl group,
Butyl, heptyl, hexyl, octyl, decyl, propenyl, butenyl, hexenyl, octenyl, 2-hydroxyethyl, 3-chloropropyl, 2-cyanoethyl, N, N-dimethylaminoethyl group, 2-bromoethyl group, 2- (2-methoxyethyl) oxyethyl group, 2-methoxycarbonylethyl group, 3-carboxypropyl group, a benzyl group, etc.), - OCOR _B group (R _B, the R the same meaning as _a), - COOR _B group, -COR _B group, -N (R _C) (
R _C ) (R _C represents a hydrogen atom or the same content as R _A , which may be the same or different), —NHCON
HR _B group, -NHCOOR _B group, -Si (R _B ) ₃ group,-
A CONHR _C group, a —NHCOR _B group, and the like.
These substituents may be substituted plurally in the alkyl group), a linear or branched alkenyl group having 2 to 12 carbon atoms which may be substituted (for example, vinyl group, propenyl group, butenyl group, pentenyl group) Group, hexenyl group, octenyl group, decenyl group, dodecenyl group, and the like, as the group substituted with these groups, those having the same contents as the groups substituted with the above-mentioned alkyl group can be mentioned.) An aralkyl group which may be substituted (for example, benzyl group, phenethyl group, 3-phenylpropyl group, naphthylmethyl group, 2-naphthylethyl group, etc .; And a substituted or unsubstituted alicyclic group having 5 to 10 carbon atoms (e.g., cyclopentyl, cyclopentyl) Examples of the group substituted with these groups such as a xyl group, a 2-cyclohexylethyl group, a 2-cyclopentylethyl group, a norbornyl group, and an adamantyl group include those having the same contents as the substituents of the alkyl group. A plurality of optionally substituted aryl groups having 6 to 12 carbon atoms (for example, a phenyl group or a naphthyl group, and examples of the substituent include those having the same contents as the groups substituted by the alkyl group); Or a heterocyclic group which may be condensed and contains at least one atom selected from a nitrogen atom, an oxygen atom and a sulfur atom (for example, the heterocycle includes Pyran ring,
Furan ring, thiophene ring, morpholine ring, pyrrole ring,
Thiazole ring, oxazole ring, pyridine ring, piperidine ring, pyrrolidone ring, benzothiazole ring, benzoxazole ring, quinoline ring, tetrahydrofuran ring, etc.
It may contain a substituent. Examples of the substituent include those having the same contents as the substituent in the alkyl group, and may be substituted.

Preferably, Y is a halogen atom (representing a fluorine, chlorine, bromine or iodine atom),-
Represents an OR ₁ group, a —OCOR ₂ group, or a —N (R ₃ ) (R ₄ ) group. In the —OR ₁ group, R ₁ is an optionally substituted aliphatic group having 1 to 10 carbon atoms (eg, a methyl group, an ethyl group, a propyl group, a butoxy group, a heptyl group, a hexyl group, a pentyl group, an octyl group, Nonyl, decyl, propenyl, butenyl, heptenyl, hexenyl, octenyl, decenyl, 2-hydroxyethyl, 2-hydroxypropyl, 2-methoxyethyl, 2- (methoxyethyloxo) ethyl Group, 2-
(N, N-diethylamino) ethyl group, 2-methoxypropyl group, 2-cyanoethyl group, 3-methyloxapropyl group, 2-chloroethyl group, cyclohexyl group, cyclopentyl group, cyclooctyl group, chlorocyclohexyl group, methoxycyclohexyl group Benzyl, phenethyl, dimethoxybenzyl, methylbenzyl, bromobenzyl, etc.).

In the —OCOR ₂ group, R ₂ is an aliphatic group having the same content as R ₁ or an aromatic group having 6 to 12 carbon atoms which may be substituted (the aromatic group is an aryl group in the aforementioned R). And the same as those exemplified for the group). In the —N (R ₃ ) (R ₄ ) group, R ₃ and R ₄ may be the same or different from each other.
10 optionally substituted aliphatic groups (for example, -O
R ₁ has the same contents as R ₁ ). More preferably, the sum of the carbon numbers of R ₁ and R ₂ is within 16 or less. Specific examples of the silane compound represented by the general formula (II) include the following, but are not limited thereto.

Methyltrichlorosilane, methyltribromosilane, methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane, methyltri-t-butoxysilane, ethyltrichlorosilane, ethyltribromosilane, ethyltrimethoxysilane, ethyltrimethoxysilane Ethoxysilane, ethyltriisopropoxysilane, ethyltri-t-butoxysilane, n-propyltrichlorosilane, n-propyltribromosilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, n-propyltriisopropoxysilane, n-propyltri-t-butoxysilane, n-hexyltrichlorosilane, n-hexyltribromosilane, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, n-propyl
Hexyltriisopropoxysilane, n-hexyltri-t-butoxysilane, n-decyltrichlorosilane, n-
Decyltribromosilane, n-decyltrimethoxysilane, n-decyltriethoxysilane, n-decyltriisopropoxysilane, n-decyltri-t-butoxysilane,
n-octadecyltrichlorosilane, n-octadecyltribromosilane, n-octadecyltrimethoxysilane, n-octadecyltriethoxysilane, n-octadecyltriisopropoxysilane, n-octadecyltri-t-butoxysilane, phenyltrichlorosilane, phenyltri Bromosilane, phenyltrimethoxysilane,
Phenyltriethoxysilane, phenyltriisopropoxysilane, phenyltri-t-butoxysilane, tetrachlorosilane, tetrabromosilane, tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, tetrabutoxysilane, dimethoxydiethoxysilane, dimethyldi Chlorosilane, dimethyldibromosilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldichlorosilane, diphenyldibromosilane, diphenyldimethoxysilane, diphenyldiethoxysilane, phenylmethyldichlorosilane, phenylmethyldibromosilane, phenylmethyl Dimethoxysilane, phenylmethyldiethoxysilane, triethoxyhydrosilane, tribromohydrosilane, trimethoxyhydrosilane, iso Propoxyhydrosilane, tri-t-
Butoxyhydrosilane, vinyltrichlorosilane, vinyltribromosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriisopropoxysilane, vinyltri-t-butoxysilane, trifluoropropyltrichlorosilane, trifluoropropyltribromosilane, trifluoropropyl Trimethoxysilane,
Trifluoropropyltriethoxysilane, trifluoropropyltriisopropoxysilane, trifluoropropyltri-t-butoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxysilane Propyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltriisopropoxysilane, γ-glycidoxypropyltri-t-butoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ- Methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriisopropoxysilane, γ-methacryloxypropyltri-t-butoxysilane, γ-aminopropylmethyl Silane, .gamma.-aminopropyl methyl diethoxy silane, .gamma.
Aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltriisopropoxysilane, γ-aminopropyltri-t-butoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropylmethyldiethoxysilane,
γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-mercaptopropyltriisopropoxysilane, γ-mercaptopropyltri-t-butoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-
Epoxycyclohexyl) ethyltriethoxysilane,
And the like.

The silane compound represented by the general formula (II) used in the present invention may be used in combination with a metal compound such as Ti, Zn, Sn, Zr, and Al which can be formed into a film by a sol-gel method. As the metal compound used, for example, Ti
(OR _D ) ₄ (R _D is a methyl group, an ethyl group, a propyl group,
Butyl, pentyl, hexyl, etc.), TiCl ₄ ,
Zn (OR _D ) ₂ , Zn (CH ₃ COCHCOCH ₃ ) ₂ ,
Sn (OR _D ) ₄ , Sn (CH ₃ COCHCOCH ₃ ) ₄ ,
Sn (OCOR _D ) ₄ , SnCl ₄ , Zr (OR _D ) ₄ , Z
r (CH ₃ COCHCOCH ₃ ) ₄ , Al (OR _D ) _{3 and the} like.

The amount of the metal compound used in combination is within 20 mol%, preferably within 10 mol%, based on the silane compound. Within this range, the uniformity, strength, and the like of the film formed by the sol-gel method are sufficiently maintained. In the hydrophilic undercoat layer of the present invention, the proportion of the anatase type titanium oxide particles and the resin containing a siloxane bond is 45 to 90/5.
A 5 to 10 weight ratio is preferred. More preferably 60 to 80
/ 40 to 20 weight ratio. Within this range, the strength of the film of the hydrophilic undercoat layer, the hydrophilicity of the surface after ultraviolet irradiation, and the like are well maintained, and a large number of clear printed images without background stain can be printed.

The hydrophilic undercoat layer of the present invention is preferably prepared by a sol-gel method, which can be performed by a conventionally known sol-gel method. In particular,
Saio Sakuhana, "Science of Sol-Gel Method", Agne Shofusha Co., Ltd. (published) (1988), Hirashima Tsuyoshi, "Functional Thin Film Fabrication Technology by Latest Sol-Gel Method," Integrated Technology Center (published) (19)
1992), etc., according to the method described in detail in a written copy or the like.

The coating solution for the hydrophilic undercoat layer is an aqueous solvent,
Further, a water-soluble solvent is used in combination for uniform liquefaction by suppressing precipitation during preparation of the coating liquid. Examples of the water-soluble solvent include alcohols (methanol, ethanol, propyl alcohol, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol monoethyl ether, etc.) and ethers (tetrahydrofuran , Ethylene glycol dimethyl ether, propylene glycol dimethyl ether, tetrahydropyran, etc.), ketones (acetone, methyl ethyl ketone, acetylacetone, etc.),
Esters (methyl acetate, ethylene glycol monomethyl monoacetate, etc.), amides (formamide, N-
Methylformamide, pyrrolidone, N-methylpyrrolidone, etc.), and may be used alone or in combination of two or more.

Further, in order to promote the hydrolysis and polycondensation reaction of the silane compound represented by the general formula (II) and the metal compound used in combination, it is preferable to use an acid catalyst or a basic catalyst in combination. The catalyst may be an acid or a basic compound as it is or in a state of being dissolved in a solvent such as water or alcohol (hereinafter referred to as an acidic catalyst,
(Referred to as a basic catalyst). The concentration at that time is not particularly limited, but when the concentration is high, the rate of hydrolysis and polycondensation tends to increase. However, when a highly concentrated basic catalyst is used, a precipitate may be formed in the sol solution. Therefore, the concentration of the basic catalyst is preferably 1 N (concentration conversion in an aqueous solution) or less.

The type of the acidic catalyst or the basic catalyst is not particularly limited, but when it is necessary to use a catalyst having a high concentration, a catalyst composed of an element that hardly remains in the catalyst crystal grains after sintering is used. Good. Specifically, examples of the acidic catalyst include hydrogen halides such as hydrochloric acid, nitric acid, sulfuric acid, sulfurous acid, hydrogen sulfide, perchloric acid, hydrogen peroxide, carbonic acid,
Carboxylic acids such as formic acid and acetic acid, substituted carboxylic acids in which R of the structural formula RCOOH is substituted by another element or a substituent,
Examples of the basic catalyst such as sulfonic acid such as benzenesulfonic acid include ammonia base such as aqueous ammonia, and amines such as ethylamine and aniline.
The coating solution prepared in this manner is, on a water-resistant support,
Using any of the conventionally known coating methods, coating and drying are performed to form a film. The thickness of the formed image receiving layer is 0.2 to
It is preferably 10 μm, more preferably 0.5 to 8 μm. In this range, a film having a uniform thickness is formed, and the film has sufficient strength.

The titanium oxide particles contained in the hydrophilic undercoat layer of the present invention and a resin containing a siloxane bond in which Si is connected via an oxygen atom may be mixed in the same layer. A siloxane bond-containing resin layer connected via an oxygen atom may be provided in a separate layer.

The thickness of the hydrophilic undercoat layer of the present invention is 0.0
It is preferably from 1 to 0.3 μm. In a layer thicker than 0.3 μm, the ink / water responsiveness becomes slow, and
If the layer is thinner than m, the adhesion between the silver thin film and the support becomes weak, and image skipping occurs during printing.

As the silver thin film layer according to the present invention, those obtained by a general metal thin film forming technique such as vacuum evaporation, sputtering, CVD, plating and the like can be used. Also,
On the other hand, a silver thin film layer can also be formed using a method based on physical development by a silver complex salt diffusion transfer method. In this method, when used as a printing plate, the silver thin film layer serving as an image portion is not limited to pure metallic silver, but may contain so-called lipophilic impurities such as oxides and sulfides, or may be a continuous film. However, when viewed microscopically, the unevenness of the surface is formed moderately, so that the ink transfer is better than other methods, the laser absorption rate is increased, and the sensitivity as a lithographic printing material is improved. Further, this is a preferable embodiment in that industrial mass production can be easily achieved.

In the present invention, the average particle size is 0.1.
A silver thin film layer composed of silver particles of 005 to 0.2 μm is preferably used. A silver thin film layer composed of such silver particles is
It is easily removed by heat mode laser exposure and has excellent printability. A silver thin film layer composed of silver particles having an average particle size of more than 0.2 μm and a vacuum deposited silver thin film layer having a mean particle size of less than 0.005 μm do not easily carry ink, and as a result, the image quality of printed matter is deteriorated.

In the present invention, a silver complex salt diffusion transfer method described in JP-A-11-216963 is known as a preferable method for producing a silver thin film layer. This silver complex salt diffusion transfer method is described, for example, in US Pat.
No. 8,114, No. 4,134,769, No. 4-1
No. 60,670, No. 4,336,321, No. 4,
Nos. 501,811; 4,510,228; 4,621,041; and JP-A-63-26049.
No. 1, JP-A-3-116151 and 4-282295
No., etc. As a method for producing the silver thin film layer of the present invention, JP-A-11-13902 is used.
No. 2, 11-139023 and 11-139024
And Nos. 11-139025 and 11-139026 are preferred. Further, by optimizing a processing solution composed of a developing agent, a silver halide solvent, and the like, the silver particles constituting the silver thin film layer are reduced to 0.005 to 0.005.
It can be controlled to 0.2 μm, and favorable printability can be obtained.

As a method for measuring the particle diameter of the silver particles constituting the silver thin film layer, a photograph is taken with an electron microscope, the size of each silver particle is measured from the photograph, and the average value is calculated. I do. As a simple method, an average particle may be picked up and its particle size may be measured.

In the present invention, in order to produce a good silver thin film, it is preferable to use a physical development nucleus during the production. Physical development nuclei include fine particles of metal colloids such as silver, antimony, bismuth, cadmium, cobalt, lead, nickel, palladium, rhodium, gold, and platinum; and sulfides, polysulfides, selenides, and the like of these metals. , Or a mixed crystal.

To form a layer by applying a physical development nucleus in advance, a hydrophilic polymer may be used in combination. As the hydrophilic polymer used in the physical development nucleus layer, gelatin, starch, dialdehyde starch, carboxymethylcellulose, gum arabic, sodium alginate, hydroxyethylcellulose, polystyrenesulfonic acid, sodium polyacrylate, a copolymer of vinylimidazole and acrylamide,
There are hydrophilic polymers such as copolymers of acrylic acid and acrylamide, polyvinyl alcohol and the like or oligomers thereof, and the content thereof is preferably 0.5 g / m ² or less.

Further, in the physical development nucleus layer, hydroquinone,
It may contain a developing agent such as methylhydroquinone or catechol, or a known hardener such as formalin or dichloro-s-triazine. In a preferred embodiment of the present invention, the physical development nucleus layer contains an oxide of one or more elements selected from aluminum, silicon, zirconium, and titanium. These can be the same as those used for the hydrophilic layer according to the present invention.

When a silver halide emulsion layer is provided as a silver ion donor for forming a silver thin film layer, the silver halide used may be, for example,
Silver chloride, silver bromide, silver chlorobromide, and these include silver iodide, which are used in crystalline form. The silver halide crystal may contain a heavy metal salt such as a rhodium salt, an iridium salt, a palladium salt, a ruthenium salt, a nickel salt, a platinum salt, and the like, and the addition amount is 10 ^-8 to 1 mol per mol of silver halide.
10 ^-3 mol. The crystal form of the silver halide is not particularly limited, and may be cubic to tetradecahedral grains, or core-shell or tabular grains. The silver halide crystal may be a monodisperse or polydisperse crystal having an average particle size of 0.2.
０．８0.8 μm. One preferred example is a monodispersed or polydispersed crystal containing 80 mol% or more of silver chloride, which contains a rhodium salt or an iridium salt.

As the gelatin used for the silver halide emulsion according to the present invention, any gelatin can be used as long as it is made of animal collagen, but gelatin made of collagen obtained from pig skin, cow skin and cow bone is used. Is preferred. There is no particular limitation on the kind of gelatin, but in addition to lime-treated gelatin and acid-treated gelatin,
No. 54, No. 39-5514, No. 40-12237,
And No. 42-26345, U.S. Pat. No. 2,52
No. 5,753, No. 2,594,293, No. 2,6
No. 14,928, No. 2,763,639, No. 3,
Gelatin described in 118,766, 3,132,945, 3,186,846, 3,312,553 and British Patent 1,033,189. Derivatives and the like can be mentioned, and these can be used alone or in combination of two or more.

In the present invention, hydroquinone, phenylenediamine, phenidone, dimethylphenidone and the like can be used as a reducing agent used for preparing a silver thin film.

The developing solution for preparing the silver thin film layer includes p
Alkaline substances for H adjustment, such as sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium tertiary phosphate, etc., and acidic substances such as sulfuric acid, nitric acid, phosphoric acid, etc., sulfites as preservatives, halogenation Silver solvents such as thiosulfate, thiocyanate, cyclic imide, 2-mercaptobenzoic acid, amines and the like, thickeners such as hydroxyethylcellulose, carboxymethylcellulose and the like, antifoggants such as potassium bromide, development modifiers such as It may contain a polyoxyalkylene compound, an onium compound, and the like. Further, in the developing solution, US Pat.
As described in US Pat. No. 6,728, a compound or the like that improves the ink running of the silver thin film layer on the surface can be used.

In the present invention, when a silver thin film layer composed of granular silver particles is prepared, it is preferably performed in the presence of a compound serving as a silver halide solvent. The silver thin film layer thus produced exhibits excellent ink receptivity. Examples of the silver halide solvent that can be used in the present invention include sulfites (eg, anhydrous sodium sulfite, anhydrous potassium sulfite, etc.), thiosulfates (eg, sodium thiosulfate pentahydrate, ammonium thiosulfate, etc.), And amine compounds. Among the above silver halide solvents, amine compounds are preferably used in the present invention. The silver thin film layer produced in this way exhibits further excellent ink receptivity.

The amine compound used as a silver halide solvent in the present invention includes ammonia, a substituted or unsubstituted saturated or unsaturated alkyl group, cycloalkyl group, alkoxy group, aryl group, alkanoyl group, aroyl group, heterocyclic group. And these substituents may be bonded to each other to form a ring.
Specific examples are shown below, but the present invention is not limited thereto.

[0062]

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Further, as the amines used in the present invention, compounds represented by the following general formula III are more preferable.

[0064]

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In the formula, at least one of R _{04 to} R ₀₈ represents a substituted or unsubstituted amino group;
A halogen atom, a substituted or unsubstituted saturated or unsaturated, alkyl group, cycloalkyl group, alkoxy group,
Represents an aryl group, an acyl group, an aroyl group, a heterocyclic group,
These may combine with each other to form a ring.

When the amino group has a substituent, a saturated or unsaturated alkyl group, cycloalkyl group,
It has an alkoxy group, an aryl group, an acyl group, an aroyl group, and a heterocyclic group, which may be bonded to each other to form a ring. Further, as the halogen atom, chlorine,
Bromine, iodine and the like can be mentioned.

The above-mentioned alkyl group may be further substituted with a suitable group (for example, a halogen atom, an alkoxy group, etc.). The alkyl group preferably has 1 to 1 carbon atoms.
0, for example, a methyl group, an ethyl group, an n-propyl group, an n-hexyl group, a trichloromethyl group, a vinyl group and the like.

Further, as the above cycloalkyl group,
It has about 3 to 10 carbon atoms and may be further substituted with a suitable group (eg, an alkyl group, a halogen atom, an alkoxy group, etc.). Specific examples of the cycloalkyl group include a cyclohexyl group and a cyclopentyl group.

The above alkoxy group is linear or branched, and may be further substituted with a suitable group (eg, an alkyl group, a halogen atom, an alkoxy group, etc.). The alkoxy group preferably has 1 to 10 carbon atoms.
And examples thereof include a methoxy group, an ethoxy group, an n-propoxy group, and an n-hexyloxy group.

The aryl group is preferably an aromatic group such as a phenyl group or a naphthyl group, and these aromatic groups are suitable groups (eg, a halogen atom, an alkyl group, an alkoxy group, a nitro group, etc.). May be substituted.

The above-mentioned acyl group includes a linear or branched C1-C6 group such as a formyl group, an acetyl group, a propionyl group and a pivaloyl group.

The aryl group portion of the aroyl group is preferably an aromatic group such as a phenyl group or a naphthyl group. These aromatic groups are suitable groups (eg, a halogen atom, an alkyl group, an alkoxy group, Nitro group etc.).

The above-mentioned heterocyclic group is substituted or unsubstituted, for example, a pyridyl group, a furyl group, a thienyl group and the like.

The silver halide solvent containing the above-mentioned amine compound has a molar number of 0.1 with respect to the number of gram ions of silver ion.
It is used 1 to 100 times, more preferably 1 to 50 times. These silver halide solvents can be used in combination of two or more.

The silver thin film layer after physical development in the lithographic printing plate precursor according to the present invention is preferably converted to ink receptivity or enhanced in receptivity with any known surface treatment agent. Examples of such a treatment solution include, for example, Japanese Patent Publication No. 48-2
No. 9723, U.S. Pat. No. 3,721,559, and the like.

In the present invention, in order to promote the removal of the silver thin film layer by laser irradiation and to improve the efficiency of exposing the hydrophilic layer (that is, the sensitivity of the lithographic printing original plate in the method of the present invention), a support was used. Alternatively, a light absorber that absorbs laser light may be contained in any of the hydrophilic layers. Thereby, even if a part of the laser beam passes through the silver thin film layer, it is possible to improve the thermal efficiency by absorbing the laser beam in the lower layer.

The light absorbing agent used for the above purpose may be a general dye or pigment having an absorption range upon laser exposure, such as carbon black, aniline black, graphite, copper sulfide, lead sulfide, molybdenum trisulfide. , Black titanium, metal-free or metal phthalocyanine, polymethine dyes (cyanine dyes), azulhenium dyes, pyrylium, thiopyrylium dyes, squalilium dyes, cucconium dyes, thiol nickel complex chlorine dyes, mercaptophenol, mercaptonaphthol complex dyes,
Examples include triallylmethane dyes, immonium, diimmonium dyes, and anthraquinone dyes.

After making a lithographic printing plate according to the present invention,
A hydrophilic polymer layer may be provided on the lithographic printing plate. By providing this hydrophilic polymer layer, the hydrophilicity of the hydrophilic layer where the inorganic oxide is exposed can be further increased.
The hydrophilic polymer used in the hydrophilic polymer layer can be appropriately selected from the above-mentioned hydrophilic polymers that can be used in combination with the hydrophilic layer according to the present invention. The hydrophilic polymer used in the hydrophilic polymer layer may be the same as or different from that used in the hydrophilic layer, and a single kind or a mixture of two or more kinds can be used.

The thickness of the hydrophilic polymer layer provided on the lithographic printing plate as described above is preferably 0.01 to 0.5 μm. The thickness of the hydrophilic polymer layer is 0.01μ
If less than m, the effect on dirt is small, while
When the thickness exceeds 0.5 μm, although the hydrophilic polymer has light transmittance in the infrared spectral region, it not only affects the removal sensitivity of the silver thin film layer but also delays the ink application of the image area. It is not preferable.

Further, the hydrophilic polymer layer preferably contains a hydrophobic compound at a ratio of 1 to 30% by weight.
When the content of the hydrophobic compound in the hydrophilic polymer layer is within the above range, it is possible to improve the ink transfer without substantially affecting the removal efficiency of the silver thin film layer. Further, when granular silver particles having a particle size of 0.005 to 0.2 μm are used for the silver thin film layer, they are ink-receptive and have the property of being able to carry ink alone, but the hydrophobic compound is contained in the hydrophilic polymer layer. , It is possible to stabilize ink riding.

Examples of the hydrophobic compound used in the present invention include known oils such as phthalic acid esters such as diethyl phthalate and dibutyl phthalate, and phosphoric acid esters such as tricresyl phosphate, and various animal oils and vegetable oils. be able to. Further, a mercaptotetrazole derivative having a hydrophobic group such as phenylmercaptotetrazole is also effective, and a hydrophobic compound having a mercapto group and one or more hydrophobic substituents is preferable. Examples of such hydrophobic compounds include, in addition to mercaptotetrazole derivatives such as phenylmercaptotetrazole, mercaptotriazole derivatives described in the following general formula IV, and mercaptooxadiazole derivatives described in the following general formula V .

[0082]

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[0083]

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In the formula, R ₀₉ is an alkyl group, an aryl group or an aralkyl group, and R ₁₀ is hydrogen or an acyl group. Preferably, R ₀₉ represents alkyl containing 3 to 16 carbon atoms.

Further, as the hydrophobic compound, a compound imparting ink receptivity is also preferable. Examples of this are disclosed in JP-B-48-29723 and U.S. Pat. No. 3,721,5.
No. 59, etc., and can be used.

The hydrophilic polymer layer containing a hydrophobic compound can be formed by applying a lithographic printing plate after making it. The hydrophobic compound may be added to the hydrophilic polymer aqueous solution using a known oil dispersion technique, or may be added to the hydrophilic polymer aqueous solution after dissolving in a suitable solvent. Compounds having a mercapto group and one or more hydrophobic substituents are disclosed in JP-A-6-79982 and JP-A-7-7992.
It can also be dissolved using the amine compound described in No. 48630 and added to the aqueous hydrophilic polymer solution.

After exposing the hydrophilic layer simultaneously with or after the laser exposure, at least the hydrophilic layer is exposed to U
V exposure may be performed. Here, the UV exposure means irradiating ultraviolet rays having a wavelength of 450 nm or less, preferably about 250 to 390 nm. As a lamp for irradiating ultraviolet rays, a mercury lamp or a metal halide lamp can be suitably used.

TiO ₂ , ZnO, SnO ₂ , SrTi
Inorganic oxides such as O ₃ , WO ₃ , Bi ₂ O ₃ , and Fe ₂ O ₃ have light absorption in the ultraviolet wavelength region, and when these components are contained in the hydrophilic layer, they become hydrophilic. Is promoted. The mechanism for promoting hydrophilicity is described in detail in JP-A-10-140046.

As the support used in the lithographic printing plate according to the present invention, a film or a paper coated with polyethylene can be used.

Among these, a polyester film coated with an organic copolymer and subjected to a hydrophilization treatment is preferable as the support of the film. For this purpose, there is used a polyester film which is provided with a subbing layer of an organic copolymer composition on a polyester film after a surface treatment for increasing the adhesion to the hydrophilic photographic layer. These are the following two.

One of the methods is a method of applying a composition comprising an organic solvent and an organic copolymer to serve as a swelling agent or a solubilizing agent for a polyester film (hereinafter referred to as a solvent undercoating method).
It is. Examples of this include U.S. Pat. Nos. 2,830,030, GB 772,600, and 776,1515.
Nos. 7,785,789, JP-A-50-171.
No. 8, No. 50-8259, and the like. The other is a method of applying an aqueous solution of an organic copolymer (so-called latex) substantially without an organic solvent (hereinafter referred to as an aqueous undercoating method). Examples of this are disclosed in JP-B-44-13278 and JP-B-45-10988, and
Nos. 9-11118, 51-27918 and 52-1
No. 14670, No. 54-11177, No. 55-677
No. 45, No. 58-169145, No. 59-77439
No. publication.

The solvent undercoating method is shifting to the aqueous undercoating method because of the deterioration of the physical properties of the polyester film during the undercoating step, or the problems of safety and hygiene in operation of the organic solvent and pollution. . Also, to strengthen the adhesion,
Those having a thin layer of gelatin at 0.02 to 0.1 g / m ² can be used.

The surface of the support used in the present invention may be subjected to a surface treatment for improving the adhesion to a layer provided as an upper layer, or may contain solid fine particles. In addition, a layer containing a matting agent or an antistatic agent may be provided on the surface (back surface) of the support opposite to the surface on which the hydrophilic layer or the like is provided, in consideration of transportability in a drawing apparatus or the like.

In the present invention, the laser used for removing the silver thin film layer to expose the hydrophilic layer including the hydrophilic physical development nucleus layer is a carbon dioxide laser, a nitrogen laser, an Ar laser, a He / Ne laser. Laser, gas laser such as He / Cd laser, Kr laser, liquid (dye) laser,
Solid-state laser such as ruby laser, Nd / YAG laser, G
Conventionally known lasers such as semiconductor lasers such as aAs / GaAlAs and InGaAs lasers, KrF lasers, XeCl lasers, XeF lasers, and excimer lasers such as Ar ₂ can be used.

In the present invention, the efficiency of removing the silver thin film layer (that is, the sensitivity of the lithographic printing plate in the method of the present invention) depends on the thickness of the silver thin film layer. Although easy, printing durability is reduced. Therefore, it is preferable to determine the thickness of the silver thin film layer based on the laser output used for drawing. In the heat mode type plate setter currently in practical use, the output on the printing plate surface is 0.
Is 1 to 10 W, the case of using these platesetter, it is preferable silver thin film layer is ^{0.1g / m 2 ~1.5g / m 2} . As a general tendency, when a laser of 1 W or more is used or when a long-run printing plate is desired to be obtained, a larger silver amount may be set. When the sensitivity is more important than the printing durability, that is, when a laser of 1 W or less is used, it is preferable to lower the silver amount.

[0096]

EXAMPLES The present invention will be described in detail with reference to examples below, but the contents of the present invention are not limited to these examples.

Example 1 A composition having the following contents was stirred for 60 minutes to prepare a coating solution.

<Hydrophilic undercoat liquid 1> Photocatalytic titanium oxide sol 40% aqueous dispersion: STS-21 150 g (manufactured by Ishihara Sangyo Co., Ltd., average particle size 0.02 μm) Colloidal silica: Snowtec C (20% dispersion 100 g (manufactured by Nissan Chemical Industries, Ltd.) methyltrimethoxysilane 100 g ethanol 150 g

On one side of a PET (polyethylene terephthalate) film having a thickness of 175 μm having a gelatin subbing layer of 0.04 g / m ² , a hydrophilic undercoating liquid 1 was applied so that the solid content was 1.06 g / m ^2. It was applied with a wire bar and dried. The film thickness of this hydrophilic undercoat layer is 0.2 μm
Met.

Next, on this hydrophilic undercoat layer, there is
Nucleic acid coating solution described in Example 2 of JP-A-3-21602 (containing palladium sulfide as a physical development nucleus, and as a hydrophilic polymer, a copolymer of No. 3 acrylamide and imidazole in a ratio of 4 mg / m ² ) ) Was applied and dried.

The aqueous solution of inert gelatin was kept at 60 ° C.
By adding a mixed aqueous solution of sodium chloride and potassium bromide (29.5 mol% of potassium bromide) and an aqueous solution of silver nitrate simultaneously while stirring vigorously, an average particle size of 0.2
An 8 μm silver chlorobromide emulsion was prepared, and potassium iodide corresponding to 0.5 mol% / 1 mol Ag was added to replace the surface. An emulsion layer containing these silver halide emulsion grains was coated on the above support and dried to prepare a lithographic printing material. The silver halide emulsion was composed of 70% silver chloride and 29% silver bromide.
A monodispersed silver chloroiodobromide emulsion comprising 90% by weight of all grains, within 5% of the average grain size, consisting of 5% and 0.5% silver iodide.

The silver chloroiodobromide emulsion thus prepared was coated with a wire bar so that the amount of silver chloroiodide was 1.5 g / m ² .

The lithographic printing material thus obtained was unexposed and developed with the following diffusion transfer developer 1, and the gelatin layer was immediately washed away (washed off) with running water to expose the silver thin film layer. A lithographic printing original plate 1 was produced.

<Diffusion Transfer Developer 1> Sodium hydroxide 25 g Sodium sulfite 100 g Hydroquinone 25 g 4-Hydroxymethyl-4-methyl-1-phenyl-3-pyrazolidone 4 g Sodium ethylenediaminetetraacetate 8 g Sodium thiosulfate 8 g N-methylethanolamine 40 ml carboxymethylcellulose 5 g glycerin 40 g 2-mercapto-5-n-heptyl-oxadiazole 0.2 g Water was added to 1,000 ml

The amount of silver of the lithographic printing plate precursor 1 produced as described above was measured by a fluorescent X-ray apparatus (3270, manufactured by Rigaku Corporation) and found to be 0.80 g / m ² . next,
When a photograph of the silver thin film layer was taken with a scanning electron microscope, it was found that the silver thin film layer was composed of granular silver particles. When the particle size was measured, it was in the range of 0.005 to 0.2 μm.

The lithographic printing original plate 1 was exposed with a 0.5 W semiconductor laser having a wavelength of 830 nm to expose the hydrophilic layer to obtain a lithographic printing plate 1. The contact angle of the non-image area with water was measured and found to be 10 °. This data is at the same level as when a siloxane bond-containing resin in which titanium oxide particles and Si were connected via an oxygen atom was applied to a support as it was. It was found that the siloxane bond-containing resin layer connected via atoms was exposed.

This lithographic printing plate 1 was used in an offset printing machine (RYOBI520H, manufactured by Ryobi Magics Co., Ltd.).
X), and as ink, GE manufactured by Dainippon Ink and Chemicals, Inc.
OS-G Ink N was printed using a fountain solution and a 2% dilution of Astromark III from Niken Chemical Laboratory Co., Ltd.

Before the start of printing, the plate surface was wiped with a dampening solution to start printing, and non-image area stains were visually observed. When the background dirt was not visually observed, it was evaluated as ○, when the background dirt was slightly observed, as Δ, and when the background dirt was clearly observed, as X.

After printing 1000 sheets, the printer was stopped, left for 30 minutes, and resumed as it was to evaluate the ink / water responsiveness by the number of sheets until the stain disappeared.る も の indicates that the stain can be removed with 20 sheets or less, △ indicates that the stain can be removed with 20 to 50 sheets or less, and x indicates that the stain requires 50 or more sheets.

The printing durability was evaluated as ◎ for 5000 sheets, ク リ ア for 2,000 to 5,000 sheets, and 100
Samples of not less than 2000 and not more than 2000 were rated as “△”, and those of 100 or less were rated as “x”.

Example 2 A hydrophilic undercoat layer and a silver thin film layer were formed in the same manner as in Example 1, and a hydrophilic polymer layer containing a hydrophobic compound (hydrophilic polymer coating liquid 1) was applied thereon. The planographic printing plate 2 was produced. Laser exposure and printing were performed in the same manner as in Example 1.

<Hydrophilic polymer coating liquid 1> 2-mercapto-5-n-heptyl-oxadiazole 5 g Arabic gum 50 g glycerin 50 g Adjusted to a total of 1000 ml with water.

Example 3 Thickness 17 having 0.04 g / m ² gelatin subbing layer
On one surface of a 5 μm PET (polyethylene terephthalate) film, a hydrophilic undercoat layer 1 was coated with a solid content of 2.12 g /
It was applied with a wire bar so as to obtain m ² and dried.
The thickness of this hydrophilic undercoat layer was 0.4 μm. A silver film was produced in the same manner as in Example 1, and a lithographic printing plate 3 was produced. Exposure and printing conditions were the same as in Example 1.

Example 4 A composition having the following contents was stirred for 60 minutes to prepare a coating solution.

<Hydrophilic undercoat liquid 2> Photocatalytic titanium oxide powder: 60 g of ST-41 (manufactured by Ishihara Sangyo Co., Ltd., average particle size: 0.2 μm) Colloidal silica: Snowtech C (20% dispersion) 100 g ( Nissan Chemical Industries, Ltd.) Methyltrimethoxysilane 100 g Ethanol 240 g

Except for using the hydrophilic undercoat liquid 2,
A lithographic printing plate 4 was prepared in the same manner as in Example 1, except that a hydrophilic undercoat layer and a silver thin film layer were formed. Exposure and printing were performed in the same manner as in Example 1.

Example 5 A hydrophilic undercoat was prepared in the same manner as in Example 1 except that the silver chloroiodide bromide emulsion was coated with a wire bar so that the amount of silver chloroiodide was 3.5 g / m ^2. Make a layer, and a silver film,
A lithographic printing plate 5 was produced. The silver content of this silver thin film layer is 2.0
g / m ² . Exposure was performed by the method of Example 1. However, due to an excessive amount of silver in the silver thin film layer, removal of the silver thin film layer in the non-image area was insufficient, and silver remaining could be visually observed. Printing is Example 1
Was performed in the same manner as described above.

Example 6 The lithographic printing plate 1 produced in the same manner as in Example 1 was exposed to a laser beam using a 50 mW semiconductor laser having a wavelength of 830 nm. Insufficiency was removed and silver remained visually observable. Printing was performed in the same manner as in Example 1.

Comparative Example 1 A composition having the following contents was stirred for 60 minutes to obtain a coating solution.

<Hydrophilic undercoating liquid 3> Photocatalytic titanium oxide sol 40% aqueous dispersion: STS-2 350 g (manufactured by Ishihara Sangyo Co., Ltd., average particle size 0.02 μm) Polyvinyl alcohol: PVA-217 50 g (Co., Ltd.) 1000g total with water

Other than using the hydrophilic undercoat liquid 3,
A lithographic printing plate 6 was prepared by preparing a hydrophilic undercoat layer and a silver thin film layer in the same manner as in Example 1. Exposure and printing were performed in the same manner as in Example 1.

Comparative Example 2 A composition having the following contents was stirred for 60 minutes to obtain a coating solution.

<Hydrophilic undercoat liquid 4> Colloidal silica: Snowtec C (20% dispersion) 150 g (manufactured by Nissan Chemical Industries, Ltd.) methyltrimethoxysilane 150 g ethanol 260 g

Other than using the hydrophilic undercoat liquid 4,
A lithographic printing plate 7 was prepared by preparing a hydrophilic undercoat layer and a silver thin film layer in the same manner as in Example 1. Exposure and printing were also performed by the method of Example 1.

Table 1 shows the obtained results.

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[Table 1]

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As described above, the method of making a lithographic printing plate according to the present invention can work even in a bright room and does not use a developing solution, so that the working environment is very good.
In addition, it is possible to cope with a direct drawing method using a laser, which brings about an excellent effect that an image having high resolution can be obtained at low cost. Further, a lithographic printing plate having extremely excellent ink / water responsiveness can be provided.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03F 7/004 521 G03F 7/004 521 7/11 501 7/11 501 503 503 7/36 7/36 F Term (reference) 2H025 AA02 AA12 AB03 AC08 AD03 BH01 BH03 BJ10 DA03 DA19 DA36 DA40 FA10 2H084 AA14 AA32 BB04 CC05 2H096 AA06 AA09 BA16 CA05 CA20 EA04 EA23 GA43 2H114 AA22 AA28 BA05 DA08 FA62 EA01

Claims (10)

[Claims] 1. A lithographic printing plate precursor having at least a hydrophilic undercoat layer on a support, and a silver thin film layer provided on the hydrophilic undercoat layer, is heated by laser exposure to the silver thin film layer. A method of making a lithographic printing plate for exposing a hydrophilic undercoat layer, wherein the titanium oxide particles and Si in the hydrophilic undercoat layer contain at least a siloxane bond-containing resin connected via an oxygen atom. How to make a printing plate. 2. A lithographic printing plate precursor having at least a hydrophilic undercoat layer on a support, and a silver thin film layer provided on the hydrophilic undercoat layer, is heated by laser exposure to the silver thin film layer. In the method of making a lithographic printing plate for exposing a hydrophilic undercoat layer, the titanium oxide particles and Si in the hydrophilic undercoat layer contain at least a siloxane bond-containing resin connected via an oxygen atom, and the silver A method of making a lithographic printing plate, comprising providing a hydrophilic polymer layer containing a hydrophobic compound on a thin film. 3. The method for making a lithographic printing plate according to claim 1, wherein the crystal structure of the titanium oxide is an anatase type. 4. The titanium oxide particles having a particle diameter of 0.00
4. The method according to claim 1, wherein the thickness is 1 to 0.1 [mu] m.
A method of making a lithographic printing plate according to any of the above. 5. The film thickness of the hydrophilic undercoat layer is from 0.01 to 0.01.
5. The method according to claim 4, wherein the thickness is 0.3 [mu] m. 6. The lithographic printing plate making method according to claim 1, wherein the silver thin film layer is made of physically developed silver generated by a silver complex salt diffusion transfer method. 7. A support having at least a hydrophilic undercoat layer on a support, and a physical development nucleus layer and a silver halide emulsion layer are provided on the hydrophilic undercoat layer in this order. The plate making method of a lithographic printing plate according to claim 6, wherein the silver halide emulsion layer is formed by performing a development process by a silver complex salt diffusion transfer method and washing off the silver halide emulsion layer. 8. The silver thin film layer has an average particle size of 0.3.
The lithographic printing plate making method according to any one of claims 1 to 7, wherein the lithographic printing plate is composed of granular silver particles having a particle size of 005 to 0.2 µm. 9. The lithographic printing plate making method according to claim 1, wherein the support is a film or a paper coated with polyethylene. 10. A laser is used for drawing using a laser having an output of 0.1 to 10 W on the lithographic printing plate precursor,
And process for making a lithographic printing plate according to any one of claims 1 to 9, silver amount of the silver thin film layer is characterized in that it is a 0.1 to 1.5 g / m ^2.