JP2003312157A - Lithographic printing plate material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lithographic printing plate material which can obtain a uniform coating film having excellent adhesive properties of a support to a layer on the support, excellent plate wear resistance, excellent scumming restorability by reducing blowing and liquid drawback at coating and drying time, and which has excellent plate wear resistance. <P>SOLUTION: The lithographic printing plate material comprises at least a hydrophilic layer and an image forming layer on a support. In this material, a pH value of a coating liquid of the layer adjacent to the support is 10 to 13. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a lithographic printing plate material, and more particularly, it relates to a lithographic printing plate which has an improved adhesive property between a support and a layer thereover and is excellent in printing durability, and is also excellent in stain recovery. The present invention relates to a printing plate material, and also relates to a lithographic printing plate material which is excellent in printing durability because it is possible to obtain a uniform coating film by reducing fluffiness and liquid drop during coating and drying.

[0002]

2. Description of the Related Art With the digitization of print data, CTP has become inexpensive and easy to handle and has printability equivalent to that of a PS plate.
(Computer to plate) planographic printing plate materials are required. Particularly in recent years, various types of CTP based on infrared laser recording have been proposed.

As one of these CTPs, there is a method of changing the solubility of the image forming layer of the printing plate material in a developing solution by exposure and forming an image by liquid development, which is generally called a wet type CTP. Can be mentioned.

However, in this system, as in the case of the conventional PS plate, a dedicated alkali developer is required for development, or the developability changes depending on the state of the developer (temperature, fatigue level), and stable image reproducibility is obtained. However, there are various problems such as not being obtained and the handling in a bright room being limited.

On the other hand, development of so-called dry CTP (including development on a printing machine or a device) which does not require a special development process is also in progress. Dry CTP records an image directly on the printing device and prints as it is.
It is also attracting a great deal of attention because it can be applied to a direct imaging (DI) type printing apparatus.

An ablation type CTP is one of the dry CTP methods. For example, JP-A-8-507727, JP-A-6-186750, and JP-A-6-187750.
199064, 7-314934, 10-58.
Examples thereof include those described in publications such as No. 636 and No. 10-244773.

These are, for example, those in which either a hydrophilic layer or a lipophilic layer is laminated as a surface layer on a support. When the surface layer is a hydrophilic layer, the image portion can be formed by exposing image-wise, ablating the hydrophilic layer and removing image-wise to expose the lipophilic layer.
However, there is a problem in that a large amount of energy is required to cause ablation, so that the sensitivity is low, and because image formation is performed by physical destruction of layers, the resolution is low and the point quality is poor. Further, the contamination of the inside of the exposure device due to the scattered material of the ablated surface layer is a larger problem, and it is necessary to incorporate a special suction device or other cleaning device into the device, or a cover sheet is put on the printing plate material during exposure. There is a problem that pollution prevention measures such as etc. may be necessary, and it is necessary to remove the ablated residue remaining on the printing plate surface by some means (wiping, rinsing with a dedicated device, etc.), There are still problems such as not saying that it is a complete dry treatment,
In this way, even as an ablation type CTP,
It is desired to have better performance and handleability.

On the other hand, development of a printing plate material capable of forming an image without causing ablation and requiring no developing treatment with a special developing solution or wiping treatment is under way. For example, Japanese Patent Nos. 2938397 and 29383
CTP which can be developed in fountain solution (on-press development) using heat-fusible fine particles and a water-soluble binder in the image-forming layer as disclosed in JP-A-97-96.

However, in this type of CTP,
When aluminum grain is used as the hydrophilic support, it is necessary to add a photothermal conversion material (generally colored to visible light) to the image forming layer. There is a risk of contaminating the printing press.

As a method of eliminating such contamination due to development on a printing machine, a method of using a hydrophilic support having a hydrophilic layer containing a photothermal conversion material formed on the support has been studied. There is. By using this hydrophilic layer, the photothermal conversion material can be removed from the image forming layer, and the support can be freely selected from PET (polyethylene terephthalate) and aluminum according to the purpose. However, it is very difficult to make the printing performance of the hydrophilic layer equal to that of the aluminum grain, and many studies have been made, but the one having sufficient performance has not been provided yet.

In the case of a type having a hydrophilic layer formed by such coating, it is not said that the strength is sufficient as compared with aluminum grain, and if coated paper is used for printing, good printing durability can be obtained. If printing paper is made of high-quality paper, fine dots may be peeled off from the hydrophilic layer in the non-image area due to the influence of paper dust, etc. There is.

By adding an organic binder and a cross-linking agent to the hydrophilic layer composition for the purpose of improving the toughness of the hydrophilic layer, such fine dot-like peeling is improved, but this time the soiling or soiling causes a recovery rate. It has been considered that it is very difficult to achieve both print performance and printing durability compatible with high-quality paper such as deterioration.

[0013]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above problems. That is, it is possible to provide a lithographic printing plate material which can be preferably applied to CTP which does not require a special developing solution, has excellent adhesiveness between a support and a layer thereabove and printing durability, and has excellent stain recovery property. In addition, it is an object of the present invention to provide a lithographic printing plate material having excellent printing durability, by which it is possible to obtain a uniform coating film by reducing fluffiness and liquid drop during coating and drying.

[0014]

The above objects of the present invention have been achieved by the following.

1. A lithographic printing plate material having at least a hydrophilic layer and an image forming layer on a support, wherein the pH value of a coating solution of a layer adjacent to the support is 10 to 13. material.

2. The coating liquid of the layer adjacent to the support,
Viscosity at 25 ° C. is 3.5 × 10 ^{−3 to} 11.5 ×
The lithographic printing plate material as described in 1 above, which is in the range of 10 ⁻³ Pa · s.

3. 3. The lithographic printing plate material as described in 1 or 2 above, wherein the layer adjacent to the support contains colloidal silica.

4. The lithographic printing plate material as described in any one of 1 to 3 above, wherein the layer adjacent to the support is a hydrophilic layer.

5. The lithographic printing plate material as described in any one of 1 to 3 above, wherein an intermediate layer is provided between the support and the hydrophilic layer.

6. The lithographic printing plate material as described in any one of 1 to 5 above, wherein the hydrophilic layer or the intermediate layer has a light-heat conversion function.

7. The above-mentioned 1 characterized in that the image forming layer contains heat-meltable fine particles or heat-meltable fine particles.
The lithographic printing plate material as described in any one of 1 to 6.

8. 8. The lithographic printing plate material as described in any one of 1 to 7 above, wherein the support is a resin film or an aluminum plate.

9. 9. The lithographic printing plate material as described in any one of 1 to 8 above, which is used in a printing method of developing with water or ink on a printing device and printing.

(Support) As the support of the present invention (hereinafter, also simply referred to as a support), a known material used as a support of a lithographic printing plate material can be used. For example, a metal plate such as aluminum, stainless steel, chromium, or nickel, or a plastic film such as a polyester film, a polyethylene film, or a polypropylene film, or paper, synthetic paper, or resin-coated paper on which the above-mentioned metal thin film is laminated or vapor-deposited, For example, polyester film, vinyl chloride film, nylon film and the like can be used.

Among these, aluminum and PET are preferable because they have excellent dimensional stability and toughness by heat.

These supports can be provided with a light-heat conversion function for laser recording. For example, carbon black or JP-A-52-208 can be used on the above supports.
A method of forming a vapor deposition layer or a vapor deposition film of a photothermal conversion material such as metal black such as gold, silver, aluminum, chromium, nickel, antimony, tellurium, bismuth, and selenium described in JP-A No. 42-42 is cited. Further, in the case of a plastic film, a method of kneading such a light-heat converting material before forming the film can be mentioned.

A hydrophilic support for printing may be used as the support of the present invention. Examples of the hydrophilic support for printing include an aluminum plate whose surface is grained, anodized and sealed.

Examples of the graining method include a mechanical method and an electrolytic etching method. Examples of mechanical methods include a ball polishing method, a brush polishing method, a liquid honing polishing method, and a buff polishing method.

The above-mentioned various methods can be used alone or in combination depending on the composition of the aluminum plate. The method by electrolytic etching is preferable. The electrolytic etching is carried out in a bath in which inorganic acids such as phosphoric acid, sulfuric acid, hydrochloric acid and nitric acid are used alone or in a mixture of two or more kinds. After the graining treatment, if necessary, desmut treatment is performed with an aqueous solution of alkali or acid to neutralize and wash with water.

The anodic oxidation treatment is carried out by using a solution containing one or more of sulfuric acid, chromic acid, oxalic acid, phosphoric acid, malonic acid and the like as an electrolytic solution and electrolyzing with an aluminum plate as an anode. The formed anodic oxide coating amount is 1 to 50.
mg / dm ² is suitable, preferably 10-40 mg
/ Dm ² .

Specific examples of the sealing treatment include boiling water treatment, steam treatment, sodium silicate treatment, and dichromate aqueous solution treatment.

In addition to this, for the aluminum plate support,
The water-soluble polymer compound or a metal salt such as fluorinated zirconic acid may be subjected to an undercoating treatment. The contact angle of water on the surface of the hydrophilic support is 60 degrees or less, more preferably 40 degrees or less.

A support having a thickness of 50 to 1000 μm, preferably 75 to 500 μm can be suitably used.

(Layer Structure) The layer structure of the lithographic printing plate material of the present invention has a mode in which an intermediate layer, a hydrophilic layer and an image forming layer are sequentially provided on a support, or sequentially on a support. The case of having a hydrophilic layer and an image forming layer is preferable, and therefore, the layer adjacent to the support of the present invention is preferably an intermediate layer or a hydrophilic layer.

Further, these layer constitutions may optionally have additional layers. For example, the outermost layer may have an overcoat layer.

(Hydrophilic layer) Materials used for the hydrophilic layer of the lithographic printing plate material of the present invention include materials forming a matrix, porous silica or porous aluminosilicate particles, zeolite particles, layered clay mineral particles, Examples thereof include an aqueous silicate solution, a water-soluble resin, a cationic resin, a photothermal conversion material, and particles coated with an inorganic material or an inorganic material, and it is preferable to contain these.

As a material for forming this matrix,
The metal oxide is preferable, and the metal oxide preferably contains fine metal oxide particles. Examples thereof include colloidal silica, alumina sol, titania sol, and other metal oxide sols. The form of the metal oxide fine particles may be spherical, needle-like, feather-like, or any other form. The average particle diameter is 3 to 100 nm (in the case of a spherical shape, the diameter thereof, in the case of a needle shape, the major axis, in the case of a feather shape, the outer diameter, and in the other forms, the maximum diameter of the shape, and the particle diameter is used. ) Is preferable, and several kinds of metal oxide fine particles having different average particle diameters can be used together. The surface of the particles may be surface-treated.

The metal oxide fine particles can be used as a binder by utilizing the film forming property thereof. It has less decrease in hydrophilicity than using an organic binder and is suitable for use in a hydrophilic layer.

Among the above, colloidal silica can be preferably used in the present invention. Colloidal silica has an advantage of high film forming property even under a relatively low temperature drying condition, and can obtain good strength.

The above-mentioned colloidal silica is preferably a necklace-shaped colloidal silica, which will be described later, or fine particle colloidal silica having an average particle size of 20 nm or less. Further, colloidal silica preferably exhibits alkalinity as a colloidal solution.

The hydrophilic layer of the present invention can contain a phosphate. In the present invention, it is preferable that the coating liquid for the hydrophilic layer is alkaline. Therefore, it is preferable to add trisodium phosphate or disodium hydrogen phosphate as the phosphate. By adding the phosphate, the effect of improving the mesh opening during printing can be obtained. The amount of phosphate added is 0.1 to 5 mass% as an effective amount excluding hydrate.
Is preferable, and 0.5-2 mass% is more preferable.

Further, in order to adjust the pH, water glass such as sodium hydroxide, lithium hydroxide, sodium hydrogen carbonate, sodium silicate, lithium silicate, etc., and commonly known salts exhibiting alkalinity such as ammonium salts are added. be able to.

In the present invention, the pH value of the coating liquid for the layer adjacent to the support is preferably in the range of 10 to 13, and particularly preferably 10.5 to 12. P of coating liquid
When H is in the above range, sufficient adhesion can be obtained without deteriorating the PET support, and the aluminum support is coated with a coating solution in a coating and drying step.
It is possible to slightly dissolve the aluminum surface, further improve the adhesiveness to the support, and obtain excellent printing durability. p
If it is smaller than H10, the adhesiveness to the support cannot be obtained,
When the pH is higher than 13, the support may be deteriorated and sufficient adhesion may not be obtained, so that the printing durability may be deteriorated. Therefore, the above range is preferable.

Further, the above-mentioned measurement of pH is carried out by HORIBA
The measurement was carried out with F-21 manufactured by the company, and the calibration of the pH meter was carried out using standard solutions of pH 7, 9, and 12, but it is not particularly limited as long as it has equivalent performance.

The necklace-shaped colloidal silica used in the present invention is a general term for an aqueous dispersion system of spherical silica having a primary particle diameter of the order of nm. The necklace-shaped colloidal silica used in the present invention has a primary particle size of 10 to 50.
It means a "pearl necklace-like" colloidal silica in which spherical spherical colloidal silica having a diameter of 50 nm is bonded to a length of 50 to 400 nm. The pearl necklace shape (that is, the pearl necklace shape) means that the image of a state in which silica particles of colloidal silica are connected in series has a shape like a pearl necklace. The silica particles forming the necklace-shaped colloidal silica are bonded to each other by a dehydration bond of -SiOH groups existing on the surface of the silica particles.
It is estimated to be O-Si-. Specific examples of the necklace-shaped colloidal silica include "Snowtex-PS" series manufactured by Nissan Chemical Industries, Ltd.

The product name is "Snowtex-PS-
S (average particle size in a connected state is about 110 nm) ",
"Snowtex-PS-M (average particle size of connected state is about 120 nm)" and "Snowtex-PS
-L (average particle size in the connected state is about 170 nm) "
The corresponding acidic products are "Snowtex-PS-S-O" and "Snowtex-PS".
-MO "and" Snowtex-PS-LO ".

By adding the necklace-shaped colloidal silica, it becomes possible to maintain the strength of the layer while ensuring the porosity of the layer, and it can be preferably used as a porosifying material for the matrix of the hydrophilic layer.

Among these, "Snowtex PS-S", "Snowtex PS-M", which are alkaline,
The use of "Snowtex PS-L" is particularly preferable because the strength of the hydrophilic layer is improved and the occurrence of background stain is suppressed even when the number of printed sheets is large.

It is known that the smaller the particle size of colloidal silica is, the stronger the binding force is. Therefore, it is preferable to use colloidal silica having an average particle size of 20 nm or less in the present invention, which is 3 to 15 nm. More preferably. Further, as described above, among colloidal silica, alkaline ones are highly effective in suppressing the occurrence of background stains, and therefore it is particularly preferable to use alkaline colloidal silica.

Alkaline colloidal silica having an average particle size within this range includes "Snowtex-20 (particle size 10 to 20 nm)", "Snowtex-30 (particle size 10 to 20 nm)" manufactured by Nissan Chemical Industries, Ltd., "Snowtex-40 (particle diameter 10 to 20 nm)", "Snowtex-N (particle diameter 10 to 20 nm)", "Snowtex-S (particle diameter 8 to 11 nm)", "Snowtex-X"
S (particle diameter 4 to 6 nm) ".

Colloidal silica having an average particle size of 20 nm or less is particularly preferable when it is used in combination with the above-mentioned necklace-shaped colloidal silica because the porosity of the layer can be maintained and the strength can be further improved.

The ratio of colloidal silica having an average particle size of 20 nm or less / necklace colloidal silica is 95 /
5/5/95 is preferable, 70 / 30-20 / 80 is more preferable, and 60 / 40-30 / 70 is further preferable.

As the porous material for the matrix of the hydrophilic layer of the present invention, porous metal oxide particles having a particle diameter of less than 1 μm can be contained. As the porous metal oxide particles,
Porous silica or porous aluminosilicate particles or zeolite particles described below can be preferably used.

Porous Silica or Porous Aluminosilicate Particles Porous silica particles are generally produced by a wet method or a dry method. The wet method can be obtained by drying and pulverizing a gel obtained by neutralizing an aqueous silicate solution, or pulverizing a precipitate precipitated by neutralization. The dry method is obtained by burning silicon tetrachloride with hydrogen and oxygen to precipitate silica. The porosity and particle size of these particles can be controlled by adjusting the production conditions.

As the porous silica particles, those obtained from a wet method gel are particularly preferable. The porous aluminosilicate particles are produced, for example, by the method described in JP-A-10-71764. That is, it is an amorphous composite particle composed mainly of aluminum alkoxide and silicon alkoxide synthesized by a hydrolysis method. The ratio of alumina to silica in the particles can be synthesized in the range of 1: 4 to 4: 1. In addition, alkoxides of other metals added during the production to produce composite particles of three or more components can also be used in the present invention. The porosity and particle size of these composite particles can be controlled by adjusting the production conditions.

The porosity of the particles is such that the pore volume is 0.5 ml.
/ G or more, preferably 0.8 ml / g or more, more preferably 1.0 to 2.5 ml / g or less.

The pore volume is closely related to the water retention property of the coating film. The larger the pore volume, the better the water retention property, the less likely it is to stain during printing, and the wider the water amount latitude.
If it exceeds 5 ml / g, the particles themselves become very brittle and the durability of the coating film decreases. Pore volume is 0.5 ml
If it is less than / g, printing performance may be slightly insufficient.

Zeolite particles Zeolite is a crystalline aluminosilicate, and is a porous body having pores with a regular three-dimensional network structure having a pore size of 0.3 to 1 nm. The general formula for the combination of natural and synthetic zeolites is represented as:

[0059] _{(M 1 M 2 1/2) m} (Al m Si n O 2 (m + n)) · xH 2 O wherein, M _1, M ₂ are each exchangeable cations, M
₁ is Li ⁺ , Na ⁺ , K ⁺ , Tl ⁺ , Me ₄ N ⁺ (TMA:
Me represents a methyl group), Et ₄ N ⁺ (TEA: Et represents an ethyl group), Pr ₄ N ⁺ (TPA: Pr represents a propyl group), C ₇ H ₁₅ N ^{2 +} , C ₈ H ₁₆ Represents N ^{+ and the} like, and M ₂ is
It represents Ca ²⁺ , Mg ²⁺ , Ba ²⁺ , Sr ²⁺ , C ₈ H ₁₈ N ^{2 + and the} like. Further, n ≧ m, and the value of m / n, that is, Al / S
The i ratio is 1 or less. The higher the Al / Si ratio, the higher the amount of exchangeable cations contained, and thus the higher the polarity, and the higher the hydrophilicity. A preferable Al / Si ratio is 0.4 to 1.
It is 0, and more preferably 0.8 to 1.0. x represents an integer.

The zeolite particles used in the present invention are preferably synthetic zeolites having a stable Al / Si ratio and a relatively sharp particle size distribution. For example, zeolite A: Na ₁₂ (Al ₁₂ Si ₁₂ O). ₄₈ ) ・ 27H ₂
O; Al / Si ratio 1.0, zeolite X: Na ₈₆ (A
l ₈₆ Si ₁₀₆ O ₃₈₄ ) .264H ₂ O; Al / Si ratio 0.811, zeolite Y: Na ₅₆ (Al ₅₆ Si ₁₃₆ O
₃₈₄ ) .250H ₂ O; Al / Si ratio of 0.412 and the like.

By containing highly hydrophilic porous particles having an Al / Si ratio of 0.4 to 1.0, the hydrophilicity of the hydrophilic layer itself is greatly improved, it is hard to stain during printing, and the water amount latitude is wide. Become. In addition, stains on fingerprint marks are also greatly improved. If the Al / Si ratio is less than 0.4, the hydrophilicity is insufficient, and the effect of improving the above performance becomes small.

The matrix of the hydrophilic layer of the lithographic printing plate material of the present invention can contain layered clay mineral particles. Examples of the layered mineral particles include clay minerals such as kaolinite, halloysite, talc, smectite (montmorillonite, beidellite, hectorite, savonite), vermiculite, mica (mica), and chlorite, and hydrotalcite, layered polysilicate ( Kanemite, macatite, ialite, magadiite,
Kenyaite etc.) and the like. Above all, it is considered that the higher the charge density of the unit layer (unit layer), the higher the polarity and the higher the hydrophilicity.

A preferable charge density is 0.25 or more,
More preferably, it is 0.6 or more. Examples of the layered mineral having such a charge density include smectite (charge density 0.25 to 0.6; negative charge) and vermiculite (charge density 0.6 to 0.9; negative charge). In particular,
Synthetic fluoromica is preferable because it can be obtained with stable quality such as particle size. In addition, among synthetic fluoromica,
Those which are swellable are preferable, and those which are free swelling are more preferable.

The intercalation compounds (pillar crystals, etc.) of the above-mentioned layered minerals, those subjected to ion exchange treatment, surface treatments (silane coupling treatment,
Those subjected to a composite treatment with an organic binder, etc.) can also be used.

Regarding the size of the layered mineral particles, the average particle diameter (maximum length of particles) is less than 1 μm in the state of being contained in the layer (including the case of undergoing the swelling step and the dispersion peeling step), Further, the average aspect ratio is preferably 50 or more. When the particle size is in the above range, continuity and flexibility in the plane direction, which are the characteristics of thin layered particles, are imparted to the coating film, and it is possible to obtain a coating film that is hard to crack and is tough in a dry state.

Further, in a coating liquid containing a large amount of particles, the thickening effect of the layered clay mineral can suppress the sedimentation of particles. If the particle size is larger than the above range, the coating film may have non-uniformity, and the strength may be locally weakened. Further, when the aspect ratio is not more than the above range, the number of tabular particles with respect to the added amount becomes small, the viscosity increase becomes insufficient, and the effect of suppressing sedimentation of the particles is reduced.

The content of the layered mineral particles is preferably 0.1 to 30% by mass, and more preferably 1 to 10% by mass, based on the entire layer. In particular, swelling synthetic fluoromica and smectite are preferable because the effect can be seen even when added in a small amount.

The layered mineral particles may be added to the coating solution in the form of powder, but in order to obtain a good dispersibility by a simple liquid preparation method (no dispersion step such as media dispersion), It is preferred that the particles are swelled in water alone to prepare a gel and then added to the coating solution.

As another additive material for the matrix of the hydrophilic layer of the present invention, an aqueous silicate solution can be used at the time of coating formation. As the silicate, an alkali metal silicate such as Na silicate, K silicate, and Li silicate is preferable, and its SiO ₂ / M ₂ O ratio is such that the pH of the entire coating solution when the silicate is added is 13 In order to prevent the dissolution of the inorganic particles, it is preferable to select it so as not to exceed the range.

Further, it is also possible to use an inorganic polymer or an organic-inorganic hybrid polymer by a so-called sol-gel method using a metal alkoxide. Sol
The formation of the inorganic polymer or the organic-inorganic hybrid polymer by the gel method is described, for example, in "Application of the sol-gel method" (Sakuhana Sakuo / Agne Shengfu Co., Ltd.) or cited herein. Known methods described in the literature can be used.

Further, the hydrophilic layer of the present invention may contain a water-soluble resin. As the water-soluble resin, polysaccharides, polyethylene oxide, polypropylene oxide, polyvinyl alcohol, polyethylene glycol (PEG),
Polyvinyl ether, styrene-butadiene copolymer,
Methyl methacrylate-butadiene copolymer conjugated diene polymer latex, acrylic polymer latex,
Resins such as vinyl polymer latex, polyacrylamide, polyvinylpyrrolidone and the like can be mentioned. A polysaccharide is preferably used as the water-soluble resin used in the present invention.

As the polysaccharide, starches, celluloses, polyuronic acid, pullulan, etc. can be used.
Particularly, cellulose derivatives such as methyl cellulose salt, carboxymethyl cellulose salt and hydroxyethyl cellulose salt are preferable, and sodium salt and ammonium salt of carboxymethyl cellulose are more preferable.

Since the viscosity of these cellulose derivatives can be easily adjusted by the molecular weight, the viscosity can be adjusted by adding a small amount thereof without causing scumming and deterioration of the strength of the coating film.

The viscosity of the coating solution for the layer adjacent to the support of the present invention is 3.5 × 10 ^{−3 to} 11.5 × 10 ⁻³ P at 25 ° C.
a · s, preferably 3.5 × 10 ⁻³ to 10 × 10 ⁻³ P
It is preferably a · s. More preferably 6 × 10
^-3 to 10 x 10 ^-3 Pa · s.

With such a viscosity, the state of the coating layer after coating and drying becomes uniform, and the pressure of the ink roller and the water roller during printing becomes uniform, so that the printing durability is improved. If it is less than 3.5 × 10 ⁻³ Pa · s, uneven coating and uneven coating due to liquid deviation occur during coating and drying, and a uniform coating layer cannot be obtained, resulting in 11.5 × 10 ⁻³ Pa.
・ If it is larger than s, the leveling property of the coating liquid deteriorates,
Since streak-like coating unevenness may occur and printing durability may deteriorate, the above range is preferable.

The above-mentioned viscosity measurement was carried out at a coating liquid temperature of 2
It can be fixed at 5 ° C. and measured with an E-type viscometer manufactured by Tokyo Keiki Co., Ltd.

It is preferable that the hydrophilic layer as a whole has a low content ratio of carbon-containing materials such as organic resins and carbon black in order to improve hydrophilicity, and the total content of these materials is less than 9% by mass. Preferably, 5% by mass
It is more preferable that the amount is less than the above, but it is preferable that the lower limit is substantially not contained.

Further, by containing a polysaccharide in the hydrophilic layer, the effect of forming the surface shape of the hydrophilic layer in a preferable state can be obtained.

The surface of the hydrophilic layer preferably has a concavo-convex structure with a pitch of 0.1 to 20 μm, like the aluminum grain of a PS plate, and this concavo-convex improves the water retention and the retention of the image area. .

Such a concavo-convex structure can be formed by adding an appropriate amount of a filler having an appropriate particle size to the hydrophilic layer matrix. However, the coating liquid for the hydrophilic layer contains the above-mentioned alkaline colloidal silica. Contains the aforementioned polysaccharide,
It is preferable that the hydrophilic layer is formed by causing phase separation during coating and drying, because a structure having better printability can be obtained.

The form of the concavo-convex structure (pitch, surface roughness, etc.) is determined by the type and amount of alkaline colloidal silica, the type and amount of water-soluble polysaccharide, the type and amount of other additives, and the solid concentration of the coating liquid. It is possible to control it appropriately by the wet film thickness, the drying condition and the like.

The water-soluble resin added to the hydrophilic layer matrix in the present invention preferably exists in a water-elutable state while at least a part thereof remains in the water-soluble state. This is because even if a water-soluble material is cross-linked by a cross-linking agent or the like and becomes insoluble in water, its hydrophilicity is lowered and printability may be deteriorated.

Further, a cationic resin may be further contained, and as the cationic resin, polyalkylene polyamines such as polyethylene amine and polypropylene polyamine or derivatives thereof, tertiary amino group and quaternary ammonium group are included. Examples of the acrylic resin include diacrylamine and the like. The cationic resin may be added in the form of fine particles. This is, for example, in Japanese Patent Laid-Open No. 6-161101.
The cationic microgels described in No.

The coating solution for the hydrophilic layer of the present invention may contain a water-soluble surfactant for the purpose of improving the coating property. Although a Si-based or F-based surfactant can be used, it is particularly preferable to use a surfactant containing an Si element because there is no concern that print stains will occur. The content of the surfactant is preferably 0.01 to 3% by mass of the entire hydrophilic layer (solid content as a coating liquid),
3-1 mass% is more preferable.

Further, a light-heat conversion material described later may be contained in order to have a light-heat conversion function. In the case of a particulate material, the photothermal conversion material preferably has a particle size of less than 1 μm.

Inorganic particles having a particle size of 1 μm or more or particles coated with an inorganic material As the inorganic particles, known metal oxide particles such as silica, alumina, titania and zirconia can be used. It is preferable to use porous metal oxide particles in order to suppress the sedimentation of the metal oxide.

As the porous metal oxide particles, the above-mentioned porous silica particles or porous aluminosilicate particles can be preferably used.

Examples of the particles coated with an inorganic material include particles obtained by coating a core material of organic particles such as PMMA (polymethylmethacrylate) and polystyrene with inorganic particles having a smaller particle size than the core material particles. The particle size of the inorganic particles is preferably about 1/10 to 1/100 of that of the core particles. Further, as the inorganic particles, similarly known metal oxide particles such as silica, alumina, titania, zirconia can be used.

As the coating method, various known methods can be used. The core material particles and the coating material particles are caused to collide with each other at high speed in air such as a hybridizer to coat the coating material particles on the surface of the core material particles. A dry coating method of biting, fixing and coating can be preferably used.

Also, particles obtained by metal-plating a core material of organic particles can be used. Examples of such particles include "Micropearl AU" manufactured by Sekisui Chemical Co., Ltd. in which resin particles are plated with gold.

The particle size is preferably 1 to 10 μm, and 1.5 to
8 μm is more preferable, and 2 μm to 6 μm is still more preferable. If the particle size exceeds 10 μm, the resolution of image formation may decrease and the blanket stain may deteriorate. Therefore, the above range is preferable.

The addition amount of the particles having a particle diameter of 1 μm or more and coated with an inorganic material or an inorganic material is 1 for the entire hydrophilic layer.
It is preferably -50% by mass, more preferably 5-40% by mass.

Photothermal conversion material The hydrophilic layer or the intermediate layer of the present invention can have a photothermal conversion function, and therefore a photothermal conversion material can be contained in the layer. Examples of the photothermal conversion material include the following materials.

Cyanine dyes, croconium dyes, polymethine dyes, azurenium dyes, squalium dyes, thiopyrylium dyes, naphthoquinone dyes, anthraquinone dyes, and other organic compounds which are general infrared absorbing dyes, phthalocyanine dyes , Naphthalocyanine series,
Examples thereof include azo-based, thioamide-based, dithiol-based, and indoaniline-based organometallic complexes. Specifically, JP-A-63-139191, JP-A-64-33547,
JP-A-1-160683, JP-A1-280750
JP-A-1-293342, JP-A-2-2074
Japanese Patent Application Laid-Open No. 3-26593, Japanese Patent Application Laid-Open No. 3-30991
JP-A-3-34891, JP-A-3-36093
No. 3, JP-A-3-36094, JP-A-3-36095
JP-A-3-42281, JP-A-3-97589
And compounds described in JP-A-3-103476 and the like. These can be used alone or in combination of two or more.

Examples of pigments include carbon, graphite, metals and metal oxides. It is particularly preferable to use furnace black or acetylene black as the carbon. The particle size (d50) is preferably 100 nm or less, more preferably 50 nm or less.

The graphite has a particle size of 0.5 μm or less, preferably 100 nm or less, more preferably 50 n.
Fine particles of m or less can be used.

As the metal, any metal can be used as long as it has a particle size of 0.5 μm or less, preferably 100 nm or less, more preferably 50 nm or less.

The shape may be any shape such as spherical, flaky or needle-like. Especially colloidal metal particles (Ag, Au
Etc.) are preferred.

As the metal oxide, it is possible to use a material that exhibits a black color in the visible light region, or a material that itself has conductivity or is a semiconductor. Examples of the former include black iron oxide (Fe ₃ O ₄ ) and black complex metal oxides containing two or more kinds of metals described above. As the latter, for example, Sb-doped SnO ₂ (AT
O), In ₂ O ₃ (ITO) added with Sn, TiO ₂ ,
TiO2 (titanium oxynitride, generally titanium black) obtained by reducing TiO ₂ and the like can be mentioned. In addition, core materials (BaSO ₄ , TiO ₂ , 9Al ₂ O ₃ ·.
2B ₂ O, K ₂ O, nTiO ₂ etc.) may be used. These particle sizes are 0.5 μm or less,
It is preferably 100 nm or less, more preferably 50 nm or less.

Among these light-heat converting materials, the carbon atom-containing material is preferably in an amount such that the total amount of the carbon atom-containing material in the hydrophilic layer is less than 9% by mass, preferably 5% by mass.
You may add in the range which becomes less.

A particularly preferable embodiment of the photothermal conversion material is that the metal oxide is a black composite metal oxide composed of oxides of two or more kinds of metals.

Specifically, Al, Ti, Cr, Mn, F
It is a composite metal oxide composed of two or more metals selected from e, Co, Ni, Cu, Zn, Sb, and Ba. These are disclosed in JP-A-8-27393 and JP-A-9-2512.
6, JP-A-9-237570, JP-A-9-
It can be manufactured by the methods disclosed in Japanese Patent No. 241529, Japanese Patent Application Laid-Open No. 10-231441, and the like.

As the complex metal oxide used in the present invention,
In particular, a Cu-Cr-Mn-based or Cu-Fe-Mn-based mixed metal oxide is preferable. Cu-Cr-Mn
In the case of a system, in order to reduce the elution of hexavalent chromium,
It is preferable to perform the processing disclosed in Japanese Patent Application Laid-Open No. 8-27393. These mixed metal oxides have good coloring with respect to the added amount, that is, good light-heat conversion efficiency.

These composite metal oxides preferably have an average primary particle diameter of 1 μm or less, more preferably 0.01 to 0.5 μm. When the average primary particle diameter is 1 μm or less, the photothermal conversion efficiency with respect to the added amount becomes better, and when the average primary particle diameter is in the range of 0.01 to 0.5 μm, the photothermal conversion efficiency with respect to the added amount is It will be better. However, the photothermal conversion efficiency with respect to the added amount is greatly influenced by the degree of dispersion of particles, and the better the dispersion, the better. Therefore, it is preferable to disperse these composite metal oxide particles as a dispersion liquid (paste) by a separately known method before adding them to the layer coating liquid. The average primary particle size is 0.
When it is less than 01, dispersion becomes difficult, which is not preferable.
A dispersant or the like can be appropriately used for dispersion. The amount of the dispersant added is preferably 0.01 to 5% by mass, more preferably 0.1 to 2% by mass, based on the composite metal oxide particles. The type of dispersant is not particularly limited, but it is preferable to use a Si-based surfactant containing a Si element.

The addition amount of these complex metal oxides is 0.1 to 50% by mass with respect to the hydrophilic layer.
30 mass% is preferable, and 3 to 25 mass% is more preferable.

(Intermediate Layer) When an intermediate layer is provided, the same material as the hydrophilic layer can be used as the material for the intermediate layer. However, the content of the porosifying agent in the hydrophilic matrix is hydrophilic because the intermediate layer has little advantage of being porous, and rather, the lower porosity improves the coating strength. Preferably less than layers,
Furthermore, it is more preferable not to contain it.

The addition amount of the particles coated with an inorganic material or an inorganic material having a particle diameter of 1 μm or more may be 1 to
It is preferably 50% by mass, and more preferably 5 to 40% by mass.

As in the case of the hydrophilic layer as a whole, it is preferable that the content ratio of carbon-containing materials such as organic resin and carbon black is low in order to improve hydrophilicity, and the total of these materials is 9%. It is preferably less than 5% by mass, more preferably 5% by mass or less.

(Image forming layer) The image forming layer of the present invention comprises
The heat fusible particles and / or the heat fusible particles and the following materials can be contained.

-Heat-melting fine particles The heat-melting fine particles used in the present invention are fine particles formed of a material generally classified as a wax because of its low viscosity when melted among thermoplastic materials. . As the physical properties, the softening point is 40 ° C or higher and 120 ° C or lower, and the melting point is 60.
℃ or more and 150 ℃ or less is preferable, softening point 40
More preferably, the melting point is not lower than 100 ° C and not higher than 100 ° C, and the melting point is not lower than 60 ° C and not higher than 120 ° C. When the melting point is lower than 60 ° C, the storage stability becomes a problem, and when the melting point is higher than 150 ° C, the ink inking sensitivity may be lowered. Therefore, the above range is preferable.

Examples of usable materials include paraffin, polyolefin, polyethylene wax, microcrystalline wax, and fatty acid wax. These have a molecular weight of about 800 to 10,000.
Further, these waxes may be oxidized to introduce a polar group such as a hydroxyl group, an ester group, a carboxyl group, an aldehyde group or a peroxide group in order to facilitate emulsification. Furthermore, in order to lower the softening point and improve workability, stearamide, linolenamide,
Lauryl amide, myristamide, hardened beef fatty acid amide, palmitoamide, stearyl amide, oleic acid amide, rice sugar fatty acid amide, coconut fatty acid amide or methylol compound of these fatty acid amides, methylenebisstearamide, ethylenebissteararoamide, etc. It is also possible to add. Also, coumarone-indene resin,
A rosin-modified phenol resin, a terpene-modified phenol resin, a xylene resin, a ketone resin, an acrylic resin, an ionomer, and a copolymer of these resins can also be used.

Among these, carnauba wax and fatty acid amide emulsions are particularly preferable.

Since these have relatively low melting points and low melt viscosities, it is possible to form images with high sensitivity. Also,
Since these have lubricity, damage when a shearing force is applied to the surface of the printing plate material is reduced, and resistance to printing stains due to scratches and the like is improved.

The heat-meltable fine particles are preferably dispersible in water, and the average particle size thereof is preferably 0.01 to 10 μm, more preferably 0.1 to 3 μm. When the average particle size is smaller than 0.01 μm, when the coating solution for the layer containing the heat-meltable fine particles is applied onto the porous hydrophilic layer described later, the heat-meltable fine particles have pores in the hydrophilic layer. It easily enters inside or into the gaps of minute irregularities on the surface of the hydrophilic layer, development on the printing machine becomes insufficient, and there is a concern of scumming. If the diameter is larger than 10 μm, the resolution may decrease, and therefore the above range is preferable.

The composition of the inside and the surface of the heat-meltable fine particles may be continuously changed, or may be covered with a different material. As a coating method, a known microcapsule forming method, sol-gel method or the like can be used.

The content of the heat-meltable fine particles in the image forming layer is preferably from 1 to 90% by mass, based on the total amount of the layer, and from 5 to 80% by mass.
Mass% is more preferable.

Thermofusible Particles The thermofusible particles of the present invention include thermoplastic hydrophobic high molecular weight polymer particles. There is no particular upper limit to the softening temperature of the thermoplastic hydrophobic polymer particles, but the temperature is preferably lower than the decomposition temperature of the polymer polymer particles. The weight average molecular weight (Mw) of the high molecular polymer is 10,
It is preferably in the range of 000 to 1,000,000.

Specific examples of the high molecular weight polymer which constitutes the high molecular weight polymer fine particles include, for example, polypropylene, polybutadiene, polyisoprene, diene (co) polymers such as ethylene-butadiene copolymer, and styrene-butadiene. Synthetic rubbers such as copolymers, methyl methacrylate-butadiene copolymer, acrylonitrile-butadiene copolymer, polymethyl methacrylate, methyl methacrylate- (2-ethylhexyl acrylate) copolymer, methyl methacrylate-methacrylic acid copolymer, Methyl acrylate- (N-methylol acrylamide) copolymer, (meth) acrylic acid ester such as polyacrylonitrile, (meth) acrylic acid (co) polymer, polyvinyl acetate, vinyl acetate-vinyl propionate copolymer, acetic acid Vinyl-ethylene Vinyl ester (co) polymer of the polymer such as, vinyl acetate - (2-ethylhexyl acrylate)
Examples thereof include copolymers, polyvinyl chloride, polyvinylidene chloride, polystyrene and the like, and copolymers thereof. Among these, (meth) acrylic acid ester, (meth) acrylic acid (co) polymer, vinyl ester (co) polymer, polystyrene, and synthetic rubbers are preferably used.

The above-mentioned fine polymer particles may be composed of a high polymer polymerized by any known method such as emulsion polymerization method, suspension polymerization method, solution polymerization method and gas phase polymerization method. As a method of micronizing a polymer polymerized by a solution polymerization method or a gas phase polymerization method, a solution of an organic solvent of the polymer polymer is sprayed in an inert gas, and a method of micronizing by drying, Dissolve the high molecular weight polymer in an organic solvent immiscible with water,
Examples include a method in which this solution is dispersed in water or an aqueous medium and the organic solvent is distilled off to form fine particles. In any of the methods, a surfactant such as sodium lauryl sulfate, sodium dodecylbenzene sulfonate, or polyethylene glycol, or a water-soluble resin such as polyvinyl alcohol is used as a dispersant or stabilizer in polymerization or microparticulation, if necessary. May be used.

The heat-fusible fine particles are preferably dispersible in water, and their average particle size is 0.01 to 10 μm.
Is preferable, and more preferably 0.1 to 3 μm.
Is. When the average particle diameter is smaller than 0.01 μm, when the coating solution for the layer containing the heat-fusible particles is applied on the porous hydrophilic layer described later, the heat-fusible particles become the hydrophilic layer. It is easy for the particles to get into the pores or into the gaps of fine irregularities on the surface of the hydrophilic layer, and the on-press development becomes insufficient, which may cause scumming, and the average particle size is 10 μm.
If it is larger than the above range, the resolution may be lowered, so that the above range is preferable.

The heat-fusible fine particles may have the composition of the inside and the surface layer continuously changed, or may be covered with a different material. As a coating method, a known microcapsule forming method, sol-gel method or the like can be used.

The content of the heat-fusible fine particles in the image forming layer is preferably 1 to 90% by mass, and preferably 5 to 80% by mass based on the whole layer.
Mass% is more preferable.

Water-Soluble Material The image forming layer according to the invention may further contain a water-soluble material. By containing the water-soluble material, it is possible to improve the removability when the image forming functional layer in the unexposed portion is removed using a dampening water or ink on the printing machine.

As the water-soluble material, the water-soluble resins listed as the materials that can be contained in the hydrophilic layer can be used, but saccharides are preferably used as the image forming layer of the present invention, and oligosaccharides are particularly preferable. It is preferable to use.

Since the oligosaccharide is rapidly dissolved in water, the image-forming layer in the unexposed area on the printing apparatus can be removed very quickly, and printing on a normal PS plate can be performed without paying attention to any special removing operation. It can be removed by printing by the same operation as the printing operation, and the loss of printed paper does not increase. Also,
The oligosaccharide has no fear of decreasing the hydrophilicity of the hydrophilic layer,
Good printability of the hydrophilic layer can be maintained.

Oligosaccharides are water-soluble crystalline substances having a generally sweet taste, and are formed by dehydration condensation of several monosaccharides by glycosidic bonds. Since oligosaccharides are a type of o-glycoside that uses sugar as an aglycone, they are easily hydrolyzed by an acid to give monosaccharides, and disaccharides, trisaccharides, tetrasaccharides, pentasaccharides, etc. depending on the number of monosaccharides produced. are categorized. The oligosaccharide in the present invention refers to disaccharide to decasaccharide.

These oligosaccharides are roughly classified into reducing oligosaccharides and non-reducing oligosaccharides depending on the presence or absence of a reducing group.
Homo-oligosaccharides composed of a single monosaccharide and 2
It is also classified as a heterooligosaccharide composed of more than one type of monosaccharide.

Oligosaccharides naturally occur in free form or as glycosides and can also be obtained by partial hydrolysis of polysaccharides with acids or enzymes. Various oligosaccharides are also produced by glycosyl transfer by other enzymes.

Oligosaccharides often exist as hydrates in normal atmosphere. Further, hydrates and anhydrides have different melting points, and examples thereof are as shown in Table 1.

[0130]

[Table 1]

In the present invention, it is preferable to form a layer containing a saccharide by coating with an aqueous coating solution. Therefore, when the oligosaccharide present in the layer is a hydrate-forming oligosaccharide, its melting point is hydrated. It is considered to be the melting point of the substance. in this way,
Since it has a relatively low melting point, oligosaccharides also melt in the temperature range where the heat-melting fine particles melt and the temperature range where the heat-melting fine particles fuse, and the heat-melting fine particles melt and permeate into the porous hydrophilic layer. It does not interfere with image formation such as fusion of heat fusion particles.

Among oligosaccharides, trehalose, which is in a relatively high-purity state, is industrially available at low cost and has a very low hygroscopicity despite its high solubility in water. The developability and storability above are very good.

When oligosaccharide hydrate is melted by heat to remove water of hydration and then solidified, anhydrous crystals are formed (for a short time after solidification), but trehalose is more anhydrous than hydrate. Is characterized by having a high melting point of 100 ° C. or higher. This means that the exposed portion is heat-melted by infrared exposure, and immediately after re-solidification, the exposed portion has a high melting point and is in a state where it is difficult to melt, which has an effect of making it difficult to cause image defects during exposure such as banding.

To achieve the object of the present invention, trehalose is particularly preferable among oligosaccharides.

The content of oligosaccharides in the intermediate layer is preferably 1 to 90% by mass, more preferably 10 to 80% by mass, based on the total weight of the layer.

(Image formation and printing) The lithographic printing plate material of the present invention is, for example, directly subjected to image-wise thermal recording by a thermal recording head or the like, or a solid laser or semiconductor laser emitting infrared rays having a wavelength of 700 to 1200 nm, High-intensity flash light such as a xenon discharge lamp or photothermal conversion type exposure such as infrared lamp exposure can also be used.

The image may be written by either the surface exposure method or the scanning method. In the case of the former, the infrared irradiation method,
This is a method in which high-luminance short-time light of a xenon discharge lamp is irradiated onto the original plate to generate heat by photothermal conversion.

When a surface exposure light source such as an infrared lamp is used, the preferable exposure amount changes depending on the illuminance, but normally the surface exposure intensity before modulation with a printing image is 0.1 to 10 J /. preferably in the range of cm ² ,
The range of 0.1 to 1 J / cm ² is more preferable.

When the support is transparent, it can be exposed through the support from the back side of the support. The exposure time is 0.01 to 1 msec. , Preferably 0.01 to
0.1 msec. It is preferable to select the exposure illuminance so that the above-mentioned exposure intensity can be obtained by the irradiation. When the irradiation time is long, it is necessary to increase the exposure intensity due to the competitive relationship between the generation rate of thermal energy and the diffusion rate of generated thermal energy.

In the latter case, a method is used in which a laser light source containing a large amount of infrared components is used to modulate a laser beam with an image and scan the original plate. Examples of the laser light source include a semiconductor laser, a helium neon laser, a helium cadmium laser, and a YAG laser. Irradiation with a laser having a laser output of 0.1 to 300 W can be performed. When a pulsed laser is used, it is preferable to irradiate a laser having a peak output of 1000 W, preferably 2000 W. In this case, the exposure amount is preferably such that the surface exposure intensity before modulation with the printing image is in the range of 0.1 to 10 J / cm ² ,
The range of 0.1 to 1 J / cm ² is more preferable.

The lithographic printing plate material of the present invention can be used by mounting the imagewise exposed lithographic printing plate material on a printing machine without further treatment. When printing is started using ink and water, the unexposed portion of the image forming layer is removed by the dampening water and ink. Water adheres to the hydrophilic layer appearing on the surface, ink is inked in the image-exposed portion, and printing is started.

(Coating) Examples of the solvent used when preparing the coating composition for the image forming layer and the intermediate layer according to the present invention include alcohols: polyhydric alcohol derivatives such as sec-butanol and isobutanol. , N-hexanol, benzyl alcohol, diethylene glycol,
Triethylene glycol, tetraethylene glycol,
1,5-Pentanediol, ethers: propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, ketones, aldehydes: diacetone alcohol, cyclohexanone, methylcyclohexanone, and esters: ethyl lactate Butyl lactate,
Preferable examples include diethyl oxalate and methyl benzoate.

The prepared coating composition (layer coating solution) can be coated on a support by a conventionally known method and dried to prepare a lithographic printing plate material. Examples of the coating method of the coating liquid include an air doctor coater method, a blade coater method, a wire bar method, a knife coater method, a dip coater method, a reverse roll coater method, a gravure coater method, a cast coating method, a curtain coater method and an extrusion coater method. Can be mentioned.

When the drying temperature of the image forming layer is low, sufficient printing durability cannot be obtained, and when it is too high, not only Marangoni occurs, but also fog occurs in the non-image area. A preferable drying temperature range is 60 to 160 ° C.
Is preferable, more preferably 80 to 140 ° C., and particularly preferably 90 to 120 ° C.

[0145]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited thereto. In addition, "part" in an Example represents a "mass part" unless there is particular notice.

Preparation of planographic printing plate materials (1-A to 4-A) (hydrophilic layer coating / drying step) The following hydrophilic layer coating liquid was applied onto the following support by a wire bar coating method and the post-drying amount was It was applied at 2.25 g / m ² , dried at 100 ° C. for 1 minute, and then aged at 60 ° C. for 24 hours.

(Image Forming Layer Coating and Drying Step) The following image forming layer coating liquid was applied onto the hydrophilic layer by a wire bar coating method.
Apply so that the coating amount after drying is 0.73 g / m ² ,
It was dried at 50 ° C. for 3 minutes and further aged at 40 ° C. for 24 hours, and the lithographic printing plate material (1-A) using the support 1 and the lithographic printing plate material (2) using the support 2 were respectively described below. -A) and a lithographic printing plate material (3-A) using the support 3 were obtained.

(Laminating process) On the other hand, a polyurethane adhesive was applied to the surface of a degreased 1050 aluminum support having a thickness of 0.2 mm so as to be 3 g / m ^2, and the PET film of the support 1 was applied. The surfaces on which a removable layer is not formed on the printing apparatus of No. 1 are bonded together, and the hydrophilic layer and the image forming layer are formed on the aluminum surface in the same manner as above by using this as a support, and further aging at 40 ° C. for 48 hours. After that, it was cut into a size of 730 mm × 600 mm to obtain a planographic printing plate material (4-A).

Preparation of planographic printing plate materials (1-B to 4-B) (intermediate layer coating / drying step) The following coating liquid for intermediate layer was applied to the following support by the wire bar coating method, and the post-drying amount was shown in Table 4. Was coated as described in 1. and dried at 100 ° C. for 1 minute.

(Hydrophilic layer coating and drying step) Next, the following hydrophilic layer coating liquid was applied onto the intermediate layer by a wire bar coating method.
Apply so that the post-drying amount is as shown in Table 4, and
It was dried at 00 ° C. for 1 minute and then aged at 60 ° C. for 24 hours.

(Image forming layer coating and drying step) The following image forming layer coating liquid was applied onto the hydrophilic layer by a wire bar coating method.
Apply so that the dry coating amount is 0.6 g / m ² , and apply 50
After drying at 3 ° C. for 3 minutes and aging at 40 ° C. for 24 hours, the lithographic printing plate material using the support 1 (1-B) and the lithographic printing plate material using the support 2 (2- B) and a lithographic printing plate material using the support 3 (3
-B) was obtained.

(Laminating process) Degreased 1 having a thickness of 0.2 mm
Polyurethane adhesive was applied to the surface of 050 aluminum base material so that the amount of polyurethane adhesive was 3 g / m ²
The surfaces of the T film on which a layer that can be removed on the printing device is not formed are adhered to each other, and an intermediate layer, a hydrophilic layer and an image forming layer are formed on the aluminum surface as a support in the same manner as above. After aging at 40 ° C. for 48 hours, it was cut into a size of 730 mm × 600 mm to obtain a planographic printing plate material (4-B).

Support 1 ... PET film of 50 μm (PET film (H
S74: Teijin Ltd.)) was used.

Support 2 ... Aluminum plate A 0.24 mm thick aluminum plate (material 1050, tempered H16) was immersed in a 5% sodium hydroxide aqueous solution kept at 65 ° C. and degreased for 1 minute. It was washed with water and used.

Support 3 ... A PET film having a thickness of 175 μm (having the same water-based coating subbing as that of Support 1, different thickness from Support 1 (HS74: Teijin Limited)) was used.

(Preparation of Coating Liquid for Intermediate Layer) (Preparation of Intermediate Layer Paste) The materials shown in Table 2 were sufficiently stirred and mixed using a homogenizer, and then filtered to prepare an intermediate layer paste.

<Coating Liquid 1 for Intermediate Layer> Intermediate layer paste 16.25% by mass Colloidal silica: Snowtex XS (manufactured by Nissan Kagaku Co., solid content 20% by mass) 73.30% by mass aqueous sodium hydroxide solution (10% by mass) ) 0.90% by mass Pure water 9.55% by mass <Intermediate layer coating liquid 2> Intermediate layer paste 16.25% by mass Colloidal silica: Snowtex XS (manufactured by Nissan Kagaku Co., solid content 20% by mass) 71.95 Mass% Sodium hydroxide aqueous solution (10 mass%) 1.80 mass% Methylcellulose: Metroze SM-400 (manufactured by Shin-Etsu Chemical Co., Ltd.) 0.18 mass% Pure water 9.82 mass% <Comparative intermediate layer coating liquid 1> Intermediate Layer paste 16.25% by mass Colloidal silica: Snowtex XS (manufactured by Nissan Kagaku Co., solid content 20% by mass) 73.75% by mass Pure water 10.00 Amount% <Comparative Intermediate Layer Coating Liquid 2> Intermediate layer paste 9.03% by mass Polyacrylic acid: 10% aqueous solution of Aquaric RS-40K (manufactured by Nippon Shokubai Co., Ltd.) 81.94% by mass Pure water 9.03% by mass ( Preparation of Hydrophilic Layer Coating Liquid) (Preparation of Hydrophilic Layer Paste) The materials shown in Table 2 were sufficiently stirred and mixed using a homogenizer, and then filtered to prepare a hydrophilic layer paste.

A coating solution for the hydrophilic layer was prepared by using the above-mentioned hydrophilic layer paste and having the following composition.

[0159]

[Table 2]

<Coating Liquid 1 for Hydrophilic Layer> Hydrophilic layer paste 12.25% by mass Colloidal silica: Snowtex S (manufactured by Nissan Kagaku, solid content 30% by mass) 6.02% by mass Colloidal silica: Snowtex PSM (Nissan Chemical Co., Ltd., solid content 20% by mass) 3.55% by mass aqueous sodium hydroxide solution (10% by mass) 0.35% by mass pure water 67.84% by mass <Coating liquid 2 for hydrophilic layer> Hydrophilic layer Paste 12.25% by mass Colloidal silica: Snowtex S (Nissan Chemical Co., Ltd., solid content 30% by mass) 5.97% by mass Colloidal silica: Snowtex PSM (Nissan Chemical Co., Ltd., solid content 20% by mass) 13.44 Mass% Sodium hydroxide aqueous solution (10 mass%) 0.7 mass% Pure water 67.64 mass% <Coating liquid 3 for hydrophilic layer> Hydrophilic layer paste 12.25 mass Colloidal silica: Snowtex S (manufactured by Nissan Chemical Co., solid content 30 mass%) 5.79 mass% Colloidal silica: Snowtex PSM (manufactured by Nissan Chemical Co., solid content 20 mass%) 13.02 mass% Sodium hydroxide aqueous solution (10% by mass) 2.10% by mass Pure water 66.84% by mass <Coating liquid 4 for hydrophilic layer> Hydrophilic layer paste 12.25% by mass Colloidal silica: Snowtex S (Nissan Chemical Co., Ltd., solid content 30) Mass%) 5.93 mass% colloidal silica: Snowtex PSM (manufactured by Nissan Chemical Industries, solid content 20 mass%) 13.34 mass% sodium hydroxide aqueous solution (10 mass%) 0.7 mass% carboxymethylcellulose sodium :( (Reagent manufactured by Kanto Chemical Co., Inc.) 4% by mass aqueous solution 0.88% by mass pure water 66.91% by mass <Coating liquid 5 for hydrophilic layer> Hydrophilic Layer paste 12.25% by mass Colloidal silica: Snowtex S (manufactured by Nissan Kagaku, solid content 30% by mass) 5.88% by mass Colloidal silica: Snowtex PSM (manufactured by Nissan Kagaku, solid content 20% by mass) 13. 34% by mass aqueous sodium hydroxide solution (10% by mass) 0.7% by mass sodium carboxymethylcellulose: 4% by mass aqueous solution of (Kanto Chemical Co., Inc. reagent) 1.75% by mass pure water 66.19% by mass <for hydrophilic layer Coating liquid 6> Hydrophilic layer paste 12.25% by mass Colloidal silica: Snowtex S (manufactured by Nissan Kagaku, solid content 30% by mass) 5.79% by mass Colloidal silica: Snowtex PSM (manufactured by Nissan Kagaku, solid content) 20% by mass) 13.02% by mass Sodium hydroxide aqueous solution (10% by mass) 0.7% by mass Carboxymethyl cellulose Thorium: (Kanto Chemical Co., Ltd. reagent) 4% by mass aqueous solution 3.50% by mass Pure water 64.74% by mass <Coating liquid 1 for comparative hydrophilic layer> Hydrophilic layer paste 12.25% by mass Colloidal silica: Snowtex S (Nissan Chemical Co., Ltd., solid content 30 mass%) 6.07 mass% Colloidal silica: Snowtex PSM (Nissan Chemical Co., Ltd., solid content 20 mass%) 13.65 mass% Pure water 68.03 mass% <Comparison Hydrophilic layer coating liquid 2> Hydrophilic layer paste 12.25% by mass Polyacrylic acid: 10% aqueous solution of Aquaric RS-40K (manufactured by Nippon Shokubai Co., Ltd.) 45.5% by mass Pure water 42.25% by mass or more The properties of the hydrophilic layer coating liquid and the intermediate layer coating liquid are summarized in Table 3. In the table, ST-S is Snowtex S.
ST-PSM is Snowtex PSM, and S
T-SX represents Snowtex SX. The viscosity and pH were measured using those described in the specification.

[0161]

[Table 3]

(Preparation of coating liquid for image forming layer) <Coating liquid for image layer> Disaccharide: 5% aqueous solution of trehalose powder (Trehaose, manufactured by Hayashibara Shoji Co., Ltd., melting point 97 ° C.) 30.00% by mass Carnauba wax 5% water dilution of emulsion A118 (Gifu Shellac, solid content 40%) 62.50% by weight Amide wax: CANAX L271 (Chukyo Yushi Co., solid content 24.8% by weight) 5% water dilution 7.50% by mass (image formation) The prepared lithographic printing plate material was wound around an exposure drum and fixed. A laser beam having a wavelength of 830 nm and a spot diameter of 10.58 μm was used for the exposure, and the exposure energy was 300 mJ / cm ² at 2400 dpi (dpi).
Represents the number of dots per 2.54 cm. ), 17
The image was formed with 5 lines.

(Printing method) Printing apparatus: Shiraioi 70 kg, dampening water Astromark 3 (manufactured by Nikken Chemical Laboratory Co., Ltd.) 2% by mass, ink (TOYO) using DAIYAF-1 manufactured by Mitsubishi Heavy Industries, Ltd. Printing was performed using Toyo King High Echo M Beni manufactured by Ink Co., Ltd.

<Evaluation Method> (Number of Printing Durability) 50% square dot image of printed matter is 2% in energy amount that faithfully reproduces the original image without thinning or thickening. The number is set.

(Stain recovery) After the water supply to the printing plate was turned off and ink was applied to the entire surface to start printing, the water supply was restarted, and the density of the non-image area became less than 0.08 from that point. Was evaluated. In addition, it standardized by the following criteria.

◎: Less than 20 sheets ○: 20 or more and less than 25 sheets Δ: 25 or more and less than 30 sheets ×: 30 sheets or more (fine dot peeling of non-image area after printing 12,000 sheets) 120
After printing 00 sheets, observe the non-image part of the printing plate with a microscope,
It was visually evaluated whether the intermediate layer or the hydrophilic layer was scraped off by the paper dust generated from the Shiraioi high-quality paper and the support was exposed in fine dots. In addition, it standardized by the following criteria.

⊚: No minute dot-like peeling ○: There is fine dot-like peeling but ink is not inked Δ: There is fine dot-like peeling and ink is inked, but it does not appear in the printed matter X: Table 4 shows the results in which a large number of minute spots were peeled off, or the ink adhered to the minute spots peeled to stain the printed matter.

[0168]

[Table 4]

[0169]

INDUSTRIAL APPLICABILITY The present invention has excellent adhesiveness between a support and a layer above it, excellent printing durability, and excellent stain recovery.
In addition, it was possible to provide a lithographic printing plate material having excellent printing durability, by which it was possible to obtain a uniform coating film by reducing fluffiness and liquid leakage during coating and drying. Further, when an experiment was carried out by changing the support to the support 3, the lithographic printing plate material of the present invention showed good performance as in the above.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2H025 AA12 AA14 AB03 AC08 AD01                       AD03 CC20 DA18 DA29 DA35                       DA36 FA03                 2H096 AA07 AA08 BA16 BA20 CA05                       CA20 EA04                 2H114 AA04 AA23 AA28 BA01 BA10                       DA15 EA03 FA14

Claims (9)

[Claims] 1. A lithographic printing plate material having at least a hydrophilic layer and an image forming layer on a support, wherein the pH value of a coating solution of a layer adjacent to the support is 10 to 13. And planographic printing plate material. 2. The coating solution for the layer adjacent to the support is 2
Viscosity at 5 ° C. is 3.5 × 10 ^{−3 to} 11.5 × 1
The lithographic printing plate material according to claim 1, which is in the range of 0 ^-3 Pa · s. 3. The lithographic printing plate material according to claim 1, wherein the layer adjacent to the support contains colloidal silica. 4. The lithographic printing plate material according to claim 1, wherein the layer adjacent to the support is a hydrophilic layer. 5. The lithographic printing plate material according to claim 1, wherein an intermediate layer is provided between the support and the hydrophilic layer. 6. The lithographic printing plate material according to claim 1, wherein the hydrophilic layer or the intermediate layer has a photothermal conversion function. 7. The image forming layer contains heat fusible particles or heat fusible particles.
7. The lithographic printing plate material as described in any one of 1 to 6 above. 8. The lithographic printing plate material according to claim 1, wherein the support is a resin film or an aluminum plate. 9. The lithographic printing plate material according to claim 1, which is used in a printing method of developing with water or ink on a printing device and performing printing.