WO2007083506A1

WO2007083506A1 - Printing plate material, process for producing printing plate material, and method for lithography

Info

Publication number: WO2007083506A1
Application number: PCT/JP2006/326195
Authority: WO
Inventors: Takeshi Sampei
Original assignee: Konica Minolta Medical & Graphic, Inc.
Priority date: 2006-01-17
Filing date: 2006-12-28
Publication date: 2007-07-26

Abstract

This invention provides a printing plate material, which is less likely to cause a coating failure during the production thereof, is excellent in coating defect preventive properties, has high sensitivity, and is excellent in initial ink deposition rate and printing durability, and a production process of the printing plate material, and a method for lithography using the printing plate material. The printing plate material comprises a base material and a hydrophilic layer and an image forming functional layer provided on the base material layer and is developable on a printing machine. The printing plate material is characterized in that the hydrophilic layer contains metal oxide particles having a coercive force(HC) of not more than 8 kA/m in a magnetic field of 400 kA/m.

Description

Specification

Printing plate material, printing plate material manufacturing method and planographic printing method

Technical field

[0001] The present invention relates to a printing plate material, a method for producing the same, and a lithographic printing method, and more particularly, a printing plate material capable of image formation by a computer 'to' plate _(CTP) method and developable on a printing press, The present invention relates to a manufacturing method and a planographic printing method using the same.

Background art

[0002] Along with the digitalization of print data, there is a need for CTP (computer-to-one-plate) technology that is inexpensive, easy to handle! /, And has the same printability as the PS version.

In recent years, in order to reduce the burden on the global environment, there is an increasing expectation for a CTP printing plate that does not require a developer treatment with a special chemical. Among them, in recent years, an image is formed on a printing plate material with an infrared thermal laser, and then it can be installed in a printing machine without being treated with chemicals, and unnecessary parts can be removed immediately with dampening water and ink. A printing method using a so-called on-press developable printing plate material (see Patent Document 1) has attracted attention.

[0004] When these printing plate materials are exposed to an infrared thermal laser, heat is generated by the photothermal conversion material contained in the printing plate material, thereby forming an image. As a printing plate material that can be developed on a printing press using heat generated by the photothermal conversion material, the substrate has a hydrophilic layer containing metal oxide particles and an image forming functional layer as the photothermal conversion material. Printing plate materials are known (see Patent Document 2).

[0005] However, in the conventional printing method using the on-press developable printing plate material as described above, the coating failure is likely to occur or the printing sensitivity is low. In some cases, the printing performance is insufficient or the printing durability is insufficient. There was a strong demand for printing plate materials that solved these problems.

Patent Document 1: Japanese Patent Laid-Open No. 2000-225780

Patent Document 2: JP 2004-167973 A

Disclosure of the invention Problems to be solved by the invention

[0006] An object of the present invention is to provide a printing plate material that is excellent in coating defect prevention property, in which coating failure is unlikely to occur during manufacturing, has high sensitivity, and is excellent in initial ink landing property and printing durability, its production method, and use thereof It is to provide a lithographic printing method.

Means for solving the problem

[0007] The object of the present invention is achieved by the following means.

1. A printing plate material that can be developed on a printing press having a hydrophilic layer and an image forming functional layer on a substrate, and the hydrophilic layer has a coercive force (HC) force of 8 kAZm or less in a magnetic field of OOkAZm. A printing plate material comprising metal oxide particles.

2. The printing plate material according to 1, wherein the metal oxide particles are metal oxide particles mainly composed of titanium oxide and iron oxide.

3. The printing plate material according to 1 or 2, wherein the image-forming functional layer contains heat-fusible particles or heat-fusible particles.

4. The printing plate material according to any one of 1 to 3, wherein the metal oxide particles are contained in a hydrophilic layer adjacent to the image forming functional layer.

5. A method for producing a printing plate material that can be developed on a printing press having a hydrophilic layer and an image forming functional layer on a substrate, wherein the coercive force (HC) is applied to the hydrophilic layer coating liquid that forms the hydrophilic layer. ) Has a step of containing metal oxide particles that are 8 kAZm or less in a magnetic field of 4 OOkAZm.

6. Any force of 1 to 4 After image exposure of the printing plate material described in item 1, it is mounted on a printing press, and dampening water and ink are supplied to the surface of the printing plate material to remove non-image areas. A lithographic printing method characterized by printing.

The invention's effect

[0008] According to the above-described configuration of the present invention, a printing plate material excellent in coating defect prevention property, in which coating failure is unlikely to occur during manufacturing, and having high sensitivity, initial ink flaking property, and printing durability, a manufacturing method thereof, and the same A lithographic printing method using can be provided.

BEST MODE FOR CARRYING OUT THE INVENTION [0009] The present invention relates to a printing plate material which can be developed on a printing press having a hydrophilic layer and an image forming functional layer on a substrate, and the hydrophilic layer has a coercive force (HC) of 400 kAZm at a temperature of 20 ° C. It is characterized by containing metal oxide particles that are 8 kAZm or less in a magnetic field.

[0010] In the present invention, particularly when the hydrophilic layer contains metal oxide particles having a coercive force (HC) of 8 kAZm or less in a magnetic field of 400 kAZm at a temperature of 20 ° C, a coating failure occurs during production. A printing plate material that is excellent in the prevention of coating defects and has high sensitivity and excellent initial ink setting and printing durability can be obtained.

[0011] (Metal oxide particles)

In the present invention, the hydrophilic layer contains metal oxide particles having a coercive force (HC) of 8 kAZm or less in a magnetic field of 400 kAZm at a temperature of 20 ° C.

[0012] In the present invention, the coercive force (HC) means the magnitude of the magnetic field in the opposite direction that must be added in order to turn over the magnetic polarity of the magnet. Can be measured.

[0013] In the case of a coating liquid and a coating material containing the above particles with a large coercive force !, the particles reaggregate to form a uniform dispersion, which causes various problems. It tends to occur.

The coercive force (HC) is measured with a magnetometer, and can be measured using, for example, a vibrating sample type magnetometer VSM-P7-15 manufactured by Toei Kogyo Co., Ltd.

[0015] The coercive force (HC) of the metal oxide particles used in the present invention is a force that is 8 kAZm or less in the magnetic field of 400 kAZm as described above, preferably OAZm or more and 6.5 kAZm or less, more preferably OAZm. Above 5kAZm.

[0016] The metal oxide particles according to the present invention having such a coercive force are preferably metal oxide particles mainly having titanium oxide and iron oxide strength. Specifically, ilmenite (FeTiO 3) particles, pseudo brookite (Fe TiO 2) particles described in JP-A-1-298028,

3 2 5 Kaihei 3 — pseudoburkite and hematite (Fe 2 O 3) -ilmenite described in No. 2276

twenty three

Particles having a mixed composition of (FeTiO 3), ferrous salt described in JP 2001-253717

Three

Iron-titanium composite oxide particles produced by spray pyrolysis using an emulsion containing an aqueous solution, a hydrolyzable organotitanium compound and an emulsifier as a spray pyrolysis solution, a rutile TiO phase described in JP 2002-129063 A The substrate was coated with Fe TiO phase Particles or composite oxides mainly composed of Fe TiO as described in JP-A-2005-68323

twenty four

Can be exemplified, also, Fe and Fe (II) to Ti in a total amount of 150 to 300 atomic ^_0/0 of Fe (III) and Fe (II) to the total amount of Fe (III) (II) is 0.50 Particles having the L value of the coating film by the Hoover-type Muller method of 9.0 or less are preferably used.

[0017] The metal oxide particles according to the present invention can be produced by the method described in the aforementioned published patent publication. One of the characteristics of the metal oxide particles according to the present invention is that they are relatively safe and harmless to the environment and the human body.

[0018] The metal oxide particles according to the present invention are used as a photothermal conversion agent in a hydrophilic layer where black particles are preferred.

[0019] The photothermal conversion agent preferably has an L * value power in the L * aV color system of not less than 13 and not more than 13, and more preferably has an L * value of not less than 0 and not more than 10. Here, the “L * a * b * color system” is a color system used to represent the color of an object. It was standardized by the International Commission on Illumination (CIE) in 1976, and also in Japan. Used in JIS (Z8729). In the L * a * b * color system, lightness is represented by L *, and chromaticity representing hue and saturation is represented by a * and b *. In the present invention, the L * value, which is an index indicating brightness, is evaluated as an index of blackness. The smaller the L * value, the better the blackness. That is, when the L * value of the black particles is 0 or more and 10 or less, the black particle has sufficient blackness as a photothermal conversion agent.

[0020] The photothermal conversion ability with respect to the addition amount of the metal oxide particles according to the present invention is greatly affected by the degree of dispersion of the particles, and the better the dispersion, the better. Before being added to the coating solution for the hydrophilic layer, the product particles are put in a sand grinder together with various media having a particle diameter of 0.2 to 2 mm as described in, for example, JP-A-2002-226842. The dispersion is preferably carried out as a dispersion or paste by a method such as a method of dispersing for 1 to 60 minutes at a rotation speed of 2000 to 8000 rpm Z. A dispersing agent can be used for dispersion as needed. As the dispersant, a known one (for example, a surfactant described in JP-A-2002-226842) can be used. The addition amount of the dispersant is preferably 0.01 to 5% by mass, more preferably 0.1 to 2% by mass with respect to the metal oxide particles.

[0021] When the printing plate material according to the present invention is produced, the dispersion or paste is mixed with the hydrophilic layer coating liquid according to the present invention, and this is applied onto a substrate to provide a hydrophilic layer. But this In this case, the mixing ratio is preferably 5 to 85% by mass with respect to the hydrophilic layer coating solution.

In this mixing, a known disperser can be used, and among these, it is preferable to perform a dispersion treatment using a medialess disperser. Among the medialess dispersers, an internal shear type medialess disperser is particularly preferably used. The internal shear type medialess disperser is a device that has a rotor and a stator that rotate at high speed, and applies shear to the inside of the coating liquid with a narrow clearance between them to disperse. Examples of this disperser include CLEAMIX manufactured by MTechnic Co., Ltd., Tornado manufactured by Asada Steel Co., Ltd., and high-pressure homogenizer and particle sizer manufactured by LosoAvi.

[0022] Further, it is preferable that the time until the dispersion treatment force is applied is between about 0 to 3 minutes of developing surface force on the printing press. This dispersion treatment is preferably performed by installing a disperser in the middle of the coating liquid feeding pipe or in the middle of the coating liquid feeding circulation pipe.

[0023] It is also possible to increase the processing effect by connecting a plurality of dispersers.

[0024] Examples of the mode in which the disperser is installed in the coater include, for example, a mode in which the mechanism of an extrusion coater incorporating a stirring rotor in a coater chamber described in JP-A-5-50001 is applied to a slide coater. There is.

[0025] Such dispersion of the coating solution can also be performed while feeding and circulating the coating solution. Specifically, for example, the coating liquid is circulated by supplying an excessive amount of coating liquid to the die chamber of the slide coater in excess of the required amount of application, drawing out the excessive coating liquid from the coater die chamber, and drawing it out. The liquid can be returned to the coating liquid supply tank or the liquid feeding pipe from the coating liquid supply tank to the coater.

[0026] The average particle size of the metal oxide particles contained in the hydrophilic layer is such that the average particle size is preferably not more than Lm. The average particle size is 0.01 to 0.8 / zm. It is better to be in range. By making the average particle size 1 m or less, the photothermal conversion ability with respect to the added amount becomes better, and by making the average primary particle size within the range of 0.01 to 0.8 m, photothermal conversion with respect to the added amount is achieved. Performance is better. However, the photothermal conversion ability with respect to the amount added is greatly affected by the degree of dispersion of the particles, and the better the dispersion, the better. Accordingly, these metal oxide particles are dispersed by a known method before being added to the layer coating solution to form a dispersion (paste). It is preferable to keep it. An average primary particle size of less than 0.01 m is not preferable because dispersion becomes difficult.

[0027] The average particle size refers to the number average primary particle size. The particle size is increased by 10,000 times by observation with a transmission electron microscope, and the short side and the long side of 100 particles are measured at random. The value obtained by dividing the total value by 200 is ヽぅ.

[0028] The addition amount of the metal oxide particles according to the present invention is 5% by mass or more and 80% by mass with respect to the total solid content of the hydrophilic layer in terms of sensitivity and prevention of generation of abrasion residue. It is less than 10% by mass and more preferably less than 70% by mass and more preferably less than 70% by mass and more preferably in the range of 15% by mass to less than 60% by mass.

[0029] (Hydrophilic layer)

The hydrophilic layer according to the present invention is a non-image part that has low affinity for ink and repels ink when the printing plate material of the present invention is used as a printing plate, and has high affinity for water and retains water. The image forming layer is provided on the hydrophilic layer (on the side opposite to the substrate).

[0030] The hydrophilic layer may be composed of a plurality of layers. In this case, the metal oxide particles according to the present invention are preferably contained in a hydrophilic layer adjacent to the image forming layer.

[0031] The hydrophilic layer according to the present invention preferably has a porous structure.

[0032] In order to form the hydrophilic layer having the porous structure, a hydrophilic material that forms the hydrophilic matrix described below is preferably used.

[0033] As the hydrophilic material forming the hydrophilic matrix, a metal oxide is preferably used.

[0034] As the metal oxide, the following hydrophilic materials are preferably used. However, the metal oxide particles according to the present invention may partially serve as a hydrophilic material.

[0035] <Hydrophilic material>

(Metal oxide)

As the metal oxide, metal oxide particles are preferred. Examples thereof include colloidal silica, alumina sol, titasol, and other metal oxide sols. The form of the metal oxide fine particles may be any of spherical, needle-like, feather-like, and other average particle sizes. Therefore, several kinds of metal oxide particles having different average particle sizes, preferably in the range of 3 to: LOOnm, can be used in combination. Further, the surface of the particles may be subjected to a surface treatment.

[0036] The metal oxide particles can be used as a binder by utilizing the film-forming property. It is suitable for use in a hydrophilic layer where the decrease in hydrophilicity is less than when an organic binder is used.

[0037] (Colloidal silica)

Among these, colloidal silica can be particularly preferably used. Colloidal silica has the advantage of high film-forming properties even under relatively low temperature drying conditions, and can provide good strength. The colloidal silica preferably includes a necklace-shaped colloidal silica, which will be described later, and a fine particle colloidal silica having an average particle size of 20 ηm or less. Further, the colloidal silica preferably exhibits alkalinity when used as a colloid solution.

[0038] Necklace-shaped colloidal silica is a general term for an aqueous dispersion of spherical silica having an order of primary particle size of 111, and spherical colloidal silica having a primary particle size of 10 to 50 nm has a length of 50 to 400 nm. It means the combined “pearl necklace” colloidal silica. The shape of a pearl necklace (that is, a pearl necklace shape) means that it has a shape similar to that of a pearl necklace in which the silica particles of colloidal silica are joined together.

[0039] The bond between the silica particles constituting the necklace-shaped colloidal silica is presumed to be -Si-O-Si-, which is present on the surface of the silica particles-SiOH groups are dehydrated. Specific examples of colloidal silica in the form of necklace include the “Snowtex 3” series manufactured by Nissan Chemical Industries, Ltd., and the product name is “Snowtex—PS—S” (average particle size in the connected state). "Snowtex PS-M (the average particle size in the connected state is about 120 nm)" and "Snowtex PS-L (the average particle size in the connected state is about 170 nm)" Acidic products corresponding to each of these are “Snowtex—PS—S—O”, “Snowtex PS—M-0” and “Snowtex PS—L-0”.

[0040] By adding necklace-like colloidal silica, it becomes possible to maintain the strength while ensuring the porosity of the layer, and it can be preferably used as a porous material for the hydrophilic layer matrix. Among these, alkaline "Snowtex PS-S", "Snowtex PS-M" "Snowtex PS-L" improves the strength of the hydrophilic layer and increases the number of printed sheets.

V, especially preferred, even if the occurrence of soiling is suppressed.

[0041] Further, it is known that the colloidal silica has a stronger binding force as the particle diameter is smaller. In the present invention, it is preferable to use colloidal silica having an average particle diameter of 20 nm or less, and more preferably 3 ~ 15nm.

[0042] As described above, the colloidal silica is particularly preferable because it is alkaline and has an effect of suppressing the occurrence of soiling. Average particle size force S Alkaline colloidal silica in this range includes, for example, “Snowtex-20 (particle size 10-20 nm)”, “Snowtex-30” (particle size 10 to 20nm), "Snowtex-40 (particle size 10-20nm)"

, "Snowtex I N (Particle size 10-20nm)", "Snowtex I S (Particle size 8: L lnm

) ”,“ Snowtex XS (particle size 4-6nm) ”.

[0043] Colloidal silica having an average particle size of 20 nm or less is particularly preferred, when used in combination with the above-mentioned necklace-shaped colloidal silica, since the strength of the layer to be formed can be further improved while maintaining the porosity. .

[0044] The ratio of colloidal silica Z necklace colloidal silica having an average particle size of 20 nm or less is preferably in the range of 95Z5 to 5Z95, more preferably in the range of 70Z30 to 20Z80, and more preferably in the range of 60/40 to 30/70. The range power is even better! / ヽ.

In the present invention, porous metal oxide particles having a particle size of less than 1 μm can be contained as a porous material having a hydrophilic layer matrix structure.

[0046] (Porous metal oxide particles)

As the porous metal oxide particles, the following porous silica particles, porous aluminosilicate particles, or zeolite particles can be preferably used.

[0047] (Porous silica particles, porous aluminosilicate particles)

The porous silica particles are generally produced by a wet method or a dry method. In the wet method, the gel obtained by neutralizing the aqueous silicate solution can be obtained by drying and pulverizing, or by pulverizing the precipitate precipitated after neutralization. In the dry method, silicon tetrachloride is combusted with hydrogen and oxygen, and silica is deposited. These particles can be adjusted by adjusting manufacturing conditions.

It is possible to control the porosity and particle size. As the porous silica particles, the wet method The gel strength is particularly preferred.

[0048] Porous aluminosilicate particles are produced, for example, by the method described in JP-A-10-71764. That is, amorphous composite particles synthesized by hydrolysis using aluminum alkoxide and silicon alkoxide as main components. The ratio of alumina to silica in the particles can be synthesized in the range of 1: 4 to 4: 1. In addition, particles produced by adding alkoxides of other metals during 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 also be controlled by adjusting the production conditions.

[0049] As the porosity of the particles, the pore volume is preferably 0.5 mlZg or more, more preferably 0.8 ml Zg or more, and more preferably 1.0 to 2.5 mlZg. preferable.

[0050] (Zeolite particles)

Zeolite is a crystalline aluminosilicate, and is a porous body having regular three-dimensional network voids having a pore diameter of 0.3 to Lnm.

[0051] Further, the hydrophilic layer matrix structure constituting the hydrophilic layer may contain layered mineral particles.

[0052] Examples of the layered mineral particles include clay minerals such as kaolinite, rhosite, talc, smectite (montmorillonite, noiderite, hectorite, sabonite, etc.), vermiculite, my power (mica), chlorite. And hydrated talcite, layered polysilicate (kanemite, macatite, eyelite, magadiite, Kenyaite, etc.). In particular, the higher the charge density of the unit layer (unit layer), the higher the polarity and the higher the hydrophilicity. The charge density is preferably 0.25 or more, more preferably 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), vermiculite (charge density 0.6 to 0.9; negative charge), and the like. . In particular, synthetic fluorine mica is preferable because it can be obtained with stable quality such as particle size. Further, among the synthetic fluorine mica, those which are free swellable are preferred, which are swellable.

[0053] Also, intercalation compounds (such as billard crystals) of the above layered minerals, those subjected to ion exchange treatment, surface treatment (silane coupling treatment, composite treatment with organic noinder) Etc.) can also be used. [0054] As for the size of the layered mineral particle, the average particle size (maximum particle length) is 1 μm in the state of being contained in the layer (including the case where it has undergone the swelling process and dispersion peeling process). It is preferably less than m and the average aspect ratio is 50 or more. When the particle size is in the above range, the continuity and flexibility in the planar direction, which are the characteristics of the lamellar particles, are imparted to the coating film, and cracks can be formed to make the coating film strong in the dry state. . Further, in a coating solution containing a large amount of particulate matter, sedimentation of the particulate matter can be suppressed by the thickening effect of the layered clay mineral. When the particle diameter is larger than the above range, non-uniformity may occur in the coating film, and the strength may be locally reduced. Further, when the aspect ratio is not more than the above range, the number of tabular grains with respect to the addition amount is reduced, the viscosity is insufficient, and the effect of suppressing the sedimentation of the particles is reduced.

[0055] The content of the layered mineral particles is preferably 0.1 to 30% by mass, more preferably 1 to 10% by mass, based on the entire layer. In particular, swellable synthetic fluoromica is preferred because smectite is effective even when added in small amounts. The layered mineral particles may be added to the coating solution as a powder! /, But in order to obtain a good degree of dispersion even with a simple preparation method (no need for a dispersion step such as media dispersion) It is preferable to prepare a gel in which layered mineral particles are swelled alone in water and then add it to the coating solution.

[0056] In the hydrophilic layer matrix constituting the hydrophilic layer, an aqueous silicate solution can also be used as another additive material. Alkali metal silicates such as Na, Ca and Li are preferred. The SiO / M O ratio is the pH of the whole coating solution when the silicate is added.

twenty two

In order to prevent the inorganic particles from dissolving, it is preferable to select such a value that does not exceed 13.

[0057] Further, an inorganic polymer or an organic-inorganic hybrid polymer by a so-called sol-gel method using a metal alkoxide can also be used. Regarding the formation of inorganic polymers or organic-inorganic hybrid polymers by the sol-gel method, for example, the force described in “Application of the sol-gel method” (published by Zakune Sakuo, Zagne Jofusha Co., Ltd.) or cited in this document. The known methods described in the literature can be used.

[0058] Further, the hydrophilic layer may contain water-soluble rosin!

[0059] Examples of the water-soluble rosin include polysaccharides, polyethylene oxide, and polypropylene oxide. Side, polybutyl alcohol, polyethylene glycol (PEG), polybutyl ether, styrene butadiene copolymer, methyl methacrylate-butadiene copolymer conjugated diene polymer latex, acrylic polymer latex, vinyl polymer latex Strengths including resins such as polyacrylamide and polyvinylpyrrolidone As the water-soluble rosin used in the present invention, it is preferable to use polysaccharides.

[0060] As polysaccharides, starches, celluloses, polyuronic acids, pullulans, and the like can be used. Cellulose derivatives such as methylcellulose salts, carboxymethylcellulose salts, hydroxyethylcellulose salts and the like are preferred. Sodium salt and ammonium salt are preferred. This is because the effect of forming the surface shape of the hydrophilic layer in a favorable state can be obtained by including the polysaccharide in the hydrophilic layer.

[0061] The surface of the hydrophilic layer preferably has a concavo-convex structure with a pitch of 0.1 to 20 m like the aluminum grain of the PS plate, and this concavo-convex improves water retention and image area retention. . Such a concavo-convex structure can be formed by containing an appropriate amount of a filler having an appropriate particle size in the hydrophilic layer matrix. The alkaline colloidal silica and the aqueous solution described above are added to the coating solution for the hydrophilic layer. It is preferable to form a phase separation when the hydrophilic polysaccharide is applied and dried to form a structure having better printability.

[0062] The shape of the concavo-convex structure (pitch, surface roughness, etc.) depends on the type and amount of alkaline colloidal silica, the type and amount of water-soluble polysaccharides, the type and amount of other additives, and the solid content of the coating liquid. It is possible to appropriately control the concentration, wet film thickness, drying conditions, and the like.

[0063] It is preferable that the water-soluble rosin added to the hydrophilic matrix structure is present in a state where at least a part thereof is water-soluble and can be eluted in water. 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, there is a concern that its hydrophilicity is lowered and printability is deteriorated. Further, examples of the cationic resin that may further contain a cationic resin include polyalkylene polyamines such as polyethyleneamine and polypropylene polyamine or derivatives thereof, tertiary amino groups and quaternary compounds. Examples thereof include acrylic resin having an ammonium group and diacrylamine. Cationic rosin May be added in the form of fine particles, for example, a cationic microgel described in JP-A-6-161101.

[0064] In order to provide hydrophilicity according to the present invention, it is a preferred embodiment to form a layer by coating and drying using a coating solution for the hydrophilic layer. As described above, in order to include the metal oxide particles according to the present invention in the coating liquid for the hydrophilic layer, before adding the metal oxide particles, the dispersion is performed by a known method. Or it is preferable to make it a paste.

[0065] That is, in the production method of the present invention, a method for producing a printing plate material developable on a printing press having a hydrophilic layer and an image forming functional layer on a substrate, wherein the hydrophilic layer is formed. And a hydrophilic layer coating solution containing metal oxide particles having a coercive force (HC) according to the present invention of 8 kAZm or less in a magnetic field of 400 kAZm.

[0066] Further, an embodiment in which this step is a step in which the metal oxide particles according to the present invention are dispersed and then added to the hydrophilic layer coating solution is a preferable embodiment.

[0067] The coating solution used for coating the hydrophilic layer can contain a water-soluble surfactant for the purpose of improving the coating property, and a surfactant such as S-type or F-type is added. Although it can be used, it is particularly preferable to use a surfactant containing Si element because there is no concern of causing printing stains. The content of the surfactant is preferably 0.01 to 3% by mass, more preferably 0.03 to 1% by mass, based on the entire hydrophilic layer (solid content as the coating solution).

[0068] The hydrophilic layer may contain a phosphate. In the present invention, since the hydrophilic layer coating solution is preferably alkaline, the phosphate is preferably added as trisodium phosphate or disodium hydrogen phosphate. By adding phosphate, the effect of improving the mesh opening during printing can be obtained. The addition amount of phosphate is preferably 0.1 to 5% by mass, more preferably 0.5 to 2% by mass, excluding hydrates.

[0069] (Photothermal conversion agent)

In the present invention, the hydrophilic layer contains the metal oxide particles according to the present invention as a photothermal conversion agent, but may contain a photothermal conversion agent other than the metal oxide particles.

[0070] In addition, a photothermal conversion agent may be included in the image forming functional layer, the hydrophilic overcoat layer and the other layers provided in the present invention.

[0071] Examples of such a photothermal conversion material include infrared absorbing dyes or pigments. [0072] (Infrared absorbing dye)

Common infrared absorbing dyes such as cyanine dyes, croconium dyes, polymethine dyes, azurenium dyes, squalium dyes, thiopyrylium dyes, naphthoquinone dyes, anthraquinone dyes and other organic compounds, phthalocyanine dyes, naphthalocyanine dyes , Azo, thiamide, dithiol, and indoor diphosphorus organometallic complexes. Specifically, JP-A-63-139191, JP-A-64-33547, JP-A-1-160683, JP-A-280750, JP-A-1-293342, JP-A-2-2074, JP-A-3-26593 3-30991, 3-34891, 3-36093, 3-36094, 3-36094, 3-42281, 3-97589, 3-103476, Examples thereof include compounds described in JP-A-7-43851, JP-A-7-102179, and JP-A-2001-117201. These can be used alone or in combination of two or more.

[0073] Examples of the pigment include carbon, graphite, metal, metal oxides other than the metal oxide particles, and the like.

[0074] As carbon, furnace black or acetylene black is particularly preferable. The particle size (d50) is preferably lOOnm or less, more preferably 50 nm or less.

[0075] The graphite has a particle size of 0.5 μm or less, preferably lOOnm or less, more preferably

Fine particles of 50 nm or less can be used.

[0076] As the metal, any metal can be used as long as it has a particle size of 0.5 µm or less, preferably lOOnm or less, more preferably 50nm or less. The shape may be any shape such as a sphere, a piece, or a needle. Colloidal metal fine particles (Ag, Au, etc.) are particularly preferred.

[0077] As the metal oxide, it is possible to use a material that exhibits a black color in a visible light castle !, a material that is electrically conductive, or that is a semiconductor.

[0078] (Image forming functional layer)

The printing plate material that can be developed on a printing press in the present invention is a printing plate material having an image forming functional layer that can be developed on a printing press.

[0079] The image forming layer that can be developed on a printing press is subjected to processing with a special chemical after image exposure. A layer that can be formed into a printable printing plate by removing dampening water or dampening water and printing ink to remove the non-image area and exposing the hydrophilic layer, which is a non-image area, on a lithographic printing press. It is.

[0080] The image forming functional layer of the present invention is preferably an image forming functional layer containing heat-fusible particles or heat-fusible particles.

[0081] (Hot-melting particles)

The heat-meltable particles that can be used in the image-forming functional layer according to the present invention are particles formed of a material generally classified as a wax having a low viscosity when melted, among thermoplastic materials. .

[0082] As physical properties, the surface strength of storability and ink deposition property is also preferably a soft point of 40 ° C to 120 ° C and a melting point of 60 ° C to 150 ° C. More preferably, the temperature is 40 ° C or higher and 100 ° C or lower, and the melting point is 60 ° C or higher and 120 ° C or lower.

[0083] Examples of materials that can be used include paraffin, polyolefin, polyethylene wax, microcrystalline wax, and fatty acid wax. These have a molecular weight of about 800 to 10,000, and in order to facilitate emulsification, these waxes are acidified to introduce polar groups such as hydroxyl groups, ester groups, carboxyl groups, aldehyde groups, and peroxide groups. You can also. Furthermore, in order to lower the soft spot or improve the workability, these waxes include, for example, stearamide, linolenamide, laurylamide, myristamide, hardened beef fatty acid amide, palmitoamide, oleic acid amide, rice It is also possible to add sugar fatty acid amide, coconut fatty acid amide, methylolated products of these fatty acid amides, methylene bissteraroamide, ethylene bissteraroamide, and the like. Coumarone-indene resin, rosin-modified phenol resin, terpene-modified phenol resin, xylene resin, ketone resin, acrylic resin, ionomer, and copolymers of these resins can also be used.

Among these, it is preferable to contain any one of polyethylene, microcrystalline, fatty acid ester, and fatty acid. Since these materials have a relatively low melting point and a low melt viscosity, high-sensitivity image formation can be performed. Further, since these materials 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. [0085] These heat-meltable particles are preferably dispersible in water, and the average particle size is preferably 0.01 to 10 111 from the viewpoint of on-machine developability. Is 0.05-3 / ζ πι.

[0086] In order to disperse these heat-meltable particles in water, it is preferable to use a nonionic surfactant, a ionic surfactant, a cationic surfactant or a polymer surfactant. . By using these compounds, an aqueous dispersion of hot-melt fine particles can be stabilized, and a uniform coated product can be obtained without failure.

[0087] In addition, the composition of the heat-meltable particles may vary continuously between the inside and the surface layer, or may be coated with a different material. As a coating method, a known microcapsule formation method, a sol-gel method, or the like can be used.

[0088] The content of the heat-meltable particles in the constituent layers is preferably 1 to 90% by mass, more preferably 5 to 80% by mass of the entire layer.

[0089] (Heat bonding particles)

Examples of the heat-fusible particles include thermoplastic hydrophobic polymer particles, and there is no specific upper limit to the softening temperature of the thermoplastic hydrophobic polymer particles. It is preferably lower than the decomposition temperature of the polymer fine particles. The weight average molecular weight (Mw) of the polymer is preferably in the range of 10,000 to 1,000,000! /.

[0090] Specific examples of the polymer constituting the thermoplastic hydrophobic polymer particles include, for example, gen (co) polymers such as polypropylene, polybutadiene, polyisoprene and ethylene butadiene copolymer, styrene. Synthetic rubbers such as butadiene copolymer, methyl methacrylate butadiene copolymer, acrylonitrile butadiene copolymer, polymethyl methacrylate, methyl methacrylate (2-ethylhexyl acrylate) copolymer, methyl methacrylate Methacrylic acid copolymer, methyl acrylate (N-methyl acrylamide) copolymer, (meth) acrylic acid ester such as polyacrylonitrile, (meth) acrylic acid (co) polymer, polyvinyl acetate, vinyl acetate Vinyl pionate copolymer, vinyl acetate-ethylene copolymer, etc. Vinyl ester (co) polymer, vinyl acetate- (2-ethylhexyl acrylate) copolymer, polychlorinated butyl, polysalt-vinylidene, polystyrene and the like and their copolymers. Of these, (meth) acrylic acid ester Tellurium, (meth) acrylic acid (co) polymers, vinyl ester (co) polymers, polystyrene, and synthetic rubbers are preferably used.

[0091] The thermoplastic hydrophobic polymer particles may be a polymer polymer polymerized by any known method such as emulsion polymerization, suspension polymerization, solution polymerization, and gas phase polymerization. ,. The polymer polymerized by the solution polymerization method or the gas phase polymerization method is made into fine particles by spraying a solution in an organic solvent of the polymer polymer into an inert gas and drying it. And a method in which a polymer is dissolved in an organic solvent immiscible in water, this solution is dispersed in water or an aqueous medium, and the organic solvent is distilled off to form fine particles.

[0092] Further, the heat-meltable particles and the heat-fusible particles can be used as a dispersant or a stabilizer, for example, sodium lauryl sulfate, dough, etc. A surfactant such as sodium decylbenzenesulfonate and polyethylene glycol, and a water-soluble resin such as polybutyl alcohol may be used. Also, tryletylamine, triethanolamine and so on.

[0093] The heat-fusible particles are preferably dispersible in water, and the average particle size is preferably 0.01 to 10 m from the viewpoint of on-image development and resolution. More preferably, it is 0.1-3 μm.

[0094] The composition of the heat-fusible particles may be continuously changed between the inside and the surface layer, or may be coated with a different material. As a coating method, a known microcapsule formation method, a sol-gel method, or the like can be used.

[0095] The content of the heat-fusible particles in the constituent layer is more preferably 5 to 80% by mass, preferably 1 to 90% by mass of the entire layer.

[0096] (Water-soluble binder)

The image-forming functional layer may contain a water-soluble binder. Examples of water-soluble binders include polysaccharides, polyethylene oxide, polypropylene oxide, polybutyl alcohol, polyethylene glycol (PEG), polybutyl ether, and styrene butadiene. Examples thereof include copolymers, conjugation polymer latex of methyl methacrylate-butadiene copolymer, acrylic polymer latex, vinyl polymer latex, polyacrylamide, polytalic acid or salts thereof, and resins such as polybulurpyrrolidone. . [0097] Among them, it is preferable to use polyacrylic acid or a salt or polysaccharide thereof that does not deteriorate the printing performance!

[0098] Further, the above-described photothermal conversion material can be contained. The dry coating mass of the image-forming functional layer is preferably 0.1 to 1.5 g / m ² , more preferably 0.1-1-1. Og / m ² .

[0099] (Substrate)

As the substrate according to the present invention, a known substrate used for a conventional printing plate material can be used.

[0100] The thickness of the substrate is not particularly limited as long as it can be attached to a printing press! /

1S Usually 50 to 500 μm is handled! /, Easy! /.

[0101] Examples of the substrate include a metal plate, a plastic film, paper treated with polyolefin, a composite support obtained by appropriately bonding the above materials, and the like in the present invention. Alternatively, an aluminum alloy (hereinafter referred to as aluminum) metal plate is preferably used.

[0102] Plastic films include polyethylene terephthalate and polyethylene naphthalate

And films of polyimide, polyamide, polycarbonate, polysulfone, polyphenylene oxide, cellulose ester and the like.

[0103] In the present invention, among these plastic films, polyester films such as polyethylene terephthalate (hereinafter sometimes abbreviated as PET) and polyethylene naphthalate (hereinafter sometimes abbreviated as PEN) are used as base materials. Are preferably used.

[0104] Further, it is preferable to use a support obtained by the method described in JP-A-10-10676 and having a thermal dimensional change at 120 ° C for 30 seconds of from 0.001% to 0.04%.

[0105] A preferred polyester film is an unstretched polyester film, a uniaxially stretched polyester film, or a biaxially stretched polyester film.

Of these, a longitudinally stretched polyester film that is uniaxially stretched in the film extrusion direction (longitudinal direction) is particularly preferred.

[0107] PET is polymerized with terephthalic acid and ethylene glycol, and PEN polymerized with naphthalene dicarboxylic acid and ethylene glycol as constituent components.

[0108] Dicarboxylic acid or diol constituting PET or PEN is used as another appropriate one, or May be a mixture of two or more third components and polymerized. A suitable third component is a compound having a divalent ester-forming functional group. Examples of the dicarboxylic acid include the following.

[0109] Terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, diphenylsulfone dicarboxylic acid, diphenyl ether dicarboxylic acid, diphenylethanedicarboxylic acid And cyclohexanedicarboxylic acid, diphenyldicarboxylic acid, diphenylthioether dicarboxylic acid, diphenylketone dicarboxylic acid, phenylindanedicarboxylic acid, and the like.

[0110] Examples of glycols include propylene glycol, tetramethylene glycol, cyclohexane dimethanol, 2,2-bis (4-hydroxyphenol) propane, 2,2-bis (4-hydroxyethoxy). (Phenol) propane, bis (4-hydroxyphenol) snorephone, bisphenol full orange hydroxyethyl ether, diethylene glycol, neopentyl alcohol, hydroquinone, cyclohexanediol and the like.

[0111] As the third component, a polyfunctional carboxylic acid or a polyhydric alcohol can also be mixed, but these can be mixed in an amount of about 0.005 to 5% by mass with respect to all the polyester components.

[0112] The intrinsic viscosity of the polyester film is preferably 0.5 to 0.8. In addition, different intrinsic viscosities may be mixed and used.

[0113] The method for polymerizing the polyester film is not particularly limited, and can be produced according to a conventionally known method for polymerizing a polyester.

[0114] For example, polymerization is carried out by directly reacting a dicarboxylic acid component with a diol component, diesterifying one hydroxyl group of the diol to a dicarboxylic acid, and heating one of the diols under reduced pressure to distill off the excess diol. In addition, a dialkyl ester (for example, dimethyl ester) is used as a dicarboxylic acid component, and the diol component is subjected to an ester exchange reaction to distill alkyl alcohol (for example, methanol) to distill the diol. It is possible to use a transesterification method in which one hydroxyl group is esterified to a dicarboxylic acid, and the excess diol component is polymerized by heating and distilling off under reduced pressure. [0115] As the catalyst, a transesterification catalyst, a polymerization reaction catalyst, and a heat-resistant stabilizer that are used for the synthesis of ordinary polyesters can be used. For example, transesterification catalysts include Ca (OAc) ·) O, Zn (OAc) · 2Η Ο, Mn (OAc) · 4Η Ο, Mg (OAc) · 4Η Ο, etc.

2 2 2 2 2 2 2 2 and Sb 2 O and GeO can be mentioned as polymerization reaction catalysts. Also resistant

2 3 2

Thermal stabilizers include phosphoric acid, phosphorous acid, PO (OH) (CH), PO (OC H), P (OC H)

3 3 6 5 3 6 5 3 etc. In addition, anti-coloring agents, crystal nucleating agents, slipping agents, stabilizers, anti-blocking agents, UV absorbers, viscosity modifiers, clearing agents, antistatic agents, pH adjusters, dyes, pigments, etc. May be added.

[0116] In order to stabilize the dimensions during printing and prevent color misregistration during color printing, it is preferable to heat-treat the polyester film after stretching and heat setting.

[0117] The heat treatment is accomplished by the following means after cooling and winding after heat setting and then unwinding in a separate step.

[0118] As a heat treatment method, a transport method in which both ends of a film such as a tenter are gripped by pins or clips, a roll transport method using a plurality of roll groups, a method of transporting air by blowing air onto the film, and the like (Method of spraying heated air from one or both sides of a film surface from a plurality of slits), a method of using radiant heat by an infrared heater, a method of heat-treating a method of contacting with a plurality of heated rolls singly or in combination, In addition, it is preferable to hang the film by its own weight and use a method such as winding or the like below alone or in combination.

[0119] The tension of the heat treatment can be adjusted by adjusting the torque of the take-up roll and Z or the delivery roll, and / or by installing a dancer roll in the process and adjusting the load applied to it.

[0120] When changing the tension during heat treatment and during cooling after Z or after heat treatment, set a desired tension state by installing dancer rolls before and after these processes and in Z or in the process and adjusting their load. May be. In addition, it is possible to effectively change the conveyance tension by vibration by reducing the span between the heat treatment rolls.

[0121] In order to reduce the dimensional change during the subsequent heat treatment (heat development) without hindering the progress of the heat shrinkage, it is desirable to lower the transport tension as much as possible and lengthen the heat treatment time. [0122] The processing temperature is preferably in the temperature range of ₈ + 50 ° 〇 to ₈ + 150 ° 〇 of polyester film, and 5 Pa to lMPa is more preferable as the transport tension. Is 5 Pa to 500 kPa, more preferably 5 Pa to 200 kPa, and the treatment time is preferably 30 seconds to 30 minutes, more preferably 30 seconds to 15 minutes. By using the above temperature range, conveyance tension range, and treatment time, fine scratches due to friction with the conveyance roll, etc., which do not deteriorate the flatness of the support due to partial differences in the thermal contraction of the support during heat treatment, are possible. Occurrence etc. can be avoided.

[0123] It is preferable to perform the heat treatment at least once in order to obtain a desired rate of dimensional change. It is also possible to perform the heat treatment twice or more as necessary.

[0124] The heat-treated polyester film is cooled from a temperature near Tg to room temperature and wound up by force, and in order to prevent deterioration of flatness due to cooling at this time, at least 5 ° between Tg and lowering to room temperature It is preferable to have a process of cooling at a speed of CZ seconds or more.

[0125] In the case of a polyester film substrate, in order to carry it well in an exposure apparatus or the like

The water content of the substrate is preferably 0.5% by mass or less. The moisture content of the substrate is D ′ represented by the following formula.

[0126] D '(mass ⁰ / o) = (w' W) X 100

Where W is the mass of the support in a humidity-controlled equilibrium under an atmosphere of 25 ° C and 60% relative humidity, and w 'is the mass of the support in a humidity-controlled equilibrium under an atmosphere of 25 ° C and 60% relative humidity. Represents moisture content.

[0127] The moisture content of the base material is preferably 0.5% by mass or less, more preferably 0.01 to 0.5% by mass, particularly preferably 0.01 to 0.3% by mass. %.

[0128] Means for controlling the moisture content of the base material to 0.5% by mass or less are as follows: (1) The support is heat-treated at 100 ° C or higher immediately before the coating liquid for the hydrophilic layer and other layers is applied. (2) Control the relative humidity in the process of applying the coating solution for the hydrophilic layer and other layers. (3) Before applying the coating solution for the hydrophilic layer and other layers, place the support at 100 ° C. For example, heat treatment, cover with a moisture-proof sheet, store, and apply immediately after opening. Two or more of these may be combined.

[0129] (Fine particles) In order to improve the handling property in polyester base, it is preferable to add 0.01 ~ 101111 particles to 1 ~ 1 OOOppm! /.

[0130] The particles may be organic or inorganic, which may be misaligned! /.

[0131] For example, as the inorganic substance, silica described in Swiss Patent No. 330, 158, etc., glass powder described in French Patent No. 1,296, 995, etc., British Patent No. 1, 173, No. 181 Alkaline earth metals or carbonates such as cadmium and zinc described in the specification and the like can be used. Organic substances include starch described in U.S. Pat.No. 2,322,037, etc., starch derivatives described in Belgian Patent 625,451 and British Patent 981,198, etc. Polyvinyl alcohol described in Japanese Patent Publication No. 44-3643 etc., polystyrene or polymetatalylate described in Swiss Patent No. 330,158, etc., described in US Pat. No. 3,079,257, etc. Organic fine particles such as polyacrylonitrile, polycarbonates described in US Pat. No. 3,022,169 and the like can be used. The shape of the particles may be either regular or irregular.

[0132] (Applying undercoat layer to substrate)

In the polyester film substrate, easy adhesion treatment or undercoat layer coating can be performed to give various functions.

[0133] Examples of the easy adhesion treatment include corona discharge treatment, flame treatment, plasma treatment, and ultraviolet irradiation treatment.

[0134] As the undercoat layer, a layer containing gelatin or latex or the like is preferably provided on the polyester film support. Among them, the antistatic undercoat layer described in paragraph Nos. 0044 to 0116 of JP-A-7-191433 is preferably used. In addition, the conductive polymer-containing layer described in paragraph Nos. 0031 to 0073 of JP-A-7-20596 is a conductive layer such as the metal oxide-containing layer described in paragraph Nos. 0074 to 0081 of JP-A-7-20596. It is preferred to have it! / ヽ. The conductive layer may be coated on the side of slippage as long as it is on the polyester film support, but is preferably coated on the opposite side of the image forming functional layer with respect to the support. When this conductive layer is provided, the chargeability is improved, the adhesion of dust and the like is reduced, and the whiteout failure during printing is greatly reduced.

[0135] The aluminum metal plate is not roughened or anodized to form a hydrophilic surface. It is preferable to use it after applying it.

[0136] The aluminum metal plate is preferably subjected to a degreasing treatment in order to remove the rolling oil on the aluminum surface prior to the roughening treatment. As the degreasing treatment, a degreasing treatment using a solvent such as trichlene or thinner, an emulsion degreasing treatment using an emulsion such as kesilon or triethanol, or the like is used. In addition, an alkaline aqueous solution such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium phosphate or the like can be used for the degreasing treatment. When an alkaline aqueous solution is used for the degreasing treatment, it cannot be removed only by the above degreasing treatment! Dirt and acid film can also be removed.

[0137] The roughening of the substrate can be performed by chemical roughening, mechanical roughening, or a roughening treatment appropriately combining these.

[0138] Following the roughening treatment, an anodizing treatment is preferably performed.

[0139] A known method without particular limitation can be used for the method of anodizing treatment.

[0140] The anodized base material may be subjected to a sealing treatment as necessary. These sealing treatments can be performed using known methods such as hot water treatment, boiling water treatment, water vapor treatment, dichromate aqueous solution treatment, nitrite treatment, and acetic acid ammonium treatment.

[0141] Further, the anodized base material can be appropriately subjected to a surface treatment other than the sealing treatment. Examples of the surface treatment include known treatments such as silicate treatment, phosphate treatment, various organic acid treatments, PVP A treatment, and boehmite toe treatment. Further, the treatment with an aqueous solution containing a bicarbonate described in JP-A-8-314157 or the treatment with an aqueous solution containing a bicarbonate may be followed by an organic acid treatment such as citrate.

[0142] In order to improve the adhesion to the coating layer, it is preferable to perform easy adhesion treatment or undercoat layer coating on the coated surface. For example, a method of performing sufficient drying after dipping in a liquid containing a coupling agent such as a silane coupling agent or applying a liquid.

[0143] <Lithographic printing method>

(Image exposure)

The printing plate material of the present invention forms an image by irradiating an active ray from the surface having the image forming functional layer according to image data.

[0144] As the image exposure according to the present invention, more specifically, in the infrared and Z or near infrared region. Scanning exposure using a laser that emits light, that is, emits light in the wavelength range of 700 to 1500 nm is preferably used.

A gas laser may be used as the laser, but it is particularly preferable to perform scanning exposure using a semiconductor laser that emits light in the near infrared region.

[0146] As an apparatus suitable for scanning exposure that can be used in the present invention, any system can be used as long as it can form an image on the surface of a printing plate material in accordance with an image signal using a semiconductor laser. Even the device! /.

[0147] In general, (1) A method of exposing the entire surface of the printing plate material by performing two-dimensional scanning on the printing plate material held by the flat plate holding mechanism using one or more laser beams.

(2) The printing plate material held along the cylindrical surface inside the fixed cylindrical holding mechanism is used in the circumferential direction of the cylinder (mainly using one or more laser beams from the inside of the cylinder). (Scanning direction) while moving in the direction perpendicular to the circumferential direction (sub-scanning direction) while scanning in the scanning direction) (3) Cylindrical drum surface rotating around the axis as a rotating body In the direction perpendicular to the circumferential direction (sub-scanning direction), the printing plate material held on the plate is scanned in the circumferential direction (main scanning direction) by rotating the drum using one or more laser beams from the outside of the cylinder. And exposing the entire surface of the printing plate material.

With regard to the present invention, the scanning exposure method (3) is particularly preferred, and the exposure method (3) is used particularly for an apparatus that performs exposure on a printing apparatus.

[0149] The printing plate material on which an image has been formed in this way can be printed without being subjected to development processing. The printing plate material after image formation is directly attached to the plate cylinder of the printing press, or image formation is performed after the printing plate material is attached to the plate cylinder of the printing press, and the water supply roller and Z or The non-image portion of the image forming layer can be removed by bringing the ink supply roller into contact with the printing plate material.

[0150] The non-image part removing step of the image forming functional layer according to the present invention can be performed by a normal printing sequence using a PS plate, and is a step performed by so-called on-press development processing. U is preferred.

[0151] (Ink)

The ink that can be used in the lithographic printing method of the present invention can be used for lithographic printing. However, specific examples include rosin-modified phenolic resins and vegetable oils (such as flax oil, tung oil, soybean oil), petroleum-based solvents, pigments, and oxidation polymerization catalysts (cobalt, manganese). , Lead, iron, zinc, etc.), UV-curable UV inks composed of components such as acrylic oligomers, acrylic monomers, photopolymerization initiators and pigments, and the properties of oil-based inks. Hybrid inks that combine the properties of UV inks.

[0152] (Printing machine)

In the lithographic printing method of the present invention, a known lithographic printing machine having a plate cylinder on which a printing plate material is mounted, a member for supplying dampening water on the printing plate surface, and a member for supplying ink can be used.

Example

[0153] Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited thereto. In the examples, “parts” represents “parts by mass” unless otherwise specified.

[0154] (Preparation of substrate 1)

(PET resin)

To 100 parts by mass of dimethyl terephthalate and 65 parts by mass of ethylene glycol, 0.05 part by mass of magnesium acetate hydrate was added as a transesterification catalyst, and transesterification was performed according to a conventional method. To the obtained product, 0.05 part by mass of antimony trioxide and 0.03 part by mass of trimethyl ester phosphate were added.

[0155] Next, the temperature was gradually raised and the pressure was reduced, and polymerization was carried out at 280 ° C and 66 Pa to obtain polyethylene terephthalate (PET) resin having an intrinsic viscosity of 0.70.

[0156] Using the PET resin obtained as described above, a biaxially stretched PET film was prepared as follows.

[0157] (Biaxially oriented PET film)

A PET resin-coated pellet is vacuum-dried at 150 ° C for 8 hours, then melt-extruded in layers from a T die at 285 ° C, and brought into close contact with electrostatic printing on a 30 ° C cooling drum and cooled. The film was solidified to obtain an unstretched film.

[0158] This unstretched sheet was stretched 3.3 times in the longitudinal direction at 80 ° C using a roll-type longitudinal stretching machine. [0159] Following the obtained uniaxially stretched film, using a tenter-type transverse stretching machine, the first stretching zone was stretched by 50% of the total transverse stretching ratio at 90 ° C, and further at the second stretching zone at 100 ° C. Total transverse stretching Ratio 3. Stretched to 3 times.

[0160] Next, pre-heat treatment was performed at 70 ° C for 2 seconds, and heat setting was further performed at the first fixing zone at 150 ° C for 5 seconds, and then heat setting was performed at the second fixing zone at 220 ° C for 15 seconds. Next, relax 5% in the lateral (width) direction at 160 ° C, exit the tenter, cool to room temperature over 60 seconds, release the film from the clip, slit, wind up each, A biaxially stretched PET film was obtained. The biaxially stretched PET film had a Tg of 79 ° C. The obtained substrate had a thickness distribution of 2%.

[0161] Corona discharge treatment of 8WZm ² 'on the surface of the biaxially oriented PET film on the image forming functional layer

The undercoating liquid a-1 was applied so that the dry film thickness was 0.8 / zm, and dried at 123 ° C. to provide the undercoating layer A-1 on the hydrophilic side.

[0162] After that, the upper surface of the undercoat layer A-1 was subjected to a corona discharge treatment of 8 WZm ² ', and the undercoat coating solution a-2 was applied to the undercoat layer A-1 with a dry film thickness of 0. .: Applied to L m, dried at 123 ° C, provided with subbing layer A-2, and further heat-treated at 140 ° C for 2 minutes to obtain substrate 1 with a single-sided subbing layer formed .

[0163] (Undercoat liquid a-1)

Styrene Z Glycidyl metatalylate Z butyl acrylate = 60Z39Zl (molar ratio) terpolymer latex (Tg = 75 ° C) Solid content 30% by mass 250g

Styrene Z Glycidyl metatalylate Z butyl attalylate = 20Z40Z40 (molar ratio) terpolymer latex (Tg = 20 ° C) Solid content 30% by mass 25g

Car-on surfactant S-1 (2% by mass) 30 g Water was used to make 1 kg.

[0164] (Undercoat liquid a-2)

Modified aqueous polyester L 4 solution (23% by mass) 31 g Kuraray exeval (copolymer of polybulal alcohol and ethylene) RS-2117 5% aqueous solution 58g

Anionic surfactant S-1 (2% by mass) 6g

Hardener H-1 (0.5 mass%) 100g

Spherical silica matting agent (Nippon Shokubai Co., Ltd. Sea Hoster KE-P50) 2% by mass dispersion

10g

Distilled water was added to make 1000 ml.

[0165] [Chemical 1]

S

[0166] (Preparation of aqueous polyester (L 4) solution)

Dimethyl terephthalate 35.4 parts by mass, dimethyl isophthalate 33.63 parts by mass, 5-sulfoisophthalic acid dimethyl sodium salt 17.92 parts by mass, ethylene glycol 62 parts by mass, calcium acetate monohydrate 0.065 parts by mass, Manganese acetate tetrahydrate was subjected to a transesterification reaction while distilling off methanol at 170 to 220 ° C under a nitrogen stream, and then 0.04 parts by mass of trimethyl phosphate as a polycondensation catalyst. Add 0.04 parts by mass of antimony trioxide and 6.8 parts by mass of 1,4-cyclohexanedicarboxylic acid, and distill off the theoretical amount of water at a reaction temperature of 220 to 235 ° C. went.

[0167] Thereafter, the inside of the reaction system was further depressurized and heated for about 1 hour, and finally polycondensation was carried out at 280 ° C and 133 Pa or lower for about 1 hour to produce an aqueous polyester.

[0168] The obtained aqueous polyester had an intrinsic viscosity of 0.33 (100 mlZg).

[0169] The weight average molecular weight was 80,000 to 100,000.

[0170] Next, 850 ml of pure water was placed in a 2 L three-necked flask equipped with a stirring blade, a reflux condenser, and a thermometer, and 150 g of aqueous polyester was gradually added while rotating the stirring blade. [0171] After stirring for 30 minutes at room temperature, the mixture was heated to an internal temperature of 98 ° C over 1.5 hours and dissolved at this temperature for 3 hours. After completion of the heating, the mixture was cooled to room temperature over 1 hour and left overnight to prepare a 15% by mass aqueous polyester solution A1.

[0172] <Preparation of modified aqueous polyester solution>

Place 1900 ml of the 15% by weight aqueous polyester A1 solution in a 3 L four-necked flask equipped with a stirring blade, reflux condenser, thermometer, and dropping funnel, and keep the internal temperature at 80 ° C while rotating the stirring blade. Until heated.

[0173] In this, 6.52 ml of a 24% aqueous solution of ammonium peroxide was added, and the monomer mixture (glycidyl methacrylate 28.5 g, ethyl acrylate 21.4 g, methyl methacrylate 21.4 g ) Is added dropwise over 30 minutes and the reaction is continued for another 3 hours.

[0174] Thereafter, the mixture was cooled to 30 ° C or lower and filtered to prepare a modified aqueous polyester B1 solution (vinyl component modification ratio 20 mass%) having a solid content concentration of 18 mass%. A modified water-based polyester L-4 was prepared with a vinyl-based component modification ratio of 5% by mass.

[0175] (Substrate 2 (Aluminum substrate))

Aluminum plate having a thickness of 0.24 mm: AA1050 was degreased using an aqueous sodium hydroxide solution. The amount of aluminum dissolved was ² gZm2. After thoroughly washing with pure water, it was immersed in a 1 mass% disodium hydrogenphosphate aqueous solution at 70 ° C for 30 seconds. Next, after thoroughly washing with pure water, the substrate 2 was obtained by drying.

[Preparation of coating solution for back coating layer]

Colloidal silica: Snowtex - XS (Nissan Chemical Industries, Ltd., solid content 20 mass ^_0/0)

33. 60 咅

Acrylic Emma Roussillon: DK- 05 (Gifu Shellac Co., Ltd., solid content of 48 mass ^_0/0)

14.00 咅

Matting agent (PMMA average particle size 5.5 μm) 0.56 parts

Pure water 51. 84

Solid content concentration 14% by mass

These compositions were sufficiently stirred and mixed using a homogenizer and then filtered to prepare a backcoating layer coating solution. [0177] (Application of back coating layer)

Apply the coating solution for the knock coating layer on the surface opposite to the undercoat layer A-1 of the base material 1 above, and apply a corona discharge treatment of 8 W / m ² Zmin to the undercoated sample using wire bar # 6. However, the drying zone set at 100 ° C with a length of 15m was passed at a speed of 15mZ.

[0178] amount with the back coating layer was 2. OgZm ^2.

[0179] (Lower hydrophilic layer)

The composition shown in Table 1 was sufficiently stirred and mixed using a homogenizer, and then filtered to prepare a lower hydrophilic layer coating solution.

[0180] [Table 1]

[0181] (Upper hydrophilic layer)

The composition shown in Table 2 was sufficiently stirred and mixed using a homogenizer, and then filtered to prepare an upper hydrophilic layer coating solution.

[0182] [Table 2] Material

Colloidal silica (alkaline): Snowtex I S

15 copies

(Nissan Chemical Co., Ltd., solid content 30% by mass)

Colloidal silica (alkaline): SNOTEX 1 PSM

22 .9 parts

(Nissan Chemical Co., Ltd., solid content 20% by mass)

Silica sol: MP-4540M (average particle size 0.45 μιη, manufactured by Nissan Chemical Co., Ltd.,

5 parts

(Solid content 30% by mass)

Porous particle Shilton AMT08L (manufactured by Mizusawa Chemical Co., Ltd.

20 copies

Porous aluminosilicate particles, average particle size 0.8 »

Porous particles Shilton JC 1 20 (Mizuwazawa Chemical Co., Ltd.

5 parts

(Porous aluminosilicate particles, average particle size 2 m)

Metal oxide dispersion (shown in Table 3) 30 parts

Water-soluble resin: R— ¹ 130 (with silanol groups in the side chain)

1 copy

Polyvinyl alcohol resin Kuraray Kuraray R polymer)

Infrared dye 1 1 part

Silicone surfactant: FZ2161 (manufactured by Nippon Tunica) 0.1 part

[0183] [Chemical 2] Infrared dye 1

[0184] The metal oxide dispersion used for the lower hydrophilic layer and the upper hydrophilic layer was placed in a sand grinder with the following dispersion composition together with steel beads with a diameter of 1.5 mm, and the number of revolutions was 1500 rpm and 2. Dispersed for 5 hours. After dispersion, the final volume was 200 g with pure water.

[0185] (Dispersion composition)

Metal oxide particles 59.6 g

Na PO (10% aqueous solution) 4g

3 4

116.4g of pure water

Table 3 shows the metal oxide particles used. The coercive force (HC) was obtained by allowing metal oxide particles to stand in a magnetic field of 400 kAZm for 1 hour at 20 ° C using a vibrating sample magnetometer VSM-P7-15 type manufactured by Toei Industry Co., Ltd. Post HC was measured.

[Table 3] No. Metal oxide particles Coercive force (kA / m)

os— 1 BL ²⁰⁰ (made by Titanium Industry Co., Ltd., average particle size 0.2 ID FesO 11.0

OS-2 SMT_02 (Sehan Media, average particle size 0.2 im FesO-i) 9,6

OS— 3 BL100 (Titanium Industry Co., Ltd., average particle size 0.27jtim FesO.) 6.0

Ti02 (rutile titanium oxide) with an average particle size of 0.22jum

OS— 4 0.8

Metal oxide mainly composed of Fe _? T i phase

[0187] (OS-4 production method)

The hydrous acid-titanium slurry with a specific surface area of 260 m ² / g obtained by the sulfuric acid method is prepared to 150 gZ liter as acid-titanium, and ρΗ is neutralized to 9 using 400 gZ liter of caustic soda.

[0188] After stirring for 2 hours, the pH was adjusted to 6 with 200 gZ liters of hydrochloric acid, followed by filtration and washing.

After re-pulping the washed hydrous acid-titanium to prepare lOOg / liter as acid-titanium, the slurry was prepared using a salty-ferric iron solution of lOOg / liter as FeO.

twenty three

After adding 1 part by mass with respect to parts by mass, 200 gZ liters of caustic soda solution was added dropwise to adjust the pH of the slurry to 7, and the surface of the hydrous titanium oxide titanium was coated with hydroxy iron salt.

[0189] After stirring for 1 hour, filtration and washing were performed, followed by drying at 110 ° C. The dried product is put in a magnetic crucible and baked at 900 ° C for 1 hour in an electric furnace to synthesize titanium oxide with Fe TiO phase.

twenty five

did. After cooling, the obtained titanium oxide with Fe TiO phase is mixed with hydrogen gas and carbon dioxide gas

twenty five

Reduction was performed with gas at 500 ° C. for 5 hours to obtain a black powder.

[0190] Preparation of image forming functional layer coating solution

Table 4 shows the details of the material for the image forming functional layer coating solution. After sufficiently stirring and mixing, the solution was filtered and coated on the upper hydrophilic layer prepared above.

[0191] [Table 4] Material

H I— D! SPER A1 18 (Gifu Shellac, Carnauba wax

Average particle size 0.25 μ πκ Softening point 65, melting point 80 ° C; melt viscosity 8 tps at t40 ° C, 51 parts solid content 40% by weight)

Mike □ Crystalline wax emulsion A ² 06 (Gifu Shellac,

Dispersion in which 20 parts by weight of pure water was added to 5% by weight of the solid content of an average particle size of 0.6 ^ and solid content of 40% by weight.

H I-D I SPE A— 514 (Gifu Shellac Manufacturing Co., Ltd.

Dispersion liquid obtained by diluting 15 parts of hot melt particles with an average particle diameter of 0.6 _m ) to a solid content of 5% by mass with pure water

Stearic acid amide 0.1 part Isopropanol 0.1 part

2, 4, 7, 9-Tetramethyl-5-decyne-4

7_George Polypolyoxyethylene ether 1 O.f part

(Product name: Surfynol ⁴ 65 Air Products Japan Co., Ltd.)

Hydrodiether-modified starch (trade name: Benon) E66 Nissho Kagaku Co., Ltd. 2 parts Infrared dye 2 2 parts Sodium polyacrylate aqueous solution (trade name: Aqualic DL522,

9.7 parts Nippon Shokubai Co., Ltd., average molecule S 170,000 solids 30.5%: water-soluble resin)

[0192] [Chemical 3] Infrared dye 2

HNEt ₃

[0193] (Coating of lower and upper hydrophilic layers)

Use the wire bar on the undercoating surface of the base material 1 for each lower hydrophilic layer coating solution.

Then, it was applied to a dry mass of 2.8 gZm ² , and a dry zone set at 100 ° C with a length of 15 m was passed at a transport speed of 15 mZ.

[0194] Bow I Continue coating the upper hydrophilic layer coating solution using a wire bar to a dry weight of 1.80gZm ² and transport it to a drying zone set at 100 ° C with a length of 30m. speed

It was passed at a speed of 15mZ.

[0195] On the other hand, for substrate 2 (aluminum substrate), only the coating solution for the upper hydrophilic layer was applied using a wire bar to a dry weight of 1.80 gZm ² and applied to 100 ° C with a length of 30 m. Set The dried drying zone was passed at a transfer speed of 15 mZ. The sample after application was aged at 60 ° C for 2 days.

[0196] (Application of image forming layer)

The image forming layer coating solution having the composition shown in Table 3 below was applied onto the upper hydrophilic layer prepared above using a wire bar so that the dry mass was 0.55 g / m ^2. A thermal image forming layer was formed by passing through a drying zone set at ° C at a conveyance speed of 15 mZ. The coated sample was aged for 2 days at 50 ° C, and a lithographic printing plate material was obtained.

[0197] The lithographic printing plate material was cut to a width of 660 mm, and the one using the substrate 1 (PET substrate) was wound on a paper core having an outer diameter of 76 mm for 30 m to obtain a rolled lithographic printing plate material. On the other hand, a material using base material 2 (aluminum base material) was cut to a width of 660 mm to obtain a sheet-like planographic printing plate material.

[0198] In the hydrophilic layer, the metal oxide particles, silica particles, added resin or image forming layer material were changed as shown in Table 5, and in the same manner as in the preparation of the lithographic printing plate material, a roll shape was obtained. Alternatively, a sheet-like lithographic printing plate material was prepared.

[0199] <Evaluation>

Exposure method

The printing plate sample was cut in accordance with the exposure size and then fixed to the exposure drum by brazing. For exposure, a laser beam with a wavelength of 830 nm and a spot diameter of about 18 μm is used. The exposure energy is 240 mj / cm ² and 2,400 dpi (dpi is the number of dots per 2.54 cm), 175 lines. Then, an image was formed and an image-formed printing plate sample was prepared.

[0200] Printing method

Printer: DAIYA1-F manufactured by Mitsubishi Heavy Industries, Ltd., fountain solution is fast mouth mark 3 (Niken Igaku Laboratories Co., Ltd.) 2% by weight aqueous solution, ink is Space Color Fusion G ST Crimson Printing evaluation was performed using N (Dainippon Ink & Chemicals, Inc.). Other than printing durability evaluation, printing was performed using Mr. Court. During front printing, powder (trade name: Nichiro Rico M (manufactured by Nitsuka Co., Ltd.)) was used and sprayed on the powder scale 10 of the printing device.

[0201] << Evaluation of coating defect prevention >> The surface of the produced printing plate material was observed, the coating failure was visually evaluated, and the following ranking was performed as an index for preventing coating defects. Rank 5 indicates that no failure can be seen, rank 4 where failure appears slightly less than 0.3 mm in diameter, rank 3 where failure appears to have a diameter of 0.3 mm or more but less than 0.5 mm. Ranks with a fault of 5 mm or more and less than lmm were ranked 2, and those with a fault of diameter 1 mm or more were ranked 1. Rank 2 or lower is defective in printing and cannot be used practically.

[0202] << Sensitivity evaluation >>

Samples with visible exposure were obtained with a magnifying glass, and appropriate exposure energy was evaluated. Appropriate exposure energy was 50% halftone dot with a halftone dot area of 50%. The smaller the value! /, The higher the sensitivity.

[0203] << Evaluation of initial ink deposition characteristics >>

The printing start sequence was the PS printing sequence, and there was no special on-press development operation. When the plate surface was observed after printing, the non-image area of the printing plate sample was removed.

[0204] The printing start sequence was carried out using the PS printing sequence, and the number of sheets in which ink smears in the non-image area disappeared was evaluated and used as an index for initial ink setting. The smaller the number of sheets, the better the ink fillability.

[0205] << Evaluation of printing durability >>

Similarly, the exposed printing plate sample was put on the printing machine and printed on the surface side under the above conditions for 50,000 sheets. After the ink was dried, it was inverted and the back side was printed up to 50,000 sheets under the above conditions. The number of printed sheets in which more than half of the dots in the 3% halftone dot image on the back side were missing was determined as the number of printed sheets. The higher the number of prints, the better.

[0206] Table 5 shows the results obtained by the above evaluation. From Table 5, the printing plate material of the present invention has excellent coating defect prevention properties that make it difficult for coating failures to occur during production, and high initial ink inking properties.

It can be seen that the printing durability is excellent.

[0207] [Table 5]

Claims

The scope of the claims

[1] A printing plate material which can be developed on a printing press having a hydrophilic layer and an image forming functional layer on a substrate, and the hydrophilic layer has a coercive force (HC) force of 8 kAZm or less in a magnetic field of OOkAZm. A printing plate material comprising metal oxide particles.

[2] The printing plate material according to claim 1, wherein the metal oxide particles are metal oxide particles mainly composed of titanium oxide and iron oxide.

[3] The printing plate material according to claim 1 or 2, wherein the image-forming functional layer contains heat-fusible particles or heat-fusible particles.

[4] The printing according to any one of claims 1 to 3, wherein the metal oxide particles are contained in a hydrophilic layer adjacent to the image forming functional layer. Plate material.

[5] A method for producing a printing plate material that can be developed on a printing press having a hydrophilic layer and an image-forming functional layer on a substrate, wherein the coercive force ( HC) has a step of containing metal oxide particles of 8 kAZm or less in a magnetic field of 4 OOkAZm.

[6] Any force of claims 1 to 4 After image exposure of the printing plate material described in item 1, it is mounted on a printing press and dampening water and ink are applied to the surface of the printing plate material. A lithographic printing method comprising: supplying and removing a non-image portion and printing.