JP2007203611A - Lithographic printing plate material, manufacturing method thereof and printing method using the lithographic printing plate material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lithographic printing plate material which enables attainment of a coating surface being free from a coating defect, having a uniform and stable surface shape and excelling in coating properties, on a long strip-shaped substrate, by using a bar coating device and which has also a good performance, a manufacturing method thereof and a printing method using the lithographic printing plate material. <P>SOLUTION: The lithographic printing plate material having a constitution wherein a hydrophilic layer containing magnetic metal particles and an image forming layer are provided sequentially on the substrate is manufactured by the method wherein a surplus amount of hydrophilic layer coating solution is applied onto the strip-shaped substrate conveyed continuously and is scraped off and applied thereafter by using a bar. In this manufacturing method of the lithographic printing plate material, the surface material quality of the bar is a nonmagnetic one. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a lithographic printing plate material in which an excess amount of a hydrophilic layer coating solution is applied onto a support, and then the excess amount of the hydrophilic layer coating solution is scraped off and applied using a bar. The present invention relates to a printing method using a plate material.

  The present invention relates to a lithographic printing plate material, a method for producing the lithographic printing plate material, and a printing method using the lithographic printing plate material, and more particularly, can record an image based on a digital signal, and can be stably printed without application defects. The present invention relates to a lithographic printing plate material that can be obtained, a manufacturing method for scraping it off using a bar, and a printing method using the lithographic printing plate material.

  In the conventional printing process, a negative or positive film is produced from an original image, and the image is exposed to a lithographic printing plate material (lithographic printing plate precursor) having a photosensitive layer on an aluminum grain support through the film, and an alkaline development is performed. A lithographic printing plate is produced by developing with a liquid, and this is carried out by a procedure of attaching it to a printing machine and printing.

  In recent years, with the spread of computers, computer-to-plate (CTP) technology that draws original image data directly on a printing plate without using a film is becoming widespread, reducing the time and cost required for film production. Is becoming possible. In addition, as a need for printed materials, there has been a tendency for a small number of various types of products to print various high-quality images with the number of printed sheets of about several thousand to 10,000 sheets. For this reason, plate making using heat mode laser recording, which has a short drawing time and high resolution, is becoming the mainstream of CTP.

  Synchronized with the spread of CTP, the printing environment has become an office, and from the standpoint of environmental suitability, a lithographic printing plate material that does not require an alkaline developer and does not require any development processing has been desired. It was.

  For example, in JP-A-9-123387, 9-123388, and 9-131850, a lithographic printing plate precursor containing thermoplastic particles dispersed in a hydrophilic binder is attached to a printing machine, A method for producing a lithographic printing plate is disclosed. According to these techniques, it is possible to produce a printing plate without performing alkali development and without requiring a developing machine, and it is possible to provide a lithographic printing plate that does not require development processing in a pseudo manner.

  In lithographic printing plate materials, it has recently been described that a plastic film can be used as a support without using a hydrophilic aluminum substrate as the support.

  Plastic film has lower thermal conductivity than metal, and can be efficiently used for image formation without diffusing heat generated in the heat-sensitive layer by laser exposure during image formation to the support. It has the advantage of being inexpensive compared to the body.

  As a printing plate using these plastic films as a support, JP-A-9-314794 gives examples of using corona-treated surfaces, and JP-A-11-245530 discloses a plasma-treated support. Is disclosed.

  Various apparatuses are known as a coating apparatus. For example, dip coating, roller coating, fountain coating, air knife, blade coating, bar coating, slide hopper, etc.

  In recent years, as a method of simply applying to a continuously transported support in the coating method using the coating device, a bar coating device has been frequently used for thin film and high-speed coating. There is known a bar coating method using the above.

  In the bar coating method, as a first step, an appropriate amount of coating solution is applied onto a belt-like support by a roll coating device, and the bar coating device (bar is stationary or This is a method of obtaining a desired film thickness (secondary film) by pressing a bar by rotation) and scraping off an excessive coating solution. The final film thickness after scraping is determined only by the cut surface of the groove formed in the bar.

  In combination with the bar coating device, each of the above coating devices can be used as a device for applying an excessive coating liquid. Generally, a dip coating device, a roll coating device, a fountain coating device, a comma coating device, etc. Each device is used. Further, as described in JP-A-6-170312, a coating apparatus in which the overcoating and the bar coating apparatus are integrated may be used.

  Regarding lithographic printing plate materials, Patent Document 1 describes the content of providing an undercoat layer containing specific metal oxide particles on a support by bar coating, but there is no coating defect due to the bar coating method, and a stable lithographic plate. There is no mention of a printing plate manufacturing method.

  Patent Document 2 describes bar coating in which a coating liquid containing dispersed particles is applied, but does not describe the stability of coating properties on a coating film on which particles are applied. It does not describe a stable manufacturing method.

  Japanese Patent Laid-Open No. 11-28402 describes the roundness of a bar, but it does not sufficiently stabilize and improve the quality of printing performance.

Thus, there has been a demand for a bar coating production method for a lithographic printing plate material having good coating properties and stable performance without requiring a special bar coating device and without particularly changing the coating solution.
Japanese Patent Laid-Open No. 14-154278 Japanese Patent Laid-Open No. 15-175359

  An object of the present invention is a lithographic plate having a coating surface free from coating defects, uniform in surface shape and having good coating properties on a long belt-like support using a bar coating apparatus, and having good performance. It is providing the printing plate material, its manufacturing method, and the printing method using this lithographic printing plate material.

  The above object of the present invention is achieved by the following configurations.

  1. A lithographic printing plate material comprising a support and a hydrophilic layer containing magnetic metal particles in order and an image forming layer in order is coated with an excess amount of hydrophilic layer coating solution on a belt-like support that is continuously conveyed. In the method for producing a lithographic printing plate material, the surface material of the bar is a non-magnetic material in the method for producing a lithographic printing plate material, in which the excess hydrophilic layer coating solution is scraped off and applied using a bar. A method for producing a plate material.

  2. 2. The method for producing a lithographic printing plate material according to 1, wherein the surface material is titanium or DLC (diamond-like carbon).

  3. A lithographic printing plate material produced by the method for producing a lithographic printing plate material according to 3.1 or 2.

  4.3. A printing method comprising printing the lithographic printing plate material according to 4.3 by performing laser exposure on the basis of image information and performing on-press development processing.

  According to the present invention, on a long belt-like support using a bar coating apparatus, a lithographic plate having a coating surface free from coating defects, having a uniform and stable surface shape and good coating properties and good performance. A printing plate material, a production method thereof, and a printing method using the planographic printing plate material can be provided.

  As a result of intensive studies, the inventor has developed a planographic printing plate material in which a hydrophilic layer containing magnetic metal particles and an image forming layer are sequentially provided on a support, on a belt-like support that is continuously conveyed. In the method for producing a lithographic printing plate material, an excess amount of the hydrophilic layer coating solution is applied to the surface, and then the excess amount of the hydrophilic layer coating solution is scraped off and applied using a bar. Thus, it has been found that there can be obtained a method for producing a lithographic printing plate material which has no coating defects, has a uniform surface shape, is stable, has good coating properties, and has good performance.

  Hereinafter, the present invention will be described in detail.

[Bar application method]
In the present invention, an excess amount of a hydrophilic layer containing a hydrophilic layer containing magnetic metal particles on a support, and a planographic printing plate material provided with an image forming layer in that order on the support that is continuously conveyed. In the manufacturing method in which an excessive amount of coating solution is scraped off and applied using a bar after applying the coating solution, it is important that the surface material of the bar is a non-magnetic material.

  In the bar coating method, as described above, an appropriate amount of coating solution is first applied onto the support by a roll coating device, and the bar coating device (bar is stationary or This is a method of obtaining a desired film thickness (secondary film) by pressing a bar by rotation) and scraping off an excessive coating solution.

  When a hydrophilic layer coating liquid containing metal particles having magnetism is applied to a bar, an excessive amount of the hydrophilic layer coating liquid is scraped off a required amount in the gap between the support and the bar.

  In this case, if the bar surface material has magnetism, the metal particles in the hydrophilic layer coating solution have magnetism, so that they will adhere to the bar surface one after another, and bar clogging will occur during continuous application. It was. Therefore, when bar coating is performed on metal particles having magnetism, it is important that the bar surface material has no magnetism.

(bar)
In the present invention, the bar of the bar coating device is used without particular limitation such as a bar wound with a wire or a grooved bar not wound with a wire, and iron or stainless steel other than the surface material is used without limitation.

  The grooved bar may be a groove produced by engraving, or may be produced by rolling using a thread rolling round die.

  A bar produced by rolling using a thread rolling round die will be described below.

  Thread rolling is a process of rolling a screw material (screw blank) between two or several screw molds (screw rolling dies) using the plasticity of metal to create a thread. Is the method. Since this method can produce highly accurate and non-uniform screws, it is often used for rolling most ordinary screws.

  Moreover, if it is a material which does not have magnetism, you may perform the plating process on the surface as needed. The surface plating treatment may be used without particular limitation as long as it satisfies the scope of the present invention, and examples thereof include titanium and DLC (diamond-like carbon). The plating treatment may be performed singly or plural times such as further plating treatment may be performed on the one that has been plated once. Moreover, you may coat | cover the resin which does not have magnetism on the surface.

[Hydrophilic layer]
In the present invention, the hydrophilic layer is defined as a layer that can take in more water when an emulsified solution of water and ink comes during printing.

(Magnetic metal particles)
The present invention is characterized in that the hydrophilic layer contains magnetic metal particles.

  In the present invention, magnetic metal particles are defined as metal particles that can be magnetized. When metal particles are placed in a magnetic field, the direction of the metal particles can change due to the influence of magnetization, that is, the magnetic field. It is defined as having magnetism.

  Examples of magnetic metal particles include iron oxide, titanium oxide, and composite metal oxides thereof. One kind of metal particles may be used, or several kinds may be used in combination.

(Particulate matter)
It is desirable that the hydrophilic layer according to the present invention contains particles.

<Filler>
An example of the particulate material is a filler.

As the filler, carbon black, _{graphite, TiO 2, BaSO 4, ZnS} , MgCO 3, CaCO 3, ZnO, CaO, WS 2, MoS 2, MgO, SnO 2, Al 2 O 3, α-Fe 2 O 3, _{α-FeOOH, SiC, CeO 2} , BN, SiN, MoC, BC, WC, titanium carbide, corundum, artificial diamond, garnet, garnet, silica rock, tripoli, diatomaceous earth, an inorganic filler and polyethylene resin particles such as dolomite, Examples thereof include organic fillers such as fluororesin particles, guanamine resin particles, acrylic resin particles, silicon resin particles, and melamine resin particles.

  Examples of the filler include inorganic fine particles and organic fine particles, which may also serve as a release agent. Examples of the inorganic fine particles include silica gel, calcium carbonate, titanium oxide, acid clay, activated clay, alumina, and the like. Examples of the organic fine particles include resins such as fluororesin particles, guanamine resin particles, acrylic resin particles, and silicon resin particles. Particles can be mentioned.

<Filler having a core-shell structure>
As another particulate material, a filler having a core-shell structure can be exemplified.

  The particles having a core-shell structure are particles in which particles serving as shells are fixed (coated) on the surface of the core particles. The core particles and the particles that become the shell may be inorganic particles or organic particles. Any number of layers may be adhered to the core particles. The average particle diameter of the core particles is preferably from 0.1 to 15 μm, more preferably from 1 to 10 μm.

  In the particles having an uneven surface of the filler having the core-shell structure, the average particle size of the small particles to be the shell is preferably 1/3 or less, more preferably 1/10 or less of the average particle size of the core particles. It is preferable that the average particle size of the irregular surface particles does not exceed 15 μm, and is preferably 0.1 μm or more. The coverage of the small particles fixed on the surface of the core particles can be arbitrarily selected within the range in which the effect of the present invention appears.

  Particles with an uneven surface are, for example, a method using a hetero-aggregation method described in “New Development of Fine Particle Polymer” edited by Toray Research Center Co., Ltd., a method using a polymerization reaction from the surface of core particles, and “ It can be easily produced using a dry agglomeration stirring method using a hybridizer described in “Particle Design Engineering”. Certain core-shell particles can be produced by precipitating small particles on the surface of the core particles.

<wax>
Furthermore, a wax can be mentioned as another particulate matter.

  Examples of the wax include solid waxes such as beeswax, candelilla wax, paraffin wax, ester wax, montan wax, carnauba wax, amide wax, polyethylene wax, microcrystalline wax, and silicon compounds.

  Specific compounds as silicon compounds (including wax-like compounds) include straight silicone oils such as dimethyl silicone oil, methylphenyl silicone oil, and methylhydrogen silicone oil, olefin modified silicone oil, polyether modified silicone oil, and epoxy. Modified silicone oil, epoxy / polyether modified silicone oil, alcohol modified silicone oil, fluorine modified silicone oil, amino modified silicone oil, phenol modified silicone oil, mercapto modified silicone oil, carboxy modified silicone oil, higher fatty acid modified silicone oil, carnauba modified Silicone oil, amide-modified silicone oil, radical-reactive silicone oil such as (meth) acrylic-modified silicone oil, silicone diol, silicon Terminal reactive silicone oil diamine, a halogen group, an alkoxy group, and an ester group, an amide group, an organic modified silicone oil modified with an imide group.

<Metal atom-containing particles>
Examples of other particles include metal atom-containing particles. Metal atom-containing particles are metals such as iron, chromium, manganese, cobalt, nickel, copper, zinc, titanium, silver, aluminum, gold, and platinum, or their oxidation. This is a general term for compounds such as products. Specific examples of the metal atom-containing particles include ferromagnetic iron oxide powder, ferromagnetic metal powder, and cubic plate powder.

Examples of the ferromagnetic iron oxide include γ-Fe ₂ O ₃ , Fe ₃ O ₄ , or intermediate iron oxides represented by FeO _x (1.33 <x <1.50).

Ferromagnetic metal powders include Fe, Co, Fe—Al, Fe—Al—Ni, Fe—Al—Zn, Fe—Al—Co, Fe—Al—Ca, Fe—Ni. Fe-Ni-Al, Fe-Ni-Co, Fe-Ni-Zn, Fe-Ni-Mn, Fe-Ni-Si, Fe-Ni-Si-Al-Mn, Fe-Ni -Si-Al-Zn, Fe-Ni-Si-Al-Co, Fe-Al-Si, Fe-Al-Zn, Fe-Co-Ni-P, Fe-Co-Al-Ca Ferromagnetic metal powders such as metal magnetic powders mainly composed of Ni, Co, Fe, Ni, Co, etc. Among them, Fe metal powders are preferred, for example, Co-containing γ-Fe ₂ O ₃ , Co coated Adhered γ-Fe ₂ O ₃ , Co-containing Fe ₃ O ₄ , Co-coated Fe ₃ O ₄ , Co-containing magnetic Fe Examples include cobalt-containing iron oxide magnetic powders such as O _x (4/3 <x <3/2) powders.

  In the present invention, other layers may be formed between the support and the hydrophilic layer. For example, an undercoat layer that improves the adhesiveness of the hydrophilic layer, a swell forming layer that imparts a gentle roughness at a long wavelength, and a cushion layer that relieves stress applied to the hydrophilic layer. Any one of these layers may contain a photothermal conversion material.

(Image forming layer)
The image forming layer of the lithographic printing plate material of the present invention can be selected from hot melt particles that can be fused by heat and substances that exhibit lipophilicity by heat.

(Hot-melting particles that can be fused by heat)
Examples of thermally fusible particles that can be fused by heat include waxes, acrylic resins, ionomer resins, vinyl acetate resins, vinyl chloride resins, synthetic rubbers, polyurethane resins, polyester resins, fluorine resins, silicone resins, etc. And those obtained from latex or emulsion dispersed in water. Of these, those having a melting point of 70 to 180 ° C. are preferred, and the hydrophilic component of the surface energy is preferably 100 μN / cm ² or less. If the melting point is lower than this temperature, the performance during storage is likely to deteriorate, and if it is higher than this temperature, the image strength cannot be obtained and the printing durability tends to deteriorate. In addition, when the surface energy is within this range, the ink deposition property of the image portion is improved. In this respect, waxes, acrylic resins, and synthetic rubbers are particularly preferable as the hot-melt material.

  Examples of waxes that can be used in the present invention include carnauba wax, beeswax, spermaceti, wax, jojoba oil, lanolin, ozokerite, paraffin wax, montan wax, candelilla wax, ceresin wax, microcrystalline wax, rice wax. And natural waxes such as polyethylene wax, Fischer-Tropsch wax, montan wax derivatives, paraffin wax derivatives, microcrystalline wax derivatives, higher fatty acids and the like. In order to facilitate emulsification, these waxes can be oxidized to introduce polar groups such as hydroxyl groups, ester groups, carboxyl groups, aldehyde groups, and peroxide groups.

(binder)
The binder used in the image forming layer of the lithographic printing plate material of the present invention can be used without any particular limitation.

  Binder resins include polyurethane, polyester, vinyl chloride resins such as vinyl chloride copolymers, vinyl chloride resins such as vinyl chloride-vinyl acetate copolymers, polyolefin resins such as butadiene-acrylonitrile copolymers, polyvinyl Polyvinyl acetal resin such as butyral, cellulose resin such as nitrocellulose, styrene resin such as styrene-butadiene copolymer, acrylic resin such as polymethyl methacrylate, polyamide, phenol resin, epoxy resin, phenoxy resin, polyvinyl butyral And acetal resins such as polyvinyl acetoacetal and polyvinyl formal, and water-soluble resins such as polyvinyl alcohol and gelatin.

  The binder resin may be used alone or in combination of two or more.

(Hydrophilic binder)
A hydrophilic binder is added to the image forming layer containing heat-fusible particles that can be fused by heat in order to provide film-forming properties of the image-forming layer within a range that does not impair the fusing properties of the particles during laser exposure. You may make it contain.

  Usable hydrophilic binders include, for example, polyvinyl alcohol, poly (meth) acrylic acid, poly (meth) acrylamide, polyhydroxyethyl (meth) acrylate, polyvinyl methyl ether, or natural binders such as gelatin, polysaccharides, Examples thereof include dextran, pullulan, cellulose, gum arabic, and arginic acid. The hydrophilic binder may be a water-insoluble, alkali-soluble or swellable resin having a phenolic hydroxy group and / or a carboxyl group. Various surfactants, colloidal silica, and the like can also be used.

(Substance that exhibits lipophilicity by heat)
As a substance that exhibits lipophilicity by heat, a hot-melting substance having a melting point of 70 to 180 ° C. can be used. As waxes, carnauba wax, beeswax, whale wax, wood wax, jojoba oil, lanolin, ozokerite, paraffin wax Natural wax such as montan wax, candelilla wax, ceresin wax, microcrystalline wax, rice wax, polyethylene wax, Fischer-Tropsch wax, montan wax derivative, paraffin wax derivative, microcrystalline wax derivative, higher fatty acid, etc. are acrylic Examples of the resin include those obtained by copolymerization of one or more of methyl methacrylate, butyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, styrene, and the like. , Polyisoprene, polychloroprene, styrene-butadiene copolymer, acrylic ester-butadiene copolymer, methacrylic ester-butadiene copolymer, isobutylene-isoprene copolymer, acrylonitrile-butadiene copolymer, acrylonitrile- Examples include isoprene copolymers and styrene-isoprene copolymers. In addition, ionomer resins, vinyl acetate resins, vinyl chloride resins, polyurethane resins, polyester resins, fluorine resins, silicone resins, and the like can be used. These lipophilic agents are preferably used in the form of an aqueous dispersion in terms of ease of coating. Another form includes a thermal crosslinking agent covered with a thermally destructible hydrophilic coating material, and a thermal crosslinking agent in which a functional group is blocked by a protecting group that is dissociated by heat. These thermal crosslinking agents are described as lipophilic components microencapsulated in JP-A Nos. 7-1849, 7-1850, 9-311443, 10-6468, and 10-111168.

(Photothermal conversion material)
The lithographic printing plate material of the present invention preferably has a layer containing a photothermal conversion material on the side having the image forming layer of the support.

  The layer having the photothermal conversion material is preferably an image forming layer or an adjacent layer thereof, and particularly preferably an image forming layer.

  An infrared absorbing dye or pigment can be used as the photothermal conversion material.

<Infrared absorbing dye>
Examples of infrared absorbing dyes include organic dyes such as cyanine dyes, croconium dyes, polymethine dyes, azurenium dyes, squalium dyes, thiopyrylium dyes, naphthoquinone dyes, anthraquinone dyes, which are general infrared absorbing dyes. Examples thereof include compounds, phthalocyanine-based, naphthalocyanine-based, 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-A-280750, JP-A-1-293342, JP-A-2-2074, JP-A-3-26593, 3-30991, 3-34891, 3-36093, 3-36094, 3-36095, 3-42281, 3-97589, 3-103476, 7 -43851, 7-102179, JP-A-2001-117201, and the like. These can be used alone or in combination of two or more.

<Pigment>
Examples of the pigment include carbon, graphite, metal, metal oxide and the like.

  As carbon, it is particularly preferable to use furnace black or acetylene black. The particle size (d50) is preferably 100 nm or less, and more preferably 50 nm or less.

  As the graphite, fine particles having a particle size of 0.5 μm or less, preferably 100 nm or less, more preferably 50 nm or less can be used.

  As the metal, any metal can be used as long as the particle diameter is 0.5 μm or less, preferably 100 nm or less, more preferably 50 nm or less. The shape may be any shape such as a spherical shape, a piece shape, or a needle shape. Colloidal metal fine particles (Ag, Au, etc.) are particularly preferable.

As the metal oxide, a material that is black in the visible light region or a material that is conductive or that is a semiconductor can be used. Examples of the material exhibiting black color in the visible light region include black iron oxide (Fe ₃ O ₄ ) and black mixed metal oxides containing two or more metals. Specifically, it is a composite metal oxide composed of two or more metals selected from Al, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sb, and Ba. These can be produced by the methods disclosed in JP-A-8-27393, 9-25126, 9-237570, 9-241529, and 10-231441. The composite metal oxide that can be used in the present invention is particularly preferably a Cu-Cr-Mn-based or Cu-Fe-Mn-based composite metal oxide. In the case of a Cu—Cr—Mn system, it is preferable to perform the treatment disclosed in JP-A-8-27393 in order to reduce the elution of hexavalent chromium.

  These composite metal oxides have good photothermal conversion efficiency. These composite metal oxides preferably have an average primary particle size of 1 μm or less, and more preferably have an average primary particle size in the range of 0.01 to 0.5 μm. When the average primary particle diameter is 1 μm or less, the photothermal conversion ability with respect to the addition amount becomes better, and when the average primary particle diameter is within the range of 0.01 to 0.5 μm, the photothermal conversion ability with respect to the addition amount is obtained. Better. However, the photothermal conversion ability with respect to the added amount is greatly affected by the degree of dispersion of the particles, and the better the dispersion, the better. Therefore, before adding these composite metal oxide particles to the coating solution, it is preferable to disperse them by a known method to prepare a dispersion (paste). An average primary particle size of less than 0.01 is not preferable because dispersion becomes difficult. A dispersing agent can be appropriately used for the dispersion. The addition amount of the dispersant is preferably 0.01 to 5% by mass, and more preferably 0.1 to 2% by mass with respect to the composite metal oxide particles. Although the kind of dispersing agent is not specifically limited, it is preferable to use Si type surfactant containing Si element.

Examples of materials that have conductivity or are semiconductors include reduced Sb-doped SnO ₂ (ATO), Sn-added In ₂ O ₃ (ITO), TiO ₂ , and TiO ₂ . Examples thereof include TiO (titanium oxynitride, generally titanium black). Further, it is also possible to use those obtained by coating the core material _{(BaSO 4, TiO 2, 9Al} 2 O 3 · 2B 2 O, K 2 O · nTiO 2 , etc.) in these metal oxides. These particle sizes are 0.5 μm or less, preferably 100 nm or less, and more preferably 50 nm or less.

  A particularly preferable photothermal conversion material is a black complex metal oxide in which the infrared absorbing dye and the metal oxide are composed of two or more metal oxides.

  As addition amount of these photothermal conversion materials, it is 0.1-50 mass% with respect to the layer containing this, 1-30 mass% is preferable, and 3-25 mass% is more preferable.

[Support]
The support used in the present invention is not particularly limited, and paper treated with a metal, a plastic film, polyolefin, or the like, and a composite substrate obtained by appropriately bonding these materials can also be used.

  Examples of the plastic film include polyethylene terephthalate, polyethylene naphthalate, polyimide, polyamide, polypropylene, polyethylene, polyvinyl chloride, acetate, nylon, polyetherimide, polycarbonate, polysulfone, polyphenylene oxide, polyphenylene sulfide, and cellulose esters. it can. These plastic films are preferably subjected to easy adhesion treatment or undercoat layer coating on the coated surface in order to improve adhesion with the coated layer. Examples of the easy adhesion treatment include corona discharge treatment, flame treatment, and ultraviolet irradiation treatment. Examples of the undercoat layer include a layer containing gelatin or latex.

[Preparation of lithographic printing plate materials]
The lithographic printing plate material of the present invention can be produced by providing a hydrophilic layer and an image forming layer on the support described above.

  The image forming layer is prepared by kneading a photothermal conversion material, a binder resin and a colorant, and, if necessary, a lubricant, a dispersant, an antistatic agent, a filler, a filler and a solvent with a solvent to form a high-concentration image forming layer composition. It is prepared and then diluted to form an image forming layer composition for coating, which can be formed by coating and drying on the hydrophilic layer.

  The organic solvent used in the image forming layer composition is not particularly limited as long as it can dissolve or disperse the above composition. For example, alcohols (ethanol, propanol, etc.), cellosolves (methyl cellosolve, ethyl cellosolve) , Aromatics (toluene, xylene, chlorobenzene, etc.), ketones (acetone, methyl ethyl ketone, etc.), ester solvents (ethyl acetate, butyl acetate, etc.), ethers (tetrahydrofuran, dioxane, etc.), halogen solvents (chloroform, Dichlorobenzene etc.), amide solvents (eg dimethylformamide, N-methylpyrrolidone etc.) etc. can be used. For the kneading and dispersing of the colorant component, a two-roll mill, a three-roll mill, a ball mill, a pebble mill, a cobol mill, a tron mill, a sand mill, a sand grinder, a Sqgvari attritor, a high-speed impeller disperser, a high-speed stone mill, a high-speed impact mill, a disper High-speed mixers, homogenizers, ultrasonic dispersers, open kneaders, continuous kneaders, and the like can be used.

  The formation of the image forming layer on the support can be performed by, for example, applying and drying with an extrusion type extrusion coater, and in order to increase the hardness of the surface of the image forming layer in order to obtain a high resolution image, May be calendared.

[Printing method and image exposure]
The exposure light source for forming an image on the lithographic printing plate material of the present invention can be used without particular limitation as long as the light-to-heat conversion material can respond. Among them, in order to obtain a high resolution, an electromagnetic wave whose energy application area can be narrowed down, particularly an ultraviolet ray having a wavelength of 1 nm to 1 mm, a visible ray, and an infrared ray are preferable. As a light source capable of applying such light energy, for example, a laser, Light emitting diodes, xenon flash lamps, halogen lamps, carbon arc lamps, metal halide lamps, tungsten lamps, quartz mercury lamps, high pressure mercury lamps and the like can be mentioned. The energy applied at this time can be selected and used in a timely manner by adjusting the exposure distance, time, and intensity depending on the type of image forming material.

As laser light sources used in the printing method of the present invention, solid lasers such as ruby laser, YAG laser, and glass laser that are generally well known; He—Ne laser, Ar ion laser, Kr ion laser, CO ₂ laser, CO laser Gas lasers such as He-Cd laser, N ₂ laser, and excimer laser; semiconductor lasers such as InGaP laser, AlGaAs laser, GaAsP laser, InGaAs laser, InAsP laser, CdSnP ₂ laser, and GaSb laser; chemical laser, dye laser, etc. Among these, in order to cause ablation efficiently, a laser having a wavelength of 6000 to 1200 nm is preferable in terms of sensitivity because light energy can be converted into thermal energy.

  The printing method of the present invention is characterized in that printing is performed without performing development processing after laser exposure based on image information.

  The on-press development in the present invention has the following contents.

  This is a method of removing the unexposed portion of the image forming layer of the lithographic printing plate material by mounting the exposed lithographic printing plate material on the cylinder of the printing press and supplying dampening water and ink while rotating the cylinder. .

  That is, after the lithographic printing plate material is exposed, it is mounted on a printing machine as it is, and the development process is completed in a normal printing process.

  Hereinafter, embodiments of the present invention will be described, but the present invention is not limited thereto. In addition, the following "part" represents a "mass part".

Example (Production of Sample 11)
The following first hydrophilic layer coating solution A was applied to Melinex 765 (polyester film) with a film thickness of 175 μm manufactured by Teijin-Dupont Film Co., Ltd. to obtain Sample 11 having a first hydrophilic layer on a support.

  In the application of the first hydrophilic layer coating solution A, a grooved bar (manufactured by OSG System Products Co., Ltd., surface-plated titanium) was used so that the dry film was 1.8 μm.

<First hydrophilic layer coating solution A>
Snowtex-XS (Nissan Chemical Industries, Ltd., average particle size 0.005 μm)
11.64 parts Snowtex-ZL (manufactured by Nissan Chemical Industries, Ltd., average particle size 0.085 μm)
0.80 part Shilton JC-70 (manufactured by Mizusawa Chemical Co., Ltd., average particle size 4.0 μm) 3.33 parts BL-200 (manufactured by Titanium Industry Co., Ltd., iron oxide, magnetic pigment) 3.07 parts phosphorus Trisodium acid 12 water (manufactured by Kanto Chemical Co., Ltd.) 0.01 part FZ-2161 (manufactured by Nihon Unicar Co., Ltd.) 0.15 part pure water 81 parts (preparation of samples 12 to 18)
In the preparation of sample 11, the surface material of the grooved bar was changed as shown in Table 1, and the other samples 12 to 18 having the first hydrophilic layer on the support were prepared in the same manner. Samples 11 and 13, 12 and 14, and 15 have the same contents.

(Sample evaluation)
The following evaluation was performed about the produced sample.

<Coating stripe>
The coating streaks in the coating sample 1 m ² after coating with 500 m and 1000 m were evaluated according to the following criteria.

5: No generation at all 4: Some harmless streaks occur, but no problem 3: There are streaks, and there is concern about the actual harm 2: Some streaks occur, some may be harmful 1: Many streaks occur However, it has many harmful effects and is impossible.
The number of coating repellents and the size (μm) of the largest repelling in 1 m ² of the coated sample after 100 m and 1000 m coating were evaluated.

  The larger the number and the larger the size, the more disadvantageous the visual quality and the actual performance.

  The evaluation results are shown in Table 1.

(Preparation of sample 21)
The following second hydrophilic layer coating solution B is applied on the first hydrophilic layer of sample 11 with a grooved bar (surface plated titanium, manufactured by OSG System Products Co., Ltd.) so that the dry film thickness becomes 0.6 μm. And the sample 21 which has a 1st hydrophilic layer and a 2nd hydrophilic layer on a support body was obtained.

<Second hydrophilic layer coating solution B>
Snowtex-S (Nissan Chemical Co., Ltd., average particle size 0.009 μm)
3.7 parts Snowtex-PSM (manufactured by Nissan Chemical Industries, Ltd., average particle size 0.095 μm)
5.55 parts AMT-08 (manufactured by Mizusawa Chemical Co., Ltd., average particle size 0.95 μm) 0.90 parts MP-4540 (manufactured by Nissan Chemical Industries, Ltd., average particle size 0.45 μm) 3.81 parts BL- 200 (manufactured by Titanium Industry Co., Ltd., iron oxide, magnetic pigment) 17.2 parts trisodium phosphate.12 water (manufactured by Kanto Chemical Co., Ltd.) 0.01 part FZ-2161 (manufactured by Nippon Unicar Co., Ltd.) 03 parts Pure water 68.8 parts (Preparation of samples 22 to 28)
In the preparation of the sample 21, the surface material of the grooved bar is changed as shown in Table 2, and the others are similarly applied on the samples 12 to 18 having the first hydrophilic layer on the support. The liquid B or the following 2nd hydrophilic layer coating liquid C was apply | coated, and the samples 22-28 which each have a 1st hydrophilic layer and a 2nd hydrophilic layer on a support body were produced.

<Second hydrophilic layer coating solution C>
Snowtex-S (Nissan Chemical Co., Ltd., average particle size 0.009 μm)
3.7 parts Snowtex-PSM (manufactured by Nissan Chemical Industries, Ltd., average particle size 0.095 μm)
5.55 parts AMT-08 (manufactured by Mizusawa Chemical Co., Ltd., average particle size 0.95 μm) 0.90 parts MP-4540 (manufactured by Nissan Chemical Industries, Ltd., average particle size 0.45 μm) 3.81 parts BL- 200 (manufactured by Titanium Industry Co., Ltd., iron oxide, pigment having magnetism) 8.6 parts ETB-300 (manufactured by Titanium Industry Co., Ltd., pigment having iron oxide, titanium oxide and magnetism) 8.6 parts Triphosphate 3 Sodium / 12 water (manufactured by Kanto Chemical Co., Ltd.) 0.01 part FZ-2161 (manufactured by Nihon Unicar Co., Ltd.) 0.03 part Pure water 68.8 parts
The produced samples 21 to 28 were evaluated in the same manner as the samples 11 to 18.

  The evaluation results are shown in Table 2.

(Preparation of samples 31 to 38)
The following image forming layer coating solution D was applied with a grooved bar so that the dry coating amount was 0.55 (g / m ² ) on the second hydrophilic layers of Samples 21 to 28, and each was applied to the support. Samples (lithographic printing plate materials) 31 to 38 having a first hydrophilic layer, a second hydrophilic layer, and an image forming layer were obtained.

<Image forming layer coating solution D>
HI-DISPER A-206 (manufactured by Gifu Shellac Manufacturing Co., Ltd., heat-meltable particles, average particle size 0.5 μm) 2.0 parts DL-522 (manufactured by Nippon Shokubai Co., Ltd., average molecular weight 170.000) 0.75 Part HI-DISPER A-118 (manufactured by Gifu Shellac Factory, heat-meltable particles, average particle size 0.3 μm) 5.55 parts HI-DISPER A-514 (manufactured by Gifu Shellac Factory, heat-fusible Particles, average particle size 0.6 μm) 1.5 parts pure water 88.5 parts isopropyl alcohol 1.5 parts Penon JE-66 (manufactured by Nissho Chemical Co., Ltd.) 0.2 parts (Evaluation of Samples 31 to 38)
The following evaluation was performed about the produced samples 31-38.

<Exposure and printing>
Using the obtained lithographic printing plate material with a semiconductor laser light source (light source wavelength 830 nm, spot size 10 μm, resolution is 2000 dpi in both the scanning direction and the sub-scanning direction), a 175 line equivalent 50% dot image and a solid image, The exposure was performed with the irradiation energy amount on the image surface being 250 mJ / cm ² while changing the scanning speed. In addition, dpi represents the number of dots per 2.54 cm.

The exposed lithographic printing plate material is attached to a Heidel GTO printing machine without developing, and 45 times water diluted solution of SEU-3 (manufactured by Konica Corporation (former name)) as an etchant and HiEcho (Toyo Ink) as ink. (Manufactured by Manufacturing Co., Ltd.), and printing was performed using high-quality paper as printing paper.
Printing was performed in an environment of 23 ° C. and 48% RH.

<Good number>
The number of printed sheets until the finished quality of a printed product with a halftone dot image of 50% was practically usable and began to be good was visually evaluated.

  A smaller number of sheets is better with less waste paper.

<Ground dirt>
The 100th non-image area Dmin of the printed material was visually evaluated in the following rank.

5: No soil at all 4: Slightly soiled, but no actual damage 3: Slightly soiled, there is concern about the actual harm 2: There is a soil dirt, there is an actual harm 1: Many soil dirt, the actual harm Yes <Press life>
The number of prints on which 50% halftone dots were not reproduced was evaluated visually.

  The larger the number, the higher the printing durability and the better.

  Table 3 shows the evaluation results.

  From the table, it is understood that if the conditions of the present invention are satisfied, a lithographic printing plate material having good coating properties and good performance can be obtained.

Claims (4)

A lithographic printing plate material comprising a support and a hydrophilic layer containing magnetic metal particles in order and an image forming layer in order is coated with an excess amount of hydrophilic layer coating solution on a belt-like support that is continuously conveyed. In the method for producing a lithographic printing plate material, the surface material of the bar is a non-magnetic material in the method for producing a lithographic printing plate material, in which the excess hydrophilic layer coating solution is scraped off and applied using a bar. A method for producing a plate material. 2. The method for producing a lithographic printing plate material according to claim 1, wherein the surface material is titanium or DLC (diamond-like carbon). A lithographic printing plate material produced by the method of producing a lithographic printing plate material according to claim 1 or 2. A lithographic printing plate material according to claim 3, wherein the lithographic printing plate material is subjected to laser exposure based on image information and subjected to on-press development processing for printing.