JP2006076003A - Manufacturing method of original plate of lithographic printing plate and printing method using the same manufactured by the method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method (bar coating manufacturing method) of an original plate of a lithographic printing plate which makes it possible to obtain on a strip-shaped support a coated surface being free from a coating defect, having a uniform surface shape and being stable and excellent in coating by using bar coating equipment and which has also an excellent performance, and a printing method using the original plate of the lithographic printing plate manufactured by this manufacturing method. <P>SOLUTION: In the manufacturing method of the original plate of the lithographic printing plate, the original plate is constituted by providing sequentially a hydrophilic layer having particulate matters and an image forming layer on the support. The hydrophilic layer is provided by a process wherein after an excessive amount of hydrophilic layer coating solution is applied on the strip-shaped support conveyed continuously, the excess of the applied coating solution is scraped off by using a bar and then the solution applied is dried. In this method, (1/4)W≤A≤4.3D is established. Herein A(μm) denotes the average particle diameter of a kind of particulate matter having the largest average particle diameter out of the kinds of particulate matters in the hydrophilic layer, W(μm) the film thickness of this layer after the excess of the coating solution thereof is scraped off by using the bar, and D(μm) the film thickness of the hydrophilic layer after drying. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for producing a lithographic printing plate precursor and a printing method using the lithographic printing plate precursor produced by the production method.

  In the conventional printing process, a negative or positive film is produced from a document image, the image is exposed to a lithographic printing plate precursor having a photosensitive layer on an aluminum grain support through the film, and development processing is performed with an alkaline developer. Thus, a lithographic printing plate is produced and attached to a printing machine for 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. Also, as a need for printed materials, there is a tendency for a small number of various types of products to print various kinds of 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.

  Synchronizing with the spread of CTP, the printing environment has become an office, and from the viewpoint of environmental suitability, a lithographic printing plate precursor that does not require an alkaline developer and does not require any development treatment 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, and A method for producing a lithographic printing plate by development 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.

  As for the planographic printing plate precursor, it is also described that a plastic film can be used as a support in recent years without using a hydrophilic aluminum substrate as a 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. JP-A-9-314794 discloses examples of using a support having a corona-treated surface as a printing plate using these plastic films as a support, and JP-A-11-245530 discloses a plasma treatment. A 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.

  As a method of simply applying to a continuously transported support in the application method using the above-described application device, as one of the methods that has recently been frequently used for thin film / high-speed application, The bar coating method used is known.

  In the bar coating method, as a first step, an appropriate amount of coating solution is applied to the belt-like support by a roll coating device, and a bar coating device (the bar is stationary or rotating) is applied to the excess coating solution (primary film). Is a method of obtaining a desired film thickness (secondary film) by pressing a bar 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, but in general, a dip coating device, a roll coating device, a fountain coating device, a comma coating device, etc. Each device is used. Also, a coating apparatus in which overcoating and a bar coating apparatus are integrated as described in JP-A-6-170312 may be used.

  Regarding the planographic printing plate precursor, the content of providing an undercoat layer containing specific metal oxide particles on a support by bar coating is described (for example, see Patent Document 1), but there is a coating defect due to the bar coating method. There is no mention of a method for producing a stable lithographic printing plate precursor. Moreover, although it describes about bar application | coating which apply | coats the coating liquid containing a dispersion particle (for example, refer patent document 2), it does not describe the applicability stability to the coating film in which the particle thing was apply | coated, It does not describe a stable method for producing a lithographic printing plate precursor.

Therefore, there has been a demand for a method for producing a lithographic printing plate precursor by bar coating, which does not require a special bar coating device and has good coating properties and stable performance.
JP 2002-154278 A JP 2003-175359 A

  The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to use a bar coating apparatus to apply a coating support surface to a belt-like support without any coating defects and with a uniform and uniform surface shape. Is provided, and a method for producing a lithographic printing plate precursor having good performance (bar coating production method) and a printing method using the lithographic printing plate precursor produced by the production method are provided.

  The above object of the present invention can be achieved by the following constitution.

(Claim 1)
A method for producing a lithographic printing plate precursor in which a hydrophilic layer having particles and an image forming layer are sequentially provided on a support, and an excessive amount of hydrophilic is provided on a belt-like support on which the hydrophilic layer is continuously conveyed. In the method for producing a lithographic printing plate precursor provided after applying a layer coating solution, scraping off the excess of the applied hydrophilic layer coating solution using a bar, applying and drying,
(1/4) W ≦ A ≦ 4.3D
However,
A (μm): average particle size of the particle material type having the largest average particle size among the particle material types in the hydrophilic layer W (μm): hydrophilic after scraping off excess of the hydrophilic layer coating solution using a bar Layer thickness D (μm): A method for producing a lithographic printing plate precursor, which is a thickness after drying of the hydrophilic layer.

(Claim 2)
A lithographic printing plate precursor produced by the production method according to claim 1, wherein the lithographic printing plate precursor is subjected to laser exposure based on image information and subjected to on-press development processing for printing.

  According to the present invention, using a wire bar coating apparatus, a belt-like support can be obtained with a lithographic printing plate precursor having a coating surface that is free of coating defects, has a uniform surface shape, and has a good coating property and good performance. A production method (bar coating production method) and a printing method using a lithographic printing plate precursor produced by the production method can be provided.

  Hereinafter, although the best mode for carrying out the present invention will be described, the present invention is not limited to these.

The method for producing a lithographic printing plate precursor according to the present invention is a method for producing a lithographic printing plate precursor in which a hydrophilic layer having particles and an image forming layer are sequentially provided on a support, and the hydrophilic layer is continuously conveyed. A lithographic printing plate precursor provided by applying an excessive amount of the hydrophilic layer coating solution on the belt-shaped support, and then scraping and applying the excess amount of the coated hydrophilic layer coating solution using a bar, followed by drying. In the manufacturing method,
(1/4) W ≦ A ≦ 4.3D
However,
A (μm): average particle size of the particle material type having the largest average particle size among the particle material types in the hydrophilic layer W (μm): hydrophilic after scraping off excess of the hydrophilic layer coating solution using a bar Layer thickness D (μm): A thickness after drying of the hydrophilic layer. As a result, it has been found that a long and stable coating surface can be obtained without coating defects, and the printing performance can be improved.

  In addition, the above “A (μm): the average particle size of the particle material type having the largest average particle size among the particle material types in the hydrophilic layer” simply refers to “the average particle size”. It means "particulate species only related to".

  A is (1/4) W or more and 4.3D or less, and when A is less than 1 / 4W, the bar itself may damage the surface of the support due to excessive bar pressure, or the support There is a concern that the bar may be damaged due to high pressure on itself, and the bar is likely to be worn. It was also found that printing performance deteriorates and becomes unstable due to poor applicability.

  Further, it was found that when A exceeds 4.3D, particles are likely to be clogged in the bar, resulting in coating streaks, or the particles cannot be retained after being dried and detached, resulting in deterioration in printing performance.

  From the above, it was found for the first time that both the coating and printing performance are good and stable within the scope of the present invention.

(bar)
The bar used in the present invention may be a wire bar in which a wire is wound around a metal bar or a wireless bar in which no wire is wound. In addition, a wireless bar is a bar which does not use the wire produced by rolling using the screw rolling round die instead of the bar produced by winding the wire.

(Particulate matter)
-A filler can be mentioned as a particulate matter. Examples of the filler include inorganic fine particles and organic resin particles. For example, carbon black, graphite, silica gel, TiO ₂ (titanium oxide), BaSO ₄ , ZnS, MgCO ₃ , CaCO ₃ (calcium carbonate), ZnO, CaO, WS ₂ , MoS ₂ , MgO, SnO ₂ , Al ₂ O ₃ (alumina), acid clay, activated clay, α-Fe ₂ O ₃ , α-FeOOH, SiC, CeO ₂ , BN, SiN, MoC, BC, WC , Titanium carbide, corundum, artificial diamond, garnet, garnet, silica, triboli, diatomaceous earth, dolomite and other inorganic fillers, polyethylene resin particles, fluororesin particles, guanamine resin particles, acrylic resin particles, silicon resin particles, melamine resin Organic fillers such as particles can be mentioned.
-The filler which has a core-shell structure can be mentioned as a particulate matter.

  The particles having a core-shell structure are particles obtained by fixing particles to a portion that becomes a shell on the surface of the core particles. The core particles and the particles that become the shell may be inorganic particles or organic particles. The core particles may be fixed (coated) in a number of layers with the shell 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 surface uneven particles, the average particle size of the small particles is preferably 1/3 or less, more preferably 1/10 or less, of the average particle size of the core particles. The average particle diameter of the surface irregular particles is preferably not more than 15 μm, and 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.

  For example, the surface irregularity particles may be obtained by, for example, a method using the 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 the core particle, “Particle Design” It can be easily produced using a dry agglomeration stirring method using a hybridizer described in “Engineering”. Certain core-shell particles can be produced by precipitating small particles on the surface of the core particles.

  -A wax can be mentioned as a particulate matter.

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

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.
-A metal atom containing particle can be mentioned as a particulate matter.

  The metal atom-containing particles are a general term for compounds such as metals such as iron, chromium, manganese, cobalt, nickel, copper, zinc, titanium, silver, aluminum, gold, and platinum, or oxides thereof.

  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.

(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.

(binder)
The binder used in 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.

(Image forming layer)
The image forming layer of the lithographic printing plate precursor according to the invention can be selected and contained from heat-fusible particles that can be fused by heat and substances that exhibit lipophilicity by heat.

Examples of heat-meltable 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. Among these, those having a melting point of 70 to 180 ° C. are preferable, and the hydrophilic component of the surface energy is preferably 1 × 10 ⁻⁴ N / cm ² or less. When the melting point is lower than this temperature, the performance during storage tends to deteriorate, and when it is higher than this temperature, the image strength cannot be obtained and the printing durability tends to deteriorate. Further, 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, whale wax, wood wax, jojoba oil, lanolin, ozokerite, paraffin wax, montan wax, candelilla wax, ceresin wax, microcrystalline wax, rice wax, and the like. Natural wax, polyethylene wax, Fischer-Tropsch wax, montan wax derivative, paraffin wax derivative, microcrystalline wax derivative, higher fatty acid 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.

  A hydrophilic binder is added to the image forming layer containing heat-fusible particles that can be fused by heat in order to give the film-forming property of the image-forming layer within a range that does not impair the fusing property 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. Further, 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 and colloidal silica can also be used.

  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 waxes 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 resins In, for example, methyl methacrylate, butyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, styrene, or the like is copolymerized, or synthetic rubbers are polybutadiene. , 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. As another embodiment, there can be mentioned a thermal cross-linking agent covered with a thermally destructible hydrophilic coating material, and a thermal cross-linking agent in which a functional group is blocked by a protecting group 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.

(Hydrophilic layer)
The hydrophilic layer described in the present invention is defined as a layer that can take in more water when an emulsified solution of water and ink comes during printing.

  In the present invention, other layers may be formed between the substrate and the hydrophilic layer. For example, an undercoat layer that improves the adhesion of the hydrophilic layer, a swell-forming layer that imparts a gentle roughness with 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.

(Preparation of lithographic printing plate precursor)
The lithographic printing plate precursor according to the invention can be produced by providing an image forming layer as a photosensitive layer on the above-mentioned support.

  The image forming layer is prepared by kneading 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 prepare a high concentration image forming layer forming composition, Then, it is diluted to form a photosensitive layer forming composition for coating, which can be formed by coating and drying on a support.

  The organic solvent used in the coating material for forming the image forming layer is not particularly limited as long as it can dissolve or disperse the above-described composition and the metal ion complex dye represented by the general formula. For example, alcohols ( Ethanol, propanol, etc.), cellosolves (methyl cellosolve, ethyl cellosolve, etc.), aromatics (toluene, xylene, chlorobenzene, etc.), ketones (acetone, methyl ethyl ketone, etc.), ester solvents (ethyl acetate, butyl acetate, etc.) , Ethers (tetrahydrofuran, dioxane, etc.), halogenated solvents (chloroform, dichlorobenzene, etc.), amide solvents (for example, dimethylformamide, N-methylpyrrolidone, etc.) and the like can be used. In addition, the kneading dispersion of the colorant layer components is 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, Dispers, 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)
As the exposure light source for forming an image on the lithographic printing plate precursor according to the invention, any light source capable of being sensitive to a metal ion complex dye can be used without particular limitation. 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. 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.

Laser light sources used in the printing method of the present invention are generally well-known solid lasers such as ruby laser, YAG laser, and glass laser; He-Ne laser, Ar ion laser, Kr ion laser, CO ₂ laser, CO laser Gas lasers such as He-Cd laser, N ₂ laser, excimer laser; semiconductor lasers such as InGaP laser, AlGaAs laser, GaAsP laser, InGaAs laser, InAsP laser, CdSnP ₂ laser, GaSb laser; chemical laser, dye laser, etc. Among these, in order to efficiently cause ablation, a laser having a wavelength of 600 to 1200 nm is preferable in terms of sensitivity because it can convert light energy into heat 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.

(On-machine development)
The on-press development in the present invention has the following contents.

  By mounting the exposed lithographic printing plate precursor on the cylinder of the printing press and supplying dampening water and ink while rotating the cylinder, the unexposed part of the image forming layer of the lithographic printing plate precursor is removed. is there.

  That is, after the exposure of the planographic printing plate precursor, it is mounted on a printing machine as it is, and the development process is completed in a normal printing process.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these. In addition, unless otherwise indicated, "part" in an Example shows a "mass part".

Example 1
<< Production of Support 1 (Production of Polyester Film) >>
(Support 1: Polyethylene terephthalate support)
Using terephthalic acid and ethylene glycol, PET of IV (inherent viscosity) = 0.66 (measured in phenol / tetrachloroethane = 6/4 (mass ratio) at 25 ° C.) was obtained according to a conventional method. This is pelletized, dried at 130 ° C. for 4 hours, melted at 300 ° C., extruded from a T-die, rapidly cooled on a cooling drum at 50 ° C., and not yet thick enough to have an average film thickness of 175 μm after heat setting. A stretched film was prepared. With respect to the drawing temperature, the first drawing was stretched 1.3 times at 102 ° C. and the second drawing was longitudinally stretched 2.6 times at 110 ° C. Then, it was stretched 4.5 times at 120 ° C. with a tenter. Thereafter, the film was heat-fixed at 240 ° C. for 20 seconds and relaxed by 4% in the lateral direction at the same temperature. Thereafter, the chuck portion of the tenter was slit, knurled at both ends, cooled to 40 ° C. and wound at 4.8 kg / m. In this way, a biaxially stretched PET film having a thickness of 190 μm was obtained. The biaxially stretched PET film had a Tg of 79 ° C. The width of the obtained PET film (film forming width) was 2.5 m. Further, the thickness distribution of the obtained support 1 was 3%.

<< Preparation of underdrawn support 1 >>
The both sides of the film of the support 1 obtained above are subjected to a corona discharge treatment of 8 W / m ² · min, and then the following undercoat coating solution a is applied to one side so that the dry film thickness becomes 0.8 μm. After coating, undercoating liquid b was applied to a dry film thickness of 0.1 μm while performing corona discharge treatment (8 W / m ² · min), and dried at 180 ° C. for 4 minutes (undercoating surface A). ). Also, after coating the following undercoat coating solution c on the opposite side so as to have a dry film thickness of 0.8 μm, the undercoat coating solution d is dried film thickness 1 while performing corona discharge treatment (8 W / m ² · min). The coating was applied to a thickness of 0.0 μm and dried at 180 ° C. for 4 minutes (undercoating surface B). The surface electrical resistance of the undercoat surface B after coating at 25 ° C. and 25% RH was 10 ⁸ Ω.

<Undercoat coating liquid a>
Styrene / glycidyl methacrylate / butyl acrylate = 60/39/1 terpolymer copolymer latex (Tg = 75 ° C.) (solid content basis) 6.3%
Styrene / glycidyl methacrylate / butyl acrylate = 20/40/40 terpolymer latex 1.6%
Anionic surfactant S-1 0.1%
Water 92.0%
<Undercoat coating solution b>
Gelatin 1%
Anionic surfactant S-1 0.05%
Hardener H-1 0.02%
Matting agent (silica, average particle size 3.5 μm) 0.02%
Antifungal agent F-1 0.01%
Water 98.9%

<Undercoat coating liquid c>
Styrene / glycidyl methacrylate / butyl acrylate = 20/40/40 terpolymer latex (based on solid content) 0.4%
Styrene / glycidyl methacrylate / butyl acrylate / acetoacetoxyethyl methacrylate = 39/40/20/1 quaternary copolymer latex 7.6%
Anionic surfactant S-1 0.1%
Water 91.9%
<Undercoat coating solution d>
Conductive composition of component d-1 / component d-2 / component d-3 = 66/31/1 6.4%
Hardener H-2 0.7%
Anionic surfactant S-1 0.07%
Matting agent (silica, average particle size 3.5 μm) 0.03%
Water 93.4%
Component d-1;
Anionic polymer compound component d-2 comprising a copolymer of sodium styrenesulfonate / maleic acid = 50/50;
Three-component copolymer latex component d-3 comprising styrene / glycidyl methacrylate / butyl acrylate = 40/40/20;
Polymeric activator comprising styrene / sodium isoprenesulfonate = 80/20

<< Plasma treatment conditions >>
Plasma treatment was performed on the surface of each undercoat layer under the following plasma treatment conditions.

  Using a batch type atmospheric pressure plasma processing apparatus (EC-I-H-340, manufactured by EC Chemical Co., Ltd.), the high frequency output is 4.5 kW, the frequency is 5 kHz, the processing time is 5 seconds, and the gas conditions are argon, Plasma treatment was performed at a volume ratio of nitrogen and hydrogen of 90% and 5%, respectively.

《Heat treatment conditions》
The support after slitting to a width of 1.25 m was subjected to low tension heat treatment at 180 ° C. for 1 minute at a tension of 2 hPa.

<< Preparation of Samples 101 to 106 with First Hydrophilic Layer Applied >>
<< Preparation of Sample 101 >>
The first hydrophilic layer coating solution having the following composition on the undercoat surface A side of the polyester film 175 μm thickness and 120 cm width was wet film thickness (W (μm): an excess of the hydrophilic layer coating solution was scraped off using a bar. The coating is applied using a wire bar so that the hydrophilic layer thickness is 16.0 μm and the dry film thickness (D (μm): film thickness after drying of the hydrophilic layer) is 3.2 μm. Sample 101 coated with one hydrophilic layer was produced.

<First hydrophilic layer coating solution>
Snowtex-XS (manufactured by Nissan Chemical Industries, Ltd.) Average particle size 0.005 μm 9.62 parts Snowtex-ZL (manufactured by Nissan Chemical Industries, Ltd.) Average particle diameter 0.085 μm 0.6 parts Shilton JC-40 (Mizusawa Chemical Industries) Co., Ltd.] Average particle size: 4.0 μm (A (μm): average particle size of the largest particles in the hydrophilic layer) 2.22 parts Optobead 6500S [Nissan Chemical Industry Co., Ltd.] Coated particle average particle size 6.5 μm 3 parts sodium carboxymethyl cellulose (manufactured by Kanto Chemical Co., Ltd.) 0.12 parts mineral colloid MO (manufactured by Wilber-Ellis) 0.22 parts MF-4500 black (manufactured by Daiichi Seika Kogyo Co., Ltd.) Photothermal conversion material 4 parts phosphorus Trisodium acid 12 water [manufactured by Kanto Chemical Co., Ltd.] 0.06 parts FZ-2161 (manufactured by Nihon Unicar Co., Ltd.) 0.16 parts pure water 80 parts << Preparation of Sample 102 >>
In sample 101, instead of Optobead 6500S (3 parts), Shiruton JC-40 (manufactured by Mizusawa Chemical Industry Co., Ltd.) average particle size 4.0 μm (A (μm): the largest particle of the particles in the hydrophilic layer Sample 102 was prepared in the same manner except that 3 parts of (average particle diameter) was added (thus, the total amount of Shilton JC-40 was 5.22 parts).

<< Preparation of Sample 103 >>
In sample 101, instead of optobead 6500S (3 parts), optobead 10500 (manufactured by Nissan Chemical Industries, Ltd.) average particle size 10.5 μm (A (μm): average of the largest particles in the hydrophilic layer Sample 103 was prepared in the same manner except that 3 parts of (particle size) was added.

<< Preparation of Sample 104 >>
In Sample 101, instead of OptoBead 6500S (3 parts), Silicia 780 [Fuji Silysia Chemical Co., Ltd.] average particle size 11.3 μm (A (μm): average particle size of the largest particles in the hydrophilic layer Sample 104 was prepared in the same manner except that 3 parts of (diameter) was added.

<< Preparation of Sample 105 >>
In sample 101, instead of Shiruton JC-40 (2.22 parts) and Optobead 6500S (3 parts), Shiruton JC-30 [Mizusawa Chemical Industry Co., Ltd.] average particle size of 3.0 μm (A (μm): hydrophilic layer Sample 105 was prepared in the same manner except that 5.22 parts of the average particle size of the largest particles in the sample was added.

<< Preparation of Sample 106 >>
In Sample 101, instead of OptoBead 6500S (3 parts), Silicia 470 [Fuji Silysia Chemical Co., Ltd.] average particle size of 14.1 μm (A (μm): average particle size of the largest particles in the hydrophilic layer Sample 106 was prepared in the same manner except that 3 parts of (diameter) was added.

"Evaluation methods"
<Evaluation of coating defects>
After 100 m and 2000 m after the start of coating, the number of missing coating failures per m ² of the sample was visually counted. The larger the number of coating defects, the worse.

<Evaluation of missing size>
After 100 m and 2000 m after the start of coating, the size (μm) of the largest of the coating failure missing per m ² of the sample was measured.

<Evaluation of vertical stripe (application direction stripe)>
After 100 m and 2000 m after the start of coating, vertical streaks (coating direction streaks) per m ² of the sample were visually observed and evaluated according to the following evaluation criteria (rank).

5: No occurrence 4: Slight occurrence, but no actual harm 3: Slight occurrence, actual concern level 2: Slight occurrence, actual damage 1: Many occurrences, actual damage 〈Bar reusability (wear) Evaluation)
The coated bar was washed by the following washing method, and reusability related to the degree of clogging of the bar was visually observed and visually evaluated based on the following evaluation criteria.

Cleaning method:
2 L of water was placed in an ultrasonic cleaner FU-926 manufactured by Tokyo Glass Instrument Co., Ltd., and 10 ml of ultrasonic cleaner Contaminone US manufactured by Wako Pure Chemical Industries, Ltd. was added for cleaning for 24 hours.

Evaluation rank:
3: No clogging, no problem at all for reuse 2: Little clogging, no problem at all for reuse 1: Many clogs, no reuse available Table 1 shows the results.

  As apparent from Table 1, a sample coated with a stable first hydrophilic layer (sample for producing a lithographic printing plate precursor) has good coating properties as long as it is within the range of the method for producing a lithographic printing plate precursor according to the present invention. It can be seen that is obtained.

Example 2
<< Preparation of planographic printing plate precursor samples 201-206 >>
The samples 101 to 106 coated with the first hydrophilic layer obtained in Example 1 were coated with the following second hydrophilic layer and then coated with the following image forming layer to prepare lithographic printing plate precursor samples 201 to 206. . That is,
<Application of second hydrophilic layer>
The following second hydrophilic layer coating solution was applied to Samples 101 to 106 coated with the first hydrophilic layer obtained in Example 1, with W = 3.5 μm (1/4 W = 0.875 μm) and dry film thickness D = 0. A second hydrophilic layer was provided by applying and drying using a wire bar so that the thickness was 0.7 μm (at this time, A = 1.5 μm).

<Second hydrophilic layer coating solution>
Snowtex-S [Nissan Chemical Industry Co., Ltd.] average particle size 0.009 μm 2.65 parts Snowtex-PSM [Nissan Chemical Industry Co., Ltd.] average particle size 0.095 μm
3.899 parts Shilton JC-20 [Mizusawa Chemical Industry Co., Ltd.] Average particle size 1.5 μm 1.99 parts AMT-08 [Mizusawa Chemical Industry Co., Ltd.] Average particle size 0.95 μm 5.99 parts MP-4540 [Nissan] Chemical Industry Co., Ltd.] Average particle size 0.45 μm 2.99 parts Sodium carboxymethyl cellulose [Kanto Chemical Co., Ltd.] 0.19 parts Mineral colloid MO [Wilver-Ellis Co., Ltd.] 0.39 parts MF-4500 Black [Daiichi Seika Kogyo Co., Ltd.] Photothermal conversion material 1.799 parts Trisodium phosphate 12 water [Kanto Chemical Co., Ltd.] 0.0999 parts Pure water 80 parts << Application of image forming layer >>
On the second hydrophilic layer provided above, the image forming layer coating solution is coated and dried using a microgravure coating apparatus so as to have a dry film thickness of 0.60 (g / m ² ). Original plate samples 201 to 206 were prepared.

<Image forming layer coating solution>
HI-DISPER A-206
[Gifu Shellac Manufacturing Co., Ltd.] Average particle diameter of heat-meltable particles 0.5 μm 2.375 parts DL-522 [Nippon Catalyst Co., Ltd. average molecular weight 170.000] 0.7125 parts HI-DISPER A118
[Gifu Shellac Manufacturing Co., Ltd.] Average particle size of heat-meltable particles 0.3 μm
6.4125 parts Pure water 90.5 parts << Evaluation method >>
Evaluation similar to Example 1 and the following evaluation were performed.

<Exposure and printing of planographic printing plate precursor>
Using the obtained lithographic printing plate precursor, a semiconductor laser light source (light emission 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 precursor is attached to a Heidel GTO printing machine without developing, and 45 times water diluted solution of SEU-3 (manufactured by Konica Co., Ltd.) as an etchant and HiEcho (Toyo Ink Manufacturing Co., Ltd.) as an ink. )), And printing was performed using high-quality paper as printing paper.
Printing was performed in an environment of 23 degrees 48%.

<Finished print quality>
The print quality of the 30th printed product after the start of printing was visually evaluated according to the following evaluation criteria.

5: Quality is good 4: Quality is slightly inferior, but no problem in use 3: Quality is slightly inferior, but usable level 2: Poor quality, level of fear of actual damage 1: Poor quality, unusable <Print life>
After the start of printing, the number of sheets when the 50% halftone dot of the printed material was not reproduced was evaluated and measured visually. The larger the number, the higher the printing durability and the better.

  The results are shown in Table 2.

  As is apparent from Table 2, it can be seen that the coating property is good, the coating property is stable, and the printing performance is good as long as it is within the range of the production method and printing method of the planographic printing plate precursor of the present invention.

Claims (2)

A method for producing a lithographic printing plate precursor in which a hydrophilic layer having particles and an image forming layer are sequentially provided on a support, and an excessive amount of hydrophilic is provided on a belt-like support on which the hydrophilic layer is continuously conveyed. In the method for producing a lithographic printing plate precursor provided after applying a layer coating solution, scraping off the excess of the applied hydrophilic layer coating solution using a bar, applying and drying,
(1/4) W ≦ A ≦ 4.3D
However,
A (μm): average particle size of the particle material type having the largest average particle size among the particle material types in the hydrophilic layer W (μm): hydrophilic after scraping off excess of the hydrophilic layer coating solution using a bar Layer thickness D (μm): A method for producing a lithographic printing plate precursor, which is a thickness after drying of the hydrophilic layer. A lithographic printing plate precursor produced by the production method according to claim 1, wherein the lithographic printing plate precursor is subjected to laser exposure based on image information and subjected to on-press development processing for printing.