JP2005169966A - Manufacturing method for planographic printing plate original plate, planographic printing plate original plate and printing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for a planographic printing plate original plate using a bar coating method, by which a coated surface free from coating defects, having a uniform surface shape, stable and excellent coating properties can be obtained and which has excellent printing performance, and a planographic printing plate original plate manufactured using the method and a printing method. <P>SOLUTION: In the planographic printing plate original plate, a hydrophilic layer containing particular subjects is formed on a support, and an image-forming layer is formed on the hydrophilic layer. Reynolds number Re in a liquid supply pipeline of the hydrophilic layer coating liquid is adjusted to 3.000 to 10.000, the excess amount of the hydrophilic layer coating liquid is once applied on a continuously conveyed support strip and then coating is performed while the excess amount of the hydrophilic layer coating liquid is scraped off with the bar. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for producing a lithographic printing plate precursor, and furthermore, image recording based on a digital signal produced thereby is possible, and a stable printed matter can be obtained without coating defects. The present invention relates to a planographic printing plate precursor and a printing method.

  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, and the time and cost required for film production can be reduced. It has become possible.

  In addition, as a need for printed materials, there has been a tendency for high-quality, low-volume, multi-product printing that prints a variety of high-quality images with several thousand to 10,000 printed 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 standpoint of environmental suitability, a lithographic printing plate material that does not require an alkaline developer and does not require any development treatment has been desired. It was.

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

  In line with the above trend, it has been demanded that a lithographic printing plate precursor can use a plastic film as a support in recent years 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.

  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.

  In recent years, as a method of simply applying to a belt-like support that is continuously conveyed in the application method using the above-described application device, a bar coating device that has been widely used for thin film and high-speed application has been used. Bar coating methods are known.

  In the bar coating method, as a first step, a roll coating apparatus is used to apply an excessive amount of coating liquid to the belt-like support, and the excessive coating liquid (primary film) is coated with a bar coating apparatus (the bar is stationary or rotating). In this method, a desired film thickness (secondary film) is obtained by pressing a bar and scraping off an excessive coating solution. In the bar coating method, the final film thickness after scraping is determined only by the cut surface of the groove formed in the bar.

  There is no particular limitation on the device for applying an excessive coating liquid in combination with the bar coating device, and each of the above coating devices can be used. Generally, devices such as a dip coating device, a roll coating device, a fountain coating device, and a comma coating device are used. Also, a coating apparatus in which the overcoating and the bar coating apparatus are integrated as described in JP-A-6-170312 may be used.

Regarding the production of a lithographic printing plate, Patent Document 1 describes that an undercoat layer containing specific metal oxide particles is provided on a support by bar coating, but there is no description of appropriate conditions and the like. . Further, Patent Document 2 discloses a method for producing a resin layer in which the number of lay nozzles of the circulating fluid is defined, but there is no description relating to the bar coating method in the production of a lithographic printing plate precursor, particularly the coating stability.
Japanese Patent Laid-Open No. 14-154278 JP-A-5-1108

  As described above, after applying an excessive amount of the coating solution onto the belt-like support that is continuously conveyed, the excess amount of the coating solution is scraped off using a bar, and the lithographic printing plate precursor is coated by applying an appropriate amount. However, it has not yet been clarified what a lithographic printing plate coating method with good coating properties and stable performance does not require a special bar coating device. There is no current situation.

  The object of the present invention is to provide a stable coated surface having good coating properties with no coating defects, uniform surface shape, and good performance on a long belt-like support using a wire bar coating device. It is an object of the present invention to provide a method for producing a lithographic printing plate precursor using a coating method, and a lithographic printing plate precursor and a printing method produced using the same.

The object of the present invention has been achieved by adopting the following constitution.
(Claim 1)
In the method for producing a lithographic printing plate precursor in which a hydrophilic layer containing a particulate matter is coated on a support, and an image forming layer is coated on the hydrophilic layer, The number of lay nozzles (Re) is adjusted to 3.000 or more and 10.000 or less, and once an excessive amount of hydrophilic layer coating solution is applied onto the belt-like support that is continuously conveyed, the excessive amount of hydrophilic layer A method for producing a lithographic printing plate precursor, wherein the coating solution is applied while being scraped off using a bar.
(Claim 2)
A lithographic printing plate precursor produced by the method for producing a lithographic printing plate precursor according to claim 1.
(Claim 3)
A lithographic printing plate precursor produced by the method for producing a lithographic printing plate precursor according to claim 1 is subjected to laser exposure based on image information, subjected to on-machine development treatment to produce a lithographic printing plate and print it. Printing method.

  If the configuration of the present invention is satisfied, stable coating properties during production and good performance of the finished lithographic printing plate precursor can be obtained even if the coating line and the operator are different. The reason for this is not necessarily clear, but when manufactured under conditions deviating from the structural requirements of the present invention, stable applicability in the width direction and in the longitudinal direction cannot be obtained, and as a lithographic printing plate precursor Only performance with large fluctuations can be obtained.

  According to the present invention, a long bar-shaped support using a wire bar coating apparatus has a coating surface free from coating defects and having a uniform surface shape, a stable and good coating property, and a good performance. A lithographic printing plate precursor using the lithographic printing plate, a lithographic printing plate precursor produced using the lithographic printing plate precursor, and a printing method can be provided.

  According to the present invention, the number of lay nozzles (Re) in the liquid feeding pipe of the hydrophilic layer coating liquid is adjusted to 3.000 or more and 10.000 or less, and an excessive amount of the hydrophilic layer is formed on the belt-like support continuously conveyed. After applying the coating solution, the hydrophilic layer is applied by a bar coating method in which excess coating solution is scraped off using a bar, and then an image forming layer is formed on the hydrophilic layer. A lithographic printing plate precursor having a uniform, stable and good coating surface can be obtained.

[Number of ray nozzles]
The number of lay nozzles (Re) in the present invention is a number representing the state of fluid flow and is defined as follows.

The number of fluid lay nozzles (Re) is
(Pipe diameter x flow velocity x fluid density) / (fluid viscosity)
Given in.

  In actual application, by adjusting the values of each of these requirements, the number of lay nozzles (Re) of the fluid can be determined appropriately by the above formula, stable long application, good application performance, printing performance Has been found to be able to obtain a remarkably stable lithographic printing plate precursor.

  That is, when the number of lay nozzles (Re) of the fluid was variously evaluated and the number of lay nozzles (Re) was 3000 or more, particle aggregation in the pipe was prevented both microscopically and macroscopically. It has been found that long continuous coating has good applicability and has good printing performance.

  However, it has been found that when the number of lay nozzles (Re) exceeds 10,000, it is difficult to form a primary film stably on the base in bar coating, a coating failure occurs, and printing performance is not stable.

  The number of lay nozzles (Re) can be controlled over a wide range by a circulation pump, and a circulation pump such as a Mono pump, a gear pump, or a diaphragm pump can be used without particular limitation.

[Particulate matter]
The particulate matter in the present invention may have a spherical shape, a needle shape, or an irregular shape, and is not particularly limited, but has a particle size, filler, matting agent, dispersion, The binder (insoluble matter, polymerized product) that is not soluble in the solvent is shown, and a plurality of these may be used in combination.

For example, 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, fluororesin Examples include organic fillers such as particles, guanamine resin particles, acrylic resin particles, silicon resin particles, and melamine resin particles.

  A typical particulate material in the present invention can include a filler, but examples of the filler include inorganic fine particles and organic resin particles, which may also serve as a release agent. Examples of the inorganic fine particles include silica gel, calcium carbonate, titanium oxide, acidic clay, activated clay, and alumina. Examples of the organic fine particles include resin particles such as fluorine resin particles, guanamine resin particles, acrylic resin particles, and silicone resin particles. Can be mentioned.

  A matting agent having a core-shell structure can also be exemplified as the particulate matter.

  The particles having a core-shell structure are particles formed by fixing particles that become shells on the surface of the core particles. The portion of the core-shell particle that becomes the shell may be an inorganic particle or an organic particle. 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 particles having irregularities on the surface, the average particle size of the small particles constituting the convex portion 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 particle is a method using the hetero-aggregation method described in “New Development of Fine Particle Polymer” edited by Toray Research Center, Inc., a method using a polymerization reaction from the surface of the core particle, “Particle Design Engineering” edited by the Powder Engineering Society. Can be easily produced using a dry agglomeration stirring method using the hybridizer described in 1. above. Certain core-shell particles can be produced by precipitating small particles on the surface of the core particles.

  Furthermore, 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 Radical reactive silicone oil such as silicone oil, amide modified silicone oil, (meth) acrylic modified silicone oil, silicone diol, Terminal reactive silicone oil such as Njiamin, a halogen group, an alkoxy group, and an ester group, an amide group, an organic modified silicone oil modified with an imide group.

  In the present invention, metal atom-containing particles can also be used.

  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 FeOx (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 Ox (4/3 <x <3/2) powders.

[Support]
The support used in the present invention is not particularly limited, and a plastic film, paper treated with 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 the adhesion to 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 resin]
The binder resin for coating solution used in the present invention is not particularly limited and can be used.

  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)
In the image forming layer of the lithographic printing plate precursor according to the invention, it is possible to select from among heat-meltable 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 100 μN / cm ² or less. If the melting point is lower than this temperature, performance deterioration during storage tends to occur, and if it is higher than this temperature, the image strength cannot be obtained and 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, whale wax, wood 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.

  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 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. Examples of resins include those obtained by copolymerizing one or more of methyl methacrylate, butyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, styrene, and the like. Ene, 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. ing.

[Hydrophilic layer and other layers]
In the present invention, it is preferable that a hydrophilic layer is provided on the planographic printing plate precursor. A hydrophilic layer is defined as a layer that can take in more water when it comes into contact with an emulsified solution of water and ink during printing.

  In the present invention, other layers may be formed between the support and the hydrophilic layer. For example, there are an undercoat layer that improves the adhesion 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.

[Preparation of lithographic printing plate precursor]
The lithographic printing plate precursor according to the invention can be produced by providing a photosensitive layer on the above-mentioned support.

  The photosensitive 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 photosensitive layer forming composition, This can be 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 paint for forming the photosensitive 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), aromatics (toluene, xylene, chlorobenzene etc.), ketones (acetone, methyl ethyl ketone etc.), ester solvents (ethyl acetate, butyl acetate etc.), ether (Tetrahydrofuran, dioxane, etc.), halogen 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.

  Formation of the photosensitive layer on the support can be performed, for example, by coating and drying with an extrusion type extrusion coater. In order to increase the hardness of the photosensitive layer surface in order to obtain a high-resolution image, the surface is formed. Calendar processing may be performed.

[Printing method and image exposure]
As an 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 the metal ion complex dye represented by the above general formula 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. 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.

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.

[On-machine development]
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.

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

  In other words, the lithographic printing plate precursor is exposed and then 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, the aspect of this invention is not limited to this. In the following text, “parts” means “parts by mass” and “%” means “% by mass” unless otherwise specified.

[Example 1]
<< Preparation of Support >>: Preparation 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.

  The stretching temperature was stretched longitudinally by 1.3 times at 102 ° C. in the former stage stretching and 2.6 times at the latter stage stretching 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 up at 48 N / 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 >>
Both sides of the film of the support 1 obtained above were subjected to a corona discharge treatment of 8 W / m ² · min, and then, as shown in Table 4, the following undercoat coating solution a was applied to one side as a dry film. After coating to a thickness of 0.8 μm, the undercoating liquid b was applied to a dry film thickness of 0.1 μm while performing corona discharge treatment (8 W / m ² · min), each at 180 ° C. for 4 minutes. Dried (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.

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

<< Undercoat coating liquid a >>
Styrene / glycidyl methacrylate / butyl acrylate = 60/39/1 ternary copolymer latex (Tg = 75 ° C.) 6.3% (based on solid content)
Styrene / glycidyl methacrylate / butyl acrylate = 20/40/40 terpolymer latex 1.6%
Anionic surfactant S-1 0.1%
Water 92.0%
<< Undercoat coating liquid b >>
Gelatin 1.0%
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 ternary copolymer latex 0.4% (based on solid content)
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 liquid 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;
An anionic polymer compound comprising a copolymer of sodium styrenesulfonate / maleic acid = 50/50; component d-2;
Three-component copolymer latex consisting of styrene / glycidyl methacrylate / butyl acrylate = 40/40/20 component d-3;
Polymeric activator comprising styrene / sodium isoprenesulfonate = 80/20

<< Plasma treatment conditions >>
Using a batch type atmospheric pressure plasma processing apparatus (AP-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, nitrogen and Plasma treatment was performed with hydrogen mixing volume ratios 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.

  The polyester film was provided on the undercoat surface A side of the polyester film having a thickness of 175 μm and a width of 120 cm in the order of the following coating solutions.

  The coating solution was applied using a wire bar so that the dried film became 3.2 μm.

At this time, coating was carried out by adjusting the number of lay nozzles to 4000 (piping 0.015 m, flow rate 0.7843 m / sec, fluid density 1700 kg / m ² , fluid viscosity 0.005 kg / m · sec).

<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 size 0.085 μm) 0.6 parts Shilton JC-40 (Mizusawa Chemical Industry Co., Ltd .: Average particle size 4.0 μm) 2.22 parts Opto beads (Nissan Chemical Industry Co., Ltd .: coated particle average particle size 6.5 μm) 3 parts Sodium carboxymethylcellulose (Kanto Chemical Co., Ltd.) 0.12 parts Mineral Colloid MO (manufactured by Wilber-Ellis) 0.22 parts MF-4500 black (manufactured by Dainichi Seika Kogyo Co., Ltd .: photothermal conversion material) 4 parts trisodium phosphate 12 hydrate (manufactured by Kanto Chemical Co., Ltd.) 0.06 parts FZ -161 (Nihon Unicar Co., Ltd.) 0.16 parts pure water 80 parts This sample is designated as sample 101.

Similarly, change the Reynolds number by changing the diameter and flow velocity of the pipe at the time of application, and change the sample number. Sample Nos. 2 to 113 were evaluated. The following evaluation was performed using samples 1-113.

(Coating defects)
Omission of samples per m ² after the coating after 100,2000M (uncoated portion), trailing (those are Sujiba' around the uncoated portions) were counted coating defects.

  As the number of coating defects increases, the number of missing defects increases and there are coating defects.

(Omitted size)
The size (diameter: μm) of the largest coating failure missing per sample m ² after 100 and 2000 m after coating was measured.

(Applied muscle)
The coating streaks (bar streaks) of sample m ² 100 and 2000 m after coating were evaluated according to the following rank.
3: Nothing at all 2; Slightly, no harm area 1: Very many occurrences, actual damage (surface roughness)
As a guideline for evaluating the coating accuracy of the length and width, the surface roughness after coating and drying was measured as an average surface roughness of m ² after 100 and 2000 m after coating.

  The average surface roughness was measured by RST + TLUS manufactured by WYKO.

(Bar reusability)
The bar after application | coating was wash | cleaned by the following method, and the clogging degree of a wire and reusability were evaluated visually.

  If the amount of sediment in the coating solution increases, bar clogging tends to occur.

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

Evaluation rank 3: No clogging, no re-use problem 2; Little clogging, no re-use problem 1: High clogging, non-reusable (sink in pipe)
The sediment in the piping after liquid circulation for 24 hours was evaluated in the following rank.
3: No sediment, no problem at all 2; Sediment is a little, but there is no actual problem 1: Large amount of sediment, remarkably time is required for cleaning work Also, the pipe diameter of the sample 101 (m), flow velocity (m / sec) ) Were also evaluated at the same time and are shown in Table 1.

  As is apparent from Table 1, it can be seen that a sample having a sufficiently stable coatability is obtained when the conditions of the present invention are satisfied.

[Example 2]
On the hydrophilic layer of the sample 101 obtained in Example 1, the following second hydrophilic layer was applied using a wire bar so that the dry film thickness was 0.6 μm. The number of lay nozzles at this time was 5000 (piping diameter 0.015 m, flow rate 0.729 m / sec, fluid density 1600 kg / m3, fluid viscosity 0.0035 kg / m · sec).

<Second hydrophilic layer coating solution>
Snowtex-S (manufactured by Nissan Chemical Industries, Ltd .: average particle size 0.009 μm) 1.56 parts Snowtex-PSM (manufactured by Nissan Chemical Industries, Ltd .: average particle size 0.095 μm) 2.34 parts Shilton JC-20 (Mizusawa) 1.2 parts AMT-08 (Mizusawa Chemical Co., Ltd .: average particle size 0.95 μm) 3.6 parts MP-4540 (Nissan Chemical Industries Co., Ltd .: average particle size) 0.45 μm) 1.8 parts sodium carboxymethylcellulose (manufactured by Kanto Chemical Co., Ltd.) 0.12 parts mineral colloid MO (manufactured by Wilber-Ellis Co., Ltd.) 0.24 parts MF-4500 black (manufactured by Dainichi Seika Kogyo Co., Ltd .: photothermal conversion material) ) 1.08 parts trisodium phosphate.12 hydrate (manufactured by Kanto Chemical Co., Ltd.) 0.06 parts pure water 88 parts The resulting hydrophilic layer laminate product has a dry film thickness of 0.60 (g / m ² ). Gravure It was subjected to the following image formation layer coating using the apparatus.

<Image forming layer coating solution>
HI-DISPER A-206 (manufactured by Gifu Shellac Manufacturing Co., Ltd .: average particle diameter of heat-fusible particles 0.5 μm) 2.375 parts DL-522 (manufactured by Nippon Shokubai Co., Ltd .: average molecular weight 170.000) 0.7125 parts HI- DISPER A118 (manufactured by Gifu Shellac Manufacturing Co., Ltd .: average particle diameter of heat-fusible particles 0.3 μm) 6.4125 parts pure water 90.5 parts This sample is designated as sample 201.

Performance Evaluation In the same manner as in Example 1, the number of application defects, the size of application defects, and application stripes were evaluated, and the following evaluation was performed.

(Exposure and printing of lithographic 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 mounted on a Heidel GTO printing machine without developing, and is diluted with SEU-3 (manufactured by Konica Minolta) as a 45-fold water dilution, and ink is HiEcho (manufactured by Toyo Ink). And printing was performed using high-quality paper as printing paper.

  Printing was performed in an environment of 23 ° C. and 48% RH.

(Number of prints)
After the start of printing, the number of sheets when the printed matter was completely obtained was evaluated.

  The smaller the number of sheets, the less the waste paper and the shorter the time to start printing.

(Printed quality)
The finished quality of the 30th sheet after the start of printing was visually evaluated at the following rank.
5 ... Good quality 4 ... Slightly inferior but no problem in use 3 ... Slightly inferior in quality, but usable level 2 ... Poor quality, Practical concern level 1 ... Poor quality, Unusable (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, actual concern 2 ... With soil, actual damage 1 ... Many soil, actual damage (Print life)
The number of prints where 50% halftone dots were not reproduced was visually evaluated.

  The larger the number, the better the printing durability.

  Similarly, a second hydrophilic layer and an image forming layer were installed on the samples 102 to 113 of Example 1, and the same evaluation was performed.

  The results are shown in Table 2.

  As is clear from Table 2, it can be seen that a sample having satisfactory coating performance and sufficiently stable printing performance is obtained only when all the layers satisfy the present invention.

Claims (3)

In the method for producing a lithographic printing plate precursor in which a hydrophilic layer containing a particulate matter is coated on a support, and an image forming layer is coated on the hydrophilic layer, The number of lay nozzles (Re) is adjusted to 3.000 or more and 10.000 or less, and once an excessive amount of hydrophilic layer coating solution is applied onto the belt-like support that is continuously conveyed, the excessive amount of hydrophilic layer A method for producing a lithographic printing plate precursor, wherein the coating solution is applied while being scraped off using a bar. A lithographic printing plate precursor produced by the method for producing a lithographic printing plate precursor according to claim 1. A lithographic printing plate precursor produced by the method for producing a lithographic printing plate precursor according to claim 1 is subjected to laser exposure based on image information, subjected to on-machine development treatment to produce a lithographic printing plate and print it. Printing method.