JP2007313472A - Coating method, bar coating apparatus, and method for preparing planographic printing plate material using coating method and coating apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating method and coating apparatus capable of preventing clogging which may occur in practicing a coating method that employs a bar such as a wire bar or a wireless bar whereby a faulty coating is prevented and a stable and long coating can be formed and further a method for preparing a planographic printing plate material using the coating method and coating apparatus. <P>SOLUTION: The coating method that employs a bar coating apparatus is characterized in that coating is carried out while ultrasonic vibration is being applied to the coating apparatus. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a coating method, a bar coating apparatus, and a method for producing a lithographic printing plate material using them. Specifically, the present invention relates to a coating method for coating a solid particle dispersion or the like on a support using a bar coating device such as a wire bar, a coating device, and a method for producing a lithographic printing plate material using them.

  Many types of apparatuses are known as apparatuses for providing various coating layers on a support. For example, dip coating, roller coating, fountain coating, air knife, blade coating, bar coating, slide hopper, etc.

  Among the coating methods using the coating device, a bar coating method using a bar coating device is known as a method suitable for coating on a belt-like support that is continuously conveyed. In recent years, the bar coating method has been widely used for thin film and high-speed coating.

  In the bar coating method, as a first step, an appropriate amount of coating solution is applied to the belt-like support with a roll coating device or the like, and the excess coating solution (primary film) is applied to the bar coating device (the bar is stationary or rotating). ) To obtain a desired film thickness (secondary film) by pressing and scraping the bar. In this bar coating method, the final film thickness after scraping is determined only by the shape of the cut surface perpendicular to the bar axis direction of the groove formed in the bar, so that the accuracy is good.

  Each of the above coating devices can be used as a device for applying an excessive coating liquid in combination with a bar coating device. Generally, a dip coating device, a roll coating device, a fountain coating device, and a comma coating device are used. It has been. It is also possible to use a coating apparatus in which an apparatus for overcoating and a bar coating apparatus are integrated as described in JP-A-6-170312.

  In a conventional bar coating apparatus using a wire bar, a wireless bar, or the like, a coating liquid is brought into contact with a support with a fountain or a bat, and then applied while being scraped off with a wire bar or the like. However, if the coating liquid contains a matting agent or pigment, clogging occurs in the bar wires and uneven parts during long coating, which causes abnormal coating film thickness, uneven coating, and streaking. The so-called coating failure called “has occurred”.

  That is, in the method of scraping off the coating liquid attached to the support with a bar rotating in the forward or reverse direction to obtain the required film thickness, when the liquid containing solid particles is applied, Particles are clogged in the uneven portions of the bar, which triggers a problem that a coating failure occurs over time.

  As a countermeasure against this, there is a device in which a brush for cleaning the coating liquid attached to the wire of the rotating wire bar is brought into contact with the rotating bar as disclosed in Patent Document 1. In Patent Document 2, a blade is used as an improvement measure. However, in Patent Document 3, ultrasonic waves are applied to the coating liquid itself by an in-line ultrasonic dispersing machine at the time of coating, and particles in the coating liquid are redispersed for coating. It shows how to improve sex.

  However, the device disclosed in Patent Document 1 is incomplete in the liquid scraping operation with the brush on the wire bar in advance, and even if the brush is brought into contact with the wire bar surface, the particulate matter in the surplus coating cannot be scraped off. Clogging occurs and the uniformity of the coating thickness becomes insufficient. Also, there is no description of sliding the brush in particular, and there is a doubt about long-term use.

In Patent Document 2, the effect may not be exhibited depending on the particle size of the contained particles. Further, in Patent Document 3, even if this means is used, there is a possibility that the wire will become clogged to some extent if long coating is performed.
Japanese Utility Model Publication No. 62-50767 JP 11-47677 A JP 2005-254474 A

  The present invention has been made in view of the above problems, and its object is to prevent clogging in a coating method using a bar such as a wire bar or a wireless bar, thereby preventing a coating failure in advance and a stable long length. It is providing the application | coating method and coating device which enable isometric coating. Furthermore, it is providing the manufacturing method of the lithographic printing plate material using them.

  The above-mentioned problem according to the present invention is solved by the following means.

  1. A coating method using a bar coating device, wherein coating is performed while applying ultrasonic vibration to the coating device.

  2. 2. The coating method according to 1 above, wherein when applying a dispersion liquid in which solid particles are dispersed in a liquid, ultrasonic vibration is applied to the bar coating apparatus.

  3. The coating method according to claim 1 or 2, wherein the frequency of ultrasonic vibration applied during coating increases in proportion to the coating speed.

  4). A bar coating apparatus comprising an apparatus that generates ultrasonic vibrations that can be applied by the coating method according to any one of the above items 1 to 3.

  5. In the method for producing a lithographic printing plate material having at least a hydrophilic layer and an image forming layer on a support, the hydrophilic layer coating liquid for forming the hydrophilic layer is continuously transported on the belt-shaped support. A method for producing a lithographic printing plate material, which is applied by the coating method according to 1 to 3.

  According to the configuration of the present invention, in a coating method using a bar such as a wire bar or a wireless bar, a coating method and a coating apparatus that prevent clogging and thereby prevent a coating failure and enable stable long coating. Can be provided. Furthermore, the manufacturing method of the lithographic printing plate material using them can be provided.

The coating method of the present invention is characterized in that in the coating method using a bar coating device, coating is performed while applying ultrasonic vibration to the bar coating device. More specifically, the coating method of the present invention is characterized in that ultrasonic vibration is applied to the bar coating device when a dispersion liquid in which solid particles are dispersed in a liquid is applied.

  Hereinafter, the present invention will be described in detail.

(Applicator)
The coating method of the present invention can be applied to various coating apparatuses, and FIG. 1 shows a schematic side view of the entire example of the coating apparatus according to the present invention. 2 and 3 are front views of the bar coating apparatus according to the present invention.

  In FIG. 1, the coating liquid 9 in the coating liquid supply tank 1 is supplied to the coating liquid bat 3 by the liquid feed pump 2. The support 4 wound around the back roller 1 and conveyed around the bat 3 and dipped in the coating solution 9 is scraped off by the wire bar 8 to obtain a predetermined film thickness. The support 4 on which the coating liquid 9 has been applied then enters a drying zone and is dried. The wire bar 8 can be rotated in the forward or reverse direction with respect to the support 4.

  FIG. 2 is a front view of a conventional coater unit.

  FIG. 3 shows the configuration of the present invention, in which an ultrasonic transducer is installed at the end of the wire bar.

(Ultrasonic vibration)
The present invention is characterized in that a bar coating apparatus such as a wire bar or a wireless bar is vibrated in an ultrasonic region. The frequency of the vibration is not particularly limited as long as it is in the ultrasonic range, but is preferably 20 kHz to 100 kHz, and more preferably 30 kHz to 80 kHz.

  In the present invention, it is preferable that the frequency of ultrasonic vibration applied at the time of coating increases in proportion to the coating speed from the viewpoint of the effect according to the present invention.

(Ultrasonic transducer)
In the present invention, it is preferable to use an ultrasonic vibrator as a method of vibrating the bar. Any type of vibrator, such as electrostrictive type or magnetostrictive type, can be used, but because of its simple structure and reliability, and ease of control of oscillation frequency and output, electrostrictive Langevin type An ultrasonic transducer is preferably used. Furthermore, the types of vibration include axial vibration, torsional vibration, and flexural vibration, but the axial vibration method is preferable from the viewpoint of the effect on the bar coating apparatus.

  In order to attach the ultrasonic vibrator to the coating apparatus, it is an essential condition that energy can be transmitted to the wire bar or the like without loss. Examples of the place include a bar support, a chuck part holding the bar, a chuck shaft part, a bar end, and the like, but it is preferable to directly contact the bar end. By direct contact, energy can be transmitted to the bar without deteriorating.

(Bar member)
The bar according to the present invention is used without particular limitation such as a bar wound with a wire or a bar (wireless bar) without winding a wire, and the material is also used without limitation such as iron or stainless steel.
Further, the surface may be plated as necessary. 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 nickel, cobalt, hard chromium, titanium, and DLC (diamond-like carbon). The plating process may be performed alone, or a plurality of processes such as a hard chrome plating process may be further performed on the nickel plated process.

  The coating method of the present invention can be used in various technical fields. As a specific example, a case where the coating method is used in a process of producing a printing plate material will be described. That is, in the method for producing a lithographic printing plate material having at least a hydrophilic layer and an image forming layer on a support, the hydrophilic layer coating liquid for forming the hydrophilic layer is continuously conveyed on the belt-like support. The case of applying by the coating method of the present invention will be described.

(Support)
The support used in the present invention is not particularly limited, and a plastic film, paper treated with polyolefin or the like, a composite substrate obtained by appropriately bonding these materials, aluminum, or the like 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.

(Solid particle dispersion)
The solid particles according to the present invention mean fillers having a particle size, matting agents, dispersions, and binders that are not soluble in a solvent (undissolved materials, polymerized materials). Specific examples of the constituent material of the solid particles include the following.

  The solid particles may have a spherical shape, a needle shape, or an indeterminate shape. Examples of the solid particles include a filler.

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 thereof include organic fillers such as particles, guanamine resin particles, acrylic resin particles, silicon resin particles, and melamine resin particles.

  The filler may also serve as a release agent. A matting agent having a core-shell structure can also be mentioned as the particulate matter.

The particles having a core-shell structure also include particles obtained by fixing particles of a shell portion on the surface of the core particles. In this case, the core particle and the part of the particle serving as 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.

Moreover, the small particle | grains adhere to the surface of a large particle, and the particle | grains with an uneven surface may be sufficient. For example, a method using the heteroaggregation 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, and described in “Particle Design Engineering” edited by the Powder Engineering Society It can be easily manufactured using a dry agglomeration stirring method using a hybridizer. Some core-shell particles can be produced by precipitating small particles on the surface of the core particles.
Metal atom-containing particles may be used as the particle composition. 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.

(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.
The particulate matter contained in the hydrophilic layer has been described above.

  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.

  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.

(Image forming layer)
The image forming layer of the lithographic printing plate material according to the present invention can be selected and selected 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. 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, 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. 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 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.

  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), 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.

  The image forming layer can be formed, for example, by applying and drying with an extrusion type extrusion coater. In order to increase the hardness of the surface of the photosensitive layer in order to obtain a high resolution image, the surface can be calendered. Good.

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

[Printing method and image exposure]
The exposure light source for forming an image on the lithographic printing plate material according to the present invention can be used without particular limitation as long as the lithographic printing plate material can respond to the light source. 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 according to 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 Gas laser such as laser, He-Cd laser, N ₂ laser, excimer laser; semiconductor laser 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 ablate, 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. .

  In addition, the conventionally well-known various methods can be used for the printing method which concerns on this invention. For example, after laser exposure based on image information, it is possible to adopt a method of printing without performing development processing.

  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, “part” in the sentence represents “part by mass”.

(Production of support)
(Polyethylene terephthalate (PET) support)
Using terephthalic acid and ethylene glycol, PET of IV (inherent viscosity) = 0.66 (measured at 25 ° C. in phenol / tetrachloroethane = 6/4 (mass ratio)) 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 at 4.8 kg / m. In this way, a biaxially stretched PET film having a thickness of 190 μm was obtained. The glass transition temperature (Tg) of this biaxially stretched PET film was 79 ° C. The width of the obtained PET film (film forming width) was 2.5 m. Further, the thickness distribution of the obtained support was 3%.

《Preparation of underdrawn support》
A corona discharge treatment of 8 W / m ² · min is applied to both surfaces of the support film obtained above, and then the following undercoat coating solution a is applied to one surface so as to have a dry film thickness of 0.8 μm. After the coating, the undercoating liquid b was applied so as to have a dry film thickness of 0.1 μm while performing a corona discharge treatment (8 W / m ² · min), and each was 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 108Ω.

  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 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 liquid 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 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:
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 (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.

[Hydrophilic layer]
The following coating solution was provided on the underside A side of the polyethylene terephthalate film 175 μm and 120 cm width.

The coating solution was applied using a conventional wire bar coating device and a wire bar coating device having the configuration of the present invention so that the coating film had a dry film of 3.2 μm (coating conditions: wire count # 4, wire bar rotation speed). 30 rpm, bar pushing amount 10 mm, coating speed 40 m / min). In the latter coating apparatus, an ultrasonic vibrator was installed at the end of the wire bar. The ultrasonic vibration conditions were an oscillation frequency of 50 kHz and a vibration amplitude of 60 μm.

<< Hydrophilic layer coating liquid >>
Snowtex-XS (Nissan Chemical Industry Co., Ltd.) average particle size 0.005 μm
9.62 parts Snowtex-ZL (Nissan Chemical Co., Ltd.) average particle size 0.085 μm
0.6 part Silton JC-40 (manufactured by Mizusawa Chemical Co., Ltd.) average particle size 4.0 μm 2.22 parts Opt beads (manufactured by Nissan Chemical Industries Ltd.) Coated particle average particle diameter 6.5 μm 3.0 parts Sodium carboxymethylcellulose (manufactured by Kanto Chemical Co., Ltd.) 0.12 parts Mineral colloid MO (manufactured by Wilber-Ellis Co., Ltd.) 0.22 parts MF-4500 black (manufactured by Dainichi Seika Kogyo Co., Ltd., photothermal conversion material) 4 0.0 part trisodium phosphate 12 water (manufactured by Kanto Chemical Co., Ltd.) 0.06 part FZ-2161 (manufactured by Nippon Unicar Co., Ltd.) 0.16 part pure water 80 parts [Evaluation]
<Prevention of coating defects>
The uncoated portion (where the coating liquid is missing partially) and coating defects, each 1 m ² in a sample after application 2,000 m, were counted coating defects in the area of 10 m ^2. The greater the number of coating defects, the more clogging of the bar. Samples after application of 2,000 m and having 3 or less application defects per 10 m ² were accepted.

<Prevention of applied muscle>
When the bar is clogged, application streaks occur. In the sample after application 2,000m by 1m ^2, 10m ² minutes of applying muscle (bar streak) were measured, and evaluated according to the following rank, it was passed a rank 2 or more.
3: Nothing at all 2: There is a little, no harm area 1: Very many occurrences, actual harm <Bar reusability>
The bar after coating was thoroughly washed with distilled water and then washed by the following method, and the degree of clogging of the wire and reusability were visually evaluated. 2L (liter) of water is put into an ultrasonic cleaner FU-926 manufactured by Tokyo Glass Instrument Co., Ltd., and 10ml of ultrasonic cleaner Contaminone US manufactured by Wako Pure Chemical Industries, Ltd. is added to perform cleaning for 24 hours. The degree of soiling was evaluated. Rank 2 was accepted.

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 summarizes the results of the above various evaluations.

  As is apparent from Table 1, in the examples according to the present invention, it can be seen that the coating defect prevention and coating streak prevention properties are excellent and the bar reusability is excellent.

Schematic diagram of an entire example of a coating apparatus according to the present invention Front view of conventional bar coating device The front view of the bar coating device which installed the ultrasonic vibrator concerning the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Coating liquid supply tank 2 Liquid feeding pump 3 Coating liquid bat 4 Support body 5 Conveyance roller 6 Back roller 1
7 Back roller 2
8 Wire Bar 9 Coating Solution 10 Chuck 11 Bar Support 12 Ultrasonic Vibrator 13 Vibrator Base

Claims (5)

A coating method using a bar coating device, wherein coating is performed while applying ultrasonic vibration to the coating device. The coating method according to claim 1, wherein when applying a dispersion liquid in which solid particles are dispersed in a liquid, ultrasonic vibration is applied to the bar coating device. The coating method according to claim 1 or 2, wherein the frequency of ultrasonic vibration applied during coating increases in proportion to the coating speed. A bar coating apparatus comprising an apparatus that generates ultrasonic vibrations that can be applied by the coating method according to claim 1. In the method for producing a lithographic printing plate material having at least a hydrophilic layer and an image forming layer on a support, the hydrophilic layer coating liquid for forming the hydrophilic layer is continuously conveyed on the belt-shaped support. The manufacturing method of the lithographic printing plate material characterized by apply | coating by the coating method of claim | item 1-3.

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