JPH04368848A - Method and device for manufacturing lithographic plate - Google Patents

Abstract

PURPOSE:To provide method and device for manufacturing lithographic plate which is optimum for developing or etching image part or non-image part in so-called direct processing photosensitive lithographic plate for forming toner image by not only conventional so-called PS plate but also electrophotographic method. CONSTITUTION:After image part and man-image part are formed on the face of a photosensitive lithographic original plate, a reservoir 10 for keeping etching liquid is formed by combining a plurality of rollers 7, 8, and 9. The etching liquid is supplied to the reservoir 10 and the photosensitive lithographic original plate is conveyed in the etching liquid in the reservoir for treating it with etching. A device for manufacturing lithographic plate comprises the reservoir 10 for the etching liquid to be formed by combination of the plurality of rollers 7, 8, and 9, a means for supplying the etching liquid to the reservoir 10, and a convey means for conveying the photosensitive lithographic original plate in the reservoir.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for manufacturing lithographic printing plates. More specifically, in addition to the conventionally known so-called PS plate, a toner image is formed by an electrophotographic method using a photoconductive printing plate, and the non-image area is eluted by an etching process to perform lithographic printing. The present invention relates to a method and apparatus for manufacturing a lithographic printing plate, characterized in that improved development or etching processing is performed when the lithographic printing plate is manufactured by a so-called direct plate making method.

0002

Background of the Invention In the so-called PS plate, a film original is exposed to light on the plate surface to form a latent image, and this latent image is developed to form an image area and a non-image area. Lithographic printing plates are manufactured by dissolving the photosensitive layer, and various devices are available for dissolving the image area or non-image area, such as a dip tank method, a shower method, a spray method, and a scraping method using a brush roller. something is known.

On the other hand, a printing original plate of the type in which the support is a metal plate such as aluminum and a photoconductive photosensitive layer is coated on the surface thereof is used, and after a toner image is formed on the surface by an electrophotographic method, alkaline A method of preparing a lithographic printing plate by eluating non-image areas through an etching process using an etching solution that is an aqueous solution, that is, a so-called direct plate making method, is described, for example, in JP-A-58-25477 and JP-A-58-25477;
It is disclosed in the publication No. 8-80659.

[0004] The above-mentioned direct plate making technique uses a conductive metal plate such as an aluminum plate as a support, and an organic optical semiconductor (OPC) based on an organic pigment is placed on this support using a material such as a phenol resin. It is applied to a lithographic printing original plate coated with a photoconductive photosensitive layer dispersed in a resin, particularly a photoconductive photosensitive layer in which copper-phthalocyanine is dispersed in a novolac resin. In addition, the elution processing method for a lithographic printing original plate using an electrophotographic method as described above is different from the conventional type development processing method for a so-called PS plate/water or lithographic printing plate in that the non-image areas are eluted and removed using an alkaline etching solution. The principle is the same.

[0005]

[Problems to be Solved by the Invention] However, all of the above-mentioned conventional developing methods for so-called PS plates cannot be directly applied to the etching process of lithographic printing original plates using the electrophotographic method. Problems specific to the processing of printing plates remain. In particular, in electrophotographic lithographic printing original plates, the toner image formed on the surface of the photosensitive layer is used as a resist to elute and remove non-image areas, so if the toner image is scratched for some reason, the photosensitive layer in that area will be damaged. It will be eluted and removed, making it impossible to obtain a good image. For example, as disclosed in Japanese Unexamined Patent Publication No. 55-32044, when a method is used in which a small amount of etching solution is diffused onto the printing plate using a diffusion plate placed close to the conveyance path, foreign particles such as dust If the particles are present on the printing plate, the foreign particles will be caught between the diffusion plate and transported while being pressed against the printing plate, and as a result, the foreign particles will cause streak-like scratches on the toner image.

On the other hand, in the shower method or spray method, in which the etching solution is stored in a dip bath and the lithographic printing original plate is immersed in the electrophotographic method, the etching solution is circulated and reused and an etching replenisher is used. It was difficult to control fluctuations in the activity of the etching solution. In particular, compared to the conventional type of so-called PS plates, which change the solubility of the photosensitive layer in the developer by exposure, in electrophotographic lithographic printing plates, fluctuations in the activity of the etching solution have a large effect on the finish. become. That is, a difference occurs in so-called side etching at the boundary between the image area and the non-image area, which affects the reproducibility of the original image.

Therefore, in order to avoid the adverse effects caused by fluctuations in the activity of the etching solution, it is recommended to supply substantially unused etching solution for processing, for example, by providing an etching solution diffusion plate to spread the etching solution. However, with these methods, the amount of etching solution on the printing plate becomes uneven, which tends to cause uneven elution, or Poor elution may occur in the tail and side regions. In addition, processing defects have also occurred in which debris from the photosensitive layer in the non-image area that has been eluted and removed is reattached.

Furthermore, in addition to improving the processing defects mentioned above, there are also demands for reducing the amount of etching solution and speeding up the etching process, and conventional equipment cannot satisfy these demands. . In particular, when etching processing is performed at high speed, the rate at which the above-mentioned etching defects occur increases, and improvement thereof is required.

The inventors of the present application have improved the above-mentioned points, and in particular have conducted research on a method or apparatus most suitable for use in etching processing of lithographic printing original plates using an electrophotographic method.
For example, improvements have been proposed in Japanese Patent Application No. 1-168641, but the present invention was completed as part of such research, and its first purpose is to provide a stable and economical solution. The purpose of this invention is to clarify a method and apparatus for etching the non-image area of a lithographic printing original plate using an electrophotographic method, and the second purpose is to always obtain a uniform finish even using a small amount of etching solution, and to The purpose of the present invention is to clarify an etching processing method and processing device that prevents etching defects from occurring at the top and sides of printing plates.
The third purpose is to clarify an etching processing method and processing device that can obtain a good planographic printing plate with no scratches on both the front and back sides, and in particular, to clarify a good planographic printing plate with no scratches on the toner image. The purpose of this invention is to clarify a processing method or a processing device for a planographic printing original plate that can be obtained.

Another object of the present invention is to apply not only the etching process of lithographic printing plates by electrophotography, but also the development process of photosensitive lithographic printing plates that require an original film such as a conventional type of so-called PS plate. The object of the present invention is to clarify a developing method or a developing processing apparatus that is preferably applied to the present invention.

[0011]

[Means for Solving the Problems] The method for manufacturing a lithographic printing plate according to the present invention includes: (1) After forming an image area and a non-image area on the plate surface, a liquid pool in which an etching solution is collected is formed by a combination of a plurality of rollers; forming a liquid pool, supplying an etching liquid to this liquid pool, and carrying out an etching process by transporting the photosensitive lithographic printing original plate in the etching liquid in this liquid pool; (1) arranging a lithographic printing plate to form a liquid pool in the space between the two, supplying an etching liquid to this liquid pool, and carrying out an etching process by transporting the photosensitive lithographic printing original plate in the etching liquid in this liquid pool; A liquid pool is formed by at least two sets of paired rollers and an intermediate roller disposed between them, an etching solution is supplied to the liquid pool, and a photosensitive lithographic printing original plate is conveyed in the etching liquid in this liquid pool. To carry out the etching process, ■ Place the liquid supply roller in contact with the upper roller of the pair of rollers located on the front side of the pair of rollers that form the liquid pool, and apply the etching liquid to the liquid pool through this liquid supply roller. ■Using an etching solution that is substantially unused; ■Dipping treatment using a dip bath and/or using a brush roller after the etching process that utilizes the etching solution pool formed by the roller. The lithographic printing plate manufacturing apparatus according to the present invention is characterized in that etching processing is performed by scraping processing, and the device for producing a lithographic printing plate according to the present invention is characterized in that: (i) a pool of etching solution is formed by a combination of a plurality of rollers; It has a means for supplying the liquid, and a conveying means for conveying the photosensitive lithographic printing original plate through this liquid pool. ■ A roller is placed in contact with the lower roller of one pair of rollers, and the liquid is supplied in the space between them. (1) The liquid reservoir is formed by at least two sets of paired rollers and an intermediate roller disposed between them.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS The method and apparatus of the present invention will now be described in more detail with reference to the accompanying drawings.

FIGS. 1 and 2 show an example of a processing apparatus in which the method of the present invention is applied to a lithographic printing plate produced by an electrophotographic method.

In FIG. 1, A is a first etching section where a first etching process is carried out, B is a second etching section where a second etching process is carried out, C is a first rinsing section where a process is carried out with a rinsing liquid, D is a second rinsing part, E is a gumming part for protecting the plate surface, F is a drying part, and an enlarged view of the main part of the first etching part A is shown in FIG.

The present invention is characterized by the configuration of the first etched portion A, and the present invention also includes an embodiment in which the second etched portion B is not provided.

[0016] A device G for forming a toner image by exposing the photosensitive layer portion of the photosensitive lithographic printing original plate P is arranged upstream of the processing apparatus shown in FIG. It is guided by the carry-in roller 1 and processed while being conveyed along a conveyance path shown by an imaginary line. Etching solution is prepared in a stock solution tank 1, introduced into a dilution tank 3 by a pump 2, stirred with dilution water introduced from a dilution water tank 4, and diluted to a specified concentration. It is fed under pressure and supplied to the first etching section A through the supply pipe 6. In the first etched part A,
As shown in FIG. 2, an etching liquid reservoir 10 formed by rollers 7 to 9 is prepared, and a supply pipe 6
For example, the etching solution supplied through PET (
It passes through the inner slit of a thin film-like guide member 11 made of polyethylene terephthalate (polyethylene terephthalate), etc.
The liquid is introduced so as to be uniformly coated on the surface of the liquid guiding roller 12 , flows down the surface of the roller 8 against its rotation, and is guided to the liquid pool 10 .

Rollers 7 to 9 forming the side ends of the liquid reservoir 10
A liquid leakage prevention plate 13 made of an alkali-resistant resin such as Teflon, polyethylene, polyvinyl chloride, polypropylene, polyester, or polystyrene, rubber, or metal such as stainless steel is arranged at both ends.

When the photosensitive lithographic printing original plate P exists in the first etching area A, the etching liquid flowing down along the roller 8 is directly supplied onto the plate surface of the photosensitive lithographic printing original plate P, and the etching liquid is , the coating is uniformly applied onto the plate surface of the photosensitive lithographic printing original plate P.

The amount of etching solution supplied through the supply pipe 6 is 200 to 1000c per meter in the width direction of the roller.
c/min, the conveyance speed of the photosensitive lithographic printing original plate P is 1
It is preferable that the etching rate is 0 to 40 mm/sec, and the amount of etching solution applied to the plate surface is 70 to 700 cc/m2.

The etching solution flowing down from the first etching section A is collected by the saucer 14, collected in the dilution tank 3, and reused, but it can be used in the second etching section B described later, or , discard as waste liquid, and
The present invention also includes an embodiment in which only substantially unused etching solution is used in the etching section A. Note that "substantially unused" refers to a state in which the activity without replenishment, that is, a state in which the etching speed decreases by 5% or less compared to completely unused.

The eccentric angle α between roller 7 and roller 8 is
Adjust the perpendicular from the center of the roller 7 to 0 degrees and the clockwise direction as positive in the range of ±15 degrees, preferably in the range of -5 degrees to -12 degrees, and the eccentric angle β between the roller 8 and the liquid guide roller 12 is , preferably in the range of -10 degrees to +30 degrees. Depending on the eccentric angle α between rollers 7 and 8, the position of roller 9 is changed to adjust the form and transportability of liquid pool 10.

It is preferable to use a roller 9 with a surface made of stainless steel, but it is also possible to use a roller 9 made of other metals, or a surface coated with a resin such as Teflon, PVC (polyvinyl chloride), silicone resin, or acrylic resin. If it has the property of not adhering to the back side of the photosensitive planographic printing plate P, such as a plate that does not adhere to the back side of the photosensitive lithographic printing plate P, it can be used because the conveyance performance will not be hindered. Any material can be used as long as it does not directly touch the back surface of the photosensitive planographic printing plate P.

Furthermore, as shown in FIG. 3, an embodiment in which the liquid pool 10 is formed by an elastic blade 9A made of rubber or synthetic resin in place of the roller 9 is also included in the present invention. The point of the etching solution supply method described above is the ability to form a liquid pool 10. In order to increase this, firstly, the adhesion between the rollers must be improved, and secondly, the roller end This is to prevent liquid leakage from the parts. For the former requirement, in consideration of alkali resistance and adhesion, a roller whose surface is formed of butyl rubber, silicone rubber, etc. is preferable, and the hardness is preferably 40 degrees or less. In addition, as measures to prevent liquid leakage, in addition to the method using the liquid leakage prevention plate 13 described above,
It is also possible to adopt a configuration in which a flange is attached to the end of the roller 9 so that it comes into close contact with the end of the roller 7, or a configuration in which various watertight structures are arranged between the side plates to which the rollers 7 and 9 are attached. Furthermore, in order to prevent such liquid leakage from causing friction that would impede the rotation of the rollers 7 and 9, for example, a member made of resin such as Teflon or PVC or a metal member with good slipperiness may be used. It is preferable to do so.

The rollers 15 and 16 are transport rollers that transport the photosensitive lithographic printing original plate P from the first etching section A to the second etching section B, and carry the etching liquid supplied onto the plate surface in the first etching section A. In order to prevent squeezing, only the edges of the plate are nipped and conveyed, or rollers with roughened surfaces as shown in the specification and drawings of Japanese Patent Application No. 1-168641 are used. It is preferable that the etching liquid on the printing plate be carried into a second etching section B, which will be described later, so that the etching time is increased.

In an embodiment in which the second etching section B is not provided, in order to prevent the etching solution from being brought into the first rinsing section C, the rollers 15 and 16 are provided with a squeezing function, or a squeeze roller is provided separately. Prepare.

Next, the structure of the second etched portion B will be explained.

17 is a dip tank, 18 is a conveyance roller,
19 is a guide roller, 20 is a brush roller, 21 is a lower surface support member, and 22 and 23 are squeeze rollers.

The photosensitive lithographic printing original plate P is conveyed while being immersed in the etching solution stored in the dip bath 17 as the roller 18 rotates, and then scraped by the brush roller 19.

Conveyance roller 18 used in dip tank 17
For smooth conveyance, it is preferable to use rollers with a relatively large diameter, and it is also possible to use skewer-shaped rollers or even brush rollers.

As described above, the etching solution used in the second etching section B is divided into two modes: a substantially unused etching solution supplied by the pump 5;
There is a mode in which the substantially unused etching solution used in the etching section A and recovered is circulated and reused. In the latter embodiment, the etching liquid stored in a liquid receiving part 24 provided below the first etching part A is filtered to remove etching residue by a filter 25 and then supplied to a dip tank 17 or a shower nozzle 27 by a pump 26. do. Furthermore, the present invention also includes a mode in which the used etching solution collected in the liquid receiving part 24 is replenished with a highly active liquid and then supplied to the dip tank 17 and the shower nozzle 27.

[0031] The photosensitive lithographic printing original plate P is transported by the conveying roller 1
5 and 16, the dip tank 17, the brush roller 20, and the squeeze rollers 22 and 23 are conveyed in a curved state, so the pressure on the plate surface by the conveyance rollers 15 and 18 and the squeeze roller 22 is strong, and the plate is eluted by the etching process. There is a risk that the photosensitive layer components deposited on the non-image areas may adhere. For this reason, by providing a sufficient distance between each roller or adjusting the vertical position, the pressure on the plate surface due to curved conveyance can be reduced, and the squeeze rollers 22 and 23 can be For example, it is preferable to take measures such as arranging it in an inclined state with an eccentricity of 5 to 30 degrees.

[0032] In the scraping process performed by the brush roller 20 in the second etching section B, the circumferential speed is 10 to 50 m.
It is preferable to do this at a scrubbing speed of about /min. Strong scrubbing may damage the image area, so it is preferable not to apply the scrubbing force more than necessary. The setting is made to be weaker than the rubbing caused by No. 29.

A liquid receiver is arranged on the lower surface of the squeeze roller 23 so that the roller can be washed while rotating, and the tip of the brush of the brush roller 20 is arranged so as to come into contact with the squeeze roller 22. It is also preferable to supply an etching solution to the printing plate in order to prevent so-called development residue from re-adhering to the plate surface. Incidentally, while the processing is stopped or the conveyance of the photosensitive lithographic printing original plate P is interrupted, the etching solution in the liquid receiving part 24 is supplied through the supply pipe 27, and the brush roller 20 and squeeze roller 22 are・It is also a preferable embodiment to perform the washing in step 23.

The photosensitive lithographic printing original plate P which has undergone the etching process by the first etching part A and the second etching part B as described above is rinsed by the first rinsing part C and the second rinsing part D, and then After being conveyed to the gumming section E and subjected to the gumming process, it is dried at the drying section F, and the processing is completed. Note that the present invention is characterized by etching processing, and therefore, for rinsing processing, gumming processing, and drying processing, conventional methods and devices and various configurations that will be developed in the future may be used. is arbitrarily selected and used.

The photosensitive lithographic printing original plate P handled by the method or apparatus of the present invention is prepared using water as the main solvent (50 wt% of the solvent It is a printing material having a layer in which a non-image area layer is eluted by an alkaline etching solution (the above is water), such as a negative PS plate using a diazo compound as a photosensitive component, or an o-quinosine diazide compound as a photosensitive component. A positive-working PS plate using a conductive support such as aluminum, a lithographic printing material in which a photoconductive layer is formed on the surface of a conductive support such as aluminum, a toner image is formed by an electrophotographic method, and the non-image area can be removed by an elution process. It is.

The photosensitive lithographic printing original plate P to which the present invention is particularly advantageously applied has an organic pigment-based organic photosemiconductor (OPC) on the plate surface of a conductive support having a surface that can be used as a lithographic plate surface.
A photosensitive material for plate making provided with a photoconductive layer containing a photoconductive layer, on which a toner image can be formed by processing including printing, exposure, development, and fixing,
Preferably, the surface of the aluminum plate is subjected to electropolishing, anodizing, graining, or other surface roughening treatment, and then a photoconductive organic pigment is dispersed in a resin such as a phenolic resin on the rough surface. It is an electrophotographic photoreceptor coated with a layer, particularly a photoconductive photosensitive layer in which a phthalocyanine pigment is dispersed in a novolak resin.

The lithographic printing plate material to which the method of the present invention is applied contains a photoconductive pigment and/or as an organic photoconductor in the photoconductor layer.
Alternatively, a photoconductor layer containing a photoconductive material in a binder resin having a completely soluble solvent (a soluble photoconductive material) is included. The effect of the present invention is particularly high for lithographic printing plate materials having a photoconductor layer using a pigment-based organic photoconductor. As such organic photoconductive pigments, Japanese Patent Publication No. 40-2780 and Japanese Patent Publication No. 44-12671
No. 46-30035, No. 44-16474, No. 48-30513, No. 50-7434, JP-A-47
-18543, 47-18544, 47-30
No. 330, No. 47-37543, No. 49-11136
No. 49-99142, No. 51-109841,
No. 54-134632, No. 55-11715, No. 5
No. 5-105254, No. 55-153948, No. 5
No. 5-161250, No. 56-1944, No. 56-2
No. 352, No. 56-9752, No. 56-19063, No. 56-29250, No. 56-69644, No. 5
No. 6-50050, No. 59-125751, No. 59-
No. 176756, No. 60-17751, No. 60-17
No. 752, No. 60-17753, No. 60-17754
No. 60-17755, No. 60-17756, No. 60-17757, No. 60-17758, No. 60-
No. 17759, No. 60-17760, No. 60-177
Perylene pigments, quinacridone pigments, bisbenzimidazole pigments, aromatic polycondensed ring compounds, monoazo pigments described in No. 61, No. 60-17762, No. 60-35750, No. 61-67869, No. 61-67870, etc. ,
Photoconductive pigments include disazo pigments, trisazo pigments, metal or metal-free phthalocyanine pigments, zinc oxide, and the like. Among pigment-based organic photoconductors, the effect of the present invention is particularly great for lithographic printing plate materials having a photoconductor layer using phthalocyanine pigments.

The binding resin for the photoconductor layer of the lithographic printing plate material to which the processing method of the present invention is applied is preferably a polymer compound that is soluble or dispersible in the above-mentioned etching solution.

Specifically, for example, copolymers of styrene and maleic anhydride, copolymers of styrene and monoalkyl maleic anhydride, methacrylic acid/methacrylic acid ester copolymers, styrene/methacrylic acid/methacrylic acid Ester copolymers, acrylic acid/methacrylic ester copolymers, styrene/acrylic acid/methacrylic ester copolymers, vinyl acetate/crotonic acid ester copolymers, vinyl acetate/crotonic acid/methacrylic ester copolymers, etc. Acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid, maleic anhydride, such as acrylic acid ester, methacrylic acid ester, styrene, vinyl acetate, etc.
Copolymers with carboxylic acid-containing monomers such as fumaric acid or acid anhydride group-containing monomers, methacrylic acid amide,
Vinyl pyrrolidone, copolymers containing monomers with phenolic hydroxyl groups, sulfonic acid groups, sulfonamide groups, sulfonimide groups, phenolic resins, partially saponified vinyl acetate resins, xylene resins, vinyl acetal resins such as polyvinyl butyral can be given.

A copolymer containing a monomer having an acid anhydride group or a carboxylic acid group as a copolymerization component and a phenol resin have a high charge retention ability of the photoconductive layer when used as a photoreceptor for electrophotographic engraving. It can be used with good results.

As the copolymer containing a monomer having an acid anhydride group as a copolymerization component, a copolymer of styrene and maleic anhydride is preferred. Half esters of this copolymer can also be used. As a copolymer containing a monomer having a carboxylic acid group as a copolymerization component, a copolymer of two or more elements of acrylic acid or methacrylic acid and an alkyl ester, aryl ester or aralkyl ester of acrylic acid or methacrylic acid is used. preferable. Further, preferable examples include a copolymer of vinyl acetate and crotonic acid, and a terpolymer of vinyl acetate, a vinyl ester of a carboxylic acid having 2 to 18 carbon atoms, and crotonic acid. Among the phenolic resins, particularly preferred are novolak resins obtained by bonding phenol, o-cresol, m-cresol, or p-cresol with formaldehyde or acetaldehyde under acidic conditions. The binding resins may be used alone or in combination of two or more.

[0042] The above phenolic resins include phenol, o-cresol, m-cresol, p-cresol,
Ethylphenol, isopropylphenol, t-butylphenol, t-amylphenol, hexylphenol, t-octylphenol, cyclohexylphenol, 3-methyl-4-chloro-6-t-butylphenol, isopropylcresol, t-butylcresol, t-amyl A resin obtained by condensing at least one formaldehyde of substituted phenols such as cresol, hexyl cresol, t-octyl cresol, and cyclohexyl cresol, and aliphatic and aromatic aldehydes such as acetaldehyde, acrolein, crotonaldehyde, and furfural. It can be used as a typical resin. Further, a polyhydroxyphenyl resin obtained by polycondensation of pyrogallol or resorcinol and acetone can also be used.

Among these phenolic resins, preferred are phenol, o-cresol, m-cresol, and p-cresol.
It is a novolac type phenol resin obtained by condensing at least one type of cresol with formaldehyde or acetaldehyde under acidic conditions.

[0044] The average molecular weight of this phenolic resin is 350
-20,000, preferably about 350-6,000. These phenolic resins include ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl acetate, and dioxane, and butyl acetate and ethyl acetate. Those soluble in organic solvents such as esters are desirable.

In order to produce a lithographic printing plate material to which the method of the present invention is applied, for example, 1 part by weight of a photoconductive material and 0.01 to 100 parts by weight of a phenolic resin as a binder (preferably a photoconductive layer) are used. can be dissolved and removed by an alkaline solution) in the organic solvent, and if necessary, an electron-accepting compound or an electron-donating compound is added in an amount of 0.01 to 100 mol (preferably 0.01 to 100 mol) based on the pigment. 10 mol) and then uniformly dispersed using a ball mill, ultrasonic disperser, etc. The obtained photosensitive liquid is coated on the conductive support described below to a thickness of 1 to 50 μm, preferably 1 to 10 μm, and dried, and as described above, in order to increase the solubility of the photoconductive layer in the photoconductive layer removal solution. Obtained by heat treatment at 70°C or higher.

Further, in the method for forming a lithographic printing plate according to the present invention, a printing plate is formed by a normal electrophotographic method using a lithographic printing plate material obtained by coating and drying a photoconductive layer on a conductive support. In this case, the photoconductive layer is preferably heat-treated in a fixing step before removal.

The support for the lithographic printing plate material according to the present invention may be an aluminum plate, a resin laminated with aluminum, or a bimetallic plate such as a zinc plate, a copper-aluminum plate, a copper-stainless steel plate, a chrome-copper plate, or A conductive support having a hydrophilic surface such as a trimetal plate such as a chromium-copper-aluminum plate, a chromium-lead-iron plate, or a chromium-copper-stainless steel plate is used.

[0048] Particularly in the case of a support having an aluminum surface, surface treatments such as graining, anodizing, and immersion in an aqueous solution of sodium silicate, potassium fluorozirconate, phosphate, etc. are carried out. It is preferable that In addition, as described in U.S. Pat.
As described in Japanese Patent No. 5125, an aluminum plate which is anodized and then immersed in an aqueous solution of an alkali metal silicate is also preferably used. The above-mentioned anodizing treatment is carried out by electrolysis using an aqueous or non-aqueous solution of an inorganic acid such as phosphoric acid, chromic acid, sulfuric acid, nitric acid, etc., or an organic acid such as oxalic acid, sulfamic acid, or a salt thereof, either alone or in combination of two or more. This is carried out by passing an electric current through a liquid using an aluminum plate as an anode.

Silicate electrodeposition as described in US Pat. No. 3,658,662 is also effective. Treatment with polyvinylphosphonic acid as described in DE 1621478 is also suitable.

These hydrophilic treatments are carried out in order to make the surface of the support hydrophilic, and also to prevent harmful reactions with the photoconductive layer provided thereon, and to prevent harmful reactions between the photoconductive layer and the photoconductive layer. This is applied to improve adhesion.

In the present invention, an alkali-soluble material such as casein, polyvinyl alcohol, ethyl cellulose, phenol resin, styrene-maleic anhydride copolymer, polyacrylic acid, etc. is optionally provided between the conductive support and the photoconductive layer. An intermediate layer may be provided for the purpose of improving the adhesion between the support and the photoconductive layer or the photosensitive electrostatic properties.

Further, in the present invention, an overcoat layer that dissolves when the photoconductive layer is removed is provided on the photoconductive layer, if necessary, for the purpose of improving the electrostatic properties of the photoconductive layer, the development properties during toner development, or the image properties. be able to.

The developer (toner) used in the present invention is preferably hydrophobic and ink-receptive, such as polystyrene resins, polyester resins (amino group-containing acrylic esters, long-chain acrylic esters, etc.), acrylic resins, etc. These include polymeric substances such as resins (such as resins with phenolic hydroxyl groups or sulfone groups), epoxy resins, vegetable oil-modified alkyds, cyclized rubbers, asphalt, and vinyl chloride. In addition, colorants such as carbon black, nigrosine pigments, carmine 6B, phthalocyanine blue, benzidine yellow, phthalocyanine green, etc., and charge control agents such as fatty acids and naphthenic acid metals, to the extent that they do not adversely affect the granulation and fixing properties of the toner. It can contain salts, metal-containing pigments, sulfonates, and the like.

There are no restrictions on the means for forming a toner image by electrophotography, and any commonly used means can be used; however, for toner development, a coloring agent (carbon black, copper phthalocyanine, etc.), a coating material, and a charge control agent, especially one or more of polyethylene, polypropylene, ethylene copolymer, and propylene copolymer as a coating material to control charge. It is preferable to use an electrophotographic liquid developer using a negative charge control agent consisting of a phosphate ester surfactant as the material.

The etching solution used in the method or apparatus of the present invention includes an alkali metal hydroxide, an alkali metal silicate,
A strong alkali aqueous solution having a pH of 12 or more is included, which is composed of an alkali metal phosphate or an alkali metal aluminate, water, and if necessary, a surfactant and other additives.

[0056] Etching solutions used in the method or apparatus of the present invention include, for example, Japanese Patent Application Laid-open No. 77401/1983;
Anionic surfactants such as those described in Publications No. 51-80228, No. 53-44202, and No. 55-52054 have a solubility in water of 10 at room temperature.
It includes an aqueous solution consisting of an organic solvent, an alkaline agent, water and, if necessary, an antifouling agent in an amount of not more than % by weight. Further, a developer solution for both a negative PS plate and a positive PS plate as described in JP-A-60-130741 can also be used.

In order to improve the applicability of the etching solution, a surfactant is added to increase the surface tension to 45 dyne.
/cm or less, preferably 35 dyne/cm or less.

[0058] As the rinsing liquid, Japanese Patent Application No. 3-17835
In addition to those described in the specification of the No. 1, water or an aqueous solution containing an alkaline agent can be used. Note that in an embodiment in which the etching process and the rinsing process are performed continuously, it is obvious that the etching liquid is carried into the rinsing process and the rinsing liquid becomes alkaline.

FIGS. 4 and 5 show other embodiments of forming the liquid reservoir 10.

In the figure, reference numerals 30 and 31 denote a pair of upper and lower rollers, which are configured so that a liquid reservoir 10 is formed by sealing the lower surface side with an intermediate roller 32. In the mode shown in FIG. 4, the photosensitive lithographic printing original plate P is conveyed in a substantially horizontal state, whereas in the mode shown in FIG. The planographic printing original plate P is conveyed in a slightly upwardly tilted state. Note that the present invention also includes an embodiment in which a roller having a roughened surface as described in the specification of Japanese Patent Application No. 1-168641 is used as the upper roller of the pair of rollers 31.

In the embodiments shown in FIGS. 4 and 5, the method of supplying the etching solution to the liquid reservoir 10 is not only the method shown in FIG. A mode in which the liquid is introduced into the liquid reservoir 10 is also included in the present invention.

[0062]

[Experimental Examples] The present invention will now be illustrated by experimental examples. still,
Parts mean parts by weight unless otherwise specified.

Experimental Example 1 3 parts of phenolic resin having the following structural formula and 0.1 part of maleic anhydride

[0064]

After dissolving [Chemical 1] in ethylene glycol monoethyl ether 20, copper phthalocyanine Lionol manufactured by Toyo Ink Co., Ltd.
Blue-ER (ε-type copper phthalocyanine) 1 was added and glass beads were dispersed for 30 minutes to obtain a dispersion. next,
An aluminum plate of 1100 mm x 400 mm was grained by electrolytic polishing in a hydrochloric acid bath, further anodized, and sealed with hot water, and then the above dispersion was applied so that the dry film thickness was 5 μm. and dried to obtain a photosensitive lithographic printing original plate P. A toner image was created on the plate surface of this photosensitive lithographic printing original plate P using a semiconductor laser exposure type electrophotographic engraving machine. Incidentally, as the developer, a liquid developer manufactured by the method described below was used.

Octadecyl methacrylate/methacrylic acid copolymer (90:5) 10% Isopar G solution

10 copies
MA-100 (carbon black: manufactured by Mitsubishi Kasei Corporation)
One part of the above mixture was dispersed with glass beads for 5 hours.

Furthermore, Sunwax 151 is added to the above mixture.
P (polyethylene average molecular weight 2000: manufactured by Mitsubishi Chemical Corporation)
1 part was added, heated to 80°C, and further dispersed for 3 hours. This dispersion was diluted 80 times to obtain a liquid developer. still,
The conditions for fixing after development were 130° C. for 2 minutes.

As described above, the photosensitive lithographic printing original plate P on which the toner image has been formed is conveyed with a conveyance width of 1150 mm as shown in FIG.
An etching process was performed to elute the non-image area using a processing device.

An etching solution having the following composition was used and diluted to a volume ratio of 1:5 (water).

Benzyl alcohol

6.0 parts propylene glycol

6.0 parts pt-butylbenzoic acid
5.0 parts benzoic acid


2.0 parts 2-hydroxy-3 naphthoic acid

2.0 parts KOH50% aqueous solution

26.3 parts Potassium silicate aqueous solution (SiO2: 26% by weight) (manufactured by Nippon Kagaku Co., Ltd., Potassium silicate A)

29.0 parts Perex NBL (
Kao Atlas Co., Ltd., sodium alkylnaphthalene sulfonate)

0.2 parts EDTA (ethylenediaminetetraacetic acid)
0.3 parts water

24.0 parts The above etching solution was adjusted to 27° C., and supplied from the supply pipe 6 at a rate of 400 cc/min, and the conveyance speed was adjusted so that the etching time was 15 seconds.

Note that the etching solution applied onto the plate surface of the photosensitive lithographic printing original plate P in the first etching section A is 1
It was 80cc/m2.

The guide member 11 for transmitting the etching liquid supplied from the supply pipe 6 to the liquid guide roller 12 includes:
Synthetic resin films with a thickness of 175 μm on the lower side and 100 μm on the upper side were used.

The eccentric angle α between rollers 7 and 8 is -8 degrees,
The eccentric angle β between the roller 8 and the liquid guide roller 12 was set to 10 degrees.

The brush roll 20 in the second etching part B has a roll diameter of 40 mmφ and a thickness of 0.05 mmφ.
Nylon 6 and 12 are planted in a channel-shaped member so that the bristles are 12 mm in length, and this member is further wound around a roller core, using a so-called channel brush, and the circumferential speed is 14 m/min. I rotated it like that.

As the conveying roller 15, there are three rollers at both ends and the center.
A roller was used to nip the portions with a width of 10 mm.

[0075] As the conveying roller 18, the roll diameter is 100 mm.
10mm of disc-shaped EPT rubber with mmφ and hardness of 40 degrees
A skewer-shaped piece was used, which was cut into thick pieces and attached to a shaft at 100 mm intervals.

[0076] When 100 photosensitive lithographic printing original plates P were continuously processed under the processing conditions described above and the performance of the etching process was checked, the finish was good in all cases. However, no stains were observed.

Experimental Example 2 The same treatment as in Experimental Example 1 was carried out by sufficiently forming a reservoir 10 with the etching solution and reducing the supply amount of the etching solution by half compared to that in Experimental Example 1.

Experimental Example 3 In the processing apparatus used in Experimental Example 1, the brush roller 2
0 was removed and the same process as in Experimental Example 1 was performed.

Experimental Example 4 In addition to removing the brush roller 20 in Experimental Example 3, the dip tank 17 was removed and transported horizontally, and the same treatment as in Experimental Example 1 was performed.

Experimental Example 5 In the processing apparatus used in Experimental Example 1, the transport roller 15
The same treatment as in Experimental Example 1 was carried out using a grooved roller having a depth and pitch of 5 mm.

Experimental Example 6 Using the apparatus shown in FIGS. 1 and 2, an experiment was conducted in which a commercially available conventional type so-called PS plate was developed. The processing performance was as shown in Table-2.

As the PS plate, SMP (positive type) manufactured by Konica Corporation was used, and SD32 manufactured by Konica Corporation was used in place of the etching solution used in Experimental Examples 1 to 5. Note that the etching time was set to 20 seconds.

Comparative Example 1 In the processing apparatus used in Experimental Example 1, the roller 9 was removed and the liquid pool 10 was prevented from forming.
The same process was performed.

Comparative Example 2 Using the apparatus used in Comparative Example 1, the same treatment as in Experimental Example 1 was carried out by halving the amount of etching solution supplied.

Experimental Examples 1 to 5 treated as above, and
Table 1 shows the processing performance of Comparative Examples 1 and 2.

[0086]

[Table 1] (Note 1) ○ Good △ Slightly poor ×
Failure (Note 2): If the minimum etching time is shorter than this, the components of the photosensitive layer will adhere to the non-image area over the entire surface.
The processing performance is △. Evaluation was made separately from poor elution at the tip and side. (Note 3) Each evaluation was performed using the shortest etching time.

As is clear from Table 1, it has been demonstrated that the lithographic printing plate manufacturing method or manufacturing apparatus according to the present invention has excellent processing performance and can solve the above-mentioned problems. Ta. Furthermore, the present invention also applies to conventional type PS
It turns out that it can also be applied to prints.

[0088]

Effects of the Invention As is clear from the above experimental results, when the etching process is performed using the method or apparatus of the present invention, when the etching process is performed using the conventional method or apparatus, and furthermore, the etching process described in JP-A-1-168641 is Even when compared with the method or apparatus described above, good etching processing performance is obtained and the above-mentioned problems are solved.

[Brief explanation of drawings]

FIG. 1: Schematic diagram of an apparatus to which the method of the present invention is applied.

[Figure 2]
Enlarged view of main parts of first etched part A

FIG. 3 is a schematic diagram showing another embodiment.

FIG. 4 is a schematic diagram showing another embodiment.

FIG. 5 is a schematic diagram showing another embodiment.

[Explanation of symbols]

A First etching processing section B Second etching processing section C 1st rinse part D Second rinse section E Gum pulling part F Drying section G Toner image forming device P Photosensitive lithographic printing original plate 1　　　　　Still solution tank 2 Pump 3 Diluted tanuru 4 Dilution water tank 5 Pump 6 Supply pipe 7 Roller 8 Roller 9 Roller 9a Blade 10 Liquid puddle 11 Guide member 12 Liquid guide roller 13 Liquid leakage prevention plate 14 Saucer 15 Roller 16 Roller 17 Dip tank 18 Conveyance roller 19 Guide roller 20 Brush roller 21 Lower surface support member 22 Squeeze roller 23 Squeeze roller 24 Liquid receiving part 25 Filter 26 Pump 27 Shower nozzle 28 Brush roller 29 Brush roller 30 vs. roller 31 Anti-roller 32 Intermediate roller

Claims (9)

[Claims] Claim 1: After forming an image area and a non-image area on a printing plate, a pool in which an etching solution is stored is formed by a combination of a plurality of rollers, and the etching solution is supplied to this pool to remove the etching solution. 1. A method for producing a lithographic printing plate, which comprises transporting a photosensitive lithographic printing original plate in an etching solution to perform an etching process. Claim 2: A roller is arranged in contact with the lower roller of one pair of rollers, a liquid pool is formed in the space between the two, and an etching liquid is supplied to this liquid pool, so that the etching liquid in this liquid pool is 2. The method for producing a lithographic printing plate according to claim 1, wherein the photosensitive lithographic printing original plate is transported and subjected to etching treatment. 3. A liquid pool is formed by at least two sets of paired rollers and an intermediate roller disposed between them, and an etching solution is supplied to the liquid pool, and photosensitive lithographic printing is carried out in the etching liquid in this liquid pool. 2. The method of manufacturing a lithographic printing plate according to claim 1, wherein the etching process is carried out by transporting the original plate. 4. A liquid supply roller is disposed in contact with the upper roller of the pair of rollers located on the front side of the pair of rollers forming the liquid pool, and the etching liquid is supplied to the liquid pool through the liquid supply roller. 2. The method for producing a lithographic printing plate according to claim 1. 5. The method for producing a lithographic printing plate according to claim 1, wherein the etching solution is substantially unused. 6. A claim characterized in that an etching process using a pool of etching solution formed by a roller is followed by an etching process using a dipping bath and/or a scraping process using a brush roller. Item 6. The method for producing a lithographic printing plate according to any one of Items 1 to 5. 7. An etching solution reservoir formed by a combination of a plurality of rollers, a means for supplying the etching solution to the solution reservoir, and a transport means for transporting the photosensitive lithographic printing original plate through the solution reservoir. An apparatus for producing a lithographic printing plate using an electrophotographic method, characterized by: 8. The lithographic printing plate manufacturing apparatus according to claim 7, wherein a roller is disposed in contact with the lower roller of one pair of rollers, and a liquid reservoir is formed in the space between the rollers. 9. The lithographic printing plate manufacturing apparatus according to claim 7, wherein a liquid reservoir is formed by at least two pairs of paired rollers and an intermediate roller disposed between them.