JPH10161322A - Planographic printing plate processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a planographic printing plate processor capable of obtaining a very excellent printing plate surface by efficiently removing unwanted matter on the surface of a planographic printing plate, without damaging it. SOLUTION: In this device, the fixed processing of electrification, development with toner, fixation, elution, etc., is consecutively attained for an electrophotographic system planographic printing plate coated with a photoreceptive layer including a photoconductive material on an aluminum substrate after pebbling hydrophilic processing is attained. It is constituted so that out of a pair of squeezing rolls 23 and 24 provided in an eluting part, at least the circumferential speed of the outer periphery of the roll 23 coming into contact with the side of the photoreceptive layer 2A of the planographic printing plate 2 is different from the carrying speed of the printing plate 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lithographic printing plate processing apparatus for performing a predetermined treatment while transporting a lithographic printing plate. More specifically, the present invention relates to a lithographic printing plate processing apparatus. While transporting an electrophotographic lithographic printing plate coated with a photosensitive layer including, charging, toner development, fixing,
The present invention relates to a lithographic printing plate processing apparatus for performing processing such as elution.

[0002]

2. Description of the Related Art Conventionally, as a lithographic offset printing plate,
Positive photosensitive agents containing a quinonediazide compound and a phenol resin as main components and PS plates using a negative photosensitive agent containing acrylic monomers or prepolymers as main components have been put to practical use. However, since all of these methods have low sensitivity, plate making is performed by contact exposure of a film master on which an image has been recorded in advance. On the other hand, due to advances in computer image processing, large-capacity data storage, and data communication technology, in recent years, computer operation has been consistently performed from document input, correction, editing, layout, and page layout to high-speed communication networks. An electronic editing system that can immediately output to a remote terminal plotter by satellite communication or satellite communication has been put to practical use. In particular, the demand for an electronic editing system is high in the newspaper printing field, which requires immediacy.
Also, the original manuscript is currently saved in film form,
Even in the field where printing plates are duplicated as needed based on this, with the development of large-capacity recording media such as optical disks, the originals will be stored as digital data on these recording media. As a result, a direct-type printing plate for producing a printing plate directly from the output of a terminal plotter has come into practical use. This includes the light source of the output plotter (eg, He-Ne laser, semiconductor laser, etc.)
Therefore, a direct printing plate having a sensitivity high enough to produce a printing plate within a practical time is used.

[0003] An electrophotographic photosensitive member is used as a photosensitive member having high photosensitivity capable of providing a direct printing plate. As a method of preparing a printing plate using electrophotography, a method of removing a photoconductive layer in a non-image portion after forming a toner image is already known. For example, Japanese Patent Publication No. 37-17162 and 38-6
No. 961, No. 38-7758, No. 41-2426,
Nos. 46-39405, JP-A-50-19509, JP-A-50-19510, JP-A-52-2437, and JP-A-54-1
No. 45538, No. 54-134632, No. 55-10
No. 5254, No. 55-153948, No. 55-161
No. 250, No. 57-147656, No. 57-1618
No. 63, for example, an electrophotographic printing plate precursor. In the above method, a binding resin that dissolves in an alkaline solvent or swells and releases is used as a binding resin of the electrophotographic photoreceptor, and the hydrophilic surface is exposed by removing a portion other than the toner image portion using the toner image as a resist. ,
Use a lithographic printing plate.

[0004] In the case of producing the above-described electrophotographic planographic printing plate, for example, after a predetermined process (corona discharge), an exposure process such as laser exposure and a reversal development using a liquid toner are performed. Then, after drying and fixing, the lithographic printing plate processing apparatus 300 shown in FIG. 3 performs processing. That is, after drying and fixing, for example, the lithographic printing plate is cooled in the cooling unit 30, and in the elution unit 31, a portion other than the toner image portion is removed by using the toner image as a resist to expose the hydrophilic surface. After washing with water, a plate surface protection treatment is performed with a gum solution in the gum portion 33 to form a lithographic printing plate. In addition, the transport roll of the printing plate and each squeeze roll 5
0 and the cooling means 4 which conveys the above-mentioned parts by the squeeze rolls 55 and 56 and blows cold water or the like between them.
Then, the eluate is supplied by the eluate supply means 45, and alkali etching is performed to finally remove the eluted substances and the like appropriately by the squeeze rolls 55 and 56 of the eluate, and water is supplied by the washing water supply means 46. Then, after performing a predetermined cleaning process, the gum solution is supplied by the gum solution supply means 47 to perform the protection process.

[0005]

In the lithographic printing plate processing apparatus 300 as described above, among the rolls of the elution section 31, particularly, the elution section squeeze rolls 55 and 56 are used for the elution section 3
The insoluble portion of the photosensitive layer component eluted in the eluate 1 is squeezed and removed from the surface of the photosensitive layer together with the eluate.
The insoluble portion from the photosensitive layer and the non-image portion adhere to the dissolving portion squeeze rolls 55 and 56, and the toner resin pieces that have fallen off due to the dissolution adhere and accumulate, and a part thereof is transferred to the printing plate surface, There was a problem that the portion was stained by printing.
On the other hand, as a cleaning device for cleaning rolls, JP-A-63-165243 discloses that when a PS plate is not processed, a pair of rolls are rotated in a forward direction or a reverse direction at different peripheral speeds from each other. Patent Document 1 discloses a device that removes dust and the like attached to the roll surface by causing friction between the rolls.

However, it has been found that the cleaning method disclosed in the above publication is insufficient. The reason is that in the case of electrophotographic printing plates, toner is used, and the toner resin pieces are dispersed in the eluate,
If the toner adheres to the squeeze roll, the toner resin is relatively soft, so that it cannot be easily removed by rubbing between the rolls. The toner resin adhering in this manner is difficult to remove even with a fixed brush.

[0007] An object of the present invention is to provide a lithographic printing plate processing apparatus capable of eliminating transfer dirt from a squeeze roll without damaging the surface of the lithographic printing plate and providing an extremely good plate surface.

[0008]

SUMMARY OF THE INVENTION The object of the present invention is to provide an electrophotographic lithographic printing plate having a photosensitive layer containing a photoconductive substance coated on a grained and hydrophilic aluminum support. In a lithographic printing plate processing apparatus that continuously performs processes such as toner development, fixing, and elution, among a pair of squeeze rolls provided in an elution section that performs elution, at least the photosensitive layer side of the lithographic printing plate comes into contact. The lithographic printing plate processing apparatus is characterized in that the peripheral speed of the outer peripheral surface of the roll is configured to be different from the transport speed of the lithographic printing plate (claim 1).

The squeeze roll pair may be configured such that the outer diameter of at least the roll contacting the photosensitive layer side of the lithographic printing plate is different from the outer diameter of another reference transport roll. ).

The outer diameter of at least one of the squeeze roll pairs that contacts the photosensitive layer side of the lithographic printing plate is set to differ from the outer diameter of the reference transport roll by 1 to 5%. It is more preferable to carry out (claim 3).

Further, it is more preferable that the peripheral speed of at least the roll in contact with the photosensitive layer side of the lithographic printing plate in the squeeze roll pair is set to be higher than the peripheral speed of another reference transport roll. 4).

[0012] In the lithographic printing plate processing apparatus according to the present invention, among the squeeze roll pairs provided in the elution section, at least the peripheral speed of the outer peripheral surface of the roll that comes into contact with the photosensitive layer side of the lithographic printing plate is the lithographic printing plate. The squeeze roll and the photosensitive layer are configured to have a different friction speed between the squeeze roll and the photosensitive layer, or the grained surface of the printing plate exposed by elution and the squeeze roll surface are rubbed. As a result, the dirt adhering to the surface of the squeeze roll is immediately removed, and the dirt does not accumulate. In other words, the dirt that is transferred from the squeeze roll surface and generates print dirt can be prevented. Here, the left speed between the plate and the roll may be slightly small, and the roll surface can be made soft, and the plate surface is not damaged.

In the lithographic printing plate processing apparatus according to the present invention, the outer diameter of at least one of the squeeze roll pairs that contacts the photosensitive layer side of the lithographic printing plate is different from the outer diameter of another reference transport roll. In this case, the structure for setting the squeeze roll to a predetermined peripheral speed becomes extremely simple.

In the lithographic printing plate processing apparatus according to the present invention, the outer diameter of at least one of the squeeze roll pairs that contacts the photosensitive layer side of the lithographic printing plate is 1 to 5 with respect to the outer diameter of the reference transport roll. Since the difference is set in the range of the percentage, the cleaning action can be effectively exerted. That is, if the speed difference is too large, the frictional force of the roll against the photosensitive layer surface is too large to damage or adversely affect the photosensitive layer. On the other hand, if the speed difference is too small, the cleaning effect is reduced. Setting gives good results.

In the lithographic printing plate processing apparatus according to the present invention, the peripheral speed of at least the roll of the squeeze roll pair that contacts the photosensitive layer side of the lithographic printing plate is set to be higher than the peripheral speed of another reference transport roll. By that
The rotation of the squeeze roll is in a forward direction with respect to the transport direction of the printing plate, and an effective cleaning action can be performed on the printing plate without adversely affecting the transport.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS. 1 and 2. FIG. FIG. 1 is a schematic view showing an outline of a lithographic printing plate processing apparatus 100 of the present invention, and FIG. 2 is a perspective view of a main part thereof. As shown in FIG. 1, a planographic printing plate processing apparatus 100 according to the present invention
For example, after performing a predetermined process (corona discharge) on the lithographic printing plate 2, an exposure process such as laser exposure is performed, and then, in the developing and fixing unit 1, for example, reversal development is performed using a liquid toner.

After drying and fixing, the lithographic printing plate 2 is cooled in, for example, a cooling unit 30 as a post-fixing process of the toner. After the exposed surface is exposed and washed with a water washing unit 32, a plate surface protection process is performed with a gum solution in a gum unit 33 to form a lithographic printing plate. The lithographic printing plate 2 is cooled by the cooling means 40 which sprays cold water, for example, while being conveyed through the above-mentioned parts by the conveying rolls, the squeeze rolls 50 of each part, the squeeze rolls 23 and 24 of the elution part, and subsequently, for example, the printing The eluate is supplied from an eluate supply means 45 for appropriately discharging the eluate from a pipe member arranged along the width direction of the plate, and rubbed with a brush roll 41 to perform alkali etching.
In the final part of 1, the squeeze rolls 23 and 24 are used to appropriately remove eluted substances and the like, and after a predetermined washing treatment is performed by the washing water supply means 46 and the brush roll 42, the gum solution is supplied by the gum solution supply means 47. Then, it is protected and discharged.

The squeeze roll 2 provided in the elution section
3 and 24, the peripheral speed of the outer peripheral surface of the roll (squeeze roll 23 in FIGS. 1 and 2) that contacts at least the photosensitive layer side of the lithographic printing plate 2 is different from the transport speed of the lithographic printing plate. It is configured. Squeeze roll 23
As shown in FIG. 2, for example, at least one of the squeeze rolls 23 and 24 has a peripheral speed of the outer peripheral surface of the lithographic printing plate 2 that is different from the transport speed of the lithographic printing plate 2.
The outer diameter D of the roll 23 contacting the photosensitive layer side 2A may be different from the outer diameter d of the other reference transport roll 50 (the outer diameter of the squeeze roll 24 is d in this embodiment). .

In order to make the peripheral speed of the outer peripheral surface of the squeeze roll 23 different from the transport speed of the lithographic printing plate 2, for example, at least the photosensitive layer side 2A of the lithographic printing plate 2 among the squeezing rolls 23 and 24 is used. Roll 2 contacting
By setting the outer diameter D of No. 3 to be different from the outer diameter d of the other reference transport rolls 50 by 1 to 5%, a good result can be obtained.

Further, among the squeeze rolls 23 and 24, at least the peripheral speed of the roll 23 contacting the photosensitive layer side 2A of the lithographic printing plate 2 is higher than the peripheral speed of the other reference transport rolls 50. it can. As this configuration, for example, as shown in FIG.
0, the squeeze roll 24 and the squeeze roll 23 are driven by a motor (not shown) for the first gear 23b, the second gear 24b, the pinion gear 26, and the like.
b and the second gear 24b have a gear ratio of 1: 1.
3 is made larger than the outer diameter d of the other reference transport rolls 50. The outer diameters of the squeeze rolls 23 and 24 may be the same, and the peripheral speed of the rolls may be changed by changing the number of gears and chain sprockets. it can. Further, as shown in FIG.
The squeeze rolls 23 and 24 can be appropriately cleaned by, for example, a configuration in which a brush-shaped roll cleaning unit 58 is brought into contact with each other.

The electrophotographic lithographic printing plate applied to the present invention can be prepared by a conventionally known method. That is, the electrophotographic lithographic printing original plate is sheet-fed in a dark place, charged in a charging section, then charged substantially uniformly, and forms an electrostatic latent image by image exposure. As an exposure method, a semiconductor laser, He-Ne
Scanning exposure using a laser or the like, or reflection image exposure using a xenon lamp, tungsten lamp, fluorescent lamp, etc. as a light source,
Contact exposure through a transparent positive film, and the like.
Next, the electrostatic latent image is developed with toner. As the developing method, various conventionally known methods such as cascade development, magnetic brush development, powder cloud development, and liquid development can be used. Among them, liquid development is capable of forming a fine image and is suitable for preparing a printing plate. In addition, it is possible to use either a normal development in which toner is attached to a non-exposed portion or a reversal development in which toner is attached to an exposed portion. The formed toner image can be fixed by a known fixing method, for example, heat fixing, pressure fixing, solvent fixing and the like. The lithographic printing plate can be prepared by using the toner image thus formed as a resist and removing the electrophotographic photosensitive layer in the non-image area with an eluent. If necessary, the plate-making section, which includes a cooling section as a post-step of the toner fixing section, a rinsing section, a washing section, a gumming section, a drying section, and a CCD sensor, etc. It is possible to provide a bender for processing the plate into a predetermined shape, and a step for removing toner adhered to a punch portion, a plate accumulating portion or a printing plate edge.

Next, the electrophotographic planographic printing plate precursor used in the present invention will be described. As a conductive substrate of the electrophotographic printing original plate of the present invention, an aluminum plate is suitable, and its thickness is preferably 0.1 to 3 mm, and particularly preferably 0.1 to 0.
5 mm is preferred. For example, a plastic sheet having a conductive surface or paper made especially solvent-impermeable and conductive, an aluminum plate, a zinc plate, or a bimetal plate such as a copper-aluminum plate, a copper-stainless plate, a chromium-copper plate, or a chromium- Copper-aluminum plate, chrome-lead-
A conductive substrate having a hydrophilic surface such as an iron plate or a trimetal plate such as a chromium-copper-stainless plate is used, and the thickness thereof is preferably 0.1 to 3 mm, particularly preferably 0.1 to 0.5 mm. . Among these substrates, an aluminum plate is preferably used. The aluminum plate used in the electrophotographic printing plate precursor of the present invention is a plate-like body such as pure aluminum containing aluminum as a main component or an aluminum alloy containing a trace amount of a different atom. , And public materials can be appropriately used. This aluminum plate can be used after graining and anodizing by a conventionally known method. Prior to the graining treatment, a degreasing treatment with a surfactant or an alkaline aqueous solution is performed, if desired, to remove the rolling grease on the surface of the aluminum plate, and the graining treatment is performed. The graining method includes
There are a method of mechanically roughening the surface, a method of electrochemically dissolving the surface, and a method of chemically selectively dissolving the surface. As a method for mechanically roughening the surface, a known method called a ball polishing method, a brush polishing method, a blast polishing method, a buff polishing method, or the like can be used. Further, as an electrochemical surface roughening method, there is a method of performing alternating current or direct current in a hydrochloric acid or nitric acid electrolytic solution. Also, Japanese Patent Application Laid-Open
As disclosed in JP-A-63902, a method combining the two can also be used.

The roughened aluminum plate is subjected to an alkali etching treatment and a neutralization treatment as required. The aluminum plate thus treated is anodized. As the electrolyte used for the anodizing treatment, sulfuric acid, phosphoric acid, oxalic acid, chromic acid, or a mixed acid thereof is used, and the electrolyte and the concentration thereof are appropriately determined depending on the type of the electrolyte. Since the anodizing treatment conditions vary depending on the electrolyte used, they cannot be specified unconditionally. Generally, however, the concentration of the electrolyte is 1 to 80% by weight, the solution temperature is 5 to 70 ° C., and the current density is 5 to 60 A / dm ² , voltage 1-100V, electrolysis time 1
It is preferable to be within the range of 0 seconds to 50 minutes. Anodized film weight is preferably 0.1 to 10 g / m ^2, but more preferably from 1 to 6 g / m ^2. The thickness of these aluminum plates is preferably 0.1 to 3 mm, particularly 0.1 to 0.5 mm.
mm is preferred. Further, an aluminum plate as described in JP-B-47-5125, which is anodized and then immersed in an aqueous solution of an alkali metal silicate, is also preferably used. No. 3,658,662.
Electrodeposition of silicate as described in the document is also effective.
The treatment with polyvinyl sulfonic acid described in German Patent No. 162,478 is also suitable.

As the photoconductive material, many conventionally known compounds can be used. For example, triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives,
Arylamine derivatives, amino-substituted chalcone derivatives,
N, N-bicarbazyl derivatives, oxazole derivatives, styryl anthracene derivatives, fluorenone derivatives, hydrazone derivatives, benzidine derivatives, stilbene derivatives and the like. Further, in addition to the low molecular weight photoconductive compound as described above, the following high molecular weight compounds can also be used.
For example, vinyl carbazole and derivatives thereof, polyvinylpyrene, polyvinylanthracene, poly-2-vinyl-4- (4'-dimethylaminophenyl) -5-phenyloxazole, vinyl polymers such as poly-3-vinyl-N-ethylcarbazole, etc. And polyacenaphthylene, polyindene, polymers such as a copolymer of acenaphthylene and styrene, and condensed resins such as a pyrene-formaldehyde resin, a bromopyrene-formaldehyde resin, and an ethylcarbazole-formaldehyde resin.

For the purpose of improving the sensitivity of the photoconductor and providing a desired photosensitive wavelength range, various pigments,
Sensitizing infection fees can be used. Examples of these include monoazo, bisazo, trisazo pigments, αβετx
Metal phthalocyanine having various crystal structures such as T-type or metal-free phthalocyanine, phthalocyanine pigments such as naphthalocyanine, perylene pigments, indigo, thioindigo derivatives, quinacridone pigments, polycyclic quinone pigments, bisbenzimidazole pigments, squarium Salt pigments, azulhenium salt pigments and the like. As the sensitizing infection fee, “Sensitizer”, page 125, Kodansha (198)
7), "Electrophotography", Vol. 12, p. 9 (1973), "Organic Synthetic Chemistry", Vol. 11, 1010 (19
66) and the like can be used. For example, there are pyrylium dyes, triarylmethane dyes, cyanine dyes, styryl dyes, and the like. For the purpose of improving the sensitivity, for example, an electron-withdrawing compound such as trinitrofluorenone, chloranil, or tetracyanoethylene can be used in the photoconductive layer. These materials can be used alone or in combination of two or more. When the charge generating agent has not only a charge generating ability but also a charge transporting ability, a photosensitive member can be prepared by dispersing and applying the charge generating agent in a binder as a basic material. That is, it is not always necessary to use a combination of an organic photoconductive compound known as a charge transporting agent. In addition, the photoconductive layer can be a single layer or a plurality of layers as necessary.

The binder resin used in the electrophotographic planographic printing plate is not particularly limited as long as the non-image portion can be removed with an eluent after toner development, and examples thereof include, but are not limited to, the following. That is, styrene, (meth) acrylate,
Copolymerization of vinyl acetate, etc. with carboxylic acid-containing monomers such as (meth) acrylic acid, itaconic acid, crotonic acid, maleic acid, maleic anhydride, maleic anhydride monoalkyl ester, fumaric acid, or acid anhydride group-containing monomers A copolymer can be preferably used, and specifically, a styrene / maleic anhydride copolymer, a styrene / maleic anhydride monoalkyl ester copolymer, a (meth) acrylic acid / (meth) acrylate copolymer, Styrene / (meth)
Acrylic acid / (meth) acrylic acid ester copolymer, vinyl acetate / crotonic acid copolymer, vinyl acetate / crotonic acid / (meth) acrylic acid ester copolymer, vinyl acetate /
Examples thereof include vinyl ester of carboxylic acid having 2 to 18 carbon atoms / crotonic acid copolymer. Also, (meta)
A copolymer containing a monomer having acrylamide, vinylpyrrolidone, phenolic hydroxyl group, sulfonic acid group, sulfonamide group, sulfonimide group, or the like can also be used. Furthermore, phenol, o-cresol, m-cresol or p-cresol and novolak resin obtained by condensing formaldehyde or acetaldehyde, partially saponified vinyl acetate resin, polyvinyl acetal resin such as polyvinyl butyral, polyurethane having carboxylic acid Resins and the like can also be used.

Among these, copolymers of (meth) acrylic acid ester, styrene, vinyl acetate and the like with carboxylic acid-containing monomers such as (meth) acrylic acid are particularly suitable for their electrophotographic properties, elution properties and printability. It is excellent and can be preferably used. More preferably methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, butyl alcohol, isobutyl alcohol,
(Meth) acrylic acid esters and (meth) acrylic acids of aliphatic or aromatic alcohols such as sec-butyl alcohol, tert-butyl alcohol, n-amyl alcohol, isoamyl alcohol, hexyl alcohol, octyl alcohol, benzyl alcohol and phenethyl alcohol Can be used.

An electrophotographic lithographic printing plate can be obtained by coating a photoconductive layer on an aluminum substrate according to a conventional method. In producing the photoconductive layer, a method of including the components constituting the photoconductive layer in the same layer or a method of using the charge carrier generating material and the charge carrier transport material separately in different layers is known. It can also be created by the method of. The coating liquid is prepared by dissolving each component constituting the photoconductive layer in an appropriate solvent. When a component insoluble in a solvent such as a pigment is used, the particle size may be reduced by a dispersing machine such as a ball mill, paint shaker, dyno mill, and attritor.
It is used by dispersing it to a size of μm or less. The binder resin and other additives used in the photoconductive layer can be added during or after the dispersion of the pigment or the like. An electrophotographic lithographic printing plate is prepared by applying the coating solution prepared in this manner onto a substrate by a known method such as spin coating, blade coating, knife coating, reverse roll coating, dip coating, rod bar coating, or spray coating. Can be obtained. Examples of the solvent for preparing the coating liquid include halogenated hydrocarbons such as dichloromethane, dichloroethane, and chloroform; alcohols such as methanol and ethanol; ketones such as acetone, methyl ethyl ketone and cyclohexanone; ethylene glycol monomethyl ether; and 2-methoxyethyl acetate. Glycol ethers such as, propylene glycol monomethyl ether, propylene glycols such as propylene glycol monomethyl ether acetate, tetrahydrofuran, ethers such as dioxane, ethyl acetate,
Esters such as butyl acetate are exemplified.

In addition to the photoconductive compound and the binder resin, a plasticizer, a surfactant, a matting agent and other various kinds of plasticizers, surfactants, matting agents, etc. Additives can be added. These additives can be contained in a range that does not deteriorate the electrostatic properties and dissolution properties of the photoconductive layer. On the other hand, if the photoconductive layer is too thin, the surface potential required for development cannot be charged. Conversely, if the photoconductive layer is too thick, side etching tends to occur, and a good printing plate cannot be obtained. The thickness of the photoconductive layer is 0.1 to 30 μm.
m, preferably 0.5 to 10 μm. The content of the binding resin and the photoconductive compound in the photoconductive layer is such that if the content of the photoconductive compound is small, the sensitivity is reduced. Therefore, the photoconductive compound per 1 part by weight of the binding resin is from 0.02 parts by weight. 1.2
It is preferably used in an amount of from 0.05 to 1.0 part by weight, more preferably from 0.05 to 1.0 part by weight. In the electrophotographic lithographic printing plate, if necessary, an intermediate layer may be provided for the purpose of improving the adhesiveness between the aluminum substrate and the photoconductive layer, the electrical properties of the photoconductive layer, the elution property, the printing properties, and the like.

As the resin component of the toner forming the image area, a resin having resist properties to the eluate and having low adhesiveness to the conductive support can be used. Accordingly, the resin is selected depending on the eluate or the support, and is not particularly limited, and examples thereof include the following resins. For example, methacrylic acid, acrylic resin using acrylic acid and their esters, vinyl acetate resin, copolymer resin such as vinyl acetate and ethylene or vinyl chloride,
Vinyl chloride resin, vinylidene chloride resin, vinyl acetal resin such as polyvinyl butyral, polystyrene,
Copolymer resins such as styrene and butadiene and methacrylate, polyethylene, polypropylene and chlorinated products thereof, polyester resins (eg, polyethylene terephthalate, polyethylene isophthalate, polycarbonate of bisphenol A, etc.), phenolic resins, xylene resins, alkyd resins, vinyl Modified alkyd resin,
Examples include gelatin, cellulose ester derivatives such as carboxymethyl cellulose, waxes, polyolefins, waxes and the like. Among these, particularly from the viewpoint of dispersibility or elution resistance, methacrylic acid, acrylic resin using various esters of acrylic acid, methacrylic acid, copolymer resin of various esters of acrylic acid and styrene, styrene resin,
A vinyl acetate resin or the like can be suitably used.

As the eluent for removing the photoconductive insulating layer in the non-image portion of the toner after the formation of the toner image, any solvent can be used as long as it can remove the photoconductive insulating layer. Preferably, but not necessarily, an alkaline solvent is used. The alkaline solvent mentioned here is an aqueous solution containing an alkaline compound, an organic solvent containing an alkaline compound, or a mixture of an aqueous solution containing an alkaline compound and an organic solvent. Examples of the alkaline compound include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, potassium silicate, lithium silicate, sodium metasilicate, potassium metasilicate, sodium phosphate, potassium phosphate, ammonia and monoethanolamine, Diethanolamine, triethanolamine, monoisopropanolamine, triisopropanolamine, diethylaminoethanol,
Organic and inorganic arbitrary alkaline compounds such as 2-amino-2-methylpropanol can be mentioned.
Among these, in particular, a silicate represented by the general formula mSiO ₂ / nM ₂ O (M: alkali metal atom, m / n = 0.5 to 8.5) is contained in the eluate, whereby more favorable results are obtained. Dissolution and printing characteristics can be obtained. Molar ratio m / n of mSiO ₂ / nM ₂ O used in the present invention is 0.5 to 8.
5 is preferred. Various organic solvents can be added to the eluate mainly composed of water, if necessary. Preferred organic solvents include methanol, ethanol, propanol, butanol, benzyl alcohol, lower alcohols and aromatic alcohols such as phenethyl alcohol and ethylene glycol, diethylene glycol, triethylene glycol, polyhydric alcohols such as polyethylene glycol, ether alcohols, Organic solvents such as ether esters, ethers, ketones, and esters, or surfactants, defoamers, and other various additives can be contained.

[0032]

EXAMPLES The present invention will be described more specifically with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist of the invention. In the processing apparatus shown in FIGS. 1 and 2, the processing of the examples (Tests 1 to 5) and the comparative example (Test 7) were performed under the following conditions and as shown in Table 1. Squeeze roll pair (23, 24) Upper roll 2
3 and the outer diameter of the lower roll 24 were changed, and the other outer diameters of the drive roll and the bus roll (reference transport roll 50) were all 40 mm, and the line speed was 50 mm.
It was set to 00 mm / min.

First, the lithographic printing plate to be processed has JIS1
Polishing 050 aluminum sheet with Pumice water suspension
The surface was grained with a rotating nylon brush as an agent.
The surface roughness at this time (center line average roughness) was 0.5 μm.
Was. After washing with water, immerse in 10% caustic soda aqueous solution at 70 ° C
And the dissolution amount of aluminum is 6 g / m^TwoD
I did it. After washing, soak in 30% nitric acid aqueous solution for 1 minute
Then, the mixture was neutralized and thoroughly washed with water. Then 0.7
13V in anode and 6V in cathode
Using a square wave alternating waveform (Japanese Patent Publication No. 55-19191)
Japanese Patent Application Laid-Open Publication No. 2004-27139) Performed electrolytic surface roughening for 20 seconds,
After immersing in a 50 ° C solution to wash the surface,
Was. Furthermore, the weight of the anodic oxide film in a 20% nitric acid aqueous solution
3.0 g / m ^TwoAnodizing so that water
A substrate was prepared by washing and drying.

The following coating solution for a photoconductive layer was coated on the substrate with a bar coater and dried at 120 ° C. for 10 minutes to prepare a printing plate for electrophotographic plate making. Coating solution for photoconductive layer: ε-type phthalocyanine (Liophoton-ERPC manufactured by Toyo Ink Co., Ltd.) 1.0 part Benzyl methacrylate / methacrylic acid copolymer (methacrylic acid 40 mol%) 10.0 parts Tetrahydrofuran 48 6.0 parts Cyclohexanone 16.0 parts The above was placed in a 500 ml glass container together with glass beads,
The mixture was dispersed with a paint shaker (Toyo Seiki Seisakusho Co., Ltd.) for 60 minutes to prepare a coating solution for a photoconductive layer. The dry film thickness of the electrophotographic printing plate thus prepared was 4 μm. Next, this material was charged to a surface voltage of 400 V by a corona charger in a dark place, and then exposed to tungsten light.
By performing reversal development at a bias voltage of 220 V using the following toner, a clear positive image could be obtained.
Further, the formed image was heated at 120 ° C. for 2 minutes to fix the toner image.

Here, as a process for preparing the toner (liquid developer), a reaction vessel equipped with a reflux condenser, a stirring blade, and a nitrogen inlet tube was charged with 200 g of toluene, 50 g of methyl methacrylate, 40 g of n-octyl methacrylate, 106 g of styrene, N, N-dimethylethyl methacrylate 4g
And the temperature was raised to 70 ° C. in a nitrogen stream, and polymerization initiator 2,
2-Azobis- (2,4-dimethylvaleronitrile) was added in an amount of 1 mol% based on the above monomers, and a polymerization reaction was carried out at 70 ° C. for 6 hours. Then, 8 g of methyl p-toluenesulfonate was added, followed by heating for 1 hour. It was reprecipitated in 5 l of methanol. The precipitate was vacuum dried at 50 ° C. to obtain a copolymer resin. The resin was pulverized by a sample mill (average diameter: 10 μm), and 1 part (by weight) of sorbene 120, which is a styrene-butadiene copolymer, was added.
5 (St / Bu ratio, 25/75 wt ratio, manufactured by Asahi Kasei) and 10 parts of 5 wt% of Isopar H (manufactured by Exxon, isoparaffin-based hydrocarbon solvent) were mixed with glass beads (diameter of 4).
Paint shaker (Toyo Seiki Co., Ltd.)
Pre-dispersion for 20 minutes. Next, the glass beads (diameter of 1
mm) as a media, and wet dispersion was performed for 2 hours. 20 g of this dispersion was diluted with 1 liter of Isopar G solution of naphthenic acid Zr 5 × 10 ⁻⁷ M to prepare a positively charged liquid developer.

In the elution portion, the non-image portion of the plate prepared in the above-described step was etched with an etching solution (eluent) having the following composition. Potassium silicate solution ^{(40Be -: 20 ° C)} m · SiO 2 n · K 2 O m / n = 3 35 parts by weight of potassium hydroxide, 15 parts by weight of pure water 690 parts by weight of benzyl alcohol 10 parts by weight monoethanolamine (pH 13. 15 (27 ° C)) 10 parts by weight

Regarding the above processing steps, 400 mm × 60
Table 1 shows the results of processing the lithographic printing plate of 0 mm size for one week on a 30 plate / day basis.

[0038]

[Table 1]

In Table 1 above, test Nos. 1, 2, 3,
Reference numerals 4 and 5 show embodiments according to the present invention. Test No.6
7 is a comparative example. In the comparative example, the roll diameter is 40 mm
Roll moves at the same peripheral speed as the plate, and does not rub against the plate. In the test of the embodiment, a roll having a roll diameter of not more than 40 mm causes a rubbing phenomenon with the plate. And it turns out that the roll which contacts the upper surface of a printing plate is rubbed well, and it becomes difficult to attach dirt. That is, since a grained surface appears in the non-image portion on the upper surface of the printing plate, the rubbing effect is increased. Since the lower surface of the plate is a smooth surface, the rubbing effect is smaller than that of the upper surface. If the diameter of the other roll is different even if the diameter is 40 mm, there is also an effect that the rolls rub against each other during idle running when the printing plate has not passed, but there is also an effect that dirt can be removed.
From this example, it can be seen that the rubbing effect between the upper surface of the printing plate and the upper roll, which is a squeeze roll, is very large. Table 1
In the embodiment of the present invention, the outer diameter of the upper roll contacting the photosensitive layer side of the printing plate is 1 to the outer diameter of the reference transport roll.
The configuration is different in the range of ５5%. More favorable results were obtained when the peripheral speed of the upper roll contacting the photosensitive layer side was set higher than the peripheral speed of the other reference transport rolls as in Test Nos. 3, 4, and 5.

[0040]

As described above, according to the processing apparatus of the present invention, among the squeeze roll pairs provided in the elution section, at least the peripheral velocity of the outer peripheral surface of the roll contacting the photosensitive layer side of the lithographic printing plate is reduced. Since the lithographic printing plate is configured to have a speed different from that of the lithographic printing plate, appropriate friction occurs between the squeeze roll and the photosensitive layer side, and the cleaning effect of the squeeze roll is enhanced. Therefore, the accumulation of dirt on the squeeze roll can be prevented, and as a result, the transfer of dirt to the plate surface can be prevented, and a lithographic printing plate having an extremely good plate surface can be provided. Further, in the lithographic printing plate processing apparatus according to the present invention, the outer diameter of a roll that contacts at least the photosensitive layer side of the lithographic printing plate in the squeeze roll pair is different from the outer diameter of another reference transport roll. If
Not only the cleaning effect is high, but also a structure for setting the squeeze roll to a predetermined peripheral speed can be achieved extremely easily. Furthermore, in the lithographic printing plate processing apparatus according to the present invention, at least 1% to 5% of the outer diameter of the roll of the squeeze roll pair that comes into contact with the photosensitive layer side of the lithographic printing plate with respect to the outer diameter of the reference transport roll. According to the configuration set to be different in the range, the cleaning action can be effectively exerted. Furthermore, in the lithographic printing plate processing apparatus according to the present invention, the peripheral speed of at least the roll of the squeeze roll pair that contacts the photosensitive layer side of the lithographic printing plate is higher than the peripheral speed of another reference transport roll. According to this, the rotation of the squeeze roll is in the forward direction with respect to the transport direction of the printing plate, and a more effective cleaning action can be performed on the printing plate without adversely affecting the transport.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an embodiment of a planographic printing plate processing apparatus according to the present invention.

FIG. 2 is an enlarged perspective view of a main part of the apparatus of the present invention shown in FIG.

FIG. 3 is a schematic diagram of a conventional lithographic printing plate processing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Developing / fixing part 2 Lithographic printing plate 23, 24 Elution part squeeze roll 30 Cooling part 31 Elution part 32 Rinse part 33 Gum part 40 Cooling means 41, 42 Brush roll 45 Eluate supply means 46 Rinse water supply means 47 Gum liquid supply Means 50 Reference transport / squeeze roll 58 Roll cleaning means 100 Lithographic printing plate processing device

Claims (4)

[Claims] 1. An electrophotographic lithographic printing plate comprising a photosensitive layer containing a photoconductive substance coated on an aluminum support which has been subjected to a graining and hydrophilizing treatment.
In a lithographic printing plate processing apparatus that continuously performs predetermined processing such as elution, among the squeeze roll pairs provided in the elution section that performs elution, the outer peripheral surface of a roll that contacts at least the photosensitive layer side of the lithographic printing plate Wherein the peripheral speed of the lithographic printing plate is different from the transport speed of the lithographic printing plate. 2. The squeeze roll pair, wherein at least the outer diameter of a roll that contacts the photosensitive layer side of the lithographic printing plate is different from the outer diameter of another reference transport roll. Item 4. A planographic printing plate processing apparatus according to Item 1. 3. The squeeze roll pair is set so that at least the outer diameter of the roll contacting the photosensitive layer side of the lithographic printing plate is different from the outer diameter of the reference transport roll by 1 to 5%. 3. The lithographic printing plate processing apparatus according to claim 2, wherein 4. The squeeze roll pair, wherein a peripheral speed of at least a roll contacting the photosensitive layer side of the lithographic printing plate is set to be higher than a peripheral speed of another reference transport roll. A lithographic printing plate processing apparatus according to any one of claims 1 to 3.