JPH0451253A - Production of electrophotographic planographic printing plate - Google Patents

Abstract

PURPOSE:To prevent the staining of end parts by the printing plate obtd. by subjecting an electrophotographic planographic printing original plate to reversal development by providing a stage for desensitizing the end faces of the electrophotographic planographic printing plate as a post-stage of a toner developing stage. CONSTITUTION:The end faces of the printing plate are desensitized by applying a desensitizing liquid on the end faces of the printing original plate in any stage after tone4r development in the process for producing the electrophotographic planographic printing plate by a stage for electrifying, a stage for exposing, a stage for making development by using toners, a stage for fixing the toner images, and a stage for removing photoconductive layers exclusive of the toner images. The end faces of the printing original plate are effectively desensitized particularly when the toners sticking to the end faces of the printing original plate are mechanically removed by rubbing the end faces by a brush or cloth, etc., or when the desensitizing liquid is applied on the end faces of the printing original plate after the toners are removed by a solvent or the like which dissolves the toners. The application of the desensitizing liquid is executed by coating with, for example, a brush, sponge, roller, etc., or by spray coating.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention provides toner l1ii! on a photoconductive layer. An electrophotographic lithographic printing original plate, in which a printing plate is obtained by removing non-image areas other than toner image areas after forming i#, and in particular, an electrophotographic method for producing a lithographic printing plate that is prevented from printing smudges. Regarding lithographic printing original plates.

[Conventional technology]

Today, as lithographic offset printing plates, PS plates that use positive-working photosensitive agents whose main components are diazo compounds and phenolic resins, and negative-working GT photosensitive agents whose main components are acrylic monomers and prepolymers have been put into practical use. However, due to the low sensitivity of all of these, τ plate making is performed by contact exposure of a film original plate that has been recorded in advance. Ten thousand,
Thanks to advances in computer image processing, large-capacity data storage, and data communication technology, in recent years, a team of staff members has been working on computer operations for 1RB, high-speed communication networks, and satellite communications, from manuscript input, correction, editing, and layout. An electronic editing system that can immediately output data to a terminal plotter in a remote location has been put into practical use. In particular, electronic editing systems are highly reliable in the field of newspaper printing, which requires immediacy. However, even in fields where original manuscripts are currently preserved in film form and printed versions are reproduced as needed, the development of high-capacity recording media such as optical discs has made this difficult.
Therefore, it is thought that the original will be stored as digital data on these recording media.

However, direct printing plates, in which printing plates are created directly from the output of a terminal plotter, have hardly been put into practical use, and even in places where electronic editing systems are in operation, output is performed on silver halide photographic film. The printing plate is created by contact exposure to the Ps plate. This is the light source of the output plotter (Gae td, He-
There are seven reasons why it is difficult to develop a direct printing plate with such high sensitivity t-V that a printing plate can be produced within a practical time using a Ne laser, a semiconductor laser, etc.

An electrophotographic photoreceptor can be considered as an octamer that can provide a high gt degree for all direct printing plates.

As a method for producing printing plates using electrophotography, the most popular method is to remove the photoconductive layer in non-image areas after toner image formation.
ing. For example, fPJ, Special Publication No. 37-77142, No. 3
r-6ri 6/issue, same 3! -77sr, same≠l-24L
Jt issue, Hirotsu-32nd Oj issue, Tokukai Sho! O-/ri10
ri issue, same! 0-/ri No. 570, jJ-24437,
Same j4cmIQ! ! Jt issue, same≠-/34143λ issue, same! ! -/Qjλyo Hirogo, same! ! -/! Jrint issue,
same! j-/6/210, j7-/4A74J4,
The printing original plate for electrophotographic plate making described in the same Z'y-ITTRT, No. 3 publication, and the like is mentioned.

In the above method, it is necessary to remove the non-image area of the electrophotographic photoreceptor by etching and expose the hydrophilic surface. lf
A binding resin that is released by R is often used.

However, when printing using a printing plate obtained in this way, the size of the printing plate can be changed using a normal sheet-fed printing press. ) also poses no problem when the edges of the printing plate do not become the printing surface, such as when printing on small paper, but 9. When printing on paper, printing stains occur at locations corresponding to the edges of the printing plate. This stain n is particularly noticeable when toner development is performed by reversal development.

An insulating resin layer is provided on the end surface (side surface) of the lithographic printing original plate for electrophotographic platemaking to prevent edge contamination caused by the lithographic printing plate obtained by full reversal development. In particular, a method has been proposed to prevent gold adhesion on toner particles (% 1973-/7r2≠O).However, even with the above-mentioned measures, the edge staining was rarely sufficiently eliminated.Therefore, It has been proposed in Japanese Patent Application No. 1999/-1 Core 3RI and No. 4AOμ to prevent edge contamination by desensitizing the edges of the printing plate, but it is generally not Desensitizing liquids are often electrically conductive, and a toner layer is generated during development, especially during reversal development, and edge contamination is insufficiently removed.

[Means to solve the problem]

Even with the above method, if a lithographic printing plate obtained by performing reversal development to form a toner layer and removing the photoconductive layer in the non-image area is used to print newspapers, etc., the edges still remain. No printing stains were observed.

As a result of intensive studies to solve the above-mentioned drawbacks, the present inventors have found that an electrophotographic planographic printing plate having a photoconductive layer provided on a conductive substrate includes at least a step of charging and a step of exposing to light.
In a method for producing a V electrophotographic lithographic printing plate by a step including a step of developing with a toner, a step of fixing the toner at a certain level, and a step of removing a photoconductive layer other than the toner image, 1. Post-process of the toner development step The above-mentioned drawbacks can be improved by producing an electrophotographic lithographic printing plate which is characterized by the following step of completely desensitizing the edges of the electrophotographic lithographic printing plate.

The present invention will be explained in detail below.

As the conductive substrate of the electronic 4-type printing original plate of the present invention, 6
Additional supports can be used. For example, plastic sheets that are widely used in the electrically conductive sector are firstly made into solvent-impermeable and electrically conductive paper, aluminum plates, zinc plates, z-thin copper-aluminum plates, copper-stainless steel plates, chrome-steel plates, etc. A conductive substrate with a hydrophilic material such as a bimetal plate, a chrome-copper-aluminum plate, a tri-metal plate such as a lead-Fc plate, a chrome-steel-stainless steel plate, etc. is used, Its thickness is preferably 0.7 to Jfnm
t is preferably <, particularly 0.7 to 0.1 mm. Among these substrates, aluminum plates are preferably used. The altanium plate used in the present invention is a plate-shaped body such as pure aluminum whose main component is aluminum wafer or aluminum sheet metal containing a trace amount of foreign atoms, and whose composition is not specified.
(Conventional orbital and public materials can be used as appropriate.)

This Altanium plate can be used by being grained and made into an anode plate by a conventionally known method. Prior to the graining treatment, in order to remove rolling fat from the surface of the aluminum plate, a degreasing treatment using an aqueous alkali solution and an F surfactant is performed as desired, and a graining treatment is performed. The graining treatment method includes a method of mechanically roughening the surface, a method of electrochemically dissolving the surface, and a method of selectively dissolving the surface chemically. As a method for mechanically roughening the surface, known methods such as ball polishing, brush polishing, blast polishing, puff polishing, etc. can be used. Also, as an electrochemical surface roughening method, salt Ill'! Alternatively, there is a method of converting alternating current into direct current in a nitrous electrolyte. A method combining the two can also be used, as disclosed in JP-A-74A-43-02.

The roughened zero-order aluminum plate is subjected to alkali etching treatment and neutralization treatment as necessary.

The n7t-altanium plate thus treated is then anodized. As the electrolyte used in the anodizing process, sulfuric acid, phosphoric acid, oxalic acid, chromic acid, or a mixed acid such as 7N is used. Ru. Since the processing conditions for anodizing vary depending on the electrolyte used, - generally speaking, it is necessary to add %,
- For boat fishing, the electrolyte concentration is /-, rO weight 1% solution, liquid temperature is j~700CS'WL flow density [jN40A/dm
, voltage/-/QO■, and electrolysis time in the range of 10 minutes to jQ minutes are suitable. Anodic oxide film amount is 0.1-1027
m2 is preferred, but Fx is preferably in the range of /-4r/m2.

As the photoconductive material used in the present invention, many conventionally known compounds can be used. If kept, triazole derivatives, oxbutiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline visiting conductors, bilanro/'ej conductors, phenyle/diamine derivatives, aryl amide/derivatives, aba) substituted chalcone derivatives, etc.

Examples include N-bicalbasil derivatives, oxazole derivatives, stecyla/thracene derivatives, fluorenone derivatives, hydrazone derivatives, benzidine derivatives, and stellhene derivatives.

In addition to the above-mentioned low-molecular light guiding compounds, the following high-molecular compounds can also be used. If you line up,
Polyvinylcarbazole and its derivatives, polyvinylpyrene, polyvinylanthrace/, poly(lambda)-vinyl-(μ'-dimethylaminophenyl)-s-7 22-oxazole, poly-3-vinyl-N-ethercarbazole, etc. polymers such as polyacenaphthylene, polyindene, copolymers of acenaphthylene and styrene,
Condensation resins such as pyrene-formaldehyde resin, bromopyrene-formaldehyde resin, and ethylcarbazole-formaldehyde resin are used.

Improved sensitivity of 17t% original conductor, desired photosensitive wavelength range 1R
For purposes such as making people wait Q9, various II fees, infection charges, etc. 1! ' can be used. For these columns,
Monoazo, bisazo, trisazo pigments, gold Il! 7 talocyanii/or metal-free 7 talocyanii 7S family such as 7 talonani 7, perylene sa, indigo, deoi/digo derivatives, quinacridone pigments, polycyclic quinone IIA materials, bisbenzimidazole pigments, squalium base pigments,
Azulenium salt type! These include the Il family.

Y7t, as a sensitizing agent, "Sensitizer J /2!2t#
Dansha r/ri r7), “Electronic 3 True” /2 Ta (li73
) "Usoiso synthesis character" ko4t A//1OIO(/P4
All known compounds described in 4) etc. can be used.

Examples include pyrylium dyes, triarylmethane dyes, cyanine dyes, and steryl dyes.

These can be used alone or in combination. In addition, these charge generating agents have not only charge generation ability but also charge transport ability.
II & element can be prepared by dispersing and applying the charge generating agent in a binder/der. That is, it is not necessarily necessary to use an organic photoconductive compound such as a cypress in combination as a charge transport agent.

The photoconductive NI of the present invention includes, for the purpose of improving sensitivity, etc.
Electron-withdrawing compounds such as trinitrofluorenone, chloranil, and tetra-7anoethylene can be used.

The binding resin used in the printing original plate P for Densusha X plate making of the present invention is Toner GengI! Removal of gold in the non-image area after p! Although not necessarily specific, from the viewpoint of pollution and ease of handling, it is preferable to use an etching solution mainly composed of alkaline water injection Sat.
Ru. Therefore, it is preferable that the binding resin be a compound that can be removed by preparing it in an alkaline aqueous solution. For example, a copolymer of styrene and maleic anhydride, a copolymer of styrene and maleic anhydride monoalkyl ester, and methacrylic aI! /methacrylic acid ester copolymer, styrene/methacrylic I
II! /methacrylic acid ester copolymer, acrylic acid methacrylate ester copolymer, styrene/acrylic acid/
Methacrylic acid ester copolymer, vinegar vinyl/Kroto/
Acid copolymer, vinyl acetate/klotho/i! I! Acrylic acid esters such as methacrylic acid ester copolymers, methacrylic Hs, styrene, vinyl acetate, etc., and acrylic acid, methacrylic acid, itaconic acid, chloroacid, maleic acid, maleic anhydride/Il! , copolymers with carbonic acid-containing monomers such as fumaric acid or acid anhydride group-containing monomers, methacrylic acid amide, vinyl pyrrolidone, monomers with phenolic hydroxyl groups, sulfo/acid groups, sulfonamide groups, and sulfonimide groups. Examples include copolymers containing phenol resins, partially vinylated vinyl acetate resins, xyleno resins, and vinyl acetal resins such as polyvinyl butyral. Acid anhydride group, 17t is Carme/
A copolymer containing a monomer that grows acid groups as a copolymerization component and a phenol resin have a high charge retention ability of the photoconductive layer when used as an electrophotographic X-sensitive material, and can be conveniently used with good results. can.

Examples of copolymers containing monomers carrying acid anhydride groups include co-X of styrene and maleic anhydride;
Combination is preferred. Additionally, half esters of this copolymer can also be used.

Carbon IIi! A copolymer containing monomers having a group kV as one component, or acrylic acid (%L) is a copolymer containing one or more methacrylic acid and an alkyl ester, aryl ester, or aralkyl ester of acrylic acid (% LIm) of methacrylic acid. Body is preferred. I constant, vinyl acetate and a-ton acid copolymer, vinyl acetate and carbon number λ~/
A ternary copolymer of a vinyl ester of carbonic acid in r and crotonic acid is also a preferred hook. Among the phenolic resins, phenol, 0-talesol, m-cresol, 19 is p-cresol, and formaldehyde is obtained by condensation with acetofyldehyde under acidic conditions. For example, a novolac resin tube may be used.The binding resin may be used alone or in combination.The printing plate for electronic 4 plate making of the present invention is prepared by applying a photoconductive layer onto a conductive substrate according to a conventional method. The photoconductive layer can be obtained by coating the photoconductive layer. Although there is a known method for separating and using a layer called t-A, it can be produced by any method.

The coating solution is prepared by dissolving each component constituting the photoconductive layer in an appropriate solvent. When using a component that is insoluble in a solvent such as a pigment, it is added to a dispersing machine such as a ball mill, paint shaker, Dyno Mill, or Ato2 Iter with an F particle size of jμ to 0. /μ and use 1. The binding resin and other additives used in the photoconductive layer can be added during or after dispersing the pigment. Create 1 in this way, then apply the coating solution by rotating, blade coating, knife coating, reverse roll coating 1
A printing plate for an electrophotographic exhibition plate can be obtained by coating and drying on a substrate by a known method such as dip coating, rod coating, or spray coating. Examples of the fi medium for preparing the coating solution include halogenated hydrocarbon ICs such as dichloromethane, dichloroethane, and chloroform, alcohol bases such as methanol and ethanol, keto/#I, etele/ such as acetone, methyl ether ketone, and cyclohequitenone. Glycol monomethyl ether, glycol ethers such as comethoxy7-edel acetate, tetrahydro-7, dioxa/
Examples include ethers such as ethyl acetate, ethyl acetate, butyl acetate, and the like.

In addition to the photoconductive compound and the R5 resin, the photoconductive layer of the present invention includes a F plasticizer, a surfactant, a mantle agent, etc., in order to improve the flexibility of the photoconductive layer and the coated surface condition. Other 6 supplements 7) 0 agents can be added.

These additives can be contained within a range that does not completely deteriorate the electrostatic customization and etching properties of the photoconductive layer.

However, if the thickness of the photoconductive layer of the present invention is too thin, it will not be possible to charge the surface potential T required for shallow immersion, and on the other hand, if it is too thick, side etching will occur when removing the photoconductive layer. Etching occurs in the plane direction, which is called etching, and a good printing plate cannot be obtained. The thickness of the photoconductive layer is 0. /~30μ, preferably 0.1-/Qμ. In the printing original plate for electrophotographic platemaking of the present invention, an intermediate layer may be provided, if necessary, for the purpose of improving the contact properties between the substrate and the photoconductive layer, the electrical properties of the photoconductive layer, etching properties, printing characteristics, etc. I can do it. In addition, an overcoat layer that can be removed by the photoconductive layer etching solution may be provided on the photoconductive layer, if necessary, for the purpose of improving the electrical properties of the F photoconductive layer, the image characteristics when toner is shallowly immersed, the adhesion with the toner, etc. I can do it. Mechanically, this overcoat layer does not work even if it is a resin layer containing 7 t% of a matting agent.

As the etching solution for removing the photoconductive insulating layer in the non-toner image area after toner image formation, any solvent can be used as long as it can remove the photoconductive insulating layer, and there is no particular limitation. However, preferably alkaline solvents are used. The alkaline solvent mentioned here is water*g containing an alkaline compound, an organic solvent containing an alkaline gold compound, or a mixture of an aqueous solution containing an alkaline compound and an organic solvent.

Examples of alkaline compounds include sodium hydroxide, aqueous potassium dispersion, sodium carbonate, sodium silicate, potassium silicate, sodium metasilicate, potassium metasilicate, sodium phosphate, potassium chloride, ammonia, $
Examples include organic and inorganic arbitrary alkaline compounds such as P and amino alcohols such as monoethanolamine, jetanolamine, and triethanolamine. As mentioned above, the solvent for the etching solution is
Water or many organic solvents can be used, but
From the viewpoint of odor and pollution, an etching solution mainly composed of water and metal is preferably used.

If necessary, all of the V solvent can be added to the water-metal slag and etching solution. Preferred organic solvents include lower alcohols and aromatic alcohols such as methanol, ethanol, propatool, butanol, benzyl alcohol, and 7-enedel alcohol, as well as ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, Celnorgs, i?
Examples include amino alcohols such as monoethanolamine, jetanolamine, and triethanolamine.

In addition, the etching solution may contain surfactants, antifoaming agents, and other various agents as required.
Ru.

In the present invention, the toner forming the image area is not particularly limited as long as it has resistivity to the etching solution, but in general, a WN fat fraction that has resistivity to the etching solution is used. It is preferable that it contains.

As resin components, acrylic resins/vinyl acetate resins using methacrylic acid, acrylic acid, and these esters, copolymer resins of vinyl acetate and ethylene or vinyl chloride, vinyl chloride resins, vinylidene chloride resins, polyvinyl Vinyl acetal resins such as butyral, polystyrene, copolymer resins such as sterene and butadiene, methacrylic acid esters, polyethylene, polypropylene and chlorinated resins, polyester resins (IPII, polyethele/terephthalate, polyethele/iso7talate, bisphenol A) polycarbonate, etc.], phenolic resin, resin, alkyd resin, vinyl-modified alkyd resin, gelaten, cellulose such as carboxymethylcellulose, wax, polyolefin,
Examples include wax.

The printing plate for electronic photographic printing plates of the present invention can be created by the following process. That is, it is substantially uniformly charged by a known charging method such as a corotron or scorotron,
Forms an electrostatic latent image on the image*g light. The exposure method includes scanning using a semiconductor laser, )le-N e laser, etc.
Examples include reflective exposure using a xenon lamp, tungsten lamp, firefly lamp, etc. as a light source, and contact exposure using a transparent positive film. Next, the static IIE# image is lightly immersed in toner. As the scratching method, conventionally known methods such as cascade dipping, magnetic brush development, bakugokura 9-doping development, and liquid dipping can be used. Among them, % liquid shallow dipping is suitable for preparing printing plates since it is possible to form minute me. At this time, depending on the combination of the charge polarity of the photoconductor and the charge polarity of the toner, the current gII method of forward shallow dipping and reverse shallow dipping is possible. The formed toner image can be fixed by a known fixing method, such as heat fixing, pressure fixing, solvent fixing, or the like. An F printing plate can be prepared by using the toner image formed in this way to act as a resist and removing the electrophotographic photosensitive layer in the non-image area with an etching solution.

The desensitization step of the present invention is carried out as a subsequent step of the toner shallow soaking step of the above steps. That is, the end surfaces can be desensitized by applying a desensitizing liquid described below to the end surfaces of the printing original plate several times after the toner is shallowly immersed. In a more preferred embodiment, the toner is applied to the edge of the printing plate and then removed mechanically by rubbing the edge of the printing plate with a brush or cloth, or after being removed with a solution that dissolves the toner. It is effective to desensitize the processed surface by applying a desensitizing liquid to the end face of the printing original plate.

t7t, F, Etch 77 to apply a resin layer removable with an etching liquid to the edge of the S crimped printing original plate.
After removing the adhered toner and the dissolved layer, desensitization'P/! By applying No. 1, the edges of the printing plate can be desensitized.

As for the method of applying the desensitizing liquid, if the pet is fed, it may be applied by a brush, sponge, roller, etc., or by a method known to conventional artisans, such as spray application. The edge surface of the first coating varies depending on the usage of the printing plate, and if only one side of the printing plate is to be printed, it is best to apply desensitizing liquid to only one edge of the printing plate. , moderate usage form a't-
Preferably, the coating is applied to two opposing end faces, most preferably to the outer circumferential end face (ie, all four end faces).

As the desensitizing liquid used in the present invention, a desensitizing liquid consisting of water containing a hydrophilic polymer compound can be effectively used.

Specific hydrophilic polymers include 9'lJ, and natural polymers include starches such as Kansho starch, #in starch, tapioca starch, wheat starch, and cornstarch, carragithene, laminaran, sea buckthorn mannan, funori, Products obtained from algae such as iris moss, agar and sodium alginate, molasses, mannan, quince 7ide, gelaten, gum tragacanth, gum karaya, xanthine gum, guarbing gum, locust bingham, gum arabic, kyallo, bugum and benci/gum Mucilages, glues, etc. made using the production of microorganisms, such as homopolysaccharides such as dextran, bulcan, and liver, and heteropolysaccharides such as succinoglycium and Santaph gum. Examples include proteins such as gelatin, casetene, and collagen. Half heat movement (half heat movement)
Thealalginate furopylene gellicol ester O and others
Cellulose enzyme conductors such as fc, hiscose, methylcellulose, ethylcellulose, methylethylcellulose, carboxymethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, hydroxypropyl ethylcellulose, and hydroxypropylmethylcellulose phthalate, as well as modified starches, etc. nru.

Processed starches include white dextrin/, roasted starch such as yellow texturin and British gum, and fermented starch/
and enzyme-modified dextrin such as Schardinger dextrin, acid-decomposed starch as shown in solubilized starch, oxidized starch as shown in dialdehyde starch, pregelatinized starch such as modified pregelatinized starch and unmodified pregelatinized starch, '
)7iII! Starch, fatty starch, sulfate starch, nitrate starch, esterified starch such as xanthate starch and carbamate starch, carboxyfuralkyl starch, hydroxyalkyl starch, sulfoalkyl starch, cyanoethyl M powder, allyl starch, benzyl starch , etherified starch such as carbamyl ether starch and dialkylamino starch, crosslinked starch such as methylol crosslinked starch, hydroxyalkyl crosslinked starch, sour/acid crosslinked starch and dicarboxylic acid crosslinked starch, starch polyacrylamide copolymer, starch polyacrylic acid copolymer copolymer, starch polyvinyl acetate copolymer, starch polyacrylonitrile copolymer, cationic starch polyacrylic ester copolymer, cationic starch vinyl polymer copolymer, starch polystere/maleic copolymer, and starch polyethylene oxide Starch graft copolymers such as copolymers are included. Synthetic products include polyvinyl alcohol,
Partially acetalized polyvinyl alcohol, allyl-modified polyvinyl alcohol, modified polyvinyl alcohol such as polyvinyl methyl ether, polyvinylethyl ether and polyvinyl imbutyl ether, polysodium acrylate, partially saponified polyacrylic ester, partially saponified polyacrylic ester copolymer polyacrylic acid derivatives and polymethacrylic acid derivatives such as polymethacrylates and polyacrylamides, polyethylene glycol, polyethylene oxide, polyvinylpyrrolidone, copolymers of polyvinylpyrrolidone and vinyl acetate, carboxyvinyl polymers, styrene maleic acid Copolymer, sterol crotonic acid copolymer, etc.

It is preferable that the desensitizing liquid of the present invention further contains a metal salt of a strong acid, thereby increasing the desensitizing effect. Specific examples of metal salts of strong acids include:
nitric acid salt, potassium salt, magnesium salt, calcium salt and zinc salt, sodium salt of sulfuric acid, potassium salt, magnesium salt, calcium salt and zinc salt, sodium salt of chromium salt, potassium salt, Magne 7 wamu salt,
Examples include calcium and zinc salts, and sodium and potassium fluoride. These metal salts of strong acids can be used in combination of two or more,
The amount is preferably less than about 0.01-j weight based on the total weight of the desensitizing liquid.

9H when using a strong acid metal salt in the non-inventive desensitizing liquid.
/From j, more good IL< is Kokara Hiro,! ■It is preferable to use within the range.

In addition, instead of the metal salt of the strong acid, -drink cost rn 8 t
02/n M 20 (M: alkali metal atom,
m/mouth=0. ! ～r, z)
Even if M is included in the A-shaped forehead, the desensitizing effect can be enhanced. Specific details! As the salt, sodium silicate, potassium silicate, lithium silicate, etc. can be used. The silicate used in the present invention is approximately O3 in the total desensitizing solution.
It is preferable to use Hiroshi weight S to about 0 weight, good Y[, (is about o, r weight to about ko J weight.

In the case of using a silicate in the desensitizing liquid of the present invention, the pH ranges from pHr to /4c, jv'! L<t! It is preferable to use it within the range of 5'2)-ra/J.

It is preferable that the desensitizing liquid used in the present invention contains a humectant agent and/or a surfactant to improve the applicability of the desensitizing liquid for dry skin. can. As a specific dampening agent, lower polyhydric alcohol is preferable! L<, I
IRJ is ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, futilekyl, penta/diol, hegiclene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, tripropylene glycol, glycerin, sorbitol, Examples include hantaerythritol, but the preferred one for n%% is glycerin.

17 Part 1 Surfactants include nonionic surfactants such as polyoxyethylene alkyl phenyl ether and holoxyethylene polyoxypropylene block copolymers, fatty acid salts, and full*ATilH varnish.
Anionic surfactants such as RutjNlt, alkylbenzene sulfonates, alkylnaphthalene sulfonates, dialkyl sulfosuccinic esters, alkyl phosphate ester salts, naphthalene sulfonic acid formalin condensates, betaine type, glycine type, and alanine when fed. Amphoteric surfactants of the type and sulfobemaine type can be used.

Is desensitization convenient for the present invention? I is made of an aqueous solution of a hydrophilic polymer compound as described above, but the target is US Patent No. 2j3 Tatata, US Patent No. 4Lλ6741J, US Patent No. 1734c1! Number F! It is possible to use the emulsified desensitizing liquid % described in Specification A. The amount of desensitizing liquid applied to the end surface of the original printing plate is preferably in the range of about 10 to 7 m2.

[Practical] The invention will be described in more detail in terms of implementation, but the present invention is not limited to the following embodiments unless it exceeds the gist thereof.

Practical row I The surface of a JIS10!0 full ξ nicum sheet was grained with a rotating nylon brush using a humid water suspension as an abrasive. The surface roughness (center line average roughness) at this time is 0. jμ
Demetsu friend. After washing with water, the sea urchin etch/glue was immersed in a 70% caustic soda water bath solution at 700C until the amount of aluminum dissolved was t t7m. After washing with water, dissolve in 30% nitric acid water.
It was neutralized by soaking for a minute, and thoroughly washed with water. After that, in a solution at 0°7% nitric 7%, anode voltage/3 volts,
Electrolytic surface treatment was carried out for 20 seconds using a rectangular wave alternating waveform with a tortoise pressure of 6 melts at the cathode (noted in Tokusho!!-/RI/RI No. 1) for 20 seconds. After washing the surface by immersion, it was washed with water.Furthermore, it was anodized in a 20% aqueous sulfur solution so that the weight of the anodized film was J, O97m2, washed with water, and dried to prepare a substrate. did.

The following photoconductive layer coating solution was applied onto this substrate using a bar coater and dried for 10 minutes to prepare an electrophotographic lithographic printing plate.

Type C Copper 7 Taro 7 Ani/(Toyo Ink@g Liopoton - EFLPC) /, o part Copolymer of benzyl methacrylate and methacrylic acid (methanolyl M 30 mol%) 10.0 parts f trahuman cx79y 4Lt, o part cyclohexanone Disperse 6.0 parts or more in a 300m glass container with glass beads for 6Q minutes using a bay/door knee car (Toyo 'nI Ki Seisakusho ■) to prepare a dispersion for light guide skin.

The dry film thickness of the electrophotographic lithographic printing original plate prepared in this manner was determined by reference μ.

Next, this sample was charged to a surface potential of +aooV using a Corona Tei IE machine in a dark place, and the negative image GL was exposed to light using a 3D/Gesten source.
ooV) I was able to obtain a clear positive image. Next, a nylon rotating brush is used to remove the toner that adheres to the edge of the printing plate and then desensitizes it. W(1)T-It was applied to the edge of the printing plate using a sponge and dried. Furthermore, the created image g/l was heated at 12o @C for 2 minutes to form a toner image g/l.
Establish II.

This non-#J part was mixed with potassium silicate ≠ θ parts, potassium hydroxide 10 parts, ethanol 1 ooH to water.

After diluting the etching solution into an etching solution, it was thoroughly washed with water, and then a gum solution (Fuji Photo Film Gum Gt for PS plates) was used.
J-7) I coated it and created an offset printing plate.

When this printing plate was set in an offset printing machine and printing was carried out, all of the resulting n2 prints were good prints with no %f'5f'L at all in the portions corresponding to the edges of the printing plate.

Toluene oooy, methyl methacrylate in the reaction volume with reflux device, stirring blade and nitrogen inlet tube! Of%n
- octyl methacrylate aoy.

Styrene 104y%N,N-dimeter ether methacrylate at was added, the temperature was raised to 700C in a nitrogen stream, and 1 mole of polymerization initiator Co-Anobis(Co-Dimethylpareronitrile) was added to the above monomer. The polymerization reaction was carried out at 70'C for 4 hours. Next, p-toluenesulfoheptate was added and heated for an hour.Then, the reaction solution was cooled to room temperature and then diluted with methanol. This precipitate was dried under vacuum to obtain a copolymer resin.

Grind this resin with a sample mill (average diameter of several lOμm)
After LI'C, 1 part (1!L amount) of turprene lλOj (S t /
Isopar H (manufactured by Exxon, imparaffinic hydrocarbon solvent)! ■ Mix with 10 parts of t% and add glass beads (@diameter μ~j
mm) f is used with JO in India Shaker (manufactured by Toyo Seiki)
The molecular preparations were dispersed. Next, glass beads (II diameter approx./mm) were cut using a Dyno Mill (manufactured by Turprise Co., Ltd.).
Wet dispersion was carried out for one hour using as a media.

Next, this dispersion liquid of naphthenic acid Zrz×10-7
% Isopar G solution/IK was diluted to prepare a positively charged liquid powder.

Hydroxypropyl ether starch (degree of substitution o, or) 4.0 parts Potassium silicate solution (j2Be: λO@C) /, 1 part Potassium hydroxide (Hir, z%) 1.0 part Pure water
Ta/, Hirobe Kono non-image S all-silicate potash Hiro'fRrs potassium hydroxide io part, ethanol 1ooB
was removed by etching solution diluted with 100 parts of water,
After thorough washing with water, a gum solution (PS plate gum GU-7 manufactured by Fuji Photo Film Co., Ltd.) was applied to prepare a lithographic printing plate.

When this printing plate was set in an offset printing machine and printing was carried out, all of the resulting NFC prints were clean prints with no stains at all, even in the areas corresponding to the edges of the printing plate.

Example 2 A lithographic molding was prepared in exactly the same manner except that the following desensitizing liquid (2) was used in place of the desensitizing liquid (1) in Example 2.

30% gum arabic aqueous solution 61.0 parts Sodium hexametaphosphate 0.7 parts Sodium nitrate
i, o part magnesium sulfate
/, Part 2! %m&
λ, μ part polyoxyenale/polyoxyprobile/floc copolymer/, Ji pure water
jO, 0 copies When printing was carried out in the same manner as in IpH/ using this printing plate, all of the printed matter obtained were in good condition with no stains at all even in the portions corresponding to the edges of the printing plate. I failed.

Comparative lpHl An F printing plate was prepared in exactly the same manner except that no desensitizing liquid (1 ml) was applied to the end surface in Example 1.

When printing was carried out using this printing plate in the same manner as in the example, the image area of the resulting printed matter was clean and clean, but the portion corresponding to the edge of the printing plate was Streaks of dirt were generated in the case, making it unsuitable for personal use.

Practical row 3 A photoconductive layer was placed on an L aluminum substrate in the same manner as in practical row 1, and then the following alkali-soluble resin was applied to the edge of the substrate to form an electrophotographic lithographic printing plate. In the same way as in the AK process, charging, exposure, toner development, fixing, and etching are performed. After that, apply desensitizing liquid (3) to the edges in the same manner as in row 1 and print.

When this printing plate was set in an offset printing machine and printing was carried out, all of the printed matter obtained was in good condition with no stains at all even in the portions corresponding to the edges of the printing plate.

Copolymer of benzyl methacrylate and methacrylic acid (methanolyl 11124LO mol%) io, o part tetrahydrofuran hi r, o part chlorhexanone l ot, O part water soluble content j more than a little by weight cream dextrin (cream dextrin #3, Matsutani Chemical ■l! 10.0 parts Potassium silicate (j Be: 20 'C) 2, 0 parts Potassium hydroxide (at, t%) i, o parts Sodium isopropylnaphthalene sulfonate 0.j parts Pure water
r≦,! In place of the desensitizing solution (3) in Part I pH 4 and 9' lJ/, desensitize the following! Create a lithographic printing plate using exactly the same procedure except for using (4).

Desensitizing liquid (4) 30% gum arabic aqueous solution 70.0 parts Zinc nitrate 0.7 parts Sodium nitrate
／、≠part magnesium sulfate
7. Part 3! whisper phosphoric acid
!・6 parts Polyokine ether/nonyl phenyl ether 7.0 parts Petroleum solvent (K-solvent)/≠, O parts When this printing plate was set in an offset printing machine and printed, all of the resulting printed matter had 8 parts. '] I am very impressed with the beautiful print, with no stains even in the areas corresponding to the edges of the printing plate.

Examples J5-6 The electrophotographic lithographic printing original plate in Example 1 was charged in a dark place to a corona tsIK hexagonal potential of +4 LooV, and then a positive image was exposed to tungsten light, and a liquid developer Ricoh M was used.
I was able to obtain a clear positive #I by using RP (Ricoh ■) at current 9 (bias voltage +5oV). Next, all the toner adhering to the edge of the printing plate is removed using a rotating nylon brush, and then it becomes desensitized. f! , (58 (6)) was applied to the edge of the printing plate with a sponge and dried.Furthermore, the prepared toner image was heated at 0°C for 2 minutes to form a toner image.

This non-image area is removed by the same operation as Execution-J/,
Obtain a lithographic printing plate.

When this printing plate was set in an offset printing machine and all printing was performed, all NFC printed matter obtained had a percentage of % in the portion corresponding to the edge of the printing plate. I rarely got good prints with no fyn at all.

Desensitizing liquid (5) Calfki 7 Mether cellulose 2.3s Magnesium nitrate 12.41C Part Nitrification Natriwam / Ko, Da part l! whisper phosphoric acid
μ, θ section pure water
6/, Yube Potassium silicate (jλBe: 20 0C) Potassium hydroxide (μr, j%) Butylnaphthalenesulfo/acid sodium pure water 2.0 parts/, 0 parts j, 0 parts Octopus, 5 parts

Claims (1)

[Claims] At least a step of charging an electrophotographic lithographic original plate having a photoconductive layer on a conductive support, a step of exposing it to light,
A method for producing an electrophotographic lithographic printing plate by a step including a step of developing with a toner, a step of fixing a toner image, and a step of removing a photoconductive layer other than the toner image,
1. A method for producing an electrophotographic lithographic printing plate, comprising the step of desensitizing the end surface of the electrophotographic lithographic printing plate as a subsequent step of the toner development step.