JPH0520734B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a printing original plate for electrophotographic engraving and a printing plate obtained by exposing and developing the original plate. Specifically, the present invention relates to a printing plate precursor that is sensitive to semiconductor lasers and can be directly plated by electrophotography, and a printing plate obtained by exposing and developing the same. (Conventional technology) Due to technological advances in computer image processing and large-capacity data communication, computers now process images and transmit the digital image information via telephone lines, communication satellites, etc. to the receiving side. A new system, so-called electrotransmission printing, has been proposed that prints by scanning and exposing images using a laser scanner. The mainstream of conventional printing plates for plate making is a method using photosensitive resin (PS plate method). In the case of this PS plate method, the electronically transmitted information is written on a silver halide film, and this film is closely exposed to the original plate for plate making to make the plate, which requires large-scale equipment and takes time to make the plate. There are other problems. Furthermore, many PS plate-based photosensitive materials utilize photochemical reactions, require large amounts of exposure, and generally have low sensitivity. For this reason, PS plate type photosensitive materials also have the disadvantage that sufficiently satisfactory image information cannot be obtained by exposure with a low-output, inexpensive semiconductor laser. In order to solve the above-mentioned problems of the PS plate method, a method using a silver halide photosensitive material as a printing original plate for plate making and a method using an electrophotographic method have been proposed, and some of them have been put into practical use. The former method has good sensitivity, but has the drawbacks of poor printing durability and high cost per sheet. On the other hand, the latter method allows direct plate making and has the potential to produce printing plates with relatively high sensitivity, low cost, and high printing durability.
It has been actively researched in recent years. In printing original plates for electrophotographic engraving, zinc oxide, organic compounds, and the like are used as photoconductive substances. Printing plates for plate making using zinc oxide are generally (A) easily smudged due to poor hydrophilicity of the non-image areas of the resulting printing plate, and (B) easily stained by mechanical pressure applied during printing and penetration of soaking water. (C) Dye sensitization is performed to provide sensitivity in the visible light region, but it is still sufficient in the long wavelength region of 600 nm or more. It has drawbacks such as lack of sensitivity and difficulty in semiconductor laser exposure. In the case of a printing original plate for plate making using an organic photoconductive compound, a photosensitive material in which the organic photoconductive compound is dispersed in a binder mainly composed of an alkali-soluble resin is used on a substrate such as a grained aluminum plate. After forming a photosensitive layer on a plate, a toner image is formed on this photosensitive layer by electrophotography, and the non-image area is dissolved and removed using an alkaline eluent to make a plate. Many printing original plates for electrophotographic engraving have been proposed which are provided with a photosensitive layer in which an organic photoconductive compound is dispersed in an alkali-soluble resin. For example, JP-A-54
In each of the publications No. 134632, No. 55-105254, and No. 55-153948, a phenolic resin is used as the alkali-soluble resin. However, when a phenolic resin is used as a binder for an organic photoconductive compound, the formed film is brittle, resulting in disadvantages such as poor printing durability. JP-A-58-76843, JP-A No. 59-147355, JP-A No. 60-
In each of the publications No. 17752, No. 60-243670, No. 62-198864, and No. 64-23260, a styrene-maleic acid copolymer is used as the alkali-soluble resin. However, when a styrene-maleic acid copolymer is used as a binder for an organic photoconductive compound, there are drawbacks such as the formed film is hard and tends to crack when the printing plate is bent. Acrylic resins are also often used, and in JP-A-54-89801, for example, an aqueous acrylic resin is used as a binder and ε-type crystalline copper phthalocyanine is used as an organic photoconductive compound. Images can be formed using these materials by electrophotography, but they have drawbacks such as not being easy to perform etching treatment with aqueous alkaline solutions, and not being able to be exposed to light in the near-infrared region using semiconductor lasers or the like. In JP-A-56-146145, an acrylic resin such as acrylic acid/methyl methacrylate/butyl acrylate copolymer is used as a binder, and a fused polycyclic quinone pigment and a fused polycyclic quinone pigment are used as organic photoconductive compounds. Methods using oxadiazole derivatives are disclosed. Although these materials can be easily etched with an alkaline aqueous solution, they have problems in that their electrophotographic properties are not fully satisfactory and their storage stability is poor. Furthermore, it also has the disadvantage that it cannot be exposed to light in the near-infrared region, such as with a semiconductor laser. Further, they have problems such as not being able to perform exposure in the near-infrared region such as a semiconductor laser, or even if it is possible, only insufficient electrophotographic properties can be obtained, resulting in poor printing properties. JP-A No. 57-161863, No. 58-145495, No. 63-
No. 136052, No. 63-199359 and No. 64-31165 use binders such as butyl methacrylate/methacrylic acid copolymer, styrene/2-ethylhexyl acrylate/acrylic acid copolymer, methyl methacrylate/ethyl methacrylate/ A method is disclosed in which an acrylic resin such as methyl acrylate/itaconic acid copolymer is used and a pyrazoline derivative, zinc oxide, or α-type phthalocyanine is used as a photoconductive material. All of these have drawbacks such as poor charging properties, poor printing properties due to insufficient alkali elution properties, low printing durability, and poor printing stability of the printing plate. Further, they have problems such as not being able to perform exposure in the near-infrared region such as with a semiconductor laser, or even if it is possible, insufficient electrophotographic properties are obtained, resulting in poor printing properties. (Problems to be Solved by the Invention) Therefore, an object of the present invention is to provide a novel printing original plate for electrophotolithography and a printing plate obtained by exposing and developing the same. Another object of the present invention is to provide an improved printing original plate for electrophotographic engraving and a printing plate for lithographic printing using an organic photoconductive compound. Still another object of the present invention is to provide a printing original plate for electrophotographic engraving that has excellent electrophotographic properties and alkali elution properties, and a printing plate for lithographic printing that has excellent printing properties. Another object of the present invention is to provide a printing original plate for electrophotolithography that provides a printing plate with good storage stability and printing durability. Still another object of the present invention is to provide a printing original plate for electrophotolithography having a photosensitive layer with excellent light resistance and weather resistance using a binder that has good adhesion to a substrate and good mechanical strength. It's about doing. Another object of the present invention is to provide a printing original plate for electrophotographic engraving that has high sensitivity even in the near-infrared long wavelength region and can be exposed using a semiconductor laser or the like. (Means for Solving the Problems) These objects are achieved by providing a printing original plate for electrophotolithography in which a photosensitive layer made of an alkali-soluble binder containing an organic photoconductive compound is provided on a conductive support. The organic photoconductive compound has the general formula [However, in the formula, R is a -SZ group (Z is a phenyl group,
is a phenyl group or naphthyl group substituted with an alkyl group having 1 to 5 carbon atoms], and the binder is
(a) 0.5 to 40% by weight of at least one compound selected from the group consisting of hydroxyalkyl acrylates and hydroxyalkyl methacrylates whose alkyl group has 2 to 10 carbon atoms; (b) acrylic acid, methacrylic acid, and itacon; At least one copolymerizable unsaturated carboxylic acid selected from the group consisting of acids 10 to 40
% by weight, (c) at least one styrene compound 10~
70% by weight, (d) at least one acrylic ester selected from the group consisting of alkyl acrylates in which the alkyl group has 1 to 12 carbon atoms and cycloalkyl acrylates in which the cycloalkyl group has 5 to 7 carbon atoms; 5 to 50% by weight and (e) the number of carbon atoms in the alkyl group is 1
A monomer mixture consisting of 0 to 40% by weight of at least one methacrylic ester selected from the group consisting of ~12 alkyl methacrylates and cycloalkyl methacrylates in which the cycloalkyl group has 5 to 7 carbon atoms is polymerized. The number average molecular weight obtained by
This is achieved using a printing original plate for electrophotographic engraving, which is characterized by being a copolymer of 50,000. These purposes are to form a toner image on the printing original plate for electrophotographic engraving by electrophotography, and after fixing, remove the non-image area by etching with an alkaline etching liquid. is also achieved. (Function) The printing original plate for electrophotographic engraving according to the present invention has a photosensitive layer formed on a conductive support, and the photosensitive layer is made of an alkali-soluble binder containing an organic photoconductive compound. It is what it is. The organic photoconductive compound used in the present invention is a zinc phthalocyanine represented by the above general formula. The zinc phthalocyanine has excellent electrophotographic properties among alkali-soluble binders, and does not interfere with alkali elution. Specific examples of the zinc phthalocyanine represented by the above general formula () include the following. In addition, in any of the following compounds, the fluorine atom is represented by the following formula () 1, 4, 5 of the phthalocyanine nucleus represented by
A total of 8 pieces were introduced at the 8th, 9th, 12th, 13th, and 16th positions. Note that the names in [ ] are abbreviations. Octafluoro-octakis (phenylthio)
Zinc phthalocyanine [F ₈ (PhS) ₈ ZnPc] Octalofluoro-octakis (o-tolylthio) zinc phthalocyanine [F ₈ (o-MePhS) ₈ ZnPc] Octafluoro-octakis (m-tolylthio) zinc phthalocyanine [F ₈ (m -MePhS) ₈ ZnPc] Octafluoro-octakis (p-tolylthio) zinc phthalocyanine [F ₈ (p-MePhS) ₈ ZnPc] Octalofluoro-octakis (2,4-xylylthio) zinc phthalocyanine [F ₈ (2,4- MePhS) ₈ ZnPc] Octafluoro-octakis (2,3-xylylthio) zinc phthalocyanine [F ₈ (2,3-MePhS) ₈ ZnPc] Octafluoro-octakis (o-ethylphenylthio) zinc phthalocyanine [F ₈ (o -EtPhS) ₈ ZnPc] Octalofluoro-octakis (p-ethylphenylthio) zinc phthalocyanine [F ₈ (p-EtPhS) ₈ ZnPc] Octafluoro-octakis (o-isopropylphenylthio) zinc phthalocyanine [F ₈ ( o-IPrPhS) ₈ ZnPc] Octafluoro-octakis (P-isopropylphenylthio) zinc phthalocyanine [F ₈ (p-IPrPhS) ₈ ZnPc] Octafluoro-octakis (o-butylphenylthio) zinc phthalocyanine [F ₈ (o-BuPhS) ₈ ZnPc] Octafluoro-octakis (m-butylphenylthio) zinc phthalocyanine [F ₈ (m-BuPhS) ₈ ZnPc] Octalofluoro-octakis (p-butylphenylthio) zinc phthalocyanine [F ₈ ( o-BuPhS) ₈ ZnPc] Octafluoro-octakis (p-tertiarybutylphenylthio) zinc phthalocyanine [F ₈ (p-t-BuPhS) ₈ ZnPc] Octalofluoro-octakis (naphthylthio) zinc phthalocyanine [F ₈ ( NPhS) ₈ ZnPc] Zinc phthalocyanine represented by the general formula is
For example, it can be produced as follows using 3,4,5,6-tetrafluorophthalonitrile as a starting material. 3,4,5,6-tetrafluorophthalonitrile is converted into RSH, RSNa or RSK (where R
represents a phenyl group or a naphthyl group, etc.) to synthesize 3,4,5,6-tetrafluorophthalonitrile in which the fluorine atoms at the 4- and 5-positions have been substituted with a functional group, and then The obtained substituent-introduced phthalonitrile and zinc powder or zinc halide are heated and melted or heated in an organic solvent to obtain the zinc phthalocyanine. The binder used in the present invention includes (a) at least one compound selected from the group consisting of hydroxyalkyl acrylate and hydroxyalkyl methacrylate, and (b) at least one compound selected from the group consisting of hydroxyalkyl acrylate and hydroxyalkyl methacrylate. a polymerizable unsaturated carboxylic acid, (c) at least one styrene compound, and (d) at least one compound selected from acrylic esters other than hydroxyalkyl acrylate in (a), and optionally (e) ( It is a copolymer obtained by polymerizing a monomer mixture consisting of at least one compound selected from methacrylic acid esters other than hydroxyalkyl methacrylate in a). Monomer (a) is a hydroxyalkyl acrylate and a hydroxyalkyl methacrylate in which the hydroxyalkyl group has 2 to 10 carbon atoms, preferably 2 to 6 carbon atoms (hereinafter, acrylic acid and methacrylic acid are collectively referred to as "(meth) acrylic acid). Specific examples of hydroxyalkyl (meth)acrylate include (meth)
2-hydroxyethyl acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, glycerol mono(meth)acrylate, tri(meth)acrylate Examples include methylolpropane. The use of monomer (a) improves electrophotographic properties and durability as a printing plate. Moreover, a uniform and clean coating film can be obtained. By introducing a hydroxy group into the binder, the adhesion of the binder to the conductive support or the affinity with the phthalocyanine of the present invention can be improved, resulting in improved dispersibility. This is thought to be the result of improved performance. It also has the effect of improving alkali etching properties, and can also lower the proportion of copolymerizable unsaturated carboxylic acid, which deteriorates electrophotographic properties when the proportion increases. The proportion of monomer (a) used is 0.5 of the total monomer mixture.
-40% by weight, preferably 2-25% by weight. This usage percentage is less than 0.5% by weight or 40% by weight
Exceeding this is not preferable because the electrophotographic properties and durability of the printing plate deteriorate. Monomer (b) is at least one copolymerically unsaturated carboxylic acid. The copolymerizable unsaturated carboxylic acids include monocarboxylic acids such as (meth)acrylic acid, dicarboxylic acids such as maleic acid, itaconic acid, and citraconic acid, and dicarboxylic acid monoesters such as monoisopropyl maleate. It is possible to use unsaturated monomers having at least one carboxyl group. Among these, (meth)acrylic acid and/or itaconic acid are preferably used. The proportion of monomer (b) used is 10 to 40% by weight of the total monomer mixture, preferably
It is 15-30% by weight. If the proportion used is less than 10% by weight, the alkali solubility of the resulting copolymer will be low and the etching rate will be low. On the other hand, if it exceeds 40% by weight, the chargeability will decrease and it will no longer be possible to use it as a photosensitive layer. In the copolymer used as a binder in the present invention, in order to obtain good etching properties, carboxylic acid is introduced into the copolymer to adjust the acid value to a range of 50 to 300 mg-KO/g. That is, by using the copolymerizable carboxylic acid in a specific proportion as described above, it is possible to improve the etching properties without impairing the electrophotographic properties. Monomer (c) is a styrene compound. As the styrene compound, alkylstyrenes such as styrene, methylstyrene, ethylstyrene, and isopropylstyrene are preferably used, and styrene is particularly preferably used. The proportion of monomer (c) used is 10 to 70% by weight, preferably 25 to 55% by weight of the total monomer mixture. If the proportion used is less than 10% by weight, the strength, affinity with phthalocyanine (dispersibility), and chargeability will decrease. On the other hand, if it exceeds 70% by weight, the proportion of monomers (a) and (b) decreases relatively, so the above-mentioned effects of using monomers (a) and (b) are lost, which is not preferable. . Monomer (d) is at least one compound selected from acrylic esters other than hydroxyalkyl acrylate as monomer (a). Specifically, this acrylic ester is an alkyl acrylate in which the alkyl group has 1 to 12 carbon atoms, preferably 2 to 8 carbon atoms, or a cycloalkyl group has 5 to 8 carbon atoms.
7 cycloalkyl acrylate. Specific examples of alkyl acrylate or cycloalkyl acrylate include methyl acrylate, ethyl acrylate, isopropyl acrylate, and n-acrylate.
Examples include propyl, 2-ethylhexyl acrylate, lauryl acrylate, cyclohexyl acrylate, and cycloheptyl acrylate. The proportion of alkyl acrylate or cycloalkyl acrylate used is 5 to 50% of the total monomer mixture.
% by weight, preferably 10-40% by weight. When this usage ratio is within the above range, the lipophilicity can be increased, and the binding strength of the resulting copolymer is increased,
Flexibility also improves, but if it exceeds 50% by weight, the proportion of monomers (a), (b) and (c) decreases, so monomers (a), (b) and The above-mentioned effect due to the use of (c) is lost, which is not preferable. In the present invention, the monomer (e) used as necessary is at least one compound selected from methacrylic acid esters other than hydroxyalkyl methacrylate monomer. Specific examples of the methacrylic ester include alkyl methacrylates in which the alkyl group has 1 to 12 carbon atoms, preferably 2 to 8 carbon atoms, or cycloalkyl methacrylates in which the cycloalkyl group has 5 to 7 carbon atoms. Specific examples of alkyl methacrylate or cycloalkyl methacrylate include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate, and methacrylic acid. Examples include t-butyl, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, and cycloheptyl methacrylate. The proportion of alkyl methacrylate or cycloalkyl methacrylate used is 0 to 40% by weight of the total monomer mixture, preferably 15% by weight or less. If this usage rate is within the above range,
Durability can be improved, and if it exceeds 40% by weight, the dispersibility with phthalocyanine becomes poor, which is not preferable. The compositions and ratios of typical monomer mixtures (p-1) to (p-10) among the above monomer mixtures are shown below. (p-1) 2-hydroxypropyl acrylate/acrylic acid/styrene/butyl acrylate (5/20/35/40 (weight ratio, same below)), (p-2) 2-hydroxyethyl methacrylate /methacrylic acid/styrene/butyl acrylate (2/23/40/35), (p-3) 2-hydroxybutyl methacrylate/acrylic acid/styrene/isopropyl acrylate (15/25/45/15) , (p-4) 3-hydroxypropyl methacrylate/acrylic acid/styrene/methyl acrylate/ethyl methacrylate (5/20/35/25/15), (p-5) 3-hydroxybutyl acrylate /Methacrylic acid/Styrene/Isobutyl acrylate/Isopropyl methacrylate (20/30/25/
20/5), (p-6) 2-hydroxyethyl methacrylate/methacrylic acid/styrene/propyl acrylate/ethyl methacrylate (5/25/40/25/5), (p-7) methacrylic acid- 2-Hydroxybutyl/Itaconic acid/Styrene/Butyl acrylate/
Methyl methacrylate (10/15/35/30/10), (p-8) 3-hydroxybutyl acrylate/acrylic acid/styrene/ethyl acrylate/
Butyl methacrylate (5/20/25/40/10). There are no particular restrictions on the polymerization method for the above monomer mixture, such as bulk polymerization, solution polymerization, or suspension polymerization in the presence of a radical polymerization initiator such as peroxides, hydroperoxides, or azobisisobutyronitrile. 50~ by the usual polymerization method of
It can be carried out at a temperature of 100°C, preferably 70-90°C. The monomer mixture can be added all at once,
Partial addition, continuous addition, or a combination thereof can be selected as appropriate. The number average molecular weight of the copolymer obtained by polymerizing the above monomer mixture is 1000 to 50000, preferably 3000.
~30000. A copolymer obtained by polymerizing the monomer conjugate described above, particularly a copolymer having a number average molecular weight within the above range, is soluble in an alkaline substance, and this copolymer can be used as the photoconductive material. The photosensitive layer obtained by coating with the phthalocyanine compound exhibits good alkali solubility and excellent etching properties. The printing original plate for electrophotographic engraving of the present invention has a photosensitive layer formed by applying a coating liquid comprising the above-mentioned photoconductive phthalocyanine compound and the above-mentioned copolymer as a binder onto a conductive support. There are no particular restrictions on the method for preparing the above coating solution; the binder (or photoconductive phthalocyanine compound) is dissolved or dispersed in a suitable solvent, and the photoconductive phthalocyanine compound (or binder) is dissolved in this. Alternatively, it may be prepared by dispersing the binder and the photoconductive phthalocyanine compound, or by separately dissolving or dispersing the binder and the photoconductive phthalocyanine compound in a solvent and then mixing the two. Examples of the solvent used for dissolving or dispersing the binder and photoconductive phthalocyanine compound include aromatic hydrocarbons such as benzene and toluene, cyclic ethers such as tetrahydrofuran and dioxane, chloroform, dichloromethane,
halogen-containing hydrocarbons such as dichloroethane,
Ketones such as acetone and methyl ethyl ketone,
Organic solvents such as esters such as ethyl acetate and cellosolves such as methyl cellosolve can be used. When preparing the above coating solution, the photoconductive phthalocyanine compound is preferably used in an amount of 3 to 50% by weight, preferably 5 to 30% by weight of the binder. Further, the concentration of the photoconductive phthalocyanine compound and the binder dissolved or dispersed in the solvent is usually 0.5 to 50% by weight, preferably 5 to 30% by weight. The thickness of the photosensitive layer is preferably 2 to 10 μm, particularly 3 to 6 μm. If the film is too thick, side edges are likely to appear during etching, and fine lines are likely to be scraped off, which is undesirable. If the film thickness becomes thinner, the charging property will deteriorate, which is not preferable. The coating solution for forming the above-mentioned photosensitive layer contains a polybasic acid organic compound, such as a compound represented by the following general formula, and succinic anhydride and anhydride. Electrophotographic properties can be further improved by containing at least one compound selected from maleic acid as a sensitizer. (In the formula, X ¹ to ^{X 5} may be the same or different, and each represents hydrogen, fluorine, -COOH
or −represents NO ₂ ). (In the formula, Y ¹ to ^{Y 4} may be the same or different, and each represents hydrogen, fluorine, -COOH
or −represents NO ₂ ). (In the formula, ^Z1 to ^Z2 may be the same or different and each represents hydrogen, fluorine, -COOH or _-NO2 ). Specific examples of these sensitizers include succinic anhydride, maleic anhydride, phthalic acid, tetrafluorophthalic acid, 4-nitrophthalic acid, phthalic anhydride,
Tetrafluorophthalic anhydride, 4-nitrophthalic anhydride, trimellitic acid, trimellitic anhydride,
Examples include pyromellitic acid, pyromellitic anhydride, benzoic acid, pentafluorobenzoic acid, and tetrafluorobenzoic acid. Preferably,
Succinic anhydride, tetrafluorophthalic anhydride, benzoic acid, pentafluorobenzoic acid and tetrafluorobenzoic acid, particularly preferred are tetrafluorophthalic anhydride, pentafluorobenzoic acid and tetrafluorobenzoic acid. The above sensitizer is a photoconductive phthalocyanine compound.
It is preferably used in a proportion of 0.01 to 10% by weight, preferably 2.0% by weight or less. In addition, the coating liquid for forming the photosensitive layer may include oxazole derivatives, oxadiazole derivatives, pyrazoline derivatives, hydrazone derivatives, or triphenylamine derivatives in the photosensitive layer that is used after being charged with negative polarity. The properties of the electrophotographic photoreceptor can be further improved by incorporating a charge transfer substance and/or an aminotriazine resin. As the charge transfer substance, it is preferable to use a hydrazone derivative represented by the following general formula. (In the formula, R ¹ and R ² represent an aryl group or an aralkyl group, R ³ is a hydrogen atom, and has 1 to 4 carbon atoms.
represents an alkyl group, a benzyl group, an alkoxy group having 1 to 4 carbon atoms, a phenoxy group, or a benzyloxy group. ) Specific examples of the hydrazine compounds represented by the above general formula include the following. Examples of aminotriazine resins include melamine resin, benzoguanamine resin, acetoguanamine resin, and CTU guanamine resin (trade name, Ajinomoto Co., Ltd.).
Co., Ltd.) and cyclohexylcarboguanamine resin. In particular, it is preferable to use cyclohexycarboguanamine resin. Aminotriazine resin is an aminotriazine resin composition obtained by reacting aminotriazine with formaldehyde and optionally an alcohol such as butanol, that is, a methylolated product or alkyl ether methylolated product of aminotriazine as it is or by moderate dehydration condensation of each. is used. The charge transfer substance and/or the aminotriazine resin account for 60% by weight or less of the photoconductive phthalocyanine compound;
In particular, it is preferably used in a proportion of 0.1 to 20% by weight. There are no particular restrictions on the conductive support used in the present invention, and commonly used aluminum plates, zinc plates, copper-aluminum plates, copper-
Bimetal plates such as stainless steel plates, chrome-copper plates, or chrome-copper-aluminum plates, chrome-copper-
A material having a hydrophilic surface, such as an iron plate or a tri-metal plate such as a chrome-copper-stainless steel plate, can be used. The thickness of the conductive support is 0.05~0.5
Approximately mm is preferable. In particular, in the case of a support having an aluminum surface, it is preferable to use a surface treatment such as graining treatment, immersion treatment in an aqueous solution of sodium silicate or potassium fluorinated zirconate, or anodization treatment. The above anodizing treatment is performed by applying an electric current using an aluminum plate as an anode in an electrolytic solution consisting of a solution of an inorganic acid such as phosphoric acid, chromic acid, sulfuric acid, or boric acid, or an organic acid such as oxalic acid sulfamic acid, or a salt thereof. It can be carried out by flowing. In addition, in the present invention, in order to improve printing durability, a material within the scope of the present invention, which has a higher acid value than the binder in the photosensitive layer, is used between the conductive support base material and the photoconductive photosensitive layer. It is particularly preferable to provide an intermediate layer made of a resin of the same composition. There are no particular limitations on the plate-making method for the printing original plate for electrophotolithography of the present invention, and it can be carried out by conventionally known methods. For example, first, according to the usual electrophotographic method, the film is uniformly charged in a dark place using a corona charger, and then exposed to a reflective image using a light source such as a tungsten lamp, a halogen lamp, a xenon lamp, or a fluorescent lamp, or a transparent positive film. An electrostatic latent image is formed by contact image exposure through the lens, or by scanning exposure with a laser beam such as a He-Ne laser, argon laser, or semiconductor laser, and this electrostatic latent image is developed with toner and fixed by heating. , to obtain a toner image on the photosensitive layer. The toner must be hydrophobic, ink-receptive, and have sufficient adhesion to printing plates to withstand printing, and must also have resistivity when etched with an alkaline aqueous etching solution. Further, as the electrophotographic developer, it is preferable to use a liquid developer which has better resolution than a powder developer. To meet these conditions, it is recommended to use toner containing styrene resin, acrylic resin, styrene-acrylic resin, styrene-methacrylic resin, polyester resin, epoxy resin, etc. as the resin in the liquid developer. good. Also,
Examples of the dispersion medium include organic solvents having a low dielectric constant and high electrical insulation properties, such as isoparaffin hydrogen carbonate. In addition, pigments and dyes for coloring and charge control agents may be added to the extent that they do not adversely affect the safety or fixing properties of the toner, and the toner with a positive charge or the toner with a negative charge may be used depending on the purpose. It is better. Next, when the printing plate for plate making on which the toner image has been formed is immersed in an alkaline eluent, the photosensitive layer in the non-image area that is not masked by the toner image is dissolved and removed, and the hydrophilicity of the conductive support is removed. The surface is exposed and only the image area of the toner image remains on the surface of the support, making it possible to obtain the intended printing plate for lithographic printing. Examples of the alkaline eluent used to dissolve and remove the photosensitive layer in the non-image area include alkaline aqueous solutions of inorganic salts such as sodium silicate, sodium phosphate, sodium hydroxide, and sodium carbonate, triethanolamine, ethylenediamine, etc. An alkaline aqueous solution containing an organic amine, or a solution prepared by adding an organic solvent such as ethanol, benzyl alcohol, ethylene glycol, or glycerin or a surfactant to these can be used. For example, an alkaline aqueous etching solution having the following composition is used. EDTA-4H 4g Benzyl alcohol 30g Monoethanolamine 5g Adjust the total amount to 1 part with water Triethanolamine 60g NaOH 25g In addition, the printing original plate for electrophotographic engraving can also be used as an electrophotographic photoreceptor for a laser planter (OPC). . In laser printers,
The developed toner is transferred to paper and fixed on the paper. (Example) Hereinafter, the present invention will be explained in more detail with reference to Production Examples and Examples. In addition, "part" and "%"
means "parts by weight" and "% by weight" unless otherwise specified. Production example 1 [Production of F ₈ (PhS) ₈ ZnPc] (1) Synthesis of starting materials 3,4,5,6-
19.6 g (98 mmol) of tetrafluorophthalonitrile, 21.6 g (196 mmol) of thiophenol,
Potassium fluoride (KF) 17.1g (294 mmol)
Add 100ml of acetonitrile and heat at 50℃.
The reaction was carried out under stirring for 12 hours. Thereafter, it was cooled to room temperature, the resulting yellow solid was filtered, and the resulting cake was purified by washing with methanol and then warm water to produce 3,6-difluoro-4,5-bisphenylthiophthalonitrile. 34.5g (vs. 3, 4,
5,6-tetrafluorophthalonitrile yield:
92.5 mol%) was obtained. (2) Synthesis of F ₈ (PhS) ₈ ZnPc Add 3,6-difluoro-4,5-bisphenylthiophthalonitrile to a 100 ml four-necked flask.
10 g (26.2 mmol), zinc iodide 3.14 g (9.8
millimoles) and 50 ml of benzonitrile were added, and the mixture was reacted at 175°C for 6 hours with stirring.
Thereafter, it is cooled and the resulting green solid is filtered and then washed using a Soxhlet in the order of methanol, benzene, acetone and _F8
(PhS) ₈ SnPc (vs. 3,6-difluoro-4,5
-Bisphenylthiophthalonitrile yield: 79.4
mol%) was obtained. Production Example 2 [Production of Copolymer] A copolymer can be produced, for example, as follows. After putting 40 parts of isopropanol as a solvent into a separable flask equipped with a stirrer, a thermometer, a cooling tube, a nitrogen introduction tube, a monomer mixture dropping funnel, and a polymerization initiator dropping funnel, nitrogen was introduced from the nitrogen introduction tube. to create a nitrogen atmosphere inside the flask. Next, 60 parts of the monomer mixture is charged into the monomer-fitted dropping funnel, and 0.2 part of azobisisobutyronitrile is charged into the polymerization initiator dropping funnel. While adjusting the internal temperature of the flask to 80°C, the monomer mixture and polymerization initiator were added dropwise over 2 hours, and then heated at 80°C for 2 hours, then at 85-90°C for 2 hours, and then cooled. Example 1 1.5 parts of F ₈ (o-MePhS) ₈ ZnPc, 0.05 parts of pentafluorobenzoic acid, 12.0 parts of the copolymer obtained from the monomer mixture (P-1), and 83 parts of dichloroethane were dispersed in a paint shaker. It was dispersed by machine for 2 hours. The resulting dispersion was grained with a bar coater to a thickness of 0.15 mm, coated on an anodized aluminum plate, heated with hot air at 60°C for 30 minutes, and further heated under reduced pressure (1 mm).
Hg) It was dried at 100°C for 2 hours to form a photosensitive layer. The film (photosensitive layer) thickness at this time was 5 μm. The thus obtained single-layer electrophotographic photoreceptor as a printing original plate for electrophotographic engraving was tested at +6.0 kV using an electrostatic charging tester (SP-428 manufactured by Kawaguchi Electric Co., Ltd.).
It was positively charged. Then, after holding for 5 seconds in a dark place, use a white light (tungsten lamp) to
After exposure for seconds, the charging characteristics (surface potential (V ₀ ), potential after being held in the dark for 5 seconds (V ₅ ), and the amount of exposure required to attenuate the potential before exposure to 1/2 by exposure ( E
1/2) (Lux·scc)) and 780 nm monochromatic light separated by a spectral filter at 0.5 μw/cm ² to determine the half-path light energy sensitivity (μj/cm ² ). Next, this single-layer electrophotographic photoreceptor was immersed in an aqueous solution containing 0.5% sodium hydroxide and washed with water to remove the photosensitive layer. The alkali elution property was determined based on the removal rate of the photosensitive layer at this time. Next, a single-layer electrophotographic photoreceptor formed on this separately prepared grained aluminum plate was manufactured by Toppan Printing Co., Ltd.
Plate making was performed by a liquid development method using a TTP laser plate making machine (manufactured by Toppan Printing Co., Ltd.). For corona charging, an electrostatic latent image was developed with a negative developer at +6 kV and fixed by heating to form a toner image. The formed toner image was washed out with an alkaline aqueous etching solution and washed with water to prepare a printing plate for lithographic printing. The printing plate thus prepared was printed using an offset printing machine in a conventional manner, and the degree of scumming and the clarity of printing were evaluated initially and after printing 100,000 sheets. Table 2 shows the results of the evaluation of the electrophotographic properties, alkali elution property, and printing performance. Examples 2 to 17 In Example 1, instead of the copolymer of _F8 (o-MePhS) _8ZnPc and the monomer mixture (p-1), the photoconductive phthalocyanine compounds shown in Table 1,
A printing original plate for electrophotolithography was prepared in the same manner as in Example 1 except that the copolymer obtained from any of the monomer mixtures (P-1) to (P-8) and the sensitizer were used. The electrophotographic properties, alkali elution properties, and printing performance were evaluated, and the results are shown in Table 2. In addition, the electrophotographic photoreceptor prepared above was
When the electrophotographic characteristics and printing performance were measured after being left in a room with fluorescent lights on, there was almost no difference in performance even after two months. Comparative Examples 1 to 6 In Example 1, instead of the copolymer of _F8 (o-MePhs) _8ZnPc and monomer mixture (P-1), the photoconductive phthalocyanine compounds shown in Table 1,
Copolymers and sensitizers obtained from monomer mixtures of (P-1) to (P-8) or the following (S-1) to (S-5) produced in the same manner as Production Example 2 The electrophotographic properties, alkali elution property, and printing performance were evaluated in the same manner as in Example 1 except that
The results are shown in Table 2. (S-1) Acrylic acid/Butyl acrylate/Butyl methacrylate (25/20/55), (S-2) Methacrylic acid/Styrene/Isopropyl acrylate (30/15/55), (S-3) Methacrylate Acid/methyl acrylate/ethyl methacrylate (15/60/25), (S-4) acrylic acid/styrene/ethyl acrylate/methyl methacrylate (25/8/20/47), (S-5) Acrylic Acid/butyl acrylate/methyl methacrylate/2-hydroxyethyl methacrylate (10/40/40/10).

【table】

[Table] Examples 18 to 27 In Example 1, instead of the copolymer of F ₈ (o-MePhS) ₈ ZnPc and the monomer mixture (P-1), the photoconductive phthalocyanine compounds shown in Table 3,
A printing original plate for electrophotolithography was prepared in the same manner as in Example 1, except that the copolymer obtained from any of the monomer mixtures (P-1) to (P-8) and the additive were used. The single-layer electrophotographic photoreceptor thus obtained as a printing original plate for electrophotographic engraving was negatively charged at -6.0 kV using a static zone tester.
Thereafter, electrophotographic properties, alkali elution properties, and printing performance were evaluated in the same manner as in Example 1, and the results are shown in Table 4.

【table】

[Table] (Effects of the Invention) Since the printing original plate for electrophotographic engraving according to the present invention has the above configuration, it has the following effects. (1) It has excellent electrophotographic properties and can perform electrophotographic engraving efficiently. (2) It has excellent alkali elution properties and can perform effective etching during the plate-making process. (3) A thin photosensitive layer with low phthalocyanine content and good electrophotographic properties (charging properties, sensitivity) can be obtained. (4) Since it exhibits good sensitivity even in the long wavelength region, it can be exposed using not only ordinary light sources such as tungsten lamps but also low-power lasers. Therefore, direct plate making is possible using various light sources. (5) The binder has high affinity for zinc phthalocyanine and has good dispersibility. (6) Printing plates obtained by electrophotographic engraving have excellent printing properties and can produce clear prints even after being used more than 100,000 times. It also has excellent storage stability.

Claims (1)

[Scope of Claims] 1. A printing original plate for electrophotolithography comprising a photosensitive layer made of an alkali-soluble binder containing an organic photoconductive compound on a conductive support, wherein the organic photoconductive compound is generally formula [However, in the formula, R is a -SZ group (Z is a phenyl group,
is a phenyl group or naphthyl group substituted with an alkyl group having 1 to 5 carbon atoms], and the binder is
(a) 0.5 to 40% by weight of at least one compound selected from the group consisting of hydroxyalkyl acrylates and hydroxyalkyl methacrylates whose alkyl group has 2 to 10 carbon atoms; (b) acrylic acid, methacrylic acid, and itacon; At least one copolymerizable unsaturated carboxylic acid selected from the group consisting of acids 10 to 40
% by weight, (c) at least one styrene compound 10~
70% by weight, (d) at least one acrylic ester selected from the group consisting of alkyl acrylates in which the alkyl group has 1 to 12 carbon atoms and cycloalkyl acrylates in which the cycloalkyl group has 5 to 7 carbon atoms; 5 to 50% by weight and (e) the number of carbon atoms in the alkyl group is 1
A monomer mixture consisting of 0 to 40% by weight of at least one methacrylic ester selected from the group consisting of ~12 alkyl methacrylates and cycloalkyl methacrylates in which the cycloalkyl group has 5 to 7 carbon atoms is polymerized. The number average molecular weight obtained by
A printing original plate for electrophotographic engraving characterized by being a copolymer of 50,000. 2. The printing original plate for electrophotolithography according to claim 1, wherein the photosensitive layer that is used while being positively charged contains a sensitizer. 3. The printing original plate for electrophotolithography according to claim 2, wherein the sensitizer is at least one selected from the group consisting of a compound represented by the following general formula and, succinic anhydride, and maleic anhydride. (In the formula, X ¹ to ^{X 5} may be the same or different, and each represents hydrogen, fluorine, -COOH
or −represents NO ₂ ), (In the formula, Y ¹ to ^{Y 4} may be the same or different, and each represents hydrogen, fluorine, -COOH
or −represents NO ₂ ) and (In the formula, ^Z1 to ^Z2 may be the same or different and each represents hydrogen, fluorine, -COOH or _-NO2 ). 4. The photosensitive layer according to claim 1, which is negatively charged and used, and the photosensitive layer contains at least one charge transfer substance selected from the group consisting of oxazole derivatives, oxadiazole derivatives, pyrazoline derivatives, hydrazone derivatives, and triphenylamine derivatives. Original printing plate for electrophotographic printing. 5. The printing original plate for electrophotolithography according to claim 4, wherein the charge transfer substance is represented by the following general formula. (In the formula, R ¹ and R ² represent an aryl group or an aralkyl group, and R ³ is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a benzyl group, an alkoxy group having 1 to 4 carbon atoms, a phenoxy group, or a benzyloxy group. 6. The printing original plate for electrophotolithography according to claim 1, wherein the photosensitive layer is negatively charged and used, and the photosensitive layer contains an aminotriazine resin. 7. The electrophotographic plate according to claim 6, wherein the aminotriazine resin is at least one selected from the group consisting of a benzoguanamine resin composition, a cyclohexylcarboguanamine resin composition, a melamine resin composition, and an acetoguanamine resin composition. Original printing plate. 8. The printing original plate for electrophotolithography according to claim 6, wherein the aminotriazine resin and the composition thereof are a condensate of methylolated aminotriazine, an alkyl ether, and a condensate of methylolated aminotriazine, respectively. 9. A lithographic printing obtained by forming a toner image on the printing original plate for electrophotographic plate according to any one of claims 1 to 8 by an electrophotographic method, and after fixing, removing the non-image area by etching with an alkaline etching liquid. Edition.