Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G5/00—Recording-members for original recording by exposure, e.g. to light, to heat or to electrons; Manufacture thereof; Selection of materials therefor
  • G03G5/02—Charge-receiving layers
  • G03G5/04—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor
  • G03G5/05—Organic bonding materials; Methods for coating a substrate with a photoconductive layer; Inert supplements for use in photoconductive layers
  • G03G5/0528—Macromolecular bonding materials
  • G03G5/0589—Macromolecular compounds characterised by specific side-chain substituents or end groups

Definitions

• This invention relates to an electrophotographic lithographic printing plate precursor made by an electrophotographic system and more particularly, it is concerned with an improvement in a photoconductive layer forming composition for the lithographic printing plate precursor.
• a number of offset masters for directly producing printing plates have hitherto been proposed and some of them have already been put into practical use. Widely employed among them is a system in which a photoreceptor comprising a conductive support having provided thereon a photoconductive layer mainly comprising photoconductive particles, for example, of zinc oxide and a binder resin is subjected to an ordinary electrophotographic processing to form a highly lithographic toner image on the surface of the photoreceptor, followed by treating the surface with an oil-desensitizing solution referred to as an etching solution to selectively render non-image areas hydrophilic and thus obtain an offset printing plate.
• an oil-desensitizing solution referred to as an etching solution
• Requirements of offset masters for obtaining satisfactory prints include: (1) an original should be reproduced faithfully on the photoreceptor; (2) the surface of the photoreceptor has affinity with an oil-desensitizing solution so as to render non-image areas sufficiently hydrophilic, but, at the same time, has resistance to solubilization; and (3) a photoconductive layer having an image formed thereon is not released during printing and is well receptive to dampening water so that the non-image areas retain the hydrophilic properties to be free from stains even upon printing a large number of prints.
• the background staining is a phenomenon associated with the degree of oil-desensitization achieved and it has been made apparent that the oil-desensitization of the photoconductive layer surface depends on not only the binder resin/zinc oxide ratio in the photoconductive layer, but also the kind of the binder resin used to a great extent.
• binder resins or resin grains are those which form hydrophilic groups through hydrolysis or hydrogenolysis with an oil-desensitizing solution or dampening water used during printing.
• various problems e.g. deterioration of the electrophotographic properties (dark charge retention, photosensitivity, etc,) which are considered to be caused in the case of using resins intrinsically having hydrophilic groups per se, and at the same time, a number of prints with clear image quality and without background stains can be obtained, since the hydrophilic property of non-image areas rendered hydrophilic with an oil-desensitizing solution is further increased by the above described hydrophilic groups formed through decomposition in the binder resin or resin grains to make clear the lipophilic property of image areas and the hydrophilic property of non-image areas and to prevent the non-image areas from adhesion of a printing ink during printing.
• the hydrophilic group previously masked with a protective group is subjected to decomposition reaction with a processing solution to release the protective group,
• the protective group removing reaction rapidly proceeds to form a hydrophilic group and the hydrophilic property of non-image areas can be improved.
• hydrophilic group-forming functional group which is stably present without decomposition even under severer conditions, e.g. during storage at a high temperature and high humidity for a long time, results in difficulty in a rapid decomposition with a processing solution and rapid feasibility of hydrophilic property.
• an electrophotographic lithographic printing plate precursor comprising a conductive support having provided thereon at least one photoconductive layer containing photoconductive zinc oxide and a binder resin, wherein the photoconductive layer contains resin grains containing at least one polymeric component having functional groups represented by the following General Formula (I) and/or General Formula (II) and having an average grain diameter of same as or smaller than the maximum grain diameter of the photoconductive zinc oxide grains: wherein -W 1 - and -W 2 - represent respectively -S0 2 -, -CO- or -OOC- and n 1 and n 2 represent respectively 0 or 1 and X represents a halogen atom.
• General Formula (I) and/or General Formula (II) having an average grain diameter of same as or smaller than the maximum grain diameter of the photoconductive zinc oxide grains: wherein -W 1 - and -W 2 - represent respectively -S0 2 -, -CO- or -OOC- and n 1 and n 2 represent respectively 0 or 1 and X
• the above described binder resin in the photoconductive layer contains at least one of the following Resins [A]: Resin [A]
• Resin A is preferably a resin having a weight average molecular weight of 1x10 3 to 2x10 4 , containing at least 30% by weight of recurring unit represented by the following General Formula (IV) as polymeric components and at least one polar group is bonded to one end of the polymer main chain, selected from the group consisting of -P0 3 H 2 , S0 3 H, -COOH, -OH, and wherein R 1 is a hydrocarbon group or-OR 2 (R 2 is a hydrocarbon group), and cyclic acid anhydride-containing groups:
• the polymeric component having the functional groups represented by General Formula (I) and/or General Formula (II) can have a crosslinked structure and in this case, the resin has water proof property which is preferable, when the hydrophilic property is realized through reaction with a processing solution for rendering hydrophilic.
• Resin [A'] of the present invention is preferably one containing, as the copolymeric component represented by General Formula (III), at least one of aryl group-containing methacrylate components represented by the following General Formula (IIIa) and General Formula (illb):
• the photoconductive layer comprises at least one of the resin grains consisting of a resin (which will hereinafter be referred to as Resin [L]) containing at least one of the functional groups represented by the above described General Formula (I) and/or General Formula (II) and optionally, at least one of the binder resins [A] or [A'].
• Resin [L] a resin
• the functional groups represented by the above described General Formula (I) and/or General Formula (II) optionally, at least one of the binder resins [A] or [A'].
• the resin grains are such that when processing with a processing solution containing at least one hydrophilic compound with nucleophilic reactivity, the hydrophilic compound with nucleophilic reactivity can additionally be reacted with the end of the functional group represented by the General Formula (I) or (II), whereby the photoconductive layer can reveal more hydrophilic property, and when the resin grains have a crosslinked structure, they are not or hardly soluble in water and exhibit water-swelling property while maintaining the hydrophilic property.
• the resin grains are dispersed in the photoconductive layer in the form of grains whose average grain diameter is same or smaller than the maximum grain diameter of the photoconductive zinc oxide grains. If there are resin grains having larger grain diameters than zinc oxide grains, the electrophotographic properties are deteriorated and in particular, uniform electrification cannot be obtained, thus resulting in density unevenness in an image, disappearance of letters orfine lines and background staining in a non-image area in a reproduced image.
• the crosslinked resin grains do not meet with dissolving-out with dampening water during printing so that good printing properties can be maintained even after a number of prints are obtained.
• the binder resin [A'] has a relatively low molecular weight and the specified copolymeric component containing the polar group (including cyclic acid anhydride groups unless otherwise indicated in this specification) at one end thereof, which adsorbs on the stoichiometric defects of the photoconductive zinc oxide, so that the covering property of the surface of the photoconductor is improved to compensate trapping of the photoconductor and the humidity property is remarkably improved, while simultaneously dispersion of the photoconductor is sufficiently carried out to suppress aggregation thereof. Furthermore, the resin grains are uniformly dispersed in the similar manner to suppress an unnecessary interaction between the resin grains and photoconductor.
• the lithographic printing plate precursor of the present invention has various advantages that an image faithful to an original can be reproduced,even when environmental conditions are changed or a laser beam of a low output is used, without occurrence of background stains owing to the high hydrophilic property of non-image areas, the smoothness and electrostatic characteristics of the photoconductive layer are excellent and furthermore, the durability is largely improved.
• the lithographic printing plate precursor of the present invention is notsensitive to environmental influences during plate making, is very excellent in storage property before processing and is capable of undergoing rapidly a processing for rendering hydrophilic.
• the resin grains of the present invention has the feature that only when non-image areas as a lithographic printing plate precursor is subjected to oil-desensitization, they are reacted with a nucleophilic compound in a processing solution as described above, whereby the hydrophilic group is added to the end thereof and they are rendered hydrophilic. Since the resin grains are not reactive with moisture in the air, there is no problem to be feared in storage of the lithographic printing plate precursor of the present invention. Since vinylsulfone group, vinylcarbonyl group or acryloxy group, represented by General Formula (I), is a functional group which is very rapidly reactive with a nucleophilic compound, it is possible to rapidly render hydrophilic.
• the functional group represented by General Formula (II) can be converted into the corresponding functional group represented by General Formula (I) by an alkali treatment to readily remove the hydrogen halide as shown in Reaction Formula (1) and can thus be used in the similar manner to General Formula (I).
• the resin grains of the present invention have an average grain diameter of same as or less than the maximum diameter ofthe photoconductive zinc oxide grains.
• the resin grains of the present invention have a maximum grain diameter of at most 10 pm, preferably at most 5 ⁇ m and an average grain diameter of at most 1.0 pm, preferably at most 0.5 ⁇ m.
• the specific surface areas of the hydrophilic resin grains are increased with the decrease of the grain diameter, resulting in good electrophotographic properties, and the grain size of colloidal grains, i.e., about 0.01 ⁇ m or smaller is sufficient.
• very small grains cause the similar troubles to those in the case of molecular dispersion and accordingly a grain size of 0.005 pm or larger is preferable.
• zinc oxide has generally a grain diameter of 0.05 to 10 pm, preferably 0.1 to 5 ⁇ m.
• copolymer constituent containing the functional group represented by General Formula (I) and/or General Formula (II) of Resin [L] include those represented by the following repeating unit of General Formula (V):
• Z represents preferably -COO-, -OCO, - O-, -CO-, wherein r 1 represents hydrogen atom, an optionally substituted alkyl group of 1 to 8 carbon atoms, such as methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl, 2-chloroethyl, 2-bromoethyl, 2-cyanoethyl, 2-methoxyethyl, 2-hydroxyethyl, 3-bromopropyl groups etc., an optionally substituted aralkyl group of 7 to 9 carbon atoms, such as benzyl, phenethyl, 3-phenylpropyl, chlorobenzyl, bromobenzyl, methylbenzyl, methoxybenzyl, chloromethylbenzyl, dibromobenzyl groups, etc., an optionally substituted aryl group
• Y represents a direct bond or an organic radical for connecting -Z- and -W o .
• b 1 and b 2 may be the same or different, and have the same meaning as a 1 and a 2 in Formula (IV),each being a hydrogen atom, a halogen atom (e.g., chlorine, bromine), a cyano group, a hydrocarbon residue (an optically substituted alkyl group containing 1 to 12 carbon atoms, such as methyl, ethyl, propyl, butyl, methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, butoxycarbonyl, hexyloxycarbonyl, methoxycarbonylmethyl, ethoxycarbonylmethyl, butoxycarbonylmethyl, etc., an aralkyl group such as benzyl, phenetyl, etc., and an aryl group such as phenyl, tolyl, xylyl, chlorophenyl, etc.
• a hydrocarbon residue an optically substituted alkyl group containing 1 to 12 carbon atoms
• linkage moiety ( ⁇ Z-Y) ⁇ in General Formula (V) may directly connect the moiety to the moiety -W o .
• the polymeric component containing the functional group represented by General Formula (I) and/or General Formula (II) is generally in a proportion of 1 to 95% by weight, preferably 50 to 95% by weight based on the whole copolymer in a case where Resin [L] is of the copolymer.
• this resin has a molecular weight of 10 3 to 10 8 , particulady 5x10 3 to 5x10 5 .
• the resin containing the polymeric component containing the functional group represented by General Formula (I) or (II) as described above can be synthesized by any of known methods, for example, by a method comprising subjecting to polymerization reaction a monomer containing the functional group represented by General Formula (I) or (II) and a polymerizable double bond group in the molecule (e.g. monomer corresponding to the recurring unit of General Formula (V)) and a method comprising reacting a low molecular compound containing the functional group represented by General Formula (I) or (II) with a high molecular compound containing a polymeric constituent containing a functional group reactive with the low molecular compound, which is called "polymer reaction".
• the resin containing the functional group represented by General Formula (I) can be synthesized by synthesizing the resin containing the functional group represented by General Formula (II) and then subjecting to an alkali treatment to remove the corresponding hydrogen halide.
• the polymerizable functional group in the above described monomer synthesis includes ordinary polymerizable double bond groups, for example,
• sulfonylation, carbonylation or carboxylic acid esterification can be carried out by methods, for example, described in Nippon Kagakukai, Shin-Jikken Kagaku Koza, Vol. 14, "Yuki Kagobutsu no Gosei to Hanno (Synthesis and Reaction of Organic Compounds)" page 751, 1000 and 1759 (1978), published by Maruzen KK and S. Patai, Z. Rappoport and C. Stirling "The Chemistry of Sulfones and Sulphoxides" page 165 (1988), published by John Wiley & Sons.
• examples of the monomer copolymerizable with the monomer containing the functional group represented by the above described General formula (I) and/or (II) are a-olefins, alkanic acid vinyl or allyl esters, acrylonitrile, methacrylonitrile, vinyl ethers, acrylamides, methacrylamides, styrenes, alicyclic vinyls such as vinylpyrrolidone, vinylpyridine, vinylimidazole, vinylthiophene, vinylpyridineimidazoline, vinylpyrazole, vinyldioxane, vinylquinoline, vinylthiazole, vinyloxazine and the like.
• At least a part of the resin grains may be crosslinked.
• a resin that at least a part of the polymer is previously crosslinked is preferably a resin which is hardly soluble or insoluble in acidic or alkaline solutions when the above described functional group contained in the resin gives hydrophilic property through an oil-desensitization treatment.
• the solubility of the resin in distilled water at 20 to 25°C is preferably at most 90% by weight, more preferably at most 70% by weight.
• Introduction of a crosslinked structure in a polymer can be carried out by known methods, that is, (I) a method comprising subjecting a monomer containing the functional group of General Formula (I) and/or (II) to polymerization reaction in the presence of a multi-functional monomer (monomer containing two or more polymerizable functional groups) or a multifunctional oligomer and effecting crosslinking among molecules, (2) a method comprising incorporating functional groups for proceeding the crosslinking reaction in the polymer and crosslinking the polymer containing both the functional groups with a crosslinking agent or hardening agent and (3) a method comprising subjecting the crosslinking functional group-containing polymer to polymer reaction with a compound containing the group of General Formula (I) or (II).
• Any of monomers containing two or more same or different ones of these polymerizable functional groups can be used as the multifunctional monomer or oligomer in the above-described method (3).
• styrene derivatives such as divinyl benzene and trivinyl benzene
• esters of polyhydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycols Nos.
• 1,3-butylene glycol 1,3-butylene glycol, neopentyl glycol, dipropylene glycol, polypropylene glycol, trimethylolpropane, trimethylolethane, pentaerythritol and the like or polyhydroxyphenols such as hydroquinone, resorcinol, catechol and derivatives thereof with methacrylic acid, acrylic acid or crotonic acid, vinyl ethers and allyl ethers; vinyl esters of dibasic acids such as malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, maleic acid, phthalic acid, itaconic acid and the like, allyl esters, vinylamides and allylamides; and condensates of polyamines such as ethylenediamine, 1,3-propylenediamine, 1,4-butylenediamine and the like with carboxylic acids containing vinyl groups such as methacrylic acid, acrylic acid, crotonic acid
• ester derivatives or amide derivatives containing vinyl groups of carboxylic acids containing vinyl group such as methacrylic acid, acrylic acid, methacryloylacetic acid, acryloylacetic acid, methacryloyl- propionic acid, acryloylpropionic acid, itaconyloylacetic acid and itaconyloylpropionic acid, reaction products of carboxylic anhydrides with alcohols or amines such as allyloxycarbonylpropionic acid, allyloxycarbonylacetic acid, 2-allyloxycarbonylbenzoic acid, allylaminocarbonylpropionic acid and the like, for example, vinyl methacrylate, vinyl acrylate, vinyl itaconate, allyl methacrylate, allyl acrylate, allyl itaconate, vinyl methacryloylacetate, vinyl methacryloylpropionate
• carboxylic acids containing vinyl group such as methacrylic acid, acrylic acid, methacryloylacetic
• the monomer or oligomer containing two or more polymerizable functional groups of the present invention is generally used in a proportion of at most 10 mole%, preferably at most 5 mole% to all monomers, which is polymerized to form a resin.
• polymerizable double bond groups e.g., above-described as a polymerizable double bond group, or a combination of reactive groups capable of forming chemical bonds by chemical reaction.
• crosslinking of polymers by reacting reactive groups among the polymers and forming chemical bonds according to the latter can be carried out in the similar manner to the ordinary reactions of organic low molecular compounds, for example, as disclosed in Yoshio Iwakura and Keisuke Kurita "Reactive Polymers (Hannosei Kobunshi)” published by Kohdansha (1977) and Ryohei Oda "High Molecular Fine Chemical (Kobunshi Fine Chemical)” published by Kohdansha (1976).
• R and R' have the same meaning as the foregoing r 5 and r e .
• crosslinking functional groups can be incorporated in one copolymeric constituent with the functional groups represented by General Formula (I) or (11), or can be incorporated in another copolymeric constituent than a copolymeric constituent containing the functional groups represented by General Formula (I) or (II).
• Examples of the monomer corresponding to the copolymer constituent containing these crosslinking functional groups include vinyl compounds containing the functional groups copolymerizable with the polymeric constituents of General Formula (V).
• vinyl compounds include those described in, for example, Kobunshi Gakkai "Polymer Data Handbook -Kisohen-", published by Baihukan, 1986, for example, acrylic acid, a and/or ⁇ -substituted acrylic acid such as a-acetoxy, a-acetoxymethyl, a-(2-amino)ethyl, a-chloro, a-bromo, a-fluoro, a-tributylsilyl, a-cyano, ⁇ -chloro, ⁇ -bromo, ⁇ -chloro- ⁇ -methoxy and a,p-dichloro substituted ones, methacrylic acid, itaconic acid, itaconic acid semi-esters, itaconic acid semiamides, crotonic acid, 2-alkenylcarboxylic acids such as 2- pentenoic acid, 2-methy)-2-hexenoic acid, 2-octenoic acid, 4-methyl-2-hex
• Resin [L] of the present invention can optionally be added a reaction promoter so as to promote the crosslinking reaction, for example, acids such as acetic acid, propionic acid, butyric acid, benzenesulfonic acid, p-toluenesulfonic acid, etc., peroxides, azobis compounds, crosslinking agents, sensitizers, photopolymerizable monomers and the like.
• acids such as acetic acid, propionic acid, butyric acid, benzenesulfonic acid, p-toluenesulfonic acid, etc.
• peroxides peroxides
• azobis compounds crosslinking agents
• sensitizers photopolymerizable monomers and the like.
• crosslinking agent in the present invention there can be used compounds commonly used as aosslinking agents, for example, described in Shinzo Yamashita and Tosuke Kaneko "Handbook of Crosslinking Agents (Kakyozai Handbook)" published by Taiseisha (1981) and Kobunshi Gakkai Edition "High Molecular Data Handbook -Basis- (Kobunshi Data Handbook -Kisohen-)” published by Baihunkan (1986).
• crosslinking agent examples include organosilane compounds such as vinyltrimethoxysilane, vinyl- tributoxysilane, ⁇ -glyddoxypropyltrimethoxysilane, y-mercaptopropyltriethoxysilane, y-aminopropyltriethoxysilane and other silane coupling agents; polyisocyanate compounds such as tolylene diisocyanate, o-tolylene diisocyanate, diphenylmethane diisocyanate, triphenylmethane diisocyanate, triphenylmethane triisocyanate, polymethylenepolyphenyl isocyanate, hexamethylene diisocyanate, isophorone diisocyanate, high molecular polyisocyanates; polyol compounds such as 1,4- butanediol, polyoxypropylene glycol, polyoxyalkylene glycol, 1,1,1,-trimethylolpropane and the like;
• Resin [L] containing at least one of functional groups capable of forming at least one hydrophilic group by processing with a processing solution containing a compound with nucleophilic reactivity is in the form of grains with a maximum grin diameter of at most 10 ⁇ m and an average grain diameter of at most 1.0 ⁇ m.
• the resin grains of the present invention are produced by dispersing the resin powder as it is, when preparing the composition for forming a photoconductive layer, to thus give a desired grain size.
• a known method of directly pulverizing a resin powder to give fine grains by a known grinder or dispersing machine e.g., ball mill, point shaker, sand mill, hammer mill, jet mill, keddy mill, etc.
• a known method of producing latex grains of paings or liquid developers for electrophotography is a method comprising dispersing the resin powder by the joint use of a dispersing polymer, more specifically previously mixing the resin powder and dispersion aid polymer followed by pulverizing, and then dispersing the pulverized mixture in the presence of the dispersing polymer.
• the prior art method of obtaining readily latex grains or particles by suspension polymerization or dispersion polymerization can also be used in the present invention, for example, as described in Soichi Muroi "Chemistry of High Molecular Latex (Kobunshi Latex no Kagaku)" published by Kobunshi Kankokai (1970), Taira Okuda and Hiroshi Inagaki “Synthetic Resin Emulsions (Gosei Jushi Emulsion)" published by Kobunshi Kankokai (1978), Soichi Muroi "Introduction to High Molecular Latexes (Kobunshi Latex Nyumon)” published by Kobunsha (1983).
• formation of a photoconductive layer can be carried out by any of methods of dispersing photoconductive zinc oxide in an aqueous system, for example, described in Japanese Patent Publication Nos. 450/1976, 18599/1972 and 41350/1971 and methods of dispersing in a non-aqueous solvent system, for example, described in Japanese Patent Publication No. 31011/1975 and Japanese Patent Laid-Open Publication Nos. 54027/1978, 20735/1979, 202544/1982 and 68046/1983. If water remains in the photoconductive layer, however, the electrophotographic property is deteriorated, and accordingly, the latter methods using a non-aqueous solvent system is preferable. Therefore, in order to adequately disperse the resin latex grains of the present invention in the photoconductive layer dispersed in a non-aqueous system, the latex grains are preferably non-aqueous system latex grains.
• non-aqueous solvent for the non-aqueous system latex there can be used any of organic solvents having a boiling point of at most 200°C, individually or in combination.
• organic solvent are alcohols such as methanol, ethanol, propanol, butanol, fluorinated alcohols and benzyl alcohol, ketones such as acetone, methyl ethyl ketone, cyclohexanone and diethyl ketone, ethers such as diethyl ether, tetrahydrofuran and dioxane, carboxylic acid esters such as methyl acetate, ethyl acetate, butyl acetate and methyl propionate, aliphatic hydrocarbons containing 6 to 14 carbon atoms such as hexane, octane, decane, dodecane, tridecane, cyclohexane and cyclooctane, aromatic hydrocarbons such as benz
• the average grain diameter of the latex grains can readily be adjusted to at most 1 lim while simultaneously obtaining grains of monodisperse system with a very narrow distribution of grain diameters.
• Such a method is described in, for example, K.E.J.
• the resin grains of the present invention form hydrophilic groups by the reaction with a hydrophilic compound with nucleophilic property through processing with an oil-desensitizing solution or dampening water used during printing. Therefore, in the lithographic printing plate precursor having a photoconductive layer containing the resin grains, the hydrophilic property of non-image areas rendered hydrophilic with an oil-desensitizing solution is further increased by the above-described hydrophilic groups formed in the resin grains to make clear the lipophilic property of image areas and the hydrophilic property of non-image areas and to prevent the non-image areas from adhesion of a printing ink during printing. Consequently, a number of prints with clear image quality and without background stains can be obtained.
• the effect of improving the hydrophilic property can unchangeably be maintained, or even if printing conditions are severer, e.g., enlargement of a printing machine and fluctuation of printing pressure taking place, a number of prints with clear image quality and without background stains can be obtained.
• binder resin of the present invention there can be used all of known resins, typical of which are vinyl chloride-vinyl acetate copolymers, styrenebutadiene copolymers, styrene-methacrylate copolymers, methacrylate copolymers, acrylate copolymers, vinyl acetate copolymers, polyvinyl butyral, alkyd resins, silicone resins, epoxy resins, epoxyester resins, polyester resins and the like, as described in Takaharu Kurita and Jiro Ishiwataru "High Molecular Materials (Kobunshi)"17,278 (1968), Harumi Miyamoto and Hidehiko Takei "Imaging” No.
• the binder resin of the present invention is preferably Resin A containing at least 30% by weight of the specified recurring unit represented by the foregoing General Formula (III) as polymeric components and 0.5 to 15% by weight of polymeric components having the specified polar groups and/or cyclic acid arihydride groups (in this specification, the polar group is defined to include cyclic acid anhydride polar groups unless otherwise indicated.), and having a relatively low molecular weight, i.e. a weight average molecular weight of 1x10 3 to 2x10 4 and a glass transition point of -20 to 110°C, preferably -10 to 90°C.
• a relatively low molecular weight i.e. a weight average molecular weight of 1x10 3 to 2x10 4 and a glass transition point of -20 to 110°C, preferably -10 to 90°C.
• the binder resin is Resin A' having a weight average molecular weight of 1x1Q 3 to 2x10 4 , containing at least 30% by weight of recurring unit represented by the following general formula (IV) as polymeric components and at least one polar group is bonded to one end of the polymer main chain, selected from the group consisting of -P0 3 H 2 , -S0 3 H, -COOH, -OH, and wherein R 1 is a hydrocarbon group or -OR 2 (R 2 : hydrocarbon group) and cyclic acid anhydride-containing groups:
• a 1 and a 2 represent, hydrogen atoms, halogen atoms, cyano groups and hydrocarbon groups, - COO-R a or-COO-R 6 via a hydrocarbon group, wherein R 8 represents a hydrocarbon group, and R 3 represents a hydrocarbon group.
• the weight average molecularweight is 1x10 3 to 2x10 4 , preferably 3x10 3 1x10 4 and a glasstran- sition point of -20°C to 110°C, preferably -10 ° C to 90°C.
• the polymeric components corresponding to the recurring unit of General Formula (III) or (IV) are generally in a proportion of at least 30% by weight, preferably 50 to 97% by weight and the copolymeric components containing the polar groups bonded to the end of the main chain are generally in a proportion of 0.5 to 15% by weight, preferably 1 to 10% by weight.
• Resin [A] or Resin [A'] is less than 0.5% by weight, the initial potential is too low to obtain a sufficient image density, while if more than 15% by weight, the dispersibility is lowered in spite of its lower molecular weight, and background staining is increased when used as an offset master.
• R 3 represents hydrocarbon groups, for example, alkyl groups, aralkyl groups and aromatic groups, preferably aralkyl groups and aromatic groups as hydrocarbon groups containing benzene ring or naphthalene rain.
• R 3 represents optionally substituted alkyl groups containing 1 to 18 carbon atoms such as methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl, decyl, dodecyl, tridecyl, tetradecyl, 2-chloroethyl, 2-bromoethyl, 2-cyanoethyl, 2-hydroxyethyl, 2-methoxyethyl, 2-ethoxyethyl, and 3-hydroxypropyl groups, optionally substituted alkenyl groups containing 2 to 18 carbon atoms such as vinyl, allyl, isopropenyl, butenyl, hexenyl, heptenyl and octenyl groups, optionally substituted aralkyl groups containing 7 to 12 carbon atoms such as benzyl, phenethyl, naphthylmethyl, 2-naphthylethyl,
• Resin [A'] there is preferably used a Resin [A'] having the polar group bonded to the end and containing the methacrylate component having the specified substituent containing a benzene ring having the specified substituent on 2- and/or 6-position or non-substituted naphthalene ring, represented by General Formula (IIIa) and/or(IIIb), which low molecularweight polymer will hereinafter be referred to as Resin [A"].
• the methacrylate components corresponding to the recurring units of General Formula (IIIa) and/or (IIIb) are generally in a proportion of at least 30% by weight, preferably 50 to 90% by weight and the polar groups contained at the end of the polymer main chain are generally in a proportion of 0.5 to 15% by weight, preferably 1 to 10% by weight based on 100% by weight of Resin [A"].
• a 1 and a 2 preferably represent hydrogen atoms, cyano groups, alkyl groups containing 1 to 18 carbon atoms, such as methyl, ethyl, propyl and butyl groups, - COO-R 3 or -COO-R 8 via a hydrocarbon group, wherein R 8 represents a hydrocarbon group preferably an alkyl group containing 1 to 18 carbon atoms, alkenyl group, aralkyl group, alicyclic group or aryl group, which can be substituted, specifically the same meanings as R 3 .
• the hydrocarbon group in the above-described -CO-OR 8 group via a hydrocarbon group for example, there is methylene, ethylene, propylene group, etc.
• preferable copolymeric components of Resin [A] or [A'] are copolymeric components of methacrylates containing substituted benzene rings or naphthalene ring, represented by the following General Formula (IIIa) and/or (Illb).
• Resin [A"] contains this copolymeric component and the copolymeric component containing the polar group bonded to one end of the polymer chain.
• T, and T 2 each represent independently hydrogen atom, hydrocarbon groups containing 1 to 10 carbon atoms, chlorine atom, bromine atom, -COR 9 or -COOR 9 wherein Rg represents a hydrocarbon group containing 1 to 10 carbon atoms, and L, and L 2 each represents direct bonds for bonding -COO-and benzene ring or bonding groups containing 1 to 4 bonding atoms.
• T, and T 2 each represents, same or different, hydrogen atom, chlorine atom, bromine atom, hydrocarbon groups containing 1 to 10 carbon atoms, more preferably alkyl groups containing 1 to 4 carbon atoms such as methyl, ethyl, propyl and butyl groups, aralkyl groups containing 7 to 9 carbon atoms such as benzyl, phenethyl, 3-phenylpropyl, chlorobenzyl, dichlorobenzyl, bromobenzyl, methylbenzyl, methoxybenzyl and chloromethylbenzyl groups and aryl groups such as phenyl, tolyl, xylyl, bromophenyl, methoxyphenyl, chlorophenyl and dichlorophenyl groups, and -COR 9 and -COOR 9 wherein R 9 is preferably that described for the foregoing preferable hydrocarbon groups containing 1 to 10 carbon atoms.
• L, and L 2 each represent a direct bond for bonding -COO- and benzene ring or bonding groups containing 1 to 4 bondingatoms such as ( ⁇ CH 2 ) ⁇ n3 wherein n 3 is an integer of 1 to 3, - CH 2 OCO-, -CH 2 CH 2 OCO-, ( ⁇ ECH 2 ) ⁇ m2 wherein m 2 is an integer of 1 or 2 and -CH 2 CH 2 O-, preferably a direct bond or bonding groups containing 1 or 2 bonding atoms.
• n is an integer of 1 to 4
• m is 0 or an integer of 1 to 4
• p is an integer of 1 to 3
• R 10 to R 13 each represent -C n H 2n+1 or ( ⁇ CH 2 ) ⁇ m C 8 H 5 wherein n and m have the same meaning as described above, and X 1 and X 2 each represent any of -Cl, -Br and -1.
• the polar group optionally bonded to one end of the polymer main chain of Resin [A] to [A'] will now be illustrated.
• the polar group is at least one member selected from the group consisting of -P0 3 H 2 , -S0 3 H, -CO-OH, and cyclic acid anhydride-containing groups.
• R represents a hydrocarbon group or -OR 2 group wherein R 2 is a hydrocarbon group.
• R represents optionally substituted hydrocarbon groups containing 1 to 22 carbon atoms such as methyl, ethyl, propyl, butyl, hexyl, octyl, decyl, dodecyl, octadecyl, 2-chloroethyl, 2-methoxyethyl, 3-ethoxypropyl, allyl, crotonyl, butenyl, cyclohexyl, benzyl, phenethyl, 3-phenylpropyl, methylbenzyl, chlorobenzyl, fluorobenzyl, methoxybenzyl groups, etc.
• hydrocarbon groups containing 1 to 22 carbon atoms such as methyl, ethyl, propyl, butyl, hexyl, octyl, decyl, dodecyl, octadecyl, 2-chloroethyl, 2-methoxyethyl
• R 2 has the same meaning as R 1 .
• the cyclic acid anhydride-containing group means a group containing at least one cyclic acid anhydride, illustrative of which are aliphatic dicarboxylic acid anhydrides and aromatic dicarboxylic acid anhydrides.
• Examples of the aliphatic dicarboxylic acid anhydride include rings of succinic anhydride, glutaconic anhydride, maleic anhydride, cyclopentane-1,2-dicarboxylic anhydride, cydohexane-1,2-dicarboxylicanhydride, cyclohexene-1,2-dicarboxylic anhydride and 2,3-bicyclo[2,2,2]octadicarboxylic anhydride.
• These rings can be substituted, for example, by halogen atoms such as chlorine and bromine atoms and/or alkyl groups such as methyl, ethyl, butyl and hexyl groups.
• aromatic dicarboxylic acid anhydride examples include rings of phthalic anhydride, naphthalene dicarboxylic anhydride, pyridine dicarboxylic anhydride and thiophene dicarboxylic anhydride. These rings can be substituted by, for example, halogen atoms such as chlorine and bromine atoms, alkyl groups such as methyl, ethyl, propyl and butyl groups, hydroxyl group, cyano group, nitro group, alkoxycarbonyl groups wherein alkoxy groups are methoxy and ethoxy groups, and the like.
• halogen atoms such as chlorine and bromine atoms
• alkyl groups such as methyl, ethyl, propyl and butyl groups
• hydroxyl group cyano group
• alkoxycarbonyl groups wherein alkoxy groups are methoxy and ethoxy groups, and the like.
• any bonding group can be used, for example, selected from the group consisting of: wherein d 1 and d 2 each represent, same or different, hydrogen atoms, halogen atoms such as chlorine and bromine atoms, OH groups, cyano groups, alkyl groups such as methyl, ethyl, 2-chloroethyl, 2-hydroxyethyl, propyl, butyl, hexyl groups, etc., aralkyl groups such as benzyl, phenethyl groups, etc., phenyl group and the like; wherein d 3 and d 4 have the same meanings as d 1 and d 2 ; wherein d 5 represents a hydrogen atom or hydrocarbon group, illustrative of which are hydrocarbon groups containing 1 to 12 carbon atoms, such a methyl, ethyl, propyl, butyl hexyl
• the binder resins [A] to [A"] can contain, in addition to the copolymeric component represented by the foregoing General Formulae (III) and (IV) including ones represented by General Formulae (ilia) and (Illb), 0,5 to 10% by weight of a copolymeric component, as a polymeric component to be copolymerized therewith, containing at least one polar group selected from the group consisting of -P0 3 H 2 , -S0 3 H, -COOH, and cyclic acid anhydride-containing groups, whereby the electrostatic properties are improved.
• the copolymeric component represented by the foregoing General Formulae (III) and (IV) including ones represented by General Formulae (ilia) and (Illb) 1,5 to 10% by weight of a copolymeric component, as a polymeric component to be copolymerized therewith, containing at least one polar group selected from the group consisting of -P0 3 H 2 , -S0 3 H, -COOH, and
• These specified polar groups have the same contents as the polar groups bonded to one end of the polymer main chain.
• the presence ratio of the polar groups contained as the copolymeric component and those bonded to one end of the polymer main chain depends on the kinds and amounts of other binder resins, spectral sensitizing dyes, chemical sensitizers and other additives and it is preferable to control the ratio in suitable manner. Furthermore, it is important that the total amounts of both the polar groups are in the range of 0.5 to 15% by weight.
• the copolymeric component containing the polar groups according to the present invention can be vinyl compounds containing the polar group copolymerizable with a monomer corresponding to the recurring unit represented by General Formula (III) including General Formulae (IIIa) and (IIIb), for example, described in, for example, Kobunshi Gakkai "Polymer Data Handbook - Kisohen-", published by Baihukan, 1986, for example, acrylic acid, a and/or ⁇ -substituted acrylic acid such as a-acetoxy, a-acetoxymethyl, a-(2-amino)ethyl, a-chloro, a-bromo, a-fluoro, a-tributylsilyl, a-cyano, ⁇ -chloro, ⁇ -bromo, ⁇ -chloro- ⁇ -methoxy and a,p-dichloro substituted ones, methacrylic acid, itaconic acid, itaconic acid semi-est
• Examples of the copolymeric component containing the polar group are shown in the following, in which e 1 is H or CH 3 , e 2 is H, CH 3 or CH 2 COOCH 3 , R 14 is an alkyl group of 1 to 4 carbon atoms, R 15 is an alkyl group of I to 6 carbon atoms, benzyl group or phenyl group, c is an integer of 1 to 3, d is an integer of 2 to 11, e is an integer of 1 to 11, f is an integer of 2 to 4 and g is an integer of 2 to 10.
• Resin [A] to Resin [A'] of the present invention can contain, in addition to the monomers of General Formulae (III), (ilia) and/or (IIIb) and the monomers containing the polar groups, other monomers as copolymeric components.
• methacrylic acid esters containing other substituents than those represented by General Formula (III) acrylic acid esters, crotonic acid esters, a-olefins, vinyl or allyl esters of carboxylic acids such as acetic acid, propionic acid, butyric acid, valeic acid, benzoic acid, naphthalene carboxylic acid and the like, acrylonitrile, methacrylonitrile, vinyl esters, itaconic acid esters such as dimethyl ester, diethyl ester and the like, acrylamide, methacrylamide, styrenes such as styrene, vinyltoluene, chlorostyrene, hydroxystyrene, N,N-dimethylaminomethylstyrene, methoxycarbonylstyrene, methanesulfonyloxystyrene, vinylnaphthalene and the like, vinyls
• these other monomers are respectively in a proportion of less than 30% by weight in Resin [A], [A'] or [A"].
• bonding the polar group to one end of the polymer main chain is generally carried out by a method comprising reacting the end of a living polymer obtained by the prior art anionic polymerization or cationic polymerization with various reagents (method by ionic polymerization), method comprising radical polymerization using a chain transfer agent and/or polymerization initiator containing a specific acid group in the molecule, method comprising subjecting a polymer containing a reactive group such as amino group, halogen atoms, epoxy group, acid halides group or the like at the end thereof, obtained by the ionic polymerization or radical polymerization as described above, to polymer reaction convert it into the specified polar group according to the present invention, for example, as described in introductions and literatures cited therein of P.
• chain transfer agent for example, there can be used mercapto compounds having the above-described polar group or reactive group capable of being converted into the polar group, such as thioglycolic acid, thiomalic acid, thiosalicylic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, 3-mercaptobutyric acid, N-(2-mercaptopropionyl)glycine, 2-mercaptonicotinic acid, 3-[N-(2-mercaptoethyl)carbamoyl]propionic acid, 3-[N-(2-mercaptoethyl)amino]propionic acid, N-(3-mercaptopropionyl)alanine, 2-mercaptoethanesulfonic acid, 3-mercaptopropanesulfonic acid, 4-mercaptobutanesulfonic acid, 2-mercaptoethanol, 3-mercapto-1,2-propane diol, 1-mercapto-2-propanol, 3-
• polymerization initiator containing the polar group or the specified reactive group capable of being converted into the polar group for example, 4,4'- azobis(4-cyanovaleic acid), 4,4'-azobis(4-cyanovaleic acid chloride), 2,2'-azobis(2-cyanopropanol), 2,2'azobis(2-cyanopentanol), 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)-propionamide], 2,2'-azobis ⁇ 2-methyl-N-(1,1-bis(hydroxymethyl)-2-hydroxyethyl]propionamide ⁇ , 2,2'-azobis(2-[1-(2-hydroxyethyl)-2-imidazoline-2-il]propane), 2,2'-azobis[2-(2-imidazoline-2-il)propane] and 2,2'-azobis[2-(4,5,6,7-tetrahydro-1 H-1,3-diazepine-2-il)propane].
• chain transfer agents or polymerization initiators are generally used in a proportion of 0.5 to 15 parts by weight, preferably 2 to 10 parts by weight to 100 parts by weight of all the monomers.
• the low molecular weight resins [A] to [A"] as described above are preferably used jointly with the prior art resins for photoconductive zinc, in particular, in a proportion of 5 to 50 of the former to 95 to 50 of the latter by weight.
• the other resin there can be used medium to high molecular weight resins with a molecular weight of 3x10 4 to 1 x1 0 6 , preferably 5x10 * to 5x10 5 and a glass transition point of -10°C to 120°C, preferably 0°C to 90°C.
• olefin polymers and copolymers vinyl chloride copolymers, vinylidene chloride copolymers, vinyl alkanate polymers and copolymers, allyl alkanate polymers and copolymers, styrene and its derivative polymers and copolymers, butadienestyrene copolymers, isoprene-styrene copolymers, butadiene- unsaturated carboxylic acid ester copolymers, acrylonitrile copolymers, metharylonitrile copolymers, alkyl vinyl ether copolymers, acrylic acid ester polymers and copolymers, methacrylic acid ester polymers and copolymers, styrene-acrylic acid, styrene-methacrylic acid ester copolymers, itaconic acid diester polymers and copolymers, maleic anhydride copolymers, acrylamide copolymers, methacrylamide copolymers, meth
• the medium to high molecular weight resins to be jointly used there are preferably used polymers containing at least 30% by weight of a polymeric component of a recurring unit represented by the following General Formula (V) and satisfying the foregoing properties:
• Examples of the medium to high molecular weight binder resin containing the polymeric component represented by General Formula (V), which will hereinafter be referred to as Resin [B], are random copolymer resins containing the polymeric component represented by General Formula (V), as described in Japanese Patent Laid-Open Publication Nos. 49817/1988, 220149/1988 and 220148/1988, jointly used resins of the random copolymers with crosslinking resins, as described in Japanese Patent Laid-Open Publication Nos. 211766/1989 and 102573/1989, copolymers containing the polymeric component represented by General Formula (V) and previously partially crosslinked as described in Japanese Patent Laid-Open Publication Nos.
• block copolymers of graft type obtained by polymerization of monofunctional macromonomer comprising the specified recurring unit and a monomer corresponding to the constituent represented by General Formula (V), as described in Japanese Patent Application Nos. 203933/1988, 207317/1988, 163796/1989, 212994/1989, 229379/1989 and 189245/1989.
• Resins [A], [A'] and [A"] are copolymers containing at least methacrylate copolymeric components having the specified substituents and copolymeric components containing the polar groups which adsorb on the stoichiometric defects of the photoconductive zinc oxide, so that the covering property of the surface of the photoconductive zinc oxide is improved, because of the low molecular weight materials, to compensate trapping of the photoconductive zinc oxide and the humidity property is remarkably improved, while simultaneously dispersion of the photoconductive zinc oxide is sufficiently carried out to suppress aggregation thereof. Furthermore, the resin grains capable of exhibiting hydrophilic property by processing with a processing solution containing a compound having nucleophilic reactivity are uniformly dispersed without unfavorably affecting the photoconductive zinc oxide.
• Resin [A], [A'] or [A"] and Resin [B] are jointly used as the binder resin and the weight average molecular weight Mw of each of these resins and the contents of the polar groups in the resins are specified to thus change the intensity of the interaction between the inorganic photoconductor and resins.
• Resin [A], [A'] or [A"] having a stronger interaction adsorbs on a photoconductor selectively and suitably, while Resin [B] having a weaker interaction than Resin [A], [A'] or [A"] interacts moderately with an inorganic photoconductor to such an extent that the polar group bonded to the specified position to the polymer chain in the resin does not deteriorate the electrophotographic property and Resins [B] each having long molecular length and graft chain length interact with each other, whereby both the electrophotographic property and mechanical film strength are markedly improved.
• photoconductive zinc oxide of the present invention there can be used ordinary ones well known in the art, i.e. not only the so-called zinc oxide, but also zinc oxide subjected to processing with an acid.
• the quantity of the binder resin used for photoconductive zinc oxide is generally in a proportion of 10 to 100 parts by weight of the binder resin, preferably 15 to 50 parts by weight to 100 parts by weight of the photoconductive zinc oxide.
• various coloring matters or dyes can be used as a spectro sensitizer, depending on the variety of light sources such as exposure to visible rays and semiconductor laser beam, illustrative of which are carbonium dyes, diphenylmethane dyes, triphenylmethane dyes, xanthene dyes, phthalein dyes, polymethine dyes such as oxonol dyes, merocyanine dyes, cyanine dyes, rhodacyanine dyes, styryl dyes, etc. and phthalocyanine dyes which can contain metals, as described in Harumi Miyamoto and Hidehiko Takei "Imaging" No.
• polymethine dyes such as oxonol dyes, merocyanine dyes, cyanine dyes and rhodacyanine dyes
• polymethine dyes such as oxonol dyes, merocyanine dyes, cyanine dyes and rhodacyanine dyes
• dyes described in F.M. Harmmer The Cyanine Dyes and Related Compounds” and specifically dyes described in U.S. Patent Nos. 3,047,384, 3,110,591, 3,121,008, 3,125,447, 3,128,179, 3,132,942 and 3,622,317; British Patent Nos. 1,226.892.1.309.274 and 1,405,898; and Japanese Patent Publication Nos. 7814/1973 and 18892/1980.
• polymethine dyes capable of spectrally sensitizing near infrared radiations to infrared radiations with longer wavelengths of at east 700 nm are described in Japanese Patent Publication No. 41061/1976; Japanese Patent Laid-Open Publication Nos. 840/1972, 44180/1972, 5034/1974, 45122/1974, 46245/1982, 35141/1981, 157254/1982, 26044/1986 and 27551/1986; U.S. Patent Nos. 3,619,154 and 4,175,956; and "Research Disclosure" 2416, pages 117-118 (1982).
• the photoreceptor of the present invention is excellent in that its performance is hardly fluctuated even if it is used jointly with various sensitizing dyes.
• various additives for electrophotographic light-sensitive layers such as chemical sensitizers, well known in the art can jointly be used as occasion demands, for example, electron accepting compounds such as benzoquinone, chloranil, acid anhydrides, organic carboxylic acids and the like, described in the foregoing "Imaging” No. 8, page 12 (1973) and polyarylalkane compounds, hindered phenol compounds, p-phenylenediamine compounds and the like, described in Hiroshi Komon et al.
• the amounts of these additives are not particularly limited, but are generally 0.0001 to 2.0 parts by weight based on 100 parts by weight of the photoconductive zinc oxide.
• the thickness of the photoconductive layer is generally 1 to 100 pm, preferably 10 to 50 pm.
• the thickness of the charge producing layer is generally 0.01 to 1 pm, preferably 0.05 to 0.5 pm.
• the charge transporting material of the laminate type photoreceptor there are preferably used polyvi- nylcarbazole, oxazole, dyes, pyrazoline dyes, triphenylmethane dyes and the like.
• the charge transporting layer has generally a thickness of 5 to 40 pm, preferably 10 to 30 pm.
• thermoplastic resins and thermosetting resins such as polystyrene resins, polyester resins, cellulose resins, polyether resins, vinyl chloride resins, vinyl acetate resins, vinyl chloride-vinyl acetate copolymer resins, polyacrylic resins, polyolefin resins, urethane resins, epoxy resins, melamine resins and silicone resins.
• the photoconductive layer of the present invention can be provided on a support as well known in the art.
• a support for an electrophotographic light-sensitive layer is preferably electroconductive and as the electroconductive support, there can be used, as known in the art, substrates such as metals, papers, plastic sheets, etc.
• Production of a print using the electrophotographic lithographic printing plate precursor of the present invention can be carried out in known manner by forming a copied image and subjecting the non-image area to an oil-desensitizing treatment.
• the oil-desensitization of the resin of the present invention can be accomplished by processing with a solution containing a compound having hydrophilic groups capable of readily undergoing nucleophilic reaction with the double bonds in water or a water-soluble organic solvent.
• the hydrophilic compound causing a nucleophilic substitution reaction with the double bond of the functional group represented by General Formula (I) includes a hydrophilic compound containing a substituent having a nucleophilic constant n of at least 5.5 (Cf. R.G. Pearson, H. Sobel and J. Songstad "J. Amer. Chem.
• Examples of the mercapto compound are 2-mercaptoethanol, 2-mercaptoethylamine, N-methyl-2-mercaptoethylamine, N-(2-hydroxyethyl)-2-mercaptoethylamine, thioglycolic acid, thiomalic acid, thiosalicylic acid, mercaptobenzenedicarboxylic acid, 2-mercaptoethanesulfonic acid, 2-mercaptoethylphosphonic acid, mer- captobenzenesulfonic acid, 2-mercaptopropionylaminoacetic acid, 2-mercapto-1-aminoacetic acid, 1-mercap- toproplonylaminoacatic acid, 1,2-dimercaptopropionytaminoacetic acid, 2,3-dihydroxypropylmercaptan, 2-methyl-2-mercapto-1-aminoacetic acid and the like.
• sulfinic acid examples include 2-hydroxy-ethylsulfinic acid, 3-hydroxypropanesulfinic acid, 4-hyd- roxybutanesulfinic acid, carboxybenzenesulfinic acid, dicarboxybenzenesulfinic acid and the like.
• hydrazide compound examples include 2-hydrazinoethanesulfonic acid, 4-hydrazinobutanesulfonic acid, hydrazinobenzenesulfonic acid, hydrazinobenzenedisulfonic acid, hydrazinobenzoic acid, hydrazinoben- zenedicarboxylic acid and the like.
• Examples of the primary or secondary amine compound are N-(2-hydroxyethyl)amine, N,N-di(2-hydroxyethyl)amine, N,N-di(2-hydroxyethyl)ethylenediamine, tri-(2-hydroxyethyl)ethylenediamine, N-(2,3-dihydroxypropyl)amine, N,N-di(2,3-dihydroxypropyl)amine, 2-aminopropionic acid, aminobenzoic acid, aminopyridine, aminobenzenedicarboxylic acid, 2-hydroxyethylmorpholine, 2-carboxyethylmorpholine, 3-car- boxypiperidine and the like.
• the nudeophilic compounds are used in such a manner that each of them is contained in the foregoing oil-desensitization processing solution of the photoconductor or in the foregoing processing solution of the binder resin.
• the quantity of the nucleophilic compound in such a processing solution is generally 0.1 to 10 mol/l, preferably 0.5 to 5 mol/t.
• the processing solution has preferably a pH of at least 4.
• the processing conditions are a temperature of 15 to 60°C and a period of time of 10 seconds to 5 minutes.
• the processing solution may contain other compounds, for example, water-soluble organic solvents, individually or in combination, in a proportion of 1 to 50 parts by weight to 100 parts by weight of water, examples of which are alcohols such as methanol, ethanol, propanol, propargyl alcohol, benzyl alcohol, phenethyl alcohol, etc., ketones such as acetone, methyl ethyl ketone, acetophenone etc., ethers such as dioxane, trioxane, tetrahydrofuran, ethylene glycol, propylene glycol, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, tetrahydropyran, etc., amides such as dimethylformamide, dimethylacetamide, etc., esters such as methyl acetate, ethyl acetate, ethyl formate, etc.
• alcohols such as methanol, ethanol, propanol, propargyl alcohol, benzy
• a surfactant can be incorporated in the processing solution in a proportion of 0.1 to 20 parts by weight to 100 parts by weight of water, illustrative of which are anionic, cationic and nonionic surfactants well known in the art, for example, described in Hiroshi Horiguchi "New Surfactants (Shin-Kaimen Kasseizai)" published by Sankyo Shuppan KK, 1975, Ryohei Oda and Kazuhiro Teramura “Synthesize of Surfactants and Applications Thereof (Kaimen Kasseizai no Gosei to sono Oyo)” published by Maki Shoten, 1980.
• the ol-desensitization of the resin of the present invention is characterized in that it is rendered hydrophilic by carrying ou the hydrogen halide removing reaction as shown in the foregoing Reaction Formula (I) and then subjecting the resulting double bond to nudeophilic reaction with a nucleophilic reagent.
• the processing solution has a pH of at least 8.
• the oil-desensitization can be carried out with the processing solution containing the nucleophilic compound.
• a mixed solution of 95 g of dodecyl methacrylate, 5 g of acrylic acid and 200 g of toluene was heated to 70°C while stirring under a nitrogen stream, and 1.5 g of 2,2-azobis(isobutyronitrile) (referred to as A.I.B.N.) was added thereto and reacted for 8 hours.
• A.I.B.N. 2,2-azobis(isobutyronitrile)
• a mixture of 7,5 g (as solid content) of the above described Dispersed Resin [P-1], 50 g of a monomer [M-1] having the following structure and 200 g of methyl ethyl ketone was heated to 65°C while stirring under a nitrogen stream, and 0.7 g of 2,2-azobis(isovaleronitrile) (referred to as A. I. V. N.) was then added thereto and reacted for 6 hours.
• Preparation Example 1 was repeated except using a mixed solution of 20 g of a monomer [M-3] having the following structure, 5 g of a macromonomer [P-2] having the following structure and 150 g of methyl ethyl ketone, thus obtaining a white latex [L-3] having a mean grain diameter of 0.30 ⁇ m.
• Preparation Example 1 was repeated except using a mixed solution of 20 g of a monomer [M-4] having the following structure, 2.0 g of divinylbenzene, 6 g of a macromonomer [P-2] having the following structure and 150 g of methyl isobutyl ketone, thus obtaining a white latex [L-4] having a mean grain diameter of 0.25 ⁇ m.
• Preparation Example 1 was repeated except using a mixed solution of 20 g of a monomer [M-5] having the following structure, 2.5 g of ethylene glycol diacrylate, 5 g of acrylic acid, 6 g of a macromonomer [P-2] having the following structure and 200 g of methyl ethyl ketone, thus obtaining a white latex [L-5] having a mean grain diameter of 0.20 ⁇ m.
• Preparation Example 4 was repeated except using monomers described in the following Table 2 instead of Monomer [M-4], thus obtaining resin grains [L-6] to [L-13].
• Preparation Example 1 was repeated except using a mixed solution of 20 g of a monomer [M] of the following Table 3, predetermined amounts of monomers for bridging, 5 g of a macromonomer [P-4] having the following structure and 200 g of methyl ethyl ketone, thus obtaining latexes [L-14] to [L-20].
• a mixed solution of 95 g of benzyl methacrylate, 5 g of acrylic acid and 200 g of toluene was heated at a temperature of 90°C under a nitrogen stream, to which 6.0 g of A.I.B.N. was then added, followed by reacting for 4 hours. 2 g of A.I.B.N. was further added thereto and reacted for 2 hours to obtain a copolymer [A-1] with a molecular weight Mw of 8500.
• a mixed solution of 95 g of 2,6-dichlorophenyl methacrylate, 5 g of acrylic acid, 2 g of n-dodecylmercaptan and 200 g of toluene was heated at a temperature of 90°C under a nitrogen stream, to which 2 g of A.I.B.N. was then added, followed by reacting for 4 hours, 0.5 g of A.I.B.N. was then added thereto and reacted for 2 hours and 0.5 g of A.I.B.N. was further added and reacted for 3 hours.
• reaction mixture was subjected to reprecipitation in 2000 ml of a mixed solution of methanol/water (9/1) and the precipitate was collected by decantation and dried under reduced pressure to obtain 78 g of a waxlike copolymer with a molecular weight Mw of 6.3x10 3 .
• a mixed solution 96 g of benzyl methacrylate, 4 g of thiosalicylic acid and 200 g of toluene was heated at a temperature of 75°C under a nitrogen stream.
• 1.0 g of A. I. B. N. was added thereto and reacted for 4 hours, 0.4 g of A. 1.
• B. N. was further added and stirred for 2 hours and 0.2 g of A. I. B. N. was then added and stirred for 3 hours.
• the resulting copolymer (A-1) has the following structure and a weight average molecular weight Mw of 6.8x10 3 :
• Synthetic Example 30 was repeated except using monomers shown in the following Table 5 instead of 96 g of benzyl methacrylate, thus obtaining Resins A-31 to A-42. Each of these resins had Mw of 6.0x10 3 to 8x10 3 .
• Synthetic Example 30 was repeated except using methacrylates and mercapto compounds as shown in Table 6 instead of 96 g of benzyl methacrylate and 4 g of thiosalicylic acid and using 150 g of toluene and 50 g of isopropanol instead of 200 g of toluene, thus obtaining Resins A-43 to A-53.
• a mixed solution of 100 g of 1-naphthyl methacrylate, 150 g of toluene and 50 g of isopropanol was heated at 80°C under a nitrogen stream.
• 5.0 g of 4,4'-azobis(4-cyano)valeic acid (hereinafter referred to as A. C. V.) was then added thereto and stirred for 5 hours, 1 g of A. C. V. was further added and stirred for 2 hours and then 1 g of A. C. V. was further added and stirred for 3 hours.
• the thus resulting polymer has a weight average molecular weight Mw of 7.5x10 3 .
• a mixed solution of 50 g of methyl methacrylate and 150 g of methylene chloride was cooled-at -20°C under a nitrogen stream, to which 1.0 g of a 10% hexane solution of 1,1-diphenylhexyllithium, prepared just before it, was added, followed by stirring for 5 hours.
• Carbon dioxide was introduced thereinto at a flow rate of 10 ml/cc while stirring for 10 minutes, cooling was then stopped and the reaction mixture was stirred and allowed to stand until the temperature became room temperature.
• the reaction mixture was reprecipitated in a solution of 1000 ml of methanol in which 50 ml of 1N hydrochloric acid had been dissolved and a white powder was collected by filtering. The thus resulting white powder was washed with water and dried under reduced pressure, thus obtaining 18 g of a polymer with M of 6.5x10 3 .
• a mixed solution of 95 g of benzyl methacrylate, 4 g of thioglycolic acid and 200 g of toluene was heated at a temperature of 75°C. 1.0 g of A. C. V. was added thereto and reacted for 6 hours and then 0.4 g of A. I. B. N. was further added and reacted for 3 hours.
• the thus resulting copolymer had Mw of 7.8x10 3.
• a mixture 6 g (as solid content) of Resin [A-7], 30 g (as solid content) of Resin [B-1], 4 g (as solid content) of Resin Grains [L-1], 0.018 g of Methine Dye [I], 0,15 g of salicylic acid and 30 g of toluene was ball milled for 3 hours to prepare a light-sensitive layer-forming composition, which was then applid to a paper rendered electrically conductive to give a dry coverage of 25 g/m 2 by a wire bar coater, followed by drying at 110°C for 30 seconds. The thus coated paper was allowed to stand in a dark place at a temperature of 20°C and a relative humidity of 65% for 24 hours to prepare an electrophotographic light-sensitive material.
• Example 1 was repeated except omitting 4.0 g of Resin Grains [L-1] and using 34 g of Resin [B-1] to prepare an electrophotographic light-sensitive material for comparison.
• the light-sensitive materials of the present invention and Comparative Example A showed excellent smoothness and electrostatic characteristics of the photoconductive layer and gave a reproduced image free from background stains and excellent in image quality. This tells that the photoconductive material and binder resin are sufficiently adsorbed and coated on the grain surfaces.
• Example 1 was repeated except using 5.5 g (as solid content) of Resin [A-1], 30 g of Resin [B-2] having the following structure and 4.5 g (as solid content) of Resin Grains P-3], thus preparing an electrophotographic light-sensitive material.
• the light-sensitive material of the present invention was then subjected to measurement of the properties to obtain the following results: Water Retention; good Printing Durability; 5000 prints
• the light-sensitive material of the present invention exhibited excellent electrostatic characteristics and printing property.
• Example 1 was repeated except using 6 g (as solid content) of Resin [A-10], 30 g of Resin [B-3] having the following structure and 4 g (as solid content) of Resin Grains [1-6] and 0.02 g of methine dye [II] having the following structure, thus preparing an electrophotographic light-sensitive material.
• the resulting light-sensitive was subjected to evaluation of the electrophotographic characteristics and printing performances in an analogous manner to Example 1,thus obtaining the following results: Water Retention; good Printing Durability; 5000 prints
• the light-sensitive material of the present invention exhibited excellent electrostatic characteristics and printing property.
• Example 1 was repeated except using 6.0 g (as solid content) of each of Resins [A], 4 g (as solid content) of each of Resin Grains [L], shown in Table 8, 30 g of the following Resin [B-4] (partially crosslinked) and 0.018 g of Methine Dye [III] to prepare a light-sensitive material.
• a mixed solution of 98 g of ethyl methacrylate, 2 g of ethylene glycol dimethacrylate, 1 g of thioglycolic acid and 200 g of toluene was heated at 70°C with agitation in a nitrogen stream. Then, 1.0 g of A.I.B.N. was added thereto and reacted for 4 hours to obtain a polymer [B-4] with a weight average molecular weight Mw of 8x104.
• the light-sensitive materials exhibited very good results even under severer conditions of a temperature of 30°C and a humidity of 80% RH, i.e. gave good image quality in practice, excellent water retention as an offset master plate and such a high printing durability as to resist to 5000 prints.
• each of the light-sensitive materials exhibited good electrostatic characteristics and image quality, but that of Example 20 in which Resin [A-1] had been jointly used gave better photosensitivity and a reproduced image with a clearer image quality.
• the light-sensitive material of the present invention When using as an offset master plate, the light-sensitive material of the present invention exhibited good water retention and such a printing durability that there occurred little bad reproduction of fine lines and fine letters on a print when printing 5000 prints in the case of Example 20 and 4500 prints in the case of Example 21. This is probably due to the reproducibility of a reproduced image on an offset master plate.
• Example 20 was repeated except using 6.0 g (as solid content) of Resins [A] and 5 g (as solid content) of Resin Grains [L], shown in Table 10, thus preparing light-sensitive materials.
• Each of the light-sensitive materials of the present invention exhibited excellent electrostatic characteristics, dark decay retention and photosensitivity and gave a clear reproduced image that was free from occurrence of background stains and disappearance of fine lines even under severer conditions, e.g. high temperature and high humidity (30°C, 80% RH).
• the thus resulting plate was subjected to printing under the same printing conditions as in Example 1. 5000 prints were obtained with a good water retention as well as good image quality.
• the light-sensitive material obtained in Example I was processed by the following oil-desensitizing processing to prepare an offset printing master plate.
• the light-sensitive material of Example 1 was immersed in a processing solution [E-2] for rendering hydrophilic for 30 seconds, washed with water and passed once through an etching processor using ELP-EX diluted by 10 times with distilled water.
• E-2 processing solution
• ELP-EX etching processor
• Example 1 The light-sensitive material of Example 1 was subjected to plate making, to oit-desensitization in the same manner as described above and then to estimation of the printing durability in an analogous manner to Example 1. 5000 prints were obtained with a clear image without forming background stains.
• the light-sensitive material of the present invention has an improved hydrophilic property independently of the order of the processings.
• Example 20 was repeated except using 35.5 g of binder resins shown in Table 12 instead of 5.5 g of Resin [A-1] in Example 20 to prepare electrophotographic materials.
• Each of the light-sensitive materials of the present invention exhibited excellent electrostatic characteristics, dark decay retention and photosensitivity and gave a clear reproduced image that was free from occurrence of background stains and disappearance of fine lines even under severer conditions, e.g. high temperature and high humidity (30°C, 80% RH).
• a mixture of 6 g (as solid content) of Resin [A-33], 30 g (as solid content) of Resin [B-1 ], 4 g (as solid content) of Resin Grains [L-1], 0.018 g of Methine Dye [I], 0.15 g of salicylic acid and 30 g of toluene was ball milled for 3 hours to prepare a light-sensitive layer-forming composition, which was then applied to a paper rendered electrically conductive to give a dry coverage of 25 g/m 2 by a wire bar coater, followed by drying at 110°C for 30 seconds. The thus coated paper was allowed to stand in a dark place at a temperature of 20°C and a relative humidity of 65% for 24 hours to prepare an electrophotographic light-sensitive material.
• Example 47 was repeated except omitting 4.0 g of Resin Grains [L-1] and using 34 g of Resin [B-1] to prepare an electrophotographic light-sensitive material for comparison.
• Example 47 was repeated except using 36 g of Resin [B-1] instead of 6 g of Resin [A-1] and 30 g of Resin [B-1] to prepare an electrophotographic light-sensitive material.
• the light-sensitive materials of the present invention and Comparative Example B showed excellent smoothness and electrostatic characteristics of the photoconductive layer and gave a reproduced image free from background stains and excellent in image quality. This tells that the photoconductive material and binder resin are sufficiently adsorbed and coated on the grain surfaces.
• Comparative Example C the electrostatic characteristics were markedly deteriorated and a reproduced image with a satisfactory image quality could not be obtained.
• the water retention as an offset master plate was good by the effect of the resin grains, but the master plate after plate making could not give a satisfactory reproduced image from the start of printing.
• Example 47 was repeated except using 5.5 g (as solid content) of Resin [A-30], 30 g of Resin [B-2] having the following structure and 4.5 g (as solid content) of Resin Grains [I-3], thus preparing an electrophotographic light-sensitive material.
• the resulting light-sensitive was subjected to evaluation of the electrophotographic characteristics and printing performances in an analogous manner to Example 1 except using the following processing solution [E-2] for rendering hydrophilic instead of the processing solution [E-1] for rendering hydrophilic, respectively used in Examples 1 and 2.
• the light-sensitive material of the present invention was then subjected to measurement of the properties to obtain the following results: Water Retention; good Printing Durability; 5000 prints
• the light-sensitive material of the present invention exhibited excellent electrostatic characteristics and printing property.
• Example 47 was repeated except using 6 g (as solid content) of Resin [A-39], 30 g of Resin [B-3] having the following structure, 4 g (as solid content) of Resin Grains [1-6] and 0.02 g of a methine dye [II] having the following structure, thus preparing an electrophotographic light-sensitive material.
• the resulting light-sensitive was subjected to evaluation of the electrophotographic characteristics and printing performances in an analogous manner to Example 47, thus obtaining the following results: Water Retention; good Printing Durability; 5000 prints
• the light-sensitive material of the present invention exhibited excellent electrostatic characteristics and printing property.
• Example 47 was repeated except using 6.0 g (as solid content) of Resins [A], shown in Table 14, 4 g (as solid content) of each of Resin Grains [L], shown in Table 14, 30 g of Resin [B-4] (partially crosslinked) and 0.018 g of a Methine Dye [III] to prepare a light-sensitive material.
• the light-sensitive materials exhibited very good results even under severer conditions of a temperature of 30°C and a humidity of 80% RH, i.e. gave good image quality in practice, excellent water retention as an offset master plate and such a high printing durability as to resist to 5000 prints.
• each of the light-sensitive materials exhibited good electrostatic characteristics and image quality, but that of Example 66 in which Resin [A-30] had been jointly used gave better photosensitivity and a reproduced image with a clearer image quality.
• the light-sensitive material of the present invention When using as an offset master plate, the light-sensitive material of the present invention exhibited good water retention and such a printing durability that there occurred little bad reproduction of fine lines and fine letters on a print when printing 5000 prints in the case of Example 66 and 4500 prints in the case of Example 67. This is probably due to the reproducibility of a reproduced image on an offset master plate.
• Example 66 was repeated except using 6.0 g (as solid content) of Resins [A] and 5 g (as solid content) of Resin Grains [L], shown in Table 16, thus preparing light-sensitive materials.
• Each of the light-sensitive materials of the present invention exhibited excellent electrostatic characteristics, dark decay retention and photosensitivity and gave a clear reproduced image that was free from occurrence of background stains and disappearance of fine lines even under severer conditions, e.g. high temperature and high humidity (30°C, 80% RH).
• master plates for offset printing were prepared by carrying out the etching treatment as in the following.
• the thus resulting plate was subjected to printing under the same printing conditions as in Example 47. thus, 5000 prints were obtained with a good water retention as well as good image quality.
• the light-sensitive material obtained in Example 47 was processed by the following oil-desensitizing processing to prepare an offset printing master plate.
• the light-sensitive material of Example 47 was immersed in a processing solution [E-2] for rendering hydrophilic for 30 seconds, washed with water and passed once through an etching processor using ELP-EX diluted by 10 times with distilled water.
• E-2 processing solution
• ELP-EX etching processor
• Example 47 The light-sensitive material of Example 47 was subjected to plate making, to oil-desensitization in the same manner as described above and then to estimation of the printing durability in an analogous manner toExample 47. 5000 prints were obtained with a clear image without forming background stains.
• the light-sensitive material of the present invention has an improved hydrophilic property independently of the order of the processings.
• an electrophotographic lithographic printing plate precursor having an excellent image and high printing durability even under severer conditions. Furthermore, the lithographic printing plate of the present invention is useful for the scanning exposure system using a semiconductor laser beam.

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• Photoreceptors In Electrophotography (AREA)

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• 1991
  • 1991-05-09 EP EP19910304167 patent/EP0456486A3/en not_active Withdrawn

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