Fuji Photo Film Company, Limited

Hideyuki Hattori

Eiichi Kato

Kazuo Ishii

Takao Nakayama

Hiroshi Tashiro

Shigeyuki Dan

Ryosuke Itakura

Ryousuke Itakura

Process for producing lithographic printing plate

Disclosed is a process for producing a lithographic printing plate using a lithographic printing plate precursor comprising a support having a volume resistivity of more than 1.times.10.sup.10 .OMEGA..cm, an electrically conductive layer provided on one surface of the support and having a volume resistivity of 1.times.10.sup.5 .OMEGA..cm or less and a photoconductive layer provided on the electrically conductive layer and containing zinc oxide and a binder, the process comprising applying negative corona discharge to the lithographic printing plate precursor from the photoconductive layer side and at this discharging, contacting an electric conductor having an earth potential at least with the support of the lithographic printing plate precursor to electrically charging the photoconductive layer of the lithographic printing plate precursor.

Production process of lithographic printing plate

A liquid developer for electrostatic photography which comprises a non-aqueous solvent having an electric resistance of at least 10.sup.9 .OMEGA..multidot.cm and a dielectric constant of not higher than 3.5, at least toner grains comprising a resin as a main component, and (a) at least one compound (A) having an effect for increasing the amount of charge and (b) at least one compound (B) having an effect for reducing the amount of charge. There is also disclosed a duplicating method using a liquid developer as described above, which is useful for developing a large number of electrophotographic materials over a long period of time.

Liquid developer for electrostatic photography and duplicating method

A liquid developer for electrostatic photography is disclosed. The liquid developer comprises at least resin grains dispersed in a non-aqueous solvent having an electric resistance of at least 10.sup.9 cm and a dielectric constant of not higher than 3.5, wherein the dispersed resin grains are copolymer resin grains obtained by polymerizing a solution containing (1) at least a mono-functional monomer (A) which is soluble in the above-described non-aqueous solvent but becomes insoluble therein by being polymerized, and, optionally, a monomer (C) represented by the formula (III) or a monomer (D) represented by the formula (IV), in the presence of a dispersion-stabilizing resin soluble in the non-aqueous solvent, which is a graft type copolymer. The liquid developer of the present invention is excellent in re-dispersibility, storability, stability, image-reproducibility, and fixability, and provide a master plate for offset printing having high printing durability.

Liquid developer for electrostatic photography

A liquid developer for electrostatic photography is disclosed. The liquid developer comprises at least resin grains dispersed in a non-aqueous solvent having an electric resistance of at least 10.sup.9 cm and a dielectric constant of not higher than 3.5, wherein the dispersed resin grains are copolymer resin grains obtained by polymerizing a solution containing (1) at least a mono-functional monomer (A) which is soluble in the above-described non-aqueous solvent but becomes insoluble therein by being polymerized, and, optionally, a monomer (B-1) represented by the formula (III) or a monomer (B-2) represented by the formula (IV), in the presence of a dispersion-stabilizing resin soluble in the non-aqueous solvent, which is an AB type block copolymer. The liquid developer of the present invention is excellent in re-dispersibility, storability, stability, image-reproducibility, and fixability, and provide a master plate for offset printing having high printing durability.

A liquid developer for electrostatic photography is disclosed. The liquid developer comprises at least resin grains dispersed in a non-aqueous solvent having an electric resistance of at least 10.sup.9 .OMEGA.cm and a dielectric constant of not higher than 3.5, wherein the dispersed resin grains are polymer resin grains obtained by polymerizing a solution containing (1) at least a mono-functional monomer (A) which is soluble in the aforesaid non-aqueous solvent but becomes insoluble therein by being polymerized in the presence of a dispersion-stabilizing resin (BA) soluble in the non-aqueous solvent, which is a polymer containing a recurring unit represented by the formula (I) described in the specification, at least a part of the main chain of the polymer being crosslinked, and, optionally, (2) a monomer (B-1) represented by the formula (II-1) described in the specification. The liquid developer of this invention is excellent in re-dispersibility, storability, stability, image-reproducibility, and fixability.

A liquid developer for electrostatic photography is disclosed. The liquid developer comprises resin grains dispersed in a non-aqueous solvent having an electric resistance of at least 10.sup.9 .OMEGA. cm and a dielectric constant of not higher than 3.5, wherein the dispersed resin grains are polymer resin grains obtained by polymerizing a solution containing at least one kind of a mono-functional monomer (A) which is soluble in the non-aqueous solvent but becomes insoluble in the non-aqueous solvent by being polymerized, in the presence of a dispersion-stabilizing resin which is soluble in the non-aqueous solvent and is a comb-like copolymer comprising (1) at least a mono-functional macromonomer (M) having a weight average molecular weight of from 1.times.10.sup.3 to 2.times.10.sup.4 and (2) at least a monomer represented by formula (III) as defined in the specification. The liquid developer according to the present invention is excellent in re-dispersibility, storability, stability, image-reproducibility, and fixability.

A liquid developer for electrostatic photography is disclosed. The liquid developer comprises resin grains dispersed in a non-aqueous solvent having an electric resistance of at least 10.sup.9 .OMEGA. cm and a dielectric constant of not higher than 3.5, wherein the dispersed resin grains asre copolymer resin grains obtained by polymerizing a solution containing at least one kind of a mono-functional monomer (A) which is soluble in the non-aqueous solvent but becomes insoluble in the non-aqueous solvent by being polymerized, in the presence of a dispersion-stabilizing resin which is soluble in the non-aqueous solvent and is a comb-like copolymer comprising at least (1) a mono-functional macromonomer (M) having a weight average molecular weight of from 1.times.10.sup.3 to 2.times.10.sup.4 and (2) a monomer represented by the general formula (III) described below, the mono-functional macromonomer (M) comprising at least one polymer component corresponding to a repeating unit represented by the general formula (IIa) or (IIb) described below and at least one polymer component containing at least one polar group selected from --COOH, --PO.sub.3 H.sub.2, --SO.sub.3 H, --OH, ##STR1## wherein R.sub.1 represents --R.sub.2 or -OR.sub.2 (wherein R.sub.2 represents a hydrocarbon group)), --SH, a formyl group and an amino group, and the monofunctional macromonomer (M) having a polymerizable double bond group represented by the general formula (I) described below bonded to only one terminal of the main chain thereof; ##STR2## wherein X.sub.0 represents --COO--, --OCO--, --CH.sub.2 OCO--, --CH.sub.2 COO--, or --O--, --SO.sub.2 --, --CO--, ##STR3## wherein R.sub.11 represents a hydrogen atom or a hydrocarbon group), and a.sub.1 and a.sub.2, which may be the same or different, each represents a hydrogen atom, a halogen atom, a cyano group, a hydrocarbon group, --COO--Z.sub.1 or --COO--Z.sub.1 bonded via a hydrocarbon group (wherein Z.sub.1 represents a hydrogen atom or a hydrocarbon group); ##STR4## wherein X.sub.1 has the same meaning as X.sub.0 in the general formula (I); Q.sub.1 represents an aliphatic group having from 1 to 22 carbon atoms or an aromatic group having from 6 to 12 carbon atoms; b.sub.1 and b.sub.2, which may be the same or different, have the same meaning as a.sub.1 and a.sub.2 in the general formula (I); and V represents --CN, --CONH.sub.2, or ##STR5## (wherein Y represents a hydrogen atom, a halogen atom, an alkoxy group or --COOZ.sub.2 (wherein Z.sub.2 represents an alkyl group, an aralkyl group, or an aryl group)); ##STR6## wherein X.sub.2 has the same meaning as X.sub.0 in the general formula (I); Q.sub.2 has the same meaning as Q.sub.1 in the general formula (IIa); and d.sub.1 and d.sub.2, which may be the same or different, have the same meaning as a.sub.1 and a.sub.2 in the general formula (I), with the proviso that, in the component of the mono-functional macromonomer (M) represented by the general formula (II) and in the component of the monomer represented by the general formula (III), at least one of Q.sub.1 and Q.sub.2 represents an aliphatic group having from 10 to 22 carbon atoms.

A liquid developer for electrostatic photography is disclosed. The liquid developer of this invention comprises resin grains dispersed in a non-aqueous solvent having an electric resistance of at least 10.sup.9 .OMEGA.cm and a dielectric constant of not higher than 3.5, wherein the dispersed resin grains are copolymer resin grains obtained by polymerizing a solution containing at least one mono-functional monomer (A) which is soluble in the above non-aqueous solvent but becomes insoluble in the non-aqueous solvent by being polymerized, in the presence a dispersion-stabilizing resin, which is soluble in the non-aqueous solvent and is composed of at least one recurring unit represented by the formulae (Ia) and (Ib) having a weight average molecular weight of from 1.times.10.sup.3 to 2.times.10.sup.4 as defined in the specification. The liquid developer according to the present invention is excellent in redispersibility, storability, stability, image-reproducibility and fixability.

A liquid developer for electrostatic photography comprising resin grains dispersed in a non-aqueous solvent having an electric resistance of at least 10.sup.9 cm and a dielectric constant of not higher than 3.5 is disclosed. The dispersed resin grains contained therein are grains of a copolymer obtained by polymerizing a solution containing at least one monofunctional monomer (A) which is soluble in the aforesaid non-aqueous solvent but becomes insoluble after being polymerized and at least one monfunctional macromonomer (M) having a number average molecular weight of not more than 1.times.10.sup.4 and having a polymerizable double bond group represented by formula (M-II) bonded to only one terminal of a polymer main chain composed of a recurring unit represented by formula (M-I) in the presence of a dispersion stabilizing resin which is a polymer having at least a recurring unit represented by formula (I), a part of which has been crosslinked, and has a polymerizable double bond group copolymerizable with the monofunctional monomer (A) bonded to only one terminal of at least one polymer main chain thereof, the dispersion stabilizing resin being soluble in the non-aqueous solvent. The liquid developer is excellent in redispersibility, storability, stability, image-reproducibility and fixability.

A liquid developer for electrostatic photography is disclosed. The liquid developer comprises resin grains dispersed in a non-aqueous solvent having an electric resistance of at least 10.sup.9 .OMEGA.cm and a dielectric constant of not higher than 3.5, wherein the dispersed resin grains are copolymer resin grains obtained by polymerizing a solution containing at least one kind of a monofunctional monomer (A), which is soluble in the above non-aqueous solvent but becomes insoluble therein by being polymerized, in the presence of a dispersion-stabilizing resin soluble in the non-aqueous solvent and an oligomer (B) having a number average molecular weight of not more than 1.times.10.sup.4. The dispersion-stabilizing resin is a polymer containing at least a recurring unit represented by the formula (I) described in the specification, a part of which has been crosslinked, and has a double bond group which is copolymerizable with the monofunctional monomer (A) and which is bonded to only one terminal of at least one polymer main chain, and the oligomer (B) is a polymer comprising a recurring unit represented by the formula (II) described in the specification and has at least one kind of a polar group. The light developer according to the present invention is excellent in re-dispersibility, storability, stability image-reproducibility, and fixability.

A liquid developer for electrostatic photography comprising a resin dispersed in a non-aqueous solvent having an electric resistance of at least 10.sup.9 .OMEGA.cm and a dielectric constant of not higher than 3.5, wherein the dispersed resin is a polymer resin obtained by polymerizing a solution containing at least one monofunctional monomer (A) which is soluble in the aforesaid non-aqueous solvent but become insoluble after being polymerized, in the presence of a dispersion-stabilizing resin which is soluble in the aforesaid non-aqueous solvent and at least one oligomer (B) having a number average molecular weight of not more than 1.times.10.sup.4 and having at least one polar group selected from a carboxy group, a sulfo group, a hydroxy group, a formyl group, an amino group, a phosphono group, and ##STR1## wherein R.sup.0 represents a hydrocarbon group or --OR.sup.1, (wherein R.sup.1 represents a hydrocarbon group) bonded to only one terminal of the main chain of a polymer composed of a recurring unit represented by following formula (II): ##STR2## wherein V.sup.1, R.sup.2, a.sup.1 and a.sup.2 are as defined in the specification. The liquid developer is excellent in dispersion stability, re-dispersibility, and fixability, and also is capable of forming an offset printing plate having excellent ink-receptivitiy for printing ink and excellent printing durability by electrophotography.

A liquid developer for electrostatic photography comprising a resin dispersed in a non-aqueous solvent having an electric resistance of at least 10.sup.9 .OMEGA.cm and a dielectric constant of not higher than 3.5, wherein the dispersed resin is a polymer resin obtained by polymerizing a solution containing at least one mono-functional monomer (A) which is soluble in the aforesaid non-aqueous solvent but becomes insoluble after being polymerized, in the presence of at least one resin which is soluble in the aforesaid non-aqueous solvent and does not have a graft group polumerizable with the monomer and at least one oligomer (B) having a number average molecular weight of not more than 1.times.10.sup.4 and having at least one polar group selected from a carboxy group, a sulfo group, a hydroxy group, a formyl group, an amino group, a phosphono group, and ##STR1## wherein R.sup.0 represents a hydrocarbon group or --OR.sup.1, (wherein R.sup.1 represents a hydrocarbon group) bonded to one terminal only of the main chain of a polymer composed of a recurring unit represented by following formula (I): ##STR2## wherein V.sup.1, R.sup.2, a.sup.1 and a.sup.2 are as defined in the specification. The liquid developer is excellent in dispersion stability, re-dispersibilty, and fixability, and also is capable of forming an offset printing plate having excellent ink-receptivity for printing ink and excellent printing durability by electrophotography.

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Shizuoka, Japan

Hideyuki Hattori