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US 4,062,789 AGranted
Liquid developer for electrophotography
AssigneeFuji Photo Film Co., Ltd.
InventorsTasuo Tamai, Sadao Osawa, Hajime Miyatuka, Masaya Yamamoto
Life of this patent
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Abstract
A liquid developer for electrophotography is disclosed which comprises toner particles, a regulating agent composed of a copolymer of a half-alkylamide of maleic acid and .alpha.-diisobutylene and an electric insulating carrier liquid and, if desired, an organic acid.
Claims17
A liquid developer for use in electrophotographic processes consisting essentially of:
- 1. a carrier liquid having a specific resistance of more than about 10.sup.11 .OMEGA. cm selected from the group consisting of cyclohexane, decalin, kerosene, isoparaffinic hydrocarbon solvents, light oil, gasoline, chlorofluorinated hydrocarbon solvents and silicon oil,
- 2. from about 0.0003 to about 0.5 parts by weight per 1000 parts by weight of said carrier liquid of a copolymer of a half alkylamide of maleic acid and diisobutylene, the molar ratio of said half alkylamide of maleic acid to said diisobutylene in said copolymer being in the range of from about 1:1 to about 1:5 and said copolymer having from about 4 to about 50 monomer units in the copolymer chain, and
- 3. from about 0.05 to about 50 parts by f weight per 1000 parts by weight of said carrier liquid of positively charged toner particles having an average particle size of less than about 5 microns.
A liquid developer for use in electrophotographic processes consisting essentially of:
- 1. a carrier liquid having a specific resistance of more than about 10.sup.11 .OMEGA.cm selected from the group consisting of cyclohexane, decalin, kerosene, isoparaffinic hydrocarbon solvents, light oil, gasoline, chlorofluorinated hydrocarbon solvents and silicon oil.
- 2. positively charged toner pigment particles insoluble in said carrier liquid at a level of from about 0.5 to about 50 parts by weight per 1000 parts by weight of said carrier liquid,
- 3. a resin soluble in said carrier liquid, said resin being present in said carrier liquid in an amount of from about 0.5 to about 100 parts by weight per 1000 parts by weight of said carrier liquid, and
- 4. a copolymer of half-alkylamide of maleic acid and diisobutylene at a level of from about 0.0003 to about 0.5 parts by weight per 1000 parts by weight of said carrier liquid, the molar ratio of said half alkylamide of maleic acid to said diisobutylene in said copolymer being in the range of from about 1:1 to about 1:5 and said copolymer having from about 4 to about 50 monomer units in the copolymer chain.
1 more element
A liquid developer for use in electrophotographic processes consisting essentially of:
- 1. a carrier liquid having a specific resistance of more than about 10.sup.11 .OMEGA.cm selected from the group consisting of cyclohexane, decalin, kerosene, isoparaffinic hydrocarbon solvents, light oil, gasoline, chlorofluorinated hydrocarbon solvents and silicon oil,
- 2. from about 0.5 to about 50 parts by weight per 1000 parts by weight of said carrier liquid of positively charged toner particles having an average particle size of less than about 5 microns, said toner particles comprising particles of a reaction product produced by the graft polymerization to carbon black of an alkyl ester of acrylic or methacrylic acid, and
- 3. from about 0.0003 to about 0.5 parts by weight per 1000 parts by weight of said carrier liquid of a copolymer of a half alkylamide of maleic acid and diisobutylene, the molar ratio of said half alkylamide of maleic acid to said diisobutylene in said copolymer being in the range of from about 1:1 to about 1:5 and said copolymer having from about 4 to about 50 monomer units in the copolymer chain.
Dependencies are inferred from the claim text.