The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 23, 1985
Filed:
Nov. 12, 1981
Toshiaki Narusawa, Sagamihara, JP;
Seiji Okada, Kawasaki, JP;
Kiyohide Muramatsu, Tokyo, JP;
Teruo Yagishita, Kawasaki, JP;
Hirofumi Okuyama, Sagamihara, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A developer material for electrostatic images comprising a mixture of (1) a coated carrier and (2) a toner. (1) The carrier consists of core beads coated with a coating resin comprising a butadiene homopolymer of a molecular weight of from 10,000 to 100,000, for the butadiene homopolymer is 1,2-polybutadiene and/or cyclized cis-1,4-polybutadiene or a mixture of at least one of these homopolymers and a styrene/butadiene copolymer of a molecular weight of from 10,000 to 100,000, the mixture containing from 7.5 to 100% by weight, based on the weight of the mixture, of butadiene in polymerized form. (2) The toner comprises, based on the weight of the toner, (A) from 85 to 95% by weight of a binder resin comprising, based on the weight of the binder resin, from 50 to 100% by weight of an epoxy resin of a molecular weight of from 900 to 8,000 and from 0 to 50% by weight of a styrene/alkyl methacrylate copolymer, the alkyl group having from 1 to 4 carbon atoms, of a molecular weight of from 10,000 to 100,000; (B) a colorant comprising, based on the weight of the toner, from 0 to 10% by weight of fine carbon and from 0.5 to 8% by weight of a nigrosine dye, and; (C) from 0 to 8% by weight of a charge controlling agent, based on the weight of the toner, comprising a quaternary ammonium alkyl sulfonate, the alkyl group having from 4 to 20 carbon atoms, or di-(polyhydroxyethoxy ethyl) octadecyl amine, or a polyamine. The ratio of the total surface area of the coated carrier to the total projection area of the toner particles is in the range of from 1:0.5 to 1:2.0.