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:
Jun. 20, 1989
Filed:
Apr. 15, 1987
Akira Otsu, Tokyo, JP;
Hiroshi Nagase, Tokyo, JP;
Fujikura Kasei Co., Ltd., Tokyo, JP;
Abstract
A positively chargeable toner for use in dry electrophotography, said toner comprising (A) a resinous binder composed of at least one resin selected from copolymers of styrene and/or alpha-methylstyrene with alkyl (meth)acrylates, polyester resins and epoxy resins, (B) 1 to 100 parts by weight, per 100 parts by weight of the resinous binder, of a copolymer containing a quaternary ammonium salt group, said copolymer having a weight average molecular weight of from 2,000 to 10,000 and composed of 65 to 97% by weight of recurring units represented by the formula ##STR1## wherein R.sub.1 represents a hydrogen atom or a methyl group, and 35 to 3% by weight of recurring units represented by the formula ##STR2## wherein R.sub.2 represents a hydrogen atom or a methyl group, R.sub.3 represents an alkylene group, and each of R.sub.4, R.sub.5 and R.sub.6 represents an alkyl group, and (C) a coloring agent.