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:
Oct. 24, 2000
Filed:
Dec. 04, 1997
Nippon Zeon Co., Ltd., Tokyo, JP;
Abstract
A monomer for a shell or a mixture of at least two monomers for a shell was suspension polymerized in the presence of core particles and a polymerization initiator to obtain polymer particles, wherein said core particles are formed of a polymer obtained by polymerization of a monomer for a core or a mixture of at least two monomers for a core and containing a colorant, wherein said monomer for a shell or mixture of monomers for a shell is one which gives upon polymerization a polymer having a glass transition temperature higher than that of the polymer forming the core particle, and wherein said polymerization initiator is represented by the following formula 1: ##STR1## wherein X.sup.1, X.sup.2, X.sup.3 and X.sup.4 independently represent oxygen atom, sulfur atom, >NR (wherein R is hydrogen atom, alkyl group, or group); R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.6 independently represent alkyl group, aryl group, or alkyl or aryl group having at least one substituent which is --OR, --OH, --NHR, or --NR.sub.2 (wherein R is alkyl group or aryl group), and n and m independently represent an integer of 1 to 10. An outer additive was applied on the polymer particle to obtain a polymerized toner. This polymerized toner has low fixing temperature, excellent overhead projector transparency, good shelf stability, and exhibiting a less pronounced reduction in electric charge under conditions of high humidity and high temperature.