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, 2000
Filed:
Dec. 07, 1999
Tetsuhiro Semura, Wakayama, JP;
Yoshihiro Ueno, Wakayama, JP;
Kao Corporation, Tokyo, JP;
Abstract
A toner for electrophotography comprising a resin binder comprising a polyester resin, as a main component, obtained by polycondensing an alcohol component with a carboxylic acid component, wherein the alcohol component comprises an alkylene oxide adduct of bisphenol A represented by the formula (I): ##STR1## wherein R is an alkylene group having 2 or 3 carbon atoms; x and y are positive numbers showing an average molar number of an added oxyalkylene group, wherein a sum of x and y is from 1.5 to 10, in an amount of 60% by mol or more of the alcohol component, and wherein the carboxylic acid component comprises a tricarboxylic acid compound, wherein a number-average molecular weight of the polyester resin is 1,000 to 8,000; and a coloring agent, wherein an alkylene oxide adduct of bisphenol A of which addition molar number is 3 or more is not present in the polyester resin, or remains in an amount of less than 1.0% by weight.