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:
Dec. 05, 1989
Filed:
Aug. 24, 1987
Hiroshi Yamashita, Shizuoka, JP;
Kenkichi Muto, Kanagawa, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
A method of producing polymer particles having a particle size distribution of .+-.25% with respect to each average particle size in an amount of 95 wt. % or more, within the average particle sizes ranging from 1 .mu.m to 100 .mu.m, is disclosed, which comprises the steps of: (1) adding a polymer dispersion stabilizer in an amount of 0.1 to 10 wt. % to a hydrophilic organic liquid in which the polymeric dispersion stabilizer is soluble; (2) adding thereto at least one vinyl monomer in an amount of not more than 50 times by weight the amount of the polymeric dispersion stabilizer, which monomer is soluble in the hydrophilic organic liquid, but a polymer synthesized from the monomer being swelled or substantially insoluble in the hydrophilic organic liquid; and (3) polymerizing the monomer under the condition that the amount of the vinyl monomer is 200 wt. % or less of the hydrophilic organic liquid.