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:
Feb. 27, 1990
Filed:
Jun. 28, 1988
Jiro Yamashiro, Kobe, JP;
Takashi Miki, Tatsuno, JP;
Bando Chemical Industries, Ltd., Kobe, JP;
Abstract
A process for producing toners for use in electrophotography which comprises: stirring a mixture of a radical polymerizable liquid monomer and carbon black in the presence of a peroxide polymerization initiator, thereby to disperse the carbon black uniformly and minutely in the monomer; adding an azobisnitrile polymerization initiator to the resultant monomer composition; suspension polymerizing the monomer in an aqueous medium; and recovering and drying the resultant spherical polymer particles. In a preferred process, the suspension polymerization is carried out in an aqueous medium which contains polyvinyl alcohol as a suspending agent, and after the polymerization, the polyvinyl alcohol remaining on the polymer particles is saponified or nitrated to produce a toner with a higher quality.