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:
Jan. 07, 2003
Filed:
Aug. 29, 2001
Allan K. Chen, Oakville, CA;
George Liebermann, Mississauga, CA;
Tie Hwee Ng, Mississauga, CA;
Arthur Helbrecht, Oakville, CA;
Emily L. Moore, Mississauga, CA;
Abdisamed Sheik-qasim, Etobicoke, CA;
Patricia A. Burns, Milton, CA;
Nam S. Ro, Mississauga, CA;
Xerox Corporation, Stamford, CT (US);
Abstract
A process for the preparation of a latex polymer consistent with E/A (emulsion/aggregation/coalescence) toner manufacture. The process utilizes a standard (universal) latex composition and involves chain-transfer agent partitioning, emulsion polymerization that provides a latex polymer with a wide range of molecular properties. In particular, the process customizes a wide range M (weight average molecular weight) latex, without substantially varying the M (number average molecular weight) and hence, without substantially varying Tg (glass transition temperature) such that good toner performance is maintained. In a preferred process, a latex polymer is prepared by mixing a seed particle latex, generated by aqueous emulsion polymerization of a first portion of a monomer emulsion, with a second portion of the monomer emulsion and at least one chain-transfer agent. The mixing is done in the presence of a free-radical initiator and heated, and wherein the monomer emulsion comprises a mixture of polymerization reagents of at least one monomer, at least one chain-transfer agent, at least one surfactant, and water. This process may be applied to core-shell polymerization as well. These latex polymers are ideally suited in the manufacture of toner and developer for electrophotographic imaging and printing.