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:
Nov. 16, 2004
Filed:
May. 23, 2003
Toagosei Co., Ltd., Tokyo, JP;
Abstract
A process in which an aqueous solution of a vinyl monomer is subjected to photopolymerization to produce a water-soluble polymer which has a high molecular weight, is highly soluble in water, and reduced in unreacted monomer content is provided. The process comprises subjecting an aqueous solution of a vinyl monomer to photopolymerization with the aid of an azo compound having a 10-hour half-life decomposition temperature of 90° C. or lower as a photopolymerization initiator in such a manner that first-stage light irradiation is conducted at an irradiation intensity of 0.5 to 7 W/m and second-stage or subsequent light irradiation is conducted at an irradiation intensity higher than that in the first stage and in an integrated quantity of light of 70,000 J/m or larger.