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. 15, 1991
Filed:
Aug. 04, 1989
William Alexander, Naperville, IL (US);
Mark Anderson, Wheaton, IL (US);
Barbara R Regan, Glenview, IL (US);
American Colloid Company, Arlington Heights, IL (US);
Abstract
A method of preparing a solid water absorbing resin including mixing a monomer solution of (A) acrylic acid neutralized 70-100 mole percent; and (B) a water-miscible to water-soluble polyvinyl monomer in a combined concentration of at least 30 wt. %; with water to form a mixed monomer solution, and adding a thermal initiator and a redox initiator to the mixed monomer solution to form an initiated mixed monomer solution, and wherein the mixed monomer solution is at a temperature below the decomposition temperature of the thermal initiator when the thermal initiator is added to the mixed monomer solution and wherein the temperature of the mixed monomer solution is high enough such that addition of the redox initiator thereto causes sufficient polymerization of the monomers to raise the temperature of the initiated mixed monomer solution to a level sufficient that the thermal initiator decomposes sufficiently to provide, together with the redox initiator, substantially complete polymerization.