ALEXANDRIA, Va., Dec. 31 -- United States Patent no. 12,509,535, issued on Dec. 30, was assigned to DENKA COMPANY Ltd. (Tokyo).
"Polyvinyl alcohol-based polymer" was invented by Akihiro Yamashita (Tokyo).
According to the abstract* released by the U.S. Patent & Trademark Office: "A PVA excellent in resistance to melting at high temperature is provided. The polyvinyl alcohol-based polymer is a saponificated product of a homopolymer composed of a vinyl ester monomer, a copolymer of a vinyl ester monomer and a monofunctional monomer other than the vinyl ester, a copolymer of a vinyl ester monomer and a polyfunctional monomer, or a copolymer of a vinyl ester monomer, a monofunctional monomer other than vinyl ester, and a polyfunctional monome...