Patent ID: 9321863
Filing Date: 2016-04-26
CPC Classification: C08F,C08G,C08L,C09D,H01B,H01G

Claim Text:
1. A polyvinyl sulfonic acid comprising a vinyl sulfonic acid unit represented by the following general formula (1): wherein R 1 , R 2 and R 3 each independently represent hydrogen, or an alkyl group or alkylene group, which has 1 to 15 carbon atoms; and Z represents hydrogen, halogen, an alkyl group or alkylene group, which has 1 to 15 carbon atoms, a metal ion, an ammonium ion, a protonated primary, secondary or tertiary amine, or a quaternary ammonium ion, wherein the polyvinyl sulfonic acid has an absorbance of 0.1 or greater (aqueous solution: 0.2 mass %, cell length: 10 mm) in a wavelength range of 255 to 800 nm wherein the polyvinyl sulfonic acid is prepared by the steps of: (a) polymerizing a vinyl sulfonic acid monomer represented by the following general formula (1)′: wherein R to obtain a polyvinyl sulfonic acid; and