Process for making polyvinylpyrrolidone polymer having predetermined characteristics
AssigneeISP Investments Inc.
InventorsJenn S. Shih, Jui-Chang Chuang, Robert B. Login
Life of this patent
Estimating the term…
Abstract
A process for making a solution of PVP K-90 polymer having a weight average molecular weight, Mw, of about 630,000 to 750,000 and a molecular weight distribution, Mw/Mn, where Mn is the number average molecular weight of the polymer, of 5 or less, which comprises free radical polymerizing about 5-30% by weight vinylpyrrolidone, preferably 10-20%, at about 40.degree.-100.degree. C., preferably 60.degree.-75.degree. C., in an aqueous-alcohol solvent selected from the group consisting of about (a) 5% isopropanol-95% water, (b) 10% ethanol-90% water and (c) 20% methanol-80% water.
Claims6
A process for making a solution of PVP K-90 polymer having a weight average molecular weight, Mw, of about 630,000 to 750,000 and a molecular weight distribution, Mw/Mn, where Mn is the number average molecular weight of the polymer, of 5 or less, which comprises free radical polymerizing about 5-30% by weight vinylpyrrolidone at about 40.degree.-100.degree. C. in an aqueous-alcohol solvent selected from the group consisting of about (a) 5% isopropanol-95% water, (b) 10% ethanol-90% water and (c) 20% methanol-80% water, wherein said PVP polymer has a residual vinylpyrrolidone level of <0.1% therein.
Dependencies are inferred from the claim text.