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US 4,908,100 AGranted
Hydrolyzed polyacrylamide blends as starch retention aids
AssigneeCalgon Corporation
InventorsW. E. Hunter, Ronald J. Falcione
Life of this patent
Estimating the term…
Abstract
A method of improving the retention of starch in papermaking using blends of high and low molecular weight acrylic acid/acrylamide copolymers.
Claims2
A method of improving starch retention in papermaking comprising adding an effective amount of composition comprising:
- (a) a polymer having a molecular weight of from about 2,000,000 to about 8,000,000 which comprises from about 5 to about 50%, by weight, of acrylic acid or methacrylic acid and from about 50 to about 95%, by weight, of acrylamide or methacrylamide;
- and
- (b) a polymer having a molecular weight of from about 10,000,000 to about 20,000,000 which comprises from about 5 to about 50%, by weight, acrylic acid or methacrylic acid and from about 50 to about 95%, by weight, of acrylamide or methacrylamide;
- to an aqueous papermaking stock solution containing starch, wherein the weight ratio of (a):(b) ranges from about 95:5 to about 5:95, on an active basis.
1 more element
A composition comprising:
- (a) an aqueous papermaking stock solution;
- (b) starch;
- and
- (c) a composition comprising:
- (i) a polymer having a molecular weight of from about 2,000,000 to about 8,000,000 which comprises from about 5 to about 50%, by weight, of acrylic acid or methacrylic acid and from about 50 to about 95%, by weight, of acrylamide or methacrylamide;
- and
- (ii) a polymer having a molecular weight of from about 10,000,000 to about 20,000,000 which comprises from about 5 to about 50%, by weight, acrylic acid or methacrylic acid and from about 50 to about 95%, by weight, of acrylamide or methacrylamide;
- wherein the weight ratio of (i):(ii) ranges from about 95:5 to about 5:95, on an active basis and wherein an effective amount of (c) for the purpose of improving starch retention is present.
5 more elements
Dependencies are inferred from the claim text.