Betzdearborn, Inc.

W. R. Grace Co.-conn.

Roger Yiming Leung

Lawrence L Kuo

Kenneth S Williams

Thord G Hassler

Steven R Prescott

Production of paper and paperboard

A method of flocculating coagulated and/or finely divided suspended matter in aqueous systems comprising adding to the system from 0.005 to 1 weight percent based on the dry weight of the coagulated and/or finely suspended matter of at least one water soluble cationic polymer selected from a water soluble cationic copolymer (I) composed of the polymerization reaction of an N-vinylamide with at least one cationic quaternary amine monomer.

Water-soluble cationic copolymers and their use as flocculants

A water-soluble cationic copolymer comprising a reaction product of N-vinylamide having the general formula: ##STR1## and a cationic quaternary amine having the formula: ##STR2## wherein Y is C(.dbd.O)O(CH.sub.2).sub.n N.sup..sym. R.sup.4 R.sup.5 R.sup.6 X.sup..crclbar., or ##STR3## X.sup..crclbar.,n is 1 to 5; R.sup.1, R.sup.2, R.sup.3 are independently H or C.sub.1 to C.sub.3 alkyl, R.sup.4, R.sup.5, and R.sup.6 are independently C.sub.1 to C.sub.3 alkyl, X is a halide, hydroxyl or alkylsulfate anion. The copolymers of this invention are useful as flocculating agents, and are particularly useful as drainage/retention aids in pulp and papermaking operations.

Water-soluble cationic copolymers and their use as flocculants and

A water-soluble cationic copolymer having the general formula: ##STR1## wherein Z represents --C(.dbd.O)O(CH.sub.2).sub.n N.sup..sym. R.sup.4 R.sup.5 R.sup.6 X.sup..crclbar., --C(.dbd.O)NH(CH.sub.2).sub.n N.sup..sym. R.sup.4 R.sup.5 R.sup.6 X.sup..crclbar., ##STR2## or residual groups of --CH.sub.2 N.sup..sym. (R.sup.4 R.sup.5)CH.sub.2 CH.dbd.CH.sub.2 X.sup..crclbar. or mixtures thereof, and n is 1 to 5; R.sup.1, R.sup.2 and R.sup.3 are independently selected from the group consisting of H or C.sub.1 to C.sub.3 alkyl; R.sup.4, R.sup.5 and R.sup.6 are independently C.sub.1 to C.sub.3 alkyl; and X is a halide, hydroxyl or alkylsulfate anion; and wherein x, y, and q represent molar percents of monomeric units in the copolymer such that q is 1 to 99 mol %, and the molar ratio of x to y is from 0 to 10. The copolymers of this invention are useful as flocculating agents and as drainage/retention aids in pulp and papermaking operations.

A method of preparing a high molecular weight water-soluble cationic copolymer by reacting in an aqueous solution at least one N-vinylamide and at least one cationic quaternary amine monomer in the presence of a free radical initiator and a salt of ethylenediamine tetraacetic acid and subjecting the formed polymer to an acid or base to form an N-vinylamide/N-vinylamine/cationic quaternary amine copolymer product.

Method of producing water-soluble cationic copolymers

A method of preparing paper or paper board product from an aqueous pulp suspension comprising adding to the suspension an effective amount of a drainage retention aid composition of a) microparticles and b) at least one water soluble cationic polymer selected from a water soluble cationic copolymer composed of the polymerization reaction of an N-vinylamide with at least one cationic quaternary amine monomer. The copolymers of this invention are useful as useful as drainage/retention aids in pulp and papermaking operations.

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Ellicott City, MD, United States of America

Roger Yiming Leung