Azetidinium polymers for improving wet strength of paper
AssigneeHercules Incorporated
InventorAnthony J. Allen
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Abstract
The use of polymers and copolymers of N,N-diallyl-3-hydroxyazetidinium salts as agents for improving the wet strength of paper wherein the polymers have a reduced level of organohalide by-products. Also encompassed are paper furnishes and paper containing the polymers and copolymers.
Claims70
A process for making paper with increased wet strength comprising:
- (a) providing an aqueous pulp slurry;
- (b) forming the aqueous pulp slurry into a sheet;
- and
- (c) drying the sheet;
- wherein there is added to the aqueous pulp slurry or to the sheet at a size press, or both, an aqueous solution of a polymer or copolymer of N,N-diallyl-3-hydroxy azetidinium halide wherein at least 15 mole percent of the monomer units present in the copolymer are derived from N,N-diallyl-3-hydroxy azetidinium halide;
- wherein said polymer or copolymer is added at a level of at least about 0.1% on a dry basis based on the dry weight of the pulp;
- and
- wherein said aqueous polymer or copolymer solution contains organic halide by-products comprised of 1,3-dihalo-2-propanol, 2,3-dihalo-1-propanol and 3-halo-1,2-propanediol at a level of less than about 10,000 ppm based on the dry weight of polymer.
A process for making paper with increased wet strength comprising:
- (a) providing an aqueous pulp slurry;
- (b) forming the aqueous pulp slurry into a sheet;
- and
- (c) drying the sheet;
- wherein there is added to the aqueous pulp slurry or to the sheet at a size press, or both, an aqueous solution of a polymer prepared by polymerizing monomer consisting essentially of N,N-diallyl-3-hydroxy azetidinium halide;
- and
- wherein said polymer is added at a level of at least about 0.1% on a dry basis based on the dry Weight of the pulp.
A process for making paper with increased wet strength comprising:
- (a) providing an aqueous pulp slurry;
- (b) forming the aqueous pulp slurry into a sheet;
- and
- (c) drying the sheet;
- wherein there is added to the aqueous pulp slurry or to the sheet at a size press, or both, an aqueous solution of a copolymer of N,N-diallyl-3-hydroxy azetidinium halide and at least one unsaturated comonomer, wherein at least 15 mole percent of the monomer units present in the copolymer are derived from N,N-diallyl-3-hydroxy azetidinium halide;
- and
- wherein said copolymer is added at a level of at least about 0.1% on a dry basis based on the dry weight of the pulp.
A paper making furnish comprising an aqueous pulp slurry and a N,N-diallyl-3-hydroxy azetidinium halide polymer wherein said paper making furnish contains organic halide by-products comprised of 1,3-dihalo-2-propanol, 2,3-dihalo-1-propanol and 3-halo-1,2-propanediol at a level of less than about 10,000 ppm based on the dry weight of polymer.
Dependencies are inferred from the claim text.