Reactive cationic resins for use as dry and wet strength agents in sulfite ion-containing papermaking systems
AssigneeHercules Incorporated
InventorsShane Cyr, Henk Bakker, Willem Stevels, Ronald Staib
Life of this patent
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Abstract
This invention relates to resins useful for imparting strength to paper, the process of incorporating these resins into paper and the paper produced containing the resins. In particular the invention relates to resins useful for imparting dry-strength and wet-strength to paper under conditions of high sulfite ion concentrations.
Claims21
A reactive cationic resin comprising a dialdehyde reactive copolymer produced from a comonomer which is dialdehyde reactive, a cationic comonomer and a dialdehyde wherein the cationic comonomer is selected from the group consisting of diallyldimethylammonium chloride (DADMAC), [2-(acrylamido)ethyl]trimethylammonium chloride, [2-(methacrylamido)ethyl]trimethylammonium chloride, [3-(acrylamido)propyl]trimethylammonium chloride, [3-(methacrylamido)propyl]trimethylammonium chloride, N-methyl-2-vinylpyridinium N-methyl-4-vinylpyridinium, p-vinylphenyltrimethylammonium chloride, p-vinylbenzyltrimethyammonium chloride, [2-(acryloyloxy)ethyl]trimethylammonium chloride, [2-(methacryloyloxy)ethyl]trimethylammonium chloride, [3-(acryloyloxy)propyl]trimethylammonium chloride, [3-(methacryloyloxy)propyl]trimethylammonium chloride and wherein the cationic comonomer comprises greater than 10 mole % of the dialdehyde reactive copolymer before reaction with dialdehyde.
A process for making paper comprising the steps of;
- a. forming an aqueous suspension of cellulosic fibers wherein the aqueous suspension contains a sulphite level in excess of 20 ppm,
- b. adding an effective amount of a cationic resin to the aqueous suspension of cellulosic fibers,
- c. forming the celluosic fibers into a sheet, and
- d. drying the sheet to produce a paper,
- wherein the cationic resin comprising a copolymer produced from a comonomer which is dialdehyde reactive, a cationic comonomer and a dialdehyde wherein the cationic comonomer is selected from the group consisting of diallyldimethylammonium chloride (DADMAC), [2-(acrylamido)ethyl]trimethylammonium chloride, [2-(methacrylamido)ethyl]trimethylammonium chloride, [3-(acrylamido)propyl]trimethylammonium chloride, [3-(methacrylamido)propyl]trimethylammonium chloride, N-methyl-2-vinylpyridinium N-methyl-4-vinylpyridinium, p-vinylphenyltrimethylammonium chloride, p-vinylbenzyltrimethyammonium chloride, [2-(acryloyloxy)ethyl]trimethylammonium chloride, [2-(methacryloyloxy)ethyl]trimethylammonium chloride, [3-(acryloyloxy)propyl]trimethylammonium chloride, [3-(methacryloyloxy)propyl]trimethylammonium chloride and wherein the cationic comonomer comprises greater than 10 mole % of the copolymer before reaction with dialdehyde.
Dependencies are inferred from the claim text.