Paper containing cationic starch graft copolymers from starch, N,N'-methylenebisacrylamide, and polyamines

• Main Author: TESSLER; MARTIN M
• Format: Patent
• Language: English
• Published: 18.05.1982
• Subjects: CHEMISTRY; COMPOSITIONS BASED THEREON; IMPREGNATING OR COATING OF PAPER; MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVINGCARBON-TO-CARBON UNSATURATED BONDS; MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONSONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; PAPER NOT OTHERWISE PROVIDED FOR; PAPER-MAKING; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; PRODUCTION OF CELLULOSE; PULP COMPOSITIONS; TEXTILES; THEIR PREPARATION OR CHEMICAL WORKING-UP; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G

Novel cationic starch-g-poly(N,N'-methylenebisacrylamide-co-amine) copolymers, useful as pigment retention aids for paper, are prepared by reacting a starch base with N,N'-methylenebisacrylamide and a polyamine or with preformed copolymer. The reactions are carried out at 15 DEG to 80 DEG C. for 0.5 to 20 hours under alkaline conditions using an aqueous slurry or dispersion of a starch base and preferably a salt such as sodium sulfate. The starch base may be derivatized, prior to the graft copolymerization, to introduce ether groups. The polyamines contain at least two amine groups selected from primary and secondary amines; preferably they contain up to 4 amine nitrogens, some of which may be unreactive tertiary amine nitrogens. The starch-g-coplymers are used in amounts of from about 0.05 to 2.0% by weight, based on the dry pulp. The reaction mixture itself may be added directly to the paper stock.