Preparation of hydrophilic styrene maleic anhydride copolymer fibers for use in papermaking

Claim 1

A process for the preparation of a fibrous pulp containing hydrophilic synthetic polymer fibers which comprises stirring a suspension of the fibers of a spurted fibrous styrene-maleic anhydride copolymer composition in a dilute aqueous admixture of water-soluble nitrogen-containing cationic and anionic polymers, said cationic polymer being (a) the reaction product of ammonia or a lower alkyl amine and an epichlorohydrin-modified aminopolyamide derived from a dicarboxylic acid and a polyalkylene polyamine having two primary amine groups and at least one secondary or tertiary amine group, or (b) the reaction product of epichlorohydrin and a condensate of cyanamide or dicyandiamide with a polyalkylene polyamine having the formula H 2 N(C n H 2n NH) x H, wherein n is an integer 2 through 8 and x is an integer 2 or more, or (c) a poly(diallyldialkylammonium chloride) or (d) a poly(acrylate or methacrylate alkyl ester containing quaternary ammonium groups), and said anionic polymer being the reaction product of glyoxal and (a) a polyacrylamide containing from about 2 to about 15% acrylic acid units or (b) a partially hydrolyzed, branched poly(β-alanine) containing from about 1 to about 10 mole percent carboxyl groups based on amide repeating units, the ratio of said cationic polymer to said anionic polymer in said admixture of said polymers being in the range of from about 3:1 to about 1:5 by weight and the amount of said admixture of said polymers deposited on the fibers of said fibrous composition being from about one to about 15% by weight based on said fibrous composition.