Weyerhaeuser Company Limited

Margot J Harding

Jerome M Gess

Robert C Gaines

The invention is a fibrous cellulosic product, containing a uniformly dispersed polymeric material which has been deposited in an aqueous suspension from an anionic latex, and the method for its manufacture. Cellulosic fiber is first cationized by treating it in an aqueous suspension with the condensation product of epichlorohydrin and dimethylamine. Up to 30% of the dimethylamine may be replaced with a crosslinking agent which can be ammonia or an aliphatic diamine such as hexamethylene diamine. The cationized fiber, with or without small quantities of alum, will effectively retain a wide variety of anionic latices when treated in an aqueous environment.

Latex treated cationic cellulose product and method for its preparation

The invention is a fibrous, cationic cellulose pulp product and the method for preparing it. A water suspension of cellulosic fiber is treated under alkaline conditions with a condensate of epichlorohydrin and dimethylamine. Up to 30 molar percent of the DMA may be replaced by a crosslinking agent such as ammonia or a lower aliphatic diamine. The process may be carried out at room or elevated temperatures. It is practical to add the condensate at one of the later alkaline stages of a bleaching process; e.g., an alkaline extraction or peroxide stage. This is most preferably done later than any chlorination or hypochlorite stages. The product shows greatly improved retention of acid and other anionic dyes. It also shows superior retention of some pigments and latices without the need for other cationic aids. In some cases a small amount of alum appears to have a synergistic retention effect with the cationic pulp product when used with titanium dioxide and certain anionic latices.

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Federal Way, WA, United States of America

Margot J Harding