Patent Number: 6,310,157

Title: Anionic water soluble polymer made by reverse phase emulsion polymerization

Abstract: Paper is made by a dual soluble polymer process in which a cellulosic suspension which usually contains alum or cationic coagulant is first flocculated with a high IV cationic synthetic polymer or cationic starch and, after shearing, the suspension is reflocculated by the addition of a branched anionic water soluble polymer having IV above 3 dl/g and tan delta at 0.005 Hz of at least 0.5. The process gives an improved combination of formation, retention and drainage.

Inventors: Heard; Michael (Suffolk, VA), Chen; Gordon (Suffolk, VA), Stockwell; John Oliver (West Yorkshire, GB)

Assignee: Ciba Specialty Chemicals Water Treatment Limited

International Classification: D21H 23/14 (20060101); D21H 21/10 (20060101); D21H 23/00 (20060101); D21H 17/44 (20060101); D21H 17/42 (20060101); D21H 17/00 (20060101); C08F 020/04 ()

Expiration Date: 10/30/2018