The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 30, 1993
Filed:
Nov. 13, 1992
Robert W Novak, Lisle, IL (US);
Thomas C Fallon, West Chicago, IL (US);
Nalco Chemical Company, Naperville, IL (US);
Abstract
The invention provides a method for improving the retention of mineral fillers and cellulose fibers on a cellulosic fiber sheet. The method comprising the steps of preparing a cellulose pulp slurry; adding before a shearing step an effective amount of a copolymer flocculant to the cellulose pulp slurry, the copolymer flocculant is a high molecular weight cationic copolymer of acrylamide and diallyl dimethyl ammonium chloride, the flocculant copolymer should contain from about 20 to about 60 mole percent diallyl dimethyl ammonium chloride mer units. After a shearing step adding an effective amount of a high molecular weight water-soluble anionic flocculant. A cellulosic fiber sheet is then formed from the cellulose pulp slurry which includes both the copolymer flocculant and anionic flocculant.