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:
Jul. 25, 1995
Filed:
May. 09, 1994
John H Collins, Bloomingdale, IL (US);
Dodd W Fong, Naperville, IL (US);
Anthony G Sommese, Naperville, IL (US);
Amy M Tseng, Woodridge, IL (US);
Nalco Chemical Company, Naperville, IL (US);
Abstract
The invention comprises a process for removing true and apparent color from pulp and paper waste waters. It comprises treating these waste waters with a coagulant and vinylamine polymer. The coagulant is selected from the group consisting of epichlorohydrin-dimethylamine, guanidine-formaldehyde condensation polymers, cyanoguanidine-formaldehyde condensation polymers, urea-formaldehyde condensation polymers, polyethyleneimines, polydiallyldimethylammonium chloride, copolymers of polydiallyldimethylammonium chloride and acrylamide, and ethylenedichloride-ammonia. The vinylamine polymer includes from about 1 to about 100 mole percent vinylamine and from about 1 to about 99 mole percent of at least one monomer selected from the group consisting of amidine vinylformamide, vinyl alcohol, vinyl acetate, vinyl pyrrolidinone and the esters, amides, nitriles and salts of acrylic acid and methacrylic acid.