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:
Jan. 29, 1991
Filed:
Apr. 09, 1990
Applicant:
Inventors:
Stephen B Christensen, Midland, MI (US);
Gary J Schulz, Midland, MI (US);
Susan Kling, Midland, MI (US);
Assignee:
The Dow Chemical Company, Midland, MI (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B01D / ;
U.S. Cl.
CPC ...
536127 ; 210692 ; 210917 ;
Abstract
A method of removing undesirable material from water-soluble polysaccharide ethers, such as water-soluble cellulose ethers, via contact of an aqueous solution of the water-soluble polysaccharide ether with an anion exchange resin. Anion exchange resins that are useful in the invention are derived from epoxy resin polymers, acrylic based copolymers or a copolymer of styrene-divinylbenzene. The method significantly reduces the amount of colored bodies in the polysaccharide ether.