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:
Oct. 21, 1980
Filed:
Mar. 05, 1979
Applicant:
Inventor:
Maurice L Zweigle, Midland, MI (US);
Assignee:
The Dow Chemical Company, Midland, MI (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C08B / ;
U.S. Cl.
CPC ...
536 89 ; 536 84 ; 536 85 ; 536 91 ; 536 94 ; 536100 ;
Abstract
In the preparation of organosoluble cellulose ethers, the content of alkali metal (hydroxides and the salts thereof) in the resulting cellulose ether is reduced by forming a solution of the cellulose ether and an organic solvent, converting the alkali metal hydroxide therein to an alkali metal salt and heating the resulting solution at conditions sufficient to (1) increase the size of the alkali metal salt particles and (2) remove any water therefrom. Filtering the resulting mixture and drying the filtrate yields a cellulose ether containing a very small percentage of alkali metal salt, e.g., often less than about 500 ppm.