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. 19, 2002
Filed:
Dec. 30, 1999
Erik-Andreas Klohr, Walsrode, DE;
Jörg Neubauer, Walsrode, DE;
Wolfgang Koch, Bomlitz, DE;
Klaus Szablikowski, Walsrode, DE;
Detmar Redeker, Walsrode, DE;
Wolfgang Wagenknecht, Teltow, DE;
Fritz Loth, Teltow, DE;
Wolff Walsrode AG, Walsrode, DE;
Abstract
A cellulose ether that is predominantly substituted in the C3 position of the anhydroglucose unit of the cellulose is described. In an embodiment of the present invention, the partial degree of substitution in the C3 position of the cellulose ether is ≧60%, based on the total degree of substitution. Also described is a process for preparing the cellulose ether of the present invention. The process involves, reacting cellulose, dissolved in N-methylmorpholine-N-oxide monohydrate (NMMNO) and optionally other inert organic solvents, with alkylation reagents. The reaction takes place in the presence of: (i) an insoluble solid phase catalyst, e.g., solid ion exchange resins based on polystyrene having quaternary ammonium groups; (ii) stabilizers, e.g., propyl gallate; and (iii) optionally additional soluble co-catalysts, e.g., trimethylbenzylammonium hydroxide.