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:
Apr. 12, 1983
Filed:
Oct. 20, 1981
Lothar Brandt, Wiesbaden, DE;
Arno Holst, Wiesbaden, DE;
Hoechst Aktiengesellschaft, Frankfurt am Main, DE;
Abstract
Disclosed is a process for preparing water-soluble phosphonomethyl ethers of cellulose from cellulose and halogenomethane phosphonic acid or one of its salts or acid derivatives, in an aqueous, alkaline medium. The process is carried out in such a way that, for each mole of the cellulose, from about 2.1 to 15 moles of hydroxide ions and from about 0.4 to 3.0 moles of halogenomethane phosphonate ions as etherifying agent are caused to react in from about 3 to 50 parts by weight, per part by weight of the cellulose, of a mixture which is composed of an inert, preferably water-miscible organic solvent and water and in which the proportion of water ranges from about 2 to 60 percent by weight, the reaction is continued until the phosphonomethyl cellulose has a DS of at least about 0.13.