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. 15, 1980
Filed:
Nov. 01, 1976
Otto Wichterle, Prague, CS;
Artur Stoy, Prague, CS;
Ceskoslovenska akademie ved, Prague, CS;
Abstract
There is disclosed a method of producing hydrogel tubes comprising partially hydrolyzing an acrylonitrile-containing polymer in an inorganic acidic solvent solution at temperature of about -10.degree. to 50.degree. C., extruding said hydrolyzed polymer solution through a circular nozzle into an aqueous coagulating bath, the same or similar coagulating bath simultaneously being fed through a central tube or pin of the nozzle. Preferably, the surface of the tube is made very slippery in wet condition, by treating it with chemical agents causing either a further hydrolysis or other reaction leading to carboxylic, sulfonic or sulfuric groups, or an esterification with polyols such as glycerol, glycols or polyvinyl alcohol, preferably with simultaneous sulfonation or sulfuration.