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:
Mar. 25, 2003
Filed:
Mar. 21, 2000
Acordis Kelheim GmbH, Kelheim, DE;
Abstract
In the manufacture of viscose, and an elongate cellulose member such as standard viscose rayon fibre, with reduced alkali ratio from dissolving-grade cellulose such as wood pulp by irradiation with a high energy beam at a dose of 1-30 kGy, steeping in aqueous sodium hydroxide, pressing to form alkali cellulose, xanthating to form cellulose xanthate, dissolving in aqueous liquor to form viscose and (when elongate cellulose members are required) extruding through a die into an acid bath for coagulation and regeneration to form an elongate cellulose member which is then washed and dried, viscose filtration can be improved by including in the dissolving liquor for the cellulose xanthate an amount of from 200 to 10000 ppm by weight of a salt which consists of alkali metal or ammonium cations and anions of a strong acid.