Manufacture of viscose and of articles therefrom

US6538130B1 · kind B1 · utility

Assignee

• Acordis Kelheim GmbH · DE

Inventors

• Klaus Fischer · Speyer, DE
• Heinzhorst Möbius · Ribnitz-Damgarten, DE
• Tatjana Poggi · Ribnitz-Damgarten, DE

Key dates

• Filing date: Mar 21, 2000
• Grant date: Mar 25, 2003
• Expiry date: Mar 21, 2020

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08B9/00
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

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.