Spinning of segmented polyurethane-urea elastomers in a steam atmosphere

US5057260A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Ulrich Reinehr · Dormagen, DE
• Heinz Gall · Herrenberg, DE
• Josef Kulig · Dormagen, DE
• Rudi Dauscher · Dormagen, DE
• Rolf-Burkhard Hirsch · Dormagen, DE

Key dates

• Filing date: Apr 4, 1990
• Grant date: Oct 15, 1991
• Expiry date: Apr 4, 2010

Classification

• Technology area (CPC D): Textiles; Paper
• CPC primary: D01D5/04
• WIPO field: Textile and paper machines
• WIPO sector: Mechanical engineering

Abstract

An improved dry spinning process for the production of polyurethane elastomer threads using superheated steam as the spinning medium, comprising PA0 (1) spinning polyurethane-urea elastomers prepared by chain lengthening of NCO prepolymers with diamine from a solution containing dimethylformamide or dimethylacetamide via a hot spinneret having a nozzle at not less than 100.degree. C. and at a spinning solution temperature in the nozzle of not less than 100.degree. C. into a heated spinning chimney at a chimney wall temperature of not less than 160.degree. C., while PA0 (2) introducing superheated steam into the spinning chimney at a temperature above 250.degree. C. as the spinning medium in an amount of at least 20 kg/h, if the chimney diameter is less than or equal to 28 cm, or if the chimney diameter is greater than 28 cm, in an amount of at least 20 kg/h increased by up to a factor H, wherein factor H is equal to the chimney cross-section/615 cm.sup.2, PA0 (3) feeding the spinning medium and spinning solvent to a recovery step at the end of the spinning chimney, and PA0 (4) maintaining a take-off speed of the threads from the chimney of at least 250 m/min. The improved process y…