Thermoplastic polyurethane elastomers prepn. - by introducing components into extruder inlet zone, and maintaining definite temp. profile in extruder

• Main Authors: DIETER ZETTLER,HANS, DOERFEL,HELMUT,.DR, EGER,KNUT,.DR, KRIEGER,HEINRICH, FALKENSTEIN,GEORG,.DR, HAMMELMANN,HERBERT, DENNI,RAYMOND,.DR
• Format: Patent
• Language: English; German
• Published: 08.04.1976
• Edition: 2
• Subjects: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOIDCHEMISTRY; CHEMISTRY; COMPOSITIONS BASED THEREON; MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONSONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; THEIR PREPARATION OR CHEMICAL WORKING-UP; THEIR RELEVANT APPARATUS; TRANSPORTING

Thermoplastic polyurethane elastomers, esp. linear organosoluble, polyurethane elastomers are prepd. continuously by reacting polyhydroxy cpds., diisocyanates, and low mol. wt. chain extenders in a multi-screw extruder. The components are introduced directly and separately in measured amts. into the inlet zone of the extruder, and a temp. profile is maintained in the extruder, this ranging from 240 degrees C in the inlet zone to 190 degrees C at the extrusion die. Economic prodn. of prods. having a very uniform quality is possible. These can be easily obtd. in the form of granules, profiles, tubes and cable sheaths. The prod. is soluble in org. solvents, and the solns. are suitable for coating purposes. The granules can be processed by most methods used for thermoplasts, e.g. extrusion, injection moulding and calendering.