process for continuous production of thermoplastic processable polyurethane elastomers and use of thermoplastic polyurethane elastomers

摘要

process for the continuous production of thermoplastic processable polyurethane elastomers, and use of thermoplastic polyurethane elastomers. The invention relates to a method for the continuous production of improved homogeneity thermoplastic processable polyurethane elastomers, whereby a polyisocyanate (a), a compound (b) with an average of at least 1.8 and at most 3.0 hydrogen atoms with zerewitinoff activity, an average molecular weight of 450 g / mol to 5000 g mol, in a ratio of 1 to 80% equivalent, relative to the content of isocyanate groups in polyisocyanate (a), a chain extender ( (c) with an average of at least 1.8 and at most 3.0 hydrogen atoms with zerewitinoff activity per molecule, an average numerical molecular weight of 60 to 400 g / mol, in a proportion of 12 to 99% equivalent by weight of the isocyanate group content of polyisocyanate (a) or 30% by weight of catalysts by weight of the total amount of polyurethane elastomers and other adjuncts and additives (d), in a molar ratio: n from 0.9: 1 to 1.2: 1 of polyisocyan (a) for the total compound (b), chain extender (c) and other adjuncts and additives are fed to a self-cleaning twin screw extruder operated at a high drag speed, the mixture then discharged from the self-cleaning twin-screw extruder into an additional reaction device, characterized in that the self-cleaning twin-screw extruder is equipped with trawling speeds above 6000 s ^ -1 ^ and residence within 1 to 20 seconds.