Melt-processable polyurethanes and a process for their production
Melt-processable polyurethanes containing certain waxes are produced. These polyurethanes are useful for the production of films, coatings and injection moldings.
1 . A melt-processable polyurethane produced from:
A) one or more organic diisocyanates,
B) one or more linear hydroxyl-terminated polyols with weight-average molecular weights of 500 to 5000,
C) one or more diol chain extenders and optionally diamine chain extenders with molecular weights of 60 to 490,
in the presence of
D) optionally catalysts
with the addition of
E) optional auxiliary substances and additives,
in amounts such that the molar ratio of NCO groups in A) to isocyanate-reactive groups in B) and C) is from 0.9:1 to 1.2:1,
containing from 0.02 to 2 wt. %, based on total weight of melt processable polyurethane, of
F) a mixture of reaction products of
a) alkylene diamines with one or more linear fatty acids, and
b) alkylene diamines with 12-hydroxystearic acid
and/or
c) alkylene diamines with 12-hydroxystearic acid and one or more linear fatty acids.
2 . The melt-processable polyurethane of claim 1 in which
component A) is 4,4′-diphenylmethane diisocyanate, isophorone diisocyanate, 1,6-hexamethylene diisocyanate, 1,5-naphthylene diisocyanate or 4,4′-dicyclohexyl diisocyanate or a mixture thereof,
component B) is a linear polyester diol, polyether diol, polycarbonate diol or a mixture thereof
and component C) is ethylene glycol, butanediol, hexanediol, 1,4-di(betahydroxyethyl)hydroquinone, 1,4-di(betahydroxyethyl)bisphenol A or a mixture thereof.
3 . A process for the continuous production of the melt-processable polyurethane if claim 1 in which the mixture F) is metered into an extruder together with the components A), B), C) and optionally D) and E).
4 . The process of claim 3 in which the mixture F) is mixed into the polyol B) in advance and this mixed product is metered into the extruder together with the components A), C) and optionally D) and E).
5 . A coating comprising the polyurethane of claim 1 .
6 . A film comprising the polyurethane of claim 1 .
7 . An injection molding comprising the polyurethane of claim 1 .