Granules and moulded parts prodn., for use in e.g. vehicle construction - by thermoplastic processing of crosslinked polyurethane(s) or polyurea(s), e.g. by the RIM method, opt. with addn. of thermoplastics

摘要

Prepn. of granulates and moulded prods. from (A) crosslinked isocyanate-based plastics, opt. mixed with (B) thermoplastics, with wt. ratio (A):(B) = (100:0)-(9.99:90.01) is new. (A) are polyurethanes, polyureas and/or polyurethane-ureas, with mean functionality at least 2.5 in the flexible segment and density at least 0.6 (pref. 0.6-1.1) without filler. (A) are prepd. from (a) polyisocyanates, (b) cpds. of mol. wt. 1800-12,000 contg. at least 2.5 NCO-reactive gps. (mean), opt. (c) ether gp.-contg. (cyclo)alkane-polyols and/or -polyamines with mol.wt. 60-1799 and opt. (d) diamines of mol. wt. 108-400 with 2 prim. and/or sec. aromatic amino gps., opt. with addn. of (e) known polyurethane additives etc.. The prepn. is carried out in one or more stages, with NCO index 60-140 and with total amt. of (c) and/or (d) = at least 5 wt.% w.r.t. (b). USE/ADVANTAGE - The prods. are used e.g. in vehicle construction, electrical and electronic prods., sports goods, domestic appliances etc.. The process enables the prodn. or recycling of crosslinked polyurethane (PU) materials in the form of homogeneous pellets, granules etc. (by extrusion) or mouldings (by direct injection moulding), without the disadvantages of prior-art processes (e.g. very high moulding pressures, addn. of at least 10% (B), expensive grinding operations if (A) is used as a filler).