| 摘要 |
Solid or microcellular moulded articles with a solid integral skin and bulk density of greater than 900Kg/cu/m. are produced from polyurethanes contg. urea gps. by reacting a) a polyisocyanate component contg. at least 1 aromatic isocyanate gp. with b) a cpd. with at least 2 reactive H atoms with a mol.wt. = 400-12,000 c) opt. cpds. with at least two reactive H atoms with a mol.wt. = 60-399 and d) opt. usual processing aids and additives using a RIM technique. - The novel steps are (i) reacting 0.15 mol. per mol. NCO gps. of component (a) in the presence of water to a predetermined NCO number of 70-125 based on all components (ii) introducing the reaction mixt. into a closed mould at a pressure above 40bar during the reaction such that CO2 formed in the reaction remains wholly or partly dissolved in the moulding. - Pref. the component (a) consists of an opt. urethane, carbodiimide, and/or isocyanate modified polyisocyanate or mixt. of polyisocyanates of the diphenyl methane series. Component b) is pref. a polyester and/or a polyether polyol with a mol.wt. of 400-12000.
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