| 摘要 |
The pressurised isocyanate-semiprepolymer mixt. (I) is obtd. by reacting (A) a mixt. of poly-hydroxy cpd(s). and a 1-25C linear, branched or cyclic, satd. or unsatd. mono-alcohol (Ali) and/or a hydroxy-ketone (Alii) with (B) polyisocyanate(s) in a reactor in the presence of blowing agent(s) (II), or by making the isocyanate semi-prepolymer first and then adding (II). Also claimed is (i) a mixt. (I) obtd. as above, in which the prepolymer is obtd. by reacting mixt. (A) and (B) in presence of (C) catalysts, (D) surfactants, opt. (E) blowing agents and opt. (F) other additives; (ii) a process for the prodn. of dimensionally stable polyurethane (PU) foam by depressurising the above storage-stable, blowing agent-contg. semi-prepolymer and allowing it to harden in the atmos.
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