| 摘要 |
<p>Prodn. of a polyurethane comprises reacting (i) an organic compsn. contg. at least two Zerewitinoff-active H atoms, and (ii) an organic polyisocyanate in the presence of, as gel catalyst, (iii) a stannous halide-alcohol complex. Pref. the alcohol is a polyether polyol, e.g. poly(oxyethylene)- or poly(oxypropylene)-glycol or triol, a monohydric alcohol or a glycol. (iii) is pref. of formula SnX2.aA (I) (where X is halide; A is an alcohol; a is not zero). Pref. X is Cl or Br. Blowing catalyst (iv) is opt. included. Cpd. (I) is novel when a is 1 or 2 and whenever X is Br. Also novel is (I) (X is Cl, A is polyoxyalkylene glycol (POAG)), as is a soln. of (I) (A is POAG) in excess POAG. Polymers can be used as sealants, cushions, filters, etc. The Sn complexes have high gelling but low blowing activity, and are non-toxic, permit use of "damp" charge to urethane elastomer prodn. and allow possible delay in gelation.</p> |
