Process for the preparation of molded flexible elastic articles containing urethane groups, devoid of fluorochlorohydrocarbons, having a cellular core and a compact outer layer

摘要

The invention relates to a process for the production of soft-elastic mouldings which contain urethane groups and are free from chlorofluorocarbons (CFCs), and have a cellular core and a compacted peripheral zone with an essentially pore-free, smooth surface, by reacting

  a) organic and/or modified organic polyisocyanates with
  b) at least one relatively high-molecular-weight compound containing at least two reactive hydrogen atoms, and optionally
  c) low-molecular-weight chain extenders and/or crosslinking agents, in the presence of
  d) blowing agents,
  e) catalysts,
  f) crystalline, microporous molecular sieves having a cavity diameter and cavity entrance aperture of less than 1.3 nm, comprising metal oxides or metal phosphates and optionally further additives, and
  g) assistants,
in a closed mould with compaction, expediently by reaction injection moulding (RIM).