| 摘要 |
Microporous, water vapour permeable sheets or shaped articles are produced from a sedimenting but redispersible aqueous polyurethane (-urea) dispersions, or pastes produced from these dispersions, whic in the filler-free condition contain (I) 65-99% wt. polyurethane (-urea) with an average transverse diameter of 2-500 mu, pref. 8-100 mu, contng. surface groups capable of reaction with component (II), the particles being insoluble i methyl ethyl ketone, and forming non-homogeneous films by themselves at temps. below 60 deg.C., and (II) 1-35% wt. polyfunctional thermoplastic polymer contng. at least two groups capable for reacting with the surface groups of (I), per 2000 mol. wt. units, and/or a low mol. wt. crosslinking agent for the surface groups of (I),. |
