| abstract |
A compsn. (I) which hardens to form a gasket material which is elastic when compressed, is based on one or multi-component, silane-functional, isocyanate-functional prepolymers or polysiloxane prepolymers. Compsn. (I) contains hollow plastic microspheres with elastic wall material (II). Also claimed is a process for the prodn. of (I) by incorporating the solid components into the liq. components under low shear conditions. Pref. compsn. (I) contains oxyalkylene polymer(s) with terminal and/or lateral silane gps. contg. Si atoms with hydrolysable gps. and/or opt. OH gps.. (I) pref. also contains 0.05-10 wt.% microspheres (II) with a mean particle dia. of 10-80 (pref. 20-50) microns. The hollow microspheres (II) consist of PVDC, copolymers of vinylidene chloride with acrylonitrile and/or (meth)acrylate esters, polystyrene, styrene/(meth)acrylate copolymers or (meth)acrylate homo- or co-polymers. Pref. (II) are coated with an inert component, i.e. talc, TiO2, SiO2, CaCO3, CaSO4 and/or Al oxide hydrate. |