| abstract |
Silylated polyurethanes exhibiting a superior combination of mechanical properties andnwhich cure in reasonable time to a low-tack sealant, without excessive viscosity, are preparednby reacting a polyol component having terminal unsaturation of less than 0.02 meq/g with andiisocyanate component to form a hydroxyl-terminated prepolymer, and endcapping thenprepolymer with an isocyanate silane of the formula OCN-R-Si-(X) m (-OR 1) 3-m nwherein m is 0, 1 or 2, each R 1 is alkyl containing 1 to 4 carbon atoms, each X is alkylncontaining 1 to 4 carbon atoms, and R is a difunctional organic group. |