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