| 摘要 |
<p>A composite material comprising a fibrous sheet which is impregnated with a polyurethane elastomer. The polyurethane elastomer comprises the reaction product of (A) a polymeric diol having a molecular weight of about 800-4000; (B) an organic diisocyanate having the formula (I) <IMAGE> wherein R' and R2 are hydrogen or an alkyl group having 1-5 carbon atoms, respectively, and (C) a chain extender comprising an organic diamine having the formula (II) <IMAGE> wherein R' and R2 are hydrogen or 40-95 mole % alkyl group having 1-5 carbon atoms, respectively, and a phthalic acid dihydrazide having the formula (III) <IMAGE> This composite sheet material is useful as a synthetic leather, especially as a suede-like leather sheet material, and has high density, good flexiblity and crease resistance, a supple touch and 60-5 mole % pertinent rubber-like repulsive elasticity.</p> |
