Dense, elegant and pliable sheet material comprising fibrous base impregnated with a diol-hindered amine polyurethane system

Abstract

A composite sheet material comprising a fibrous sheet which is impregnated and/or coated with a polyurethane elastomer, wherein said polyurethane elastomer comprises the reaction product of (A) a polymeric diol having a molecular weight of about 800-5000, (B) an organic polyisocyanate, and (C) a chain extender comprising a low molecular weight organic diol, and if desired, (D) a chain terminator; wherein more than 2 mol % of (C) and/or (D) comprise a hindered amine compound having the formula I ##STR1## wherein R.sup.1 is a substituent selected from the group consisting of hydrogen, oxygen, an alkyl group containing 1-12 carbon atoms, an aralkyl group containing 7-18 carbon atoms, an acyl group containing 1-12 carbon atoms, --(R.sup.5 O).sub.n H and --(COR.sup.6 CO.sub.2 R.sup.7 O).sub.m --H, wherein R.sup.5 is an alkylene group containing 1-12 carbon atoms, R.sup.6 is a residue of an alkenyl group containing 2-12 carbon atoms, an organic dicarboxylic acid containing 2-12 carbon atoms, R.sup.7 is a residue of an organic diol containing 2-12 carbon atoms, n is an integer from 1 to 50 and m is an integer from 1 to 15; R.sup.2 is a substituent selected from the group consisting of hydrogen, an alkyl group containing 1-12 carbon atoms, an aryl group containing 6-18 carbon atoms and a cyano group; X is a substituent selected from the group consisting of a hydroxyl group, an amino group and a monoalkylamino group containing 1-12 carbon atoms, and said substituents whose part or all of are hydrogen atoms bonded to oxygen and/or nitrogen may be substituted by --(R.sup.5 O).sub.n --H and/or --(COR.sup.6 CO.sub.2 R.sup.7 O).sub.m --H, and wherein R.sup.3 and R.sup.4 are the same or different alkyl groups containing 1-12 carbon atoms, R.sup.3 and R.sup.4 being independent or bonded to form a 5-12-membered alicyclic ring. Said composite sheet material is useful as a synthetic leather, especially as a suede-like leather. It has a dense and elaborate structure, as well as a good flexibility and pliability. Furthermore, it has superior initial properties and superior abrasion resistance after being worn for a long time.

Dependencies are inferred from the claim text.