Polyurethane Coated Fabric Products

Abstract

A polyurethane-coated fabric product, particularly a polyurethane-coated glove, has a fabric liner and, on the surface of the liner, a microporous foam layer comprising polyurethane and a bifunctional sulphur-containing alkoxysilane. The microporous foam layer exhibits increased abrasion resistance, durability and increased resistance to water penetration. Preferably, the bifunctional sulphur-containing alkoxysilane is bis(triethoxysilylpropyl)tetrasulphane. The polyurethane-coated fabric product is manufactured by a method that includes providing a fabric liner, applying a io coating to at least part of the surface of the liner, wherein the coating comprises a solution, in a polar aprotic solvent, of a polyurethane resin and a bifunctional sulphur-containing alkoxysilane, treating the coated fabric with water, thereby causing the polyurethane to coagulate and form a microporous foam layer on the fabric liner, and drying the polyurethane-coated fabric is product.

1 . A polyurethane-coated fabric product comprising a fabric liner and, on the surface of the liner, a microporous foam layer comprising polyurethane and a bifunctional sulphur-containing alkoxysilane. 
     
     
         2 . A polyurethane-coated fabric product according to  claim 1 , wherein the bifunctional sulphur-containing alkoxysilane is selected from bis(triethoxysilylpropyl)disulphane, bis(triethoxysilylpropyl)trisulphane, bis(triethoxysilylpropyl)tetrasulphane, bis(triethoxysilylpropyl)penta-sulphane and mixtures of any two or more of these. 
     
     
         3 . A polyurethane-coated fabric product according to  claim 1 , wherein the bifunctional sulphur-containing alkoxysilane is present in the polyurethane in any amount of from 1 to 20% by weight. 
     
     
         4 . A polyurethane-coated fabric product according to  claim 3 , wherein the bifunctional sulphur-containing alkoxysilane is present in the polyurethane in an amount of from 5 to 15% by weight. 
     
     
         5 . A polyurethane-coated fabric product according to  claim 1 , wherein the polyurethane-coated fabric product is a polyurethane-coated glove. 
     
     
         6 . A polyurethane-coated fabric product according to  claim 5 , wherein the fabric liner is a glove liner made with nylon, polyester, high performance polyethylene, glass or steel yarns. 
     
     
         7 . A method of manufacturing the polyurethane-coated fabric product of  claim 1 , comprising the steps of
 (a) providing a fabric liner;   (b) applying a coating to at least part of the surface of the liner wherein the coating comprises a solution, in a polar aprotic solvent, of a polyurethane resin and a bifunctional sulphur-containing alkoxysilane;   (c) treating the coated fabric liner with water, thereby causing the polyurethane resin to coagulate and form a microporous foam layer on the fabric liner; and   (d) drying the polyurethane-coated fabric product.   
     
     
         8 . A method according to  claim 7 , wherein step (c) is followed by one or more additional steps in which the coated fabric liner is treated with to water. 
     
     
         9 . A method according to  claim 7 , wherein the polar aprotic solvent is selected from dimethyl sulphoxide, dimethyl pyrrolidone, dimethylacetamide, methyl ethyl ketone and N,N-dimethylformamide. 
     
     
         10 . A method according to  claim 9 , wherein the polar aprotic solvent is N,N-dimethylformamide. 
     
     
         11 . A method according to  claim 7 , wherein in step (b) the coating is applied to the surface of the fabric liner by spraying, curtain or shower coating, printing or dipping. 
     
     
         12 . A method according to  claim 11 , wherein the coating is applied to the surface of the fabric liner by dipping and wherein the coating comprises an N,N-dimethylformamide solution containing the polyurethane resin and the bifunctional sulphur-containing alkoxysilane having a viscosity in the range of from 1000 to 1100 centipoise. 
     
     
         13 . A method according to  claim 12 , wherein the polyurethane-coated fabric product is a glove, wherein a fabric glove liner is loaded onto a hand shaped metal former and the loaded former is dipped into the polyurethane resin solution. 
     
     
         14 . A method according to  7 , wherein the bifunctional sulphur-containing alkoxysilane is selected from bis(triethoxysilylpropyl)disulphane, bis(triethoxysilylpropyl)trisulphane, bis(triethoxysilylpropyl)tetrasulphane and bis(triethoxysilylpropyl)-pentasulphane and mixtures of any two or more of these. 
     
     
         15 . A method according to  claim 14 , wherein the bifunctional sulphur-containing alkoxysilane is bis(triethoxysilylpropyl)tetrasulphane. 
     
     
         16 . A method according to  claim 7 , wherein the bifunctional sulphur-containing alkoxysilane is present in the polyurethane solution in an amount of from 1 to 20% by weight based on the weight of polyurethane.