Suede-like synthetic leather and method of making the same

Abstract

A suede-like synthetic leather includes a substrate and a suede-like layer formed on the substrate from a polymeric foam which has a surface provided with piles projecting therefrom. The suede-like synthetic leather is formed by a process which includes the steps of forming the polymeric foam on the substrate, and forming the piles on the surface of the polymeric foam by rubbing, tumbling, or abrading the surface of the polymeric foam.

What is claimed is: 
     
         1 . A suede-like synthetic leather, comprising:
 a substrate; and   a suede-like layer formed on said substrate from a polymeric foam which has a surface provided with piles projecting therefrom;   wherein said suede-like synthetic leather is formed by a process which includes the steps of:   forming said polymeric foam on said substrate; and   forming said piles on said surface of said polymeric foam by rubbing, tumbling, or abrading said surface of said polymeric foam.   
     
     
         2 . The suede-like synthetic leather of  claim 1 , wherein said polymeric foam is a water-based polyurethane foam. 
     
     
         3 . The suede-like synthetic leather of  claim 1 , wherein said polymeric foam has a thickness ranging from 0.1˜2.0 mm. 
     
     
         4 . The suede-like synthetic leather of  claim 1 , wherein said substrate has a first surface connected with said suede-like layer, and a second surface opposite to said first surface, said suede-like synthetic leather further comprising a first adhesive layer disposed between said first surface of said substrate and said suede-like layer. 
     
     
         5 . The suede-like synthetic leather of  claim 4 , wherein said substrate is a fabric having a porous structure, said suede-like synthetic leather further comprising an impregnation layer filling pores of said substrate and extending out of said substrate through said first surface to connect with said first adhesive layer, said impregnation layer including a penetrating portion distributed inside said substrate, a first connecting portion extending out of said substrate from said penetrating portion through said first surface to connect with said suede-like layer, and a second connecting portion extending out of said substrate from said penetrating portion through said second surface. 
     
     
         6 . The suede-like synthetic leather of  claim 1 , wherein said substrate includes a fabric layer, and a polymeric film layer connected to said fabric layer, said suede-like layer being connected to a surface of said polymeric film layer opposite to said fabric layer, said polymeric film layer being a polyurethane film. 
     
     
         7 . The suede-like synthetic leather of  claim 1 , wherein said substrate is a fabric selected from the group consisting of polyester, rayon, nylon, polyurethane, polyamide and cotton. 
     
     
         8 . The suede-like synthetic leather of  claim 1 , wherein said surface of said suede-like layer is patterned to be a three-dimensional patterned surface. 
     
     
         9 . A method of making a suede-like synthetic leather, comprising the steps of:
 (a) preparing a foamable liquid composition, the foamable liquid composition including a polymer and a foaming agent;   (b) applying the foamable liquid composition on a substrate;   (c) heating the substrate to foam the foamable liquid composition and to form a polymeric foam; and   (d) forming piles on a surface of the polymeric foam by rubbing, tumbling or abrading the surface.   
     
     
         10 . The method of  claim 9 , wherein in step (b), the foamable liquid composition is applied on the substrate by a coating method using an applicator or an impregnation method. 
     
     
         11 . The method of  claim 9 , wherein in step (a), a viscosity of the foamable liquid composition is adjusted to be in the range of 200˜15000 cps. 
     
     
         12 . The method of  claim 9 , wherein in step (a), the polymer is selected from polyurethane resins, and the foaming agent includes microspheric powder particles each having a diameter ranging from 6 μm˜50 μm. 
     
     
         13 . The method of  claim 9 , wherein in step (a), the foamable liquid composition further includes a solvent and a thickener, and a viscosity of the foamable liquid composition is adjusted to be in the range of 200˜15000 cps. 
     
     
         14 . The method of  claim 13 , wherein in step (a), the solvent is selected from one of methyl ethyl ketone (MEK), isopropyl alcohol (IPA), ethyl acetate (EAC) and acetone, and the thickener is selected from one of calcium carbonate and wood flour. 
     
     
         15 . The method of  claim 9 , wherein in step (a), the polymer is a water-based polyurethane resin, the foaming agent includes microspheric powder particles each having a diameter ranging from 6 μm˜50 μm, and the foamable liquid composition further includes a solvent which is water. 
     
     
         16 . The method of  claim 15 , wherein in step (a), the foamable liquid composition further includes a water-based thickener and a water-based crosslinker. 
     
     
         17 . The method of  claim 9 , wherein in step (c), the substrate is heated at a temperature in the range of 120˜250□ for 2˜5 minutes. 
     
     
         18 . The method of  claim 9 , wherein in step (c), the substrate is first heated at a temperature lower than a foaming temperature to form the foamable liquid composition into a preformed body, after which the substrate is heated a second time at a temperature to foam the preformed body, the substrate being heated at a temperature in the range of 40˜100□ for 2˜5 minutes in the first heating, and at a temperature in the range of 120˜250□ for 20 seconds to 5 minutes in the second heating. 
     
     
         19 . The method of  claim 9 , wherein step (b) includes step (b-1) and step (b-2), in step (b-1), a polymeric adhesive is coated on a surface of the substrate, and is solidified, water washed and dried to form a first adhesive layer; and in step (b-2), the foamable liquid composition is applied on the first adhesive layer. 
     
     
         20 . The method of  claim 9 , wherein the substrate used in step (b) is a porous fabric, and step (b) includes step (b-1) and step (b-2), in step (b-1), a polymeric impregnating solution is coated on the substrate, and is solidified, water washed and dried to form a impregnation layer that penetrates and covers the substrate; and in step (b-2), the foamable liquid composition is applied on at least one surface of the impregnation layer. 
     
     
         21 . The method of  claim 9 , wherein the substrate used in step (b) is a porous fabric, and step (b) includes step (b-1), step (b-2) and step (b-3), in step (b-1), a polymeric impregnating solution is coated on the substrate, and is solidified, water washed and dried to form an impregnation layer that penetrates and covers the substrate; in step (b-2), a polymeric adhesive having a viscosity larger than that of the polymeric impregnating solution is coated on at least one surface of the impregnation layer, and is solidified, water washed and dried to form a first adhesive layer; and in step (b-3), the foamable liquid composition is applied on the first adhesive layer. 
     
     
         22 . The method of  claim 9 , wherein in step (b), wherein the substrate used in step (b) has a fabric layer and a non-foamed polymeric film layer connected to the fabric layer, and step (b) includes step (b-1) and step (b-2), in step (b-1), a polymer coating solution is applied on the fabric layer, and is solidified, water washed and dried to form the non-foamed polymeric film layer; and in step (b-2), the foamable liquid composition is applied on the non-foamed polymeric film layer. 
     
     
         23 . The method of  claim 9 , wherein in step (b), the foamable liquid composition is coated on a surface of a release paper having a three-dimensional raised pattern, and is dried by heating at a temperature lower than a foaming temperature to form a preformed body, the preformed body being connected to the substrate using a polyurethane adhesive, the release paper being removed after the polyurethane adhesive is completely dried; and in step (d), the polymeric foam has a three-dimensional patterned surface. 
     
     
         24 . The method of  claim 9 , wherein in step (c), an embossed method is used to form a raised pattern on a surface of the polymeric foam, and in step (d), the polymeric foam has a three-dimensional patterned surface.