Napped artificial leather and production method thereof

Abstract

Disclosed is a production method of a napped artificial leather including the steps of: providing a fiber sheet including a non-woven fabric of ultrafine fibers with a fineness of 1 dtex or less that has been impregnated with a first elastic polymer; napping one or both surfaces of the fiber sheet to form a napped surface thereon; applying, to the napped surface, a resin solution containing a second elastic polymer having solubility in a predetermined solvent; and applying the predetermined solvent to the surface to which the resin solution is applied. Also disclosed is a napped artificial leather including a fiber sheet obtained by impregnating a first elastic polymer into a non-woven fabric that is an entangled body of ultrafine fibers with a fineness of 1 dtex or less, wherein the fiber sheet includes, on one or both surfaces thereof, a napped surface obtained by the ultrafine fibers, and a second elastic polymer is fixed to basal portions of the napped ultrafine fibers.

1 . A production method of a napped artificial leather, comprising the steps of:
 providing a fiber sheet including a non-woven fabric of ultrafine fibers with a fineness of 1 dtex or less that has been impregnated with a first elastic polymer;   napping one or both surfaces of the fiber sheet to form a napped surface thereon;   applying, to the napped surface, a resin solution containing a second elastic polymer having solubility in a predetermined solvent; and   applying the solvent to the surface to which the resin solution is applied.   
     
     
         2 . The production method of a napped artificial leather in accordance with  claim 1 ,
 wherein the first elastic polymer is an elastic polymer having insolubility in the solvent.   
     
     
         3 . The production method of a napped artificial leather in accordance with  claim 2 ,
 wherein the solubility corresponds to a rate of dissolution in the solvent of 90% or more, and the insolubility corresponds to a rate of dissolution in the solvent of 10% or less.   
     
     
         4 . The production method of a napped artificial leather in accordance with  claim 2 ,
 wherein the first elastic polymer is an elastic polymer that forms a cross-linked structure, and the second elastic polymer is an elastic polymer that does not form a cross-linked structure.   
     
     
         5 . The production method of a napped artificial leather in accordance with  claim 1 ,
 wherein the first elastic polymer is an aqueous polyurethane, and the second elastic polymer is a solvent-based polyurethane.   
     
     
         6 . The production method of a napped artificial leather in accordance with  claim 1 ,
 wherein the ultrafine fibers are filaments.   
     
     
         7 . The production method of a napped artificial leather in accordance with  claim 1 ,
 wherein the second elastic polymer has a weight per area that is 0.001 to 0.05 times a weight per area of the first elastic polymer.   
     
     
         8 . A napped artificial leather produced by the production method of  claim 1 , comprising
 a fiber sheet obtained by impregnating a first elastic polymer into a non-woven fabric that is an entangled body of ultrafine fibers with a fineness of 1 dtex or less,   wherein the fiber sheet includes, on one or both surfaces thereof, a napped surface formed by the napped ultrafine fibers, and   further includes a second elastic polymer that is fixed to basal portions of the napped ultrafine fibers and is unevenly distributed on a surface layer of the fiber sheet.   
     
     
         9 . The napped artificial leather in accordance with  claim 8 ,
 wherein the first elastic polymer has insolubility in a predetermined solvent, and the second elastic polymer has solubility in the solvent.   
     
     
         10 . The napped artificial leather in accordance with  claim 9 ,
 wherein the solubility corresponds to a rate of dissolution in the solvent of 90% or more, and the insolubility corresponds to a rate of dissolution in the solvent of 10% or less.   
     
     
         11 . The napped artificial leather in accordance with  claim 8 ,
 wherein the first elastic polymer is an aqueous polyurethane, and the second elastic polymer is a solvent-based polyurethane.   
     
     
         12 . The napped artificial leather in accordance with  claim 11 ,
 wherein the aqueous polyurethane has a cross-linked structure, and the solvent-based polyurethane does not have a cross-linked structure.   
     
     
         13 . The napped artificial leather in accordance with  claim 8 ,
 wherein the second elastic polymer is permeated into and unevenly distributed on the surface layer of the fiber sheet in a form of a layer or film, and a region where the second elastic polymer is permeated into and unevenly distributed has an average thickness of 5 to 60 μm.   
     
     
         14 . The napped artificial leather in accordance with  claim 8 ,
 wherein the ultrafine fibers are filaments.   
     
     
         15 . The napped artificial leather in accordance with  claim 8 ,
 wherein the second elastic polymer has a weight per area that is 0.001 to 0.05 times a weight per area of the first elastic polymer.   
     
     
         16 . The napped artificial leather in accordance with  claim 8 ,
 wherein the napped ultrafine fibers have a nap length of 30 to 200 μm.