Polishing cloth and method for producing same

Abstract

A high performance polishing cloth having a densified surface state with ultrafine fiber bundles uniformly dispersed therein and having excellent smoothness is provided. The polishing cloth comprises a nonwoven fabric formed by entangling the ultrafine fiber bundles formed by bundling ultrafine fibers with an average single fiber diameter of 0.05 to 2.0 μm and a polymeric elastic material, wherein the average size of the surface fiber-napped portions constituted by the aforementioned ultrafine fiber bundles of the aforementioned nonwoven fabric in the width direction of the ultrafine fiber bundles is 50 to 180 μM.

1 . A polishing cloth mainly comprising a nonwoven fabric formed by entangling the ultrafine fiber bundles including ultrafine fibers with an average single fiber diameter of 0.05 to 2.0 μm and a polymeric elastic material, wherein the average size of the surface fiber-napped portions constituted by the aforementioned ultrafine fiber bundles of the aforementioned nonwoven fabric in the width direction of the ultrafine fiber bundles is 50 to 180 μm. 
     
     
         2 . A polishing cloth, according to  claim 1 , wherein the average size of the surface fiber-napped portions in the width direction of the ultrafine fiber bundles is 50 to 120 μm. 
     
     
         3 . A polishing cloth, according to  claim 1  or  2 , wherein the surface roughness of the polishing cloth is 5 to 18 μm. 
     
     
         4 . A polishing cloth, according to  claim 1 , wherein the CV of the ultrafine fiber is 1 to 30%. 
     
     
         5 . A method for producing a polishing cloth comprising at least the following steps (1) through (5) in combination, wherein the number of islands-in-sea type composite fibers convertible into ultrafine fibers, which can be brought in by needle punching of the following step (2), is 3 to 6 fibers/1 barb: 
       (1) producing islands-in-sea type composite fibers convertible into ultrafine fibers with an average single fiber diameter of 0.05 to 2.0 μm; 
       (2) laminating fiber webs by a card and a crosslapper using said islands-in-sea type composite fibers, and obtaining a nonwoven fabric by needle punching; 
       (3) giving a polymeric elastic material to said nonwoven fabric by 10 to 200 mass % based on the mass of the ultrafine fibers obtained by converting the composite fibers; 
       (4) buffing at least one surface; and 
       (5) converting said islands-in-sea type composite fibers into ultrafine fibers. 
     
     
         6 . A method for producing a polishing cloth, according to  claim 5 , wherein the number of islands-in-sea type composite fibers brought in by needle punching is 3 to 4 fibers/1 barb.