Foam composition, foam member and method of manufacture

Abstract

A foam composition that includes a polymer material such as polyurethane or polyurea and a leachable water-soluble fine powder is provided. This composition can he used in a relatively simple process to obtain a foam body (porous body) that is uniform only at the surface or uniform throughout. The foam body can be suitably used as a golf ball member in golf balls required to have good controllability on approach shots. Also provided is a method for producing a foam member, which method includes the steps of to molding the foam composition to obtain a solid molded body, and then leaching out and removing the water-soluble fine powder so as to obtain a foam-molded body.

1 . A foam composition comprising a polymer material and a leachable water-soluble fine powder. 
     
     
         2 . The foam composition of  1 , wherein the polymer material is polyurethane or polyurea. 
     
     
         3 . The foam composition of  claim 1 , wherein the water-soluble fine powder has an average particle size of from 1 to 800 μm. 
     
     
         4 . The foam composition of  claim 1 , wherein the water-soluble fine powder has a melting point of at least 100° C. 
     
     
         5 . The foam composition of  claim 1 , wherein the water-soluble fine powder is at least one selected from the group consisting of sodium chloride, calcium chloride, potassium chloride, magnesium chloride, sodium sulfate, potassium sulfate, magnesium sulfate, sodium nitrate, calcium nitrate, potassium nitrate, sodium tetraborate, potassium tetraborate, calcium tetraborate, soluble starch, monosaccharides, disaccharides, trisaccharides, oligosaccharides, polysaccharides, and hydrates thereof. 
     
     
         6 . The foam composition of  claim 1 , wherein the content of the water-soluble fine powder is from 1 to 600 parts by weight per 100 parts by weight of the polymer material. 
     
     
         7 . The foam composition of  claim 1 , wherein the water-soluble powder has a solubility in water of at least 1 g per 100 g of water at 20° C. 
     
     
         8 . The foam composition of  claim 1  which, when molded, yields a foam-molded body having a specific gravity of from 0,2 to 1.2. 
     
     
         9 . The foam composition of  claim 1  which, when molded, yields a foam-molded body having a rebound resilience, as measured in accordance with JIS-K 6255, of from 9 to 62%. 
     
     
         10 . A method for producing a foam member, which method comprises the steps of, in order:
 molding the foam composition of  claim 1  so as to obtain a solid molded body; and   leaching out and removing the water-soluble fine powder, thereby giving a foam-molded body.   
     
     
         11 . A foam member that can be used as an encasing member formed at a surface or periphery of a core material, which foam member is a foam-molded body obtained by the method of  claim 10 . 
     
     
         12 . The foam member of  claim 11  which is a golf ball cover.