Bonding of granular materials to polyolefin surfaces

Abstract

A permanent roughened or textured surface is applied to parts molded from polyolefins, particularly from polyethylene by applying to the surface of the part a coating mixture of a tackifier resin and polyolefin particles in a liquid carrier and incorporating a granular or particulate matter in the coating, either by application to the coating or by admixing the granular or particulate matter into the coating mixture. The coated surfaced is heated to the melt temperature of the polyolefin for a short time, sufficient to gel the polyolefin particles of the coating into the surface of the part, but insufficient to cause any thermal distortion of the part.

What is claimed is:  
     
         1 . The method of treating a polyolefin object to obtain a permanently textured surface which comprises: 
 a. coating the surface with a mixture of a tackifier and polyolefin powders in a liquid carrier;    b. incorporating particulate solids having a size range passing a 15 mesh standard screen size into the coating;    c. drying the coating and heating the coating and polyolefin surface to the polyolefin melt temperature for a sufficient time to gel the coating into the surface but insufficient to cause thermal distortion of the polyolefin object.    
     
     
         2 . The method of  claim 1  wherein the polyolefin object is a polyethylene object.  
     
     
         3 . The method of  claim 2  wherein the polyolefin powder is polyethylene powder.  
     
     
         4 . The method of  claim 3  wherein the particles of the polyethylene powder have a size range less than 140 microns.  
     
     
         5 . The method of  claim 1  wherein said tackifier is an aliphatic or cycloaliphatic hydrocarbon resin.  
     
     
         6 . The method of  claim 1  wherein said active ingredients comprise from 15 to 30 weight percent tackifier and from 85 to 70 weight percent polyolefin powder.  
     
     
         7 . The method of  claim 6  wherein said liquid carrier is a hydrocarbon solvent.  
     
     
         8 . The method of  claim 6  wherein said liquid carrier is water and including sufficient surfactant to disperse the active ingredients in water.  
     
     
         9 . A coating mixture comprising: 
 a. active ingredients comprising from 15 to 30 weight percent tackifier and from 85 to 70 weight percent polyolefin powders having a size range from 1 to about 140 microns; and    b. a liquid carrier selected from the group consisting of hydrocarbon solvents and surfactant containing water in an amount from 1 to about 2 weight parts per part of active ingredients.    
     
     
         10 . The coating mixture of  claim 9  wherein the polyolefin powder is polyethylene powder.  
     
     
         11 . The coating mixture of  claim 10  wherein the particles of the polyethylene powder have a size range from 5 to about 40 microns.  
     
     
         12 . The coating mixture of  claim 1  wherein said tackifier is an aliphatic or cycloaliphatic hydrocarbon resin.