Process for making metallic platelets

Abstract

A method is provided for producing metallic platelets. By determining the ratio of the diameter of the metal source to the thickness of the metallic platelet and the workability of the metal source, a high quality metallic platelet can be developed. According to this method, the platelets that are produced can be used in such applications as building and construction materials for improved weather-resistance, heat-reflection/management, anti-fouling resistance and architectural appearance.

What is claimed:  
     
         1 . A process for making a platelet, said process comprising rolling a metal piece in one-step to form the platelet, wherein: 
 D=diameter of the metal piece    t=thickness of the platelet    and 1≦D/t≦15.    
     
     
         2 . A process for making a platelet according to  claim 1 , wherein said metal piece is selected from the group consisting of metal chops, shot, cut-wire, shavings, powders, granules and mixtures thereof.  
     
     
         3 . A process for making a platelet according to  claim 1 , wherein said metal piece comprises a substance selected from the group consisting of copper, bronze, brass, tin, aluminum, stainless steel, iron, lead, gold, silver, platinum, nickel, cobalt and alloys thereof.  
     
     
         4 . A process for making a platelet according to  claim 1 , wherein said platelet is flat and free from visible cracks or splits and an aspect ratio <2.  
     
     
         5 . A process for making a platelet according to  claim 1 , wherein substantially all of said metal pieces have a diameter of from about 0.01 inches to about 0.50 inches.  
     
     
         6 . A process for making a platelet according to  claim 1 , wherein substantially all of said platelets have a thickness of from about 0.005 inches to about 0.020 inches.  
     
     
         7 . A process for making a platelet according to  claim 1 , wherein the D/t<7.  
     
     
         8  A process for making a platelet comprising the process of  claim 1  and further comprising using a secondary operation to alter the appearance of the platelet.  
     
     
         9 . A process according to  claim 8 , wherein said secondary operation comprises using an acidic, a basic or a solvent solution.  
     
     
         10 . A process according to  claim 8 , wherein said secondary operation comprises using a post-heat treatment under an atmosphere containing one or more substances selected from the group consisting of air, hydrogen, nitrogen and inert gases.  
     
     
         11 . A process according to  claim 8 , wherein said secondary operation comprises electroplating another metal onto the surface of the platelet.  
     
     
         12 . A process according  claim 8 , wherein said secondary operation comprises coating the metallic platelet with an organic or organic coating.  
     
     
         13 . A method for making a metallic platelet comprising: 
 a. determining a desired thickness of a metallic platelet;    b. selecting a metal piece based on said desired thickness of said metallic platelet; and    c. forming said metallic platelet from said metal piece.    
     
     
         14 . A method for making a metallic platelet according to the method of  claim 13 , wherein step (b) comprises selecting said metal piece such that it has a diameter that is less than 15 times the desired thickness of said metallic platelet.  
     
     
         15 . A method for making a metallic platelet according to  claim 13 , wherein said a diameter that is less than 7 times the desired thickness of said metallic platelet.  
     
     
         16 . A method for making a metallic platelet according to  claim 13 , further comprising rolling said metal piece.  
     
     
         17 . A method for making a metallic platelet of  claim 14  for use in roofing, building and construction materials.  
     
     
         18 . A method for making a roof comprising combining said metallic platelet of  claim 11  with a roofing material.  
     
     
         19 . A method for making a roof according to  claim 18 , wherein said roofing material is asphalt.