Decorative surface finish and method of forming same

Abstract

A decorative metal finish for a part with a non-conductive surface where the non-conductive surface is lightly roughened to improve its adherence capabilities. A thin metal layer is electrolessly deposited on the lightly roughened surface to provide a bright durable metal finish on the non-conductive surface. An organic coating layer is deposited over the thin metal layer to provide protection for the metal finish.

1 . A method of preparing an article with a decorative metal finish, comprising:
 providing an electrically non-conductive article having at least one surface to receive the decorative metal finish;   mildly roughening said at least one surface such that its adherence capabilities are enhanced;   non-electrolytically depositing a thin first metal layer on said at least one surface; and   depositing at least one top protective translucent layer on said thin first metal layer.   
     
     
         2 . The method of  claim 1 , further comprising:
 activating said at least one surface of the electrically non-conductive article, and electrolessly plating the activated surface to deposit said thin first metal layer.   
     
     
         3 . The method of  claim 2 , wherein activating said at least one surface comprises chemically modifying said at least one surface to make it hydrophilic and adsorbing precious metal cations and/or nanoscopic precious metal particles on the hydrophilic surface. 
     
     
         4 . The method of  claim 3 , wherein the step of chemically modifying said at least one surface to make it hydrophilic is selected from one of the following: chemically oxidizing said at least one surface, electrolytically oxidizing said at least one surface, oxidizing said at least one surface with a plasma, sulfonation of said at least one surface, alkaline hydrolysis of said at least one surface, acid hydrolysis of said at least one surface, or a combination of these steps. 
     
     
         5 . The method of  claim 3 , wherein the step of chemically modifying said at least one surface to make it hydrophilic is selected from one of the following: chrome acid etch of said at least one surface, chrome sulfuric acid etch of said at least one surface, nitric acid etch of said at least one surface, or any combination of acid hydrolysis. 
     
     
         6 . The method of  claim 1 , wherein said at least one surface of said non-conductive article is a polymeric material that is selected from ABS terpolymer, polycarbonate, a blend of an ABS terpolymer and a polycarbonate, a thermoplastic polyolefin, nylon, or polyamide. 
     
     
         7 . The method of  claim 1 , wherein said non-conductive surface is mildly roughened to an rms roughness of from about 0.002 um to 0.1 um. 
     
     
         8 . The method of  claim 1 , wherein said non-conductive surface is mildly roughened to an rms roughness of about 0.02 um. 
     
     
         9 . The method of  claim 1 , wherein said thin first metal layer is comprised of nickel, silver, copper, or cobalt. 
     
     
         10 . The method of  claim 1 , further comprising:
 depositing a thin second metal layer over said thin first metal layer.   
     
     
         11 . The method of  claim 1 , wherein said thin first metal layer has a thickness of about 50 nm to 500 nm. 
     
     
         12 . The method of  claim 1 , wherein said thin first metal layer has a thickness of about 100 nm. 
     
     
         13 . The method of  claim 10 , wherein said thin second metal layer has a thickness of about 100 nm. 
     
     
         14 . The method of  claim 10 , wherein said thin second metal layer is comprised of a metal selected from silver, nickel, copper, cobalt, tin, palladium, rhodium, ruthenium or platinum. 
     
     
         15 . The method of  claim 10 , wherein said thin first metal layer is non-electrolytically deposited using an electroless plating technique. 
     
     
         16 . A method of preparing an article with a decorative metal finish, comprising:
 providing an electrically non-conductive article having at least one surface to receive the decorative metal finish;   electrolessly depositing a first metal layer on said at least one surface; and   depositing at least one top protective translucent layer on said first metal layer.   
     
     
         17 . The method of  claim 16 , further comprising:
 non-aggressively roughening said at least one surface such that its adherence capabilities are enhanced.   
     
     
         18 . The method of  claim 16 , further comprising:
 electrolessly depositing said first metal layer on a plurality of electrically non-conductive surfaces of the article.   
     
     
         19 . The method of  claim 17 , wherein said at least one surface is non-aggressively roughened to an rms roughness of from about 0.002 um to 0.1 um. 
     
     
         20 . The method of  claim 19 , wherein said at least one surface is non-aggressively roughened to an rms roughness of about 0.002 um. 
     
     
         21 . The method of  claim 17 , wherein said first metal layer has a thickness of 50 nm to 500 nm. 
     
     
         22 . The method of  claim 21 , wherein said first metal layer has a thickness of about 100 nm. 
     
     
         23 . The method of  claim 16 , further comprising:
 depositing a second metal layer over said first metal layer.   
     
     
         24 . The method of  claim 16 , wherein said first metal layer is comprised of a metal selected from nickel, silver, copper or cobalt. 
     
     
         25 . The method of  claim 23 , wherein said second metal layer is comprised of a metal selected from silver, nickel, copper, cobalt, tin, palladium, rhodium, ruthenium or platinum. 
     
     
         26 . A method of preparing an article with a decorative metal finish comprising:
 providing an electrically non-conductive article having a plurality of surfaces;   electrolessly depositing a first metal layer on substantially all of said plurality of surfaces to provide a decorative metal finish;   depositing at least one top protective translucent layer on said first metal layer.   
     
     
         27 . The method of  claim 26 , further comprising:
 non-aggressively roughening at least one of said plurality of surfaces such that its adherence capabilities are enhanced.   
     
     
         28 . The method of  claim 27 , wherein said at least one surface is non-aggressively roughened to an rms roughness of from about 0.002 um to 0.1 um. 
     
     
         29 . The method of  claim 28 , wherein said at least one surface is non-aggressively roughened to an rms roughness of about 0.02 um. 
     
     
         30 . The method of  claim 27 , wherein said first metal layer has a thickness of 50 nm to 500 nm. 
     
     
         31 . The method of  claim 30 , wherein said first metal layer has a thickness of about 100 nm. 
     
     
         32 . The method of  claim 26 , further comprising:
 depositing a second metal layer over said first metal layer.   
     
     
         33 . The method of  claim 26 , wherein said first metal layer is comprised of a metal selected from nickel, silver, copper or cobalt. 
     
     
         34 . The metal of  claim 32 , wherein said second metal layer is comprised of a metal selected from silver, nickel, copper, cobalt, tin, palladium, rhodium, ruthenium or platinum.