Process for increasing the adhesion of a metal surface to a polymer

Abstract

A process for increasing the adhesion between a copper or copper alloy surface and a polymeric material is disclosed. The process comprises treating the copper or copper alloy surface with an aqueous solution of cupric ions at a pH from 2.8 to 4.2 to form an oxide conversion coating on the copper or copper alloy surface. The so treated surface can then be bonded to the polymeric material.

1 . A process for increasing the adhesion of a copper or copper alloy surface to a material comprising polymers, said process comprising:
 a) contacting the copper or copper alloy surface with a composition comprising:
 1. water; 
 2. a source of cupric ions; 
 at a pH from 2.8 to 4.2; 
 such that a conversion coating is formed on the copper or copper alloy surface. 
   
     
     
         2 . A process according to  claim 1 , wherein the composition is substantially free of azole compounds. 
     
     
         3 . A process according to  claim 1  wherein the composition also comprises a buffer. 
     
     
         4 . A process according to  claim 4  wherein the buffer is selected from the group consisting of potassium or sodium carbonate, sodium citrate and sodium hydrogen phosphate, and potassium hydrogen phthalate and sodium hydroxide. 
     
     
         5 . A process according to  claim 1  wherein the source of cupric ions is selected from the group consisting of cupric sulfate, cupric chloride, cupric acetate and mixtures of the foregoing. 
     
     
         6 . A process according to  claim 1  wherein the pH is from 3 to 4. 
     
     
         7 . A process according to  claim 3 , wherein the composition is substantially free of azole compounds. 
     
     
         8 . A process according to  claim 7  wherein the buffer is selected from the group consisting of potassium or sodium carbonate, sodium citrate and sodium hydrogen phosphate, and potassium hydrogen phthalate and sodium hydroxide. 
     
     
         9 . A process according to  claim 8  wherein the source of cupric ion source selected from the group consisting of cupric sulfate, cupric chloride, cupric acetate, and mixtures of the foregoing. 
     
     
         10 . A process according to  claim 9  wherein the pH is from 3 to 4.