Use of an aqueous alkaline composition for the electroless deposition of a metal or metal alloy on a metal surface of a substrate

Abstract

An aqueous alkaline deposition composition for the electroless deposition or metal or metal alloy on a metal surface, the composition comprising:(a) functionalized urea derivatives and/or salts thereof selected from the group comprising compounds having formula I and/or salts thereof:whereinX is selected as oxygen;R1 and R2 are independently selected as nitrogen-comprising heteroaromatic compounds;wherein R1 and R2 can be identical or different;m is an integer from 1 to 6; andn is an integer from 1 to 6;wherein m and n can be identical or different;(b) one source of metal ions to be deposited onto the metal surface of the substrate wherein the deposited metal or metal alloy is different from the metal or metal alloy of the metal surface; and(c) optionally one source of alloying metal ions; and a method for the electroless deposition.

1 . A method of electroless deposition of a metal or metal alloy on a metal surface of a substrate, comprising immersion of the substrate into an aqueous alkaline deposition composition comprising:
 (a) functionalized urea derivatives and/or salts thereof selected from the group comprising compounds having formula I and/or salts thereof:   
       
         
           
           
               
               
           
         
         wherein
 X is selected as oxygen; 
 R 1  and R 2  are independently selected as nitrogen-comprising heteroaromatic compounds; 
 wherein R 1  and R 2  can be identical or different; 
 m is an integer from 2 to 6; and 
 n is an integer from 2 to 6; 
 wherein m and n can be identical or different; 
 
         (b) at least one source of metal ions providing metal ions to be deposited as metal onto the metal surface of the substrate wherein the deposited metal or metal alloy is different from the metal or metal alloy of the metal surface; 
         (c) optionally at least one source of alloying metal ions; and 
         wherein the compounds having formula I and/or salts thereof are present in the composition at a total concentration from 1 wt.-% to 20 wt.-% based on the total weight of the composition. 
       
     
     
         2 . The method according to  claim 1  wherein the at least one source of metal ions is selected from a group consisting of
 (ii) a metal anode material which is in contact with the aqueous alkaline deposition composition, wherein said metal anode material is oxidized by applying an electric current to said anode, to enable an anodic oxidation method, resulting in a release of metal ions into the aqueous alkaline deposition composition; and 
 (iii) a solid metal piece which is in contact with the aqueous alkaline deposition composition, wherein said solid metal piece is oxidized by an oxidizing agent dissolved the aqueous alkaline deposition composition, to enable an oxidation process, resulting in a release of metal ions into the aqueous alkaline deposition composition. 
 
     
     
         3 . The method according to  claim 1 ,
 wherein R 1  and R 2  is selected as substituted and/or unsubstituted imidazole, optionally comprising at least one substituent selected as C 1 -C 6  alkyl.   
     
     
         4 . The method according to  claim 1 , wherein n is an integer from 2 to 3 and/or m is an integer from 2 to 3. 
     
     
         5 . The method according to  claim 1 , wherein the aqueous alkaline deposition composition has a pH value from 7.1 to 13. 
     
     
         6 . The method according to  claim 1 , wherein the functionalized urea derivatives and/or salts thereof are selected as compounds having formula I and/or salts thereof, wherein m is 3, wherein n is 3,
 wherein R 1  is imidazole, optionally comprising at least one substituent selected as C 1 -C 6  alkyl;   and wherein R 2  is imidazole, optionally comprising at least one substituent selected as C 1 -C 6  alkyl.   
     
     
         7 . The method according to  claim 1 , wherein the compounds having formula I and/or salts thereof are present in the composition at a total concentration from 2 wt.-% to 15 wt.-%. 
     
     
         8 . The method according to  claim 2 , wherein the oxidizing agent for oxidizing the solid metal piece of the aqueous alkaline deposition composition comprises oxygen dissolved in the aqueous alkaline deposition composition. 
     
     
         9 . The method according to  claim 1 , wherein the at least one source of metal ions providing metal ions is selected from the group consisting of manganese, silver, copper, cobalt, and nickel. 
     
     
         10 . The method according to  claim 1 , wherein the at least one source of metal ions providing metal ions is present in the composition at a total concentration from 0.1 wt.-% to 15 wt.-% based on the total weight of the composition. 
     
     
         11 . The method according to  claim 1  wherein the composition does not comprise a reducing agent and/or an anionic agent. 
     
     
         12 . A method for the electroless deposition of a metal or metal alloy on a metal surface of a metal substrate, the method comprising the steps:
 (A) providing an aqueous alkaline deposition composition for the electroless deposition of a metal or metal alloy on a metal surface of a metal substrate according to  claim 1 , and   (B) contacting the substrate with said aqueous alkaline deposition composition such that the metal or metal alloy is deposited on the metal surface of the metal substrate in an electroless way.   
     
     
         13 . The method according to  claim 12  wherein the substrates to be treated comprise metals or metal alloys selected from the group consisting of aluminum, copper, nickel, cobalt, manganese, zinc, lead, antimony, tin, rare earth metals, copper-zinc alloy, copper-tin alloy, copper-nickel alloy, and aluminum-magnesium alloy. 
     
     
         14 . The method according to  claim 12  wherein the metal ions to be deposited are selected from the group consisting of silver ions, nickel ions, manganese ions, cobalt ions and copper ions. 
     
     
         15 . The method according to  claim 12 , wherein the method comprises the further step:
 (C) recycling the aqueous alkaline deposition composition after method step (B), wherein step (C) comprises the steps:
 (C1) Optionally increasing the temperature of the aqueous alkaline deposition composition to obtain a temperature-increased aqueous alkaline deposition composition, 
 (C2) Filtering the aqueous alkaline deposition composition or the optionally temperature-increased aqueous alkaline deposition composition to obtain a filtered aqueous alkaline deposition composition; and 
 (C3) Adding a source of metal ions and reapplying the filtered aqueous alkaline deposition composition to method step (A). 
   
     
     
         16 . The method according to  claim 1 , wherein the composition comprises (c) at least one source of alloying metal ions. 
     
     
         17 . The method according to  claim 3 , wherein the R1 or the R2 or both the R1 and the R2 are substituted imidazole comprising at least one substituent selected as C1-C6 alkyl. 
     
     
         18 . The method according to  claim 6 , wherein the R1 or the R2 or both the R1 and the R2 are substituted imidazole comprising at least one substituent selected as C1-C6 alkyl. 
     
     
         19 . The method according to  claim 15 , wherein step (C) comprises the steps:
 (C1) Increasing the temperature of the aqueous alkaline deposition composition to obtain a temperature-increased aqueous alkaline deposition composition, and   (C2) Filtering the temperature-increased aqueous alkaline deposition composition to obtain a filtered aqueous alkaline deposition composition.