Method for electrodeposition of bronzes

Abstract

Abstract of the Disclosure A method for electrodeposition of bronzes, with which the substrate to be coated is plated in an acid electrolyte that contains at least tin and copper ions, an alkylsulfonic acid and a wetting agent, and the preparation of such an electrolyte.

1.  A method for electrolytic deposition of bronze onto a substrate, the method comprising: 
      immersing a substrate in an aqueous acidic electrolyte containing: 
      a) tin ions; 
      b) copper ions; 
      c) an alkylsulfonic acid; and 
      d) a nonionic wetting agent selected from the group consisting of aliphatic nonionic wetting agents, substituted dithioglycols, and combinations thereof. 
   
   
       2.  The method of  claim 1  wherein the alkylsulfonic acid is present in the electrolyte at a concentration of from 140 to 382 g/L of electrolyte. 
   
   
       3.  The method of  claim 1  wherein the alkylsulfonic acid comprises methanesulfonic acid in a concentration of at least about 290 g/L. 
   
   
       4.  The method of  claim 1  wherein the electrolyte further contains an oxidation inhibitor. 
   
   
       5.  The method of  claim 1  wherein the electrolyte further contains a dihydroxybenzene compound as an oxidation inhibitor. 
   
   
       6.  The method of  claim 1  wherein the bronze deposited onto the substrate comprises at least about 60% by weight Cu. 
   
   
       7.  The method of  claim 1  wherein the nonionic wetting agent is present in the electrolyte at a concentration of from about 2 to about 40 g/L. 
   
   
       8.  The method of  claim 1  wherein tin methanesulfonate is present in the electrolyte in an amount of from about 5 to about 195 g/L of electrolyte, thereby providing the tin ions at a concentration of from about 2 to about 75 g/L of electrolyte. 
   
   
       9.  The method of  claim 1  wherein copper methanesufonate is present in the electrolyte in an amount of from about 8 to about 280 g/L of electrolyte, thereby providing the copper ions at a concentration of from about 2 to about 70 g/L of electrolyte. 
   
   
       10.  The method of  claim 1  wherein the electrolyte has a pH of less than about 1. 
   
   
       11.  The method of  claim 1  wherein the nonionic wetting agent comprises an aliphatic fatty alcohol ethoxylate. 
   
   
       12.  The method of  claim 1  wherein the nonionic wetting agent comprises the substituted dithioglycols. 
   
   
       13.  An aqueous acidic electrolyte containing: 
      a) tin ions; 
      b) copper ions; 
      c) an alkylsulfonic acid; and 
      d) a nonionic wetting agent selected from the group consisting of aliphatic nonionic wetting agents, substituted dithioglycols, and combinations thereof. 
   
   
       14.  The electrolyte of  claim 13  wherein the alkylsulfonic acid is present at a concentration of from about 140 to about 382 g/L of electrolyte. 
   
   
       15.  The electrolyte of  claim 13  wherein the alkylsulfonic acid comprises methanesulfonic acid in a concentration of at least about 290 g/L. 
   
   
       16.  The electrolyte of  claim 13  further containing an oxidation inhibitor. 
   
   
       17.  The electrolyte of  claim 13  further containing a dihydroxybenzene compound as an oxidation inhibitor. 
   
   
       18.  The electrolyte of  claim 13  wherein the nonionic wetting agent is present in the electrolyte at a concentration of from about 2 to about 40 g/L of electrolyte. 
   
   
       19.  The electrolyte of  claim 13  wherein the tin ions are present at a concentration of from about 2 to about 75 g/L of electrolyte, and the copper ions are present at a concentration of from about 2 to about 70 g/L of electrolyte. 
   
   
       20.  The electrolyte of  claim 13  wherein the aliphatic nonionic wetting agent comprises an aliphatic fatty alcohol ethoxylate. 
   
   
       21.  The electrolyte of  claim 13  wherein the nonionic wetting agent is the substituted dithioglycol. 
   
   
       22.  The electrolyte of  claim 21  wherein the substituted dithioglycol is selected from the group consisting of Thiobis(diethyleneglycol), Thiobis(hexaethylene glycol), Thiobis(pentadecaglycelol), Thiobis(icosaethyleneglycol), Thiobis(pentacontaethyleneglycol), 4,10-dioxa-7-thiatridecane-2,12-diol, Thiodiglycerin, Thiobis(triglycerin), 2,2'-Thiodibutanolbis(octaethyleneglycolpentaglycerol) ether, Thiobis(octaethyleneglycol)bis(2-chloroethyl)ether, Thiobis(decaethyleneglycol)bis(carboxymethyl)ether, Thiobis(dodecaethyleneglycol)bis(2-nitroethyl)ether, Thiodiglycolbis(carboxymethyl)ether, Dithiodiglycolbis(carboxymethyl)ether, Thiobis(dodecaethyleneglycol), Dithiobis(hentetracontaethyleneglycol), Dithiobis(icosaethyleneglycolpentapropyleneglycol), Dithiobis(triglycerol), Dithiobis(decaglycelol), 3,6-Dithiaoctane-1,8-diol, 1,3-Propanedithiolbis(decaethyleneglycol)thioether, 1,4-Buthanedithiolbis(pentadecaglycerol)thioether, 1,3-Dithioglycerolbis(pentaethyleneglycol)thioether, 1,2-Ethanedithiolbis(penta(1-ethyl)ethyleneglycol)thioether, 1,3-Dithioglycerolbis(di(1-ethyl)ethyleneglycol)thioether,2-Mercaptoethylsulfide bis(hexatriacontaethylene-glycol), 2-Mercaptoethylsulfidebis(icosaethyleneglycol)di-methylether, 2-Mercaptoethyletherbis(diethyleneglycol), Thiodiglyceroltetra(decaethyleneglycol)ether,Diethyleneglycolmonomethylthioether, Decaglycerolmono(6-methylthiohexyl)thioether, 2-Mercaptoethylsulfide-ω-{(2-bromoethyl) icosaethyleneglycol}thioether-ω'-{(2-bromoethyl) hectaethyleneglycol}thioether, 1,4-Butanediol-ω-{(2-benzyloxy-1-methyl)ethyl}thioether-ω'-(de capropyleneglycoloctacontaethyleneglycol)thioether, Dithiobis(icosaethyleneglycol)bis(2-methyl-thioethyl)ether, 1,2-Ethanediol-ω-(4-methoxybenzyl)thioether-ω'-(pentacontaethyleneglycol)thioether, Triacontaethyleneglycolmono(4-cyanobenzyl)thioether, Thiobis(pentadecaethyleneglycol)bisallylether, Tricosaethyleneglycolmono(4-formylphenetyl)thioether, Pentadecaethyleneglycolmono{(acetylmethyl)thioethyl}thioether, 1,2-Ethanediol-ω-(glycidyl)thioether-ω'-icosaethyleneglycolthioether, Octadecaethyleneglycolbis(2-methylthioethyl)ether, Hexadecaethyleneglycolmono(2-ethylthioethyl)thioether, Icosaethyleneglycolmonomethylthioether,  Undecaethyleneglycoldi(n-propyl)thioether, Dodecaethyleneglycolbis(2-hydroxyethyl)thioether, Undecaethyleneglycoldimethylthioether, Pentatriacontaethyleneglycolmono(2-n-butyldithioethyl)dithioether, 4,8,12-trithiapentadecane-1,2,6,10,14,15-hexaol, Icosaglycerolmono(2-ethylthioethyl)thioether, Triacontaethyleneglycolmono(2-methylthioethyl)thioether, Dithiobis(icosaethyleneglycol)dibenzylether, Tridecaethyleneglycolmonomethylthioether, Hexadecaethyleneglycol dimethylthioether, 1,2-Ethanedithiolbis(icosaethyleneglycol)thioether, Dithiobis(pentadecaethyleneglycol), 3,3'-thiodipropanol, and combinations thereof. 
   
   
       23.  The electrolyte of  claim 13  further containing a gluconate. 
   
   
       24.  The electrolyte of  claim 13  further containing hydroquinone. 
   
   
       25.  The electrolyte of  claim 13  having a pH of less than 1. 
   
   
       26.  An aqueous acidic electrolyte containing: 
      a) divalent tin ions at a concentration of from about 2 to about 75 g/L of electrolyte; 
      b) divalent copper ions at a concentration of from about 2 to about 70 g/L of electrolyte; 
      c) an aromatic, nonionic wetting agent at a concentration of from about 2 to about 40 g/L of electrolyte; 
      d) a stabilizer, complexing agent, or mixture thereof at a concentration of less than about 50 g/L of electrolyte; 
      e) a wetting agent selected from the group consisting of an anionic wetting agent, a nonionic, aliphatic wetting agent, and mixtures thereof at a concentration of less than about 10 g/L of electrolyte; 
      f) an oxidation inhibitor at a concentration of less than about 5 g/L of electrolyte; 
      g) a brightener at a concentration of less than about 5 g/L of electrolyte; and 
      h) an alkylsulfonic acid at a concentration of at least about 140 g/L of electrolyte. 
   
   
       27.  The electrolyte of  claim 26  wherein the alkylsulfonic acid comprises methanesulfonic acid in a concentration of at least about 290 g/L.