High purity electrolytic sulfonic acid solutions

Abstract

Disclosed is a solution for an electrochemical process, the solution containing a sulfonic acid and having a low concentration of sulfur compounds, either low or high valence, that are susceptible to reduction and which is intended for use in electrodeposition, batteries, conductive polymers and descaling processes.

1 . An aqueous solution for use in an electrochemical process, the solution comprising a sulfonic acid and low concentrations of low-valent sulfur (II) and sulfur (IV) compounds and higher valent sulfur (VI) compounds that are susceptible to reduction.  
     
     
         2 . The solution of  claim 1  wherein the low-valent sulfur (II) and sulfur (IV) compounds and higher-valent sulfur (VI) compounds are dimethyl disulfide, dimethyl sulfide, dimethyl sulfone, tricloromethyl methyl sulfone, dichloromethyl methyl sulfone, methyl methanethiosulfonate, and methyl methanesulfonate.  
     
     
         3 . The solution of  claim 1  for use in electrodeposition, batteries, conductive polymers and descaling processes.  
     
     
         4 . The solution of  claim 1  wherein the total amount of reduced sulfur(IV) compounds is less than 50 mg/liter.  
     
     
         5 . The solution of  claim 1  wherein the concentration of reduced sulfur (II) compounds is less than 50 mg/liter.  
     
     
         6 . The solution of  claim 1  wherein the sulfonic acid is derived from an alkyl monosulfonic acid, an alkyl polysulfonic acid or an aryl mono or polysulfonic acid.  
     
     
         7 . The solution of  claim 1  wherein the sulfonic acid is:  
       
         
           
           
               
               
           
         
       
       wherein a+b+c+y equals 4, R, R′ and R″ are the same or different and each independently are hydrogen, phenyl, Cl, F, Br, I, CF 3  or a lower C 1-9  alkyl group that is unsubstituted or substituted by oxygen, Cl, F, Br, I, CF 3 , or —SO 2 OH.  
     
     
         8 . The solution of  claim 7  wherein sulfonic acid is methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid, methanedisulfonic acid, monochloromethanedisulfonic acid, dichloromethanedisulfonic acid, 1,1-ethanedisulfonic acid, 2-chloro-1,1-ethanedisulfonic acid, 1,2-dichloro-1,1-ethanedisulfonic acid, 1,1-propanedisulfonic acid, 3-chloro-1,1-propanedisulfonic acid, 1,2-ethylene disulfonic acid, 1,3-propylene disulfonic acid, trifluormethanesulfonic acid, butanesulfonic acid, perfluorobutanesulfonic acid, pentanesulfonic acid, phenylsulfonic acid, phenolsulfonic acid, paratoluenesulfonic acid, xylenesulfonic acid or mixtures thereof.  
     
     
         9 . The composition of  claim 7  wherein the sulfonic acid is a free alkanesulfonic acid and has a concentration range from 1 to 1480 g/l.  
     
     
         10 . The composition of  claim 9 , wherein the concentration of the free alkanesulfonic acid is about 10 to about 700 grams per liter of solution.  
     
     
         11 . The composition of  claim 9 , wherein the concentration of the free alkanesulfonic acid is about 30 to about 500 grams per liter of solution.  
     
     
         12 . The composition of  claim 1  wherein the pH is between −2 to 13.  
     
     
         13 . The solution of  claim 1  wherein the acid is a mixture of a sulfonic acid with other inorganic or organic acids.  
     
     
         14 . The solution of  claim 1  which contains a metal sulfonate salt or other metal salts and free sulfonic acids and which is intended for use in electrodeposition, batteries, conductive polymers or descaling processes.  
     
     
         15 . The solution of  claim 14  wherein the metal salt is introduced as an alkyl or aryl sulfonic acid of formula:  
       
         
           
           
               
               
           
         
       
       wherein a+b+c+y equals 4, M is a metal selected from metals in Group 1B, 2B, 3A, 3B, 4A, 4B, 5A, 5B, 6B, 7B, 8B, lanthanide or actinide metals of the periodic table and ammonium ion or mixtures thereof, R, R′ and R″ are the same or different and each independently is hydrogen, phenyl, Cl, F, Br, I, CF 3  or a C 1-23  alkyl group that is unsubstituted or substituted by oxygen, Cl, F, Br, I, CF 3 , or —SO 2 OH.  
     
     
         16 . The solution of  claim 14  wherein the sulfonic acid of the anionic portion of the metal salt and any free sulfonic acids are introduced as an alkyl sulfonic acid of formula:  
       
         
           
           
               
               
           
         
       
       wherein a+b+c+y equals 4, 
 R, R′ and R″ are the same or different and each independently are hydrogen, phenyl, Cl, F, Br, I, CF 3  or C 1-23  alkyl group that is unsubstituted or substituted by oxygen, Cl, F, Br, I, CF 3 , or —SO 2 OH.  
 
     
     
         17 . The solution of  claim 14  wherein the metal salts will be employed at a concentration from about 1 to about 600 grams per liter of aqueous solution.  
     
     
         18 . The solution of  claim 14  wherein the sulfonic acid is methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid, trifluoromethanesulfonic acid or mixtures thereof.  
     
     
         19 . The solution of  claim 14  wherein the metal sulfonate salt or other metal salts is selected from metals in group 1B, 2B, 3A, 3B, 4A, 4B, 5A, 5B, 6B, 7B, 8B, lanthanide or actinide mews of the periodic table and ammonium ion or mixtures thereof.  
     
     
         20 . The solution of  claim 14  wherein the metal sulfonic acid salt is zinc methanesulfonate.  
     
     
         21 . The solution of  claim 14  wherein the metal sulfonic acid salt is copper methanesulfonate.  
     
     
         22 . The solution of  claim 14  wherein the metal sulfonic acid salt is nickel methanesulfonate.  
     
     
         23 . The solution of  claim 14  wherein the metal sulfonic acid salt is ferrous methanesulfonic.  
     
     
         24 . The solution of  claim 14  wherein the metal sulfonic acid salt is an alkali or alkaline earth metal.  
     
     
         25 . The solution of  claim 14  wherein the metal sulfonate salt or other metal salt is supplied as a mixture of a metal sulfonate salts selected from metals in Group 1B, 2B, 3A, 3B, 4A, 4B, 5A, 5B, 6B, 7B, 8B, lanthanide and actinide metals of the periodic table and ammonium ion.  
     
     
         26 . The solution of  claim 1  wherein a buffering agent is added to modulate the pH of the aqueous solution.  
     
     
         27 . The solution of  claim 26  wherein the buffer is boric acid.  
     
     
         28 . The solution of  claim 1  which contains an organic monomer selected from aniline or substituted aniline or pyrrole.  
     
     
         29 . A process for the preparation or high purity alkanesulfonic acids wherein free alkanesulfonic acid is first treated to remove low-valent sulfur molecules by: adding to the free alkanesulfonic acid sufficient oxidizing agent to increase the valency of the low-valent sulfur molecules, mixing the sulfonic acid at temperatures between 25° C. to about 95° C. for a sufficient time to increase the valency of the low-valent sulfur molecules, optionally, heating the alkanesulfonic acid to elevated temperatures to remove residual oxidizing agent, and optionally, adding activated carbon powder to remove residual impurities.  
     
     
         30 . The process of  claim 29  wherein the oxidizing agent is selected from hydrogen peroxide, nitric acid, permanganate, an anodic electric current, monoperoxysulfate, aqueous solution of chlorine, or a halogen in a solution of a carboxylic acid.  
     
     
         31 . A process of making metal-sulfonate solutions by dissolving sufficient pure metal, metal carbonate, metal oxide or other metal salts into an aqueous solution according to  claim 1  to provide a metal ion concentration varies from 1 g/l to 500 g/l.  
     
     
         32 . A process for the deposition of a metal from the solution in  claim 14  comprising passing an electric current through the solution to electroplate a metal or a metal alloy onto a substrate.  
     
     
         33 . The process of  claim 32  wherein the substrate is a semiconductor device, a printed circuit hoard, an inert electrode, steel, copper or copper-alloy, nickel or nickel-alloy, cobalt or cobalt alloy, a refractory metal or oxide, carbon or an organic substrate.  
     
     
         34 . The process of  claim 32  wherein the sulfonic acid is methanesulfonic acid.  
     
     
         35 . The process of  claim 32  wherein the aqueous solution contains a mixture of sulfonic acids and other inorganic and organic acids.  
     
     
         36 . The process of  claim 32  wherein the electric current is a direct current, pulsed current or periodic reverse current.  
     
     
         37 . The process of  claim 32  wherein a soluble or an insoluble or inert anode is used.  
     
     
         38 . The process of  claim 32  wherein the temperature of the metal sulfonic acid electrolyte is between 0° C. to 95° C.  
     
     
         39 . The process of  claim 32  wherein the metal is a pure metal or a metal alloy, the metal selected from Group 1B, 2B, 3A, 3B, 4A, 4B, 5A, 5B, 6B, 7B, 8B, the lanthanide or actinide metals or alloys thereof.  
     
     
         40 . A process for the de-scaling of a metal item comprising immersing a metal item having a scale layer thereon into the solution of  claim 6  and passing an electric current through the solution to remove the scale layer.  
     
     
         41 . The process of  claim 40  wherein the metal item is a semiconductor device, a printed circuit board, an inert electrode, steel, copper or copper-alloy, nickel or nickel-alloy, cobalt or cobalt alloy, a refractory metal or oxide, carbon or an organic substrate.  
     
     
         42 . The process of  claim 40  wherein the acid is methanesulfonic acid.  
     
     
         43 . The process of  claim 40  wherein the aqueous solution contains a mixture of sulfonic acids and other inorganic and organic acids.  
     
     
         44 . The process of  claim 40  wherein the electric current is a direct current, pulsed current or periodic reverse current.  
     
     
         45 . The process of  claim 40  wherein a soluble or an insoluble or inert electrode is used.