Solution for removing titanium-containing coatings and method for same

Abstract

A solution and method for removing titanium-containing coatings from the surface of substrates using the solution are provided. The solution includes 90-1000 g/L organic or inorganic acid; 70-500 g/L accelerant, the accelerant being acid or salt which contains fluorinion; 15-200 g/L secondary accelerator, the secondary accelerator being generic amino alcohols which can combine with titanium ion; 2-8 g/L inhibiter, the inhibiter being selected from one or more of the group consisting of thiourea, thiourea derivatives, and carbamide. The method for removing titanium-containing coating on the substrate mainly includes contacting the substrate with the titanium-containing coating with the solution.

1 . An aqueous solution for removing titanium-containing coatings on substrate surface, comprising:
 90-1000 g/L organic or inorganic acid;   70-500 g/L accelerant, the accelerant being an acid or salt containing fluorinion;   15-200 g/L secondary accelerator, the secondary accelerator being generic amino alcohols and can combine with titanium ion; and   2-8 g/L inhibiter, the inhibiter selected from one or more of the group consisting of thiourea, thiourea derivatives, and carbamide.   
     
     
         2 . The aqueous solution as claimed in  claim 1 , wherein the acid is selected from one or more of the group consisting of sulphuric acid, acetic acid, citric acid, and lactic acid. 
     
     
         3 . The aqueous solution as claimed in  claim 2 , wherein the acid is sulphuric acid or acetic acid. 
     
     
         4 . The aqueous solution as claimed in  claim 1 , wherein the concentration of the acid is about 90-750 g/L. 
     
     
         5 . The aqueous solution as claimed in  claim 1 , wherein the accelerant is selected from one or more of the group consisting of hydrofluoric acid, ammonium bifluoride, sodium fluoride, potassium fluoride, sodium fluoborate, and zirconium sodium fluoride. 
     
     
         6 . The aqueous solution as claimed in  claim 5 , wherein the accelerant is hydrofluoric acid and/or ammonium bifluoride. 
     
     
         7 . The aqueous solution as claimed in  claim 1 , wherein the concentration of the accelerant is about 75-300 g/L. 
     
     
         8 . The aqueous solution as claimed in  claim 1 , wherein the secondary accelerator is selected from one or more of the group consisting of ethanolamine, diethanolamine, and triethanolamine. 
     
     
         9 . The aqueous solution as claimed in  claim 1 , wherein the concentration of the secondary accelerator is about 30-80 g/L. 
     
     
         10 . The aqueous solution as claimed in  claim 1 , wherein the inhibiter is thiourea or thiourea derivatives. 
     
     
         11 . The aqueous solution as claimed in  claim 1 , wherein the concentration of the inhibiter is about 3-5g/L. 
     
     
         12 . A method for removing titanium-containing coating on substrate, comprising:
 providing an aqueous solution, the aqueous solution containing 90-1000 g/L organic or inorganic acid, 70-500 g/L accelerant, the accelerant being an acid or salt containing fluorinion, 15-200 g/L secondary accelerator, the secondary accelerator being generic amino alcohols and can combine with titanium ion, and 2-8 g/L inhibiter, the inhibiter being selected from one or more of the group consisting of thiourea, thiourea derivatives, and carbamide; and   contacting the substrate with the titanium-containing coating with the aqueous solution.   
     
     
         13 . The method as claimed in  claim 12 , wherein the acid is selected from one or more of the group consisting of sulphuric acid, acetic acid, citric acid, and lactic acid. 
     
     
         14 . The method as claimed in  claim 12 , wherein the accelerant is selected from one or more of the group consisting of hydrofluoric acid, ammonium bifluoride, sodium fluoride, potassium fluoride, sodium fluoborate, and zirconium sodium fluoride. 
     
     
         15 . The method as claimed in  claim 12 , wherein the secondary accelerator is selected from one or more of the group consisting of ethanolamine, diethanolamine, and triethanolamine. 
     
     
         16 . The method as claimed in  claim 12 , wherein the aqueous solution has a temperature of about 20-30° C., the contact time between the substrate and the aqueous solution is about 0.5-2 hours. 
     
     
         17 . The method as claimed in  claim 12 , wherein the substrate is made of metal or plastic. 
     
     
         18 . The method as claimed in  claim 17 , wherein the metal is one of the ferric-based alloy, copper, and copper alloy. 
     
     
         19 . The method as claimed in  claim 12 , wherein the titanium-containing coating is titanium nitride coating, titanium carbide coating, or titanium carbonitride coating. 
     
     
         20 . The method as claimed in  claim 12 , wherein the substrate contacts the aqueous solution by immersion or spraying.