Trivalent chromium plating solution and trivalent chromium plating method using same

Abstract

A trivalent chromium plating solution that does not cause the problems including the occurrence of deposition failure of the plating and color unevenness, such as a brown stripe pattern, in the plating even though a metal impurity is incorporated into the plating solution, and a trivalent chromium plating method are provided by a trivalent chromium plating solution containing a trivalent chromium compound, a chloride as a conductive salt, a pH buffering agent, and a complexing agent, further containing an unsaturated sulfonic acid compound represented by the following general formula (1) (wherein in the formula (1), R1 represents a hydrocarbon group having a number of carbon atoms of from 1 to 10, hydrogen, or a halogen; R2 represents nothing or a hydrocarbon group having a number of carbon atoms of from 1 to 10; and X represents hydrogen or an alkali metal), and a trivalent chromium plating method using the same.R1—CH═CH—R2—SO3X  (1)

1 . A trivalent chromium plating solution, comprising:
 a trivalent chromium compound,   a chloride as a conductive salt,   a pH buffering agent,   a complexing agent, and   an unsaturated sulfonic acid compound of formula (1):
   R 1 —CH═CH—R 2 —SO 3 X  (1)
 
   wherein R 1  represents a hydrocarbon group having a number of carbon atoms of from 1 to 10, hydrogen, or a halogen;   R 2  represents nothing or a hydrocarbon group having a number of carbon atoms of from 1 to 10; and   X represents hydrogen or an alkali metal.   
     
     
         2 . The trivalent chromium plating solution according to  claim 1 , wherein the unsaturated sulfonic acid compound is at least one selected from the group consisting of sodium vinylsulfonate, sodium allylsulfonate, sodium p-styrenesulfonate, and sodium β-styrenesulfonate. 
     
     
         3 . The trivalent chromium plating solution according to  claim 1 , wherein the chloride is at least one selected from the group consisting of potassium chloride, ammonium chloride, and sodium chloride. 
     
     
         4 . The trivalent chromium plating solution according to  claim 1 , further comprising:
 a metal impurity.   
     
     
         5 . The trivalent chromium plating solution according to  claim 1 , further comprising:
 nickel.   
     
     
         6 . The trivalent chromium plating solution according to  claim 1 , wherein the trivalent chromium plating solution comprises substantially no iron and/or cobalt. 
     
     
         7 . A trivalent chromium plating method, comprising:
 electroplating an article with the trivalent chromium plating solution according to  claim 1 .   
     
     
         8 . A method for enhancing resistance of a trivalent chromium plating solution against metal impurities contained in the trivalent chromium plating solution, the method comprising:
 adding an unsaturated sulfonic acid compound in the trivalent chromium plating solution,   wherein the trivalent chromium plating solution comprises a trivalent chromium compound, a chloride as a conductive salt, a pH buffering agent, and a complexing agent, and   the unsaturated sulfonic acid compound is a compound of formula (1):
   R 1 —CH═CH—R 2 —SO 3 X  (1)
 
   wherein R 1  represents a hydrocarbon group having a number of carbon atoms of from 1 to 10, hydrogen, or a halogen; R 2  represents nothing or a hydrocarbon group having a number of carbon atoms of from 1 to 10; and X represents hydrogen or an alkali metal.   
     
     
         9 . A method for preventing burnt deposit in a high current density in plating with a trivalent chromium plating solution, the method comprising:
 adding an unsaturated sulfonic acid and nickel in the trivalent chromium plating solution,   wherein the trivalent chromium plating solution comprises a trivalent chromium compound, a chloride as a conductive salt, a pH buffering agent, and a complexing agent, and   the unsaturated sulfonic acid compound is a compound of formula (1):
   R 1 —CH═CH—R 2 —SO 3 X  (1)
 
   wherein R 1  represents a hydrocarbon group having a number of carbon atoms of from 1 to 10, hydrogen, or a halogen; R 2  represents nothing or a hydrocarbon group having a number of carbon atoms of from 1 to 10; and X represents hydrogen or an alkali metal.   
     
     
         10 . A chromium-plated product comprising:
 an article, electroplated with the trivalent chromium plating solution according to  claim 1 .   
     
     
         11 . The chromium-plated product according to  claim 10 , wherein the chromium plating comprises substantially no iron and/or cobalt.