Powder coated with copper (i) oxide, and process for production thereof

Abstract

Disclosed is a powder coated with copper (I) oxide, in which copper (I) oxide is adhered well, which can be dispersed well in a stain-proof coating, and which can impart high storage stability to a stain-proof coating. Also disclosed is a process for producing a powder coated with copper (I) oxide, which comprises the following steps: a surface treatment step of contacting a core material with at least one aqueous surface treatment solution selected from an aqueous solution of a tin salt, an aqueous solution of a silver salt and an aqueous solution of a palladium salt to produce a surface-treated product of the core material; an electrodeposition step of dispersing the surface-treated product of the core material in an aqueous electrolyte solution containing an electrolyte and an anti-oxidant agent, and electrodepositing copper (I) oxide on the surface of the surface-treated product of the core material by using metal copper as an anode to produce a powder coated with copper (I) oxide; and a water-washing step of washing the powder coated with copper (I) oxide with water to produce the desired powder coated with copper (I) oxide, wherein the aqueous electrolyte solution has a chlorine ion concentration of 20 to 200 g/L.

1 . A cuprous oxide-coated powder comprising a core material and cuprous oxide coating the surface of the core material, wherein
 a mass ratio of the core material/the cuprous oxide is 95/5 to 10/90, and   an amount of chlorine ions dissolved from the cuprous oxide-coated powder in water is 0.1% by mass or less with respect to the cuprous oxide-coated powder.   
     
     
         2 . The cuprous oxide-coated powder according to  claim 1 , wherein the core material is a silicic acid-containing inorganic compound. 
     
     
         3 . The cuprous oxide-coated powder according to  claim 1 , wherein the core material is an alkaline earth metal compound. 
     
     
         4 . The cuprous oxide-coated powder according to  claim 1 , wherein the core material is an organic compound. 
     
     
         5 . The cuprous oxide-coated powder according to  claim 1 , wherein the core material is alumina. 
     
     
         6 . A method for manufacturing a cuprous oxide-coated powder, comprising:
 a surface treatment step of contacting a core material with any one or two or more surface treatment aqueous solutions of an aqueous solution of a stannous salt, an aqueous solution of a silver salt, and an aqueous solution of a palladium salt to obtain a surface-treated core material;   an electrodeposition step of dispersing the surface-treated core material in an electrolytic aqueous solution containing an electrolyte and an antioxidant, and electrodepositing cuprous oxide on the surface of the surface-treated core material, using metal copper as an anode, to obtain a cuprous oxide-coated powder; and   a water-washing step of water-washing the cuprous oxide-coated powder to obtain a cuprous oxide-coated powder, wherein   the concentration of chlorine ions in the electrolytic aqueous solution is 20 to 200 g/L.   
     
     
         7 . The method for manufacturing a cuprous oxide-coated powder according to  claim 6 , wherein the surface treatment aqueous solution is any one or two or more of an aqueous solution of tin fluoride, an aqueous solution of silver nitrate, and an aqueous solution of palladium chloride. 
     
     
         8 . The method for manufacturing a cuprous oxide-coated powder according to  claim 6 , wherein the electrolyte is sodium chloride. 
     
     
         9 . The method for manufacturing a cuprous oxide-coated powder according to  claim 6 , wherein the antioxidant is glycerin. 
     
     
         10 . The method for manufacturing a cuprous oxide-coated powder according to  claim 6 , wherein the water-washing step is performed by washing the cuprous oxide-coated powder with wash water containing an antioxidant.