Method for producing aluminum film

Abstract

Provided is a method for producing an aluminum film, which is capable of continuously mass-producing aluminum films having excellent surface smoothness and a mirror surface. A method for producing an aluminum film includes electrodepositing aluminum on a surface of a substrate in an electrolyte solution, in which the electrolyte solution contains, as components, (A) an aluminum halide, (B) at least one compound selected from the group consisting of an alkyl pyridinium halide, an alkyl imidazolium halide, and a urea compound, and (C) 1,10-phenanthroline monohydrate; in which the mixing ratio (molar ratio) of the component (A) to the component (B) is in the range of 1:1 to 3:1; and in which the concentration of the 1,10-phenanthroline monohydrate in the electrolyte solution is controlled to be in the range of 0.05 to 7.5 g/L.

1 . A method for producing an aluminum film comprising electrodepositing aluminum on a surface of a substrate in an electrolyte solution,
 wherein the electrolyte solution contains, as components:   (A) an aluminum halide,   (B) at least one compound selected from the group consisting of an alkyl pyridinium halide, an alkyl imidazolium halide, and a urea compound, and   (C) 1,10-phenanthroline monohydrate;   wherein the mixing ratio (molar ratio) of the component (A) to the component (B) is in the range of 1:1 to 3:1; and   wherein the concentration of the 1,10-phenanthroline monohydrate in the electrolyte solution is controlled to be in the range of 0.05 to 7.5 g/L.   
     
     
         2 . The method for producing an aluminum film according to  claim 1 , wherein the concentration of the 1,10-phenanthroline monohydrate in the electrolyte solution is controlled by measuring an overvoltage during electrodeposition of aluminum in the electrolyte solution and by adjusting the amount of 1,10-phenanthroline monohydrate added to the electrolyte solution such that the measured value of the overvoltage is within a set range. 
     
     
         3 . The method for producing an aluminum film according to  claim 1 , wherein the component (A) is aluminum chloride and the component (B) is 1-ethyl-3-methylimidazolium chloride. 
     
     
         4 . The method for producing an aluminum film according to  claim 1 , wherein the substrate is a resin molded body having a three-dimensional network structure which has been subjected to conductivity-imparting treatment.