Surface-treated steel sheet, metal container, and method for producing surface-treated steel sheet

Abstract

There is provided a surface-treated steel sheet ( 1 ) comprising: a tin-plated steel sheet ( 10 ) obtained by tin-plating a steel sheet ( 11 ); a phosphate compound layer ( 20 ) containing tin phosphate formed on the tin-plated steel sheet ( 10 ); and an aluminum-oxygen compound layer ( 30 ) on the phosphate compound layer ( 20 ), a main constituent of the aluminum-oxygen compound layer ( 30 ) being an aluminum-oxygen compound; wherein, when the 3d 5/2 spectrum of tin in the aluminum-oxygen compound layer ( 30 ) is determined using an X-ray photoelectron spectroscopy, the ratio of the integration value of the profile derived from tin oxide to the integration value of the profile derived from tin phosphate (tin oxide/tin phosphate) is 6.9 or more.

1 . A surface-treated steel sheet comprising:
 a tin-plated steel sheet obtained by tin-plating a steel sheet;   a phosphate compound layer containing tin phosphate formed on the tin-plated steel sheet; and   an aluminum-oxygen compound layer formed on the phosphate compound layer, a main constituent of aluminum-oxygen compound layer being an aluminum-oxygen compound,   wherein, when the 3d 5/2  spectrum of tin in the aluminum-oxygen compound layer is determined using an X-ray photoelectron spectroscopy, the ratio of the integration value of the profile derived from tin oxide to the integration value of the profile derived from tin phosphate (tin oxide/tin phosphate) is 6.9 or more.   
     
     
         2 . The surface-treated steel sheet according to  claim 1 , wherein the aluminum-oxygen compound layer contains aluminum phosphate. 
     
     
         3 . The surface-treated steel sheet according to  claim 1 , wherein the total amount of phosphorus contained in each of the layers formed on the tin-plated steel sheet is 0.5 to 20 mg/m 2 . 
     
     
         4 . The surface-treated steel sheet according to  claim 1 , wherein the content of aluminum in the aluminum-oxygen compound layer is 3 to 40 mg/m 2 . 
     
     
         5 . The surface-treated steel sheet according to  claim 1 , wherein the aluminum-oxygen compound layer comprises substantially no fluorine. 
     
     
         6 . The surface-treated steel sheet according to  claim 1 , wherein the tin-plated steel sheet consists of the steel sheet, a tin alloy layer formed on the steel sheet, and a tin-plating layer formed on the tin alloy layer, and the total amount of tin in the tin alloy layer and the tin-plating layer is 1.0 g/m 2  or more. 
     
     
         7 . A metal container formed of the surface-treated steel sheet according to  claim 1 . 
     
     
         8 . A metal container comprising:
 the surface-treated steel sheet according to  claim 1 , and   a coating layer formed on the aluminum-oxygen compound layer, a main constituent of the coating layer being an organic material.   
     
     
         9 . A method for producing a surface-treated steel sheet comprising:
 forming a phosphate compound layer on a tin-plated steel sheet by means of cathode electrolytic treatment, wherein the tin-plated steel sheet is obtained by tin-plating a steel sheet; and   forming an aluminum-oxygen compound layer on the phosphate compound layer by means of electrolytic treatment using an electrolytic treatment liquid containing aluminum.   
     
     
         10 . The method for producing a surface-treated steel sheet according to  claim 9 , wherein the phosphate compound layer is formed on the tin-plated steel sheet by means of the cathode electrolytic treatment after anode electrolytic treatment is conducted. 
     
     
         11 . The method for producing a surface-treated steel sheet according to  claim 9 , wherein a treatment liquid having a phosphate content of 0.55 g/L or less in terms of phosphorus is used as the electrolytic treatment liquid.