Patent ID: 8486491

Claim:
A process for producing surface conditioned aluminum castings, comprising a step of applying to aluminum castings an alkaline surface conditioning liquid which comprises: at least one alkaline ingredient (A) selected from the group consisting of hydroxides, silicates, aluminates, phosphates and condensed phosphates Of sodium and potassium; at least one organic builder and/or one chelating agent, wherein the alkaline surface conditioning liquid has a surface conditioning activity “CD” in mol/l, “CD” being defined as a value “CA”, in mol/l, of content in terms of sodium hydroxide as measured according to a first method, minus a value “CB”, mol/l, of content in terms of sodium hydroxide as measured according to a second method; and a coefficient of gloss “CE” in g/mol, “CE” being defined as a value “CC”, in g/l, of concentration of the at least one organic builder and/or chelating agent, divided by the surface conditioning activity “CD”, in mol/l, both of which are set to respectively satisfy conditions: 0.05≦CD≦2.3 and 2.8≦CE≦90, wherein the first method provides a value measured in terms of acid consumption amount based on JIS K 0102.15.2, and the second method provides a total of a value obtained by first measuring an amount of inorganic carbon by inorganic carbon measurement of TOC measurement based on JIS K 0102.22 and then calculating a value alkaline ingredient in terms of sodium hydroxide converted to Na 2 CO 3 using the amount of inorganic carbon as amount of carbon present as Na 2 CO 3 and a value obtained by first measuring an aluminum concentration based on JIS K 0102.58 and then calculating a value of alkaline ingredient in terms of sodium hydroxide converted to as NaAl(OH) 4 using the aluminum concentration as amount Of aluminum present as NaAl(OH) 4 .