Surface-treated metal material and producing method thereof

1. A surface-treated metal material comprising a composite film formed on a surface of a metal material, the composite film containing:

an organic silicon compound (W) having two or more functional groups (a) represented by Formula SiR 1 R 2 R 3 , where each of R 1 , R 2 and R 3 represents an alkoxy group or a hydroxyl group independently from each other, and at least one of them represents an alkoxy group; and one or more hydrophilic functional group (b) of at least one kind selected from a hydroxyl group different from what can be included in the functional group (a) and an amino group, in a molecule, wherein the organic silicon compound (W) has an average molecular weight of 1000 to 10000;

at least one kind of fluorine compound (X) selected from titanium hydrofluoric acid and zirconium hydrofluoric acid;

a phosphoric acid (Y);

a vanadium compound (Z); and

at least one kind of lubricant (J) selected from the group consisting of water dispersible polyethylene wax, polypropylene wax, and polytetrafluoroethylene and has a number average particle size of 0.01 μm to 1.0 μm and a softening temperature of 100° C. or more,

wherein the organic silicon compound (W) is obtained by combining a silane coupling agent (A) containing one amino group in a molecule and a silane coupling agent (B) containing one glycidyl group in a molecule, at a solid content mass ratio (A)/(B) of 0.5 to 1.7; and

ratios of components of the composite film satisfy the following conditions (1) to (5), respectively:

(1) a solid content mass ratio (X)/(W) of the organic silicon compound (W) and the fluorine compound (X) is in the range of 0.02≦(X)/(W)≦0.07,

(2) a solid content mass ratio (Y)/(W) of the organic silicon compound (W) and the phosphoric acid (Y) is in the range of 0.03≦(Y)/(W)≦0.12,

(3) a solid content mass ratio (Z)/(W) of the organic silicon compound (W) and the vanadium compound (Z) is in the range of 0.05≦(Z)/(W)≦0.17,

(4) a solid content mass ratio (Z)/(X) of the fluorine compound (X) and the vanadium compound (Z) is in the range of 1.3≦(Z)/(X)≦6.0, and

(5) a solid content mass ratio (J)/(W+X+Y+Z) of the lubricant (J); and the organic silicon compound (W), the fluorine compound (X), the phosphoric acid (Y), and the vanadium compound (Z) is in the range of 0.02≦(J)/(W+X+Y+Z)≦0.12.

2. The surface-treated metal material according to claim 1 , wherein

the composite film further contains at least one kind of cobalt compound (C) selected from the group consisting of cobalt sulfate, cobalt nitrate, and cobalt carbonate, in which a solid content mass ratio (C)/(W) of the organic silicon compound (W) and the cobalt compound (C) is in the range of 0.01 to 0.1.

3. The surface-treated metal material according to claim 1 , wherein

a film weight of the composite film after drying is in the range of 0.05 g/m 2 to 2.0 g/m 2 .

4. The surface-treated metal material according to claim 1 , wherein

the metal material is a zinc plated steel sheet.

5. A method of producing a surface-treated metal material, the method comprising the steps of:

applying an aqueous metal surface treatment agent satisfying the following conditions (1) to (7) onto a surface of a metal material; and

drying the aqueous metal surface treatment agent at a temperature of more than 50° C. and less than 250° C. so that a film weight is in the range of 0.05 g/m 2 to 2.0 g/m 2 , wherein

(1) the aqueous metal surface treatment agent contains an organic silicon compound (W) having two or more functional groups (a) represented by Formula SiR 1 R 2 R 3 , where each of R 1 , R 2 and R 3 represents an alkoxy group or a hydroxyl group independently from each other, and at least one of them represents an alkoxy group; and one or more hydrophilic functional group (b) of at least one kind selected from a hydroxyl group different from what can be included in the functional group (a) and an amino group, in a molecule, wherein the organic silicon compound (W) has an average molecular weight of 1000 to 10000; at least one kind fluorine compound (X) selected from titanium hydrofluoric acid and zirconium hydrofluoric acid; a phosphoric acid (Y); a vanadium compound (Z); and at least one kind lubricant (J) selected from the group consisting of water dispersible polyethylene wax, polypropylene wax, and polytetrafluoroethylene and has a number average particle size of 0.01 μm to 1.0 μm and a softening temperature of 100° C. or more,

(2) the organic silicon compound (W) is obtained by combining a silane coupling agent (A) containing one amino group in a molecule and one glycidyl group in a molecule, at a solid content mass ratio (A)/(B) of 0.5 to 1.7,

(3) a solid content mass ratio (X)/(W) of the organic silicon compound (W) and the fluorine compound (X) is in the range of 0.02≦(X)/(W)≦0.07,

(4) a solid content mass ratio (Y)/(W) of the organic silicon compound (W) and the phosphoric acid (Y) is in the range of 0.03≦(Y)/(W)≦0.12,

(5) a solid content mass ratio (Z)/(W) of the organic silicon compound (W) and the vanadium compound (Z) is in the range of 0.05≦(Z)/(W)≦0.17,

(6) a solid content mass ratio (Z)/(X) of the fluorine compound (X) and the vanadium compound (Z) is in the range of 1.3≦(Z)/(X)≦6.0, and

(7) a solid content mass ratio (J)/(W+X+Y+Z) of the lubricant (J) and the components except the lubricant (J) is in the range of 0.02≦(J)/(W+X+Y+Z)≦0.12.