초록 ▼

A metal material is provided with a bismuth coating which enables the subsequent coating to be accomplished at a high throwing power, and has excellent corrosion resistance, coating adhesion and is able to be produced with reduced damage to the environment. The metal material has a surface and a bis

A metal material is provided with a bismuth coating which enables the subsequent coating to be accomplished at a high throwing power, and has excellent corrosion resistance, coating adhesion and is able to be produced with reduced damage to the environment. The metal material has a surface and a bismuth-containing layer deposited on at least a part of the surface of the metal material, wherein the percentage of bismuth atoms in the number of atoms in the surface layer of the metal material with a bismuth coating is at least 10%.

대표청구항 ▼

1. A surface treating solution for use in a chemical conversion of a metal material surface conducted as a pretreatment of a coating, wherein the surface treating solution contains bismuth ions and a first ligand for the bismuth ions in an amount effective to form a bismuth chemical conversion film

1. A surface treating solution for use in a chemical conversion of a metal material surface conducted as a pretreatment of a coating, wherein the surface treating solution contains bismuth ions and a first ligand for the bismuth ions in an amount effective to form a bismuth chemical conversion film on the metal surface. 2. The surface treating solution according to claim 1, wherein said coating is by cationic electrodeposition. 3. The surface treating solution according to claim 1, further comprising a brightener. 4. The surface treating solution according to claim 3, wherein the brightener is an organic compound having at least one member selected from the group consisting of an aromatic ring, a sulfone group, a formyl group, a carboxy group and an amino group. 5. The surface treating solution according to claim 3, wherein the solution at the time of the surface treatment contains the brightener at a weight concentration of 10 to 10,000 ppm. 6. The surface treating solution according to claim 3, wherein the first ligand is at least one member selected from the group consisting of an minopolycarboxylic acid and a carboxylic acid, and the solution contains at least one ligand which has a stability for the bismuth ions higher than a stability for an ion of a metal constituting the metal material. 7. The surface treating solution according to claim 3, wherein the first ligand is at least one member selected from the group consisting of an aminopolycarboxylic acid and/e a carboxylic acid, and has a stability for the bismuth ions higher than a stability for an ion of a metal constituting the metal material, andthe solution further comprises a second ligand which has a stability for the ion of the metal constituting the metal material higher than a stability for the bismuth ions. 8. The surface treating solution according to claim 3, wherein the solution at the time of the surface treatment contains the bismuth ions at a weight concentration of 5 to 1,000 ppm. 9. The surface treating solution according to claim 3, having a pH of at least 2 and less than 10.5. 10. The surface treating solution according to claim 1, wherein the first ligand is at least one member selected from the group consisting of an aminopolycarboxylic acid and a carboxylic acid, and the solution contains at least one ligand which has a stability for the bismuth ions higher than a stability for an ion of a metal constituting the metal material. 11. The surface treating solution according to claim 1, wherein, the first ligand is an aminopolycarboxylic acid and has a stability for the bismuth ions higher than a stability for an ion of a metal constituting the metal material; andthe solution further comprises a second ligand which has a stability for the ion of a metal constituting the metal material higher than a stability for the bismuth ions. 12. The surface treating solution according to claim 1, wherein the solution at the time of the surface treatment contains the bismuth ions at a weight concentration of 5 to 1,000 ppm. 13. The surface treating solution according to claim 12, wherein the solution at the time of the surface treatment contains the first ligand at a weight concentration of 5 to 25,000 ppm. 14. The surface treating solution according to claim 1, having a pH of at least 2 and less than 10.5.