Pigment and process for producing the same

• US 5,308,394 A
• Filed: 08/20/1992
• Issued: 05/03/1994
• Est. Priority Date: 04/05/1990
• Status: Expired due to Term

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Tanaka, Yuji, Handa, Junichi, Ito, Hiroshi, Minohara, Taketoshi
• Primary Examiner(s): Bell, Mark L.
• Assistant Examiner(s): EINSMANN, MARGARET V
• Application Number:
  US07/930,463
• Time in Patent Office: 621 Days
• Field of Search: 106/403, 106/417, 106/436, 106/437, 106/455, 106/479, 106/DIG. 3
• US Class Current: 106/403
• CPC Class Codes: C01P 2004/20 extending in two dimensions, e.g. plate-like
• CPC Class Codes: C01P 2004/84 one phase coated with the other
• CPC Class Codes: C09C 1/0078 Pigments consisting of flaky, non-metallic substrates, characterised by a surface-region containing free metal
• CPC Class Codes: Y10S 106/03 Mica

Abstract

Disclosed are a pigment including a light-transparent ceramic scaly substrate, a tin compound layer coated on a surface of the substrate in an amount of 0.6 to 0.75% by weight with respect to the substrate, the amount being converted into metallic tin, a rutile type titanium dioxide layer formed on a surface of the substrate coated with the tin compound, a metal compound layer coated on a surface of the titanium dioxide layer in an amount of 0.15 to 0.6% by weight with respect to the substrate, metal of the metal compound being at least one selected from the group consisting of Bi, Sb, As, Cd, Zn, Mn, Pb and Cr, and the amount being converted into metal, and metallic glossy dots formed on the surfaces in a scattering manner, the metallic glossy dots occupying 0.05 to 95% of a total surface area of the surfaces, and a process for producing the same. Since the metallic glossy dots are formed preferentially between the titanium dioxide layer and the substrate on which the tin compound layer facilitating the metallic glossy dots formation selectively is coated. Therefore, the particle diameters of the metallic glossy dots are made uniform, and accordingly the light scattering and the light reflection are also made uniform. As a result, the pigment produces a color tone which varies less. With the production process, it is possible to stably produce a pigment producing a less varying color tone.

Claims

1. A pigment comprising:

a light-transparent ceramic scaly substrate;

a tin compound layer coated on a surface of said substrate in an amount of 0.6 to 0.75% by weight with respect to said substrate, said amount being converted into metallic tin;

a rutile type titanium dioxide layer formed on a surface of said substrate coated with said tin compound;

a metal compound layer coated on a surface of said titanium dioxide layer in an amount of 0.15 to 0.6% by weight with respect to said substrate, the metal of said metal compound being at least one selected from the group consisting of Bi, Sb, As, Cd, Zn, Mn, Pb and Cr, and said amount being converted into metal; and

metallic glossy dots formed on said substrate in a scattering manner, said metallic glossy dots occupying 0.05 to 95% of a total surface area of said surfaces,

wherein said metal dots are of uniform particle diameters and are formed between said titanium dioxide layer and said substrate.

2. The pigment according to claim 1, wherein said substrate is at least one selected from the group consisting of mica and molybdenum disulfide.

3. The pigment according to claim 2, wherein said mica is at least one selected from the group consisting of natural mica and synthetic mica.

4. The pigment according to claim 3, wherein said natural mica is at least one selected from the group consisting of muscovite, biotite and phlogopite.

5. The pigment according to claim 1, wherein said substrate has a thickness of 0.05 to 0.1 micrometers and a length of 3 to 50 micrometers.

6. The pigment according to claim 1, wherein said metallic glossy dots includes at least one metal selected from the group consisting of gold, silver, copper, palladium, cobalt, nickel-phosphorus alloy, nickel-boron alloy, nickel-cobalt-phosphorus alloy, nickel-tungsten-phosphorous alloy, silver-gold alloy, and cobalt-silver alloy.

7. The pigment according to claim 1, wherein said metallic glossy dots occupy 0.1 to 15% of the total surface area of said surfaces.

8. A process for producing a pigment comprising the steps of:

(1) coating tin compound on a surface of a light-transparent ceramic scaly substrate in an amount of 0.6 to 0.75% by weight with respect to said substrate, said amount being converted into metallic tin;

(2) forming rutile type titanium dioxide layer on a surface of said substrate including said tin compound;

(3) coating compound of metal on a surface of said titanium dioxide layer in an amount of 0.15 to 0.6% by weight with respect to said substrate, said metal being at least one selected from the group consisting of Bi, Sb, As, Cd, Zn, Mn, Pb and Cr, and said amount being converted into metal; and

(4) forming metallic glossy dots on said substrate in a scattering manner, said metallic glossy dots occupying 0.05 to 95% of the total surface area of said surfaces, wherein said metal dots are of uniform particle diameters and are formed between said titanium dioxide layer and said substrate.

9. The process for producing a pigment according to claim 8, wherein said substrate is at least one selected from the group consisting of mica and molybdenum disulfide.

10. The process for producing a pigment according to claim 9, wherein said mica is at least one selected from the group consisting of natural mica and synthetic mica.

11. The process for producing a pigment according to claim 10, wherein said natural mica is at least one selected from the group consisting of muscovite, biotite and phlogopite.

12. The process for producing a pigment according to claim 8, wherein said substrate has a thickness of 0.05 to 0.1 micrometers and a length of 3 to 50 micrometers.

13. The process for producing a pigment according to claim 8, wherein said metallic glossy dots includes at least one metal selected from the group consisting of gold, silver, copper, palladium, cobalt, nickel-phosphorus alloy, nickel-boron alloy, nickel-cobalt-phosphorus alloy, nickel-tungsten-phosphorous alloy, and silver-gold alloy, cobalt-silver alloy.

14. The process for producing a pigment according to claim 8, wherein said metallic glossy dots occupy 0.1 to 15% of the total surface area of said surfaces.

15. A pigment produced by the process according to claim 8.