Conductive pigment

• US 5,320,781 A
• Filed: 04/16/1993
• Issued: 06/14/1994
• Est. Priority Date: 04/18/1992
• Status: Expired due to Term

• Current Assignee: Merck Patent GmbH (Merck & Co., Inc.)
• Original Assignee: Merck Patent GmbH (Merck & Co., Inc.)
• Inventors: Gobel, Wilhelm, Thon, Manfred, Kieser, Manfred, Pfaff, Gerhard, Glausch, Ralf, Stahlecker, Otto
• Primary Examiner(s): Bell, Mark L.
• Assistant Examiner(s): THOMPSON, WILLIE
• Application Number:
  US08/047,083
• Time in Patent Office: 424 Days
• Field of Search: 106/417, 106/415, 106/419, 106/436, 106/441, 106/442, 106/455, 428/403, 252/512, 252/518
• US Class Current: 252/518.1
• CPC Class Codes: C01P 2002/02 Amorphous compounds
• CPC Class Codes: C01P 2004/10 extending in one dimension, e.g. needle-like
• CPC Class Codes: C01P 2004/20 extending in two dimensions, e.g. plate-like
• CPC Class Codes: C01P 2004/32 Spheres
• CPC Class Codes: C01P 2004/38 cube-like
• CPC Class Codes: C01P 2004/54 Particles characterised by their aspect ratio, i.e. the ratio of sizes in the longest to the shortest dimension
• CPC Class Codes: C01P 2004/61 Micrometer sized, i.e. from 1-100 micrometer
• CPC Class Codes: C01P 2004/80 Particles consisting of a mixture of two or more inorganic phases
• CPC Class Codes: C01P 2006/40 Electric properties
• CPC Class Codes: C01P 2006/60 Optical properties, e.g. expressed in CIELAB-values
• CPC Class Codes: C01P 2006/80 Compositional purity
• CPC Class Codes: C08K 7/00 Use of ingredients characterised by shape
• CPC Class Codes: C08K 9/02 Ingredients treated with inorganic substances
• CPC Class Codes: C09C 1/00 Treatment of specific inorganic materials other than fibrous fillers tenebrescent materials C09K9/00; luminescent materials C09K11/00; Preparation of carbon black
• CPC Class Codes: C09C 1/0081 Composite particulate pigments or fillers, i.e. containing at least two solid phases, except those consisting of coated particles of one compound C09C1/0015, C09C1/0078 take precedence
• CPC Class Codes: C09C 1/405 containing combined silica, e.g. mica
• CPC Class Codes: C09D 11/037 characterised by the pigment
• CPC Class Codes: C09D 5/24 Electrically-conducting paints conductive materials H01B1/00
• CPC Class Codes: H01B 1/00 Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
• CPC Class Codes: H01B 1/08 oxides
• CPC Class Codes: H01B 1/20 : Conductive material dispersed in non-conductive organic material organic macromolecular compounds or compositions C08
• CPC Class Codes: H05K 1/095 : for polymer thick films, i.e. having a permanent organic polymeric binder
• CPC Class Codes: Y10T 428/2991 : Coated

Abstract

There is disclosed an electrically conductive pigment containing 20 to 95% by weight of a component A comprising one or more conductive platelet-like pigments and 5 to 80% by weight of a component B comprising one or more conductive needle-shaped or fibrous pigments.

Claims

1. An electroconductive pigment comprising 5 to 95% by weight of a component A which comprises at least one electroconductive platelet-shaped pigment, and 5% to 95% by weight of a component B which comprises at least one electroconductive non-platelet-shaped pigment.

2. A pigment according to claim 1, wherein the platelet-shaped pigment of component A comprises (a) a platelet-shaped support optionally coated with at least one metal oxide, (b) a platelet-shaped metal oxide, each of (a) and (b) being coated with a conductive layer, or (c) a conductive platelet-shaped metal oxide.

3. A pigment according to claim 1, wherein the conductive layer is a metal oxide doped with a metal or with a halogen, is an inherently conductive compound or metal.

4. A pigment according to claim 3, wherein the conductive layer is antimony doped tin oxide, aluminum doped zinc oxide, fluorine doped tin oxide or fluorine doped titanium oxide.

5. A pigment according to claim 1 wherein the pigment of component B comprises particles having approximately identical dimensions along all three directions in space.

6. A pigment according to claim 5, wherein the particles are cubes or spheres.

7. A pigment according to claim 1, wherein the pigment of component B is (a) at least one non-platelet-shaped metal oxide, (b) is a non-platelet-shaped support coated with at least one metal oxide, each of (a) and (b) being coated with a conductive layer, or is (c) a conductive non-platelet-shaped metal oxide.

8. A pigment according to claim 7, wherein the conductive layer is a metal oxide doped with a metal or with a halogen, is an inherently conductive compound or metal.

9. A pigment according to claim 8, wherein the conductive layer is antimony doped tin oxide, aluminum doped zinc oxide, fluorine doped tin oxide or fluorine doped titanium oxide.

10. A pigment according to claim 7, wherein component B contains at least one needle-shaped or fibrous pigment.

11. A pigment according to claim 2, wherein the support is mica, talc, kaolin or glass.

12. A pigment according to claim 1, wherein component A is a nacreous pigment.

13. A pigment according to claim 7, wherein the support is particles of barium sulfate, mica, kaolin or talc, or fibers of glass alumina or titanium dioxide.

14. A pigment according to claim 1, wherein component B is carbon fibers.

15. A process for the preparation of a pigment according to claim 1, comprising mixing platelet-like and non-platelet-like base materials, optionally coating said materials with metal oxide and coating said materials with a doped metal oxide or inherently conductive compound.

16. In a paint, printing ink, plastic system or coating pigmented with a conductive pigment, the improvement wherein the pigment is one according to claim 1.

17. A pigment according to claim 1, comprising at least 50% by weight of the platelet-shaped pigment.

18. In a paint, printing ink, plastic system or coating pigmented with a conductive pigment, the improvement wherein the pigment is one according to claim 17.