US4456486A
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US
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Yellow nacreous pigments having calcined CR oxide and phosphate layer for improved light-fastness, process and use
Assignee: Merck Patent GmbH
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Filing: 1982-09-22
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Granted: 1984-06-26
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Expires: 2002-09-22
Abstract
Abstract Nacreous pigments having a yellow powder color and an improved light-fastness comprise a mica platelet coated with titanium dioxide and on the titanium dioxide layer, a thin layer of calcined chromium oxide and/or chromium phosphate as a protective layer. The pigments are produced by coating mica platelets coated with metal oxides and/or hydroxides, with a thin layer of a sparingly soluble chromium(III) compound and calcining at about 500°-1000° C.
Inventors
- 👤 Horst Bernhard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:08
CPC Classifications
C; C09; C09C; C09C1/00; C09C1/0015; C01; C01P; C01P2006/00; C01P2006/60; C09C2200/00; C09C2200/10; C09C2200/102; C09C2200/30; C09C2200/301; C09C2200/302; C09C2210/00; C09C2210/20; C09C2220/00; C09C2220/10; C09C2220/103; C09C2220/106
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
78 words
A nacreous pigment having a yellow powder color and an improved light-fastness comprising a mica platelet coated with a plurality of metal oxide layers, wherein the metal oxide layers comprise the sequence rutile/SnO 2 /rutile and the outermost layer is rutile, and on the outermost rutile layer a thin layer of calcined chromium oxide as a protective layer, and in the chromium oxide layer a phosphate content of up to the stoichiometric amount based on the chromium content.
Claim 2
Dependent Claim
78 words
A nacreous pigment having a yellow powder color and an improved light-fastness comprising a mica platelet coated with a plurality of metal oxide layers, wherein the metal oxide layers comprise the sequence rutile/SnO 2 /rutile and the outermost layer is rutile, and on the outermost rutile layer a thin layer of calcined chromium oxide as a protective layer, and in the chromium oxide layer a phosphate content of up to the stoichiometric amount based on the chromium content.
Claim 3
Dependent Claim
34 words
A nacreous pigment of claim 1, wherein the chromium content of the protective layer, calculated as Cr 2 O 3 , is about 0.2-3% by weight, relative to the total weight of the pigment.
Claim 4
Dependent Claim
45 words
A nacreous pigment of claim 1 wherein the protective layer is applied to the titanium dioxide layer by first applying a chromium hydroxide layer or a chromium phosphate layer thereto and then calcining the pigment at a temperature of about 500° to about 1000° C.
Claim 5
Dependent Claim
41 words
A nacreous pigment of claim 1 wherein the mica platelet is of a diameter of about 5-200 μm and a thickness of about 0.1 to 5 μm, and the titanium dioxide layer is of a weight of 50-500 mg/m 2 .
Claim 6
Dependent Claim
21 words
A nacreous pigment of claim 1, wherein the chromium content of the protective layer is converted into chromium titanate during calcination.
Claim 7
Dependent Claim
33 words
A lustrous composition comprising a base composition in which it is desired to achieve a lustrous effect and an amount of a nacreous pigment of claim 1 effective to achieve a lustrous effect.
Claim 8
Dependent Claim
14 words
A lustrous composition of claim 6, wherein the base composition is a cosmetic formulation
Claim 9
Dependent Claim
14 words
A lustrous composition of claim 6 wherein the base composition is a car paint.
Claim 10
Dependent Claim
100 words
A process for preparing a yellow nacreous pigment having improved light-fastness and comprising a mica platelet coated with metal oxides, comprising (a) coating a mica platelet successively with at least three layers of titanium hydroxide, tin hydroxide and titanium hydroxide, the outermost layer being a titanium hydroxide layer, and optionally washing, drying and calcining the pigment, (b) coating this pigment with a thin layer of a sparingly soluble chromium (III) compound, which contains phosphate ions of up to the stoichiometric amount based on the chromium content, and then (c) calcining it at a temperature of about 500° to 1000° C.
Claim 11
Dependent Claim
100 words
A process for preparing a yellow nacreous pigment having improved light-fastness and comprising a mica platelet coated with metal oxides, comprising (a) coating a mica platelet successively with at least three layers of titanium hydroxide, tin hydroxide and titanium hydroxide, the outermost layer being a titanium hydroxide layer, and optionally washing, drying and calcining the pigment, (b) coating this pigment with a thin layer of a sparingly soluble chromium (III) compound, which contains phosphate ions of up to the stoichiometric amount based on the chromium content, and then (c) calcining it at a temperature of about 500° to 1000° C.
Claim 12
Dependent Claim
46 words
A process of claim 9 wherein the sparingly soluble chromium(III) compound is applied in an amount which, after calcination, produces a chromium content, calculated as Cr 2 O 3 , of about 0.2 to about 3% by weight, relative to the total weight of the pigment.
Claim 13
Dependent Claim
17 words
A process of claim 9, wherein the sparingly soluble chromium(III) compound is chromium hydroxide and/or chromium phosphate.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-06-26 | 1987-12-26 | 1988-06-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-06-26 | 1991-12-26 | 1992-06-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-06-26 | 1995-12-26 | 1996-06-26 | $7700.00 | Window Closed / Lapsed |