US4867793A
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Nacreous pigments
Assignee: Merck Patent GmbH
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Filing: 1987-05-22
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Granted: 1989-09-19
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Expires: 2007-05-22
Abstract
Abstract Platelet-shaped colored pigments in which a platelet-shaped substrate is provided with a compact coating containing iron(II) oxide, which coating has a high gloss and, depending on the layer thickness, shows the interference color of thin platelets, are described.
Inventors
- 👤 Klaus D. Franz
- 👤 Kalus Ambrosius
- 👤 August Kanpp
- 👤 Hans D. Brucker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 17:41
CPC Classifications
C; C08; C08K; C08K9/00; C08K9/02; C09; C09C; C09C3/00; C09C3/06; A; A61; A61K; A61K8/00; A61K8/02; A61K8/0241; A61K8/0254; A61K8/18; A61K8/19; A61Q; A61Q1/00; A61Q1/02; C09C1/00; C09C1/0015; C09C1/0021; A61K2800/00; A61K2800/40; A61K2800/41; A61K2800/412; A61K2800/42; A61K2800/43; A61K2800/436; A61K2800/60; A61K2800/65; A61K2800/651; C01; C01P; C01P2006/00; C01P2006/42; C09C2200/00; C09C2200/10; C09C2200/102; C09C2200/1054; C09C2200/1087; C09C2200/30; C09C2200/301; C09C2200/302; C09C2200/306; C09C2200/50; C09C2200/505; C09C2220/00; C09C2220/10; C09C2220/103
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
43 words
A platelet-shaped nacreous pigment comprising a platelet-shaped substrate and coated thereon, a smooth and compact layer containing an amount of iron(II) oxide and having sufficient smoothness and compactness that when in contact with a this platelet, it is capable of producing interference colors.
Claim 2
Dependent Claim
43 words
A platelet-shaped nacreous pigment comprising a platelet-shaped substrate and coated thereon, a smooth and compact layer containing an amount of iron(II) oxide and having sufficient smoothness and compactness that when in contact with a this platelet, it is capable of producing interference colors.
Claim 3
Dependent Claim
33 words
A pigment according to claim 1, wherein the iron(II) oxide layer contains iron(II) oxide particles packed sufficiently densely that the distance between adjacent particles is generally smaller than the diameter of the particles.
Claim 4
Dependent Claim
23 words
A pigment according to claim 1, wherein the diameter of the particles in the iron(II) oxide layer generally does not exceed 0.3 μm.
Claim 5
Dependent Claim
19 words
A pigment according to claim 1, wherein the substrate is mica, a glass platelet, a metal platelet or graphite.
Claim 6
Dependent Claim
46 words
A pigment as to claim 1, wherein the substrate is mica coated with TiO 2 , ZrO 2 , SnO 2 , Cr 2 O 3 , BiOCl, Fe 2 O 3 , Al 2 O 3 , SiO 2 , ZnO or a mixture thereof.
Claim 7
Dependent Claim
24 words
A pigment according to claim 1, wherein the iron(II) oxide is a mixed oxide with an oxide of a di-, tri- or tetravalent metal.
Claim 8
Dependent Claim
31 words
A pigment as to claim 6, wherein the iron(II) oxide is substantially pure iron(II) oxide, FeAl 2 O 4 , FeCr 2 O 4 , FeSiO 4 or FeTiO 3 .
Claim 9
Dependent Claim
16 words
A pigment as to claim 1, wherein the iron oxide layer is 0.1-250 nm in thickness.
Claim 10
Dependent Claim
20 words
A pigment as to claim 1, wherein the content of iron(II) oxide is 0.1-200% by weight based on the substrate.
Claim 11
Dependent Claim
15 words
A pigment of claim 1, wherein the iron(II) oxide is magnetite or the wustite phase.
Claim 12
Dependent Claim
47 words
A process for the preparation of a pigment of claim 1, comprising simultaneously adding an iron (II) salt solution and a separate solution of an oxidizing agent to an aqueous suspension of a platelet-shaped substrate under conditions which effect precipitation of an iron(II)-containing layer onto the substrate.
Claim 13
Dependent Claim
28 words
A process according to claim 11, wherein the temperature is 0-100° C. and the pH is greater than 7 and the temperature and pH are maintained substantially constant.
Claim 14
Dependent Claim
20 words
A process according to claim 11, wherein the iron(II) salt is ammonium iron(II) sulfate, an iron(II) halide or iron(II) sulfate.
Claim 15
Dependent Claim
22 words
A process according to claim 11, wherein iron oxide hydrate is deposited on the substrate without secondary precipitation occurring in the suspension.
Claim 16
Dependent Claim
16 words
A process according to claim 11, wherein the oxidizing agent is a nitrate or a chlorate.
Claim 17
Dependent Claim
14 words
A process according to claim 14, wherein the oxidizing agent is KNO 3 .
Claim 18
Dependent Claim
41 words
A process for the preparation of a pigment of claim 1, comprising exposing a platelet-shaped substrate coated with a smooth homogeneous layer of Fe 2 O 3 to a reducing atmosphere effective to convert Fe(III) to an effective amount of Fe(II).
Claim 19
Dependent Claim
13 words
A process according to claim 17, wherein the temperature is above 100° C.
Claim 20
Dependent Claim
23 words
A process according to claim 17, wherein the reducing atmosphere contains 20-60% of a reducing gas comprising hydrogen, carbon monoxide, methane or ammonia.
Claim 21
Dependent Claim
19 words
A pigment according to claim 1, wherein the content of iron(II) oxide is 5-200% by weight of the substrate.
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| 3.5 Years (Year 4) | 1992-09-18 | 1993-03-20 | 1993-09-19 | $2000.00 | Window Closed / Lapsed |
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