US4040859A
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Tin-containing lustrous pigments
Assignee: Merck Patent GmbH
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Filing: 1976-05-18
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Granted: 1977-08-09
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Expires: 1996-05-18
Abstract
Abstract Lustrous pigments based on mica flakes coated with metal oxides have a very uniform coating layer of tin dioxide, which can contain aluminum oxide, or the hydrates thereof.
Inventors
- 👤 Reiner Esselborn
- 👤 Horst Bernhard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 13:51
CPC Classifications
C; C09; C09C; C09C1/00; C09C1/0015; C09C1/0021; C01; C01P; C01P2002/00; C01P2002/50; C01P2002/52; C01P2004/00; C01P2004/60; C01P2004/61; C09C2200/00; C09C2200/10; C09C2200/102; C09C2200/30; C09C2200/301; C09C2200/302; C09C2220/00; C09C2220/10; C09C2220/106; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2911
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
52 words
A lustrous, light-stable mica flake pigment consisting essentially of mica flakes coated by precipitation with up to 90% by weight of the pigment of a continuous, smooth, uniform layer consisting essentially of tin dioxide or a hydrate thereof and up to 10% by weight of coprecipitated aluminum oxide or a hydrate thereof.
Claim 2
Dependent Claim
52 words
A lustrous, light-stable mica flake pigment consisting essentially of mica flakes coated by precipitation with up to 90% by weight of the pigment of a continuous, smooth, uniform layer consisting essentially of tin dioxide or a hydrate thereof and up to 10% by weight of coprecipitated aluminum oxide or a hydrate thereof.
Claim 3
Dependent Claim
18 words
A pigment according to claim 1, wherein the tin dioxide layer is 20 to 200 nm. in thickness.
Claim 4
Dependent Claim
25 words
A pigment according to claim 1, wherein the tin dioxide layer contains 0.001 to 7% by weight of coprecipitated aluminum oxide or a hydrate thereof.
Claim 5
Dependent Claim
45 words
A process for the production of mica flake pigments according to claim 1, which comprises hydrolyzing a Sn (II) salt solution in which mica flakes are suspended in the presence of an Sn (II) → Sn (IV) oxidizing agent to form said coated mica flakes.
Claim 6
Dependent Claim
19 words
A process according to claim 4, wherein the reaction is effected in the presence of a water-soluble aluminum salt.
Claim 7
Dependent Claim
25 words
A process according to claim 5, wherein said solution contains about 0.01 to 2 moles of water-soluble aluminum salt per mole of Sn (II) salt.
Claim 8
Dependent Claim
15 words
A process according to claim 4, wherein the Sn (II) salt is SnClO 2 .
Claim 9
Dependent Claim
19 words
A process according to claim 4, wherein the oxidizing agent is KClO 3 or H 2 O 2 .
Claim 10
Dependent Claim
17 words
A process according to claim 4, wherein the precipitation is effected at a constant pH of 0.5-3.0.
Claim 11
Dependent Claim
22 words
A process according to claim 9, wherein the tin dioxide precipitate which forms is deposited immediately and quantitatively onto said mica flakes.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-08-08 | 1981-02-07 | 1981-08-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-08 | 1985-02-07 | 1985-08-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-08 | 1989-02-07 | 1989-08-09 | $7700.00 | Window Closed / Lapsed |