US4544415A
Expired / Lapsed
US
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Weathering-resistant pearlescent pigments
Assignee: Merck Patent GmbH
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Filing: 1984-09-21
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Granted: 1985-10-01
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Expires: 2004-09-21
Abstract
Abstract Pearlescent pigments having improved weathering resistance are based on mica flakes coated with metal oxides, these pigments possessing on top of the coat of metal oxide a topcoat which contains a polysiloxane and a rare earth metal compound.
Inventors
- 👤 Klaus-Dieter Franz
- 👤 Manfred Kieser
- 👤 Otto Stahlecker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 08:27
CPC Classifications
C; C09; C09C; C09C3/00; C09C3/12; A; A61; A61K; A61K8/00; A61K8/02; A61K8/0241; A61K8/18; A61K8/19; A61K8/26; A61K8/72; A61K8/84; A61K8/89; A61K8/891; A61Q; A61Q1/00; A61Q1/02; C09C1/00; C09C1/0015; A61K2800/00; A61K2800/40; A61K2800/41; A61K2800/412; A61K2800/42; A61K2800/43; A61K2800/436; A61K2800/60; A61K2800/61; A61K2800/62; A61K2800/624; C01; C01P; C01P2006/00; C01P2006/22; C09C2200/00; C09C2200/10; C09C2200/102; C09C2200/40; C09C2200/401; C09C2200/402; C09C2200/407; C09C2200/409; C09C2220/00; C09C2220/10; C09C2220/106; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2991; Y10T428/2993; Y10T428/2995; Y10T428/2998
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
99 words
A pearlescent pigment having improved weathering resistance and comprising mica flakes coated with at least one metal oxide layer, and on top of the metal oxide layer(s), a topcoating comprising amounts of a compatible rare earth metal compound and a polysiloxane of the formula ##STR4## wherein R 1 and R 3 are independently each ##STR5## H, C 1-4 -alkyl or poly-(C 1-4 -alkylene) ether, and R 2 and R 4 are independently each ##STR6## C 1-4 -alkyl, C 1-4 -alkylacrylic ester, C 1-4 -alkylmethacrylic ester or poly-(C 1-4 -alkylene) ether, effective to improve the weathering resistance of the pigment.
Claim 2
Dependent Claim
99 words
A pearlescent pigment having improved weathering resistance and comprising mica flakes coated with at least one metal oxide layer, and on top of the metal oxide layer(s), a topcoating comprising amounts of a compatible rare earth metal compound and a polysiloxane of the formula ##STR4## wherein R 1 and R 3 are independently each ##STR5## H, C 1-4 -alkyl or poly-(C 1-4 -alkylene) ether, and R 2 and R 4 are independently each ##STR6## C 1-4 -alkyl, C 1-4 -alkylacrylic ester, C 1-4 -alkylmethacrylic ester or poly-(C 1-4 -alkylene) ether, effective to improve the weathering resistance of the pigment.
Claim 3
Dependent Claim
17 words
A pearlescent pigment of claim 1, wherein the rare earth metal compound is cerium oxide or hydroxide.
Claim 4
Dependent Claim
20 words
A pearlescent pigment of claim 1, wherein the top layer further comprises a compatible zinc or aluminum compound or both.
Claim 5
Dependent Claim
14 words
A pearlescent pigment of claim 1, wherein the top layer further comprises a silicate.
Claim 6
Dependent Claim
22 words
A pearlescent pigment of claim 1, wherein the topcoat accounts for about 0.5 to about 10% by weight of the total pigment.
Claim 7
Dependent Claim
13 words
A pigment of claim 3, wherein the top layer further comprises a silicate.
Claim 8
Dependent Claim
16 words
A pigment of claim 6, wherein the rare earth metal compound is cerium oxide or hydroxide.
Claim 9
Dependent Claim
31 words
A pigment of claim 1, wherein the amount of rare earth compound based on the metal is 0.5 to 5% by weight, and of polysiloxane is 0.5 to 5% of weight.
Claim 10
Dependent Claim
49 words
A pigment of claim 7, wherein the amount of cerium is 0.5 to 5% by weight; of silicon is 0 to 1% by weight; of aluminum is 0 to 3% of weight; of zinc is 0 to 3% by weight and of polysiloxane is 0.5 to 5% by weight.
Claim 11
Dependent Claim
20 words
A pigment of claim 9, wherein the topcoat accounts for about 0.5 to 10% by weight of the total pigment.
Claim 12
Dependent Claim
81 words
A process for preparing pearlescent pigments having improved weathering resistance and based on mica flakes coated with at least one metal oxide layer, comprising treating the coated mica flake pigment at a substantially constant pH in aqueous suspension with an aqueous solution of a siloxane and an aqueous solution of a rare earth metal salt whereby the pigment is topcoated with a layer of polysiloxane and of the rare earth compound, and, thereafter, separating the pigment, washing it and drying it.
Claim 13
Dependent Claim
81 words
A process for preparing pearlescent pigments having improved weathering resistance and based on mica flakes coated with at least one metal oxide layer, comprising treating the coated mica flake pigment at a substantially constant pH in aqueous suspension with an aqueous solution of a siloxane and an aqueous solution of a rare earth metal salt whereby the pigment is topcoated with a layer of polysiloxane and of the rare earth compound, and, thereafter, separating the pigment, washing it and drying it.
Claim 14
Dependent Claim
15 words
A process of claim 11 wherein the polisiloxane and rare earth compound are coated separately.
Claim 15
Dependent Claim
15 words
A process of claim 11, wherein the polysiloxane and rare earth compound are coated simultaneously.
Claim 16
Dependent Claim
19 words
A process of claim 11, wherein the rare earth metal salt solution is a solution of a cerium salt.
Claim 17
Dependent Claim
70 words
A process of claim 14, wherein the polysiloxane in the topcoating is of the formula ##STR7## wherein R 1 and R 3 are independently each ##STR8## H, C 1-4 -alkyl or poly-(C 1-4 -alkylene) ether, and R 2 and R 4 are independently each ##STR9## C 1-4 -alkyl, C 1-4 -alkylacrylic ester, C 1-4 -alkylmethacrylic ester or poly-(C 1-4 -alkylene) ether, effective to improve the weathering resistance of the pigment.
Claim 18
Dependent Claim
34 words
A process of claim 11, further comprising topcoating the pigments by treating them with a solution containing a zinc or aluminum salt or both, thereby including zinc, aluminum or both in the top coating.
Claim 19
Dependent Claim
27 words
A process of claim 11, further comprising topcoating the pigments by treating them with an alkali metal silicate coating solution, thereby including silicate in the top coating.
Claim 20
Dependent Claim
29 words
In a formulation of a base ingredient and a pearlescent pigment, the improvement wherein the pearlescent pigment is one of claim 1, whereby the formulation has improved weathering resistance.
Claim 21
Dependent Claim
13 words
A formulation of claim 18, wherein the base pigment is an organic polymer.
Claim 22
Dependent Claim
14 words
A formulation of claim 18, which is a paint, an ink or a plastic.
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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) | 1988-09-30 | 1989-04-01 | 1989-10-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-09-30 | 1993-04-01 | 1993-10-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-09-30 | 1997-04-01 | 1997-10-01 | $7700.00 | Window Closed / Lapsed |