US4038099A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rutile-coated mica nacreous pigments and process for the preparation thereof
Assignee: Mearl Corp
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Filing: 1971-08-30
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Granted: 1977-07-26
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Expires: 1991-08-30
Abstract
Abstract Nacreous pigment products comprising mica particles coated with translucent layers consisting essentially of titanium dioxide in the rutile form. A process for the preparation of such pigment products is disclosed, involving treatment with tin compounds, so that the TiO 2 coating will crystallize mainly in the rutile form rather than as anatase during calcination of the pigment. The rutile-coated mica exhibits markedly enhanced light stability as compared with anatase-coated mica pigment products.
Inventors
- 👤 Carmine V. DeLuca, Jr.
- 👤 Harold A. Miller
- 👤 George R. Waitkins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 05:26
CPC Classifications
C; C09; C09C; C09C1/00; C09C1/0015; C09C1/0021; A; A61; A61K; A61K8/00; A61K8/18; A61K8/19; A61K8/26; A61Q; A61Q1/00; A61Q1/02; A61Q1/10; A61K2800/00; A61K2800/40; A61K2800/42; A61K2800/43; A61K2800/436; C01; C01P; C01P2004/00; C01P2004/60; C01P2004/61; C01P2006/00; C01P2006/12; C01P2006/60; C09C2200/00; C09C2200/10; C09C2200/102; C09C2200/30; C09C2200/301; C09C2200/302; C09C2220/00; C09C2220/10; C09C2220/103
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
105 words
A process for the preparation of a nacreous pigment, which comprises, in sequence: a. treating micaceous particles with an acidic, tin compound-containing solution having a concentration, expressed as Sn, of from 0.10 to 10% by weight; b. coating said particles with titanium dioxide in the amorphous form by deposition from a titanium compound-containing coating bath; c. removing the titanium dioxide-coated particles from the coating bath and washing said particles to remove excess acid and impurities therefrom; and d. calcining said particles at a temperature in excess of 650° C. to produce the desired translucent coating consisting of titanium dioxide in the form of rutile thereon.
Claim 2
Dependent Claim
105 words
A process for the preparation of a nacreous pigment, which comprises, in sequence: a. treating micaceous particles with an acidic, tin compound-containing solution having a concentration, expressed as Sn, of from 0.10 to 10% by weight; b. coating said particles with titanium dioxide in the amorphous form by deposition from a titanium compound-containing coating bath; c. removing the titanium dioxide-coated particles from the coating bath and washing said particles to remove excess acid and impurities therefrom; and d. calcining said particles at a temperature in excess of 650° C. to produce the desired translucent coating consisting of titanium dioxide in the form of rutile thereon.
Claim 3
Dependent Claim
26 words
The process of claim 1, in which the micaceous particles are slurried in the tin compound-containing solution at concentrations of from 5 to 30% by weight.
Claim 4
Dependent Claim
49 words
The process of claim 1, in which the solution employed in step (a) contains a stannous or stannic sulfate or halide or a mixture of such compounds, and in which the reaction mixture is maintained during such step at acidities below pH 2.0 and at ambient or elevated temperature.
Claim 5
Dependent Claim
54 words
The process of claim 1, in which the micaceous particles are slurried in the coating bath of step (b) at concentrations of from 1 to 25% by weight and in which the titanium concentration in the bath is maintained within the range of from 0.5 to 7% by weight, expressed as TiO 2 .
Claim 6
Dependent Claim
53 words
The process of claim 1, in which the titanium dioxide-coated particles are dried at temperatures within the range of from 20° to 175° C. under reduced or atmospheric pressures, and are thereafter calcined in step (d) to produce the desired rutile coating at temperatures within the range of from 650° to 950° C.
Claim 7
Dependent Claim
33 words
A nacreous pigment, which consists essentially of micaceous particles having on the surfaces thereof, a translucent coating consisting of titanium dioxide in the form of rutile produced by the process of claim 1.
Claim 8
Dependent Claim
56 words
The pigment of claim 6, in which the micaceous particles are in the form of mica flakes whose major dimensions are from 1 to 75 microns and which have specific surface areas of from 1.0 to 6 square meters per gram, and in which the rutile coating has a thickness of from 20 to 350 millimicrons.
Claim 9
Dependent Claim
20 words
A nacreous composition, comprising a light-transmitting resinous medium having suspended therein or supported thereon the nacreous pigment of claim 6.
Claim 10
Dependent Claim
65 words
A process for the preparation of a nacreous pigment which comprises in sequence: a. treating micaceous particles with an aqueous, acidic solution containing a tin compound; b. coating said micaceous particles with titanium dioxide by deposition from a titanium compound containing coating bath; c. calcining said particles at an elevated temperature to produce a translucent coating of rutile form titanium dioxide on the micaceous particles.
Claim 11
Dependent Claim
65 words
A process for the preparation of a nacreous pigment which comprises in sequence: a. treating micaceous particles with an aqueous, acidic solution containing a tin compound; b. coating said micaceous particles with titanium dioxide by deposition from a titanium compound containing coating bath; c. calcining said particles at an elevated temperature to produce a translucent coating of rutile form titanium dioxide on the micaceous particles.
Claim 12
Dependent Claim
33 words
A nacreous pigment, which consists essentially of micaceous particles having on the surface thereof, a translucent coating consisting of titanium dioxide in the form of rutile produced by the process of claim 9.
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) | 1980-07-25 | 1981-01-24 | 1981-07-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-07-25 | 1985-01-24 | 1985-07-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-07-25 | 1989-01-24 | 1989-07-26 | $7700.00 | Window Closed / Lapsed |