US4299807A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Methods of producing kaolin pigments
Assignee: Georgia Kaolin Co
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Filing: 1980-06-03
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Granted: 1981-11-10
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Expires: 2000-06-03
Abstract
Abstract A method for producing kaolin pigments of improved coated brightness and opacity is provided in which kaolin is degritted, heated to the level of substantially minimum brightness and then leached. The kaolin may be comminuted before treatment, after heating or after leaching to control particle size distribution.
Inventors
- 👤 Brian R. Angel
- 👤 Robert W. Bradshaw
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 14:59
CPC Classifications
C; C09; C09C; C09C1/00; C09C1/40; C09C1/42; C04; C04B; C04B33/00; C04B33/02; C04B33/10; C01; C01P; C01P2004/00; C01P2004/51; C01P2004/60; C01P2004/61; C01P2006/00; C01P2006/60
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
73 words
A method of producing kaolin of improved brightness, opacity and particle size consisting essentially of the steps of: a. degritting a raw kaolin; b. heating said kaolin with only the grit removed following degritting to the temperature and for a time to produce substantially minimum brightness of said kaolin and aggregation of said kaolin; c. leaching said heated clay; and d. comminuting said aggregated clay following one of said heating and leaching steps.
Claim 2
Independent Claim
73 words
A method of producing kaolin of improved brightness, opacity and particle size consisting essentially of the steps of: a. degritting a raw kaolin; b. heating said kaolin with only the grit removed following degritting to the temperature and for a time to produce substantially minimum brightness of said kaolin and aggregation of said kaolin; c. leaching said heated clay; and d. comminuting said aggregated clay following one of said heating and leaching steps.
Claim 3
Dependent Claim
26 words
A method as claimed in claim 1 wherein the kaolin is heated to a temperature in the range 200° C. to 800° C. prior to leaching.
Claim 4
Dependent Claim
17 words
A method as claimed in claim 1 wherein the kaolin is comminuted prior to heating and leaching.
Claim 5
Dependent Claim
17 words
A method as claimed in claim 1 wherein the kaolin is comminuted after heating and before leaching.
Claim 6
Dependent Claim
14 words
A method as claimed in claim 1 wherein the kaolin is comminuted after leaching.
Claim 7
Dependent Claim
18 words
A method as claimed in claim 3 wherein the kaolin is comminuted to substantially below 2 microns e.s.d.
Claim 8
Dependent Claim
18 words
A method as claimed in claim 4 wherein the kaolin is comminuted to substantially below 2 microns e.s.d.
Claim 9
Dependent Claim
18 words
A method as claimed in claim 5 wherein the kaolin is comminuted to substantially below 2 microns e.s.d.
References Cited (Backward Citations)
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US2920832A
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US3343973A
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Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-11-09 | 1985-05-11 | 1985-11-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-11-09 | 1989-05-11 | 1989-11-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-11-09 | 1993-05-11 | 1993-11-10 | $7700.00 | Window Closed / Lapsed |