Patent US3816153A successfully refreshed from Google Patents.
US3816153A
Expired / Lapsed
US
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Opacity of clay films
Assignee: BASF Catalysts LLC
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Filing: 1972-07-10
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Granted: 1974-06-11
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Expires: 1992-07-10
Abstract
Abstract A small amount of a bismuth compound is incorporated with kaolin clay during the processing of the clay. The clay product is employed in an aqueous coating composition adapted for coating book or magazine paper in order to increase the opacity of the resulting clay film.
Inventors
- 👤 W Zentz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 20:16
CPC Classifications
D; D21; D21H; D21H19/00; D21H19/36; D21H19/38; D21H19/40; C; C09; C09C; C09C1/00; C09C1/40; C09C1/42; C01; C01P; C01P2004/00; C01P2004/60; C01P2004/61; C01P2004/80; C01P2006/00; C01P2006/60
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
21 words
The article of claim 1 which also contains a condensed phosphate salt in amount sufficient to deflocculate said clay in water.
Claim 2
Dependent Claim
14 words
The article of claim 1 in which said bismuth salt is a nitrate salt.
Claim 3
Dependent Claim
89 words
In the wet processing of kaolin clay to provide a coating pigment wherein a suspension of a fine size fraction of degritted clay is bleached with zinc hydrosulfite at an acidic pH and the bleached clay is filtered, washed and fluidized by adding a sodium condensed phosphate salt, the improvement which comprises adding a hydrolyzable bismuth (+3) salt to the clay in amount within the range of 0.05 percent to 1 percent of the dry clay weight after filtering the clay and before adding said sodium condensed phosphate salt.
Claim 4
Dependent Claim
90 words
In the wet processing of kaolin clay to provide a coating pigment wherein a suspension of a fine size fraction of degritted clay is bleached and filtered at an acid pH and the resulting acidic clay filter cake is washed and fluidized by adding a clay dispersing agent, the improvement which comprises adding a hydrolyzed bismuth (+3) salt to the washed acidic clay filter cake before adding the dispersing agent, the bismuth salt being added in amount within the range of 0.05 to 1 percent of the dry clay weight.
References Cited (Backward Citations)
US2910372A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-10 | 1977-12-10 | 1978-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-10 | 1981-12-10 | 1982-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-10 | 1985-12-10 | 1986-06-11 | $7700.00 | Window Closed / Lapsed |