Patent US4235768A successfully refreshed from Google Patents.
US4235768A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of readily dispersible titanium dioxide pigments
Assignee: Kerr-Mcgee Pigments & Co KG GmbH
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Filing: 1979-08-28
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Granted: 1980-11-25
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Expires: 1999-08-28
Abstract
Abstract In the homogeneous coating of a titanium dioxide pigment with an organic polymer in which an aqueous solution of a polymer containing carboxyl groups is added to a dispersion of titanium dioxide in water, the polymer is applied to the pigment, the coated pigment is separated off from the aqueous medium, washed, dried and, optionally ground, the improvement which comprises employing as the polymer a polymer of the formula <IMAGE> in which R1 each independently is hydrogen or methyl, R2 is hydrogen, or alkyl or cycloalkyl containing from 1 to 8 carbon atoms, M is sodium or potassium, R3 is hydrogen, alkyl or cycloalkyl containing from 1 to 12 carbon atoms, or hydroxyalkyl containing from 2 to 6 carbon atoms, m=0.2 to 1.
Inventors
- 👤 Helmut Ritter
- 👤 Heinz-Peter Hemmerich
- 👤 Hans J. Rosenkranz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:10
CPC Classifications
C; C09; C09C; C09C1/00; C09C1/36; C09C1/3607; C09C1/3676; C01; C01P; C01P2004/00; C01P2004/80; C01P2004/82; C01P2004/84
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
160 words
In the homogeneous coating of a titanium dioxide pigment with an organic polymer in which an aqueous solution of a polymer containing carboxyl groups is added to a dispersion of titanium dioxide in water, the polymer is applied to the pigment, the coated pigment is separated off from the aqueous medium, washed, dried and, optionally, ground, the improvement which comprises employing as the polymer a polymer of the formula ##STR3## in which R 1 each independently is hydrogen or methyl, R 2 is hydrogen, or alkyl or cycloalkyl containing from 1 to 8 carbon atoms, M is sodium or potassium, R 3 is hydrogen, alkyl or cycloalkyl containing from 1 to 12 carbon atoms, or hydroxyalkyl containing from 2 to 6 carbon atoms, m=0.2 to 1.5, and n=0 to 0.5, the polymer being added to the titanium dioxide dispersion in the form of a weakly alkaline aqueous solution in about 0.05 to 2.5% by weight based on the titanium dioxide.
Claim 2
Dependent Claim
160 words
In the homogeneous coating of a titanium dioxide pigment with an organic polymer in which an aqueous solution of a polymer containing carboxyl groups is added to a dispersion of titanium dioxide in water, the polymer is applied to the pigment, the coated pigment is separated off from the aqueous medium, washed, dried and, optionally, ground, the improvement which comprises employing as the polymer a polymer of the formula ##STR3## in which R 1 each independently is hydrogen or methyl, R 2 is hydrogen, or alkyl or cycloalkyl containing from 1 to 8 carbon atoms, M is sodium or potassium, R 3 is hydrogen, alkyl or cycloalkyl containing from 1 to 12 carbon atoms, or hydroxyalkyl containing from 2 to 6 carbon atoms, m=0.2 to 1.5, and n=0 to 0.5, the polymer being added to the titanium dioxide dispersion in the form of a weakly alkaline aqueous solution in about 0.05 to 2.5% by weight based on the titanium dioxide.
Claim 3
Dependent Claim
23 words
A process according to claim 1, wherein the polymer is added in about 0.2 to 0.8% by weight based on the titanium dioxide.
Claim 4
Dependent Claim
12 words
A coated titanium dioxide pigment produced by the process of claim 1.
Claim 5
Dependent Claim
11 words
A pigment according to claim 3 in a solid organic binder.
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) | 1983-11-25 | 1984-05-26 | 1984-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-11-25 | 1988-05-26 | 1988-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-11-25 | 1992-05-26 | 1992-11-25 | $7700.00 | Window Closed / Lapsed |