Patent US3643756A successfully refreshed from Google Patents.
Patent US4224080A successfully refreshed from Google Patents.
US4224080A
Expired / Lapsed
US
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Method of treating inorganic oxide pigments
Assignee: Tronox Pigment UK Ltd
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Filing: 1978-10-10
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Granted: 1980-09-23
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Expires: 1998-10-10
Abstract
Abstract Inorganic oxides pigments, coated with alumina are treated with water soluble hydroxy acids or salts for example sodium citrate, and with water soluble di- or polyhydric alcohols, for example pentaerythritol, or with a water soluble reaction product of excess di- or polybasic organic hydroxy acids with di- or polyhydric alcohol. Titanium dioxide pigment so treated may be used in both emulsion paint and in organic based paint systems.
Inventors
- 👤 Hubert H. Chambers
- 👤 Brian J. Tear
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 23:33
CPC Classifications
C; C09; C09C; C09C3/00; C09C3/08; C09C1/00; C09C1/36; C09C1/3607; C09C1/3669; C01; C01P; C01P2004/00; C01P2004/80; C01P2004/82; C01P2004/84; C01P2006/00; C01P2006/60; Y; Y10; Y10S; Y10S516/00; Y10S516/01; Y10S516/06
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
149 words
A method for producing particles of titanium dioxide pigment useful for dispersion in aqueous or organic media, which comprises; in sequence, precipitating onto particles of titanium dioxide an inorganic oxide surface coating comprising alumina; washing the inorganic oxide coated particles to remove dissolved salts; treating the washed particles by contacting them with an aqueous solution of an agent selected from the group consisting of the water soluble reaction product of (i) an equivalent excess of an organic hydroxy acid selected from the group consisting of di- and tribasic hydroxy acids, with (ii) an alcohol containing from 2 to 6 hydroxyl groups; and salts thereof; said reaction product containing unesterfied carboxyl groups; said treating being conducted while the washed particles are in an aqueous medium; and washing, drying and milling the treated particles; whereby there is obtained a grade of pigment which will disperse in both aqueous and organic media.
Claim 2
Independent Claim
149 words
A method for producing particles of titanium dioxide pigment useful for dispersion in aqueous or organic media, which comprises; in sequence, precipitating onto particles of titanium dioxide an inorganic oxide surface coating comprising alumina; washing the inorganic oxide coated particles to remove dissolved salts; treating the washed particles by contacting them with an aqueous solution of an agent selected from the group consisting of the water soluble reaction product of (i) an equivalent excess of an organic hydroxy acid selected from the group consisting of di- and tribasic hydroxy acids, with (ii) an alcohol containing from 2 to 6 hydroxyl groups; and salts thereof; said reaction product containing unesterfied carboxyl groups; said treating being conducted while the washed particles are in an aqueous medium; and washing, drying and milling the treated particles; whereby there is obtained a grade of pigment which will disperse in both aqueous and organic media.
Claim 3
Dependent Claim
24 words
A method as claimed in claim 1 wherein the surface coating also comprises one or more oxides of cerium, antimony, silicon, titanium or tin.
Claim 4
Dependent Claim
35 words
A method as claimed in claim 2 wherein the alumina and one or more oxides of other inorganic elements is present in an atomic ratio of aluminum to other elements of from 1:1 to 3:2.
Claim 5
Dependent Claim
25 words
A method as claimed in claim 1 wherein the surface coating is from 0.1% to 15% based on the dry weight of the coated pigment.
Claim 6
Dependent Claim
21 words
A method as claimed in claim 1 wherein the alumina has been precipitated onto the pigment particles at an alkaline pH.
Claim 7
Dependent Claim
18 words
A method as claimed in claim 1 wherein the alcohol contains from 4 to 6, inclusive, hydroxyl groups.
Claim 8
Dependent Claim
31 words
A method as claimed in claim 1 wherein the hydroxy acid (i) is saturated with respect to chemical bonding and has a carbon chain of from 3 to 6 carbon atoms.
Claim 9
Dependent Claim
27 words
A method as claimed in claim 7 wherein the alcohol (ii) contains from 4 to 6, inclusive, hydroxyl groups and are saturated with respect to chemical bonding.
Claim 10
Dependent Claim
33 words
A method as claimed in claim 1 wherein the contacting is carried out by adding a solution of the agent to an aqueous slurry or to an undried filtercake of the pigment particles.
Claim 11
Dependent Claim
30 words
A method as claimed in claim 1 wherein the hydroxy acids or salts thereof are selected from the group consisting of citric acid, tartaric acid, sodium and potassium salts thereof.
Claim 12
Dependent Claim
12 words
A method as claimed in claim 10 wherein the alcohol comprises pentaerythritol.
Claim 13
Dependent Claim
8 words
The product of the process of claim 1.
References Cited (Backward Citations)
US3542575A
Cited
US3728142A
Cited
GB1277565A
Cited
US3957526A
Cited
US3825438A
Cited
GB1427210A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-09-23 | 1984-03-24 | 1984-09-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-09-23 | 1988-03-24 | 1988-09-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-09-23 | 1992-03-24 | 1992-09-23 | $7700.00 | Window Closed / Lapsed |