US4052223A
Expired / Lapsed
US
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Treatment of pigment
Assignee: Tioxide Group Ltd
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Filing: 1976-08-03
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Granted: 1977-10-04
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Expires: 1996-08-03
Abstract
Abstract A process for the production of the highly durable titanium dioxide pigment in which the pigment is coated with a phosphate, a silicate and a hydrous oxide of zirconium and aluminium in specified carefully controlled amounts and order of deposition.
Inventors
- 👤 Peter Barry Howard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:14
CPC Classifications
C; C09; C09C; C09C1/00; C09C1/36; C09C1/3607; C09C1/3653; C09C1/3661; C01; C01P; C01P2004/00; C01P2004/80; C01P2004/82; C01P2004/84
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
243 words
A process for the treatment of titanium dioxide pigment which comprises forming an aqueous dispersion of titanium dioxide containing as a dispersant 0.1% to 0.3% by weight of monoisopropanolamine, a water-soluble phosphate in an amount of 0.05% to 0.5% by weight expressed as P 2 O 5 or a mixture thereof, or a water-soluble silicate in an amount of 0.1% to 0.5% by weight expressed as SiO 2 used alone or together with monoisopropanolamine and/or the phosphate, adding to the aqueous dispersion a water-soluble phosphate in an amount of 0.05% to 1.0% by weight expressed as P 2 O 5 when the dispersing agent is not solely a phosphate, a water-soluble hydrolysable acidic compound of zirconium in an amount of from 0.2% to 2.5% by weight expressed as ZrO 2 , a water-soluble hydrolysable acidic compound of aluminium in an amount of from 0.2% to 2.5% by weight expressed as Al 2 O 3 , a water-soluble compound of silicon in an amount of from 0% to 1% by weight expressed as SiO 2 , and a water-soluble hydrolysable alkaline compound of aluminium in an amount of 0.5% to 2.5% by weight expressed as Al 2 O 3 , and adjusting the pH of the dispersion, if necessary, to a value of pH 6.5 to 8.5 prior to recovering the treated pigment from the dispersion will all the percentages by weight being based on the weight of titanium dioxide in the aqueous dispersion.
Claim 2
Dependent Claim
243 words
A process for the treatment of titanium dioxide pigment which comprises forming an aqueous dispersion of titanium dioxide containing as a dispersant 0.1% to 0.3% by weight of monoisopropanolamine, a water-soluble phosphate in an amount of 0.05% to 0.5% by weight expressed as P 2 O 5 or a mixture thereof, or a water-soluble silicate in an amount of 0.1% to 0.5% by weight expressed as SiO 2 used alone or together with monoisopropanolamine and/or the phosphate, adding to the aqueous dispersion a water-soluble phosphate in an amount of 0.05% to 1.0% by weight expressed as P 2 O 5 when the dispersing agent is not solely a phosphate, a water-soluble hydrolysable acidic compound of zirconium in an amount of from 0.2% to 2.5% by weight expressed as ZrO 2 , a water-soluble hydrolysable acidic compound of aluminium in an amount of from 0.2% to 2.5% by weight expressed as Al 2 O 3 , a water-soluble compound of silicon in an amount of from 0% to 1% by weight expressed as SiO 2 , and a water-soluble hydrolysable alkaline compound of aluminium in an amount of 0.5% to 2.5% by weight expressed as Al 2 O 3 , and adjusting the pH of the dispersion, if necessary, to a value of pH 6.5 to 8.5 prior to recovering the treated pigment from the dispersion will all the percentages by weight being based on the weight of titanium dioxide in the aqueous dispersion.
Claim 3
Dependent Claim
19 words
A process according to claim 1 in which the titanium dioxide to be treated is a calcined titanium dioxide.
Claim 4
Dependent Claim
32 words
A process according to claim 1 in which the titanium dioxide to be treated contains from 0.1% to 0.5% by weight Al 2 O 3 on the weight of TiO 2 .
Claim 5
Dependent Claim
30 words
A process according to claim 1 in which the titanium dioxide is rutile titanium dioxide containing at least 95% by weight of its TiO 2 content in the rutile form.
Claim 6
Dependent Claim
18 words
A process according to claim 1 in which the water-soluble phosphate is a water-soluble salt of phosphoric acid.
Claim 7
Dependent Claim
16 words
A process according to claim 5 in which the phosphate is an alkali metal dihydrogen phosphate.
Claim 8
Dependent Claim
15 words
A process according to claim 1 in which the water-soluble phosphate is a polymeric phosphate.
Claim 9
Dependent Claim
13 words
A process according to claim 7 in which the phosphate is sodium hexametaphosphate.
Claim 10
Dependent Claim
28 words
A process according to claim 1 in which the water-soluble hydrolysable acid compound is added in an amount equivalent to 0.25% to 0.75% by weight ZrO 2 .
Claim 11
Dependent Claim
34 words
A process according to claim 1 in which the water-soluble hydrolysable acidic compound of aluminium is added in an amount of from 0.5% to 1.5% by weight expressed as Al 2 O 3 .
Claim 12
Dependent Claim
26 words
A process according to claim 1 in which acid compounds of zirconium and of aluminium are added to the aqueous dispersion as a mixed aqueous solution.
Claim 13
Dependent Claim
36 words
A process according to claim 1 in which the water-soluble hydrolysable alkaline compound is added to the aqueous dispersion in an amount of from 1.0% to 1.5% by weight expressed as Al 2 O 3 .
Claim 14
Dependent Claim
210 words
A process for the treatment of titanium dioxide pigment prepared by the vapor phase oxidation of a titanium halide, which comprises forming an aqueous dispersion of titanium dioxide containing as a dispersant a water-soluble phosphate in an amount of 0.05% to 0.5% by weight expressed as P 2 O 5 , adding to the aqueous dispersion a water-soluble phosphate in an amount of 0.05% to 1.0 % by weight expressed as P 2 O 5 , a water-soluble hydrolysable acidic compound of zirconium in an amount of from 0.2% to 2.5% by weight expressed as ZrO 2 , a water-soluble hydroylsable acidic compound of aluminum in an amount of from 0.2% to 2.5% by weight expressed as Al 2 O 3 , a water-soluble compound of silicon in an amount of from 0% to 1% by weight expressed as SiO 2 , and a water-soluble hydrolysable alkaline compound of aluminum in an amount of 0.5% to 2.5% by weight expressed as Al 2 O 3 , and adjusting the pH of the dispersion, if necessary, to a value of pH 6.5 to 8.5 prior to recovering the treated pigment from the dispersion with all the percentages by weight being used on the weight of titanium dioxide in the aqueous dispersion.
Claim 15
Dependent Claim
210 words
A process for the treatment of titanium dioxide pigment prepared by the vapor phase oxidation of a titanium halide, which comprises forming an aqueous dispersion of titanium dioxide containing as a dispersant a water-soluble phosphate in an amount of 0.05% to 0.5% by weight expressed as P 2 O 5 , adding to the aqueous dispersion a water-soluble phosphate in an amount of 0.05% to 1.0 % by weight expressed as P 2 O 5 , a water-soluble hydrolysable acidic compound of zirconium in an amount of from 0.2% to 2.5% by weight expressed as ZrO 2 , a water-soluble hydroylsable acidic compound of aluminum in an amount of from 0.2% to 2.5% by weight expressed as Al 2 O 3 , a water-soluble compound of silicon in an amount of from 0% to 1% by weight expressed as SiO 2 , and a water-soluble hydrolysable alkaline compound of aluminum in an amount of 0.5% to 2.5% by weight expressed as Al 2 O 3 , and adjusting the pH of the dispersion, if necessary, to a value of pH 6.5 to 8.5 prior to recovering the treated pigment from the dispersion with all the percentages by weight being used on the weight of titanium dioxide in the aqueous dispersion.
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) | 1980-10-03 | 1981-04-04 | 1981-10-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-10-03 | 1985-04-04 | 1985-10-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-10-03 | 1989-04-04 | 1989-10-04 | $7700.00 | Window Closed / Lapsed |