Patent US4052222A successfully refreshed from Google Patents.
US4052222A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Treatment of pigment
Assignee: Tioxide Group Ltd
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Filing: 1976-06-04
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Granted: 1977-10-04
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Expires: 1996-06-04
Abstract
Abstract A process for the treatment of titanium dioxide pigment in which there is added to a slurry of the pigment a compound of silicon, of aluminium, of zirconium and of titanium, changing the pH of the slurry to 7.5 to 8.5 prior to adding a compound of silicon, an acidic compound of aluminium and an alkaline compound of aluminium, thereby producing a coated pigment.
Inventors
- 👤 Peter Barry Howard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 22:50
CPC Classifications
C; C09; C09C; C09C1/00; C09C1/36; C09C1/3607; C09C1/3653; C09C1/3661; C09C1/3692; C09C3/00; C09C3/06; C09C3/063; C09C3/08; C01; C01P; C01P2004/00; C01P2004/80; C01P2004/82; C01P2004/84; C01P2006/00; C01P2006/80
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
229 words
A process for the treatment of titanium dioxide pigment comprising a. forming an aqueous dispersion of pigmentary titanium dioxide containing a first water-soluble compound of silicon in an amount of from 1 to 2% by weight expressed as SiO 2 , b. adding to the dispersion a first acidic water-soluble compound of aluminum in an amount of from 1.5 to 2.5% by weight expressed as Al 2 O 3 , an acidic water-soluble compound of zirconium in an amount of from 0.5 to 1.5% by weight expressed as ZrO 2 , and an acidic water-soluble compound of titanium in an amount of from 1.0 to 2.0% by weight expressed as TiO 2 , c. changing the pH of the dispersion to a value in the range 7.5 to 8.5, and then d. adding to the dispersion a second water-soluble compound of silicon in an amount of from 1 to 2% by weight expressed as SiO 2 , then a second acidic water-soluble compound of aluminum in an amount of from 1 to 2% by weight expressed as Al 2 O 3 , and then an alkaline water-soluble compound of aluminum in an amount of from 0 to 1.5% by weight expressed as Al 2 O 3 , all the percentages by weight being based on the weight of TiO 2 in the pigment and recovering the so treated pigment.
Claim 2
Dependent Claim
229 words
A process for the treatment of titanium dioxide pigment comprising a. forming an aqueous dispersion of pigmentary titanium dioxide containing a first water-soluble compound of silicon in an amount of from 1 to 2% by weight expressed as SiO 2 , b. adding to the dispersion a first acidic water-soluble compound of aluminum in an amount of from 1.5 to 2.5% by weight expressed as Al 2 O 3 , an acidic water-soluble compound of zirconium in an amount of from 0.5 to 1.5% by weight expressed as ZrO 2 , and an acidic water-soluble compound of titanium in an amount of from 1.0 to 2.0% by weight expressed as TiO 2 , c. changing the pH of the dispersion to a value in the range 7.5 to 8.5, and then d. adding to the dispersion a second water-soluble compound of silicon in an amount of from 1 to 2% by weight expressed as SiO 2 , then a second acidic water-soluble compound of aluminum in an amount of from 1 to 2% by weight expressed as Al 2 O 3 , and then an alkaline water-soluble compound of aluminum in an amount of from 0 to 1.5% by weight expressed as Al 2 O 3 , all the percentages by weight being based on the weight of TiO 2 in the pigment and recovering the so treated pigment.
Claim 3
Dependent Claim
21 words
A process according to claim 1 in which the aqueous dispersion of pigmentary titanium dioxide is formed from calcined titanium dioxide.
Claim 4
Dependent Claim
24 words
A process according to claim 1 in which the titanium dioxide contains at least 95% of its TiO 2 content in the rutile form.
Claim 5
Dependent Claim
32 words
A process according to claim 1 in which the said titanium dioxide pigment contains from 0.1 to 0.5% by weight Al 2 O 3 based on the weight of TiO 2 .
Claim 6
Dependent Claim
24 words
A process according to claim 1 in which the aqueous dispersion of pigmentary titanium dioxide containing the water-soluble compound of silicon is wet milled.
Claim 7
Dependent Claim
32 words
A process according to claim 1 in which the amount of the first acidic water-soluble compound of aluminium is from 1.8 to 2.2% by weight expressed as Al 2 O 3 .
Claim 8
Dependent Claim
29 words
A process according to claim 1 in which the amount of the acidic water-soluble compound of zirconium is from 0.8 to 1.2% by weight expressed as ZrO 2 .
Claim 9
Dependent Claim
29 words
A process according to claim 1 in which the amount of the acidic water-soluble compound of titanium is from 1.2 to 1.6% by weight expressed as TiO 2 .
Claim 10
Dependent Claim
31 words
A process according to claim 1 in which the acidic water-soluble compounds of aluminium, titanium and zirconium are added to the aqueous dispersion in the form of a mixed aqueous solution.
Claim 11
Dependent Claim
29 words
A process according to claim 9 in which the mixed aqueous solution contains aluminium sulphate, titanyl sulphate and zirconium sulphate and has a pH of from 0.7 to 1.2.
Claim 12
Dependent Claim
31 words
A process according to claim 1 in which the pH of the aqueous dispersion is changed to a value within the range 7.5 to 8.5 by the addition of an alkali.
Claim 13
Dependent Claim
29 words
A process according to claim 1 in which the amount of the second water-soluble compound of silicon is from 1.4 to 1.6% by weight expressed as SiO 2 .
Claim 14
Dependent Claim
31 words
A process according to claim 1 in which the amount of the second water-soluble compound of aluminium is from 1.2 to 1.7% by weight expressed as Al 2 O 3 .
Claim 15
Dependent Claim
37 words
A process according to claim 1 in which the alkaline watersoluble compound of aluminium is added to the aqueous dispersion in an amount of from 0.7 to 1.2% by weight expressed as Al 2 O 3 .
Claim 16
Dependent Claim
20 words
A process according to claim 1 in which the treated titanium dioxide recovered is milled in a fluid energy mill.
Claim 17
Dependent Claim
21 words
A process according to claim 15 in which the pigment is treated with an amine, alkanolamine or a polyol during milling.
Claim 18
Dependent Claim
68 words
A process as claimed in claim 1 wherein the amount of said alkaline water-soluble compound of aluminum added is 0 and the pH of said dispersion is maintained in the range 4.0-4.5 by the simultaneous but separate addition of alkali during the addition of said second acidic water-soluble compound of aluminum, the pH of said dispersion then being raised to pH 8.0 before recovery of the treated pigment.
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 |