US4241042A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Spherical titanium dioxide particles and process of manufacture
Assignee: Montedison SpA
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Filing: 1978-06-19
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Granted: 1980-12-23
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Expires: 1998-06-19
Abstract
Abstract Titanium dioxide, in the form of discrete, solid substantially spherical particles of a substantially uniform shape and size, is obtained by providing an aerosol comprising discrete liquid particles of a hydrolyzable titanium compound, contacting the aerosol with water vapor in dynamic flow to hydrolyze the liquid titanium (IV) compound to titanium dioxide, and recovering the desired product.
Inventors
- 👤 Egon Matijevic
- 👤 Mario Visca
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 12:56
CPC Classifications
C; C01; C01G; C01G23/00; C01G23/04; C01G23/047; C01G23/053; C01G23/0536; C01G23/0538; B; B82; B82Y; B82Y30/00; C01P; C01P2004/00; C01P2004/01; C01P2004/03; C01P2004/04; C01P2004/30; C01P2004/32; C01P2004/51; C01P2004/52; C01P2004/60; C01P2004/61; C01P2004/62; C01P2004/64
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
65 words
A method of preparing titanium dioxide, comprising: (A) providing a liquid aerosol comprising discrete liquid droplets of a hydrolyzable titanium (IV) compound; (B) contacting the liquid aerosol with water vapor in dynamic flow, to hydrolyze the liquid titanium (IV) compound to titanium dioxide in the form of discrete, solid, substantially spherical particles of a substantially uniform shape and size; and (C) recovering the titanium dioxide.
Claim 2
Independent Claim
65 words
A method of preparing titanium dioxide, comprising: (A) providing a liquid aerosol comprising discrete liquid droplets of a hydrolyzable titanium (IV) compound; (B) contacting the liquid aerosol with water vapor in dynamic flow, to hydrolyze the liquid titanium (IV) compound to titanium dioxide in the form of discrete, solid, substantially spherical particles of a substantially uniform shape and size; and (C) recovering the titanium dioxide.
Claim 3
Dependent Claim
94 words
The method of claim 1 wherein the liquid aerosol is made by a process comprising: (a) cooling a vapor of the hydrolyzable titanium (IV) compound, in the presence of an inert gas, to a temperature at least sufficient to condense the vapor into discrete liquid droplets without condensing the inert gas; (b) evaporating the liquid droplets of the titanium (IV) compound from (a); and (c) re-condensing the vapor of the hydrolyzable titanium (IV) compound from (b) to liquid droplets of said compound in a narrower particle size distribution, to form the desired liquid aerosol.
Claim 4
Dependent Claim
16 words
The process of claim 2 wherein steps (b) and (c) are each repeated at least once.
Claim 5
Dependent Claim
19 words
The process of claim 2 wherein the hydrolyzable titanium (IV) compound and the inert gas are in dynamic flow.
Claim 6
Dependent Claim
26 words
The process of claim 2 wherein the vapor of the hydrolizable titanium (IV) compound is condensed in the presence of the inert gas using homogeneous nucleation.
Claim 7
Dependent Claim
26 words
The process of claim 2 hwerein the vapor of the hydrolyzable titanium (IV) compound is condensed in the presence of the inert gas using heterogeneous nucleation.
Claim 8
Dependent Claim
23 words
The process of claim 6 wherein the heterogeneous nucleation comprises condensing the vapor of the hydrolyzable titanium (IV) compound on solid condensation nuclei.
Claim 9
Dependent Claim
22 words
The method of claim 1 wherein the hydrolyzable titanium (IV) compound is selected from among liquid titanium (IV) alkoxides and titanium tetrachloride.
Claim 10
Dependent Claim
106 words
The method of claim 1 wherein the liquid aerosol contacting with water is effected by a process comprising: (a) introducing a stream of an inert gas saturated with water vapor into a flowing stream of the liquid aerosol, at the temperature of condensation of the aerosol, to form a partial hydrolyzate of the titanium (IV) compound; (b) introducing a second stream of an inert gas saturated with water vapor into a flowing stream of the partially hydrolyzed liquid aerosol from step (a); and (c) heating the mixture from step (b) at a temperature at least sufficient to completely hydrolyze the titanium (IV) compound to titanium dioxide.
Claim 11
Dependent Claim
32 words
The process of claim 9 wherein the mixture comprising the water vapor-saturated inert gas and partially hydrolyzed liquid aerosol is heated at a temperature in the range between 100° and 250° C.
Claim 12
Dependent Claim
25 words
The method of claim 1 wherein the spherical particles of titanium dioxide are heated at a temperature in the range between 250° and 1,100° C.
Claim 13
Dependent Claim
27 words
The method of claim 11 wherein the spherical particles of titanium dioxide are heated at a temperature in the range between 250° and 1,100° C., before recovery.
Claim 14
Dependent Claim
27 words
The method of claim 11 wherein the spherical particles of titanium dioxide are heated at a temperature in the range between 150° and 1,100° C., after recovery.
Claim 15
Dependent Claim
26 words
The method of claim 1 wherein the titanium dioxide particles have an average (modal) diameter in the range of from about 0.05 to about 3 μm.
Claim 16
Dependent Claim
22 words
The method of claim 14 wherein the titanium dioxide particles have a width of particle size distribution, σo, as low as 0.1.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-12-23 | 1984-06-23 | 1984-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-23 | 1988-06-23 | 1988-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-23 | 1992-06-23 | 1992-12-23 | $7700.00 | Window Closed / Lapsed |