Patent US4241042A successfully refreshed from Google Patents.
US4241042A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Spherical titanium dioxide particles and process of manufacture
Assignee: Montedison SpA
•
Filing: 1978-06-19
•
Granted: 1980-12-23
•
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 14:49
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.
References Cited (Backward Citations)
US1842620A
Cited
US1819184A
Cited
US1931380A
Cited
GB743508A
Cited
US2998391A
Cited
US3062621A
Cited
US3403001A
Cited
US3406012A
Cited
US3663283A
Cited
US3914396A
Cited
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 |