US4478805A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of high purity berlinite
Assignee: Dow Chemical Co
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Filing: 1983-09-22
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Granted: 1984-10-23
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Expires: 2003-09-22
Abstract
Abstract High purity berlinite is prepared by formation of an organoaluminum phosphate hydrogel in an organic solvent and subsequently hydrolyzing the hydrogel by reaction with water at pH less than or equal to 3.0. The berlinite is useful as a replacement for silicon-based quartz in electronic applications and in piezoelectric devices.
Inventors
- 👤 Horst G. Langer
- 👤 Jere D. Fellmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 22:50
CPC Classifications
C; C07; C07F; C07F5/00; C07F5/06; C07F5/069; C01; C01B; C01B25/00; C01B25/16; C01B25/26; C01B25/36
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
95 words
A process for preparing berlinite comprising: (1) forming in an organic solvent an organoaluminum phosphate hydrogel having an aluminum to phosphorus atomic ratio of from about 1:1 to about 1:1.2 comprising at least one compound corresponding to the formula: ##STR3## where each R is hydrogen or R 1 , and R 1 is an alkyl, dialkylaminoalkyl or alkoxyalkyl group of up to about 10 carbons; (2) hydrolyzing the organoaluminum phosphate hydrogel by heating in the presence of water at a pH of less than about 3.0 to thereby form berlinite; and (3) recovering the berlinite.
Claim 2
Dependent Claim
95 words
A process for preparing berlinite comprising: (1) forming in an organic solvent an organoaluminum phosphate hydrogel having an aluminum to phosphorus atomic ratio of from about 1:1 to about 1:1.2 comprising at least one compound corresponding to the formula: ##STR3## where each R is hydrogen or R 1 , and R 1 is an alkyl, dialkylaminoalkyl or alkoxyalkyl group of up to about 10 carbons; (2) hydrolyzing the organoaluminum phosphate hydrogel by heating in the presence of water at a pH of less than about 3.0 to thereby form berlinite; and (3) recovering the berlinite.
Claim 3
Dependent Claim
20 words
A process according to claim 1 wherein the organic solvent is an aliphatic or aromatic hydrocarbon or halogenated derivative thereof.
Claim 4
Dependent Claim
18 words
A process according to claim 2 wherein the organic solvent has a boiling point above about 100° C.
Claim 5
Dependent Claim
11 words
A process according to claim 3 wherein the solvent is toluene.
Claim 6
Dependent Claim
13 words
A process according to claim 1 wherein R 1 is butoxyethyl or sec-butyl.
Claim 7
Dependent Claim
57 words
A process according to claim 1 wherein the organoaluminum phosphate hydrogel is formed by reacting an aluminum alkoxide or hydrogen aluminum alkoxide corresponding to the formula Al(OR 1 ) 3 or HAl(OR 1 ) 4 wherein R 1 is an alkyl, dialkylaminoalkyl, or alkoxyalkyl group of up to about 10 carbons, with phosphoric acid or phosphorus pentoxide.
Claim 8
Dependent Claim
24 words
A process according to claim 6 wherein the hydrolysis is performed by heating to at least about 90° C. up to about 200° C.
Claim 9
Dependent Claim
26 words
A process according to claim 7 wherein the temperature is about 160° C. and the hydrolysis is conducted in a sealed pressure reactor at elevated pressures.
Claim 10
Dependent Claim
16 words
A process according to claim 7 wherein the hydrolysis is obtained by refluxing at atmospheric pressure.
Claim 11
Dependent Claim
40 words
A process according to claim 9 wherein during the hydrolysis from about 0.1 to about 1 mole of alcohol of the formula R 1 OH per mole of hydrogel is added to the hydrolysis mixture prior to the hydrolysis reaction.
References Cited (Backward Citations)
GB634837A
Cited
US4324773A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-10-23 | 1988-04-23 | 1988-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-23 | 1992-04-23 | 1992-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-23 | 1996-04-23 | 1996-10-23 | $7700.00 | Window Closed / Lapsed |