US4544782A
Expired / Lapsed
US
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Thermal styrene formation in the presence of O2
Assignee: University of California, San Diego
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Filing: 1984-02-01
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Granted: 1985-10-01
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Expires: 2004-02-01
Abstract
Abstract Single-stage thermolysis of C8 and C9 aromatics at temperatures in excess of 900 DEG C. and pressures of less than 0.2 torr or in the presence of steam in excess of 800 DEG C., in the absence of catalysts yields styrene and/or p-methylstyrene in high yields, providing a process for the conversion of xylenes and p-ethyltoluene to preferred styrene monomers.
Inventors
- 👤 Orville L. Chapman
- 👤 Uh-Po E. Tsou
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 21:34
CPC Classifications
C; C07; C07C; C07C5/00; C07C5/22; C07C5/27; C07C5/31; C07C5/42; C07C5/48
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
79 words
A process for the production of a polymerizable styrene, which comprises the gas-phase thermolysis, in the absence of a dehydrogenation catalyst, of an aromatic compound having the formula: ##STR6## in the presence of an oxygen pressure in an amount of at least 0.2 torr up to about 5% of the aromatic compound, wherein R is alkyl, hydroxyalkyl or alkylhalide; R' is H,alkyl, hydroxyalkyl, or alkylhalide, or where R and R' together form cyclobutene; and R" is H or alkyl.
Claim 2
Dependent Claim
79 words
A process for the production of a polymerizable styrene, which comprises the gas-phase thermolysis, in the absence of a dehydrogenation catalyst, of an aromatic compound having the formula: ##STR6## in the presence of an oxygen pressure in an amount of at least 0.2 torr up to about 5% of the aromatic compound, wherein R is alkyl, hydroxyalkyl or alkylhalide; R' is H,alkyl, hydroxyalkyl, or alkylhalide, or where R and R' together form cyclobutene; and R" is H or alkyl.
Claim 3
Dependent Claim
32 words
The process of claim 1 wherein R is methyl or isopropyl; R' is H or methyl, or where R and R' taken together are cyclobutene; and R" is H, methyl or ethyl.
Claim 4
Dependent Claim
50 words
A process for the production of styrene, which comprises subjecting xylene to gas-phase thermolysis at a temperature of at least 900° C. in the presence of an oxygen pressure of from about 0.2 torr up to less than about 5% of the xylene, in the absence of a dehydrogenation catalyst.
Claim 5
Dependent Claim
50 words
A process for the production of styrene, which comprises subjecting xylene to gas-phase thermolysis at a temperature of at least 900° C. in the presence of an oxygen pressure of from about 0.2 torr up to less than about 5% of the xylene, in the absence of a dehydrogenation catalyst.
Claim 6
Dependent Claim
55 words
A process for the production of styrene, which comprises subjecting xylene to gas-phase thermolysis at a temperature of at least about 800° C. in admixture with an inert diluent in the presence of an oxygen pressure of from about 0.2 torr up to about 5% of the xylene, in the absence of a dehydrogenation catalyst.
Claim 7
Dependent Claim
55 words
A process for the production of styrene, which comprises subjecting xylene to gas-phase thermolysis at a temperature of at least about 800° C. in admixture with an inert diluent in the presence of an oxygen pressure of from about 0.2 torr up to about 5% of the xylene, in the absence of a dehydrogenation catalyst.
Claim 8
Dependent Claim
11 words
The process of claim 4 wherein the inert diluent is steam.
Claim 9
Dependent Claim
50 words
A process for the production of p-methylstyrene from p-ethyltoluene, which comprises subjecting p-ethyltoluene to gas-phase thermolysis at a temperature of at least 900° C. in the presence of an oxygen pressure of from about 0.2 torr up to about 5% of the p-ethyltoluene, in the absence of a dehydrogenation catalyst.
Claim 10
Dependent Claim
50 words
A process for the production of p-methylstyrene from p-ethyltoluene, which comprises subjecting p-ethyltoluene to gas-phase thermolysis at a temperature of at least 900° C. in the presence of an oxygen pressure of from about 0.2 torr up to about 5% of the p-ethyltoluene, in the absence of a dehydrogenation catalyst.
Claim 11
Dependent Claim
54 words
A process for the production of p-methylstyrene which comprises subjecting p-ethyltoluene to gas-phase thermolysis at a temperature of at least 800° C. in admixture with an inert diluent, in the presence of an oxygen pressure from about 0.2 torr up to about 5% of the p-ethyltoluene, in the essential absence of a dehydrogenation catalyst.
Claim 12
Dependent Claim
54 words
A process for the production of p-methylstyrene which comprises subjecting p-ethyltoluene to gas-phase thermolysis at a temperature of at least 800° C. in admixture with an inert diluent, in the presence of an oxygen pressure from about 0.2 torr up to about 5% of the p-ethyltoluene, in the essential absence of a dehydrogenation catalyst.
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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) | 1988-09-30 | 1989-04-01 | 1989-10-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-09-30 | 1993-04-01 | 1993-10-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-09-30 | 1997-04-01 | 1997-10-01 | $7700.00 | Window Closed / Lapsed |