US3894097A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of hexafluoroisobutylene
Assignee: Honeywell International Inc
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Filing: 1974-05-10
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Granted: 1975-07-08
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Expires: 1994-05-10
Abstract
Abstract In one embodiment, a process of producing hexafluoroisobutylene is provided which comprises combining a ketene-generating compound with hexafluoroacetone in a reaction chamber maintained at a temperature in the range of about 340* to 1000*C., retaining the reactants in said chamber for a residence time between about 0.1 seconds to 5 minutes whereby hexafluoroisobutylene is formed and thereafter collecting the reaction product. In a second embodiment, a process of producing hexafluoroisobutylene is provided which comprises heating a ketene-generating compound, optionally together with hexafluoroacetone, in a heating chamber maintained at a temperature in the range of about 340* to 1000*C., retaining said compound in said chamber for a residence time of between about 0.1 to 10 seconds, combining said compound with hexafluoroacetone if the same is not present in said chamber, cooling the resultant mixture to a temperature below about 150*C. to form a liquid and whereby Beta , Beta -bis(trifluoromethyl)- Beta -propiolactone is formed, heating said lactone in a reaction chamber maintained at a temperature of about 340* to 1000*C. whereby hexafluoroisobutylene is formed and collecting the reaction product.
Inventors
- 👤 Jr Nicholas Vanderkooi
- 👤 Herbert J Huthwaite
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 16:38
CPC Classifications
C; C07; C07D; C07D305/00; C07D305/02; C07D305/10; C07D305/12; C07C; C07C17/00; C07C17/26; C07C17/263; C07C17/361; C07C17/363
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
72 words
PROCESS OF PRODUCING HEXAFLUOROISOBUTYLENE COMPRISING COMBINING A COMPOUND SELECTED FROM THE GROUP CONSISTING OF ACETIC ANHYDRIDE, ACETONE, ACETIC ACID, ISOPROPENYL ACETATE, ACETYL ACETONE, DIKETONE AND MIXTURES THEREOF, WITH HEXAFLUOROACETONE IN A REACTION CHAMBER MAINTAINED AT A TEMPERATURE IN THE RANGE OF ABOUT 340* TO ABOUT 1000*C, RETAINING THE REACTANTS IN SAID CHAMBER FOR A RESIDENCE TIME BETWEEN ABOUT 0.1 SECONDS TO 5 MINUTES WHEREBY HEXAFLUOROISOBUTYLENE IS FORMED AND COLLECTING THE REACTION PRODUCT.
Claim 2
Dependent Claim
72 words
PROCESS OF PRODUCING HEXAFLUOROISOBUTYLENE COMPRISING COMBINING A COMPOUND SELECTED FROM THE GROUP CONSISTING OF ACETIC ANHYDRIDE, ACETONE, ACETIC ACID, ISOPROPENYL ACETATE, ACETYL ACETONE, DIKETONE AND MIXTURES THEREOF, WITH HEXAFLUOROACETONE IN A REACTION CHAMBER MAINTAINED AT A TEMPERATURE IN THE RANGE OF ABOUT 340* TO ABOUT 1000*C, RETAINING THE REACTANTS IN SAID CHAMBER FOR A RESIDENCE TIME BETWEEN ABOUT 0.1 SECONDS TO 5 MINUTES WHEREBY HEXAFLUOROISOBUTYLENE IS FORMED AND COLLECTING THE REACTION PRODUCT.
Claim 3
Dependent Claim
11 words
The process of claim 1 wherein said compound is diketene compound.
Claim 4
Dependent Claim
24 words
The process of claim 1 wherein said compound is selected from the group consisting of acetic anhydride, acetic acid and acetone and mixtures thereof.
Claim 5
Dependent Claim
11 words
The process of claim 3 wherein said compound is acetic anhydride.
Claim 6
Dependent Claim
17 words
The process of claim 4 wherein said temperature is in the range of about 400* to 700*C.
Claim 7
Dependent Claim
17 words
The process of claim 3 wherein said temperature is in the range of about 550* to 1000*C.
Claim 8
Dependent Claim
19 words
The process of claim 1 wherein said residence time is in the range of about 2 to 40 seconds.
Claim 9
Dependent Claim
25 words
The process of claim 1 wherein the mole feed ratio of said compound to said hexafluoroacetone is in the range of about 0.5:1 to 4:1.
Claim 10
Dependent Claim
39 words
The process of claim 1 including separating said hexafluoroisobutylene from the reaction product by scrubbing the reaction product with an aqueous caustic solution, drying the scrubbed product to remove water and condensing the evaporated product whereby hexafluoroisobutylene is obtained.
Claim 11
Dependent Claim
19 words
The process of claim 1 including volatilizing said compound prior to combination with hexafluoroacetone gas in said reaction chamber.
Claim 12
Dependent Claim
127 words
A process of producing hexafluoroisobutylene comprising heating a compound selected from the group consisting of acetic anhydride, acetone, acetic acid, isopropenyl acetate, acetyl acetone, diketene and mixtures thereof and mixtures with hexafluoroacetone, in a heating chamber maintained at a temperature in the range of about 340* to 1000*C., retaining said compound in said chamber for a residence time between about 0.1 to 10 seconds, combining said compound with hexafluoroacetone if the same is not present in said chamber, cooling the resultant mixture to a temperature below about 150*C. to liquefy said mixture and whereby Beta , Beta -bis(trifluoromethyl)- Beta -propiolactone is formed, heating said lactone in a reaction chamber maintained at a temperature of about 340* to 1000*C. whereby hexafluoroisobutylene is formed and collecting the reaction product.
Claim 13
Dependent Claim
127 words
A process of producing hexafluoroisobutylene comprising heating a compound selected from the group consisting of acetic anhydride, acetone, acetic acid, isopropenyl acetate, acetyl acetone, diketene and mixtures thereof and mixtures with hexafluoroacetone, in a heating chamber maintained at a temperature in the range of about 340* to 1000*C., retaining said compound in said chamber for a residence time between about 0.1 to 10 seconds, combining said compound with hexafluoroacetone if the same is not present in said chamber, cooling the resultant mixture to a temperature below about 150*C. to liquefy said mixture and whereby Beta , Beta -bis(trifluoromethyl)- Beta -propiolactone is formed, heating said lactone in a reaction chamber maintained at a temperature of about 340* to 1000*C. whereby hexafluoroisobutylene is formed and collecting the reaction product.
Claim 14
Dependent Claim
11 words
The process of claim 11 wherein said compound is diketene comPound.
Claim 15
Dependent Claim
24 words
The process of claim 11 wherein said compound is selected from the group consisting of acetic anhydride, acetic acid and acetone and mixtures thereof.
Claim 16
Dependent Claim
11 words
The process of claim 13, wherein said compound is acetic anhydride.
Claim 17
Dependent Claim
21 words
The process of claim 14 wherein said temperature in said heating chamber is in the range of about 400* to 700*C.
Claim 18
Dependent Claim
21 words
The process of claim 13 wherein said temperature in said heating chamber is in the range of about 550* to 1000*C.
Claim 19
Dependent Claim
22 words
The process of claim 11 wherein said reaction chamber is maintained at a temperature in the range of about 400* to 700*C.
Claim 20
Dependent Claim
23 words
The process of claim 11 wherein the residence time in said reaction chamber is in the range of about 0.1 to 10 seconds.
Claim 21
Dependent Claim
53 words
The process of claim 11 wherein said heating chamber and said reaction chamber comprise a single tube maintained at the desired temperature by means of a single heating source and a portion of said tube outside of said heating source is maintained at a temperature below about 150*C. to form said liquid phase.
Claim 22
Dependent Claim
39 words
The process of claim 11 including separating said hexafluoroisobutylene from the reaction product by scrubbing the reaction product with an aqueous caustic solution, drying the scrubbed product to remove water and condensing the evaporated product whereby hexafluorisobutylene is obtained.
Claim 23
Dependent Claim
24 words
The process of claim 11 wherein the molar feed ratio of said compound to hexafluoroacetone is in the range of about 0.5:1 to 4:1.
Claim 24
Dependent Claim
19 words
The process of claim 11 including volatilizing said compound prior to combination with hexafluoroacetone gas in said heating chamber.
References Cited (Backward Citations)
US3345420A
Cited
US3544591A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-07-07 | 1979-01-06 | 1979-07-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-07 | 1983-01-06 | 1983-07-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-07 | 1987-01-06 | 1987-07-08 | $7700.00 | Window Closed / Lapsed |