US4159276A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for purifying methyl alkyl siloxane lubricants
Assignee: RCA Corp
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Filing: 1978-08-29
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Granted: 1979-06-26
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Expires: 1998-08-29
Abstract
Abstract A method of purifying methyl alkyl siloxane lubricants of the formula ##STR1## wherein R is an alkyl group of 4-20 carbon atoms and x is an integer which comprises multiply extracting with acetone.
Inventors
- 👤 Nitin V. Desai
- 👤 Richard J. Himics
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 05:51
CPC Classifications
C; C07; C07F; C07F7/00; C07F7/02; C07F7/08; C07F7/20
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
71 words
A method of purifying a methyl alkyl siloxane of the formula ##STR5## wherein R is an alkyl group of 4-20 carbon atoms and x is an integer containing chemically unbound antioxidant of the formula ##STR6## which comprises extracting the methyl alkyl siloxane with acetone until all of the chemically unbound antioxidant is dissolved in the acetone, separating the methyl alkyl siloxane and acetone layers and collecting the chemically unbound antioxidant-free siloxane.
Claim 2
Independent Claim
71 words
A method of purifying a methyl alkyl siloxane of the formula ##STR5## wherein R is an alkyl group of 4-20 carbon atoms and x is an integer containing chemically unbound antioxidant of the formula ##STR6## which comprises extracting the methyl alkyl siloxane with acetone until all of the chemically unbound antioxidant is dissolved in the acetone, separating the methyl alkyl siloxane and acetone layers and collecting the chemically unbound antioxidant-free siloxane.
Claim 3
Dependent Claim
23 words
A method according to claim 1 wherein the collected layer is treated at about 80° C. under vacuum to remove any acetone present.
Claim 4
Dependent Claim
17 words
A method according to claim 1 wherein equal volumes of acetone and methyl alkyl siloxane are employed.
Claim 5
Dependent Claim
15 words
A method according to claim 1 wherein two extraction steps and separation steps are employed.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-06-25 | 1982-12-25 | 1983-06-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-06-25 | 1986-12-25 | 1987-06-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-06-25 | 1990-12-25 | 1991-06-26 | $7700.00 | Window Closed / Lapsed |