US4447630A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for making cyclopolydimethylsiloxanes
Assignee: General Electric Co
•
Filing: 1983-08-29
•
Granted: 1984-05-08
•
Expires: 2003-08-29
Abstract
Abstract A method is provided for making cyclopolysiloxanes by hydrolyzing diorganodichlorosilanes and aqueous hydrochloric acid in the presence of an effective amount of a perfluorinated alkyl substituted organic material, such as a perfluorinated alkyl sulfonic acid salt.
Inventors
- 👤 Robert E. Williams, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 14:40
CPC Classifications
C; C07; C07F; C07F7/00; C07F7/02; C07F7/21
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
75 words
A method for making cyclopolydimethylsiloxanes of the formula [(CH.sub.3).sub.2 SiO].sub.m which comprises, (A) hydrolyzing dimethyldichlorosilane in an aqueous reaction medium in the presence of an effective amount of a perfluoroalkyl sulfonic acid salts of the formula (C.sub.x F.sub.2x+1)SO.sub.3 M and (B) recovering the cyclopolydimethylsiloxane from the mixture of (A), where M is an alkali metal, or a tetralkylammonium radical, x is 6 to 16 and m is a whole number equal to from 3-6 inclusive.
Claim 2
Independent Claim
75 words
A method for making cyclopolydimethylsiloxanes of the formula [(CH.sub.3).sub.2 SiO].sub.m which comprises, (A) hydrolyzing dimethyldichlorosilane in an aqueous reaction medium in the presence of an effective amount of a perfluoroalkyl sulfonic acid salts of the formula (C.sub.x F.sub.2x+1)SO.sub.3 M and (B) recovering the cyclopolydimethylsiloxane from the mixture of (A), where M is an alkali metal, or a tetralkylammonium radical, x is 6 to 16 and m is a whole number equal to from 3-6 inclusive.
Claim 3
Dependent Claim
12 words
A method in accordance with claim 1, where the cyclopolydimethylsiloxane is octamethylcyclotetrasiloxane.
Claim 4
Dependent Claim
20 words
A method in accordance with claim 1, where the perfluoroalkylsulfonic acid is a mixture of C-8 to C-10 potassium salts.
Claim 5
Independent Claim
52 words
A method for making decamethylcyclopentasiloxane by equilibrating octamethylcyclotetrasiloxane in the presence of an effective amount of a perfluoroalkylsulfonic acid having the formula, (C.sub.x F.sub.2x+1)SO.sub.3 M where M is an alkali metal such as potassium, sodium, lithium, or a tetralkylammonium radical, and x is an integer having a value of 6 to 16.
Claim 6
Independent Claim
52 words
A method for making decamethylcyclopentasiloxane by equilibrating octamethylcyclotetrasiloxane in the presence of an effective amount of a perfluoroalkylsulfonic acid having the formula, (C.sub.x F.sub.2x+1)SO.sub.3 M where M is an alkali metal such as potassium, sodium, lithium, or a tetralkylammonium radical, and x is an integer having a value of 6 to 16.
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) | 1987-05-08 | 1987-11-07 | 1988-05-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-08 | 1991-11-07 | 1992-05-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-08 | 1995-11-07 | 1996-05-08 | $7700.00 | Window Closed / Lapsed |