US3607898A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing cyclic syn-tetramethyltetravinyltetrasiloxane
Assignee: General Electric Co
•
Filing: 1969-08-20
•
Granted: 1971-09-21
•
Expires: 1989-08-20
Abstract
Abstract Cyclic sym-tetramethyltetravinyltetrasiloxane is produced from a hydrolyzate, consisting primarily of methylvinylpolysiloxane employing lithium hydroxide, in combination with a cocatalyst. Heating of the hydrolyzate with lithium hydroxide in combination with one of the cocatalysts provides for rearrangement of the hydrolyzate into cyclic organopolysiloxanes and for a high yield of the cyclic sym-tetramethyltetravinyltetrasiloxane to be distilled from the heated mixture avoiding cleavage of the vinyl groups and gelation of the starting material.
Inventors
- 👤 Robert J Macher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 12:23
CPC Classifications
C; C08; C08G; C08G77/00; C08G77/04; C07; C07F; C07F7/00; C07F7/02; C07F7/08; C07F7/0834; C07F7/0838; C07F7/0872; C07F7/0874; C07F7/21
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
4 words
heating the mixture; and
Claim 2
Dependent Claim
4 words
heating the mixture; and
Claim 3
Dependent Claim
79 words
A process for forming sym-tetramethyltetravinylcyclotetrasiloxane from the hydrolysis product of methylvinyldichlorosilane comprising heating the hydrolysis product in the presence of lithium hydroxide and a cocatalyst selected from the class consisting of: CH3(CH2)a-O (CH2)bOx(CH2)cCH3; where a is from 0 to 8, b is from 1 to 3, c is from 0 to 8, x is from 2 to 6, the sum a+c+ bx is from 3 to 18 and the molecular weight is a maximum of 350, and triphenylphosphine oxide.
Claim 4
Dependent Claim
12 words
A process for forming sym-tetramethyltetravinylcyclotetrasiloxane from the hydrolysis product of methylvinyldichlorosilane comprising:
Claim 5
Dependent Claim
8 words
distilling from the mixture a mixture of sym-methylvinylcyclopolysiloxanes.
Claim 6
Dependent Claim
9 words
distilling from the heated mixture a blend of sym-methylvinylcyclopolysiloxanes.
Claim 7
Dependent Claim
19 words
The process of claim 3 wherein hydrolysis product is added to the distillation mixture as cyclic polysiloxanes are removed.
Claim 8
Dependent Claim
10 words
The process of claim 3 wherein the polyether is: CH3OCH2CH2OCH2CH2OCH2CH2OCH2CH2OCH3.
Claim 9
Dependent Claim
18 words
The process of claim 3 wherein the amount of polyether is equal to the amount of hydrolysis product.
Claim 10
Dependent Claim
18 words
The process of claim 3 wherein a portion of the hydrolysis product of methylvinyldichlorosilane is provided by sym-polymethylpolyvinylcyclopolysiloxanes.
Claim 11
Dependent Claim
12 words
A process For forming sym-tetramethyltetravinylcyclotetrasiloxane from the hydrolysis product of methylvinyldichlorosilane comprising:
Claim 12
Dependent Claim
15 words
The process of claim 8 wherein the solvent is a high boiling mineral oil solvent.
Claim 13
Dependent Claim
19 words
The process of claim 8 wherein hydrolysis product is added to the distillation mixture as cyclic polysiloxanes are removed.
Claim 14
Dependent Claim
29 words
The process of claim 8 wherein the lithium hydroxide is employed in an amount of approximately 1% and the triphenylphosphine oxide is employed in an amount of approximately 1%.
Claim 15
Dependent Claim
18 words
The process of claim 8 wherein a portion of the hydrolysis product of methylvinyldichlorosilane is provided by sym-polymethylpolyvinylcyclopolysiloxanes.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-09-20 | 1975-03-22 | 1975-09-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-20 | 1979-03-22 | 1979-09-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-20 | 1983-03-22 | 1983-09-21 | $7700.00 | Window Closed / Lapsed |