US4077994A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Siloxanes
Assignee: Associated Portland Cement Manufacturers Ltd
•
Filing: 1975-09-16
•
Granted: 1978-03-07
•
Expires: 1995-09-16
Abstract
Abstract A method of producing a cyclic siloxane by silylating a cyclic silicate with a chlorosilane characterized by reacting the silicate with the chlorosilane in a ketone which is a solvent for the chlorosilane, in the presence of a minor molar proportion with respect to the chlorosilane, of a hydroxy compound soluble in the ketone, and purifying the resulting reaction mixture to recover the cyclic siloxane therefrom.
Inventors
- 👤 William Grenville Davies
- 👤 Howard Victor Andrew Beedle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 06:02
CPC Classifications
C; C08; C08G; C08G77/00; C08G77/04; C08G77/045; C07; C07F; C07F7/00; C07F7/02; C07F7/21
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
109 words
A method of producing a cyclic siloxane by silylating pseudo wollastonite with a chlorosilane characterised by reacting the pseudo wollastonite at ambient or elevated temperature with the chlorosilane in a ketone, in the presence of a minor molar proportion with respect to the chlorosilane, of a hydroxy compound soluble in the reaction medium, and purifying the resulting reaction mixture to recover the cyclic siloxane therefrom, the chlorosilane being R 3 SiCl and the cyclic siloxane produced being of the general formula: ##STR3## wherein the members R may differ and each R is selected from the group comprising hydrogen and the substituted and unsubstituted radicals alkyl, aryl, alkaryl and alkenyl.
Claim 2
Independent Claim
109 words
A method of producing a cyclic siloxane by silylating pseudo wollastonite with a chlorosilane characterised by reacting the pseudo wollastonite at ambient or elevated temperature with the chlorosilane in a ketone, in the presence of a minor molar proportion with respect to the chlorosilane, of a hydroxy compound soluble in the reaction medium, and purifying the resulting reaction mixture to recover the cyclic siloxane therefrom, the chlorosilane being R 3 SiCl and the cyclic siloxane produced being of the general formula: ##STR3## wherein the members R may differ and each R is selected from the group comprising hydrogen and the substituted and unsubstituted radicals alkyl, aryl, alkaryl and alkenyl.
Claim 3
Dependent Claim
19 words
A method according to claim 1, wherein the chlorosilane is trimethylchlorosilane and the cyclic siloxane produced is hexa(trimethylsiloxy) cyclotrisiloxane.
Claim 4
Dependent Claim
21 words
A method according to claim 1, wherein the ketone is selected from the group comprising acetone, methyl propyl ketone and cyclohexanone.
Claim 5
Dependent Claim
23 words
A method according to claim 1, wherein the hydroxy compound is selected from the group comprising water, alcohols, ether alcohols, and mixtures thereof.
Claim 6
Dependent Claim
18 words
A method according to claim 1, wherein the ketone is acetone and the hydroxy compound is tertiary butanol.
Claim 7
Dependent Claim
24 words
A method according to claim 1, wherein the minor proportion of hydroxy compound is from 0.01 to 25 mol percent based on the chlorosilane.
Claim 8
Dependent Claim
24 words
A method according to claim 1, wherein the minor proportion of hydroxy compound is from 0.1 to 16 mol percent based on the chlorosilane.
Claim 9
Dependent Claim
24 words
The method as defined in claim 1 including the further step of polymerizing the recovered cyclic siloxane in the presence of a polymerization catalyst.
Claim 10
Independent Claim
76 words
The method of producing a cyclic siloxane intermediate product having a structure of discrete rings, which comprises the steps of: (a) silylating pseudo wollastonite by reacting pseudo wollastonite with a chlorosilane in a ketone which is a solvent for the chlorosilane, in the presence of a minor molar proportion with respect to the chlorosilane of a hydroxy compound soluble in the in the ketone; and (b) purifying the resulting reaction mixture to recover the cyclic siloxane.
Claim 11
Independent Claim
76 words
The method of producing a cyclic siloxane intermediate product having a structure of discrete rings, which comprises the steps of: (a) silylating pseudo wollastonite by reacting pseudo wollastonite with a chlorosilane in a ketone which is a solvent for the chlorosilane, in the presence of a minor molar proportion with respect to the chlorosilane of a hydroxy compound soluble in the in the ketone; and (b) purifying the resulting reaction mixture to recover the cyclic siloxane.
Claim 12
Dependent Claim
24 words
The method as defined in claim 9 in which said wollastonite is provided by heating natural wollastonite above a temperature of about 1200° C.
Claim 13
Dependent Claim
30 words
The method as defined in claim 9 in which said pseudo wollastonite is provided by combining silica and calcium carbonate in equimolar amounts at a temperature of about 1200° C.
Claim 14
Dependent Claim
35 words
The method as defined in claim 9 in which the pseudo wollastonite is provided by preparing pure calcium silicate synthetically by precipitation from sodium silicate and calcium chloride and heating the precipitate above 1200° C.
References Cited (Backward Citations)
US3310526A
Cited
US3297632A
Cited
US3398173A
Cited
US3590064A
Cited
US3694405A
Cited
US3792072A
Cited
US3842110A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-03-06 | 1981-09-05 | 1982-03-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-03-06 | 1985-09-05 | 1986-03-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-03-06 | 1989-09-05 | 1990-03-07 | $7700.00 | Window Closed / Lapsed |