US4152343A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing silicon-tin compounds
Assignee: Wacker Chemie AG
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Filing: 1978-02-09
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Granted: 1979-05-01
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Expires: 1998-02-09
Abstract
Abstract Silicon-tin compounds of the formula R.sub.a Si(OSnR.sup.1 R.sup.2 OOCR.sup.3).sub.4-a in which R represents an alkyl or phenyl radical, R 1 , R 2 and R 3 are alkyl radicals and a is 0 or 1 and their use as condensation catalysts in the preparation of organopolysiloxane elastomers.
Inventors
- 👤 Ernst Wohlfarth
- 👤 Wolfgang Hechtl
- 👤 Paul Hittmair
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:12
CPC Classifications
C; C07; C07C; C07C67/00; C07C67/48; C07C67/52; C07C67/54; C07F; C07F7/00; C07F7/02; C07F7/04; C07F7/08; C07F7/0834; C07F7/0836; C07F7/22; C07F7/2224; C08; C08K; C08K5/00; C08K5/56; C08K5/57
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
161 words
A process for preparing a compound which is crystalline at room temperature having the formula R.sub.a Si(OSnR.sup.1 R.sup.2 OOCR.sup.3).sub.4-a which comprises reacting a silane of the general formula R.sub.a Si(OR.sup.4).sub.4-a with a dialkyltin salt of the general formula R.sup.1 R.sup.2 Sn(OOCR.sup.3).sub.2 in which R 4 is a monovalent hydrocarbon radical having up to 4 carbon atoms, R is selected from the group consisting of alkyl and phenyl radicals, R 1 , R 2 and R 3 each represent an alkyl radical and a is 0 to 1, in a mol ratio of (4-a) mols of dialkyltin salt per mol of silane and at a temperature in the range of from 50° to 160° C., while removing as a by-product an ester of the general formula R.sup.3 COOR.sup.4 until the amount of ester that has been removed is within the range of from 80 to 100 percent of the amount theoretically formed by complete reaction of the silane with the dialkyltin salt.
Claim 2
Dependent Claim
161 words
A process for preparing a compound which is crystalline at room temperature having the formula R.sub.a Si(OSnR.sup.1 R.sup.2 OOCR.sup.3).sub.4-a which comprises reacting a silane of the general formula R.sub.a Si(OR.sup.4).sub.4-a with a dialkyltin salt of the general formula R.sup.1 R.sup.2 Sn(OOCR.sup.3).sub.2 in which R 4 is a monovalent hydrocarbon radical having up to 4 carbon atoms, R is selected from the group consisting of alkyl and phenyl radicals, R 1 , R 2 and R 3 each represent an alkyl radical and a is 0 to 1, in a mol ratio of (4-a) mols of dialkyltin salt per mol of silane and at a temperature in the range of from 50° to 160° C., while removing as a by-product an ester of the general formula R.sup.3 COOR.sup.4 until the amount of ester that has been removed is within the range of from 80 to 100 percent of the amount theoretically formed by complete reaction of the silane with the dialkyltin salt.
Claim 3
Dependent Claim
12 words
The process of claim 1, wherein R 4 is a methyl radical.
Claim 4
Dependent Claim
21 words
The process of claim 1, wherein the silane is selected from the class consisting of tetramethyl silicate, tetraethyl silicate and methylytriethoxysilane.
Claim 5
Dependent Claim
13 words
The process of claim 1, wherein the dialkyltin salt is a di-n-butyltin diacetate.
Claim 6
Dependent Claim
13 words
The process of claim 1, wherein the reaction is conducted at atmospheric pressure.
Claim 7
Dependent Claim
15 words
The process of claim 1, wherein the reaction is conducted in the absence of water.
Claim 8
Dependent Claim
12 words
The process of claim 1, wherein the ester is removed by distillation.
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) | 1982-04-30 | 1982-10-30 | 1983-05-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-04-30 | 1986-10-30 | 1987-05-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-04-30 | 1990-10-30 | 1991-05-01 | $7700.00 | Window Closed / Lapsed |