US4071498A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of chain extending organosiloxanes
Assignee: Dow Silicones Corp
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Filing: 1975-12-29
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Granted: 1978-01-31
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Expires: 1995-12-29
Abstract
Abstract Mixing methylvinyldi-(epsilon-caprolactamo)silane with an organosiloxane having silicon-bonded hydroxyl radicals increases the molecular weight by chain extension. This method is particularly useful in making high molecular weight polydiorganosiloxanes containing vinyl radicals from hydroxyl endblocked polydiorganosiloxane fluids.
Inventors
- 👤 Cecil L. Frye
- 👤 Jerome M. Klosowski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 22:19
CPC Classifications
C; C08; C08G; C08G77/00; C08G77/04; C08G77/20; C08K; C08K5/00; C08K5/54; C08G77/14; C08G77/16; C08G77/22; C08G77/24
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
62 words
A method of increasing the molecular weight of a hydroxyl endblocked polydiorganosiloxane having silicon-bonded hydroxyl radicals consisting essentially of mixing the polydiorganosiloxane wherein the organic groups are monovalent hydrocarbon radicals or monovalent halogenated hydrocarbon radicals and methylvinyldi-(epsiloncaprolactamo)silane, thereafter recovering a product polydiorganosiloxane having a molecular weight higher than the polydiorganosiloxane mixed with the silane and having methylvinylsiloxane units in the product polydiorganosiloxane.
Claim 2
Independent Claim
62 words
A method of increasing the molecular weight of a hydroxyl endblocked polydiorganosiloxane having silicon-bonded hydroxyl radicals consisting essentially of mixing the polydiorganosiloxane wherein the organic groups are monovalent hydrocarbon radicals or monovalent halogenated hydrocarbon radicals and methylvinyldi-(epsiloncaprolactamo)silane, thereafter recovering a product polydiorganosiloxane having a molecular weight higher than the polydiorganosiloxane mixed with the silane and having methylvinylsiloxane units in the product polydiorganosiloxane.
Claim 3
Dependent Claim
18 words
The method in accordance with claim 1 in which the organic groups of the polydiorganosiloxane are methyl radicals.
Claim 4
Dependent Claim
17 words
The method in accordance with claim 2 in which the polydiorganosiloxane recovered in a gum consistency polydiorganosiloxane.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-01-30 | 1981-08-01 | 1982-01-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-01-30 | 1985-08-01 | 1986-01-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-01-30 | 1989-08-01 | 1990-01-31 | $7700.00 | Window Closed / Lapsed |