US2884432A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of preparing cyclic siloxanes
Assignee: Dow Silicones Corp
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Filing: 1956-02-09
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Granted: 1959-04-28
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Expires: 1976-02-09
Abstract
No abstract record available.
Inventors
- 👤 Arthur F Gordon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:54
CPC Classifications
C; C07; C07F; C07F7/00; C07F7/02; C07F7/21
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
135 words
THE METHOD WHICH COMPRISES HEATING A FLUID SILOXANE COPOLYMER COMPOSED OF SILOXANE UNITS OF THE FORMULAS ME2SIO, PHR2SIO5 AND R''2SIO, WHICH COPOLYMER MAY CONTAIN A MINOR AMOUNT OF SILOXANE UNITS OF THE GROUP CONSISTING OF R''SIO1.5 AND SIO2 UNITS, IN WHICH SILOXANE UNITS EACH R IS OF THE GROUP CONSISTING OF PHENYL AND METHYL RADICALS, EACH R'' IS A MONOVALENT HYDROCARBON RADICAL OF LESS THAN 8 CARBON ATOMS AND AT LEAST ON R'' PER DIORGANOSILOXANE UNIT HAS MORE THAN ONE CARBON ATOM, IN THE PRESENCE OF A SMALL AMOUNT OF AN ALKALINE CATALYST OF THE GROUP ALKALI METAL HYDROXIDES, QUATERNARY AMMONIUM HYDROXIDES AND ORGANOSILANOL SALTS OF SUCH HYDROXIDES, AT A TEMPERATURE OF AT LEAST 80*C. UNDER CONDITIONS OF PRESSURE WHICH WILL ALLOW VOLATILES TO ESCAPE FROM THE REACTION ZONE WHEREBY MIXED CYCLIC DIORGANOSILOXANES ARE PRODUCED.
Claim 2
Independent Claim
135 words
THE METHOD WHICH COMPRISES HEATING A FLUID SILOXANE COPOLYMER COMPOSED OF SILOXANE UNITS OF THE FORMULAS ME2SIO, PHR2SIO5 AND R''2SIO, WHICH COPOLYMER MAY CONTAIN A MINOR AMOUNT OF SILOXANE UNITS OF THE GROUP CONSISTING OF R''SIO1.5 AND SIO2 UNITS, IN WHICH SILOXANE UNITS EACH R IS OF THE GROUP CONSISTING OF PHENYL AND METHYL RADICALS, EACH R'' IS A MONOVALENT HYDROCARBON RADICAL OF LESS THAN 8 CARBON ATOMS AND AT LEAST ON R'' PER DIORGANOSILOXANE UNIT HAS MORE THAN ONE CARBON ATOM, IN THE PRESENCE OF A SMALL AMOUNT OF AN ALKALINE CATALYST OF THE GROUP ALKALI METAL HYDROXIDES, QUATERNARY AMMONIUM HYDROXIDES AND ORGANOSILANOL SALTS OF SUCH HYDROXIDES, AT A TEMPERATURE OF AT LEAST 80*C. UNDER CONDITIONS OF PRESSURE WHICH WILL ALLOW VOLATILES TO ESCAPE FROM THE REACTION ZONE WHEREBY MIXED CYCLIC DIORGANOSILOXANES ARE PRODUCED.
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) | 1962-04-27 | 1962-10-27 | 1963-04-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-04-27 | 1966-10-27 | 1967-04-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-04-27 | 1970-10-27 | 1971-04-28 | $7700.00 | Window Closed / Lapsed |