Patent US3917802A successfully refreshed from Google Patents.
US3917802A
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US
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Molecular weight control in (NPCl{11 ){11 {11 polymerization
Assignee: Bridgestone Firestone Inc
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Filing: 1973-04-11
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Granted: 1975-11-04
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Expires: 1993-04-11
Abstract
Abstract The molecular weight of the (NPCl2) polymer produced from the thermal polymerization of chlorocyclophosphazene trimer and/or tetramer or mixtures of trimer and tetramer is controlled by conducting the polymerization in the presence of controlled amounts of PCl5.
Inventors
- 👤 Harry Rex Allcock
- 👤 James Earl Gardner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 20:47
CPC Classifications
C; C01; C01B; C01B21/00; C01B21/082; C01B21/097; C01B21/098; C01B21/0986
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
78 words
IN THE POLYMERIZATION OF CHLOROCYLOPHAZINES TO PRODUCE A LINER POLYMER (NPCL2)N PRODUCT IN WHICH N IS FROM ABOUT 16 TO ABOUT 20,000, WHEREN THE POLYMERIZATION OF CYCLO TRIMER, TETRAMER OF MIXTURES THEREOF IS CONDUCTED AT TEMPERATURES OF BETWEEN 200* AND 300*C, THE IMPROVEMENT WHICH COMPRISES MAINTAINING AN AMOUNT OF PCL3 BETWEEN 0.25 MOLES AND 1X10**-5 MOLES PF PCL3 PER MOL OF CHLOREPHOSPHAZENE. PRESENT WITH SAID CHLOROPHOSPHAZENE AND CONDUCTING THE POLYMERIZATION IN THE PRESENCE OF SAID AMOUNT OF PCL5.
Claim 2
Dependent Claim
78 words
IN THE POLYMERIZATION OF CHLOROCYLOPHAZINES TO PRODUCE A LINER POLYMER (NPCL2)N PRODUCT IN WHICH N IS FROM ABOUT 16 TO ABOUT 20,000, WHEREN THE POLYMERIZATION OF CYCLO TRIMER, TETRAMER OF MIXTURES THEREOF IS CONDUCTED AT TEMPERATURES OF BETWEEN 200* AND 300*C, THE IMPROVEMENT WHICH COMPRISES MAINTAINING AN AMOUNT OF PCL3 BETWEEN 0.25 MOLES AND 1X10**-5 MOLES PF PCL3 PER MOL OF CHLOREPHOSPHAZENE. PRESENT WITH SAID CHLOROPHOSPHAZENE AND CONDUCTING THE POLYMERIZATION IN THE PRESENCE OF SAID AMOUNT OF PCL5.
Claim 3
Dependent Claim
18 words
The process of claim 1 wherein the chlorocyclophophazene is substantially all trimer and the temperature is about 250*C.
Claim 4
Dependent Claim
15 words
The process of claim 1 wherein the chlorocyclophophazene is a mixture of trimer and tetramer.
References Cited (Backward Citations)
US3370020A
Cited
US3443913A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-03 | 1979-05-05 | 1979-11-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-03 | 1983-05-05 | 1983-11-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-03 | 1987-05-05 | 1987-11-04 | $7700.00 | Window Closed / Lapsed |