US3882076A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for improving flame retardancy of polyamide compositions and resultant product
Assignee: Honeywell International Inc
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Filing: 1973-03-15
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Granted: 1975-05-06
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Expires: 1993-03-15
Abstract
Abstract Polyamide compositions containing an effective amount of an elemental phosphorus flame retardant additive, preferably red phosphorus, are rendered more flame retardant by heating the composition in the presence of oxygen at a temperature of at least about 100*C.
Inventors
- 👤 Theodore Largman
- 👤 Leon J Schmehl
- 👤 Herman Stone
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 21:31
CPC Classifications
C; C08; C08G; C08G69/00; C08G69/48; C08K; C08K3/00; C08K3/02
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
62 words
A METHOD OF INCREASING THE FLAME RETARDANCY OF A POLYAMIDE COMPOSITION COMPRISING A POLYCARBONAMIDE HAVING RECURRING -CONH- GROUPS ALONG THE POLYMER CHAIN AND AN EFFECTIVE AMOUNT OF RED OR BLACK PHOSPHORUS AS A FLAME RETARDANT ADDITIVE WHICH COMPRISES HEATING SAID POLYAMIDE COMPOSITION IN THE PRESENCE OF MOLECULAR OXYGEN TO A TEMPERATURE OF AT LEAST ABOUT 100*C FOR AT LEAST ABOUT 5 DAYS.
Claim 2
Independent Claim
62 words
A METHOD OF INCREASING THE FLAME RETARDANCY OF A POLYAMIDE COMPOSITION COMPRISING A POLYCARBONAMIDE HAVING RECURRING -CONH- GROUPS ALONG THE POLYMER CHAIN AND AN EFFECTIVE AMOUNT OF RED OR BLACK PHOSPHORUS AS A FLAME RETARDANT ADDITIVE WHICH COMPRISES HEATING SAID POLYAMIDE COMPOSITION IN THE PRESENCE OF MOLECULAR OXYGEN TO A TEMPERATURE OF AT LEAST ABOUT 100*C FOR AT LEAST ABOUT 5 DAYS.
Claim 3
Dependent Claim
31 words
The method of claim 1 wherein said polyamide composition is heated in the presence of air at atmospheric pressure at a temperature in the range of about 100*C. to about 200*C.
Claim 4
Dependent Claim
29 words
The method of claim 2 wherein said polyamide composition is heated at a temperature in the range of about 140*C. to about 180*C. for at least about 10 days.
Claim 5
Dependent Claim
18 words
The method of claim 3 wherein said polyamide composition comprises polycaprolactam and said elemental phosphorus is red phosphorus.
Claim 6
Dependent Claim
29 words
The method of claim 4 wherein said composition is heated at a temperature in the range of about 150*C. to about 170*C. for about 10 to about 20 days.
Claim 7
Dependent Claim
27 words
The method of claim 4 wherein said red phosphorus is present in an amount of about 0.1 to about 15 percent by weight based on the polycaprolactam.
Claim 8
Dependent Claim
27 words
The method of claim 6 wherein said red phosphorus is present in an amount of about 2 to about 7 percent by weight based on the polycaprolactam.
Claim 9
Dependent Claim
24 words
The method of claim 6 wherein said composition further contains about 1 to about 40 percent by weight glass fibers based on the polycaprolactam.
Claim 10
Independent Claim
96 words
A method of increasing the flame retardancy of a polyamide composition comprising a polycarbonamide having recurring -CONH-groups along the polymer chain and an effective amount of red or black phosphorus as a flame retardant additive which comprises heating said polyamide composition in the presence of molecular oxygen to a temperature of at least about 100*C. for a time sufficient to increase its Limiting Oxygen Index as measured by ASTM Test D-2863 by at least about 10 percent, the resultant heat aged composition being rated self-extinguishing as determined by the vertical burn test of U.L. Bulletin 94.
Claim 11
Independent Claim
96 words
A method of increasing the flame retardancy of a polyamide composition comprising a polycarbonamide having recurring -CONH-groups along the polymer chain and an effective amount of red or black phosphorus as a flame retardant additive which comprises heating said polyamide composition in the presence of molecular oxygen to a temperature of at least about 100*C. for a time sufficient to increase its Limiting Oxygen Index as measured by ASTM Test D-2863 by at least about 10 percent, the resultant heat aged composition being rated self-extinguishing as determined by the vertical burn test of U.L. Bulletin 94.
Claim 12
Dependent Claim
52 words
The method of claim 1 wherein said composition is heated for a time sufficient to increase its Limiting Oxygen Index as measured by ASTM Test D-2863 by at least about 25 percent, the resultant heat aged composition also being rated self-extinguishing as determined by the vertical burn test of U.L. Bulletin 94.
Claim 13
Dependent Claim
18 words
The method of claim 1 wherein said polyamide composition comprises polycaprolactam and said elemental phosphorus is red phosphorus.
Claim 14
Dependent Claim
28 words
The method of claim 11 wherein said red phosphorus is present in an amount between about 0.1 percent and about 15 percent by weight based on the polycaprolactam.
Claim 15
Dependent Claim
9 words
A product produced by the method of claim 1.
Claim 16
Dependent Claim
9 words
A product produced by the method of claim 8.
Claim 17
Dependent Claim
9 words
A product produced by the method of claim 1.
Claim 18
Dependent Claim
9 words
A product produced by the method of claim 12.
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) | 1978-05-05 | 1978-11-04 | 1979-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-05 | 1982-11-04 | 1983-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-05 | 1986-11-04 | 1987-05-06 | $7700.00 | Window Closed / Lapsed |