Patent US4191678A successfully refreshed from Google Patents.
US4191678A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fire retardant polyester-polytetrafluoroethylene compositions
Assignee: Imperial Chemical Industries Ltd
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Filing: 1977-08-24
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Granted: 1980-03-04
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Expires: 1997-08-24
Abstract
Abstract A method for the production of thermoplastic polyester compositions comprising mixing a normally flammable thermoplastic polyester, preferably containing at least 80% by weight of repeating units of ethylene terephthalate, tetramethylene, terephthalate or ethylene-1:2-diphenoxyethane-4,4'-dicarboxylate units, an effective amount of fire-retardant additives and an aqueous colloidal dispersion of PTFE, subjecting the mixture to conditions under which the polyester becomes molten and removing volatile materials from the melt.
Inventors
- 👤 Clive P. Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 05:53
CPC Classifications
C; C08; C08L; C08L67/00; C08L67/02
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
123 words
A method of producing a thermoplastic polyester composition comprising mixing a normally flammable thermoplastic polyester, an effective amount of fire-retardant additives selected from the group consisting of compounds of the formula ##STR2## where X may be --O--, --S--, --SO--, --SO 2 --and --CH 2 --, n may be 0 or 1 and each of m and p may be from 1 to 5 and polytetrafluoroethylene in the form of an aqueous colloidal dispersion, subjecting the mixture to conditions under which the polyester becomes molten and removing volatile materials from the melt, so that there is produced a composition which has a rating of 94VO according to underwriter's laboratory's test standard UL94 when measured on a sample of 1/16" thickness and which is non-dripping.
Claim 2
Independent Claim
123 words
A method of producing a thermoplastic polyester composition comprising mixing a normally flammable thermoplastic polyester, an effective amount of fire-retardant additives selected from the group consisting of compounds of the formula ##STR2## where X may be --O--, --S--, --SO--, --SO 2 --and --CH 2 --, n may be 0 or 1 and each of m and p may be from 1 to 5 and polytetrafluoroethylene in the form of an aqueous colloidal dispersion, subjecting the mixture to conditions under which the polyester becomes molten and removing volatile materials from the melt, so that there is produced a composition which has a rating of 94VO according to underwriter's laboratory's test standard UL94 when measured on a sample of 1/16" thickness and which is non-dripping.
Claim 3
Dependent Claim
19 words
A method according to claim 1 in which the dispersion has been stabilised after polymerisation with a non-ionic surfactant.
Claim 4
Dependent Claim
25 words
A method according to claim 1 in which the concentration of poly(tetrafluoroethylene) solids used by weight of the total composition is between 0.1 and 8.0%.
Claim 5
Dependent Claim
24 words
A method according to claim 3 in which the concentration of fire-retardant additive is between 3 and 25% by weight of the total composition.
Claim 6
Dependent Claim
26 words
A method according to claim 4 in which the fire retardant additive comprises a mixture of a halogenated fire retardant and a Group Vb metal oxide.
Claim 7
Dependent Claim
21 words
A method according to claim 1 in which the mixture includes from 2 to 80% by weight of a reinforcing filler.
Claim 8
Dependent Claim
20 words
A method according to claim 6 in which the reinforcing filler is glass fibre, asbestos, carbon fibre or textile fibres.
Claim 9
Dependent Claim
33 words
A method according to claim 1 in which from 5 to 50% by weight of the composition of a filler selected from talc, mica, ballotini, wollastonite, clays and hydrated aluminium oxide is added.
Claim 10
Dependent Claim
23 words
A method according to claim 8 in which the concentration of poly(tetrafluoroethylene) solids is from 0.1 to 1.0% by weight of the composition.
Claim 11
Dependent Claim
28 words
A method according to claim 1 in which at least 80% by weight of the repeating units of the polyester are ethylene terephthalate, tetramethylene terephthalate, or ethylene-1:2-diphenoxyethylene-4,4'-dicarboxylate units.
Claim 12
Dependent Claim
15 words
A method according to claim 1 in which the mixture is free of reinforcing filler.
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) | 1983-03-04 | 1983-09-03 | 1984-03-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-03-04 | 1987-09-03 | 1988-03-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-03-04 | 1991-09-03 | 1992-03-04 | $7700.00 | Window Closed / Lapsed |