US4000109A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermoplastic polyester compositions
Assignee: Imperial Chemical Industries Ltd
•
Filing: 1975-07-28
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Granted: 1976-12-28
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Expires: 1995-07-28
Abstract
Abstract Poly(tetramethylene terephthalate) compositions containing at least 2.5% by weight of the composition of a finely divided metal borate stable under the normal processing conditions for the polyester.
Inventors
- 👤 Clive Percy Smith
- 👤 Martin Keith Thompson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 08:47
CPC Classifications
H; H01; H01B; H01B3/00; H01B3/18; H01B3/30; H01B3/42; H01B3/421; H01B3/422; C; C08; C08K; C08K3/00; C08K3/01; C08K3/013; C08K3/38
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
36 words
A thermoplastic polyester composition comprising poly(tetramethylene terephthalate) and at least 2.5% by weight of the total composition of at least one finely divided metal borate that is stable under the normal processing conditions of the polyester.
Claim 2
Dependent Claim
36 words
A thermoplastic polyester composition comprising poly(tetramethylene terephthalate) and at least 2.5% by weight of the total composition of at least one finely divided metal borate that is stable under the normal processing conditions of the polyester.
Claim 3
Dependent Claim
15 words
A composition according to claim 1 which includes from 2-70% by weight of reinforcing agent.
Claim 4
Dependent Claim
29 words
A composition according to claim 2 in which the reinforcing agent is selected from at least one of glass fibre, acicular dawsonite, acicular calcium metasilicate, asbestos fibre and mica.
Claim 5
Dependent Claim
19 words
A composition according to claim 1 which includes fire retardant additives in admixture with, or copolymerised in, the polyester.
Claim 6
Dependent Claim
59 words
A composition according to claim 4 containing at least sufficient copolymerised or admixed fire retardant materials to give the composition a flame retardancy rating of 94VO and at least sufficient metal borate to prevent the composition dripping when tested according to the Vertical Burning Test of Underwriters Laboratories Test UL94 using test samples 1.5 mm or less in thickness.
Claim 7
Dependent Claim
36 words
A composition according to claim 5 in which the metal borate concentration is sufficient to give a Comparative Tracking Index rating as measured by the KC method of DIN 53480 (1972) of at least 350 volts.
Claim 8
Dependent Claim
27 words
A composition according to claim 1 in which the metal borate is a zinc borate of formula 2ZnO.3B.sub.2 O.sub.3.xH.sub.2 O where x is between 3.3 and 3.7.
Claim 9
Dependent Claim
24 words
A composition according to claim 7 in which the concentration of zinc borate is between 2.5% and 40% by weight of the total composition.
Claim 10
Dependent Claim
27 words
A composition according to claim 1 in which the intrinsic viscosity of the polyester is at least 0.75 measured as a 1% by weight solution in ortho-chlorophenol.
Claim 11
Dependent Claim
13 words
The composition of claim 1, wherein said metal borate is a hydrated borate.
Claim 12
Dependent Claim
27 words
A composition according to claim 2, in which the metal borate is a zinc borate of formula 2ZnO.3B.sub.2 O.sub.3.xH.sub.2 O where x is between 3.3 and 3.7.
Claim 13
Dependent Claim
27 words
The composition according to claim 4, in which the metal borate is a zinc borate of formula 2ZnO.3B.sub.2 O.sub.3.xH.sub.2 O where x is between 3.3 and 3.7.
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) | 1979-12-28 | 1980-06-28 | 1980-12-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-12-28 | 1984-06-28 | 1984-12-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-12-28 | 1988-06-28 | 1988-12-28 | $7700.00 | Window Closed / Lapsed |