US4334037A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Moulding compositions of a styrene polymer and PTFE particles
Assignee: Elster Metering Holdings Ltd
•
Filing: 1981-05-07
•
Granted: 1982-06-08
•
Expires: 2001-05-07
Abstract
Abstract A thermoplastic moulding composition comprises a major proportion of a thermoplastic styrene-based polymeric material having dispersed therein at least 5% by weight, based on the total weight of the composition of PTFE particles. Articles may be moulded from the compositions having good wear properties and which are relatively stable in aqueous environments. Such properties make the compositions of great utility for moulding flow meter pistons.
Inventors
- 👤 Eric H. W. Allen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 03:40
CPC Classifications
G; G01; G01F; G01F3/00; G01F3/02; G01F3/04; G01F3/06; G01F3/08; C; C08; C08L; C08L25/00; C08L25/02; C08L25/04; C08L2205/00; C08L2205/14; C08L2205/18; C08L27/00; C08L27/02; C08L27/12; C08L27/18
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
112 words
A thermoplastic moulding composition comprising a major proportion of a thermoplastic styrene-based polymeric material having dispersed therein at least 5% by weight, based on the total weight of the composition of PTFE particles, said PTFE particles being of a generally granular nature having an average particle size in the range of 1 to 10 μm with not more than 1% of the PTFE particles having sizes greater than 50 μm and wherein the maximum transverse dimension of the PTFE particles does not differ significantly from their minimum dimension, such that the melt elasticity of the composition during moulding does not differ significantly from that of the polymeric material without said PTFE particles.
Claim 2
Dependent Claim
112 words
A thermoplastic moulding composition comprising a major proportion of a thermoplastic styrene-based polymeric material having dispersed therein at least 5% by weight, based on the total weight of the composition of PTFE particles, said PTFE particles being of a generally granular nature having an average particle size in the range of 1 to 10 μm with not more than 1% of the PTFE particles having sizes greater than 50 μm and wherein the maximum transverse dimension of the PTFE particles does not differ significantly from their minimum dimension, such that the melt elasticity of the composition during moulding does not differ significantly from that of the polymeric material without said PTFE particles.
Claim 3
Dependent Claim
26 words
A composition as claimed in claim 1 containing from 5 to 30% by weight, based on the total weight of the composition of said PTFE particles.
Claim 4
Dependent Claim
26 words
A composition as claimed in claim 1 containing from 5 to 15% by weight, based on the total weight of the composition of said PTFE particles.
Claim 5
Dependent Claim
26 words
A composition as claimed in claim 1 containing from 8 to 12% by weight, based on the total weight of the composition of said PTFE particles.
Claim 6
Dependent Claim
23 words
A composition according to claim 1 wherein said PTFE particles have an average particle size in the range of 2 to 10 μm.
Claim 7
Dependent Claim
35 words
A composition according to claim 1 wherein said PTFE particles have an average particle size in the range of 5 to 7 μm and not more than 1% have particle sizes greater than 35 μm.
Claim 8
Dependent Claim
18 words
A composition according to claim 1 wherein the length:breadth ratio of the particles is not greater than 2:1.
Claim 9
Dependent Claim
18 words
A composition according to claim 7 wherein the length:breadth ratio of the particles is not greater than 1.5:1.
Claim 10
Dependent Claim
17 words
A composition according to claim 1 wherein the styrene-based polymeric material comprises a high-impact grade of polystyrene.
Claim 11
Dependent Claim
47 words
A method of producing a moulding composition according to claim 1 which comprises admixing the styrene-based polymeric material and the PTFE, heating the mixture to form a generally homogeneous plasticized mass of styrene-based polymeric material in which the PTFE particles are uniformly dispersed and granulating said mass.
Claim 12
Dependent Claim
15 words
A method according to claim 7 wherein said mass is extruded and the extrudate chopped.
Claim 13
Dependent Claim
12 words
A moulded article formed by moulding a composition according to claim 1.
References Cited (Backward Citations)
US2998397A
Cited
US3074901A
Cited
US3005795A
Cited
GB884771A
Cited
GB847861A
Cited
GB975516A
Cited
US3294871A
Cited
US3940455A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-06-07 | 1985-12-07 | 1986-06-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-06-07 | 1989-12-07 | 1990-06-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-06-07 | 1993-12-07 | 1994-06-08 | $7700.00 | Window Closed / Lapsed |