US4876033A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Moulded bodies containing carbon
Assignee: Bayer AG
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Filing: 1988-04-25
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Granted: 1989-10-24
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Expires: 2008-04-25
Abstract
Abstract This invention relates to carbon-containing moulded bodies based on thermoplastic polycarbonates and thermoplastic polyalkylene terephtalates with an addition of carbon black and graphite and to a process for the production of these moulded bodies.
Inventors
- 👤 Heinz-Jurgen Dziurla
- 👤 Dieter Freitag
- 👤 Werner Waldenrath
- 👤 Claus Burkhardt
- 👤 Bernhard Schulte
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 00:20
CPC Classifications
C; C08; C08K; C08K3/00; C08K3/02; C08K3/04; C08L; C08L69/00
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
128 words
A process for the production of articles comprising (i) intimately mixing a thermoplastic polycarbonate with a first mixture of carbon black and graphite powder or dust to produce a second mixture, (ii) working up said second mixture under degassing conditions to produce a granulate, (iii) mixing said granulate with a thermoplastic polyalkylene terephthalate to produce a blend, (iv) molding said blend by extrusion or by injection, said blend comprising 55 to 85% thermoplastic polycarbonate, 5 to 30% polyalkylene terephthalate and 10 to 35% said first mixture, said first mixture being characterized in that the weight ratio of said carbon black to said graphite is in the range of from 5:1 to 1:3 and said graphite being characterized in that its average particle size is up to 5 mm.
Claim 2
Dependent Claim
128 words
A process for the production of articles comprising (i) intimately mixing a thermoplastic polycarbonate with a first mixture of carbon black and graphite powder or dust to produce a second mixture, (ii) working up said second mixture under degassing conditions to produce a granulate, (iii) mixing said granulate with a thermoplastic polyalkylene terephthalate to produce a blend, (iv) molding said blend by extrusion or by injection, said blend comprising 55 to 85% thermoplastic polycarbonate, 5 to 30% polyalkylene terephthalate and 10 to 35% said first mixture, said first mixture being characterized in that the weight ratio of said carbon black to said graphite is in the range of from 5:1 to 1:3 and said graphite being characterized in that its average particle size is up to 5 mm.
Claim 3
Dependent Claim
83 words
Carbon-containing moulded bodies produced by the process of claim 1 and comprising: (a) 55% by weight to 85% by weight of thermoplastic polycarbonate, (b) 30% by weight to 5% by weight of thermoplastic polyalkylene terephthalate, and (c) 35% by weight to 10% by weight of carbon black and graphite, in which the ratio by weight of carbon black to graphite is in the range of from 5:1 to 1:3 and the sum of percentages by weight of components (a)+(b)+(c) is 100% by weight.
Claim 4
Dependent Claim
26 words
Moulded bodies according to claim 2, in which the ratio by weight of carbon black to graphite is in the range of from 3:2 to 2:3.
Claim 5
Dependent Claim
15 words
The process of claim 1 wherein said average particle size is up to 1 mm.
Claim 6
Dependent Claim
23 words
The process of claim 1 wherein said polyalkylene terephthalate is present in said blend in an amount of 15 to 30% by weight.
Claim 7
Dependent Claim
17 words
The process of claim 1 wherein said weight ratio is in the range of 3:2 to 2:3.
Claim 8
Dependent Claim
10 words
A molded article produced by the process of claim 5.
Claim 9
Dependent Claim
10 words
A molded article produced by the process of claim 6.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-10-23 | 1993-04-24 | 1993-10-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-10-23 | 1997-04-24 | 1997-10-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-10-23 | 2001-04-24 | 2001-10-24 | $7700.00 | Window Closed / Lapsed |