Patent EP0050175A1 successfully refreshed from Google Patents.
Patent US4937015A successfully refreshed from Google Patents.
US4937015A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of manufacturing electrically conductive pressure-formed plates comprised of plastic material
Assignee: Roehm GmbH Darmstadt
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Filing: 1988-08-24
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Granted: 1990-06-26
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Expires: 2008-08-24
Abstract
Abstract The invention relates to a method of manufacturing plastic, electrically conductive pressure-formed plates from thermoplastic plastic particles which are mechanically formed. In this method, mechanically formed, thermoplastic particles each particle having maximum particle diameter in the range of about 1 mm to about 10 mm in the middle of said particle, are mechanically mixed with an amount of at least one electric-current-conducting substance sufficient to provide electrical conductivity. The electric-current-conducting substance is furnished in the form of a plurality of particulate, electrically conducting solid bodies, said mixing being effected in the temperature region below the glass temperature (Tg) of the thermoplastic plastic material of which the thermoplastic particles are comprised. The mixture thus produced is compressed to form plastic pressure-formed plates by means of a pressure-forming device.
Inventors
- 👤 Manfred Krieg
- 👤 Armin Meyer
- 👤 Winfried Wunderlich
- 👤 Rainer Friederich
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 21:44
CPC Classifications
B; B29; B29D; B29D99/00; B29D99/001; B29C; B29C70/00; B29C70/88; B29C70/882; B29D7/00; H; H01; H01B; H01B1/00; H01B1/20; H01B1/22; H01B1/24; B29C43/00; B29K; B29K2101/00; B29K2101/12; B29K2105/00; B29K2105/25; B29K2105/251; B29K2995/00; B29K2995/0003; B29K2995/0005
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
107 words
A plastic pressure-formed plate having an electrical surface resistance in the range from 10 4 -10 7 ohm-cm, comprising (i) thermoplastic plastic particles, more than 60% of said particles having a mean particle diameter between 3-5mm, said particles being comprised of a plastic selected from the group consisting of acrylic, PVC, polystyrene, polyolefin, fluorinated vinyl polymer, polyphenylene oxide, polyamide, polycarbonate, ABS polymer, epoxy resin, polyvinyl ester, polyacrylonitrile and silicone resins; and (ii) 0.01-20 wt.% of solid electrically-conducting bodies, based on the weight of said plastic particles in said pressure-formed plate, said bodies being selected from the group consisting of carbon black, graphite, aluminum, silver, copper and zinc.
Claim 2
Dependent Claim
107 words
A plastic pressure-formed plate having an electrical surface resistance in the range from 10 4 -10 7 ohm-cm, comprising (i) thermoplastic plastic particles, more than 60% of said particles having a mean particle diameter between 3-5mm, said particles being comprised of a plastic selected from the group consisting of acrylic, PVC, polystyrene, polyolefin, fluorinated vinyl polymer, polyphenylene oxide, polyamide, polycarbonate, ABS polymer, epoxy resin, polyvinyl ester, polyacrylonitrile and silicone resins; and (ii) 0.01-20 wt.% of solid electrically-conducting bodies, based on the weight of said plastic particles in said pressure-formed plate, said bodies being selected from the group consisting of carbon black, graphite, aluminum, silver, copper and zinc.
Claim 3
Dependent Claim
24 words
The pressure-formed plate of claim 1, wherein said pressure-formed plate has an electrical surface resistance in the range from 10 3 -10 9 ohm=cm.
Claim 4
Dependent Claim
23 words
The pressure-formed plate of claim 2, wherein said plate has an electrical surface resistance in the range from 10 4 -10 7 ohm-cm.
Claim 5
Dependent Claim
27 words
The pressure-formed plate of claim 1, wherein said electrically conducting bodies are present in an amount of 0.1-10 wt.% based on the weight of the plastic particles.
Claim 6
Dependent Claim
27 words
The pressure-formed plate of claim 1;, wherein said electrically conducting bodies comprise carbon black and said carbon black is present in an amount from about 0.01-10 wt.%.
Claim 7
Dependent Claim
19 words
The pressure-formed plate of claim 5, wherein said carbon black is present in an amount from about 0.1-5 wt.%.
Claim 8
Dependent Claim
20 words
The pressure-formed plate of claim 5, wherein the surface-to-weight ratio of said carbon black is about 50-1,500 m 2 /g.
Claim 9
Dependent Claim
21 words
The pressure-formed plate of claim 1, wherein said electrically-conducting bodies have a particle size in the range of about 1-500 microns.
Claim 10
Dependent Claim
21 words
The pressure-formed plate of claim 8, wherein said electrically-conducting bodies have a particle size in the range of about 15-300 microns.
Claim 11
Dependent Claim
31 words
The pressure-formed plate of claim 1, wherein said plastic particles are comprised of a resin selected from the group consisting of acrylic, polycarbonate, polyphenylene oxide, PVC, polystyrene, polyamide and polyolefin resins.
Claim 12
Dependent Claim
23 words
The pressure-formed plate of claim 10, wherein said plastic particles are comprised of an acrylic resin containing at least 50 wt.% methyl methacrylate.
Claim 13
Dependent Claim
20 words
The pressure-formed plate of claim 1, wherein said plastic particles further comprise up to 70 wt.% of inert inorganic fillers.
Claim 14
Dependent Claim
20 words
The pressure-formed plate of claim 1, wherein said plastic particles are granule, plate, disc, cylinder, fiber, rod or cube shaped.
Claim 15
Dependent Claim
16 words
The pressure-formed plate of claim 1, wherein said plate has a translucency of at least 40%.
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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) | 1993-06-25 | 1993-12-25 | 1994-06-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-06-25 | 1997-12-25 | 1998-06-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-06-25 | 2001-12-25 | 2002-06-26 | $7700.00 | Window Closed / Lapsed |