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US4548740A
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Method of producing conductive plastics
Assignee: HILL VAN SANTEN STEADMAN
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Filing: 1984-01-09
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Granted: 1985-10-22
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Expires: 2004-01-09
Abstract
Abstract Conductive plastic parts having defined electrical properties within a relatively narrow range are produced by controlling the dosage relationship between a given plastic and a conductive material, such as long-chain conductive lampblack, as a function of an electrical value (i.e., surface resistance) measured at an extruded admixture of the plastic and conductive materials, rather than by a gravimetrical or volumetrical relation.
Inventors
- 👤 Sybille von Tomkewitsch
- 👤 Hans-Friedrich Schmidt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:05
CPC Classifications
B; B29; B29C; B29C70/00; B29C70/88; B29C70/882; B29B; B29B7/00; B29B7/30; B29B7/58; B29B7/72; B29B7/726; B29C48/00; B29C48/25; B29C48/92; B29C2948/00; B29C2948/92; B29C2948/92009; B29C2948/92238; B29C2948/92314; B29C2948/92323; B29C2948/92361; B29C2948/92409; B29C2948/92504; B29C2948/9258; B29C2948/926; B29C2948/92819; B29C2948/92828; B29C2948/92857; B29C2948/92904; B29C48/03; B29C48/285; B29C48/288; B29C48/2886; B29K; B29K2077/00; B29K2105/00; B29K2105/06; B29K2105/12; B29K2105/16; B29K2707/00; B29K2707/04; B29K2709/00; B29K2995/00; B29K2995/0003; B29K2995/0005
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
95 words
A process for producing a conductive plastic mixture comprising the steps of: admixing a selected amount of a plastic material with a selected amount of a conductive material and extruding to obtain a substantially uniform extrudate of said materials; measuring the electrical resistance of said extrudate; adjusting the quantity of said conductive material relative to the quantity of said plastic material in accordance with a function of the difference between a desired resistance value for such extrudate and such so-measured resistance value thereby to achieve and maintain approximately said desired resistance value for said extrudate.
Claim 2
Dependent Claim
95 words
A process for producing a conductive plastic mixture comprising the steps of: admixing a selected amount of a plastic material with a selected amount of a conductive material and extruding to obtain a substantially uniform extrudate of said materials; measuring the electrical resistance of said extrudate; adjusting the quantity of said conductive material relative to the quantity of said plastic material in accordance with a function of the difference between a desired resistance value for such extrudate and such so-measured resistance value thereby to achieve and maintain approximately said desired resistance value for said extrudate.
Claim 3
Dependent Claim
12 words
The process of claim 1 wherein said plastic material comprises a polyamide.
Claim 4
Dependent Claim
13 words
The process of claim 1 wherein said conductive material is a long-chain lampblack.
Claim 5
Dependent Claim
26 words
The process of claim 3 wherein the quantity of said lampblack ranges from about 4 to 6 weight percent based upon the weight of said polyamide.
Claim 6
Dependent Claim
17 words
The process of claim 1 wherein an insert particulate mineral material is additionally admixed into said extrudate.
Claim 7
Dependent Claim
31 words
The process of claim 1 wherein such extrudate has a relatively high surface resistance and a discharge time ranging from about 5,000 to 0 volts in less than about 100 ms.
Claim 8
Dependent Claim
53 words
In a method for the production of a conductive plastic mixed extrudate which comprises a plastic material and a conductive material, the improvement which comprises measuring an electrical value of said extrudate and regulating the dosing relationship between said plastic material and said conductive material as a function of said measured electrical value.
Claim 9
Dependent Claim
53 words
In a method for the production of a conductive plastic mixed extrudate which comprises a plastic material and a conductive material, the improvement which comprises measuring an electrical value of said extrudate and regulating the dosing relationship between said plastic material and said conductive material as a function of said measured electrical value.
Claim 10
Dependent Claim
17 words
The method of claim 7 wherein in said regulating the quantity of said plastic material is varied.
Claim 11
Dependent Claim
17 words
The method of claim 1 wherein in said regulating the quantity of said conductive material is varied.
Claim 12
Dependent Claim
24 words
The method of claim 7 wherein a mineral is additionally present in said extrudate to achieve a better dispersion of materials within said extrudate.
Claim 13
Dependent Claim
84 words
The method of claim 7 wherein said plastic material comprises a polyamide and said conductive material comprises a long-chain conductive lampblack and said extrudate has a discharge time of from about 5000 to 0 in less than about 100 ms, and wherein the quantity of said lampblack ranges from about 4 to 6 weight percent based upon the weight of said polyamide, and about 30 weight percent of a particulate mineral based upon the weight of said polyamide is additionally present in said extrudate.
Claim 14
Independent Claim
101 words
A method for producing a conductive plastic mixture comprising the steps of: admixing a selected amount of a polyamide with a selected amount of a conductive long chain lampblack in the presence of a selected amount of a particulate inert silica filler and extruding to obtain a substantially uniform extrudate, measuring the electrical resistance of said extrudate, adjusting the quantity of said lampblack relative to said polyamide in accordance with a function of the difference between a desired resistance value for such extrudate and such so-measured resistance value thereby to achieve and maintain approximately said desired resistance value for said extrudate.
Claim 15
Independent Claim
101 words
A method for producing a conductive plastic mixture comprising the steps of: admixing a selected amount of a polyamide with a selected amount of a conductive long chain lampblack in the presence of a selected amount of a particulate inert silica filler and extruding to obtain a substantially uniform extrudate, measuring the electrical resistance of said extrudate, adjusting the quantity of said lampblack relative to said polyamide in accordance with a function of the difference between a desired resistance value for such extrudate and such so-measured resistance value thereby to achieve and maintain approximately said desired resistance value for said extrudate.
Claim 16
Dependent Claim
54 words
The method of claim 12 wherein said extrudate contains from about 4 to 6 weight percent of said lampblack and about 30 weight percent of said silica, based upon the weight of said polyamide, and said extrudate has a discharge time of from about 5000 to 0 volts in less than about 100 ms.
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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) | 1988-10-21 | 1989-04-22 | 1989-10-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-10-21 | 1993-04-22 | 1993-10-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-10-21 | 1997-04-22 | 1997-10-22 | $7700.00 | Window Closed / Lapsed |