EP0674326B1 - Elektrischer Leiter mit einer Isolierung aus Kunststoff - Google Patents

Elektrischer Leiter mit einer Isolierung aus Kunststoff Download PDF

Info

Publication number
EP0674326B1
EP0674326B1 EP95102470A EP95102470A EP0674326B1 EP 0674326 B1 EP0674326 B1 EP 0674326B1 EP 95102470 A EP95102470 A EP 95102470A EP 95102470 A EP95102470 A EP 95102470A EP 0674326 B1 EP0674326 B1 EP 0674326B1
Authority
EP
European Patent Office
Prior art keywords
electrical conductor
fibers
metallic fibers
plastic material
metallic
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP95102470A
Other languages
English (en)
French (fr)
Other versions
EP0674326A2 (de
EP0674326A3 (de
Inventor
Dieter Hellbusch
Herbert Dust
Gerhard Lohmeier
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
3M Co
Original Assignee
Minnesota Mining and Manufacturing Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Minnesota Mining and Manufacturing Co filed Critical Minnesota Mining and Manufacturing Co
Publication of EP0674326A2 publication Critical patent/EP0674326A2/de
Publication of EP0674326A3 publication Critical patent/EP0674326A3/de
Application granted granted Critical
Publication of EP0674326B1 publication Critical patent/EP0674326B1/de
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B7/00—Insulated conductors or cables characterised by their form
    • H01B7/0009—Details relating to the conductive cores
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
    • H01B1/20—Conductive material dispersed in non-conductive organic material
    • H01B1/22—Conductive material dispersed in non-conductive organic material the conductive material comprising metals or alloys
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B5/00—Non-insulated conductors or conductive bodies characterised by their form
    • H01B5/16—Non-insulated conductors or conductive bodies characterised by their form comprising conductive material in insulating or poorly conductive material, e.g. conductive rubber

Definitions

  • the invention refers to an electrical conductor having an insulation of plastic material.
  • Electrical cable connections for the low and medium voltage range are located in housings or enclosures which are to meet a plurality of requirements. The most important is to provide for an electrical insulation between the components of the connection and the outer side of the housing. A further condition is that upon detoriation or mechanical damage of the housing a short current path is to be established for security reasons. To this purpose, a sufficient conductivity is to be provided. In the state of the art, these conditions are met by various structural solutions.
  • a metallic housing for an electrical connection can be also wrapped with an insulation tape.
  • a plastic housing can be wrapped with an electrically conductive tape.
  • plastic material conductive to a limited extent by the addition of carbon black, metallic powder, metallic fibers or the like.
  • plastic material can be used for shielding signal conductors, electronic components or the like.
  • the specific resistance of such shieldings is relatively high. Therefore, such conductive plastic material cannot be used for the conduction of larger currents as is required in case of housings for cable connections for the low or medium voltage range.
  • the desired short currents are in the range of kiloampere.
  • Semiconductive synthetic materials having a relatively large specific resistance are used for anti-electrostatic purposes. They serve to discharge electrostatic charges. The currents occurring are relatively small.
  • the invention provides an electrical conductor as set forth in claim 1 which can be easily manufactured with an outer configuration adapted to desired space requirements.
  • the invention provides an integral body which is made from a mixture of plastic material and a content of metallic fibers having a small cross-sectional dimension relative to their length by injection molding or extrusion, respectively. It is made such that the metallic fibers with respect to the flow direction during the molding process substantially concentrate on the central or medium area so that a high conductive conductor portion is formed.
  • the invention makes use of the observation that during injection molding or extrusion in the mentioned composition the metallic fibers do not distribute uniformly in the molded body, rather concentrate on an area which lies in a plane wherein the material exits from the extrusion or injection nozzle.
  • the metallic fibers concentrate substantially in the medium area of the plate-like body so that a good conductivity is achieved for orthogonal directions while in a direction perpendicular to this plane, the insulation of the plastic material becomes effective.
  • an integral conductive body is achieved which can be manufactured in a single working step.
  • conductivity values can be achieved in the order of magnitude of metallic conductors.
  • the invention has also the advantage that the external configuration of the conductor can be chosen arbitrarily in adaptation to desired requirements. If for example a housing for a cable connection is to be made, the molding of the housing or parts of the housing of suitable plastic material a suitable conductive portion can be molded in conjunction therewith which is in a position to conduct a high current in case of a short circuit current.
  • the applicability of the conductor according to the invention is unlimited. A primary application can be seen where relatively small lengths, e.g. 1 to 100 mm are required for the transmission of energy and/or signals.
  • the metallic fibers used for the conductor of the invention are essentially circular or oral in cross section and have to have a relatively large length, e.g. 5 to 15 mm. On the other hand, they have a relatively small thickness or diameter, e.g. 35 to 200 ⁇ m. The ratio between length and diameter is in the overall range of 50 to 500, particularly 240.
  • the metallic fibers are of a compound material wherein the fibers are extending substantially parallel and are bonded to each other by a polymeric adhesive substance. Thereafter defined lengths are cut.
  • a polymeric adhesive substance such as known from the DE 38 10 598.
  • the following materials would be suitable as coating agents: polyamide 6, glass-fiber reinforced poyamide, polycarbonate polymers, acrylnitril-bu-tadien-styrol or the like. It serves for the production of molded parts for the shielding of electromagnetic radiation.
  • plastic material and metallic fibers are used for the production of an electrical conductor having a resistivity preferably smaller than 10 -3 ohmcm.
  • the matrix material is to be compatible with the used coated metallic fibers and suited to be mixed with the fibers. If is preferred to use polyamides, specifically polyamide 6.6, polyamide 6, polyamide 4.6, or polyamide 10 or polyamide 11. Alternatively, polyester, terephthalate such as PBT or PET, polycarbonates or aromatic polyamides could be used.
  • the matrix material influences the electrical conductivity.
  • the metallic fibers are of a metal of high conductivity in the range of 10 to 60 m/mm 2 ⁇ and preferably of Cu, Ag, Fe, Ni, Co or of alloys thereof also in conjunction with other metals. It is particularly advantageous to use copper fibers.
  • glass fibers having a length smaller than 1 mm are added to the composition of a plastic matrix and metallic fibers.
  • the content of glass fibers can be up to 30 weight per cent.
  • the glass fibers are coated with a suitable coating agent, e.g. silane.
  • the glass fibers substantially concentrate on a medium area and do not arrive at the surface of the body molded. Furthermore, glass fibers appear to have the property to improve the contacting of the individual copper fibers during the mixing and the molding process. Basically, a good balance between the metal fibers and the glass fibers is to determine. The glass fibers prevent a separation of the metal fibers and allow to obtain a more homogenous component. The flowing characteristics of the matrix should not be too good because in this case the metal fibers are glass fibers would be separated. For a good homogeneity is is necessary to avoid any separation effect.
  • Rectangular and circular plates are made for test purposes.
  • the rectangular plates had the sizes 152x76x3.2 mm.
  • the circular plate had a diameter of 140 mm and a thickness of 3.2 mm.
  • a matrix of polyarylamide is used added by 30 weight per cent short glass fibers (length smaller than 1 mm).
  • this matrix material is mixed with copper fibers which are made according to the German patent specification 38 10 598, e.g. coated with a polyamide.
  • These copper fibers are coated with a suitable plastic material, examples thereof described in the mentioned publication.
  • the mixing ratio is between 16 and 36 weight per cent of pure copper, with the content of the coating is substantial 13% weight per cent.
  • the plates achieved are measured according to DIN 53.482 VDE. It can be derived from Fig. 1 that with a content of 30 weight per cent copper, the resistivity is significantly below 50 ohmm.
  • test plates are made by injection molding process. With this process, test bodies are produced which are shown in Fig. 2. With these test bodies, the copper fibers are completely embedded by the plastic matrix so that the test body is a completely insulated electrical conductor, e.g. an insulated cable. The copper fibers do not define a solid conductor rather, the conductive portion can be compared with a so-called braided conductor.
  • a voltage is applied to the probe body at a distance of 115 mm.
  • the current flowing has been measured, with such measurement shown in Fig. 3.
  • the upper curve corresponds to a content of 36 weight per cent of copper while the lower curve corresponds to a content of 24.6 weight per cent of copper fibers.
  • Fig. 5 shows an injection molded conductor 10 having a circular cross section produced from a mixture of copper fibers 12 and plastic material 14 (Examples for the materials are indicated above).
  • the optimum plate arrangement for the manufacture of the conductor would be to use a circular gate in the middle of the circular end of the conductor.
  • the diameter should be in the range of 0.5 to 1.0 mm. This would allow to make a conductor of a diameter of 5 mm and a length of 300 mm.
  • Fig. 6 shows an injection molded flat conductor 18 rectangular in cross section having copper fibers 20 and a plastic material 22.
  • the fibers 12 or 20, respectively concentrate on the central portion while the outer skin 24 or 26, respectively, is free from fibers.
  • the optimum gate in this case would be to produce a so-called "film gate” which is a gate of a rectangular dimension arranged at the rectangular small side of the conductor, preferably on the upper edge, extending over the entire width with a thickness of 0.5 to 1.0 mm. This, for instance, would allow to make a conductor of a rectangular cross section with a width of 20 mm and a height of 2 mm and a length of 200 mm.
  • a corner 28 of a housing is shown in a perspective view which is also made by injection molding, with the wall portions of plastic material 30 and copper fibers 32.
  • the copper fibers 32 concentrate on the medium plane while the outer skin 34 has no fibers. This is a more complex configuration and here necessitates either a combination of small circular gates as well as several film gates could be thought of.

Landscapes

  • Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Dispersion Chemistry (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Injection Moulding Of Plastics Or The Like (AREA)
  • Shielding Devices Or Components To Electric Or Magnetic Fields (AREA)
  • Conductive Materials (AREA)

Claims (16)

  1. Elektrischer Leiter mit einer Isolation aus Kunststoffmaterial und einem inneren leitfähigen Kern, gekennzeichnet durch einen einteiligen Körper (10, 18, 28), der aus einer Mischung aus Kunststoff (24, 26) und einem Anteil an Metallfasern (12, 20, 32) hergestellt ist, wobei die Fasern (12, 20, 32) eine sehr geringe Querschnittsabmessung im Verhältnis zur Länge aufweisen, und wobei der Körper (10, 18, 28) durch Spritzformen bzw. Extrudieren aus einer Mischung des Kunststoffs und der Metallfasern so hergestellt ist, daß sich die Metallfasern (12, 20, 32) im Hinblick auf die Fließrichtung beim Formprozeß im wesentlichen auf einen mittleren Bereich konzentrieren und einen gut leitfähigen Leiterabschnitt mit einer äußeren Isolation (24, 26) bilden.
  2. Leiter nach Anspruch 1, dadurch gekennzeichnet, daß die Metallfasern eine Länge von 5 bis 15 mm aufweisen.
  3. Leiter nach Anspruch 2, dadurch gekennzeichnet, daß die Metallfasern etwa eine Länge von 8 bis 12 mm, vorzugsweise 10 mm, aufweisen.
  4. Leiter nach Anspruch 1, dadurch gekennzeichnet, daß die Metallfasern einen Durchmesser oder eine Dicke von 35 bis 200 µm aufweisen.
  5. Leiter nach Anspruch 1, dadurch gekennzeichnet, daß das Verhältnis von Länge und Dicke bzw. Durchmesser der Metallfasern zwischen 50 und 500 beträgt, vorzugsweise etwa 240.
  6. Leiter nach Anspruch 1, dadurch gekennzeichnet, daß die Metallfasern mit einem thermoplastischen Kunststoffmaterial ummantelt sind.
  7. Leiter nach Anspruch 1, dadurch gekennzeichnet, daß die Metallfasern Teil eines Verbundstoffes sind, bei dem die Fasern weitgehend parallel ausgerichtet, durch eine polymere haftvermittelnde Substanz verbunden und in definierte Längen geschnitten sind.
  8. Leiter nach Anspruch 1, dadurch gekennzeichnet, daß Metallfasern aus gut leitfähigem Metall im Leitfähigkeitsbereich von 10 bis 60 m/mm2 Ω, insbesondere aus Cu, Ag, Fe, Ni, Co oder aus deren Legierungen auch mit anderen Metallen bestehen.
  9. Leiter nach Anspruch 1, dadurch gekennzeichnet, daß der Anteil an beschichteten Metallfasern bis zu 50 Gew.-% beträgt, vorzugsweise zwischen 20 und 35 Gew.-% liegt.
  10. Leiter nach Anspruch 1, dadurch gekennzeichnet, daß Glasfasern zugemischt sind von einer Länge < 1 mm.
  11. Leiter nach Anspruch 10, dadurch gekennzeichnet, daß der Anteil an Glasfasern bis zu 30 Gew.-% beträgt.
  12. Leiter nach Anspruch 10 oder 11, dadurch gekennzeichnet, daß die Glasfasern mit einem Beschichtungsmittel beschichtet sind.
  13. Leiter nach Anspruch 1, dadurch gekennzeichnet, daß der spezifische Widerstand < 10-3 Ohmcm ist.
  14. Leiter nach Anspruch 1, dadurch gekennzeichnet, daß er platten-, block- oder stabförmig ist.
  15. Leiter nach Anspruch 1, dadurch gekennzeichnet, daß das Kunststoffmaterial elastisch nachgebend ist.
  16. Verwendung des Leiters nach Anspruch 1 für Gehäuse, Kästen oder dergleichen mit leitfähigen Wänden, insbesondere für Kabelverbindungen im Mittel- oder Niederspannungsbereich.
EP95102470A 1994-03-25 1995-02-22 Elektrischer Leiter mit einer Isolierung aus Kunststoff Expired - Lifetime EP0674326B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE4410341A DE4410341A1 (de) 1994-03-25 1994-03-25 Elektrischer Leiter mit einer Isolation aus Kunststoffmaterial
DE4410341 1994-03-25

Publications (3)

Publication Number Publication Date
EP0674326A2 EP0674326A2 (de) 1995-09-27
EP0674326A3 EP0674326A3 (de) 1996-10-23
EP0674326B1 true EP0674326B1 (de) 2000-05-10

Family

ID=6513810

Family Applications (1)

Application Number Title Priority Date Filing Date
EP95102470A Expired - Lifetime EP0674326B1 (de) 1994-03-25 1995-02-22 Elektrischer Leiter mit einer Isolierung aus Kunststoff

Country Status (2)

Country Link
EP (1) EP0674326B1 (de)
DE (2) DE4410341A1 (de)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8858848B2 (en) 2010-06-14 2014-10-14 Nv Bekaert Sa Foaming agent to improve EMI shielding

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE452280C (sv) * 1981-12-30 1990-03-12 Bekaert Sa Nv Elektriskt ledande plastartikel samt foerfarande och medel foer framstaellning daerav
JPS6245659A (ja) * 1985-08-23 1987-02-27 Eng Plast Kk 導電性成形材料
SE462099B (sv) * 1985-11-15 1990-05-07 Dow Chemical Co Emi avskaermningskompositmaterial
US5034157A (en) * 1990-03-16 1991-07-23 Itt Corporation Injection moldable composite

Also Published As

Publication number Publication date
DE69516746D1 (de) 2000-06-15
EP0674326A2 (de) 1995-09-27
DE69516746T2 (de) 2000-09-07
DE4410341A1 (de) 1995-09-28
EP0674326A3 (de) 1996-10-23

Similar Documents

Publication Publication Date Title
KR102033246B1 (ko) 전기 전도성 하이브리드 중합체 재료
EP0604398B1 (de) Elektromagnetisch abgeschirmtes Kabel
US6110576A (en) Article comprising molded circuit
EP1446446B1 (de) Verfahren zur Herstellung elektrisch leitfähiger thermoplastischer Polymerzusammensetzungen
US5958303A (en) Electrically conductive compositions and methods for producing same
KR20040090487A (ko) 도전성 부여 수지계 재료로 제조된 염가의 차폐 케이블
US6974615B2 (en) Binding member for coaxial cable and an electric connector for coaxial cable both using resin solder, and a method of connecting the binding member to coaxial cable or the electric connector
KR20080011686A (ko) 도전성 섬유를 포함하는 중합체 이엠아이 하우징
MXPA06009324A (es) Conductor de corriente hecho de alambre trenzado.
EP1695358A1 (de) Metall-kunststoff-hybrid und daraus hergestellter formkörper
Crossman Conductive composites past, present, and future
US6409942B1 (en) Electrically conductive compositions and methods for producing same
US7425885B2 (en) Low cost electrical fuses manufactured from conductive loaded resin-based materials
EP3144941B1 (de) Flammhemmendes twin-axialkabel
CA2039648C (en) Electro-conductive resin composition
PL114352B1 (en) Screened electric power cable
US7326463B2 (en) Conductive circuits or cables manufactured from conductive loaded resin-based materials
US5066424A (en) Composite material for EMI/EMP hardening protection in marine environments
EP0674326B1 (de) Elektrischer Leiter mit einer Isolierung aus Kunststoff
US4691082A (en) Plastic cable
US20050204548A1 (en) Low cost electrical fuses manufactured from conductive loaded resin-based materials
EP3731242A1 (de) Kabel
JPS60184534A (ja) 導電性プラスチツク組成物
JPS58188005A (ja) シ−ルドワイヤ
JPH01148515A (ja) 導電性せんい複合樹脂の製造方法

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): DE FR GB IT

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): DE FR GB IT

17P Request for examination filed

Effective date: 19970421

17Q First examination report despatched

Effective date: 19980407

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: MINNESOTA MINING AND MANUFACTURING COMPANY

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE FR GB IT

REF Corresponds to:

Ref document number: 69516746

Country of ref document: DE

Date of ref document: 20000615

ITF It: translation for a ep patent filed
ET Fr: translation filed
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
REG Reference to a national code

Ref country code: GB

Ref legal event code: IF02

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: IT

Payment date: 20080228

Year of fee payment: 14

Ref country code: GB

Payment date: 20080227

Year of fee payment: 14

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20080218

Year of fee payment: 14

Ref country code: DE

Payment date: 20080331

Year of fee payment: 14

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20090222

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20091030

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20090901

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20090222

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20090302

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20090222