EP0729157A1 - Elément électrique conducteur tel qu'un fil muni d'un revêtement isolant inorganique - Google Patents

Elément électrique conducteur tel qu'un fil muni d'un revêtement isolant inorganique Download PDF

Info

Publication number
EP0729157A1
EP0729157A1 EP95102703A EP95102703A EP0729157A1 EP 0729157 A1 EP0729157 A1 EP 0729157A1 EP 95102703 A EP95102703 A EP 95102703A EP 95102703 A EP95102703 A EP 95102703A EP 0729157 A1 EP0729157 A1 EP 0729157A1
Authority
EP
European Patent Office
Prior art keywords
oxide layer
oxide
coating solution
conductor
electrical conductor
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.)
Granted
Application number
EP95102703A
Other languages
German (de)
English (en)
Other versions
EP0729157B1 (fr
Inventor
Kazuo C/O Osaka Works Of Sumitomo Sawada
Shinji C/O Osaka Works Of Sumitomo Inazawa
Kouichi C/O Osaka Works Of Sumitomo Yamada
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.)
Sumitomo Electric Industries Ltd
Original Assignee
Sumitomo Electric Industries Ltd
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 Sumitomo Electric Industries Ltd filed Critical Sumitomo Electric Industries Ltd
Priority to EP95102703A priority Critical patent/EP0729157B1/fr
Priority to DE1995602270 priority patent/DE69502270T2/de
Publication of EP0729157A1 publication Critical patent/EP0729157A1/fr
Application granted granted Critical
Publication of EP0729157B1 publication Critical patent/EP0729157B1/fr
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
    • H01B7/17—Protection against damage caused by external factors, e.g. sheaths or armouring
    • H01B7/29—Protection against damage caused by extremes of temperature or by flame
    • H01B7/292—Protection against damage caused by extremes of temperature or by flame using material resistant to heat
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B3/00—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties
    • H01B3/02—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of inorganic substances
    • H01B3/10—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of inorganic substances metallic oxides
    • H01B3/105—Wires with oxides
    • 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
    • H01B7/17—Protection against damage caused by external factors, e.g. sheaths or armouring
    • H01B7/29—Protection against damage caused by extremes of temperature or by flame
    • H01B7/295—Protection against damage caused by extremes of temperature or by flame using material resistant to flame

Definitions

  • the present invention relates to an electrically conducting wire with an insulating coating made of an inorganic material.
  • a wire is used for high temperature operating conditions, e.g. as an insulated lead wire or the like.
  • An insulated conductor such as a wire or a member for a thermocouple is generally used in equipment such as heating equipment or fire alarm devices, which require safe operation at high operating temperatures. Such an insulated wire is also employed in an automobile in an environment which is heated to a high temperature.
  • An insulated wire of this type is generally formed by a conductor which is coated with a heat-resistant organic resin such as polyimide, fluororesin or the like.
  • Such a resin-coated wire can merely withstand a temperature of about 300°C at the most.
  • a wire which is employed in a high vacuum apparatus for example, must have high heat resistance against baking, etc., a small emission characteristic as to absorbed gas and water for achieving and maintaining a high degree of vacuum, and a small emission of gases caused by thermal decomposition. It is impossible to satisfy such requirements for heat resistance and a non-outgassing property with a conventional wire which is coated with an organic material insulation.
  • an insulated wire is comprising a conductor which passes through an insulator tube of ceramics
  • an MI (mineral insulated) cable comprising a conductor which passes through a tube of a heat-resistant alloy, such as stainless steel alloy, that is filled with fine particles of a metal oxide such as magnesium oxide, or the like is generally used.
  • a glass braided tube insulated wire employing an insulating member of glass fiber fabric or the like is known as an insulated, heat resistant, flexible wire.
  • wires coated with organic materials were studied.
  • wires have been proposed, one of which is obtained by anodizing an aluminum (Al) conductor for forming an Al oxide layer on the outer wire surface, and another wire is obtained by mixing a frit prepared by mixing various metal oxides with each other and melting and pulverizing the as-obtained mixture for forming a slip, applying this slip to a metal conductor and heating and melting the same for forming a homogeneous composite metal oxide layer or coating on the wire surface.
  • the wire with an aluminum oxide layer is not suitable for use as a heat resistant wire since this technique is merely applicable to an aluminum conductor having a low melting point, while the as-formed film is so porous that the wire has an inferior moisture resistance and a low breakdown voltage.
  • the wire with a composite metal oxide coating is applicable to a metal conductor of copper (Cu) or nickel (Ni) having a higher heat resistance.
  • this technique is merely applicable to a metal composite oxide whose melting point is lower by about 300 to 400°C than those of Cu and Ni since the metal composite oxide layer is formed through a melting process, and the heat resistance temperature is restricted below the just mentioned level.
  • the as-formed wire is inferior in flexibility since it is difficult to reduce the thickness of the film.
  • the overall diameter is increased as compared with the conductor diameter, leading to an inferior space factor. Thus, it is impossible to feed a high current.
  • the inorganic insulating member or electrical conductor wire according to the present invention comprises a conductor of Ni or Ni alloy, an oxide layer of an oxide of the Ni or Ni alloy on an outer surface of the conductor, said oxide layer being obtained by oxidizing the conductor in a vapor phase containing oxygen, and an oxide layer of aluminum (Al) and/or silicon (Si) is provided on an outer surface of the oxide layer of Ni or Ni alloy.
  • the oxide layer of Al and/or Si is an oxide layer obtained by applying a solution prepared by hydrolyzing and polycondensing alkoxide of Al and/or Si in a solvent, drying the same for allowing gelation, and thereafter heating the obtained gel.
  • the oxide layer of Al and/or Si has a melting point exceeding that of Ni or Ni alloy.
  • the inorganic insulated member according to the present invention is applied to or used as a heat resistant wire or an incombustible wire at a high temperature which does not permit using an organic insulating material, for example.
  • the present invention is not restricted to such a wire, but is also applicable to another member such as a thermocouple.
  • Fig. 1 shows an Ni core conductor 1 coated with an Ni oxide layer 2 formed around the core conductor.
  • An Al oxide layer 3 is formed around the Ni oxide layer 2. The formation of these oxide layers will be described in more detail below.
  • Fig. 2 shows a nickel alloy conductor 11 first coated with an Ni alloy oxide layer 12 formed around the Ni alloy conductor 11.
  • An Si oxide layer 13 is formed around the Ni alloy oxide layer 12.
  • the nickel Ni core conductor 21 is first coated with an Ni oxide layer 22 formed around the Ni core conductor 21.
  • An Si oxide layer 23 is formed around the Ni oxide layer 22.
  • an Al oxide layer or Si oxide layer 24 is formed around the Si oxide layer 23.
  • a nickel alloy core conductor 31 is first coated with an Ni alloy oxide layer 32 formed around the Ni alloy core conductor 31. Then, an Al-Si composite oxide layer 33 is formed around the Ni alloy oxide layer 32.
  • a first oxide layer of Ni or an Ni alloy is first formed on an outer surface of a conductor of Ni or Ni alloy by oxidizing the conductor in a vapor phase containing oxygen. Then, a second oxide layer of Al and/or Si is formed on the first oxide layer.
  • Ni or Ni alloy is an inactive metal which has an inferior affinity for a metal oxide of Al or Si.
  • a surface of Ni or Ni alloy is directly coated with such an Al or Si oxide, a rather poor adhesion is obtained and the coating is immediately separated from the Ni or Ni alloy.
  • the present invention teaches to first oxidize a core conductor of Ni or Ni alloy in a vapor phase containing oxygen, so as to form an oxide layer of Ni or Ni alloy.
  • the so formed nickel oxide layer or Ni alloy oxide layer very strongly adheres to the surface of the Ni or Ni alloy. This strong bonding is due to the fact that the nickel oxide or the nickel alloy oxide has an excellent affinity for the nickel or nickel alloy.
  • the nickel or nickel alloy oxide has a strong affinity to aluminum oxide or silicon oxide and hence also strongly bonds to the outer layer of Al or Si oxide and to the conductor core. According to the present invention, therefore, the oxide layer of Al and/or Si is not separated for all practical purposes from the intermediate oxide layer, whereby an excellent flexibility is obtained when the inorganic insulating coating is applied to a wire forming a core conductor, for example.
  • the oxide layer of Al and/or Si is obtained by applying a solution prepared by hydrolyzing and polycondensing an alkoxide of Al and/or Si in a solvent, drying the same for allowing gelation, and thereafter heating the so-obtained gel.
  • the Al and/or Si oxide layer formed in the aforementioned manner has a melting point exceeding that of the Ni or Ni alloy. Additionally, the Al and/or Si oxide layer is formed without any melting process.
  • the critical temperature to which conductors or other members of the present invention with their inorganic insulating coatings may be exposed in operation is not restricted by the melting point of the oxide layer. Rather, the present insulating members can be heated to a temperature limited only by the melting point of the Ni core or the Ni alloy core.
  • the oxide layer formed in the aforementioned manner has characteristics such as an extreme denseness, a smooth surface and a small adsorption of gases, e.g. steam or the like.
  • the present members have an excellent insulability and a high moisture resistance.
  • Preferred embodiments have been produced as two conductors C1 and C2 which were oxidized as follows.
  • All the coating operations were, for example, performed by dipping the wire into the respective coating solution.
  • the above Table shows the breakdown voltages and the flexibility values of the wires of Examples 1 to 4 of the invention and of the two Comparative Examples.
  • the flexibility values were evaluated in terms of diameter ratios, by winding the wires on circular cylinders of a prescribed diameter D and measuring the minimum diameters causing no separation of the insulating inorganic compound coatings or layers from the conductor core.
  • the diameter D was 0.5 mm.
  • the inorganic insulating coating on a conductor wire according to the present invention forms an insulating inorganic compound layer which is well bonded to the conductor core and has an excellent heat resistance and insulability.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Ceramic Engineering (AREA)
  • Inorganic Chemistry (AREA)
  • Insulated Conductors (AREA)
EP95102703A 1995-02-24 1995-02-24 Elément électrique conducteur tel qu'un fil muni d'un revêtement isolant inorganique Expired - Lifetime EP0729157B1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
EP95102703A EP0729157B1 (fr) 1995-02-24 1995-02-24 Elément électrique conducteur tel qu'un fil muni d'un revêtement isolant inorganique
DE1995602270 DE69502270T2 (de) 1995-02-24 1995-02-24 Elektrisches Leiterelement wie ein Draht mit anorganischen Isolierbeschichtung

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP95102703A EP0729157B1 (fr) 1995-02-24 1995-02-24 Elément électrique conducteur tel qu'un fil muni d'un revêtement isolant inorganique

Publications (2)

Publication Number Publication Date
EP0729157A1 true EP0729157A1 (fr) 1996-08-28
EP0729157B1 EP0729157B1 (fr) 1998-04-29

Family

ID=8219011

Family Applications (1)

Application Number Title Priority Date Filing Date
EP95102703A Expired - Lifetime EP0729157B1 (fr) 1995-02-24 1995-02-24 Elément électrique conducteur tel qu'un fil muni d'un revêtement isolant inorganique

Country Status (2)

Country Link
EP (1) EP0729157B1 (fr)
DE (1) DE69502270T2 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7935885B2 (en) 2008-07-11 2011-05-03 Ford Global Technologies, Llc Insulated assembly of insulated electric conductors

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7572980B2 (en) 2007-01-26 2009-08-11 Ford Global Technologies, Llc Copper conductor with anodized aluminum dielectric layer

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0292780A1 (fr) * 1987-05-12 1988-11-30 Sumitomo Electric Industries, Ltd. Fil électrique
EP0416131A1 (fr) * 1989-03-28 1991-03-13 Sumitomo Electric Industries, Ltd. Fil electrique isole
EP0494424A1 (fr) * 1991-01-10 1992-07-15 Sumitomo Electric Industries, Limited Membre isolant anorganique

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA1295890C (fr) * 1985-01-14 1992-02-18 Stephen J. Duckworth Cable electrique revetu d'une couche de produit refractaire

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0292780A1 (fr) * 1987-05-12 1988-11-30 Sumitomo Electric Industries, Ltd. Fil électrique
EP0416131A1 (fr) * 1989-03-28 1991-03-13 Sumitomo Electric Industries, Ltd. Fil electrique isole
EP0494424A1 (fr) * 1991-01-10 1992-07-15 Sumitomo Electric Industries, Limited Membre isolant anorganique

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7935885B2 (en) 2008-07-11 2011-05-03 Ford Global Technologies, Llc Insulated assembly of insulated electric conductors

Also Published As

Publication number Publication date
DE69502270D1 (de) 1998-06-04
DE69502270T2 (de) 1999-01-07
EP0729157B1 (fr) 1998-04-29

Similar Documents

Publication Publication Date Title
US5436409A (en) Electrical conductor member such as a wire with an inorganic insulating coating
EP0410003B1 (fr) Fil electrique isole
US4429007A (en) Electrical wire insulation and electromagnetic coil
JPH03127809A (ja) 耐熱絶縁コイルの製造方法
US5468557A (en) Ceramic insulated electrical conductor wire and method for manufacturing such a wire
CA1295890C (fr) Cable electrique revetu d'une couche de produit refractaire
EP0729157B1 (fr) Elément électrique conducteur tel qu'un fil muni d'un revêtement isolant inorganique
CA2142765C (fr) Couche isolante en matiere chimique inorganique
JPH06229837A (ja) 被覆熱電対の製造方法および被覆熱電対用線材の製造方法
EP0494424B1 (fr) Procédé pour préparer un conducteur électrique avec un isolant inorganique
CA2050339C (fr) Cable isole pour utilisation sous hautes temperatures
JPH08264028A (ja) 絶縁被覆電気導体およびその製造方法
EP0380318B1 (fr) Procédé pour la fabrication de fils supraconducteurs
JPH02301909A (ja) 無機絶縁電線およびその製造方法
JPH0349109A (ja) 無機絶縁導体
JPH03105803A (ja) 無機絶縁電線およびその製造方法
JPH06104493A (ja) 被覆熱電対
EP0495997A1 (fr) Thermocouple
JP3336735B2 (ja) 絶縁電線
JPH05314821A (ja) 無機絶縁被覆導体
JPS6336085B2 (fr)
JPH0393107A (ja) 耐熱性絶縁電線およびその製造方法
KR940001884B1 (ko) 절연 전선
JP3074741B2 (ja) 絶縁電線
JPH0218810A (ja) 真空用耐熱性導体

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

17P Request for examination filed

Effective date: 19950927

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE FR GB

17Q First examination report despatched

Effective date: 19960829

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

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

REF Corresponds to:

Ref document number: 69502270

Country of ref document: DE

Date of ref document: 19980604

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

Ref country code: FR

Payment date: 20010213

Year of fee payment: 7

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

Ref country code: GB

Payment date: 20010221

Year of fee payment: 7

Ref country code: DE

Payment date: 20010221

Year of fee payment: 7

REG Reference to a national code

Ref country code: GB

Ref legal event code: IF02

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: 20020224

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: 20020903

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

Effective date: 20020224

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

Ref country code: FR

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

Effective date: 20021031

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST