EP0147607B1 - Varistance en oxyde de zinc - Google Patents

Varistance en oxyde de zinc Download PDF

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Publication number
EP0147607B1
EP0147607B1 EP84113877A EP84113877A EP0147607B1 EP 0147607 B1 EP0147607 B1 EP 0147607B1 EP 84113877 A EP84113877 A EP 84113877A EP 84113877 A EP84113877 A EP 84113877A EP 0147607 B1 EP0147607 B1 EP 0147607B1
Authority
EP
European Patent Office
Prior art keywords
oxide
oxygen
zinc oxide
barrier layer
materials
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
Application number
EP84113877A
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German (de)
English (en)
Other versions
EP0147607A1 (fr
Inventor
Elias Dr. Jülke
Tony Dr. Kaiser
Maged A. Dr. Osman
Roger S. Dr. Perkins
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.)
BBC Brown Boveri AG Switzerland
Original Assignee
BBC Brown Boveri AG Switzerland
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 BBC Brown Boveri AG Switzerland filed Critical BBC Brown Boveri AG Switzerland
Publication of EP0147607A1 publication Critical patent/EP0147607A1/fr
Application granted granted Critical
Publication of EP0147607B1 publication Critical patent/EP0147607B1/fr
Expired legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01C—RESISTORS
    • H01C7/00—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material
    • H01C7/10—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material voltage responsive, i.e. varistors
    • H01C7/102—Varistor boundary, e.g. surface layers
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/31504—Composite [nonstructural laminate]
    • Y10T428/31551—Of polyamidoester [polyurethane, polyisocyanate, polycarbamate, etc.]
    • Y10T428/31609—Particulate metal or metal compound-containing
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/31504—Composite [nonstructural laminate]
    • Y10T428/31652—Of asbestos
    • Y10T428/31663—As siloxane, silicone or silane
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/31504—Composite [nonstructural laminate]
    • Y10T428/31786—Of polyester [e.g., alkyd, etc.]

Definitions

  • the invention relates to a zinc oxide varistor according to the preamble of claim 1.
  • JP-PS 957 072 the degradation of zinc oxide varistors in SF 6 can be considerably slowed down by adding 10-30% oxygen. Apart from the fact that it cannot be used when the varistors are surrounded by a liquid or solid medium, this method has the disadvantage that it requires a gas-tight partitioning of the space containing the varistors from other system parts and complicates maintenance. There is also a reduction in dielectric strength.
  • the object of the invention is to improve a generic zinc oxide varistor with respect to the oxygen impermeability of the coating covering the peripheral lateral surface.
  • the at least one oxygen barrier layer contained in the coating of a zinc oxide varistor according to the invention prevents oxygen from diffusing out of the peripheral layer of the varistor part because of the substantially oxygen-impermeable inorganic filler which drastically lengthens the diffusion paths or even gives off oxygen counteracts more than the coating of known generic zinc oxide varistors.
  • the coating of a zinc oxide varistor according to the invention is hardly more difficult to produce.
  • the organic matrix material which determines the mechanical, thermodynamic and chemical properties of said oxygen barrier layer can also be significantly determined , optimized with regard to heat resistance, elasticity, thermal expansion coefficients, corrosion resistance, mechanical strength etc. and in particular also to the conditions of use such as the surrounding medium can be adapted to given special requirements essentially without regard to its oxygen permeability.
  • FIGS. 1-4 show zinc oxide varistors, which in their basic structure each contain a cylindrical active part 1 made of a sintered mass, which consists of metal oxides with a predominant proportion of zinc oxide, and on the base and top surface of the active part 1, contact layers 2a, b made of conductive material, for example aluminum, which form opposite contact surfaces 3a, b.
  • the peripheral side surface between the contact surfaces 3a, b is covered with a coating 4 consisting at least partially of an organic polymer.
  • the coating 4 is designed entirely as an oxygen barrier layer 5.
  • 6 filler particles 7 are distributed in an organic matrix material. They are platelet-shaped and consist of one of the following materials: natural mica, artificial mica, vermiculite, iron mica, glass. Epoxy resins, alkyd resins, polyurethanes, silicone resins, unsaturated polyester resins, acrylates are suitable as organic matrix material 6. These substances are also commercially available as paints. They can be mixed with the filler and the side surface of the uncoated active part can be sprayed with this mixture several times. Vortex sintering or electrostatic powder coating are also suitable as methods for applying the oxygen barrier layer. Casting is also possible, but less suitable for series production.
  • the degradation-inhibiting effect of the oxygen barrier layer 5 should be due to the fact that the filler particles 7, which are practically impermeable to oxygen, are oriented essentially parallel to the side surface of the active part 1 and thereby form a dense structure in which diffusion paths through the oxygen barrier layer 5, which run exclusively in the organic matrix material 6, are compared with the thickness of which are very long. Oxygen diffused from the edge layer of the active part 1 is thereby retained in the vicinity thereof, which increases the oxygen partial pressure there and prevents further diffusion of oxygen from the active part 1.
  • a first variant type I
  • the side surface of the active part 1 was sprayed three times with Wacotop @ (registered trademark of Heinrich Wagner & Co., Zurich, Switzerland), an epoxy resin paint containing iron mica.
  • Wacotop @ registered trademark of Heinrich Wagner & Co., Zurich, Switzerland
  • the thickness of the oxygen barrier layer 5 was 0.5 mm.
  • one or more oxygen barrier layers 5 are formed by coating a mica tape with a carrier 8 made of paper, plastic or glass fabric, which is wound around the active part 1 in one or more layers.
  • the coating faces the active part 1, the carrier 8 is on the outside.
  • the coating in turn consists of an organic matrix material 6 with embedded filler particles 7.
  • Mica is preferably suitable as the filler, but the use of other substances in connection with the previously described or the embodiment described below is also possible.
  • the mode of operation of the oxygen barrier layer or layers 5 is of course the same as in the other embodiments.
  • the carrier 8 enables oxygen barrier layers 5 to be applied very easily and quickly by machine winding.
  • a varistor according to the invention according to the second embodiment was produced as follows (type III):
  • the cylindrical active part 1 was covered with a layer of mica glass fabric tape Samicatherm @ (registered trademark of Isola, Pope, Switzerland), glued and cured at 130 ° C. for 16 hours.
  • the thickness of the tape was 0.2 mm.
  • the coating 4 is again entirely designed as an oxygen barrier layer 5.
  • Filler particles 7, which consist of one of the following metal oxides, are distributed in an organic matrix material 6: iridium oxide (IrO 2 ), osmium oxide (OsO 2 ), tellurium oxide (TeO 2 ), copper oxide (Cu 2 0), bismuth oxide (Bi 2 0 3 ), Lead oxide (PbO), antimony oxide (Sb 2 0 3 ), cobalt oxide (Co0), nickel oxide (NiO), manganese oxide (Mn0 2 , Mn 2 0 3 ), cadmium oxide (CdO), molybdenum oxide (Mo03), tin oxide (SnO 2 ), Tungsten oxide (W0 3 ), iron oxide (Fe 3 0 4 ), vanadium oxide (V 2 0 5 ), zinc oxide (ZnO). Powdered active part material is also an option.
  • the substances listed in connection with the first embodiment are suitable as organic
  • the degradation-retarding effect of the coating should be due to the fact that the filler particles 7 release oxygen and keep the ambient oxygen partial pressure in the immediate vicinity of the edge layer of the active part 1 at a level at which the active part material does not or only slightly releases oxygen.
  • the physical effect of the mostly poorly oxygen-permeable filler as a diffusion barrier should also play a role here.
  • a zinc oxide varistor according to the third embodiment was implemented in the following form (type IV):
  • Epoxy molding material Araldit @ (registered trademark of the company Ciba Geigy, Basel, Switzerland) Cy 227 was mixed with the corresponding hardener Cy 227 and zinc oxide (ZnO) of the quality Weissiegel heated to 160 °.
  • the active part 1 was cast around this mixture in a silicone mold. The mixture was then 16 h at 130 ° C. hardened.
  • the thickness of the oxygen barrier layer 5 after curing was 2 mm.

Landscapes

  • Engineering & Computer Science (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Thermistors And Varistors (AREA)
  • Glass Compositions (AREA)

Claims (8)

1. Varistor à l'oxyde de zinc ayant une partie active (1), qui possède deux faces de contact opposées l'une à l'autre (3a, 3b) et une face latérale entourant entièrement ces dernières, et ayant un revêtement (4) qui couvre la face latérale et est constitué au moins en partie d'un polymère organique, caractérisé en ce que le revêtement (4) contient au moins une couche barrière pour l'oxygène (5) constituée d'une suspension de particules de charge (7) d'une charge minérale dans un matériau matrice organique (6) qui est constitué au moins en prédominance d'un ou de plusieurs polymères organiques, la charge minérale étant constituée dans chaque cas sensiblement d'un ou de plusieurs constituants qui appartiennent chacun à l'un au moins des groupes de matériaux suivants :
- les matériaux minéraux non métalliques dont le coefficient de diffusion d'oxygène est inférieur à celui du matériau matrice organique,
- les matériaux minéraux qui libèrent de l'oxygène lorsque la pression partielle d'oxygène dans l'atmosphère environnante tombe en dessous d'une limite positive définie.
2. Varistor à l'oxyde de zinc selon la revendication 1, dans lequel au moins une couche barrière pour l'oxygène (5) contient un ou plusieurs constituants choisis parmi le groupe comprenant les matériaux minéraux non métalliques, dont le coefficient de diffusion de l'oxygène est inférieur à celui du matériau matrice organique, caractérisé en ce que ces constituants sont en prédominance sous forme de plaquettes ou de paillettes et sont de préférence choisis parmi les matériaux ou les groupes de matériaux suivants : le mica naturel, le mica artificiel, la vermiculite, le mica de fer et le verre.
3. Varistor à l'oxyde de zinc selon la revendication 1 ou 2, dans lequel au moins une couche barrière pour l'oxygène (5) contient un ou plusieurs constituants choisis parmi le groupe comprenant les matériaux minéraux qui libèrent de l'oxygène lorsque la pression partielle d'oxygène dans l'atmosphère environnante tombe en dessous d'une limite définie, caractérisé en ce que, dans le cas de l'un au moins de ces constituants, la limite de la pression partielle d'oxygène dans l'atmosphère environnante en dessous de laquelle de l'oxygène est libéré, n'est pas inférieure à celle dans le cas du matériau de la partie active (1).
4. Varistor à l'oxyde de zinc selon la revendication 3, caractérisé en ce que le constituant, dont il y a au moins un exemplaire, d'au moins une couche barrière pour l'oxygène (5), pour lequel la limite de la pression partielle d'oxygène dans l'atmosphère environnante en dessous de laquelle de l'oxygène est libéré, n'est pas inférieure à celle dans le cas du matériau de la partie active (1) est choisi parmi les matériaux suivants : l'oxyde d'iridium (IrO2), l'oxyde d'osmium (OsO2), l'oxyde de tellure (TeO2), l'oxyde de cuivre (Cu20), l'oxyde de bismuth (Bi203) l'oxyde de plomb (PbO), l'oxyde d'antimoine (Sb203), l'oxyde de cobalt (Co0), l'oxyde de nickel (NiO), l'oxyde de manganèse (MnO2, Mn2O3), l'oxyde de cadmium (CdO), l'oxyde de molybdène (MoOa), l'oxyde d'étain (SnO2), l'oxyde de tungstène (WO3), l'oxyde de fer (Fe304), l'oxyde de vanadium (V2O5), l'oxyde de zinc (ZnO), et le matériau de la partie active sous forme de poudre.
5. Varistor à l'oxyde de zinc selon l'une des revendications 1 à 4, caractérisé en ce que le matériau matrice organique (6) est constitué au moins en prédominance d'un polymère choisi parmi l'un des groupes de matériaux suivants : les résines époxy, les résines alkydes, les polyuré- thanes, les résines silicones, les résines de polyesters insatures et les acrylates.
6. Varistor à l'oxyde de zinc selon les revendications 4 et 5, ayant une couche barrière pour l'oxygène (5), caractérisé en ce que le matériau matrice organique est une résine époxy et la charge minérale est de l'oxyde de zinc (ZnO).
7. Varistor à l'oxyde de zinc selon l'une quelconque des revendications 1 à 5, caractérisé en ce que la couche barrière pour l'oxygène (5), dont il y a au moins un exemplaire, est formée par revêtement d'une bande à l'aide d'un support (8) de papier, de plastique ou de tissu de verre, dont on a appliqué au moins une épaisseur à la face latérale de la partie active (1).
8. Varistor à l'oxyde de zinc selon la revendication 7, caractérisé en ce que la bande est une bande de mica/de tissu de verre.
EP84113877A 1983-12-22 1984-11-16 Varistance en oxyde de zinc Expired EP0147607B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CH6851/83 1983-12-22
CH685183 1983-12-22

Publications (2)

Publication Number Publication Date
EP0147607A1 EP0147607A1 (fr) 1985-07-10
EP0147607B1 true EP0147607B1 (fr) 1988-05-04

Family

ID=4316023

Family Applications (1)

Application Number Title Priority Date Filing Date
EP84113877A Expired EP0147607B1 (fr) 1983-12-22 1984-11-16 Varistance en oxyde de zinc

Country Status (4)

Country Link
US (1) US4559167A (fr)
EP (1) EP0147607B1 (fr)
JP (1) JPS60158603A (fr)
DE (1) DE3470975D1 (fr)

Families Citing this family (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3670544D1 (de) * 1985-09-02 1990-05-23 Bbc Brown Boveri & Cie Ueberspannungsableiter und verfahren zu seiner herstellung.
DE69027867T2 (de) * 1989-11-08 1996-12-12 Matsushita Electric Ind Co Ltd Zinkoxid-Varistor, seine Herstellung und Zusammensetzung eines kristallisierten Glases zur Beschichtung
JPH0685363B2 (ja) * 1991-09-30 1994-10-26 ソマール株式会社 高電圧用バリスタ及びその製造方法
US5250229A (en) * 1991-10-10 1993-10-05 E. I. Du Pont De Nemours And Company Silver-rich conductor compositions for high thermal cycled and aged adhesion
US5742223A (en) * 1995-12-07 1998-04-21 Raychem Corporation Laminar non-linear device with magnetically aligned particles
US5932553A (en) * 1996-07-18 1999-08-03 The Regents Of The University Of California Illudin analogs useful as antitumor agents
TW345665B (en) * 1997-06-23 1998-11-21 Nat Science Council Zinc oxide varistor and multilayer chip varistor with low temperature sintering properties
JP2000091105A (ja) * 1998-09-11 2000-03-31 Murata Mfg Co Ltd チップ型セラミックサーミスタおよびその製造方法
JP2001176703A (ja) * 1999-10-04 2001-06-29 Toshiba Corp 電圧非直線抵抗体及びその製造方法
US6802116B2 (en) * 2001-03-20 2004-10-12 Abb Ab Method of manufacturing a metal-oxide varistor with improved energy absorption capability
DE50115800D1 (de) * 2001-07-02 2011-04-07 Abb Schweiz Ag Polymercompound mit nichtlinearer Strom-Spannungs-Kennlinie und Verfahren zur Herstellung eines Polymercompounds
US7015786B2 (en) * 2001-08-29 2006-03-21 Mcgraw-Edison Company Mechanical reinforcement to improve high current, short duration withstand of a monolithic disk or bonded disk stack
KR101166049B1 (ko) * 2010-12-28 2012-07-19 주식회사 아모텍 ＺｎＯ계 바리스터 조성물
EP3178098A4 (fr) 2014-08-08 2018-06-06 Dongguan Littelfuse Electronics, Co., Ltd. Varistance présentant un revêtement multicouche et son procédé de fabrication
EP3264427A1 (fr) * 2016-07-01 2018-01-03 ABB Schweiz AG Varistance revêtue de verre de bismuth

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US3798063A (en) * 1971-11-29 1974-03-19 Diamond Shamrock Corp FINELY DIVIDED RuO{11 {11 PLASTIC MATRIX ELECTRODE
US3872582A (en) * 1972-12-29 1975-03-25 Matsushita Electric Ind Co Ltd Process for making a voltage dependent resistor
US3938069A (en) * 1973-09-27 1976-02-10 General Electric Company Metal oxide varistor with passivating coating
US4031498A (en) * 1974-10-26 1977-06-21 Kabushiki Kaisha Meidensha Non-linear voltage-dependent resistor
US4100588A (en) * 1977-03-16 1978-07-11 General Electric Company Electrical overvoltage surge arrester with varistor heat transfer and sinking means
US4210704A (en) * 1978-08-04 1980-07-01 Bell Telephone Laboratories, Incorporated Electrical devices employing a conductive epoxy resin formulation as a bonding medium
US4247364A (en) * 1979-07-02 1981-01-27 Armstrong Cork Company Method of making a smooth, dimensionally stable, mica-filled, glass fiber sheet
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BR8103687A (pt) * 1980-06-23 1982-03-02 Gen Electric Revestimento isolante para varistores de oxido de zinco aplicaveis e para raios e protetores de picos de voltagem

Also Published As

Publication number Publication date
JPS60158603A (ja) 1985-08-20
US4559167A (en) 1985-12-17
DE3470975D1 (en) 1988-06-09
EP0147607A1 (fr) 1985-07-10

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