[go: up one dir, main page]
More Web Proxy on the site http://driver.im/

DE3229558A1 - Impregnating and encapsulating composition for electrical components - Google Patents

Impregnating and encapsulating composition for electrical components

Info

Publication number
DE3229558A1
DE3229558A1 DE19823229558 DE3229558A DE3229558A1 DE 3229558 A1 DE3229558 A1 DE 3229558A1 DE 19823229558 DE19823229558 DE 19823229558 DE 3229558 A DE3229558 A DE 3229558A DE 3229558 A1 DE3229558 A1 DE 3229558A1
Authority
DE
Germany
Prior art keywords
filler
composition
accelerator
resin
electrical components
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
DE19823229558
Other languages
German (de)
Other versions
DE3229558C2 (en
Inventor
Irene 7057 Winnenden Jennrich
Kristian Dipl.-Ing.(FH) 7151 Burgstetten Leo
Werner Dipl.-Ing. 7012 Fellbach Pfander
Wolfgang 7000 Stuttgart Scholz
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.)
Robert Bosch GmbH
Original Assignee
Robert Bosch GmbH
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 Robert Bosch GmbH filed Critical Robert Bosch GmbH
Priority to DE19823229558 priority Critical patent/DE3229558C2/en
Publication of DE3229558A1 publication Critical patent/DE3229558A1/en
Application granted granted Critical
Publication of DE3229558C2 publication Critical patent/DE3229558C2/en
Expired legal-status Critical Current

Links

Classifications

    • 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
    • H01B3/18—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances
    • H01B3/30—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances plastics; resins; waxes
    • H01B3/40—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances plastics; resins; waxes epoxy resins
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
    • C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
    • C08G59/20—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the epoxy compounds used
    • C08G59/22—Di-epoxy compounds
    • C08G59/226—Mixtures of di-epoxy compounds
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
    • C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
    • C08G59/20—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the epoxy compounds used
    • C08G59/32—Epoxy compounds containing three or more epoxy groups
    • C08G59/38—Epoxy compounds containing three or more epoxy groups together with di-epoxy compounds
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
    • C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
    • C08G59/68—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the catalysts used
    • C08G59/686—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the catalysts used containing nitrogen
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K3/00—Use of inorganic substances as compounding ingredients
    • C08K3/18—Oxygen-containing compounds, e.g. metal carbonyls
    • C08K3/24—Acids; Salts thereof
    • C08K3/26—Carbonates; Bicarbonates

Landscapes

  • Chemical & Material Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Compositions Of Macromolecular Compounds (AREA)
  • Epoxy Resins (AREA)

Abstract

A curable encapsulating composition is proposed which is used for impregnating and encapsulating electrical components and comprises a resin, a curing agent, an accelerator and a filler. The resin used is an epoxide based on bisphenol A and a cycloaliphatic compound and has a viscosity of < 5000 mPas at 25 DEG C, the curing agent used is a modified dicarboxylic anhydride, the accelerator used is an imidazole, and the filler used is chalk. The filler is preferably used in an amount of greater than 53 % by weight, based on the total composition. The proposed encapsulating composition has low viscosity, so that impregnation and encapsulation can be carried out in a single operation. The coefficient of thermal expansion and the shrinkage in volume are smaller than in commercially available compositions, and the encapsulating composition has a high glass transition temperature, which means that the composition has high heat resistance and thermal shock resistance.

Description

Imorägniervergußmasse für elektrische BauteileImpregnation casting compound for electrical components

Stand der Technik Die Erfindung geht aus von einer Vergußmasse nach der Gattung des Hauptanspruchs. Käufliche derartige Vergußmassen, mit denen elektrische Bauteile umgossen werden, um sie vor mechanischen Einwirkungen zu schützen, und die aus einem härtbaren Harz bestehen, zeigen bei einer Aushärtung zwei Stunden bei 80 OC und anschließend zwei Stunden bei 120 0 einen verhältnismaßig niedrigen Glasübergangspunkt von 30 OC, verhältnismäßig hohe lineare thermische Ausdehnungskoeffiienten zwischen 44 und 129.10-6 1/°C bei 50 bzw.PRIOR ART The invention is based on a casting compound the genre of the main claim. Such potting compounds for sale, with which electrical Components are cast around to protect them from mechanical effects, and made of a curable resin show two hours when cured at 80.degree. C. and then for two hours at 120.degree. a relatively low one Glass transition point of 30 OC, relatively high linear thermal expansion coefficient between 44 and 129.10-6 1 / ° C at 50 resp.

oberhalb 90 0 sowie einen Volumenschwund, der mit 2,2 % auch verhältnismäßig groß ist. Schließlich weisen diese rarze mit mehr als 10 000 mPas bei 25 °C eine verhältnismäßig hohe Viskosität auf, was zu Vergußmassenführt, mit der einwandfreie Imprägnierungen, beispielsweise von elektrischen Spulen, nur schwer möglich sind. Auch ist bei diesen käuflichen Vergußmassen die Temperaturwechselbeständigkeit, beispielsweise für eine Anwendung bei Hochspannungs-Zündspulen im Kraftfahrzeug, nicht ausreichend, was mit dem niedrigen Glasübergangspunkt, wie er oben genannt ist, zusammenhangt.above 90 0 as well as a decrease in volume, which at 2.2% is also proportionate is great. After all, these rare substances have a temperature of more than 10,000 mPas at 25 ° C relatively high viscosity, which leads to casting compounds, with the perfect Impregnation, for example of electrical coils, is difficult. The thermal shock resistance of these commercially available casting compounds is also important, for example for use in high-voltage ignition coils in motor vehicles, not sufficient, what with the low glass transition point, as mentioned above is related.

Vorteile der Erfindung Die erfindungsgemäße Imprägniervergußmasse mit den kennzeichnenden Merkmalen des Haupt anspruchs hat demgegenüber den Vorteil, daß sie eine niedrige Viskosität, einen kleinen thermischen Ausdehnungskoeffizienten, einen hohen Glasübergangspunkt sowie eine hohe Temperaturwechselbestandigkeit und Wärmebeständigkeit aufweist; so sind Hochspannungs-Zündspulen, die mit dieser erfindungsgemäßen ergußmasse impragniert und vergossen sind, zwischen mindestens -40 °C und mindestens 120 °C temperaturwechselbeständig und elektrisch funktionsfähig bei Temperaturen in der Wicklung von mehr als 100 °C. Durch die geringe Viskositat wird es ermöglicht, derartige elektrische Bauteile in eine: Arbeitsgang zu imprägnieren und zu umhüllen.Advantages of the Invention The impregnation potting compound according to the invention with the characteristic features of the main claim has the advantage that they have a low viscosity, a small coefficient of thermal expansion, a high glass transition point as well as a high thermal shock resistance and Has heat resistance; so are high-voltage ignition coils that work with this invention Casting compound is impregnated and potted, between at least -40 ° C and at least 120 ° C resistant to temperature changes and electrically functional at temperatures in the winding of more than 100 ° C. The low viscosity makes it possible such electrical components in one: to impregnate and encase.

Durch die in den Unteransprüchen aufgeführten Maßnahmen sind vorteilhafte Weiterbildungen und Verbesserungen der im Hauptanspruch angegebenen Imprägniervergußmasse möglich.The measures listed in the subclaims are advantageous Developments and improvements of the impregnation casting compound specified in the main claim possible.

Besonders vorteilhaft ist es, wenn der Füllstoff in einer Menge von mehr als 53 Gew.-%, bezogen auf die Gesamtmasse, in der Vergußmasse enthalten ist, da die oben angegebenen Vorteile dann besonders zutage treten.It when the filler is particularly advantageous in an amount of more than 53% by weight, based on the total mass, is contained in the potting compound, because the advantages indicated above then become particularly apparent.

Beschreibung eines Ausführungsbeispiels Verwendet wird ein Epoxidharz auf Basis Bisphenol A und einem Cycloolefin als Cycloaliphat im Verhältnis 70:30 Gev.-Teilen, das bei 25 C eine Viskosität kleiner als 5000 mPas hat. Dazu wird ein modifiziertes Dicarbonsäureanhydrid7 z. B. Phtalsäureanhydrid als Härter sowie ein Imidazol, z. B. Pyrazol als Beschleuniger und Kreide als Füllstoff zugegeben, wobei Harz, Härter und Beschleuniger im Verhältnis 100:100:0,5 Gew.-Teile eingesetzt erden und der Füllstoff in einer Menge von 55 Gew.-%, bezogen suf die Gesamtmischung, zugegeben wird. Das Ganze wird gut gemischt und stellt dann eine niedrigviskose Masse dar. Zum Imprägnieren und Vergießen einer Hochspannungs-Zündspule wird zunächst die Lagenwicklung getrocknet, die Scheibenwicklung auf eine Temperatur von etwa 100 ° temperiert, der Vorratsbehälter, in welchem sich die vergußmasse befindet, evakuiert, um die Vergußmasse zu entgasen und schließlich das Imprägnieren und Vergießen unter Vakuum vorgenommen. Nach dem Entformen wird die Vergußmasse schließlich gehärtet, und zwar zunächst 1 1/2 Stunden bei 90 °C und dann nochmals 2 Stunden bei 120 °C.Description of an exemplary embodiment An epoxy resin is used based on bisphenol A and a cycloolefin as cycloaliphatic in a ratio of 70:30 Parts that have a viscosity of less than 5000 mPas at 25 ° C. To do this, a modified dicarboxylic anhydride7 e.g. B. phthalic anhydride as a hardener and a Imidazole, e.g. B. Pyrazole added as an accelerator and chalk as a filler, with Ground resin, hardener and accelerator in a ratio of 100: 100: 0.5 parts by weight and the filler was added in an amount of 55% by weight, based on the total mixture will. The whole thing is mixed well and then represents a low-viscosity mass. In order to impregnate and cast a high-voltage ignition coil, the first step is the layer winding dried, the disc winding tempered to a temperature of about 100 °, the reservoir, in which the potting compound is located, evacuated to the To degas casting compound and finally the impregnation and potting under vacuum performed. After removal from the mold, the potting compound is finally hardened, namely first 1 1/2 hours at 90 ° C and then another 2 hours at 120 ° C.

Bei dieser beschriebenen Imprägnier-Vergußmasse ergeben sich die folgenden Eigenschaften: viskosität 25 °C (10 000 mPas 60 cc < 1 000 mPas Glasübergangspunkt ca. 140 cc olumenschwund 1,5 % Linearer therm. Ausdehnungskoeffizîent bis 110 C 38.10-6 1/°C 110 bis 130 °C 57.10-6 1/°C >130 °C 115.10-6 1/°C Die auf die beschriebene Weise imprägnierten und vergossenen Zündspulen weisen eine Temperaturwechselbeständigkeit von mindestens -40 cc bis mindestens 120 cc auf und sind elektisch funktionsfähig bei Temperaturen in der Wicklung von mehr als 100 OC.In the case of this impregnation casting compound described, the following result Properties: viscosity 25 ° C (10 000 mPas 60 cc <1 000 mPas glass transition point approx. 140 cc oil shrinkage 1.5% linear thermal expansion coefficient up to 110 C 38.10-6 1 / ° C 110 to 130 ° C 57.10-6 1 / ° C> 130 ° C 115.10-6 1 / ° C The on the described Ignition coils which are impregnated and potted in this way are resistant to temperature changes from at least -40 cc to at least 120 cc and are electrically functional at temperatures in the winding of more than 100 OC.

Claims (5)

Ansprüche S Imprãgniervergußmasse für elektrische Bauteile, die aus einem Harz, einem Härter, einem Beschleuniger und einem Füllstoff besteht, dadurch gekennzeichnet, daß als Harz ein Epoxid auf Basis Bisphenol A und Cycloaliphat mit einer Viskositat 5000 mPas bei 25 OC, als Härter ein modifiziertes Dicarbonsãureanhydrid, als Beschleuniger ein Imidazol und als Füllstoff Kreide eingesetzt wird. Claims S Impregnation casting compound for electrical components that consist of a resin, a hardener, an accelerator and a filler, thereby characterized in that an epoxy based on bisphenol A and cycloaliphatic is used as the resin a viscosity of 5000 mPas at 25 OC, a modified dicarboxylic acid anhydride as hardener, an imidazole is used as an accelerator and chalk is used as a filler. 2. Imprägniervergußmasse nach Anspruch 1, dadurch gekennzeichnet, daß als Cycloaliphat ein Cycloolefin eingesetzt wird utd das Verhältnis Bisphenol A zu Cycloaliphat 70:30 Gev.-Teile betragt. 2. Impregnation casting compound according to claim 1, characterized in that that a cycloolefin is used as the cycloaliphatic and the bisphenol ratio A to cycloaliphatic is 70:30 parts by weight. 3. Impragniervergußmasse nach Anspruch 1 oder 2, dadurch gekennzeichnet, daß Harz, Härter und Beschleuniger im 7erhaltnis 00:100:0,5 Gew.-Teile eingesetzt werden. 3. Impregnation casting compound according to claim 1 or 2, characterized in that that resin, hardener and accelerator are used in a ratio of 00: 100: 0.5 parts by weight will. 4. Imprägniervergußmasse nach einem der Ansprüche 1 bis 3, dadurch gekennzeichnet, daß der Füllstoff in einer Menge von mehr als 53 Gew.-%, bezogen auf die Gesamtmasse, enthalten ist. 4. Impregnation casting compound according to one of claims 1 to 3, characterized characterized in that the filler in an amount of more than 53 wt .-%, based on the total mass. 5. Imprägniervergußmasse nach Anspruch 4, dadurch gekennzeichnet, daß der Füllstoff in einer Menge von 53 - 60 Ges.-%, bezogen auf die Gesamtmasse, entha ten ist. 5. Impregnation casting compound according to claim 4, characterized in that that the filler is in an amount of 53 - 60% by weight, based on the total mass, is included.
DE19823229558 1982-08-07 1982-08-07 Impregnation casting compound for electrical components Expired DE3229558C2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
DE19823229558 DE3229558C2 (en) 1982-08-07 1982-08-07 Impregnation casting compound for electrical components

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19823229558 DE3229558C2 (en) 1982-08-07 1982-08-07 Impregnation casting compound for electrical components

Publications (2)

Publication Number Publication Date
DE3229558A1 true DE3229558A1 (en) 1984-02-09
DE3229558C2 DE3229558C2 (en) 1984-11-08

Family

ID=6170398

Family Applications (1)

Application Number Title Priority Date Filing Date
DE19823229558 Expired DE3229558C2 (en) 1982-08-07 1982-08-07 Impregnation casting compound for electrical components

Country Status (1)

Country Link
DE (1) DE3229558C2 (en)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0307665A2 (en) * 1987-09-15 1989-03-22 International Business Machines Corporation Encapsulation composition and use thereof
US5189080A (en) * 1989-04-25 1993-02-23 Robert Bosch Gmbh Epoxy resin composition for encapsulating electric circuit components
DE4138411A1 (en) * 1991-11-22 1993-05-27 Bosch Gmbh Robert HARDENING POWERS
DE19523897A1 (en) * 1995-06-30 1997-01-02 Bosch Gmbh Robert Use of silicone-modified epoxy resins as casting compounds for electrotechnical or electronic components
US6001902A (en) * 1996-03-27 1999-12-14 Ciba Specialty Chemicals Corp. Wollastonite-containing curable epoxy resin mixture
US6030713A (en) * 1994-07-01 2000-02-29 Ciba Specialty Chemicals Corp. Electrical or electronic components encapsulated with liquid epoxy resins containing a mixture of wollastonite and calcite fillers
EP0984463A1 (en) * 1997-05-23 2000-03-08 Hitachi, Ltd. Ignition coil unit for engine and engine provided with plastic head cover

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
NICHTS-ERMITTELT *

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0307665A3 (en) * 1987-09-15 1989-09-13 International Business Machines Corporation Encapsulation composition and use thereof
EP0307665A2 (en) * 1987-09-15 1989-03-22 International Business Machines Corporation Encapsulation composition and use thereof
US5189080A (en) * 1989-04-25 1993-02-23 Robert Bosch Gmbh Epoxy resin composition for encapsulating electric circuit components
DE4138411A1 (en) * 1991-11-22 1993-05-27 Bosch Gmbh Robert HARDENING POWERS
US6030713A (en) * 1994-07-01 2000-02-29 Ciba Specialty Chemicals Corp. Electrical or electronic components encapsulated with liquid epoxy resins containing a mixture of wollastonite and calcite fillers
DE19523897C2 (en) * 1995-06-30 2002-10-24 Bosch Gmbh Robert Use of silicone-modified epoxy resins as casting compounds for electrotechnical or electronic components
DE19523897A1 (en) * 1995-06-30 1997-01-02 Bosch Gmbh Robert Use of silicone-modified epoxy resins as casting compounds for electrotechnical or electronic components
US5965637A (en) * 1995-06-30 1999-10-12 Robert Bosch Gmbh Use of silicone-modified epoxy resins as sealing compound
US6001902A (en) * 1996-03-27 1999-12-14 Ciba Specialty Chemicals Corp. Wollastonite-containing curable epoxy resin mixture
EP0984463A4 (en) * 1997-05-23 2001-03-07 Hitachi Ltd Ignition coil unit for engine and engine provided with plastic head cover
EP1225605A2 (en) * 1997-05-23 2002-07-24 Hitachi, Ltd. Ignition coil for use in engine and engine having plastic cylinder head cover
EP1225605A3 (en) * 1997-05-23 2002-08-28 Hitachi, Ltd. Ignition coil for use in engine and engine having plastic cylinder head cover
EP0984463A1 (en) * 1997-05-23 2000-03-08 Hitachi, Ltd. Ignition coil unit for engine and engine provided with plastic head cover
US6571784B2 (en) 1997-05-23 2003-06-03 Hitachi, Ltd. Ignition coil for use in engine and engine having plastic cylinder head cover

Also Published As

Publication number Publication date
DE3229558C2 (en) 1984-11-08

Similar Documents

Publication Publication Date Title
EP0129819B1 (en) Method of impregnating and enveloping electrical coils
DE3224616A1 (en) HEAT-RADIATING INSULATION FOR THE ELECTRICAL INSULATION OF AN ELECTRICAL WINDING
DE3229558A1 (en) Impregnating and encapsulating composition for electrical components
EP1341847B1 (en) Thermally conductive casting compound
EP1337585B1 (en) Silicone-modified single-component sealing compound
DE102007062035A1 (en) Reactive resin system useful for encapsulating electronic or electrical components comprises an epoxy resin based on a monomer with three epoxy groups and an epoxy resin based on a monomer with at least four epoxy groups
DE2738890C2 (en) Process for the production of moldings and impregnations
EP0658527B1 (en) Process for making a castable ceramic
DE2230645C3 (en) Process for impregnating one or more electrical coils with a curable resin
DE3234544C2 (en) Electrical component with a thermoset insulating layer and method for insulating this component
DE1540133A1 (en) Use of an insulating material composed of two strips for the production of winding insulation, in particular of high-voltage coils
DE3137898A1 (en) Epoxy resin composition for the embedding of components of automobile electronics
DE102008049888B4 (en) Magnetic system positioned in a shroud and method of manufacturing a magnet system
DE102016205386A1 (en) Hardenable epoxy molding compound
DE10223354A1 (en) Fine wire for e.g. ignition coil winding, with insulation resisting partial breakdown, has primary insulation comprising lacquer coating
DE3137883C2 (en) Method for isolating Hall magnetic barriers
DE1490529C3 (en) Process for the production of electrical high-voltage insulators from cast resin
DE1439371A1 (en) Electrical component enveloped by a potting compound or sealed against the environment by means of this, in particular semiconductor rectifier
DE1263928B (en) Process for impregnating and encapsulating electrical coils
DE2409979C3 (en) Lubricant for wires with enamel insulation
DE3030338A1 (en) Pressure-sensitive component partic. annular-core choke - is coated with polybutylene wax mixt. before sealing in can
DE1072663B (en) Multi-layer insulation based on cast resin for electrical components
DE2213119B2 (en) High-voltage insulator made of plastic and having a shield body
DE1261919B (en) Insulating tape, especially mica tape, with a liquid, hardenable epoxy resin binder
DE3008415A1 (en) Electrical conductor insulation with filled resin compsn. - having linear heat expansion coefft. matching that of conductor

Legal Events

Date Code Title Description
OP8 Request for examination as to paragraph 44 patent law
D2 Grant after examination
8364 No opposition during term of opposition
8320 Willingness to grant licences declared (paragraph 23)
8339 Ceased/non-payment of the annual fee