US3668128A - Electrical insulating oil, and to electrical apparatus incorporating them - Google Patents

Electrical insulating oil, and to electrical apparatus incorporating them Download PDF

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Publication number
US3668128A
US3668128A US461A US3668128DA US3668128A US 3668128 A US3668128 A US 3668128A US 461 A US461 A US 461A US 3668128D A US3668128D A US 3668128DA US 3668128 A US3668128 A US 3668128A
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oil
insulating oil
insulating
alkene
percent
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John Kenneth Anderson
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Balfour Beatty PLC
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BICC PLC
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    • 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
    • H01B3/20—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances liquids, e.g. oils
    • H01B3/22—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances liquids, e.g. oils hydrocarbons
    • C—CHEMISTRY; METALLURGY
    • C05—FERTILISERS; MANUFACTURE THEREOF
    • C05B—PHOSPHATIC FERTILISERS
    • C05B11/00—Fertilisers produced by wet-treating or leaching raw materials either with acids in such amounts and concentrations as to yield solutions followed by neutralisation, or with alkaline lyes
    • C05B11/04—Fertilisers produced by wet-treating or leaching raw materials either with acids in such amounts and concentrations as to yield solutions followed by neutralisation, or with alkaline lyes using mineral acid
    • C05B11/08—Fertilisers produced by wet-treating or leaching raw materials either with acids in such amounts and concentrations as to yield solutions followed by neutralisation, or with alkaline lyes using mineral acid using sulfuric acid
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M143/00—Lubricating compositions characterised by the additive being a macromolecular hydrocarbon or such hydrocarbon modified by oxidation
    • C10M143/04—Lubricating compositions characterised by the additive being a macromolecular hydrocarbon or such hydrocarbon modified by oxidation containing propene
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M143/00—Lubricating compositions characterised by the additive being a macromolecular hydrocarbon or such hydrocarbon modified by oxidation
    • C10M143/06—Lubricating compositions characterised by the additive being a macromolecular hydrocarbon or such hydrocarbon modified by oxidation containing butene
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M143/00—Lubricating compositions characterised by the additive being a macromolecular hydrocarbon or such hydrocarbon modified by oxidation
    • C10M143/08—Lubricating compositions characterised by the additive being a macromolecular hydrocarbon or such hydrocarbon modified by oxidation containing aliphatic monomer having more than 4 carbon atoms
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M2203/00—Organic non-macromolecular hydrocarbon compounds and hydrocarbon fractions as ingredients in lubricant compositions
    • C10M2203/10—Petroleum or coal fractions, e.g. tars, solvents, bitumen
    • C10M2203/1006—Petroleum or coal fractions, e.g. tars, solvents, bitumen used as base material
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M2203/00—Organic non-macromolecular hydrocarbon compounds and hydrocarbon fractions as ingredients in lubricant compositions
    • C10M2203/10—Petroleum or coal fractions, e.g. tars, solvents, bitumen
    • C10M2203/102—Aliphatic fractions
    • C10M2203/1025—Aliphatic fractions used as base material
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M2203/00—Organic non-macromolecular hydrocarbon compounds and hydrocarbon fractions as ingredients in lubricant compositions
    • C10M2203/10—Petroleum or coal fractions, e.g. tars, solvents, bitumen
    • C10M2203/106—Naphthenic fractions
    • C10M2203/1065—Naphthenic fractions used as base material
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M2205/00—Organic macromolecular hydrocarbon compounds or fractions, whether or not modified by oxidation as ingredients in lubricant compositions
    • C10M2205/02—Organic macromolecular hydrocarbon compounds or fractions, whether or not modified by oxidation as ingredients in lubricant compositions containing acyclic monomers
    • C10M2205/024—Propene
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M2205/00—Organic macromolecular hydrocarbon compounds or fractions, whether or not modified by oxidation as ingredients in lubricant compositions
    • C10M2205/02—Organic macromolecular hydrocarbon compounds or fractions, whether or not modified by oxidation as ingredients in lubricant compositions containing acyclic monomers
    • C10M2205/026—Butene
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M2205/00—Organic macromolecular hydrocarbon compounds or fractions, whether or not modified by oxidation as ingredients in lubricant compositions
    • C10M2205/02—Organic macromolecular hydrocarbon compounds or fractions, whether or not modified by oxidation as ingredients in lubricant compositions containing acyclic monomers
    • C10M2205/028—Organic macromolecular hydrocarbon compounds or fractions, whether or not modified by oxidation as ingredients in lubricant compositions containing acyclic monomers containing aliphatic monomers having more than four carbon atoms
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
    • C10N2020/00—Specified physical or chemical properties or characteristics, i.e. function, of component of lubricating compositions
    • C10N2020/01—Physico-chemical properties
    • C10N2020/02—Viscosity; Viscosity index
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
    • C10N2020/00—Specified physical or chemical properties or characteristics, i.e. function, of component of lubricating compositions
    • C10N2020/01—Physico-chemical properties
    • C10N2020/04—Molecular weight; Molecular weight distribution
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
    • C10N2030/00—Specified physical or chemical properties which is improved by the additive characterising the lubricating composition, e.g. multifunctional additives
    • C10N2030/10—Inhibition of oxidation, e.g. anti-oxidants
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
    • C10N2040/00—Specified use or application for which the lubricating composition is intended
    • C10N2040/14—Electric or magnetic purposes
    • C10N2040/16—Dielectric; Insulating oil or insulators
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
    • C10N2040/00—Specified use or application for which the lubricating composition is intended
    • C10N2040/14—Electric or magnetic purposes
    • C10N2040/17—Electric or magnetic purposes for electric contacts

Definitions

  • the polymer is derived predomi- 5 nantly from an alkene or alkenes having from three to five car- 1 gi bon atoms and has an average molecular weight in the range 100-900, preferably in the range 250-500.
  • a mixture of such alkene polymers may be used.
  • the hydrocarbon oil is [56] References cued preferably a mineral oil, and has a viscosity of 30 centistokes UNlTED STATES PATENTS or less at 3,163,705 12/1964 Feick ..252/63 17 Claims, No Drawings ELECTRICAL INSULATING OIL, AND TO ELECTRICAL APPARATUS INCORPORATING THEM
  • the present invention relates to electric insulating oils and more especially, but not exclusively, to oils based on selected and refined mineral oils.
  • the invention is especially concerned with oils for use in the impregnation of the dielectric of power cables (chiefly paper-insulated power cables) and of other electrical apparatus, such as capacitors and transformers.
  • mineral oil having a low aromatic content In order to obtain a low power factor and a high degreeof resistance to oxidation, it is desirable to use a mineral oil having a low aromatic content.
  • mineral oil having an aromatic content of less than about 7 percent is not readily available, and it is preferable that the aromatic content should be asrclose as possible to this figure, and preferably below it if and when such oil becomes available.
  • mineral oils of low aromatic content have a tendency to evolve gas, predominately hydrogen, under the influence of an electric field, contributing to the formation of gas-filled voids in which discharges occur, leading to degration and ultimately to complete breakdown of the insulation. Similar difiiculties arise with some types of synthetic hydrocarbon oil.
  • Such gassing is reduced and preferably avoided by adding to the oil a constituent which will react with and so absorb nascent hydrogen, and oils containing such a constituent are known, and will hereinafter be referred to, as non-gassing.
  • the added constituent will for convenience be referred to as the additive.
  • an insulating oil which has good resistance to oxidation and which is also nongassing and of low viscosity comprises from l-5O percent (by weight) of a residually unsaturated alkene polymer derived predominately from an alkene or alkenes having from three to five carbon atoms (or a mixture of such alkene polymers) the or each polymer having an average molecular weight in the range l-900, and correspondingly from 9950 percent of a low viscosity hydrocarbon oil which has a viscosity of 20 centistokes or less at 20 C., and would gas if used alone.
  • the hydrocarbon oil is preferably a refined mineral oil which is preferably predominately napthenic in character or of mixed napthenic/parafi'mic composition, and preferably of low aromatic content.
  • a mineral oil having a low power factor and high oxidation resistance is preferred.
  • the alkene polymer may include a small number of units derived from ethylene and/or from higher alkenes. Polymers derived predominately from butenes are preferred.
  • the average molecular weight of the alkene polymer is preferably below 700 and more especially in the range 250-500. An average molecular weight of about 350 is suitable.
  • the preferred amount of the additive depends, subject to satisfactory non-gassing properties, upon it molecular weight and upon the viscosity desired.
  • molecular weight of additive is in the preferred range of 250-500, addition of from -15 percent is suitable for oils for use in oil-filled cables having internal oil channels, and from 10-40 percent for oils for use either in accessories of such cables or in pipe-type cables.
  • the invention includes electrical apparatus comprising a body of porous and/or laminated insulating material impregnated with the oils described; it further includes oil-filled paper insulated electric cables in which the paper is impregnated with the oils described.
  • the amount of additive required for any desired degree of gas absorption is less than when conventional additives of the aromatic type are used.
  • the viscosity of the oil can be controlled at a low value
  • the additive has no appreciable deleterious effect and may on the contrary have a beneficial effect on the oxidative stability or electrical properties of the oil;
  • theadditive is formed as aby-product in the manufacture of alkylene polymers of high molecular weight, and is therefore relatively inexpensive;
  • the oil is less sensitive that conventional, oils to the presence of traces of moisture.
  • oils A and D are examples of selected refinednaphthenic mineral. base oils, sold by the Burmah Oil Trading C0,, Dussek Division under the designations T3252 andT 3251-. respectively, oils B, B1 and E examples of oils in accordance with the invention for oil-filled cables of the type having internaloil channels and oils C and F examples of accessory oils in accordance with the invention.
  • the polybutene additive in oils B, C, E and F is a commercial polybutene sold under the Trade Name PQLYVIS 00v and having an average molecular weight of 350 and a viscosity at 20 C. of 120 centistokes.
  • the polybutene additive in Oil B1 is another commercial polybutene having an average molecular weight of 300.
  • An insulating oil which has good resistance to oxidation and which is also non-gassing and of low viscosity comprising a. from l-50 percent by weight of at least one residually unsaturated alkene polymer having an average molecular weight in the range lOO-900, and derived predominately from at least one alkene having from three to five carbon atoms and b. correspondingly from 99-50 percent of a low viscosity hydrocarbon oil which has a viscosity of 30 centistokes or less at C. and would gas if used alone.
  • Electrical apparatus comprising a body of insulating material impregnated with the insulating oil claimed in claim 1.
  • An insulating oil which has good resistance to oxidation and which is also non-gassing and of low viscosity comprising a. from 1-50 percent by weight of at least one residually unsaturated alkene polymer'having an average molecular weight in the range 100-900, and derived predominately from at least one alkene having from three to five carbon atoms and b. correspondingly from 99-50 percent of a low viscosity refined mineral oil having a viscosity of 30 centistokes or less at 20 C.
  • An insulating oil as claimed in claim 8 in which the molecular weight of said alkene polymer is in the range 250-500.
  • An insulating oil as claimed in claim 9 suitable for use in accessories of oil-filled cables having internal oil channels and for use in pipe-type cables and comprising from 10-40 percent of said alkene polymer.
  • An insulating oil as claimed in claim 9 suitable for use in oil-filled cables having internal oil channels comprising from 5-15 percent by weight of said alkene polymer, and correspondingly from -85 percent of said low viscosity refined mineral oil.
  • Electrical apparatus comprising a body of insulating material impregnated with the insulating oil as claimed in claim 6.

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  • Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Organic Insulating Materials (AREA)

Abstract

An insulating oil which has good resistance to oxidation and which is also non-gassing and of low viscosity comprises from 150 percent (by weight) of a residually unsaturated alkene polymer, and correspondingly from 99-50 percent of a low viscosity hydrocarbon oil. The polymer is derived predominantly from an alkene or alkenes having from three to five carbon atoms and has an average molecular weight in the range 100-900, preferably in the range 250-500. A mixture of such alkene polymers may be used. The hydrocarbon oil is preferably a mineral oil, and has a viscosity of 30 centistokes or less at 20* C.

Description

I United States Patent [151 3,668,128 Anderson 5] June 6, 1972 [54] ELECTRICAL INSULATING OIL, AND 3,573,209 3 1971 de Dryven .252/63 TO ELECTRICAL APPARATUS 3,318,799 5/1967 Acker..... INCORPORATING THEM 2,719,182 9/1955 Ross ..252/63 X 2,870,385 1/1959 Rice ..252/63 X [72] Inventor: John Kenneth Anderson, Bexley, England 2921 01 1 H 9 0 ordeltmu 252 X Assigneez British Insulated Callendervs Robinson X Limited, London, England Primary Examiner-Robert F. Burnett [22] Filed: Jan. 2, 1970 Assistant Examiner-M. E. McCamish [21] APP] NW 461 Attorney-Buell, Blenko and Ziesenheim [57] ABSTRACT [30] Foreign Application Priority Data An insulating oil which has good resistance to oxidation and Jan. 9, 1969 Great Britain ..1,298/69 which is also nomgassing and f km viscosity comprises from 1-50 percent (by weight) of a residually unsaturated alkene [52] US. Cl ..252/63, 1 17/154, 1 17/201, polymer, and correspondingly from 99 50 Percent of a low 51 174/25 203/14 viscosity hydrocarbon oil. The polymer is derived predomi- 5 nantly from an alkene or alkenes having from three to five car- 1 gi bon atoms and has an average molecular weight in the range 100-900, preferably in the range 250-500. A mixture of such alkene polymers may be used. The hydrocarbon oil is [56] References cued preferably a mineral oil, and has a viscosity of 30 centistokes UNlTED STATES PATENTS or less at 3,163,705 12/1964 Feick ..252/63 17 Claims, No Drawings ELECTRICAL INSULATING OIL, AND TO ELECTRICAL APPARATUS INCORPORATING THEM The present invention relates to electric insulating oils and more especially, but not exclusively, to oils based on selected and refined mineral oils. The invention is especially concerned with oils for use in the impregnation of the dielectric of power cables (chiefly paper-insulated power cables) and of other electrical apparatus, such as capacitors and transformers.
In order to obtain a low power factor and a high degreeof resistance to oxidation, it is desirable to use a mineral oil having a low aromatic content. At the present time mineral oil having an aromatic content of less than about 7 percent is not readily available, and it is preferable that the aromatic content should be asrclose as possible to this figure, and preferably below it if and when such oil becomes available. However, it is found that mineral oils of low aromatic content have a tendency to evolve gas, predominately hydrogen, under the influence of an electric field, contributing to the formation of gas-filled voids in which discharges occur, leading to degration and ultimately to complete breakdown of the insulation. Similar difiiculties arise with some types of synthetic hydrocarbon oil.
Such gassing is reduced and preferably avoided by adding to the oil a constituent which will react with and so absorb nascent hydrogen, and oils containing such a constituent are known, and will hereinafter be referred to, as non-gassing. The added constituent will for convenience be referred to as the additive.
Hitherto, when an oil of low viscosity (e.g., below 40 centistokes at 20 C.) was required, aromatic additives, conventionally napthalenic extracts of petroleum, have been used, with the result that the power factor of the oil was raised, and its oxidation resistance decreased,
In accordance with the present invention, an insulating oil which has good resistance to oxidation and which is also nongassing and of low viscosity comprises from l-5O percent (by weight) of a residually unsaturated alkene polymer derived predominately from an alkene or alkenes having from three to five carbon atoms (or a mixture of such alkene polymers) the or each polymer having an average molecular weight in the range l-900, and correspondingly from 9950 percent of a low viscosity hydrocarbon oil which has a viscosity of 20 centistokes or less at 20 C., and would gas if used alone.
The hydrocarbon oil is preferably a refined mineral oil which is preferably predominately napthenic in character or of mixed napthenic/parafi'mic composition, and preferably of low aromatic content. Naturally, a mineral oil having a low power factor and high oxidation resistance is preferred.
In addition to propene, butylenes and/or amylenes, the alkene polymer may include a small number of units derived from ethylene and/or from higher alkenes. Polymers derived predominately from butenes are preferred.
The average molecular weight of the alkene polymer is preferably below 700 and more especially in the range 250-500. An average molecular weight of about 350 is suitable.
The preferred amount of the additive depends, subject to satisfactory non-gassing properties, upon it molecular weight and upon the viscosity desired. When the molecular weight of additive is in the preferred range of 250-500, addition of from -15 percent is suitable for oils for use in oil-filled cables having internal oil channels, and from 10-40 percent for oils for use either in accessories of such cables or in pipe-type cables.
The invention includes electrical apparatus comprising a body of porous and/or laminated insulating material impregnated with the oils described; it further includes oil-filled paper insulated electric cables in which the paper is impregnated with the oils described.
The principal advantages of the insulating oils in accordance with the invention may be summarized as follows:
i. the amount of additive required for any desired degree of gas absorption is less than when conventional additives of the aromatic type are used.
ii. the viscosity of the oil can be controlled at a low value;
iii. the additive has no appreciable deleterious effect and may on the contrary have a beneficial effect on the oxidative stability or electrical properties of the oil;
iv. theadditive is formed as aby-product in the manufacture of alkylene polymers of high molecular weight, and is therefore relatively inexpensive;
v. the low temperature hydraulic behavior of the oil is good, and in particular its pour point is not unduly raised; and,
vi. under conditions of electric stress, the oil is less sensitive that conventional, oils to the presence of traces of moisture.
In the following tables, oils A and D are examples of selected refinednaphthenic mineral. base oils, sold by the Burmah Oil Trading C0,, Dussek Division under the designations T3252 andT 3251-. respectively, oils B, B1 and E examples of oils in accordance with the invention for oil-filled cables of the type having internaloil channels and oils C and F examples of accessory oils in accordance with the invention. The polybutene additive in oils B, C, E and F is a commercial polybutene sold under the Trade Name PQLYVIS 00v and having an average molecular weight of 350 and a viscosity at 20 C. of 120 centistokes. The polybutene additive in Oil B1 is another commercial polybutene having an average molecular weight of 300.
TABLE I Oil A B Bl C Mineral Oil 100% 87% 70% Content Oil A Oil A Oil A Polybutene Nil 10% 13% 30% additive content Viscosity (CS) at 20C. 5.5 6.0 6.0 l l 60C. 2.0 2.3 2.3 3.6 Specific Gravity at 0.86 0.86 0.86 0.85
20C. Flash Point (closedcup) I10 I10 H0 H0 C. (Typical Pour Point C. 85 75 75 64 Gassing characevolving nonnon- Strongly ter in range evolving evolving non- 0-l 30C. evolving TABLE II Oil D E F Mineral oil 90% 70% content D Oil Oil D Polybutene additive Nil 10% 30% content Viscosity (cS) at 20C. l4 17 27 60C. 4.5 5.2 6.2 Specific gravity at 20C. 0.88 0.87 0.86 Flash point (closed cup) "C. (Typical) 130 28 Pour Point C. 65 62 -57 Gassing character evolving non- Strongly in range evolving non- 0- l 30 C. evolving What I claim as my invention is: 1. An insulating oil which has good resistance to oxidation and which is also non-gassing and of low viscosity comprising a. from l-50 percent by weight of at least one residually unsaturated alkene polymer having an average molecular weight in the range lOO-900, and derived predominately from at least one alkene having from three to five carbon atoms and b. correspondingly from 99-50 percent of a low viscosity hydrocarbon oil which has a viscosity of 30 centistokes or less at C. and would gas if used alone.
2. An insulating oil as claimed in claim 1 in which the molecular weight of said alkene polymer is in the range 3. An insulating oil as claimed .in claim 2 in which the molecular weight of said alkene polymer is in the range 250-500.
4. Electrical apparatus comprising a body of insulating material impregnated with the insulating oil claimed in claim 1.
5. An oil-filled paper insulated electric cable in which the paper is impregnated with the insulating oil claimed in claim 1.
6. An insulating oil which has good resistance to oxidation and which is also non-gassing and of low viscosity comprising a. from 1-50 percent by weight of at least one residually unsaturated alkene polymer'having an average molecular weight in the range 100-900, and derived predominately from at least one alkene having from three to five carbon atoms and b. correspondingly from 99-50 percent of a low viscosity refined mineral oil having a viscosity of 30 centistokes or less at 20 C.
7. An insulating oil as claimed in claim 6 in which said alkene is butene.
8 An insulating oil as claimed in claim 6 in which the molecular weight of said alkene polymer is in the range 100-700.
9. An insulating oil as claimed in claim 8 in which the molecular weight of said alkene polymer is in the range 250-500.
10. An insulating oil as claimed in claim 9 suitable for use in accessories of oil-filled cables having internal oil channels and for use in pipe-type cables and comprising from 10-40 percent of said alkene polymer.
11. An insulating oil as claimed in claim 9 suitable for use in oil-filled cables having internal oil channels comprising from 5-15 percent by weight of said alkene polymer, and correspondingly from -85 percent of said low viscosity refined mineral oil.
12. An insulating oil as claimed in claim 11 in which said alkene polymer is a polybutene.
13. An oil-filled paper-insulated electric cable in which the paper is impregnated with the insulating oil claimed in claim ll.
14. An insulating oil as claimed in claim 6 in which the refined mineral oil is predominately naphthenic in character.
15. An insulating oil as claimed in claim 6 in which the refined mineral oil is of mixed naphthenic/paraffinic composition.
16. Electrical apparatus comprising a body of insulating material impregnated with the insulating oil as claimed in claim 6.
17. An oil-filled paper insulated electric cable in which the paper is impregnated with the insulating oil claimed in claim 6.

Claims (16)

  1. 2. An insulating oil as claimed in claim 1 in which the molecular weight of said alkene polymer is in the range 100-700.
  2. 3. An insulating oil as claimed in claim 2 in which the molecular weight of said alkene polymer is in the range 250-500.
  3. 4. Electrical apparatus comprising a body of insulating material impregnated with the insulating oil claimed in claim 1.
  4. 5. An oil-filled paper insulated electric cable in which the paper is impregnated with the insulating oil claimed in claim 1.
  5. 6. An insulating oil which has good resistance to oxidation and which is also non-gassing and of low viscosity comprising a. from 1-50 percent by weight of at least one residually unsaturated alkene polymer having an average molecular weight in the range 100-900, and derived predominately from at least one alkene having from three to five carbon atoms and b. correspondingly from 99-50 percent of a low viscosity refined mineral oil having a viscosity of 30 centistokes or less at 20* C.
  6. 7. An insulating oil as claimed in claim 6 in which said alkene is butene.
  7. 8. An insulating oil as claimed in claim 6 in which the molecular weight of said alkene polymer is in the range 100-700.
  8. 9. An insulating oil as claimed in claim 8 in which the molecular weight of said alkene polymer is in the range 250-500.
  9. 10. An insulating oil as claimed in claim 9 suitable for use in accessories of oil-filled cables having internal oil channels and for use in pipe-type cables and comprising from 10-40 percent of said alkene polymer.
  10. 11. An insulating oil as claimed in claim 9 suitable for use in oil-filled cables having internal oil channels comprising from 5-15 percent by weight of said alkene polymer, and correspondingly from 95-85 percent of said low viscosity refined mineral oil.
  11. 12. An insulating oil as claimed in claim 11 in which said alkene polymer is a polybutene.
  12. 13. An oil-filled paper-insulated electric cable in which the paper is impregnated with the insulating oil claimed in claim 11.
  13. 14. An insulating oil as claimed in claim 6 in which the refined mineral oil is predominately naphthEnic in character.
  14. 15. An insulating oil as claimed in claim 6 in which the refined mineral oil is of mixed naphthenic/paraffinic composition.
  15. 16. Electrical apparatus comprising a body of insulating material impregnated with the insulating oil as claimed in claim 6.
  16. 17. An oil-filled paper insulated electric cable in which the paper is impregnated with the insulating oil claimed in claim 6.
US461A 1969-01-09 1970-01-02 Electrical insulating oil, and to electrical apparatus incorporating them Expired - Lifetime US3668128A (en)

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Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3930112A (en) * 1974-03-25 1975-12-30 Pirelli Mixed fluid impregnant for oil filled electric cables
DE2704277A1 (en) * 1976-02-03 1977-08-04 Nippon Oil Co Ltd ELECTRIC INSULATING OIL MIXTURES
DE2719218A1 (en) * 1976-05-01 1977-11-17 Nippon Oil Co Ltd ELECTRIC INSULATING OIL
US4189391A (en) * 1976-05-01 1980-02-19 Nippon Oil Co., Ltd. Electrical insulating oil compositions
US4417093A (en) * 1981-01-14 1983-11-22 Societa Cavi Pirelli S.P.A. High voltage direct current cable with impregnated tape insulation
WO1999033066A1 (en) * 1997-12-22 1999-07-01 Abb Ab A dielectric gelling composition, a method of manufacturing such a dielectric gelling composition and an electric dc-cable comprising an insulation system impregnated with such a dielectric gelling composition
WO1999033067A1 (en) * 1997-12-22 1999-07-01 Abb Ab Dielectric gelling composition, the use of such dielectric gelling composition, an insulated electric dc-cable comprising such gelling composition and a method for manufacturing an insulated electric dc-cable comprising such gelling composition
WO1999033068A1 (en) * 1997-12-22 1999-07-01 Abb Ab An insulated electric direct current cable
US6245426B1 (en) 1996-07-04 2001-06-12 Abb Research Ltd. Electric device with a porous conductor insulation impregnated with a dielectric fluid exhibiting a rheologic transition point
US20090036337A1 (en) * 2007-07-31 2009-02-05 Chevron U.S.A. Inc. Electrical Insulating Oil Compositions and Preparation Thereof

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JPH0834066B2 (en) * 1990-01-29 1996-03-29 株式会社関西テツク Electrical insulating oil

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US2719182A (en) * 1951-12-28 1955-09-27 Sprague Electric Co Dielectric compositions
US2870385A (en) * 1956-02-02 1959-01-20 Sprague Electric Co Impregnated electrical capacitors
US2921011A (en) * 1955-04-29 1960-01-12 British Petroleum Co Insulating oil compositions
US2993156A (en) * 1956-05-24 1961-07-18 Sprague Electric Co Capacitor dielectric
US3163705A (en) * 1959-08-21 1964-12-29 Anaconda Wire & Cable Co Oil insulated impregnant for high voltage electrical apparatus
US3318799A (en) * 1963-10-31 1967-05-09 Exxon Research Engineering Co Process for obtaining mineral oils with improved resistance to oxidation
US3573209A (en) * 1963-07-22 1971-03-30 Exxon Standard Sa Insulating compositions and materials

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Publication number Priority date Publication date Assignee Title
US2719182A (en) * 1951-12-28 1955-09-27 Sprague Electric Co Dielectric compositions
US2921011A (en) * 1955-04-29 1960-01-12 British Petroleum Co Insulating oil compositions
US2870385A (en) * 1956-02-02 1959-01-20 Sprague Electric Co Impregnated electrical capacitors
US2993156A (en) * 1956-05-24 1961-07-18 Sprague Electric Co Capacitor dielectric
US3163705A (en) * 1959-08-21 1964-12-29 Anaconda Wire & Cable Co Oil insulated impregnant for high voltage electrical apparatus
US3573209A (en) * 1963-07-22 1971-03-30 Exxon Standard Sa Insulating compositions and materials
US3318799A (en) * 1963-10-31 1967-05-09 Exxon Research Engineering Co Process for obtaining mineral oils with improved resistance to oxidation

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3930112A (en) * 1974-03-25 1975-12-30 Pirelli Mixed fluid impregnant for oil filled electric cables
DE2704277A1 (en) * 1976-02-03 1977-08-04 Nippon Oil Co Ltd ELECTRIC INSULATING OIL MIXTURES
US4070297A (en) * 1976-02-03 1978-01-24 Nippon Oil Co., Ltd. Electrical insulating oil compositions
DE2719218A1 (en) * 1976-05-01 1977-11-17 Nippon Oil Co Ltd ELECTRIC INSULATING OIL
US4189391A (en) * 1976-05-01 1980-02-19 Nippon Oil Co., Ltd. Electrical insulating oil compositions
US4417093A (en) * 1981-01-14 1983-11-22 Societa Cavi Pirelli S.P.A. High voltage direct current cable with impregnated tape insulation
US6245426B1 (en) 1996-07-04 2001-06-12 Abb Research Ltd. Electric device with a porous conductor insulation impregnated with a dielectric fluid exhibiting a rheologic transition point
WO1999033066A1 (en) * 1997-12-22 1999-07-01 Abb Ab A dielectric gelling composition, a method of manufacturing such a dielectric gelling composition and an electric dc-cable comprising an insulation system impregnated with such a dielectric gelling composition
WO1999033067A1 (en) * 1997-12-22 1999-07-01 Abb Ab Dielectric gelling composition, the use of such dielectric gelling composition, an insulated electric dc-cable comprising such gelling composition and a method for manufacturing an insulated electric dc-cable comprising such gelling composition
WO1999033068A1 (en) * 1997-12-22 1999-07-01 Abb Ab An insulated electric direct current cable
US20090036337A1 (en) * 2007-07-31 2009-02-05 Chevron U.S.A. Inc. Electrical Insulating Oil Compositions and Preparation Thereof

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