US2834734A - Liquid electrical insulating compositions - Google Patents
Liquid electrical insulating compositions Download PDFInfo
- Publication number
- US2834734A US2834734A US591781A US59178156A US2834734A US 2834734 A US2834734 A US 2834734A US 591781 A US591781 A US 591781A US 59178156 A US59178156 A US 59178156A US 2834734 A US2834734 A US 2834734A
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- United States
- Prior art keywords
- oil
- gas
- gassing
- insulating
- electrical insulating
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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
-
- 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
- C10M1/00—Liquid compositions essentially based on mineral lubricating oils or fatty oils; Their use as lubricants
- C10M1/08—Liquid compositions essentially based on mineral lubricating oils or fatty oils; Their use as lubricants with additives
-
- 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
- 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
- C10M2203/02—Well-defined aliphatic compounds
-
- 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
- C10M2203/02—Well-defined aliphatic compounds
- C10M2203/022—Well-defined aliphatic compounds saturated
-
- 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
- C10M2203/02—Well-defined aliphatic compounds
- C10M2203/024—Well-defined aliphatic compounds unsaturated
-
- 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
- C10M2203/04—Well-defined cycloaliphatic compounds
-
- 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
- C10M2203/06—Well-defined aromatic compounds
-
- 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
- C10M2203/104—Aromatic fractions
-
- 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
-
- 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
- C10M2207/00—Organic non-macromolecular hydrocarbon compounds containing hydrogen, carbon and oxygen as ingredients in lubricant compositions
- C10M2207/02—Hydroxy compounds
- C10M2207/023—Hydroxy compounds having hydroxy groups bound to carbon atoms of six-membered aromatic rings
-
- 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
- C10M2207/00—Organic non-macromolecular hydrocarbon compounds containing hydrogen, carbon and oxygen as ingredients in lubricant compositions
- C10M2207/02—Hydroxy compounds
- C10M2207/023—Hydroxy compounds having hydroxy groups bound to carbon atoms of six-membered aromatic rings
- C10M2207/026—Hydroxy compounds having hydroxy groups bound to carbon atoms of six-membered aromatic rings with tertiary alkyl groups
-
- 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
- This invention relates to an improved insulating oil composition and more particularly to insulating oil compositions which are stable, non-sludging and resistant to gassing.
- Highly refined oils which consist mainly of saturated hydrocarbons tend to evolve relatively large volumes of hydrogen containing gas when subjected to electrical stress at an oil/ gas interface. This gas evolution can be inhibited by the presence in the oil of aromatic hydrocarbons whose vapor pressures permit them to be present in sufiicient concentration in the vapor phase.
- the amount of aromatic hydrocarbons which can be present for this purpose is, however, limited by the adverse effect of the aromatic hydrocarbons on the aging and sludging tendencies of the oil.
- electrical oils containing aromatic hydrocarbons produced by refining techniques generally do not contain sufiicient aromatic hydrocarbons of suitable vapor pressure to inhibit gas evolution completely although the total content of aromatic hydrocarbons may be relatively high, for example, up to 20%, depending on the nature of the original oil.
- unsaturated aliphatic hydrocarbons to inhibit gas evolution which has also been proposed, has similar disadvantages and insulating oils containing unsaturated aliphatic hydrocarbons are not in general produced in refinery practice.
- an insulating oil which is gas evolving under conditions of high electrical stress can be converted into a gas absorbing oil by addition to an insulating oil, a minor amount of a non-aromatic cyclopentene compounds having a boiling point above 150 C. at atmospheric pressure and a vapor pressure greater than that of the base oil such as dicyclopentadiene and C -C alkyl fulvenes.
- the gas evolving electrical insulating oil used in the compositions of the invention is one of the usual types of insulating oils commonly employed in electrical cables, switches, transformers, capacitors and other electrotechnical apparatus. It may be a highly refined, substantially saturated oil or a petroleum distillate fraction which has been refined by solvent extraction and treatment with sulfuric acid and adsorbent earth and contains a proportion of aromatic hydrocarbons.
- Efiective non-aromatic containing cyclopentenes for use in the compositions of the invention are dicyclopentadiene or alkyl-substituted cyclopentadienes, and more particularly cyclopentadienes obtained by replacing one or more hydrogen atoms of the cyclopentadiene ring by an alkyl group or groups, which substances are effective in producing an oil of the desired gas absorbing characteristics.
- Compounds of this type include dicyclopentadiene, methylisobutylfulvene, diisobutylfulvene, octylfulvene and the like.
- Particularly suitable compounds of this type are the fulvenes which are obtainable by the alkali-catalyzed condensation of aldehydes and ketones with cyclopentadiene, as for example, dimethylfulvene, B. P. 46 C. at 11 millimeters of mercury pressure, methylethylfulvene, B. P. 185 C. and methylisobutylfulvene, B. P. 78 C. at millimeters of mercury pressure.
- the cyclopentenes in general constitute from about 0.01% to not more than about 2% and preferably from less than 1% and usually from 0.2% to 0.5% by weight of the compositions of this invention.
- the Thornton modified gassing apparatus is a modification of the B. P. M.-Pirelli Apparatus. Particulars of both apparatus and of the experimental procedure are given in an article in the Journal of the Institute of Petroleum, 1949, 35, 735-753, particularly pages 736-7 and 740-1, by G. H. Beavan, I. A.
- Vac-V10 Gasslng coeliicient milliliters per minute cording to the procedure set out in British Standards has a higher acidity than the other oils.
- compositions of this invention which possess nonsludging and non-gassing properties include. transformer oils containing from 0.2% to 0.5% by weight of dicyclopentadiene, C -C alkyl-substituted cyclopentadiene or C -C alkyl-substituted fulvene and mixtures thereof.
- compositions of the invention possess satisfactory oxidation and electrical characteristics. desired, how:
- a suitable anti-oxidant such as 2,6-di-tert.- butyl-4-methylphenol or 2,4-dimethyl-6-tert.-butylphenol.
- a minor amount of a corrosion inhibitor may be incorporated, for example, an oil-soluble compound capable of ichelating metal ions.
- a liquid dielectric composition comprising a major amount of a gas evolving electric insulating solvent refined, acid treated and adsorbent earth treated mineral oil containing from about 0.01% to about 2% of a nonaromatic cyclopentene compound selected from the group consisting of- C C alkyl fulvene and dicyclopentadiene.
- a liquid dielectric composition comprising a major amount of a gas evolving electric insulating solvent refined, acid treated and adsorbent earth treated mineral oil containing from about 0.01% to about 2% of a C -C alkyl fulvene.
- a non-gassing liquid dielectric composition comprising a major amount of an-electric insulating solvent refined, acid treated and adsorbent earth treated mineral oil containing from about 0.01% to about 2% of dicyclopentadiene.
- A. non-gassing liquid dielectric composition comprising a major amount of an electric insulating solvent refined, acid treated and adsorbent earth treated mineral oil containing from about 0.01% to about 2% of methylisobutylfulvene.
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- Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Physics & Mathematics (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Organic Insulating Materials (AREA)
- Solid-Sorbent Or Filter-Aiding Compositions (AREA)
Description
Unite States Patent LIQUID ELECTRICAL INSULATING COMPOSITIONS Vernon Warner David, Chester, and Robert Irving, Great St. Helens, London, England, assignors to Shell Development Company, New York, N. Y., a corporation of Delaware No Drawing. Application June 18, 1956 Serial No. 591,781
Claims priority, application Great Britain AugustlZ, 1%5
4 Claims. (Cl. 252-63) This invention relates to an improved insulating oil composition and more particularly to insulating oil compositions which are stable, non-sludging and resistant to gassing.
It is well known that when hydrocarbon insulating oils used in electrotechnical apparatus, such as cables, transformers and capacitors, are subjected to high electrical stress at an oil/ gas interface, they tend todecompose producing, inter alia, gaseous products consisting mainly of hydrogen. This evolution of gas is undesirable since it may cause serious damage. Thus, bubbles of gas in the insulating oil permit local discharges in which electrical energy is dissipated as heat and in which the ions produced in the discharge and accelerated by the local electric field bombard the oil or its vapor withconsequent further decomposition of the oil and eventual failure of the apparatus.
Highly refined oils which consist mainly of saturated hydrocarbons tend to evolve relatively large volumes of hydrogen containing gas when subjected to electrical stress at an oil/ gas interface. This gas evolution can be inhibited by the presence in the oil of aromatic hydrocarbons whose vapor pressures permit them to be present in sufiicient concentration in the vapor phase. The amount of aromatic hydrocarbons which can be present for this purpose is, however, limited by the adverse effect of the aromatic hydrocarbons on the aging and sludging tendencies of the oil. In consequence electrical oils containing aromatic hydrocarbons produced by refining techniques generally do not contain sufiicient aromatic hydrocarbons of suitable vapor pressure to inhibit gas evolution completely although the total content of aromatic hydrocarbons may be relatively high, for example, up to 20%, depending on the nature of the original oil. The use of unsaturated aliphatic hydrocarbons to inhibit gas evolution, which has also been proposed, has similar disadvantages and insulating oils containing unsaturated aliphatic hydrocarbons are not in general produced in refinery practice.
It has now been found that an insulating oil which is gas evolving under conditions of high electrical stress can be converted into a gas absorbing oil by addition to an insulating oil, a minor amount of a non-aromatic cyclopentene compounds having a boiling point above 150 C. at atmospheric pressure and a vapor pressure greater than that of the base oil such as dicyclopentadiene and C -C alkyl fulvenes.
The gas evolving electrical insulating oil used in the compositions of the invention is one of the usual types of insulating oils commonly employed in electrical cables, switches, transformers, capacitors and other electrotechnical apparatus. It may be a highly refined, substantially saturated oil or a petroleum distillate fraction which has been refined by solvent extraction and treatment with sulfuric acid and adsorbent earth and contains a proportion of aromatic hydrocarbons.
Efiective non-aromatic containing cyclopentenes for use in the compositions of the invention are dicyclopentadiene or alkyl-substituted cyclopentadienes, and more particularly cyclopentadienes obtained by replacing one or more hydrogen atoms of the cyclopentadiene ring by an alkyl group or groups, which substances are effective in producing an oil of the desired gas absorbing characteristics. Compounds of this type include dicyclopentadiene, methylisobutylfulvene, diisobutylfulvene, octylfulvene and the like.
Particularly suitable compounds of this type are the fulvenes which are obtainable by the alkali-catalyzed condensation of aldehydes and ketones with cyclopentadiene, as for example, dimethylfulvene, B. P. 46 C. at 11 millimeters of mercury pressure, methylethylfulvene, B. P. 185 C. and methylisobutylfulvene, B. P. 78 C. at millimeters of mercury pressure.
The cyclopentenes in general constitute from about 0.01% to not more than about 2% and preferably from less than 1% and usually from 0.2% to 0.5% by weight of the compositions of this invention.
The terms gas evolving and gas absorbing as used in this specification and the claims mean that the oil, when heated to 50 C. and subjected to an applied voltage of 10 kv. in the Thornton modified gassing apparatus has respectively a positive or a negative gassing coefficient as defined by the equation Gassing coefficient= where V and V are the volumes of gas (in milliliters) evolved at '60 minutes and 10 minutes, respectively. The Thornton modified gassing apparatus is a modification of the B. P. M.-Pirelli Apparatus. Particulars of both apparatus and of the experimental procedure are given in an article in the Journal of the Institute of Petroleum, 1949, 35, 735-753, particularly pages 736-7 and 740-1, by G. H. Beavan, I. A. Cockburn and C. N. Thompson and entitled The evaluation of gassing tendencies of insulating oils: Apparatus, procedures and eifect of experimental variables. It is to be noted, however, that the gassing coefficient is defined in this specification by the equation given above and not as given in this article.
The effectiveness of the above particular cyclopentenes in promoting gas absorbing characteristics in a normally gas evolving electrical insulating oil is illustrated in the following Table l which summarizes the results of tests carried out in the Thornton modified gassing apparatus referred to previously in this specification. The base oil used in these tests was a solvent refined, acidand adsorbent earth-treated petroleum distillate having a viscosity of approximately 45 seconds Redwood I at F. and containing about 11% of aromatic hydrocarbons.
Table I milliliters per minute Concentration, percent wt.
Gassing 1 (ml./minute) Additive None Metgylisobutylfulvene 1 Defined by the equation:
Vac-V10 Gasslng coeliicient= milliliters per minute cording to the procedure set out in British Standards has a higher acidity than the other oils. The addition of only 0.5% by weight of dicyclopentadiene to the oil of 11% aromatic content is, however, sufficient to convert the-gas evolving oil into a gasabsorbing oil which, more-' over, has satisfactory oxidation characteristics.
TABLE II B. S. 148: 1951 oxidation characteristics and gassing properties of certain insulating oils Gassing Oil Coeflicient Sludge Acidity (mL/min.) (percent (mg.
Wt.) KOH/g.)
Oil containing 11% aromatics.---- 0. 73 1. 25 +0. 011 011 containing 11% aromatics+ 0.5% wt. dicyclopentadienefln. 0. 82 1. 20 0. 022 Oil containing 30% aromatics. l. 67 1. 75 -0. 012
B. S. 148: 1951 Specificationlimita. 1.1 (ESL) 2.5 (max) Other compositions of this invention which possess nonsludging and non-gassing properties include. transformer oils containing from 0.2% to 0.5% by weight of dicyclopentadiene, C -C alkyl-substituted cyclopentadiene or C -C alkyl-substituted fulvene and mixtures thereof.
The compositions of the invention possess satisfactory oxidation and electrical characteristics. desired, how:
ever, minor proportions of from about 0.01% to about 1%, as for example, 0.3 percent by weight, of a suitable anti-oxidant may be incorporated, such as 2,6-di-tert.- butyl-4-methylphenol or 2,4-dimethyl-6-tert.-butylphenol.
Advantageously also, a minor amount of a corrosion inhibitor may be incorporated, for example, an oil-soluble compound capable of ichelating metal ions.
We claim as our invention: v
1. A liquid dielectric composition comprising a major amount of a gas evolving electric insulating solvent refined, acid treated and adsorbent earth treated mineral oil containing from about 0.01% to about 2% of a nonaromatic cyclopentene compound selected from the group consisting of- C C alkyl fulvene and dicyclopentadiene.
2. A liquid dielectric composition comprising a major amount of a gas evolving electric insulating solvent refined, acid treated and adsorbent earth treated mineral oil containing from about 0.01% to about 2% of a C -C alkyl fulvene.
3. A non-gassing liquid dielectric composition comprising a major amount of an-electric insulating solvent refined, acid treated and adsorbent earth treated mineral oil containing from about 0.01% to about 2% of dicyclopentadiene.
4. A. non-gassing liquid dielectric composition comprising a major amount of an electric insulating solvent refined, acid treated and adsorbent earth treated mineral oil containing from about 0.01% to about 2% of methylisobutylfulvene.
References Cited in the file of this patent UNITED STATES PATENTS 2,112,735 Clark Mar. 29, 1938 2,231,248 Bowden Feb. 11, 1941 2,734,031 McNaughton Feb. 7, 1956
Claims (1)
1. A LIQUID DIELECTRIC COMPOSITION COMPRISING A MAJOR AMOUNT OF A GAS EVOLVING ELECTRIC INSULATING SOLVENT REFINED, ACID TREATED AND ADSORBENT EARTH TREATED MINERAL OIL CONTAINING FROM ABOUT 0.01% TO ABOUT 2% OF A NONAROMATIC CYCLOPENTENE COMPOUND SELECTED FROM THE GROUP CONSISTING OF C1-C8 ALKYL FULEVENE AND DICYCLOPENTADIENE.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB23328/55A GB774646A (en) | 1955-08-12 | 1955-08-12 | Improvements in or relating to liquid electrical insulating compositions |
Publications (1)
Publication Number | Publication Date |
---|---|
US2834734A true US2834734A (en) | 1958-05-13 |
Family
ID=10193831
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US591781A Expired - Lifetime US2834734A (en) | 1955-08-12 | 1956-06-18 | Liquid electrical insulating compositions |
Country Status (4)
Country | Link |
---|---|
US (1) | US2834734A (en) |
DE (1) | DE1088648B (en) |
FR (1) | FR1159684A (en) |
GB (1) | GB774646A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE2531210A1 (en) * | 1974-07-17 | 1976-02-05 | Exxon Research Engineering Co | MIXTURE BASED ON A PARAFFIN BASE OIL |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CA1088292A (en) * | 1976-03-24 | 1980-10-28 | David G. Shaw | Liquid ester impregnant for electrical devices |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2112735A (en) * | 1934-05-19 | 1938-03-29 | Gen Electric | Mineral oil product |
US2231248A (en) * | 1936-11-05 | 1941-02-11 | Bowden Frank Philip | Lubricant |
US2734031A (en) * | 1956-02-07 | Lubricants containing polymers of |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2087578A (en) * | 1933-06-16 | 1937-07-20 | Shell Dev | Mineral oil composition |
FR784540A (en) * | 1935-01-22 | 1935-07-22 | Bataafsche Petroleum | Process for the preparation of insulating oils |
DE850159C (en) * | 1950-08-22 | 1952-09-22 | Siemens Ag | Insulating fluid for high voltage electrical equipment |
-
1955
- 1955-08-12 GB GB23328/55A patent/GB774646A/en not_active Expired
-
1956
- 1956-06-18 US US591781A patent/US2834734A/en not_active Expired - Lifetime
- 1956-08-10 DE DES49944A patent/DE1088648B/en active Pending
- 1956-08-10 FR FR1159684D patent/FR1159684A/en not_active Expired
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2734031A (en) * | 1956-02-07 | Lubricants containing polymers of | ||
US2112735A (en) * | 1934-05-19 | 1938-03-29 | Gen Electric | Mineral oil product |
US2231248A (en) * | 1936-11-05 | 1941-02-11 | Bowden Frank Philip | Lubricant |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE2531210A1 (en) * | 1974-07-17 | 1976-02-05 | Exxon Research Engineering Co | MIXTURE BASED ON A PARAFFIN BASE OIL |
Also Published As
Publication number | Publication date |
---|---|
GB774646A (en) | 1957-05-15 |
DE1088648B (en) | 1960-09-08 |
FR1159684A (en) | 1958-07-01 |
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