Insulating fluid or gas-absorbing fluid for use in an electrical apparatus

Abstract

The present disclosure relates to the use of a compound of Formula (I) or a compound of Formula (II) as an insulating fluid or a gas-absorbing fluid in an electrical apparatus. The disclosure also relates to an insulating fluid or a gas-absorbing fluid for use in an electrical apparatus and an electrical apparatus comprising such fluid. Besides, the present disclosure relates to a method for preparing an electrical apparatus comprising such fluid and a method for absorbing a gas component in an electrical apparatus.

Description

[0001] INSULATING FLUID OR GAS-AB SORBING FLUID FOR USE IN AN ELECTRICAL APPARATUS

[0002] FIELD

[0003] The present disclosure generally relates to an insulating fluid or a gas-absorbing fluid for use in an electrical apparatus, an electrical apparatus comprising the same, a method for preparing an electrical apparatus and a method for absorbing a gas component in an electrical apparatus.

[0004] BACKGROUND

[0005] Insulating fluid is widely used in applications in electrical equipment to provide insulation, cooling and arc extinguishing effects. Currently, researchers generally focus on the dielectric and flow properties of insulating liquids as well as cost, fire resistance, bio-degradability, and health-safety-environment (HSE) requirements to develop new insulating liquids.

[0006] Typical insulating fluids widely used in capacitor products include mineral oils, synthetic esters, natural esters, alkyl aromatics and silicone fluids and the like.

[0007] Mineral oils have excellent dielectric and flowing properties as well as low cost, but are poor in fire resistance. In addition, mineral oils are poorly bio-degradable, which would be a burden on the environment at the end of their working life or in the event of a leakage.

[0008] Natural esters (e.g., vegetable oils) usually have poor flow properties. Most natural esters have a relatively high pouring point, which results in higher viscosity or even inability to flow at low temperatures, thus limiting the application scenarios for natural esters.

[0009] W02007126207A1 discloses a vegetable-based electrical insulating oil which exhibits superior anti-oxidability and is readily biodegradable in ecosystems after use via characteristics of vegetable oil.

[0010] Alkyl aromatics show advantages on dielectric and flowing properties. However, the low fire classification and low flash point of alkyl aromatics pose a threat to their safety in use. In addition, the non-biodegradability of alkyl aromatics is also one of the limiting factors.

[0011] Conventional synthetic esters usually have good dielectric properties and fire resistance, but it is still desirable to further improve their flowing properties and lower the cost. Although silicone oils are superior in fire resistance, the other properties remain unsatisfactory. In particular, silicone oils are not biodegradable and of high cost.

[0012] Gassing of insulating oil is defined as the chemical decomposition of certain vulnerable hydrocarbons, under the impact of electrical and thermal stresses. The primary decomposition process involves generation of short-lived free radicals via splitting up of covalent bonds in oil molecules as: R-H (hydrocarbon) — > R* + »H. Large free radicals (R») may lead to formation of insoluble colloidal compounds (a sludge in solid phase): R* + »R — > R-R (insoluble sludge) while small free radicals (H») may result in gaseous inclusions such as hydrogen (H2) gas: H* + »H — > H2 $ (soluble gas).

[0013] It is known that partial discharges (PD) tend to occur in such gaseous inclusions, and therefore the resistance to gassing of insulating liquid will affect the stability of liquid to electrical discharge. Depending on the natures of the liquid, the volume of the gas subjected to the discharges may decrease (gas-absorbing liquid) or increase (gas-evolving liquid).

[0014] In a strong gas-absorbing liquid (negative gassing tendency), discharges will quickly disappear, whereas in a gas-evolving liquid (positive gassing tendency), more discharges will be produced, leading to eventual insulation breakdown.

[0015] Therefore, the present application identifies that gas-absorption properties should also be taken into account when developing new insulting liquids. Among conventional insulating fluids, most of commonly used insulating fluids shows relatively poor gas-absorption properties.

[0016] It is therefore desirable in the field to develop an insulating fluid that exhibits superiority in all of the above-mentioned respects, particularly in gas-absorption properties.

[0017] SUMMARY

[0018] In one aspect, provided herein is use of a compound of Formula (I) or a compound of

[0019] Formula (II) as an insulating fluid or a gas-absorbing fluid in an electrical apparatus, ) wherein Mi and M2 are each independently a hydrocarbon chain comprising from 1 to 5 carbon atoms; x and y are each independently 0 or 1; R1is Ci-4 hydrocarbyl; R2is Ce-io aryl, which is optionally substituted by one or more substituents selected from C1-10 hydrocarbyl, hydroxyl, carboxyl, amino, nitro and halogen; R3is Ce-io aryl, which is optionally substituted by one or more substituents selected from C1-10 hydrocarbyl, hydroxyl, carboxyl, amino, nitro and halogen; R4is C1-17 hydrocarbyl.

[0020] In some embodiments, in Formula (I), Mi is methylene. In some embodiments, Formula (I), R1is Ci-4 alkyl, preferably propyl. In some embodiments, in Formula (I), R2is phenyl. In some embodiments, in Formula (I), x is 1.

[0021] In a specific embodiment, the compound of Formula (I) has the following formula:

[0022] In some embodiments, in Formula (II), R3is phenyl. In some embodiments, in Formula (II), R4is Ci -17 alkyl, preferably propyl. In some embodiments, in Formula (II), y is 0.

[0023] In a specific embodiment, the compound of Formula (II) has the following formula:

[0024] In another aspect, provided herein is an insulating fluid or a gas-absorbing fluid for use in an electrical apparatus, comprising a compound of Formula (I) and / or a compound of Formula

[0025] (II): wherein Mi and M2 are each independently a hydrocarbon chain comprising from 1 to 5 carbon atoms; x and y are each independently 0 or 1; R1is Ci-4 hydrocarbyl; R2is Ce-io aryl, which is optionally substituted by one or more substituents selected from C1-10 hydrocarbyl, hydroxyl, carboxyl, amino, nitro and halogen; R3is Ce-io aryl, which is optionally substituted by one or more substituents selected from C1-10 hydrocarbyl, hydroxyl, carboxyl, amino, nitro and halogen; R4is C1-17 hydrocarbyl.

[0026] In some embodiments, in Formula (I), Mi is methylene. In some embodiments, Formula (I), R1is Ci-4 alkyl, preferably propyl. In some embodiments, in Formula (I), R2is phenyl. In some embodiments, in Formula (I), x is 1.

[0027] In a specific embodiment, the compound of Formula (I) has the following formula:

[0028] In some embodiments, in Formula (II), R3is phenyl. In some embodiments, in Formula (II), R4is Ci -17 alkyl, preferably propyl. In some embodiments, in Formula (II), y is 0.

[0029] In a specific embodiment, the compound of Formula (II) has the following formula:

[0030] In some embodiments, the insulating fluid or gas-absorbing fluid as described herein may further comprises a mineral oil, a vegetable oil, an alkyl aromatic, a synthetic ester, a silicon oil, a polyolefin, an epoxy resin or a combination thereof.

[0031] In another aspect, provided herein is an electrical apparatus comprising the insulating fluid or gas-absorbing fluid as described herein.

[0032] In another aspect, provided herein is a method for preparing an electrical apparatus, comprising providing an electrical apparatus and filling the insulating fluid or gas-absorbing fluid as described herein into the electrical apparatus.

[0033] In another aspect, provided herein is a method for absorbing a gas component in an electrical apparatus, comprising applying the insulating fluid or gas-absorbing fluid as described herein to the electrical apparatus.

[0034] In some embodiments, the electrical apparatus may comprise or comprise a part of a: capacitor, transformer, voltage transformer, current transformer, reactor, cable system, bushing, converter, or a component and / or a combination thereof.

[0035] DETAILED DESCRIPTION OF EMBODIMENTS

[0036] General Definition and Terms

[0037] Unless otherwise stated, all publications, patent applications, patents and other references mentioned herein are incorporated by reference in their entirety.

[0038] Unless otherwise defined, the technical and scientific terms used herein have the same meaning as commonly understood by a person skilled in the art. If there is a contradiction, the definition provided in this application shall prevail.

[0039] Unless otherwise stated, all percentages, parts, proportions or the like are on a weight basis. When an amount, concentration or other value or parameter is given as a range, a preferable range or a preferable upper limit and lower limit or a specific value, it should be understood that it corresponds to specifically revealing any range by combining any pair of upper limit of the range or preferable range value with the lower limit of any range or preferable range value, regardless of whether the range is specifically disclosed. Unless otherwise stated, the numerical ranges listed herein are intended to include the endpoints of the range and all integers and fractions within the range.

[0040] When used with a numerical variable, the term “about” or “approximate” usually refers to the value of the variable and all the values of the variable within the experimental error (for example, within an average 95% confidence interval) or within ±10% of the specified value, or a wider range.

[0041] The term “optional” or “optionally” as used herein means the event described subsequent thereto may or may not happen. This term encompasses the cases that the event may or may not happen, and that the contents are selected in an arbitrary manner.

[0042] The terms “include”, “comprise”, “have”, “contain” or “involve” and other variants thereof as used herein are meant to be inclusive or open-ended, which do not exclude other unlisted elements or process steps. It should be understood by those skilled in the art that the above terms such as “include” encompass the meaning of “consist of’. The expression “consist of’ excludes any element, step, or ingredient not designated. The expression “substantially consist of’ means that the scope is limited to the designated elements, steps or ingredients, plus elements, steps or ingredients that are optionally present which do not substantially affect the basic and new features of the claimed subject matter. It should be understood that the expression “comprise” encompasses the expressions “substantially consist of’ and “consist of’.

[0043] The term “selected from” as used herein refers to one or more elements of the group listed thereafter, selected independently, and may encompass the combination of two or more elements.

[0044] The term “one or more” or “at least one” as used herein means one, two, three, four, five, six, seven, eight, nine or more.

[0045] Unless otherwise stated, the terms “combination thereof’ and “mixture thereof’ as used herein mean multicomponent mixtures of the elements, such as two, three, four and up to the maximum possible multicomponent mixtures.

[0046] If the number of parts or components of the present disclosure is not indicated before, it means that there is no limit to the number of parts or components. Therefore, it should be interpreted as including one or at least one, and the singular word form like “a”, “an”, “the” or the like of a part or component also includes the plural, unless the numerical value clearly indicates the singular.

[0047] As used herein, and unless otherwise specified, the term “insulating fluid”, also described as “insulating oil”, refers to a liquid that is electrically insulating.

[0048] As used herein, and unless otherwise specified, the term “gas-absorbing fluid”, also described as “gas-absorbing oil”, refers to a liquid that that can absorb gases. Gases can be absorbed by any means, preferably by chemical reaction. The absorbed gas herein refers mainly to hydrogen gas and gaseous hydrocarbons (e.g., methane, ethane, ethylene, acetylene, etc.).

[0049] As used herein, generally the term “medium voltage” relates to voltages in the range of 1 kV to 35 kV, and the term “high voltage” relates to voltages above this range.

[0050] As used herein, and unless otherwise specified, the term “hydroxyl” refers to “-OH”. The term “carboxyl” refers to “-COOH”. The term “amino” refers to “-NH2”. The term “nitro” refers to “-NO2” The term “halogen” refers to “-F”, “-C1”, “-Br” or “-I”.

[0051] As used herein, and unless otherwise specified, the term “hydrocarbon chain” refers to a straight or branched hydrocarbon chain linking the rest of the molecule to a radical group, consisting solely of carbon and hydrogen, which is saturated or contains one or more carboncarbon double or triple bonds. In one embodiment, the hydrocarbon chain may comprise 1 to 5 carbon atoms, e.g., 1, 2, 3, 4 and 5. Examples of hydrocarbon chain comprising 1 to 5 carbon atoms include, but are not limited to, methylene (-CH2-), ethylene (-CH2CH2-), propylene (- CH2CH2CH2-), n-butylene (-CH2CH2CH2CH2-), n-pentene (-CH2CH2CH2CH2-), ethenylene (- CH=CH-), propenylene (-CH=CHCH2-), n-butenylene (-CH=CHCH2CH2-) and the like.

[0052] As used herein, and unless otherwise specified, the term “aryl” refers to a monocyclic aromatic group and / or multicyclic monovalent aromatic group that contain at least one aromatic hydrocarbon ring. In certain embodiments, the aryl has from 6 to 10 ring carbon atoms (Ce-Cio aryl). Examples of aryl groups include, but are not limited to, phenyl, naphthyl. The term “aryl” also refers to bicyclic, tricyclic, or other multicyclic hydrocarbon rings, where at least one of the rings is aromatic and the others of which may be saturated, partially unsaturated, or aromatic, for example, dihydronaphthyl, indenyl, indanyl, or tetrahydronaphthyl (tetralinyl). Unless otherwise specified, an aryl group is optionally substituted.

[0053] As used herein, and unless otherwise specified, the term “hydrocarbyl” includes alkyl, alkenyl and alkynyl. The term “alkyl” refers to a straight or branched hydrocarbon chain radical consisting solely of carbon and hydrogen atoms, which is saturated. The term “alkenyl” refers to a straight or branched hydrocarbon chain radical consisting solely of carbon and hydrogen atoms, which contains one or more carbon-carbon double bonds. The term “alkynyl” refers to a straight or branched hydrocarbon chain radical consisting solely of carbon and hydrogen atoms, which contains one or more carbon-carbon triple bonds. In certain embodiments, the hydrocarbyl comprises 1 to 10 carbon atoms (C1-10 hydrocarbyl), for example C1-10 alkyl, C1-10 alkenyl, and C1-10 alkynyl, e.g., Ci, C2, C3, C4, Cs, Ce, C7, Cs, C9, Cio-alkyl, -alkenyl, and - alkynyl. In certain embodiments, the hydrocarbyl comprises 1 to 17 carbon atoms (C1-17 hydrocarbyl), for example C1-17 alkyl, C1-17 alkenyl, and C1-17 alkynyl, e.g., Ci, C2, C3, C4, Cs, Ce, C7, Cs, C9, C10, C11, C12, C13, C14, C15, Ci6, Ci7-alkyl, -alkenyl, and -alkynyl. Examples include, but are not limit to methyl (-CH3), ethyl (-CH2CH3), n-propyl (-CH2CH2CH3), 1- methylethyl (isopropyl, -CH(CH3)2), n-butyl (-CH2CH2CH2CH3), n-pentyl (- CH2CH2CH2CH2CH3), 1,1 -dimethylethyl (t-butyl, -C(CH3)3), 3-methylhexyl (- CH2CH2CH(CH3)CH2CH2CH3), 2 -methylhexyl (-CH2CH (CH3)CH2CH2CH2CH3), ethenyl (- CH=CH2), prop-l-enyl (-CEUCHCH3), prop-2-enyl (-CH2CEUCH2), but-l-enyl (- CH=CHCH2CH3), but-2-enyl (-CH2CH=CHCH3), but-3-enyl (-CH2CH2CH=CH2), pent-l-enyl (-CH=CHCH2CH2CH3), pent-2-enyl (-CH2CH=CHCH2CH3), pent-3 -enyl (- CH2CH2CH=CHCH3), pent-4-enyl (-CH2CH2CH2CH=CH2), penta- 1,4-dienyl (- CH=CHCH2CH=CH2), ethynyl (-C=CH), prop-l-ynyl (-C=CCH3), prop-2-ynyl (-CHOCH), but-l-ynyl (-C=CCH2CH3), but-2-ynyl (-CHC=CCH3), but-3-ynyl (-CH2CH2C=CH), pent-1- ynyl (-C=CCH2CH2CH3), pent-2-ynyl (-CH2C=CCH2CH3), pent-3 -ynyl (-CH2CH2C=CCH3), pent-4-ynyl (-CH2CH2CH2C=CH) and the like.

[0054] Use as an insulating fluid or a gas-absorbing fluid

[0055] In one aspect, provided herein is use of a compound of Formula (I) or a compound of Formula (II) as an insulating fluid or a gas-absorbing fluid in an electrical apparatus, u wherein Mi and M2are each independently a hydrocarbon chain comprising from 1 to 5 carbon atoms; x and y are each independently 0 or 1; R1is Ci-4 hydrocarbyl; R2is Ce-io aryl, which is optionally substituted by one or more substituents selected from Ci-io hydrocarbyl, hydroxyl, carboxyl, amino, nitro and halogen; R3is Ce-io aryl, which is optionally substituted by one or more substituents selected from Ci-io hydrocarbyl, hydroxyl, carboxyl, amino, nitro and halogen; R4is Ci-i7 hydrocarbyl.

[0056] In an embodiment, in the compound of Formula (I): Formula (I),

[0057] Mi is a hydrocarbon chain comprising from 1 to 5 carbon atoms; x is 0 or 1; R1is Ci-4 hydrocarbyl; R2is Ce-io aryl, which is optionally substituted by one or more substituents selected from Ci-io hydrocarbyl, hydroxyl, carboxyl, amino, nitro and halogen.

[0058] In an embodiment, in the compound of Formula (II): Formula (II)

[0059] M2is a hydrocarbon chain comprising from 1 to 5 carbon atoms; y is 0 or 1; R3is Ce-io aryl, which is optionally substituted by one or more substituents selected from Ci-io hydrocarbyl, hydroxyl, carboxyl, amino, nitro and halogen; R4is Ci-i7 hydrocarbyl.

[0060] The “x” is used herein to indicate whether Mi are present in Formula (I). For example, x as 0 means that there is no Mi in Formula (I) and R2is directly covalently bonded to the oxygen atom in the ester moiety; and x as 1 means that R2is covalently bonded to one end of Mi and the other end of Mi is covalently bonded to the oxygen atom in the ester moiety.

[0061] The “y” is used herein to indicate whether M2 are present in Formula (II). For example, y as 0 means that there is no M2 in Formula (II) and R3is directly covalently bonded to the carbon atom in the ester moiety; and y as 1 means that R3is covalently bonded to one end of M2 and the other end of M2 is covalently bonded to the carbon atom in the ester moiety.

[0062] As linking segments, Mi or M2 may respectively affect the properties of the compound of Formula (I) or Formula (II), such as gas-absorbing and flowing properties. In some embodiments, x is 1 and Mi is a hydrocarbon chain comprising from 1 to 5 carbon atoms. In some embodiments, y is 1 and M2 is a hydrocarbon chain comprising from 1 to 5 carbon atoms. Examples of hydrocarbon chain comprising from 1 to 5 carbon atoms include, but are not limit to methylene, ethylene, propylene, n-butylene, n-pentene, ethenylene, propenylene, n- butenylene and the like.

[0063] The hydrocarbon chain with the carbon atoms within the above range may be advantageous for the compound of Formula (I) or the compound of Formula (II) with good flowing properties. An overly long hydrocarbon chain may lead to a decrease in the flowing properties and may increase the risk of decomposition process, leading to gas generation on vulnerable hydrocarbons.

[0064] In some preferable embodiments, in Formula (I), x is 1 and Mi is methylene. Such compound of Formula (I) can be prepared via esterification of a fatty acid and benzyl alcohol.

[0065] In some preferable embodiments, in Formula (II), y is 1 and M2 is methylene. Such compound of Formula (II) can be prepared via esterification of benzoic acid and a fatty alcohol.

[0066] These compounds of Formula (I) and of Formula (II) may be of good stability and low cost.

[0067] Due to the inherent resistance to oxidation, hydrolysis and cleavage of the aryl group in R2or in R4, a compound of Formula (I) and a compound of Formula (II) has good stability under operating and non-operating conditions of electrical apparatus. Meanwhile, the aryl group in R2or in R4renders a compound of Formula (I) or a compound of Formula (II) good reactivity to the undesirable gas (such as hydrogen gas) generated during the operation of the apparatus. Therefore, owing to an aryl group in R2or in R4, a compound of Formula (I) and a compound of Formula (II) exhibit outstanding gas-absorbing properties.

[0068] In some preferable embodiments, R2is phenyl or naphthyl. In some preferable embodiments, R4is phenyl or naphthyl. As aryl groups consisting solely of aromatic rings, phenyl and naphthyl are less likely to undergo decomposition process during the operation of the electrical apparatus, even under harsh operation conditions (e.g., medium to high voltage conditions, high temperature and etc.), while phenyl and naphthyl can maintain good reactivity to the undesirable gas (such as hydrogen gas). Therefore, a compound of Formula (I) in which R2is phenyl or naphthyl, and a compound of Formula (II) in which R4is phenyl or naphthyl show better gas-absorbing properties.

[0069] In some more preferable embodiments, R2is phenyl. In some more preferable embodiments, R4is phenyl. Compared to other Ce-io aryl groups, phenyl in R2or R4may give the compound of Formula (I) or the compound of Formula (II) better gas-absorbing properties as well as flowing properties.

[0070] In Formula (I) and in Formula (II), the portion on one side of the ester moiety contains an aromatic group and the portion on the other side is consisted of an aliphatic chain. The aromatic group render a compound of Formula (I) and a compound of Formula (II) excellent gasabsorbing properties while the aliphatic chain provides the compound with good flowing properties. A compound of Formula (I) and a compound of Formula (II) may have well- balanced gas-absorbing properties and flowing properties and thus are particularly suitable for use as an insulating fluid in an electrical apparatus, especially in a capacitor.

[0071] In some embodiments, R1is Ci-4 hydrocarbyl, preferably propyl.

[0072] In some embodiments, R4is C1-17 hydrocarbyl, preferably Ci-4 hydrocarbyl, more preferably propyl.

[0073] Selection of Ci-4 hydrocarbyl as R1results in a compound of Formula (I) having better gas-absorbing properties and flowing properties (e.g., lower viscosity and pouring point) than selection of hydrocarbyl containing more carbon atoms (e.g., more than 5). Furthermore, such compound of Formula (I) possesses a more favorable swelling effect and can be synthesized with lower cost.

[0074] In Formula (I) and Formula (II), as the number of hydrogen atoms on the saturated carbon atoms increases, the risk of decomposition process of the corresponding compound may rise, leading to gas generation on vulnerable hydrocarbons.

[0075] In some embodiments, in Formula (I), the total number of hydrogen atoms on the saturated carbon atoms may be 40 or less, preferably 20 or less, more preferably 15 or less, most preferably 10 or less.

[0076] In some embodiments, in Formula (II), the total number of hydrogen atoms on the saturated carbons may be 60 or less, preferably 40 or less, more preferably 20 or less, even preferably 15 or less, and most preferably 10 or less.

[0077] In some embodiments, the compound of Formula (I) may include, but are not limit to the following structures:

[0078]

[0079] In some embodiments, the compound of Formula (I) is benzyl butyrate, wherein x is 1; Mi is methylene; R1is propyl and R2is phenyl. Benzyl butyrate is a synthetic ester with well- balanced gas-absorbing property and flowing property. The structure of benzyl butyrate is shown in the following formula: (Benzyl butyrate).

[0080] In some embodiments, the compound of Formula (II) may include, but are not limit to the following structures:

[0081] An additional carboxyl group or ester group may be attached to the R3of Formula (II) as long as it would not have a significant negative impact on properties. For example, the compound of Formula (II) may include, but are not limit to the following structures: wherein R4and R4are each independently C1-17 hydrocarbyl, preferably Ci-4 hydrocarbyl.

[0082] In some embodiments, the compound of Formula (II) may include, but are not limit to the following structures:

[0083] In some embodiments, the compound of Formula (II) is propyl benzoate, wherein y is 0, R3is phenyl and R4is propyl. Propyl benzoate is a synthetic ester with well-balanced gasabsorbing property and flowing property. The structure of propyl benzoate is shown in the following formula: (Propyl benzoate).

[0084] The compound of Formula (I) and the compound of Formula (II) have good dielectric properties (e.g., high breakdown voltage and high permittivity), gas-absorbing properties as well as flowing properties. Therefore, these compounds are suitable for use as insulating fluids or gas-absorbing fluids in electrical apparatus, e.g., in liquid-filled electrical apparatus.

[0085] Particularly, the electrical apparatus comprises or comprises a part of a: capacitor, transformer, voltage transformer, current transformer, reactor, cable system, bushing, converter, or a component and / or a combination thereof. Especially, the electrical apparatus is a liquid- filled capacitor or a cable system.

[0086] Insulating fluid or gas-absorbing fluid for use in an electrical apparatus

[0087] In another aspect, provided herein is an insulating fluid or a gas-absorbing fluid for use in an electrical apparatus, comprising a compound of Formula (I) and / or a compound of Formula (II), where each of the groups are as defined herein above.

[0088] In an embodiment, in the compound of Formula (I): R1— C — O — (M1)x- R2Formula (I)

[0089] Mi is a hydrocarbon chain comprising from 1 to 5 carbon atoms; x is 0 or 1; R1is Ci-4 hydrocarbyl; R2is Ce-io aryl, which is optionally substituted by one or more substituents selected from Ci-io hydrocarbyl, hydroxyl, carboxyl, amino, nitro and halogen.

[0090] In some embodiments, in Formula (I), Mi is methylene. In some embodiments, in Formula (I), R1is Ci-4 alkyl, preferably propyl. In some embodiments, in Formula (I), R2is phenyl. In some embodiments, in Formula (I), x is 1.

[0091] In some embodiments, the compound of Formula (I) is benzyl butyrate, wherein x is 1; Mi is methylene; R1is propyl and R2is phenyl. Benzyl butyrate is a synthetic ester with well- balanced gas-absorbing property and flowing property. The structure of benzyl butyrate is shown in the following formula: (Benzyl butyrate).

[0092] In an embodiment, in the compound of Formula (II): „ , ZTT\ Formula (II)

[0093] M2 is a hydrocarbon chain comprising from 1 to 5 carbon atoms; y is 0 or 1; R3is Ce-io aryl, which is optionally substituted by one or more substituents selected from C1-10 hydrocarbyl, hydroxyl, carboxyl, amino, nitro and halogen; R4is C1-17 hydrocarbyl.

[0094] In some embodiments, in Formula (I), R3is phenyl. In some embodiments, in Formula (I), R4is Ci-17 alkyl, preferably propyl. In some embodiments, in Formula (I), y is 0.

[0095] In some embodiments, the compound of Formula (II) is propyl benzoate, wherein y is 0, R3is phenyl and R4is propyl. Propyl benzoate is a synthetic ester with well-balanced gasabsorbing property and flowing property. The structure of propyl benzoate is shown in the following formula: (Propyl benzoate).

[0096] The advantageous effects resulting from the selection of each portion of the compound of

[0097] Formula (I) and the compound of Formula (II) are as described above.

[0098] In addition to good dielectric properties (e.g., high breakdown voltage and permittivity) and gas-absorbing properties, the compound of Formula (I) and the compound of Formula (II) also exhibit excellent flowing properties. The low viscosity of the compound of Formula (I) and / or Formula (II) is of particular advantage for application in electrical apparatus, especially in capacitors, due to effective heat dissipation to avoid local overheating and reducing partial discharges occurrence. Therefore, an insulating fluid with a high content of compound of Formula (I) and / or Formula (II) may also be applicable in cold environments.

[0099] Thus, an insulating fluid or a gas-absorbing fluid according to the present disclosure may be consisted entirely or substantially of compounds of Formula (I) and / or Formula (II), or may contain a high content of compounds of Formula (I) and / or Formula (II).

[0100] For example, based on the total weight of the insulating fluid or gas-absorbing fluid according to the present disclosure, the content of the compound of Formula (I) may be up to 100wt%, or 90wt%, or 80wt%, or 70wt%, or 60wt%.

[0101] For another example, based on the total weight of the insulating fluid or gas-absorbing fluid according to the present disclosure, the content of the compound of Formula (II) may be up to 100wt%, or 90wt%, or 80wt%, or 70wt%, or 60wt%.

[0102] For another example, based on the total weight of the insulating fluid or gas-absorbing fluid according to the present disclosure, the content of the compound of Formula (I) and Formula (II) may be up to 100wt%, or 90wt%, or 80wt%, or 70wt%, or 60wt%.

[0103] An insulating fluid or a gas-absorbing fluid according to the present disclosure may further comprise a mineral oil, a vegetable oil, an alkyl aromatic, a synthetic ester, a silicon oil, a polyolefin, an epoxy resin or a combination thereof.

[0104] As used herein, the term “mineral oil” refers to those purified by distillation from the heavy oil. Examples of the mineral oil include, but are not limited to, lubricating oil fractions obtained by atmospheric distillation and reduced pressure distillation of paraffin base crude, intermediate base crude or naphthenic base crude; paraffinic mineral oils or naphthenic mineral oils obtained, for example, by one or two or more of solvent deasphalting, solvent extraction, hydrocracking, solvent dewaxing, catalytic dewaxing, hydrogenation refining, sulfuric acid cleaning, and clay treatment. For better thermal stability, highly refined mineral oils are preferable.

[0105] As used herein, the term “vegetable oil” refers to those obtain from any part of vegetables, such as wood oil and seed oil. Examples of the vegetable oil include, but are not limited to, wood turpentine oil, China wood oil, Japanese wood oil, pine wood oil, olive oil, cacao oil, perilla oil, camellia oil, peanut oil, soybean oil, rapeseed oil, mustard oil, dehydrated castor oil, tung oil, safflower oil, linseed oil, corn oil, sunflower oil, corn oil, cottonseed oil, sesame oil, rice bran oil, hemp oil, evening primrose oil, palm oil, palm kernel oil, coconut oil, and the like. For excellent oxidation stability, palm oil, palm kernel oil, coconut oil is preferable. For further enhanced partial discharge characteristics, palm kernel oil, coconut oil is more preferable. Examples of alkyl aromatics include alkyl benzene, alkyl naphthalene and aromatic hydrocarbons containing two or more aromatic rings, such as diaryl alkane, triaryl alkane and the like.

[0106] Alkyl benzenes are aromatic hydrocarbons with one or more alkyl groups bound to a benzene ring, such as decyl benzene, undecyl benzene, dodecyl benzene, tridecyl benzene, tetradecyl benzene, heptadecyl benzene, octadecyl benzene, nonadecyl benzene, icosyl benzene.

[0107] Alkyl naphthalene are aromatic hydrocarbons with one or more alkyl groups bound to a naphthalene ring, such as decylnaphthalene, undecyl naphthalene, dodecyl naphthalene, tridecyl naphthalene, tetradecyl naphthalene, heptadecyl naphthalene, octadecylnaphthalene, nonadecyl naphthalene, icosyl naphthalene.

[0108] Diaryl alkane refers to an alkyl aromatics containing two aromatic rings in the molecule. Examples of diaryl alkane include iphenylmethane, benzyl toluene, benzyl xylene, phenyl-sec- butyl phenyl methane, di-sec-butyl diphenylmethane, diphenylethane, phenylethyl phenyl ethane, phenyl cumyl ethane, diisopropylphenyl ethane, phenyl tolyl ethane, di-sec-butyl phenyl ethane, di-tert-butylphenyl ethane, phenylxylyl ethane, phenyl-sec-butyl phenyl ethane, diphenyl propane, diphenyl butane and the like.

[0109] Triaryl alkane refers to an alkyl aromatics containing three aromatic rings in the molecule. Examples of triaryl alkane include dibenzyl benzene, dibenzyl toluene, dibenzyl xylene and their alkyl substituted derivatives, and the like.

[0110] Synthetic ester refers to an esterification product of acid and alcohol. The molecular structure of the synthetic ester may contain one or more ester groups. Synthetic ester may be prepared from fatty acids and fatty alcohols, or from aromatic acids and fatty alcohols, or from fatty acids and aromatic alcohols.

[0111] Synthetic ester may be phthalate, which is an esterification product of phthalic acid and alcohol. Examples of phthalate may include dinonyl phthalate, diisopropyl phthalate, diallyl phthalate, octodecyl phthalate, didecyl phthalate, diisopentyl phthalate and the like.

[0112] It should be understood that the synthetic insulating fluid as the additional component refers to any synthetic insulating fluid other than compounds of Formula (I)-(II). Particularly, the synthetic ester as the additional component refers to any synthetic ester other than compounds of Formula (I)-(II).

[0113] Silicon oil refers to linear polysiloxane that remain liquid at room temperature. Examples of silicon oil include dimethyl silicone oil, diethyl silicone oil, phenyl silicone oil, phenylmethyl silicone oil and the like.

[0114] Polyolefin herein refers to olefin polymers, which are usually in liquid state at room temperature. Examples of polyolefin may include poly-a-olefin (PAO), polyisobutene and the like. Epoxy resin herein refers to polymers that contain more than two epoxy groups in the molecule, which are usually in liquid state at room temperature. Examples of epoxy resin may include aliphatic epoxy resin, alicyclic epoxy resin and the like.

[0115] For environmental-friendly purposes, the additional components are biodegradable or have readily biodegradable property.

[0116] In addition to the components as described above, the insulating fluid or gas-absorbing fluid according to the present disclosure may further comprise commonly used additives. Examples of additives includes, but are not limit to an antioxidant, a decomposition inhibitor and the like. Based on the total weight of the insulating fluid or gas-absorbing fluid, the content of additives is 10 wt% or less, preferably 5 wt% or less, more preferably 2 wt% or less, and also may be 0 wt%.

[0117] The insulating fluid or gas-absorbing fluid according to the present disclosure may have a kinematic viscosity of 100 mm2 / s or less, preferably 50 mm2 / s or less, more preferably 20 mm2 / s or less at 20°C, e.g., 100 mm2 / s or less, or 90 mm2 / s or less, or 80 mm2 / s or less, or 70 mm2 / s or less, or 60 mm2 / s or less, or 50 mm2 / s or less, or 40 mm2 / s or less, or 30 mm2 / s or less, or 20 mm2 / s or less, or 10 mm2 / s or less, or 5 mm2 / s or less. The kinematic viscosity may be measured in accordance with GB / T265-1988 or ISO 3104-2020.

[0118] The insulating fluid or gas-absorbing fluid according to the present disclosure may have a kinematic viscosity of 400 mm2 / s or less, preferably 200 mm2 / s or less, more preferably 100 mm2 / s or less at -25°C, e.g., 400 mm2 / s or less, or 300 mm2 / s or less, or 250 mm2 / s or less, or 200 mm2 / s or less, or 150 mm2 / s or less, or 100 mm2 / s or less, or 50 mm2 / s or less. The kinematic viscosity may be measured in accordance with GB / T265-1988 or ISO 3104-2020.

[0119] The insulating fluid or gas-absorbing fluid according to the present disclosure may have a kinematic viscosity of 1500 mm2 / s or less, preferably 1000 mm2 / s or less, more preferably 500 mm2 / s or less at -40°C, e.g., 1500 mm2 / s or less, or 1300 mm2 / s or less, or 1000 mm2 / s or less, or 800 mm2 / s or less, or 600 mm2 / s or less, or 500 mm2 / s or less, or 200 mm2 / s or less. The kinematic viscosity may be measured in accordance with GB / T265-1988 or ISO 3104-2020.

[0120] The insulating fluid or gas-absorbing fluid according to the present disclosure may have a kinematic viscosity of 3000 mm2 / s or less, preferably 2000 mm2 / s or less, more preferably 1000 mm2 / s or less at -50°C, e.g., 3000 mm2 / s or less, or 2500 mm2 / s or less, or 2000 mm2 / s or less, or 1800 mm2 / s or less, or 1500 mm2 / s or less, or 1200 mm2 / s or less, or 1000 mm2 / s or less, or 800 mm2 / s or less. The kinematic viscosity may be measured in accordance with GB / T265- 1988 or ISO 3104-2020.

[0121] The insulating fluid or gas-absorbing fluid according to the present disclosure has a pouring point of below -50°C. The pouring point may be measured in accordance with IEC 60867-2022. An insulating fluid or gas-absorbing fluid with a kinematic viscosity and pouring point within the above preferable range has better cooling effect and better versatility, even in cold areas.

[0122] The insulating fluid or gas-absorbing fluid according to the present disclosure may have a gassing coefficient of below -20 mm3 / min, preferably below -50 mm3 / min, more preferably below -100 mm3 / min. The gassing coefficient may be measured in accordance with IEC 60628 A (Ed.2, 1985). An insulating fluid or gas-absorbing fluid with a gassing coefficient within the above preferable range can be used in electrical with higher gas-absorbing requirements, e.g., in a capacitor.

[0123] Electrical apparatus

[0124] In another aspect, provided herein is an electrical apparatus which comprises the insulating fluid or gas-absorbing fluid as described above.

[0125] Compared to a conventional insulating fluid, the insulating fluid or gas-absorbing fluid as described herein render the electrical apparatus better gas-absorbing properties. As a result, electrical apparatus containing the insulating fluid or gas-absorbing fluid as described herein may have better operational safety, especially the electrical apparatus involving harsh operating environment, such as medium to high voltage, high temperature or the like.

[0126] In some embodiments, the electrical apparatus comprises or comprises a part of a: capacitor, transformer, voltage transformer, current transformer, reactor, cable system, bushing, converter, or a component and / or a combination thereof.

[0127] In some embodiments, the electrical apparatus is a capacitor filled with the insulating fluid or gas-absorbing fluid as described herein. Breakdown is less likely to occur in such capacitor since it has better resistance to gassing and stability to electrical discharge.

[0128] Method for preparing electrical apparatus

[0129] In another aspect, provided herein is a method for preparing an electrical apparatus. The method herein comprises providing an electrical apparatus and filling the insulating fluid or gas-absorbing fluid as described herein into the electrical apparatus.

[0130] The insulating fluid or gas-absorbing fluid is preferably purified before being filled into the electrical apparatus to satisfy the requirements for use in electrical apparatus. Examples of the purification process include but are not limited to a clay filtration treatment or a vacuum dehydration treatment.

[0131] In some embodiments, the insulating fluid or gas-absorbing fluid has a neutralization value of 0.5 mgKOH / g or less before being filled into the electrical apparatus.

[0132] In some embodiments, the insulating fluid or gas-absorbing fluid has a water content of 200 ppm or less before being filled into the electrical apparatus.

[0133] Method for absorbing gas component

[0134] As described above, decreasing gaseous inclusions may be of great importance to prevent partial discharges. Before the application of insulating liquid to apparatus, the gases can be easily removed by conventional means, such as vacuuming. However, if an electrical apparatus has been equipped with insulating liquid, especially during operation period, it becomes more difficult to remove gases. For oxygen or water vapor, these gases can be absorbed by antioxidants or moisture absorbers, whereas the absorption of hydrogen or gaseous hydrocarbons remains a challenge.

[0135] The insulating fluid or gas-absorbing fluid as described herein has good excellent absorption properties for hydrogen or gaseous hydrocarbons and thus in another aspect, provided herein is a method for absorbing a gas component in an electrical apparatus, comprising applying the insulating fluid or gas-absorbing fluid as described above to the electrical apparatus.

[0136] As used herein, “absorb a gas component” refers to a process which result in a decrease on the amount of the gas component. The insulating fluid or gas-absorbing fluid as described herein realizes the process of absorbing a gas component by contacting with the target gas component to be absorbed. In some embodiments, the gas component is generated from chemical decomposition of insulating fluids filled in electrical apparatus under the impact of electrical and thermal stresses.

[0137] Gas component may be absorbed by any means, preferably by chemical reaction. The gas components may include, but are not limited to hydrogen gas and gaseous hydrocarbons, such as methane, ethane, ethylene, acetylene, etc. The preferable gas component is hydrogen gas.

[0138] The insulating fluid or gas-absorbing fluid is preferably purified before application to the electrical apparatus to obtain a further reduction of the dielectric loss of the fluids. Examples of the purification process include but are not limited to a clay filtration treatment or a vacuum dehydration treatment.

[0139] BENEFICIAL EFFECTS

[0140] The present inventors find for the first time that a compound of Formula (I) and a compound of Formula (II) can be used as an ideal insulating fluid or gas-absorbing fluid. The insulating fluid or gas-absorbing fluid according to the present disclosure shows remarkable gas-absorbing and flowing properties, as well as excellent dielectric properties, fire resistance and bio-degradability. In addition, the present insulating fluid or gas-absorbing fluid is of good commercial applicability due to low cost. EXAMPLES

[0141] The solution of the present disclosure will be further described in detail below in conjunction with specific examples.

[0142] It should be noted that the following examples are only examples for clearly explaining the technical solution of the present disclosure and are not limitations of the present disclosure. For an ordinary technical person in the art, other changes or modifications in different forms can be made on the basis of the above description, and it is unnecessary and impossible to exhaust all the embodiments herein and the obvious changes or modifications derived therefrom are still within the protection scope of the present disclosure. Unless otherwise specified, the instruments, equipment and reagent materials used herein are all commercially available.

[0143] Materials

[0144] Benzyl butyrate: CAS No. 103-37-7, purchased from Wanghua (Shandong) chemical technology Co., Ltd, China.

[0145] Propyl benzoate: CAS No. 2315-68-6, purchased from Hubei Jusheng technology Co., Ltd, China.

[0146] M / DBT (Jarylec C101): containing monobenzyl toluene and dibenzyl toluene, purchased from ARKEMA, France.

[0147] SAS-fluid: containing monobenzyl toluene and diphenyl ethane, purchased from Mitsubishi International GmbH, Germany.

[0148] Benzyl caprylate: CAS No. 10276-85-4, purchased from Weifang Tainuo chemical Co., Ltd, China.

[0149] The detailed information about formula and cost of Examples and Comparative Examples are shown in Table 1.

[0150] Table 1

[0151] Gassing Tendency Results

[0152] Table 2 showed the test results of gassing coefficient of Examples and Comparative Examples. Compared to Comparative Examples la-c, Examples la-b had a stronger negative gassing tendency. Table 2

[0153] Specifically, Comparative Examples la-c showed gassing coefficients of about -143 to - 122 mm3 / min. Examples la-b showed superior gassing coefficients (about -150 to -148 mm3 / min), which was comparable or even better gassing tendency over the Comparative Examples.

[0154] Flowing Properties Results

[0155] Pouring point test: conducted in at CEMT, Guilin (IEC 60867-2022).

[0156] Kinematic viscosity test: performed at HAECKEL, Henan and LONGHUA, Shanghai (GB / T265-1988).

[0157] The testing results of flowing properties for Examples and Comparative Examples are summarized in Table 3.

[0158] Table 3

[0159] It can be seen from Table 3 that Examples la-b had a much lower kinematic viscosity than Comparative Example la-c at room temperature and low temperatures. Such low viscosity is particularly well-suited for application in capacitors due to effective heat dissipation to avoid local overheating and reducing partial discharges occurrence.

[0160] Dielectric Properties Results

[0161] Table 4 listed the measurement results of Examples and Comparative Examples. It was found that Examples la-b had comparable or even higher breakdown voltages (with 2.5 mm electrode gap) and permittivities (at 50Hz and 100°C) than Comparative Example la-c. In capacitor products, increased permittivity enables a higher energy density to be achieved, diminishing the required quantity of insulating liquids and lowering costs.

[0162] Table 4

[0163] Swelling Properties Results

[0164] Swelling test: The capacitor film samples (BOPP (bi-axially oriented polypropylene) rough film, with a thickness of 9 micron) were immersed into different insulating fluids at an ageing temperature of 60°C for about 2 weeks to arrive at a saturated state. The swelling degree of the film samples is determined based on the weight gain of the samples.

[0165] Wight gain (%) = (W saturated -Wintial) / Wintial 100%, wherein

[0166] Wsaturated refers to the weight of a film sample that has arrived at a saturated state in in an insulating fluid,

[0167] Wintial refers to the weight of a film sample before being immersed into an insulating fluid.

[0168] Table 5

[0169] As shown in Table 5, Examples la-b had higher weight gains than Comparative Examples la-c, indicating a higher degree of swelling, which ensured a better impregnation effect between the capacitor films and the insulating fluids.

[0170] Combined insulating fluids system

[0171] Typical insulating fluids presently used in capacitor products were combined with benzyl butyrate or propyl benzoate and the detailed information about formula of Examples and Comparative Examples were shown in Table 6.

[0172] Table 7 showed the test results for gassing coefficient and kinematic viscosity, where the testing method for the gassing coefficient or kinematic viscosity in Table 7 was identical to that employed in Table 3 or 4. It can be seen from Table 7 that with the addition of benzyl butyrate or propyl benzoate, the combined insulating fluids system exhibited improved properties over those commonly used insulating fluids. Table 6 Table 7

[0173] Although the specific embodiments according to the present disclosure have been described above, it should be understood by those skilled in the art that this is by way of example only and the protection scope of the present disclosure is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principle and essence of the present disclosure, but these changes and modifications all fall within the protection scope of the present disclosure.

Claims

CLAIMS1. Use of a compound of Formula (I) or a compound of Formula (II) as an insulating fluid or a gas-absorbing fluid in an electrical apparatus,u ) whereinMi and M2 are each independently a hydrocarbon chain comprising from 1 to 5 carbon atoms; x and y are each independently 0 or 1 ;R1is Ci-4 hydrocarbyl;R2is Ce-io aryl, which is optionally substituted by one or more substituents selected from Ci-10 hydrocarbyl, hydroxyl, carboxyl, amino, nitro and halogen;R3is Ce-io aryl, which is optionally substituted by one or more substituents selected from Ci-10 hydrocarbyl, hydroxyl, carboxyl, amino, nitro and halogen;R4is Ci-17 hydrocarbyl.

2. The use according to claim 1, wherein in Formula (I),Mi is methylene; and / orR1is Ci-4 alkyl, preferably propyl; and / orR2is phenyl; and / or x is 1.

3. The use according to claim 1, wherein the compound of Formula (I) has the following formula:

4. The use according to claim 1, wherein in Formula (II),R3is phenyl; and / orR4is Ci-17 alkyl, preferably propyl; and / ory is 0.

5. The use according to claim 1, wherein the compound of Formula (II) has the following formula:

6. An insulating fluid or a gas-absorbing fluid for use in an electrical apparatus, comprising a compound of Formul ula (II):Formula (I). , . Formula (II) whereinMi and M2 are each independently a hydrocarbon chain comprising from 1 to 5 carbon atoms; x and y are each independently 0 or 1 ;R1is Ci-4 hydrocarbyl;R2is Ce-io aryl, which is optionally substituted by one or more substituents selected from Ci-10 hydrocarbyl, hydroxyl, carboxyl, amino, nitro and halogen;R3is Ce-io aryl, which is optionally substituted by one or more substituents selected from Ci-10 hydrocarbyl, hydroxyl, carboxyl, amino, nitro and halogen;R4is Ci-17 hydrocarbyl.

7. The insulating fluid or gas-absorbing fluid according claim 6, wherein in Formula (I),Mi is methylene; and / orR1is Ci-4 alkyl, preferably propyl; and / orR2is phenyl; and / or x is 1.

8. The insulating fluid or gas-absorbing fluid according claim 6, wherein the compound of Formula (I) has the following formula:

9. The insulating fluid or gas-absorbing fluid according claim 6, wherein in Formula (II), R3is phenyl; and / orR4is Ci-17 alkyl, preferably propyl; and / or y is 0.

10. The insulating fluid or gas-absorbing fluid according to claim 6, wherein the compound of Formula (II) has the following formula:

11. The insulating fluid or gas-absorbing fluid according to any one of claims 6-10, further comprising: a mineral oil, a vegetable oil, an alkyl aromatic, a synthetic ester, a silicon oil, a polyolefin, an epoxy resin or a combination thereof.

12. The insulating fluid or gas-absorbing fluid according to any one of claims 6-11, wherein the insulating fluid or gas-absorbing fluid has a kinematic viscosity of 100 mm2 / s or less, preferably 50 mm2 / s or less, more preferably 20 mm2 / s or less at 20°C measured in accordance with GB / T265-1988 or ISO 3104-2020; and / or the insulating fluid or gas-absorbing fluid has a kinematic viscosity of 400 mm2 / s or less, preferably 200 mm2 / s or less, more preferably 100 mm2 / s or less at -25°C measured in accordance with GB / T265-1988 or ISO 3104-2020; and / or the insulating fluid or gas-absorbing fluid has a kinematic viscosity of 1500 mm2 / s or less, preferably 1000 mm2 / s or less, more preferably 500 mm2 / s or less at -40°C measured in accordance with GB / T265-1988 or ISO 3104-2020; and / or the insulating fluid or gas-absorbing fluid has a kinematic viscosity of 3000 mm2 / s or less, preferably 2000 mm2 / s or less, more preferably 1000 mm2 / s or less at -50°C measured in accordance with GB / T265-1988 or ISO 3104-2020.

13. The insulating fluid or gas-absorbing fluid according to any one of claims 6-11, wherein the insulating fluid or gas-absorbing fluid has a pouring point of below -50°C measuredin accordance with IEC 60867-2022.

14. The insulating fluid or gas-absorbing fluid according to any one of claims 6-11, wherein the insulating fluid or gas-absorbing fluid has a gassing coefficient of below -20 mm3 / min, preferably below -50 mm3 / min, more preferably below -100 mm3 / min measured in accordance with IEC 60628 A (Ed.2, 1985).

15. An electrical apparatus, comprising the insulating fluid or gas-absorbing fluid according to any one of claims 6-14.

16. A method for preparing the electrical apparatus, comprising providing an electrical apparatus, and filling the insulating fluid or gas-absorbing fluid according to any one of claims 6-14 into the electrical apparatus.

17. The method according to claim 16, wherein the insulating fluid or gas-absorbing fluid is purified before being filled into the electrical apparatus.

18. The method according to claim 16 or 17, wherein the insulating fluid or gas-absorbing fluid has a neutralization value of 0.5 mgKOH / g or less before being filled into to the electrical apparatus, and / or the insulating fluid or gas-absorbing fluid has a water content of 200 ppm or less before being filled into the electrical apparatus.

19. A method for absorbing a gas component in an electrical apparatus, comprising applying the insulating fluid or gas-absorbing fluid according to any one of claims 6-14 to the electrical apparatus.

20. The method according to claim 18, wherein the gas component comprises hydrogen.

21. The use according to any one of claims 1-5, the insulating fluid or a gas-absorbing fluid according to any one of claims 6-14, the electrical apparatus according to claim 15 and the method according to any one of claims 16-20, wherein the electrical apparatus comprises or comprises a part of a: capacitor, transformer, voltage transformer, current transformer, reactor, cable system, bushing, converter, or a component and / or a combination thereof.

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