Dielectric composition, electrical device, supply method, and use of dielectric composition

Abstract

Provided are: a dielectric composition that contains a C2 halogenated olefin, carbon dioxide or nitrogen, and oxygen, wherein the carbon dioxide or nitrogen content with respect to the total amount of the halogenated olefin and the carbon dioxide or nitrogen, and the oxygen content with respect to the total amount of the halogenated olefin and the carbon dioxide or the nitrogen and the oxygen, are within specific ranges; an electrical device and a supply method in which said dielectric composition is used; and a use of said dielectric composition.

Description

Dielectric composition, electrical device, supply method, and use of dielectric composition

[0001] This disclosure relates to dielectric compositions, electrical devices, supply methods, and uses of dielectric compositions.

[0002] In medium-voltage or high-voltage electrical equipment, electrical insulation and, if necessary, electrical arc extinguishing are typically performed by a gas sealed inside the electrical equipment's enclosure. The most frequently used gas today is sulfur hexafluoride (SF6). ６ Sulfur hexafluoride has relatively high dielectric strength, good thermal conductivity, and low dielectric loss. Sulfur hexafluoride is chemically inert, non-toxic to humans and animals, and recombines almost completely immediately after being separated by an electric arc. Furthermore, sulfur hexafluoride is non-flammable and inexpensive. However, sulfur hexafluoride is a concern when the global warming index (GWP) is projected to increase over a 100-year period. ２ With a reference value of approximately 23,500 and a residual period in the atmosphere of approximately 3,200 years, it is known as one of the gases with a high greenhouse effect.

[0003] As an alternative to sulfur hexafluoride, it is known to use naturally derived gases such as air and nitrogen, which have a lower environmental impact compared to sulfur hexafluoride. However, since the dielectric strength of naturally derived gases is lower than that of sulfur hexafluoride, using naturally derived gases for electrical insulation or electric arc extinguishing in medium-voltage or high-voltage electrical equipment requires a significant increase in the volume of the electrical equipment or the gas filling pressure. Therefore, the use of naturally derived gases as an alternative to sulfur hexafluoride contradicts the efforts made over the past several decades to develop smaller electrical equipment with increasingly smaller external dimensions.

[0004] Another example of a substitute for sulfur hexafluoride is fluorinated olefins (see, for example, Patent Document 1). Fluorinated olefins have a low GWP and low toxicity to humans and animals, making them a promising compound as a substitute for sulfur hexafluoride.

[0005] International Publication No. 2021 / 206174

[0006] However, among fluorinated olefins, (E)-1,3,3,3-tetrafluoropropene and others have relatively high boiling points and are prone to liquefaction in low-temperature environments, posing challenges in handling. Furthermore, some fluorinated olefins are highly flammable. When using highly flammable gases, fire extinguishing equipment and firewalls are necessary as a fire prevention measure in the event of an equipment malfunction; therefore, it is desirable that the dielectric composition be non-flammable.

[0007] Furthermore, the dielectric composition may contain oxygen. When the dielectric composition contains oxygen, it can capture carbon generated by the decomposition of the dielectric and convert it into carbon dioxide, thereby suppressing the increase in conductivity due to carbon. However, oxygen is a combustion-supporting agent, and if electrical components are present in the container housing the dielectric composition, these components could potentially act as an ignition source, potentially leading to combustion.

[0008] In view of the above circumstances, this disclosure relates to a dielectric composition that is easy to handle due to its low GWP and low boiling point, and that can reduce the possibility of combustion in a container containing the dielectric composition while containing oxygen, as well as an electrical device and supply method using the dielectric composition, and the use of the dielectric composition.

[0009] Means for solving the above problems include the following embodiments: <1> A dielectric composition comprising a C2 halogenated olefin, carbon dioxide, and oxygen, wherein the content of carbon dioxide relative to the total amount of the C2 halogenated olefin and carbon dioxide is 82.5% by volume or more, and the content of oxygen relative to the total amount of the C2 halogenated olefin, carbon dioxide, and oxygen is 1.0 to 18.0% by volume; or a dielectric composition comprising a C2 halogenated olefin, nitrogen, and oxygen, wherein the content of nitrogen relative to the total amount of the C2 halogenated olefin and nitrogen is 88.8% by volume or more, and the content of oxygen relative to the total amount of the C2 halogenated olefin, nitrogen, and oxygen is 1.0 to 14.0% by volume. <2> A dielectric composition according to <1>, comprising a C2 halogenated olefin, carbon dioxide, and oxygen, wherein the content of carbon dioxide relative to the total amount of the C2 halogenated olefin and carbon dioxide is 85.0% by volume or more, and the content of oxygen relative to the total amount of the C2 halogenated olefin, carbon dioxide, and oxygen is 1.0 to 18.0% by volume; or comprising a C2 halogenated olefin, nitrogen, and oxygen, wherein the content of nitrogen relative to the total amount of the C2 halogenated olefin and nitrogen is 91.0% by volume or more, and the content of oxygen relative to the total amount of the C2 halogenated olefin, nitrogen, and oxygen is 1.0 to 14.0% by volume. <3> A dielectric composition according to <1> or <2>, wherein the C2 halogenated olefin comprises at least one selected from the group consisting of 1,1-difluoroethylene, (E)-1,2-difluoroethylene, (Z)-1,2-difluoroethylene, and trifluoroethylene. <4> The dielectric composition according to any one of <1> to <3>, wherein the C2 halogenated olefin is 1,1-difluoroethylene. <5> The dielectric composition according to <4>, wherein the total content of 1,1-difluoroethylene, carbon dioxide, and oxygen relative to the total amount of the dielectric composition is 99.0% by volume or more, or the total content of 1,1-difluoroethylene, nitrogen, and oxygen relative to the total amount of the dielectric composition is 99.0% by volume or more.<6> The dielectric composition according to any one of <1> to <5>, wherein the moisture content of the dielectric composition is 3,000 mass ppm or less. <7> The dielectric composition according to any one of <1> to <6>, which is in a single-phase state. <8> The dielectric composition according to any one of <1> to <7>, which is used as an electrical insulating medium or an electrical arc extinguishing medium. <9> An electrical device comprising: an electrical component; the dielectric composition according to any one of <1> to <8>; and a sealed container accommodating the dielectric composition. <10> The electrical device according to <9>, which is a gas-insulated circuit breaker, a current interruption facility, a gas-insulated power transmission line, a gas-insulated transformer, a gas-insulated substation, a gas-insulated switch, a gas-insulated disconnector, a gas-insulated load switch, or a particle accelerator. <11> A supply method of supplying the dielectric composition according to any one of <1> to <8> to an electrical device. <12> Use of a dielectric composition, wherein the dielectric composition according to any one of <1> to <8> is used at a temperature of -75°C to 60°C. <13> Use of the dielectric composition according to any one of <1> to <8> as an electrical insulating medium or an electrical arc extinguishing medium.

[0010] According to the present disclosure, there are provided a dielectric composition which has a low GWP, is easy to handle due to a low boiling point, and can reduce the possibility of combustion in a container accommodating the dielectric composition while containing oxygen, an electrical device and a supply method using the same, and use of the dielectric composition.

[0011] It is a cross-sectional view showing a configuration example of an electrical device in one aspect. It is a schematic diagram of a supply method of a dielectric composition in one aspect. It is a schematic diagram of a supply method of a dielectric composition in one aspect. It is a schematic diagram of a supply method of a dielectric composition in one aspect. It is a schematic diagram of a supply method of a dielectric composition in one aspect. It is a schematic diagram of a supply method of a dielectric composition in one aspect. It is a schematic diagram of a supply method of a dielectric composition in one aspect. It is a schematic diagram of a supply method of a dielectric composition in one aspect.

[0012] Hereinafter, modes for carrying out embodiments of the present disclosure will be described in detail. However, embodiments of the present disclosure are not limited to the following embodiments. In the following embodiments, the constituent elements (including element steps and the like) are not essential unless explicitly stated otherwise. The same applies to numerical values and their ranges, which are not intended to limit the embodiments of the present disclosure.

[0013] In the present disclosure, the term "process" includes not only a process independent of other processes, but also a process that cannot be clearly distinguished from other processes, as long as the object of the process is achieved. In the present disclosure, the numerical range indicated by using "~" includes the numerical values described before and after "~" as the minimum value and the maximum value, respectively. In the numerical ranges described stepwise in the present disclosure, the upper limit or lower limit described in one numerical range may be replaced with the upper limit or lower limit of the numerical range described in another stepwise description. Furthermore, in the numerical ranges described in the present disclosure, the upper limit or lower limit of the numerical range may be replaced with the values shown in the examples. In the present disclosure, each component may contain a plurality of types of corresponding substances. When a plurality of types of substances corresponding to each component are present in the composition, the content rate or content of each component means the total content rate or content of the plurality of types of substances present in the composition, unless otherwise specified. In the present disclosure, a combination of two or more preferred embodiments is a more preferred embodiment. In the present disclosure, even when an element is described in the singular, the existence of a plurality of elements is not excluded unless explicitly stated otherwise and as long as no technical contradiction arises. In the present disclosure, the proportion of each component in the dielectric composition represents the proportion of each component when the dielectric composition is in a gas phase state. In the present disclosure, when embodiments are described with reference to the drawings, the configuration of the embodiments is not limited to the configuration shown in the drawings. In addition, the size of members in each drawing is conceptual, and the relative relationship of the sizes between members is not limited thereto.

[0014] <Dielectric Composition> The dielectric composition of this disclosure contains a C2 halogenated olefin, carbon dioxide, and oxygen, wherein the carbon dioxide content relative to the total amount of the C2 halogenated olefin and carbon dioxide is 82.5% by volume or more, and the oxygen content relative to the total amount of the C2 halogenated olefin, carbon dioxide, and oxygen is 1.0 to 18.0% by volume; or it contains a C2 halogenated olefin, nitrogen, and oxygen, wherein the nitrogen content relative to the total amount of the C2 halogenated olefin and nitrogen is 88.8% by volume or more, and the oxygen content relative to the total amount of the C2 halogenated olefin, nitrogen, and oxygen is 1.0 to 14.0% by volume. Hereinafter, the C2 halogenated olefin will also be referred to as "specific olefin". The dielectric composition of this disclosure has a low GWP and a low boiling point, making it easy to handle, and while containing oxygen, it can reduce the possibility of combustion in a container containing the dielectric composition. For example, the dielectric composition of this disclosure is not easily combustible at 20°C.

[0015] In one embodiment, the dielectric composition comprises a specific olefin, carbon dioxide, and oxygen, wherein the carbon dioxide content relative to the total amount of the specific olefin and carbon dioxide is 85.0% by volume or more, and the oxygen content relative to the total amount of the specific olefin, carbon dioxide, and oxygen is 1.0 to 18.0% by volume; or, it comprises a specific olefin, nitrogen, and oxygen, wherein the nitrogen content relative to the total amount of the specific olefin and nitrogen is 91.0% by volume or more, and the oxygen content relative to the total amount of the specific olefin, nitrogen, and oxygen is 1.0 to 14.0% by volume. The dielectric composition of this embodiment is less flammable in higher temperature environments, for example, at 60°C.

[0016] Patent Document 1 specifically describes dielectrics containing halogenated propenees such as 1-chloro-2,3,3,3-tetrafluoropropene, 2,3,3,3-tetrafluoro-1-propene, and (E)-1,3,3,3-tetrafluoropropene. For example, (E)-1,3,3,3-tetrafluoropropene has a relatively high boiling point of approximately -19°C. Therefore, it has handling issues, such as being prone to liquefaction at low operating temperatures. On the other hand, certain olefins have relatively low boiling points, which is advantageous in terms of handling in low-temperature environments. On the other hand, some of the certain olefins are flammable, but the dielectric compositions of this disclosure can have their flammability suppressed by using carbon dioxide or nitrogen in combination.

[0017] Furthermore, since carbon dioxide and nitrogen have boiling points equivalent to or lower than those of certain olefins, they are less likely to liquefy even at low temperatures. Therefore, when the dielectric composition of this disclosure is supplied to an electrical device and operated at a predetermined temperature, it tends to be easier to maintain the internal pressure of the device.

[0018] Generally, the flammability of dielectric compositions is evaluated by mixing them with moist air, assuming that they leak from a sealed container and come into contact with air. On the other hand, since oxygen has combustion-supporting properties, it is desirable that dielectric compositions containing oxygen can ensure non-flammability even in a sealed container. Through the inventors' research, it was found that the dielectric composition of this disclosure containing oxygen suppresses flammability in a container.

[0019] In this disclosure, an embodiment relating to a dielectric composition containing a specific olefin, carbon dioxide, and oxygen, wherein the carbon dioxide content relative to the total amount of the specific olefin and carbon dioxide is 82.5% by volume or more, and the oxygen content relative to the total amount of the specific olefin, carbon dioxide, and oxygen is 1.0 to 18.0% by volume, is referred to as the "first embodiment." Furthermore, an embodiment relating to a dielectric composition containing a specific olefin, nitrogen, and oxygen, wherein the nitrogen content relative to the total amount of the specific olefin and nitrogen is 88.8% by volume or more, and the oxygen content relative to the total amount of the specific olefin, nitrogen, and oxygen is 1.0 to 14.0% by volume, is referred to as the "second embodiment." The dielectric compositions of the first and second embodiments are collectively referred to as the "dielectric compositions of this disclosure" or simply as the "dielectric compositions." Hereinafter, each component included in the dielectric compositions of this disclosure will be described in detail.

[0020] (Specific Olefins) Specific olefins are not particularly limited as long as they are olefins with two carbon atoms and contain at least one halogen atom. From the viewpoint of low environmental impact and excellent insulating and arc-extinguishing properties, specific olefins preferably contain fluorine atoms and / or chlorine atoms, and more preferably fluorine atoms. The number of halogen atoms in a specific olefin is preferably 2 to 4, and more preferably 2 or 3. Also, generally speaking, the fewer hydrogen atoms in an olefin, the lower the flammability tends to be. From this viewpoint, the number of hydrogen atoms in a specific olefin is preferably 2 or less, and may be 1 or less. Specific olefins may be used individually, or two or more may be used in combination.

[0021] The GWP of the specified olefin is preferably 500 or less, more preferably 200 or less, even more preferably 150 or less, particularly preferably 100 or less, even more preferably 50 or less, even more preferably 20 or less, even more preferably 15 or less, even more preferably 10 or less, even more preferably 7 or less, even more preferably 5 or less, even more preferably 4 or less, and even more preferably 3 or less. Unless otherwise specified, the GWP is the 100-year value from the Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report (AR6).

[0022] From the viewpoint of ease of handling in low-temperature environments, the boiling point of the specific olefin is preferably -20°C or lower, more preferably -40°C or lower, even more preferably -60°C or lower, and particularly preferably -80°C or lower. The boiling point of the specific olefin may be -100°C or higher. From this viewpoint, the boiling point of the specific olefin is preferably -100 to -20°C, more preferably -100 to -40°C, even more preferably -100 to -60°C, and particularly preferably -100 to -80°C.

[0023] Examples of specific olefins include 1,1-difluoroethylene, (E)-1,2-difluoroethylene, (Z)-1,2-difluoroethylene, vinyl fluoride, tetrafluoroethylene, and trifluoroethylene. Among these, 1,1-difluoroethylene, (E)-1,2-difluoroethylene, (Z)-1,2-difluoroethylene, and trifluoroethylene are preferred, and from the viewpoint of ease of handling due to their low boiling point, 1,1-difluoroethylene, (E)-1,2-difluoroethylene, and trifluoroethylene are more preferred, with 1,1-difluoroethylene being even more preferred.

[0024] The table below lists specific examples of the specific olefins used in the dielectric compositions of this disclosure, as well as the boiling points and GWPs of other compounds used as dielectrics. In the table below, "N.D." indicates that the compound is not listed in the IPCC Sixth Assessment Report (AR6), and is presumed to be 10 or less based on the compound's structure.

[0025]

[0026] In the first embodiment, the content of the specific olefin in the total amount of the dielectric composition is preferably 17.1 volume% or less, more preferably 15.5 volume% or less, even more preferably 14.9 volume% or less, particularly preferably 14.8 volume% or less, extremely preferably 14.5 volume% or less, and even more preferably 14.0 volume% or less, from the viewpoint of suppressing flammability. From the viewpoint of insulating performance and arc extinguishing performance, the content is preferably 3.0 volume% or more, more preferably 4.0 volume% or more, and even more preferably 5.0 volume% or more. From this viewpoint, the content is preferably 3.0 to 17.1 volume%, more preferably 3.0 to 15.5 volume%, even more preferably 3.0 to 14.9 volume%, particularly preferably 3.0 to 14.8 volume%, extremely preferably 4.0 to 14.5 volume%, and even more preferably 5.0 to 14.0 volume%. In particular, the specific olefin is 1,1-difluoroethylene, and it is preferable that the content of 1,1-difluoroethylene is within the above range.

[0027] In the second embodiment, the content of the specific olefin in the total amount of the dielectric composition is preferably 11.0 volume% or less, more preferably 9.5 volume% or less, even more preferably 8.9 volume% or less, particularly preferably 8.5 volume% or less, and extremely preferably 8.0 volume% or less, from the viewpoint of suppressing flammability. From the viewpoint of insulating performance and arc extinguishing performance, the content is preferably 3.0 volume% or more, more preferably 3.5 volume% or more, and even more preferably 4.0 volume% or more. From this viewpoint, the content is preferably 3.0 to 11.0 volume%, more preferably 3.0 to 9.5 volume%, even more preferably 3.0 to 8.9 volume%, particularly preferably 3.5 to 8.5 volume%, and extremely preferably 4.0 to 8.0 volume%. Among these, the specific olefin is 1,1-difluoroethylene, and it is preferable that the content of 1,1-difluoroethylene is within the above range.

[0028] (Carbon Dioxide) In the first embodiment, the dielectric composition contains carbon dioxide. The carbon dioxide content relative to the total amount of the specific olefin and carbon dioxide is 82.5% by volume or more, and from the viewpoint of reducing flammability, 85.0% by volume or more is preferred, 85.1% by volume or more is more preferred, 85.5% by volume or more is even more preferred, and 86.0% by volume or more is particularly preferred. From the viewpoint of better exhibiting the function of the specific olefin, the content is preferably 97.0% by volume or less, more preferably 96.0% by volume or less, and even more preferably 95.0% by volume or less. From this viewpoint, the content is preferably 82.5 to 97.0% by volume, more preferably 85.0 to 97.0% by volume, even more preferably 85.1 to 97.0% by volume, particularly preferred, and extremely preferred to 85.5 to 96.0% by volume.

[0029] In the first embodiment, when the specific olefin is 1,1-difluoroethylene, the carbon dioxide content relative to the total amount of 1,1-difluoroethylene and carbon dioxide is 82.5% by volume or more, and from the viewpoint of reducing flammability, 85.0% by volume or more is preferred, 85.1% by volume or more is more preferred, 85.5% by volume or more is even more preferred, and 86.0% by volume or more is particularly preferred. From the viewpoint of better exhibiting the function of 1,1-difluoroethylene, the content is preferably 97.0% by volume or less, more preferably 96.0% by volume or less, and even more preferably 95.0% by volume or less. From this viewpoint, the content is preferably 82.5 to 97.0% by volume, more preferably 85.0 to 97.0% by volume, even more preferably 85.1 to 97.0% by volume, particularly preferred, and extremely preferred.

[0030] In the first embodiment, the carbon dioxide content in the entire dielectric composition is preferably 67.6% by volume or more, more preferably 69.7% by volume or more, even more preferably 72.0% by volume or more, and particularly preferably 73.5% by volume or more, from the viewpoint of reducing flammability. From the viewpoint of better exhibiting the function of the specific olefin, the content is preferably 96.0% by volume or less, more preferably 95.0% by volume or less, and even more preferably 94.0% by volume or less. From this viewpoint, the content is preferably 67.6 to 96.0% by volume, more preferably 69.7 to 96.0% by volume, even more preferably 72.0 to 95.0% by volume, and particularly preferably 73.5 to 94.0% by volume.

[0031] (Nitrogen) In the second embodiment, the dielectric composition contains nitrogen. The nitrogen content relative to the total amount of the specific olefin and nitrogen is 88.8% by volume or more, and from the viewpoint of further reducing flammability, it is preferably 91.0% by volume or more, more preferably 91.1% by volume or more, even more preferably 91.5% by volume or more, and particularly preferably 92.0% by volume or more. From the viewpoint of better exhibiting the function of the specific olefin, the content is preferably 97.0% by volume or less, more preferably 96.5% by volume or less, and even more preferably 96.0% by volume or less. From this viewpoint, the content is preferably 88.8 to 97.0% by volume, more preferably 91.0 to 97.0% by volume, even more preferably 91.1 to 97.0% by volume, particularly preferably 91.5 to 96.5% by volume, and extremely preferably 92.0 to 96.0% by volume.

[0032] In the second embodiment, when the specific olefin is 1,1-difluoroethylene, the nitrogen content relative to the total amount of 1,1-difluoroethylene and nitrogen is 88.8% by volume or more, and from the viewpoint of further reducing flammability, 91.1% by volume or more is preferred, 91.5% by volume or more is more preferred, and 92.0% by volume or more is even more preferred. From the viewpoint of better exhibiting the function of 1,1-difluoroethylene, the nitrogen content is preferably 97.0% by volume or less, more preferably 96.5% by volume or less, and even more preferably 96.0% by volume or less. From this viewpoint, the nitrogen content is preferably 88.8 to 97.0% by volume, more preferably 91.1 to 97.0% by volume, even more preferably 91.5 to 96.5% by volume, and particularly preferably 92.0 to 96.0% by volume.

[0033] In the second embodiment, the nitrogen content in the entire dielectric composition is preferably 76.3% by volume or more, more preferably 78.3% by volume or more, even more preferably 79.0% by volume or more, and particularly preferably 80.0% by volume or more, from the viewpoint of reducing flammability. From the viewpoint of better exhibiting the function of the specific olefin, the nitrogen content is preferably 96.0% by volume or less, more preferably 95.0% by volume or less, and even more preferably 94.0% by volume or less. From this viewpoint, the nitrogen content is preferably 76.3 to 96.0% by volume, more preferably 78.3 to 96.0% by volume, even more preferably 79.0 to 95.0% by volume, and particularly preferably 80.0 to 94.0% by volume.

[0034] (Oxygen) In the first embodiment, the oxygen content relative to the total amount of specific olefin, carbon dioxide, and oxygen is 1.0 to 18.0 volume%. From the viewpoint of further suppressing carbon generation, the oxygen content is preferably 1.5 volume% or more, and more preferably 2.0 volume% or more. From the viewpoint of further suppressing flammability in the container containing the dielectric composition, the oxygen content is preferably 17.0 volume% or less, and more preferably 15.0 volume% or less.

[0035] In the first embodiment, the oxygen content relative to the total amount of the dielectric composition is preferably 1.0 to 18.0 volume%. From the viewpoint of further suppressing carbon generation, the oxygen content is preferably 1.5 volume% or more, and more preferably 2.0 volume% or more. From the viewpoint of further suppressing flammability in the container containing the dielectric composition, the oxygen content is preferably 17.0 volume% or less, and more preferably 15.0 volume% or less.

[0036] In the second embodiment, the oxygen content relative to the total amount of specific olefin, nitrogen, and oxygen is 1.0 to 14.0 volume%. From the viewpoint of further suppressing carbon generation, the oxygen content is preferably 1.5 volume% or more, and more preferably 2.0 volume% or more. From the viewpoint of further suppressing flammability in the container containing the dielectric composition, the oxygen content is preferably 13.5 volume% or less, and more preferably 13.0 volume% or less.

[0037] In the second embodiment, the oxygen content relative to the total amount of the dielectric composition is preferably 1.0 to 14.0 volume%. From the viewpoint of further suppressing carbon generation, the oxygen content is preferably 1.5 volume% or more, and more preferably 2.0 volume% or more. From the viewpoint of further suppressing flammability in the container containing the dielectric composition, the oxygen content is preferably 13.5 volume% or less, and more preferably 13.0 volume% or less.

[0038] (Other components) In the first embodiment, the dielectric composition may or may not contain components other than the specific olefin and carbon dioxide. In the second embodiment, the dielectric composition may or may not contain components other than the specific olefin and nitrogen.

[0039] In the first embodiment, the dielectric composition may or may not further contain nitrogen. If the dielectric composition further contains nitrogen in the first embodiment, the nitrogen content relative to the total amount of the dielectric composition is preferably 2.0 volume% or less, more preferably 1.0 volume% or less, and even more preferably 0.5 volume% or less. In the second embodiment, the dielectric composition may or may not further contain carbon dioxide. If the dielectric composition further contains carbon dioxide in the second embodiment, the carbon dioxide content relative to the total amount of the dielectric composition is preferably 2.0 volume% or less, more preferably 1.0 volume% or less, and even more preferably 0.5 volume% or less.

[0040] The dielectric composition may or may not contain components other than the specified olefin, carbon dioxide, and nitrogen. Examples of components other than the specified olefin, carbon dioxide, and nitrogen include at least one component selected from the group consisting of halogenated olefins other than the specified olefin (fluoroolefins other than the specified olefin, chloroolefins other than the specified olefin, chlorofluoroolefins other than the specified olefin, etc.), fluorocarbons, chlorofluorocarbons, chlorofluoroalkynes, methanol, ethanol, acetone, hexane, ethylene, methane, chloromethane, 1,1-dichloroethane, 1,2-dichloroethane, acetylene, 2-methyl-2-propanol, β-pinene, pentafluoroiodoethane, and carbon monoxide (hereinafter also referred to as the "first specified trace component"). These components are thought to have the function of suppressing and stabilizing the decomposition of the specified olefin, although the reason is not clear. The first specified trace component is preferably non-flammable. Specifically, the first specified trace component is preferably Class 1 according to the ASHRAE Standard 34 refrigerant safety classification standard.

[0041] In this disclosure, fluoroolefin means an unsaturated hydrocarbon compound having a carbon-carbon double bond, containing a fluorine atom as a halogen atom in the molecule but not a chlorine atom. Fluoroolefins may or may not contain a hydrogen atom in the molecule. In this disclosure, chloroolefin means an unsaturated hydrocarbon compound having a carbon-carbon double bond, containing a chlorine atom as a halogen atom in the molecule but not a fluorine atom. Chloroolefins may or may not contain a hydrogen atom in the molecule. In this disclosure, chlorofluoroolefin means an unsaturated hydrocarbon compound having a carbon-carbon double bond, containing both a fluorine atom and a chlorine atom as halogen atoms in the molecule. Chlorofluoroolefins may or may not contain a hydrogen atom in the molecule. In this disclosure, fluorocarbon means a saturated hydrocarbon compound containing a fluorine atom as a halogen atom in the molecule but not a chlorine atom. Fluorocarbons may or may not contain a hydrogen atom in the molecule. In this disclosure, chlorofluorocarbon means a saturated hydrocarbon compound containing both a fluorine atom and a chlorine atom as halogen atoms in the molecule. Chlorofluorocarbons may or may not contain a hydrogen atom in the molecule. In this disclosure, chlorofluoroalkyne refers to an unsaturated hydrocarbon compound having a carbon-carbon triple bond, containing a fluorine atom and a chlorine atom as halogen atoms in the molecule. Chlorofluoroalkyne may or may not contain a hydrogen atom in the molecule.

[0042] The first specified trace component may include fluoroolefins other than the specified olefins. Examples of fluoroolefins other than the specified olefins include hexafluoropropene, 2,3,3,3-tetrafluoro-1-propene, (E)-1,3,3,3-tetrafluoropropene, (Z)-1,3,3,3-tetrafluoropropene, (E)-1,1,1,4,4,4-hexafluorobuta-2-ene, (Z)-1,1,1,4,4,4-hexafluorobuta-2-ene, and C ４ H ４ F ４ Examples include fluorinated hydrocarbons represented by C. ４ H ４ F４ Examples of fluorinated hydrocarbons represented by include 1,3,4,4-tetrafluoro-1-butene, 3,4,4,4-tetrafluoro-1-butene, 1,1,2,3-tetrafluoro-1-butene, and 2,4,4,4-tetrafluoro-1-butene.

[0043] The first specified trace component may include chloroolefins other than the specified olefins. Examples of chloroolefins other than the specified olefins include chloroethylene, 1,1-dichloroethylene, 1,2-dichloroethylene, 1,1,2-trichloroethylene, and 1,1,2,2-tetrachloroethylene.

[0044] The first specified trace component may include chlorofluoroolefins other than the specified olefins. Examples of chlorofluoroolefins other than the specified olefins include 1,2-dichloro-1-fluoroethylene, chlorotrifluoroethylene, 1,1,2-trichloro-2-fluoroethylene, (E)-1-chloro-2,3,3,3-tetrafluoropropene, (Z)-1-chloro-2,3,3,3-tetrafluoropropene, (E)-2-chloro-1,3,3,3-tetrafluoropropene, (Z)-2-chloro-1,3,3,3-tetrafluoropropene, (E)-1-chloro-3,3,3-trifluoropropene, (Z)-1-chloro-3,3,3-trifluoropropene, 2-chloro-3,3,3-trifluoropropene, 2-chloro-1,1,3,3,3-pentafluoro-1-propene, and 1,1-dichloro-2,3,3,3-tetrafluoropropene.

[0045] The first specific trace component may contain a fluorocarbon. Examples of the fluorocarbon include monofluoromethane, difluoromethane, trifluoromethane, tetrafluoromethane, fluoroethane, 1,1-difluoroethane, 1,2-difluoroethane, 1,1,1-trifluoroethane, 1,1,2-trifluoroethane, 1,1,1,2-tetrafluoroethane, 1,1,2,2-tetrafluoroethane, 1,1,1,2,2-pentafluoroethane, 1,1,1,2-tetrafluoropropane, 1,1,1,3,3-pentafluoropropane, 1,1,1,2,2,3,3-heptafluoropropane, C ４ H ６ F ４ fluorinated hydrocarbons represented by, and octafluorocyclobutane. C ４ H ６ F ４ An example of the fluorinated hydrocarbon represented by is 1,1,2,3-tetrafluorobutane.

[0046] The first specific trace component may contain a chlorofluorocarbon. Examples of the chlorofluorocarbon include chlorodifluoromethane, chlorotrifluoromethane, 1-chloro-1,1-difluoroethane, 1-chloro-1,2-difluoroethane, 1-chloro-2,2-difluoroethane, 1,1-dichloro-1-fluoroethane, 1,1-dichloro-2-fluoroethane, 1,2-dichloro-2-fluoroethane, 2-chloro-1,1,1,2-tetrafluoropropane, 1,3-dichloro-1,1,2,2,3-pentafluoropropane, and 3,3-dichloro-1,1,1,2,2-pentafluoropropane.

[0047] The first specific trace component may contain a chlorofluoroalkyne. An example of the chlorofluoroalkyne includes 1-chloro-3,3,3-trifluoro-1-propyne.

[0048] When the dielectric composition contains a first specific trace component, the content of the first specific trace component relative to the total amount of the dielectric composition (or the total content if two or more types of the first specific trace component are included) is preferably 15,000 ppm by mass or less, and more preferably 10,000 ppm by mass or less, from the viewpoint of ensuring stability. The content may be 0 ppm by mass or more, 4 ppm by mass or more, 50 ppm by mass or more, or 100 ppm by mass or more. From this viewpoint, the content is preferably 0 to 15,000 ppm by mass, may be 50 to 10,000 ppm by mass, or 100 to 10,000 ppm by mass.

[0049] The dielectric composition may contain, but preferably does not contain, at least one trace component selected from the group consisting of chlorine, hydrogen fluoride, hydrogen chloride, acetic acid, carbonyl fluoride, phosgene, trifluoroacetic acid fluoride, acetyl chloride, carbon monoxide, formyl chloride, and chloroform. From the viewpoint of reducing the possibility that the second specific trace component may react with the metal material or dissolve in water and come into contact with the metal material, causing deterioration or embrittlement of the metal material, the content of the second specific trace component (total content if two or more types of the second specific trace component are included) relative to the total amount of the dielectric composition is preferably 5,000 ppm by mass or less, more preferably 3,000 ppm by mass or less, even more preferably 1,000 ppm by mass or less, particularly preferably 500 ppm by mass or less, extremely preferably 250 ppm by mass or less, even more preferably 100 ppm by mass or less, even more preferably 50 ppm by mass or less, even more preferably 20 ppm by mass or less, and even more preferably 0 ppm by mass. The content may be 5 ppm by mass or more, or 10 ppm by mass or more. From this viewpoint, the content may be 0 to 5,000 ppm by mass, or 5 to 3,000 ppm by mass.

[0050] The dielectric composition may contain a first specific trace component and a second specific trace component. When the dielectric composition contains a first specific trace component and a second specific trace component, the preferred ranges of their content are as described above.

[0051] In the first embodiment, the total content of the specific olefin, carbon dioxide, and oxygen relative to the total amount of the dielectric composition is preferably 99.0% by volume or more, more preferably 99.5% by volume or more, and may be 100% by volume. In the second embodiment, the total content of the specific olefin, nitrogen, and oxygen relative to the total amount of the dielectric composition is preferably 99.0% by volume or more, more preferably 99.5% by volume or more, and may be 100% by volume.

[0052] In the first embodiment, when the specific olefin is 1,1-difluoroethylene, the total content of 1,1-difluoroethylene, carbon dioxide, and oxygen relative to the total amount of the dielectric composition is preferably 99.0% by volume or more, more preferably 99.5% by volume or more, and may be 100% by volume. In the second embodiment, when the specific olefin is 1,1-difluoroethylene, the total content of 1,1-difluoroethylene, nitrogen, and oxygen relative to the total amount of the dielectric composition is preferably 99.0% by volume or more, more preferably 99.5% by volume or more, and may be 100% by volume.

[0053] (Characteristics and Usage of the Dielectric Composition) The dielectric composition of this disclosure may be in a gaseous state at 25°C, or it may be a mixture of gas and liquid. It is preferable that it be in a gaseous state before supplying power to an electrical device and inside the electrical device.

[0054] In one embodiment, the dielectric composition is preferably in a single-phase state. The dielectric composition is preferably used in a single-phase gaseous state. A single-phase gaseous state means that the entire amount of the dielectric composition is in a gaseous state within a sealed container containing the dielectric composition. Here, "used" means that the dielectric composition is used in a sealed container for a desired purpose such as an electrical insulating medium or an electrical arc extinguishing medium. By using the dielectric composition in a single-phase gaseous state, changes in the volume ratio of the dielectric composition within the container can be suppressed, and pressure changes due to temperature changes can be reduced.

[0055] It is preferable that the dielectric composition does not condense over the entire planned operating temperature range. The dielectric composition of this disclosure can suppress condensation even at relatively low operating temperatures by using a specific olefin.

[0056] From the viewpoint of allowing the dielectric composition to exist only in the gas phase, the condensation temperature of the dielectric composition is preferably 0°C or lower, more preferably -10°C or lower, even more preferably -20°C or lower, and particularly preferably -30°C or lower. From the viewpoint of economy, the condensation temperature of the dielectric composition may be -75°C or higher, or -70°C or higher. From this viewpoint, the condensation temperature of the dielectric composition is preferably -75 to 0°C, more preferably -70 to -10°C, even more preferably -70 to -20°C, and particularly preferably -70 to -30°C.

[0057] From the viewpoint of stability, the moisture content of the dielectric composition is preferably 6,000 ppm by mass or less, 5,000 ppm by mass or less, 4,000 ppm by mass or less, 3,000 ppm by mass or less, 2,500 ppm by mass or less, 1,000 ppm by mass or less, 800 ppm by mass or less, 500 ppm by mass or less, 420 ppm by mass or less, 370 ppm by mass or less, 300 ppm by mass or less, 150 ppm by mass or less, 120 ppm by mass or less, 100 ppm by mass or less, 50 ppm by mass or less, 25 ppm by mass or less, or 20 ppm by mass or less. By keeping the moisture content low, the decrease in insulating properties can be suppressed. From the viewpoint of economy, the moisture content of the dielectric composition is preferably 3 ppm by mass or more, 5 ppm by mass or more, 7 ppm by mass or more, 10 ppm by mass or more, or 15 ppm by mass or more. From this viewpoint, the moisture content of the dielectric composition is preferably 3 to 6,000 ppm by mass, and more preferably 3 to 3,000 ppm by mass. The moisture content of the dielectric composition refers to the value measured by the dew point method. For example, the moisture content of the dielectric composition is measured by the method described in International Electrotechnical Commission (IEC) 60376:2005.

[0058] The operating temperature of the dielectric composition is preferably higher than the condensation temperature of the dielectric composition in order to prevent condensation of the dielectric composition in the gas phase. From the viewpoint of climate and operating environment, the operating temperature of the dielectric composition is preferably -75°C or higher, -70°C or higher, -60°C or higher, -50°C or higher, -40°C or higher, or -30°C or higher. When the temperature is -75°C or higher, the liquefaction of specific olefins can be suitably suppressed. Furthermore, from the viewpoint of the design pressure of the equipment, it is preferably 60°C or lower, 50°C or lower, 40°C or lower, 30°C or lower, 25°C or lower, or 20°C or lower. Here, "operating temperature" refers to the temperature of the gas in the sealed container containing the dielectric composition, and this temperature may fluctuate over time, especially depending on climatic or environmental conditions. In particular, the dielectric composition is preferably used at a temperature of -75°C to 60°C, more preferably at a temperature of -70 to 50°C, and even more preferably at a temperature of -60 to 40°C.

[0059] From the viewpoint of suppressing condensation, the operating pressure of the dielectric composition is preferably positive at ambient temperature. From this viewpoint, the operating pressure of the dielectric composition is preferably 0.01 MPa or higher, more preferably 0.02 MPa or higher, and even more preferably 0.03 MPa or higher, based on a gauge pressure at -75°C. From the viewpoint of insulating properties, the dielectric composition is preferably filled at a higher pressure than sulfur hexafluoride. From this viewpoint, the operating pressure of the dielectric composition is preferably 0.3 MPa or higher, more preferably 0.4 MPa or higher, and even more preferably 0.5 MPa or higher, based on a gauge pressure at 25°C.

[0060] The applications of the dielectric composition are not particularly limited, but it is preferably used as an electrical insulating medium, an electrical arc extinguishing medium, etc. In one embodiment, the dielectric composition is used as an electrical insulating medium or an electrical arc extinguishing medium housed in a sealed container in an electrical device. The dielectric composition is particularly suitable as an electrical insulating medium and an electrical arc extinguishing medium for medium-voltage or high-voltage electrical devices. Here, "medium voltage" means a voltage of 1,000 volts or more in AC and 1,500 volts or more in DC, but less than 52,000 volts in AC and less than 75,000 volts in DC. Also, "high voltage" means a voltage of 52,000 volts or more in AC and 75,000 volts or more in DC. Details of the electrical device are described below.

[0061] <Electrical Device> In one embodiment, the electrical device of the present disclosure comprises an electrical component, the dielectric composition of the present disclosure as described above, and a sealed container containing the dielectric composition. Because the electrical device of the present disclosure uses the dielectric composition of the present disclosure as described above, it has a low environmental impact, is easy to handle, and is highly safe.

[0062] Examples of electrical equipment include gas-insulated circuit breakers, current interruption equipment, gas-insulated transmission lines, gas-insulated transformers, gas-insulated substations, gas-insulated switches, gas-insulated disconnectors, gas-insulated load switches, and particle accelerators.

[0063] Examples of electrical components include conductive members. Specific examples of conductive members and other electrical components are described below. In the electrical device of this disclosure, even if there are electrical components that could act as ignition sources inside a sealed container, the possibility of combustion inside the sealed container can be suppressed by using the dielectric composition of this disclosure.

[0064] It is advantageous to use a heating device in combination with the electrical device to ensure that the dielectric, thermal, and barrier properties of the dielectric composition are sufficient within the specified or desired temperature range. The heating device is used depending on the temperature, pressure, or density of the dielectric composition. For example, ideally, a heating resistor can be used as a heating device, which is placed at the lowest point of the electrical device where the condensed liquid converges on various components inside the device due to gravity. In this way, a gas pressure exceeding the test pressure, which is the gas pressure inside the electrical device during evaluation tests as defined by the standard, is ensured. For the same reason, it is advantageous to insulate the walls of the electrical device, insulate the electrical device or the building housing it as needed, and furthermore, heat the electrical device or these buildings as needed.

[0065] To maintain dielectric purity and equipment performance, adsorbents, desiccants, acid scavengers, etc., may be sealed inside the container. Preferably, the adsorbent is one that adsorbs organic substances in the dielectric and decomposition products of the dielectric generated during use. Suitable adsorbents include activated carbon, activated alumina, silica gel, zeolite, and metal oxides with adsorption properties (CuO, Co...). ３ O ４ MnO ２Examples include porous materials (such as porous materials coated with calcium carbonate). The adsorbent may be used alone or in combination of two or more types. The desiccant is preferably one that efficiently adsorbs moisture in the dielectric. Examples of desiccants include calcium, calcium sulfate (especially dry elite), calcium carbonate, calcium hydride, calcium chloride, potassium carbonate, potassium hydroxide, copper(II) sulfate, calcium oxide, magnesium, magnesium oxide, magnesium sulfate, magnesium perchlorate, sodium, sodium sulfate, aluminum, lithium aluminum hydride, aluminum oxide, activated alumina, montmorillonite, phosphorus pentoxide, silica gel, and cellulose filters. The desiccant may be used alone or in combination of two or more types.

[0066] Figure 1 shows an example of the configuration of an electrical device in one embodiment. In Figure 1, a gas-insulated switch is shown as an example. The electrical device 10 shown in Figure 1 comprises a metal tank (sealed container) 11 in which a conductive member (electrical component) 12 is arranged. The conductive member 12 is supported by a support member 13 in an insulated state from the metal tank 11. The metal tank 11 is an airtight container and contains a dielectric composition (not shown) inside. A high voltage is applied to the conductive member 12.

[0067] The surface of the conductor member 12 typically includes at least one selected from the group consisting of metals and metal oxides. Preferably, the metal is at least one selected from the group consisting of aluminum, copper, silver, tin, zinc, iron, and chromium, or an alloy containing at least one selected from the group consisting of aluminum, copper, silver, tin, zinc, iron, and chromium. The metal oxide may be an oxide obtained by oxidizing the aforementioned metals, or an oxide of another metal. Preferably, the metal oxide is at least one selected from the group consisting of zinc oxide, iron oxide, and aluminum oxide. The conductor member 12 may consist of multiple materials. For example, the core portion (i.e., the interior of the conductor member) may be made of a material other than metals and metal oxides. If the core portion of the conductor member is made of another material, at least a portion of the surface of the conductor member is covered with at least one selected from the group consisting of metals and metal oxides. Preferably, at least a portion of the surface of the conductor member that comes into contact with the dielectric composition filled inside the metal tank 11 is made of at least one selected from the group consisting of metals and metal oxides.

[0068] The electrical device 10 may be equipped with various devices in series or parallel along an electrical circuit including a conductor member 12. These devices include switches, circuit breakers, disconnectors, etc., for disconnecting the electrical circuit; transformers, resistors, reactors, capacitors, etc., for changing the voltage of the circuit; and insulating cables. For insulation of the inside or outside of such devices, a dielectric composition filled inside the metal tank 11 may be used. Alternatively, solid insulators, insulating oils, gel-like insulators, etc., may be used for insulation of the inside or outside of the above devices. The inside or outside of the above devices may be insulated by a vacuum. Examples of solid insulators include insulating resin materials. Examples of insulating resin materials include thermoplastic resins and thermosetting resins. Examples of thermoplastic resins include vinyl chloride-based, polyester-based, and nylon-based resins. Examples of thermosetting resins include epoxy-based and urethane-based resins. Examples of insulating oils include mineral oil, vegetable oil, animal oil, and fluorinated oil. The electrical apparatus of this disclosure is not limited to the configuration shown in Figure 1.

[0069] <Method of Supply> In one embodiment, the method of supply of the present disclosure includes supplying the dielectric composition of the present disclosure to an electrical device. In the method of supply of the present disclosure, the dielectric composition may be supplied into a sealed container provided in the electrical device. The state of the dielectric composition when supplied may be liquid, gas, or both, and may be in a critical state. When the dielectric composition is supplied into a sealed container, it may be filled as the dielectric composition, or it may be filled with some or all of the specific olefin and carbon dioxide or nitrogen and oxygen, respectively. The components before supply, for example, the specific olefin and / or carbon dioxide, may be liquefied or gaseous, depending on the convenience of storage and transportation.

[0070] Figures 2A to 2D show schematic diagrams of examples of a dielectric composition supply method according to the first embodiment. In Figure 2A, a tank 22a containing liquefied specific olefin and carbon dioxide, and an oxygen tank 24 are connected to an electrical device 50. In Figure 2B, a tank 22b containing gaseous specific olefin and carbon dioxide, and an oxygen tank 24 are connected to an electrical device 50. In Figure 2C, a tank 26 containing specific olefin, carbon dioxide, and oxygen is connected to an electrical device 50. In Figure 2D, a tank 28 containing liquefied specific olefin, a carbon dioxide tank 30, and an oxygen tank 24 are connected to an electrical device 50.

[0071] Figures 3A to 3C show schematic diagrams of examples of a dielectric composition supply method according to the second embodiment. In Figure 3A, a tank 32 containing a specific olefin and nitrogen, and an oxygen tank 34 are connected to an electrical device 50. In Figure 3B, a tank 36 containing a specific olefin, nitrogen, and oxygen is connected to an electrical device 50. In Figure 3C, a tank 38 containing liquefied specific olefin, a nitrogen tank 40, and an oxygen tank 34 are connected to an electrical device 50.

[0072] Furthermore, the method of supplying the dielectric composition to the electrical device according to this disclosure is not limited to the embodiments shown in Figures 2A to D and Figures 3A to C.

[0073] The embodiments of the present disclosure will now be described in detail with reference to examples, but the embodiments of the present disclosure are not limited to these examples. In the following examples, "HFO-1132a" represents 1,1-difluoroethylene.

[0074] <Combustion Test> In the following example, the flammability of the dielectric composition was evaluated by a combustion test. The combustion test was performed by measuring the temperature rise inside the test container before and after ignition using a measuring device based on Method A of the explosion limit measurement method stipulated in Article 2, Paragraph 1, Items (a) and (b) of the General High Pressure Gas Safety Regulations. Ignition was performed by discharge from an electrode placed in the center of the container. The discharge was performed with ignition conditions set to 16 kV, 50 mA, and 0.23 seconds. Details of the test conditions and judgment criteria are as follows.

[0075] (Test conditions) Test container: 2L spherical stainless steel container Test gas: Dielectric composition (HFO-1132a, CO２ or N ２ , and O ２ Test temperature: 20°C ± 5°C or 60°C ± 5°C Test pressure: 101.3 kPa ± 0.7 kPa (absolute pressure) Moisture content: 3,000 ppm or less Ignition method: AC discharge, voltage 16 kV, current 50 mA, 0.23 seconds Electrode position: center of container, electrode spacing 4.0 mm Stirring conditions: 300 rpm, 10 minutes

[0076] (Judgment Criteria) - If the temperature inside the test container rises by 50°C or more before and after ignition: Flame propagation present (combustible: A) - If the temperature inside the test container rises by less than 50°C before and after ignition: Flame propagation absent (non-combustible: B)

[0077] (HFO-1132a, CO ２ or N ２ , and O ２ (Non-combustible by mixing) HFO-1132a, CO ２ or N ２ , and O ２ A dielectric composition was prepared by mixing the following, and the temperature rise inside the test container was observed before and after discharge ignition under the above test conditions. In this test, HFO-1132a and CO ２ or N ２ , and O ２ The mixture was considered as a dielectric composition, and evaluations were conducted to confirm that each dielectric composition could ensure non-flammability within the container containing it.

[0078] The volume ratios of the components of each dielectric composition and the test results are shown in the table below. Tables 2 and 4 show the results at a test temperature of 20°C ± 5°C, and Tables 3 and 5 show the results at a test temperature of 60°C ± 5°C. In the table below, "Volume ratio / (HFO-1132a + CO ２ ) refers to HFO-1132a and CO ２ This represents the volume ratio of each component when the total amount is set to 100 volume%, and is expressed as "volume ratio / (HFO-1132a + N ２ ) refers to HFO-1132a and N ２ This represents the volume ratio of each component when the total amount is set to 100 volume percent. Furthermore, "volume ratio / dielectric composition" refers to the dielectric composition (i.e., HFO-1132a, CO ２ , and O ２A mixture of, or HFO-1132a, N ２ , and O ２ This table shows the volume percentage of each component when the total amount of the mixture is set to 100% by volume. Note that the volume percentages in the table are displayed to one decimal place, so the sum of the volume percentages may not equal 100.0% by volume.

[0079]

[0080]

[0081]

[0082]

[0083] Based on the results in Table 2, CO ２ Because it is non-combustible, HFO-1132a and CO ２ and O ２ It includes HFO-1132a and CO ２ CO2 ２ The content of is 82.5% by volume or more, and HFO-1132a and CO ２ and O ２ O for the total amount ２ Dielectric compositions having a content of 1.0 to 18.0 volume percent were shown to be non-flammable at 20°C ± 5°C.

[0084] Based on the results in Table 3, CO ２ Because it is non-combustible, HFO-1132a and CO ２ and O ２ It includes HFO-1132a and CO ２ CO2 ２ The content of is 85.0% by volume or more, and HFO-1132a and CO ２ and O ２ O for the total amount ２ Dielectric compositions containing 1.0 to 18.0 volume percent of the substance were shown to be non-flammable even at 60°C ± 5°C.

[0085] Based on the results in Table 4, N ２ Because it is non-combustible, HFO-1132a and N ２ and O ２ It includes HFO-1132a and N ２N for the total amount ２ The content of is 88.8% by volume or more, and HFO-1132a and N ２ and O ２ O for the total amount ２ Dielectric compositions having a content of 1.0 to 14.0 volume percent were shown to be non-flammable at 20°C ± 5°C.

[0086] Based on the results in Table 5, N ２ Because it is non-combustible, HFO-1132a and N ２ and O ２ It includes HFO-1132a and N ２ N for the total amount ２ The content of is 91.0% by volume or more, and HFO-1132a and N ２ and O ２ O for the total amount ２ Dielectric compositions containing 1.0 to 14.0 volume percent of the material were shown to be non-flammable even at 60°C ± 5°C.

[0087] The disclosure of Japanese Patent Application No. 2025-029383, filed on 26 February 2025, is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard were specifically and individually noted to be incorporated by reference.

[0088] 10 Electrical equipment 11 Metal tank 12 Conductor member 13 Support member 22a Tank containing liquefied specific olefin and carbon dioxide 22b Tank containing specific olefin and carbon dioxide 24 Oxygen tank 26 Tank containing specific olefin, carbon dioxide, and oxygen 28 Tank containing liquefied specific olefin 30 Carbon dioxide tank 32 Tank containing specific olefin and nitrogen 34 Oxygen tank 36 Tank containing specific olefin, nitrogen, and oxygen 38 Tank containing liquefied specific olefin 40 Nitrogen tank 50 Electrical equipment

Claims

1. A dielectric composition comprising a C2 halogenated olefin, carbon dioxide, and oxygen, wherein the content of carbon dioxide relative to the total amount of the C2 halogenated olefin and carbon dioxide is 82.5% by volume or more, and the content of oxygen relative to the total amount of the C2 halogenated olefin, carbon dioxide, and oxygen is 1.0 to 18.0% by volume; or a dielectric composition comprising a C2 halogenated olefin, nitrogen, and oxygen, wherein the content of nitrogen relative to the total amount of the C2 halogenated olefin and nitrogen is 88.8% by volume or more, and the content of oxygen relative to the total amount of the C2 halogenated olefin, nitrogen, and oxygen is 1.0 to 14.0% by volume.

2. A dielectric composition according to claim 1, comprising a C2 halogenated olefin, carbon dioxide, and oxygen, wherein the content of carbon dioxide relative to the total amount of the C2 halogenated olefin and carbon dioxide is 85.0% by volume or more, and the content of oxygen relative to the total amount of the C2 halogenated olefin, carbon dioxide, and oxygen is 1.0 to 18.0% by volume; or comprising a C2 halogenated olefin, nitrogen, and oxygen, wherein the content of nitrogen relative to the total amount of the C2 halogenated olefin and nitrogen is 91.0% by volume or more, and the content of oxygen relative to the total amount of the C2 halogenated olefin, nitrogen, and oxygen is 1.0 to 14.0% by volume.

3. The dielectric composition according to claim 1, wherein the C2 halogenated olefin comprises at least one selected from the group consisting of 1,1-difluoroethylene, (E)-1,2-difluoroethylene, (Z)-1,2-difluoroethylene, and trifluoroethylene.

4. The dielectric composition according to claim 1, wherein the C2 halogenated olefin is 1,1-difluoroethylene.

5. The dielectric composition according to claim 4, wherein the total content of 1,1-difluoroethylene, carbon dioxide, and oxygen relative to the total amount of the dielectric composition is 99.0% by volume or more, or the total content of 1,1-difluoroethylene, nitrogen, and oxygen relative to the total amount of the dielectric composition is 99.0% by volume or more.

6. The dielectric composition according to claim 1, wherein the water content in the dielectric composition is 3,000 ppm by mass or less.

7. The dielectric composition according to claim 1, which is in a single-phase state.

8. The dielectric composition according to claim 1, which is used as an electrical insulating medium or an electrical arc extinguishing medium.

9. An electrical device comprising an electrical component, a dielectric composition according to any one of claims 1 to 8, and a sealed container containing the dielectric composition.

10. The electrical device according to claim 9, which is a gas-insulated circuit breaker, current interruption equipment, gas-insulated transmission line, gas-insulated transformer, gas-insulated substation, gas-insulated switch, gas-insulated disconnector, gas-insulated load switch, or particle accelerator.

11. A method for supplying a dielectric composition according to any one of claims 1 to 8 to an electrical device.

12. Use of a dielectric composition, wherein the dielectric composition according to any one of claims 1 to 8 is used at a temperature of -75°C to 60°C.

13. Use of the dielectric composition according to any one of claims 1 to 8 as an electrical insulating medium or an electrical arc extinguishing medium.

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