JP2023010288A - Resin composition for power apparatus - Google Patents

Abstract

To provide a functionally gradient material which allows a dielectric constant of a resin composition to be configured so as to be gradient without laminating a different resin, and has insulation resistance.SOLUTION: A resin composition for a power apparatus contains a thermosetting resin and an inorganic filler, wherein the inorganic filler contains an antiferroelectric filler.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a resin composition for power equipment. In particular, the present invention relates to a resin composition for electric power equipment, which has excellent insulating properties and whose dielectric constant changes as the electric field strength increases.

2. Description of the Related Art Casting resin compositions such as epoxy resins are used in electric power equipment such as switchgears, switchboards and molded transformers. Epoxy resin is particularly superior in terms of high strength, high toughness, heat resistance, and electrical insulation.

In recent years, with the miniaturization of electric power equipment, there is a tendency for the electric field strength on the surface of a high-voltage conductor to increase. In order to ensure insulation performance in such electric power equipment, composite insulation is adopted in which high-voltage conductors are coated with resin. In addition, functionally graded materials whose resistivity and permittivity are graded with respect to supporting insulators in electric power equipment have been developed.

By the way, functionally graded materials that grade the dielectric constant include a method in which the base material is filled with inorganic fillers having different dielectric constants at varying ratios, and a method in which the dielectric constant of the inorganic filler in the base material changes with changes in the electric field strength. There is a method in which the dielectric constant of the resin material is graded by changing .

An insulating spacer that supports a high voltage conductor in a ground tank and is coated with a nonlinear dielectric constant material is known (see, for example, US Pat. The nonlinear permittivity material disclosed in Patent Document 1 is formed by filling an epoxy base material with a filler selected from strontium titanate, barium titanate, and calcium titanate. Suppression of electric field enhancement is possible.

Japanese Patent Application Laid-Open No. 2016-101080

Functionally graded materials filled with inorganic fillers with different dielectric constants in a base material with varying ratios require a centrifugal force or when multiple liquid mixtures are injected from multiple storage tanks. There is a problem that it is difficult to laminate resins having different dielectric constants, such as resins having different dielectric constants.

The nonlinear permittivity material disclosed in Patent Document 1 does not have sufficient insulation resistance, and there is a problem in using it for electric power equipment such as switchgear spacers that require insulation resistance.

It is desired to realize a functionally graded material in which the dielectric constant of a resin composition can be graded without laminating different resins having a plurality of dielectric constants and which has dielectric strength.

As a result of intensive studies, the inventors of the present invention came up with the idea of filling a base material resin with an antiferroelectric compound whose dielectric constant changes with changes in electric field intensity, and completed the present invention.

That is, according to one embodiment, the present invention is a resin composition for power equipment, comprising a thermosetting resin and a filler, wherein the filler comprises an antiferroelectric filler.

In the resin composition for power equipment, the antiferroelectric filler is lead zirconate, lead hafnate, lanthanum-added lead zirconate titanate, ammonium dihydrogen phosphate, sodium niobate, potassium niobate, or tungsten oxide. , and copper formate tetrahydrate.

In the resin composition for electric power equipment, it is preferable that the antiferroelectric filler is contained in an amount of 10 to 80% by volume based on the total volume of the resin composition for electric power equipment as 100%.

In the resin composition for electric power equipment, the average particle size of the antiferroelectric filler is preferably 500 μm or less.

In the resin composition for electric power equipment, the thermosetting resin preferably contains an epoxy resin base agent and a curing agent.

In the resin composition for electric power equipment, the filler is alumina, fused silica, crystalline silica, hydrated alumina, talc, dolomite, magnesium oxide, boehmite, titanium oxide, magnesium carbonate, boron nitride, calcium carbonate, silicon carbide. , and glass fibers.

ADVANTAGE OF THE INVENTION According to this invention, the resin composition excellent in electrical insulation and electric field relaxation property can be obtained, without using the conventional lamination method and the manufacturing method which applies a centrifugal force.

Embodiments of the present invention are described below. However, the present invention is not limited by the embodiments described below.

The present invention, according to one embodiment, relates to a resin composition for electric power equipment. The resin composition for power equipment according to this embodiment contains a thermosetting resin and a filler. Further, the term "for electric power equipment" means that it is used as a resin that constitutes a part of electric power equipment such as molded transformers, insulating paints, switchboards, and semiconductor devices. Therefore, the resin composition for electric power equipment according to the present embodiment preferably has predetermined dielectric properties and insulating properties.

The thermosetting resin that constitutes the resin composition for electric power equipment is not particularly limited, and any thermosetting resin that conforms to the specifications of the electric power equipment can be used. Examples of thermosetting resins include, but are not limited to, epoxy resins, phenol resins, cyanate resins, maleimide resins, memilan resins, urea resins, silicone resins, unsaturated polyester resins, and the like. In particular, it is preferable to use an epoxy resin. This is because it has excellent insulation properties and low cure shrinkage.

When an epoxy resin is used as the thermosetting resin, an epoxy resin base agent, an epoxy resin curing agent, and optionally a curing accelerator can be used.

The epoxy resin main agent may be an aliphatic epoxy resin such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, biphenyl type epoxy resin, naphthalene type epoxy resin, cresol novolak type epoxy resin, trifunctional Examples include, but are not limited to, the polyfunctional epoxy resins described above. These can be used alone or in combination of two or more.

The epoxy resin main agent may also be an alicyclic epoxy resin, including monofunctional alicyclic epoxy resins, bifunctional alicyclic epoxy resins, trifunctional or higher polyfunctional alicyclic epoxy resins, and the like. but not limited to these. Alicyclic epoxy resins can also be used alone or in combination of two or more different alicyclic epoxy resins.

The curing agent is not particularly limited as long as it can be cured by reacting with the epoxy resin main agent. Examples of curing agents include acid anhydride-based curing agents, phenol-based curing agents, and amine-based curing agents. Among them, it is preferable to use an acid anhydride curing agent. Acid anhydride-based curing agents include, for example, aromatic acid anhydrides, specifically phthalic anhydride, pyromellitic anhydride, and trimellitic anhydride. Alternatively, cyclic aliphatic acid anhydrides, specifically tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride, etc., or aliphatic acid anhydrides, specifically Specific examples include succinic anhydride, polyadipic anhydride, polysebacic anhydride, and polyazelaic anhydride.

The amount of the curing agent is preferably about 50 parts by mass or more and 170 parts by mass or less, and about 80 parts by mass or more and 150 parts by mass or less, based on 100 parts by mass of the main epoxy resin. more preferred.

The curable resin can further include a curing accelerator as an optional component. As curing accelerators, imidazole or derivatives thereof, tertiary amines, borate esters, Lewis acids, organometallic compounds, organic acid metal salts, and the like can be appropriately blended. The amount of the curing accelerator to be added is preferably 0.01 parts by mass or more and 50 parts by mass or less, and 0.1 parts by mass or more and 20 parts by mass with respect to 100 parts by mass of the main thermosetting resin. Part or less is more preferable.

The resin composition for power equipment contains a filler as an essential component. The fillers include antiferroelectric fillers, and optionally inorganic fillers that are not antiferroelectrics. The antiferroelectric filler is not particularly limited, but includes lead zirconate, lead hafnate, lanthanum-doped lead zirconate titanate, ammonium dihydrogen phosphate, sodium niobate, potassium niobate, tungsten oxide, and copper tetraformate. It can be selected from hydrates, and may be a combination of two or more of these.

The shape of the antiferroelectric filler is not particularly limited, and examples thereof include spherical, granular, acicular, flat, elliptical, plate-like, and crushed shapes. Although the shape of the antiferroelectric filler varies depending on the mode of use of the resin composition for electric power equipment, it prevents thickening of the resin composition for electric power equipment and adds a relatively large amount of the antiferroelectric filler to the resin. From the point of view of inclusion, it can be spherical.

The antiferroelectric filler preferably has a particle size of 500 μm or less, more preferably about 1 μm or more and 500 μm or less. The particle size of the antiferroelectric filler means the average particle size measured by laser diffraction. In addition, the particle size of non-spherical fillers can refer to the longest size. The preferred particle size of the antiferroelectric filler varies depending on the mode of use of the resin composition for electric power equipment, and can be appropriately set by those skilled in the art so as to suit the mode of use. Therefore, for example, when the resin composition for power devices is applied to power devices as a thin coating, the thickness can be about 1 μm or more and about 50 μm or less.

The amount of the antiferroelectric filler to be filled is preferably such that the volume of the antiferroelectric filler is 10 to 80% of the total volume of the resin composition for electric power equipment is 100%. , 10 to 60%.

Optional fillers are not particularly limited, and general fillers that have insulating properties and are not antiferroelectric fillers can be used. For example, alumina, fused silica, crystalline silica, hydrated alumina, aluminum hydroxide, talc, dolomite, magnesium oxide, boehmite, titanium oxide, magnesium carbonate, zirconia, aluminum nitride, boron nitride, calcium carbonate, silicon carbide, clay, It can be selected from inorganic fillers such as, but not limited to, mica, glass fiber. Barium titanate, strontium titanate, calcium titanate, etc. may also be included in small amounts to the extent that they do not lower the dielectric strength. These inorganic fillers may be used alone or in combination of two or more.

The particle shape of the inorganic filler other than the antiferroelectric filler is not particularly limited, and can be appropriately selected from options similar to those for the shape of the antiferroelectric filler. In some embodiments, the particle shape of the inorganic filler can be spherical. The particle size of the inorganic filler is also not particularly limited, and may include micro-fillers, nano-fillers, or mixtures thereof.

The filling amount of the inorganic filler other than the antiferroelectric filler is not particularly limited, and can be appropriately selected by those skilled in the art according to the desired properties of the resin composition applied to power equipment. Regarding the filling amount of the inorganic filler, for example, the volume fraction of the filling amount of the inorganic filler other than the antiferroelectric filler is 80% or less when the volume of the entire resin composition for electric power equipment is 100%. It is preferable to fill so that it becomes about 30 to 70%, and it is more preferable to fill so that it becomes 30 to 70%. In addition, the total amount of the antiferroelectric filler and the inorganic filler other than the antiferroelectric filler should be 10 to 80% when the volume of the entire resin composition for electric power equipment is 100%. is preferred, and 30 to 70% is more preferred.

The resin composition for electric power equipment may contain optional additives within a range that does not impair its characteristics. Examples of additives include, but are not limited to, flame retardants, pigments for coloring resins, plasticizers and silicone elastomers for improving crack resistance. Those skilled in the art can appropriately determine these optional components and their amounts to be added according to the specifications required for the resin. Moreover, it is preferable that the resin composition for electric power equipment does not contain a conductive component or the like.

The resin composition for electric power equipment can be obtained by appropriately mixing the above components. The obtained resin composition for electric power equipment can be molded into a required shape and cured by heating. The molding can be carried out, for example, by molding by a casting method, or by coating a suitable portion of the electric power device in layers by a coating method. Moreover, the heat curing can be appropriately carried out with a heating temperature, a heating time and a heating method suitable for the type of resin to be used.

According to the resin composition for electric power equipment of the present invention, it is possible to provide a functionally graded material whose permittivity is graded with respect to changes in electric field strength. In particular, the resin composition for electric power equipment according to the present invention can impart desired dielectric properties without affecting the insulating properties of the resin by using an antiferroelectric filler. It is particularly advantageous as a component of electric power equipment.

INDUSTRIAL APPLICABILITY The resin composition for electric power equipment according to the present invention is excellent in electrical insulation and electric field relaxation properties, and is therefore used for insulating spacers of switchgears, coating resins for high-voltage conductors, and the like. It can also be applied to cast resins for molded transformers, insulating coatings, switchboards, semiconductor devices, and the like.

Claims (6)

A resin composition for power equipment, comprising a thermosetting resin and a filler, wherein the filler comprises an antiferroelectric filler. The antiferroelectric filler is selected from lead zirconate, lead hafnate, lanthanum-doped lead zirconate titanate, ammonium dihydrogen phosphate, sodium niobate, potassium niobate, tungsten oxide, and copper formate tetrahydrate. The resin composition for electric power equipment according to claim 1, which is one or more kinds of compounds. 3. The resin composition for electric power equipment according to claim 1, wherein the antiferroelectric filler is contained in an amount of 10 to 80% by volume when the total volume of the resin composition for electric power equipment is taken as 100%. 4. The resin composition for electric power equipment according to claim 1, wherein the antiferroelectric filler has an average particle size of 500 μm or less. The resin composition for electric power equipment according to any one of claims 1 to 4, wherein the thermosetting resin contains an epoxy resin base agent and a curing agent. The filler is one selected from alumina, fused silica, crystalline silica, hydrated alumina, talc, dolomite, magnesium oxide, boehmite, titanium oxide, magnesium carbonate, boron nitride, calcium carbonate, silicon carbide, and glass fiber. The resin composition for electric power equipment according to any one of claims 1 to 5, further comprising the above inorganic filler.