JP2017008188A - Coating material for electronic equipment, method for producing coating material for electronic equipment, and closed insulating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating material for electronic equipment which has such a high electric field that a foreign substance existing in the electronic equipment starts floating, can suppress floating and moving of the foreign substance, and can be rapidly cured; a method for producing a coating material for electronic equipment; and a closed insulating device.SOLUTION: A coating material for electronic equipment contains a matrix resin formed of a photocurable resin; a first filler which is dispersed and contained in the matrix resin, is semi-conductive, and is formed of a whisker; a second filler which is dispersed and contained in the matrix resin, is semi-conductive, and has a spherical shape; and a third filler which is dispersed and contained in the matrix resin, is insulative, and has a flat plate form, a fiber form or a layer form.SELECTED DRAWING: Figure 2

Description

  Embodiments described herein relate generally to a paint for electrical equipment, a method for producing a paint for electrical equipment, and a hermetic insulation device.

  In a sealed insulation device such as a gas-sealed switch, which has a high-voltage conductor supported by an insulator in a container filled with an insulating gas, the insulation design is designed to reduce costs and reduce environmental impact. Downsizing by streamlining and three-phase integration has become an issue.

  The size of the metal container of the hermetic insulation device is determined by insulation design, thermal design, and the like. One of the points of insulation design is to examine the influence on the insulation performance when foreign matter is present (attached) on the inner surface of the metal container.

  If a foreign object exists inside a metal container that contains a high-voltage conductor supported by an insulator and is filled with an insulating gas, the foreign object interacts with the charge supplied from the metal container and the operating voltage. Power is generated. For this reason, foreign substances may move around inside the metal container.

  When the hermetic type insulating device is reduced in size, the electric field on the inner surface of the metal container is increased, and the movement of foreign substances existing inside the metal container tends to be active. Excessive movement of foreign matter inside the metal container may affect the insulation performance. Further, the longer the shape of the foreign material, the greater the movement of the foreign material and the greater the influence on the insulation performance.

  Therefore, in the manufacturing process, for example, a foreign matter management step is provided to remove foreign matters so that long foreign matters are not mixed inside the metal container, thereby strengthening the management of foreign matters. Furthermore, it is necessary to design the electric field strength on the inner surface of the metal container when an operating voltage is applied so that a small foreign object that is difficult to manage does not float above and move about the height considered in the design. Here, the height is the distance between the inner surface of the metal container and the foreign material.

  Since the electric field strength on the inner surface of the metal container depends on the distance between the high voltage conductor and the inner surface of the metal container, it is necessary to enlarge the metal container in order to reduce the flying height of the foreign matter. This is a factor that hinders downsizing of the hermetic insulation device.

  As a method of mitigating the influence of the foreign matter, there is a method of suppressing the movement of the foreign matter by applying an insulating paint to the inner surface of the metal container of the hermetic insulating device to form a coating layer. By providing an insulating coating layer on the inner surface of the metal container, the supply of electric charges from the inner surface of the metal container to the foreign object is suppressed, and the foreign object is difficult to move. In this case, it is necessary to control the resistivity of the coating layer provided on the inner surface of the metal container so that the movement of foreign matter can be suppressed.

Japanese Patent No. 3028975

  However, when an insulating coating layer is formed using the conventional paint as described above, electric field concentration is likely to occur at a site constituted by foreign matter, insulating gas, and coating layer. When the electric field concentration increases, a partial discharge may occur around the foreign matter, and charge may be supplied to the foreign matter. When a partial discharge occurs, the foreign material suddenly moves over a wide area and may affect the insulation performance. Also, if an overvoltage such as a lightning surge enters and the electric field on the inner surface of the metal container increases, the electric field at the electric field concentration part may further increase, and although the probability is very low, foreign matter may suddenly move around greatly. .

  In this way, in order to prevent the foreign object from moving suddenly and over a wide range, the electric field concentration between the insulating coating layer and the foreign object is alleviated to suppress the occurrence of partial discharge and field emission. There is a need to. Even when foreign matter that is difficult to be supplied with electric charge and does not move at the operating voltage is present on the surface of the insulating coating layer, foreign matter may start to move due to mechanical shock vibration caused by the operation of the sealed insulation device, etc. . In addition, a partial discharge may be generated by a higher voltage such as a lightning impulse, and foreign matter may start to move.

  On the other hand, from the viewpoint of the manufacturing process, there is a high need for a rapidly curable coating that can shorten the lead time compared to conventional coatings.

  The problem to be solved by the present invention is that the electric field (hereinafter also referred to as a foreign substance floating electric field) at which foreign substances existing in an electric device such as a sealed insulation device starts to rise is high and suppresses the floating and movement of foreign substances. It is possible to provide a coating material for electrical equipment that can be cured (hereinafter also referred to as detoxification of foreign matter) and can be rapidly cured, a method for producing the coating material for electrical equipment, and a sealed insulating device.

  The coating material for an electrical device according to the embodiment includes a matrix resin made of a photocurable resin, a first filler made of whisker that is contained in the matrix resin in a dispersed manner, and is dispersed in the matrix resin. A spherical second filler that is contained and semiconductive, and a third filler that is dispersed and contained in the matrix resin and is insulative, flat, fibrous, or layered. Containing.

It is a perspective view which shows typically the 1st filler which the coating material for electric devices of embodiment contains. It is a figure which shows typically the electroconductive path which the 1st filler and the 2nd filler form in the hardened | cured material formed by hardening | curing the coating material for electric devices of embodiment. It is a figure which shows in part a cross section the electric equipment provided with the hardened | cured material formed by hardening | curing the coating material for electric devices of embodiment. It is a figure which shows typically the method of hardening | curing the coating film of the coating material for electric devices of embodiment. It is a figure which shows typically the cross section of the test apparatus which evaluated the foreign material floating electric field.

  Hereinafter, embodiments will be described with reference to the drawings.

  The coating material for electrical equipment according to the embodiment contains a matrix resin made of a photocurable resin. And the coating material for electric equipment contains the 1st filler, 2nd filler, and 3rd filler which are disperse | distributed and contained in matrix resin. In addition, although the coating material for electrical devices has a property hardened | cured with light, when light is not irradiated, the coating material for electrical devices is not hardened but maintains the state of a viscous liquid under normal temperature normal pressure.

  The photocurable resin contained in the coating for electrical equipment is composed of monomers, oligomers, photopolymerization initiators, various additives (stabilizers, fillers, pigments, etc.) and the like.

  The photo-curable resin is a resin that cures by increasing the molecular weight by chain polymerization of monomers and oligomers that are resin components by light. Curing of a photocurable resin refers to changing from a liquid state to a solid state by the action of light energy, and a synthetic organic material that cures at this time is referred to as a photocurable resin. As a polymerization method of the photocurable resin, there are mainly cationic polymerization and radical polymerization.

  The photocurable resin that is in a liquid state at normal temperature and pressure is cured in the following steps. First, the photopolymerization initiator absorbs light, and the photopolymerization initiator that absorbs light is activated. The activated photopolymerization initiator reacts with a resin component such as a monomer or oligomer through decomposition such as cleavage to produce a reaction product. This reaction product further reacts with monomers and oligomers that are resin components, and further reaction products are generated. And such a reaction advances in a chain. As a result, the cross-linking reaction proceeds three-dimensionally to increase the molecular weight, and the photocurable resin is cured to a solid state. Thus, a cured product of the solid state photocurable resin is formed. In addition, the hardened | cured material of photocurable resin comprises the matrix of the hardened | cured material of the coating material for electrical devices.

  Ultraviolet light is generally used as light to be irradiated when the photocurable resin is cured. In particular, an ultraviolet (UV) laser that is an ultraviolet light source is useful because it has a high energy density and can be focused to a small spot diameter. In addition to ultraviolet light, visible light and near infrared light can also be used. These lights are appropriately selected according to the type of the photocurable resin.

  The monomer contained in the photocurable resin is a molecule having a functional group and constitutes a repeating structural unit of the photocurable resin that is cured by light. The monomer is polymerized by light to become a polymer. Examples of the monomer that undergoes cationic polymerization include vinyl ether monomers. Examples of the radical polymerizing monomer include acrylate monomers and phthalate monomers. The names of these vinyl ether monomers, acrylate monomers, and phthalate monomers are generic names for the compounds, and include all those having various functional groups bonded thereto. As the monomer, only one of the above-described monomers may be used, or two or more monomers may be mixed and used.

  The oligomer contained in the photocurable resin is obtained by reacting several monomers in advance, and, like the monomer, becomes a polymer by being polymerized by light. Examples of the oligomer that undergoes cationic polymerization include vinyl ether oligomers, alicyclic photocurable oligomers, and glycidyl ether photocurable oligomers. Examples of the oligomer that undergoes radical polymerization include urethane acrylate oligomers, polyester acrylate oligomers, photocurable acrylate oligomers, and acrylic acrylate oligomers. The names of these vinyl ether oligomers, alicyclic photocurable oligomers, glycidyl ether photocurable oligomers, urethane acrylate oligomers, polyester acrylate oligomers, photocurable acrylate oligomers, and acrylic acrylate oligomers are generic names of compounds. Includes all of the various functional groups attached. As the oligomer, only one of the above-described oligomers may be used, or two or more kinds may be mixed and used.

  A photocurable resin may contain only a monomer as a resin component, and may contain only an oligomer. When a photocurable resin contains a monomer and an oligomer, the content rate of a monomer and an oligomer is not specifically limited.

  The photopolymerization initiator contained in the photocurable resin absorbs light, activates (photoexcitation), is cleaved, pulls out hydrogen (proton), and causes a reaction such as electron transfer. By such a reaction, a substance that initiates a curing reaction, such as a radical molecule in the case of an acrylic photocurable resin, or a hydrogen ion in the case of an epoxy photocurable resin, is determined depending on the type of photopolymerization initiator. Generated. The generated radical molecules, hydrogen ions, and the like attack the monomers and oligomers to cause a three-dimensional polymerization and crosslinking reaction, so that the curing reaction proceeds. And when the molecule | numerator which has a fixed size or more is formed by such reaction, the photocurable resin of a light irradiation part will be hardened | cured and the hardened | cured material of a solid state photocurable resin will be formed.

  Examples of the photopolymerization initiator used for the cationic polymerization include sulfonium and iodonium. Examples of the photopolymerization initiator used for radical polymerization include benzophenone, acetophenone, and thioxanthone. The names of sulfonium, iodonium, benzophenone, acetophenone, and thioxanthone are generic names of the compounds, and include all compounds having various functional groups bonded thereto. As the photopolymerization initiator, only one of the above-described photopolymerization initiators may be used, or two or more kinds may be mixed and used.

  The photocurable resin contained in the coating material for electrical equipment is not particularly limited. Examples of the photocurable resin include an acrylic photocurable resin and an epoxy photocurable resin.

  Examples of the acrylic photocurable resin include TB3013, TB3013B, TB3013D, TB3013M, TB3014C, TB3015F, TB3016, TB3016H, TB3017, TB3017B, TB3017D, TB3017E, TB3017T, TB3018T, TB3018T, TB3018T, TB3026 , TB3027G, TB3030, TB3030B, TB3031, TB3031J, TB3033B, TB3033F, TB3034, TB3034C, TB3035, TB3036, TB3036E, TB3036G, TB3042, TB3042B, TB3042T, TB3042T, TB3042T, TB3043 B, TB3050B, TB3050C, TB3050J, TB3051, TB3051E, TB3051G, TB3052, TB3052B, TB3052C, TB3052D, TB3055, TB3055B, TB3056F, TB3057, TB3057B, TB3057E, TB3057D TB3062P, TB3062Q, TB3062S, TB3062U, TB3065E, TB3066, TB3067, TB3067B, TB3067C, TB3068B, TB3069F, TB3075, TB3081J, TB3084, TB3084E, TB3087B, TB3087 B, TB3170B, TB3170D, TB3170E, TB3170F, TB3170J, TB3177 (Three Bond Corporation, trade name any), and the like.

  Moreover, as an epoxy-type photocurable resin, TB3111B, TB3113B, TB3114, TB3114B, TB3114G (all are the brand names made by ThreeBond Co., Ltd.) etc. are mentioned, for example.

  Further, the photocurable resin may contain an improving agent that improves the curing characteristics such as visible light curable property, near infrared light curable property, moisture curable property, and heat curable property. Here, the visible light curable property refers to a property that is cured by light of about 380 nm to 780 nm, and the near infrared light curable property refers to a property that is cured by light of about 780 nm to 900 nm.

  The photocurable resin may be a resin that is cured by light, and only one of the above-described photocurable resins may be used, or a mixture of two or more types may be used. Good.

The first filler contained in the matrix resin contained in the paint for electrical equipment is semiconductive and is made of whiskers. Semiconductive means a substance having a volume resistivity of about 10 ⁻³ to 10 ⁵ Ω · cm.

  Drawing 1 is a perspective view showing typically the 1st filler 10 which the paint for electric appliances of an embodiment contains. The 1st filler 10 is comprised from the core part 11 and the acicular crystal | crystallization part 12 extended in the 4 axis direction from the nucleus part 11, and has a tetrapot shape. The first filler 10 is made of, for example, a whisker made of ZnO (hereinafter also referred to as ZnO whisker). The ZnO whisker has a volume resistivity (specific resistance) of 1 to 5000 Ω · cm and is a stable inorganic substance.

  In the cured product of the paint for electrical equipment, the first filler and the second filler form a good conductive path so that the length L of the needle-like crystal part 12 is 2 μm. The average diameter D (arithmetic average diameter) of the portion having the maximum diameter of the acicular crystal portion 12 is preferably 0.2 μm or more and 3 μm or less. An example of the first filler is Panatetra (trade name, manufactured by Amtec Corporation).

  It is preferable that 1.0 mass part or more and 50.0 mass parts or less of 1st fillers are contained with respect to 100 mass parts of photocurable resins. When the paint for electrical equipment contains the first filler in this range, the first filler and the second filler form a good conductive path in the cured product of the paint for electrical equipment, Workability such as painting of paint for electrical equipment can be secured.

  Moreover, it is preferable that surface treatments, such as a titanate coupling process, are given to the surface of the 1st filler. By subjecting the first filler to surface treatment, wettability with the matrix resin can be improved. For example, titanate coupling agents used in the titanate coupling process include isopropyl triisostearoyl tight, isopropyl tridodecylbenzenesulfonyl titanate, isopropyl-tris (dioctyl pyrophosphate) titanate, tetraisopropyl-bis (dioctyl phosphite) titanate. , Tetraoctyl-bis (ditridecyl phosphite) titanate, tetra (2,2-diallyloxymethyl-1-butyl) -bis (ditridecyl) phosphite titanate, bis (dioctylpyrophosphate) oxyacetate titanate, and the like. .

  The surface of the first filler can also be improved in wettability with the matrix resin by being subjected to a silane coupling treatment. For example, examples of the silane coupling agent used for the silane coupling treatment include photocurable silane, aminosilane, vinyl silane, methacryl silane, mercapto silane, methoxy silane, and ethoxy silane.

The second filler dispersed and contained in the matrix resin contained in the coating material for electric equipment is semiconductive and spherical. The second filler, for example, a particle composed of _Fe 2 _{O 3} or _Fe 3 _{O 4.}

A case where the second filler is composed of particles made of Fe ₂ O ₃ will be described. Fe ₂ O ₃ is a red powder and is called so-called bengara. The specific gravity of Fe ₂ O ₃ is about 5.2 g / cm ³ . The volume resistivity of Fe ₂ O ₃ is about 1 × 10 ³ Ω · cm. The average particle size of Fe ₂ O ₃ is the median in order to ensure the workability such as painting of the paint for electrical equipment while expressing the insulation resistance characteristic of the cured product of the paint for electrical equipment with the second filler alone. The diameter (D50) is preferably 0.1 μm or more and 1.0 μm or less. Furthermore, from the viewpoint of better insulation resistance characteristics, the average particle diameter of Fe ₂ O ₃ is more preferably 0.5 μm or more and 1.0 μm or less in terms of median diameter (D50). Here, the insulation resistance characteristic of the cured product of the paint for electrical equipment is that the cured product of the paint for electrical equipment has a volume resistivity of about 1 × 10 ⁶ to 1 × 10 ¹⁸ Ω · cm (hereinafter, the same). The median diameter (D50) means a median diameter calculated as a particle diameter corresponding to 50% of the cumulative distribution curve from the number-based particle size distribution. The average particle size of Fe ₂ O ₃ is, for example, a cross section of the cured product of the paint for electrical equipment is observed with a SEM (scanning electron microscope), and the particle size of each Fe ₂ O ₃ contained in the cured product is determined. Obtained by analyzing with image analysis software. Fe ₂ O ₃ is preferably contained in an amount of 1.0 to 30.0 parts by mass with respect to 100 parts by mass of the photocurable resin. When the paint for electrical equipment contains Fe ₂ O ₃ in this range, the first filler and Fe ₂ O ₃ form a good conductive path in the cured product of the paint for electrical equipment, and the electrical equipment Workability such as painting of paints can be ensured.

A case where the second filler is composed of particles made of Fe ₃ O ₄ will be described. Fe ₃ O ₄ is a black powder. The specific gravity of Fe ₃ O ₄ is about 5.2 g / cm ³ . The volume resistivity of Fe ₃ O ₄ is about 4 × 10 ⁻³ Ω · cm. The average particle size of Fe ₃ O ₄ is the median in order to ensure the workability of coating of electrical equipment paints, etc. while expressing the insulation resistance characteristics of the cured product of electrical equipment paints with the second filler alone. The diameter (D50) is preferably 0.01 μm or more and 0.10 μm or less. Furthermore, from the viewpoint of better insulation resistance characteristics, the average particle diameter of Fe ₃ O ₄ is more preferably 0.05 μm or more and 0.08 μm or less in terms of median diameter (D50). The average particle diameter of Fe ₃ O ₄ is obtained by the same method as that for Fe ₂ O ₃ described above. Fe ₃ O ₄ is preferably contained in an amount of 1.0 to 30.0 parts by mass with respect to 100 parts by mass of the photocurable resin. When the paint for electrical equipment contains Fe ₃ O ₄ in this range, the first filler and Fe ₃ O ₄ form a good conductive path in the cured product of the paint for electrical equipment, and the electrical equipment Workability such as painting of paints can be ensured.

The third filler contained in the matrix resin contained in the coating material for electrical equipment is insulative and has a flat plate shape, a fiber shape, or a layer shape. Insulating property refers to a substance having a volume resistivity of about 10 ⁶ to 10 ¹⁸ Ω · cm.

  A case where the third filler is composed of a flat material will be described. Examples of the flat material include talc and boron nitride (BN).

Talc is a flat compound composed mainly of MgO.SiO ₂ .H ₂ O. The volume resistivity of talc is about 1 × 10 ¹⁴ to 1 × 10 ¹⁵ Ω · cm. The average diameter of talc is preferably 2 μm or more and 50 μm or less, and more preferably 10 μm or more and 30 μm or less in order to suppress sedimentation of the first filler in the matrix resin. When a flat material such as talc does not form a circle, the average length of the longest straight line that can be drawn over the surface of the flat material (hereinafter referred to as the average straight line length) can be within the above range. That's fine. Here, the average diameter and the average straight line length can be obtained by observing the cured product of the paint for electrical equipment by SEM, similarly to the above Fe ₂ O ₃ .

  Boron nitride is a particle having a scaly structure. Boron nitride can be classified into hexagonal boron nitride, rhombohedral boron nitride, cubic boron nitride, turbostratic boron nitride, and wurtzite boron nitride depending on the crystal structure. Among these, hexagonal boron nitride, which is a general boron nitride, is preferably used because it has a high accept ratio, high insulation resistance, and can further increase the dielectric breakdown electric field of the material. The average particle diameter of boron nitride is preferably 1 to 10 μm in terms of median diameter (D50) in order to suppress sedimentation of the first filler in the matrix resin. Similarly to the above, the average particle diameter can be obtained by observing the cured product of the paint for electrical equipment by SEM. Further, when the third filler is boron nitride, the boron nitride itself has high thermal conductivity, so that the heat dissipation characteristics of the cured product of the paint for electrical equipment can be improved.

  A case where the third filler is composed of a fibrous substance will be described. Examples of the fibrous substance include potassium titanate whisker, glass milled fiber, and wollastonite.

  The average fiber length of the potassium titanate whisker or glass milled fiber is preferably 1 μm or more and 50 μm or less, and more preferably 10 μm or more and 20 μm or less. The average fiber length of wollastonite is preferably 75 μm or more and 200 μm or less, and more preferably 35 μm or more and 170 μm or less. When the average fiber length of the fibrous substance is within this range, the fibrous third filler enters between the first filler and the second filler, and the first filler and the second filler. The two fillers can be uniformly dispersed in the matrix resin. The average fiber length is obtained by arithmetically averaging the lengths of the respective fibers in the longitudinal direction. Here, the average fiber length is obtained by observing the cured product of the paint for electrical equipment by SEM as described above.

  A case where the third filler is composed of a layered substance will be described. Examples of the layered substance include mica and smectite.

Mica is a kind of layered silicate mineral and is a layered compound composed mainly of SiO ₂ , Al ₂ O ₃ , K ₂ O, and crystal water. There are two types of mica, hard mica and soft mica. The volume resistivity of hard mica is about 1 × 10 ¹² to 1 × 10 ¹⁵ Ω · cm. The volume resistivity of soft mica is about 1 × 10 ¹⁰ to 1 × 10 ¹³ Ω · cm. Since hard mica and soft mica exhibit similar properties in the paint for electrical equipment according to the embodiment, they will be described below without distinction.

  The average linear length of the layered substance such as mica or smectite is preferably 0.1 μm or more and 2 μm or less, and preferably 0.5 μm or more and 1 μm or less in order to suppress sedimentation of the first filler in the matrix resin. More preferably.

  In order to ensure workability such as formation of a conductive path by the first filler and the second filler in the cured product of the paint for electrical equipment, and coating of the paint for electrical equipment, the third filler It is preferable that 1.0 mass part or more and 60.0 mass parts or less are contained with respect to 100 mass parts of photocurable resins. When talc or smectite is used as the third filler, the third filler may be contained in an amount of 1.0 to 30.0 parts by mass with respect to 100 parts by mass of the photocurable resin. preferable.

  Moreover, in order to prevent generation | occurrence | production of foam in a matrix resin, or in order to extinguish the produced | generated foam, the coating material for electric equipments may contain an antifoamer. The antifoaming agent is not particularly limited, and examples thereof include a dimethyl silicone-based antifoaming agent (for example, TSA720 (trade name manufactured by Momentive Performance Materials Japan GK)).

  In addition, in order to improve the workability when applying paint for electrical equipment to the structure with a brush or when applying with airless spray etc., the paint for electrical equipment may contain a diluent for photo-curable resin. Good. By adding a diluent to the coating material for electrical equipment, the viscosity of the photocurable resin can be reduced and the viscosity of the coating material for electrical equipment can be adjusted. The diluent has photocurability. Examples of the diluent include Aronix (low-viscosity photo-curable resin, trade name manufactured by Toagosei Co., Ltd.) and the like. Among Aronix, product name: M-101A (phenol EO (ethylene oxide) modified acrylate), product name: M-117 (nonylphenol EO (ethylene oxide) modified acrylate), product name: M-220 (polypropylene glycol diacrylate), product Name: M-309 (trimethylolpropane acrylate), product name: M-350 (trimethylolpropane EO (ethylene oxide) modified acrylate) and the like are suitable. More preferably, the diluent has a molecular structure derived from triacrylate. In order to improve the workability described above, the diluent is preferably contained in an amount of 5.0 parts by mass or more and 50.0 parts by mass or less with respect to 100 parts by mass of the photocurable resin (excluding the diluent). When the amount of the diluent contained in 100 parts by mass of the photocurable resin is less than 5.0 parts by mass, the viscosity of the electrical equipment paint is not sufficiently lowered, and the above workability may not be improved. When the amount of the diluent contained in 100 parts by mass of the photocurable resin is more than 50.0 parts by mass, the curability of the photocurable resin contained in the coating for electrical equipment is deteriorated, and the lead time may be increased. is there.

  Moreover, the coating material for electrical equipment may contain various additives, for example, a thermal polymerization initiator, etc., as long as the above effects are not deteriorated. Examples of the thermal polymerization initiator include a thermal radical polymerization initiator and a thermal cationic polymerization initiator. Moreover, when hardening the coating material for electrical devices containing a thermal-polymerization initiator, you may heat-process the coating material for electrical devices with a heating furnace etc. as needed.

  FIG. 2 is a diagram schematically showing a conductive path 50 formed by the first filler 10 and the second filler 20 in the cured product 1 obtained by curing the electrical apparatus paint according to the embodiment. is there. As shown in FIG. 2, the first filler 10 having a tetrapot shape enters between the second filler 20 and the third filler 30, and the second filler 20 and the third filler 30. The fillers 30 are uniformly dispersed in the matrix 40 of the cured product 1. Thereby, the insulation resistance characteristic which the 1st filler 10 expresses can be improved. In addition, the second filler 20 contacts the first filler 10 to form a three-dimensional conductive path 50.

  In addition, since the third filler 30 having insulating properties is uniformly dispersed in the matrix 40, the first filler 10 and the second filler 20 are uniformly arranged in the cured product 1. The Therefore, the conductive path 50 formed by the first filler 10 and the second filler 20 can be lengthened. As a result, even when the cured product 1 has a film thickness or when the surface of the cured product 1 has irregularities, a stable and long conductive path 50 can be formed. Therefore, the electric field concentrated between the hardened | cured material 1 and a foreign material can be relieve | moderated by providing the hardened | cured material 1 in the inner surface of the metal container of an electric equipment.

  As described above, by uniformly dispersing the first filler 10, the second filler 20, and the third filler 30 in the matrix 40 of the cured product 1, a good conductive path 50 can be secured and high. A foreign matter floating electric field can be obtained. The higher the value of the foreign object floating electric field, the more the foreign object can be prevented from floating and moving around in the electric device.

  Here, as one of the reasons why the coating material for electrical equipment according to the embodiment has a high foreign matter floating electric field, the conductive material formed by electrically connecting the first filler 10 and the second filler 20. The thing by pass 50 is mentioned.

  For example, when the conductive path is formed only by the first filler 10, it is necessary to bring the ends of the first filler 10 close to each other. However, bringing the ends of the first filler 10 close to each other balances the thickness of the cured product 1 (about several hundred μm) and the size of the first filler 10 (about several tens of μm). It is very difficult to think about. Therefore, the conductive path 50 can be reliably formed by including the second filler 20 having semiconductivity in the paint for electrical equipment.

  Further, when the conductive path is formed only by the second filler 20, the second filler 20 is uniformly dispersed in the cured product 1 because the shape of the second filler 20 is spherical and the particle size is small. Even so, it is difficult to form a conductive path. In addition, when the content of the second filler 20 is increased, the viscosity of the electrical equipment paint increases, so that workability is reduced. Furthermore, even when a diluent is added, when the content of the second filler 20 is increased, the viscosity of the paint for electrical equipment is similarly increased. Further, when the particle size of the second filler 20 is increased, it is difficult to uniformly disperse the second filler 20 in the cured product 1, so that it is very difficult to form a conductive path. It becomes.

  For this reason, it is necessary that both the first filler 10 and the second filler 20 be contained in the electrical equipment paint in an appropriate blending amount.

  Further, the first filler 10 and the second filler 20 having different shapes form a dense packing structure, whereby the conductive path 50 is formed. Here, the first filler 10 and the second filler 20 must be semiconductive, and the volume resistivity of the first filler 10 and the volume resistivity of the second filler 20 are required. Are preferably close to each other. The reason for this is that when the volume resistivity of the first filler 10 and the volume resistivity of the second filler 20 are greatly different, at the adjacent ends of the first filler 10 and the second filler 20, This is because dielectric breakdown may occur. In addition, the volume resistivity of the first filler 10 and the volume resistivity of the second filler 20 are a semiconductive region and an antistatic region, and therefore are suitable for preventing foreign substances from being charged.

  Next, it will be described that it is necessary for the electrical equipment paint to contain the third filler 30 in addition to the first filler 10 and the second filler 20. In the method for manufacturing a paint for electrical equipment described later, the first filler 10, for example, the needle crystal part 12, may break due to the shearing force in the stirring step. Even in such a case, the third filler 30 supports the folded portion of the first filler 10 by including the third filler 30 that is insulative in the electrical equipment paint. As a result, the conductive path 50 that is an electrical path can be formed. Further, even when the first filler 10 is not broken, the conductive filler 50 can be more reliably formed by the insulating third filler 30 supporting the first filler 10. .

  Next, the manufacturing method of the coating material for electrical equipment of embodiment is demonstrated.

  First, a part of the photocurable resin to be blended (for example, about 10% by mass to 50% by mass of the total blended amount of the photocurable resin) and the total blended amount of the first filler are stirred by a rotating / revolving mixer or the like. A master batch is prepared by putting them into a machine and stirring them with a stirrer. Subsequently, the remainder of the photocurable resin to be blended and the total blended amounts of the second filler and the third filler are added to the master batch, and the mixture is stirred with a stirrer. Through such a process, a paint for electrical equipment is manufactured.

  In this way, a master batch containing the first filler is prepared, and the remaining components are mixed with the master batch, so that the second filler and the third filler are contained in the paint for electrical equipment. Can be uniformly dispersed. And a 1st filler can be uniformly disperse | distributed because a 2nd filler and a 3rd filler are disperse | distributed uniformly. By such a thing, a favorable conductive path can be formed in the hardened | cured material of the coating material for electrical devices.

  Moreover, you may manufacture the coating material for electrical devices with the following processes. First, a part of the photocurable resin to be blended (for example, about 10% to 50% by mass of the total blended amount of the photocurable resin), the first filler, the second filler, and the third filling. The total amount of the agent and media such as glass particles are put into a stirrer and stirred while applying a shearing force to prepare a master batch. Then, the remainder of the photocurable resin to mix | blend is added to a masterbatch, and these are stirred. Thereafter, the media is separated by filtration or the like. Through such a process, a paint for electrical equipment is manufactured.

  Thus, by stirring these fillers together with the media, they can be stirred with high shear. Thereby, for example, a filler which easily aggregates can be dispersed while being loosened. Therefore, the 1st filler, the 2nd filler, and the 3rd filler can be uniformly disperse | distributed in the coating material for electric devices. By such a thing, a favorable conductive path can be formed in the hardened | cured material of the coating material for electrical devices.

  Moreover, when the coating material for electrical equipment contains an antifoamer or a diluent, a predetermined amount of an antifoamer or a diluent is added to the master batch or to the master batch. In addition, in the case where bubbles are present in the manufactured electrical equipment paint or when the viscosity of the electrical equipment paint is high, an antifoaming agent or a diluent may be further added to the manufactured electrical equipment paint. .

  In addition, about the addition method of a 1st filler, you may add the 1st filler which has performed the coupling process, and the 1st filler and the coupling agent which have not performed the coupling process May be added simultaneously.

  The coating for electrical equipment manufactured as described above is rapidly cured by irradiation with light, and a solid cured product is formed. For example, paint for electrical equipment is formed into a thin film by spray painting using airless spray or application using brush, etc., and then using a predetermined light source such as UV light, the light is fixed to the paint for electrical equipment. It is possible to produce a cured product of a thin film-like paint for electrical equipment by irradiation for a period of time.

  In addition, from the viewpoint that the cured product of the coating for electrical equipment expresses insulation resistance characteristics, the larger the thickness of the cured product, the better. However, in consideration of the size of various fillers, the thickness of the cured product is 50 μm or more. preferable. Moreover, considering that workability at the time of forming the coating film of the coating material for electrical equipment decreases as the film thickness of the cured product increases, the film thickness of the cured product is preferably 500 μm or less.

  FIG. 3: is a figure which shows in part a cross section the electric equipment provided with the hardened | cured material formed by hardening | curing the coating material for electric equipment of embodiment. Note that FIG. 3 shows a hermetic insulating device 60 as an example of an electric device.

  As shown in FIG. 3, the sealed insulating device 60 includes cylindrical metal containers 67, 68, 69 that are divided in the axial direction, and a high-voltage conductor 61 that extends in the axial direction at the center. The spacer 62 is provided between the metal container 67 and the metal container 68 and between the metal container 67 and the metal container 69 via the end flange portion 63.

  The metal containers 67, 68, and 69 are configured to cover the periphery of the high voltage conductor 61 while maintaining a radial gap perpendicular to the axial direction between the metal containers 67, 68, and 69. The spacer 62 is disposed so as to divide the inside of the metal containers 67, 68, 69 in a direction perpendicular to the central axis of the metal containers 67, 68, 69. A through hole is formed in the center of the spacer 62, and the high voltage conductor 61 passes through the through hole. Thus, the high voltage conductor 61 is supported by the spacer 62.

In addition, a coating layer 64 made of a cured product of the paint for electrical equipment according to the embodiment is formed on the inner peripheral surfaces of the metal containers 67, 68, and 69. An insulating gas 65 such as SF ₆ gas is sealed in the metal containers 67, 68, and 69, for example.

  FIG. 4 is a diagram schematically illustrating a method of curing the coating film of the electrical apparatus paint according to the embodiment. The coating layer 64 is formed as follows. First, the paint for electrical equipment of the embodiment is applied to the inner peripheral surfaces of the metal containers 67, 68, and 69 by spray coating or the like to form the paint film 4 of the paint for electrical equipment. Subsequently, by using the light source 2 to irradiate the coating film 4 with light 3 for a predetermined time to cure the coating film 4, it is possible to form a thin coating layer 64 having insulation resistance characteristics. The predetermined time is, for example, about several minutes to several tens of minutes.

  As described above, the electrical equipment paint according to the embodiment can be rapidly cured by light. And the metal piece which exists in the surface of the coating layer 64 by providing the coating layer 64 which has the favorable insulation resistance characteristic which is the hardened | cured material of the coating material for electrical devices in the inner peripheral surface of the metal containers 67, 68, 69, etc. The movement of the foreign matter 66 can be suppressed. Therefore, the design electric field of the metal container can be increased as compared with the conventional hermetic insulation device, and the metal containers 67, 68, and 69 can be made compact.

  As described above, according to the embodiment, by blending the second filler 20 and the third filler 30, the first filler 10, the second filler 20, and the third filler. It is possible to obtain a coating for electrical equipment in which the agent 30 is uniformly dispersed in the matrix resin. And even if it is a case where the hardened | cured material 1 has a certain amount of thickness in the hardened | cured material 1 which hardens the coating material for electrical devices, the 1st filler 10 penetrates between the 2nd fillers 20. As a result, a good conductive path 50 is formed. Therefore, the hardened | cured material 1 of the coating material for electric devices has a high foreign material floating electric field, and can thereby improve foreign material harmlessness. Furthermore, the paint for electrical equipment can be rapidly cured by irradiating the paint for electrical equipment with light.

  Further, according to the embodiment, the first filler 10 and the second filler 20 form the conductive path 50 in the cured product 1. Since the conductive path 50 penetrates from the upper surface to the lower surface of the cured product 1, the withstand voltage performance of the cured product 1 is improved, and the cured product 1 can prevent the foreign matter from being charged. Furthermore, since the conductive path 50 can improve the heat dissipation performance (thermal conductivity), the cured product 1 of the paint for electrical equipment can also be used as a heat dissipation coating.

  Note that, in the above description, a sealed insulating device is shown and described as an example of an electric device including the cured product of the paint for an electric device according to the embodiment, but the electric device includes, for example, various electric devices, electronic devices, Industrial equipment, heavy electrical equipment, etc. may be used. And even when the paint for electrical equipment of the embodiment is applied to these electrical equipments, the same operational effects as described above can be obtained.

  Hereinafter, a detailed description will be given with reference to examples. In addition, this invention is not limited at all by these Examples.

Example 1
First, a part of photocurable resin (TB3177 (trade name, manufactured by ThreeBond Co., Ltd.)) to be blended (50% by mass of the total blended amount of the photocurable resin) and the first filler (ZnO whisker, needle crystal part) Length: 2 μm to 50 μm, the average diameter (arithmetic average diameter) of the portion having the maximum diameter of the needle-like crystal part (0.2 μm to 3 μm) A batch was prepared. Subsequently, in the master batch, the remainder of the photocurable resin, the second filler (Fe ₂ O ₃ , average particle diameter (median diameter (D50)): 0.5 μm to 1.0 μm) 10.0 parts by mass, And 10.0 parts by mass of a third filler (talc, SWE (trade name, manufactured by Nippon Talc Co., Ltd.), median diameter (D50): 20 μm to 30 μm), and stirring with a rotating and rotating mixer, Manufactured. An appropriate amount of a dimethyl silicone-based antifoaming agent (TSA720 (trade name manufactured by Momentive Performance Materials Japan GK)) was added to the masterbatch.

(Example 2 to Example 18)
A paint for electrical equipment was produced in the same manner as in Example 1 except that the materials and parts by mass shown in Table 1 were used.

(Comparative Examples 1 to 18)
A paint for electrical equipment was produced in the same manner as in Example 1 except that the materials and parts by mass shown in Table 2 were used.

  Tables 1 and 2 show the types of materials used and the parts by mass of each material contained in 100 parts by mass of the photocurable resin. In Tables 1 and 2, the materials used are as follows.

Fe ₃ O ₄ (average particle diameter (median diameter (D50)): 0.05 μm to 0.08 μm)
Boron nitride (model name: GP, median diameter (D50): 6 μm to 10 μm (manufactured by Denki Kagaku Kogyo))
Potassium titanate whisker (model name: Tismo D, average fiber diameter: 0.3 to 0.6 μm, average fiber length: 10 to 20 μm (manufactured by Otsuka Chemical))
・ Glass milled fiber (model name: EFH30-01, average fiber diameter: 10-12 μm, average fiber length: 25-35 μm (manufactured by Central Glass Fiber))
-Mica (model name: PDM-K (G) 325, median diameter (D50): 40-60 nm (manufactured by Topy Industries))
・ Smectite (model name: Lucentite SWN, median diameter (D50): 45 to 55 nm (manufactured by Corp Chemical))
・ Diluent (model name: M-350 (manufactured by Toagosei Co., Ltd.))
In addition, the ZnO whisker used what gave the titanate coupling process.

  About the manufactured coating material for electric equipment, the foreign material floating electric field shown below was evaluated. FIG. 5 is a diagram schematically showing a cross section of the test apparatus 80 in which the foreign object floating electric field was evaluated. As shown in FIG. 5, the test apparatus 80 includes a metal container 87 made of aluminum having an inner diameter of 254 mm, and a high voltage conductor 81 having a diameter of 154 mm in the center of the metal container 87. The high voltage conductor 81 was installed such that the central axes of the metal container 87 and the high voltage conductor 81 were coaxial.

  On the inner peripheral surface of the lower half of the metal container 87, an electric equipment paint was applied using an airless spray to form an electric equipment paint film. Then, the coating film is cured by irradiating the coating film from above for 10 minutes (600 seconds) with light emitted from a light source (high pressure mercury lamp, HL-100G type, manufactured by SEN Special Light Company). A coating layer 84 made of a cured product of the paint was formed. The film thickness of the coating layer 84 was 100 μm.

Subsequently, six simulated metal foreign objects 86 (diameter 0.25 mm, length 3 mm) made of aluminum were placed on the coating layer 84. Then, SF ₆ gas (0.4 MPa) was filled in the metal container 87.

  Next, an electric field was applied to the high voltage conductor 81. The applied electric field was 0.6 kVrms / mm to 4.0 kVrms / mm in alternating current (AC), and the applied electric field was increased from 0.6 kVrms / mm by 0.2 kVrms / mm every minute. Then, first, an electric field at which any one of the simulated metallic foreign objects 86 floated was measured. Here, the operation of applying the voltage to the same coating layer 84 and actually measuring the electric field on which the simulated metallic foreign material 86 floated was performed five times. The arithmetic average value of the five actually measured values for the electric field was defined as the foreign substance floating electric field (kVrms / mm) of the coating layer.

In addition, about the light source used with the evaluation method of a foreign substance floating electric field, a dominant wavelength is 365 nm and irradiation intensity | strength is 0.17 W / cm < ² >. The irradiation energy amount E (exposure amount J / cm ² ) is represented by the product of the irradiation intensity I (W / cm ² ) and the irradiation time t (seconds), and the equation is as follows. From this equation, the irradiation energy amount of the light source is calculated as follows.

E (J / cm ² ) = I (W / cm ² ) × t (seconds)
= 0.17 (W / cm ² ) x 600 (seconds)
= 102 (J / cm ² )

  Tables 1 and 2 show the evaluation results of the foreign matter floating electric field for the cured products of the electrical equipment paints produced.

  According to Examples 1 to 18, when the electrical equipment coating material contains the first filler, the second filler, and the third filler in a predetermined amount within the above range, the first filler The second filler and the third filler are uniformly dispersed in the matrix resin, and the paint for electrical equipment can form a cured product having a high foreign matter floating electric field. Furthermore, a cured product obtained by curing a coating material for electric equipment has a high foreign matter floating electric field, and thus has excellent foreign matter detoxifying properties.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 1 ... Hardened | cured material, 2 ... Light source, 3 ... Light, 4 ... Coating film, 10 ... 1st filler, 11 ... Core part, 12 ... Acicular crystal | crystallization part, 20 ... 2nd filler, 30 ... 3rd 40 ... Matrix, 50 ... Conductive path, 60 ... Sealed insulation device, 61, 81 ... High-voltage conductor, 62 ... Spacer, 63 ... End flange, 64, 84 ... Coating layer, 65 ... Insulating gas , 66 ... foreign matter, 67, 68, 69, 87 ... metal container, 80 ... test apparatus, 86 ... simulated metal foreign matter.

Claims (13)

A matrix resin made of a photocurable resin;
A first filler made of whiskers, dispersed in the matrix resin and semiconductive,
A spherical second filler dispersed in the matrix resin and semiconductive,
A coating material for electrical equipment, comprising a third filler in the form of a plate, fiber, or layer dispersed and contained in the matrix resin.   The paint for electrical equipment according to claim 1, wherein the first filler is made of ZnO.   3. The paint for electrical equipment according to claim 1, wherein the first filler is surface-treated with a titanate coupling material. The second filler, claims 1 to 3 according to any one of the electrical equipment for coating, characterized in that it consists of Fe ₂ O _3. The second filler, Fe ₃ O ₄ to consist characterized by claims 1 to 3 according to any one of the electrical equipment paints.   The said 1st filler is 1.0 mass part or more and 50.0 mass parts or less with respect to 100 mass parts of said photocurable resins, The any one of Claim 1 thru | or 5 characterized by the above-mentioned. Item 1. A paint for electrical equipment according to item 1.   The electrical equipment paint according to any one of claims 1 to 6, wherein the third filler is made of talc.   The electrical equipment paint according to claim 1, wherein the third filler is made of mica.   The paint for electrical equipment according to any one of claims 1 to 8, wherein the paint for electrical equipment further contains a diluent.   The electrical equipment paint according to any one of claims 1 to 9, wherein the electrical equipment paint further contains a thermal polymerization initiator. A step of preparing a masterbatch by stirring a part of the photocurable resin to be blended and the first filler composed of semiconductive whisker;
To the masterbatch, the remainder of the photocurable resin, the semi-conductive spherical second filler, and the insulating flat, fibrous, or layered third filler are added and stirred. A process for producing a coating material for electrical equipment. Part of the photocurable resin to be blended, a first filler made of semiconductive whisker, a spherical second filler that is semiconductive, and a flat, fibrous, or layered form that is insulative A step of producing a master batch by stirring while applying a shearing force to the third filler of
And a step of adding the remaining part of the photocurable resin to the master batch and stirring the masterbatch. A high voltage conductor extending in the axial direction;
A metal container filled with an insulating gas, covering the high voltage conductor while maintaining a radial gap between the high voltage conductor;
11. A hermetic insulation apparatus comprising: a coating layer formed on an inner surface of the metal container and formed by curing the paint for electrical equipment according to claim 1.

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