JPH0223961B2 - - Google Patents

Description

[Detailed description of the invention]

This invention relates to a heat-resistant insulated wire used for winding electrical equipment, that is, a so-called heat-resistant magnet wire for winding.It can normally be used in the same way as a conventional enamel winding wire, and forms a ceramic insulating layer at high temperatures. This makes continuous use possible at high temperatures. Recently, insulated wires whose conductors are coated with highly heat-resistant ceramics have come to be used as heat-resistant magnet wires for winding.
However, since ceramics are usually extremely hard and brittle, electric wires coated with ceramics have extremely poor flexibility and are difficult to bend or otherwise form, and as a result, their range of use is limited. . Furthermore, due to the lack of flexibility as mentioned above, cracks may occur in the ceramic insulation coating during long-term use due to vibrations during handling or use, and as a result, the metal conductor may crack due to heat shock during use. The adhesion with the ceramic insulation coating deteriorates, and the ceramic insulation coating sometimes peels off, so that the heat resistance and insulation properties are still not sufficient. By the way, depending on the type of electrical equipment that uses the magnet wire and its usage conditions, the temperature may not reach a high enough temperature to require ceramic insulation coating under normal conditions, but the temperature may rise or abnormalities may occur due to the intermittent application of a large load. Ceramic insulated wires are sometimes required only when the wires reach high temperatures, but the reality is that ordinary ceramic insulated wires have been used even under these conditions, so the problems described above cannot be avoided. It was hot. Therefore, the inventors of this invention proceeded with the development of a heat-resistant magnet wire that can skillfully meet the above conditions, and have already proposed it in Japanese Patent Application No. 53-152647 (Japanese Patent Application Laid-open No. 55-80209). As shown in Fig. 2, it shows mechanical and electrical properties similar to conventional organic enamel insulated wires during winding processing at room temperature and at normal operating temperatures close to room temperature, and ceramic insulated wires show the same mechanical and electrical properties as conventional organic enamel insulated wires at abnormally high temperatures. We have successfully developed a heat-resistant magnet wire that exhibits the following characteristics. In other words, in the heat-resistant magnet wire obtained by the proposed manufacturing method, a composite coating layer of a mixture of inorganic fine powder and silicone resin (or a mixture of inorganic fine powder, silicone resin, and other resins) is formed on the conductor. and a flexible protective resin layer is formed on this composite coating layer,
A ceramic insulating layer is formed at high temperatures. This heat-resistant magnet wire has a composite coating layer that has not been made into ceramic through artificial firing heat treatment.
During the winding process, the composite coating layer and the resin layer on it are highly flexible, and even if friction between wires or object friction occurs, the presence of the resin layer prevents the composite coating layer from peeling off. , can be processed in the same way as ordinary organic enamel insulated wires, and exhibits the same electrical and mechanical properties as ordinary organic enamel insulation under normal usage conditions below the heat resistance temperature of the resin in the composite coating layer. When exposed to high temperatures that exceed the resin's heat-resistant temperature, or when a low temperature state that is below the resin's heat-resistant temperature and a high-temperature state that is above the resin's heat-resistant temperature are repeated, the electrical characteristics may suddenly or temporarily deteriorate. The composite coating layer becomes ceramic without causing any damage, and can be used continuously from low to high temperatures as it is. However, upon further study of the heat-resistant magnet wire proposed above, it was found that the following problems existed. That is, in the composite coating layer coated on the conductor of the proposed electric wire, silicone resin (or modified silicone resin, or a mixture of silicone resin and other resins) acts as a binder for the inorganic fine powder particles. Therefore, during the winding process, the binder resin between the inorganic powder particles in the composite coating layer located outside the wrapping circumference is stretched, but at this time, the composite coating layer and the binder resin formed on it are stretched. If the overcoat resin layer is bonded to the overcoat resin layer, that is, if both layers are formed in a continuous state, the binder resin in the composite coating layer will not be able to withstand the elongation between the inorganic powder particles, causing cracks in the binder resin. If this occurs, there is a risk that cracks will occur in the overcoat resin as well, resulting in a problem that the winding processability will deteriorate. And to solve this problem,
As a resin used for the overcoat resin layer,
It has become necessary to select a binder resin that has significantly better elongation properties and is tougher than the binder resin such as silicone resin for the composite coating layer, and as a result, the range of resins to be used as the overcoat resin has become significantly narrower, depending on the purpose of use. Otherwise, you may not be able to use the most suitable resin. In addition, if the composite coating layer and the overcoat resin layer thereon are bonded together as described above, when the binder resin of the composite coating layer decomposes at high temperatures such as during abnormal times, the presence of the overcoat resin layer will cause decomposed gas to be released. When heated rapidly to high temperatures, the pressure of the cracked gas from inside rises rapidly and the overcoat resin layer and composite coating layer are locally blown away. This poses a problem in that the conductor is locally exposed and a short circuit occurs between the lines. The purpose of this invention is to improve the above-mentioned proposal so as to simultaneously solve the above-mentioned problem of winding processability and the problem of high-temperature heating. On top of the coating layer, that is, the composite coating layer that becomes ceramic at high temperatures, the composite coating layer is in a state where it is floating without being bonded to the composite coating layer, or in an adhesive state that is close to non-bonding, that is, it is only partially bonded or is easily composited. The above-mentioned problems are solved by forming a protective resin layer in a state where it can be peeled off from the coating layer (hereinafter, in this specification, this state will be referred to as a non-adhesive state). Specifically, the heat-resistant magnet wire of the present invention includes at least Si and Ti on the conductor.
10 to 200 parts by weight of a polymer whose skeleton is one or more of B, Al, and P and oxygen, and an inorganic fine powder with a particle size of 10 μm or less that is half-melted or does not melt at the decomposition temperature of the polymer and has excellent electrical properties. A composite coating layer is formed of a mixture consisting of 100 parts by weight, and a flexible resin layer is provided on the composite coating layer in a non-adhesive state to the composite coating layer. It is characterized by the formation of The heat-resistant magnet wire of the present invention will be explained in more detail below. First, the above-mentioned polymer used in the composite coating layer of the magnet wire of this invention,
In other words, the polymer whose skeleton is Si, one or more of Ti, B, Al, and P, and oxygen acts as a binder for the composite coating layer, and also acts as a binder for the composite coating layer, and also produces substances after decomposition when fired at high temperatures such as during abnormal times. acts as a binder for inorganic fine powder to form a stronger ceramic layer. For example, the skeleton is -Si-O-Ti, -Si-O-Al-, -Si-
It is a polymer consisting of O-B-, etc. In some cases, copolymers or mixtures of such polymers with organic monomers such as methyl methacrylate and acrylonitrile, and resins such as alkyd resins, phenolic resins, epoxy resins, and melamine resins may also be used as binders. . In addition, as the binder for the composite coating layer, the above-mentioned polymer may be used alone, but in consideration of mechanical strength, etc., it may be mixed with other polar resins such as epoxy resin, polycarbonate, phenolic resin, etc. It can also be used. On the other hand, as the inorganic fine powder, it is necessary to use an inorganic fine powder that is half-melted or does not melt near the decomposition temperature of the polymer used as the binder and has excellent electrical properties. For example, crystalline powder, vitreous powder, or a mixed powder thereof is used, and more specifically, alumina (Al ₂ O ₃ ),
Barium titanate (BaTiO ₃ ), zircon (ZrSiO ₄ ), steatite (MgSiO ₃ ), silica (SiO ₂ ), beryllia (BeO), magnesia (MgO)
or clay, oxides such as high melting point glass frit, nitrides such as boron nitrite (BN), or mixtures thereof. These inorganic fine powders have a particle size of
It is necessary to use a material with a diameter of 10 μm or less. The reason is as follows. In other words, high dimensional accuracy is generally required for electrical equipment windings because they are wound onto reel frames of a fixed length, but when coarse grains exceeding 10 μm are used, the thickness of the entire coating layer cannot be precisely controlled. As a result, high dimensional accuracy of the outer diameter cannot be obtained, making it unsuitable for use as a winding wire. Furthermore, when coarse inorganic fine powder exceeding 10 μm is used, the unevenness of the coating layer surface (the surface of the overcoat resin layer described later) becomes large, resulting in friction when winding it around a winding frame or when installing the winding wire into equipment. As a result, there is a risk that the coating layer will be torn due to rubbing and the conductor will be exposed. On the other hand, if a fine powder of 10 .mu.m or less is used as the inorganic powder, it is possible to obtain a magnet wire suitable for winding, which has high dimensional accuracy and is resistant to abrasion, without causing the above-mentioned problems. Further, the particle size distribution of the inorganic powder may be uniform, but it may also be a state in which large-diameter particles and small-diameter particles are well combined so that the composite coating layer has a structure as dense as possible. A flaky or fibrous material may also be used. Note that the mixture of the inorganic powder and the above-mentioned polymer that forms the composite coating layer, or the mixture of the inorganic powder, the above-mentioned polymer, and other resin, contains less binder made of the polymer or other resin than the inorganic powder. If there is too much binder, the flexibility of the coating layer will be insufficient, making it difficult to wind the coil, and conversely, if there is too much binder, the amount of gas generated as the binder resin decomposes will increase when rapidly heated to high temperatures during use. As the amount increases, problems such as the coating layer being blown away may occur, and as a result, electrical properties (insulating properties) at high temperatures may deteriorate.
For this reason, the blending ratio of the mixture is determined such that the amount of the polymer is 10 to 200 parts by weight, preferably 20 to 60 parts by weight, per 100 parts by weight of the inorganic powder. In the above case, in order to form a coating layer on the conductor, the mixture may be extruded and coated on the conductor, or the mixture may be added with a diluent in an amount of 20 to 300 parts by weight per 100 parts by weight of the inorganic powder. It is also possible to add about parts by weight to form a solution and coat the conductor with this solution. In the latter case, the diluent may be a reactive or unreactive polysiloxane with a lower viscosity than the polymer, various modified siloxanes, other inorganic polymers that produce electrically insulating residues when thermally decomposed, or low polymerization degrees. Organic polymers, or organic solvents such as xylene and toluene are used. Further, although it is usually desirable that the mixture coated or extruded onto the conductor be cured by heating (including a semi-cured state), it may be left in an uncured state in some cases. This coating layer may be applied in a single layer or in multiple layers, and in some cases, a thin layer of the same polymer as above, or a combination of that polymer and another resin used in the composite coating layer, may be applied directly on the conductor. A thin layer of the mixture may be formed and the composite coating layer may be formed on the thin layer. In such a configuration, the binder component in the composite coating layer is thinly interposed between the composite coating layer and the conductor, so the composite coating layer is firmly bonded to the conductor, improving wear resistance and flexibility. In addition, if the composite coating layer becomes ceramic due to exposure to high temperatures during use of the magnet wire, the decomposition products of the thin layer will remain as a binder between the conductor surface and the ceramic layer, so the resistance will be low in this case as well. Improves abrasion resistance. The thickness of the thin layer is preferably about 1 to 5 μm; if it is thicker than this, there is a risk that many pinholes will occur due to foaming when the decomposed gas escapes when the thin layer of polymer etc. decomposes due to high temperatures. There is.
Furthermore, in some cases, the above-mentioned thin layer is formed directly on the conductor, the above-mentioned composite coating layer is formed on the thin layer, and the above-mentioned similar thin layer is formed again on the composite coating layer. Alternatively, a plurality of the thin layers and composite coating layers may be alternately formed. Furthermore, it is desirable that the thickness of the composite coating layer is 5 to 100 μm. If the thickness is less than 5 μm, if the composite coating layer turns into ceramic due to being heated to high temperature during use, the thickness of the ceramic layer will be insufficient and the high temperature will be reduced. Insulation performance is insufficient, and
If the thickness exceeds 10 μm, problems such as a decrease in flexibility and a softening of the composite coating layer, such as a decrease in wear resistance, will occur. Conductors coated or extruded with a composite coating layer include plated copper wires made of heat-resistant metals and alloys such as nickel and silver, nickel clad copper wires, stainless steel clad copper wires, silver wires, silver alloy wires, and platinum wires. It is desirable to use heat-resistant conductors such as wire, gold wire, nichrome wire, etc.; Aluminum alloy wire can be used. A protective resin layer is overcoated on the composite coating layer as described above in a non-adhesive state to the composite coating layer. The overcoat resin layer formed in this way is intended to satisfy both processability such as winding and properties at high temperatures.First of all, from the viewpoint of processing properties, friction between wires during coil winding etc. This is to prevent the composite coating layer from peeling off due to friction and object friction, and to improve the winding properties. It is desirable that the material has excellent wear resistance. On the other hand, in terms of heat resistance, it is heat resistant enough to withstand long-term use at normal operating temperatures, and especially when used under conditions where the temperature rises rapidly during abnormal conditions. It is desirable to use a heat-resistant resin with excellent heat-softening properties, ie, a resin such as polyimide, amide-imide resin, esterimide resin, polyhydantoin, heat-resistant polyester, or polybalabanic acid. On the other hand, when the temperature does not rise rapidly as mentioned above, that is, when the temperature rises intermittent or slowly, urethane resins, fluorine resins, polyolefins, polyamides, formal resins, etc. Can be used. The thickness of the overcoat resin layer is preferably 1 to 100 μm. If it is less than 1 μm, it will be weak against friction during coil winding, and if it exceeds 100 μm, the ceramic layer may peel off during decomposition if the resin has poor degradability, and the space factor will decrease. Problems such as Moreover, this overcoat resin layer is not limited to one layer, but can be formed into multiple layers depending on the intended use of the electric wire, or may be formed into multiple layers by combining various other resins. For example, if heat softening properties and wear resistance properties are required, first coat with a polyimide etc. with excellent heat resistance properties, then coat with a material with excellent mechanical properties such as polyamideimide, formal resin, polyamide etc. It is desirable to have a multilayer structure. As mentioned above, in order to form the overcoat resin layer on the composite coating layer in a non-adhesive state,
Use a resin for the overcoat layer that has poor adhesion to the composite coating layer, such as polyimide, Teflon, or amide-imide resin that has poor adhesiveness to the polymer in the composite coating layer, and coat this resin on the composite coating layer. Alternatively, it is better to coat the wire while applying stretching force to the wire core. Alternatively, a fine powder with lubricating properties such as BN, MoS ₂ ,
Inorganic substances such as MoS ₃ , WS ₂ , PbO, silicon nitride, graphite fluoride, graphite, mica, etc., and organic substances such as fluororesin are applied as is or mixed with binder resin, and overcoat resin is applied on top. Coating or winding, tubing, extrusion coating. Furthermore, the overcoat resin layer may be formed by winding or vertically attaching a tape-shaped piece of the resin. In this case, the overcoat resin tape can be formed by adjusting the tension when winding the tape. Make sure not to tighten it too hard on the covering layer, or use something like wart tape. Furthermore, in the case of such tape winding, the overlapping portions of the tapes may be adhered by various methods as necessary. Furthermore, a hollow tube-like material may be used as the overcoat resin layer, and this tube may be inserted outside the composite coating layer. In some cases, between the composite coating layer and the overcoat resin layer,
The overcoat resin layer may be made non-adhesive to the composite coating layer by interposing another layer that is non-adhesive to at least one of these layers. Note that an anti-friction layer made of a material that provides lubricity may be provided on the overcoat resin layer formed as described above, in order to improve the sliding characteristics of the wire during winding, etc. . When heat-resistant magnet wires such as those detailed above are used in electrical equipment, they are usually coil-wound, but during the coil-winding process, the composite coating layer is not made into a ceramic material, so it is not flexible. This work can be done easily because of the abundance of Moreover, since the flexible overcoat resin layer provided on this composite coating layer is formed in a non-adhesive state to the composite coating layer, the composite coating layer on the outside of the curved radius during the winding process Even when the overcoat resin layer is stretched, the overcoat resin layer is stretched independently of the composite coating layer. Therefore, even if a crack occurs in the composite coating layer, the overcoat resin layer will be deformed by the amount of deformation of the resin itself. No cracks will occur within the deformation limits. Therefore, the workability of the electric wire as a whole is extremely good, and it can be wound into a small diameter coil in the same manner as conventional organic enamel insulated electric wires. Even if the overcoat resin layer is made of a resin whose elongation properties and toughness are not so high compared to when the overcoat resin layer is bonded to the composite coating layer, good processability can be obtained as described above. There is a wide range of choices for the coating resin layer, so the most suitable resin can be used depending on the purpose of use. Furthermore, due to the presence of the overcoat resin layer, the composite coating layer is not directly exposed to the outside surface, so there is no possibility that the composite coating layer will peel off due to friction between wires or object friction during coil winding. . When the winding made of the magnet wire of this invention is used at a temperature close to room temperature, which is below the heat resistance temperature of the polymer or overcoat resin of the composite coating layer, the composite coating layer is not ceramicized. , and because the overcoat resin layer remains on top of it, its mechanical properties are similar to conventional organic enamel insulated wires, so even when used under conditions of mechanical vibration. The insulation coating does not peel off, and its electrical characteristics are comparable to conventional organic enamel insulated wires. Therefore, it can be used in almost the same way as conventional organic enamel insulated wires for electrical equipment whose normal operating temperature is below the heat resistance temperature of overcoat resins and the like. On the other hand, when the temperature rises to a high temperature, the polymers that make up the composite coating layer decompose, their organic components disappear, and silica and composite oxides with silica are generated, and the decomposition products of this silica etc. are inorganic. It acts as a binder for the fine powder to form a strong ceramic layer. In this case, ceramification occurs without temporary or rapid deterioration of electrical properties during decomposition, and the produced ceramic layer has extremely good electrical properties (insulating properties) at high temperatures. Therefore, even if the temperature rises to a high temperature, the electrical characteristics can be used continuously without deterioration. In particular, in the heat-resistant magnet wire of the present invention, since the overcoat resin layer is provided in a non-adhesive state to the composite coating layer that turns into ceramic at high temperatures, the binder of the composite coating layer such as the polymer decomposes. Even if the overcoat resin layer has not yet decomposed and disappeared, the decomposition gas from the composite coating layer will be trapped between the composite coating layer and the overcoat resin layer, so a sudden rise in temperature will cause the decomposition to occur. Even if the decomposition progresses rapidly, it is possible to prevent the occurrence of a situation in which the overcoat resin layer and composite coating layer are blown away and the conductor is exposed due to the generation of decomposition gas. Therefore, as the resin used for the overcoat resin layer, various resins can be used depending on the purpose of use, such as resins that have excellent heat resistance and are relatively difficult to decompose and disappear. In addition, in the process where the aforementioned polymer as a binder decomposes due to rapid temperature rise due to overload due to equipment abnormality, the inorganic powder in the composite layer melts or half-melts, and the composite layer becomes in a fluid state. If this occurs, the pressure of the decomposed gas of the polymer as the binder resin will scatter the fluidized bed itself, resulting in the ceramic layer being locally peeled off and the conductor being locally exposed. However, in the case of the present invention, as mentioned above, since an inorganic powder that is half-melted or does not melt near the decomposition temperature of the polymer is used, the inorganic polymer cannot be used for a long time due to rapid temperature rise. During the decomposition process, the inorganic powder does not become softened and fluidized, so that the decomposition gas of the polymer is easily released from the gaps between the powder particles, and the composite layer is prevented from scattering. That is, the ceramic layer does not peel off locally, and can sufficiently withstand subsequent use. In addition, if the inorganic powder melts or half-melts during a rapid temperature rise and the composite layer becomes soft and fluid, the composite layers of adjacent wires will stick together, and the wires may break due to rapid heating or cooling after turning into ceramic. This may cause the coating layer to peel off, but in the case of the present invention, as mentioned above, this inorganic powder is used as a binder with a high melting point higher than the decomposition temperature of the polymer (usually around 500°C). It prevents the wires from sticking together and can withstand sudden heat and cold. Furthermore, when the polymer is decomposed, the inorganic powder does not become softened and fluidized, and the inorganic powder is bonded to form a ceramic by the decomposition residue of the polymer. particles are tightly bound together),
As a result, it is difficult for distortion to accumulate due to rapid heating or cooling after being made into ceramic, and from this point of view, it can sufficiently withstand rapid heating or cooling. Examples of the present invention will be described below along with comparative examples. [Example 1] A slurry-like mixture consisting of borodiphenylsiloxane polymer 38 parts by weight methylphenyl silicone 12 parts by weight N-methylpyrrolidone 40 parts by weight xylene 10 parts by weight alumina (average particle size 3.5 μm) 100 parts by weight Apply it on a conductor made of 1.0mmφ nickel plated copper wire, and then
The conductor was cured in a furnace controlled at a temperature of 350 to 450° C. to form a composite coating layer with a thickness of 17 μm on the conductor using a polymer having a -Si-O-B- skeleton as a binder. Next, a polyimide paint was applied onto the composite coating layer while applying tension to the conductor at an elongation rate of about 1%, and baked to obtain a heat-resistant magnet wire having an overcoat layer of about 14 μm thick in a non-adhesive state. [Example 2] Methyl phenyl silicone 48 parts by weight Tetrabutyl titanate 6 parts by weight Xylene 50 parts by weight 10% butanol water 1 part by weight Alumina (average particle size 3.5 μm) A slurry-like mixture consisting of 100 parts by weight was prepared in Example 1. alike
It was coated on a conductor made of nickel-plated copper wire with a diameter of 1.0 mm and cured by heating to form a composite coating layer having a thickness of 17 μm on the conductor using a polymer having a -Si-O-Ti- skeleton as a binder. Next, a heat-resistant magnet wire was obtained in which a polyimide overcoat layer was provided in a non-adhesive state with a thickness of 16 μm on the composite coating layer in the same manner as in Example 1. [Example 3] A mixture in which 6 parts by weight of aluminum isopropoxide Al[OCH(CH ₃ ) ₂ ] ₃ was used instead of tetrabutyl titanate (C ₄ H ₉ O) ₄ Ti in Example 2 was used in Example 1. Similarly, it is applied onto a conductor made of nickel-plated copper wire with a diameter of 1.0 mm and cured by heating.
A composite coating layer with a thickness of 17 μm was formed using a polymer having a -Si-O-Al- skeleton as a binder. Next, a heat-resistant magnet wire was obtained in which a polyimide overcoat layer was provided in a non-adhesive state with a thickness of 14 μm on the composite coating layer in the same manner as in Example 1. [Example 4] A mixture in which 6 parts by weight of tri-n-butyl phosphate (C ₄ H ₉ O) ₃ PO was used instead of tetrabutyl titanate in Example 2 was prepared in the same way as in Example 1, with a diameter of 1.0 mm.
The composite coating layer was coated on a conductor made of nickel plated copper wire and cured by heating to form a composite coating layer with a thickness of 17 μm using a polymer having a -Si-O-P- skeleton as a binder. Then on top of that composite coating layer
Wrapped with 10 μm thick polyethylene film,
Thereafter, the films were fused together by heating in a 150° C. oven to obtain a heat-resistant magnet wire provided with an overcoat layer made of polyethylene in a non-adhesive state. [Example 5] After forming a composite coating layer on a conductor in the same manner as in Example 1, a 30 μm thick polyester tape was wrapped around the composite coating layer, and then polyester varnish was applied to bond the tapes together. By doing so, a heat-resistant magnet wire was obtained in which an overcoat layer made of polyester was provided on the conductor in a non-adhesive state. [Example 6] After thoroughly mixing a composition consisting of 48 parts by weight of methylphenyl silicone, 25 parts by weight of xylene, 25 parts by weight of benzyl alcohol, and 100 parts by weight of alumina (average particle size: 3.5 μm) to form a slurry composition. Add 3 parts by weight of a 50% xylene solution of tetrabutyl titanate to this and mix thoroughly, and then add 50% of tri-n-butyl borate to this.
After adding 2 parts by weight of the xylene solution and thoroughly mixing, it was immediately applied to a 1.0 mmφ nickel-plated copper wire, and then continuously heated and hardened in a furnace at 300 to 450°C to form Si, Ti, B, and O. A composite coating layer having a polymer backbone and a binder was formed on the conductor to a thickness of 18 μm. Next, the conductor has an elongation rate of about 1%.
A heat-resistant magnet wire with a non-adhesive overcoat layer approximately 15μ thick, which is applied by applying a polyimide paint onto the composite coating layer while applying a certain amount of tension, and then curing it by heating in an oven at 300 to 450℃. I got it. [Example 7] Methylphenyl silicone used in Example 6,
After adding and mixing 3 parts by weight of a 50% tri-n-butyl borate (C ₄ H ₉ O) ₃ B xylene solution to the slurry composition consisting of xylene, benzyl alcohol, and alumina, immediately It was applied onto nickel plated copper wire and heated to partially cure it to the extent that it would not dissolve in the solvent. Then this line
30% aluminum tri-n-butoxide Al
Impregnated by immersion in a xylene solution _of ( _OC4H9 ) ₃ ,
After that, it is heated continuously in a furnace at 300-450℃,
A composite coating layer having a binder of a polymer with Si, B, Al, and O skeletons was formed on the conductor to a thickness of 18 μm. Then, as in Example 6, while stretching the conductor, a first layer of polyimide of 12 μm and a second layer of formal of 5 μm were applied to the surface of the composite coating layer.
A heat-resistant magnet wire having a thickness of m and having a two-layer overcoat layer in a non-adhesive state was obtained. [Example 8] Methyl phenyl silicone 50 parts by weight Xylene 30 parts by weight Benzyl alcohol 20 parts by weight 6 parts by weight of a 30% butyl titanate solution in xylene was added to a slurry composition consisting of 100 parts by weight of alumina (average particle size 3.5 μm). After adding and thoroughly mixing, 5 parts by weight of a 30% tri-n-butyl borate xylene solution was added and mixed, and this was immediately coated on a 1.0 mmφ nickel-plated copper wire and heated. hardened. Furthermore, this wire is then immersed in a xylene solution of 50% tri-n-butyl phosphate to form a composite coating layer containing a polymer with a skeleton of Si, Ti, P, and O as a binder.
It was formed on a conductor with a thickness of 18 μm. Next, on this composite coating layer, an overcoat layer made of polyimide resin was formed in a non-adhesive state to a thickness of 15 μm in the same manner as in Example 6 to obtain a heat-resistant magnet wire of the present invention. [Example 9] A slurry-like mixture consisting of 56 parts by weight of borodiphenylsiloxane polymer, 70 parts by weight of N-methylpyrrolidone, and 100 parts by weight of alumina (average particle size: 4.7 μm) was placed on a conductor made of nickel-plated copper wire of 1.0 mmφ. apply and then
The mixture was cured in a furnace controlled within the range of 350 to 450°C to form a composite coating layer with a thickness of about 15 μm using a polymer having a -Si-O-B- skeleton as a binder. Next, while applying tension to the conductor with an elongation rate of about 1%, polyimide paint is applied onto the composite coating layer and baked to form a thickness of about 20 μm, and formal resin is further coated on top of this to a thickness of about 5 μm. A heat-resistant magnet wire was obtained which was provided with an overcoat layer having a total thickness of about 25 μm in a non-adhesive state. [Comparative Example] A composite coating layer was formed on a conductor in the same manner as in Example 1, and then a magnet wire was obtained which was coated with a 6 μm thick urethane resin as an overcoat film. In this case, the overcoat film is adhered to the composite coating layer. The heat-resistant magnet wires of Examples 1 to 9 and Comparative Examples above were tested for the state of the overcoat layer, flexibility, and heat resistance. The results are shown in Table 1. However, the heat resistance properties due to rapid heating were evaluated after the overcoat resin had completely decomposed and disappeared by placing two twisted samples of the magnet wire in a furnace set at each temperature. Furthermore, in Table 1, the numerical values in each column of "Flexibility" indicate the number of defects generated for 20 samples. Furthermore, the evaluation in the column "Flashing of composite coating layer due to rapid heating" is as follows. 〇mark: No flaking of the coating layer. △ mark: Partial skipping occurs. × mark: The coating layer is broken and the conductor is exposed.

[Table] As is clear from the results shown in Table 1, the heat-resistant magnet wire of the embodiment of the present invention, in which the resin layer of the overcoat is configured in a non-adhesive state to the composite coating layer, is different from that of the conventional enameled wire. as well as 10%
Flexibility to withstand self-radial winding after elongation was obtained, and the composite coating layer was less likely to peel or fly even when the temperature rose rapidly. On the other hand, it can be seen that when the overcoat layer is bonded as in the comparative example, there are problems in terms of flexibility and properties at high temperatures. As explained above, the heat-resistant magnet wire of the present invention contains at least inorganic fine powder, Si, Ti,
A composite coating layer of a mixture consisting of one or more elements of B, Al, and P and a polymer having oxygen as a skeleton is formed on the conductor, and a flexible resin layer is formed on the composite coating layer. The composite coating layer is formed in a non-adhesive state with respect to the coating layer, and the composite coating layer has not been made into ceramic by artificial firing heat treatment under certain predetermined conditions, and only becomes ceramic at high temperatures during use. It was designed to be Therefore, the patent application already proposed in 1973-
Similar to the heat-resistant magnet wire invented in No. 152647 (Japanese Unexamined Patent Publication No. 55-80209), there is no problem of deformation or oxidation of the winding base material such as the winding frame, and it is similar to ordinary organic enamel insulated wire. It can be easily processed such as coil winding, and it can be used continuously for long periods of time like organic enamel insulated wire at normal operating temperatures below the heat resistance temperature of the resin, and there is no risk of abnormalities during use. When exposed to high temperatures, the composite coating layer turns into a ceramic, allowing continuous use from low to high temperatures without deteriorating its electrical properties, and even after being turned into a ceramic, it can withstand repeated rapid heating and cooling. In addition, in the magnet wire of the present invention, the composite coating layer and the resin layer thereon are in a non-adhesive state. Compare,
It has particularly good workability in winding, and even as an overcoat resin, this invention prevents a part of the conductor from being exposed due to decomposition gas when the composite coating layer turns into ceramic. Various resins can be used, and therefore, it is possible to obtain better characteristics by using the resin most suitable for the purpose of use.

Claims (1)

[Claims] 1 10 to 200 parts of a polymer whose skeleton is Si, one or more elements of Ti, B, Al, and P and oxygen on a conductor, and a material that is half-melted or does not melt near the decomposition temperature of the polymer and has electrical characteristics. A composite coating layer of a mixture consisting of 100 parts of fine inorganic powder with an excellent particle size of 10 μm or less is formed, and a flexible resin layer is placed on the composite coating layer in a non-adhesive state to the composite coating layer. A heat-resistant magnet wire characterized in that a ceramic insulating layer is formed at high temperatures.