JP2010193673A - Dry mica tape, electrical insulation coil using it, stator coil, and rotary electric machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dry mica tape in which preservation stability and enhancement in the heat resistance (glass transition temperature) of an insulating layer containing the dry mica tape and impregnating varnish are balanced, and to provide an electrical insulation coil using it, a stator coil and a rotary electric machine. <P>SOLUTION: In the dry mica tape containing mica, a reinforcing layer and a binder, the binder contains epoxy resin having three or more epoxy groups, and an acid hardener having a melting point or a softening point of 50°C or more and an acid anhydride framework. The dry mica tape is wound around a conductor which is applied with an insulation coating and cast in a specific shape thus producing an electrical insulation coil unit. Impregnating varnish containing epoxy resin and an acid hardener is then injected into the electrical insulation coil unit which is thereby hardened thus producing an electrical insulation coil. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a dry mica tape, an electrically insulated wire ring using the tape, a stator coil, and a rotating electric machine.

  The demand for higher heat resistance is increasing with the reduction in size, weight, and performance of generators and rotating electrical machines for general industrial use. For insulation of high voltage rotating electrical machines, mica tape with insulation reliability is used.

  In order to further improve the heat resistance of rotating electrical machines, optimization of the insulation method of the stator composed of an electrically insulated wire ring and iron core, creation of mica tape, which is the main insulation material for conductors, epoxy resin The creation of an impregnated varnish composed of a curing agent and a curing accelerator is an important issue.

Insulation methods for electrically insulated wire rings and stator coils using mica tape are broadly classified into single injection method, integral injection (total impregnation) method, and prepreg method described below.
(1) In the single injection system, a dry mica tape is wound around a conductor molded and insulated into a specified shape to form a single electrically insulated wire ring, and the electrically insulated wire ring alone is impregnated with varnish (epoxy resin, curing agent and After vacuum injection (impregnation) of a hardening accelerator or the like), pressure injection (impregnation) is further performed, and thermosetting is performed to obtain an electrically insulated wire ring. This electric insulated wire ring is housed in an iron core slot and fixed with a sashimi lower liner, sashimi, etc. to form a stator coil.
(2) The integral injection (full impregnation) method is to wrap a dry mica tape around a conductor that has been molded into a specified shape and covered with insulation to form a single electrically insulated wire ring, and this electrically insulated wire ring is incorporated into an iron core slot. Fixed in the slot with a sashimi lower liner, sashimi, etc., connected at the outer end of the core and integrated into a single stator. A method in which impregnated varnish is injected into this stator alone by vacuum and pressure and then thermoset to form a stator coil.
(3) In the prepreg method, a prepreg mica tape (also referred to as resin rich mica tape) is wound around a conductor that is molded into a specified shape and covered with insulation, and then thermally cured to form an electrically insulated wire ring. A method in which the wire ring is housed in an iron core slot and fixed with a sashimi lower liner, sashigi, etc. to form a stator coil.

  The single injection method and the integral injection (total impregnation) method allow the impregnating varnish to penetrate the entire stator coil, such as conductors, in a vacuum / pressurized state evenly and insulate it. It can be reduced and insulation reliability is high. Since this method requires the management of vacuum / pressurization equipment and impregnating varnish, the installation scale becomes large when applied to a production line for large-capacity rotating electrical machines.

  On the other hand, the prepreg method can simplify the equipment and suppress the capital investment as compared with the above injection method, but there is a troublesome construction of the molding and hardening process of the prepreg mica tape wound around the conductor.

  Next, dry mica tape and prepreg mica tape will be described.

  Dry mica tape applied to single injection method or integral injection method is a mica paper, a reinforcing substrate such as organic film or glass cloth, a binder composed of epoxy resin, etc., curing mainly for curing impregnating varnish Consists of accelerators. The mica paper and the reinforcing base material are bonded by a binder. As will be described later, the difference between the dry mica tape and the prepreg mica tape is that the impregnated varnish is injected, so the amount of binder impregnation is small compared to the resin composition of the prepreg mica tape. This is a point where there are voids. As described in Patent Documents 1 and 2, the binder content is generally set in the range of about 5 to 30 wt% with respect to the total weight of the dry mica tape according to the intended use.

  On the other hand, the prepreg mica tape applied to the prepreg method is made of a resin composition composed of mica paper, a reinforcing base material such as organic film and glass cloth, and epoxy resin, so it is almost the same as dry mica tape. The difference between the prepreg mica tape and the dry mica tape is that the resin composition of the prepreg mica tape is not only the role of the adhesive between the mica paper and the reinforcing substrate, but the resin composition is abundant in advance throughout the tape. It is contained, and since the resin composition plays the role of the impregnating varnish of the dry mica tape, the impregnating varnish is not required to be injected. As described in Japanese Patent No. 3748324 and Japanese Patent Application No. 52-157292, the content of this resin composition is generally in the range of about 15 to 50 wt% with respect to the total weight of the prepreg mica tape. Set accordingly.

  In the single injection method or the integral injection method, the impregnating varnish is vacuum injected after being injected into the dry mica tape, and the binder and the impregnated varnish of the dry mica tape are cured to produce an insulating layer. In order to improve the heat resistance of this insulating layer, it is necessary to increase the heat resistance of the binder and impregnating varnish of the dry mica tape which is a resin component among the constituent components.

  For this reason, a technique for improving the heat resistance of the insulating layer by improving the impregnating varnish has been studied. As such an impregnating varnish, there is a known technique that improves heat resistance by using a high heat-resistant epoxy resin, a curing agent, and a curing accelerator. However, since the impregnating varnish is repeatedly used for coil insulation treatment, it is kept at room temperature to 40 ° C., which is the temperature at the time of storage or impregnation treatment, and the viscosity is kept constant without proceeding with the curing reaction. There is also a need for technology to achieve stability at the same time.

  On the other hand, there is a technique in which a polyfunctional epoxy resin having high heat resistance is used alone as a binder. Although this method was effective in improving the adhesion of the insulating layer, when the binder was made of epoxy resin alone, it was mixed with impregnating varnish composed of epoxy resin and curing agent. Since the balance of the equivalence ratio is shifted, there is a problem that the curing reactivity is deteriorated and the effect of improving the heat resistance is small. Note that, since the insulating layer contains about 20 to 45 wt% of the impregnating varnish and about 5 to 30 wt% of the binder, the ratio of the impregnating varnish to the binder is about 3: 1. For the above reasons, when the binder is an epoxy resin alone, the equivalent ratio of the epoxy resin and the curing agent inside the insulating layer is greatly shifted. Further, there is a method using a silicone resin having high heat resistance for the binder, but it does not react with the impregnating varnish, so it is necessary to improve the heat resistance of the impregnating varnish.

  Next, as a known technique for achieving high heat resistance by dry mica tape, for example, as described in Patent Document 1, epoxy modified unsaturated which is a modified product of unsaturated imide and epoxy resin in the binder of the dry mica tape Heat resistance is increased by applying imide or phenol-modified unsaturated imide, which is a modified product of unsaturated imide and phenol resin. Moreover, as described in Patent Document 2, the heat resistance is increased by applying a polyfunctional epoxy resin containing three or more p- (2,3-epoxypropoxy) phenyl groups and a phenol curing agent. However, although these known techniques have been tried to improve heat resistance, the balance of the equivalent ratio of the epoxy resin and the curing agent when mixed with the impregnating varnish is not taken into consideration, so the curing reactivity is poor. Therefore, the effect of improving heat resistance is small.

  On the other hand, as a known technique for achieving high heat resistance by the prepreg method, for example, as described in JP-A-2005-259928 (Patent Document 3), epoxy resin or liquid acid anhydride curing is used as a resin composition of a prepreg mica tape. There is a configuration in which heat resistance is improved by optimally dispersing the layered clay mineral using an agent, a hardening accelerator, and a layered clay mineral. However, since the prepreg mica tape contains a curing accelerator, if it is not stored in a refrigerated or frozen state, the curing reaction proceeds and there is a problem that storage stability is lowered. Further, a prepreg (resin rich) mica tape described in Japanese Patent No. 3748324 (Patent Document 4) is a liquid or solid bisphenol A type epoxy resin, a liquid or solid novolac type epoxy resin, and an acid as a resin composition. There is a disclosure in which rapid curing is improved and productivity is increased by a configuration in which an anhydride curing agent is applied. However, since the focus is on improving productivity, the heat resistance of the insulating layer (cured product) is as low as 126 ° C. or less, and thus further heat resistance needs to be improved.

Japanese Patent No. 2874501 JP-A-3-77203 JP 2005-259928 A Japanese Patent No. 3748324

  An object of the present invention is to provide a dry mica tape that is excellent in storage stability and has improved heat resistance of an insulating layer made of dry mica tape and impregnated varnish, an electrically insulated wire ring, a stator coil, and a rotating electrical machine using the dry mica tape. There is to do.

  That is, the dry mica tape of the present invention is a dry mica tape containing mica, a reinforcing layer, and a binder, wherein the binder has an epoxy resin having three or more epoxy groups, a melting point or a softening point of 50 ° C. or more, :

で表される酸無水物骨格を有する酸硬化剤を含むことを特徴とする。

It contains the acid hardening agent which has an acid anhydride frame | skeleton represented by these.

  ADVANTAGE OF THE INVENTION According to this invention, the dry mica tape which was excellent in storage stability and improved the heat resistance of the insulating layer which consists of a dry mica tape and an impregnation varnish, an electrically insulated wire ring, a stator coil, and a rotary electric machine using the same is provided. can do.

It is sectional drawing which shows typically the structure of the dry mica tape of this invention. It is the external view of the (a) electric insulated wire ring of this invention, and (b) The cross-sectional enlarged view inside. It is the cross-sectional front view of (a) stator coil of this invention, and the cross-sectional enlarged view of (b) iron core slot. It is a cross-sectional perspective view of the rotary electric machine using the stator coil of this invention.

Hereinafter, the dry mica tape, the electrically insulated wire ring, the stator coil, and the rotating electric machine according to the present invention will be described in detail.
[Dry mica tape]
A cross-sectional view of the dry mica tape of the present invention is shown in FIG. The dry mica tape of the present invention is composed of mica, a reinforcing substrate, a binder, and a curing accelerator for an impregnating varnish that is added as necessary. When the impregnated varnish is injected into the dry mica tape of the present invention and cured, the insulating layer of the present invention can be produced.

  As the mica, an integrated mica or flake mica having an optimum particle size can be used according to an insulation treatment method such as a single injection method or an integral injection method.

  As the reinforcing substrate, a commercially available glass cloth, organic film, or the like corresponding to required heat resistance and insulation specifications can be used.

  The curing accelerator may be a known compound that can cure an epoxy resin or a curing agent. Examples of the known compound include epoxy adduct imidazole obtained by replacing imidazole with an epoxy resin, metal salts such as naphthenic acid and octylic acid, and the like. 1 type or 2 types or more can be used simultaneously.

  If the polyfunctional epoxy resin and the acid curing agent having a melting point or softening point of 50 ° C. or higher are not used as the binder, the effect of achieving both improved heat resistance and improved storage stability cannot be exhibited. As the polyfunctional epoxy resin of the binder, one kind or two or more kinds of epoxy resins having three or more epoxy groups can be used at the same time. Examples of such known polyfunctional epoxy resins include tris (hydroxyphenyl) alkanes and tetrakis (hydroxyphenyl) alkanes. Examples of trifunctional epoxy resins include tris (hydroxyphenyl) methane type epoxy resins and tris (hydroxyphenyl). ) Ethane type epoxy resin, tris (hydroxyphenyl) propane type epoxy resin, and the like. Examples of the tetrafunctional epoxy resin include tetrakis (hydroxyphenyl) methane type epoxy resin, tetrakis (hydroxyphenyl) ethane type epoxy resin, and tetrakis (hydroxyphenyl) propane type epoxy resin. Among these, tris (hydroxyphenyl) methane type epoxy resin, 1,1,2,2-tetrakis (hydroxyphenyl) ethane type epoxy resin and the like are more preferable. Moreover, in order to give desired characteristics, such as another softness | flexibility, a well-known epoxy group may use together one or more liquid epoxy resins. In that case, the range which does not exceed the equivalent ratio of the epoxy resin of this invention and a hardening | curing agent is good.

  The binder acid curing agent has the following formula:

で示される酸無水物骨格を有し、且つ融点もしくは軟化点が５０℃以上の酸硬化剤を１種類もしくは、２種類以上を同時に用いることができる。

One type or two or more types of acid curing agents having an acid anhydride skeleton represented by the above and having a melting point or softening point of 50 ° C. or higher can be used at the same time.

  However, when an acid curing agent having a melting point or softening point of 50 ° C. or less is used, the acid curing agent melts during storage at a general temperature of 20 to 40 ° C., and thus the acid curing agent and the epoxy resin easily undergo a curing reaction. There arises a problem that the dry mica tape becomes hard and storage stability is deteriorated. As a countermeasure against this, the problem can be reduced if stored in refrigeration or freezing, but the problem of inconvenience arises. Known acid curing agents of the present invention include methylcyclohexene tetracarboxylic dianhydride, ethylene glycol bisanhydro trimellitate, glycerin bis (hydrotrimellitate) monoacetate, benzophenone tetracarboxylic dianhydride, anhydrous Examples include pyromellitic acid. In particular, the following formula:

で示されるメチルシクロヘキセンテトラカルボン酸二無水物が耐熱性と保管安定性の向上を両立する効果が大きい。

The methylcyclohexene tetracarboxylic dianhydride represented by the formula is highly effective in achieving both heat resistance and improved storage stability.

[Electrically insulated wire ring]
The electric insulated wire ring is manufactured by winding the dry mica tape of the present invention around a conductor that is molded into a specified shape and covered with insulation, and the electric insulated wire ring is made alone in an injection tank or the like. It is manufactured by pressure injection after vacuum injection and thermosetting.

[Stator coil]
The stator coil is manufactured by winding the dry mica tape of the present invention around a conductor that is molded into a specified shape and covered with insulation to produce a single electrically insulated wire ring, and this electrically insulated wire ring is assembled into an iron core slot, and a sashimi liner , Fixed in the slot using sashigi, etc., and connected at the outer end of the core, and the electric insulated wire ring and the iron core are integrated into a single stator coil. An impregnating varnish is vacuum injected into the stator coil alone in an injection tank or the like, and then pressure-injected and thermally cured to produce a stator coil.

[Rotating electrical machines using electrically insulated wire rings]
A rotating electrical machine using the electrically insulated wire ring manufactured as described above is manufactured by incorporating the electrically insulated wire ring into an iron core slot, fixing it in the slot with a sashimi liner, sashimi, etc., and connecting it at the outer end of the iron core. The stator coil and the rotor are assembled and manufactured.

[Rotating electric machine using stator coils]
A rotating electrical machine is manufactured by assembling the stator coil and the rotor manufactured as described above.

  Hereinafter, according to the dry mica tape, the electrically insulated wire ring, the stator coil, and the rotating electrical machine of the present invention, the following effects can be obtained.

  The dry mica tape of the present invention uses a polyfunctional epoxy resin capable of improving heat resistance and an acid curing agent having a melting point or a softening point of 50 ° C. or more as a binder, so pressurizing after impregnating varnish into the dry mica tape There is an effect that the heat resistance of the insulating layer produced by injection and curing can be improved. Furthermore, the effect of improving heat resistance can be increased by using methylcyclohexene tetracarboxylic dianhydride as the acid curing agent.

  Since the dry mica tape of the present invention uses an acid curing agent having a melting point or softening point of 50 ° C. or higher for the binder, the curing reaction between the polyfunctional epoxy resin of the binder and the acid curing agent does not easily proceed. There is an effect of improving storage stability.

  The dry mica tape of the present invention adjusts the equivalent ratio of the epoxy resin that is the binder and the acid curing agent, so the balance of the equivalent ratio of the epoxy resin and the curing agent of the binder and the impregnating varnish does not collapse when thermally cured, Moreover, since the binder and the impregnating varnish are easily compatible and mixed, there is an effect that the heat resistance of the insulating layer as a whole can be improved after curing.

  For example, when the insulating layer is manufactured by combining the impregnated varnish having a heat resistance of about 155 ° C. (F type) and the dry mica tape of the present invention, the heat resistance is 180 ° C. (H type) or more. It is also possible to obtain an insulating layer.

  Even if the dry mica tape of the present invention is stored at 25 ° C. (full year) to 40 ° C. (summer), the binder uses an acid curing agent having a melting point or softening point of 50 ° C. or more, so that the curing reaction is difficult to proceed. Excellent stability.

  By applying the dry mica tape of the present invention to an electrically insulated wire ring, a stator coil, and a rotating electrical machine, there is an effect of improving insulation reliability at high temperatures.

  Next, examples in which the dry mica tape of the present invention and the electrically insulated wire ring, the stator coil, and the rotating electric machine are manufactured using the dry mica tape of the present invention will be specifically described in Examples.

Each characteristic when the impregnated varnish was poured into the dry mica tape and dry mica tape of this example was evaluated by the following measurement methods and conditions.
(1) Storage stability of dry mica tape Storage stability was evaluated by a flexibility test according to JIS standard C2116 for dry mica tape stored (left) for 40 days in air at 25 ° C. Bending characteristics were obtained by using Autograph DSS-5000 (manufactured by Shimadzu Corporation), and the sample had dimensions of length 100 mm × width 15 mm × thickness 0.2 mm. If the flexibility is 100 N / m or less, the curing reaction of the binder of the dry mica tape has not progressed so much and the taping workability is not hindered. Therefore, the judgment method is “◯” when the dry mica tape flexibility test result is within 100 N / m, and “X” when it exceeds 100 N / m.
(2) Heat resistance due to dynamic viscoelasticity of insulating layer The insulating layer is composed of 15 layers of dry mica tape (sheet) having a width of 200 mm, a length of 300 mm and a thickness of 0.20 mm. 100 parts by weight of bisphenol A type epoxy resin EP-828 (manufactured by Japan Epoxy Resin), 100 parts by weight of methylhexahydrophthalic anhydride curing agent HN-5500 (manufactured by Hitachi Chemical Co., Ltd.), cobalt [III] acetylacetonate An epoxy resin composition containing 2 parts by weight (made by Nippon Kagaku Sangyo Co., Ltd. was used as an example) was vacuum-injected at 380 Pa / 1 h and pressure-injected at 0.4 MPa / 5 h, and then from 25 ° C. to 120 ° C. The temperature was raised at 30 min and held at 120 ° C./1 h, and then heated from 120 ° C. to 200 ° C. over 2 h and held at 200 ° C./8 h. A sample of dynamic viscoelasticity was prepared by processing the insulating layer into dimensions of 25 mm long × 5 mm wide × 0.5 mm thick. The dynamic viscoelasticity (DMA) was raised from 25 ° C. to 300 ° C. at 2 ° C./min in a tensile mode using RheoSpectra DVE-V4 (manufactured by Rheology), 20 mm span, measurement frequency 10 Hz, The mechanical loss tangent (tan δ DMA) was measured under the condition of a displacement amplitude of 0.5 μm, and the temperature of the peak value of tan δ DMA due to dynamic viscoelasticity was calculated. When the temperature of the peak value of tan δ DMA due to dynamic viscoelasticity is 180 ° C. or higher, the judgment method is indicated as “◯” because the mechanical properties in the high temperature range (180 ° C. or higher) and the electrical insulation properties of the coil can be improved When the temperature was lower than 180 ° C., x was indicated, and the temperature of the peak value of tan δ DMA was shown in parentheses.
(3) tanδ of electrically insulated wire ring and stator coil
An electrically insulated wire ring and a stator coil were placed in a constant temperature bath maintained at 180 ° C., and tan δ when a rated voltage of 1 kV was applied was measured. The criterion for tan δ at 180 ° C. was 15% or less because of excellent electrical insulation. The determination was indicated as ◯ when tan δ was 15% or less, and × when it exceeded 15%.

[Examples 1-6, Comparative Examples 1-5]
The dry mica tapes of Examples 1 to 6 of the present invention will be described. FIG. 1 shows a cross-sectional view of the dry mica tape of the present invention. 1 is mica, 2 is a curing accelerator for impregnating varnish blended as necessary, 3 is a binder of the present invention, and 4 is a reinforcing substrate. The dry mica tapes of Examples 1 to 6 of the present invention consist of a binder having a composition shown in Table 1 for mica and a reinforcing base material (polyimide film) [tris (hydroxyphenyl) methane type epoxy resin as a polyfunctional epoxy resin ( Japan Epoxy Resin, product name jER1032H60), 1,1,2,2-tetrakis (hydroxyphenyl) ethane type epoxy resin (Japan Epoxy Resin, product name jER1031S), and methylcyclohexenetetracarboxylic acid as the acid curing agent Dianhydride (manufactured by DIC, product name B4400), glycerin bis (anhydrotrimellitate) monoacetate (manufactured by Shinnihon Rika Co., Ltd., product name TMTA-C), ethylene glycol bisanhydrotrimellitate (New Nippon Rika) Product name TMEG-500, TMEG-600 ] Bonded with about 10 wt% (vs. mica tape total weight), and epoxy adduct imidazole (manufactured by Japan Epoxy Resins Co., trade name P200) was used as coated mica as a curing accelerator. Further, in Example 4, for the purpose of imparting flexibility to the dry mica tape, 10 wt% of the blended amount of the polyfunctional epoxy resin as the binder is bisphenol A type epoxy resin (manufactured by Asahi Kasei Chemicals, In this example, the product name is AER-260). Example 6 is an example in which a dry mica tape was prepared by removing the curing accelerator (epoxy adduct imidazole), and thus the final curing temperature was changed to 230 ° C.

  The dry mica tapes of Comparative Examples 1 to 5 are made of a binder [tris (hydroxyphenyl) methane type epoxy resin, bisphenol A type epoxy resin (Asahi Kasei Chemicals Co., Ltd.) having the composition shown in Table 2 for mica and a reinforcing layer (polyimide film). , Product name AER-260), ethylene glycol bisanhydro trimellitate, glycerin bis (anhydro trimellitate) monoacetate, methylhexahydrophthalic anhydride] was used at about 10 wt% (based on the total weight of the mica tape). Then, epoxy adduct imidazole (manufactured by Japan Epoxy Resin, trade name P200) applied to mica as a curing accelerator was used. The dimensions of the dry mica tape were 30 mm wide x 20 m long. Each characteristic of the dry mica tape of this example and the comparative example, the binder composition used for the dry mica tape, the equivalent ratio of the epoxy resin and the curing agent of the binder, and the characteristics of the insulating layer cured by injecting the impregnating varnish were evaluated. The results are shown in Tables 1 and 2.

  As a result, the dry mica tapes of Examples 1 to 6 were evaluated for storage stability (flexibility test) after storage at 25 ° C. for 40 days. Was 100 N / m or less, so the judgment value was satisfied. Moreover, all the heat resistance of the insulating layer of Examples 1-6 was 180 degreeC or more.

  On the other hand, since the dry mica tapes of Comparative Examples 1 and 2 used a polyfunctional epoxy resin and a polyfunctional acid curing agent for the binder, the storage stability satisfied the judgment value, but the binder equivalent ratio was 1: 0. Since it was 55,1: 1.45, the heat resistance did not satisfy the judgment value. The dry mica tape of Comparative Examples 3 to 5 uses a liquid epoxy resin and a liquid curing agent for the binder, so that the curing reaction of the binder proceeds during storage, and the stability (flexibility test) of the dry mica tape is short. It became 100 N / m or more, and sufficient storage stability was not obtained. Similarly, in Comparative Examples 3 to 5, since a liquid epoxy resin and a liquid acid curing agent were used for the binder, the heat resistance could not satisfy the judgment value.

  As described above, a polyfunctional epoxy resin and an acid curing agent having a melting point or a softening point of 50 ° C. or more are simultaneously used as a binder for the dry mica tape, and the equivalent ratio of the epoxy resin and the curing agent is 1: 0.6 to 1: 1. In Examples 1 to 6, the storage stability of the dry mica tape can be improved, and the heat resistance of the insulating layer (determined by the temperature of the tan δ DMA peak due to dynamic viscoelasticity) can be achieved at 180 ° C. or more. was there.

[Examples 7-9, Comparative Examples 6-8]
A method for producing an electrically insulated wire ring using the dry mica tape of the present invention and characteristics of the obtained electrically insulated wire ring will be described. 2A is an external view of the electrically insulated wire ring 5 of Examples 7 to 9, and FIG. 2B is an enlarged internal cross-sectional view of a portion indicated by a circle in FIG.

  The electrically insulated wire ring of Example 7 was half hung with a dry mica tape (thickness 0.15 mm × width 25 mm) having the structure of Example 2 stored at 25 ° C. for 40 days on a conductor molded into a specified shape and insulated. 10 layers were wound to produce a single electric insulated wire ring. This electrically insulated wire ring alone was left in an impregnation tank maintained at 25 ° C., and 100 parts by weight of impregnating varnish [bisphenol A type epoxy resin EP-828 (manufactured by Japan Epoxy Resin Co., Ltd.), methylhexahydrophthalic anhydride cured The impregnating varnish containing 100 parts by weight of the agent HN-5500 (manufactured by Hitachi Chemical Co., Ltd.) and 2 parts by weight of cobalt [III] acetylacetonate (manufactured by Nippon Chemical Industry Co., Ltd.) was used as a vacuum at 380 Pa / 1h. After injection and pressure injection of 0.4 MPa / 5 h, thermosetting [heated from 25 ° C. to 120 ° C. over 30 min and held at 120 ° C./1 h, then raised from 120 ° C. to 200 ° C. over 2 h And maintained at 200 ° C. for 8 hours] to produce an electrically insulated wire ring of Example 7. The electric insulated wire ring of Example 8 was produced by the same method as in Example 7 except that the dry mica tape of Example 4 was used. The electric insulated wire ring alone was impregnated varnish by the same method as in Example 7. Was injected to produce an electrically insulated wire ring of Example 8. The electric insulated wire ring of Example 9 was produced in the same manner as in Example 7 except that the final curing temperature was changed to 230 ° C. using the dry mica tape of Example 6, and this electric insulated wire ring was carried out. An impregnated varnish was injected in the same manner as in Example 7 to produce an electrically insulated wire ring of Example 9.

  On the other hand, the electric insulated wire ring of Comparative Example 6 was produced by the same method as in Example 7 except that the dry mica tape having the configuration of Comparative Example 1 was used. The impregnated varnish was injected by the above method to produce an electrically insulated wire ring of Comparative Example 6. The electrical insulated wire ring of Comparative Example 7 was produced by the same method as in Example 7 except that the dry mica tape having the structure of Comparative Example 3 was used. The impregnated varnish was injected by the method to produce an electrically insulated wire ring of Comparative Example 7. The electric insulated wire ring of Comparative Example 8 was produced by the same method as in Example 7 except that the dry mica tape having the structure of Comparative Example 5 was used. The impregnated varnish was injected by the method to produce an electrically insulated wire ring of Comparative Example 8.

  The tan δ (applied voltage 1 kV) at 180 ° C. of the electrically insulated wire rings of Examples 7 to 9 and Comparative Examples 6 to 8 was measured. As a result, tan δ of the electrically insulated wire rings of Examples 7 to 9 was in the range of 12.5 to 13.2%. On the other hand, since the electrically insulated wire ring of Comparative Example 6 used the dry mica tape of Comparative Example 1, the heat resistance was low and tan δ was 16.5%. Since the electrically insulated wire ring of Comparative Example 7 used the dry mica tape of Comparative Example 3, there was a problem that the mica peeled when the dry mica tape was wound around the conductor, and there was no effect of improving the heat resistance by the binder. Therefore, tan δ was 16.9%. Since the electrically insulated wire ring of Comparative Example 8 used the dry mica tape of Comparative Example 5, there was a problem that the mica peeled off when the dry mica tape was wound around the conductor as in Comparative Example 7, and the heat resistance by the binder was further increased. Tan δ was 18.8% because there was no effect of improving the.

  As described above, the electrically insulated wire of Examples 7 to 9 is an electrically insulated wire having excellent insulation reliability by using a dry mica tape that can achieve both improved storage stability and improved heat resistance of the insulating layer. Obtained.

[Examples 10 to 12]
The example which produced the stator coil using the dry mica tape shown to this invention is demonstrated.

  3 (a) is a sectional front view of the stator coil of the present invention, and FIG. 3 (b) is a sectional view of the iron core slot (after inserting the electric insulated wire ring alone) shown by the ellipse of FIG. 3 (a) of the present invention. It is an enlarged view.

  In the stator coil of Example 10, a single electric insulated wire ring was produced in the same manner as in Example 7 using the dry mica tape of Example 1, and this electric insulated wire ring alone was placed in the iron core slot 10 of the iron core 9. After the insertion, the sashimi lower liner 11 and the sashimi 12 shown in FIG. 3 (b) were each inserted for fixing the electric insulated wire ring alone, thereby producing a stator coil alone. The stator coil alone was left in an impregnation tank maintained at 25 ° C., and the same impregnation varnish as in Example 7 was used under the same injection conditions and thermosetting conditions as in Example 7. A stator coil was prepared. Next, the stator coil of Example 11 was produced in the same manner as in Example 10 except that the dry mica tape of Example 3 was used. The stator coil of Example 12 was produced in the same manner as in Example 10 except that the dry mica tape of Example 5 was used.

  The tan δ (applied voltage 1 kV) at 180 ° C. of the stator coils of Examples 10 to 12 was measured. As a result, the stator coils of Examples 10 to 12 had a tan δ of 12.0 to 13.1%.

  As described above, the stator coils of Examples 10 to 12 can obtain a stator coil with excellent insulation reliability by using a dry mica tape that can achieve both improved storage stability and improved heat resistance of the insulating layer. It was.

Example 13
The example which applied the stator coil produced using the dry mica tape shown to this invention to the rotary electric machine of this invention is demonstrated.

  As shown in FIG. 4, the rotating electrical machine of the thirteenth embodiment is assembled by connecting the stator coil 13 and the rotor 14 using a stator coil manufactured by the same method as in the eleventh embodiment. 15 was produced.

  As described above, since the rotating electrical machine of Example 13 uses the stator having excellent insulation reliability using the dry mica tape that can improve both the storage stability and the heat resistance of the insulating layer, the insulation reliability is improved. A rotating electric machine with excellent properties was obtained.

DESCRIPTION OF SYMBOLS 1 Mica 2 Hardening accelerator 3 Binder 4 Reinforcement base material 5 Electrically insulated wire ring 6 Conductor 7 Insulating layer 8 injected with dry mica tape impregnated varnish and hardened Corona shield 9 Iron core 10 Iron core slot 11 Sashigi lower liner 12 Sashigi 13 Stator coil 14 Rotator 15 Rotating electric machine

Claims (9)

In a dry mica tape containing mica, a reinforcing layer, and a binder, the binder has an epoxy resin having three or more epoxy groups, a melting point or a softening point of 50 ° C. or more, and the following formula:

The dry mica tape characterized by including the acid hardening agent which has an acid anhydride frame | skeleton represented by these. The binder acid curing agent has the following formula:

2. The dry mica tape according to claim 1, wherein the dry mica tape has two or more acid anhydride skeletons represented by the formula, and has a melting point or a softening point of 50 ° C. or more. The binder acid curing agent has the following formula:

The dry mica tape according to claim 1, which is a methylcyclohexene tetracarboxylic dianhydride represented by the formula:   The dry mica according to any one of claims 1 to 3, wherein the binder has an equivalent ratio of an epoxy resin and an acid curing agent in a range of 1: 0.6 to 1: 1.4. tape.   The dry mica tape according to any one of claims 1 to 4, further comprising a curing accelerator in addition to the mica, the reinforcing layer, and the binder.   A dry mica tape according to any one of claims 1 to 5 is wound around a conductor that is insulation-coated and molded into a specified shape to form an electric insulated wire ring alone, and the electric insulated wire ring alone is bonded to an epoxy resin, An electrically insulated wire ring, which is cured by injecting an impregnated varnish containing an acid curing agent.   A rotating electrical machine comprising: a stator coil in which the electrically insulated wire ring according to claim 6 is incorporated in an iron core slot, and the electrically insulated wire ring is connected at an outer end of the iron core; and a rotor coil.   The dry mica tape according to any one of claims 1 to 5 is wound around a conductor that is insulation-coated and molded into a specified shape to form an electric insulated wire ring alone, and the electric insulated wire ring is incorporated into an iron core slot The electric insulated wire ring is connected at the outer end of the iron core, and the impregnated varnish containing an epoxy resin and an acid curing agent is injected and cured in a state where the electric insulated wire ring and the iron core are integrated. A stator coil characterized by.   A rotating electrical machine comprising the stator coil according to claim 8 and a rotor coil.

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