JP2008011648A - Method for applying insulating coating on surface of laminated motor core - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a convenient and inexpensive applying method excellent in coating property in comparison with a conventional technology when an electrical insulating coating is formed on the surface of a laminated motor core. <P>SOLUTION: The method for applying the insulating coating on the surface of the laminated motor core applies a processing agent comprising: one or two or more complexes each containing a polyester resin and/or an epoxy resin and silicone as an insulating coating forming agent; one or two or more of silicone powder, alumina, silica and an aluminum hydroxide; and a remnant solvent, and forms the electrical insulating coating for withstanding a high voltage. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for coating an electric insulation coating on the surface of a laminated motor core. More specifically, the present invention provides a simple coating composition comprising a composite of a resin mainly composed of silicone and a filler agent on the surface or punched surface of a motor core produced by punching a magnetic steel sheet product. The present invention relates to a method for coating an insulating film on the surface of a laminated motor core, which can form an insulating film having a high withstand voltage by applying and drying by the method.

  Motor cores used for small motors for electrical equipment parts were obtained by applying an organic coating component, organic resin + inorganic coating component, or inorganic coating component to an electrical steel sheet that was finally annealed in a continuous annealing line and drying it. The product plate is punched at a core processing factory, and then manufactured through processes such as lamination and caulking. An example of the laminated motor core is a core (A) having a shape as shown in FIG.

  The core (A) shown in FIG. 1 has a plurality of teeth (b), and the tip of each tooth is an arcuate portion, and each tooth (b) has a corner (a). Winding (c) is applied. Such a core is used as a rotor of a motor. When there is no insulation between the teeth (b) and the windings (c) of the core (A), the windings are Since the motor itself does not function due to a short circuit through A), it is necessary to insulate between the core (A) and the winding (c).

  In particular, insulation at the corner (a) of the tooth (b) that receives strong contact with the winding and the punched surface is important. The required insulation characteristics differ depending on the model to be applied. For example, in the case of a hard disk motor core, a high withstand voltage of 300 V or more is required. In this manufacturing process, a thin film insulation process is performed in advance, and a thick film insulation film process is performed in the core processing process.

  As such an insulation treatment, conventionally, a method of forming an insulating layer on the surface of the motor core by using an electrodeposition paint, a solvent spray, a powder paint or the like has been employed. However, when the insulating layer is formed with the above-mentioned paint, the insulating coating layer is less likely to adhere to the edge portion of the punched motor core due to the shape problem due to burrs at the time of punching compared to the flat portion of the steel plate. , Easy to thin. As a result, there has been a problem that the insulation characteristics are deteriorated.

  Therefore, it is necessary to increase the film thickness of the insulating layer, and it is necessary to perform a thickening process by multiple coatings 4 to 6 times sandwiching drying. Moreover, in order to obtain the said high withstand voltage, the coating process which forms a thick film like 100-200 micrometers may be forced to obtain the said high withstand voltage from the problem of the insulation of an insulating film agent, and also in workability and a cost aspect. was there.

  However, in recent years, miniaturization and thinning of motors are required, and further, a technique for forming a thin insulating film layer having a high withstand voltage is required.

  As one of the techniques for thinning an insulating layer, Patent Document 1 discloses that two insulating layers are coated on the surface of a motor core with an epoxy resin as a primer and a ceramic paint as a top coat. It is disclosed that forming an insulating layer having a good edge covering property and an excellent insulating property by forming a thickness of 50 to 80 μm. Further, Patent Document 1 discloses that the insulating layer only needs to be multi-layered, and the number of layers is not limited to two but may be increased to three or four.

  However, the technique disclosed in Patent Document 1 has a drawback in that at least two or more coating steps are required to form an insulating layer, and workability is inferior.

  Further, Patent Document 2 discloses a self-precipitation containing a resin emulsion, an acid, an oxidant, metal ions and water as a method for coating a laminated motor core surface with an excellent electrical insulating property and a conventional thin film insulation coating. The mold aqueous coating composition is contacted to form an uncured resin film on the surface of the motor core, and then the uncured resin film is heated and dried to form an electrically insulating film on the surface of the motor core. There has been proposed a method of coating an electric insulating film on the surface of a laminated motor core characterized by the above.

  However, this technique has a problem of using hydrofluoric acid and chromic acid compounds, which are problematic in terms of working environment, as coating components, and the pretreatment, processing steps, equipment, etc. of the steel sheet are complicated. Industrially, it is not a preferable technique.

JP-A-5-300681 JP-A-9-233780

  The object of the present invention is to shorten the insulating treatment process and improve the insulating coating component in forming the electrical insulating layer on the motor core surface, thereby reducing the thickness of the electrical insulating layer compared to the conventional method and simplifying the process. Furthermore, the present invention provides a coating method capable of forming an insulating film with excellent electrical insulation characteristics, particularly an insulating film with excellent electrical insulation characteristics at the corners of the core teeth, which is a problem in contact with a winding. It is in.

  As a result of intensive investigations to solve the above-described problems that have been encountered in the past, the present inventors have found that one or two of a composite of polyester resin and / or epoxy resin and silicone is used as an insulating film forming agent on the surface of the laminated motor core. By applying a treatment agent composed of one or more of silicone powder, alumina, silica, and aluminum hydroxide, and the remaining solvent, followed by drying, the surface of the motor core is more easily applied than the conventional technology. It has been found that an electric insulating film having a withstand voltage can be formed.

  This invention is made | formed based on the said knowledge, The summary is as follows.

  (1) One or more of polyester resin and silicone, epoxy resin and silicone composite, polyester resin, epoxy resin and silicone composite, silicone powder, alumina, silica, aluminum hydroxide on the surface of the laminated motor core A method of coating an insulating coating on the surface of a laminated motor core, comprising applying one or more of the above and a treatment agent comprising the remaining solvent to form an electrical insulating coating.

  (2) The ratio of the polyester and epoxy organic resin components in the base liquid composed of one or more of polyester resin and silicone, epoxy resin and silicone, and polyester resin, epoxy resin and silicone composite is 20 to 80. The method for coating an insulating film on the surface of a laminated motor core according to the above (1), characterized in that it is mass%.

(3) The polyester resin and silicone, the epoxy resin and silicone, and the polyester resin, epoxy resin and silicone composite are one or more of silicone polymers having a block structure (1) ) Or the method for coating an insulating film on the surface of the laminated motor core according to (2).
(4) Silicon powder, alumina, silica, water as a filler with respect to 100 parts by mass of one or more of polyester resin and silicone, epoxy resin and silicone, and polyester resin, epoxy resin and silicone composite. (1) to (3) above, wherein an electrical insulating coating is formed by applying a treatment agent comprising one or more aluminum oxides in the range of 10 to 400 parts by mass and a solvent substance of 5 to 400 parts by mass. The insulating film coating method on the surface of the laminated motor core according to any one of the above.

  (5) The particle size of the silicone powder, alumina, silica, or aluminum hydroxide powder used as the filler is 0.5 to 20 μm, according to any one of (1) to (4), A method for coating an insulating coating on the surface of a laminated motor core.

  (6) The method for coating an insulating film on the surface of a laminated motor core according to any one of (1) to (5), wherein the solvent contained in the treating agent has a boiling point of 100 ° C. or higher.

  (7) In the adjustment step of the insulating coating solution, after treating for 1 to 10 minutes at 40 to 100 KHz using an ultrasonic treatment apparatus, a processing agent is applied to form an electrical insulating coating. (1) The insulating film coating method on the surface of the laminated motor core according to any one of (6).

  (8) In the step of applying the insulating coating to the surface of the laminated core, after performing a dip treatment using a rotary jig, drying, or performing one or more coating treatments sandwiching the drying. The method for coating an insulating film on the surface of a laminated motor core according to any one of the above (1) to (7).

  (9) In the said drying process, drying at 120-250 degreeC including preliminary drying at 40-80 degreeC is performed, The insulation film coating method of the laminated motor core surface as described in said (8) characterized by the above-mentioned.

  In the present invention, the core insulating coating treatment is performed by a dip method using a special silicone polymer component. Thereby, a special treatment such as pretreatment is not required, and a uniform and dense insulating film can be formed easily and at a low cost as compared with conventional techniques such as electrodeposition coating. In addition, with conventional coatings, it has been unavoidable to form ultra-thick coatings as a countermeasure against insulation at the core corners, but this problem can be reduced by reforming the coating to a very dense film. It became possible to solve this problem.

  Hereinafter, the configuration of the present invention will be described in detail.

  The motor core that is the subject of the present invention is a core that is formed through a punching process, a caulking process, and the like using a plurality of electromagnetic steel sheet product plates as a starting material.

  The insulating coating agent used in the present invention is a polyester resin and silicone, an epoxy resin and silicone composite, a polyester resin, one or more of an epoxy resin and silicone composite, silicone powder, alumina, silica, and hydroxylation. It is a processing agent comprising one or more types of aluminum and the remaining solvent.

  The ratio of the polyester and / or epoxy resin component and silicone in the base solution at this time is important for thickening, heat resistance, adhesion to the corner of the teeth, and cracking resistance of the film. It is preferable that the ratio of an epoxy resin component is 20-80 mass%.

  In addition, a filler agent has an important role in the composition liquid of the present invention. One or two or more types of polyester resin and silicone, epoxy resin and silicone, and polyester resin, epoxy resin and silicone, or 100 parts by mass of silicone powder, alumina, silica, aluminum hydroxide or Two or more kinds of 10 to 400 parts by mass and 5 to 400 parts by mass of a solvent substance are added.

  When this filler powder having a particle size of 0.5 to 20 μm is added, not only the surface tension of the treatment agent is lowered and the adhesion of the liquid to the corner portion of the teeth is improved, but also the insulating property. It is a great driving force for improving the heat resistance, drying property, etc., and realizing a thin film.

  A solvent is used for dispersing the treatment agent in the present invention. As the solvent, glycol type and alcohol type which are less problematic in the working environment are used, but those having a boiling point of 100 ° C. or higher are more preferable in view of the performance of the coating film during drying. As a result, a dense insulating film free from bumping can be formed by drying for a short time.

  In the adjustment stage of this insulating film treatment solution, by performing treatment at 40-100 KHz for 1-10 minutes using an ultrasonic treatment apparatus, uniform dispersion of the filler in the solution is obtained, and uniform film treatment is performed. It is advantageous.

  In the step of applying the insulating coating agent to the surface of the laminated core, using a rotating jig as shown in FIGS. 2 (a) and (b), the core is rotated and dipped, and then dried or dried. When the coating process is performed once or more than two times, a uniform film thickness can be easily obtained over the front surface of the core, and in particular, the film thickness of the tooth portion can be made uniform.

  In the drying step, by performing drying at 120 to 250 ° C. including preliminary drying at 40 to 80 ° C., there is no outgas, excellent adhesion, a dense, high withstand voltage insulating film can be obtained. The drying temperature and time are appropriately selected depending on the coating component, solvent type, and film thickness.

  Next, the reason for limitation of the present invention will be described.

  First, the base liquid in the present invention is characterized by excellent adhesion and adhesion when polyester silicone, epoxy silicone, or polyester-epoxy composite silicone is used as the main component of the base liquid. In addition, it has the property of following expansion and contraction due to heat resistance and thermal changes during use of the drying process and core, and even in thick film processing of 100 μm or more, there are no problems such as generation of cracks in the coating or reduction in adhesion, and stable It is possible to form a thick film.

  Since these base liquids form a dense silicone polymer film after drying and form a coating with extremely excellent adhesion to a steel sheet, it is possible to form an insulating film with excellent insulating properties.

  The ratio of the organic resin component in the base liquid composed of polyester silicone, epoxy silicone, and / or polyester-epoxy composite silicone is preferably 20 to 80 parts by mass. If it is less than 20 parts by mass, the hardness of the coating after drying and curing is high, and the heat-flexible properties are deteriorated. Therefore, fine cracks may occur in the coating during the thick film treatment of 10 μm or more. In particular, cracks may occur in the film by high-temperature-low temperature repetition (heat shock test: −40 ° C. to + 170 ° C., 1000 cycles) as in the heat resistance test.

  On the other hand, if it exceeds 80 parts by mass, it is difficult to control the viscosity of the liquid, and the heat resistance in the heat shock test is insufficient.

  As the filler agent which is another main component in the present invention, silicone powder, alumina, silica and aluminum hydroxide powder are used. These powder components are effective in reducing the surface tension of the solution. Addition of 10 to 400 parts by mass per 100 parts by mass of the base liquid brings about a great effect in improving the covering ability at the corner portion of the teeth, which has been a conventional problem.

  Especially when the filler particle has a particle diameter of 2 to 15 μm, the coatability is excellent, and the coarse particle promotes adhesion and hardening of the solution to the core corner portion, so that the effect of securing a thick film is great.

  Moreover, these filler agents exhibit an extremely large effect in improving insulation (voltage resistance). When the filler particle diameter is less than 0.5 μm, depending on the dispersion condition of the solution, the powder particles may be aggregated to increase the viscosity of the liquid, making it difficult to form a flat insulating film on the entire core. When the particle diameter exceeds 20 μm, the effect of reducing the surface tension is great, but the stability of the powder in the solution is lowered, so that it is difficult to apply a homogeneous film even if the solution is circulated or stirred. .

  Moreover, the addition of the coarse particle filler is effective in improving the insulation, and the insulation improvement effect is extremely excellent compared with the case of no addition in the same coating amount (average thickness).

  If the amount of filler added is less than 10 parts by mass with respect to 100 parts by mass of the base solution, the effect of lowering the solution surface tension and the effect of improving insulation cannot be sufficiently obtained. On the other hand, when the amount is 400 parts by mass or more, the binder effect due to the base liquid is insufficient, and fine cracks are generated in the insulating film after drying. Although depending on the drying conditions, the amount of the stable and good addition is 75 to 300 parts by mass.

  The treatment agent of the present invention is dispersed by a solvent. The boiling point of the solvent is preferably 100 ° C. or higher. Use of a low-boiling solvent such as an alcohol solvent is not preferable because the treatment agent soaked between the core plates is rapidly decomposed and released, causing a bumping phenomenon and roughening the film surface. On the other hand, when a solvent having a boiling point of 100 ° C. or higher is used, decomposition of the solvent component gradually occurs following the film curing reaction, and problems such as bumping do not occur.

  From such a problem, as a solvent, for example, glycol solvents such as propylene glycol and propylene glycol methyl ether acetate are advantageous from the viewpoint of environmental problems and the like, and since they have low volatility, they are used industrially. In doing so, since the stability of the solution is excellent, it is advantageous in workability and a dense film can be formed.

  In the insulating film treatment with a silicon polymer using a solvent as in the present invention, the insulating film treatment can be performed without performing pretreatment without being affected by dirt such as punching oil adhering to the steel plate. When the insulating film is applied to the core, it is advantageous to perform ultrasonic treatment of the solution in advance at 20 to 100 KHz because the filler agent can be uniformly dispersed.

  When the ultrasonic treatment time is less than 1 minute, aggregation occurs depending on the particle size distribution of the powder. If it is 10 minutes or longer, the temperature of the solution increases due to ultrasonic waves, which is not preferable. However, these problems can be solved if the ultrasonic treatment process in which the cooling device is installed is performed by circulating the solution.

  When the coating method in the core coating is dipped using a rotary jig as shown in FIG. 2, a more uniform coating film can be advantageously obtained. According to this coating method, the thickness of the coating film can be controlled by the concentration of the liquid, the viscosity, and the number of rotations of the jig to which the core is fixed. Further, the application by the rotating jig is good in that the liquid can wrap around the entire surface of the core, and is effective in preventing the film thickness of the flat portion of the core from being unnecessarily increased.

  In the drying process, first, the majority of the solvent is dried by pre-drying at 40 to 80 ° C. to stabilize the surface of the insulating coating, and then drying is performed at 120 to 250 ° C. for about 10 to 120 minutes. Is good. In this way, by drying by heating slowly in the initial stage of drying, there is no outgas and a dense film can be formed.

  In addition, when the insulating coating is repeatedly applied, the drying conditions between the coatings are important. Drying during this application is preferably 100 ° C to 140 ° C. If it is less than 100 ° C., the film in the previous stage may be affected by the solution during repeated application. When the temperature exceeds 140 ° C., there are problems such as poor applicability of the post-treatment liquid.

Example 1
After punching into a shape as shown in FIG. 1A, a magnetic steel sheet core produced by laminating and caulking was used as a starting material. A solution having the composition shown in Table 1 was applied to the core by dip coating at 15 rpm × 15 seconds using a rotary jig, and subjected to three coating baking processes sandwiching drying. In this case, the drying between coatings was performed at 120 ° C. for 30 minutes after the preliminary drying at 50 ° C. for 15 minutes, and the final drying was similarly performed at 150 ° C. for 1 hour including the preliminary drying.

  Thereafter, the film thickness and withstand voltage of the core edge portion were measured. The results are shown in Table 1. Note that the flat part film thickness ≦ 70 μm and the withstand voltage ≧ 300 V were used as criteria.

  As a result of this test, in the insulating coating using the polyester composite silicon polymer of the present invention A1 to A4, a coating of 12 to 20 μm can be formed at the corner portion by applying twice by pretreatment, and the insulating film Due to the denseness, good withstand voltage was obtained without using multiple coating like the pretreatment-ceramic coating as in the comparative example.

  In particular, when the average particle diameter of the filler agent was 5 μm or more, excellent insulating properties were obtained.

  When the cross-section of the core insulating film at this time was observed, it was confirmed that the filler agent adhered to the corner portion in a mixed state with the base insulating film agent. It was confirmed that the filler agent contributes not only to the reduction of the solution surface tension but also to the improvement of the insulating properties of the corner portion.

  Further, even when the base resins of the present invention A5 to A6 were combined, it was confirmed that an excellent appearance was formed and a dense insulating film having excellent withstand voltage was formed despite the thin film.

(Example 2)
In the same manner as in Example 1, a magnetic steel sheet core manufactured by stacking and caulking after punching was used as a starting material. On this core, a solution having the composition shown in Table 2 was dip-coated at 10 rpm × 20 seconds using a rotary jig, and, as in Example 1, two coating baking processes sandwiching preliminary drying and drying were performed. . In this case, drying between coatings was performed at 120 ° C. for 30 minutes, and final drying was performed at 150 ° C. for 1 hour.

  The polyester-silicone composite polymer used at this time was a block-structured compound having a polyester component ratio of 45% by mass. The epoxy-silicone composite polymer used was an epoxy component ratio of 55% by mass.

  Thereafter, the film thickness and withstand voltage of the core edge portion were measured. The results are shown in Table 2. Note that the flat part film thickness ≦ 70 μm and the withstand voltage ≧ 300 V were used as criteria.

  As a result of this test, when the solution of the present invention in which the concentration was increased, the filler particle size and the blending ratio were increased by undercoating, and the filler ratio was decreased by overcoating was applied, the coating on the corner portion was performed under the conditions of two treatments A thickness of about 20 μm could be secured, and an insulating film having both an appearance and an insulating property was obtained.

  On the other hand, in the present invention C5 using IPA (boiling point 82 ° C.) as a solvent, a bubble-like unevenness that seems to be a bump mark of the solvent was slightly generated on the core end face portion, and the appearance was slightly inferior. In addition, in the present invention C6 in which the dispersion treatment is performed by ultrasonic waves in the solution adjustment stage, the coating film is very uniform and clean, the coating properties are good, the stability of the solution at the time of coating is extremely good, and the dispersion improvement effect Was noticeable.

  In addition, the present invention C7 in which drying between coatings was performed at 150 ° C. resulted in coating unevenness due to repelling of the solution at the time of overcoating, and the insulation was considerably inferior compared to other 120 ° C. dried products. became.

  When the treatment agent using only the epoxy resin of the comparative example is used, it is glossy, but it becomes a non-uniform coating film due to the swelling of the film, and the thickness of the corner portion tends to be thinner than that of the flat portion. The insulation characteristics were poor.

  According to the present invention, as described above, a uniform and dense insulating coating can be formed easily and at low cost, and the core corner portion coating can be thinned. Therefore, the present invention has high applicability as a technique for covering an insulating steel sheet with an insulating film.

It is a figure which shows an example of a laminated motor core. (A) shows the shape of a core, (b) shows the shape which expanded a part. It is a figure which shows the aspect of the rotation jig which performs a skewered core and a dip process. (A) shows a skewered core, and (b) shows a mode in which the skewered core is attached to a rotating jig.

Explanation of symbols

A Core a Corner part b Teeth c Winding

Claims (9)

  One or more of polyester resin and silicone, epoxy resin and silicone composite, polyester resin, epoxy resin and silicone composite, and silicone powder, alumina, silica, aluminum hydroxide on the surface of the laminated motor core Alternatively, a method for coating an insulating film on the surface of a laminated motor core, comprising applying a treatment agent comprising two or more kinds and a remaining solvent to form an electric insulating film.   The ratio of the organic resin component of polyester and epoxy in the base liquid consisting of one or more of the polyester resin and silicone, the epoxy resin and silicone, and the polyester resin, epoxy resin and silicone composite is 20 to 80% by mass. The method for coating an insulating film on the surface of a laminated motor core according to claim 1, wherein:   The polyester resin and silicone, the epoxy resin and silicone, and the polyester resin, the epoxy resin and silicone composite are one or more types of silicone polymers having a block structure. The method for coating an insulating coating on the surface of the laminated motor core according to claim.   For 100 parts by mass of one or more of polyester resin and silicone, epoxy resin and silicone, and polyester resin, epoxy resin and silicone composite, as filler agent, silicone powder, alumina, silica, aluminum hydroxide The lamination according to any one of claims 1 to 3, wherein a treatment agent comprising one or two or more of 10 to 400 parts by mass and a solvent substance of 5 to 400 parts by mass is applied to form an electrical insulating film. A method for coating an insulating coating on the surface of a motor core.   The insulating coating on the surface of the laminated motor core according to any one of claims 1 to 4, wherein the particle size of the silicone powder, alumina, silica, and aluminum hydroxide powder used as the filler is 0.5 to 20 µm. Coating method.   The method for coating an insulating film on the surface of a laminated motor core according to claim 1, wherein the solvent contained in the treatment agent has a boiling point of 100 ° C. or higher.   In the step of adjusting the insulating coating solution, after treating for 1 to 10 minutes at 40 to 100 KHz using an ultrasonic treatment apparatus, a processing agent is applied to form an electrical insulating coating. 7. The method for coating an insulating coating on the surface of a laminated motor core according to any one of 6 above.   In the step of applying the insulating coating to the surface of the laminated core, after performing a dipping process using a rotating jig, drying, or performing a coating process one or more times sandwiching the drying. The method for coating an insulating film on the surface of the laminated motor core according to claim 1.   The method for coating an insulating film on the surface of a laminated motor core according to claim 8, wherein in the drying step, drying at 120 to 250 ° C including preliminary drying at 40 to 80 ° C is performed.