JP5080915B2 - Heat-resistant self-bonding coating composition and heat-resistant self-bonding enameled wire - Google Patents

Description

TECHNICAL FIELD The present invention relates to a heat-resistant self-bonding coating composition for enameled wire and a heat-resistant self-bonding enameled wire that are suitably used for electric coils that require heat resistance such as industrial and automotive motors and generators.

  Self-bonding enameled wires have greatly contributed to the reduction of man-hours by impregnating varnishless, environmental friendliness, and the manufacture of deformed coreless coils represented by cathode ray tube deflection yokes. There are various fusing methods such as energization, thermostatic bath, heat fusing with hot air, solvent fusing with a low boiling point solvent such as alcohol, ethyl acetate, methyl ethyl ketone, etc., but their uses have been mainly limited to consumer equipment.

  This uses a coating mainly composed of thermoplastic resin materials with relatively low heat resistance and softening temperature, such as polyvinyl butyral resin, copolymerized polyamide resin, and polyhydroxy polyether resin, for the fused layer of self-bonding enameled wire. It depends on what has been done.

  However, in recent years, due to environmental measures and VOC (Volatile Organic Compounds) regulations, application to electric devices used in high-temperature atmospheres such as industrial and automobile motors and generators has been required. Therefore, although investigations have been made on paints using high heat-resistant engineering plastics such as polysulfone resins and polyethersulfone resins as main ingredients, these thermoplastic resins have a high softening temperature and must be applied at a temperature of 240 ° C. or higher. There is a disadvantage that the predetermined fusing force is not exhibited.

  In addition, as an attempt to impart thermosetting properties by crosslinking, a fusion varnish obtained by adding various curing agents to a main material having a functional group is baked in a semi-cured state, that is, in a B-stage state, and cured at the time of thermal fusion. The heat resistance is also being studied. In other words, a curing agent is added to the resin as the main agent, and this is applied to the conductor, and then baked in a B-stage state to form a self-bonding enameled wire, which is wound into a coil and then heat-sealed and heated. Studies have been made to improve heat resistance without causing VOC by curing.

  As an example of this fusion varnish, a curing agent such as stabilized isocyanate, various epoxy resins, resol type phenol resin, melamine resin, acid anhydride, etc. is added to polyhydroxy polyether or polyhydroxy polyether containing sulfone group. However, the curing reaction proceeds by heat during baking, and a predetermined initial fusing force is not exhibited. In addition, functional groups react gradually at room temperature, and the initial fusing power is greatly reduced due to changes over time, or the fusing power in a high-temperature atmosphere is greatly reduced due to insufficient curing, resulting in coil deformation and wire fraying. Have problems such as.

  In this way, when using self-bonding enameled wires at high temperatures, although a method using a resin with a high softening point can be taken, the temperature of the fusing process is very high, so insulation of self-bonding enameled wires There are problems such as deterioration of insulating materials other than the layer and the self-bonding enameled wire, and deterioration of workability of the bonding process itself.

  Further, regarding the thermosetting method, there is a problem in reliability such as temperature variation of the heat fusion force of the self-bonding enameled wire itself.

Accordingly, the present invention has an object to provide a heat-resistant self-bonding coating composition and a heat-resistant self-bonding enameled wire that can solve the above-mentioned problems and maintain a fusing force that has no practical problem even in a high-temperature atmosphere. To do.

The present invention was devised to achieve the above object, and the invention of claim 1 is characterized in that bismaleimide is added in an amount of 10 to 10 parts by weight per 100 parts by weight of the sulfone group-containing polyhydroxy polyether resin represented by the chemical formula (1). A heat-resistant self-fusing coating composition characterized by containing 50 parts by weight.

Invention of Claim 2 contains 10-50 weight part of bismaleimide with respect to 100 weight part of sulfone group containing polyhydroxy polyether resins shown in Chemical formula (1) , Furthermore, the said sulfone group containing polyhydroxy polyether resin 100 1 to 10 parts by weight of a lubricant with respect to parts by weight.

According to a third aspect of the present invention, in the second aspect, the lubricant is composed of one or more combinations of synthetic systems such as polyethylene wax, silicone resin and fluororesin, and natural systems such as beeswax, carnauba wax and candelilla wax. It is a heat-resistant self-fusing coating composition .

A fourth aspect of the present invention, the sulfonic-group-containing polyhydroxy polyether resin, together with a sulfonic group is contained 30-50% in a molecular skeleton, claims are dissolved in the bismaleimide and the solvent 1-3 The heat-resistant self-fusing coating composition according to any one of the above.

The invention according to claim 5 is the heat-resistant self-fusing coating composition according to claim 4 , wherein the solvent comprises at least one selected from saturated alicyclic ketones, phenols, and diethylene glycol monoalkyl ethers. .

The invention of claim 6 is a heat resistant self-bonding enameled wire in which a fusion layer is provided directly on a conductor or via another insulator, and the heat resistant self-bonding according to any one of claims 1 to 5. A heat-resistant self-bonding enameled wire, which is formed by coating and baking a coating material that forms a heat-resistant coating composition to form the above-mentioned fused layer.

  According to the present invention, it is possible to provide a heat-resistant self-fusing paint that can maintain a fusing force having no practical problem in a high-temperature atmosphere of 200 ° C.

  Hereinafter, preferred embodiments of the present invention will be described.

  A heat-resistant self-fusing paint according to the first preferred embodiment of the present invention comprises a sulfone group-containing polyhydroxy polyether resin represented by the above chemical formula (1) and bismaleimide.

  The sulfone group-containing polyhydroxy polyether resin is not particularly limited as long as it is industrially practical, but more preferably, the content of the sulfone group in the molecular skeleton is from the balance of heat-fusibility and heat resistance. 30-50% is suitable.

  As the bismaleimide, 4,4′-diphenylmethane bismaleimide, m-phenylene bismaleimide, bisphenol A diphenyl ether bismaleimide, 3,3′-dimethyl-5,5′diethyl-4,4′-diphenylmethane bismaleimide, 4, 4′-diphenyl ether bismaleimide, 4,4′-diphenylsulfone bismaleimide, 1,3-bis (3-maleimidophenoxy) benzene, 1,3-bis (4-maleimidophenoxy) benzene, 1,6′-bismaleimide -(2,2,4-trimethyl) hexane, polyphenylmethanemaleimide, and the like. Although not particularly limited, 4,4'- is preferred because of availability of materials and appropriate reactivity with sulfone group-containing polyhydroxypolyether resins. Diphenylmethane bismaleimide is most preferred Properly, m- phenylene bismaleimide are also suitable.

  The amount of bismaleimide added is desirably 10 to 100 parts by weight, more preferably 10 to 50 parts by weight, based on 100 parts by weight of the sulfone group-containing polyhydroxy polyether resin. If the amount is less than 10 parts by weight, the reaction with the sulfone group-containing polyhydroxypolyether resin is insufficient, and the fusing force at a high temperature of 200 ° C. decreases. If the amount exceeds 100 parts by weight, problems such as the fusion layer becoming hard and brittle, bismaleimide being precipitated in the varnish coating, and the initial fusion force being lowered.

  The solvent for the heat-resistant self-fusing paint according to the first embodiment may be any solvent that can dissolve the sulfone group-containing polyhydroxypolyether resin and bismaleimide, such as saturated alicyclic ketones such as cyclohexanone, and phenol such as cresol. And at least one selected from diethylene glycol monoalkyl ethers such as methyl carbitol can be used, but cyclohexanone is preferred from the standpoint of residual solvent and odor control in the fused film after baking. Further, it can be appropriately diluted with xylene, high boiling point alkylbenzene or the like.

  The heat-resistant self-fusing paint according to the first embodiment is obtained by dissolving a sulfone group-containing polyhydroxy polyether resin and bismaleimide in the solvent described above.

  Next, an example of the heat-resistant self-bonding enameled wire using the heat-resistant self-bonding paint according to the first embodiment will be described with reference to FIG.

  As shown in FIG. 1, the heat-resistant self-bonding enameled wire 10 according to the first embodiment is provided with an insulating layer (for example, made of polyamideimide) 2 as another insulator on the conductor 1, It is obtained by applying the above-mentioned heat-resistant self-bonding paint on the insulating layer 2 and baking it to form a bonding layer (fusion film) 3.

  The operation of the first embodiment will be described.

  The heat-resistant self-fusing paint according to the first embodiment comprises a sulfone group-containing polyhydroxy polyether resin represented by chemical formula (1) and bismaleimide.

  For this reason, when the heat-resistant self-bonding coating material according to the first embodiment is applied and baked and used as the bonding layer 3 of the heat-resistant self-bonding enameled wire 10, the solvent is almost vaporized during baking, and the B stage state The heat-resistant self-bonding enameled wire 10 is obtained by baking on the insulating layer 2. This heat-resistant self-bonding enameled wire 10 can be used for winding as an electric coil that requires heat resistance, such as industrial and automobile motors and generators.

  When the heat-resistant self-bonding enameled wire 10 is used for the winding, the enamel adjacent at a temperature lower than 240 ° C., preferably 220 ° C., lower than the prior art, by a fusing method such as energization, thermostatic bath, hot fusing with hot air, etc. The wires express a sufficient fusing force and cause a thermosetting reaction at the same temperature, so that the fusing layer 3 has a crosslinked structure.

  Thereby, according to the heat-resistant self-bonding coating material according to the first embodiment, when used in the heat-resistant self-bonding enameled wire 10, it retains a bonding force that has no practical problem in a high temperature atmosphere of 200 ° C. be able to.

  In the heat-resistant self-bonding paint according to the first embodiment, the temperature of the fusing process is lower than that of the conventional one. Therefore, the insulating layer 2 of the heat-resistant self-bonding enameled wire 10 or an insulating material other than the enameled wire is used. Deterioration can be prevented, and the workability of the fusing process itself is improved.

  Furthermore, the heat-resistant self-bonding coating material according to the first embodiment has a small temperature variation in the bonding force of the heat-resistant self-bonding enameled wire 10 itself and is highly reliable.

  Next, a second embodiment will be described.

  The heat-resistant self-fusing paint according to the second embodiment includes a lubricant with respect to 100 parts by weight of the sulfone group-containing polyhydroxy polyether resin in addition to the configuration of the heat-resistant self-fusing paint according to the first embodiment. Containing.

  The lubricant is not particularly limited, and there are synthetic systems such as polyethylene wax, silicone resin and fluororesin, and natural systems such as beeswax, carnauba wax and candelilla wax, and these are used alone or in combination. be able to. Use of beeswax is preferred from the viewpoint of solubility in paint, slipperiness after formation of a film (film), and availability.

  Further, the addition amount of the lubricant is preferably 1 to 10 parts by weight, more preferably 1 to 5 parts by weight with respect to 100 parts by weight of the sulfone group-containing polyhydroxy polyether resin. If it is less than 1 part by weight, the slipping property does not reach a desired value. If it exceeds 10 parts by weight, dispersion of the lubricant in the varnish may be greatly deteriorated.

  If an enameled wire similar to the heat-resistant self-bonding enameled wire 10 in FIG. 1 is produced using the heat-resistant self-bonding coating material according to the second embodiment, the slipping property can be imparted to the melted film by the lubricant. A heat-resistant self-bonding enameled wire having a static friction coefficient of 0.10 or less is obtained.

  In the above embodiment, the heat-resistant self-bonding enameled wire 10 having a two-layer structure in which the fusion layer 3 is provided on the conductor 1 via the insulating layer 2 has been described. The paint can also be applied to a heat-resistant self-bonding enameled wire having a single-layer structure in which a bonding layer is directly provided on a conductor.

  Next, examples of the thermosetting heat-resistant self-bonding enameled wire according to the present invention will be described together with comparative examples.

(Production of polyamide-imide enamel wire)
As shown in FIG. 1, a polyamide-imide enamel wire having an insulating layer 2 with a film thickness of 0.030 mm was obtained by applying and baking a polyamide-imide paint on a conductor 1 having a conductor diameter of φ0.8 mm.

Example 1
100 parts by weight of a sulfone group-containing polyhydroxy polyether resin having a sulfone group content of 40% in the molecular skeleton and 10 parts by weight of 4,4′-diphenylmethane bismaleimide were collected. This was dissolved in a mixed solvent composed of cyclohexanone and high-boiling alkylbenzene to prepare a heat-resistant self-fusing paint having a resin concentration of 25%.

  Next, the heat-resistant self-fusing property shown in FIG. 1 having the fusion layer 3 having a thickness of 0.010 mm is obtained by applying and baking the heat-resistant self-fusing coating material of Example 1 on the polyamideimide enameled wire. An enameled wire 10 was obtained.

(Example 2)
A heat-resistant self-bonding enameled wire 10 was obtained in the same manner as in Example 1 except that 4,4′-diphenylmethane bismaleimide was changed to 30 parts by weight.

(Example 3)
A heat-resistant self-bonding enameled wire 10 was obtained in the same manner as in Example 1 except that 50 parts by weight of 4,4′-diphenylmethane bismaleimide was used.

Example 4
A heat-resistant self-bonding enameled wire 10 was obtained in the same manner as in Example 1 except that 75 parts by weight of 4,4′-diphenylmethane bismaleimide was used.

(Example 5)
A heat-resistant self-bonding enameled wire 10 was obtained in the same manner as in Example 1 except that 100 parts by weight of 4,4′-diphenylmethane bismaleimide was used.

(Example 6)
A heat-resistant self-bonding enameled wire 10 was obtained in the same manner as in Example 1 except that 30 parts by weight of m-phenylene bismaleimide was used instead of 4,4′-diphenylmethane bismaleimide.

(Example 7)
100 parts by weight of sulfone group-containing polyhydroxy polyether resin having a sulfone group content of 40% in the molecular skeleton and 30 parts by weight of 4,4′-diphenylmethane bismaleimide were collected. This was dissolved in a mixed solvent composed of cyclohexanone and high-boiling alkylbenzene to prepare a heat-resistant self-fusing paint of Example 2 having a resin concentration of 25%.

  1 part by weight of beeswax was added thereto and dissolved to obtain the heat-resistant self-fusing paint of Example 7. A heat-resistant self-bonding enameled wire 10 having a fusion layer thickness of 0.010 mm was obtained by applying and baking the coating material of Example 7 on the polyamideimide enameled wire.

(Example 8)
A heat-resistant self-bonding enameled wire 10 was obtained in the same manner as in Example 7 except that the amount of beeswax added was 2.5 parts by weight.

Example 9
A heat-resistant self-bonding enameled wire 10 was obtained in the same manner as in Example 7 except that the amount of beeswax added was 5.0 parts by weight.

(Example 10)
A heat-resistant self-bonding enameled wire 10 was obtained in the same manner as in Example 7 except that the amount of beeswax added was 10.0 parts by weight.

(Comparative Example 1)
The fusion coating composition of Comparative Example 1 having a resin content concentration of 25% by dissolving a sulfo group-containing polyhydroxy polyether resin having a sulfone group content of 40% in the molecular skeleton in a mixed solvent composed of cyclohexanone and high-boiling alkylbenzene. Was made.

  A self-adhesive enameled wire having a fused layer thickness of 0.010 mm was obtained by applying and baking the fused paint of Comparative Example 1 on the polyamideimide enameled wire.

(Comparative Example 2)
A heat-resistant self-bonding enameled wire was obtained in the same manner as in Example 1 except that 7.5 parts by weight of 4,4′-diphenylmethane bismaleimide was used.

(Comparative Example 3)
A heat-resistant self-bonding enameled wire was obtained in the same manner as in Example 1 except that 4,4′-diphenylmethane bismaleimide was changed to 110 parts by weight.

(Comparative Example 4)
A heat-resistant self-bonding enameled wire was obtained in the same manner as in Example 7 except that the amount of beeswax added was 0.5 parts by weight.

(Comparative Example 5)
A heat-resistant self-bonding enameled wire was obtained in the same manner as in Example 7 except that the amount of beeswax added was 12.5 parts by weight.

(Comparative Example 6)
A heat-resistant self-bonding enameled wire was obtained in the same manner as in Example 1 except that 15 parts by weight of resol type phenol resin H-2181 (manufactured by Hitachi Chemical Co., Ltd.) was used instead of 4,4′-diphenylmethane bismaleimide. It was.

(Comparative Example 7)
A heat resistant self-bonding enameled wire was obtained in the same manner as in Example 1 except that 5 parts by weight of stabilized isocyanate AP-STABLE was used instead of 4,4′-diphenylmethane bismaleimide.

(Comparative Example 8)
A fusion paint of Comparative Example 8 having a resin concentration of 25% was prepared by dissolving polysulfone resin in a mixture of cresol and xylene. Next, the fusion-bonding paint of Comparative Example 8 was applied onto the polyamide-imide enamel wire and baked to obtain a self-bonding enamel wire having a fusion layer thickness of 0.010 mm.

(Test method for self-bonding enameled wire)
(1) Thermal fusibility test The thermal fusibility test was performed in accordance with NEMA standards. The heat resistant self-bonding enamel wire for the test was a 70-turn helical coil with an inner diameter of 5.6 mm. This helical coil was heated at a predetermined temperature for 10 minutes to heat-seal between adjacent wires. Next, the helical coil in which the adjacent lines were thermally fused was subjected to a buckling test at room temperature (20 ° C.), and the buckling strength was defined as the fusion force.

(2) Adhesive strength test at high temperature It was performed in conformity with the NEMA standard in the same manner as the thermal fusion test. The heat-resistant self-bonding enamel wire for the test was made into a 70-turn helical coil with an inner diameter of 5.6 mm and heated at 220 ° C. for 10 minutes to thermally bond the adjacent wires. Only Comparative Example 8 was heated at 240 ° C. for 10 minutes and thermally fused. Next, the helical coil in which the adjacent wires were heat-sealed was placed at 200 ° C. for 10 minutes, and a buckling test was performed at 200 ° C. to determine the buckling strength as the adhesive strength.

(3) Confirmation of thermosetting Take two heat-resistant self-bonding enameled wires and 10 cm of self-bonding enameled wires for testing, and measure the outer diameter with a micrometer. After one of the two samples was immersed in methyl ethyl ketone for 10 minutes at room temperature (20 ° C), the heat-resistant self-bonding enameled wire and the surface of the self-bonding enameled wire were wiped with absorbent cotton and the outer diameter was measured with a micrometer. Was measured, and it was confirmed whether or not the fused layer was peeled off. The other was heated at 220 ° C. for 10 minutes, cooled, and then similarly immersed in methyl ethyl ketone at room temperature (20 ° C.) for 10 minutes, and the outer diameter after wiping was measured to confirm the presence or absence of thermosetting. Comparative Example 8 was excluded because it did not dissolve in methyl ethyl ketone.

(4) Static Friction Coefficient FIG. 2 shows an outline of the gradient method static friction coefficient tester used for measuring the static friction coefficient of the heat resistant self-bonding enameled wire of FIG.

  Using this testing machine, as shown in FIG. 2, three heat-resistant self-bonding enamel wires with a length of 400 mm were taken, the gauge distance was 350 mm, and after 3% elongation, two were used as sample 23. Another plate is cut in half on the plate 21 provided so as to be inclined, and each is attached to the plate 22 as a sample 23. Then, the plate 22 is overlaid on the plate 21 so that the lines are at right angles. In that case, it is confirmed that the sample 23 is in contact. Next, the plate 21 is inclined at an inclination speed of 1 degree / 3 seconds, and the inclination angle θ of the plate 21 when the plate 22 starts to move even a little is obtained. The static friction coefficient (μ) is obtained by μ = tan θ. Note that tan θ is displayed on the tan θ display board 24 so that it can be read directly from the position of the pointer 25. If the level 26 is not level when the tilt angle θ is 0, the level adjustment screw 27 is used to adjust the level.

  Table 1 shows the composition of the heat-resistant self-bonding paints of Examples 1 to 10 (the fusion layer 3 after the enamel wire is prepared), the fusing force and the static friction coefficient of the heat-resistant self-bonding enamel wire. In Table 2, it shows similarly to Table 1 about Comparative Examples 1-8.

  As shown in Table 1, Examples 1 to 10 exhibit a sufficient heat-sealing force at a temperature of less than 240 ° C., and have a sufficient adhesive force in a high-temperature atmosphere of 200 ° C. I understand.

  On the other hand, Comparative Example 1, which is a sulfone group-containing polyhydroxy polyether resin alone without adding bismaleimide, is significantly inferior to Examples 1-10 in adhesive strength at high temperatures.

  In Comparative Example 2, the amount of bismaleimide added is 7.5 parts by weight, and the adhesive strength at high temperature is about half that of the example.

  In Comparative Example 3, the amount of bismaleimide added is 110 parts by weight, the adhesive strength at high temperature is not improved as compared with Examples 1 to 10, and precipitates are generated in the varnish.

  In Comparative Example 4, 0.5 part by weight of the lubricant is added, but the slipping property is lowered as compared with Examples 7 to 10 in which the specified amount (1 to 5 parts by weight) of the lubricant is added.

  In Comparative Example 5, 12.5 parts by weight of a lubricant was added. In one week, a part of the lubricant in the varnish was precipitated and poor dispersion occurred.

  In Comparative Example 6, a resol type phenol resin was used as a curing agent instead of bismaleimide, but the adhesive strength under high temperature did not reach that of Examples 1 to 9 and was left in an atmosphere at 40 ° C. for about 1 week. As a result, the heat sealing force decreases. This is a big problem in practical use because it is considered that cross-linking progresses with time and the flow of the fusion layer is inhibited.

  In Comparative Example 7, stabilized isocyanate was used as a curing agent in place of bismaleimide, but curing progressed during baking and the thermal fusion power was significantly low.

  Although the comparative example 8 uses a polysulfone resin, the heat-sealing force at 220 ° C. is low, and a condition at a higher temperature (240 ° C. or higher) is required. Also, the adhesive strength at high temperatures is not as good as in the examples.

  In particular, each of Examples 1 to 6 with respect to Comparative Examples 1 to 8 has good heat-sealing power at 220 ° C. and adhesive strength at high temperatures. Further, the time-dependent change of the heat sealing force as in Comparative Example 6 does not occur.

  In Examples 7-10, beeswax was added as a lubricant to Example 2, but the slipperiness was remarkably improved and the winding property was expected to be improved. Moreover, the heat sealing | fusion force and the adhesive force under high temperature also show the value equivalent to Examples 1-6.

It is a cross-sectional view showing an example of a heat-resistant self-bonding enameled wire using a heat-resistant self-bonding paint that is a preferred first embodiment of the present invention. 2A is a plan view of a gradient method static friction coefficient tester used for measuring the static friction coefficient of an enamel wire in the embodiment, FIG. 2B is a front view thereof, and FIG. 2C is a side view thereof. is there.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Conductor 2 Insulating layer 3 Fusion layer 10 Heat resistant self-bonding enameled wire

Claims (6)

A heat-resistant self-fusing coating composition comprising 10 to 50 parts by weight of bismaleimide with respect to 100 parts by weight of a sulfone group-containing polyhydroxy polyether resin represented by chemical formula (1) .

10 to 50 parts by weight of bismaleimide with respect to 100 parts by weight of the sulfone group-containing polyhydroxy polyether resin represented by the chemical formula (1), and further with respect to 100 parts by weight of the sulfone group-containing polyhydroxy polyether resin. 1 to 10 parts by weight of a heat-resistant self-fusing coating composition,   The heat-resistant self-bonding paint according to claim 2, wherein the lubricant is composed of one or a combination of synthetic systems such as polyethylene wax, silicone resin, fluororesin, and natural systems such as beeswax, carnauba wax, and candelilla wax. Composition.   The heat-resistant self according to any one of claims 1 to 3, wherein the sulfone group-containing polyhydroxy polyether resin contains 30 to 50% of a sulfone group in a molecular skeleton and is dissolved in the bismaleimide and a solvent. A fusible coating composition.   The heat-resistant self-bonding coating composition according to claim 4, wherein the solvent comprises at least one selected from saturated alicyclic ketones, phenols, and diethylene glycol monoalkyl ethers.   The heat-resistant self-bonding coating composition according to any one of claims 1 to 5 is formed in a heat-resistant self-bonding enameled wire in which a bonding layer is provided directly on the conductor or via another insulator. A heat-resistant self-bonding enameled wire formed by coating and baking a paint to form the above-mentioned fused layer.

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