JPS595092B2 - Manufacturing method of resin-impregnated coil - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a resin-impregnated coil having an excellent cured insulation structure and good appearance without using a mold.

35 Conventionally, dry coils are made by placing the coil in a mold that has been treated with a release agent, vacuum impregnating it with a thermosetting resin, and then heating and curing the coil.

In this case, the curing of the resin takes a long time to avoid the occurrence of cracks. Since the mold cannot be removed during this time, it is necessary to prepare many molds. Also,
Epoxy resin is often used as a resin, and its excellent adhesive properties have many drawbacks, such as the fact that it takes time to remove the mold and clean the mold, and it also requires treatment with a mold release agent. It was hot. Therefore, an object of the present invention is to solve the above-mentioned manufacturing problems all at once, and to produce a resin-impregnated coil having an excellent hardened insulation structure and good appearance 1 without using a mold. A manufacturing method is provided. In order to achieve such an object, the present invention includes a step of impregnating the coil 1 with a solvent-free varnish containing a photocurable resin having a polymerizable unsaturated group in the molecule and a thermosetting epoxy resin, and This process consists of a step of irradiating the coil (including the end face) with ultraviolet rays and a heating step of thermosetting the coil after the irradiation, and will be described in detail below using examples.

First, each step of the five methods for manufacturing a resin-impregnated coil according to the present invention will be explained in detail.

Regarding the step of impregnating a coil with a solvent-free varnish containing a photocurable resin having 6 polymerizable unsaturated groups in its molecules and a thermosetting epoxy resin, the photocurable resin has 2.0 polymerizable unsaturated groups in its molecules. It is possible to target a blur polymer with a

For example, various epoxy resins (e.g. bisphenol A
Diglycidyl ether, bisphenol F diglycidyl ether, resorcinol diglycidyl ether, brominated bisphenol A diglycidyl ether, novolac glycidyl ether, polyalkylene diglycidyl ether, etc., phthalic acid,
3. of the glycidyl ether type, such as the diglycidyl ether of tetrahydrophthalic acid and hexahydrophthalic acid; mono-, di-, tri-, tetra-, (meth)acrylic esters of polyester polyols, unsaturated polyester resins, oligoesters of polycarganic acid and glycidyl methacrylate An example of an adjunct is J. This prepolymer may also be combined with vinyl monomers such as glycol di(meth)acrylates (e.g. ethylene di(meth)acrylates).
acrylate, propylene di(meth)acrylate, diethylene di(meth)acrylate, neopentel di(meth)acrylate), di(meth)acrylates of polyols (e.g. tri(meth)acrylate of glycerin, etc.), styrene, dipinylbenzene, diallyl ptalate, vinyl Pyrrolidone, vinyltoluene, dimethylstyrene, vinyl acetate, etc. can be added. Further, the photocurable resin may be a prepolymer or a blurred polymer to which a monomer is added and used as it is.

Furthermore, in order to impart photocuring ability, it is preferable to incorporate a photosensitizer. Examples of the photosensitizer include benzoin compounds such as methyl, ethyl, and propyl ethers of benzoin, quinone compounds such as anthraquinone, sulfur organic compounds such as disulfide, and azoin compounds such as azobisisoprotrine. Compounds, such as dyes, which are excited by light of a specific wavelength are used, and the amount of addition thereof may be usually 0.5 to 5 parts by weight. In addition, as the thermosetting epoxy resin, those mentioned above are directly applicable, and as the curing agent, for example, acid anhydrides (e.g., phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylmezic anhydride, methyltetrahydrophthalic acid, succinic anhydride, maleic anhydride, pyrotritic anhydride, trimellitic anhydride, etc.), latent curing agents (e.g., amine complexes of boron trifluoride, dicyandiamine, etc.), and even amines. , blended into epoxy resin.

Further, as described above, the thickener-free varnish is obtained by blending a thermosetting epoxy resin with a photocurable resin having a polymerizable unsaturated group in its molecule.

When the amount of the photocurable resin is less than 5% by weight, it tends to be difficult to trap the thermosetting epoxy resin sufficiently in the network structure depending on the weight of the resin. It is of course possible to use photocurable resin alone as a varnish for coil treatment, but it also has a wide variety of performances required as an insulating structure (mechanical, electrical, heat resistance, water resistance, chemical resistance, etc.) In order to balance this by partially modifying the composition of the varnish, it is preferable to use a thermosetting epoxy resin in combination with the thermosetting epoxy resin, and it is preferable that the amount of the thermosetting epoxy resin is 10 parts by weight or more. 03) Coil surface portion (side surface and end surface) (Step of irradiating FC violet rays) First, Fig. 1 shows a configuration in which a varnish-impregnated coil is irradiated with ultraviolet rays using a plurality of ultraviolet irradiation devices.
This ultraviolet irradiation causes a rapid polymerization reaction in the photocurable resin, and the photocurable resin forms a network structure in which molecular chains are three-dimensionally developed and is cured.

At this time, the thermosetting epoxy resin, which is another varnish component, is not induced to react by ultraviolet irradiation. Therefore, the varnish properties are such that the part exposed to ultraviolet rays has a thickness corresponding to the penetration depth of the ultraviolet rays, and thermosetting epoxy resin is trapped in a network structure of photocurable resin. It has a leather-like to glass-like appearance. The degree of change in appearance mainly depends on the blending ratio of the photocurable resin, and the higher the content of the photocurable resin, the harder the glass-like appearance becomes. Therefore, the surface of the varnish-impregnated coil is completely covered with a solidified resin layer. Note that FIG. 1 is a configuration diagram in which a varnish-impregnated coil is irradiated with ultraviolet light using a plurality of ultraviolet irradiation devices.

1 is a varnish-impregnated coil; 2a, 2b, and 2e are ultraviolet irradiation devices arranged to irradiate the coil surface 1a1 and coil end faces 1b and 1c of the varnish-impregnated coil 1 with ultraviolet rays; and 3 is a rotating jig.

First, the varnish-impregnated coil 1 is installed with the coil surface 1a facing up using a rotating jig, and then rotated gently. become.

On the other hand, the ultraviolet irradiation devices 2b and 2c solidify the resin on the coil end faces 1b and 1c of the varnish-impregnated coil 1, respectively. In this case, the arrangement of the violet ray irradiation devices 2b and 2c allows the light to travel straight, so the coil end face 1b has a depth.
and 1c for sufficient irradiation. Further, the rotational speed of the varnish-impregnated coil 1 may be selected depending mainly on the viscosity of the varnish used to find conditions under which the varnish can be maintained smoothly on the surface of the coil without dripping. In addition, the ultraviolet irradiation time depends on the amount of photocurable resin compounded in the varnish used, its photocuring ability, the output and wavelength distribution of the ultraviolet irradiation devices 2a to 2e, or the irradiation atmosphere (in the air or with an inert gas such as CO2). , N2, etc.), but the objective can be sufficiently achieved in approximately 30 to 15 seconds.

Further, it is also easy to increase the size of this solidified resin layer to form a more excellent thick protective layer.

For this purpose, the surface of the varnish-impregnated coil on which the solidified resin layer has been formed may be sprinkled with the required amount of the above-mentioned solvent-free varnish, and the coil may be irradiated with light in the same manner as described above. This operation may be repeated multiple times as necessary.
At this time, in order to make the sprinkled varnish uniform on the coil surface 1a, the coating amount is adjusted and the coated surface is smoothed using a film thickness adjusting jig (for example, bar corner, knife corner, etc.). In general, the number of solidified resin layers that can be formed on the coil surface is approximately 15! ! It also becomes Lm. In this case, the value of this solidified resin layer varies somewhat depending on the amount of photocurable resin blended into the solvent-free varnish and the intensity of ultraviolet rays, but it can be easily obtained. On the other hand, the varnish impregnated inside the coil is in an unsolidified state. Regarding the heat curing process of thermally curing the coil after O irradiation, an organic peroxide ( For example, it is desirable to add 0.5 to 3 parts by weight of a radical initiator such as benzoyl peroxide, methyl ethyl ketone peroxide, dicumyl peroxide, tertiary hydroperoxide, etc. to the solvent-free varnish in advance.

Then, under normal resin curing conditions, for example, a furnace temperature of 100 to 18
What is necessary is just to make it harden at 0 degreeC for 24 to 5 hours. The curing conditions may be selected in consideration of the heat capacity of the coil to be treated. Note that FIGS. 2 and 3 are other configuration diagrams in which a varnish-impregnated coil is irradiated with ultraviolet rays using a plurality of violet ray irradiation devices, respectively. In particular, in FIG. 2, the coil surface 1a of the varnish-impregnated coil 1 is irradiated by an ultraviolet irradiation device 2a, and the coil end surfaces 1b and 1c are irradiated by reflecting the light from the ultraviolet irradiation device 2a with reflecting mirrors 4a and 4b. It is something. In this case, compared to FIG. 1, the violet ray irradiation devices 2b and 2c can be omitted, which is extremely advantageous in terms of energy saving. The layout of the reflecting mirrors 4a and 4b can be easily adjusted by adjusting the angle so that the light is well reflected on the coil end faces 1b and 1c. In addition, in order to irradiate the coil end surfaces 1b and 1c with stronger light for faster curing, a convex lens (preferably made of quartz) may be placed between the coil end surfaces 1b and 1c and the reflecting mirror 4a. . Moreover, FIG. 3 shows a case where concave mirrors 5a and 5b are used as reflecting mirrors.

In this case, it is extremely effective when the coil end faces 1b and 1e have a donut shape. That is, the coil end face 1
It is more efficient to irradiate light concentratedly on b and 1c. The dimensions and radial line (curvature) may be changed to suit the needs of the user.In addition, a plurality of concave mirrors 5a and 5b are installed to form a plurality of light condensing portions on the coil end faces 1b and 1,''1c to achieve more rapid curing. Note that the reflecting mirrors 4a and 4b1 and concave mirrors 5a and 5b are not only ordinary glass mirrors, but also quartz glass with metal (for example, Al, Cr, etc.) vapor-deposited Δ in order to efficiently reflect ultraviolet rays. Metal plates with a film or mirror finish (e.g. stainless steel, aluminum, chrome)
You can also use In addition, Fig. 4 shows the coil end face 1b.
and a resin finishing mechanism for perfecting the finish of 1c; 2. FIG.

Usually, the end of an insulating thin material such as paper, nonwoven fabric, or film made of a heat-resistant polymer material is accumulated on the coil end faces 1b and 1e, so that a slight gap occurs due to the winding of the thin material. For this reason, there are fine irregularities 3 on the coil end faces 1b and 1c, and it is important to smooth these parts by varnishing.For example, the concave mirror 5 shown in FIG.
The solvent-free varnish 3j is resupplied through the hollow spatula-shaped jig 7, for example, on the coil end faces 1b and 1c which are not irradiated with the spot-like light beams 6a and 6c from the coils a and 5b. In this case, since the coil to be processed is rotating,
After the varnish supplied from the jig 7 is leveled, it is exposed to spot-like light speeds 6a and 6b to quickly form a solidified layer while being uniform.
V (Next, this will be explained in more detail with reference to examples. Example 1 4 parts by weight of benzoin ethyl ether was dissolved in 100 parts by weight of epoxy acrylate (an adduct of 8281 mol of Epicote and 2 mol of methacrylic acid) to form a photocurable resin. do.

A thermosetting epoxy resin is prepared by dissolving 80 parts by weight of methyltetrahydrophthalic acid and 5 parts by weight of zinc octylate in 100 parts by weight of Epicoat 828.

Next, 100 parts by weight of a thermosetting epoxy resin and 20 parts by weight of a photocurable resin are dissolved to form a solvent-free varnish composition. Then, a coil (outer diameter 22?φ) was placed in a vacuum impregnation tank.
, inner diameter 20CT! This solvent-free varnish was poured into a tube (1φ, length 25 cm) and impregnated. The varnish-impregnated coil was then taken out from the vacuum impregnation tank, immediately mounted on a rotating jig, and irradiated with ultraviolet rays using the configuration shown in FIG. The irradiation conditions are as follows. (a) Distance between ultraviolet ray irradiation device 2a and coil surface 1a - 10CTn (b) Distance between violet ray irradiation devices 2b and 2c and coil end faces 1b and 1c - 12 (1-J mo VZ← U Rotation speed - 20
Rotations/min (d) Atmosphere - In air (e) Irradiation time - 4 minutes After this irradiation process, about 2 mm of the coil surface 1a, which is equal to the varnish adhesion depth, had a solidified jelly-like appearance.

Further, the coil end faces 1b and 1c were similarly solidified. Next, this irradiation coil was statically cured in a 130° C. oven for 8 hours. The obtained coil was a resin-embedded coil with extremely excellent momme appearance. Example 2 A coil impregnated with varnish in the same manner as in Example 1 was attached to a rotating jig and irradiated with ultraviolet rays using the configuration shown in FIG.

The irradiation conditions were as follows. (a) Violet male ray irradiation device 2a
Distance between and coil surface 1a - 10cm (b) Reflector 4a
and 4b were installed on the coil end surfaces 1b and 1c so that the upper ends of the coils were approximately the same as the upper surface of the coil surface 1a.

(c) Rotation speed - 20 revolutions/min (d) Atmosphere - air (4) Irradiation time - 6 minutes The coil thus obtained has the same momme view as in Example 1 on the coil surface 1a and coil end faces 1b and 1c. The coil after heat curing also became an excellent resin-embedded coil.

Example 3 A coil impregnated with varnish in the same manner as in Example 1 was mounted on a rotating jig and irradiated with violet rays using the configuration shown in FIG.

This irradiation condition is based on Example 2, and a concave mirror (outer diameter 6?, focal length 7C!11) is placed between the coil end faces 1b and 1c and the reflecting mirrors 4a and 4b, respectively, and the condensed light is irradiated onto the coil end face. The irradiation time was 3 minutes. The thus obtained coil has a coil surface 1a and coil end surfaces 1b and 1c.
exhibits the same appearance as Example 1. Next, after heating and curing, the coil No. 1 also became an excellent resin-embedded coil. Example 4 A varnish-impregnated coil was attached to a rotating jig in the same manner as in Example 1, and ultraviolet rays were irradiated using the configuration shown in FIG.

This irradiation was carried out in accordance with Example 3, and while the solvent-free varnish of Example 1 was resupplied to the coil end faces 1b and 1c on the lower side of the coil 1, the varnish was leveled with a spatula. This leveled deposited varnish was irradiated with ultraviolet light focused by a concave mirror to solidify it. This operation was sufficient to form a smooth end surface in one operation, and the irradiation was carried out for 3 minutes. The coil thus obtained was heat cured in the same manner as in Example 1. This coil had a particularly smooth finish not only on the coil surface 1a but also on the coil end surfaces 1b and 1c. As explained in detail above, according to the method for manufacturing a resin-impregnated coil according to the present invention, it is possible to extremely easily manufacture a coil embedded in a cured resin without using a mold, and the end face of the coil can be extremely easily manufactured. It is extremely easy to cover the coil surface J and the hardened resin layer on the end face of the coil (for example, when the switch is on or off).
The coil is completely embedded in a thick solidified layer, so there is no varnish leakage during curing, so multiple heat treatments can be performed. Since the generation of volatile components is prevented, it is possible to provide an extremely high-performance cured resin composition without compositional fluctuations, and the problem of odor generation, which has been a problem in the past, can be solved all at once. The surface of the coil is covered with a thick solidified resin, and the thermosetting epoxy resin is trapped in the network structure formed by polymerization and hardening of the solidified photocurable resin. Through the heat curing process, varnish leakage is completely prevented, the volatilization of the thermosetting epoxy resin component is also prevented, and the generation of bad odors is eliminated.This means that there is no fluctuation in the varnish components. A high-performance hardened structure can be obtained.

Further, there is an effect that a large number of objects to be treated can be carried into the heating furnace and cured at the same time.

[Brief explanation of the drawing]

Figure 1 is a block diagram of a varnish-impregnated coil irradiated with ultraviolet rays using multiple ultraviolet irradiation devices, and Figures 2 and 3 are other diagrams of irradiation of a varnish-impregnated coil with ultraviolet rays using multiple ultraviolet irradiation devices, respectively. The configuration diagram, FIG. 4, is a diagram showing a resin finishing treatment mechanism for perfecting the finish of the end face of the coil. 1 is a varnish impregnation treatment → illumination, 1a is a coil surface, 1b and 1c are coil end faces, 2a, 2b and 2c are ultraviolet irradiation equipment, 3 is a rotating jig, 4a and 4b are reflective mirrors, 5
a and 5b are concave mirrors, 6a and 6b are spot-shaped light beams, 7 is a spatula-shaped jig, and e is an arrow indicating the rotation direction of the varnish-impregnated coil 1.

Claims (1)

[Scope of Claims] 1. A step of impregnating a coil with a solvent-free varnish containing a photocurable resin having a polymerizable unsaturated group in its molecule and a thermosetting epoxy resin, and the surface (including the end surface) of the varnish-impregnated coil.
A method for manufacturing a resin-impregnated coil, comprising the steps of: irradiating the coil with ultraviolet rays; and heating the coil after irradiation with ultraviolet rays to harden the resin. 2. The method for manufacturing a resin-impregnated coil according to claim 1, wherein the photocurable resin contained in the solvent-free varnish is at least 5 parts by weight. 3. In the process of irradiating the surface (including the end face) of the varnish-impregnated coil with ultraviolet rays, the varnish-impregnated coil is irradiated with ultraviolet irradiation equipment installed on the top of the coil side surface and on the coil end face, respectively, while rotating the coil side surface horizontally. A method for manufacturing a resin-impregnated coil according to claim 1, characterized in that: 4. In the step of irradiating the surface (including the end face) of the varnish-impregnated coil with ultraviolet rays, an ultraviolet irradiation device is placed above the side surface of the coil, and the irradiation of ultraviolet rays onto the end face of the coil is performed via a reflecting mirror. A method for manufacturing a resin-impregnated coil according to claim 1. 5. In the step of irradiating the surface (including the end face) of the varnish-impregnated coil with ultraviolet rays, one or more concave mirrors are used to irradiate the end face of the coil with ultraviolet rays, and the thickness of the coil is intensively irradiated with ultraviolet rays. A method for manufacturing a resin-impregnated coil according to claim 1, characterized in that: 6 In the process of irradiating the surface (including the end face) of the varnish-impregnated coil with ultraviolet rays, one package uses one or more concave mirrors to irradiate the end face of the coil with ultraviolet rays, and the coil is not irradiated with focused light from the concave mirror. 2. The method for manufacturing a resin-impregnated coil according to claim 1, further comprising resupplying the end face with solvent-free varnish.