JPH0320001B2 - - Google Patents

Description

[Detailed description of the invention]

Recently, electrical equipment has become increasingly smaller and lighter, has harsher usage conditions, and has become more reliable. From the point of view of energy saving and rationalization in insulation treatment work, short processing time has become desirable. For this reason, there has been a strong shift from conventionally widely used solvent-based varnishes to solvent-free varnishes, and in particular, unsaturated polyester-based varnishes (hereinafter referred to as polyester (It's called varnish.)
has become widely used. Polyester varnishes contain resins, crosslinkable monomers, organic peroxides, curing accelerators, polymerization inhibitors, inorganic fillers, etc. as necessary, but regular polyester varnishes are difficult to use in terms of cured product properties, price, etc. Since then, styrene monomer has been used as a crosslinking monomer. In addition, recently, styrene monomers have been used in large amounts to reduce the viscosity of varnishes in rotating equipment, in order to eliminate the need to scrape off the hardened varnish that adheres to the inner surface of the core of motor stators (hereinafter referred to as stators). I am using it. When insulating the stator, the stator is immersed in varnish and then pulled up.
The varnish is cured by heating at ~140°C for 1 to 4 hours. However, with conventional varnishes that use only styrene monomer as a crosslinking monomer, the styrene monomer evaporates during heating, resulting in less varnish adhesion after curing, and in particular, the sticking of coil ends and coil binding threads. There were times when it was insufficient. Moreover, a similar tendency exists not only in the stator but also in the case of the armature, in which case only the coil portion was further treated with varnish after the varnish had been cured. As a result of extensive studies, the present inventors have found that the above-mentioned drawbacks can be improved by using a crosslinkable monomer that is less volatile than styrene monomer and has a vapor pressure of 78 mmHg or less at 100°C. The present invention uses a styrene monomer with a vapor pressure of 78°C at 100°C.
Crosslinkable monomers other than styrene monomers below mmHg,
A resin composition containing a radically polymerizable resin and an organic peroxide, the resin composition containing 5 to 30 parts by weight of a crosslinking monomer other than the above-mentioned styrene monomer based on 100 parts by weight of the resin composition. This invention relates to a method for manufacturing insulated electrical equipment, in which the electrical equipment is insulated with a material. Next, the resin composition in the present invention will be explained.
This resin composition contains a crosslinkable monomer other than styrene monomer with a vapor pressure of 78 mmHg or less at 100°C, a radically polymerizable resin, a styrene monomer, an organic peroxide, and, if necessary, a curing accelerator and a polymerization inhibitor. Contains additives, inorganic fillers, etc. Examples of crosslinkable monomers other than styrene monomers having a vapor pressure of 78 mmHg or less at 100°C in the present invention include vinyltoluene, t-butylstyrene, divinylbenzene, dicyclopentadiene acrylate, dicyclopentadiene methacrylate, diallyl phthalate, Hydroxyethyl methacrylate, hydroxypropyl methacrylate, diacrylate and dimethacrylate of ethylene glycol,
Diacrylate and dimethacrylate of diethylene glycol, diacrylate and dimethacrylate of tetraethylene glycol, diacrylate and dimethacrylate of 1,6-hexanediol, triacrylate and trimethacrylate of trimethylolpropane, etc. alone or in combination of two or more. used. The amount of the crosslinking monomer other than the styrene monomer mentioned above is in the range of 5 to 30 parts by weight per 100 parts by weight of the resin composition. If it is less than 5 parts by weight, the amount of varnish deposited on the surface layer will be small and the adhesion strength will be poor. It is weak, and if it exceeds 30 parts by weight, the adhesion force is almost saturated, and depending on the crosslinking monomer, the varnish viscosity increases, which may actually reduce workability and heat cycle resistance (cracking resistance) of the cured product. It is inappropriate for this purpose. Further, since all of the crosslinking monomers other than the styrene monomer are more expensive than the styrene monomer, they are also disadvantageous in terms of economy, and are preferably in the range of 5 to 20 parts by weight. Examples of radically polymerizable resins include unsaturated polyesters, unsaturated epoxy ester resins, modified polybutadiene resins having reactive unsaturated bonds, acrylic ester oligomers, and methacrylic ester oligomers, which can be used alone or used in combination. The unsaturated polyester is synthesized from an acid component and an alcohol component, or in some cases, an acid component, an alcohol component, and a modified component. Acid components include unsaturated acids such as maleic acid, maleic anhydride, fumaric acid, itaconic acid, citraconic acid, endomethylenetetrahydrophthalic anhydride, tetrahydrophthalic anhydride, phthalic acid, phthalic anhydride, isophthalic acid, and terephthalic acid. , acids having no reactive unsaturated bonds such as adipic acid and benzoic acid, vegetable oil fatty acids such as soybean oil, tall oil, coconut oil, and linseed oil, and derivatives thereof. Alcohol components include ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, butanediol,
Neopentyl glycol, glycerin, trimethylolpropane, pentaerythritol, etc. are used. As the modifying component, dicyclopentadiene, cyclopentadiene, derivatives thereof, etc. can be used. Unsaturated epoxy ester resin contains 1 in 1 molecule.
It is synthesized from an epoxy resin with more than 3 epoxy groups and an acid component with unsaturated bonds. As the epoxy resin, bisphenol A type epoxy resins are preferred, including Epicote 828, 1001, 1004, 1007 (manufactured by Ciel Chemical), DER331, 661, 664, 667 (manufactured by Dow Chemical), Araldite 260, 6071,
6084, 6097 (manufactured by Ciba Geigy), etc.
Alicyclic epoxy resins, novolac type epoxy resins, etc. can also be used. As acid components having unsaturated bonds, acrylic acid, methacrylic acid,
Crotonic acid, maleic anhydride, etc. can be used. Modified polybutadiene resins having reactive unsaturated bonds include modified polybutadiene resins having acrylic or methacrylic groups at the terminals (for example,
TE-2000 manufactured by Nippon Soda, R- manufactured by Idemitsu Petrochemical
45ACR), modified polybutadiene resins with reactive unsaturated bonds (for example, Hitachi Chemical's WP-
2601). For acrylic ester oligomers and methacrylic ester oligomers, Toagosei Co., Ltd.
Co., Ltd.'s M-6100, M-8060, M-7100, etc., Showa Kobunshi Co., Ltd.'s SP-1507, SP-1563, etc., Thiokol Co., Ltd.'s SP-1507, SP-1563, etc.
Uvitane782, 893, etc., of Kyoeisha Yushi Chemical Industry
14EG-A, BP-6EA, BP-6EM, BP-2EM
etc. In the method of insulating electrical equipment with the resin composition of the present invention, for example, the stator coil can be
After pre-drying at 140°C for 30 to 60 minutes, the stator coil is immersed in the resin composition of the present invention for 1 to 5 minutes, and then the stator coil is pulled up and further dried at 100 to 140°C for 1 to 5 minutes.
It is cured by heating for 4 hours. Examples of organic peroxides include acyl peroxides such as benzoyl peroxide and acetyl peroxide, tert-butyl peroxide,
Hydroperoxides such as cumene hydroperoxide, methyl ethyl ketone peroxide,
Ketone peroxides such as cyclohexanone peroxide, ditertiary butyl peroxide, dicumyl peroxide, and tertiary butyl perbenzoate are used. The amount of this organic peroxide used is determined in the resin composition of the present invention.
It is preferably in the range of 0.1 to 5.0 parts by weight per 100 parts by weight. As the hardening accelerator, naphthenates and octenoates of iron, cobalt, manganese, lead, nickel, tin, zinc, etc. are used. The amount of this curing accelerator used is preferably in the range of 0.2 to 2.0 parts by weight based on 100 parts by weight of the resin composition in the present invention. As the polymerization inhibitor, hydroquinone, pyrogallol, quinones, and other commonly used ones are used. The amount of the polymerization inhibitor to be used is preferably 0.1 part by weight or less based on 100 parts by weight of the resin composition of the present invention. Silica, alumina, calcium carbonate, asbestos, mica powder, etc. are used as the inorganic filler. The amount of this inorganic filler used is preferably based on 100 parts by weight of the resin composition in the present invention.
It ranges from 10 to 200 parts by weight. Electrical equipment to which the present invention is applied include, for example, motor stator coils, armature coils, and electromagnetic coils. An example of the present invention is shown. Examples 1 to 7 Isophthalic acid 498g (3 mol), tetrahydrophthalic anhydride 456g (3 mol)), maleic anhydride 392
(4 mol), diethylene glycol 530 g (5 mol), and propylene glycol 456 g (6 mol) in a four-necked flask, stirred while blowing nitrogen gas, kept at 180°C for 2 hours, and reacted at 210-220°C. Then, an unsaturated polyester with an acid value of 20 was obtained.
2000 g of this resin, 0.3 g of hydroquinone, and 857 g of styrene monomer were mixed and stirred to obtain a mixture A having a resin content of 70% by weight. Various crosslinkable monomers having a vapor pressure of 78 mmHg or less at 100° C. were used in this mixture A, and the properties were measured using the formulations shown in Table 1. In each case, 0.1 part by weight of manganese naphthenate (8%) and 1.0 part by weight of tert-butyl perbenzoate were added to 100 parts by weight of the total amount of mixture A and crosslinkable monomer. . Comparative Examples 1 to 3 The mixture A obtained in Examples 1 to 7 had a vapor pressure of 100
Using isobutyl methacrylate, a styrene monomer with a temperature exceeding 78 mmHg at °C, as in the example, based on 100 parts by weight of the total amount of mixture A and crosslinkable monomer,
Added 0.1 part by weight of manganese naphthenate (8%) and 1.0 part by weight of tert-butyl perbenzoate,
Characteristics were measured. Examples 8-15 Using mixture A, for vinyltoluene and trimethylolpropane trimethacrylate,
As shown in Table 2, the characteristics were measured by changing the amount added. Similarly to Examples 1 to 7 and Comparative Examples 1 to 3, 0.1 part by weight of manganese naphthenate (8%) and tert-butyl perbenzoate were added to 100 parts by weight of the total amount of mixture A and crosslinkable monomer. 1.0 part by weight was added. Examples 16-21 376 g of diglycidyl ether of 4,4'-isopropylidene diphenol (manufactured by Schiel Chemical, E _p -828, epoxy equivalent 188), 172 g of methacrylic acid, 2 g of benzyldimethylamine, 0.05 hydroquinone
g was placed in a four-neck flask and reacted at 115°C for 6 to 10 hours to obtain an unsaturated epoxy ester resin with a resin acid value of 2.8. 490 g of this resin, 0.07 g of hydroquinone, and 210 g of styrene monomer were mixed and stirred to obtain a mixture B having a resin content of 70% by weight. Various crosslinkable monomers having a vapor pressure of 78 mmHg or less at 100° C. were used in this mixture B, and the properties were measured using the formulations shown in Table 3. In each case, 0.1 part by weight of manganese naphthenate (8%) and 1.0 part by weight of tert-butyl perbenzoate were added to 100 parts by weight of the total amount of mixture B and the crosslinkable monomer. Comparative Examples 4 to 6 Same as Examples 16 to 21, using styrene monomer and isobutyl methacrylate having a vapor pressure of 78 mmHg or higher at 100°C as mixture B, based on 100 parts by weight of the total amount of mixture B and crosslinkable monomer. Then, 0.1 part by weight of manganese naphthenate (8%) and 1.0 part by weight of tert-butyl perbenzoate were added, and the properties were measured.

【table】

[Table] The unit of formulation in the table is parts by weight.

【table】

[Table] The unit of formulation in the table is parts by weight.

【table】

[Table] The unit of formulation in the table is parts by weight. <Test method> (1) Viscosity: Put the resin composition in a 300 ml tall beaker, and use a BL type rotational viscometer (manufactured by Tokyo Keiki) to measure the temperature at 25°C. The viscosity was measured at (2) Amount of monomer dissipated: 1 g of the resin composition was placed in a metal shear dish of φ60×12 mm, and cured at 120° C. for 2 hours, and the amount of monomer dissipated was determined from the difference in mass before and after curing. (3) Helical coil adhesive strength: Create a helical coil using φ1.0 polyester copper wire (PEW) according to JIS C 2105. After this helical coil is immersed in the resin composition, it is left standing in a horizontal position and cured at 120° C. for 2 hours. The adhesive strength of the helical coil obtained by curing the resin composition at 25° C. was measured according to JIS C 2105 using Autograph IM-100 manufactured by Shimadzu Corporation. (4) Evaluation using stator: φ0.8mm, single-phase 125W stator using 1PEW (core size 140×110×35
mm) was preheated at 120°C for 30 minutes, left at room temperature for 10 minutes, and then immersed in the resin compositions obtained in Examples and Comparative Examples for 1 minute. Leave it for a minute. after that,
After heating at 120°C for 2 hours, the stator is cooled to room temperature. With the stator at room temperature, the adhesion of the coils and binding threads and the adhesion of varnish to the inner surface of the core were evaluated. (i) Adhesiveness of the coil and binding thread 〇: Both the coil and the binding thread are sufficiently fixed, △: The adhesion strength of the sagging wire portion of the coil is insufficient, ×: The coil and the binding thread move easily and are fixed. Not yet. (ii) Adhesion on the inner surface of the core 〇: No accumulation of resin composition, △: Slight accumulation of resin composition, ×: Much accumulation of resin composition. (5) Heat cycle resistance Using the stator used in the evaluation in (4), heat cycle test (1 cycle: 120℃ / 2 hours ← → Low temperature / 2 hours, the low temperature was tested from 0℃, and curing was performed for 3 cycles. If no cracks occurred in the product, lower the low temperature side by 10°C) and check the temperature until cracks occurred. From the results in Table 1, Table 2, and Table 3, it is clear that a crosslinkable monomer with a vapor pressure of 78 mmHg or less at 100°C is added to the radically polymerizable resin using styrene as a crosslinkable monomer according to the present invention. By insulating rotating equipment, etc. using the resin composition containing the resin composition, it is possible to omit the work of scraping the resin composition adhered to the inner surface of the core.
In addition, it is possible to manufacture highly reliable electrical equipment with excellent coil insulation and fixing properties.

Claims (1)

[Claims] 1 A resin composition containing a styrene monomer, a crosslinking monomer other than the styrene monomer with a vapor pressure of 78 mmHg or less at 100°C, a radically polymerizable resin, and an organic peroxide, in which 100 parts by weight of the resin composition On the other hand, crosslinkable monomer 5 other than the above styrene monomer
1. A method for producing an insulated electrical device, comprising insulating the electrical device with a resin composition containing ~30 parts by weight.