JPS6150369B2 - - Google Patents

Description

[Detailed description of the invention]

Unsaturated polyester resin has electrical, mechanical,
Due to its well-balanced thermal properties, workability, price, etc., it is used for a variety of purposes including FRP and laminates, but it is also used for electrical insulation due to its properties, workability, and cost.
It is generally well-balanced in terms of price, so it is often used for coil impregnation, casting, etc. However, when unsaturated polyester resin using styrene monomer is used for impregnating or casting coils of power transformers and fluorescent lamp ballasts, the vinyl chloride lead wires (hereinafter referred to as lead wires) used as lead wires are ) is affected by the styrene monomer, especially in cold weather (5 to -10
℃), it had the disadvantage of easily causing clutching due to mechanical stress. The causes of this crack are as follows: (1) If the cured resin film is hard, when the lead wire is bent, cracks first occur in the cured resin film, and as a result of mechanical stress concentrated at that point, it easily breaks. (2) When a lead wire is immersed in a styrene monomer, etc., the softening agent contained in the lead wire is extracted into the styrene monomer, etc., and as a result, the lead wire itself becomes hard and easily breaks. When curing, it is usually 100 to 120 for impregnation.
It is thought that by raising the temperature to ℃, the styrene monomer etc. swells the lead wire and penetrates into the inside of the lead wire, and as a result, when the resin is heated and hardened, the lead wire becomes hard and easily breaks. In order to prevent this lead wire from bending, (1) the unsaturated polyester resin should be made flexible, (2) should not use styrene or the like as a reactive monomer, and (3) should be cured. Methods such as lowering the temperature are commonly employed. The method (1) of making an unsaturated polyester resin flexible can generally be improved by modifying the resin composition with vegetable oil or using flexible raw materials for the acid component and alcohol component. However, when styrene or the like is used as the reactive monomer, problems (2) and (3) mentioned above arise, and satisfactorily results cannot be obtained simply by changing the resin composition. Unsaturated polyester resin (2), which does not use styrene or the like as a reactive monomer, can provide good results in preventing lead wire breakage, but has drawbacks such as slow curing and high cost. However, it is not commonly used. On the other hand, regarding method (3) of lowering the curing temperature, it is necessary to make the resin fast-curing, which results in an extremely short pot life of the resin.
It is not a good idea for impregnation because it has poor workability. As a result of various studies, the present inventors have discovered a method for manufacturing electrical equipment that can significantly reduce the risk of lead wires breaking even in winter, even when using conventional unsaturated polyester resins made from styrene, etc. Ta. That is, the present invention applies a photocurable resin composition that can be cured at low temperature to the parts of electrical equipment impregnated with thermosetting varnish and where there is a risk of bending of the lead wires, and then irradiates the composition with light to cure the composition in a short time. This method reduces the negative impact on lead wires such as styrene, and then immerses the entire electrical device in thermosetting varnish and heats it to harden, achieving the purpose of insulating the electrical device. The present invention provides electrical equipment that has been insulated, in which a photocurable resin composition is applied to a portion of a vinyl chloride lead wire to be impregnated with a thermosetting varnish, and after photocuring, the thermosetting varnish is impregnated. Concerning the manufacturing method. The light used for photocuring in the present invention is as follows:
Ultraviolet light with a wavelength range of 2000 Å to 6000 Å can be used, and a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a chemical lamp, an arc lamp, etc. can be used as a light source. There are no particular restrictions on the conditions for photocuring. The photocurable resin composition is applied by spraying, brushing, impregnation, or the like. The photocurable resin composition used in the present invention is an unsaturated polyester resin containing an unsaturated polyester, a crosslinkable monomer, a photosensitizer, and optionally a radical polymerization initiator, a curing accelerator, and a polymerization inhibitor. It is a composition. More specifically, unsaturated polyester is synthesized from an acid component and an alcohol component, or in some cases from an acid component, an alcohol component, and a modified component, and there are no restrictions on the method of production. Acid components include maleic acid, maleic anhydride, fumaric acid, itaconic acid, citraconic acid, endomethylenetetrahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, tetrahydrophthalic anhydride, and other unsaturated acids, phthalic acid, and anhydride. Acids that do not have reactive unsaturated bonds such as phthalic acid, isophthalic acid, terephthalic acid, adipic acid, and benzoic acid, vegetable oil fatty acids obtained from soybean oil, tall oil, coconut oil, castor oil, etc., and derivatives thereof, etc. is used. 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. Examples of crosslinking monomers include styrene and its derivatives, divinylbenzene, acrylic ester,
A methacrylic acid ester or the like is used, and there are no particular limitations. Examples of photosensitizers include benzoyl ethers such as benzoin, benzoin ethyl ether, benzoin isopropyl ether, and benzoin phenyl ether, benzointhioethers, benzophenone, acetophenone, 2-ethylanthraquinone furoin, benzoin ether-Michler-ketone series, and chloride. You can use anything you like, such as decile. Examples of radical polymerization initiators include acyl peroxides such as benzoyl peroxide and acetyl peroxide, hydroperoxides such as tertiary butyl peroxide and kyumene hydroperoxide, ketone peroxides such as methyl ethyl ketone peroxide and cyclohexanone peroxide, Alkyl peroxides such as tertiary butyl peroxide and dicumyl peroxide, and oxyperoxides such as tertiary butyl peroxyacetate are used. As hardening accelerators, naphthenates of iron, cobalt, lead, manganese, nickel, tin, zinc, etc.
Octenoic acid salts and the like are used. As the polymerization inhibitor, quinones such as hydroquinone, paratertiary butylcatechol, pyrogallol, and other commonly used ones are used. In addition, as the thermosetting varnish to be impregnated after photocuring, commonly used solvent-based varnishes, unsaturated polyester varnishes, epoxy varnishes, etc. can be used, but the present invention is particularly suitable for styrene monomer type unsaturated polyester varnishes. , is particularly effective. Examples and comparative examples are shown. Parts are parts by weight, and % are weight %. Production of unsaturated polyester resin A Maleic anhydride 98g (1 mol), phthalic anhydride
75g (0.5mol), soybean oil fatty acid 282g (0.5mol)
and propylene glycol 167.2g (2.2mol)
The mixture was charged into a four-necked flask, stirred under nitrogen gas blowing, kept at 180°C for 1 hour, and the reaction continued at 210-220°C to obtain unsaturated polyester A with an acid value of 20.0. 50 parts of styrene was stirred and mixed with 50 parts of this unsaturated polyester A, and 0.01% of hydroquinone and manganese naphthenate (metal content: 8
%) and 1% benzoyl peroxide were added and mixed and stirred to obtain a uniform varnish and unsaturated polyester resin A. Preparation of Varnish B Varnish B was obtained by mixing and stirring 100 parts of unsaturated polyester resin A and 1 part of benzoin ethyl ether. Preparation of Varnish C To 50 parts of the unsaturated polyester A, 50 parts of styrene, 0.01 part of hydroquinone, 0.2 parts of manganese naphthenate (metal content 8%), and 1 part of benzoin ethyl ether were mixed and stirred to obtain a uniform solution varnish C. . Comparative Example 1 A test piece (75
×150×0.8mm iron plate 2 made by Hitachi Cable Co., Ltd.
20 UL1015 orange, UL1007 orange vinyl chloride lead wires 1, polyester film adhesive tape 4
(width: 10 mm, thickness: 0.05 mm), bend the lead wires to sandwich the iron plate, and then secure with polyester film adhesive tape to prevent the vinyl chloride lead wires from moving. ), immersed in Varnish A for 10 minutes, pre-dropped for 5 minutes, and cured at 100°C for 3 hours. The crack test conditions were as follows: After being left in a low temperature chamber at 0° C. for 4 hours, the lead wire was immediately expanded to an angle of 180 degrees, and the number of cracks that had occurred in the lead wire was checked. As a result, the UL1015 lead wire is
Cracks occurred on 15 wires and 20 on UL1007 lead wires. Example 1 The test piece used in Comparative Example 1 was immersed in Varnish B for 10 minutes.
After pre-dropping for 5 minutes, as in Example 1, the immersed part of the varnish was exposed to ultraviolet light using a high-pressure mercury lamp (manufactured by Matsushita Electric Works Co., Ltd., 1KW, 1-lamp type) from a distance of 200 mm as shown in Figure 1. When irradiated, the surface of the lead wire was cured in 3 minutes. Furthermore, this test piece was immersed in varnish A for 10 minutes, and after pre-dropping for 5 minutes, it was heated to 100°C.
Leave it in a dryer for 180 minutes to harden. When this test piece was tested under the same conditions as Comparative Example 1,
Cracks occurred in 0 of the UL1015 lead wires and 5 of the UL1007 lead wires. The above comparative examples and examples are summarized in Table 1.

[Table] Number of cracks in the table The numbers in the table are

Claims (1)

[Claims] 1. An insulation-treated insulation-treated vinyl chloride lead wire characterized in that a photocurable resin composition is applied to a portion of a vinyl chloride lead wire to be impregnated with thermosetting varnish, and after photocuring, impregnation treatment with thermosetting varnish is performed. Method of manufacturing electrical equipment.