JPS6217635B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ultraviolet curing bind tape used as a fastening member for laminated cores or windings of electrical equipment. Ultraviolet curable bind tape cures quickly by irradiating it with ultraviolet rays, so in the production of bind-wound laminated cores or wound wires, it saves labor in tape curing work, reduces curing time, saves energy, and shortens manufacturing time. It is very useful in that it is possible. The method of manufacturing a bind-wound laminated core or wound wire using UV-curable bind tape is to wrap the bind tape in several layers while applying tension.
The process consists of curing the resin by irradiating it with ultraviolet light. Applying tension when wrapping bind tape is absolutely necessary in order to strengthen the adhesion between the tape layers and increase the strength of the bind tape after curing by allowing each tape layer to harden as one after the resin hardens. . However, because the UV-curable resin contained in conventional UV-curable bind tape has a relatively low molecular weight, it lacks so-called stiffness, has low tape strength when uncured, and breaks when tension is applied when winding the tape. There were flaws. In other words, if the tension is applied uniformly along the transverse direction of the tape, it will not break, but in actual laminated cores or wound wires, the surface in contact with the tape is uneven, so the tension is not applied uniformly to the tape, and the fibers are not broken due to the impregnated resin. The bonds between the fibers are first broken, the fibers are separated, and the tension concentrates on one fiber within the separated fibers, causing this fiber to break, and then the tension concentrates on the next fiber, causing it to break. be done. In this way, it is thought that the rupture due to the concentrated tension occurs one after another, and finally the entire bind tape ruptures. Furthermore, conventional UV-curable bind tapes have the disadvantage of low tape strength after curing at high temperatures, that is, low heat resistance. The present invention has been made to solve the above-mentioned drawbacks, and an object of the present invention is to provide an ultraviolet curable bind tape that does not break even when winding tension is applied and has excellent heat resistance. That is, the present invention comprises (a) an epoxy resin and (meth)
Consists of a mixed resin component consisting of an ultraviolet curable resin which is a vinyl ester synthesized from acrylic acid and (b) a mixture or reactant of a phenolic resin and an acrylonitrile-butadiene copolymer, and glass cloth and glass yarn with no folded weft threads. The present invention provides an ultraviolet curable bind tape characterized by being made of glass fiber selected from the group consisting of: Preferably, (a) a resin component prepared by mixing 10 to 50 parts by weight of a mixture or reaction product of (b) a phenolic resin and an acrylonitrile-butadiene copolymer with respect to 100 parts by weight of the ultraviolet curable resin and glass fibers. The present invention provides an ultraviolet curable bind tape characterized by comprising: The glass fiber according to the invention uses a glass cloth or a glass yarn without weft turns, such as a unidirectionally aligned glass yarn. Glass cloth has conventionally been available with or without folded wefts, but in the present invention, among these, glass cloth without folded wefts is used. As the ultraviolet curable resin in the present invention, a vinyl ester synthesized from an epoxy resin and (meth)acrylic acid is used. The epoxy resin is not particularly limited, and has two oxirane rings.
It can be used as long as it is a compound having at least
Epoxy resins obtained by reacting bisphenol A, hydrogenated bisphenol A, bisphenol F or novolak resin with epichlorohydrin, or (methyl)glycidyl ether, (methyl)glycidyl ester, (methyl)glycidylamine type epoxy resins, or Aliphatic or cycloaliphatic epoxy resins or epoxy resins having heterocycles can be used. One or more vinyl esters obtained from these epoxy resins and (meth)acrylic acid can be mixed and used as an ultraviolet curable resin. Furthermore, fillers, colorants, flame retardants, and plasticizers that do not reduce the adhesiveness and light transmittance of the bind tape may be mixed with the ultraviolet curable resin. The mixture or reaction product of (b) the phenolic resin and the acrylonitrile-butadiene copolymer used in the present invention can be produced by mixing or reacting in a conventional manner. Preferably, 1 to 100 parts by weight of a phenolic resin is mixed or reacted with 100 parts by weight of an acrylonitrile-butadiene copolymer. If the amount of phenolic resin is less than 1 part by weight, the heat resistance of the tape strength after curing will be insufficient, and if it is more than 100 parts by weight. The bind tape becomes hard and brittle, and the glass fibers break during the winding process. As the phenolic resin, when producing a mixture with an acrylonitrile-butadiene copolymer, a low molecular weight phenolic resin having a molecular weight of about 300 to 1000 is suitable in order to increase the compatibility with the acrylonitrile-butadiene copolymer. Alkylphenol resins are suitable for increasing compatibility. On the other hand, when a phenolic resin is used as a reaction product with an acrylonitrile-butadiene copolymer, the phenolic resin is not particularly limited. The acrylonitrile-butadiene copolymer preferably has an acrylonitrile content of 10% to 50% by weight and a molecular weight of 1,000 to 10,000, and in the case of a copolymer that reacts with a phenol resin, it reacts with the phenol resin at the end or inside of the molecule. Use one having one or more functional groups. Examples of the reactive functional group include a carboxyl group, an acid anhydride group, a vinyl group, an epoxy group, a cyanate group, and an isocyanate group. The ultraviolet curable bind tape according to the present invention includes:
Add appropriate photosensitizers, solvents, etc. to a mixture of (a) a vinyl ester synthesized from an epoxy resin and methacrylic acid or acrylic acid, and (b) a mixture or reaction product of a phenol resin and an acrylonitrile-butadiene copolymer. After the addition, it can be produced by coating or impregnating glass fibers with a brush or roller, and then drying this. The tape after solvent drying has moderate tackiness. The amount of the resin component applied to the glass fibers is preferably 20 to 30 parts by weight per 100 parts by weight of the glass fibers. The ultraviolet curable bind tape according to the present invention includes:
Normal winding tension (7 to 15 kgf per 1 mm of tape width)
The tape does not break even when added, and the cured tape has excellent heat resistance and good oil resistance, making it useful as a tightening member for bind-wound laminated cores and windings. The present invention will be specifically explained below with reference to Examples and Comparative Examples. In addition, in Examples and Comparative Examples, Table 1 below
The characteristic values shown in were determined using the following test method: Bond strength: Cut uncured bind tape into 50 mm length pieces, sandwich them between chucks parallel to the fibers, set the gap between the chucks at 20 mm, and cut the tape in the lateral direction of the tape. The chuck was pulled at a moving speed of 10 mm/min, and the maximum strength until the resin bond between the fibers broke and separated, and the elongation when the fibers separated were determined. There is a relationship between this bonding force and breakage due to winding tension; that is, a tape with a large bonding force will not break even if winding tension is applied. As for the bonding strength, it is not enough to simply have a high separation strength between the fibers, but also elongation that relieves the concentration of tension is necessary. Tensile strength after curing: Measured by the ring method according to JIS2412. The ring test fitting is split type and has an inner diameter.
It is 156mm and the tape winding width is 19mm. Tensile samples were prepared with a tape width of 19 mm and a winding tension of 130 kgf.
After wrapping it around the metal fitting three times, the test metal fitting was cured by irradiating it with ultraviolet rays while rotating it. In the tensile test, each divided piece was pulled in opposite directions at a speed of 20 mm/min, and the strength at break was defined as the tensile strength. In the following Comparative Examples and Examples, parts refer to parts by weight. Examples 1 to 3 (a) For 100 parts of vinyl ester synthesized from Epikote 828 (epoxy resin, trade name of Ciel Co., Ltd.) as an ultraviolet curable resin and methacrylic acid, (b)
50 parts of Durez 12687 (phenolic resin, trade name of Durez) and Hycar 1001 as a mixture of phenolic resin and acrylonitrile-butadiene copolymer.
(Acrylonitrile-butadiene copolymer, Gutdrich Co., Ltd. trade name) 100 parts gives a solid content of 10 parts (Example 1), 30 parts (Example 2) and 50 parts (Example 3) in methyl ethyl ketone. Mix and dissolve the resin component as described above, add 1 part of benzoin isobutyl ether as a photosensitizer, and then add toluene to make the viscosity 1000 cp or less. Then, make a unidirectionally aligned glass yarn (ECG1502/290). Apply with a roller so that the resin adhesion amount is 24 to 26% and the tape width is 30 mm, and the temperature is 100℃.
The solvent was removed by drying with hot air for 5 minutes to obtain an ultraviolet curable bind tape with surface adhesiveness. The tapes obtained in this example (Examples 1 to 3) were subjected to tension (7 to 7 per 1 mm width of tape) on the uneven laminated core.
It did not break even when wrapped with a load of 15 kgf).
Bond strength of these tapes and 20℃ and 180℃
Table 1 shows the tape tensile strength after curing measured in an atmosphere of Example 4 (a) 100 parts of vinyl ester synthesized from DEN438 (epoxy resin, trade name of Dow Chemical Company) and methacrylic acid as an ultraviolet curable resin, and (b) phenolic resin and acrylonitrile-butadiene copolymer. As a reaction product, 20 parts of Durez 12687 (resol type) and 100 parts of Hycar 1300 x 8 (terminated carboxylacrylonitrile-butadiene copolymer, product name of Gutduritsu Co., Ltd.) were heated and reacted in 150 parts of toluene at 100°C for 2 hours with stirring. 30 parts (in terms of solid content) of the reaction product obtained were mixed to form a resin component, 1 part of benzoin isobutyl ether as a photosensitizer was added to this, and the resin was diluted with methyl ethyl ketone to a viscosity of 1000 cp or less. The mixed solution was applied to glass yarn and dried in the same manner as in Example 1 to obtain a bind tape with surface adhesiveness. This tape did not break even when winding tension was applied. The bond strength and tensile strength are shown in Table 1. Example 5 (a) Reaction of 100 parts of vinyl ester synthesized from Epicote 1001 (epoxy resin, trade name of Ciel Co., Ltd.) as an ultraviolet curable resin and methacrylic acid, and (b) phenolic resin and acrylonitrile-butadiene copolymer. A resin component is obtained by mixing 30 parts of Evergrip 709MP (trade name of Certilny Co., Ltd.), which is mainly composed of phenol-modified nitrile rubber, and adding 1 part of the photosensitizer benzoin isobutyl ether, followed by 70 parts of toluene/methyl ethyl ketone. /30 parts) diluted with a mixed solvent to a viscosity of 1000 cp or less. This mixed solution was applied to a glass yarn and dried in the same manner as in Example 1 to obtain an ultraviolet curable bind tape with surface adhesiveness. Table 1 shows the bond strength and tensile strength of this tape. Example 6 1 part of photosensitizer benzoin isobutyl ether was added to the resin component used in Example 5, and toluene/
Reduce the viscosity to 500 cps or less with a mixed solvent of methyl ethyl ketone (70 parts/30 parts), impregnate a 19 mm wide glass cloth to a resin adhesion of 24 to 26%, and heat it at 100℃ for 50 minutes.
It was dried with hot air for a minute to obtain a surface-adhesive UV-curable bind tape. This tensile strength is shown in Table-1. Comparative Example 1 Add 1 part of photosensitizer benzoin butyl ether to 100 parts of vinyl ester synthesized from Epicote 1001 and methacrylic acid, dilute with toluene/methyl ethyl ketone (70 parts/30 parts) mixed solvent to a viscosity of 500 cp or less, and make a 19 mm width The amount of resin adhered to the glass cloth
It was impregnated to a concentration of 24 to 26% and dried with hot air at 100°C for 5 minutes to obtain an ultraviolet curable bind tape with surface adhesiveness. Table 1 shows the tensile strength of the tape after curing.
Shown below. 【table】

Claims (1)

[Claims] 1. (a) an ultraviolet curable resin which is a vinyl ester synthesized from an epoxy resin and (meth)acrylic acid, and (b) a phenolic resin and acrylonitrile.
An ultraviolet curable bind tape characterized by comprising a resin component mixed with a mixture or reaction product of a butadiene copolymer, and glass fibers selected from the group consisting of glass cloth and glass yarn with no folded weft threads. 2. A patent claim consisting of (a) a mixed resin component of 10 to 50 parts by weight of a mixture or reaction product of a phenolic resin and an acrylonitrile-butadiene copolymer (b) and glass fibers based on 100 parts by weight of an ultraviolet curable resin The ultraviolet curable bind tape according to item 1. 3 (b) Phenolic resin and acrylonitrile
Acrylonitrile-butadiene copolymer for 1 to 100 parts by weight of phenolic resin as a mixture or reaction product of butadiene copolymer
The ultraviolet curable bind tape according to claim 1, which is obtained by mixing or reacting 100 parts by weight.