Insulating resin composition, cured product, wound coil, and rotating machine

Abstract

Provided are: an insulating resin composition which contains a biomass material as a starting material and nevertheless can give cured objects having a better surface touch; a cured object obtained from the insulating resin composition; a wire coil having a satisfactory surface touch; and a rotating machine including the wire coil. The insulating resin composition comprises a heat-curable resin having both an epoxy group and a (meth)acryloyl group, a free-radical polymerization initiator, a hardener for epoxy groups, a polyfunctional vinyl monomer produced from a biomass material as a starting material, and monofunctional vinyl monomers produced from a biomass material as a starting material. The monofunctional vinyl monomers comprise both a vinyl monomer having an isobornyl skeleton and a vinyl monomer having the skeleton of a cyclic ether of a saturated hydrocarbon. The insulating resin composition has a biomass ratio of 60-84%.

Description

[Technical Field]

[0001] The present disclosure relates to an insulating resin composition, a cured product, a wound coil, and a rotating machine. [Background technology]

[0002] Patent Document 1 discloses an example of a solventless varnish composition used as an insulating varnish. To adjust the viscosity of the solventless varnish composition, a monofunctional vinyl monomer such as 2-hydroxyethyl methacrylate (2-HEMA) is added as a reactive diluent. After impregnating a coil with the solventless varnish composition, the composition is heated to cure. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2017 / 061006 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in insulating resin compositions such as the solventless varnish composition of Patent Document 1, a portion of the monofunctional vinyl monomer may volatilize in the curing oven during curing heating. Here, 2-hydroxyethyl methacrylate, which is used as the monofunctional vinyl monomer, is highly hydrophilic due to its molecular structural characteristics, i.e., the presence of a highly flexible hydroxyl group on a relatively short hydrocarbon backbone. Therefore, 2-hydroxyethyl methacrylate easily reacts with moisture in the air and may reattach to the surface of the cured product. This may result in a sticky feeling on the surface of the cured product. Furthermore, there is a growing need for insulating resins that use fewer petroleum-derived raw materials, for example, to comply with environmental regulations, which have become increasingly strict due to recent international interest in environmental issues.

[0005] The present disclosure is directed to solving such problems. The present disclosure provides an insulating resin composition using biomass materials as raw materials and capable of improving the surface tactile properties of the cured product, as well as a wound coil with a good surface tactile properties and a rotating machine using the same. [Means for solving the problem]

[0006] The insulating resin composition according to the present disclosure comprises a thermosetting resin having both an epoxy group and a meth(acryloyl) group, a radical polymerization initiator and a curing agent for the epoxy group, a polyfunctional vinyl monomer derived from a biomass material, and a monofunctional vinyl monomer derived from a biomass material, wherein the monofunctional vinyl monomer comprises both a vinyl monomer having an isobornyl skeleton and a vinyl monomer having a saturated hydrocarbon cyclic ether skeleton, and the vinyl monomer having a saturated hydrocarbon cyclic ether skeleton is tetrahydrofurfuryl methacrylate or tetrahydrofurfuryl acrylate, and the total amount of the vinyl monomer having an isobornyl skeleton and the vinyl monomer having a saturated hydrocarbon cyclic ether skeleton is 60 wt% or more and 84 wt% or less.

[0007] The cured product according to the present disclosure is obtained by curing the insulating resin composition described above.

[0008] The wound coil according to the present disclosure is impregnated with the insulating resin composition described above.

[0009] The rotating machine according to the present disclosure is a rotating machine used in a hoisting machine that drives the cage of a rope elevator, and includes a stator using the above-described winding coil. [Effects of the Invention]

[0010] The insulating resin composition according to the present disclosure can improve the surface tactile properties of a cured product even when a biomass material is used as a raw material. Also, the surface tactile properties of a wound coil made from a biomass material can be improved. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 10 is a conceptual diagram showing an example of a state in which insulating resin is hardened. [Figure 2] FIG. 1 is a cross-sectional view of a hoisting machine according to a first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] Embodiment 1 Hereinafter, embodiments for implementing the subject matter of the present disclosure will be described. Note that the subject matter of the present disclosure is not limited to the following embodiments, and any component of the embodiments may be modified or omitted within the scope of the gist of the present disclosure. Furthermore, the embodiments and examples in the present disclosure are illustrative in all respects and should not be construed as restrictive.

[0013] In the first embodiment, a liquid insulating resin composition (X) and a cured product (Y) thereof will be described. Also, a winding coil for a rotating machine using the insulating resin composition (X) and a rotating machine using the same in a stator will be described.

[0014] 1. Insulating resin composition (X) and its cured product (Y) The insulating resin composition (X) of the first embodiment is used, for example, in the coil of a rotating machine to maintain the insulation properties and mechanical strength. The coil is formed, for example, by winding a winding such as an enameled wire around an iron core. The device to which the coil is applied is not limited to a specific device. The coil is applied, for example, to an electric motor such as a motor, or a rotating machine such as a generator. The coil is applied, for example, to an elevator hoist or an electric compressor. The insulating resin composition (X) is impregnated into the coil by, for example, an immersion method in which the coil is immersed in an impregnation tank filled with the insulating resin composition (X). The insulating resin composition (X) is heated and cured in a curing furnace to form a cured product (Y).

[0015] The insulating resin used to impregnate the coils of rotating machines to ensure their insulation and mechanical strength is generally highly viscous, making it difficult to penetrate the insulating resin into the coils between the windings. In particular, the long and thick coils of large rotating machines make it even more difficult for high-viscosity insulating resin to penetrate.

[0016] In particular, when applying insulating resin to large rotating machines, a material design suitable for the coils of large rotating machines is required. Methods for filling insulating resin between windings in rotating machine coils include the dipping method and the dripping method. For example, for coils that are relatively small and have low winding density, such as those used in compressors, both the dipping method and the dripping method can be used. On the other hand, for large rotating machines such as those used in generators or traction machines, it is difficult to apply insulating resin uniformly between windings all the way to the inside of the coil using the dripping method. For this reason, the dipping method in air or vacuum is generally used for large rotating machines.

[0017] The immersion method involves immersing a coil in a tank or impregnation tank filled with insulating resin under atmospheric or vacuum conditions, allowing the insulating resin to penetrate between the wound wire. When the coil is removed from the immersion tank after immersion impregnation, a large amount of excess insulating resin adheres to the coil windings, iron core, and other components. The coil removed from the immersion tank is often placed in a curing oven for curing and heating, still carrying excess insulating resin. As a result, the excess insulating resin adhering to the coil may harden and form a cured mass on, for example, the bottom of the coil, the recesses in the iron core, or other components. Furthermore, the insulating resin, whose viscosity decreases due to the curing and heating, drips down below the coil, sometimes forming large resin puddles in the curing oven.

[0018] Agglomerates of cured resin formed under coils, in recesses in the core, or on other components can damage windings and components due to thermal stress such as curing shrinkage, potentially resulting in reduced insulation. Furthermore, the cured resin blocks can interfere with the assembly of the coil into the fixing member, necessitating their removal. Resin puddles formed in the curing oven can cause smoke due to the heat of curing. Resin puddles can form large cured masses on the hearth of the curing oven, making regular oven cleaning essential. These problems are particularly pronounced in large rotating machines, creating a growing need for low-viscosity insulating resins that can prevent the formation of cured masses and resin puddles.

[0019] Adding organic solvents such as styrene or vinyltoluene to insulating resins is an effective way to reduce their viscosity and improve their permeability. However, with the recent increase in environmental concerns, there is a growing demand for reducing the environmental impact of insulating resins, so it is preferable to limit the use of these organic solvents. Therefore, instead of adding these organic solvents, a method of adjusting the viscosity can be adopted in which a reactive diluent, a low-molecular-weight material that has active groups that contribute to the curing reaction and reduces volatile substances generated by curing heat, is added to the insulating resin. Monofunctional monomers, particularly 2-hydroxyethyl methacrylate, are effective as such reactive diluents.

[0020] FIG. 1 is a conceptual diagram showing an example of the state of curing of insulating resin. In FIG. 1, an example of insulating resin 2 curing on the surface of the winding of coil 1 is shown. During the curing reaction, most of the reactive diluent added to insulating resin 2 is incorporated into the cured product, but a portion 3 of the reactive diluent volatilizes and fills the interior of the curing oven. Here, moisture 4 is contained in the air inside the oven. A thin film 5 made of paraffin may be formed on the surface of curing insulating resin 2.

[0021] 2-Hydroxyethyl methacrylate is highly hydrophilic due to its molecular structure, namely, the presence of a highly flexible hydroxyl group on a relatively short hydrocarbon backbone. Therefore, when used as a reactive diluent, some of the volatilized 2-hydroxyethyl methacrylate reacts easily with moisture in the air and can reattach to the surface of the cured product. This can leave a sticky feeling on the cured surface. Because the stickiness of the cured surface hinders the assembly process that follows the impregnation process, insulating resins are required to eliminate the stickiness of the cured surface and improve its tactile properties.

[0022] The insulating resin composition (X) of the first embodiment includes a thermosetting resin (A) having both an epoxy group and a meth(acryloyl) group, a radical polymerization initiator and a curing agent for the epoxy group (B), a polyfunctional vinyl monomer (C) derived from a biomass material, and a monofunctional vinyl monomer (D) derived from a biomass material. The monofunctional vinyl monomer (D) has a cyclic structure in its molecule. The monofunctional vinyl monomer (D) includes both a vinyl monomer (D-1) having an isobornyl skeleton and a vinyl monomer (D-2) having a saturated hydrocarbon cyclic ether skeleton. Here, the meth(acryloyl) group refers to an acryloyl group or a methacryloyl group. Furthermore, in this disclosure, a numerical range expressed using "x to y" refers to a numerical range including a lower limit x and an upper limit y.

[0023] The insulating resin composition (X) preferably has low viscosity and good drainage so as to prevent excess adhesion to the coil when it is pulled out of the immersion bath after impregnation by the immersion method. The overall viscosity of the insulating resin composition (X) is desirably 10 mPa·s to 200 mPa·s, preferably 10 mPa·s to 100 mPa·s, and more preferably 15 mPa·s to 50 mPa·s.

[0024] 1.1.Thermosetting resin (A) The thermosetting resin (A) includes a resin having both an epoxy group and a meth(acryloyl) group in one molecule. The thermosetting resin (A) may be the resin used alone, or may be used by mixing the resin with a second resin containing either or both of an epoxy group and a meth(acryloyl) group in one molecule. The second resin may be a mixture of multiple resins.

[0025] The thermosetting resin (A) promotes three-dimensional crosslinking reactions through both an addition reaction mediated by free radicals generated from organic peroxides with meth(acryloyl) groups as reactive groups, and a ring-opening polymerization reaction with epoxy groups as reactive groups. This accelerates the curing reaction and improves the heat resistance and mechanical strength of the cured product.

[0026] For ease of viscosity adjustment, the thermosetting resin (A) preferably has a number average molecular weight (Mn) of 15,000 or less, preferably 1,000 to 10,000, and a viscosity at 60° C. of 10,000 mPa·s or less.

[0027] The epoxy equivalent of the thermosetting resin (A) blended in the insulating resin composition (X) is preferably 500 to 5000, more preferably 1000 to 4000. By controlling the epoxy equivalent within the above range, the curing rate can be improved without reducing the usable life of the insulating resin composition (X), and further the crosslink density of the cured product (Y) can be improved.

[0028] 1.2. Radical polymerization initiator and curing agent for epoxy groups (B) In order to cure the thermosetting resin (A) and the monofunctional vinyl monomer (D), an organic peroxide is used as a radical polymerization initiator that acts mainly on meth(acryloyl) groups, and a curing catalyst for epoxy groups.

[0029] 1.2.1.Organic peroxides The organic peroxide is primarily used as a reaction initiator for meth(acryloyl) groups, and those known in the art can be used. The organic peroxide is not particularly limited as long as it has a 10-hour half-life temperature of 40°C or higher. However, from the viewpoint of shortening the curing time and adjusting the curing temperature, a 10-hour half-life temperature of 100°C to 170°C is preferred. Examples of such organic peroxides include ketone peroxides, peroxyketals, hydroperoxides, dialkyl peroxides, diacyl peroxides, peroxyesters, and peroxydicarbonates. These organic peroxides may be used alone or in combination.

[0030] Examples of organic peroxides having such a 10-hour half-life temperature include 1,1-di(t-butylperoxy)cyclohexane, 1,1-di(t-hexylperoxy)cyclohexane, 1,1-di(t-hexylperoxy)-3,3,5-trimethylcyclohexane, 1,1-di(t-butylperoxy)-2-methylcyclohexane, 2,2-di(4,4-di-(butylperoxy)cyclohexyl)propane, n-butyl 4,4-di-(t-butylperoxy)valerate, 2,2-di-(t-butylperoxy)butane, t-hexylperoxyisopropyl monocarbonate, t-butylperoxymaleic acid, t-butylperoxy-3,5,5-trimethylhexanoic acid, t-butylperoxylauric acid, t-butylperoxyisopropyl monocarbonate, t-butylperoxybenzoate, and t-butylperoxyacetate. peroxide, t-hexyl peroxybenzoate, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, t-butylperoxy 2-ethylhexyl monocarbonate, di(2-t-butylperoxyisopropyl)benzene, dicumyl peroxide, di-t-hexyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, t-butylcumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3, p-menthane hydroperoxide, t-butylperoxyallyl monocarbonate, methyl ethyl ketone peroxide, 1,1,3,3-tetramethylbutyl hydroperoxide, t-butyl hydroperoxide, cumin hydroperoxide, diisopropylbenzene hydroperoxide, etc. These may be used alone or in combination of two or more.

[0031] The amount of organic peroxide in the insulating resin composition (X) is not particularly limited, but is preferably 0.1 to 10 parts by mass, and more preferably 0.5 to 5 parts by mass, relative to 100 parts by mass of the total of the thermosetting resin (A), polyfunctional vinyl monomer (C), and monofunctional vinyl monomer (D). If the amount of organic peroxide is less than 0.1 part by mass, the crosslink density will be low and the required mechanical strength will not be obtained. On the other hand, if the amount of organic peroxide is more than 10 parts by mass, the usable life of the insulating resin composition will tend to be significantly shortened.

[0032] 1.2.2. Hardeners for epoxy groups The curing agent for epoxy groups may be any known agent in the art. Examples of the curing agent for epoxy groups include amine compounds, boric acid ester compounds, organometallic compounds, organophosphorus compounds, quaternary ammonium salts, quaternary phosphonium salts, amine complexes, imidazole compounds, compounds containing transition metals such as titanium and cobalt, acid anhydrides, imidazole compounds, polymercaptan compounds, phenols, Lewis acids, and isocyanate compounds. These may be used alone or in combination of two or more.

[0033] Specific examples of amine-based curing agents include tertiary amines and tertiary amine salts, such as lauryl dimethylamine, N,N-dimethylcyclohexylamine, N,N-dimethylbenzylamine, N,N-dimethylaniline, (N,N-dimethylaminomethyl)phenol, 2,4,6-tris(N,N-dimethylaminomethyl)phenol, 1,8-diazabicyclo[5.4.0]undecene-7 (DBU), 1,5-diazabicyclo[4.3.0]nonene-5 (DBN), ethylenediamine, 1,3-diaminopropane, 1,4-diaminobutane, hexamethylenediamine, dipropylenediamine, polyetherdiamine, 2,5-dimethylhexamethylenediamine, trimethylhexamethylenediamine, diethylenetriamine, iminobispropylamine, bis(hexamethyl)triamine, triethylenetetramine, tetramethylhexamethylenediamine ... Examples of tertiary amine salts include triethylenepentamine, pentaethylenehexamine, aminoethylethanolamine, tri(methylamino)hexane, dimethylaminopropylamine, diethylaminopropylamine, methyliminobispropylamine, menthanediamine, isophoronediamine, bis(4-amino-3-methyldicyclohexyl)methane, diaminodicyclohexylmethane, bis(aminomethyl)cyclohexane, N-aminoethylpiperazine, 3,9-bis(3-aminopropyl)-2,4,8,10-tetraoxaspiro[5,5]undecane, m-xylenediamine, metaphenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, diaminodiethyldiphenylmethane, dicyandiamide, and organic acid dihydrazides. Examples of tertiary amine salts include the carboxylates, sulfonates, and inorganic acid salts of the above-mentioned tertiary amines. Examples of carboxylates include salts of carboxylic acids having 1 to 30 carbon atoms (particularly, salts of fatty acids) such as octylate salts. Examples of sulfonates include p-toluenesulfonate, benzenesulfonate, methanesulfonate, and ethanesulfonate. Representative examples of tertiary amine salts include salts of 1,8-diazabicyclo[5.4.0]undecene-7 (DBU) (e.g., p-toluenesulfonate, octylate). However, these are merely examples.The use of amine-based curing agents other than these does not depart from the scope of the present disclosure.

[0034] Examples of borate esters include trimethyl borate, triethyl borate, tripropyl borate, tributyl borate, and cyclic borate ester compounds. However, these are merely examples. The use of borate esters other than these does not depart from the scope of the present disclosure.

[0035] Examples of organometallic compounds include zinc octoate, tin octoate, zinc naphthenate, cobalt naphthenate, tin stearate, zinc stearate, and aluminum acetylacetone complex. However, these are merely examples. The use of organometallic compounds other than these does not depart from the scope of the present disclosure.

[0036] Examples of organophosphorus compounds include tetraphenylphosphonium tetraphenylborate and triphenylphosphine. However, these are merely examples. The use of other organophosphorus compounds does not depart from the scope of the present disclosure.

[0037] Examples of quaternary ammonium salts include tetramethylammonium chloride, tetramethylammonium bromide, tetramethylammonium iodide, tetraethylammonium chloride, tetraethylammonium bromide, tetraethylammonium iodide, tetrabutylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium iodide, triethylbenzylammonium chloride, triethylbenzylammonium bromide, triethylbenzylammonium iodide, triethylphenethylammonium chloride, and triethylphenethylammonium bromide. However, these are merely examples. The use of quaternary ammonium salts other than these does not deviate from the scope of the present disclosure.

[0038] Examples of quaternary phosphonium salts include tetrabutylphosphonium chloride, tetrabutylphosphonium iodide, tetrabutylphosphonium acetate, tetraphenylphosphonium chloride, tetraphenylphosphonium bromide, tetraphenylphosphonium iodide, ethyltriphenylphosphonium chloride, ethyltriphenylphosphonium bromide, ethyltriphenylphosphonium iodide, ethyltriphenylphosphonium ethyl acetate, ethyltriphenylphosphonium phosphate, propyltriphenylphosphonium chloride, propyltriphenylphosphonium bromide, propyltriphenylphosphonium iodide, butyltriphenylphosphonium chloride, butyltriphenylphosphonium bromide, and butyltriphenylphosphonium iodide. However, these are merely examples. The use of quaternary phosphonium salts other than these does not depart from the scope of the present disclosure.

[0039] Examples of the amine complex include boron halide amine complexes, which are complexes of boron halides such as boron trifluoride, boron trichloride, and boron tribromide with amine compounds. Examples of the amine compound include aliphatic tertiary amines such as trimethylamine, tri-n-propylamine, N,N-dimethyloctylamine, and N,N-dimethylbenzylamine, aromatic tertiary amines such as N,N-dimethylaniline, heterocyclic tertiary amines such as substituted or unsubstituted imidazole or pyridine alkylated at the 1-position, aliphatic primary amines such as monoethylamine and n-hexylamine, aliphatic primary amines containing an aromatic ring such as benzylamine, aromatic primary amines such as aniline, and secondary amines such as piperidine. Representative examples of boron halide amine complexes include boron trifluoride monoethylamine complex, boron trifluoride diethylamine complex, boron trifluoride isopropylamine complex, boron trifluoride chlorophenylamine complex, boron trifluoride-triallylamine complex, boron trifluoride benzylamine complex, boron trifluoride aniline complex, boron trichloride monoethylamine complex, boron trichloride phenol complex, boron trichloride piperidine complex, boron trichloride dimethyl sulfide complex, boron trichloride N,N-dimethyloctylamine complex, boron trichloride N,N-dimethyldodecylamine complex, and boron trichloride N,N-diethyldioctylamine complex. However, these are merely examples. The use of amine complexes other than these does not deviate from the scope of the present disclosure.

[0040] Examples of imidazole compounds include 2-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-phenylimidazole, 1-benzyl-2-methylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-(2-cyanoethyl)-2-ethyl-4-methylimidazole, 2,4-diamino-6(2'-methylimidazole(1'))ethyl-s-tri ... azine, 2,4-diamino-6(2'-undecylimidazole(1'))ethyl-s-triazine, 2,4-diamino-6(2'-ethyl,4-methylimidazole(1'))ethyl-s-triazine, 2,4-diamino-6(2'-methylimidazole(1'))ethyl-s-triazine·isocyanuric acid adduct, 2-methylimidazole isocyanuric acid 2:3 adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-3,5-dihydroxymethylimidazole, 2-phenyl-4-hydroxymethyl-5-methylimidazole, and 1-cyanoethyl-2-phenyl-3,5-dicyanoethoxymethylimidazole. However, these are merely examples. The use of imidazole-based curing agents other than these does not deviate from the scope of the present disclosure.

[0041] Specific examples of acid anhydride curing agents include methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, and methylnadic anhydride. However, these are merely examples. The use of acid anhydride curing agents other than these does not depart from the scope of the present disclosure.

[0042] The amount of the epoxy group curing agent can be adjusted as appropriate depending on the type of thermosetting resin (A) and the type of curing agent. The amount of curing agent is preferably about 0.5 to 2 equivalents relative to the epoxy equivalent of the thermosetting resin (A). If the amount of curing agent is less than 0.5 equivalents, the curing of the thermosetting resin (A) may not proceed sufficiently. If the amount of curing agent is more than 2 equivalents, the heat resistance, mechanical properties, etc. of the cured product may be reduced.

[0043] 1.2.3. Curing accelerators for epoxy groups In addition to the above-mentioned epoxy curing agent, a curing accelerator may be used in combination to accelerate or control the curing reaction. Examples of the curing accelerator include tertiary amines and their salts, quaternary ammonium compounds, imidazole, and alkali metal alkoxides. However, these are merely examples. The use of a curing accelerator other than these does not depart from the scope of the present disclosure.

[0044] The amount of the curing accelerator to be added is preferably about 0.01% by mass or more and 30% by mass or less (more preferably about 0.05% by mass or more and 20% by mass or less) relative to the mass of the thermosetting resin (A). If the amount is less than 0.01% by mass, the accelerating effect may be small. If the amount is more than 30% by mass, the storage stability of the insulating resin composition (X) and the moldability of the cured product may be reduced.

[0045] 1.3. Polyfunctional vinyl monomer (C) The polyfunctional vinyl monomer (C) is a monomer derived from biomass material. The polyfunctional vinyl monomer (C) is optionally blended as one of the reactive diluents of the insulating resin composition (X). The polyfunctional vinyl monomer (C) is not limited to any particular monomer as long as it contributes to a radical polymerization reaction. However, it is preferable to use a monomer having two reactive groups, meth(acryloyl) groups or allyl groups, per molecule. Because such polyfunctional vinyl monomers (C) have two reactive groups per molecule, they are polymerized and completely incorporated during the curing process of the insulating resin composition (X), resulting in significantly less volatilization during the curing process. Therefore, adding the polyfunctional vinyl monomer (C) as a reactive diluent can reduce the viscosity of the insulating resin composition (X) and also suppress re-adsorption due to volatilization during curing heating. Furthermore, because the polyfunctional vinyl monomer (C) has multiple reactive groups, it actively participates in the polymerization reaction of the insulating resin composition (X) and can promote three-dimensional crosslinking of the insulating resin composition (X). This also makes it possible to improve the heat resistance and mechanical strength of the cured product (Y).

[0046] The amount of the polyfunctional vinyl monomer (C) may be within a range that ensures the amount of the monofunctional vinyl monomer (D), and from the viewpoint of mechanical strength and heat resistance, it is desirable that the amount be within a range of 3 wt % to 20 wt % of the total amount of the thermosetting resin (A), the polyfunctional vinyl monomer (C), and the monofunctional vinyl monomer (D).

[0047] 1.4. Monofunctional vinyl monomer (D) The monofunctional vinyl monomer (D) uses biomass materials as part of its raw material. The monofunctional vinyl monomer (D) is used mainly to adjust the viscosity of the insulating resin composition (X) as well as to adjust the crosslinking structure. In order to maintain the usable life of the insulating resin composition (X), the monofunctional vinyl monomer (D) is preferably a monofunctional one, with one functional group contributing to the reaction per molecule.

[0048] The monofunctional vinyl monomer (D) is a low-viscosity monomer having an ether or ester bond and a cyclic structure. Here, a vinyl monomer (D-1) having an isobornyl skeleton and a vinyl monomer (D-2) having a saturated hydrocarbon cyclic ether skeleton are used in combination. Examples of the vinyl monomer (D-1) having an isobornyl skeleton include isobornyl methacrylate and isobornyl acrylate. Examples of the vinyl monomer (D-2) having a saturated hydrocarbon cyclic ether skeleton include tetrahydrofurfuryl methacrylate and tetrahydrofurfuryl acrylate.

[0049] The amount of monofunctional vinyl monomer (D) is preferably as high as possible to increase the biomass content of the insulating resin composition (X) and thereby reduce environmental impact, and to facilitate drainage of the insulating resin composition (X) when the coil is removed from the immersion bath, thereby preventing the formation of a block of cured material on the coil and other components. On the other hand, although the monofunctional vinyl monomer (D) contributes to increasing the number of crosslinking points, it is a low-molecular-weight monomer, and some of it volatilizes during curing heating, so not all of it contributes to the curing reaction. Therefore, excessive amounts of the monofunctional vinyl monomer (D) reduce the mechanical strength of the cured product (Y). Therefore, the amount of the monofunctional vinyl monomer (D) must be adjusted within a range that achieves both the conflicting functions of increasing the biomass content, preventing the formation of a block of cured material, and ensuring the mechanical strength of the cured product (Y). From the viewpoints of increasing the biomass content and preventing the formation of a block of cured material, the amount of the monofunctional vinyl monomer (D) should be at least 60 wt %, preferably at least 65 wt %, of the total amount of the insulating resin composition (X). On the other hand, from the viewpoint of the mechanical strength of the cured product (Y), it is desirable that the amount of the monofunctional vinyl monomer (D) is 85 wt% or less, preferably 75 wt% or less, and more preferably 70 wt% or less of the total amount of the insulating resin composition (X). Therefore, in order to achieve both of the required two functions, the amount of the monofunctional vinyl monomer (D) is desirably 60 to 85 wt% of the total amount of the insulating resin composition (X), preferably 60 to 85 wt%, and more preferably 65 to 85 wt%.

[0050] In the monofunctional vinyl monomer (D), a monofunctional vinyl monomer having one meth(acryloyl) group or one allyl group per molecule may be blended in addition to the above-mentioned vinyl monomers (D-1) and (D-2). Examples of such monofunctional vinyl monomers include 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, lauryl methacrylate, ethoxydiethylene glycol methacrylate, 4-hydroxybutyl methacrylate, and n-octyl acrylate. These monofunctional vinyl monomers may be used alone or in combination.

[0051] 2. Method for producing insulating resin composition (X) and its cured product (Y) 2.1. Insulating resin composition (X) The insulating resin composition (X) can be produced by the following production method. The amounts of (A) to (D) are as described in the Examples and Comparative Examples. The mixing method can be any method known in the art, and is not particularly limited as long as it allows for uniform mixing.

[0052] (a) A mixture of a thermosetting resin, a polyfunctional vinyl monomer, and a monofunctional vinyl monomer The thermosetting resin (A) and the multifunctional vinyl monomer (C) are heated to approximately 50°C and weighed out so that the viscosity can be changed from a semi-solid state to fluidity. The monofunctional vinyl monomer (D) is added to this and stirred with a planetary centrifugal mixer until a homogeneous solution is obtained.

[0053] (b) Preparation of insulating resin composition (X) A radical polymerization initiator and a curing agent for epoxy groups (B) are uniformly mixed into the mixed solution of (A), (C) and (D) prepared in (a) above.

[0054] 2.2.Cured product (Y) The cured product (Y) is a cured product of the insulating resin composition (X). The cured product (Y) is typically produced by heating the insulating resin composition (X). The cured product (Y) is used in various forms and shapes depending on the application. The cured product (Y) can be molded into a desired shape by various molding methods such as impregnation, coating, casting, and sheet molding.

[0055] The cured product (Y) has excellent insulating properties and heat resistance. Therefore, the cured product (Y) is suitable for applications requiring at least one of insulating properties and heat resistance. The cured product (Y) is suitable for insulating materials for heavy electrical equipment such as rotating machines and power transmission and transformation equipment. Examples of insulating materials include varnishes, insulating paints, cable covering materials, insulating sheets, and sealing materials.

[0056] When the cured product (Y) is obtained by impregnating a coil of a rotating machine or the like with the insulating resin composition (X) and curing the impregnated product, the impregnation process for the coil is not particularly limited. Here, an example of a production method consisting of a total of five steps including a preheating step and an air-cooling step before impregnation, followed by the impregnation step, a dripping removal step, and a heat-curing step will be described.

[0057] The preheating process is an annealing process for improving the crazing resistance of a coil winding such as an enameled wire. In the preheating process, the coil is heated to a predetermined temperature. The heating temperature in the preheating process is not particularly limited as long as it can improve the crazing resistance, but the process is carried out at 150°C, for example.

[0058] The air-cooling step is a step of cooling the coil to a predetermined temperature in order to suppress a rise in temperature of the insulating resin composition (X). The temperature of the coil after cooling is not particularly limited as long as it is within a temperature range that does not affect the usable life of the insulating resin composition (X), but a temperature of 30°C to 50°C, for example, is suitable.

[0059] The impregnation process can be performed using methods known in the art, such as immersion, dripping, pressure impregnation, and vacuum impregnation. However, for coils of large rotating machines, impregnation is typically performed by immersion or pressure / vacuum impregnation. When immersion impregnation is performed, the coil is gently immersed in an impregnation bath filled with the insulating resin composition (X). While the immersion time is not particularly limited, especially for coils wound with a tightly aligned winding, air adhering between the enameled wires and on the components tends to form bubbles and rise to the surface. Therefore, it is desirable to immerse the coil until these bubbles cease to form. The time required for the bubbles to cease to form varies depending on the coil size, but for large rotating machines, the time required for the bubbles to cease to form is approximately 10 to 60 minutes. From the perspective of improving the efficiency (shortening) of the manufacturing process, approximately 15 to 30 minutes is desirable. Immersion times of less than 10 minutes do not allow the insulating resin composition (X) to penetrate the entire coil. Immersion times of more than 60 minutes, at which point the bubbles cease to form, do not increase the amount of insulating resin composition (X) that penetrates the coil. The impregnation temperature, i.e., the temperature of the insulating resin composition (X) in the impregnation tank, is not particularly limited as long as it is within a temperature range in which thickening due to curing does not begin. For most insulating resins, the temperature is set to room temperature, 25°C to 60°C. Since the insulating resin composition (X) has a low viscosity, impregnation can also be carried out at room temperature, 25°C.

[0060] In the heat-curing step, the insulating resin composition (X) impregnated into the coil in the impregnation step is heated in a curing furnace and cured to form a cured product (Y). The heating temperature in the heat-curing step is not particularly limited as long as it is equal to or higher than the reaction initiation temperature (half-life temperature) of the reaction initiator added to the insulating resin composition (X), and is generally 130°C to 180°C, preferably 140°C to 170°C. Generally, the heating time in the heat-curing step is affected by the curing rate of the insulating resin composition (X) and the amount of the composition attached to the coil, and also varies depending on the raw material composition. Furthermore, the time required for curing depends on the heating temperature, and generally, the higher the heating temperature, the shorter the time required for complete curing. Therefore, the heating temperature and heating time in the heat-curing step are set to the temperature and time required for complete curing depending on the composition of the insulating resin composition (X). Here, if the heating temperature or heating time is insufficient, the insulating resin composition (X) may not be completely cured, resulting in uncured portions. In this case, various properties of the cured product (Y), such as electrical properties, mechanical properties, and heat resistance, may be reduced. On the other hand, excessive heating temperature or heating time can disrupt the balance of the crosslinking reaction due to the curing heat, which may cause cracks to occur in the cured product (Y). The heating temperature and heating time are set within a range that does not cause these problems. The insulating resin composition (X) of the present disclosure is completely cured in 30 minutes to 8 hours at 130 to 180°C. Complete curing is not achieved with a curing time of less than 30 minutes. On the other hand, the mechanical strength (bonding strength of the electric wire) of the cured product (Y) gradually develops and improves after curing, and tends to converge after a certain time, here 4 hours or more. Therefore, from the viewpoint of complete curing and strength convergence, the heating time in the heat curing step is preferably 1 to 4 hours, more preferably 1 to 2 hours.

[0061] 2.3. Winding coil for rotating machine and stator using same The insulating resin composition (X) of the first embodiment is applied to, for example, a large rotating machine for a hoisting machine of a rope-type elevator. FIG. 2 is a cross-sectional view of the hoisting machine 10 according to the first embodiment.

[0062] The hoist 10 shown in FIG. 2 includes a rotating unit 11, a brake unit 12, and a motor unit 13.

[0063] Rotating section 11 includes sheave 14, rotor 15, brake disc 16, and rotating shaft 17. Sheave 14, rotor 15, and brake disc 16 are coaxially connected by rotating shaft 17. A main rope (not shown) is wound around sheave 14. An elevator car (not shown) supported by the main rope is driven by friction between the main rope and sheave 14.

[0064] The brake unit 12 includes a movable brake shoe (not shown). The brake unit 12 generates a force for braking the rotating unit 11 by friction generated by pressing the brake shoe against the brake disc 16.

[0065] The motor unit 13 includes a frame 18 and a stator 19. The stator 19 is fixed to the frame 18 by press fitting or shrink fitting. The stator 19 includes an annular iron core 20. A winding 21 is wound around each tooth of the iron core 20. The winding 21 and the iron core 20 are insulated by an insulator 22. The winding 21 is fixed by the insulator 22. The windings 21 wound around each tooth are connected to each other in a set order, and generate magnetic flux when current is applied.

[0066] The stator 19 is manufactured by a method including, for example, the following steps. First, wires insulated with enamel are prepared. The wires are conductive. The wires are made of, for example, copper, aluminum, or silver. The type of enamel is not particularly limited, but a combination of polyesterimide, polyamideimide, polyamide, and the like is used. The enamel insulating coating layer may contain an inorganic filler to improve the dielectric strength voltage. These enameled wires may be commercially available enameled wires for motor coils. The insulatingly coated enameled wires are wound around each tooth of the iron core 20 to form the windings 21. The windings 21 are then impregnated with the insulating resin composition (X) using the impregnation process described above, and the insulating resin composition (X) is cured using a heat curing process.

[0067] In the insulating resin composition (X), a low-molecular-weight monofunctional vinyl monomer (D) is used as a reactive diluent that reduces viscosity to improve impregnation into coils. Therefore, the insulating resin composition (X) easily penetrates into the interior of even the coils of large rotating machines, which have long and thick coils. Furthermore, the low viscosity of the insulating resin composition (X) prevents the formation of excess cured blocks. This improves the manufacturability of large rotating machines.

[0068] 3. Working Example The present disclosure will be described below with reference to examples, but the scope of the present disclosure is not limited to the examples.

[0069] 3.1. Production of insulating resin composition (X) and its cured product (Y) The insulating resin composition (X) and its cured product (Y) of each of the examples and comparative examples were produced as follows.

[0070] 3.1.1. Preparation of materials The following materials were prepared:

[0071] ·Thermosetting resin (A) A thermosetting resin that has both epoxy and meth(acryloyl) groups in one molecule, a number-average molecular weight of approximately 2000, and a viscosity of approximately 3900 mPa·s at 60°C. · Epoxy curing agent and radical polymerization initiator (B) Hardener: Zinc octoate Initiator: 2,5-dimethyl-2,5-di(t-butylperoxy)hexane Multifunctional vinyl monomers (C) Bis-A type epoxy acrylate with a weight average molecular weight of approximately 500 Monofunctional vinyl monomers (D) (D-1) Biomass-derived isobornyl methacrylate (D-2) Biomass-derived tetrahydrofurfuryl methacrylate (D-3) 2-Hydroxyethyl methacrylate (2-HEMA)

[0072] 3.1.1.1. Examples 1 to 9 The thermosetting resin (A) and the polyfunctional vinyl monomer (C) were preheated to 40°C to achieve a viscosity suitable for easy stirring. The thermosetting resin (A), polyfunctional vinyl monomer (C), and monofunctional vinyl monomer (D) were weighed out according to the blending amounts shown in Table 1 below. The weighed thermosetting resin (A), polyfunctional vinyl monomer (C), and monofunctional vinyl monomer (D) were then mixed and stirred using a planetary stirrer to obtain a uniform mixed solution. The epoxy group curing agent and radical polymerization initiator (B) were added to this mixed solution in the ratios shown in Table 1 below to obtain an insulating resin composition (X).

[0073] [Table 1]

[0074] In Table 1, the weight percentage (wt%) of the reaction initiator represents the weight ratio of the thermosetting resin (A) and the monofunctional vinyl monomer (D) to the total. Also, in Table 1, 1 phr represents the amount of curing agent blended per 100 parts by weight of the thermosetting resin (A), the polyfunctional vinyl monomer (C), and the monofunctional vinyl monomer (D). In the "Main Components" column for the monofunctional vinyl monomer (D) in Table 1, "(D-1), (D-2)" indicates that the monofunctional vinyl monomer (D) contains both isobornyl methacrylate (D-1) and tetrahydrofurfuryl methacrylate (D-2). In the same column, "(D-3)" indicates that the monofunctional vinyl monomer (D) contains 2-HEMA (D-3) instead of isobornyl methacrylate (D-1) and tetrahydrofurfuryl methacrylate (D-2). In the same column, "(D-1)" indicates that the monofunctional vinyl monomer (D) contains isobornyl methacrylate (D-1) but does not contain tetrahydrofurfuryl methacrylate (D-2). In the same column, "(D-2)" indicates that the monofunctional vinyl monomer (D) contains tetrahydrofurfuryl methacrylate (D-2) but does not contain isobornyl methacrylate (D-1).

[0075] 3.1.1.2. Comparative Examples 1 to 4 Insulating resin compositions were prepared in the same manner as in Examples 1 to 9, using the blending amounts shown in Table 1. As shown in Table 1, in Comparative Examples 1 and 2, the total blending amount of (D-1) and (D-2) exceeds 85 wt% of the total amount of insulating resin composition (X). In Comparative Examples 3 and 4, the total blending amount of (D-1) and (D-2) is less than 60 wt% of the total amount of insulating resin composition (X).

[0076] 3.1.1.3. Comparative Examples 5 and 6 An insulating resin composition (X) was prepared in the same manner as in Example 3, except that 2-HEMA (D-3) was used as the monofunctional vinyl monomer (D) in place of isobornyl methacrylate (D-1) and tetrahydrofurfuryl methacrylate (D-2) in accordance with the blending amounts shown in Table 1.

[0077] Comparative Example 7 An insulating resin composition (X) was prepared in the same manner as in Example 3, except that only isobornyl methacrylate (D-1) was used as the monofunctional vinyl monomer (D) in accordance with the blending amounts shown in Table 1.

[0078] 3.1.1.5. Comparative Example 8 An insulating resin composition (X) was prepared in the same manner as in Example 3, except that only tetrahydrofurfuryl methacrylate (D-2) was used as the monofunctional vinyl monomer (D) in accordance with the blending amounts shown in Table 1.

[0079] Evaluation The insulating resin composition (X) and its cured product (Y) were evaluated as follows.

[0080] 3.2.1. Biomass ratio The biomass content of the insulating resin composition (X) is 14 The measurement method was based on ASTM D6866, and the prepared insulating resin composition (X) was oxidized to carbon dioxide or graphitize, and then dissolved in a scintillator liquid to prepare a sample for measurement with a Liquid Scintillation Counter (LSC). Then, the radioactive carbon in this sample was measured using a liquid scintillation counter. 14 The number of C was measured, and the total carbon ( 12 C. 13 C. 14 The biomass ratio of the insulating resin composition (X) was calculated from the ratio of 14C in C). The results are shown in the "Biomass ratio" column of Table 1. 14 The method for measuring C is not limited to the above method, and for example, accelerator mass spectrometry (AMS) may be used.

[0081] 3.2.2. Viscosity The viscosity of the insulating resin composition (X) was measured using an E-type viscometer. The measurement results at room temperature are shown in the "total viscosity" column of Table 1.

[0082] 3.2.3. Mechanical strength (helical coil fixing strength) Helical coils were fabricated as test specimens using a 1 mm linear magnet wire (Hitachi Metals KMK-20E) according to JIS C 3216-1 and JIS C 3216-6. These helical coils were then preheated at 150°C for 120 minutes and then cooled to room temperature. These helical coils were gently immersed in the insulating resin composition (X), allowed to stand for 1 minute, then lifted and suspended in a heating furnace with an appropriate gap between them. These coils were heated for a predetermined time to cure the insulating resin composition (X). The heating conditions were 170°C for 2 hours. A three-point bending test was performed on the helical coils obtained by heat curing using an autograph (strength tester). The evaluation results are shown in the "Strength" column in Table 1. In this evaluation, a bond strength of 100 N or greater is desirable. A bond strength of 100 N or greater is rated as "+," a bond strength less than 100 N is rated as "-," and a bond strength exceeding 120 N is rated as "++."

[0083] 3.2.4. Formation of hardened block A sample simulating the stator 19 shown in FIG. 2 was prepared, impregnated with the insulating resin composition (X) shown in Table 1, and cured. The thickness of the cured block formed on the underside of the wound coil (coil end) and on the insulator was measured. The evaluation results are shown in the "Icicle" column in Table 1. In this evaluation, the necessity of removal processing was used as the criterion, with a thickness of 10 mm or more requiring cutting and grinding being rated as --, a thickness of 5 mm or more but less than 10 mm that did not require cutting but required grinding being rated as -, a thickness of 2 mm or more but less than 5 mm that required grinding in some places being rated as +, and a thickness of less than 2 mm that did not require grinding being rated as ++.

[0084] 3.2.5. Touchability The cured product of the insulating resin composition (X) formed on the surface of the coil or component of the sample simulating the helical coil and stator 19 was touched with a finger, and the finger tactility was evaluated based on whether or not the finger stuck to it. The evaluation results are shown in the "Finger Tactility" column in Table 1. In this evaluation, insulating resin composition (X) that stuck to the finger in a liquid or gel state was rated as --, that had a tacky feel but did not stick to the finger was rated as -, and that was tacky and smooth and did not stick to the finger was rated as +.

[0085] Overall evaluation The insulating resin composition (X) is required to have both mechanical strength and the ability to suppress the formation of a blocky cured product, as well as a good feel to the touch and a biomass content of 60% or more. The results of this comprehensive evaluation are shown in the "Judgment" column of Table 1. In Table 1, the final judgment results are shown, with a "+" indicating that all of these requirements are met and a "-" indicating that one or more of the requirements are not met.

[0086] 3.3. Results and Discussion As can be seen from Table 1, Examples 1 to 9 have improved finger touch properties compared to Comparative Examples 5 and 6. This is thought to be because the monofunctional vinyl monomers (D-1) and (D-2) having a cyclic skeleton and no hydroxyl group with a high degree of freedom in the molecule have an effect of suppressing moisture adsorption from the air.

[0087] Next, based on the results of Examples 1 to 9 and Comparative Examples 1 to 4, the amounts of the biomass-derived monofunctional vinyl monomers (D-1) and (D-2) added will be discussed.

[0088] The total amount of monofunctional vinyl monomers (D-1) and (D-2) was 82 wt% to 84 wt% in Examples 1 and 2, 65 wt% to 78 wt% in Examples 3 to 6, and 60 wt% to 64 wt% in Examples 7 to 9. In Examples 1 to 6, the thickness of the cured block was 2 mm or less, eliminating the need for removal, and the mechanical strength was also excellent, exceeding 100 N, a benchmark. In particular, Examples 3 to 6 achieved mechanical strengths exceeding 120 N. In Examples 7 to 9, the mechanical strength exceeded 100 N, while the thickness of the cured block was 2 mm to 5 mm. While Examples 7 to 9 cannot completely eliminate the process of removing the cured block, the process time and the number of areas requiring processing can be significantly reduced, resulting in improved productivity. In Examples 1 to 9, the viscosity of the insulating resin composition (X) as a whole was 10 mPa·s to 80 mPa·s. Furthermore, in Examples 1 to 9, good results were obtained with respect to the feel to the touch after curing.

[0089] On the other hand, in Comparative Examples 1 and 2, the combined amount of monofunctional vinyl monomers (D-1) and (D-2) exceeded 85 wt%. Although the thickness of the cured block was 2 mm or less, meaning removal was completely unnecessary, the required mechanical strength of 100 N was not achieved. Furthermore, some of the blocks were sticky to the touch. This is presumably due to the extremely high amount of monofunctional vinyl monomer, some of which volatilized in the curing oven without contributing to the curing reaction, filling the oven and redepositing on the coil surface. Furthermore, in Comparative Examples 3 and 4, where the combined amount of monofunctional vinyl monomers (D-1) and (D-2) was 57 wt% or less, the mechanical strength was rated +, but the thickness of the cured block exceeded 5 mm or 10 mm, resulting in a rating of - or --.

[0090] This is because the monofunctional vinyl monomer (D) contributes to improved drainage by reducing the viscosity of the insulating resin composition (X) and has the effect of suppressing the formation of a block of cured material, but because it has a low molecular weight and tends to volatilize during curing, it affects the mechanical strength and tactile feel of the cured material (Y). In other words, there is a trade-off between the suppression of block formation and the mechanical strength and tactile feel, depending on the amount of monofunctional vinyl monomer (D). As a result of extensive research in the present disclosure, it has been found that to achieve both of these properties, the amount of monofunctional vinyl monomer (D), particularly the amount of monofunctional vinyl monomers (D-1) and (D-2), should be 60 wt% to 84 wt%, and more preferably 65 wt% to 78 wt%.

[0091] Next, the effect of the monofunctional vinyl monomer having a cyclic structure will be discussed by comparing Example 3 and Comparative Example 5. Example 3 contains isobornyl methacrylate (D-1) and tetrahydrofurfuryl methacrylate (D-2), both of which have cyclic skeletons. Comparative Example 5 uses 2-HEMA (D-3) instead of these, with the same amount of monofunctional vinyl monomer (D). Both examples produce good results with a thickness of 2 mm or less in the cured block, but differences are observed in mechanical strength and tactile properties. Example 3, which uses a monofunctional vinyl monomer having a cyclic structure, has a mechanical strength of over 120 N and good tactile properties. On the other hand, Comparative Example 5, which uses 2-HEMA, has a mechanical strength of less than 100 N and shows no improvement in tactile properties. This is thought to be due to the fact that the molecular skeleton of the monofunctional vinyl monomer with a cyclic skeleton is stronger than that of 2-HEMA, which has a chain structure, and that the monofunctional vinyl monomer with a cyclic skeleton is highly hydrophobic (hydrophilicity is suppressed) because it does not have a hydroxyl group with a high degree of freedom.

[0092] Next, the effect of using two monofunctional vinyl monomers having a cyclic structure in combination will be discussed by comparing Example 3 with Comparative Examples 7 and 8. Example 3 contains both isobornyl methacrylate (D-1) and tetrahydrofurfuryl methacrylate (D-2), both of which have cyclic skeletons. Comparative Examples 7 and 8 contain only either isobornyl methacrylate (D-1) or tetrahydrofurfuryl methacrylate (D-2). While Example 3 exhibits good results, with a mechanical strength exceeding 100 N, Comparative Examples 7 and 8 show a slight decrease to less than 100 N. This is thought to be because the bulky isobornyl skeleton inhibits the crosslinking structure when isobornyl methacrylate (D-1) is used alone, preventing the required mechanical strength from being achieved. On the other hand, when tetrahydrofurfuryl methacrylate (D-2) is used alone, the required mechanical strength is likely to be lower than when the isobornyl skeleton is used, preventing the required mechanical strength from being achieved.

[0093] As explained above, in the insulating resin composition (X), the (C) polyfunctional vinyl monomer and the (D) polyfunctional vinyl monomer use plant-derived biomass materials as raw materials, and therefore have a greater effect in reducing the environmental impact than insulating resins made from petroleum-derived raw materials. Furthermore, the insulating resin composition (X) of the present disclosure can obtain biomass mark certification (containing 10% or more biomass materials) from the government or a third-party organization due to its blending ratio, and can contribute to the creation of a recycling-oriented society.

[0094] Furthermore, the monofunctional vinyl monomer (D) reduces the viscosity of the insulating resin composition (X) and improves the drainage of the insulating resin composition (X) when the coil is removed from the immersion bath, thereby preventing excess insulating resin composition (X) from adhering to the inside of the coil and the components, and suppressing the formation of a cured block.

[0095] In addition, among the monofunctional vinyl monomers (D) contained in the insulating resin composition (X), the vinyl monomer (D-1) having an isobornyl skeleton and the vinyl monomer (D-1) having a cyclic ether skeleton contain a cyclic skeleton in their molecules, resulting in superior heat resistance and strength compared to vinyl monomers with chain structures. As mentioned above, adding a reactive diluent is effective for lowering the viscosity of insulating resins. However, adding large amounts of monofunctional monomers with a chain structure and low molecular weight to achieve the required viscosity reduces the heat resistance and mechanical strength of the cured product. In contrast, the vinyl monomer (D-1) having an isobornyl skeleton and the vinyl monomer (D-1) having a cyclic ether skeleton used in the present disclosure have superior thermal and mechanical properties compared to monomers with chain structures due to the effect of the cyclic structure in their molecules. Therefore, even when these monomers are blended in large amounts, the heat resistance and strength properties of the cured product (Y) are not reduced, and the heat resistance and strength properties are improved.

[0096] Furthermore, the vinyl monomer (D-1) having an isobornyl skeleton and the vinyl monomer (D-1) having a cyclic ether skeleton do not have a highly flexible hydroxyl group in the molecule, and therefore are less hydrophilic than 2-HEMA, which is used as a reactive diluent. In other words, their low affinity with moisture in the air prevents redeposition of the insulating resin composition (X) on the surface of the cured product (Y), thereby improving the surface tactility.

[0097] In the present disclosure, the vinyl monomer (D-1) having an isobornyl skeleton and the vinyl monomer (D-1) having a cyclic ether skeleton are biomass materials, and are contained in the monofunctional vinyl monomer (D) at a ratio of approximately 60 wt% to 84 wt% as main components. Therefore, the biomass content of the insulating resin composition (X) is determined by the blending amounts of the vinyl monomer (D-1) having an isobornyl skeleton and the vinyl monomer (D-1) having a cyclic ether skeleton, and is 60% or more and 84% or less.

[0098] Therefore, due to the effects described above, an insulating resin composition (X) is provided which uses a biomass material as a raw material and can provide a cured product with improved surface tactility.

[0099] The scope of the present disclosure is not limited to the examples described above, but should be defined by the claims. The scope of the present disclosure includes all modifications within the meaning equivalent to the claims. The scope of the present disclosure also includes all modifications within the scope equivalent to the claims. [Industrial Applicability]

[0100] The rotating machine according to the present disclosure can be applied to the hoisting machine of a rope-type elevator. The wound coil according to the present disclosure can be applied to the rotating machine. The insulating resin composition and its cured product according to the present disclosure can be used to maintain the insulation properties and mechanical strength of the coil. [Explanation of symbols]

[0101] 1 coil, 2 insulating resin, 3 volatilized reactive diluent, 4 moisture, 5 thin film, 10 hoist, 11 rotating part, 12 brake part, 13 motor part, 14 sheave, 15 rotor, 16 brake disc, 17 rotating shaft, 18 frame, 19 stator, 20 iron core, 21 winding, 22 insulator

Claims

1. a thermosetting resin having both an epoxy group and a meth(acryloyl) group; a radical polymerization initiator and a curing agent for epoxy groups; a polyfunctional vinyl monomer derived from a biomass material; a monofunctional vinyl monomer derived from a biomass material; Including, The monofunctional vinyl monomer is a vinyl monomer having an isobornyl skeleton, and Vinyl monomers with a saturated hydrocarbon cyclic ether skeleton Includes both the vinyl monomer having a saturated hydrocarbon cyclic ether skeleton is tetrahydrofurfuryl methacrylate or tetrahydrofurfuryl acrylate, the total amount of the vinyl monomer having an isobornyl skeleton and the vinyl monomer having a saturated hydrocarbon cyclic ether skeleton is 60 wt % or more and 84 wt % or less; Insulating resin composition.

2. The viscosity is 10 mPa·s or more and 80 mPa·s or less, The insulating resin composition according to claim 1 .

3. A cured product obtained by curing the insulating resin composition described in claim 1 or claim 2.

4. A wound coil impregnated with the insulating resin composition described in claim 1 or claim 2.

5. It is a rotating machine used in the hoisting machine that drives the cage of a rope elevator. A stator using the winding coil according to claim 4. A rotating machine comprising:

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