JP7187725B1 - Curable composition and electric member - Google Patents

Abstract

A curable composition having excellent adhesion and strength is provided. A curable composition according to an embodiment comprises (A) a heterocyclic (meth)acrylate having a five- or six-membered heterocyclic ring containing an oxygen atom, (B) an alicyclic (meth) (C) a (meth)acrylate other than the component (A) and the component (B), which has a molecular weight or weight average molecular weight of 200 to 30,000 and a number of functional groups of 1 or 2. . The total content of components (A) and (B) is 70 to 95 parts by mass per 100 parts by mass of components (A) to (C). The mass ratio (A)/(B) of the content of component (A) to the content of component (B) is 0.6-20. [Selection figure] None

Description

The present invention relates to a curable composition and an electrical member using the same.

In electrical members, exposed metal portions such as terminals are coated or sealed with resin to prevent metal corrosion. A curable composition that is cured by heat or light is used as a resin composition for such corrosion protection of electrical members.

Patent Document 1 discloses, as a thermosetting composition capable of forming a cured product having excellent sealability, a composition containing polybutadiene having a (meth)acryloyl group at its end and a thermal polymerization initiator. Patent Document 1 discloses that a (meth)acrylate compound may be used in combination, and in particular, a (meth)acrylate compound in which an alicyclic hydrocarbon group is ester-bonded is used as the compound.

Japanese Patent Application Laid-Open No. 2021-54902

However, in Patent Document 1, an oxygen atom-containing heterocyclic (meth)acrylate is used together with an alicyclic (meth)acrylate, and these are combined with a (meth)acrylate having a specific molecular weight in a predetermined ratio. is not disclosed.

Curable compositions for preventing corrosion of metals in electrical members are required to have excellent adhesion to metals. It wasn't.

In view of the above points, an object of the embodiments of the present invention is to provide a curable composition having excellent adhesion and strength.

The present invention includes embodiments shown below.
[1] (A) a heterocyclic (meth)acrylate having a five- or six-membered heterocyclic ring containing an oxygen atom, (B) an alicyclic (meth)acrylate, and (C) the above (A) a (meth)acrylate other than the component and the component (B) having a molecular weight or weight average molecular weight of 200 to 30000 and a functional group number of 1 or 2, the component (A), The total content of the component (A) and the component (B) is 70 to 95 parts by mass with respect to the total content of the component (B) and the component (C) of 100 parts by mass, and the component (B) A curable composition, wherein the mass ratio (A)/(B) of the content of component (A) to the content of component is 0.6-20.
[2] The curable composition according to [1], which contains a polybutadiene structure-containing (meth)acrylate having a weight average molecular weight of 200 to 30,000 and 1 or 2 functional groups as the component (C).
[3] The curable composition according to [1], which contains a urethane (meth)acrylate having a molecular weight or weight average molecular weight of 200 to 30,000 and having 1 or 2 functional groups as the component (C).
[4] As the component (C), a polybutadiene structure-containing (meth)acrylate having a weight average molecular weight of 200 to 30,000 and a functional group number of 1 or 2, and a molecular weight or a weight average molecular weight of 200 to 30,000, and The curable composition according to [1], comprising a urethane (meth)acrylate having 1 or 2 functional groups.
[5] The curable composition according to any one of [1] to [4], wherein the heterocyclic ring of component (A) is a saturated heterocyclic ring.
[6] The total content of the component (A), the component (B) and the component (C) with respect to 100% by mass of the curable composition is 80% by mass or more, [1] to [5] A curable composition according to any one of claims 1 to 3.
[7] The curable composition according to any one of [1] to [6], which is used for electrical members.
[8] A cured product obtained by curing the curable composition according to any one of [1] to [7].
[9] An electrical member containing the cured product of [8].

According to the embodiments of the present invention, it is possible to provide a curable composition having excellent adhesion and strength.

The curable composition according to this embodiment is a curable resin composition containing the following components (A), (B) and (C).
(A) a heterocyclic (meth)acrylate containing an oxygen atom (B) an alicyclic (meth)acrylate (C) a (meth)acrylate other than the above components (A) and (B)

As used herein, "(meth)acrylate" represents at least one of acrylate and methacrylate. "(Meth)acrylic acid" represents at least one of acrylic acid and methacrylic acid. A "(meth)acryloyl group" represents at least one of an acryloyl group and a methacryloyl group. A "(meth)acryloyloxy group" represents at least one of an acryloyloxy group and a methacryloyloxy group.

[(A) heterocyclic (meth)acrylate]
In the present embodiment, the component (A) is a heterocyclic (meth)acrylate having a five- or six-membered heterocyclic ring containing an oxygen atom (hereinafter referred to as heterocyclic (meth)acrylate (A)). is used. The heterocyclic (meth)acrylate (A) is a compound having the above heterocycle and a (meth)acryloyl group in the molecule. Heterocyclic (meth)acrylate (A) is involved in improving adhesion to metals.

The above heterocycles may be saturated or unsaturated, but are preferably saturated heterocycles. The heterocyclic ring may have one or two oxygen atoms as heteroatoms. The above heterocyclic ring may have only an oxygen atom as a heteroatom, but may have other heteroatoms such as a nitrogen atom and a sulfur atom together with the oxygen atom. Preferably, the heteroatoms are only oxygen atoms. Specific examples of the heterocyclic ring include tetrahydrofuran ring, dioxolane ring, tetrahydropyran ring, 1,2-dioxane ring, 1,3-dioxane ring and 1,4-dioxane ring.

The heterocyclic (meth)acrylate (A) may be a polyfunctional (meth)acrylate having a plurality of (meth)acryloyl groups, but is preferably a monofunctional (meth)acrylate having one (meth)acryloyl group. . In the heterocyclic (meth)acrylate (A), the (meth)acryloyloxy group may be directly bonded to the carbon atom of the heterocyclic ring, or may be bonded via a linking group. In one embodiment, the (meth)acryloyloxy group may be attached to the heterocycle via a C1-C6 alkanediyl group, for example via a methylene group. The heterocyclic ring may have a substituent other than the (meth)acryloyloxy group, or may be unsubstituted. Although the substituent is not particularly limited, a hydrocarbon group is preferred. For example, the heterocyclic ring may have one or more C 1-6 hydrocarbon groups (eg, alkyl groups) as substituents.

Examples of the heterocyclic (meth)acrylate (A) include
(A1) those having a (meth)acryloyloxy group bonded to a substituted or unsubstituted tetrahydrofuran ring via an alkanediyl group having 1 to 6 carbon atoms (e.g., tetrahydrofurfuryl (meth)acrylate);
(A2) Those having a (meth)acryloyloxy group bonded to a substituted or unsubstituted dioxolane ring through an alkanediyl group having 1 to 6 carbon atoms (for example, (2-methyl-2-ethyl-1,3- dioxolan-4-yl)methyl (meth)acrylate),
(A3) those having a (meth)acryloyloxy group bonded to a substituted or unsubstituted dioxane ring via an alkanediyl group having 1 to 6 carbon atoms (e.g., cyclic trimethylolpropane formal (meth)acrylate);
(A4) substituted or unsubstituted tetrahydrofurfuryl alcohol (meth)acrylic acid polymeric esters, and the like. Any one of these may be used, or two or more thereof may be used in combination.

In one embodiment, heterocyclic (meth)acrylate (A) is tetrahydrofurfuryl (meth)acrylate, (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, At least one selected from the group consisting of cyclic trimethylolpropane formal (meth)acrylate and tetrahydrofurfuryl alcohol (meth)acrylic acid polymeric ester may be used.

Commercially available heterocyclic (meth)acrylates (A) include, for example, tetrahydrofurfuryl acrylate ("Viscoat #150, THFA" manufactured by Osaka Organic Chemical Industry Co., Ltd., "Light Acrylate THF-A" manufactured by Kyoeisha Chemical Co., Ltd. ), tetrahydrofurfuryl methacrylate ("Light ester THF (1000)" manufactured by Kyoeisha Chemical Co., Ltd.), (2-methyl-2-ethyl-1,3-dioxolan-4-yl) methyl (meth) acrylate (Osaka organic "MEDOL-10" manufactured by Kagaku Kogyo Co., Ltd.), cyclic trimethylolpropane formal acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd. "Viscoat #200, CTFA"), tetrahydrofurfuryl alcohol acrylic acid multimeric ester represented by the following formula (“Viscoat #150D” manufactured by Osaka Organic Chemical Industry Co., Ltd.) and the like.

[(B) Alicyclic (meth)acrylate]
In this embodiment, an alicyclic (meth)acrylate (hereinafter referred to as alicyclic (meth)acrylate (B)) is used as the component (B). The alicyclic (meth)acrylate (B) is a compound having an alicyclic hydrocarbon group and a (meth)acryloyl group, which are carbocyclic rings having no aromaticity, in the molecule. The alicyclic (meth)acrylate (B) has good wettability to metals and small cure shrinkage, so it contributes to the improvement of adhesion.

The above alicyclic hydrocarbon group may be saturated or unsaturated, but is preferably a saturated carbocyclic ring. Alicyclic hydrocarbon groups may be monocyclic or polycyclic. The alicyclic hydrocarbon group preferably has 6 or more ring-forming carbon atoms, more preferably 6-10.

The alicyclic (meth)acrylate (B) may be a polyfunctional (meth)acrylate having a plurality of (meth)acryloyl groups or a monofunctional (meth)acrylate having one (meth)acryloyl group. In the alicyclic (meth)acrylate (B), the (meth)acryloyloxy group may be directly bonded to the alicyclic hydrocarbon group, or may be bonded via a linking group. When bonding via a linking group, the (meth)acryloyloxy group may be bonded to the alicyclic hydrocarbon group via an alkanediyl group having 1 to 6 carbon atoms, for example, via a methylene group. may The alicyclic hydrocarbon group may have a substituent other than the (meth)acryloyloxy group, or may be unsubstituted. The substituent is not particularly limited, but is preferably a hydrocarbon group. For example, an alicyclic hydrocarbon group may have one or more C 1-6 hydrocarbon groups (eg, alkyl groups) as substituents.

As the alicyclic (meth)acrylate (B), for example,
(B1) those having a (meth)acryloyloxy group directly bonded to a substituted or unsubstituted norbornane ring (e.g., isobornyl (meth)acrylate),
(B2) Those having a (meth)acryloyloxy group directly bonded to a substituted or unsubstituted cyclohexyl ring (e.g., t-butylcyclohexyl (meth)acrylate, 3,3,5-trimethylcyclohexyl (meth)acrylate, cyclohexyl ( meth) acrylate),
(B3) Those having a (meth)acryloyloxy group bonded to a substituted or unsubstituted tricyclodecane ring through an alkanediyl group having 1 to 6 carbon atoms (e.g., dimethylol-tricyclodecane di(meth)acrylate)
(B4) Those having a substituted or unsubstituted dicyclopentenyl ring or a (meth)acryloyloxy group bonded directly or via an oxyalkylene group having 1 to 4 carbon atoms to a dicyclopentenyl ring (e.g., dicyclopentenyl oxyethyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentanyl (meth)acrylate)
etc. Any one of these may be used, or two or more thereof may be used in combination.

In one embodiment, cycloaliphatic (meth)acrylate (B) is isobornyl (meth)acrylate, t-butylcyclohexyl (meth)acrylate, 3,3,5-trimethylcyclohexyl (meth)acrylate, cyclohexyl (meth)acrylate , dimethylol-tricyclodecane di (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, dicyclopentenyl (meth) acrylate, and at least one selected from the group consisting of dicyclopentanyl (meth) acrylate .

Examples of commercially available alicyclic (meth)acrylates (B) include isobornyl acrylate (“Viscoat IBXA” manufactured by Osaka Organic Chemical Industry Co., Ltd., “Light acrylate IB-XA” manufactured by Kyoeisha Chemical Co., Ltd.), iso Bornyl methacrylate (“Light Ester IB-X” manufactured by Kyoeisha Chemical Co., Ltd.), 4-t-butylcyclohexyl acrylate (“TBCHA” manufactured by KJ Chemicals Co., Ltd.), 3,3,5-trimethylcyclohexyl acrylate (Osaka Organic Chemical Industry "Viscoat #196, TMCHA" manufactured by Co., Ltd.), cyclohexyl acrylate ("Viscoat #155, CHA" manufactured by Osaka Organic Chemical Industry Co., Ltd.), dimethylol-tricyclodecane diacrylate (manufactured by Kyoeisha Chemical Co., Ltd. "Light acrylate DCP-A ”), dicyclopentenyloxyethyl methacrylate (“FA-512M” manufactured by Showa Denko Materials Co., Ltd.), dicyclopentenyl acrylate (“FA-511A” manufactured by Showa Denko Materials Co., Ltd.), dicyclopentenyloxyethyl acrylate ( "FA-512A" manufactured by Showa Denko Materials Co., Ltd.), dicyclopentanyl acrylate ("FA-513A" manufactured by Showa Denko Materials Co., Ltd.), and the like.

[(C) (meth)acrylates other than the above components (A) and (B)]
In the present embodiment, the (C) component is a (meth)acrylate other than the above components (A) and (B), having a molecular weight or weight average molecular weight of 200 to 30000 and a functional group number of 1 or 2. A certain (meth)acrylate (hereinafter referred to as (meth)acrylate (C)) is used. (Meth)acrylate (C) contributes to the improvement of adhesion when blended together with components (A) and (B). The (meth)acrylate (C) having the above molecular weight and number of functional groups may be used alone, or two or more thereof may be used. The number of functional groups is the number of (meth)acryloyl groups contained in one molecule.

Here, regarding the above molecular weight or weight average molecular weight, when the (meth)acrylate (C) is a compound having a single structure, the molecular weight is used, and when it has a molecular weight distribution like a polymer or oligomer uses its weight average molecular weight (Mw). When the (meth)acrylate (C) has a molecular weight or weight average molecular weight of 200 or more, flexibility can be imparted to the cured product, and adhesion to metals and the like can be improved. The weight average molecular weight of (meth)acrylate (C) is measured by the GPC method (gel permeation chromatography method) under the following conditions, and using a calibration curve prepared from the molecular weight and elution time of standard polystyrene, the measurement sample It can be calculated from the elution time.
Column: TSKgel Hxl (Tosoh Corporation)
Mobile phase: THF (tetrahydrofuran)
Mobile phase flow rate: 1.0 mL/min
Column temperature: 40°C
Sample injection volume: 50 μL
Sample concentration: 0.2% by mass

By using a (meth)acrylate (C) having 1 or 2 functional groups, it is possible to impart flexibility to the cured product and improve adhesion to metals and the like. As the (meth)acrylate (C), only those with 1 functional group may be used, only those with 2 functional groups may be used, and those with 1 functional group and those with 2 functional groups may be used in combination. good.

As (meth)acrylate (C), it is preferable to use (C1) polybutadiene structure-containing (meth)acrylate and/or (C2) urethane (meth)acrylate. That is, in one embodiment, the (meth)acrylate (C) includes (C1) a polybutadiene structure-containing (meth)acrylate having a weight average molecular weight of 200 to 30,000 and a number of functional groups of 1 or 2, and (C2) a molecular weight or weight average It preferably contains at least one selected from the group consisting of urethane (meth)acrylates having a molecular weight of 200 to 30,000 and one or two functional groups.

The polybutadiene structure-containing (meth)acrylate of component (C1) is a (meth)acrylate having a polybutadiene structure, for example, one having a (meth)acryloyl group at the end of the polybutadiene molecule, or having a hydroxy group at the end of the polybutadiene molecule. Examples include those obtained by reacting a polyol with a polyisocyanate and further with a hydroxyl group-containing (meth)acrylate. The double bonds of the polybutadiene skeleton may be hydrogenated. The number of functional groups of component (C1) is preferably bifunctional, and for example, polybutadiene di(meth)acrylate having (meth)acryloyl groups at both ends of polybutadiene is preferably used.

The (meth)acrylate of component (C1) preferably has a weight average molecular weight of 1,000 to 30,000, more preferably 3,000 to 20,000, and still more preferably 5,000 to 15,000.

The urethane (meth)acrylate of component (C2) is a compound having a (meth)acryloyl group and a urethane bond in the molecule.

As the urethane (meth)acrylate of component (C2), for example, (C2-1) obtained by reacting a terminal hydroxy group-containing urethane prepolymer obtained by reacting polyol and polyisocyanate with (meth)acrylic acid. (C2-2) obtained by reacting a terminal isocyanate group-containing urethane prepolymer obtained by reacting a polyol and a polyisocyanate with a hydroxyl group-containing (meth)acrylate; (C2-3) an isocyanate compound Examples thereof include those obtained by reacting a hydroxy group-containing (meth)acrylate.

Examples of polyols in the component (C2) include polyether-based polyols, polyester-based polyols, and polycarbonate-based polyols. Examples of polyisocyanates include aromatic diisocyanates, aliphatic diisocyanates, and alicyclic diisocyanates. Examples of hydroxy group-containing (meth)acrylates include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, ethylene glycol mono(meth)acrylate, and propylene glycol mono(meth)acrylate.

Regarding the number of functional groups of component (C2), the above (C2-1) and (C2-2) are preferably bifunctional, and the above (C2-3) is preferably monofunctional.

Regarding the molecular weight or weight average molecular weight of the (meth)acrylate of component (C2), the weight average molecular weight of (C2-1) and (C2-2) is preferably 1,000 to 30,000, more preferably 5,000 to 30,000. Yes, more preferably 10,000 to 30,000. The molecular weight or weight average molecular weight of (C2-3) is preferably from 200 to 5,000, more preferably from 200 to 2,000, still more preferably from 200 to 1,000.

When the curable composition contains both the (C1) component and the (C2) component as the (C) component, the mass ratio (C1)/(C2) of the contents of the (C1) component and the (C2) component is Although not particularly limited, it is preferably 0.2 to 5, more preferably 0.3 to 3, and may be 0.4 to 1. Here, when the (C1) component and the (C2) component are used together, those having a polybutadiene structure together with the (meth)acryloyl group and the urethane bond are not the (C2) component but the (C1) component, (C1)/( Calculate the mass ratio of C2).

[(D) polymerization initiator]
The curable composition according to the present embodiment may further contain (D) a polymerization initiator. (D) The polymerization initiator is not particularly limited as long as it can initiate the radical polymerization of the components (A), (B) and (C). (D) The polymerization initiator may be (D1) a photopolymerization initiator, (D2) a thermal polymerization initiator, or both may be used in combination.

(D1) Photopolymerization initiators include, for example, alkylphenone compounds, acylphosphine oxide compounds, oxime ester compounds, thioxanthone compounds, and anthraquinone compounds. These may be used singly or in combination of two or more.

Examples of alkylphenone compounds include benzyl methyl ketal compounds such as 2,2′-dimethoxy-1,2-diphenylethan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1 -hydroxycyclohexylphenyl ketone, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1-{4-[4-(2 α-hydroxyalkylphenone compounds such as -hydroxy-2-methylpropionyl)benzyl]phenyl}-2-methylpropan-1-one, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropane-1 -one, 2-benzylmethyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone and other aminoalkylphenone compounds. Examples of acylphosphine oxide compounds include phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide and diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide. These can be used either singly or in combination of two or more.

(D2) Thermal polymerization initiators include, for example, azo compounds such as azobisisobutyronitrile (AIBN), 1,1′-azobis(cyclohexanecarbonitrile) (ABCN), di-t-butyl peroxide, t- Examples include organic peroxides such as butyl hydroperoxide, t-butyl peroxypivalate, benzoyl peroxide, and methyl ethyl ketone peroxide. These may be used singly or in combination of two or more.

(D) As the polymerization initiator, when both the (D1) photopolymerization initiator and the (D2) thermal polymerization initiator are included, the mass ratio of the content of the component (D1) and the component (D2) (D1)/( D2) is not particularly limited, but is preferably from 0.3 to 10, more preferably from 0.5 to 5, and may be from 1 to 3.

[(E) cross-linking agent]
The curable composition according to this embodiment may further contain (E) a cross-linking agent. Examples of cross-linking agents include tri- or higher functional (meth)acrylates. Specific examples include trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, and pentaerythritol tetra(meth)acrylate. These may be used singly or in combination of two or more.

[Other additives]
In addition to the components described above, the curable composition according to the present embodiment may optionally contain additives such as antioxidants, polymerization inhibitors, colorants, and antifungal agents. can be added as long as it does not impair the purpose of In addition, the curable composition may contain (meth)acrylates other than the above components (A), (B), (C) and (E) within a range that does not impair the purpose of the present embodiment. .

[Curable composition]
In the curable composition according to the present embodiment, the contents of component (A) and component (B) are set as follows. The total content of components (A) and (B) is 70 to 95 parts by mass with respect to the total content of components (A), (B) and (C) of 100 parts by mass. Therefore, the content of component (C) is 5 to 30 parts by mass with respect to the total content of 100 parts by mass. When the total content of components (A) and (B) is 70 parts by mass or more, adhesion, particularly adhesion to metals, can be improved. Moreover, when the total content is 95 parts by mass or less, flexibility can be imparted to the cured product, and adhesion can be improved.

In the curable composition, the mass ratio (A)/(B) of the content of component (A) to the content of component (B) is 0.6-20. When (A)/(B) is 0.6 or more, adhesion to metal can be improved. When (A)/(B) is 20 or less, the strength can be improved. (A)/(B) is preferably 0.7-16, more preferably 0.8-10.

The curable composition may consist only of components (A), (B) and (C), but usually further contains (D) a polymerization initiator. The content of component (D) with respect to 100 parts by mass of the total content of components (A), (B) and (C) is not particularly limited, but is preferably 0.1 to 10 parts by mass, and more It is preferably 0.5 to 5 parts by mass, and may be 1 to 3 parts by mass.

When the curable composition contains (E) a cross-linking agent, the content of (E) a cross-linking agent is not particularly limited. It may be 0.1 to 10 parts by mass, 0.3 to 5 parts by mass, or 0.5 to 3 parts by mass.

The total content of components (A), (B) and (C) is preferably 80% by mass or more, more preferably 90% by mass or more, relative to 100% by mass of the curable composition. Preferably, it is 95% by mass or more. The upper limit of the total content of components (A), (B) and (C) is not particularly limited, and may be, for example, 99.9% by mass or less, 99.5% by mass or less, or 99% by mass or less. good.

The curable composition according to this embodiment is cured by light and/or heat to obtain a cured product. Specifically, when (D) a polymerization initiator (D1) contains a photopolymerization initiator, it is mainly cured by light, and when it contains (D2) a thermal polymerization initiator, it is mainly cured by heat.

The use of the curable composition according to the present embodiment is not particularly limited, but it is preferably used for electrical members such as electronic control unit (ECU) substrates, coils, and connectors. Specifically, the curable composition has excellent adhesion to metals such as copper and aluminum and resins such as glass epoxy resin, and has a high volume resistivity. It is preferably used for stopping. Corrosion of the metal in the exposed portion can be prevented by shielding the exposed portion of the metal from the external environment containing moisture by means of the cured product of the curable composition. Therefore, the curable composition according to the present embodiment is preferably used as a corrosion-resistant resin composition for electrical members. In addition, since the cured product has a high volume resistivity, it can be used as a resin composition for insulation and sealing in electrical members.

The curable composition will be described in detail below based on examples, but the present invention is not limited thereto.

Raw materials used in Examples and Comparative Examples are shown below.

[Heterocyclic (meth)acrylate (A)]
・THFA: Tetrahydrofurfuryl acrylate ("Viscoat #150, THFA" manufactured by Osaka Organic Chemical Industry Co., Ltd.)
・CTFA: cyclic trimethylolpropane formal acrylate ("Viscoat #200, CTFA" manufactured by Osaka Organic Chemical Industry Co., Ltd.)

[Alicyclic (meth)acrylate (B)]
・ IBXA: Isobornyl acrylate ("Viscoat IBXA" manufactured by Osaka Organic Chemical Industry Co., Ltd.)
・ TBCHA: 4-t-butylcyclohexyl acrylate (“TBCHA” manufactured by KJ Chemicals Co., Ltd.)

・ＵＮ６２０７：ポリエーテル系ウレタンアクリレート（根上工業株式会社製「ＵＮ－６２０７」、Ｍｗ：２７０００、官能基数：２）
・ＫＲＭ９２７６：ウレタンアクリレート（ダイセル・オルネクス株式会社製「ＫＲＭ９２７６」、Ｍｗ：２１５、官能基数：１） [(Meth)acrylate (C)]
BAC-45: polybutadiene diacrylate represented by the following formula ("BAC-45" manufactured by Osaka Organic Chemical Industry Co., Ltd., Mw: 10000, number of functional groups: 2)

・ UN6207: Polyether-based urethane acrylate ("UN-6207" manufactured by Negami Kogyo Co., Ltd., Mw: 27000, number of functional groups: 2)
・KRM9276: urethane acrylate (“KRM9276” manufactured by Daicel Allnex Co., Ltd., Mw: 215, number of functional groups: 1)

[Initiator (D)]
・Initiator 1: α-hydroxyalkylphenone ("Omnirad 184" manufactured by IGM Resins B.V.)
・Initiator 2: diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide ("Omnirad TPO" manufactured by IGM Resins B.V.)
・ Initiator 3: t-butyl peroxypivalate ("Perbutyl PV" manufactured by NOF Corporation)

[Other ingredients]
・Methyl acrylate: molecular weight 86
- TMPTA: trimethylolpropane triacrylate (crosslinking agent, molecular weight: 296.3, number of functional groups: 3)

[Examples 1 to 17 and Comparative Examples 1 to 16]
According to the formulations (parts by mass) shown in Tables 1 to 3 below, each component was mixed and stirred to prepare curable compositions of Examples 1 to 17 and Comparative Examples 1 to 16. "A+B+C" in the table indicates the total parts by weight of components (A), (B) and (C). "A+B" indicates the total parts by mass of components (A) and (B) with respect to 100 parts by mass of the total content of components (A), (B) and (C). "A/B" indicates the mass ratio of the content of component (A) to the content of component (B).

Adhesion, tensile strength, tensile elongation, and specific volume resistivity were measured and evaluated for each curable composition. The measurement and evaluation methods are as follows.

[Adhesion]
A copper plate, an aluminum plate and a glass epoxy substrate were used as substrates. Each curable composition was applied to the substrate using a bar coater to a thickness of 100 μm, and the curable composition was cured using an ultraviolet (UV) irradiation device as a curing device. As the UV irradiation device, a belt conveyor type UV curing device (trade name: CSN2-40A, manufactured by GS Yuasa) equipped with a metal halide lamp was used. Irradiation conditions were an integrated illuminance of 2000 mJ/cm ² . The cured product (cured product layer) on the substrate was subjected to a cross-cut test specified in JIS-K5600-5-6:1999, and the adhesion was evaluated by the number of remaining squares. When the number of remaining squares was less than 60, it was evaluated as x; The adhesion to the glass epoxy substrate, copper plate and aluminum plate is shown as "adhesion GFRP", "adhesion Cu" and "adhesion Al", respectively.

[Tensile strength, tensile elongation]
A tensile test was performed using a universal testing machine to evaluate tensile strength (MPa) and tensile elongation (%). Specifically, a mold release agent is applied to a stainless steel plate, a 12 cm × 12 cm enclosure is formed on it with a backer, a predetermined amount of curable composition liquid is added so that the thickness of the cured product is 1 mm, and the LED - Cured with a UV irradiator. The obtained cured product sheet was punched out with a dumbbell to prepare a test piece for a tensile test. A tensile test (tensile speed: 200 mm/min) was performed using an Autograph (precision universal testing machine) manufactured by Shimadzu Corporation, and strength (tensile strength) and elongation (tensile elongation) were measured when the test piece broke. Tensile strength was evaluated as ◯ when 1 MPa or more, and as x when less than 1 MPa. A tensile elongation of 10% or more was evaluated as ◯, and a tensile elongation of less than 10% was evaluated as x.

[Volume resistivity]
A mold release agent is applied to a stainless steel plate, a 6 cm × 6 cm enclosure is made on it with a backer, a predetermined amount of curable composition liquid is added so that the thickness of the cured product is 1 mm, and an LED-UV irradiation machine is applied. hardened with The volume resistivity of the obtained cured product sheet was measured with a digital ultra-high resistance/micro current meter manufactured by ADCMT. As a measure of good insulation, the specific volume resistivity was evaluated as ◯ when 1.0×10 ¹⁴ Ω·cm or more, and as x when less than that.

The results are shown in Tables 1-3. In Comparative Examples 1 and 10, although the components (A) to (C) were included, the total amount of the components (A) and (B) was small, so the adhesion to metal was poor. Comparative Examples 2, 4 to 7 do not contain the (B) component, so the tensile strength is inferior, and among them, in Comparative Examples 2, 5, and 7, the total amount of the (A) component and the (B) component is also small. Therefore, the adhesiveness to metal was also inferior.

Since Comparative Examples 3, 8 and 9 did not contain the (A) component, and Comparative Examples 9, 11, 14, 15 and 16 did not contain the (C) component, the adhesiveness was poor. Comparative Example 12 contained components (A) to (C), but was inferior in tensile strength because A/B was larger than the specified value. In Comparative Example 13, since A/B was smaller than the specified value, the adhesiveness to metal was poor. In Comparative Examples 4, 5, 15 and 16, the volume resistivity was small and the insulation was poor.

In contrast, Examples 1 to 17 were excellent in adhesion and tensile strength. In addition, the tensile elongation was maintained, the volume resistivity was large, and the material had insulating properties.

It should be noted that the various numerical ranges described in the specification can be arbitrarily combined with their upper and lower limits, and all combinations thereof are described in this specification as preferred numerical ranges. Further, the description of the numerical range "X to Y" means X or more and Y or less.

Although several embodiments of the invention have been described above, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments, their omissions, replacements, modifications, etc., are included in the invention described in the scope of claims and equivalents thereof, as well as being included in the scope and gist of the invention.

Claims (3)

(A) at least one heterocyclic (meth) selected from the group consisting of tetrahydrofurfuryl (meth)acrylate, cyclic trimethylolpropane formal (meth)acrylate, and tetrahydrofurfuryl alcohol (meth)acrylic acid multimeric ester; acrylate,
(B) at least one alicyclic selected from the group consisting of isobornyl (meth)acrylate, t-butylcyclohexyl (meth)acrylate, 3,3,5-trimethylcyclohexyl (meth)acrylate, and cyclohexyl (meth)acrylate (meth)acrylate, and
(C) A (meth) acrylate other than the (A) component and the (B) component , wherein (C1) a polybutadiene structure-containing (meth) acrylate having a weight average molecular weight of 1000 to 30000 and a functional group number of 1 or 2 ) acrylates and (C2) urethane (meth)acrylates having a molecular weight or weight average molecular weight of 200 to 30000 and having 1 or 2 functional groups (excluding those containing a polybutadiene structure) at least one selected (meth)acrylate,
A curable composition comprising
The total content of the component (A) and the component (B) is 70 to 95 parts by mass with respect to the total content of the component (A), the component (B) and the component (C) of 100 parts by mass. can be,
The mass ratio (A)/(B) of the content of the component (A) to the content of the component (B) is 0.6 to 20,
A curable composition for electrical members, wherein the total content of the component (A), the component (B) and the component (C) is 80% by mass or more relative to 100% by mass of the curable composition . A cured product obtained by curing the curable composition according to claim 1 . An electrical member comprising the cured product according to claim 2 .