WO2023074481A1 - Amide compound and curable resin composition containing same - Google Patents

Abstract

The present invention provides a compound (in particular, a curing agent) which enables the achievement of a cured product that has excellent flexibility and excellent dielectric characteristics, while maintaining adequate heat resistance and mechanical characteristics. The present invention relates to an amide compound which is represented by general formula (1). (In formula (1), R represents a hydrogen atom or an aryl group; X represents a divalent hydrocarbon group derived from an aliphatic dicarboxylic acid having 10 or more carbon atoms; Y represents a divalent hydrocarbon group derived from an aliphatic diamine having 10 or more carbon atoms; and n represents a number of 1 or more.)

Description

Amide compound and curable resin composition containing the same

The present invention relates to an amide compound and a curable resin composition containing the same.

Curable resins such as epoxy resins have excellent heat resistance, mechanical properties, and electrical properties, and are widely used industrially, mainly in electrical and electronic materials such as insulating materials for printed wiring boards and semiconductor sealing materials. ing.

In recent years, in the field of power semiconductors, represented by automotive power modules, there is a demand for higher current, smaller size, and higher efficiency, and the shift to silicon carbide (SiC) semiconductors is progressing. Since SiC semiconductors can operate under higher temperature conditions than conventional silicon (Si) semiconductors, semiconductor sealing materials used for SiC semiconductors are required to have higher heat resistance than ever before.

On the other hand, in the field of insulating materials for printed wiring boards, in order to reduce the transmission loss of signals in order to increase the speed and frequency of signals in electronic equipment, insulating materials with low dielectric constant, low dielectric loss tangent, etc. Dielectric properties are sought after. In addition, since the number of cases where insulating materials are manufactured or used in a high-temperature region is increasing, insulating materials are required to be flexible in order to reduce cracking, peeling, and the like.

As for resins used in electrical and electronic materials such as insulating materials for printed wiring boards and semiconductor sealing materials, for example, Patent Document 1 discloses a cured product obtained by using a compound having an imide structure in an epoxy resin. However, although the cured product of Patent Document 1 is excellent in heat resistance, mechanical properties and dielectric properties, its flexibility is insufficient. It is generally known that heat resistance and flexibility are contradictory properties, and it has been difficult to achieve both of these properties.

International publication 2019/225166 pamphlet

The present invention provides a compound (particularly a curing agent) capable of obtaining a cured product excellent in flexibility and dielectric properties while maintaining heat resistance and mechanical properties, and a curable resin composition using the compound. for the purpose.

As a result of intensive studies on the above problems, the present inventors found that the above objects can be achieved by using the amide compound represented by the general formula (1) as a curing agent, and have completed the present invention.

That is, the gist of the present invention is as follows.
<1> An amide compound represented by the general formula (1).

(In the formula (1), R is a hydrogen atom or an aryl group, X is a divalent hydrocarbon group derived from an aliphatic dicarboxylic acid having 10 or more carbon atoms, Y is a divalent diamine derived from an aliphatic diamine having 10 or more carbon atoms valence hydrocarbon group, n indicates a number of 1 or more.)
<2> The amide compound according to <1>, wherein the amide compound has a number average molecular weight of 1000 or more.
<3> A curing agent comprising the amide compound according to <1> or <2>.
<4> A curable resin composition containing the amide compound according to <1> or <2> as a curing agent and a curable resin.
<5> The curable resin composition according to <4>, further comprising another curing agent different from the amide compound.
<6> The curable resin composition according to <4> or <5>, wherein the curable resin is an epoxy resin.
<7> The curable resin composition according to any one of <4> to <6>, further comprising a curing accelerator.
<8> The curable resin composition according to any one of <4> to <7>, wherein the amide compound accounts for 35% by mass or less of the total amount of the curable resin and the curing agent.
<9> The curable resin composition according to any one of <4> to <8>, wherein the amide compound accounts for 10 to 18% by mass of the total amount of the curable resin and the curing agent.
<10> The curable resin composition further includes a diimidedicarboxylic acid compound as a curing agent different from the amide compound,
The curable resin contains a bisphenol A type epoxy resin,
The curable resin composition according to <9>, wherein in general formula (1), R represents a hydrogen atom, and n represents a number of 2 or more and 3 or less.
<11> A cured product of the curable resin composition according to any one of <4> to <10>.
<12> An electrical insulating material comprising the cured product according to <11>.
<13> A sealing material containing the cured product according to <11>.
<14> The sealing material according to <13>, which is used for a power semiconductor module.
<15> A printed wiring board containing the cured product according to <11>.

INDUSTRIAL APPLICABILITY According to the present invention, a compound capable of obtaining a cured product excellent in flexibility and dielectric properties while maintaining good heat resistance and mechanical properties, and a curable resin composition using the compound are provided. can be done.
A cured product obtained by curing the curable resin composition of the present invention can be suitably used for electrical insulating materials, sealing materials, and printed wiring boards.

1 is a TEM photograph showing a sea-island phase separation structure of the cured product of Example 1. FIG.

<Compound>
The compound of the present invention is an amide compound represented by general formula (1).

In general formula (1), X represents a divalent hydrocarbon group derived from an aliphatic dicarboxylic acid having 10 or more carbon atoms. Specifically, X is a group (so-called residue) that exhibits a partial structure other than an amide bond when the above-mentioned aliphatic dicarboxylic acid forms an amide bond, and is a divalent saturated or unsaturated aliphatic hydrocarbon group. may be The above carbon number is the carbon number of the aliphatic dicarboxylic acid that provides the X group. Therefore, the number of carbon atoms in X (that is, the divalent hydrocarbon group) corresponds to the number of carbon atoms in the aliphatic dicarboxylic acid minus 2. The number of carbon atoms in the aliphatic dicarboxylic acid giving the X group is usually 10 to 50, preferably 20 to 50, more preferably 30 to 30, from the viewpoint of further improving heat resistance, mechanical properties, flexibility and dielectric properties. 42, more preferably 34-38.

Aliphatic dicarboxylic acids that provide the X group include, for example, sebacic acid (C10), dodecanedioic acid (12), octadecanedioic acid (18), nonadecanedioic acid (19), eicosanedioic acid ( 20), heneicosanedioic acid (21), docosanedioic acid (22), tricosanedioic acid (23), tetracosanedioic acid (24), pentacosanedioic acid (25), hexacosanedioic acid (26) ), heptacosanedioic acid (27), octacosanedioic acid (28), nonacosanedioic acid (29), triacontanedioic acid (30), hentriacontanedioic acid (31), dotriacontanedioic acid (No. 32), tritriacontanedioic acid (No. 33), tetratriacontanedioic acid (No. 34), pentatriacontanedioic acid (No. 35), and dimer acid (No. 36). Among them, dimer acid is preferable because it has high versatility and improves the flexibility of the resulting cured product. A dimer acid is a compound obtained by an addition reaction of two molecules selected from unsaturated fatty acids such as oleic acid and linoleic acid. The two molecules may be the same type of molecule, or they may be heterologous molecules to each other. The dimer acid may be a dicarboxylic acid having an unsaturated bond, or a dicarboxylic acid whose degree of unsaturation has been reduced by hydrogenation, depending on the purpose of use. The aliphatic dicarboxylic acid may have been subjected to a hydrogenation reaction, or may have a cyclic structure. Here, the cyclic structure of the aliphatic dicarboxylic acid means a saturated carbocyclic ring having no aromaticity. Moreover, the aliphatic dicarboxylic acid may have a branch or an unsaturated bond. The aliphatic dicarboxylic acid preferably has a high purity. Commercial products of dimer acid include "Tsunodime 395" manufactured by Tsuno Foods Co., Ltd., "PRIPOL1009" manufactured by Croda Japan, and "PRIPOL1004" manufactured by Croda Japan. Among the above aliphatic dicarboxylic acids, one type may be used alone, or two or more types may be used in combination.

In general formula (1), Y represents a divalent hydrocarbon group derived from an aliphatic diamine having 10 or more carbon atoms. Y is, more specifically, a group (so-called residue) that exhibits a partial structure other than an amide bond when the above-mentioned aliphatic diamine forms an amide bond, and is a divalent saturated or unsaturated aliphatic hydrocarbon group. There may be. The above carbon number is the carbon number of the aliphatic diamine that provides the Y group. Therefore, the carbon number of Y (ie, the divalent hydrocarbon group) corresponds to the same value as the carbon number of the aliphatic diamine. The number of carbon atoms in the aliphatic diamine that provides the Y group is usually 10 to 50, preferably 20 to 50, more preferably 30 to 42, from the viewpoint of further improving heat resistance, mechanical properties, flexibility and dielectric properties. , more preferably 34-38.

Examples of aliphatic diamines that provide the Y group include decanediamine (identical to 10), dodecanediamine (identical to 12), octadecanediamine (identical to 18), nonadecanediamine (identical to 19), icosanediamine (identical to 20), Henicosanediamine (21), docosanediamine (22), tricosanediamine (23), tetracosanediamine (24), pentacosanediamine (25), hexacosanediamine (26), hepta cosanediamine (27), octacosanediamine (28), nonacosanediamine (29), triacontanediamine (30), hentriacontanediamine (31), dotriacontanediamine (32), triacontanediamine (No. 33), tetratriacontanediamine (No. 34), pentatriacontanediamine (No. 35), and dimer diamine (No. 36). Among them, dimer diamine is preferable because of its high versatility and improved flexibility of the resulting cured product. A dimer diamine is, for example, a compound obtained by reducing and aminating (reductive amination) the dimer acid described above. The dimer diamine may be a diamine having an unsaturated bond or a diamine whose degree of unsaturation is reduced by hydrogenation reaction, depending on the purpose of use. The aliphatic diamine may be hydrogenated or have a cyclic structure. Here, the cyclic structure of the aliphatic diamine is a saturated carbocyclic ring having no aromaticity. Also, the aliphatic diamine may have a branch or an unsaturated bond. The aliphatic diamine preferably has a high purity. Commercial products of dimer diamine include "Versamin 551" manufactured by BASF Japan, "Versamin 552" manufactured by BASF Japan (hydrogenated product of Versamin 551), "PRIAMINE 1075" manufactured by Croda Japan, and manufactured by Croda Japan. "PRIAMINE 1074" can be mentioned. Among the above aliphatic diamines, one may be used alone, or two or more may be used in combination.

In general formula (1), each R independently represents a hydrogen atom or an aryl group. Aryl groups include, for example, a phenyl group, a tolyl group, a xylyl group, and a naphthyl group. From the viewpoint of further improving heat resistance, mechanical properties, dielectric properties and flexibility, R is preferably a hydrogen atom.

In the general formula (1), n must be an integer of 1 or more, and from the viewpoint of further improving mechanical properties and flexibility, it is preferably an integer of 2 or more, and an integer of 3 or more It is more preferable to have When n is 0, heat resistance, mechanical properties and flexibility are lowered. The upper limit of n is not particularly limited, and n is usually an integer of 10 or less, particularly 5 or less, and preferably an integer of 3 or less from the viewpoint of further improving heat resistance, mechanical properties, dielectric properties and flexibility. and more preferably 2.

The molecular weight of the amide compound of the present invention is preferably 1000 or more, more preferably 2000 to 5000, more preferably 2000 to 4000, from the viewpoint of further improving heat resistance, mechanical properties, dielectric properties and flexibility. 2000 to 3000 is particularly preferable.

The molecular weight of the amide compound is the number average molecular weight, and the polystyrene conversion value measured by gel permeation chromatography (GPC) is used.

The amide compound of the present invention can be used as a curing agent by using it together with a curing resin.

The method for producing the amide compound of the present invention is not particularly limited, but for example, the above-mentioned aliphatic dicarboxylic acid and the above-mentioned aliphatic diamine are reacted to produce an amide compound, which is further reacted with trimellitic anhydride and heated. A method of carrying out a ring closure reaction is mentioned. Furthermore, if necessary, an esterification reaction may be carried out to esterify the terminal. In the case of esterification, a known esterification reaction may be used, and examples thereof include a method of reacting a catalyst with phenols and a method of utilizing transesterification.

<Curable resin composition>
The curable resin composition of the present invention can be obtained by mixing an amide compound represented by formula (1) and a curable resin.

Examples of curable resins include epoxy resins, cyanate resins, phenol resins, imide resins, maleimide resins, benzoxazine resins, silicone resins, acrylic resins, and fluorine resins. Among them, epoxy resin is more preferable. Among the above curable resins, one type may be used alone, or two or more types may be used in combination.

The epoxy resin preferably has two or more epoxy groups in one molecule. Examples of epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, naphthalene type epoxy resin, biphenyl type epoxy resin, dicyclopentadiene type epoxy resin, phenol novolac type epoxy resin, and cresol novolak. type epoxy resins, isocyanurate type epoxy resins, alicyclic epoxy resins, acrylic acid-modified epoxy resins, polyfunctional epoxy resins, brominated epoxy resins, and phosphorus-modified epoxy resins. From the viewpoint of further improving heat resistance, mechanical properties, dielectric properties and flexibility, the epoxy resin is preferably a bifunctional epoxy resin such as a bisphenol A type epoxy resin or a biphenyl type epoxy resin. is more preferred. The epoxy equivalent of the epoxy resin is preferably 100-3000 g/eq, more preferably 150-300 g/eq.

The molecular weight of the curable resin is not particularly limited. For example, in the case of epoxy resin, the molecular weight may be such that the epoxy equivalent weight described above is achieved.

The curable resin composition of the present invention may contain other curing agents in order to further improve heat resistance. Another curing agent means a curing agent having a structure different from that of the amide compound represented by the general formula (1). Other curing agents include, for example, phenol-based curing agents (for example, novolac-type phenolic resin curing agents), thiol-based curing agents, amine-based curing agents, acid anhydride-based curing agents, cyanate-based curing agents, and active ester-based curing agents. and imide curing agents. Among them, from the viewpoint of further improving heat resistance, mechanical properties, dielectric properties and flexibility, imide-based curing agents and/or phenol-based curing agents (especially novolac-type phenol resin curing agents) are preferred, and imide-based curing agents are more preferred. preferable. Other curing agents may be used alone or in combination of two or more of the above. By using the amide compound of the present invention in combination with another curing agent, it is possible to form a sea-island phase separation structure in which the amide compound of the present invention serves as islands in the cured product. Other curing agents and epoxy resins serve as the sea component, so heat resistance and mechanical properties are more sufficiently maintained, while the amide compound and the epoxy resin of the present invention serve as island components, resulting in greater flexibility. It is sufficiently expressed, and a cured product having sufficiently excellent dielectric properties can be obtained.

Examples of imide-based curing agents include compounds having 1 to 4 imide groups and 2 to 4 glycidyl group-reactive functional groups in the molecule. A glycidyl group-reactive functional group is a functional group having reactivity with a glycidyl group, and may be, for example, a carboxyl group, a hydroxyl group, or an amino group. Examples of the imide-based curing agent include, for example, a compound obtained by reacting two trimellitic anhydrides with one 4,4'-diaminophenyl ether (for example, a diimide dicarboxylic acid compound), one 3,3', 4,4'-Benzophenonetetracarboxylic dianhydride and two 2-aminoterephthalic acid reacted compounds (e.g., diimidotetracarboxylic acid compounds), one trimellitic anhydride and one 2-aminoterephthalic acid Acid-reacted compounds (for example, monoimidetricarboxylic acid compounds) can be mentioned. The imide-based curing agent is preferably a diimide dicarboxylic acid compound from the viewpoint of further improving heat resistance, mechanical properties, dielectric properties and flexibility.

In the curable resin composition of the present invention, the ratio of the amide compound represented by the general formula (1) to the total of the curable resin and the curing agent is from the viewpoint of further improving heat resistance, mechanical properties, dielectric properties and flexibility. Therefore, it is preferably 35% by mass or less (especially 2 to 35% by mass), more preferably 20% by mass or less (especially 10 to 20% by mass), and 18% by mass or less (especially 10 to 18% by mass). is more preferable, 10 to 15% by mass is sufficiently preferable, and 12 to 14.5% by mass is particularly preferable. The total of the curable resin and the curing agent is the total of the curable resin and the amide compound when only the amide compound of general formula (1) is used as the curing agent, and the curing agent is the general formula (1) When another curing agent is used together with the amide compound, it is the sum of the curing resin, the amide compound and the other curing agent.

In the curable resin composition of the present invention, the ratio of the curing agent (including the amide compound represented by the general formula (1)) is not particularly limited, and is 80 to 120 with respect to the curable resin (100 mol%). It may be mol %, preferably 90 to 110 mol %, more preferably 98 to 102 mol %, from the viewpoint of further improving heat resistance, mechanical properties, dielectric properties and flexibility. When the curing agent contains the amide compound represented by formula (1) and other curing agents, the proportion of the curing agent is the total proportion thereof.

To the curable resin composition of the present invention, other additives such as curing accelerators, inorganic fillers, antioxidants, flame retardants, organic solvents, etc. may be added as long as they do not impair the effects of the present invention.

Curing accelerators include, for example, imidazoles such as 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole; 4-dimethylaminopyridine, benzyldimethylamine, 2-(dimethylaminomethyl)phenol, tertiary amines such as 2,4,6-tris(dimethylaminomethyl)phenol; and organic phosphines such as triphenylphosphine and tributylphosphine. One of the above curing accelerators may be used alone, or two or more thereof may be used in combination. When using a curing accelerator, the amount is preferably 0.01 to 2.0% by mass with respect to the total of the curable resin and the curing agent, and the heat resistance and dielectric properties of the resulting cured product are 0.01 to 1% by mass, more preferably 0.05 to 0.5% by mass.

Examples of inorganic fillers include silica, barium sulfate, alumina, aluminum nitride, boron nitride, silicon nitride, glass powder, glass frits, glass fibers, carbon fibers, and inorganic ion exchangers. Among the above inorganic fillers, one may be used alone, or two or more may be used in combination. When an inorganic filler is used, the average particle size of the inorganic filler is preferably from 50 nm to 4 μm, and more preferably from 100 nm to 3 μm because it is superior in coatability and workability.

Examples of antioxidants include hindered phenol-based antioxidants, phosphorus-based antioxidants, and thioether-based antioxidants. Among the above antioxidants, one may be used alone, or two or more may be used in combination.

Flame retardants include non-halogen flame retardants, phosphorus flame retardants, nitrogen flame retardants, and silicone flame retardants. Among them, non-halogen flame retardants are preferred from the viewpoint of environmental impact. One of the above flame retardants may be used alone, or two or more thereof may be used in combination.

The organic solvent is not particularly limited as long as the curing agent and the curing resin can be uniformly dissolved and coated, and a non-halogenated solvent is preferable from the viewpoint of environmental impact. Non-halogenated solvents include, for example, N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone. One of the above organic solvents may be used alone, or two or more thereof may be used in combination.

The method for producing the curable resin composition of the present invention is not particularly limited. A method of mixing the resin with other additives that are added as necessary can be mentioned. From the viewpoint of dissolving each component in the organic solvent, the mixture may be heated to 80 to 200° C. (especially 100 to 150° C.).

<Cured product>
By heating the curable resin composition of the present invention, the amide compound represented by the general formula (1) and the curable resin can be reacted to obtain a cured product. The heating temperature (curing temperature) is preferably 80 to 350°C, more preferably 130 to 300°C. The heating time (curing time) is preferably 1 minute to 24 hours, more preferably 5 minutes to 10 hours. In addition, in the case of a curable resin composition containing an organic solvent, the organic solvent is distilled off by heating.

In the present invention, the characteristic values of the cured product are evaluated in comparison with a specific cured product that does not have a softening component. The “specific cured product having no softening component” means a cured product containing another specific curing agent instead of the amide compound represented by formula (1). The specific other curing agent refers to the case where the curable resin composition of the present invention constituting the cured product to be evaluated contains a curable resin, an amide compound represented by formula (1), and another curing agent. Other curing agents. When the curable resin composition contains two or more other curing agents, the other curing agent contained in the largest amount is referred to as the "specific other curing agent". Therefore, when the curable resin composition of the present invention contains a curable resin, an amide compound represented by formula (1), and other curing agents, the cured product of the present invention produced from the curable resin composition The characteristic values are those of a cured product produced in the same manner as the cured product of the present invention except that the other curing agent is further used instead of the amide compound (i.e., a "specific cured product having no softening component"). evaluated in comparison with

The difference between the glass transition temperature of the cured product of the present invention and the glass transition temperature of the "specific cured product having no softening component" is preferably 20°C or less, and preferably 10°C or less, from the viewpoint of heat resistance. is more preferable.

From the viewpoint of flexibility, the tensile modulus of the cured product of the present invention is preferably 75% or less, more preferably 70% or less, compared to the "specific cured product having no flexible component". , 65% or less.

From the viewpoint of mechanical properties, the tensile strength at break of the cured product of the present invention is preferably 60% or more, preferably 65% or more, compared to the "specific cured product having no flexible component". , more preferably 70% or more.

The dielectric loss tangent of the cured product of the present invention is preferably equal to or less than the dielectric loss tangent of the "specific cured product having no flexible component", and more preferably less than the dielectric loss tangent of the "specific cured product having no flexible component". .

<Application of cured product>
The cured product of the present invention is excellent in flexibility and dielectric properties while maintaining heat resistance and mechanical properties, so that it can be suitably used as an electrical insulating material. Specifically, the cured product of the present invention is a sealing material (e.g., power semiconductor module sealing material), printed wiring board, molding material (e.g., bushing transformer molding material, solid insulation switchgear molding material). , electrical penetrations for nuclear power plants, build-up laminates, interlayer insulating materials (eg, organic rewiring layers, insulating adhesive films), photosensitive insulating materials, conductive pastes, and the like. Among them, the cured product of the present invention can be used more preferably for sealing materials, printed wiring boards, and interlayer insulating materials.

For example, when the cured product of the present invention is used as a sealing material (particularly, an insulating material for sealing material), after producing a power semiconductor module, an epoxy resin solution (particularly, The cured product of the present invention can be obtained by filling, drying and curing the curable resin composition of (1).
Further, for example, when the cured product of the present invention is used as a printed wiring board (especially an insulating material for printed wiring boards), the epoxy resin solution (especially the curable resin composition of the present invention) is impregnated or applied to a glass cloth. , drying and curing to obtain the cured product of the present invention.
Further, for example, when the cured product of the present invention is used as an interlayer insulating material, an epoxy resin solution (particularly, the curable resin composition of the present invention) is processed into a sheet, dried, and laminated on both sides of an inner layer substrate. , to obtain the cured product of the present invention.

The present invention will be specifically described below with reference to examples, but the present invention is not limited to these.

A. Raw Materials Raw materials used in Examples and Comparative Examples are shown below.
(A) Curing resin/Bisphenol A type epoxy resin: manufactured by Tokyo Chemical Industry Co., Ltd., epoxy equivalent 170 g/eq
· Biphenyl type epoxy resin: "YX4000H" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent 180 g / eq

(B) Curing agent raw material, curing agent/dimer acid: "PRIPOL 1009" manufactured by Croda Japan Co., Ltd.
・Dimer diamine: "PRIAMINE 1075" manufactured by Croda Japan Co., Ltd.
- Trimellitic anhydride: manufactured by Tokyo Chemical Industry Co., Ltd. - 4,4'-diaminodiphenyl ether: manufactured by Tokyo Chemical Industry Co., Ltd. - 1-naphthyl acetate: manufactured by Tokyo Chemical Industry Co., Ltd. - Novolac type phenolic resin: manufactured by DIC Corporation "PHENOLITE TD-2131" ”
· Poly (propylene glycol) bis (2-aminopropyl ether): HUNTSMAN "ELASTAMINE RP-2009", molecular weight 2000

・Diimidodicarboxylic acid F
50 parts by mass of dimer diamine and 35.9 parts by mass of trimellitic anhydride were mixed and pulverized for 3 minutes at a rotational speed of 9000 rpm using Wonder Crusher WC-3C manufactured by Osaka Chemical Co., Ltd. The treated sample was transferred to a glass container, and an imidization reaction was carried out at 300° C. for 2 hours in an inert oven DN411I manufactured by Yamato Kagaku Co., Ltd. to obtain diimide dicarboxylic acid F.
Diimidodicarboxylic acid F was confirmed by ¹ H-NMR to have a structure represented by general formula (1) (n=0, R is a hydrogen atom, Y is a dimer diamine residue). Further, the diimidedicarboxylic acid E had a number average molecular weight of 890 and was solid at room temperature.

・Diimidodicarboxylic acid G
Diimidodicarboxylic acid F61.4 parts by mass and 1-naphthyl acetate 38.6 parts by mass were charged into a reaction vessel equipped with a heating mechanism and a stirring mechanism. Thereafter, the mixture was heated at 300° C. under stirring, and the reaction was carried out for 3 hours at normal pressure under a nitrogen stream while removing condensed water out of the system. Then, it was washed with methanol and dried to obtain imidodicarboxylic acid G.
The diimidodicarboxylic acid G was confirmed by ¹ H-NMR and GPC to have the structure represented by the general formula (1) (n=0, R is a naphthyl group, Y is a dimer diamine residue). Further, the imidodicarboxylic acid G had a number average molecular weight of 1137 and was solid at room temperature.

・Diimidodicarboxylic acid H
Diimidedicarboxylic acid H was obtained in the same manner as imidedicarboxylic acid F, except that 18.8 parts by weight of 4,4'-diaminodiphenyl ether was used instead of 50 parts by weight of dimer diamine.
Diimidodicarboxylic acid H was confirmed by ¹ H-NMR to be a compound composed of trimellitic acid-4,4′-diaminodiphenyl ether-trimellitic acid. Further, the diimidedicarboxylic acid H had a number average molecular weight of 549 and was solid at room temperature.

(C) curing accelerator 2-ethyl-4-methylimidazole: manufactured by Tokyo Chemical Industry Co., Ltd.

(D) Organic solvent N, N-dimethylformamide: manufactured by Tokyo Chemical Industry Co., Ltd. Toluene: manufactured by Tokyo Chemical Industry Co., Ltd.

B. Evaluation Method The compounds and cured products obtained in Examples and Comparative Examples were evaluated as follows.
In particular, the object of comparison (or comparison standard) when evaluating the cured products obtained in Examples and Comparative Examples was "a specific cured product having no softening component", and the details were as follows.
The cured product of Reference Example 1 was compared with the cured products of Examples 1-7 and Comparative Examples 1-4.
The cured product of Example 8 was compared with the cured product of Reference Example 2.
The cured product of Example 9 was compared with the cured product of Reference Example 3.

(1) Composition of Curing Agents (Compounds A to G) The curing agents were subjected to ¹ H-NMR analysis using a high-resolution nuclear magnetic resonance spectrometer (JNM-ECA500 NMR manufactured by JEOL Ltd.) to determine each copolymer. The resin composition was determined from the peak intensities of the components (resolution: 500 MHz, solvent: deuterated dimethylsulfoxide, temperature: 25°C).

(2) Number average molecular weight of curing agent (compounds A to G) Using gel permeation chromatography (GPC), the GPC of standard polystyrene was measured under the following conditions to prepare a calibration curve, and then the curing agent (compound A to G) was measured by GPC under the same conditions to determine the average molecular weight in terms of polystyrene.
<GPC measurement conditions>
Apparatus: HLC-8220GPC manufactured by Tosoh Corporation
Column: Showa Denko Shodex GPC KF-405L HQ 3 Solvent: Chloroform Flow rate: 0.3 mL/min
Temperature: column 40°C
Sample concentration: 0.2% by mass
Detector: RI detector Calibration sample: standard polystyrene

(3) Glass transition temperature of cured product (heat resistance)
Cured products obtained in Examples and Comparative Examples were measured using a differential scanning calorimeter (DSC) under the following conditions.
<Measurement conditions>
Apparatus: DSC 6000 manufactured by Perkin Elmer
Heating rate: 10° C./min The temperature was raised from 25° C. to 300° C., and the starting temperature of the discontinuous change derived from the transition temperature in the obtained heating curve was taken as the glass transition temperature.

A value A was obtained from the following formula and evaluated according to the following criteria.
Value A = [Glass transition temperature of "specific cured product having no softening component"] - [Glass transition temperature of cured products obtained in Examples and Comparative Examples]
<Evaluation Criteria>
◎: 20 ° C. or less (best)
×: exceeds 20 ° C. (defective)

(4) Tensile modulus of cured product (flexibility) and tensile strength at break (mechanical properties)
The cured products obtained in Examples and Comparative Examples were cut into a width of 10 mm and a length of 100 mm to prepare a test piece, which was measured according to ISO 178.

Values B and C were obtained from the following formulas and evaluated according to the following criteria.
<Evaluation of tensile modulus>
Value B = [tensile elastic modulus of cured products obtained in Examples and Comparative Examples]/[tensile elastic modulus of “specific cured product having no flexible component”] × 100
◎: value B ≤ 65% (best)
○: 65% < value B ≤ 70% (good)
△: 70% < value B ≤ 75% (normal)
×: 75% < value B (defective)

<Evaluation of tensile strength at break>
Value C = [Tensile breaking strength of cured products obtained in Examples and Comparative Examples]/[Tensile breaking strength of “specified cured product having no flexible component”] × 100
◎: 70% ≤ value C (best)
○: 65% ≤ value C < 70% (good)
△: 60% ≤ value C < 65% (good)
×: value C < 60% (defective)

(5) Dielectric loss tangent of cured product (dielectric properties)
The dielectric loss tangent of the cured products obtained in Examples and Comparative Examples was measured using the following equipment under the following conditions.
<Measurement conditions>
Device: Keysight Technologies PNA network analyzer N5222B
CP-521 for 5.8 GHz cavity resonator manufactured by Kanto Denshi Applied Development Co., Ltd.
Sample size: length 80 mm x width 2 mm x thickness 100 μm
Frequency: 5.8GHz
Measurement temperature: 23°C
Test environment: 23°C ± 1°C, 50% RH ± 5% RH

It was compared with the dielectric loss tangent of the "specified cured product having no flexible component" (reference example) and evaluated according to the following criteria.
<Evaluation of dielectric loss tangent>
◎: the dielectric loss tangent of the cured products obtained in Examples and Comparative Examples is lower than the dielectric loss tangent of the “specific cured product having no flexible component” (good);
○: The dielectric loss tangent of the cured products obtained in Examples and Comparative Examples is the same as the dielectric loss tangent of the “specific cured product having no flexible component” (normal); and ×: Cured products obtained in Examples and Comparative Examples The dielectric loss tangent of the product is higher than the dielectric loss tangent of the "specified cured product having no flexible component" (defective).

(6) Phase separation structure of cured product The cured products obtained in Examples and Comparative Examples were cut using a Leica EM UC-7 ultramicrotome, and a section with a thickness of 80 nm was taken from the cured product under the following conditions. A phase-separated structure was observed. FIG. 1 shows a TEM photograph showing the sea-island phase separation structure of the cured product of Example 1. As shown in FIG.
<Measurement conditions>
Apparatus: JEM-1230 TEM manufactured by JEOL Ltd.
Measurement method: Transmission measurement Measurement conditions: Accelerating voltage 100 kV

The obtained TEM photograph was evaluated according to the following criteria.
<Evaluation of phase separation structure>
A: It had a sea-island phase separation structure as shown in FIG.
x: It did not have a sea-island phase separation structure as shown in FIG.

(7) Comprehensive evaluation Based on the evaluation results of heat resistance, mechanical properties, dielectric properties and flexibility, comprehensive evaluation was made.
⊚: All the evaluation results were ⊚.
○: Among all the evaluation results, the lowest evaluation result was ○.
△: Among all the evaluation results, the lowest evaluation result was △.
x: Among all evaluation results, the lowest evaluation result was x.

Example 1
(Compound A)
35.2 parts by mass of dimer acid and 50 parts by mass of dimer diamine were charged into a reaction vessel equipped with a heating mechanism and a stirring mechanism. After that, the mixture was heated at 230° C. with stirring, and polymerization was carried out for 2 hours at normal pressure under a nitrogen stream while condensed water was removed from the system. Then, it was once cooled to 50° C., and 11.9 parts by mass of trimellitic anhydride was added. The mixture was again heated at 210° C. under stirring to carry out a ring-closing reaction with heating for 1 hour to obtain compound A.
Compound A has a structure represented by general formula (1) (n=2, R is a hydrogen atom, Y is a dimer diamine residue, and X is a dimer acid residue), as confirmed by ¹ H-NMR and GPC. there were. The compound A had a number average molecular weight of 2762 and was a viscous liquid at room temperature.

(Curable resin composition)
The obtained compound A, bisphenol type epoxy resin, imidodicarboxylic acid H, 2-ethyl-4-methylimidazole and N,N-dimethylformamide were mixed at 130° C. for 0.5 hours at the blend ratios shown in Table 1. was heated under reflux to dissolve. After cooling, other additives were mixed and stirred to obtain a curable resin composition.

(cured product)
The resulting curable resin composition was applied to an aluminum substrate to a thickness of 300 μm, and heated in an inert oven at 120° C. for 1 hour in a nitrogen atmosphere, and then heated to 300° C. over 8 hours. C. for 1 hour to remove the solvent and perform a curing reaction.
After that, the aluminum substrate was removed from the aluminum substrate on which the resin layer was formed to obtain a cured product. The thickness of the cured product was 100 µm.

Example 2
(Compound B)
Compound B was obtained in the same manner as in Example 1, except that 42.2 parts by mass of dimer acid and 11.9 parts by mass of trimellitic anhydride were used in place of 7.1 parts by mass.
Compound B has a structure represented by general formula (1) (n=4, R is a hydrogen atom, Y is a dimer diamine residue, and X is a dimer acid residue), as confirmed by ¹ H-NMR and GPC. Met. The compound B had a number average molecular weight of 4900 and was a viscous liquid at room temperature.

Using the obtained compound B, the same operation as in Example 1 was performed except that the compounding amount was changed so that the composition shown in Table 1 was obtained, to prepare a curable resin composition and to prepare a cured product. done.

Example 3
(Compound C)
Compound C was obtained in the same manner as in Example 1, except that 26.4 parts by mass of dimer acid and 11.9 parts by mass of trimellitic anhydride were used instead of 17.8 parts by mass.
Compound C has a structure represented by general formula (1) (n=1, R is a hydrogen atom, Y is a dimer diamine residue, and X is a dimer acid residue), as confirmed by ¹ H-NMR and GPC. Met. Compound C had a number average molecular weight of 1861 and was semi-solid at room temperature.

Using the obtained compound C, the same operation as in Example 1 was performed except that the compounding amount was changed so that the composition shown in Table 1 was obtained, to prepare a curable resin composition and to prepare a cured product. done.

Example 7
(Compound D)
84.7 parts by mass of Compound A and 15.3 parts by mass of 1-naphthyl acetate were charged into a reaction vessel equipped with a heating mechanism and a stirring mechanism. Thereafter, the mixture was heated at 300° C. under stirring, and the reaction was carried out for 3 hours at normal pressure under a nitrogen stream while removing condensed water out of the system. After that, it was washed with methanol and dried to obtain a compound D.
Compound D has a structure represented by general formula (1) (n=2, R is a naphthyl group, Y is a dimer diamine residue, and X is a dimer acid residue), as confirmed by ¹ H-NMR and GPC. there were. The compound D had a number average molecular weight of 3273 and was a viscous liquid at room temperature.

Using the obtained compound D, the same operation as in Example 1 was performed except that the compounding amount was changed so that the composition shown in Table 1 was obtained, to prepare a curable resin composition and to prepare a cured product. done.

Comparative example 1
(Polyamide E)
A reaction vessel equipped with a heating mechanism and a stirring mechanism was charged with 50 parts by mass of dimer acid and dimer diamine. Thereafter, the mixture was heated at 230° C. with stirring, and polymerization was carried out at normal pressure for 2 hours under a nitrogen stream while condensed water was removed from the system to obtain polyamide E.
Polyamide D was confirmed by ¹ H-NMR and GPC to have a structure in which dimer acid and dimer diamine were alternately polymerized. Polyamide E had a number average molecular weight of 2703 and was a viscous liquid at room temperature.

Using the obtained polyamide E, the same operation as in Example 1 was performed except that the blending amount was changed so that the composition shown in Table 2 was obtained, to prepare a curable resin composition and to prepare a cured product. done.

Examples 4-9, Comparative Examples 2-4 and Reference Examples 1-3
A curable resin composition was produced and a cured product was produced in the same manner as in Example 1 except that the raw materials and compounding amounts were changed so that the compositions shown in Tables 1 to 3 were obtained.

The table shows the composition of the curable resin composition and the evaluation results of the obtained cured product.

All of the cured products of Examples 1 to 6, in the general formula (1), R is a hydrogen atom, X is a divalent hydrocarbon group derived from an aliphatic dicarboxylic acid having 10 or more carbon atoms, and Y is 10 or more carbon atoms. When a compound having a divalent hydrocarbon group derived from an aliphatic diamine and n being 1 or more was used, it had a sea-island type phase separation structure. For this reason, the cured products of Examples 1 to 6 have a glass transition temperature difference of 20° C. or less and a tensile strength at break of 60% with respect to the “specific cured product having no flexible component” (Reference Example 1). Thus, the dielectric loss tangent was smaller and the tensile elastic modulus was 75% or less. As a result, the cured products of Examples 1 to 6 were excellent in flexibility and dielectric properties while maintaining heat resistance and mechanical properties.

In the cured product of Example 7, in the general formula (1), R is a naphthyl group, X is a divalent hydrocarbon group derived from an aliphatic dicarboxylic acid having 10 or more carbon atoms, and Y is derived from an aliphatic diamine having 10 or more carbon atoms. When a compound having a divalent hydrocarbon group of n and a number of 1 or more was used, it had a sea-island type phase separation structure. Therefore, the cured product of Example 7 had a glass transition temperature difference of 20° C. or less and a tensile strength at break of 60% or more with respect to the “specific cured product having no flexible component” (Reference Example 1). It had a smaller dielectric loss tangent and a tensile modulus of 75% or less. As a result, the cured product of Example 7 was excellent in flexibility and dielectric properties while maintaining heat resistance and mechanical properties.

Further, in the cured product of Example 8, in the general formula (1), R is a hydrogen atom, X is a divalent hydrocarbon group derived from an aliphatic dicarboxylic acid having 10 or more carbon atoms, Y is an aliphatic having 10 or more carbon atoms When a diamine-derived divalent hydrocarbon group, n, used a compound having a number of 1 or more, it had a sea-island type phase separation structure. Therefore, the cured product of Example 8 had a glass transition temperature difference of 20° C. or less and a tensile strength at break of 60% or more with respect to the “specific cured product having no flexible component” (Reference Example 2). It had a smaller dielectric loss tangent and a tensile modulus of 75% or less. As a result, the cured product of Example 8 was excellent in flexibility and dielectric properties while maintaining heat resistance and mechanical properties.

In the cured product of Example 9, in the general formula (1), R is a hydrogen atom, X is a divalent hydrocarbon group derived from an aliphatic dicarboxylic acid having 10 or more carbon atoms, and Y is derived from an aliphatic diamine having 10 or more carbon atoms. When a compound having a divalent hydrocarbon group of n and a number of 1 or more was used, it had a sea-island type phase separation structure. Therefore, the cured product of Example 9 had a glass transition temperature difference of 20°C or less and a tensile strength at break of 60% or more with respect to the "specific cured product having no flexible component" (Reference Example 3). It had a smaller dielectric loss tangent and a tensile modulus of 75% or less. As a result, the cured product of Example 9 was excellent in flexibility and dielectric properties while maintaining heat resistance and mechanical properties.

The cured product of Comparative Example 1 used a polyamide composed of dimer acid and dimer diamine, and therefore had a tensile strength at break of less than 60% with respect to the "specific cured product having no flexible component" (Reference Example 1).
Since the cured product of Comparative Example 2 did not use the amide compound represented by the general formula (1), the glass transition temperature difference was 20° C. with respect to the "specific cured product having no flexible component" (Reference Example 1). and the tensile modulus exceeded 75%.
Since the cured product of Comparative Example 3 did not use the amide compound represented by the general formula (1), the dielectric loss tangent was greater than the dielectric loss tangent of the "specific cured product having no flexible component" (Reference Example 1).
Since the cured product of Comparative Example 4 did not use the amide compound represented by the general formula (1), the glass transition temperature difference was 20° C. with respect to the "specified cured product having no flexible component" (Reference Example 1). and the tensile modulus exceeded 75%.

A cured product obtained by using the amide compound of the present invention as a curing agent is excellent in heat resistance, mechanical properties, flexibility and dielectric properties. Therefore, materials requiring at least one of these properties (for example, It can be suitably used as an electrical insulating material).

Claims (15)

1. An amide compound represented by the general formula (1).
   

   

   (In the formula (1), R is a hydrogen atom or an aryl group, X is a divalent hydrocarbon group derived from an aliphatic dicarboxylic acid having 10 or more carbon atoms, Y is a divalent diamine derived from an aliphatic diamine having 10 or more carbon atoms valence hydrocarbon group, n indicates a number of 1 or more.)
2. The amide compound according to claim 1, wherein the amide compound has a number average molecular weight of 1000 or more.
3. A curing agent comprising the amide compound according to claim 1 or 2.
4. A curable resin composition comprising the amide compound according to claim 1 or 2 as a curing agent and a curable resin.
5. The curable resin composition according to claim 4, further comprising another curing agent different from the amide compound.
6. The curable resin composition according to claim 4, wherein the curable resin is an epoxy resin.
7. The curable resin composition according to claim 4, further comprising a curing accelerator.
8. The curable resin composition according to claim 4, wherein the ratio of the amide compound to the total of the curable resin and the curing agent is 35% by mass or less.
9. The curable resin composition according to claim 4, wherein the ratio of the amide compound to the total of the curable resin and the curing agent is 10-18% by mass.
10. The curable resin composition further comprises a diimidedicarboxylic acid compound as a curing agent different from the amide compound,
    The curable resin contains a bisphenol A type epoxy resin,
    The curable resin composition according to claim 9, wherein in general formula (1), R represents a hydrogen atom, and n represents a number of 2 or more and 3 or less.
11. A cured product obtained by curing the curable resin composition according to claim 4.
12. An electrical insulating material containing the cured product according to claim 11.
13. A sealing material containing the cured product according to claim 11.
14. The sealing material according to claim 13, which is used for a power semiconductor module.
15. A printed wiring board containing the cured product according to claim 11.

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