Bonded magnet compound, bonded magnet, and motor

Abstract

To provide a bonded magnet compound having high mechanical strength and excellent high temperature stability even when a thermosetting resin is subjected to a curing reaction under a low temperature condition, and to provide a bonded magnet and a motor.SOLUTION: The bonded magnet compound is a mixture of a thermosetting resin composition containing an epoxy resin (A), a curing agent (B), and a curing accelerator (C), and magnetic particles (D), wherein the thermosetting resin composition is solid at 25°C, and when a melt viscosity of the thermosetting resin composition at 100°C is defined as (X) (mPa s) and a melt viscosity of the thermosetting resin composition at 100°C after heating at 100°C for 30 minutes is defined as (Y) (mPa s), (X) and (Y) satisfy the following formulae (1) and (2). 0.01≤(X)≤30...(1), 1≤(Y) / (X)≤500...(2)SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a bonded magnet compound, a bonded magnet, and a motor. [Background technology]

[0002] A bonded magnet is a molded body made by mixing magnetic particles with binders such as resin components and processing them into a specific shape. Because bonded magnets contain resin components, they have a high degree of freedom in shape and are more moldable than sintered magnets, so they are increasingly being used in applications such as motors for automobiles, general home appliances, communication and audio equipment, medical equipment, and general industrial equipment.

[0003] On the other hand, these motors are expected to have higher rotation speeds in anticipation of higher output, so bonded magnets, which are exposed to strong centrifugal forces and intense heat, tend to be required to have mechanical strength that can prevent cracking and chipping, as well as high-temperature stability that can withstand the heat generated by the motor.

[0004] Patent Document 1 discloses a bonded magnet compound containing an epoxy resin, a phenolic resin curing agent, a curing accelerator, and magnet powder, in which the epoxy resin contains a naphthalene structure and the curing accelerator contains a tetra-substituted borate, resulting in a bonded magnet compound with excellent mechanical strength at room temperature and at high temperatures. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] WO2020 / 225885 Summary of the Invention [Problem to be solved by the invention]

[0006] Bonded magnets are molded using two methods: compression molding and injection molding. Bonded magnets are typically molded by applying heat and pressure to a composite material called a "compound" made by mixing magnetic particles with binders such as resin components. In compression molding, heating is used to promote the curing reaction of the thermosetting resin, but the magnetic particles in the compound are sensitive to heat, and the surfaces of the magnetic particles are easily oxidized in a heated environment, leading to a deterioration in magnetic properties.

[0007] Therefore, there is a demand for compounds for bonded magnets that have the mechanical strength to prevent cracking or chipping of bonded magnets even when reacting with thermosetting resins under low-temperature conditions (for example, below 150°C) and the high-temperature stability to withstand the heat generated by motors.

[0008] In contrast, compounds for bonded magnets, such as those described in Patent Document 1, which contain an epoxy resin containing a naphthalene structure and a curing accelerator containing a tetra-substituted borate, have room for improvement in mechanical strength and high-temperature stability when the thermosetting resin is cured under lower temperature conditions.

[0009] The problem to be solved by the present invention is to provide a bonded magnet compound that has high mechanical strength and excellent high-temperature stability even when a thermosetting resin is cured under low-temperature conditions. [Means for solving the problem]

[0010] As a result of extensive research into solving the above problems, the inventors have found that the above problems of the conventional techniques can be solved by the following technical means, and have thus completed the present invention.

[0011] That is, the present invention includes the following aspects. [1] A bonded magnet compound which is a mixture of a thermosetting resin composition containing an epoxy resin (A), a curing agent (B), and a curing accelerator (C), and magnetic particles (D), wherein the thermosetting resin composition is solid at 25°C, and the melt viscosity of the thermosetting resin composition at 100°C is (X) (mPa·s), and the melt viscosity of the thermosetting resin composition at 100°C after heating at 100°C for 30 minutes is (Y) (mPa·s), (X) and (Y) satisfy the following formulas (1) and (2): 0.01≦(X)≦30 (1) 1≦(Y) / (X)≦500 (2) A bonded magnet compound, wherein the epoxy resin (A) contains a structure represented by the following formula (A1), and the curing agent (B) contains a structure represented by the following formula (B1).

[0012] [ka]

[0013] (In formula (A1), R 11 ~R 20 are each independently a hydrogen atom, an alkyl group, an aromatic group, a substituent containing a heteroatom, or a substituent containing a halogen atom, and R 11 ~R 20 At least one of the groups contains a reactive group with the curing agent (B), and R 11 ~R 20 may be the same or different from each other.

[0014] [ka]

[0015] (In formula (B1), R 31 ~R 40 are each independently a hydrogen atom, an alkyl group, an aromatic group, a substituent containing a heteroatom, or a substituent containing a halogen atom, and R 31 ~R 40 At least one of the groups contains a reactive group with the epoxy resin (A), and R 31 ~R40 may be the same or different from each other.

[0016] [2] The bonded magnet compound according to [1], wherein the epoxy resin (A) contains a structure represented by the following formula (A2):

[0017] [ka]

[0018] (In formula (A2), R 41 ~R 54 are each independently a hydrogen atom, an alkyl group, an aromatic group, a substituent containing a heteroatom, or a substituent containing a halogen atom, and R 41 ~R 54 At least one of the groups contains a reactive group with the curing agent (B), and R 41 ~R 54 may be the same or different from each other.

[0019] [3] The bonded magnet compound according to [1] or [2], wherein the curing agent (B) contains a structure represented by formula (B2).

[0020] [ka]

[0021] (In formula (B2), R 61 ~R 74 are each independently a hydrogen atom, an alkyl group, an aromatic group, a substituent containing a heteroatom, or a substituent containing a halogen atom, and R 61 ~R 74 At least one of the groups contains a reactive group with the epoxy resin (A), and R 61 ~R 74 may be the same or different from each other.

[0022] [4] The bonded magnet compound according to [1] or [2], wherein the curing accelerator (C) contains an imidazole compound.

[0023] [5] The bonded magnet compound according to [4], wherein the molecular weight of the imidazole compound is 120 or more and 500 or less.

[0024] [6] The bonded magnet compound according to [4], wherein the imidazole compound has at least one hydroxy group.

[0025] [7] The bonded magnet compound according to [4], wherein the imidazole compound comprises at least one compound selected from the group consisting of compounds represented by the following formula (C1) and compounds represented by the following formula (C2):

[0026] [ka]

[0027] In formula (C1), R1 and R2 each independently represent a hydrogen atom, a hydroxy group, a carboxy group, a cyano group, a nitro group, a halogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, or a cycloalkyl group having 6 to 20 carbon atoms which may have a substituent. R1 and R2 may be the same or different, and R1 and R2 may be bonded to form a fused ring having no aromaticity. X represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkenyl group having 2 to 20 carbon atoms which may have a substituent, an aralkyl group having 7 to 20 carbon atoms which may have a substituent, or a cycloalkyl group having 6 to 20 carbon atoms which may have a substituent. is a heteroarylalkyl group having a prime number of 4 to 20. Each Y is independently a hydrogen atom, a halogen atom, a hydroxy group, a carboxy group, a cyano group, a nitro group, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxy group having 1 to 20 carbon atoms which may have a substituent, an alkenyl group having 2 to 20 carbon atoms which may have a substituent, an aryl group having 6 to 20 carbon atoms which may have a substituent, an aryloxy group having 6 to 20 carbon atoms which may have a substituent, or an acyl group having 1 to 20 carbon atoms which may have a substituent. Two or more Ys may be bonded to form a monocycle or a condensed ring. Each m is independently an integer of 1 to 4.

[0028] [ka]

[0029] In formula (C2), X represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkenyl group having 2 to 20 carbon atoms which may have a substituent, an aralkyl group having 7 to 20 carbon atoms which may have a substituent, or a heteroarylalkyl group having 4 to 20 carbon atoms which may have a substituent. Each Y represents independently a hydrogen atom, a halogen atom, a hydroxy group, a carboxy group, a cyano group, a nitro group, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxy group having 1 to 20 carbon atoms which may have a substituent, an alkenyl group having 2 to 20 carbon atoms which may have a substituent, an aryl group having 6 to 20 carbon atoms which may have a substituent, an aryloxy group having 6 to 20 carbon atoms which may have a substituent, or a heteroarylalkyl group having 4 to 20 carbon atoms which may have a substituent. and an acyl group having 1 to 20 carbon atoms. Two or more Y's may be bonded to form a monocycle or a condensed ring. Each m is independently an integer of 1 to 4. Each Z is independently a hydrogen atom, a halogen atom, a hydroxy group, a carboxy group, a cyano group, a nitro group, a halogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxy group having 1 to 20 carbon atoms which may have a substituent, an alkenyl group having 2 to 20 carbon atoms which may have a substituent, an aryl group having 6 to 20 carbon atoms which may have a substituent, an aryloxy group having 6 to 20 carbon atoms which may have a substituent, or an acyl group having 1 to 20 carbon atoms which may have a substituent. Two or more Z's may be bonded to form a monocycle or a condensed ring. Each n is independently an integer of 1 to 4.

[0030] [8] A bonded magnet molded from the bonded magnet compound according to any one of [1] to [7].

[0031] [9] A motor molded from the bonded magnet described in [8]. [Effects of the Invention]

[0032] According to the present invention, it is possible to provide a bonded magnet compound, a bonded magnet, and a motor that have high mechanical strength and excellent high-temperature stability even when a thermosetting resin is cured under low-temperature conditions. DETAILED DESCRIPTION OF THE INVENTION

[0033] Hereinafter, a mode for carrying out the present invention (hereinafter referred to as "the present embodiment") will be described in detail. Note that the following present embodiment is an example for explaining the present invention, and the present invention is not limited to the following embodiment. The present invention can be carried out by appropriately modifying it within the scope of its gist.

[0034] In this embodiment, a numerical range indicated using "to" means a range that includes the numerical values before and after "to" as the minimum and maximum values, respectively.

[0035] In the numerical ranges described in this embodiment in stages, the upper or lower limit value described in a certain numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. Furthermore, in the numerical ranges described in this disclosure, the upper or lower limit value described in a certain numerical range may be replaced with a value shown in an example.

[0036] In this embodiment, a combination of two or more preferred aspects is a more preferred aspect.

[0037] In this embodiment, when there are multiple substances corresponding to each component, the amount of each component means the total amount of the multiple substances unless otherwise specified.

[0038] Bonded magnet compound The bonded magnet compound of this embodiment (hereinafter also referred to simply as "compound") is a mixture of a thermosetting resin composition containing an epoxy resin (A), a curing agent (B), and a curing accelerator (C), and magnetic particles (D).

[0039] ≪Thermosetting resin composition≫ The compound contains a thermosetting resin composition (hereinafter simply referred to as "resin composition"). The compound is a mixture of the resin composition and magnetic particles (D). The resin composition undergoes a curing reaction upon heat treatment, forming three-dimensional crosslinks around the magnetic particles (D), so the bonded magnet, which is the cured product of the compound, exhibits high mechanical strength.

[0040] The resin composition is solid at 25° C. In this specification, a resin composition that is solid or solid at 25° C. refers to a resin composition that does not contain a liquid component such as an organic solvent, and whose shape and volume do not easily change due to an external force at 25° C.

[0041] The melt viscosity (X) (mPa·s) of the resin composition at 100° C. satisfies the following formula (1).

[0042] 0.01≦(X)≦30 (1)

[0043] By satisfying the above formula (1), a compound having high mechanical strength and excellent high-temperature stability can be obtained even when the thermosetting resin is cured under low-temperature conditions. Although the reason for this is unclear, the inventors speculate as follows.

[0044] In the production of bonded magnets, improving the adhesion between the resin composition and the magnetic particles (D) is important to achieve both high mechanical strength and excellent high-temperature stability. Therefore, during compound molding, the resin composition is often heated above its softening point (e.g., approximately 100°C) to soften it, thereby promoting the wetting and spreading of the resin composition over the magnetic particle surfaces. The value of (X) in formula (1) indicates the melt viscosity of the resin composition at 100°C. When the value of (X) is within the above range, the resin composition has an appropriate viscosity and can achieve good wetting and spreading. However, if the value of (X) is too small, sedimentation or segregation of the magnetic particles may occur, resulting in a decrease in mechanical strength. Therefore, it is presumed that when the resin composition satisfies the above formula (1), a compound with high mechanical strength and excellent high-temperature stability can be obtained even when the thermosetting resin is cured under low-temperature conditions. However, the reason is not limited to this.

[0045] In this embodiment, the value of (X) is preferably 0.05 or more, more preferably 0.1 or more, and even more preferably 0.5 or more, in order to further suppress sedimentation of the magnetic particles in the resin composition. In order to more easily wet and spread the resin composition on the surfaces of the magnetic particles, the value of (X) is preferably 20 or less, more preferably 15 or less, even more preferably 10 or less, and even more preferably 8 or less. When the value of (X) is within the above range, a compound tends to be obtained that has higher mechanical strength and better high-temperature stability, even when the thermosetting resin is subjected to a curing reaction under low-temperature conditions.

[0046] The melt viscosity (X) can be controlled by adjusting the structure and molecular weight of the epoxy resin and curing agent.

[0047] In the resin composition, (X) (mPa·s) is the melt viscosity of the resin composition at 100°C, and (Y) (mPa·s) is the melt viscosity of the resin composition at 100°C after heating at 100°C for 30 minutes. (X) and (Y) satisfy the following formula (2).

[0048] 1≦(Y) / (X)≦500 (2)

[0049] By satisfying the above formula (2), a compound having high mechanical strength and excellent high-temperature stability can be obtained even when the thermosetting resin is cured under low-temperature conditions. Although the reason for this is unclear, the inventors speculate as follows.

[0050] In bonded magnets obtained using a thermosetting resin composition, the curing reaction of the resin composition progresses over time due to heating during molding, and the viscosity increases. Meanwhile, it takes time for the resin composition to wet and spread over the magnetic particles, so it is important to suppress the viscosity increase of the resin composition for a certain period of time. The value of (Y) / (X) in formula (2) is an index showing the change in viscosity before and after heating the resin composition at 100°C for 30 minutes. A (Y) / (X) value within the above range indicates that the viscosity increase of the resin composition after heating can be effectively suppressed. Note that a smaller (closer to 1) value of (Y) / (X) indicates that the viscosity increase of the resin composition after heating can be effectively suppressed. Therefore, it is presumed that a resin composition satisfying formula (2) above can produce a compound with high mechanical strength and excellent high-temperature stability even when the thermosetting resin is cured under low-temperature conditions. However, the reason for this is not limited to this.

[0051] In this embodiment, in order for the resin composition to wet and spread more easily on the surfaces of the magnetic particles, formula (2) preferably satisfies 1≦(Y) / (X)≦100, more preferably 1≦(Y) / (X)≦50, and even more preferably 1≦(Y) / (X)≦10. When the value of (Y) / (X) is within the above range, a compound tends to be obtained that has higher mechanical strength and better high-temperature stability, even when the thermosetting resin is subjected to a curing reaction under low-temperature conditions.

[0052] Methods for controlling the value of (Y) / (X) in formula (2) include methods for changing the structures of the epoxy resin (A), the curing agent (B), and the curing accelerator (C).

[0053] <Epoxy resin (A)> The resin composition contains an epoxy resin (A), and the epoxy resin (A) contains a structure represented by the following formula (A1): The epoxy resin (A) may be used alone or in combination of two or more types.

[0054] [ka]

[0055] In formula (A1), R 11 ~R 20 are each independently a hydrogen atom, an alkyl group, an aromatic group, a substituent containing a heteroatom, or a substituent containing a halogen atom, and R 11 ~R 20 At least one of R 11 ~R 20 may be the same or different from each other.

[0056] When the epoxy resin (A) contains the above-mentioned specific structure and the compound contains such an epoxy resin, the compound surprisingly exhibits high mechanical strength and excellent high-temperature stability even when the thermosetting resin is cured under low-temperature conditions. Such effects cannot be easily predicted from the structure of the epoxy resin (A), etc.

[0057] Furthermore, in the process of arriving at the compound of this embodiment, the inventors have investigated the effects of epoxy resins having various structures and have found that the epoxy resin (A) of this embodiment is the optimum compound for imparting the above-mentioned effects. Although the mechanism of the above-mentioned effects is unclear, the inventors speculate as follows.

[0058] Aromatic epoxy resins are often used as thermosetting resin components for bonded magnets. Aromatic compounds have a rigid molecular skeleton, which allows them to achieve high mechanical strength and excellent high-temperature stability. However, aromatic compounds are known to have coordination capabilities with metals, and it is thought that when aromatic compounds coexist with metal particles (magnetic particles), the movement of the aromatic compounds is restricted around the metal particles. Therefore, when aromatic epoxy resins are cured, the cross-linked structure around the magnetic particles is disrupted, which may prevent them from achieving high mechanical strength and excellent high-temperature stability.

[0059] On the other hand, it is known that in epoxy resins containing the structure represented by formula (A1), the planes of the two phenyl groups are twisted by approximately 45°. Therefore, even when an epoxy resin containing the structure represented by formula (1) coexists with metal particles (magnetic particles), it is presumed that steric hindrance makes it difficult for the metal particles to coordinate with the epoxy resin. As a result, when an epoxy resin containing the structure represented by formula (1) is cured, a uniform crosslinking reaction is possible even around the magnetic particles, and the bonded magnet is presumed to have high mechanical strength and excellent high-temperature stability. However, the reason is not limited to this.

[0060] In formula (A1), the alkyl group may be linear or branched. The number of carbon atoms in the alkyl group is preferably 1 to 18, more preferably 1 to 15, even more preferably 1 to 10, and even more preferably 1 to 5. Examples of the alkyl group include a methyl group, an ethyl group, an isopropyl group, a butyl group, an isobutyl group, a pentyl group, a hexyl group, an octyl group, a 2-ethylhexyl group, a decyl group, and an undecyl group. When formula (A1) contains such an alkyl group, a compound tends to be obtained that has higher mechanical strength and better high-temperature stability, even when the thermosetting resin is cured under low-temperature conditions.

[0061] Examples of aromatic groups include phenyl, tolyl, xylyl, and naphthyl groups. Examples of aromatic groups include aromatic groups having a hydrocarbon group on a ring with a total of 7 to 20 carbon atoms, such as phenyl and naphthyl groups. Examples of such aromatic groups include groups in which one or more linear or branched alkyl groups having 1 to 10 carbon atoms are introduced on an aromatic ring, such as phenyl and naphthyl groups. The alkyl groups may be as described above. In addition, adjacent aromatic groups may be bonded to each other via a divalent hydrocarbon group. Examples of the divalent hydrocarbon group include divalent hydrocarbon groups having 1 to 20 carbon atoms. Such hydrocarbon groups are preferably alkylene groups. Examples of alkylene groups include methylene, dimethylene, trimethylene, tetramethylene, and octamethylene groups. When the hydrocarbon group is an alkylene group, a compound tends to be obtained that has higher mechanical strength and better high-temperature stability, even when the thermosetting resin is subjected to a curing reaction under low-temperature conditions.

[0062] Examples of the substituent containing a hetero atom include a hydroxy group, a carboxy group, a sulfo group, a phosphate group, a phosphonate group, and a sulfonamide group. Examples of the substituent containing a hetero atom include -OR 1 , -C(=O)-OR 2 , -SR 3 , -S(=O)2-R 4 , and -S(=O)2-OR 5 R 1 ~R 5 Examples of the alkyl group include alkyl groups. For the alkyl group, the above may be referred to.

[0063] Examples of the substituent containing a halogen atom include a halogenated alkyl group. Specific examples include a fluoroalkyl, a difluoroalkyl, a trifluoroalkyl, a chloroalkyl, a dichloroalkyl, and a trichloroalkyl. In this specification, examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0064] The reactive group with the curing agent (B) is not particularly limited as long as it is a group that reacts with a group of the curing agent (B). Such a reactive group may, for example, be an epoxy group.

[0065] R 11 ~R 20 In R, the groups other than the reactive group with the curing agent (B) are each independently preferably a hydrogen atom, an alkyl group, or an aromatic group. 11 ~R 20 When the above condition is satisfied, a compound having higher mechanical strength and superior high-temperature stability tends to be obtained even when the thermosetting resin is subjected to a curing reaction under low-temperature conditions.

[0066] The epoxy resin (A) may have a structure in which units of formula (A1) are bonded to each other. Alternatively, the epoxy resin (A) may have a structure in which adjacent units of formula (A1) are bonded to each other via a divalent hydrocarbon group or aromatic group. The above-mentioned divalent hydrocarbon group may be referred to for the divalent hydrocarbon group.

[0067] Examples of such epoxy resins (A) include biphenyl-type epoxy resins, biphenyl novolac-type epoxy resins, and tetramethyl-type epoxy resins. The epoxy resin (A) preferably contains one or more selected from the group consisting of biphenyl novolac-type epoxy resins and tetramethyl-type epoxy resins, and more preferably contains a biphenyl novolac-type epoxy resin. When the epoxy resin (A) is as described above, a compound tends to be obtained that has higher mechanical strength and better high-temperature stability, even when the thermosetting resin is cured under low-temperature conditions. These may be used alone or in combination of two or more.

[0068] The epoxy resin (A) preferably contains a structure represented by the following formula (A2), since this provides a compound having better high-temperature stability and higher mechanical strength.

[0069] [ka]

[0070] In formula (A2), R 41 ~R 54 are each independently a hydrogen atom, an alkyl group, an aromatic group, a substituent containing a heteroatom, or a substituent containing a halogen atom, and R 41 ~R 54 At least one of R 41 ~R 54 may be the same or different from each other.

[0071] In formula (A2), the alkyl group, aromatic group, substituent containing a hetero atom, substituent containing a halogen atom, and reactive group with curing agent (B) have the same meanings as the alkyl group, aromatic group, substituent containing a hetero atom, substituent containing a halogen atom, and reactive group with curing agent (B) in formula (A1), respectively.

[0072] R 41 ~R 54 In R, the groups other than the reactive group with the curing agent (B) are each independently preferably a hydrogen atom, an alkyl group, or an aromatic group. 41 ~R 54 When the above condition is satisfied, a compound having higher mechanical strength and superior high-temperature stability tends to be obtained even when the thermosetting resin is subjected to a curing reaction under low-temperature conditions.

[0073] The epoxy equivalent of the epoxy resin (A) is preferably 170 or more and 350 or less, more preferably 200 or more and 300 or less, and even more preferably 230 or more and 280 or less. When the epoxy equivalent is within the above range, the melt viscosity (X) value can be easily controlled within a desired range. Furthermore, when the epoxy equivalent is within the above range, a compound tends to be obtained that has higher mechanical strength and better high-temperature stability, even when the thermosetting resin is cured under low-temperature conditions. In this specification, the epoxy equivalent is the mass of the epoxy resin per equivalent of epoxy groups, and can be measured specifically according to JIS K7236.

[0074] The epoxy resin (A) preferably contains an epoxy resin that is solid at room temperature (25°C). The content of the epoxy resin that is solid at room temperature is preferably 50% by mass or more, more preferably 75% by mass or more, even more preferably 95% by mass or more, and even more preferably 100% by mass, relative to the total amount of the epoxy resin (A). The upper limit of the content of the epoxy resin that is solid at room temperature is, for example, 100% by mass or less. When the epoxy resin (A) satisfies the above constitution, blocking during storage of the compound tends to be suppressed. Furthermore, when the epoxy resin (A) satisfies the above constitution, a compound that has higher mechanical strength and better high-temperature stability tends to be obtained, even when the thermosetting resin is subjected to a curing reaction under low-temperature conditions.

[0075] In this specification, an epoxy resin being solid at room temperature (25°C) means that the epoxy resin does not contain any liquid components such as organic solvents, and the shape and volume of the resin do not easily change due to external forces at 25°C. The same definition is also used for the curing agent described below.

[0076] The content of epoxy resin (A) is preferably 0.3 to 20% by mass, more preferably 0.5 to 15% by mass, and even more preferably 0.8 to 10% by mass, relative to the total mass of the bonded magnet compound. By keeping the content of epoxy resin (A) within this range, the bonded magnet tends to have a better balance between magnetic properties and mechanical strength.

[0077] <Curing agent (B)> The resin composition contains a curing agent (B), and the curing agent (B) contains a structure represented by the following formula (B1): The curing agent (B) may be used alone or in combination of two or more types.

[0078] [ka]

[0079] In formula (B1), R 31 ~R 40 are each independently a hydrogen atom, an alkyl group, an aromatic group, a substituent containing a heteroatom, or a substituent containing a halogen atom, and R 31 ~R 40 At least one of R 31 ~R 40 may be the same or different from each other.

[0080] When the compound contains the curing agent (B) having the specific structure described above, the compound surprisingly exhibits high mechanical strength and excellent high-temperature stability even when the thermosetting resin is cured under low-temperature conditions. Such effects cannot be easily predicted from the structure of the curing agent (B).

[0081] Furthermore, in the process of arriving at the compound of this embodiment, the inventors have examined the effects of curing agents having various structures and found that the curing agent (B) of this embodiment is the optimal compound for imparting the above-mentioned effect. Although the mechanism of this effect is unclear, the inventors speculate that the effect is obtained through a mechanism similar to that of the epoxy resin (A) containing the structure represented by the above formula (A1).

[0082] In formula (B1), the reactive group with the alkyl group, aromatic group, substituent containing a hetero atom, and substituent containing a halogen atom has the same meaning as the alkyl group, aromatic group, substituent containing a hetero atom, and substituent containing a halogen atom in formula (A1), respectively.

[0083] The reactive group with the epoxy resin (A) is not particularly limited as long as it is a group that reacts with the epoxy group of the epoxy resin (A), and examples of such reactive groups include a hydroxy group, a mercapto group, an acid anhydride, and a cyanate ester.

[0084] R 31 ~R 40 In the formula, the groups other than the reactive group with the epoxy resin (A) are each independently preferably a hydrogen atom or an aromatic group. The reactive group with the epoxy resin (A) is preferably a hydroxy group. 31 ~R 40 When the above condition is satisfied, the compound tends to have higher mechanical strength and better high-temperature stability even when the thermosetting resin is subjected to a curing reaction under low-temperature conditions.

[0085] The curing agent (B) may have a structure in which units of formula (B1) are bonded to each other. Alternatively, adjacent units of formula (B1) are bonded to each other via a divalent hydrocarbon group or aromatic group, and the curing agent (B) may have a structure having this unit structure. For the divalent hydrocarbon group, the above may be referred to.

[0086] Examples of such curing agents (B) include phenolic resins. The phenolic resins preferably include biphenyl-type phenolic resins and biphenyl novolac-type phenolic resins, and more preferably biphenyl novolac-type phenolic resins. When the curing agent (B) is as described above, the bonded magnet tends to have higher mechanical strength and even better high-temperature stability. These may be used alone or in combination of two or more.

[0087] The curing agent (B) preferably contains a structure represented by the following formula (B2), since this provides a compound having better high-temperature stability and higher mechanical strength.

[0088] [ka]

[0089] In formula (B2), R 61 ~R 74 are each independently a hydrogen atom, an alkyl group, an aromatic group, a substituent containing a heteroatom, or a substituent containing a halogen atom, and R 61 ~R 74 At least one of the groups contains a reactive group with the epoxy resin (A), and R 61 ~R 74 may be the same or different from each other.

[0090] In formula (B2), the alkyl group, aromatic group, substituent containing a hetero atom, substituent containing a halogen atom, and reactive group with epoxy resin (A) have the same meanings as the alkyl group, aromatic group, substituent containing a hetero atom, substituent containing a halogen atom, and reactive group with epoxy resin (A) in formula (B1), respectively.

[0091] R 61 ~R 74 In the formula, the groups other than the reactive group with the epoxy resin (A) are each independently preferably a hydrogen atom or an aromatic group. The reactive group with the epoxy resin (A) is preferably a hydroxy group. 61~R 74 When the above condition is satisfied, a compound having higher mechanical strength and superior high-temperature stability tends to be obtained even when the thermosetting resin is subjected to a curing reaction under low-temperature conditions.

[0092] When the curing agent (B) has a hydroxy group as a reactive group with the epoxy resin (A), the hydroxy group equivalent of the curing agent (B) is preferably 100 or more and 350 or less, more preferably 130 or more and 300 or less, and even more preferably 160 or more and 250 or less. Having a hydroxy group equivalent within the above range makes it easier to control the melt viscosity (X) value within a desired range. Furthermore, having a hydroxy group equivalent within the above range tends to result in a compound having higher mechanical strength and superior high-temperature stability even when the thermosetting resin is cured under low-temperature conditions. In this specification, the hydroxy group equivalent can be calculated by dividing the molecular weight of KOH by the hydroxy group value measured according to JIS K1557-1.

[0093] The curing agent (B) preferably contains a curing agent that is solid at room temperature (25°C). The content of the curing agent that is solid at room temperature is preferably 50% by mass or more, more preferably 75% by mass or more, even more preferably 95% by mass or more, and even more preferably 100% by mass, relative to the total amount of the curing agent (B). The upper limit of the content of the curing agent that is solid at room temperature is, for example, 100% by mass or less. When the curing agent (B) satisfies the above constitution, blocking during storage of the compound tends to be suppressed. Furthermore, when the curing agent (B) satisfies the above constitution, a compound that has higher mechanical strength and better high-temperature stability tends to be obtained, even when a thermosetting resin is subjected to a curing reaction under low-temperature conditions.

[0094] The content of curing agent (B) is preferably 0.3% by mass or more and 20% by mass or less, more preferably 0.5% by mass or more and 15% by mass or less, and even more preferably 0.8% by mass or more and 10% by mass or less, based on the total mass of the bonded magnet compound. By keeping the content of curing agent (B) within this range, the bonded magnet tends to be able to more favorably achieve both magnetic properties and mechanical strength. Furthermore, by keeping the content of curing agent (B) within this range, the compound tends to have higher mechanical strength and better high-temperature stability, even when the thermosetting resin is cured under low-temperature conditions.

[0095] When the curing agent (B) has a hydroxyl group as a reactive group with the epoxy resin (A), the ratio of the epoxy group to its hydroxyl group in the epoxy resin is preferably 0.5 to 1.5 equivalents, more preferably 0.7 to 1.4 equivalents, and even more preferably 0.8 to 1.3 equivalents, per equivalent of the epoxy group in the epoxy resin. When the ratio satisfies the above range, the bonded magnet tends to have better high-temperature stability as well as higher mechanical properties and heat resistance.

[0096] <Curing accelerator (C)> The resin composition contains a curing accelerator (C). The curing accelerator (C) may be used alone or in combination of two or more.

[0097] The curing accelerator (C) is not particularly limited as long as it is a compound or composition that accelerates the polymerization reaction between the epoxy resin (A) and the curing agent (B).

[0098] The curing accelerator (C) preferably contains a latent curing accelerator, since this provides a bonded magnet with better storage stability and higher fixing strength when cured at low temperatures. Furthermore, by including a latent curing accelerator in the curing accelerator (C), a compound tends to be obtained that has higher mechanical strength and better high-temperature stability even when the thermosetting resin is cured under low-temperature conditions.

[0099] Examples of the latent curing accelerator include phosphorus-based curing accelerators; imidazole compounds; onium salts; amine-based adduct compounds; microcapsule-type curing agents obtained by coating these; and curing accelerators obtained by adsorbing these onto a porous body.

[0100] Examples of phosphorus-based curing accelerators include tetrabutylphosphonium tetraphenylborate and triphenylborane-triphenylphosphine complex.

[0101] Examples of onium salts include aromatic diazonium salts, aromatic sulfonium salts, and aliphatic sulfonium salts.

[0102] Examples of amine-based adduct compounds include amine-epoxy adducts, amine-urea adducts, and compounds obtained by reacting one or more selected from the group consisting of carboxylic acid compounds, sulfonic acid compounds, urea compounds, isocyanate compounds, and epoxy resins with an amine-based curing agent. Examples of amine-based curing agents include aliphatic amines and aromatic amines. Examples of aliphatic amines include diethylenetriamine, triethylenetetramine, tetraethylenepentamine, m-xylenediamine, trimethylhexamethylenediamine, 2-methylpentamethylenediamine, isophoronediamine, 1,3-bisaminomethylcyclohexane, bis(4-aminocyclohexyl)methane, norbornenediamine, and 1,2-diaminocyclohexane. Aromatic amines include, for example, diaminodiphenylmethane, m-phenylenediamine, diaminodiphenylsulfone, diethyltoluenediamine, trimethylenebis(4-aminobenzoate), and polytetramethyleneoxide-di-p-aminobenzoate.

[0103] The curing accelerator (C) preferably contains an imidazole compound, since this allows a compound with superior mechanical strength to be obtained. Furthermore, when the curing accelerator (C) contains an imidazole compound, a compound with even higher mechanical strength and even better high-temperature stability tends to be obtained, even when the thermosetting resin is cured under low-temperature conditions.

[0104] Since the compound tends to have higher mechanical strength and even better high-temperature stability, the molecular weight of the imidazole compound is preferably from 120 to 500, more preferably from 140 to 450, even more preferably from 160 to 400, and even more preferably from 160 to 360. When the molecular weight of the imidazole compound is within the above range, a compound tends to be obtained that has even higher mechanical strength and even better high-temperature stability, even when the thermosetting resin is cured under low-temperature conditions.

[0105] Examples of the imidazole compound include imidazole, 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenylimidazole, 1-benzyl-2-phenylimidazole, benzimidazole, 2-phenylbenzimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-1-methylimidazole, 1-Cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazole, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenyl-4,5-dihydroxy imidazoles such as dimethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 1-aminoethyl-2-methylimidazole, 1-(2-hydroxy-3-phenoxypropyl)-2-methylimidazole, 1-(2-hydroxy-3-phenoxypropyl)-2-ethyl-4-methylimidazole, 1-(2-hydroxy-3-butoxypropyl)-2-methylimidazole, and 1-(2-hydroxy-3-butoxypropyl)-2-ethyl-4-methylimidazole, compounds represented by the following formula (C1), imidazoles such as compounds represented by the following formula (C2), and compounds having an imidazole structure obtained by reacting these imidazole compounds with one or more members selected from the group consisting of carboxylic acid compounds, sulfonic acid compounds, urea compounds, isocyanate compounds, and epoxy resins.

[0106] It is preferred that the imidazole compound have at least one hydroxy group, as the compound tends to have higher mechanical strength as well as better high temperature stability.

[0107] Since the compound tends to have even better high-temperature stability, even higher mechanical strength, and even better moist heat stability, it is more preferable that the imidazole compound includes one or more compounds selected from the group consisting of compounds represented by the following formula (C1) and compounds represented by the following formula (C2):

[0108] [ka]

[0109] In formula (C1), R1 and R2 each independently represent a hydrogen atom, a hydroxy group, a carboxy group, a cyano group, a nitro group, a halogen atom, an optionally substituted alkyl group having 1 to 20 carbon atoms, or an optionally substituted cycloalkyl group having 6 to 20 carbon atoms. R1 and R2 may be the same or different, and R1 and R2 may be bonded to form a non-aromatic fused ring. X is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkenyl group having 2 to 20 carbon atoms which may have a substituent, an aralkyl group having 7 to 20 carbon atoms which may have a substituent, or a heteroarylalkyl group having 4 to 20 carbon atoms which may have a substituent. Each Y is independently a hydrogen atom, a halogen atom, a hydroxy group, a carboxy group, a cyano group, a nitro group, an alkyl group of 1 to 20 carbon atoms which may have a substituent, an alkoxy group of 1 to 20 carbon atoms which may have a substituent, an alkenyl group of 2 to 20 carbon atoms which may have a substituent, an aryl group of 6 to 20 carbon atoms which may have a substituent, an aryloxy group of 6 to 20 carbon atoms which may have a substituent, or an acyl group of 1 to 20 carbon atoms which may have a substituent. Two or more Ys may be bonded to form a monocycle or a condensed ring. Each m is independently an integer of 1 to 4.

[0110] [ka]

[0111] In formula (C2), X is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkenyl group having 2 to 20 carbon atoms which may have a substituent, an aralkyl group having 7 to 20 carbon atoms which may have a substituent, or a heteroarylalkyl group having 4 to 20 carbon atoms which may have a substituent. Each Y is independently a hydrogen atom, a halogen atom, a hydroxy group, a carboxy group, a cyano group, a nitro group, an alkyl group of 1 to 20 carbon atoms which may have a substituent, an alkoxy group of 1 to 20 carbon atoms which may have a substituent, an alkenyl group of 2 to 20 carbon atoms which may have a substituent, an aryl group of 6 to 20 carbon atoms which may have a substituent, an aryloxy group of 6 to 20 carbon atoms which may have a substituent, or an acyl group of 1 to 20 carbon atoms which may have a substituent. Two or more Ys may be bonded to form a monocycle or a condensed ring. Each m is independently an integer of 1 to 4. Each Z is independently a hydrogen atom, a halogen atom, a hydroxy group, a carboxy group, a cyano group, a nitro group, a halogen atom, an alkyl group of 1 to 20 carbon atoms which may have a substituent, an alkoxy group of 1 to 20 carbon atoms which may have a substituent, an alkenyl group of 2 to 20 carbon atoms which may have a substituent, an aryl group of 6 to 20 carbon atoms which may have a substituent, an aryloxy group of 6 to 20 carbon atoms which may have a substituent, or an acyl group of 1 to 20 carbon atoms which may have a substituent. Two or more Zs may be bonded to form a monocycle or a condensed ring. Each n is independently an integer of 1 to 4.

[0112] In formula (C1), the alkyl group having 1 to 20 carbon atoms, which may have a substituent, represented by R1, R2, X, and Y, may be linear or branched. The number of carbon atoms in the alkyl group is preferably 1 to 18, more preferably 1 to 15, even more preferably 1 to 10, and even more preferably 1 to 5. When the number of carbon atoms in the alkyl group is within the above range, a compound tends to be obtained that has higher mechanical strength and better high-temperature stability, even when a thermosetting resin is cured under low-temperature conditions. In formula (C2), the alkyl group having 1 to 20 carbon atoms, which may have a substituent, represented by X, Y, and Z can refer to the alkyl group having 1 to 20 carbon atoms, which may have a substituent, in formula (C1). In addition, examples of the alkyl group having 1 to 20 carbon atoms include those exemplified in formula (A1) above.

[0113] In formula (C1), the carbon number of the cycloalkyl group having 6 to 20 carbon atoms, which may have a substituent, in R1 and R2 is preferably 6 to 18, more preferably 6 to 15. When the carbon number of the cycloalkyl group is within the above range, a compound having higher mechanical strength and superior high-temperature stability tends to be obtained even when the thermosetting resin is cured under low-temperature conditions. Examples of such cycloalkyl groups include a cyclohexyl group, a cycloheptane group, and a cyclooctane group.

[0114] In formula (C1), examples of the non-aromatic fused ring that can be formed by combining R1 and R2 include cyclopentane, cyclohexane, and dicyclopentadiene.

[0115] The alkyl group having 1 to 20 carbon atoms, the cycloalkyl group having 6 to 20 carbon atoms, and the non-aromatic fused ring that may be formed by bonding R1 and R2 may have a substituent. Examples of the substituent include a halogen atom, a cyano group, a hydroxy group, an alkoxy group, an amino group, an ester group, an arylsulfonyl group, an alkylsulfonyl group, a phenyl group, and a nitro group. Preferred examples of the substituent include a hydroxy group and an alkoxy group. When the substituent is one of the above, a compound tends to be obtained that has higher mechanical strength and better high-temperature stability even when the thermosetting resin is cured under low-temperature conditions. Specific examples of these substituents may be found in the examples of groups described herein.

[0116] In formula (C1), the alkenyl groups having 2 to 20 carbon atoms in X and Y, which may have a substituent, may be linear or branched. The number of carbon atoms in the alkenyl group is preferably 2 to 18, more preferably 2 to 15. When the number of carbon atoms in the alkenyl group is within the above range, a compound tends to be obtained that has higher mechanical strength and better high-temperature stability, even when the thermosetting resin is cured under low-temperature conditions. Examples of such alkenyl groups include vinyl groups, aryl groups, 1-propenyl groups, isopropenyl groups, 2-butenyl groups, 3-butenyl groups, 2-pentenyl groups, and 2-hexenyl groups. In formula (C2), the alkenyl groups having 2 to 20 carbon atoms, which may have a substituent, in X, Y, and Z can refer to the alkenyl groups having 2 to 20 carbon atoms, which may have a substituent, in formula (C1).

[0117] In formula (C1), the aralkyl group having 7 to 20 carbon atoms, which may have a substituent, for X may be linear or branched. The number of carbon atoms in the aralkyl group is preferably 7 to 18, more preferably 7 to 15. When the number of carbon atoms in the aralkyl group is within the above range, a compound tends to be obtained that has higher mechanical strength and better high-temperature stability, even when a thermosetting resin is cured under low-temperature conditions. Examples of such aralkyl groups include a benzyl group, a phenethyl group, and a naphthylmethyl group. In formula (C2), the aralkyl group having 7 to 20 carbon atoms, which may have a substituent, for X can refer to the aralkyl group having 7 to 20 carbon atoms, which may have a substituent, in formula (C1).

[0118] In formula (C1), the heteroarylalkyl group having 4 to 20 carbon atoms, which may have a substituent, for X may be linear or branched. The number of carbon atoms in the heteroarylalkyl group is preferably 4 to 18, more preferably 4 to 15. When the number of carbon atoms in the heteroarylalkyl group is within the above range, a compound tends to be obtained that has higher mechanical strength and better high-temperature stability, even when a thermosetting resin is cured under low-temperature conditions. Examples of such heteroarylalkyl groups include a triazinylmethyl group, a triazinylethyl group, a 2-pyridylmethyl group, a 2-pyridylethyl group, a 3-pyridylmethyl group, a 3-pyridylethyl group, a 4-pyridylmethyl group, and a 4-pyridylethyl group. In formula (C2), the heteroarylalkyl group having 4 to 20 carbon atoms, which may have a substituent, for X can refer to the heteroarylalkyl group having 4 to 20 carbon atoms, which may have a substituent, for formula (C1).

[0119] The alkenyl group having 2 to 20 carbon atoms, the aralkyl group having 7 to 20 carbon atoms, and the heteroarylalkyl group having 4 to 20 carbon atoms may have a substituent. Examples of the substituent include a halogen atom, a cyano group, a nitro group, a hydroxy group, an alkoxy group, an amino group, an ester group, an arylsulfonyl group, an alkylsulfonyl group, and a phenyl group. Preferred examples of the substituent are a cyano group, an alkoxy group, an amino group, an ester group, and a phenyl group. Specific examples of these substituents may be found in the examples of groups described in this specification.

[0120] In formula (C1), the alkoxy group having 1 to 20 carbon atoms, which may have a substituent, for Y may be linear or branched. The number of carbon atoms in the alkoxy group is preferably 1 to 18, more preferably 1 to 15. When the number of carbon atoms in the alkoxy group is within the above range, a compound tends to be obtained that has higher mechanical strength and better high-temperature stability, even when a thermosetting resin is cured under low-temperature conditions. Examples of such alkoxy groups include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, a hexyloxy group, and a 2-ethylhexyloxy group. In formula (C2), the alkoxy group having 1 to 20 carbon atoms, which may have a substituent, for Y and Z can refer to the alkoxy group having 1 to 20 carbon atoms, which may have a substituent, in formula (C1).

[0121] In formula (C1), the carbon number of the aryl group having 6 to 20 carbon atoms, which may have a substituent, in Y is preferably 6 to 18, and more preferably 6 to 15. When the carbon number of the aryl group is within the above range, a compound tends to be obtained that has higher mechanical strength and better high-temperature stability, even when the thermosetting resin is cured under low-temperature conditions. Examples of such aryl groups include a phenyl group, a naphthyl group, an anthracenyl group, and a biphenyl group. In formula (C2), the aryl group having 6 to 20 carbon atoms, which may have a substituent, in Y and Z can refer to the aryl group having 6 to 20 carbon atoms, which may have a substituent, in formula (C1).

[0122] In formula (C1), the carbon number of the aryloxy group having 6 to 20 carbon atoms, which may have a substituent, in Y is preferably 6 to 18, and more preferably 6 to 15. When the carbon number of the aryloxy group is within the above range, a compound tends to be obtained that has higher mechanical strength and better high-temperature stability, even when a thermosetting resin is cured under low-temperature conditions. Examples of such aryloxy groups include a phenyloxy group, a naphthyloxy group, an anthracenyloxy group, and a biphenyloxy group. In formula (C2), the aryloxy group having 6 to 20 carbon atoms, which may have a substituent, in Y and Z can refer to the aryloxy group having 6 to 20 carbon atoms, which may have a substituent, in formula (C1).

[0123] In formula (C1), the carbon number of the acyl group having 1 to 20 carbon atoms, which may have a substituent, in Y is preferably 1 to 18, and more preferably 1 to 15. When the carbon number of the acyl group is within the above range, a compound tends to be obtained that has higher mechanical strength and better high-temperature stability, even when the thermosetting resin is cured under low-temperature conditions. Examples of such acyl groups include an acetyl group, a benzoyl group, and a pivaloyl group. In formula (C2), the acyl group having 1 to 20 carbon atoms, which may have a substituent, in Y and Z can refer to the acyl group having 1 to 20 carbon atoms, which may have a substituent, in formula (C1).

[0124] In formula (C1), examples of the structure in which two or more Y's are bonded to form a monocyclic or fused ring include a naphthyl group and an anthracenyl group. In formula (C2), examples of the structure in which two or more Y's are bonded to form a monocyclic or fused ring and the structure in which two or more Z's are bonded to form a monocyclic or fused ring refer to the structure in formula (C1) in which two or more Y's are bonded to form a monocyclic or fused ring.

[0125] The alkoxy group having 1 to 20 carbon atoms, the aryl group having 6 to 20 carbon atoms, the aryloxy group having 6 to 20 carbon atoms, and the acyl group having 1 to 20 carbon atoms may have a substituent. Examples of the substituent include an alkyl group, a halogen atom, a hydroxy group, a carboxy group, an alkoxy group, a nitro group, an ester group, and a phenyl group. Preferred examples of the substituent are an alkyl group, a hydroxy group, a carboxy group, and an alkoxy group. Specific examples of these substituents may be found by reference to the examples of groups described in this specification.

[0126] In formula (C1), Y may be substituted at any of the ortho, meta, and para positions of the phenyl group that is the substituent at the 2-position of the imidazole. When the phenyl group has a substituent, it is preferably substituted at a position other than the ortho position, more preferably at least at the meta position, and even more preferably at the meta position with a hydroxy group or an alkoxy group having 1 to 20 carbon atoms that may have a substituent. When the phenyl group has such a substituent, a compound tends to be obtained that has higher mechanical strength and better high-temperature stability even when the thermosetting resin is cured under low-temperature conditions. Y in formula (C2) has the same meaning as Y in formula (C1).

[0127] Y in formula (C1), or Y and Z in formula (C2), are each preferably independently a hydrogen atom, a hydroxy group, a carboxy group, an unsubstituted alkoxy group having 1 to 20 carbon atoms, an alkyl group having 1 to 20 carbon atoms and having at least one substituent selected from the group consisting of hydroxy groups and carboxy groups, an alkoxy group having 1 to 20 carbon atoms and having at least one substituent selected from the group consisting of hydroxy groups and carboxy groups, an aryl group having 6 to 20 carbon atoms and having at least one substituent selected from the group consisting of hydroxy groups and carboxy groups, an aryloxy group having 6 to 20 carbon atoms and having at least one substituent selected from the group consisting of hydroxy groups and carboxy groups, or an acyl group having 1 to 20 carbon atoms and having at least one substituent selected from the group consisting of hydroxy groups and carboxy groups. When Y and Z are as described above, the compound tends to have higher mechanical strength and better high-temperature stability, even when the thermosetting resin is cured under low-temperature conditions.

[0128] It is more preferable that Y in formula (C1), or Y and Z in formula (C2), are each independently a hydroxy group, a carboxy group, an unsubstituted alkoxy group having 1 to 20 carbon atoms, an alkyl group having 1 to 20 carbon atoms and having at least one substituent selected from the group consisting of hydroxy groups and carboxy groups, an alkoxy group having 1 to 20 carbon atoms and having at least one substituent selected from the group consisting of hydroxy groups and carboxy groups, an aryl group having 6 to 20 carbon atoms and having at least one substituent selected from the group consisting of hydroxy groups and carboxy groups, an aryloxy group having 6 to 20 carbon atoms and having at least one substituent selected from the group consisting of hydroxy groups and carboxy groups, or an acyl group having at least one substituent selected from the group consisting of hydroxy groups and carboxy groups. When Y is as described above, the coordination ability to metal particles is further increased, which tends to further improve the mechanical strength of the bonded magnet.

[0129] Examples of the compound represented by the above formula (C1) include the following imidazole compounds.

[0130] Examples of such compounds include 4,5-bis(hydroxymethyl)-2-phenylimidazole, (4-methyl-2-phenyl-imidazol-5-yl)methanol, 2-(2-hydroxyphenyl)imidazole, 2-(2-hydroxyphenyl)-4(5)-methylimidazole, 4(5)-ethyl-2-(2-hydroxyphenyl)imidazole, 4,5-dimethyl-2-(2-hydroxyphenyl)imidazole, 4-ethyl-(2-hydroxyphenyl)-5-methylimidazole, (2-hydroxyphenyl)-4-isopropyl-5-methylimidazole, 4-butyl-(2-hydroxyphenyl)-5-methylimidazole, 2-(2-hydroxy-3-methylphenyl)imidazole, 2-(2-hydroxy ... 4-isopropyl-5-methylimidazole, 4-butyl-(2-hydroxy-3-methylphenyl)-5-methylimidazole, 2-(2-hydroxy-4-methylphenyl)imidazole, 2-(2-hydroxy-4-methylphenyl)-4(5)-methylimidazole, and 4(5)-ethyl-2-(2-hydroxy-4-methylphenyl)imidazole.

[0131] Examples of such compounds include 4,5-dimethyl-2-(2-hydroxy-4-methylphenyl)imidazole, 4-ethyl-(2-hydroxy-4-methylphenyl)-5-methylimidazole, (2-hydroxy-4-methylphenyl)-4-isopropyl-5-methylimidazole, 4-butyl-(2-hydroxy-4-methylphenyl)-5-methylimidazole, 2-(2-hydroxy-5-methylphenyl)imidazole, 2-(2-hydroxy-5-methylphenyl)-4(5)-methylimidazole, and 4(5)-ethyl-2-(2-hydroxy-5-methylphenyl)imidazo imidazole, 4,5-dimethyl-2-(2-hydroxy-5-methylphenyl)imidazole, 4-ethyl-(2-hydroxy-5-methylphenyl)-5-methylimidazole, (2-hydroxy-5-methylphenyl)-4-isopropyl-5-methylimidazole, 4-butyl-(2-hydroxy-5-methylphenyl)-5-methylimidazole, 2-(3-t-butyl-2-hydroxyphenyl)imidazole, 2-(3-t-butyl-2-hydroxyphenyl)-4(5)-methylimidazole, and 2-(3-t-butyl-2-hydroxyphenyl)-4(5)-ethylimidazole.

[0132] Further examples of such compounds include 2-(3-t-butyl-2-hydroxyphenyl)-4,5-dimethylimidazole, 2-(3-t-butyl-2-hydroxyphenyl)-4-ethyl-5-methylimidazole, 2-(3-t-butyl-2-hydroxyphenyl)-4-isopropyl-5-methylimidazole, 4-butyl-2-(3-t-butyl-2-hydroxyphenyl)-5-methylimidazole, 2-(4-fluoro-2-hydroxyphenyl)imidazole, 2-(4-fluoro-2-hydroxyphenyl)-4(5)-methylimidazole, 2-(4-fluoro-2-hydroxyphenyl)-4(5)- ethylimidazole, 2-(4-fluoro-2-hydroxyphenyl)-4,5-dimethylimidazole, 4-ethyl-2-(4-fluoro-2-hydroxyphenyl)-5-methylimidazole, 2-(4-fluoro-2-hydroxyphenyl)-4-isopropyl-5-methylimidazole, 4-butyl-2-(4-fluoro-2-hydroxyphenyl)-5-methylimidazole, 2-(4-chloro-2-hydroxyphenyl)imidazole, 2-(4-chloro-2-hydroxyphenyl)-4(5)-methylimidazole, and 2-(4-chloro-2-hydroxyphenyl)-4(5)-ethylimidazole.

[0133] Furthermore, examples of such compounds include 2-(4-chloro-2-hydroxyphenyl)-4,5-dimethylimidazole, 2-(4-chloro-2-hydroxyphenyl)-4-ethyl-5-methylimidazole, 2-(4-chloro-2-hydroxyphenyl)-4-isopropyl-5-methylimidazole, 4-butyl-2-(4-chloro-2-hydroxyphenyl)-5-methylimidazole, 2-(4-bromo-2-hydroxyphenyl)imidazole, 2-(4-bromo-2-hydroxyphenyl)-4(5)-methylimidazole, and ethylimidazole, 2-(4-bromo-2-hydroxyphenyl)-4(5)-ethylimidazole, 2-(4-bromo-2-hydroxyphenyl)-4,5-dimethylimidazole, 2-(4-bromo-2-hydroxyphenyl)-4-ethyl-5-methylimidazole, 2-(4-bromo-2-hydroxyphenyl)-4-isopropyl-5-methylimidazole, 2-(4-bromo-2-hydroxyphenyl)-4-butyl-5-methylimidazole, and 2-(2,3-dihydroxyphenyl)imidazole.

[0134] Furthermore, examples of such compounds include 2-(2,3-dihydroxyphenyl)-4(5)-methylimidazole, 2-(2,3-dihydroxyphenyl)-4(5)-ethylimidazole, 2-(2,3-dihydroxyphenyl)-4,5-dimethylimidazole, 2-(2,3-dihydroxyphenyl)-4(5)-phenylimidazole, 2-(2,3-dihydroxyphenyl)-4,5-diphenylimidazole, 2-(2,5-dihydroxyphenyl)imidazole, 2-(2,5-dihydroxyphenyl)-4(5)-methylimidazole, 2-(2,5-dihydroxyphenyl)-4(5)-ethylimidazole, 2-(2,5-dihydroxyphenyl)-4,5-dimethylimidazole, 2-(2,5-dihydroxyphenyl)-4(5)-phenylimidazole, 2-(2,5 4,5-dihydroxyphenyl)-4,5-diphenylimidazole, 2-(2-hydroxy-4-methoxyphenyl)imidazole, 2-(2-hydroxy-4-methoxyphenyl)-4(5)-methylimidazole, 4(5)-ethyl-2-(2-hydroxy-4-methoxyphenyl)imidazole, 4,5-dimethyl-2-(2-hydroxy-4-methoxyphenyl)imidazole, 2-(2-hydroxy-4-methoxyphenyl)-4(5)-phenylimidazole, 4,5-diphenyl-2-(2-hydroxy-4-methoxyphenyl)imidazole, 2-(2-hydroxy-3-methoxyphenyl)imidazole, 2-(2-hydroxy-3-methoxyphenyl)-4(5)-methylimidazole, and 4(5)-ethyl-2-(2-hydroxy-3-methoxyphenyl)imidazole.

[0135] Examples of such compounds include 4,5-dimethyl-2-(2-hydroxy-3-methoxyphenyl)imidazole, 2-(2-hydroxy-3-methoxyphenyl)-4(5)-phenylimidazole, 4,5-diphenyl-2-(2-hydroxy-3-methoxyphenyl)imidazole, 2-(2-hydroxy-3(5)-methoxyphenyl)imidazole, 2-(2-hydroxy-5-methoxyphenyl)-4(5)-methylimidazole, 4(5)-ethyl-2-(2-hydroxy-5-methoxyphenyl)imidazole, 4,5-dimethyl-2-(2-hydroxy-5-methoxyphenyl)imidazole, 2-(2-hydroxy-5-methoxyphenyl)-4(5)-phenylimidazole, 4,5-diphenyl-2-(2-hydroxy-5-methoxyphenyl)imidazole, 2-(2-hydroxy-6-methoxyphenyl)imidazole, azole, 2-(2-hydroxy-6-methoxyphenyl)-4(5)-methylimidazole, 4(5)-ethyl-2-(2-hydroxy-6-methoxyphenyl)imidazole, 4,5-dimethyl-2-(2-hydroxy-6-methoxyphenyl)imidazole, 2-(2-hydroxy-6-methoxyphenyl)-4(5)-phenylimidazole, 4,5-diphenyl-2-(2-hydroxy-6-methoxyphenyl)imidazo imidazole, 2-(3-ethoxy-2-hydroxyphenyl)imidazole, 2-(3-ethoxy-2-hydroxyphenyl)-4(5)-methylimidazole, 2-(3-ethoxy-2-hydroxyphenyl)-4(5)-ethylimidazole, 4,5-dimethyl-2-(3-ethoxy-2-hydroxyphenyl)imidazole, and 2-(3-ethoxy-2-hydroxyphenyl)-4(5)-phenylimidazole.

[0136] Further, examples of such compounds include 4,5-diphenyl-2-(3-ethoxy-2-hydroxyphenyl)imidazole, 2-(5-ethoxy-2-hydroxyphenyl)imidazole, 2-(5-ethoxy-2-hydroxyphenyl)imidazole, 2-(5-ethoxy-2-hydroxyphenyl)-4(5)-methylimidazole, 2-(5-ethoxy-2-hydroxyphenyl)-4(5)-ethylimidazole, 4,5-dimethyl-2-(5-ethoxy-2-hydroxyphenyl)imidazole, 2-(5-ethoxy-2-hydroxyphenyl)-4(5)-phenylimidazole, 4,5-diphenyl-2-(5-ethoxy-2-hydroxyphenyl)imidazole, 2-(4-allyl 2-(4-allyl-2-hydroxy-3-methoxyphenyl)imidazole, 2-(4-allyl-2-hydroxy-3-methoxyphenyl)-4(5)-methylimidazole, 2-(4-allyl-2-hydroxy-3-methoxyphenyl)-4(5)-ethylimidazole, 2-(4-allyl-2-hydroxy-3-methoxyphenyl)-4,5-dimethylimidazole, 2-(4-allyl-2-hydroxy-3-methoxyphenyl)-4(5)-phenylimidazole, 2-(4-allyl-2-hydroxy-3-methoxyphenyl)-4,5-diphenylimidazole, and 2-(4,6-dimethoxy-2-hydroxyphenyl)imidazole.

[0137] Furthermore, examples of such compounds include 2-(4,6-dimethoxy-2-hydroxyphenyl)-4(5)-methylimidazole, 2-(4,6-dimethoxy-2-hydroxyphenyl)-4(5)-ethylimidazole, 2-(4,6-dimethoxy-2-hydroxyphenyl)-4,5-dimethylimidazole, 2-(4,6-dimethoxy-2-hydroxyphenyl)-4(5)-phenylimidazole, 2-(4,6-dimethoxy-2-hydroxyphenyl)-4,5-diphenylimidazole, 2-(2-fluoro-5-hydroxyphenyl)imidazole, 2-(2-fluoro-5-hydroxyphenyl)- Examples include 4(5)-methylimidazole, 2-(2-fluoro-5-hydroxyphenyl)-4(5)-ethylimidazole, 2-(2-fluoro-5-hydroxyphenyl)-4,5-dimethylimidazole, 2-(2-fluoro-5-hydroxyphenyl)-4(5)-phenylimidazole, 2-(2-fluoro-5-hydroxyphenyl)-4,5-diphenylimidazole, 2-(5-fluoro-2-hydroxyphenyl)imidazole, 2-(5-fluoro-2-hydroxyphenyl)-4(5)-methylimidazole, and 2-(5-fluoro-2-hydroxyphenyl)-4(5)-ethylimidazole.

[0138] Furthermore, examples of such compounds include 2-(5-fluoro-2-hydroxyphenyl)-4,5-dimethylimidazole, 2-(5-fluoro-2-hydroxyphenyl)-4(5)-phenylimidazole, 2-(5-fluoro-2-hydroxyphenyl)-4,5-diphenylimidazole, 2-(5-chloro-2-hydroxyphenyl)imidazole, 2-(5-chloro-2-hydroxyphenyl)-4(5)-methylimidazole, 2-(5-chloro-2-hydroxyphenyl)-4(5)-ethylimidazole, 2-(5-chloro-2-hydroxyphenyl)-4,5-dimethylimidazole, 2-(5-chloro-2-hydroxyphenyl)-4(5)-phenylimidazole, nilic imidazole, 2-(5-chloro-2-hydroxyphenyl)-4,5-diphenylimidazole, 2-(5-bromo-2-hydroxyphenyl)imidazole, 2-(5-bromo-2-hydroxyphenyl)-4(5)-methylimidazole, 2-(5-bromo-2-hydroxyphenyl)-4(5)-ethylimidazole, 2-(5-bromo-2-hydroxyphenyl)-4,5-dimethylimidazole, 2-(5-bromo-2-hydroxyphenyl)-4(5)-phenylimidazole, 2-(5-bromo-2-hydroxyphenyl)-4,5-diphenylimidazole, and 2-(6-fluoro-2-hydroxy-3-methoxyphenyl)imidazole.

[0139] Examples of such compounds include 2-(6-fluoro-2-hydroxy-3-methoxyphenyl)-4(5)-methylimidazole, 2-(6-fluoro-2-hydroxy-3-methoxyphenyl)-4(5)-ethylimidazole, 2-(6-fluoro-2-hydroxy-3-methoxyphenyl)-4,5-dimethylimidazole, 2-(6-fluoro-2-hydroxy-3-methoxyphenyl)-4(5)-phenylimidazole, 2-(6-fluoro-2-hydroxy-3-methoxyphenyl)-4,5-diphenylimidazole, 2-(1-hydroxynaphthalen-2-yl)imidazole, 2-(1-hydroxynaphthalen-2-yl)-4(5)-methylimidazole, 2-(1-hydroxynaphthalen-2-yl)-4(5)-ethyl imidazole, 4,5-dimethyl-2-(1-hydroxynaphthalen-2-yl)imidazole, 2-(1-hydroxynaphthalen-2-yl)-4(5)-phenylimidazole, 4,5-diphenyl-2-(1-hydroxynaphthalen-2-yl)imidazole, 2-(2-hydroxynaphthalen-1-yl)imidazole, 2-(2-hydroxynaphthalen-1-yl)-4(5)-methylimidazole, 2-(2-hydroxynaphthalen-1-yl)-4(5)-ethylimidazole, 4,5-dimethyl-2-(2-hydroxynaphthalen-1-yl)imidazole, 2-(2-hydroxynaphthalen-1-yl)-4(5)-phenylimidazole, and 4,5-diphenyl-2-(2-hydroxynaphthalen-1-yl)imidazole.

[0140] Examples of the compound represented by the above formula (C2) include the following imidazole compounds.

[0141] Examples of such compounds include 2-(2-hydroxyphenyl)benzimidazole, 2-(2-hydroxyphenyl-3-methoxyphenyl)benzimidazole, 2-(2-hydroxyphenyl-5-methoxyphenyl)benzimidazole, 2-(2-hydroxy-3-methylphenyl)benzimidazole, 2-(2-hydroxy-4-methylphenyl)benzimidazole, 2-(2-hydroxy-5-methylphenyl)benzimidazole, 2-(3-t-butyl-2-hydroxyphenyl)benzimidazole, 2-(4-chloro-2-hydroxyphenyl)benzimidazole, 2-(4-bromo-2-hydroxyphenyl)benzimidazole, 2-(2,3-dihydroxyphenyl)benzimidazole, 2-(2,5-dihydroxyphenyl)benzimidazole, 2-(2-hydroxy-4-methoxyphenyl)benzimidazole, 2-(2-hydroxy-3-methoxyphenyl)benzimidazole benzoimidazole, 2-(2-hydroxy-5-methoxyphenyl)benzimidazole, 2-(2-hydroxy-6-methoxyphenyl)benzimidazole, 2-(3-ethoxy-2-hydroxyphenyl)benzimidazole, 2-(5-ethoxy-2-hydroxyphenyl)benzimidazole, 2-(4-allyl-2-hydroxy-3-methoxyphenyl)benzimidazole, 2-(4,6-dimethoxy-2-hydroxyphenyl)benzimidazole, 2-(5-fluoro-2-hydroxyphenyl)benzimidazole 2-(hydroxyphenyl)benzimidazole, 2-(5-chloro-2-hydroxyphenyl)benzimidazole, 2-(5-bromo-2-hydroxyphenyl)benzimidazole, 2-(6-fluoro-2-hydroxy-3-methoxyphenyl)benzimidazole, 2-(1-hydroxynaphthalen-2-yl)benzimidazole, 2-(2-hydroxynaphthalen-1-yl)benzimidazole, and 2-(2-hydroxyphenyl)benzimidazole-6-carboxylic acid.

[0142] Among these, the compound represented by formula (C1) is preferably a compound in which R1 and R2 are both hydrogen atoms, and a compound in which R1 and R2 have different substituents. Examples of such compounds include 2-(2-hydroxyphenyl)imidazole, 2-(2-hydroxyphenyl)-4-methylimidazole, 2-(2-hydroxyphenyl)-5-methylimidazole, 4,5-bis(hydroxymethyl)-2-phenylimidazole, (4-methyl-2-phenyl-imidazol-5-yl)methanol, 4-ethyl-(2-hydroxyphenyl)-5-methylimidazole, (2-hydroxyphenyl)-4-isopropyl-5-methylimidazole, 4-butyl-(2-hydroxyphenyl)-5-methylimidazole, 2-(2-hydroxy-3-methoxyphenyl)imidazole, and 2-(2-hydroxy-5-methoxyphenyl)imidazole, with 2-(2-hydroxyphenyl)imidazole being more preferred. When the cured product (B) contains the compound represented by formula (C1), it has better solubility in the epoxy resin (A) and solvent, making it easier to obtain a uniform compound. The compounds also tend to have better high temperature stability and higher mechanical strength, as well as better heat resistance.

[0143] Examples of the compound represented by formula (C2) include 2-(2-hydroxyphenyl)benzimidazole, 2-(2-hydroxy-3-methoxyphenyl)benzimidazole, 2-(2-hydroxy-5-methoxyphenyl)benzimidazole, 2-(2-hydroxyphenyl-3-methoxyphenyl)benzimidazole, 2-(2-hydroxyphenyl-5-methoxyphenyl)benzimidazole, 2-(1-hydroxynaphthalene-2-yl)benzimidazole, 2-(2-hydroxynaphthalene Preferred are 2-(2-hydroxyphenyl)benzimidazole, 2-(2-hydroxy-3-methoxyphenyl)benzimidazole, 2-(2-hydroxy-5-methoxyphenyl)benzimidazole, 2-(2-hydroxyphenyl-3-methoxyphenyl)benzimidazole, and 2-(2-hydroxyphenyl-5-methoxyphenyl)benzimidazole. When the cured product (B) contains a compound represented by formula (C2) above, it has better solubility in the epoxy resin (A) and solvents, which tends to make it easier to obtain a homogeneous compound. In addition, the compound tends to have better high-temperature stability, higher mechanical strength, and even better heat resistance.

[0144] The content of the curing accelerator (C) is preferably 0.1 parts by mass or more, more preferably 0.3 parts by mass or more, and even more preferably 0.5 parts by mass or more, based on 100 parts by mass of the epoxy resin (A). When the content of the curing accelerator (C) is within the above range, it becomes easier to control the curing reaction of the thermosetting resin under low temperature conditions, and therefore a compound having higher mechanical strength and better high-temperature stability tends to be obtained.

[0145] The content of the curing accelerator (C) is preferably 15.0 parts by mass or less, more preferably 12.0 parts by mass or less, and even more preferably 10.0 parts by mass or less, relative to 100 parts by mass of the epoxy resin (A). When the content of the curing accelerator (C) is within the above range, the storage stability of the compound tends to be easier to control. Furthermore, when the content of the curing accelerator (C) is within the above range, the curing reaction of the thermosetting resin under low temperature conditions becomes easier to control, and therefore, a compound having higher mechanical strength and better high-temperature stability tends to be obtained.

[0146] <Magnetic particles (D)> The compound contains magnetic particles (D). The magnetic particles may be used singly or in combination of two or more types. When two or more types of magnetic particles are used, for example, two or more types of magnetic particles with different alloy compositions, particle sizes (particle size distribution), shapes, specific surface areas, properties (isotropy and anisotropy), and surface treatments may be mixed and used. The alloy composition of the magnetic particles is not particularly limited as long as it does not deteriorate the curing properties of the resin composition.

[0147] Examples of magnetic particles include samarium-cobalt (Sm-Co) alloy particles (rare earth magnetic particles), neodymium-iron-boron (Nd-Fe-B) alloy particles (rare earth magnetic particles), samarium-iron-nitrogen (Sm-Fe-N) alloy particles (rare earth magnetic particles), neodymium-iron-nitrogen (Nd-Fe-N) alloy particles (rare earth magnetic particles), iron-cobalt (Fe-Co) alloy particles, Al-Ni-Co alloy particles, and ferrite magnetic particles.

[0148] The magnetic particles are preferably rare earth magnetic particles. Rare earth magnetic particles have superior coercivity and magnetic flux density compared to other magnetic particles. Therefore, when a compound contains rare earth magnetic particles, the magnetic force of, for example, a bonded magnet tends to be improved. Furthermore, when the magnetic particles contain rare earth magnetic particles, it becomes easier to control the curing reaction of the thermosetting resin under low temperature conditions, and therefore a compound tends to be obtained that has higher mechanical strength and better high-temperature stability. In this specification, rare earth magnetic particles refer to magnetic particles containing a rare earth element.

[0149] The magnetic particles may have a spherical, flat, prismatic, or needle shape, and may be used alone or in combination.

[0150] The shape of magnetic particles can be evaluated, for example, by the circularity coefficient obtained by image processing of an image observed under a microscope. The circularity coefficient is a value calculated using the following formula (3). The higher the circularity coefficient value, the more rounded and spherical the particle is. Since the magnetic particles rotate more easily during magnetic field molding and can be further improved in orientation, it is preferable that the magnetic particles contain one or more types of magnetic particles with a circularity coefficient of 0.60 or more. Furthermore, by including such magnetic particles in the magnetic particles, it becomes easier to control the curing reaction of the thermosetting resin under low-temperature conditions, and therefore compounds tend to be obtained that have higher mechanical strength and better high-temperature stability.

[0151] Circularity coefficient = (4πS / L 2 )···(3) In equation (3), S is the two-dimensional projected area of the magnetic particle (μm 2 ) and L is the two-dimensional projected perimeter of the magnetic particle (μm).

[0152] The magnetic particles may be coarse particles (hereinafter simply referred to as "coarse particles") or fine particles (hereinafter simply referred to as "fine particles"), either alone or in combination. It is preferable to use a combination of coarse and fine magnetic particles. The use of such magnetic particles tends to result in a compound with higher mechanical strength and better high-temperature stability, even when the thermosetting resin is cured under low-temperature conditions.

[0153] The average particle size (D50) of the coarse particles is preferably 30 μm or more and 300 μm or less, more preferably 40 μm or more and 250 μm or less. Since coarse particles usually have high magnetic properties, if the average particle size (D50) of the coarse particles is within the above range, it becomes easier to adjust the magnetic properties of the bonded magnet depending on the amount of coarse particles added. Furthermore, if the average particle size (D50) of the coarse particles is within the above range, it becomes easier to control the curing reaction of the thermosetting resin under low temperature conditions, which tends to result in a compound with higher mechanical strength and better high-temperature stability.

[0154] The average particle size (D50) of the fine particles is preferably 0.5 μm or more and 30 μm or less, more preferably 1 μm or more and 20 μm or less. Because the fine particles can increase the loading of magnetic particles, when the average particle size (D50) of the fine particles is within the above range, the magnetic properties of the bonded magnet tend to be further improved. Furthermore, when the average particle size (D50) of the coarse particles is within the above range, it becomes easier to control the curing reaction of the thermosetting resin under low-temperature conditions, and therefore the compound tends to have higher mechanical strength and better high-temperature stability.

[0155] In this specification, the average particle size (D50) and particle size distribution are measured as volume-based median diameters using a laser diffraction light scattering particle size distribution measuring device.

[0156] The magnetic particles can be anisotropic magnetic particles or isotropic magnetic particles, either singly or in combination. The magnetic particles preferably contain anisotropic magnetic particles. By using anisotropic magnetic particles to prepare a compound, the magnetic particles in the bonded magnet compact obtained by magnetic field molding are oriented, which tends to further improve the magnetic properties of the bonded magnet.

[0157] The magnetic particles are preferably subjected to a rust-proofing treatment. Examples of such rust-proofing treatments include a phosphoric acid treatment to form a phosphoric acid compound layer, a metal alkoxy oligomer treatment to form an organometallic compound layer, a coupling treatment to form a coupling agent layer, and a gradual oxidation treatment to form an oxide film. The rust-proofing treatment may be a single type of treatment or a combination of multiple types of treatments.

[0158] The content of magnetic particles is preferably 70% by mass or more and 99.5% by mass or less, more preferably 80% by mass or more and 99.0% by mass or less, and even more preferably 90% by mass or more and 98.5% by mass or less, based on the total mass of the bonded magnet compound. Having the content of magnetic particles within this range makes it easier to control the curing reaction of the thermosetting resin under low-temperature conditions, which tends to result in a compound with higher mechanical strength and better high-temperature stability. Furthermore, having the content of magnetic particles within this range tends to more effectively achieve both the magnetic properties and mechanical strength of the bonded magnet.

[0159] <Lubricant> The compound may contain a lubricant. By including a lubricant in the compound, the fluidity and moldability of the compound are further improved, and the releasability of the compound is also further improved. As a result, the accuracy of the shape and dimensions of the bonded magnet is further improved, which tends to make it easier to suppress structural defects in the bonded magnet. The lubricant may be included in the resin composition. One type of lubricant may be used alone, or two or more types may be used in combination.

[0160] Examples of lubricants include saturated fatty acids, saturated fatty acid salts, and saturated fatty acid esters. Specific examples include lauric acid, myristic acid, pentadecylic acid, palmitic acid, margaric acid, stearic acid, arachidic acid, heneicosylic acid, behenic acid, lignoceric acid, cerotic acid, montanic acid, melissic acid, calcium laurate, calcium myristate, calcium pentadecylate, calcium palmitate, calcium margaric acid, calcium stearate, calcium arachidic acid, calcium heneicosylate, calcium behenate, calcium lignocerate, calcium cerotic acid, calcium montanic acid, calcium melissic acid, barium laurate, and barium myristate. Examples of suitable esters include barium pentadecylate, barium palmitate, barium margarate, barium stearate, barium arachidate, barium heneicosylate, barium behenate, barium lignocerate, barium cerotate, barium montanate, barium melissate, laurate, myristate, pentadecylate, palmitate, margarate, stearate, arachidate, heneicosylate, behenate, lignocerate, cerotate, montanate, and melissate.

[0161] Other lubricants include, for example, magnesium salts of the saturated fatty acids, aluminum salts of the saturated fatty acids, 1,2-hydroxystearic acid, calcium ricinoleate, stearamide, oleamide, erucamide, behenamide, palmitamide, lauric amide, hydroxystearamide, methylene bisstearamide, ethylene bisstearamide, ethylene bislauric amide, distearyl adipamide, ethylene bisoleamide, dioleyl adipamide, N-stearyl stearamide, N-oleyl stearamide, N-stearyl erucamide, methylol stearamide, methylol behenamide, ethylene glycol, stearyl alcohol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, silicone oil, silicone grease, fluorine-based oil, fluorine-based grease, fluorine-containing resin powder, paraffin wax, polyethylene wax, amide wax, polypropylene wax, ester wax, carnauba wax, and microwax. The compound may contain one type of lubricant selected from the above, or may contain multiple types of lubricants selected from the above.

[0162] The lubricant content is preferably 0.01% by mass or more and 10% by mass or less of the total mass of the bonded magnet compound. By keeping the lubricant content within this range, the bonded magnet tends to have a better balance between magnetic properties and mechanical strength.

[0163] In this embodiment, instead of or in addition to blending a lubricant into the compound and / or resin composition, a dispersion of an internal lubricant may be used. The dispersant is usually applied to the inner wall surface of the mold die (the wall surface that comes into contact with the punch). The use of a dispersant improves the accuracy of the shape and dimensions of the bonded magnet, which tends to more easily suppress structural defects in the bonded magnet.

[0164] <Coupling agent> The compound may contain a coupling agent. By including a coupling agent, the adhesion between the resin composition and the surface of the magnetic particles can be further increased, which tends to further improve the mechanical strength of the bonded magnet. The coupling agent may be included in the resin composition. The coupling agent may be used alone or in combination of two or more types.

[0165] Examples of coupling agents include coupling agents of silane-based compounds such as epoxysilane, mercaptosilane, aminosilane, alkylsilane, ureidosilane, and vinylsilane; coupling agents of titanium-based compounds; coupling agents of aluminum chelates; and coupling agents of aluminum and zirconium-based compounds.

[0166] The content of the coupling agent is preferably 0.01% by mass or more and 10% by mass or less of the total mass of the bonded magnet compound. By keeping the content of the coupling agent in this range, it tends to be possible to more effectively achieve both magnetic properties and mechanical strength of the bonded magnet.

[0167] <Flow aid> The compound may contain an inorganic filler as a flow aid. The inorganic filler may be composed of one type of particle or a combination of two or more types of particles. The flow aid may be contained in the resin composition. The flow aid may be used alone or in combination of two or more types.

[0168] The average particle size (D50) of the inorganic filler is preferably 1 μm or less, more preferably 500 nm or less, and even more preferably 100 nm or less. When the average particle size (D50) of the inorganic filler is within the above range, the space filling rate of the bonded magnet is further improved, and the bonded magnet tends to be able to more favorably achieve both magnetic properties and mechanical strength. The lower limit of the average particle size (D50) is, for example, 1 nm or more.

[0169] Examples of inorganic fillers include inorganic fine particles such as silica, alumina, calcium carbonate, kaolin clay, titanium oxide, barium sulfate, zinc oxide, aluminum hydroxide, magnesium hydroxide, talc, and mica.

[0170] The content of the flow aid is preferably 0.01% by mass or more and 10% by mass or less of the total mass of the bonded magnet compound. By keeping the content of the flow aid in this range, it tends to be possible to more effectively achieve both magnetic properties and mechanical strength of the bonded magnet.

[0171] <Flame retardant> The compound may contain a flame retardant. By containing a flame retardant, the fire resistance of the compound can be further improved. The flame retardant may be contained in the resin composition. The flame retardant may be used alone or in combination of two or more.

[0172] From the viewpoints of environmental safety, recyclability, moldability, and low cost, the flame retardant preferably contains at least one selected from the group consisting of bromine-based flame retardants, phosphorus-based flame retardants, hydrated metal compound-based flame retardants, silicone-based flame retardants, nitrogen-containing compounds, hindered amine compounds, organometallic compounds, and aromatic engineering plastics.

[0173] The content of the flame retardant is preferably 0.01% by mass or more and 10% by mass or less of the total mass of the bonded magnet compound. By keeping the content of the flame retardant in this range, it tends to be possible to more favorably achieve both magnetic properties and mechanical strength of the bonded magnet.

[0174] <Organic solvents> In the compound manufacturing process, a uniform compound can be obtained by coating the surface of each magnetic particle that constitutes the magnetic particles with an organic solvent in which a resin composition is dissolved.

[0175] Examples of the organic solvent include solvents that can dissolve each component in the resin composition. Examples of such organic solvents include acetone, methyl ethyl ketone, methyl isobutyl ketone, benzene, toluene, and xylene. The organic solvents may be used alone or in combination of two or more.

[0176] In consideration of workability, the organic solvent is preferably a liquid at room temperature, and more preferably has a boiling point of 50° C. or higher and 150° C. or lower. Such an organic solvent preferably includes one or more selected from the group consisting of acetone and methyl ethyl ketone.

[0177] <Compound manufacturing method> Methods for producing the compound of this embodiment include, for example, a method of mixing the resin composition at or above its melting point (hereinafter simply referred to as "melt mixing"), and a method of dissolving the resin composition in an organic solvent and mixing it (hereinafter simply referred to as "dissolution mixing").

[0178] The melt mixing may be carried out, for example, by the following method. A mixed powder of the compound raw materials is obtained by thoroughly mixing the compound raw materials (e.g., epoxy resin (A), curing agent (B), curing accelerator (C), magnetic particles (D), and other additives as needed) using a mixer or the like. The obtained mixed powder of the compound raw materials is heated and mixed at a temperature equal to or higher than the softening temperature of the resin composition, and the solid matter is crushed as needed to obtain the compound.

[0179] The heating and mixing temperature can be set appropriately depending on the type and amount of the resin composition, but is preferably 40° C. or higher and 140° C. or lower, and more preferably 60° C. or higher and 120° C. or lower. When the heating and mixing temperature is within the above range, the curing reaction of the resin composition tends to be further suppressed, while the dispersibility of the materials in the compound tends to be further improved.

[0180] As the mixing device, for example, a heat kneader can be used. In the heat kneader, the input amount of the compound raw materials can be appropriately changed, and the material dispersibility can be further controlled.

[0181] The dissolving and mixing may be carried out, for example, by the following method. A resin composition solution is obtained by dissolving the raw materials for the resin composition, including epoxy resin (A), curing agent (B), and curing accelerator (C), as well as other additives as necessary, in an organic solvent. Magnetic particles are added to the solution to disperse the magnetic particles in the resin composition solution, and the organic solvent is then removed from the solution containing the magnetic particles and resin composition by distillation under reduced pressure and drying. As a result, the surfaces of the magnetic particles are coated with the resin composition, and a compound is obtained that is a mixture of the magnetic particles and the resin composition.

[0182] In the step of removing the organic solvent from the solution containing the magnetic particles and the resin composition, it is preferable to use an evaporator to perform vacuum distillation of the organic solvent at room temperature while stirring the solution. Furthermore, in the process of vacuum distillation of the organic solvent, it is preferable to repeat the following operations in this order several times: reducing the pressure, restoring the pressure to normal pressure, and loosening the aggregated dried solids, in order to uniformly remove the organic solvent. The solid obtained by vacuum distillation is further dried using a vacuum dryer or the like, and then appropriately pulverized to obtain a compound. Instead of vacuum distillation, atmospheric distillation may be performed while stirring the solution using a kneader or the like. The solid obtained by distillation may be dried by heating the solid, for example, at 80°C or less, preferably 60°C or less, and more preferably 40°C or less. The lower limit of the drying temperature is, for example, 10°C or more.

[0183] <Manufacturing method of bonded magnets> For example, the compound obtained by the manufacturing method described above is filled into a mold and compression molded to obtain a compound compact. The higher the molding pressure, the higher the density of the bonded magnet, but the more likely the magnetic particles are to crack. The molding pressure can be set arbitrarily, for example, depending on the characteristics of the compound and the bonded magnet.

[0184] Further heat treatment of the molded body cures the resin composition in the molded body, and the magnetic particles in the molded body are bound to each other by the cured resin composition, resulting in a bonded magnet. The heat treatment temperature for the molded body is preferably set to a temperature at which the resin composition is sufficiently cured. Furthermore, from the viewpoint of further suppressing oxidation of the magnetic particle surfaces, it is preferable to cure at a low temperature for a short time. The curing temperature is preferably 200°C or less, more preferably 180°C or less, and even more preferably 150°C or less. The lower limit of the curing temperature is, for example, 100°C or more. The curing time is preferably 120 minutes or less, more preferably 60 minutes or less, and even more preferably 30 minutes or less. The lower limit of the curing time is, for example, 1 minute or more.

[0185] Orienting the magnetic particles gives the bonded magnet better magnetic properties. Examples of orientation methods include applying a magnetic field before and during compaction molding and heat treatment of the molded body. Examples of applying a magnetic field during heat treatment of the molded body include heating the molded body to approximately 95°C or higher and 110°C or lower to soften the resin composition and then applying a magnetic field. Such methods can further improve the orientation rate of the magnetic particles, and after magnetic field orientation, tend to allow the compression pressure to be increased until the molded body reaches a predetermined density. [Example]

[0186] The present embodiment will be described in more detail below with reference to specific examples and comparative examples, but the present invention is not limited to these examples and comparative examples. In the following, "parts" and "%" are by mass unless otherwise specified.

[0187] [Bonded magnet compound] (Epoxy resins (A-1) to (A-6)) Table 1 shows the epoxy resins (A-1) to (A-6) used in each of the examples and comparative examples.

[0188] [Table 1]

[0189] (Hardening agents (B-1) to (B-2)) Table 2 shows the curing agents (B-1) and (B-2) used in each of the examples and comparative examples.

[0190] [Table 2]

[0191] (Curing accelerators (C-1) to (C-10)) Table 3 shows the curing accelerators (C-1) to (C-10) used in each of the examples and comparative examples.

[0192] [Table 3]

[0193] (Magnetic particles (D-1)~(D-2)) Table 4 shows the magnetic particles (D-1) and (D-2) used in each of the examples and comparative examples.

[0194] [Table 4]

[0195] [Preparation of bonded magnet compound] Example 1 A solution of a thermosetting resin composition (resin solution) was prepared by mixing 2.00 g of epoxy resin (A-1), 1.47 g of curing agent (B-1), 0.05 g of curing accelerator (C-1), and 20 g of acetone as an organic solvent in a 300 mL recovery flask and stirring at 25°C for 30 minutes. The content of the epoxy resin that is solid at room temperature (25°C) was 100% by mass relative to the total amount of epoxy resin (A-1). The content of the curing agent that is solid at room temperature (25°C) was 100% by mass relative to the total amount of curing agent (B-1). The obtained resin solution was distilled under reduced pressure using an evaporator to obtain a thermosetting resin composition from which the organic solvent had been removed. The thermosetting resin composition was solid at 25°C.

[0196] To the recovery flask containing the resin solution, 13.3 g of magnetic particles (D-1) as magnetic particles (1) and 53.3 g of magnetic particles (D-2) as magnetic particles (2) were added and stirred at 25°C for 30 minutes. Subsequently, using an evaporator, the acetone in the resulting solution was removed under a reduced pressure of 0.1 MPa or less. During the acetone removal process, the flask was depressurized, the flask was returned to normal pressure, and the aggregated contents in the flask were loosened in this order several times to ensure uniform removal of the acetone. After the acetone was removed, the mixture of the thermosetting resin composition and magnetic particles was recovered from the flask and spread on a flat plate. The mixture on the flat plate was vacuum-dried at room temperature in a vacuum dryer, the vacuum dryer was returned to normal pressure, and the aggregated contents were loosened in this order several times to obtain a bonded magnet compound (CPD-1). The total content of magnetic particles (1) and (2) was 95.0 mass % of the total mass of the bonded magnet compound (CPD-1).

[0197] The resin solution and the resulting bonded magnet compound (CPD-1) were evaluated as described below, and the results are shown in Tables 5 and 6.

[0198] (Examples 2 to 11 and Comparative Examples 1 to 5) Resin solutions and bonded magnet compounds (CPD-2) to (CPD-16) were obtained in the same manner as in Example 1, except that the formulation was changed to that shown in Table 5. Using the resulting resin solutions and bonded magnet compound (CPD-1), evaluations were carried out in the same manner as in Example 1. The results are shown in Tables 5 and 6.

[0199] 〔evaluation〕 (1) Melt viscosity (X) and (Y) at 100°C The resin solutions prepared in the examples and comparative examples were each distilled under reduced pressure using an evaporator to obtain thermosetting resin compositions that did not contain magnetic particles. The melt viscosities (X) and (Y) of the resulting thermosetting resin compositions at 100°C were measured using a rheometer (HAKKE MARS III (trade name), manufactured by ThermoScientific).

[0200] Specifically, 0.3 g of the thermosetting resin composition was placed on a stage adjusted to 100°C in a rheometer (HAKKE MARS III (trade name)), and the thermosetting resin composition was measured under the following measurement conditions to obtain a dynamic viscosity curve. From the obtained dynamic viscosity curve, the melt viscosity (X) (mPa·s) of the thermosetting resin composition at 100°C and the melt viscosity (Y) at 100°C after heating the thermosetting resin composition at 100°C for 30 minutes were determined. Because the thermosetting resin composition is solid at 25°C, the melt viscosity (X) was taken as the minimum value of the observed dynamic viscosity curve, taking into account the time until melting was complete.

[0201] [Measurement conditions] Measurement mode: Oscillation mode Frequency: 1Hz Diameter of the template: 20mm Gap: 0.5mm ·Measurement temperature: 100℃ constant

[0202] The thermosetting resin composition can be separated from the bonded magnet compound by mixing the bonded magnet compound with an organic solvent such as acetone and extracting only the thermosetting resin composition.Methods for removing the magnetic particles include, for example, filtration and centrifugation.

[0203] (2) Mechanical strength of bonded magnets Each of the bonded magnet compounds prepared in the examples and comparative examples was heated in a 100°C thermostatic bath for 30 minutes to obtain a heated bonded magnet compound. The heated bonded magnet compound was then filled into a molding die and compression molded for 1 minute at a molding pressure of 150 MPa using a hydraulic molding machine to obtain a 4mm x 4mm x 4mm compression molded body. The compression molded body was then heated in a 150°C thermostatic bath for 30 minutes to produce a bonded magnet molded body.

[0204] The obtained bonded magnet molded body was placed in a desktop precision universal testing machine (Autograph AGS-H (trade name), manufactured by Shimadzu Corporation), and a compressive pressure was applied at a crosshead speed of 1.0 mm / min. The maximum compressive pressure at which the bonded magnet molded body broke was taken as the mechanical strength (MPa). The mechanical strength measurement was carried out at 25°C.

[0205] The mechanical strength of the bonded magnet was evaluated based on the obtained mechanical strength value and the following criteria: Evaluation results of A, B, and C ranks were considered to be acceptable. <Standards> A: The mechanical strength was 85 MPa or more. B: The mechanical strength was 75 MPa or more and less than 85 MPa. C: The mechanical strength was 65 MPa or more and less than 75 MPa. D: The mechanical strength was 55 MPa or more and less than 65 MPa. E: The mechanical strength was less than 55 MPa.

[0206] (3) Humidity and heat resistance of bonded magnets Each of the bonded magnet molded bodies obtained in the above section on measuring the mechanical strength of bonded magnets was left in a high-temperature, high-humidity environment (temperature 85°C, humidity 85%) for 7 days to obtain a bonded magnet molded body after leaving it.The mechanical strength (MPa) of the bonded magnet molded body after leaving it was then measured in the same manner as in the measurement of the mechanical strength of the bonded magnets above.The mechanical strength retention rate (%) was calculated from the mechanical strength before and after leaving it and the following formula (4). Mechanical strength retention rate (%) = mechanical strength after storage / mechanical strength before storage × 100 (4)

[0207] The bonded magnets were evaluated for their resistance to humidity and heat based on the obtained mechanical strength retention rate (%) and the following criteria: A and B ranks were considered to be acceptable. <Standards> A: Mechanical strength retention rate was 85.0% or more. B: The mechanical strength retention rate was 75.0% or more and less than 85.0%. C: The mechanical strength retention rate was 65.0% or more and less than 75.0%. D: The mechanical strength retention rate was less than 65.0%.

[0208] (4) High temperature stability of bonded magnets Each of the bonded magnet compounds prepared in the examples and comparative examples was heated in a constant temperature bath at 150°C for 30 minutes to obtain a bonded magnet compound in which the thermosetting resin composition was cured. The resulting bonded magnet compound was measured using a simultaneous differential thermal and thermogravimetric analyzer (TG / DTA7220 (trade name), manufactured by Hitachi High-Tech Corporation) from 25°C to 250°C at 10°C / min to obtain a thermogravimetric measurement curve. From the obtained curve, the weight loss rate (%) at 175°C and the weight loss rate (%) at 200°C were calculated.

[0209] The bonded magnets were evaluated for high temperature stability based on the weight loss rate (%) obtained and the following criteria: Evaluation results of A and B ranks were considered to be acceptable. <Based on 175℃> A: The weight loss rate was less than 0.01%. B: The weight loss rate was 0.01% or more and less than 0.02%. C: The weight loss rate was 0.02% or more and less than 0.03%. D: The weight loss rate was 0.03% or more.

[0210] <Based on 200℃> A: The weight loss rate was less than 0.015%. B: The weight loss rate was 0.015% or more and less than 0.03%. C: The weight loss rate was 0.03% or more and less than 0.045%. D: The weight loss rate was 0.045% or more.

[0211] [Table 5]

[0212] [Table 6] [Industrial Applicability]

[0213] Because the bonded magnet compound of this embodiment has high mechanical strength and excellent high-temperature stability even when the thermosetting resin is cured under low-temperature conditions, it has industrial applicability as a material for various bonded magnets.

Claims

1. A bonded magnet compound which is a mixture of a thermosetting resin composition containing an epoxy resin (A), a curing agent (B), and a curing accelerator (C), and magnetic particles (D), the thermosetting resin composition is solid at 25°C; When the melt viscosity of the thermosetting resin composition at 100°C is (X) (mPa s) and the melt viscosity of the thermosetting resin composition at 100°C after heating at 100°C for 30 minutes is (Y) (mPa s), (X) and (Y) satisfy the following formula (1) and formula (2), respectively: 0.01≦(X)≦30...(1) 1≦(Y) / (X)≦500...(2) The epoxy resin (A) contains a structure represented by the following formula (A1): The curing agent (B) contains a structure represented by the following formula (B1): Bonded magnet compound. 【Chemical 1】 (In formula (A1), R 11 ~R 20 are each independently a hydrogen atom, an alkyl group, an aromatic group, a substituent containing a heteroatom, or a substituent containing a halogen atom, and R 11 ~R 20 At least one of the groups contains a reactive group with the curing agent (B), and R 11 ~R 20 may be the same or different from each other. 【Chemistry 2】 (In formula (B1), R 31 ~R 40 are each independently a hydrogen atom, an alkyl group, an aromatic group, a substituent containing a heteroatom, or a substituent containing a halogen atom, and R 31 ~R 40 At least one of the groups contains a reactive group with the epoxy resin (A), and R 31 ~R 40 may be the same or different from each other.

2. 2. The bonded magnet compound of claim 1, wherein the epoxy resin (A) comprises a structure represented by the following formula (A2): 【Chemistry 3】 (In formula (A2), R 41 ~R 54 are each independently a hydrogen atom, an alkyl group, an aromatic group, a substituent containing a heteroatom, or a substituent containing a halogen atom, and R 41 ~R 54 At least one of the groups contains a reactive group with the curing agent (B), and R 41 ~R 54 may be the same or different from each other.

3. 3. The bonded magnet compound of claim 1, wherein the curing agent (B) comprises a structure represented by formula (B2). 【Chemistry 4】 (In formula (B2), R 61 ~R 74 are each independently a hydrogen atom, an alkyl group, an aromatic group, a substituent containing a heteroatom, or a substituent containing a halogen atom, and R 61 ~R 74 At least one of the groups contains a reactive group with the epoxy resin (A), and R 61 ~R 74 may be the same or different from each other.

4. 3. The bonded magnet compound of claim 1, wherein the curing accelerator (C) comprises an imidazole compound.

5. 5. The bonded magnet compound of claim 4, wherein the imidazole compound has a molecular weight of 120 or more and 500 or less.

6. 5. The bonded magnet compound of claim 4, wherein the imidazole compound has at least one hydroxy group.

7. 5. The bonded magnet compound according to claim 4, wherein the imidazole compound comprises at least one compound selected from the group consisting of a compound represented by the following formula (C1) and a compound represented by the following formula (C2): 【Chemistry 5】 (In formula (C1), R 1 and R 2 are each independently a hydrogen atom, a hydroxy group, a carboxy group, a cyano group, a nitro group, a halogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, or a cycloalkyl group having 6 to 20 carbon atoms which may have a substituent. 1 and R 2 may be the same or different, R 1 and R 2 may be bonded to form a fused ring that does not have aromaticity. X is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkenyl group having 2 to 20 carbon atoms which may have a substituent, an aralkyl group having 7 to 20 carbon atoms which may have a substituent, or a heteroarylalkyl group having 4 to 20 carbon atoms which may have a substituent. Each Y is independently a hydrogen atom, a halogen atom, a hydroxy group, a carboxy group, a cyano group, a nitro group, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxy group having 1 to 20 carbon atoms which may have a substituent, an alkenyl group having 2 to 20 carbon atoms which may have a substituent, an aryl group having 6 to 20 carbon atoms which may have a substituent, an aryloxy group having 6 to 20 carbon atoms which may have a substituent, or an acyl group having 1 to 20 carbon atoms which may have a substituent. Two or more Ys may be bonded to form a monocycle or a condensed ring. Each m is independently an integer of 1 to 4. 【Chemistry 6】 (In formula (C2), X represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkenyl group having 2 to 20 carbon atoms which may have a substituent, an aralkyl group having 7 to 20 carbon atoms which may have a substituent, or a heteroarylalkyl group having 4 to 20 carbon atoms which may have a substituent. Each Y is independently a hydrogen atom, a halogen atom, a hydroxy group, a carboxy group, a cyano group, a nitro group, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxy group having 1 to 20 carbon atoms which may have a substituent, an alkenyl group having 2 to 20 carbon atoms which may have a substituent, an aryl group having 6 to 20 carbon atoms which may have a substituent, an aryloxy group having 6 to 20 carbon atoms which may have a substituent, or an acyl group having 1 to 20 carbon atoms which may have a substituent. Two or more Ys may be bonded to form a monocycle or a condensed ring. Each m is independently an integer of 1 to 4. Each Z is independently a hydrogen atom, a halogen atom, a hydroxy group, a carboxy group, a cyano group, a nitro group, a halogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxy group having 1 to 20 carbon atoms which may have a substituent, an alkenyl group having 2 to 20 carbon atoms which may have a substituent, an aryl group having 6 to 20 carbon atoms which may have a substituent, an aryloxy group having 6 to 20 carbon atoms which may have a substituent, or an acyl group having 1 to 20 carbon atoms which may have a substituent. Two or more Zs may be bonded to form a monocycle or a condensed ring. Each n is independently an integer of 1 to 4.

8. A bonded magnet molded from the bonded magnet compound according to any one of claims 1 to 7.

9. A motor molded from the bonded magnet according to claim 8.

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