Composite, molded body, and cured product

Abstract

A composite material comprising at least a metal powder and a resin composition, the resin composition containing at least an epoxy resin and a phosphate ester, the content of the metal powder in the composite material being 97.0 mass% or more and 97.5 mass% or less.

Description

TECHNICAL FIELD

[0001] One embodiment of the present application relates to a composite, a molded body, and a cured product. BACKGROUND

[0002] A composite containing a metal powder and a thermosetting resin is used as a raw material for various industrial products such as an inductor, depending on each property of the metal powder (see Patent Documents 1 and 2 below).

[0003] PRIOR ART DOCUMENTS

[0004] PATENT DOCUMENTS

[0005] Patent Document 1: Japanese Patent Publication No. 2011-211026

[0006] Patent Document 2: Japanese Patent Publication No. 2017-133071 SUMMARY

[0007] PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] When an industrial product is manufactured from a composite, the composite is supplied and filled into a mold through a flow path, or a part such as a coil is embedded in the composite in the mold. In these processes, the flowability of the composite is required. When the composite does not have sufficient flowability, the composite is difficult to uniformly fill into the mold, and a void is easily formed in a molded body formed from the composite. The flowability of the composite increases as the content of the metal powder in the composite decreases.

[0009] On the other hand, in order to improve the magnetic properties of a composite used in an inductor and the like, it is preferable that the content (filling rate) of the metal powder in the composite be high. For example, the magnetic property values of the composite such as relative magnetic permeability and saturation magnetic flux density increase as the content of the metal powder in the composite increases. However, as the content of the metal powder in the composite increases, the melt viscosity of the composite increases. In particular, when the content of the metal powder in the composite is 97.0 mass% or more, the melt viscosity of the composite significantly increases, and the composite hardly flows.

[0010] The present application has been achieved in view of the above-described problems, and an object of one embodiment of the present application is to provide a composite excellent in flowability, a molded body containing the composite, and a cured product of the composite.

[0011] MEANS FOR SOLVING THE PROBLEMS

[0012] The composite of one embodiment of the present application contains at least a metal powder and a resin composition, the resin composition contains at least an epoxy resin and a phosphate ester, and the content of the metal powder in the composite is 97.0 mass% or more and 97.5 mass% or less.

[0013] The proportion of the phosphate ester with respect to 100 parts by mass of the metal powder can be 0.02 parts by mass or more and 0.10 parts by mass or less.

[0014] The melt viscosity of the composite at 140°C can be 10 Pa-s or more and 1500 Pa-s or less.

[0015] The composite of one embodiment of the present application can be used for at least one of transfer molding and compression molding.

[0016] The molded article of one embodiment of the present application includes the above composite.

[0017] The cured product of one embodiment of the present application is a cured product of the above composite.

[0018] Effects of the Invention

[0019] According to one embodiment of the present application, a composite with excellent fluidity, a molded article including the composite, and a cured product of the composite are provided. DETAILED DESCRIPTION

[0020] Hereinafter, preferred embodiments of the present application will be described. However, the present application is not limited to any of the following embodiments.

[0021] <Summary of Composite>

[0022] The composite of this embodiment includes at least a metal powder and a resin composition. That is, the composite can be a mixture of the metal powder and the resin composition. The composite can be referred to as a magnetic seal.

[0023] The metal powder is composed of a plurality of metal particles. The metal powder can contain, for example, at least one selected from the group consisting of a metal monomer (a pure metal), an alloy, an amorphous powder, and a metal compound. The metal powder can be referred to as a filler formed of a metal.

[0024] The resin composition contains at least an epoxy resin and a phosphate ester.

[0025] The epoxy resin melts at a temperature lower than a curing temperature, whereby the fluidity of the composite is improved. Further, the epoxy resin bonds the metal powders to each other by thermal curing. Furthermore, the epoxy resin electrically insulates the metal powders from each other.

[0026] The phosphate ester can be represented by OP(OR 1 )(OR 2 )(OR 3 ), for example. R 1 , R 2 , and R 3 are each hydrogen or any hydrocarbon group, and R 1 , R 2 , and R 3at least one of R1, R2, and R3is a hydrocarbon group. The hydrocarbon group can be, for example, an alkyl group or an aryl group. The phosphate ester is a different compound from the phosphite ester. The phosphite ester can be represented by P(OR 1 )(OR 2 )(OR 3 ), for example. The resin composition can contain a phosphite ester in addition to the phosphate ester. However, a composite containing no phosphate ester and containing a phosphite ester is less likely to have high flowability than the composite of the present embodiment. The resin composition can contain other dispersants (e.g., coupling agents) in addition to the phosphate ester.

[0027] The phosphate ester can be a dispersant. The phosphate group of the phosphate ester has polarity, and thus is easily selectively adsorbed to the surface of the metal particles. On the other hand, the hydrocarbon group of the phosphate ester has lipophilicity, and thus the resin composition containing the epoxy resin is easily present between the metal particles to which the phosphate ester is adsorbed. Thus, the aggregation of the metal powder is suppressed due to the phosphate ester, and the individual metal particles are easily dispersed in the composite. In other words, the metal particles are less likely to directly contact each other due to the phosphate ester, and direct friction between the metal particles is easily suppressed, and friction between the metal particles and the resin composition is also easily suppressed. As described above, the flowability of the composite is improved by the phosphate ester acting as a dispersant for the metal powder. For example, the melt viscosity of the composite is reduced by the composite containing the phosphate ester. The flowability of the composite containing the phosphate ester has a tendency to be superior to that of a composite containing a dispersant other than the phosphate ester. Direct friction between the metal particles can be evaluated in terms of a torque value measured by a measuring device for gelation time (vulcanization tester). The more the direct friction between the metal particles is suppressed, the less the torque value is reduced. As the measuring device for gelation time, a CURELASTOMETER manufactured by JSR Corporation can be used.

[0028] The content of the metal powder in the composite is 97.0 mass% or more and 97.5 mass% or less. As the content (filling rate) of the metal powder in the composite increases, the relative magnetic permeability and the saturation magnetic flux density of the composite easily increase. The composite having a high relative magnetic permeability and a high saturation magnetic flux density is suitable for, for example, a raw material of a magnetic core of an inductor or a seal for an inductor. However, as the content of the metal powder in the composite increases, the melt viscosity of the composite increases. In particular, when the content of the metal powder in the composite not containing the phosphate ester is 97.0 mass% or more, the melt viscosity of the composite significantly increases, and the composite hardly flows. However, even in the case where the content of the metal powder in the composite is 97.0 mass% or more, the composite of the present embodiment contains the epoxy resin and the phosphate ester, and thus can have a high flowability (low melt viscosity). When the content of the metal powder in the composite not containing the phosphate ester is less than 97.0 mass%, the melt viscosity of the composite is high, but the composite can flow. When the content of the metal powder in the composite exceeds 97.5 mass%, since the content of the resin composition in the composite is relatively small, it is difficult to obtain a high flowability caused by the epoxy resin and the phosphate ester in the resin composition, and the melt viscosity of the composite is significantly high. As a result, it is difficult to perform transfer molding which requires the flowability of the composite. Since the composite easily has a high flowability, the content of the metal powder in the composite can also be 97.0 mass% or more and 97.3 mass% or less.

[0029] The proportion of the phosphate ester with respect to 100 mass parts of the metal powder can be 0.02 mass parts or more and 0.10 mass parts or less. When the proportion of the phosphate ester is 0.02 mass parts (preferably 0.04 mass parts) or more, a high flowability (low melt viscosity) of the composite caused by the phosphate ester is easily obtained. The phosphate ester can hinder the curing of the epoxy resin. However, when the proportion of the phosphate ester is 0.10 mass parts or less, the hindering of the curing of the epoxy resin caused by the phosphate ester is easily suppressed. In other words, when the proportion of the phosphate ester is 0.10 mass parts or less, the gelling time (curing time) of the composite is shortened. For the same reason, the proportion of the phosphate ester with respect to 100 mass parts of the metal powder can also be 0.040 mass parts or more and 0.060 mass parts or less.

[0030] The melt viscosity of the composite at 140°C can be 10 Pa-s or more and 1500 Pa-s or less, 573 Pa-s or more and 1489 Pa-s or less, 573 Pa-s or more and 998 Pa-s or less, 573 Pa-s or more and 826 Pa-s or less, or 573 Pa-s or more and 633 Pa-s or less. Even in the case where the content of the metal powder in the composite is 97.0 mass% or more, by the composite containing the epoxy resin and the phosphate ester, the composite can have a low melt viscosity (high flowability) as described above. When the melt viscosity of the composite is within the above range, the molten composite easily fills uniformly into a mold, and defects (voids or burrs, etc.) in a molded body and a cured product formed from the composite are easily suppressed. Therefore, the composite having a low melt viscosity as described above is suitable for transfer molding.

[0031] The content of the epoxy resin in the composite can be 0.95 mass% or more and 1.72 mass% or less. In other words, the proportion of the epoxy resin with respect to 100 parts by mass of the metal powder can be 0.98 parts by mass or more and 1.77 parts by mass or less. There is a tendency that the flowability of the composite increases as the content of the epoxy resin in the composite increases. When the content of the epoxy resin in the composite is within the above range, and the composite contains the phosphate ester, the composite easily has high flowability (low melt viscosity). Even when the content of the epoxy resin in the composite is within the above range, when the composite does not contain the phosphate ester, the composite is difficult to have high flowability. When the content of the epoxy resin in the composite is greater than the upper limit value, it is difficult to balance the magnetic properties and the flowability of the composite. Since the composite easily has high flowability, the content of the epoxy resin in the composite can be 1.24 mass% or more and 1.41 mass% or less. In other words, the proportion of the epoxy resin with respect to 100 parts by mass of the metal powder can be 1.28 parts by mass or more and 1.46 parts by mass or less.

[0032] <Details of the composition of the composite>

[0033] (resin composition)

[0034] The resin composition can be a component including the epoxy resin and the phosphate ester, and be a remaining component (non-volatile component) among all components constituting the composite except for the metal powder and the organic solvent. That is, the resin composition can contain other components in addition to the epoxy resin and the phosphate ester. For example, the resin composition can further contain a curing agent. The resin composition can further contain a curing accelerator. The resin composition can further contain a wax (mold release agent). The resin composition can further contain an additive. The additive can be, for example, a coupling agent or a flame retardant, etc.

[0035] The resin composition has a function as a binding material (binder) of metal particles that constitute the metal powder, and imparts mechanical strength to a molded body formed from the composite. For example, when the composite is molded at high pressure using a mold, the resin composition included in the composite is filled between the metal particles, and the metal particles are bonded to each other. Through curing of the resin composition in the molded body, the cured product of the resin composition further firmly bonds the metal particles to each other, and a cured product of the composite having excellent mechanical strength is obtained.

[0036] The resin composition can adhere to the surface of each metal particle that constitutes the metal powder. The resin composition can cover a part of the surface of each metal particle, or can cover the entire surface of each metal particle. The composite can include the metal powder and the uncured resin composition. The composite can include the metal powder and a semi-cured product of the resin composition (for example, a B-stage resin composition). The composite can also include both the uncured resin composition and the semi-cured product of the resin composition. The composite can be a powder. The composite can also be a cake. The composite can also be a paste.

[0037] The content of the resin composition in the composite is 2.5% by mass or more and 3.0% by mass or less.

[0038] [Phosphoric acid ester]

[0039] The resin composition can contain one phosphoric acid ester. The resin composition can also contain a plurality of phosphoric acid esters. The phosphoric acid ester included in the resin composition can be at least one phosphoric acid ester selected from the group consisting of a phosphoric acid monoester, a phosphoric acid diester, and a phosphoric acid triester.

[0040] The phosphoric acid ester included in the resin composition can be at least one phosphoric acid ester selected from the group consisting of a phosphoric acid ester salt of a copolymer containing an acid group, Compound 1 represented by Chemical Formula 1 below, Compound 2 represented by Chemical Formula 2 below, Compound 3 represented by Chemical Formula 3 below, and Compound 4 represented by Chemical Formula 4 below. When at least one of these phosphoric acid esters is included in the resin composition, the composite easily has high flowability. In particular, when the phosphoric acid ester salt of the copolymer containing an acid group is included in the resin composition, the composite easily has high flowability.

[0041] The phosphoric acid ester salt of the copolymer containing an acid group can be disperbyk-111 (trade name) manufactured by BYK-Chemie GmbH, for example. The acid value of the phosphoric acid ester salt of the copolymer containing an acid group can be 129. The acid value of disperbyk-111 is 129.

[0042] Compound 1 represented by Chemical Formula 1 below can be JP-504 manufactured by JOHOKU CHEMICAL CO., LTD., for example.

[0043] The compound 2 represented by the following Chemical Formula 2 can be, for example, JP-506H manufactured by JOHOKU CHEMICAL CO., LTD.

[0044] The compound 3 represented by the following Chemical Formula 3 can be, for example, JP-508 manufactured by JOHOKU CHEMICAL CO., LTD.

[0045] The compound 4 represented by the following Chemical Formula 4 can be, for example, JP-513 manufactured by JOHOKU CHEMICAL CO., LTD.

[0046] (C4H9O) n OP(OH) 3-n (1)

[0047] n in the above Chemical Formula 1 can be 1 or 2. n in the above Chemical Formula 1 can also be 1 or more and 3 or less.

[0048] (C4H9OCH2CH2O) n OP(OH) 3-n (2)

[0049] n in the above Chemical Formula 2 can be 1 or 2. n in the above Chemical Formula 2 can also be 1 or more and 3 or less.

[0050] (C4H9C2H5CHCH2O) n OP(OH) 3-n (3)

[0051] n in the above Chemical Formula 3 can be 1 or 2. n in the above Chemical Formula 3 can also be 1 or more and 3 or less.

[0052] (iso-C 13 H 27 O) n OP(OH) 3-n (4)

[0053] n in the above Chemical Formula 4 can be 1 or 2. n in the above Chemical Formula 4 can also be 1 or more and 3 or less.

[0054] [epoxy resin]

[0055] The resin composition contains at least an epoxy resin as a thermosetting resin. By the composite containing an epoxy resin having relatively excellent flowability in the thermosetting resin, flowability, filling property, storage stability, and moldability of the composite are improved. However, the composite can contain other resins in addition to the epoxy resin as long as the effects of the present application are not hindered. For example, the resin composition can contain at least one of a phenol resin and a polyamide-imide resin as a thermosetting resin. When the resin composition contains both the epoxy resin and the phenol resin, the phenol resin can also function as a curing agent for the epoxy resin. The resin composition can contain a thermoplastic resin in addition to the thermosetting resin. The thermoplastic resin can be, for example, at least one selected from the group consisting of an acrylic resin, polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyethylene terephthalate, and rubber (elastomer). The resin composition can also contain a silicone resin.

[0056] The epoxy resin can be, for example, a resin having two or more epoxy groups in one molecule. The epoxy resin can be, for example, at least one selected from the group consisting of a biphenyl type epoxy resin, a biphenyl aralkyl type epoxy resin, a biphenyl aralkyl type epoxy resin, a stilbene type epoxy resin, a diphenylmethane type epoxy resin, a sulfur atom-containing type epoxy resin, a novolak type epoxy resin, a dicyclopentadiene type epoxy resin, a pyrogallol type epoxy resin, a copolymerization type epoxy resin of naphthol and phenol, an epoxide of an aralkyl type phenol resin, a bisphenol type epoxy resin, an epoxy resin containing a bisphenol skeleton, a glycidyl ether type epoxy resin of an alcohol, a glycidyl ether type epoxy resin of a p- and / or m-xylene modified phenol resin, a glycidyl ether type epoxy resin of a terpene-modified phenol resin, a cyclopentadiene type epoxy resin, a glycidyl ether type epoxy resin of a polycyclic aromatic ring-modified phenol resin, a glycidyl ether type epoxy resin of a naphthalene ring-containing phenol resin, a glycidyl ester type epoxy resin, a glycidyl type or methyl glycidyl type epoxy resin, an alicyclic type epoxy resin, a halogenated phenol novolak type epoxy resin, an o-cresol novolak type epoxy resin, a hydroquinone type epoxy resin, a trimethylpropane type epoxy resin, and a linear aliphatic epoxy resin obtained by oxidizing an olefinic bond with a peracid such as peracetic acid.

[0057] From the viewpoint of excellent flowability, the epoxy resin can be at least one selected from the group consisting of a biphenyl type epoxy resin, an o-cresol novolak type epoxy resin, a phenol novolak type epoxy resin, a bisphenol type epoxy resin, an epoxy resin having a bisphenol skeleton, a pyrogallol novolak type epoxy resin, and a naphthol novolak type epoxy resin.

[0058] The epoxy resin can be a crystalline epoxy resin. Although the molecular weight of the crystalline epoxy resin is relatively low, the crystalline epoxy resin has a relatively high melting point and is excellent in flowability. The crystalline epoxy resin (highly crystalline epoxy resin) can be, for example, at least one selected from the group consisting of a hydroquinone type epoxy resin, a bisphenol type epoxy resin, a thioether type epoxy resin, and a biphenyl type epoxy resin. The commercially available product of the crystalline epoxy resin can be, for example, at least one selected from the group consisting of EPICLON 860, EPICLON 1050, EPICLON 1055, EPICLON 2050, EPICLON 3050, EPICLON 4050, EPICLON 7050, EPICLON HM-091, EPICLON HM-101, EPICLON N-730A, EPICLON N-740, EPICLON N-770, EPICLON N-775, EPICLON N-865, EPICLON HP-4032D, EPICLON HP-7200L, EPICLON HP-7200, EPICLON HP-7200H, EPICLON HP-7200HH, EPICLON HP-7200HHH, EPICLON HP-4700, EPICLON HP-4710, EPICLON HP-4770, EPICLON HP-5000, EPICLON HP-6000, N500P-2, and N500P-10 (all are trade names of DIC Corporation), NC-3000, NC-3000-L, NC-3000-H, NC-3100, CER-3000-L, NC-2000-L, XD-1000, NC-7000-L, NC-7300-L, EPPN-501H, EPPN-501HY, EPPN-502H, EOCN-1020, EOCN-102S, EOCN-103S, EOCN-104S, CER-1020, EPPN-201, BREN-S, BREN-10S (all are trade names of Nippon Kayaku Co., Ltd.), YX-4000, YX-4000H, YL4121H, and YX-8800 (all are trade names of Mitsubishi Chemical Corporation).

[0059] From the viewpoint of easily reducing the molding shrinkage of the composite, the resin composition can contain an isocyanate-modified epoxy resin as the epoxy resin. A commercially available product of the isocyanate-modified epoxy resin can be, for example, AER-4001 manufactured by Asahi Kasei Corporation (old asahi kasei E-Materials Corporation).

[0060] The resin composition can contain one of the epoxy resins described above. The resin composition can also contain a plurality of the epoxy resins described above.

[0061] [Curing agent]

[0062] Curing agents are classified into a curing agent that cures an epoxy resin in a range from low temperature to room temperature and a heat-curing type curing agent that cures an epoxy resin with heating. The curing agent that cures an epoxy resin in a range from low temperature to room temperature is, for example, an aliphatic polyamine, a polyamine-based amide, a polythiol, or the like. The heat-curing type curing agent is, for example, an aromatic polyamine, an acid anhydride, a novolak resin, dicyandiamide (DICY), or the like.

[0063] When a curing agent that cures an epoxy resin in a range from low temperature to room temperature is used, the glass transition point of the cured product of the epoxy resin is low, and the cured product of the epoxy resin tends to be soft. As a result, the molded body formed from the composite also tends to be soft. On the other hand, from the viewpoint of improving the heat resistance of the molded body, the curing agent can be preferably a heat-curing type curing agent, more preferably a phenolic resin, and further preferably a novolak resin. In particular, by using a novolak resin as the curing agent, a cured product of an epoxy resin having a high glass transition point is easily obtained. As a result, the heat resistance and the mechanical strength of the molded body are easily improved.

[0064] The phenolic resin can be, for example, at least one selected from the group consisting of an aralkyl type phenolic resin, a dicyclopentadiene type phenolic resin, a salicylaldehyde type phenolic resin, a novolak type phenolic resin, a copolymer type phenolic resin of a benzaldehyde type phenol and an aralkyl type phenol, a p-xylene and / or m-xylene-modified phenolic resin, a melamine-modified phenolic resin, a terpene-modified phenolic resin, a dicyclopentadiene type naphthalene phenolic resin, a cyclopentadiene-modified phenolic resin, a polycyclic aromatic ring-modified phenolic resin, a biphenyl type phenolic resin, and a triphenylmethane type phenolic resin. The phenolic resin can also be a copolymer composed of two or more of the above.

[0065] The novolak resin may, for example, be a resin obtained by condensing or co-condensing a phenol and / or a naphthol with an aldehyde under an acidic catalyst. The phenol constituting the novolak resin may, for example, be at least one selected from the group consisting of phenol, cresol, xylenol, resorcinol, catechol, bisphenol A, bisphenol F, phenylphenol, and aminophenol. The naphthol constituting the novolak resin may, for example, be at least one selected from the group consisting of a-naphthol, β-naphthol, and dihydroxynaphthalene. The aldehyde constituting the novolak resin may, for example, be at least one selected from the group consisting of formaldehyde, acetaldehyde, propionaldehyde, benzaldehyde, and salicylaldehyde.

[0066] The curing agent may, for example, also be a compound having two phenolic hydroxyl groups in one molecule. The compound having two phenolic hydroxyl groups in one molecule may, for example, be at least one selected from the group consisting of resorcinol, catechol, bisphenol A, bisphenol F, and substituted or unsubstituted diphenylolpropane.

[0067] The resin composition can contain one of the above-mentioned novolak resins. The resin composition can also contain a plurality of the above-mentioned novolak resins. The resin composition can contain one of the above-mentioned curing agents. The resin composition can also contain a plurality of the above-mentioned curing agents.

[0068] The ratio of the active groups (phenolic OH groups) in the curing agent that react with the epoxy groups in the epoxy resin, relative to 1 equivalent of the epoxy groups in the epoxy resin, can preferably be 0.5 to 1.5 equivalents, more preferably 0.6 to 1.4 equivalents, and further preferably 0.8 to 1.2 equivalents. When the ratio of the active groups in the curing agent is less than 0.5 equivalents, it is difficult to obtain sufficient elastic modulus of the obtained cured product. On the other hand, when the ratio of the active groups in the curing agent exceeds 1.5 equivalents, there is a tendency for the mechanical strength after curing of the molded body formed of the composite to decrease.

[0069] [Curing Accelerator]

[0070] The curing accelerator is not particularly limited as long as it is a composition that accelerates the curing of the epoxy resin in reaction with the epoxy resin. The curing accelerator can be, for example, an imidazole such as an alkyl-substituted imidazole or a benzimidazole. The resin composition can contain one curing accelerator. The resin composition can also contain a plurality of curing accelerators. By the resin composition containing a curing accelerator, the moldability and the releasability of the composite are easily improved. Also, by the resin composition containing a curing accelerator, the mechanical strength of a molded body (for example, an electronic part) manufactured using the composite is improved, or the storage stability of the composite under a high-temperature and / or high-humidity environment is improved. As a commercially available imidazole-based curing accelerator, at least one selected from the group consisting of 2MZ-H, C11Z, C17Z, 1,2DMZ, 2E4MZ, 2PZ-PW, 2P4MZ, 1B2MZ, 1B2PZ, 2MZ-CN, C11Z-CN, 2E4MZ-CN, 2PZ-CN, C11Z-CNS, 2P4MHZ, TPZ, and SFZ (all manufactured by Shikoku Chemicals Corporation) can be used, for example.

[0071] The blending amount of the curing accelerator is not particularly limited as long as it is an amount that can obtain a curing acceleration effect. However, from the viewpoint of improving the curing property and the flowability of the resin composition at the time of moisture absorption, the blending amount of the curing accelerator can be preferably 0.1 parts by mass or more and 30 parts by mass or less, more preferably 1 part by mass or more and 15 parts by mass or less, with respect to 100 parts by mass of the epoxy resin. The content of the curing accelerator is preferably 0.001 parts by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the total of the mass of the epoxy resin and the curing agent (for example, a phenol resin). When the blending amount of the curing accelerator is less than 0.1 parts by mass, it is difficult to obtain a sufficient curing acceleration effect. When the blending amount of the curing accelerator exceeds 30 parts by mass, the storage stability of the composite easily decreases.

[0072] [Coupling agent]

[0073] The coupling agent improves the adhesiveness of the resin composition to the metal particles constituting the metal powder, and improves the flexibility and mechanical strength of the molded body formed from the composite. The coupling agent can be, for example, at least one selected from the group consisting of silane-based compounds (silane coupling agents), titanium-based compounds, aluminum-based compounds (aluminum chelate-based compounds), and aluminum / zirconium-based compounds. The silane coupling agent can be, for example, at least one selected from the group consisting of epoxy silanes, mercapto silanes, amine silanes, alkyl silanes, ureido silanes, acid anhydride-based silanes, and vinyl silanes. In particular, an amine phenyl-based silane coupling agent is preferred. The resin composition can contain one of the above-described coupling agents, or can contain a plurality of the above-described coupling agents. Commercially available coupling agents can be, for example, at least one selected from the group consisting of vinyltrimethoxysilane (KBM-1003), vinyltriethoxysilane (KBE-1003), 2-(3,4-epoxy cyclohexyl)ethyltrimethoxysilane (KBM-303), 3-glycidyloxypropylmethyldimethoxysilane (KBM-402), 3-glycidyloxypropyltrimethoxysilane (KBM-403), p-styryltrimethoxysilane (KBM-1403), 3-methacryloyloxypropylmethyldimethoxysilane (KBM-502), 3-methacryloyloxypropyltrimethoxysilane (KBM-503), 3-methacryloyloxypropylmethyldiethoxysilane (KBE-502), 3-methacryloyloxypropyltriethoxysilane (KBE-503), 3-acryloyloxypropyltrimethoxysilane (KBM-5103), N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane (KBM-602), N-2-(aminoethyl)-3-aminopropyltrimethoxysilane (KBM-603), 3-aminopropyltrimethoxysilane (KBM-903), 3-aminopropyltriethoxysilane (KBE-903), 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine (KBE-9103), N-phenyl-3-aminopropyltrimethoxysilane (KBM-573), hydrochloride of N-vinylbenzyl-2- aminoethyl-3-aminopropyltrimethoxysilane (KBM-575), tris- (trimethoxysilylpropyl)isocyanurate (KBM-9659), 3-ureidopropyltrialkoxysilane (KBE-585), 3-mercaptopropylmethyldimethoxysilane (KBM-802), 3-mercaptopropyltrimethoxysilane (KBM-803), 3-isocyanatopropyltriethoxysilane (KBM-9007), octenyltrimethoxysilane (KBM-1083), glycidyloxyoctyltrimethoxysilane (KBM-4803), methacryloyloxyoctyltrimethoxysilane (KBM-5803), methyltrimethoxysilane (KBM-13), methyltriethoxysilane (KBE-13), dimethyldimethoxysilane (KBM-22), dimethyldiethoxysilane (KBE-22), phenyltrimethoxysilane (KBM-103), phenyltriethoxysilane (KBE-103), n-propyltrimethoxysilane (KBM-3033), n-propyltriethoxysilane (KBE-3033), hexyltriethoxysilane (KBM-3063), hexyltriethoxysilane (KBE-3063), octyltriethoxysilane (KBE-3083), decyltrimethoxysilane (KBM-3103C), 1,6- (trimethoxysilyl)hexane (KBM-3066), trifluoropropyltrimethoxysilane (KBM-7103), hexamethyldisilazane (SZ-31), and siloxane containing a hydrolyzable group (KPN-3504) (the above are trade names manufactured by Shin-Etsu Chemical Co., Ltd.). The coupling agent can also be a silicone alkoxy oligomer (silicone oligomer having an alkoxy group). The silicone alkoxy oligomer can have at least one alkoxy group selected from the group consisting of a methoxy group and an ethoxy group. The silicone alkoxy oligomer can have at least one organic substituent selected from the group consisting of an epoxy group, a methyl group, a mercapto group, an acryloyl group, a methacryloyl group, a vinyl group, and a phenyl group. The silicone alkoxy oligomer can be, for example, at least one selected from KR-517, X-41-1059A, X-24-9590, KR-516, X-41-1805, X-41-1818, X-41-1810, KR-513, X-40-9296, KR-511, KC-89S, KR-515, KR-500, X-40-9225, X-40-9246, X-40-9250, KR-41N, X-40-9227, KR-510, KR-9218, and KR-213 (the above are trade names manufactured by Shin-Etsu Chemical Co., Ltd.).

[0074] [ Wax ]

[0075] The wax improves the flowability of the compound during molding (e.g., transfer molding) of the compound and functions as a release agent. The wax can be at least any one of a fatty acid such as higher fatty acid, a fatty acid ester, and a fatty acid amide.

[0076] The wax can be, for example, at least one selected from the group consisting of a fatty acid such as montanic acid, stearic acid, 12-oxystearic acid, lauric acid, or an ester of these, a fatty acid salt such as zinc stearate, calcium stearate, barium stearate, aluminum stearate, magnesium stearate, zinc laurate, calcium laurate, zinc linoleate, calcium ricinoleate, zinc 2-ethylhexanoate, a fatty acid amide such as stearic acid amide, oleic acid amide, erucic acid amide, behenic acid amide, palmitic acid amide, lauric acid amide, hydroxystearic acid amide, methylenebisstearic acid amide, ethylenebisstearic acid amide, ethylenebislauric acid amide, distearyladipic acid amide, ethylenebisoctadecanoic acid amide, N-steryl stearic acid amide, N-oleyl stearic acid amide, N-steryl erucic acid amide, hydroxymethyl stearic acid amide, hydroxymethyl behenic acid amide, a fatty acid ester such as butyl stearate, an alcohol such as ethylene glycol, stearyl alcohol, a polyether such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and a modification of these, a polysiloxane such as silicone oil and silicone grease, a fluorine compound such as fluorine oil, fluorine grease, and fluorine resin powder, and a wax such as paraffin wax, polyethylene wax, amide wax, polypropylene wax, ester wax, carnauba wax, and microcrystalline wax.

[0077] [Other components in the resin composition]

[0078] For environmental safety, recyclability, moldability, and low cost of the compound, the compound can contain a flame retardant. The flame retardant can be, for example, at least one selected from the group consisting of a bromine-based flame retardant, a phosphorus-based flame retardant, a hydrated metal compound-based flame retardant, a silicone-based flame retardant, a nitrogen-containing compound, a hindered amine compound, an organic metal compound, and an aromatic engineering plastic. The resin composition can contain one of the above-described flame retardants, or can contain a plurality of the above-described flame retardants.

[0079] (Metal powder)

[0080] The metal powder may, for example, contain at least one selected from the group consisting of a metal monomer (pure metal) and an alloy. The metal powder may, for example, be composed of at least one selected from the group consisting of a metal monomer (pure metal), an alloy, an amorphous powder, and a metal compound. The alloy can include at least one selected from the group consisting of a solid solution, a eutectic, and an intermetallic compound. The alloy may, for example, be a stainless steel (Fe-Cr-based alloy, Fe-Ni-Cr-based alloy, etc.). The metal powder can include one metal element or a plurality of metal elements. The metal element included in the metal powder may, for example, be a base metal element, a noble metal element, a transition metal element, or a rare earth element. The composite can include one metal powder, or a plurality of metal powders.

[0081] The metal element included in the metal powder may, for example, be at least one selected from the group consisting of iron (Fe), copper (Cu), titanium (Ti), manganese (Mn), cobalt (Co), nickel (Si), zinc (Zn), aluminum (Al), tin (Sn), chromium (Cr), barium (Ba), strontium (Sr), lead (Pb), silver (Ag), praseodymium (Pr), neodymium (Nd), samarium (Sm), and dysprosium (Dy). The metal powder can include an element other than the metal element. For example, the metal powder can include oxygen (O), beryllium (Be), phosphorus (P), boron (B), or silicon (Si). The metal powder can be a magnetic powder. The metal powder can be a soft magnetic alloy or a strong magnetic alloy. The metal powder may, for example, be a magnetic powder composed of at least one selected from the group consisting of an Fe-Si-based alloy, an Fe-Si-Al-based alloy (Sendust), an Fe-Ni-based alloy (Permalloy), an Fe-Cu-Ni-based alloy (high permeability alloy), an Fe-Co-based alloy (Permendur), an Fe-Cr-Si-based alloy (electromagnetic stainless steel), an Nd-Fe-B-based alloy (rare earth magnet), an Sm-Fe-N-based alloy (rare earth magnet), and an Al-Ni-Co-based alloy (Alnico). The metal powder can be a copper alloy such as a Cu-Sn-based alloy, a Cu-Sn-P-based alloy, a Cu-Ni-based alloy, or a Cu-Be-based alloy. The metal powder can be composed of only one element or composition. The metal powder can also include a plurality of elements or compositions.

[0082] The metal powder can also be Fe single body (pure iron). The metal powder can be an alloy containing iron (Fe-based alloy). The Fe-based alloy can be, for example, an Fe-Si-Cr-based alloy, an Nd-Fe-B-based alloy, or a Sm-Fe-N-based alloy. The metal powder can also be at least any one of amorphous iron powder and carbonyl iron powder. When the metal powder contains at least any one of Fe single body and Fe-based alloy, a molded body having a high space factor and excellent magnetic properties can be easily produced from the composite. The metal powder can also be an Fe amorphous alloy. As a commercially available product of Fe amorphous alloy powder, at least one selected from the group consisting of AW2-08, KUAMET-6B2 (trade names of products manufactured by Epson Atmix Corporation), DAP MS3, DAP MS7, DAP MSAlO, DAP PB, DAP PC, DAP MKV49, DAP 410L, DAP 430L, DAP HYB series (trade names of products manufactured by Daido Steel Co., Ltd.), MH45D, MH28D, MH25D, and MH20D (trade names of products manufactured by Kobe Steel, Ltd.) can be used, for example.

[0083] The average particle diameter of the metal powder is not particularly limited, and can be, for example, 1 μm or more and 300 μm or less. The average particle diameter can be measured by a particle size distribution meter, for example. The shape of each metal particle constituting the metal powder is not limited, and can be, for example, spherical, flat, angular columnar, or needle-like. The composite can contain a plurality of metal powders having different average particle diameters.

[0084] <Use of the composite>

[0085] The composite can be used for at least one of transfer molding and compression molding. The transfer molding is one of injection molding methods of thermosetting resins. The transfer molding can be referred to as pressure casting. The transfer molding can include a step of heating the composite in a heating chamber to fluidize the composite, a step of supplying (pressing) the fluidized composite from the heating chamber to a mold through a casting runner, and a step of heating the composite in the mold to cure the composite. The transfer molding can include a step of heating the composite in a heating chamber to fluidize the composite, a step of supplying the fluidized composite powder from the heating chamber to a plunger, a step of supplying (pressing) the composite from the plunger to a mold through a casting runner, and a step of heating the composite in the mold to cure the composite. The pressure applied to the composite in the transfer molding can be, for example, 3 MPa or more and 100 MPa or less. The composite of the present embodiment easily flows in a fine casting runner and easily fills a space (cavity) in a mold uniformly because of excellent fluidity and filling property by heating. Therefore, the composite is processed by the transfer molding, and thus a molded body and a cured product having few defects such as voids or burrs can be manufactured. The molding method of the composite can also be compression molding.

[0086] According to the composition or combination of the metal powder included in the composite, each property (for example, electromagnetic property or magnetic property) of the molded body and the cured product each formed from the composite can be easily controlled. Therefore, the molded body and the cured product can be used for various industrial products or raw materials thereof. The molded body formed from the composite can include at least any one of an uncured resin composition and a B-stage resin composition (semi-cured product of the resin composition). The molded body can be composed only of the composite. The cured product of the composite or the molded body can include a C-stage resin composition (cured product of the resin composition).

[0087] The industrial product manufactured using the composite can be, for example, an automobile, a medical device, an electronic device, an electrical device, an information communication device, a home appliance, a sound equipment, and a general industrial equipment. For example, when the composite includes a permanent magnet such as an Sm-Fe-N-based alloy or an Nd-Fe-B-based alloy as the metal powder, the composite can be used as a material of a bonded magnet. When the composite includes a soft magnetic substance such as an Fe-Si-Cr-based alloy as the metal powder, the composite can be used as a material (for example, a seal or a magnetic core) of an inductor (for example, an EMI filter) or a transformer. The sheet-shaped molded body or the cured product formed from the composite can be used as an electromagnetic wave shield.

[0088] <Method for manufacturing the composite>

[0089] The composite is obtained by mixing the metal powder and the resin composition while heating. For example, the metal powder and the resin composition can be kneaded with a kneader, a roll, a blender or the like while heating. By heating and mixing the metal powder and the resin composition, the resin composition adheres to a part or the whole of the surface of each metal particle constituting the metal powder to coat each metal particle. By kneading, a part or the whole of the epoxy resin in the resin composition can become a semi-cured product.

[0090] For example, the metal powder, the epoxy resin, the phosphate ester (dispersant), the curing agent, the curing accelerator, the coupling agent and the wax can be kneaded at one time in a tank. The metal powder, the epoxy resin, the phosphate ester, the curing agent, the curing accelerator, the coupling agent and the wax can be further kneaded in the tank after mixing the metal powder and at least one of the phosphate ester and the coupling agent in the tank. The mixture of these and the curing accelerator can be further kneaded in the tank after kneading the metal powder, the epoxy resin, the phosphate ester, the curing agent, the coupling agent and the wax in the tank. The epoxy resin, the phosphate ester, the curing agent, the curing accelerator and the wax can be mixed in advance to produce a resin mixture powder. The metal powder and the coupling agent can be mixed in advance to produce a metal mixture powder. The metal mixture powder and the above-described resin mixture powder can be kneaded to obtain the composite.

[0091] The kneading time depends on the type of the kneading machine, the volume of the kneading machine and the production amount of the composite. The kneading time is preferably 1 minute or more, more preferably 2 minutes or more, and further preferably 3 minutes or more, for example. Also, the kneading time is preferably 20 minutes or less, more preferably 15 minutes or less, and further preferably 10 minutes or less. When the kneading time is less than 1 minute, the kneading is insufficient, which impairs the moldability of the composite, and the degree of curing of the composite varies. When the kneading time exceeds 20 minutes, the flowability, the filling property and the moldability of the composite are easily impaired by the curing of the resin composition (e.g., the epoxy resin and the phenol resin) in the tank, for example. When the raw materials in the tank are kneaded with a kneader while heating, the heating temperature can be a temperature at which a semi-cured product of the epoxy resin (a B-stage epoxy resin) is generated and the generation of a cured product of the epoxy resin (a C-stage epoxy resin) is suppressed, for example. The heating temperature can also be a temperature lower than the activation temperature of the curing accelerator. The heating temperature is preferably 50°C or more, more preferably 60°C or more, and further preferably 70°C or more, for example. The heating temperature is preferably 150°C or less, more preferably 120°C or less, and further preferably 110°C or less. When the heating temperature is within the above-described range, the resin composition in the tank softens to easily coat the surface of the metal particle constituting the metal powder, so that the semi-cured product of the epoxy resin is easily generated, and the complete curing of the epoxy resin in the kneading is easily suppressed.

[0092] Example

[0093] Hereinafter, the present application will be described in further detail according to Examples and Comparative Examples. The present application is not limited to these Examples.

[0094] (Example 1)

[0095] [Production of composite]

[0096] Epoxy resin 1, epoxy resin 2, dispersant (phosphate ester), curing agent 1, curing agent 2, curing accelerator, releasing agent 1 (wax), and releasing agent 2 (wax) were charged into a plastic container. By mixing the contents of the plastic container for 10 minutes, a resin mixture was produced. The resin mixture corresponds to all the components in the resin composition except for the coupling agent.

[0097] As the epoxy resin 1, NC-3000 (biphenyl aralkyl type epoxy resin) manufactured by Nippon Kayaku Co., Ltd. was used.

[0098] As the epoxy resin 2, TECHMORE VG3101L (3 functional epoxy resin) manufactured by PRINTEC, INC. was used.

[0099] As the dispersant, disperbyk-111 manufactured by BYK-Chemie GmbH was used.

[0100] As the curing agent 1, MEHC-7500-3S (triphenol methane type phenol resin) manufactured by Meiwa Plastic Industries, Ltd. was used.

[0101] As the curing agent 2, MEHC-7851SS (biphenyl aralkyl type phenol resin) manufactured by Meiwa Plastic Industries, Ltd. was used.

[0102] As the curing accelerator, 2E4MZ (2-ethyl-4-methylimidazole) manufactured by Shikoku Chemicals Corporation was used.

[0103] As the releasing agent 1, Licowax OP manufactured by Clariant Chemicals Co., Ltd. was used. Licowax OP is a lignocerate ester partially saponified by calcium hydroxide.

[0104] As the releasing agent 2, zinc stearate manufactured by NOF CORPORATION was used.

[0105] The iron powder 1 and the iron powder 2 were uniformly mixed for 5 minutes by using a pressurized double shaft kneader to prepare a metal powder. Both the iron powder 1 and the iron powder 2 were amorphous.

[0106] As the iron powder 1, KUAMET 9A4-II075C03 manufactured by Epson Atmix Corporation was used. The average particle diameter of the iron powder 1 was 24 μm.

[0107] As the iron powder 2, AW2-08 manufactured by Epson Atmix Corporation was used. The average particle diameter of the iron powder 2 was 5.3 μm.

[0108] As the pressurized double shaft kneader, a pressurized double shaft kneader manufactured by Nihon Spindle Manufacturing Co., Ltd. was used. The capacity of the pressurized double shaft kneader was 5 L.

[0109] The coupling agent 1, the coupling agent 2, and the additive (stress relaxation agent) were added to the metal powder in the double shaft kneader. Next, the contents of the double shaft kneader were heated to 90°C, and while maintaining the temperature of the contents, the contents of the double shaft kneader were mixed for 10 minutes. Next, the above resin mixture was added to the contents of the double shaft kneader. While maintaining the temperature of the contents at 120°C, the contents were mixed for 15 minutes. After the obtained mixture was cooled to room temperature, the mixture was pulverized with a hammer so that the mixture had a prescribed particle size.

[0110] As the coupling agent 1, KBM-5803 (methacryloxyoctyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd. was used.

[0111] As the coupling agent 2, KBM-403 (3-glycidyloxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd. was used.

[0112] As the additive, DBL-C32 (caprolactone-modified dimethyl silicone) manufactured by Gelest, Inc. was used.

[0113] The composite of Example 1 was produced by the above method.

[0114] The mass (unit: g) of each component constituting the composite is shown in Table 1 below.

[0115] The content (unit: mass %) of the metal powder in the composite is shown in Table 1 below.

[0116] The content (unit: mass %) of the epoxy resin in the composite is shown in Table 1 below.

[0117] The proportion of the epoxy resin (unit: mass parts) with respect to 100 mass parts of the metal powder is shown in Table 1 below.

[0118] The proportion of the phosphate ester (dispersant) (unit: mass parts) with respect to 100 mass parts of the metal powder is shown in Table 1 below.

[0119] [Measurement of melt viscosity]

[0120] The minimum melt viscosity of the composite at 140°C was measured as described below. As a measuring device, CFT-100 (flow tester) manufactured by Shimadzu Corporation was used. As a sample for measurement, an ingot was prepared from 7 g of the composite. The flowability of the composite was evaluated under the conditions of 140°C, 20 seconds of residual heat, and 100 kg of load. The penetration distance of the plunger until the flow of the composite stopped (unit: mm) was measured as the flow tester stroke. The time until the flow of the composite stopped was measured as the flow time. These measured values were used as indices of the flowability. The measured melt viscosity (unit: Pa-s) of Example 1 is shown in Table 1 below.

[0121] [Measurement of circular plate flow]

[0122] As a sample for measurement, 5 g of the composite (powder) was used. The composite was placed on the flat surface of the lower mold. The flat upper mold was pressed onto the composite, and the composite was clamped with the upper mold and the lower mold. The composite between the upper mold and the lower mold was compressed for 360 seconds with a load of 8 kg, whereby a molded body in the shape of a substantially circular plate formed of the composite was formed. The temperature of the composite during compression was maintained at 140°C. The maximum diameter and the minimum diameter of the molded body in the shape of a circular plate were measured. The average of the major diameter and the minor diameter corresponds to the circular plate flow. The circular plate flow (unit: mm) of Example 1 is shown in Table 1 below.

[0123] (Examples 2 to 5 and Comparative Examples 1 to 3)

[0124] The mass of each component constituting the composite in each of Examples 2 to 5 and Comparative Examples 1 to 3 is shown in Table 1 below. In addition to the mass of each component constituting the composite, the composite in each of Examples 2 to 5 and Comparative Examples 1 to 3 was produced in the same manner as in Example 1.

[0125] In the case of Examples 2 to 5 and Comparative Examples 1 to 3, the content of the metal powder in the composite was the value shown in Table 1 below.

[0126] In the case of Examples 2 to 5 and Comparative Examples 1 to 3, the content of the epoxy resin in the composite was the value shown in Table 1 below.

[0127] In the case of Examples 2 to 5 and Comparative Examples 1 to 3, the proportion of the epoxy resin with respect to 100 parts by mass of the metal powder was the value shown in Table 1 below.

[0128] In the case of Examples 2 to 5 and Comparative Examples 1 to 3, the proportion of the phosphoric acid ester (dispersant) with respect to 100 parts by mass of the metal powder was the value shown in Table 1 below.

[0129] The melt viscosity and the circular plate flow of each of the composites of Examples 2 to 5 and Comparative Examples 1 to 3 were measured in the same manner as in Example 1. The melt viscosity and the circular plate flow of each of the composites of Examples 2 to 5 and Comparative Examples 1 to 3 were the values shown in Table 1 below. However, in the case of Comparative Examples 2 and 3, the composite hardly flowed, and it was difficult to measure the melt viscosity. That is, the more difficult it was to measure, the higher the melt viscosity was in the case of Comparative Examples 2 and 3.

[0130]

[0131] Industrial applicability

[0132] Since the flowability and the filling property of the composite of the present application are excellent, it is possible to manufacture various industrial products such as inductors in various shapes by molding of the composite.

Claims

1. A composite comprising at least a metal powder and a resin composition, the metal powder is a soft magnetic body, and is at least any one of pure iron and an Fe-based alloy containing iron, the resin composition contains at least an epoxy resin and a phosphate ester, a content of the metal powder in the composite is 97.0 mass% or more and 97.5 mass% or less, a proportion of the phosphate ester with respect to 100 mass parts of the metal powder is 0.02 mass parts or more and 0.10 mass parts or less.

2. The composite according to claim 1, wherein, a melt viscosity of the composite at 140°C is 10 Pa-s or more and 1500 Pa-s or less.

3. The composite according to claim 1 or 2, which is used for at least one of transfer molding and compression molding.

4. A molded body comprising the composite according to any one of claims 1 to 3.

5. A cured product which is a cured product of the composite according to any one of claims 1 to 3.

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