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 phosphoric acid ester, the content of the epoxy resin in the composite material being 1.0 mass% or more and 2.0 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 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 composite becomes difficult to flow.

[0010] The present application has been achieved in view of the above 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 epoxy resin in the composite is greater than or equal to 1.0 mass% and less than or equal to 2.0 mass%.

[0013] The proportion of the phosphate ester with respect to 100 mass parts of the metal powder can be greater than or equal to 0.01 mass part and less than or equal to 0.05 mass part.

[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 content of the metal powder in the composite can be 90 mass% or more and 98 mass% or less.

[0016] The composite of one embodiment of the present application can be used for at least one of transfer molding and compression molding.

[0017] The molded article of one embodiment of the present application includes the above composite.

[0018] The cured product of one embodiment of the present application is a cured product of the above composite.

[0019] Effects of the Invention

[0020] 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

[0021] Hereinafter, preferred embodiments of the present application are described. However, the present application is not limited to any of the following embodiments.

[0022] [Outline of Composite]

[0023] The composite of this embodiment includes at least a metal powder and a resin composition. That is, the composite can be a mixture of a metal powder and a resin composition. The composite can be referred to as a magnetic seal.

[0024] The metal powder is composed of a plurality of metal particles. The metal powder can contain at least one selected from the group consisting of a metal monomer (a pure metal), an alloy, an amorphous powder, and a metal compound, for example. The metal powder can be referred to as a filler formed of a metal.

[0025] The resin composition contains at least an epoxy resin and a phosphate ester.

[0026] The epoxy resin melts at a temperature lower than the curing temperature, whereby the flowability of the composite is improved. Also, 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. The content of the epoxy resin in the composite is 1.0 mass% or more and 2.0 mass% or less. When the content of the epoxy resin in the composite is within the above range, and the composite contains the phosphate ester, the composite can have high flowability (low melt viscosity). When the content of the epoxy resin in the composite is less than the lower limit value, the composite can hardly have high flowability. When the content of the epoxy resin in the composite is within the above range, and the composite does not contain the phosphate ester, the composite can also hardly have high flowability. When the content of the epoxy resin in the composite is more than the upper limit value, it is difficult to manufacture the composite. Since the composite easily has high flowability, the content of the epoxy resin in the composite can be 1.86 mass% or more and 1.90 mass% or less. In other words, the proportion of the epoxy resin with respect to 100 mass parts of the metal powders can be 1.92 mass parts or more and 1.97 mass parts or less.

[0027] 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 at least one of R 1 , R 2 , and R 3 is a hydrocarbon group. The hydrocarbon group can be an alkyl group or an aryl group, for example. 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 the phosphite ester in addition to the phosphate ester. However, the composite that does not contain the phosphate ester and contains the phosphite ester can hardly have high flowability as compared with the composite of the present embodiment. The resin composition can contain other dispersants (for example, coupling agents) in addition to the phosphate ester.

[0028] The phosphate ester can be a dispersing agent. 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 inhibited due to the phosphate ester, and each metal particle is easily dispersed in the composite. In other words, the metal particles are difficult to directly contact with each other due to the phosphate ester, and direct friction between the metal particles and friction between the metal particles and the resin composition are easily inhibited. As described above, the flowability of the composite is improved by the phosphate ester acting as a dispersing agent on 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 dispersing agent other than the phosphate ester. The direct friction between the metal particles can be evaluated from the torque value measured by a gelling time measuring device. The more the direct friction between the metal particles is inhibited, the more the torque value is reduced. As the gelling time measuring device, a CURE LASTOMETER manufactured by JSR Corporation can be used.

[0029] The melt viscosity of the composite at 140°C can be 10 Pa-s or more and 1500 Pa-s or less, and preferably 40 Pa-s or more and 650 Pa-s or less. When the content of the epoxy resin in the composite is within the above range, and the composite contains 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 is easily uniformly filled into a mold, and defects (voids or burrs, etc.) in a molded body and a cured product formed from the composite are easily inhibited. Thus, the composite having a low melt viscosity as described above is suitable for transfer molding.

[0030] The proportion of the phosphate ester with respect to 100 parts by mass of the metal powder can be 0.01 parts by mass or more and 0.05 parts by mass or less. When the proportion of the phosphate ester is 0.01 parts by mass (preferably 0.02 parts by mass) or more, the high flowability (low melt viscosity) of the composite due to 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 0.05 parts by mass or less, the hindering of the curing of the epoxy resin due to the phosphate ester is easily inhibited. In other words, when the proportion of the phosphate ester is 0.05 parts by mass 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 parts by mass of the metal powder can also be 0.02 parts by mass or more and 0.03 parts by mass or less.

[0031] The content of the metal powder in the composite can be 90 mass% or more and 98 mass% or less, or 96 mass% or more and 97.5 mass%. 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 seal for an inductor or a raw material for a magnetic core of an inductor. However, as the content of the metal powder in the composite increases, the composite becomes difficult to flow. In the case where the content of the metal powder in the composite is 90 mass% or more, the melt viscosity of the composite significantly increases. However, even in the case where the content of the metal powder in the composite is 90 mass% or more, the composite of the present embodiment contains the epoxy resin and the phosphoric acid ester, and thus can have a high flowability (low melt viscosity). When the content of the metal powder in the composite is the upper limit value or less, a high flowability (low melt viscosity) due to the epoxy resin and the phosphoric acid ester is easily obtained.

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

[0033] (resin composition)

[0034] The resin composition can be a component containing the epoxy resin and the phosphoric acid ester, and be a remaining component (non-volatile component) other than the metal powder and the organic solvent among all the components constituting the composite. That is, the resin composition can contain other components in addition to the epoxy resin and the phosphoric acid 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, or the like.

[0035] The resin composition has a function as a binding material (binder) of the metal particles constituting the metal powder, and imparts mechanical strength to the molded body formed of the composite. For example, when the composite is molded at a high pressure using a mold, the resin composition contained in the composite is filled between the metal particles, and the metal particles are bonded to each other. By the 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 constituting 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 contain the metal powder and the uncured resin composition. The composite can contain the metal powder and a semi-cured product of the resin composition (for example, a B-stage resin composition). The composite can contain 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 an ingot. The composite can also be a paste.

[0037] The content of the resin composition in the composite can be, for example, 2% by mass or more and 10% 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 contained 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 contained 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, a compound 1 represented by the following Chemical Formula 1, a compound 2 represented by the following Chemical Formula 2, a compound 3 represented by the following Chemical Formula 3, and a compound 4 represented by the following Chemical Formula 4. When at least one of these phosphoric acid esters is contained 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 contained 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, for example, disperbyk-111 (trade name) manufactured by BYK-Chemie GmbH. 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] The compound 1 represented by the following Chemical Formula 1 can be, for example, JP-504 manufactured by JOHOKU CHEMICAL CO., LTD.

[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] (C4H9C2H s CHCH2O) 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 a 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 may, for example, be a resin having two or more epoxy groups in one molecule. The epoxy resin may, for example, be 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 diphenyl methane type epoxy resin, a sulfur atom-containing type epoxy resin, a novolak type epoxy resin, a dicyclopentadiene type epoxy resin, a m-cresol type epoxy resin, a copolymer type epoxy resin of naphthol and phenol, an epoxy of an aralkyl type novolak resin, a bisphenol type epoxy resin, an epoxy resin containing a bisphenol skeleton, a glycerol ether type epoxy resin of an alcohol, a glycerol ether type epoxy resin of a p- and / or m-xylene modified phenol resin, a glycerol ether type epoxy resin of a terpene modified phenol resin, a cyclopentadiene type epoxy resin, a glycerol ether type epoxy resin of a polycyclic aromatic ring modified phenol resin, a glycerol ether type epoxy resin of a naphthalene ring-containing phenol resin, a glycidyl ester type epoxy resin, a glycidyl 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 fluidity, the epoxy resin may 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 m-cresol 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, EPTCLON 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-aminopropyl-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), methacryloxyoctyltrimethoxysilane (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 the group consisting of 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 salt.

[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, ethylenebisoelic 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 (Ni), 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 transfer molding. 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 an easter 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 an easter 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 easter 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 electric device, an information communication device, a home appliance, a sound equipment, and a general industrial device. 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 material 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 to impair 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 inhibited, 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, thereby easily generating the semi-cured product of the epoxy resin and easily inhibiting the complete curing of the epoxy resin during kneading.

[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, U-CAT 3512T manufactured by San-Apro Ltd. was used.

[0103] As the releasing agent 1, POWDER BASE L (zinc laurate) manufactured by NOF CORPORATION was used.

[0104] As the releasing agent 2, Licowax OP manufactured by Clariant Chemicals Co., Ltd. was used. Licowax OP is a lignocerate ester partially saponified by calcium hydroxide.

[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 an 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 with respect to 100 parts by mass of the metal powder (unit: parts by mass) is shown in Table 1 below.

[0118] The proportion of the phosphate ester (dispersant) with respect to 100 parts by mass of the metal powder (unit: parts by mass) 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 the measuring device, CFT-100 (flow tester) manufactured by Shimadzu Corporation was used. As the measuring sample, an ingot was made 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 disc flow]

[0122] As the measuring sample, 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 on the composite, and the composite was clamped with the upper and lower molds. The composite between the upper and lower molds was compressed for 360 seconds with a load of 8 kg, whereby a molded body in the shape of a substantially disc 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 disc-shaped molded body were measured. The average of the major and minor diameters corresponds to the disc flow. The disc flow (unit: mm) of Example 1 is shown in Table 1 below.

[0123] [Measurement of gelation time]

[0124] The gelation time (gelation time) of the composite at 140°C was measured. As the measuring device of the gelation time (vulcanization tester), a sulfurization tester (CURELASTOMETER) manufactured by JSR Corporation was used. The gelation time (unit: seconds) of Example 1 is shown in Table 1 below.

[0125] (Examples 2 to 4 and Comparative Example 1)

[0126] The mass of each component constituting the composite of each of Examples 2 to 4 and Comparative Example 1 is shown in Table 1 below. In addition to the mass of each component constituting the composite, the composite of each of Examples 2 to 4 and Comparative Example 1 was produced in the same manner as Example 1.

[0127] In the case of Examples 2 to 4 and Comparative Example 1, the content of the metal powder in the composite was the value shown in Table 1 below.

[0128] In the case of Examples 2 to 4 and Comparative Example 1, the content of the epoxy resin in the composite was the value shown in Table 1 below.

[0129] In the case of Examples 2 to 4 and Comparative Example 1, the ratio of the epoxy resin with respect to 100 parts by mass of the metal powder was the value shown in Table 1 below.

[0130] In the case of Examples 2 to 4 and Comparative Example 1, the ratio of the phosphate ester (dispersant) with respect to 100 parts by mass of the metal powder was the value shown in Table 1 below.

[0131] The melt viscosity, the circular plate flow, and the gelling time of the composite of each of Examples 2 to 4 and Comparative Example 1 were measured in the same manner as Example 1. The melt viscosity, the circular plate flow, and the gelling time of the composite of each of Examples 2 to 4 and Comparative Example 1 were the values shown in Table 1 below.

[0132]

[0133] Industrial Applicability

[0134] Since the flowability and the filling property of the composite of the present application are excellent, various shapes of industrial products such as inductors can be manufactured 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 material and is at least one of pure iron and Fe-based alloys containing iron. The resin composition contains at least an epoxy resin and a phosphate ester. The epoxy resin content in the composite is 1.0% by mass or more and 2.0% by mass or less. The proportion of the phosphate ester relative to 100 parts by weight of the metal powder is 0.02 parts by weight or more and 0.05 parts by weight or less. The compound is used for at least one of transfer molding and compression molding.

2. The complex according to claim 1, wherein, The melt viscosity of the composite at 140°C is above 10 Pa·s and below 1500 Pa·s.

3. The complex according to claim 1 or 2, wherein, The content of the metal powder in the composite is above 90% by mass and below 98% by mass.

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

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

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