Composites, molded bodies and cured products

Abstract

The composite comprises at least metal powder and a resin composition, the resin composition comprising at least epoxy resin and phosphate ester, and the epoxy resin content in the composite is more than 1.0% by mass and less than 2.0% by mass.

Description

Technical Field

[0001] One aspect of the present invention relates to a composite, a molded body, and a cured product. Prior Technology

[0002] The composite containing metal powder and thermosetting resin is used as a raw material for various industrial products such as inductors, based on the many physical properties of the metal powder (see Patent Documents 1 and 2 below).

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2011-211026 [Patent Document 2] Japanese Patent Application Publication No. 2017-133071

[0004] When manufacturing industrial products from composites, the composite is supplied and filled into a mold through a flow path, or components such as coils are embedded in the composite within the mold. In these steps, the flowability of the composite is required. When the composite does not have sufficient flowability, it is difficult to fill the mold uniformly, and voids are easily formed within the molded body formed from the composite. The flowability of the composite increases as the content of metal powder in the composite decreases.

[0005] On the other hand, a higher content (filling rate) of metal powder in the composite is preferable in order to improve the magnetic properties of the composite used in inductors and the like. For example, the magnetic property values ​​of the composite, such as relative permeability and saturation flux density, increase with the increase of the metal powder content in the composite. However, as the metal powder content in the composite increases, the composite becomes more difficult to flow. Summary of the Invention

[0006] The present invention was made in view of the above-mentioned problems. One aspect of the present invention is to provide a composite with excellent flowability, a molded body comprising the composite, and a cured product of the composite.

[0007] The composite of one aspect of the present invention comprises at least metal powder and a resin composition, wherein the resin composition comprises at least epoxy resin and phosphate ester, and the epoxy resin content in the composite is more than 1.0% by mass and less than 2.0% by mass.

[0008] The ratio of phosphate ester to 100 parts by weight of metal powder can be more than 0.01 parts by weight and less than 0.05 parts by weight.

[0009] The melt viscosity of the composite at 140℃ can be above 10 Pa·s and below 1500 Pa·s.

[0010] The content of metal powder in the composite can be above 90% by mass and below 98% by mass.

[0011] The composite of one aspect of the present invention can be used in at least one of transfer molding and compression molding.

[0012] One embodiment of the present invention comprises the above-described composite.

[0013] One embodiment of the present invention is a cured product of the above-mentioned composite material. [Invention Effects]

[0014] According to one aspect of the present invention, a composite with excellent flowability, a molded body comprising the composite, and a cured product of the composite are provided. Implementation

[0015] The preferred embodiments of the present invention will now be described. However, the present invention is not limited to any of the embodiments described below.

[0016] <Summary of the Complex> The composite of this embodiment comprises at least metal powder and a resin composition. That is, the composite can be a mixture of metal powder and a resin composition. The composite can be referred to as a magnetic seal.

[0017] Metal powder is composed of multiple metal particles. Metal powder may contain at least one component selected from the group consisting of metal monomers (pure metals), alloys, amorphous powders, and metal compounds. Metal powder can be referred to as a filler material formed of metal.

[0018] The resin composition contains at least epoxy resin and phosphate ester.

[0019] The epoxy resin melts at a temperature below its curing temperature, thereby increasing the fluidity of the composite. Furthermore, the epoxy resin bonds the metal powders together through thermal curing. Additionally, the epoxy resin provides electrical insulation between the metal powders. The epoxy resin content in the composite is 1.0% by mass or more and 2.0% by mass or less. When the epoxy resin content in the composite is within the above range, and the composite contains phosphate esters, the composite exhibits high fluidity (low melt viscosity). When the epoxy resin content in the composite is less than the lower limit, the composite is unlikely to exhibit high fluidity. When the epoxy resin content in the composite is within the above range, and the composite does not contain phosphate esters, the composite is also unlikely to exhibit high fluidity. When the epoxy resin content in the composite exceeds the upper limit, it is difficult to manufacture the composite. Because the composite readily exhibits high fluidity, the epoxy resin content in the composite can be 1.86% by mass or more and 1.90% by mass or less. In other words, the ratio of epoxy resin to 100 parts by mass of metal powder can be 1.92 parts by mass or more and 1.97 parts by mass or less.

[0020] Phosphate esters can be represented, for example, as OP(OR 1)(OR 2)(OR 3). R 1, R 2, and R 3 are 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, for example, alkyl or aryl. Phosphate esters are compounds different from phosphites. Phosphites can be represented, for example, as P(OR 1)(OR 2)(OR 3). In addition to phosphate esters, resin compositions may also contain phosphites. However, composites containing phosphites but not phosphate esters are less likely to have high fluidity compared to the composites of this embodiment. In addition to phosphate esters, resin compositions may also contain other dispersants (e.g., coupling agents).

[0021] Phosphate esters can be used as dispersants. The phosphate groups of phosphate esters are polar, thus readily and selectively adsorb onto the surface of metal particles. On the other hand, the hydrocarbon groups of phosphate esters are lipophilic, allowing resin compositions containing epoxy resins to easily exist between the adsorbed phosphate ester metal particles. Therefore, due to the phosphate ester, the agglomeration of the metal powder is suppressed, and each metal particle is easily dispersed in the composite. In other words, due to the phosphate ester, metal particles are less likely to directly contact each other, easily suppressing direct friction between metal particles and friction between metal particles and the resin composition. As described above, by using phosphate esters as dispersants on metal powders, the flowability of the composite is improved. For example, by containing phosphate esters in the composite, the melt viscosity of the composite is reduced. Composites containing phosphate esters tend to have better flowability than composites containing dispersants other than phosphate esters. Direct friction between metal particles can be evaluated using torque values ​​measured by a gel time measuring device. The more direct friction between metal particles is suppressed, the lower the torque value. A curing apparatus (CURELASTOMETER) manufactured by JSR Corporation can be used as a gel time measuring device.

[0022] The melt viscosity of the composite at 140°C can be 10 Pa·s or higher and 1500 Pa·s or lower, preferably 401 Pa·s or higher and 650 Pa·s or lower. When the epoxy resin content in the composite is within the above range, and the composite contains phosphate esters, the composite can have the low melt viscosity (high fluidity) described above. When the melt viscosity of the composite is within the above range, the molten composite can easily and uniformly fill the mold, and defects (voids or burrs, etc.) in the molded body and cured product formed by the composite can be easily suppressed. Therefore, the composite with the low melt viscosity described above is suitable for transfer molding.

[0023] The proportion of phosphate ester relative to 100 parts by weight of metal powder can be 0.01 parts by weight or more and 0.05 parts by weight or less. When the proportion of phosphate ester is 0.01 parts by weight (preferably 0.02 parts by weight) or more, it is easy to obtain high flowability (low melt viscosity) of the composite caused by the phosphate ester. Phosphate ester can hinder the curing of epoxy resin. However, when the proportion of phosphate ester is 0.05 parts by weight or less, it is easy to suppress the curing hindrance of epoxy resin caused by phosphate ester. In other words, when the proportion of phosphate ester is 0.05 parts by weight or less, the gelation time (curing time) of the composite is shortened. For the same reason, the proportion of phosphate ester relative to 100 parts by weight of metal powder can also be 0.02 parts by weight or more and 0.03 parts by weight or less.

[0024] The content of metal powder in the composite can be 90% by mass or more and 98% by mass or less, or 96% by mass or more and 97.5% by mass or less. As the content (filling rate) of metal powder in the composite increases, the relative permeability and saturation flux density of the composite tend to increase. Composites with high relative permeability and high saturation flux density are suitable, for example, for seals for inductors or raw materials for inductor cores. However, as the content of metal powder in the composite increases, the composite becomes difficult to flow. Assuming that the content of metal powder in a phosphate-free composite is 90% by mass or more, the melt viscosity of the composite increases significantly. However, even when the content of metal powder in the composite is 90% by mass or more, the composite of this embodiment contains epoxy resin and phosphate ester, thus enabling high flowability (low melt viscosity). When the content of metal powder in the composite is below the above-mentioned upper limit, high flowability (low melt viscosity) caused by epoxy resin and phosphate ester is easily obtained.

[0025] <Detailed information on the composition of the complex> (Resin composition) The resin composition may include epoxy resin and phosphate esters, and is the remaining (non-volatile) component of all constituents of the composite, excluding metal powder and organic solvents. That is, in addition to epoxy resin and phosphate esters, the resin composition may also contain other components. For example, the resin composition may also contain a curing agent. The resin composition may also contain a curing accelerator. The resin composition may also contain wax (release agent). The resin composition may also contain additives. Additives may include, for example, coupling agents or flame retardants.

[0026] The resin composition functions as a binding material (adhesive) for the metal particles constituting the metal powder, imparting mechanical strength to the molded body formed from the composite. For example, when the composite is molded under high pressure using a mold, the resin composition contained in the composite is filled between the metal particles, causing the metal particles to adhere to each other. Through the curing of the resin composition in the molded body, the cured resin composition further firmly bonds the metal particles together, resulting in a cured composite with excellent mechanical strength.

[0027] The resin composition can adhere to the surface of each metal particle constituting the metal powder. The resin composition can cover a portion or the entire surface of each metal particle. The composite can comprise metal powder and an uncured resin composition. The composite can comprise a semi-cured form of metal powder and a resin composition (e.g., a resin composition in stage B). The composite can also comprise both an uncured resin composition and a semi-cured form of the resin composition. The composite can be a powder. The composite can also be an ingot. The composite can also be a paste.

[0028] The content of the resin component in the composite can be, for example, more than 2% by mass and less than 10% by mass.

[0029] [Phosphate ester] The resin composition may contain one phosphate ester. The resin composition may also contain multiple phosphate esters. The phosphate ester contained in the resin composition may be at least one phosphate ester selected from the group consisting of monophosphate, diester, and triphosphate esters.

[0030] The phosphate ester included in the resin composition may be at least one phosphate ester selected from the group consisting of a phosphate ester salt of a copolymer containing an acid group, compound 1 represented by chemical formula 1, compound 2 represented by chemical formula 2, compound 3 represented by chemical formula 3, and compound 4 represented by chemical formula 4. When at least one of these phosphate esters is included in the resin composition, the complex tends to have high fluidity. In particular, when a phosphate ester salt of a copolymer containing an acid group is included in the resin composition, the complex tends to have high fluidity. Phosphate salts of copolymers containing acid groups can be, for example, disperbyk-111 (trade name) manufactured by BYK-Chemie GmbH. The acid value of phosphate salts of copolymers containing acid groups can be 129. The acid value of disperbyk-111 is 129. Compound 1, represented by the following chemical formula 1, can be, for example, JP-504 manufactured by JOHOKU CHEMICAL CO.,LTD. Compound 2, represented by the following chemical formula 2, can be, for example, JP-506H manufactured by JOHOKU CHEMICAL CO.,LTD. Compound 3, represented by the following chemical formula 3, can be, for example, JP-508 manufactured by JOHOKU CHEMICAL CO.,LTD. Compound 4, represented by the following chemical formula 4, can be, for example, JP-513 manufactured by JOHOKU CHEMICAL CO.,LTD. (C 4H 9O) nOP(OH) 3-n(1) In the above chemical formula 1, n can be 1 or 2. Alternatively, n in the above chemical formula 1 can be more than 1 but less than 3. (C 4H 9OCH 2CH 2O) nOP(OH) 3-n(2) In the above chemical formula 2, n can be 1 or 2. Alternatively, n in the above chemical formula 2 can be more than 1 but less than 3. (C 4H 9C 2H 5CHCH 2O) nOP(OH) 3-n(3) In the above chemical formula 3, n can be 1 or 2. Alternatively, n in the above chemical formula 3 can be more than 1 but less than 3. (isо‐C 13H 27O) nOP(OH) 3‐n(4) In the above chemical formula 4, n can be 1 or 2. Alternatively, n in the above chemical formula 4 can be more than 1 but less than 3.

[0031] [Epoxy Resin] The resin composition contains at least epoxy resin as a thermosetting resin. By including epoxy resin, which has relatively excellent flowability among thermosetting resins, the flowability, filling properties, storage stability, and moldability of the composite are improved. However, as long as it does not hinder the effects of the present invention, the composite may contain other resins besides epoxy resin. For example, the resin composition may also contain at least one of phenolic resin and polyamide-imide resin as a thermosetting resin. When the resin composition contains both epoxy resin and phenolic resin, the phenolic resin can also function as a curing agent for the epoxy resin. In addition to thermosetting resins, the resin composition may also contain thermoplastic resins. Thermoplastic resins may be, for example, at least one selected from the group consisting of acrylic resin, polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyethylene terephthalate, and rubber (elastomer). The resin composition may also contain silicone resin.

[0032] Epoxy resins can be, for example, resins having two or more epoxy groups in one molecule. Examples of epoxy resins include those selected from biphenyl-type epoxy resins, biphenyl aralkyl-type epoxy resins, biphenyl aralkyl-type epoxy resins, arsenic-type epoxy resins, diphenylmethane-type epoxy resins, sulfur-containing epoxy resins, phenolic varnish-type epoxy resins, dicyclopentadiene-type epoxy resins, salicol-type epoxy resins, copolymer epoxy resins of naphthol and phenol, epoxides of aralkyl-type phenolic resins, bisphenol-type epoxy resins, epoxy resins containing a bisphenol backbone, glycidyl ether-type epoxy resins of alcohols, glycidyl ether-type epoxy resins modified with p- and / or inter-p-p-modified phenolic resins, and terpene-modified phenolic resins. The epoxy resin comprises at least one of the following groups: glycidyl ether type epoxy resin, cyclopentadiene type epoxy resin, glycidyl ether type epoxy resin of polycyclic aromatic ring modified phenolic resin, glycidyl ether type epoxy resin containing naphthalene ring phenolic resin, glycidyl ester type epoxy resin, glycidyl type or methyl glycidyl type epoxy resin, alicyclic epoxy resin, halogenated phenolic varnish type epoxy resin, o-cresol phenolic varnish type epoxy resin, hydroquinone type epoxy resin, trimethylpropane type epoxy resin, and linear aliphatic epoxy resin obtained by oxidizing olefin bonds with peracetic acid such as peracetic acid.

[0033] From the viewpoint of excellent flowability, the epoxy resin can be at least one selected from the group consisting of biphenyl type epoxy resin, o-cresol phenolic varnish type epoxy resin, phenolic varnish type epoxy resin, bisphenol type epoxy resin, epoxy resin having a bisphenol backbone, salamide phenolic varnish type epoxy resin and naphthol phenolic varnish type epoxy resin.

[0034] Epoxy resins can be crystalline epoxy resins. Although crystalline epoxy resins have relatively low molecular weights, they have relatively high melting points and excellent flowability. Crystalline epoxy resins (highly crystalline epoxy resins) can be, for example, at least one selected from the group consisting of hydroquinone-type epoxy resins, bisphenol-type epoxy resins, thioether-type epoxy resins, and biphenyl-type epoxy resins. Commercially available crystalline epoxy resins include, for example, 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-7200HHH, EPICLON HP-7200HHH, EPICLON HP-4700, and EPICLON... HP-4710, EPICLON HP-4770, EPICLON HP-5000, EPICLON HP-6000, N500P-2 and N500P-10 (the above are trade names manufactured by 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 (the above are trade names manufactured by Nippon Kayaku) At least one of the following: YX-4000, YX-4000H, YL4121H and YX-8800 (all trade names manufactured by Mitsubishi Chemical Corporation).

[0035] From the perspective of easily reducing the molding shrinkage rate of the composite, the resin composition can contain isocyanate-modified epoxy resin as the epoxy resin. Commercially available isocyanate-modified epoxy resins include, for example, AER-4001 manufactured by Asahi Kasei Corporation (formerly asahi kasei E-Materials Corporation).

[0036] The resin composition may contain one of the epoxy resins mentioned above. The resin composition may also contain multiple of the epoxy resins mentioned above.

[0037] [Curing agent] Curing agents are classified into curing agents that cure epoxy resins in a range from low temperature to room temperature, and heat-curing curing agents that cure epoxy resins with heat. Examples of curing agents that cure epoxy resins in a range from low temperature to room temperature include aliphatic polyamines, polyamides, and polythiols. Examples of heat-curing curing agents include aromatic polyamines, acid anhydrides, phenolic varnish resins, and dicyandiamide (DICY).

[0038] When a curing agent that cures epoxy resin in a range from low temperature to room temperature is used, the cured epoxy resin tends to have a low glass transition point and be soft. As a result, the molded body formed from the composite also tends to become soft. On the other hand, from the viewpoint of improving the heat resistance of the molded body, the curing agent is preferably a heat-curing type, more preferably a phenolic resin, and even more preferably a phenolic varnish resin. In particular, by using a phenolic varnish resin as a curing agent, it is easy to obtain a cured epoxy resin with a high glass transition point. As a result, the heat resistance and mechanical strength of the molded body are easily improved.

[0039] Phenolic resins can be, for example, at least one selected from the group consisting of aryl phenolic resins, dicyclopentadiene phenolic resins, salicylaldehyde phenolic resins, phenolic varnish phenolic resins, copolymers of benzaldehyde phenol and aryl phenol, stubble- and / or inter-stubble-modified phenolic resins, melamine-modified phenolic resins, terpene-modified phenolic resins, dicyclopentadiene naphthol resins, cyclopentadiene-modified phenolic resins, polycyclic aromatic ring-modified phenolic resins, biphenyl phenolic resins, and triphenylmethane phenolic resins. Phenolic resins can also be copolymers composed of two or more of the above.

[0040] Phenolic varnish resin can be, for example, a resin obtained by condensing or co-condensing phenols and / or naphthols with aldehydes under an acidic catalyst. The phenols constituting the phenolic varnish resin can be, for example, at least one selected from the group consisting of phenol, cresol, xylenol, resorcinol, catechol, bisphenol A, bisphenol F, phenylphenol, and aminophenol. The naphthols constituting the phenolic varnish resin can be, for example, at least one selected from the group consisting of α-naphthol, β-naphthol, and dihydroxynaphthalene. The aldehydes constituting the phenolic varnish resin can be, for example, at least one selected from the group consisting of formaldehyde, acetaldehyde, propionaldehyde, benzaldehyde, and salicylaldehyde.

[0041] The curing agent may also be a compound having two phenolic hydroxyl groups in one molecule. A compound having two phenolic hydroxyl groups in one molecule may be at least one selected from the group consisting of resorcinol, catechol, bisphenol A, bisphenol F, and substituted or unsubstituted biphenols.

[0042] The resin composition may contain one of the phenolic resins mentioned above. The resin composition may also contain multiple of the phenolic resins mentioned above. The resin composition may contain one of the curing agents mentioned above. The resin composition may also contain multiple of the curing agents mentioned above.

[0043] The ratio of active groups (phenolic OH groups) in the curing agent that react with the epoxy groups in the epoxy resin to 1 equivalent of epoxy groups in the epoxy resin is preferably 0.5 to 1.5 equivalents, more preferably 0.6 to 1.4 equivalents, and even more preferably 0.8 to 1.2 equivalents. When the ratio of active groups in the curing agent is less than 0.5 equivalents, it is difficult to obtain a sufficient modulus of elasticity in the cured product. On the other hand, when the ratio of active groups in the curing agent exceeds 1.5 equivalents, there is a tendency for the mechanical strength of the molded article formed by the composite to decrease after curing.

[0044] [Curing Accelerator] Curing accelerators are not limited to any composition that promotes the curing of epoxy resin by reacting with it. For example, curing accelerators can be imidazoles such as alkyl-substituted imidazoles or benzimidazoles. The resin composition may contain one curing accelerator. The resin composition may also contain multiple curing accelerators. By containing curing accelerators in the resin composition, the moldability and release properties of the composite are easily improved. Furthermore, by containing curing accelerators in the resin composition, the mechanical strength of molded parts (e.g., electronic components) manufactured using the composite is improved, or the storage stability of the composite under high temperature and / or high humidity environments is improved. Commercially available imidazole-based curing accelerators may include, for example, 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 (the above are trade names manufactured by Shikoku Chemicals Corporation).

[0045] The amount of curing accelerator prepared is only required to achieve the desired curing acceleration effect and is not particularly limited. However, from the viewpoint of improving the curing properties and flowability of the resin composition when it is hygroscopic, the amount of curing accelerator prepared relative to 100 parts by weight of epoxy resin is preferably 0.1 parts by weight or more and 30 parts by weight or less, more preferably 1 part by weight or more and 15 parts by weight or less. The content of curing accelerator is preferably 0.001 parts by weight or more and 5 parts by weight or less relative to the total mass of epoxy resin and curing agent (e.g., phenolic resin). When the amount of curing accelerator prepared is less than 0.1 parts by weight, it is difficult to obtain a sufficient curing acceleration effect. When the amount of curing accelerator prepared exceeds 30 parts by weight, the storage stability of the composite tends to decrease.

[0046] [Coupling agent] Coupling agents improve the adhesion between the resin composition and the metal particles constituting the metal powder, and enhance 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 compounds (silane coupling agents), titanium compounds, aluminum compounds (aluminum chelates), and aluminum / zirconium compounds. Silane coupling agents can be, for example, at least one selected from the group consisting of epoxy silanes, mercaptosilanes, amino silanes, alkyl silanes, ureosilanes, acid anhydride silanes, and vinyl silanes. In particular, aminophenyl silane coupling agents are preferred. The resin composition may contain one or more of the above-mentioned coupling agents. Commercially available coupling agents can be selected from vinyltrimethoxysilane (KBM-1003), vinyltriethoxysilane (KBE-1003), 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane (KBM-303), 3-glycidoxypropylmethyldimethoxysilane (KBM-402), 3-glycidoxypropyltrimethoxysilane (KBM-403), p-styryltrimethoxysilane (KBM-1403), 3-methacryloxypropylmethyldimethoxysilane (KBM-502), 3-methacryloxypropyltrimethoxysilane (KBM- 503), 3-methylpropenoxypropylmethyldiethoxysilane (KBE-502), 3-methylpropenoxypropyltriethoxysilane (KBE-503), 3-propenoxypropyltrimethoxysilane (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-Butylene)propylamine (KBE-9103), N-Phenyl-3-aminopropyltrimethoxysilane (KBM-573), N-Vinylbenzyl-2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride (KBM-575), Tris-(Trimethoxysilylpropyl)isocyanurate (KBM-9659), 3-Urethylpropyltrialkoxysilane (KBE-585), 3-Mercaptopropylmethyl 3-Mercaptopropyltrimethoxysilane (KBM-802), 3-mercaptopropyltrimethoxysilane (KBM-803), 3-isocyanate propyltriethoxysilane (KBM-9007), octenyltrimethoxysilane (KBM-1083), glycidoxyoctyltrimethoxysilane (KBM-4803), methacrylic acid octyltrimethoxysilane (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), The coupling agent is at least one of the following groups: hexyltriethoxysilane (KBE-3063), octyltriethoxysilane (KBE-3083), decyltrimethoxysilane (KBM-3103C), 1,6-(trimethoxysilyl)hexane (KBM-3066), trifluoropropyltrimethoxysilane (KBM-7103), hexamethyldisilazane (SZ-31), and a hydrolyzable siloxane (KPN-3504) (all trade names manufactured by Shin-Etsu Chemical Co., Ltd.). The coupling agent may also be a silicone alkoxy oligomer (a silicone oligomer containing an alkoxy group). The silicone alkoxy oligomer may contain at least one alkoxy group selected from methoxy and ethoxy groups. Silicone alkoxy oligomers may have at least one organic substituent selected from the group consisting of epoxy, methyl, mercapto, acrylonitrile, methacryl, vinyl and phenyl. Silicone alkoxy oligomers 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 (trade names manufactured by Shin-Etsu Chemical Co., Ltd.).

[0047] [wax] Waxes improve the flowability of the composite during molding (e.g., transfer molding) and act as a release agent. Waxes can be at least one of higher fatty acids, fatty acid esters, and fatty acid salts.

[0048] Waxes can be, for example, fatty acids such as linalic acid, stearic acid, 12-hydroxystearic acid, lauric acid, or their esters; fatty acid salts such as zinc stearate, calcium stearate, barium stearate, aluminum stearate, magnesium stearate, zinc laurate, calcium laurate, zinc linoleate, calcium ricinoleate, and zinc 2-ethylhexanoate; stearylamine, oleylamine, erucic acid amide, betaine amide, palmitate amide, laurate amide, hydroxystearylamine, methylene distearate amide, ethyl distearate amide, ethyl bislaurate amide, distearate adipate amide, ethyl dioleate amide, dioleenyl adipate amide, N... - At least one of the following groups: stearyl stearylamine, N-oleyl stearylamine, N-stearyl erucic acid amine, hydroxymethyl stearylamine, hydroxymethyl betaine amine and other fatty acid amines, fatty acid esters such as butyl stearate, alcohols such as ethylene glycol and stearyl alcohol, polyethers including polyethylene glycol, polypropylene glycol, polytetramethylene glycol and their modified forms, polysiloxanes such as silicone oil and silicone grease, fluorinated oils, fluorinated greases and fluorinated resin powders and other fluorinated compounds, and waxes such as paraffin wax, polyethylene wax, acetylamine wax, polypropylene wax, ester wax, carnauba wax and microcrystalline wax.

[0049] [Other components in the resin composition] To ensure the environmental safety, recyclability, processability, and low cost of the composite, the composite may contain flame retardants. Flame retardants may be, for example, at least one selected from the group consisting of brominated flame retardants, phosphorus-based flame retardants, hydrated metal compound flame retardants, silicone-based flame retardants, nitrogen-containing compounds, hindered amine compounds, organometallic compounds, and aromatic engineering plastics. The resin composition may contain one or more of the above-mentioned flame retardants.

[0050] (Metal powder) Metal powders may contain at least one element selected from the group consisting of metal monomers (pure metals) and alloys. Metal powders may also be composed of at least one element selected from the group consisting of metal monomers (pure metals), alloys, amorphous powders, and metal compounds. Alloys may contain at least one element selected from the group consisting of solid solutions, eutectics, and intermetallic compounds. Alloys may, for example, be stainless steel (Fe-Cr alloys, Fe-Ni-Cr alloys, etc.). Metal powders may contain one or more metallic elements. The metallic elements contained in metal powders may, for example, be base metals, noble metals, transition metals, or rare earth elements. Composites may contain one or more metal powders.

[0051] The metallic element contained in the metal powder may 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), ferroium (Pr), neodymium (Nd), samarium (Sm), and dysprosium (Dy). The metal powder may contain elements other than metallic elements. For example, the metal powder may contain oxygen (O), beryllium (Be), phosphorus (P), boron (B), or silicon (Si). The metal powder may be magnetic powder. The metal powder may be a soft magnetic alloy or a strong magnetic alloy. Metal powder can be, for example, a magnetic powder composed of at least one element selected from the group consisting of Fe-Si alloys, Fe-Si-Al alloys (Aluminum-Silicon-Iron Powder (Sendust)), Fe-Ni alloys (High Permeability Alloys (Permalloy)), Fe-Cu-Ni alloys (High Permeability Alloys), Fe-Co alloys (Iron-Co Alloys (Permendur)), Fe-Cr-Si alloys (Electromagnetic Stainless Steel), Nd-Fe-B alloys (Rare Earth Magnets), Sm-Fe-N alloys (Rare Earth Magnets), and Al-Ni-Co alloys (AlNiCo Magnets). Metal powder can also be a copper alloy such as Cu-Sn alloys, Cu-Sn-P alloys, Cu-Ni alloys, or Cu-Be alloys. Metal powder can consist of only one element or composition. Metal powder can also contain multiple elements or compositions.

[0052] The metal powder can also be Fe monomer (pure iron). The metal powder can also be an alloy containing iron (Fe-based alloy). Examples of Fe-based alloys include Fe-Si-Cr alloys, Nd-Fe-B alloys, or Sm-Fe-N alloys. The metal powder can also be at least one of amorphous iron powder and carbonyl iron powder. When the metal powder contains at least one of Fe monomer and Fe-based alloy, it is easy to fabricate a shaped body with a high space factor and excellent magnetic properties from the composite. The metal powder can also be an amorphous Fe alloy. As a commercially available Fe amorphous alloy powder, for example, at least one of the following can be used: AW2-08, KUAMET-6B2 (trade names manufactured by Epson Atmix Corporation), DAP MS3, DAP MS7, DAP MSA10, DAP PB, DAP PC, DAP MKV49, DAP 410L, DAP 430L, DAP HYB series (trade names manufactured by Daido Steel Co., Ltd.), MH45D, MH28D, MH25D and MH20D (trade names manufactured by Kobe Steel, Ltd.).

[0053] The average particle size of the metal powder is not particularly limited; for example, it can be greater than 1 μm and less than 300 μm. The average particle size can be measured, for example, by a particle size analyzer. The shape of the individual metal particles constituting the metal powder is not limited; for example, they can be spherical, flat, prismatic, or needle-shaped. The composite can contain multiple metal powders with different average particle sizes.

[0054] <Uses of the complex> The compound can be used in at least one of transfer molding and compression molding. Transfer molding is a type of injection molding for thermosetting resins. Transfer molding can also be called compression molding. Transfer molding may include: the step of heating the compound in a heating chamber to fluidize it; the step of supplying (pressing in) the fluidized compound from the heating chamber into the mold through a casting runner; and the step of heating the compound in the mold to cure it. Transfer molding may include: the step of heating the compound in a heating chamber to fluidize it; the step of supplying the fluidized compound powder from the heating chamber into the plunger, and supplying (pressing in) the compound from the plunger into the mold through a casting runner; and the step of heating the compound in the mold to cure it. The pressure applied to the compound in transfer molding may be, for example, 3 MPa or more and 100 MPa or less. The compound of this embodiment exhibits excellent fluidity and filling properties due to heating, thus it easily flows in narrow runners and easily fills the space (mold cavity) within the mold. Therefore, by processing the composite through transfer molding, it is possible to manufacture molded bodies and cured products with fewer defects such as voids or burrs. The composite can also be molded by compression molding.

[0055] Depending on the composition or combination of the metal powders contained in the composite, various properties (e.g., electromagnetic or magnetic properties) of the molded article and cured product formed from the composite can be freely controlled. Therefore, the molded article and cured product can be used in a wide variety of industrial products or their raw materials. The molded article formed from the composite may contain at least one of an uncured resin composition and a B-stage resin composition (a semi-cured resin composition). The molded article may consist solely of the composite. The cured composite or molded article may contain a C-stage resin composition (a cured resin composition).

[0056] Industrial products manufactured using composites include automobiles, medical devices, electronic devices, electrical equipment, information and communication equipment, home appliances, audio equipment, and general industrial equipment. For example, when a composite contains permanent magnets such as Sm-Fe-N alloys or Nd-Fe-B alloys as metal powder, it can be used as a material for bonding magnets. When a composite contains soft magnetic materials such as Fe-Si-Cr alloys as metal powder, it can be used as a material for inductors (e.g., EMI filters) or transformers (e.g., seals or magnetic cores). Sheet-like molded bodies or cured products formed from composites can be used as electromagnetic wave shielding components.

[0057] <Method for manufacturing the complex> A composite material is obtained by heating and mixing metal powder and a resin composition. For example, the metal powder and resin composition can be mixed while heating using a kneader, roller, mixer, etc. Through heating and mixing, the resin composition adheres to part or all of the surface of each metal particle constituting the metal powder, thus coating the metal particles. Through mixing, part or all of the epoxy resin in the resin composition can become a semi-cured product.

[0058] For example, metal powder, epoxy resin, phosphate ester (dispersant), curing agent, curing accelerator, coupling agent, and wax can be mixed in a tank in one step. Alternatively, after mixing metal powder and at least one of phosphate ester and coupling agent in a tank, the metal powder, epoxy resin, phosphate ester, curing agent, curing accelerator, coupling agent, and wax can be further mixed in a tank. Alternatively, after mixing metal powder, epoxy resin, phosphate ester, curing agent, coupling agent, and wax in a tank, the mixture and curing accelerator can be further mixed in a tank. Epoxy resin, phosphate ester, curing agent, curing accelerator, and wax can be pre-mixed to prepare a resin mixture powder. Metal powder and coupling agent can be pre-mixed to prepare a metal mixture powder. The metal mixture powder and the above-mentioned resin mixture powder can be mixed to obtain a composite.

[0059] The mixing time depends on the type of mixing machinery, its volume, and the quantity of the compound produced. A mixing time of 1 minute or more is preferred, 2 minutes or more is better, and 3 minutes or more is even better. Furthermore, a mixing time of 20 minutes or less is preferred, 15 minutes or less is better, and 10 minutes or less is even better. When the mixing time is less than 1 minute, insufficient mixing impairs the moldability of the compound, and deviations in the degree of curing occur. When the mixing time exceeds 20 minutes, for example, curing of resin components (e.g., epoxy resin and phenolic resin) in the tank can easily impair the flowability, filling properties, and moldability of the compound. When the raw materials in the tank are heated while being mixed using a kneader, the heating temperature should be, for example, the temperature at which the semi-cured epoxy resin (stage B epoxy resin) is formed and the formation of the cured epoxy resin (stage C epoxy resin) is inhibited. The heating temperature can also be lower than the activation temperature of the curing accelerator. A heating temperature of 50°C or higher is preferred, 60°C or higher is more preferred, and 70°C or higher is even more preferred. A heating temperature of 150°C or lower is preferred, 120°C or lower is more preferred, and 110°C or lower is even more preferred. When the heating temperature is within the above range, the resin composition in the tank softens and easily coats the surface of the metal particles constituting the metal powder, thereby easily generating a semi-cured epoxy resin and easily inhibiting the complete curing of the epoxy resin in the mixing process. [Example]

[0060] The present invention will now be described in further detail with reference to embodiments and comparative examples. The present invention is not limited to these examples.

[0061] (Example 1) [Preparation of the complex] Epoxy resin 1, epoxy resin 2, dispersant (phosphate ester), curing agent 1, curing agent 2, curing accelerator, release agent 1 (wax), and release agent 2 (wax) were placed into a plastic container. The contents of the plastic container were mixed for 10 minutes to create a resin mixture. The resin mixture represents all components of the resin composition except for the coupling agent. As epoxy resin 1, NC-3000 (a type of phenyl aralkyl epoxy resin) manufactured by Nippon Kayaku Co., Ltd. was used. As epoxy resin 2, TECHMORE VG3101L (a trifunctional epoxy resin) manufactured by PRINTEC, INC. was used. As a dispersant, disperbyk-111 manufactured by BYK-Chemie GmbH was used. As curing agent 1, MEHC-7500-3S (triphenol-methane type phenolic resin) manufactured by Meiwa Plastic Industries, Ltd. was used. As curing agent 2, MEHC-7851SS (a type of phenyl aralkyl phenolic resin) manufactured by Meiwa Plastic Industries, Ltd. was used. U-CAT 3512T manufactured by San-Apro Ltd. was used as a curing accelerator. As mold release agent 1, POWDER BASE L (zinc laurate) manufactured by NOF CORPORATION was used. As mold release agent 2, LicowaxOP manufactured by Clariant Chemicals Co., Ltd. was used. LicowaxOP is a lignite ester that is partially saponified by calcium hydroxide.

[0062] Iron powder 1 and iron powder 2 were uniformly mixed for 5 minutes using a pressure-type biaxial kneader to prepare metal powder. Both iron powder 1 and iron powder 2 are amorphous. Iron powder 1 was made of KUAMET 9A4-II 075C03 manufactured by Epson Atmix Corporation. The average particle size of iron powder 1 was 24 μm. Iron powder 2 was made using Epson Atmix Corporation's AW2-08. The average particle size of iron powder 2 was 5.3 μm. As a pressure-type biaxial kneader, a pressure-type biaxial kneader manufactured by Nihon Spindle Manufacturing Co., Ltd. was used. The capacity of the pressure-type biaxial kneader is 5L.

[0063] Coupling agent 1, coupling agent 2, and additive (stress reliever) were added to the metal powder inside a biaxial kneader. The contents of the biaxial kneader were then heated to 90°C and mixed for 10 minutes while maintaining the temperature. Next, the aforementioned resin mixture was added to the contents of the biaxial kneader. The contents were kneaded for 15 minutes while maintaining the temperature at 120°C. After cooling the resulting mixture to room temperature, it was pulverized with a hammer to achieve the desired particle size. As coupling agent 1, KBM-5803 (methacrylic acid octyl trimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd. was used. As coupling agent 2, KBM-403 (3-glycidoxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd. was used. As an additive, DBL-C32 (caprolactone-modified dimethyl silicone) manufactured by Gelest, Inc. was used.

[0064] The complex of Example 1 was prepared using the above method. The mass (in g) of each component constituting the complex is shown in Table 1 below. The content of metal powder in the composite (unit: mass%) is shown in Table 1 below. The epoxy resin content (unit: mass%) in the composite is shown in Table 1 below. The ratio of epoxy resin to 100 parts by mass of metal powder (unit: parts by mass) is shown in Table 1 below. The ratio of phosphate ester (dispersant) to 100 parts by mass of metal powder (unit: parts by mass) is shown in Table 1 below.

[0065] [Measurement of melt viscosity] As described below, the minimum melt viscosity of the composite at 140°C was measured. A CFT-100 (flow tester) manufactured by Shimadzu Corporation was used as the measuring apparatus. A 7g ingot of the composite was prepared as the test sample. The flowability of the composite was evaluated under the conditions of 140°C, 20 seconds of residual heat, and a 100kg load. The plunger's insertion distance (in mm) until the flow of the composite stopped was measured as the flow tester stroke. The time until the flow of the composite stopped was measured as the flow time. These measurements were used as indicators of flowability. The measured melt viscosity (in Pa·s) of Example 1 is shown in Table 1 below.

[0066] [Measurement of Circular Plate Flow] 5g of the composite (powder) was used as the test sample. 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 held by the upper and lower molds. The composite between the upper and lower molds was compressed for 360 seconds under a load of 8kg, thereby forming a roughly circular plate-shaped molded body made of the composite. The temperature of the composite during compression was maintained at 140°C. The maximum and minimum diameters of the circular plate-shaped molded body were measured. The average of the major and minor diameters corresponds to the circular plate flow. The circular plate flow (unit: mm) of Example 1 is shown in Table 1 below.

[0067] [Measurement of gelation time] The gel time (gelation time) of the composite at 140°C was measured. A curing apparatus (curing tester) manufactured by JSR Corporation was used as the measuring device (curing tester). The gel time (in seconds) of Example 1 is shown in Table 1 below.

[0068] (Examples 2-4 and Comparative Example 1) The masses of each component constituting the complex in Examples 2-4 and Comparative Example 1 are shown in Table 1 below. Except for the masses of each component constituting the complex, the complexes in Examples 2-4 and Comparative Example 1 were prepared using the same method as in Example 1. In Examples 2-4 and Comparative Example 1, the content of metal powder in the composite is shown in Table 1 below. In Examples 2-4 and Comparative Example 1, the epoxy resin content in the composite was as shown in Table 1 below. In Examples 2-4 and Comparative Example 1, the ratio of epoxy resin to 100 parts by mass of metal powder is shown in Table 1 below. In Examples 2-4 and Comparative Example 1, the ratio of phosphate ester (dispersant) to 100 parts by mass of metal powder is shown in Table 1 below.

[0069] The melt viscosity, disc flow, and gel time of the composites of Examples 2-4 and Comparative Example 1 were measured using the same method as in Example 1. The melt viscosity, disc flow, and gel time of the composites of Examples 2-4 and Comparative Example 1 are shown in Table 1 below.

[0070] Table 1 unit Comparative Example 1 Example 3 Example 4 Example 1 Example 2 resin composition Epoxy Resin 1 g 50 50 50 50 50 Epoxy Resin 2 g 50 50 50 50 50 Curing agent 1 g 30.5 30.5 30.5 30.5 30.5 Curing agent 2 g 25.0 25.0 25.0 25.0 25.0 Curing accelerator g 5 5 5 5 5 Coupling agent 1 g 3 3 3 3 3 Coupling agent 2 g 2 2 2 2 2 additive g 15 15 15 15 15 Dispersant (phosphate ester) g 0 3 5 1 1.5 Release agent 1 g 2 2 2 2 2 Release agent 2 g 1 1 1 1 1 Metal powder Iron powder 1 g 3798.6 3860.7 3902.1 3819.3 3829.6 Iron Powder 2 g 1260.8 1281.4 1295.1 1267.7 1271.1 complex Metal powder content quality% 96.5 96.5 96.5 96.5 96.5 Epoxy resin content quality% 1.91 1.88 1.86 1.90 1.89 Epoxy resin relative to 100 parts by weight metal powder ratio Quality 1.98 1.94 1.92 1.97 1.96 Phosphate relative to 100 parts by mass metal powder ratio Quality 0.00 0.06 0.09 0.02 0.03 Liquidity melt viscosity Pa･s 1504 481 401 650 463 Circular plate flow mm 46 62 67 55 60 gel time Second 170 194 208 170 176 [Industrial Applicability]

[0071] Because the composite of the present invention has excellent flowability and filling properties, it is possible to manufacture industrial products of various shapes, such as inductors, by molding the composite.

Claims

1. A composite comprising at least a metal powder and a resin composition, wherein the composite comprises a soft magnetic material as the metal powder, the resin composition comprises 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 phosphate ester is in the proportion of 100 parts by mass of the metal powder being 0.02 parts by mass or more and 0.05 parts by mass or less, the phosphate ester being selected from at least one phosphate ester selected from the group consisting of a phosphate ester salt containing an acid group copolymer, compound 1 represented by chemical formula 1, compound 2 represented by chemical formula 2, compound 3 represented by chemical formula 3, and compound 4 represented by chemical formula 4, (C4H9O)nOP(OH)3-n (1) (C4H9OCH2CH2O)nOP(OH)3-n (2) (C4H9C2H5CHCH2O)nOP(OH)3-n (3) (Iso-C13H27O)nOP(OH)3-n (4) The n in the above chemical formula 1 is 1 or more and 3 or less, the n in the above chemical formula 2 is 1 or more and 3 or less, the n in the above chemical formula 3 is 1 or more and 3 or less, the n in the above chemical formula 4 is 1 or more and 3 or less. The above-mentioned composite is used for transfer molding, the above-mentioned metal powder is the above-mentioned soft magnetic material and is at least one of pure iron and Fe alloy containing iron.

2. The composite as claimed in claim 1, wherein the content of the aforementioned epoxy resin in the composite is 1.86% by mass or more and 1.90% by mass or less.

3. The composite as claimed in claim 1, wherein the melt viscosity of the aforementioned composite at 140°C is above 10 Pa·s and below 1500 Pa·s.

4. The composite as claimed in claim 1, wherein the content of the aforementioned metal powder in the composite is 90% by mass or more and 98% by mass or less.

5. The composite as claimed in claim 1, wherein the ratio of the aforementioned epoxy resin to 100 parts by weight of the aforementioned metal powder is 1.92 parts by weight or more and 1.97 parts by weight or less.

6. The composite as claimed in claim 1, wherein the aforementioned epoxy resin is at least one selected from the group consisting of biphenyl aryl epoxy resins and trifunctional epoxy resins.

7. The composite as claimed in claim 1, wherein the aforementioned resin composition further comprises a curing agent, the aforementioned curing agent being at least one selected from the group consisting of pyromethane-type phenolic resins and phenylaryl-type phenolic resins.

8. The composite as claimed in claim 1, wherein the aforementioned resin composition further comprises a curing accelerator.

9. The complex as claimed in claim 1, wherein the aforementioned resin composition further comprises a wax, the wax being at least one selected from the group consisting of zinc laurate and a lignite ester partially saponified by calcium hydroxide.

10. The composite as claimed in claim 1, wherein the aforementioned resin composition further comprises a coupling agent selected from the group consisting of methacryloyloxyoctyltrimethoxysilane and 3-glycidoxypropyltrimethoxysilane.

11. The complex as claimed in claim 1, wherein the aforementioned resin composition further comprises caprolactone-modified dimethyl silicone.

12. The composite material as described in claim 1, used in inductors, transformers, or electromagnetic shielding components.

13. The composite material as described in claim 1, used as a raw material for inductor seals or inductor cores.

14. A molded article comprising the composite described in any one of claims 1 to 13.

15. A cured product, which is a cured product of the composite described in any one of claims 1 to 13.