Composite, shaped body, and cured product of the composite

Abstract

A one-side composite of the present invention has a metal powder, and a resin composition containing an epoxy resin and a phenol resin, the epoxy resin including a first epoxy resin having a biphenylene aralkyl skeleton, and a second epoxy resin having an epoxy equivalent smaller than that of the first epoxy resin, the phenol resin including a first phenol resin having a biphenylene aralkyl skeleton, and a second phenol resin having a hydroxyl equivalent smaller than that of the first phenol resin, the content of the metal powder being 90 mass% or more and less than 100 mass%.

Description

TECHNICAL FIELD

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

[0002] A composite containing a metal powder and a resin composition is used as a raw material for various industrial products depending on the physical properties of the metal powder. For example, the composite is used as a raw material for an inductor, a seal, electromagnetic wave shielding (EMI shielding), or a bonded magnet (see Patent Literature 1 below).

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent Application Publication No. 2014-13803 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] When an industrial product is manufactured from a composite, a molded body is produced by tightly attaching the composite to a metal member and curing the composite, and then the molded body is heated. In the process of heating the molded body, cracks are easily formed in the molded body due to the difference in thermal expansion rate between the cured product of the composite and the metal member, the explosion of water vapor in the inside of the package, and the like. Therefore, it is necessary to improve the rewelding resistance of the molded body.

[0008] The present application has been achieved in view of the above-described circumstances, and aims to provide a composite capable of forming a molded body having excellent rewelding resistance, a molded body using the composite, and a cured product of the composite.

[0009] MEANS FOR SOLVING THE PROBLEMS

[0010] The composite according to one aspect of the present application includes a metal powder and a resin composition containing an epoxy resin and a phenolic resin, the epoxy resin includes a first epoxy resin having a biphenylene aralkyl skeleton and a second epoxy resin having an epoxy equivalent smaller than that of the first epoxy resin, the phenolic resin includes a first phenolic resin having a biphenylene aralkyl skeleton and a second phenolic resin having a hydroxyl equivalent smaller than that of the first phenolic resin, and the content of the metal powder is 90% by mass or more and less than 100% by mass.

[0011] The molded body according to one aspect of the present application includes the above-described composite.

[0012] The cured product of the composite of one aspect of the present application is a cured product of a composite having a metal powder and a resin composition containing an epoxy resin and a phenol resin, the content of the metal powder being 90 mass% or more and less than 100 mass%, the flexural strength at 250°C being 4.6 MPa or more, the flexural modulus of elasticity at 250°C being less than 1.0 GPa, the flexural strength divided by the value of the flexural modulus of elasticity being 9.5 x 10 -3 or more.

[0013] Effects of Invention

[0014] According to the present application, a composite capable of forming a molded body excellent in reflow soldering resistance, a molded body using the composite, and a cured product of the composite are provided. DETAILED DESCRIPTION

[0015] Hereinafter, a preferred embodiment of the present application will be described. However, the present application is not limited by the following embodiment in any way.

[0016] [Composite]

[0017] The composite of the present embodiment has a metal powder and a resin composition containing an epoxy resin and a phenol resin. The metal powder may, for example, contain at least one selected from the group consisting of a metal monomer, an alloy, an amorphous powder, and a metal compound. The resin composition may, in addition to containing the epoxy resin and the phenol resin, contain other components. The resin composition may also contain a curing accelerator, a release agent, an additive, and the like. The resin composition can be a component capable of containing the epoxy resin, the phenol resin, the curing accelerator, the release agent, and the additive, and a remaining component (non-volatile component) other than the organic solvent and the metal powder. The additive is a component of a remaining portion of the resin composition other than the resin, the release agent, the curing agent, and the curing accelerator. The additive is, for example, a coupling agent, a flame retardant, a lubricant, and the like. The composite can be a powder (composite powder).

[0018] The composite can have a metal powder and a resin composition attached to the surface of each metal particle constituting the metal powder. The resin composition can cover the entire surface of the particle, or can cover only a part of the surface of the particle. The composite can have an uncured resin composition and a metal powder. The composite can also have a semi-cured product of the resin composition (for example, a B-stage resin composition) and a metal powder. The composite can also have both an uncured resin composition and a semi-cured product of the resin composition. The composite can also be composed of a metal powder and a resin composition.

[0019] The content of the metal powder in the composite is 90% by mass or more and less than 100% by mass relative to the total mass of the composite. As the content of the metal powder increases, it becomes difficult to ensure the moldability of the shaped body, and the workability tends to deteriorate. From the viewpoint of the magnetic properties of the shaped body, the content of the metal powder is preferably 92% by mass or more, more preferably 94% by mass or more, further preferably 95% by mass or more, and particularly preferably 96% by mass or more. The upper limit of the content of the metal powder can be 99% by mass or less, 98% by mass or less, or 97.5% by mass or less.

[0020] (resin composition)

[0021] The resin composition of the present embodiment can improve the flowability, storage stability, and moldability of the composite by containing a specific epoxy resin as a thermosetting resin. The epoxy resin contains a first epoxy resin having a biphenylene aralkyl skeleton, and a second epoxy resin having an epoxy equivalent smaller than the epoxy equivalent of the first epoxy resin.

[0022] The resin composition contains the first epoxy resin, whereby the elastic modulus of the shaped body formed from the composite can be reduced, and the resistance to reflow soldering can be improved. The epoxy equivalent of the first epoxy resin is preferably 240 g / eq or more and 300 g / eq or less, more preferably 250 g / eq or more and 290 g / eq or less, and further preferably 260 g / eq or more and 280 g / eq or less.

[0023] The content of the first epoxy resin in the resin composition can be 20 to 80% by mass, 30 to 70% by mass, or 40 to 60% by mass, based on the total mass of the epoxy resins.

[0024] As the first epoxy resin, a commercially available product such as a biphenylene aralkyl type epoxy resin (NC-3000 manufactured by Nippon Kayaku Co., Ltd.) can be used.

[0025] The resin composition contains the second epoxy resin, whereby the mechanical strength of the shaped body can easily be increased. The epoxy equivalent of the second epoxy resin is preferably 130 g / eq or more and less than 240 g / eq, or more preferably 140 g / eq or more and 230 g / eq or less, and further preferably 150 g / eq or more and 220 g / eq or less.

[0026] The second epoxy resin can be at least one selected from the group consisting of a stilbene type epoxy resin, a diphenylmethane type epoxy resin, a sulfur atom-containing epoxy resin, a novolac type epoxy resin, a dicyclopentadiene type epoxy resin, a salicylal type epoxy resin, a copolymerization type epoxy resin of naphthol and phenol, an epoxide of aralkyl type phenol aldehyde resin, a bisphenol type epoxy resin, a biphenyl type epoxy resin, an epoxy resin containing a bisphenol skeleton, an epoxy propyl ether type epoxy resin of an alcohol, an epoxy propyl ether type epoxy resin of a p-xylene and / or m-xylene modified phenol aldehyde resin, an epoxy propyl ether type epoxy resin of a terpene modified phenol aldehyde resin, a cyclopentadiene type epoxy resin, an epoxy propyl ether type epoxy resin of a polycyclic aromatic ring modified phenol aldehyde resin, an epoxy propyl ether type epoxy resin of a naphthalene ring-containing phenol aldehyde resin, an epoxy propyl ester type epoxy resin, an epoxy propyl type or a methyl epoxy propyl type epoxy resin, an alicyclic type epoxy resin, a halogenated phenol novolac type epoxy resin, an o-cresol novolac type epoxy resin, a p-quinol type epoxy resin, a trimethylolpropane type epoxy resin, and a linear aliphatic epoxy resin obtained by oxidizing an olefinic bond with a peroxy acid such as peroxoacetic acid.

[0027] The second epoxy resin can be at least one selected from the group consisting of an o-cresol novolac type epoxy resin, a phenol novolac type epoxy resin, a bisphenol type epoxy resin, an epoxy resin having a bisphenol skeleton, a salicylal novolac type epoxy resin, and a naphthol novolac type epoxy resin from the viewpoint of excellent fluidity.

[0028] The second 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 excellent fluidity. The crystalline epoxy resin (highly crystalline epoxy resin) can be at least one selected from the group consisting of a p-quinol type epoxy resin, a bisphenol type epoxy resin, a sulfide type epoxy resin, and a biphenyl type epoxy resin.

[0029] The crystalline epoxy resin can be, for example, at least one selected from the group consisting of EPICLON 860, EPICLON 1050, EPICLON 1055, EPICLON 2050, EPICLON 3050, EPICLON 4050, EPICLON 7050, EPICLON HM-091, EPICLON HM-101, EPICLON N-730A, EPICLON N-740, EPICLON N-770, EPICLON N-775, EPICLON N-865, EPICLON HP-4032D, EPICLON HP-7200L, EPICLON HP-7200, EPICLON HP-7200H, EPICLON HP-7200HH, EPICLON HP-7200HHH, EPICLON HP-4700, EPICLON HP-4710, EPICLON HP-4770, EPICLON HP-5000, EPICLON HP-6000, N500P-2, and N500P-10 (product 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 (product names manufactured by Nippon Kayaku Co., Ltd.), and YX-4000, YX-4000H, YL4121H, and YX-8800 (product names manufactured by Mitsubishi Chemical Corporation).

[0030] The resin composition of the present embodiment can improve flowability, storage stability, and moldability of the composite by containing a specific phenol aldehyde resin as a curing agent. The phenol aldehyde resin contains a first phenol aldehyde resin having a biphenylene aralkyl skeleton, and a second phenol aldehyde resin having a smaller hydroxyl equivalent weight than the first phenol aldehyde resin.

[0031] The resin composition contains the first phenol formaldehyde resin, whereby the elastic modulus of the molded body can be reduced, and the resistance to reflow soldering can be improved. The hydroxyl equivalent of the first phenol formaldehyde resin is preferably 140 g / eq or more and 230 g / eq or less, more preferably 150 g / eq or more and 220 g / eq or less, and further preferably 160 g / eq or more and 210 g / eq or less.

[0032] The content of the first phenol formaldehyde resin in the resin composition can be 20 to 80 parts by mass, 30 to 70 parts by mass, or 40 to 60 parts by mass, with respect to 100 parts by mass of the epoxy resin.

[0033] Commercially available examples of the biphenylene aralkyl type phenol formaldehyde resin include MEHC-7851SS, MEHC-7841-4S, and the like, manufactured by Meiwa Plastic Industries, Ltd.

[0034] The resin composition contains the second phenol formaldehyde resin, whereby the mechanical strength of the molded body can be easily increased. The hydroxyl equivalent of the second phenol formaldehyde resin is preferably 80 g / eq or more and less than 140 g / eq, or more preferably 90 g / eq or more and 130 g / eq or less, and further preferably 100 g / eq or more and 120 g / eq or less.

[0035] The second phenol formaldehyde resin can be, for example, at least one selected from the group consisting of aralkyl type phenol formaldehyde resin, dicyclopentadiene type phenol formaldehyde resin, salicylaldehyde type phenol formaldehyde resin, novolak type phenol formaldehyde resin, copolymer type phenol formaldehyde resin of benzaldehyde type phenol and aralkyl type phenol, p-xylene and / or m-xylene modified phenol formaldehyde resin, melamine modified phenol formaldehyde resin, terpene modified phenol formaldehyde resin, dicyclopentadiene type naphthol formaldehyde resin, cyclopentadiene modified phenol formaldehyde resin, polycyclic aromatic ring modified phenol formaldehyde resin, and triphenylmethane type phenol formaldehyde resin. Commercially available examples of the second phenol formaldehyde resin include HE910-09, manufactured by AIR WATER INC., HP-850N, manufactured by Hitachi Chemical Co., Ltd., and the like.

[0036] The ratio of the active group (phenolic OH group) in the curing agent that reacts with the epoxy group in the epoxy resin can be preferably 0.5 to 1.5 equivalents, more preferably 0.6 to 1.4 equivalents, and further preferably 0.7 to 1.2 equivalents, with respect to 1 equivalent of the epoxy group in the epoxy resin. When the ratio of the active group in the curing agent is within the above range, the flowability of the composite can be easily improved.

[0037] 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, a phosphorus-based curing accelerator, an imidazole-based curing accelerator, or a urea-based curing accelerator. The resin composition contains the curing accelerator, whereby the moldability and the releasability of the composite can be improved. Also, by the resin composition containing the 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 / high-humidity environment is improved.

[0038] As the phosphorus-based curing accelerator, for example, a phosphine compound and a phosphonium salt compound can be given.

[0039] As a commercially available product of the 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 (product names manufactured by Shikoku Chemicals Corporation) can be used.

[0040] As the urea-based curing accelerator, there is no particular limitation as long as it is a curing accelerator having a urea group, and from the viewpoint of improving the storage stability, an alkyl urea-based curing accelerator having an alkyl urea group is preferred. As the alkyl urea-based curing accelerator having an alkyl urea group, for example, an aromatic alkyl urea and an aliphatic alkyl urea can be given. As commercially available products of the alkyl urea-based curing accelerator, for example, U-CAT3512T (product name, manufactured by San-Apro Ltd., aromatic dimethyl urea) and U-CAT3513N (product name, manufactured by San-Apro Ltd., aliphatic dimethyl urea) can be given. Among these, from the aspect that the cracking temperature is appropriately low and the composite is easily cured efficiently, an aromatic alkyl urea is preferred.

[0041] The amount of the curing accelerator to be blended is not particularly limited as long as an effect of accelerating curing is obtained. However, from the viewpoint of improving the curing property and flowability of the resin composition in a hygroscopic state, the amount of the curing accelerator to be blended 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, relative 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, relative to the total of 100 parts by mass of the epoxy resin and the phenolic resin. When the amount of the curing accelerator to be blended is less than 0.1 parts by mass, it is difficult to obtain a sufficient effect of accelerating curing. When the amount of the curing accelerator to be blended exceeds 30 parts by mass, the storage stability of the compound tends to decrease. However, the effects of the present application can be obtained even when the amount and content of the curing accelerator are outside the above ranges.

[0042] The coupling agent improves the adhesiveness of the resin composition to the metal element-containing particles constituting the metal powder, and improves the flexibility and mechanical strength of the molded body formed from the compound. The coupling agent can be, for example, at least one selected from the group consisting of a silane-based compound (silane coupling agent), a titanium-based compound, an aluminum compound (aluminum chelate-based compound), and an aluminum / zirconium-based compound. The silane coupling agent can be, for example, at least one selected from the group consisting of an epoxy silane, a mercapto silane, an amino silane, an alkyl silane, a urea silane, an acid anhydride-based silane, and a vinyl silane. The resin composition can contain one of the above coupling agents, or can contain a plurality of the above coupling agents.

[0043] From the viewpoint of easily reducing the molding shrinkage of the compound and easily improving the heat resistance and voltage resistance of the molded body, the resin composition can contain a compound having a siloxane bond (siloxane compound). The siloxane bond is a bond including two silicon atoms (Si) and one oxygen atom (O), and can be represented by -Si-O-Si-. The compound having a siloxane bond can be a polysiloxane compound.

[0044] In order to improve the 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 flame retardants, or can contain a plurality of the above flame retardants.

[0045] When a mold is used and a molded body is formed from the compound, the resin composition can contain a wax. The wax improves the flowability of the compound during molding (for example, transfer molding) of the compound, and functions as a mold release agent. The wax can be at least any one of a higher fatty acid such as a fatty acid and a fatty acid ester.

[0046] The wax may be, for example, at least one selected from the group consisting of fatty acids such as montanic acid, stearic acid, 12-oxystearic acid, lauric acid, and the like, or esters of these, zinc stearate, calcium stearate, barium stearate, aluminum stearate, magnesium stearate, calcium laurate, zinc linoleate, calcium ricinoleate, zinc 2-ethylhexanoate, and the like, fatty acid salts such as calcium laurate, zinc linoleate, calcium ricinoleate, and the like, fatty acid amides such as stearic acid amide, oleic acid amide, erucic acid amide, behenic acid amide, palmitic acid amide, lauric acid amide, hydroxystearic acid amide, methylenebis stearic acid amide, ethylenebis stearic acid amide, ethylenebis lauric acid amide, distearyhexanediol amide, dioleylhexanediol amide, N-steryl stearic acid amide, N-oleylyl stearic acid amide, N-steryl erucic acid amide, hydroxymethyl stearic acid amide, hydroxymethyl behenic acid amide, and the like, fatty acid esters such as butyl stearate, and the like, alcohols such as ethylene glycol, stearyl alcohol, and the like, polyethers including polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and modifications of these, polysiloxanes such as silicone oil, silicone grease, and the like, fluorine-based oils, fluorine-based greases, fluorine-containing resin powders, and the like, and waxes such as paraffin wax, polyethylene wax, amide wax, polypropylene wax, ester wax, carnauba, micro wax, and the like.

[0047] (Metal powder)

[0048] The metal powder (metal element-containing particle) may, for example, contain at least one selected from the group consisting of a metal monomer, an alloy, and a metal compound. The metal element-containing powder may, for example, consist of at least one selected from the group consisting of a metal monomer, an alloy, and a metal compound. The alloy may include at least one selected from the group consisting of a solid solution, a eutectic, and an intermetallic compound. The alloy may be, for example, stainless steel (Fe-Cr-based alloy, Fe-Ni-Cr-based alloy, and the like). The metal compound may be, for example, an oxide such as wustite. The metal powder may include one metal element or a plurality of metal elements. The metal element included in the metal powder may be, for example, a base metal element, a noble metal element, a transition metal element, or a rare earth element. The composite may include one metal element-containing powder or a plurality of metal element-containing powders having different compositions.

[0049] The metal powder is not limited to the above composition. The metal element included in the metal powder can be, for example, 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), niobium (Nb), barium (Ba), strontium (Sr), lead (Pb), silver (Ag), praseodymium (Pr), neodymium (Nd), samarium (Sm), and dysprosium (Dy). The metal powder can further include an element other than the metal element. The metal powder can include, for example, carbon (C), oxygen (O), beryllium (Be), phosphorus (P), sulfur (S), boron (B), or silicon (Si).

[0050] The metal powder can be a magnetic powder. The metal powder can be a soft magnetic alloy or a hard magnetic alloy. The metal powder can be, for example, 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), an Al-Ni-Co-based alloy (aluminum-nickel-cobalt magnet), and ferrite. The ferrite can be, for example, spinel ferrite, hexagonal ferrite, or garnet ferrite. 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 include one of the above elements and compositions, or can include a plurality of the above elements and compositions.

[0051] The metal powder can be Fe monomer. The metal powder can be an alloy including iron (Fe-based alloy). The Fe-based alloy can be, for example, an Fe-Si-Cr-based alloy or an Nd-Fe-B-based alloy. The metal element-containing powder can also be at least any one of amorphous iron powder and carbonyl iron powder. When the metal powder includes at least any one of Fe monomer and Fe-based alloy, it is easy to manufacture a molded body having a high space factor and excellent magnetic properties from a composite. The metal powder can also be an Fe amorphous alloy.

[0052] As a commercially available product of the Fe amorphous alloy powder, for example, at least one selected from the group consisting of AW2-08, KUAMET-6B2 (product 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 (product names manufactured by Daido Steel Co., Ltd.), MH45D, MH28D, MH25D, and MH20D (product names manufactured by Kobe Steel, Ltd.) can be used.

[0053] <Method for manufacturing the composite>

[0054] In the manufacturing of the composite, the metal powder and the resin composition (each component constituting the resin composition) are mixed while being heated. For example, the metal powder and the resin composition can be mixed while being heated by a kneader, a roll, a blender, or the like. By the heating and mixing of the metal powder and the resin composition, the resin composition coats the metal element-containing particles constituting the metal powder partially or entirely on the surface thereof, and a part or all of the epoxy resin in the resin composition becomes a semi-cured product. As a result, the composite is obtained. A wax can be further added to the powder obtained by the heating and mixing of the metal powder and the resin composition, whereby the composite is obtained. The resin composition and the wax can be mixed in advance.

[0055] In the mixing, the metal powder, the epoxy resin, the phenol resin, the curing accelerator, the siloxane compound, and the coupling agent can be mixed in a tank. The epoxy resin, the phenol resin, and the curing accelerator can be added to the tank after the metal powder, the siloxane compound, and the coupling agent are mixed in the tank, and the raw materials in the tank can be mixed. The siloxane compound, the epoxy resin, the phenol resin, and the coupling agent can be mixed in a tank, and the curing accelerator can be added to the tank, and the raw materials in the tank can be further mixed. A mixed powder of the epoxy resin, the phenol resin, and the curing accelerator (resin mixed powder) can be prepared in advance, and then, a metal mixed powder can be prepared by mixing the metal powder, the siloxane compound, and the coupling agent, and then, the metal mixed powder and the resin mixed powder can be mixed.

[0056] The kneading time also depends on the type of kneading machine, the volume of the kneading machine, and the production amount of the composite, and is preferably 1 minute or more, more preferably 2 minutes or more, and further preferably 3 minutes or more. Furthermore, the kneading time is preferably 20 minutes or less, more preferably 15 minutes or less, and further preferably 10 minutes or less. When the kneading time is less than 1 minute, the kneading is insufficient, which impairs the moldability of the composite, and the degree of curing of the composite varies. When the kneading time exceeds 20 minutes, the flowability and moldability of the composite are easily impaired, for example, by performing curing of the resin composition (e.g., an epoxy resin and a phenol resin) in a tank. When the raw material in the tank is kneaded with a kneader while being heated, the heating temperature can be, for example, a temperature at which a semi-cured product of an epoxy resin (an epoxy resin in the B stage) is generated and generation of a cured product of an epoxy resin (an epoxy resin in the C stage) is suppressed. The heating temperature can also be a temperature lower than the activation temperature of a curing accelerator. The heating temperature is preferably 50°C or higher, more preferably 60°C or higher, and further preferably 70°C or higher. The heating temperature is preferably 150°C or lower, more preferably 120°C or lower, and further preferably 110°C or lower. When the heating temperature is within the above range, the resin composition in the tank is softened, which easily coats the surface of the metal element-containing particles that constitute the metal powder, thereby easily generating a semi-cured product of an epoxy resin and easily suppressing complete curing of the epoxy resin during kneading.

[0057] [Shaped body]

[0058] The shaped body of the present embodiment can include the above-described composite. The shaped body of the present embodiment can include a cured product of the above-described composite. The shaped body can include at least one selected from the group consisting of an uncured resin composition, a semi-cured product of a resin composition (a resin composition in the B stage), and a cured product of a resin composition (a resin composition in the C stage). The shaped body of the present embodiment can be used as an electronic component or a sealant for an electronic circuit substrate. According to the present embodiment, cracking of the shaped body due to a difference in the thermal expansion rate between a metal member included in the electronic component or the electronic circuit substrate and the shaped body (the sealant) can be suppressed.

[0059] The cured product of the composite is a cured product of a metal powder and a resin composition containing an epoxy resin and a phenol resin, and the content of the metal powder is 90 mass% or more and less than 100 mass%. From the viewpoint of improving the strength of the cured product, the flexural strength at 250°C of the cured product is 4.6 MPa or more, preferably 4.8 MPa or more, and more preferably 5.0 MPa or more. The upper limit of the flexural strength is about 10 MPa. From the viewpoint of imparting flexibility to the cured product, the flexural modulus at 250°C of the cured product is less than 1.0 GPa, preferably 0.1 GPa or more and less than 1.0 GPa, more preferably 0.2 GPa or more and 0.8 GPa or less, further preferably 0.3 GPa or more and 0.7 GPa or less, and particularly preferably 0.4 GPa or more and 0.68 GPa or less. The value obtained by dividing the flexural strength at 250°C (MPa) by the flexural modulus at 250°C (GPa) can be used as an index of the reliability of the cured product. The index is preferably 9.5 x 10 -3 or more, more preferably 10 x 10 -3 or more, and further preferably 10.5 x 10 -3 or more. The upper limit of the index is not particularly limited, and for example, can be 5 x 10 -2 or less.

[0060] <Method for manufacturing shaped body>

[0061] The method for manufacturing the shaped body of the present embodiment can include a step of pressing the composite in a mold. The method for manufacturing the shaped body can include a step of pressing the composite in the mold, and the composite can be pressed in the mold only. The method for manufacturing the shaped body can include a first step, a second step, and a third step. Details of each step are described below.

[0062] In the first step, the composite is produced by the above-described method.

[0063] In the second step, the shaped body (B-stage shaped body) is obtained by pressing the composite in a mold. In the second step, the shaped body (B-stage shaped body) is obtained by pressing the composite in the mold. In the second step, the resin composition is filled between the metal element-containing particles that constitute the metal element-containing powder. Furthermore, the resin composition functions as a binding material (binder) that bonds the metal element-containing particles to each other.

[0064] As the second step, transfer molding of the composite can also be performed. In the transfer molding, the composite can be pressurized at a pressure of 5 MPa or more and 50 MPa or less. The higher the molding pressure, the more likely it is to obtain a molded body having excellent mechanical strength. When the productivity of the molded body and the life of the mold are taken into consideration, the molding pressure is preferably 8 MPa or more and 20 MPa or less. The density of the molded body formed by the transfer molding, with respect to the true density of the composite, can be preferably 75% or more and 86% or less, and more preferably 80% or more and 86% or less. When the density of the molded body is 75% or more and 86% or less, a molded body having excellent mechanical strength is easily obtained. In the transfer molding, the second step and the third step can also be collectively performed.

[0065] In the third step, the molded body is cured by heat treatment to obtain a C-stage molded body. The temperature of the heat treatment can be any temperature at which the resin composition in the molded body is sufficiently cured. The temperature of the heat treatment can be preferably 100°C or more and 300°C or less, and more preferably 110°C or more and 250°C or less. In order to suppress oxidation of the metal powder in the molded body, it is preferable to perform the heat treatment under an inert atmosphere. When the heat treatment temperature exceeds 300°C, the metal powder is oxidized or the resin cured product is deteriorated due to trace amounts of oxygen inevitably contained in the atmosphere of the heat treatment. In order to suppress oxidation of the metal powder and deterioration of the resin cured product and to sufficiently cure the resin composition, the holding time of the heat treatment temperature can be preferably several minutes or more and 10 hours or less, and more preferably 3 minutes or more and 8 hours or less.

[0066] Examples

[0067] Hereinafter, the present application will be further explained in detail by examples and comparative examples, but the present application is not limited by any of these examples.

[0068] Details of each component used for the preparation of the composite in the examples and comparative examples are shown below.

[0069] (First Epoxy Resin)

[0070] Biphenylene aralkyl type epoxy resin (product name: NC-3000, manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent: 275 g / eq)

[0071] (Second Epoxy Resin)

[0072] Polyfunctional epoxy resin (product name: TECHMORE VG3101L, manufactured by Printec Corporation, epoxy equivalent: 215 g / eq)

[0073] Triphenylmethane type multifunctional epoxy resin (EPPN-501HY manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent: 169 g / eq)

[0074] O-cresol novolak type epoxy resin (product name: EPICLON N-500P-2 manufactured by DIC Corporation, epoxy equivalent: 202 g / eq)

[0075] (1st phenol resin)

[0076] Biphenylene aralkyl type phenol resin (product name: MEHC-7851SS manufactured by Meiwa Plastic Industries, Ltd., hydroxyl equivalent: 202 g / eq)

[0077] Biphenylene aralkyl type phenol resin (product name: MEHC-7841-4S manufactured by Meiwa Plastic Industries, Ltd., hydroxyl equivalent: 166 g / eq)

[0078] (2nd phenol resin)

[0079] Triphenylmethane type phenol resin (product name: HE910-09 manufactured by AIR WATER INC., hydroxyl equivalent: 101 g / eq)

[0080] Novolak type phenol resin (product name: HP-850N manufactured by Hitachi Chemical Co., Ltd., hydroxyl equivalent: 103 g / eq)

[0081] (Curing accelerator)

[0082] Urea-based curing accelerator (product name: U-CAT 3512T manufactured by San-Apro Ltd.)

[0083] (Coupling agent)

[0084] Methacryloyloxyoctyltrimethoxysilane (product name: KBM-5803 manufactured by Shin-Etsu Chemical Co., Ltd.)

[0085] 3-Mercaptopropyltrimethoxysilane (product name: KBM-803 manufactured by Shin-Etsu Chemical Co., Ltd.)

[0086] (Siloxane compound)

[0087] Caprolactone-modified dimethyl silicone (product name: DBL-C32 manufactured by Gelest, Inc.)

[0088] (Release agent)

[0089] Zinc laurate (product name: Powder base L manufactured by NOF CORPORATION)

[0090] Partially saponified montanic acid ester wax (product name: LICOWAX OP manufactured by Clariant Chemicals Co., Ltd.)

[0091] (Metal powder)

[0092] Amorphous iron powder (product name: 9A4-II manufactured by Epson Atmix Corporation, average particle diameter: 24 μm)

[0093] Amorphous iron powder (product name: AW2-08 manufactured by Epson Atmix Corporation, average particle diameter: 5.3 μm)

[0094] [Preparation of composite]

[0095] (Examples 1 to 3)

[0096] The epoxy resin, phenol resin, curing accelerator and release agent shown in Table 1 were put into a plastic container in the blending amounts (unit: g) shown in Table 1. A resin mixture was prepared by mixing these materials in the plastic container for 10 minutes. The resin mixture corresponds to all the components in the resin composition except for the siloxane compound and coupling agent.

[0097] The two kinds of amorphous iron powder shown in Table 1 were uniformly mixed for 5 minutes with a pressurized double screw kneader (manufactured by Nihon Spindle Manufacturing Co., Ltd., capacity 5 L) to prepare a metal powder. The coupling agent and siloxane compound shown in Table 1 were added to the metal powder in the double screw kneader. Then, the contents of the double screw kneader were heated to 90°C, and while maintaining this temperature, the contents of the double screw kneader were mixed for 10 minutes. Then, the above resin mixture was added to the contents of the double screw kneader, and while maintaining the temperature of the contents at 120°C, the contents were melt / kneaded for 15 minutes. After the kneadate obtained by the above melt / kneading was cooled to room temperature, the kneadate was pulverized with a hammer so that the kneadate had a prescribed particle size. In addition, the above "melt" means the melting of at least a part of the resin composition in the contents of the double screw kneader. The metal powder in the composite does not melt during the preparation of the composite. The composite of Examples 1 to 3 was prepared by the above method.

[0098] (Comparative Examples 1 to 5)

[0099] The compounds of Comparative Examples 1 to 5 were prepared in the same manner as in the examples except that the kind and blending amount of each component were changed as shown in Table 2.

[0100] [Evaluation of the compound]

[0101] The compounds obtained in the examples and comparative examples were evaluated as follows. The results are shown in Table 1 and Table 2.

[0102] (Flowability)

[0103] The flowability was evaluated using a flow tester CFT-100 manufactured by SHIMADZU CORPORATION. 7 g of the compound was molded to prepare a tablet. The flowability was evaluated using the tablet under the conditions of 130°C, residual heat for 20 seconds, and a load of 100 kg. The pushing distance of the plunger until the flow of the compound stopped (unit: mm) was set as the flow tester stroke, and the time until the flow of the compound stopped was set as the flow time, and these were measured as indices of the flowability.

[0104] (Gel time)

[0105] The gel time of the compound was measured by the following method. A curing instrument (manufactured by JSR Trading Co., Ltd.) was used, and the gel time was measured under the conditions of a sample amount of 1.5 mL and 140°C. The time at which the torque of the obtained graph began to rise was set as the gel time. The shorter the gel time, the higher the curability.

[0106] (Bending test)

[0107] After the compound was subjected to transfer molding under the conditions of a molding die temperature of 140°C, a molding pressure of 13.5 MPa, and a curing time of 360 seconds, the test piece was obtained by post curing at 180°C for 2 hours. The size of the test piece was 80 mm in length, 10 mm in width, and 3.0 mm in thickness.

[0108] The bending test of the test piece was performed using an Autograph with a constant temperature bath at room temperature and at 250°C in a 3-point support type. As the Autograph, AGS-500A manufactured by Shimadzu Corporation was used. In the bending test, one face of the test piece was supported by two support points. A load was applied to the center position between the two support points on the other face of the test piece. The load at the time when the test piece was broken was measured. The measurement conditions of the bending test were as follows.

[0109] Distance Lv between the two support points: 64.0 ± 0.5 mm

[0110] Head speed: 2.0 ± 0.2 mm / min

[0111] Chart speed: 100 mm / min

[0112] Chart full scale: 490 N (50 kgf)

[0113] The bending strength σ (unit: MPa) was calculated according to the following equation (A). The bending elastic modulus E (unit: GPa) was calculated according to the following equation (B). In the following equations, "P" is the load at the time of breakage of the test piece (unit: N). "Lv" is the distance between the two supports (unit: mm). "W" is the lateral width of the test piece (unit: mm). "t" is the thickness of the test piece (unit: mm). "F / Y" is the slope of the straight line portion of the load-deflection curve (unit: N / mm).

[0114] σ = (3 x P x Lv) / (2 x W x t 2 ) (A)

[0115] E = [Lv 3 / (4 x W x t 3 )] x (F / Y) (B)

[0116] (Reliability)

[0117] The value obtained by dividing the bending strength at 250°C (MPa) by the bending elastic modulus at 250°C (GPa) can be used as an evaluation index for reliability. The greater this value, the more excellent the balance between strength and elastic modulus.

[0118] (Rewelding treatment)

[0119] A molded body was obtained by sealing a copper metal member with the composite and curing the composite by transfer molding. The molded body was subjected to a rewelding treatment. The maximum heating temperature in the rewelding treatment was 260°C. The heating time was 300 seconds. After the rewelding treatment, the molded body was observed to check whether or not cracks were formed in the molded body. "A" in the table indicates that no cracks were formed in the molded body, and "B" indicates that cracks were formed in the molded body.

[0120] [Table 1]

[0121]

[0122] [Table 2]

[0123]

Claims

1. A composite comprising a metal powder, and a resin composition containing an epoxy resin and a phenolic resin, the epoxy resin comprises a first epoxy resin having a biphenylene aralkyl skeleton, and a second epoxy resin having an epoxy equivalent weight smaller than that of the first epoxy resin, the phenolic resin comprises a first phenolic resin having a biphenylene aralkyl skeleton, and a second phenolic resin having a hydroxyl equivalent weight smaller than that of the first phenolic resin, the metal powder contains at least one selected from the group consisting of a metal monomer and an alloy, the content of the metal powder is 90 mass% or more and less than 100 mass%, the metal powder contains at least any one of a Fe monomer and a Fe-based alloy.

2. The composite according to claim 1, wherein the first epoxy resin has an epoxy equivalent weight of 240 g / eq or more and 300 g / eq or less.

3. The composite according to claim 1, wherein the first phenolic resin has a hydroxyl equivalent weight of 140 g / eq or more and 230 g / eq or less.

4. The composite according to any one of claims 1 to 3, wherein the content of the first epoxy resin is 20 to 80 mass% based on the total mass of the epoxy resin.

5. A shaped body comprising the composite according to any one of claims 1 to 4.

6. A cured product of a composite, which is a cured product of a composite comprising a metal powder, and a resin composition containing an epoxy resin and a phenolic resin, the epoxy resin comprises a first epoxy resin having a biphenylene aralkyl skeleton, and a second epoxy resin having an epoxy equivalent weight smaller than that of the first epoxy resin, the phenolic resin comprises a first phenolic resin having a biphenylene aralkyl skeleton, and a second phenolic resin having a hydroxyl equivalent weight smaller than that of the first phenolic resin, the metal powder contains at least one selected from the group consisting of a metal monomer and an alloy, the content of the metal powder is 90 mass% or more and less than 100 mass%, the metal powder contains at least any one of a Fe monomer and a Fe-based alloy, the metal powder contains at least any one of a Fe monomer and a Fe-based alloy. a bending strength at 250°C of 4.6 MPa or more, a bending elastic modulus at 250°C of less than 1.0 GPa, and a value of the bending strength divided by the bending elastic modulus of 9.5 x 10 -3 The above.

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