TW202138462A - Compound, molded article, and cured product of compound - Google Patents

Abstract

A compound according to one aspect of the present invention comprises a metal powder and a resin composition containing an epoxy resin, a curing agent, and a plasticizer. The plasticizer contains core-shell rubber particles. A molded article according to one aspect of the present invention contains said compound.

Description

Composites, shaped bodies, and cured products of composites

The present invention relates to a composite, a formed body and a cured product of the composite.

Compounds containing metal powders and resin compositions are used as raw materials for various industrial products based on the various physical properties of metal powders. For example, composites are used as raw materials for inductors, seals, electromagnetic wave shields (EMI shields), or bonded magnets ( Refer to Patent Document 1 below.)

[Patent Document 1] JP 2014-13803 A

When manufacturing an industrial product from a composite, the composite and the metal member are brought into close contact, and the composite is cured to produce a molded body, and then the molded body is heated. In the step of heating the molded body, cracks are likely to be formed in the molded body due to the difference in the thermal expansion coefficient between the cured product of the composite and the metal member, and the explosion of water vapor in the package body. Therefore, it is necessary to improve the reflow resistance of the formed body.

The present invention was completed in view of the above circumstances, and its object is to provide a composite capable of forming a molded body with excellent reflow resistance, a molded body using the composite, and a cured product of the composite.

A composite of one aspect of the present invention includes a metal powder and a resin composition. The resin composition contains an epoxy resin, a curing agent, and a plasticizer, and the plasticizer includes core-shell rubber particles.

The molded body of one aspect of the present invention includes the above-mentioned composite. The cured product of one aspect of the present invention is the cured product of the above-mentioned composite. [Effects of the invention]

According to the present invention, there is provided a composite capable of forming a molded body having excellent reflow resistance, a molded body using the composite, and a cured product of the composite.

Hereinafter, preferred embodiments of the present invention will be described. However, the present invention is not limited at all by the following embodiments.

[Complex] The composite of this embodiment includes a metal powder and a resin composition. The metal powder may contain, for example, at least one selected from the group consisting of a single metal, an alloy, an amorphous powder, and a metal compound. The resin composition contains at least an epoxy resin, a curing agent, and a plasticizer. The plasticizer contains core shell rubber particles. In the composite, metal powder, epoxy resin, curing agent and plasticizer are mixed. The resin composition may also contain curing accelerators, mold release agents, additives, etc. as other components. The resin composition may be a component that can contain an epoxy resin, a curing agent, a plasticizer, a curing accelerator, a release agent, and an additive, and may be a remaining component (nonvolatile component) other than the organic solvent and the metal powder. The remaining components of the additive-based resin composition except for the resin, the release agent, the curing agent, and the curing accelerator. The additives are, for example, coupling agents, flame retardants, lubricants, and the like. The composite may be a powder (composite powder).

The composite may include a metal powder and a resin composition attached to the surface of each metal particle constituting the metal powder. The resin composition may cover the entire surface of the particle or only a part of the surface of the particle. The composite may include an uncured resin composition and metal powder. The composite may include a semi-cured resin composition (for example, a B-stage resin composition) and metal powder. The composite may include 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.

The content of the metal powder in the composite is preferably 90% by mass or more and less than 100% by mass relative to the mass of the entire composite. When the content of the metal powder increases, it is difficult to ensure the mold releasability of the molded body, and the handleability tends to deteriorate. From the viewpoint of the magnetic properties of the molded body, the content of the metal powder is preferably 90% by mass or more, more preferably 92% by mass or more, more preferably 94% by mass or more, and particularly preferably 96% by mass or more. The upper limit of the content of the metal powder may be 99% by mass or less, 98% by mass or less, or 97.5% by mass or less.

The average particle diameter of the metal powder is not particularly limited, and may be, for example, 1 μm or more and 300 μm or less. The average particle diameter can be measured with a particle size distribution meter, for example. The shape of each metal particle constituting the metal powder is not limited, and may be, for example, a spherical shape, a flat shape, a prismatic shape, or a needle shape. The composite may have a plurality of metal powders with different average particle diameters.

According to the composition or combination of the metal powder contained in the composite, various characteristics such as electromagnetic properties of the molded body formed from the composite can be freely controlled, and the molded body can be used for various industrial products or such raw materials. The industrial products manufactured using the compound can be, for example, automobiles, medical equipment, electronic equipment, electrical equipment, information communication equipment, home appliances, audio equipment, and general industrial equipment. For example, when the composite contains permanent magnets such as Sm-Fe-N-based alloys or Nd-Fe-B-based alloys as metal powders, the composites can be used as raw materials for bonded magnets. When the composite contains soft magnetic powders such as Fe-Si-Cr alloys or ferrite as metal powders, the composites can be used as raw materials for inductors (such as EMI filters) or transformers (such as magnetic cores). When the composite contains iron and copper as metal powders, the formed body (such as a sheet) formed from the composite can be used as an electromagnetic wave shield.

(Resin composition) The resin composition functions as a binding material (binder) for the metal particles constituting the metal powder, and imparts mechanical strength to the molded body formed of the composite. For example, when a composite is formed under high pressure using a mold, the resin composition contained in the composite is filled between metal particles to bond the particles to each other. By curing the resin composition in the molded body, the cured product of the resin composition causes the metal particles to bond to each other more firmly, so that the mechanical strength of the molded body is improved.

The resin composition of this embodiment can improve the fluidity of the composite by containing an epoxy resin as a thermosetting resin. The epoxy resin may be, for example, a resin having two or more epoxy groups in one molecule. The type of epoxy resin is not particularly limited, and can be selected according to the desired characteristics of the composition and the like.

The epoxy resin may be selected from the group consisting of biphenyl type epoxy resin, stilbene type epoxy resin, diphenylmethane type epoxy resin, sulfur atom-containing epoxy resin, novolak type epoxy resin, and dicyclopentadiene, for example. Type epoxy resin, salicylic type epoxy resin, copolymer type epoxy resin of naphthol and phenol type, epoxide of aralkyl type phenol resin, bisphenol type epoxy resin, epoxy resin containing bisphenol skeleton Glycidyl ether epoxy resin of resin, alcohol, glycidyl ether epoxy resin of phenol resin modified by stubble and/or stubble, glycidyl resin of terpene modified phenol resin Ether type epoxy resin, cyclopentadiene type epoxy resin, polycyclic aromatic ring modified phenol resin, glycidyl ether type epoxy resin, naphthalene ring-containing phenol resin, glycidyl ether type epoxy resin , Glycidyl ester type epoxy resin, glycidyl type or methyl glycidyl type epoxy resin, alicyclic epoxy resin, halogenated phenol novolak type epoxy resin, o-cresol novolak type At least one of the group consisting of epoxy resin, hydroquinone type epoxy resin, trimethylpropane type epoxy resin, and linear aliphatic epoxy resin obtained by oxidizing olefin bonds with peracetic acid and other peracids.

From the viewpoint of fluidity, the epoxy resin may be selected from the group consisting of biphenyl type epoxy resin, o-cresol novolak type epoxy resin, phenol novolak type epoxy resin, bisphenol type epoxy resin, and having a bisphenol skeleton. At least one of the epoxy resin, salicylic novolac epoxy resin and naphthol novolac epoxy resin.

From the viewpoint of mechanical strength, the epoxy resin may include at least one selected from the group consisting of a biphenyl aralkyl type epoxy resin and an o-cresol novolak type epoxy resin.

The epoxy resin may be a crystalline epoxy resin. Although the molecular weight of the crystalline epoxy resin is relatively low, the crystalline epoxy resin has a relatively high melting point and is excellent in fluidity. The crystalline epoxy resin (epoxy resin with high crystallinity) may include, for example, a group selected from hydroquinone epoxy resins, bisphenol epoxy resins, thioether epoxy resins, and biphenyl epoxy resins. At least one of them. As commercially available products of crystalline epoxy resins, for example, EPICLON 860, EPICLON 1050, EPICLON 1055, EPICLON 2050, EPICLON 3050, EPICLON 4050, EPICLON 7050, EPICLON HM-091, EPICLON HM-01, 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 (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 the product names manufactured by Nippon Kayaku Co., Ltd. ) And YX-4000, YX-4000H, YL4121H and YX-8800 (the above are the trade names manufactured by Mitsubishi Chemical Corporation).

The resin composition may contain one of the epoxy resins mentioned above. The resin composition may contain a plurality of epoxy resins mentioned above. Among the aforementioned epoxy resins, the resin composition may contain an epoxy resin containing a biphenyl skeleton, an o-cresol novolak type epoxy resin, and a multifunctional epoxy resin containing two or more epoxy groups.

The curing agent is classified into a curing agent that cures epoxy resin in the range from low temperature to room temperature, and a heat curing type curing agent that cures epoxy resin with heating. The curing agent for curing the epoxy resin in the range from low temperature to room temperature is, for example, aliphatic polyamine, polyaminoamide, and polythiol. The heat-curable curing agent is, for example, aromatic polyamines, acid anhydrides, phenol novolac resins, and dicyandiamine (DICY). The type of curing agent is not particularly limited, and can be selected according to the desired characteristics of the composition.

When using a curing agent that cures the epoxy resin in the range from low temperature to room temperature, the glass transition point of the cured product of the epoxy resin is low, and the cured product of the epoxy resin tends to be soft. As a result, the molded body formed of the composite is also likely to become soft. On the other hand, from the viewpoint of improving the heat resistance of the molded body, the curing agent may preferably be a heat curing type curing agent, more preferably a phenol resin, and still more preferably a phenol novolak resin. In particular, by using a phenol novolak resin as a curing agent, it is easy to obtain a cured product of an epoxy resin with a high glass transition point. As a result, the heat resistance and mechanical strength of the molded body are easily improved.

The phenol resin may include, for example, a copolymerized phenol resin selected from the group consisting of aralkyl type phenol resin, dicyclopentadiene type phenol resin, salicylic phenol resin, novolak type phenol resin, benzaldehyde type phenol and aralkyl type phenol. , Stubble and/or stubble modified phenol resin, melamine modified phenol resin, terpene modified phenol resin, dicyclopentadiene type naphthol resin, cyclopentadiene modified phenol resin, polycyclic aromatic At least one of the group consisting of a cyclic modified phenol resin, a biphenyl type phenol resin, and a triphenylmethane type phenol resin. The phenol resin may also be a copolymer composed of two or more of the above. As a commercially available product of the phenol resin, for example, Tamanol 758 manufactured by Arakawa Chemical Industries, Ltd., HP-850N manufactured by Hitachi Chemical Co., Ltd., etc. can be used.

The phenol novolak resin may be, for example, a resin obtained by condensing or co-condensing phenols and/or naphthols and aldehydes under an acidic catalyst. The phenols constituting the phenol novolak resin may include, for example, a group selected from the group consisting of phenol, cresol, xylenol, resorcinol, catechol, bisphenol A, bisphenol F, phenylphenol, and aminophenol. At least one of them. The naphthols constituting the phenol novolak resin may include, for example, at least one selected from the group consisting of α-naphthol, β-naphthol, and dihydroxy naphthalene. The aldehydes constituting the phenol novolak resin may include, for example, at least one selected from the group consisting of formaldehyde, acetaldehyde, propionaldehyde, benzaldehyde, and salicaldehyde.

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

The resin composition may contain one of the above-mentioned phenol resins. The resin composition may include a plurality of phenol resins in the above. The resin composition may contain one of the above-mentioned curing agents. The resin composition may contain a plurality of curing agents mentioned above.

The ratio of the active group (phenolic OH group) in the curing agent that reacts with the epoxy group in the epoxy resin to 1 equivalent of the epoxy group in the epoxy resin may preferably be 0.5 to 1.5 equivalents, more preferably It is 0.6 to 1.4 equivalents, more preferably 0.7 to 1.2 equivalents. When the ratio of the active groups in the curing agent is less than 0.5 equivalent, it is difficult to obtain a sufficient elastic modulus of the cured product obtained. On the other hand, when the ratio of the active groups in the curing agent exceeds 1.5 equivalents, the cured mechanical strength of the molded body formed of the composite tends to decrease. However, even when the ratio of the active groups in the curing agent is outside the above range, the effects of the present invention can be obtained.

The resin composition contains a plasticizer containing core shell rubber particles, whereby the molded body has an excellent balance between elastic modulus and strength, and can improve reflow resistance. The core shell rubber particles may be at least one selected from the group consisting of butadiene rubber particles, acrylic rubber particles, silicone rubber particles, and silicone/acrylic rubber particles. The core shell rubber particles may be dispersed in a thermosetting resin such as a liquid epoxy resin.

From the viewpoint of improving the dispersibility into the epoxy resin, the average primary particle size of the core shell rubber particles may be 500 to 1000 nm.

Commercial products of core shell rubber particles include, for example, Kane Ace MX series manufactured by Kaneka Corporation, PARALOID series manufactured by Daw Chemical Company, METABLEN S series manufactured by Mitsubishi Chemical Corporation, and Shin-Etsu Chemical Co., Ltd. The KMP series and so on.

From the viewpoint of improving the fluidity of the resin composition, relative to 100 parts by mass of epoxy resin, the amount of plasticizer can be 1 part by mass or more and 16 parts by mass or less, 3 parts by mass or more and 14 parts by mass or less, or 5 parts by mass or more and 12 parts by mass or less.

The curing accelerator is not limited, for example, as long as it is a composition that reacts with the epoxy resin to promote the curing of the epoxy resin. The curing accelerator may be, for example, a phosphorus-based curing accelerator, an imidazole-based curing accelerator, or a urea-based curing accelerator. The resin composition contains a curing accelerator, whereby the moldability and mold release properties of the composite can be improved. In addition, when the resin composition contains a curing accelerator, the mechanical strength of a molded body (for example, an electronic part) manufactured using the composite is improved, or the storage stability of the composite under a high temperature/high humidity environment is improved.

Examples of the phosphorus-based curing accelerator include phosphine compounds and phosphonium salt compounds.

As a commercially available product of the imidazole-based curing accelerator, for example, one selected from 2MZ-H, C11Z, C17Z, 1, 2DMZ, 2E4MZ, 2PZ-PW, 2P4MZ, 1B2MZ, 1B2PZ, 2MZ-CN, C11Z-CN, 2E4MZ- At least one of CN, 2PZ-CN, C11Z-CNS, 2P4MHZ, TPZ and SFZ (the above are the product names manufactured by Shikoku Chemicals Corporation).

The urea-based curing accelerator is not particularly limited as long as it is a curing accelerator having a urea group. From the viewpoint of improving storage stability, an alkylurea-based curing accelerator having an alkylurea group is preferred. Examples of alkylurea-based curing accelerators having an alkylurea group include aromatic alkyl ureas and aliphatic alkyl ureas. Examples of commercially available alkylurea curing accelerators include U-CAT3512T (product name, manufactured by San-Apro Ltd., aromatic dimethylurea) and U-CAT3513N (product name, San-Apro Ltd. .Manufacturing, aliphatic dimethylurea). Among them, the aromatic alkyl urea is preferred from the viewpoint that the cracking temperature is suitably low and the composite is easily cured effectively.

The blending amount of the curing accelerator is not particularly limited as long as the curing accelerator effect can be obtained. However, from the viewpoint of improving the curability and fluidity of the resin composition during moisture absorption, the amount of the curing accelerator may preferably be 0.1 parts by mass or more and 30 parts by mass relative to 100 parts by mass of epoxy resin. Hereinafter, it is more preferably 1 part by mass or more and 15 parts by mass or less. It is preferable that the content of the curing accelerator is 0.001 parts by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the total mass of the epoxy resin and the phenol resin. When the blending amount of the curing accelerator is less than 0.1 parts by mass, it is difficult to obtain a sufficient curing acceleration effect. When the blending amount of the curing accelerator exceeds 30 parts by mass, the storage stability of the composite tends to decrease. However, even when the blending amount and content of the curing accelerator are outside the above range, the effects of the present invention can be obtained.

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

The resin composition may contain a compound having a siloxane bond (siloxane compound) from the viewpoint that the molding shrinkage rate of the composite is easily reduced and the heat resistance and voltage resistance of the molded body are easily improved. The siloxane bond system contains two silicon atoms (Si) and one oxygen atom (O) bond, which can be represented by -Si-O-Si-. The compound having a siloxane bond may be a polysiloxane compound.

For the environmental safety, recyclability, molding processability and low cost of the composite, the composite may contain a flame retardant. The flame retardant can be selected from brominated flame retardants, phosphorus flame retardants, hydrated metal compound flame retardants, silicone flame retardants, nitrogen-containing compounds, hindered amine compounds, organometallic compounds, and aromatic engineering. At least one of the group consisting of plastic. The resin composition may contain one of the above-mentioned flame retardants, or may contain multiple kinds of the above-mentioned flame retardants.

When a mold is used and a molded body is formed from the composite, the resin composition may contain wax. Wax improves the fluidity of the composite during molding (for example, transfer molding), and acts as a release agent. The wax may be at least any one of fatty acids such as higher fatty acids and fatty acid esters.

The wax may be selected from fatty acids such as montanic acid, stearic acid, 12-oxystearic acid (12-oxystearic acid), and lauric acid or esters thereof, zinc stearate, calcium stearate, and stearic acid. Barium, aluminum stearate, magnesium stearate, calcium laurate, zinc linoleate, calcium ricinoleate, zinc 2-ethylhexanoate and other fatty acid salts, amide stearate, amide oleate, erucic acid Amide, Behenate Amide, Amide Palmitate, Amide Laurate, Amide Hydroxystearate, Methylene Distearate Amide, Ethylene Distearate, Ethylene Di Lauramide, distearyl adipate amide, ethylene dioleate amide, dioleyl adipate amide, N-stearyl stearic acid amide, N-oleyl Fatty acid amides such as amide stearate, N-stearyl erucamide, hydroxymethyl stearic acid amide, hydroxymethyl behenate amide, fatty acid esters such as butyl stearate, ethylene Alcohols, stearyl alcohol and other alcohols, polyethers including polyethylene glycol, polypropylene glycol, polytetramethylene glycol and these modified substances, silicone oils, silicone greases and other polysiloxanes, fluorine Fluorine compounds such as oil, fluorine grease, fluorine-containing resin powder, and paraffin wax, polyethylene wax, amide wax, polypropylene wax, ester wax, carnauba wax, micro wax, etc. At least one of the group consisting of waxes:

(mineral powder) The metal powder (particles containing metal elements) may contain, for example, at least one selected from the group consisting of metal monomers, alloys, and metal compounds. The metal powder may be composed of, for example, at least one selected from the group consisting of a single metal, an alloy, and a metal compound. The alloy may include at least one selected from the group consisting of solid solution, eutectic, and intermetallic compound. The alloy may be stainless steel (Fe-Cr-based alloy, Fe-Ni-Cr-based alloy, etc.), for example. The metal compound may be an oxide such as ferrite. The metal powder may contain one metal element or a plurality of metal elements. The metal element contained in the metal powder may be, for example, a base metal element, a precious metal element, a transition metal element, or a rare earth element. The composite may contain one kind of metal element-containing powder, or it may contain plural kinds of metal element-containing powders with different compositions.

The metal powder is not limited to the above-mentioned composition. The metal element contained in the metal powder may be selected from, for example, 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), samarium (Pr), neodymium (Nd), samarium ( At least one of the group consisting of Sm) and Dy (Dy). The metal powder may further contain elements other than metal elements. The metal powder may include carbon (C), oxygen (О), beryllium (Be), phosphorus (P), sulfur (S), boron (B), or silicon (Si), for example.

The metal powder may be a magnetic powder. The metal powder may be a soft magnetic alloy or a strong magnetic alloy. The metal powder may be selected from Fe-Si-based alloys, Fe-Si-Al-based alloys (Sendust), Fe-Ni-based alloys (Permalloy), and Fe-Cu-based alloys. Ni-based alloy (high-permeability alloy), Fe-Co-based alloy (Permendur), Fe-Cr-Si-based alloy (electromagnetic stainless steel), Nd-Fe-B-based alloy (rare earth magnet), Sm -Fe-N series alloy (rare earth magnet), Al-Ni-Co series alloy (aluminium nickel cobalt magnet) and ferrite iron are composed of at least one kind of magnetic powder. Fertilizer iron may be spinel ferrite, hexagonal ferrite, or garnet ferrite, for example. The metal powder may be a copper alloy such as Cu-Sn-based alloy, Cu-Sn-P-based alloy, Cu-Ni-based alloy, or Cu-Be-based alloy. The metal powder may contain one of the above-mentioned elements and compositions, or may contain a plurality of the above-mentioned elements and compositions.

The metal powder may be Fe alone. The metal powder may be an alloy containing iron (Fe-based alloy). The Fe-based alloy may be, for example, Fe-Si-Cr-based alloy or Nd-Fe-B-based alloy. The metal element-containing powder may also be at least any one of amorphous iron powder and carbonyl iron powder. When the metal powder contains at least any one of Fe single body and Fe-based alloy, it is easy to produce a molded body having a high space factor and excellent magnetic properties from the composite. The metal powder may also be Fe amorphous alloy.

As commercial products of Fe amorphous alloy powder, for example, AW2-08, KUAMET-6B2 (the above are 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 (the above are the product names manufactured by Daido Steel Co., Ltd.), MH45D, MH28D, MH25D and MH20D (the above are the product names manufactured by Kobe Steel, Ltd.) At least one of the group.

＜Method of manufacturing compound＞ In the production 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 kneaded with a kneader, roll, stirrer, etc. while heating. By heating and mixing the metal powder and the resin composition, the resin composition adheres to a part or the whole of the surface of the metal element-containing particles constituting the metal powder and coats the metal element-containing particles. The epoxy resin in the resin composition Part or all of it becomes semi-cured. As a result, a composite is obtained. It is also possible to add wax to the powder obtained by heating and mixing the metal powder and the resin composition to obtain a composite. It is also possible to mix the resin composition and wax in advance.

In the kneading, the metal powder, epoxy resin, curing agent, plasticizer, curing accelerator, and coupling agent can be kneaded in the tank. After the metal powder, plasticizer, and coupling agent are put into the tank and mixed, the epoxy resin, phenol resin, and curing accelerator may be put into the tank, and the raw materials in the tank may be kneaded. After kneading the plasticizer, epoxy resin, curing agent, and coupling agent in the tank, the curing accelerator may be put into the tank, and the raw materials in the tank may be further kneaded. It is also possible to make a mixed powder of epoxy resin, curing agent and curing accelerator (resin mixed powder) in advance, and then knead the metal powder, plasticizer and coupling agent to produce the metal mixed powder, and then, the metal mixed powder and The above-mentioned resin mixed powder is kneaded.

The kneading time also depends on the type of kneading machine, the volume of the kneading machine, and the production volume of the compound. For example, 1 minute or more is preferable, 2 minutes or more is more preferable, and 3 minutes or more is more preferable. In addition, the kneading time is preferably 20 minutes or less, more preferably 15 minutes or less, and even more preferably 10 minutes or less. When the kneading time is less than 1 minute, the kneading is insufficient to impair the moldability of the composite, and the degree of curing of the composite varies. When the kneading time exceeds 20 minutes, for example, the resin composition (for example, epoxy resin and phenol resin) is cured in the tank, and the fluidity and moldability of the composite are easily impaired. When the raw materials in the tank are heated while kneading with a kneader, the heating temperature is, for example, to produce semi-cured epoxy resin (epoxy resin in the B stage) and suppress the cured epoxy resin (epoxy resin in the C stage). The temperature at which the oxygen resin is generated is sufficient. The heating temperature may also be a temperature lower than the activation temperature of the curing accelerator. The heating temperature is preferably 50°C or higher, more preferably 60°C or higher, and more preferably 70°C or higher. The heating temperature is preferably 150°C or less, more preferably 120°C or less, and even more preferably 110°C or less. When the heating temperature is within the above range, the resin composition in the tank is softened and easily coats the surface of the metal element-containing particles constituting the metal powder, thereby easily generating semi-cured epoxy resin and easily suppressing mixing during kneading. Complete curing of epoxy resin.

[Formed body] The molded body of this embodiment may include the above-mentioned composite. The molded body of this embodiment may include a cured product of the above-mentioned composite. The molded body may include at least one selected from the group consisting of an uncured resin composition, a semi-cured resin composition (B-stage resin composition), and a cured resin composition (C-stage resin composition) . The molded body of this embodiment can be used as an electronic component or a sealing material for an electronic circuit board. According to this embodiment, it is possible to suppress cracks in the molded body due to the difference in thermal expansion coefficient between the metal member and the molded body (seal) included in the electronic component or the electronic circuit board.

The cured product of the composite is a cured product of a metal powder and a resin composition, and the content of the metal powder is 90% by mass or more and less than 100% by mass. From the viewpoint of increasing the strength of the cured product, the bending strength at 250° C. of the cured product may be 5.5 MPa or more, 6.0 MPa or more, or 6.5 MPa or more. The upper limit of the bending strength is about 10 MPa. From the viewpoint of imparting flexibility to the cured product, the flexural modulus of elasticity at 250°C of the cured product may be 1.2 GPa or less, 1.1 GPa or less, or 1.0 GPa or less. The lower limit of the bending elastic modulus is about 0.1 GPa.

＜Method of manufacturing molded body＞ The method of manufacturing a molded body of this embodiment may include a step of pressurizing the composite in a mold. The manufacturing method of the molded body may include a step of pressurizing a part or the entire composite covering the surface of the metal member in a mold. The manufacturing method of the molded body may include only the step of pressurizing the composite in the mold, and may include other steps in addition to this step. The manufacturing method of the molded body may include the first step, the second step, and the third step. Hereinafter, the details of each step will be described.

In the first step, the above-mentioned method is used to make a composite.

In the second step, a molded body (B-stage molded body) is obtained by pressurizing the composite in a mold. In the second step, a molded body (B-stage molded body) is obtained by pressing a part or the entire composite covering the surface of the metal member in a mold. In the second step, the resin composition is filled between the metal element-containing particles constituting the metal element-containing powder. In addition, the resin composition functions as a bonding material (binder) and binds particles containing metal elements to each other.

As the second step, transfer molding of the composite can also be implemented. In 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 easier it is to obtain a molded body with excellent mechanical strength. When considering the mass productivity of the molded body and the life of the mold, 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 may preferably be 75% or more and 86% or less, and more preferably 80% or more and 86% or less, relative to the true density of the composite. When the density of the molded body is 75% or more and 86% or less, it is easy to obtain a molded body having excellent mechanical strength. In transfer molding, the second step and the third step can also be performed at one time.

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 may be a temperature at which the resin composition in the molded body is sufficiently cured. The temperature of the heat treatment may preferably be 100°C or higher and 300°C or lower, more preferably 110°C or higher and 250°C or lower. In order to suppress the oxidation of the metal powder in the molded body, it is preferable to perform the heat treatment in 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 the trace amount of oxygen inevitably contained in the heat treatment atmosphere. In order to suppress the oxidation of the metal powder and the deterioration of the cured resin and fully cure the resin composition, the holding time of the heat treatment temperature may preferably be a few minutes or more and 10 hours or less, more preferably 3 minutes or more and 8 hours or less. [Example]

Hereinafter, the present invention will be described in further detail with examples and comparative examples, but the present invention is not limited by these examples in any way.

The details of each component used in the preparation of the complexes of Examples and Comparative Examples are shown below.

(Epoxy resin) Triphenylmethane type multifunctional epoxy resin (EPPN-501HY manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent: 169g/eq) Biphenyl aralkyl epoxy resin (product name manufactured by Nippon Kayaku Co., Ltd.: NC-3000, epoxy equivalent: 275g/eq) (Hardener) Triphenylmethane type phenol resin (product name manufactured by Meiwa Plastic Industries, Ltd.: MEHC-7500-3S, hydroxyl equivalent: 103g/eq) Biphenyl aralkyl phenol resin (product name manufactured by Meiwa Plastic Industries, Ltd.: MEHC-7851SS, hydroxyl equivalent: 202g/eq)

(Plasticizer) Core shell rubber particles shown in Table 1

【Table 1】 Plasticizer Core shell rubber particles Thinner The content of core shell rubber particles (mass%) 1 Kane Ace MX-154 Kaneka Corporation Butadiene series Bisphenol A type epoxy resin 40 2 Kane Ace MX-965 Kaneka Corporation Silicone series Bisphenol F type epoxy resin 25 3 PARALOID EXL-2330 Daw Chemical Acrylic - 100 4 PARALOID EXL-2311 Daw Chemical Acrylic - 100 5 PARALOID EXL-2655 Daw Chemical Butadiene series - 100 6 METABLEN SRK-200E Mitsubishi Chemical Corporation Silicone・Acrylic - 100

(Curing accelerator) Imidazole curing accelerator (product name manufactured by Shikoku Chemicals Corporation: 2P4MZ) Imidazole curing accelerator (product name manufactured by Shikoku Chemicals Corporation: C17Z) (Coupling agent) Methacryloxyoctyl trimethoxysilane (product name manufactured by Shin-Etsu Chemical Co., Ltd.: KBM-5803) 3-Mercaptopropyl trimethoxysilane (product name manufactured by Shin-Etsu Chemical Co., Ltd.: KBM-803) (Release agent) Zinc laurate (product name manufactured by NOF CORPORATION: powdered base material L) Partially saponified montanic acid ester wax (product name manufactured by Clariant Chemicals Co., Ltd.: LICOWAX OP) (Silicone compound) Caprolactone modified dimethyl silicone (product name manufactured by Gelest, Inc.: DBL-C32)

(mineral powder) Amorphous iron powder (product name manufactured by Epson Atmix Corporation: 9A4-II, average particle size 24μm) Amorphous iron powder (product name manufactured by Epson Atmix Corporation: AW2-08, average particle size 5.3μm)

[Preparation of the complex] (Examples 1-7) Put the epoxy resin, curing agent, curing accelerator, mold release agent and plasticizer shown in Table 2 into the plastic container in the blending amount (unit: g) shown in Table 2. The resin mixture is prepared by mixing these materials in a plastic container for 10 minutes. The resin mixture corresponds to all other components in the resin composition except for the silicone compound and the coupling agent.

The two types of amorphous iron powders shown in Table 2 were uniformly mixed for 5 minutes using a pressurized biaxial kneader (manufactured by Nihon Spindle Manufacturing Co., Ltd., volume 5L) to prepare metal powders. The coupling agent and silicone compound shown in Table 2 were added to the metal powder in the biaxial kneader. Then, the contents of the biaxial kneader were heated to 90°C, and the contents of the biaxial kneader were mixed for 10 minutes while maintaining the temperature. Then, the above-mentioned resin mixture was added to the contents of the biaxial kneader, and the contents were melted/kneaded for 15 minutes while maintaining the temperature of the contents at 120°C. After cooling the kneaded material obtained by the above melting/kneading to room temperature, the kneaded material is crushed with a hammer until the kneaded material has a predetermined particle size. In addition, the above-mentioned "melting" refers to the melting of at least a part of the resin composition in the contents of the biaxial kneader. The metal powder in the composite does not melt during the preparation of the composite. The complexes of Examples 1 to 5 were prepared by the above method.

(Comparative Examples 1 to 2) Except for changing the type and blending amount of each component as shown in Table 3, the same procedure as in the example was performed to prepare the composites of Comparative Examples 1 and 2.

[Evaluation of the complex] The following evaluations were performed on the composites obtained in the examples and comparative examples. The results are shown in Table 2 and Table 3.

(fluidity) The flow tester CFT-100 manufactured by SHIMADZU CORPORATION was used to evaluate the flowability. 7 g of the composite was formed to prepare a compressed tablet. Using compressed tablets, the fluidity was evaluated under conditions of 130°C, residual heat for 20 seconds, and a load of 100 kg. The pushing distance (unit: mm) of the plunger until the flow of the compound stops is defined as the flow tester stroke, and the time until the flow of the compound stops is measured as the flow time, which is used as an index of fluidity.

(Gel time) The gel time of the complex was measured by the following method. Using a curing meter (manufactured by JSR Trading Co., Ltd.), the gel time was measured under the conditions of a sample volume of 1.5 mL and 140°C. The time when the torque of the obtained graph starts to rise is regarded as the gel time. It means that the shorter the gel time, the higher the curability.

(Bending test) The composite 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, and then post-cured at 180°C for 2 hours to obtain a test piece. The size of the test piece is 80 mm in vertical width × 10 mm in horizontal width × 3.0 mm in thickness.

Using an Autograph with a constant temperature bath, the test piece was subjected to a 3-point support type bending test at 250°C. As Autograph, AGS-500A manufactured by Shimadzu Corporation was used. In the bending test, one surface of the test piece was supported by two fulcrums. A load was applied at the center position between the two fulcrums on the other surface of the test piece. The load when the test piece was broken was measured. The measurement conditions of the bending test are as follows. The distance between two pivots Lv: 64.0±0.5mm Head speed: 2.0±0.2mm/min Chart speed: 100mm/min Chart full scale: 490N (50kgf)

The bending strength σ (unit: MPa) was calculated according to the following formula (A). Calculate the bending elastic modulus E (unit: GPa) according to the following formula (B). The bending elongation ε (unit: %) was calculated according to the following formula (C). In the following formula, "P" is the load (unit: N) when the test piece is broken. "Lv" is the distance between two pivots (unit: mm). "W" is the horizontal width of the test piece (unit: mm). "T" is the thickness of the test piece (unit: mm). "F/Y" is the slope of the linear part of the load-deflection curve (unit: N/mm). "S" is the deflection of the test piece just before the test piece is broken (unit: mm). σ=(3×P×Lv)/(2×W×t ² )……(A) E=[Lv ³ /(4×W×t ³ )]×(F/Y)……(B) ε =(600×s×t)/Lv ² ……(C)

(reliability) The value obtained by dividing the bending strength (MGa) at 250°C by the bending elastic modulus (GPa) at 250°C can be used as an evaluation index of reliability. It means that the larger the value, the better the balance between strength and elastic modulus.

(Reflow treatment) By transfer molding, the copper metal member is sealed by the composite, and the composite is cured, thereby obtaining a molded body. Reflow treatment is applied to the formed body. The maximum heating temperature in the reflow process is 260°C. The heating time is 300 seconds. After the reflow treatment, observe the formed body to check whether the formed body has cracks. "A" in the table indicates that no cracks were formed on the molded body, and "B" indicates that cracks were formed on the molded body.

【Table 2】 Example 1 2 3 4 5 6 7 Epoxy resin EPPN-501HY 100 - - - - - - NC-3000 - 100 100 100 100 100 100 Hardener MEHC-7500-3S 40 27 27 27 27 27 27 MEHC-7851SS 33 twenty two twenty two twenty two twenty two twenty two twenty two Curing accelerator C17Z 1.2 1.5 1.5 1.5 1.5 1.5 1.5 2P4MZ 0.5 1.0 1.0 1.0 1.0 1.0 1.0 Coupling agent KBM-5803 1.5 1.5 1.5 1.5 1.5 1.5 1.5 KBM-803 1.0 1.0 1.0 1.0 1.0 1.0 1.0 Release agent Powdery base material L 4.0 4.0 4.0 4.0 4.0 4.0 4.0 LICOWAX OP 2.0 2.0 2.0 2.0 2.0 2.0 2.0 Siloxane compounds DBL-C32 30 30 30 30 30 30 30 Plasticizer Plasticizer 1 10 10 - - - - - Plasticizer 2 - - 10 - - - - Plasticizer 3 - - - 10 - - - Plasticizer 4 - - - - 10 - - Plasticizer 5 - - - - - 10 - Plasticizer 6 - - - - - - 10 Metal powder 9A4-II 4881 4378 4378 4378 4378 4378 4378 AW2-08 1071 961 961 961 961 961 961 Metal powder content (mass%) 96.4 96.4 96.4 96.4 96.4 96.4 96.4 Flow Tester@130℃ Stroke length (mm) 10.8 10.6 10.8 11.1 10.7 10.5 10.8 Flow time (seconds) twenty three 33 19 twenty three 35 36 34 Gel time@140℃(sec) 190 180 175 200 190 200 205 250°C bending strength Elongation(%) 0.85 1.00 0.94 1.02 1.03 1.02 1.03 Modulus of Elasticity (GPa) 1.0 0.7 0.7 0.7 0.7 0.7 0.7 Strength (MPa) 8.9 6.5 6.3 6.8 6.8 7.1 6.3 Reliability index (×10 ^-3 ) 8.6 9.8 9.4 9.6 10.1 9.9 9.4 Reflow evaluation A A A A A A A

【table 3】 Comparative example 1 2 Epoxy resin EPPN-501HY 100 - NC―3000 - 100 Hardener MEHC-7500-3S 40 27 MEHC-7851SS 33 twenty two Curing accelerator C17Z 1.2 1.5 2P4MZ 0.5 1.0 Coupling agent KBM-5803 1.5 1.5 KBM-803 1.0 1.0 Release agent Powdery base material L 4.0 4.0 LICOWAX OP 2.0 2.0 Siloxane compounds DBL-C32 30 30 Metal powder 9A4-II 4662 4159 AW2-08 1023 913 Metal powder content (mass%) 96.4 96.4 Flow tester @ 130℃ Stroke length (mm) 10.4 10.7 Flow time (seconds) 26 31 Gel time@140℃(sec) 180 175 250°C bending strength Elongation(%) 0.73 0.87 Modulus of Elasticity (GPa) 1.0 0.6 Strength (MPa) 6.8 5.0 Reliability index (×10 ^-3 ) 6.9 7.9 Reflow evaluation B B

Claims (6)

A composite comprising metal powder and a resin composition, the aforementioned resin composition containing an epoxy resin, a curing agent and a plasticizer, The aforementioned plasticizer includes core-shell rubber particles. The compound according to claim 1, wherein The core shell rubber particles are at least one selected from the group consisting of butadiene rubber particles, acrylic rubber particles, silicone rubber particles, and silicone/acrylic rubber particles. The compound described in claim 1 or claim 2, wherein The content of the plasticizer is 1 part by mass or more and 16 parts by mass or less with respect to 100 parts by mass of the epoxy resin. The compound according to any one of claims 1 to 3, wherein The content of the aforementioned metal powder is 90% by mass or more and less than 100% by mass. A shaped body comprising the compound according to any one of claims 1 to 3. A cured product, which is a cured product of the composite described in any one of Claims 1 to 3.