JP2018165359A - Resin composition and inductor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin having an appropriately low viscosity and excellent coatability, a high glass transition temperature of a cured product and excellent heat resistance, and an ability to enhance the adhesion of a cured product to a member to be coated at a high temperature. The composition is provided. A resin composition according to the present invention contains a bisphenol type epoxy compound, a polyfunctional epoxy compound different from the bisphenol type epoxy compound, and a thermosetting agent, and has a viscosity at 25 ° C. of 40 Pa · s or less. When a cured product is obtained by curing at 190 ° C. for 30 minutes, the glass transition temperature of the cured product is 170 ° C. or higher. [Selection diagram] Fig. 1

Description

  The present invention relates to a resin composition containing a thermosetting compound and a thermosetting agent. The present invention also relates to an inductor using the above resin composition.

  Conventionally, in various electronic components, a resin composition has been used to bond members or coat surfaces of members.

  An inductor is known as an electronic component. Inductors are used in mobile phones, televisions, digital cameras, and the like. In particular, in an inductor corresponding to a large current, a core material such as a ferrite core is disposed with a gap. Conventionally, an adhesive (resin composition) that does not include particles and an adhesive (resin composition) that includes particles such as glass beads are used for the gaps (adhesive portions).

  As an example of the resin composition, Patent Document 1 below discloses a one-part curable resin composition containing a specific epoxy resin. Patent Document 1 describes that both low-temperature curability and securing of adhesive strength can be achieved.

  The following Patent Document 2 discloses an adhesive containing nonmagnetic particles (particles). The adhesive may be a curable adhesive.

WO2015 / 060440A1 JP 2004-235462 A

  High heat resistance is calculated | required by the cured | curing material of the resin composition used for an electronic component. However, the thermosetting compound having high heat resistance after curing may increase the viscosity of the resin composition before curing. In the conventional resin composition, it is difficult to achieve both high heat resistance and good coatability.

  Furthermore, in the conventional resin composition, the adhesive strength of the cured product to the application target member at high temperature cannot be sufficiently increased, and the adhesion of the cured product to the application target member at high temperature may be lowered. .

  The object of the present invention is to have a reasonably low viscosity and excellent coatability, to have a high glass transition temperature of the cured product and excellent heat resistance, and to improve the adhesion of the cured product to a coating target member at a high temperature. It is providing the resin composition which can be performed. Another object of the present invention is to provide an inductor using the above resin composition.

  According to a wide aspect of the present invention, the bisphenol-type epoxy compound, a polyfunctional epoxy compound different from the bisphenol-type epoxy compound, and a thermosetting agent are used, the viscosity at 25 ° C. is 40 Pa · s or less, and 190 ° C. When a cured product is obtained by curing for 30 minutes, a resin composition is provided in which the cured product has a glass transition temperature of 170 ° C. or higher.

  In a specific aspect of the resin composition according to the present invention, the polyfunctional epoxy compound has a naphthalene skeleton, a fluorene skeleton, a glycoluril skeleton, a dicyclopentadiene skeleton, or a phenol novolac skeleton.

  In a specific aspect of the resin composition according to the present invention, the bisphenol type epoxy compound is a bisphenol A type epoxy compound, a bisphenol F type epoxy compound, or a bisphenol E type epoxy compound.

  In a specific aspect of the resin composition according to the present invention, when a cured product is obtained by curing at 190 ° C. for 30 minutes, the weight reduction of the cured product with respect to the resin composition before curing is 5% by weight or less. .

  In a specific aspect of the resin composition according to the present invention, a ratio of the content of the polyfunctional epoxy compound to the content of the bisphenol-type epoxy compound is 1/9 or more and 4/6 or less on a weight basis. is there.

  In a specific aspect of the resin composition according to the present invention, when a cured product is obtained by curing at 190 ° C. for 30 minutes, a 5% weight loss temperature by thermogravimetric analysis of the cured product is 360 ° C. or higher.

  In a specific aspect of the resin composition according to the present invention, the resin composition includes spacer particles.

  On the specific situation with the resin composition which concerns on this invention, the said resin composition is an adhesive agent for electronic components.

  On the specific situation with the resin composition which concerns on this invention, the said resin composition is used for adhesion | attachment of a ferrite core.

  On the specific situation with the resin composition which concerns on this invention, the said resin composition is used for adhesion | attachment of the ferrite core in an inductor.

  According to a wide aspect of the present invention, there is provided an inductor comprising a ferrite core and an adhesive part that adheres the ferrite core, wherein the material of the adhesive part is the resin composition described above.

  The resin composition according to the present invention includes a bisphenol-type epoxy compound, a polyfunctional epoxy compound different from the bisphenol-type epoxy compound, and a thermosetting agent. In the resin composition according to the present invention, the viscosity at 25 ° C. is 40 Pa · s or less. In the resin composition according to the present invention, when a cured product is obtained by curing at 190 ° C. for 30 minutes, the glass transition temperature of the cured product is 170 ° C. or higher. Since the resin composition according to the present invention has the above-described configuration, it has a reasonably low viscosity and excellent coatability, has a high glass transition temperature of the cured product and excellent heat resistance, and at high temperatures. The adhesion of the cured product to the coating target member can be improved.

FIG. 1 is a cross-sectional view schematically showing an inductor using a resin composition according to an embodiment of the present invention.

  Details of the present invention will be described below.

(Resin composition)
The resin composition according to the present invention includes a thermosetting compound and a thermosetting agent. The resin composition according to the present invention includes a bisphenol type epoxy compound and a polyfunctional epoxy compound different from the bisphenol type epoxy compound as the thermosetting compound. The viscosity at 25 ° C. of the resin composition according to the present invention is 40 Pa · s or less. The viscosity of the resin composition according to the present invention is relatively low and excellent in applicability. When the cured composition is obtained by curing the resin composition according to the present invention at 190 ° C. for 30 minutes, the glass transition temperature of the cured product is 170 ° C. or higher. From the viewpoint of improving the adhesion of the cured product to the coating target member at a high temperature, the glass transition temperature of the cured product is preferably 180 ° C. or higher, and more preferably 190 ° C. or higher.

  In the present invention, the viscosity is moderately low and the coating property is excellent, and the glass transition temperature is high and the heat resistance is excellent. In this invention, since said compounding component is combined, a viscosity can be made low effectively and a glass transition temperature can be made high effectively. Furthermore, in the present invention, since the above configuration is adopted, the adhesion of the cured product to the application target member at a high temperature can be sufficiently increased. In this invention, since the adhesive strength of the hardened | cured material with respect to the application target member under high temperature can fully be raised, the adhesiveness of the hardened | cured material with respect to the application target member under high temperature becomes high. Furthermore, since the resin composition according to the present invention has a reasonably low viscosity, the thickness of the cured product can be controlled uniformly when applied onto the application target member. For example, when a cured product is disposed between members, the gap controllability can be improved. When bonding a ferrite core in an inductor, a core material such as a ferrite core needs to be disposed with a gap. In such a case, applying the present invention to improve the gap controllability has high technical significance.

  From the viewpoint of further improving the gap controllability, the viscosity (η25) at 25 ° C. of the resin composition is preferably 40 Pa · s or less, more preferably 30 Pa · s or less, and further preferably 20 Pa · s or less. It is.

  The viscosity (η25) is determined using, for example, an E-type viscometer (“TVE22L” manufactured by Toki Sangyo Co., Ltd.) and the like, and conditions of 25 ° C. and 5 rpm, and a spiral viscometer (“PCU-02V” manufactured by Malcolm). And can be measured at 25 ° C. and 10 rpm. When the particle diameter of the spacer particles in the resin composition is 20 μm or less, an E-type viscometer (“TVE22L” manufactured by Toki Sangyo Co., Ltd.) is preferably used. When the particle diameter of the spacer particles in the resin composition exceeds 20 μm, a spiral viscometer (“PCU-02V” manufactured by Malcolm) is preferably used.

  From the viewpoint of further improving the heat resistance reliability, when the resin composition is cured at 190 ° C. for 30 minutes to obtain a cured product, a 5% weight reduction temperature by thermogravimetric analysis (TGA) of the cured product. Is preferably 360 ° C. or higher, more preferably 380 ° C. or higher, and further preferably 390 ° C. or higher. The 5% weight reduction temperature is a temperature at which the weight of the cured product is reduced by 5% by weight.

  Specifically, the 5% weight reduction temperature can be measured under the condition of a temperature rising rate of 10 ° C./min using a differential thermothermal gravimetric simultaneous measurement device (“TG-DTA6200” manufactured by Seiko Instruments Inc.). .

  Next, the detail of the component contained in the said resin composition is demonstrated.

Thermosetting compound:
The resin composition includes a bisphenol type epoxy compound and a polyfunctional epoxy compound different from the bisphenol type epoxy compound as a thermosetting compound. The polyfunctional epoxy compound in the resin composition according to the present invention does not include a bisphenol type epoxy compound. The polyfunctional epoxy compound has two or more epoxy groups. As for the said bisphenol-type epoxy compound, only 1 type may be used and 2 or more types may be used together. As for the said polyfunctional epoxy compound, only 1 type may be used and 2 or more types may be used together.

  Examples of the bisphenol type epoxy compound include a bisphenol A type epoxy compound, a bisphenol F type epoxy compound, a bisphenol E type epoxy compound, and a bisphenol S type epoxy compound.

  The bisphenol type epoxy compound is preferably a bisphenol A type epoxy compound, a bisphenol F type epoxy compound, or a bisphenol E type epoxy compound, more preferably a bisphenol F type epoxy compound or a bisphenol E type epoxy compound, More preferably, it is a bisphenol E type epoxy compound. The bisphenol type epoxy compound may be a bisphenol F type epoxy compound. The glass transition temperature can be further improved when the bisphenol-type epoxy compound satisfies the above preferred embodiment. As for these preferable bisphenol type epoxy compounds, only 1 type may be used and 2 or more types may be used together.

  Examples of the polyfunctional epoxy compound include naphthalene type epoxy compounds, fluorene type epoxy compounds, glycoluril type epoxy compounds, dicyclopentadiene type epoxy compounds, phenol novolac type epoxy compounds, and resorcinol type epoxy compounds.

  The polyfunctional epoxy compound preferably has a naphthalene skeleton, a fluorene skeleton, a glycoluril skeleton, a dicyclopentadiene skeleton, a phenol novolac skeleton or a resorcinol skeleton, and has a naphthalene skeleton, a fluorene skeleton, a glycoluril skeleton, or a dicyclopentadiene skeleton. More preferably. When the polyfunctional epoxy compound satisfies the above preferred embodiment, the glass transition temperature can be further improved. As for these preferable polyfunctional epoxy compounds, only 1 type may be used and 2 or more types may be used together.

  The content of the thermosetting compound in 100% by weight of the resin composition is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, still more preferably 1% by weight or more, and particularly preferably 15%. % By weight or more, preferably 90% by weight or less, more preferably 80% by weight or less, and still more preferably 70% by weight or less. The total content of the bisphenol-type epoxy compound and the polyfunctional epoxy compound in 100% by weight of the resin composition is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, and still more preferably 1% by weight or more, particularly preferably 15% by weight or more. The total content of the bisphenol type epoxy compound and the polyfunctional epoxy compound in 100% by weight of the resin composition is preferably 90% by weight or less, more preferably 80% by weight or less, and further preferably 70% by weight or less. It is. When the content of the thermosetting compound and the total content of the bisphenol type epoxy compound and the polyfunctional epoxy compound are equal to or higher than the lower limit, the glass transition temperature is further improved. When the content of the thermosetting compound and the total content of the bisphenol type epoxy compound and the polyfunctional epoxy compound are not more than the above upper limit, the glass transition temperature is further improved.

  From the viewpoint of further improving the gap controllability, the ratio of the polyfunctional epoxy compound content to the bisphenol type epoxy compound content (polyfunctional epoxy compound content / bisphenol type epoxy compound content) Is preferably 1/9 or more, preferably 4/6 or less, more preferably 3/7 or less on a weight basis.

Thermosetting agent:
The thermosetting agent thermosets the thermosetting compound. Examples of the thermosetting agent include an imidazole curing agent, a phenol curing agent, an amine curing agent, an acid anhydride curing agent, a thermal cation initiator, and a thermal radical generator. As for the said thermosetting agent, only 1 type may be used and 2 or more types may be used together.

  The imidazole curing agent is not particularly limited. Examples of the imidazole curing agent include 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6. -[2'-methylimidazolyl- (1 ')]-ethyl-s-triazine and 2,4-diamino-6- [2'-methylimidazolyl- (1')]-ethyl-s-triazine isocyanuric acid adducts Etc.

  The amine curing agent is not particularly limited. Examples of the amine curing agent include hexamethylenediamine, octamethylenediamine, decamethylenediamine, 3,9-bis (3-aminopropyl) -2,4,8,10-tetraspiro [5.5] undecane, bis (4 -Aminocyclohexyl) methane, metaphenylenediamine, diaminodiphenylsulfone and the like.

  The thermal cation initiator is not particularly limited. Examples of the thermal cation initiator include iodonium cation curing agents, oxonium cation curing agents, and sulfonium cation curing agents. Examples of the iodonium-based cationic curing agent include bis (4-tert-butylphenyl) iodonium hexafluorophosphate. Examples of the oxonium-based cationic curing agent include trimethyloxonium tetrafluoroborate. Examples of the sulfonium-based cationic curing agent include tri-p-tolylsulfonium hexafluorophosphate.

  The thermal radical generator is not particularly limited. Examples of the thermal radical generator include azo compounds and organic peroxides. Examples of the azo compound include azobisisobutyronitrile (AIBN). Examples of the organic peroxide include di-tert-butyl peroxide and methyl ethyl ketone peroxide.

  The content of the thermosetting agent is not particularly limited. The content of the thermosetting agent with respect to 100 parts by weight of the thermosetting compound is preferably 0.01 parts by weight or more, more preferably 1 part by weight or more, preferably 200 parts by weight or less, more preferably 100 parts by weight or less, more preferably 75 parts by weight or less, particularly preferably 50 parts by weight or less, and most preferably 10 parts by weight or less. The content of the thermosetting agent is preferably 0.01 parts by weight or more, more preferably 1 part by weight or more with respect to 100 parts by weight in total of the bisphenol type epoxy compound and the polyfunctional epoxy compound. The content of the thermosetting agent is preferably 200 parts by weight or less, more preferably 100 parts by weight or less, and still more preferably 75 parts by weight with respect to a total of 100 parts by weight of the bisphenol type epoxy compound and the polyfunctional epoxy compound. Part or less, particularly preferably 50 parts by weight or less, and most preferably 10 parts by weight or less. It is easy to fully harden a resin composition as content of the said thermosetting agent is more than the said minimum. When the content of the thermosetting agent is not more than the above upper limit, an excessive thermosetting agent that is not involved in the curing after curing hardly remains, and the heat resistance of the cured product is further enhanced.

Spacer particles:
From the viewpoint of controlling the thickness of the cured product of the resin composition with higher accuracy, the resin composition preferably includes spacer particles. The resin composition containing spacer particles can be used as a gap control material. When the resin composition containing the spacer is used for bonding a ferrite core, particularly a ferrite core in an inductor, the thickness of the cured product of the resin composition can be controlled with higher accuracy.

  Examples of the spacer particles include resin particles, inorganic particles excluding metal particles, organic-inorganic hybrid particles, and metal particles. The spacer particle may be a core-shell particle including a core and a shell disposed on the surface of the core. The core may be an organic core. The shell may be an inorganic shell. When stress is applied to the cured product or when vibration is applied to the cured product, from the viewpoint of relaxing stress and vibration and maintaining high adhesion, the spacer particles are preferably spacer particles excluding metal particles, More preferred are inorganic particles or organic-inorganic hybrid particles excluding resin particles, metal particles. The spacer particles are particularly preferably resin particles or organic-inorganic hybrid particles because they are more excellent due to the effects of the present invention. When the resin composition containing spacer particles is used for adhesion of ferrite cores, particularly ferrite cores in inductors, and further used in applications where stress or vibration is applied such as in-vehicle use, the stress relaxation performance of the spacer particles is effective. Yes, stress and vibration can be more effectively reduced by the spacer particles.

  The spacer particles are preferably resin particles formed of resin. When the spacer particles are resin particles, when stress or vibration is applied to the cured product, the stress and vibration can be relaxed, and high adhesion can be maintained.

  Various organic materials are suitably used as the resin for forming the resin particles. Examples of the resin for forming the resin particles include polyolefin resins such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyisobutylene, and polybutadiene; acrylic resins such as polymethyl methacrylate and polymethyl acrylate; Alkylene terephthalate, polycarbonate, polyamide, phenol formaldehyde resin, melamine formaldehyde resin, benzoguanamine formaldehyde resin, urea formaldehyde resin, phenol resin, melamine resin, benzoguanamine resin, urea resin, epoxy resin, unsaturated polyester resin, saturated polyester resin, polysulfone, polyphenylene Oxide, polyacetal, polyimide, polyamideimide, polyether ether Ketones, polyether sulfones, and polymers such as obtained by a variety of polymerizable monomer having an ethylenically unsaturated group is polymerized with one or more thereof. Since the hardness of the spacer particles can be easily controlled within a suitable range, the resin for forming the resin particles is a polymer obtained by polymerizing one or more polymerizable monomers having a plurality of ethylenically unsaturated groups. It is preferably a coalescence.

  When the resin particles are obtained by polymerizing a polymerizable monomer having an ethylenically unsaturated group, the polymerizable monomer having an ethylenically unsaturated group may be a non-crosslinkable monomer or a crosslinkable monomer. And the monomer.

  Examples of the non-crosslinkable monomer include styrene monomers such as styrene and α-methylstyrene; carboxyl group-containing monomers such as (meth) acrylic acid, maleic acid, and maleic anhydride; (Meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl ( Alkyl (meth) acrylate compounds such as meth) acrylate and isobornyl (meth) acrylate; 2-hydroxyethyl (meth) acrylate, glycerol (meth) acrylate, polyoxyethylene (meth) acrylate, glycidyl (meth) acrylate, etc. Elemental-containing (meth) acrylate compounds; nitrile-containing monomers such as (meth) acrylonitrile; vinyl ether compounds such as methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether; acids such as vinyl acetate, vinyl butyrate, vinyl laurate, vinyl stearate Vinyl ester compounds; unsaturated hydrocarbons such as ethylene, propylene, isoprene, and butadiene; halogen-containing monomers such as trifluoromethyl (meth) acrylate, pentafluoroethyl (meth) acrylate, vinyl chloride, vinyl fluoride, and chlorostyrene Etc.

  Examples of the crosslinkable monomer include tetramethylolmethane tetra (meth) acrylate, tetramethylolmethane tri (meth) acrylate, tetramethylolmethane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, and dipenta Erythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, glycerol tri (meth) acrylate, glycerol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) Polyfunctional (meth) acrylate compounds such as acrylate, (poly) tetramethylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate; triallyl (iso) cyanide Silane-containing monomers such as salts, triallyl trimellitate, divinylbenzene, diallyl phthalate, diallylacrylamide, diallyl ether, γ- (meth) acryloxypropyltrimethoxysilane, trimethoxysilylstyrene, vinyltrimethoxysilane, etc. Is mentioned.

  The resin particles can be obtained by polymerizing the polymerizable monomer having an ethylenically unsaturated group by a known method. Examples of this method include a method of suspension polymerization in the presence of a radical polymerization initiator, and a method of polymerizing by swelling a monomer together with a radical polymerization initiator using non-crosslinked seed particles.

  When the spacer particles are inorganic particles or organic-inorganic hybrid particles excluding metal particles, examples of inorganic substances for forming the spacer particles include silica and carbon black. The inorganic substance is preferably not a metal. The particles formed from the silica are not particularly limited. For example, after forming a crosslinked polymer particle by hydrolyzing a silicon compound having two or more hydrolyzable alkoxysilyl groups, firing may be performed as necessary. The particle | grains obtained by performing are mentioned. Examples of the organic / inorganic hybrid particles include organic / inorganic hybrid particles formed of a crosslinked alkoxysilyl polymer and an acrylic resin.

  From the viewpoint of further improving the adhesion, the average particle diameter of the spacer particles is preferably 20 μm or more, more preferably 25 μm or more, further preferably 30 μm or more, preferably 200 μm or less, more preferably 150 μm or less. More preferably, it is 130 μm or less.

  From the viewpoint of further improving the adhesion, the CV value of the particle diameter of the spacer particles is preferably 1% or more, preferably 10% or less, more preferably 5% or less.

From the viewpoint of further improving the adhesion, the compression modulus (10% K value) when the spacer particles are compressed by 10% is preferably 980 N / mm ² or more, more preferably 1200 N / mm ² or more. preferably 4900 N / mm ² or less, and more preferably not more than 3000N / mm ^2.

  The CV value (coefficient of variation) is expressed by the following formula.

CV value (%) = (ρ / Dn) × 100
ρ: Standard deviation of spacer particle diameter Dn: Average value of spacer particle diameter

  The 10% K value of the spacer particles can be measured as follows.

  Using a micro-compression tester, spacer particles are compressed under a condition that a smooth tester end face of a cylinder (diameter 50 μm, made of diamond) is loaded at 25 ° C. and a maximum test load of 90 mN over 30 seconds. The load value (N) and compression displacement (mm) at this time are measured. From the measured value obtained, the compression elastic modulus can be obtained by the following formula. As the micro compression tester, for example, “Fischer Scope H-100” manufactured by Fischer is used.

K value (N / mm ² ) = (3/2 ^1/2 ) · F · S ⁻³ / ² · R ^−1/2
F: Load value when the spacer particles are 10% compressively deformed (N)
S: Compression displacement (mm) when the spacer particles are 10% compressively deformed
R: Radius of spacer particle (mm)

  From the viewpoint of further improving moisture resistance and adhesion, and further improving the uniformity of the thickness of the cured product, the content of the spacer particles in 100% by weight of the resin composition is preferably 1% by weight or more, More preferably, it is 2% by weight or more, more preferably more than 5% by weight, preferably 15% by weight or less, more preferably 12% by weight or less.

Inorganic filler:
From the viewpoint of further improving the moisture resistance, the resin composition preferably contains an inorganic filler. Examples of the inorganic filler material include silica, talc, clay, mica, hydrotalcite, alumina, magnesium oxide, aluminum hydroxide, aluminum nitride, and boron nitride.

  From the viewpoint of further improving the moisture resistance, the inorganic filler is preferably silica or alumina, more preferably silica, and still more preferably fused silica. By using silica, the thermal expansion coefficient of the cured product is further lowered, and the adhesion reliability is further enhanced.

  From the viewpoint of further improving the moisture resistance, the inorganic filler is preferably a surface-treated product with a coupling agent.

  Examples of the coupling agent include silane coupling agents, titanium coupling agents, and aluminum coupling agents. From the viewpoint of further improving the adhesion, the inorganic filler is preferably a surface-treated product with a silane coupling agent.

  Examples of the silane coupling agent include phenyl silane, vinyl silane, amino silane, imidazole silane, and epoxy silane. From the viewpoint of further improving the moisture resistance, phenylsilane is preferred.

  From the viewpoint of further improving the moisture resistance, the content of the inorganic filler is preferably 10% by weight or more, more preferably more than 30% by weight, still more preferably more than 35% by weight in 100% by weight of the resin composition. Particularly preferred is 40% by weight or more. From the viewpoint of further improving the adhesion, the content of the inorganic filler is preferably 90% by weight or less, more preferably 75% by weight or less, further preferably 70% by weight or less, particularly preferably 65% by weight or less, and most preferably. Is 60% by weight or less.

  From the viewpoint of improving both adhesion and moisture resistance in a balanced manner, in the resin composition, the ratio of the spacer particle content to the inorganic filler content (spacer particle content / inorganic filler content). Is preferably 1/60 or more, more preferably 1/30 or more, and 1/3 or less, more preferably 1/4 or less, on a weight basis.

  From the viewpoint of further improving the adhesion, the ratio of the average particle diameter of the inorganic filler to the average particle diameter of the spacer particles (average particle diameter of the inorganic filler / average particle diameter of the spacer particles) is preferably 0.1 or less. More preferably, it is 0.01 or less. From the viewpoint of further improving the moisture resistance, the above ratio (average particle diameter of inorganic filler / average particle diameter of spacer particles) is preferably 0.00005 or more, more preferably 0.0005 or more.

  The average particle diameter indicates a number average particle diameter. The average particle diameter of the inorganic filler and the spacer particles can be obtained, for example, by observing 50 arbitrary inorganic fillers or 50 arbitrary spacer particles with an electron microscope or an optical microscope and calculating an average value.

solvent:
The said resin composition may contain the solvent and does not need to contain the solvent. The solvent is generally removed by volatilization when the resin composition is cured. As for the said solvent, only 1 type may be used and 2 or more types may be used together.

  The solvent is generally an organic solvent. Examples of the organic solvent include ketone compounds such as methyl ethyl ketone and cyclohexanone, aromatic hydrocarbon compounds such as toluene, xylene, and tetramethylbenzene, cellosolve, methyl cellosolve, butyl cellosolve, carbitol, methyl carbitol, butyl carbitol, and propylene glycol monomethyl. Glycol ether compounds such as ether, dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, tripropylene glycol monomethyl ether, ethyl acetate, butyl acetate, butyl lactate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, butyl carbitol acetate, propylene Glycol monomethyl ether acetate, diethylene glycol monoethyl ether Seteto, dipropylene glycol monomethyl ether acetate, ester compounds such as propylene carbonate, octane, aliphatic hydrocarbon compounds decane, petroleum ether, petroleum solvent and dibasic ester such as naphtha. The dibasic acid ester is a solvent called DBE.

  From the viewpoint of suppressing excessive wetting and spreading of the resin composition after coating, the solvent content in the resin composition is preferably small. That is, when the resin composition is cured at 190 ° C. for 30 minutes to obtain a cured product, the weight loss of the cured product with respect to the resin composition before curing is preferably 5% by weight or less, more preferably 3% by weight. % Or less. The weight reduction at the time of curing corresponds to the weight percent decreased in the cured product obtained by curing the resin composition with respect to 100% by weight of the resin composition before curing. The amount of volatile components affects the weight reduction before and after the curing. In the present invention, since the above blending composition is employed, the viscosity of the resin composition can be sufficiently lowered even if no solvent is used or the content of the solvent is reduced.

Other ingredients:
The said resin composition may contain the photocurable component, and may contain the photocurable compound and the photoinitiator.

  From the viewpoint of further improving the adhesion, the resin composition preferably contains a coupling agent.

  Examples of the coupling agent include silane coupling agents, titanium coupling agents, and aluminum coupling agents. From the viewpoint of further improving the adhesion, the resin composition preferably contains a silane coupling agent.

  Examples of the silane coupling agent include phenyl silane, vinyl silane, amino silane, imidazole silane, and epoxy silane.

  From the viewpoint of further improving the adhesion, the content of the coupling agent is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, preferably 100% by weight in the resin composition. It is 2% by weight or less, more preferably 1% by weight or less.

  From the viewpoint of effectively improving the coating property, further improving the uniformity of the thickness of the cured product, further improving the adhesion, and further suppressing the generation of voids, the resin composition contains a thixotropic agent. It is preferable.

  Examples of the thixotropic agent include inorganic particles such as metal particles, calcium carbonate, fumed silica, aluminum oxide, boron nitride, aluminum nitride, and aluminum borate.

  From the viewpoint of effectively improving the coating property, further improving the uniformity of the thickness of the cured product, further improving the adhesion, and further suppressing the generation of voids, the thixotropy in 100% by weight of the resin composition. The content of the imparting agent is preferably 0.1% by weight or more, more preferably 0.5% by weight or more, preferably 10% by weight or less, more preferably 5% by weight or less.

  The resin composition may be, for example, a filler, an extender, a softener, a plasticizer, a polymerization catalyst, a curing catalyst, a colorant, an antioxidant, a heat stabilizer, a light stabilizer, an ultraviolet absorber, Various additives such as a lubricant, an antistatic agent and a flame retardant may be included.

(Use of resin composition)
The resin composition can be used for various applications. The resin composition is preferably an adhesive or a coating material, and more preferably an adhesive. The resin composition is preferably an adhesive for electronic components or a coating material for electronic components, and more preferably an adhesive for electronic components. Since the said resin composition can make adhesive strength and adhesiveness high, it can be used suitably as an adhesive agent for electronic components.

  Since the effects of the present invention are particularly effectively exhibited, the resin composition is preferably used for adhesion of a ferrite core, and is preferably used for adhesion of a ferrite core in an inductor. When bonding a ferrite core in an inductor, a core material such as a ferrite core needs to be disposed with a gap. The resin composition is excellent in gap controllability, heat resistance, and coatability, and can be expected to have excellent performance for adhesion of a ferrite core in an inductor. The resin composition is preferably an inductor adhesive resin composition, and is preferably an inductor adhesive.

(Electronic parts)
The resin composition is preferably an adhesive for electronic parts. Examples of the electronic component include an inductor and a sensor chip.

  The inductor preferably includes a ferrite core and an adhesive portion that bonds the ferrite core. In the inductor, the material of the upper adhesive portion is preferably the above-described resin composition. The adhesive part is preferably a cured product of the resin composition. The adhesive portion is preferably formed by curing the resin composition.

  It is preferable that the ferrite core is disposed on the opposite surfaces of the adhesive portion. It is preferable that there is a gap in the ferrite core due to the adhesive portion.

  FIG. 1 is a cross-sectional view schematically showing an inductor using a resin composition according to an embodiment of the present invention.

  The inductor 1 shown in FIG. 1 includes a ferrite core 11, a ferrite core 12, and an adhesive portion 13. Inductor 1 includes a plurality of ferrite cores (ferrite core 11 and ferrite core 12). Inductor 1 includes a coil iron core for a transformer component. The ferrite core 11 is an E-type ferrite core. The ferrite core 12 is an I-type farite core. Of the three convex portions of the E-type ferrite core 11, the tips of the outer two convex portions and the side surface of the I-type ferrite core 12 are opposed to each other and have a gap. An adhesive portion 13 is disposed in this gap. The material of the bonding part 13 is the above-described resin composition. In the present embodiment, the thickness of the bonding portion 13 is equal to the particle diameter of the spacer particles included in the bonding portion 13. The spacer particles are in contact with both the ferrite core 11 and the ferrite core 12.

  Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. The present invention is not limited only to the following examples.

  The following materials were prepared.

(Bisphenol type epoxy compound)
Bisphenol type epoxy compound 1: Bisphenol E type epoxy resin, “R1710” manufactured by Printec Co., Ltd.
Bisphenol type epoxy compound 2: Bisphenol F type epoxy resin, “EXA830CRP” manufactured by DIC (“830CRP” in the table)
Bisphenol type epoxy compound 3: bisphenol A type epoxy resin, "Jer825" manufactured by Mitsubishi Chemical Corporation

(Epoxy compound different from bisphenol type epoxy compound)
Polyfunctional epoxy compound 1: Naphthalene type epoxy compound, “HP4710” manufactured by DIC
Polyfunctional epoxy compound 2: fluorene type epoxy compound, “ogsol PG100” manufactured by Osaka Gas Chemical Company (“PG100” in the table)
Polyfunctional epoxy compound 3: glycoluril type epoxy compound, “TG-G” manufactured by Shikoku Kasei Kogyo Co., Ltd.
Polyfunctional epoxy compound 4: dicyclopentadiene type epoxy compound, “HP7200” manufactured by DIC
Polyfunctional epoxy compound 5: phenol novolac type epoxy compound, “DEN431” manufactured by DOW
Multifunctional epoxy compound 6: Resorcinol type epoxy compound, “TDG-LC” manufactured by Kyoeisha Chemical Co., Ltd.

(Thermosetting agent)
Thermosetting agent 1: Imidazole curing accelerator, “2MZA” manufactured by Shikoku Kasei Kogyo Co., Ltd.
Thermosetting agent 2: Acid anhydride type curing agent, “YH307” manufactured by Mitsubishi Chemical Corporation

(Inorganic filler)
Inorganic filler 1: Silica, average particle size 1 μm, “SE-4050 SPE” manufactured by Admatechs (“4050 SPE” in the table)

(Spacer particles)
Spacer particles 1: Average particle size 20 μm, CV value 5%, 10% K value 3600 N / mm ² , “SP-220” manufactured by Sekisui Chemical Co., Ltd., resin particles Spacer particles 2: Average particle size 25 μm, CV value 7%, “SPM-25” manufactured by Union, glass particles

(solvent)
Solvent 1: Methyl ethyl ketone

(Examples 1-19 and Comparative Examples 1-7)
(1) Preparation of resin composition (adhesive) According to the compositions of Tables 1 to 3, an adhesive composition was obtained by stirring and mixing each material other than the spacers with a rotation and revolution mixer. The resin composition (adhesive) was produced by mix | blending spacer particle | grains with the obtained adhesive composition according to the composition of Tables 1-3, and stir-mixing using a rotation revolution mixer.

(2) Manufacture of inductor The obtained resin composition was filled into a 10 mL syringe (Musashi Engineering Co., Ltd.), and a precision nozzle (Musashi Engineering Co., Ltd., nozzle tip inner diameter 0.3 mm) was attached to the tip of the syringe. Using “SHOT MASTER300” manufactured by Musashi Engineering Co., Ltd., it was applied to the I-type core and bonded to the E-type core. Thereafter, it was cured in a reflow furnace to obtain an inductor.

(Evaluation)
(1) Viscosity The viscosity (η25) at 25 ° C. of the resin composition was measured using an E-type viscometer (“TVE22L” manufactured by Toki Sangyo Co., Ltd.) at 25 ° C. and 5 rpm.

(2) Glass transition temperature The adhesive was heated at 190 ° C for 30 minutes to obtain a cured product. The tan δ of the obtained cured product was measured using a dynamic viscoelasticity measuring device (manufactured by IT Measurement Control Co., Ltd.) at a heating rate of 10 ° C./min, a grip width of 20 mm, and a frequency of 5 Hz. The temperature at which tan δ was maximized was taken as the glass transition temperature.

(3) 5% weight reduction temperature The resin composition was heated at 190 ° C. for 30 minutes to obtain a cured product. About the obtained hardened | cured material, it measures on the conditions of the temperature range of 30 to 480 degreeC, and the temperature increase rate of 10 degree-C / min using the differential thermothermal weight simultaneous measurement apparatus ("TG-DTA6200" by Seiko Instruments Inc.). Thus, the 5% weight reduction temperature of the resin composition was evaluated. The 5% weight loss temperature was determined according to the following criteria.

[Criteria for 5% weight loss temperature]
○: 5% weight reduction temperature is 380 ° C. or more Δ: 5% weight reduction temperature is 360 ° C. or more and less than 380 ° C. ×: 5% weight reduction temperature is less than 360 ° C.

(4) High temperature adhesion (adhesion)
Using the obtained resin composition, it apply | coated to the test piece by SPCC-SB company, and test specimens were adhere | attached on the conditions for 30 minutes at 190 degreeC. After bonding, the shear strength was measured at a speed of 1 mm / min and 150 ° C. with a universal testing machine (Tensilon UTA manufactured by Orientec Co., Ltd.) to evaluate the high-temperature bonding strength. From the adhesive strength, the high temperature adhesive strength (adhesiveness) was determined according to the following criteria.

[Criteria for high-temperature adhesive strength]
○: High-temperature adhesive force is 10 MPa or more Δ: High-temperature adhesive force is 6 MPa or more and less than 10 MPa ×: High-temperature adhesive force is less than 6 MPa

(5) Gap controllability In the obtained inductor, using a laser displacement meter (“KS-1100” manufactured by KEYENCE Inc.), the gap distance after curing and the gap distance gap 3σ (σ: standard deviation) are measured. did. The gap controllability was evaluated from the variation 3σ in the gap distance / the value X of the gap distance after curing. Gap controllability was determined according to the following criteria.

[Criteria for gap controllability]
○○: Value X is less than 0.15 ○: Value X is 0.15 or more and less than 0.2 Δ: Value X is 0.2 or more and less than 0.4 ×: Value X is 0.4 or more

(6) Weight loss during curing (amount of volatile components)
The resin composition was heated at 190 ° C. for 30 minutes to obtain a cured product. The amount of volatile components in the resin composition was evaluated by measuring the weight loss of the cured product relative to the resin composition before curing. The weight loss at the time of curing was judged according to the following criteria.

[Criteria for weight reduction during curing]
○: Weight reduction is 2% or less △: Weight reduction is over 2% and 5% or less ×: Weight reduction is over 5%

  Details and results are shown in Tables 1 to 3 below.

1 ... Inductor 11 ... Ferrite core (E type)
12 ... Ferrite core (type I)
13: Adhesive part

Claims (11)

A bisphenol-type epoxy compound,
A polyfunctional epoxy compound different from the bisphenol type epoxy compound,
A thermosetting agent,
The viscosity at 25 ° C. is 40 Pa · s or less,
The resin composition whose glass transition temperature of the said hardened | cured material is 170 degreeC or more when it hardens | cures at 190 degreeC for 30 minutes and obtained hardened | cured material.   The resin composition according to claim 1, wherein the polyfunctional epoxy compound has a naphthalene skeleton, a fluorene skeleton, a glycoluril skeleton, a dicyclopentadiene skeleton, or a phenol novolac skeleton.   The resin composition according to claim 1 or 2, wherein the bisphenol type epoxy compound is a bisphenol A type epoxy compound, a bisphenol F type epoxy compound, or a bisphenol E type epoxy compound.   The weight reduction of the said hardened | cured material with respect to the resin composition before hardening is 5 weight% or less when it hardens | cures for 30 minutes at 190 degreeC, and is any one of Claims 1-3. Resin composition.   The ratio of the content of the polyfunctional epoxy compound to the content of the bisphenol-type epoxy compound is 1/9 or more and 4/6 or less on a weight basis. Resin composition.   The resin according to any one of claims 1 to 5, wherein when a cured product is obtained by curing at 190 ° C for 30 minutes, a 5% weight loss temperature by thermogravimetric analysis of the cured product is 360 ° C or higher. Composition.   The resin composition according to claim 1, comprising spacer particles.   The resin composition according to claim 1, which is an adhesive for electronic parts.   The resin composition of any one of Claims 1-8 used for adhesion | attachment of a ferrite core.   The resin composition according to claim 1, which is used for bonding a ferrite core in an inductor. A ferrite core,
With an adhesive part adhering the ferrite core,
The inductor whose material of the said adhesion part is the resin composition of any one of Claims 1-10.

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