Resin composition

Abstract

An object of the present invention is to provide a resin composition capable of obtaining a cured product having excellent impact resistance. The solution of the present invention is a resin composition comprising (A) an epoxy resin, (B) a thiol compound, and (C) a magnetic powder, wherein the elastic modulus of the cured product of the resin composition at 25°C is 500 MPa or less, and the elongation at break of the cured product of the resin composition at 25°C is 30% or more.

Description

Technical Field

[0001] The present invention relates to a resin composition containing magnetic powder. Further, the present invention relates to a cured product, an electronic component, a motor including a neodymium magnet, etc. obtained by using the resin composition. Background Art

[0002] In electronic components having a magnetic circuit such as a permanent magnet and a yoke, a problem with the use of a conventional adhesive is that magnetic flux leakage occurs in the electronic component using the adhesive, resulting in a decrease in the performance of electronic components such as a motor due to magnetic loss.

[0003] Regarding such a problem, a technique is known in which magnetic powder is added to an adhesive to make the adhesive magnetic, suppressing magnetic leakage in the bonding portion of the magnetic circuit and improving the performance of electronic components such as a motor (Patent Document 1).

[0004] Generally, when used in a camera module or the like, an adhesive with low elasticity is preferred for impact resistance. However, if magnetic powder is filled in the adhesive, the cured product of the adhesive becomes hard and tends to have a high elastic modulus.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Japanese Patent Laid-Open No. 1-289883. Summary of the Invention

[0008] Problems to be Solved by the Invention

[0009] Therefore, an object of the present invention is to provide a resin composition containing magnetic powder and capable of obtaining a cured product having excellent impact resistance.

[0010] Means for Solving the Problems

[0011] As a result of intensive studies to achieve the object of the present invention, the present inventors have found that the problems of the present invention can be solved by using a resin composition containing a thiol compound, and thus completed the present invention.

[0012] That is, the present invention includes the following.

[0013] [1] A resin composition comprising (A) an epoxy resin, (B) a thiol compound, and (C) magnetic powder,

[0014] The elastic modulus of the cured product of the resin composition at 25°C is 500 MPa or less, and

[0015] The elongation at break of the cured product of the resin composition at 25°C is 30% or more.

[0016] [2] The resin composition according to [1] above, wherein the epoxy equivalent of component (A) is 200 g / eq. to 1000 g / eq.

[0017] [3] The resin composition according to [1] or [2] above, wherein component (B) is a thiol compound having two or more functional groups.

[0018] [4] The resin composition according to any one of [1] to [3] above, wherein the ratio of the total number of mercapto groups of the thiol compound (B) to the total number of epoxy groups of the epoxy resin (A) (mercapto group / epoxy group) is 0.3 to 1.0.

[0019] [5] The resin composition according to any one of [1] to [4] above, wherein the content of component (C) is 40% by mass to 75% by mass when the non-volatile components in the resin composition are taken as 100% by mass.

[0020] [6] The resin composition according to any one of [1] to [5] above, which further contains a latent curing accelerator.

[0021] [7] The resin composition according to any one of [1] to [6] above, wherein component (A) contains (A-1) an epoxy resin having a flexible skeleton.

[0022] [8] The resin composition according to any one of [1] to [7] above, wherein the reaction peak temperature based on differential scanning calorimetry is 100°C or lower.

[0023] [9] The resin composition according to any one of [1] to [8] above, which is used as an adhesive.

[0024]

[10] The resin composition according to [9] above, which is used as an adhesive for bonding neodymium magnets as adherends.

[0025]

[11] The resin composition according to any one of [1] to [8] above, which is used as a sealing material.

[0026]

[12] A cured product of the resin composition according to any one of [1] to

[11] above.

[0027]

[13] A motor containing a neodymium magnet, which contains the cured product according to

[12] above.

[0028]

[14] An electronic component, which contains the cured product according to

[12] above.

[0029]

[15] An electronic component, which contains a motor containing a neodymium magnet and the cured product according to

[12] above.

[0030] Advantages of the Invention

[0031] According to the present invention, there is provided a resin composition containing magnetic powder and capable of obtaining a cured product having excellent impact resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a DSC chart showing the differential scanning calorimetry curve (DSC curve) before and after curing of the resin composition obtained in Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0033] Hereinafter, the present invention will be described in detail according to its suitable embodiments. However, the present invention is not limited to the following embodiments and illustrative examples, and can be arbitrarily modified within the scope of the claims of the present invention and their equivalent scope.

[0034] <Resin Composition>

[0035] The resin composition of the present invention contains (A) an epoxy resin, (B) a thiol compound, and (C) magnetic powder. The elastic modulus at 25°C of the cured product of the resin composition of the present invention is 500 MPa or less. The elongation at break at 25°C of the cured product of the resin composition of the present invention is 30% or more. The cured product of such a resin composition has excellent impact resistance.

[0036] In addition to (A) an epoxy resin, (B) a thiol compound, and (C) magnetic powder, the resin composition of the present invention may further contain (D) a stabilizer, (E) a dispersant, (F) a curing accelerator, (G) an organic filler, (H) other additives, and (I) an organic solvent. Hereinafter, each component contained in the resin composition will be described in detail.

[0037] <(A) Epoxy Resin>

[0038] The resin composition of the present invention contains (A) an epoxy resin. (A) An epoxy resin refers to a curable resin having an epoxy group.

[0039] (A) The epoxy equivalent of the epoxy resin is not particularly limited. From the viewpoint of suppressing the elastic modulus to a low level and increasing the elongation at break point, it is preferably 50 g / eq. or more, more preferably 100 g / eq. or more, further preferably 150 g / eq. or more, still further preferably 180 g / eq. or more, and particularly preferably 200 g / eq. or more. The upper limit of the epoxy equivalent of (A) the epoxy resin is not particularly limited. In the case of using it as an adhesive or a sealing material, from the viewpoint of obtaining a resin composition that is easier to handle, it is preferably 5000 g / eq. or less, more preferably 2000 g / eq. or less, further preferably 1000 g / eq. or less, still further preferably 700 g / eq. or less, and particularly preferably 500 g / eq. or less. The epoxy equivalent is the mass of the resin per 1 equivalent of epoxy groups on average. The epoxy equivalent can be measured in accordance with JIS K7236.

[0040] (A) The weight average molecular weight (Mw) of the epoxy resin is preferably 100 to 5,000, more preferably 250 to 3,000, and further preferably 400 to 1,500. The weight average molecular weight of the resin can be measured by gel permeation chromatography (GPC) method as a value in terms of polystyrene conversion.

[0041] The content of (A) the epoxy resin in the resin composition is not particularly limited. When the non-volatile components in the resin composition are taken as 100% by mass, it is preferably 99% by mass or less, more preferably 90% by mass or less, further preferably 80% by mass or less, still further preferably 65% by mass or less, and particularly preferably 50% by mass or less. The lower limit of the content of (A) the epoxy resin in the resin composition is not particularly limited. When the non-volatile components in the resin composition are taken as 100% by mass, it is preferably 1% by mass or more, more preferably 5% by mass or more, further preferably 10% by mass or more, still further preferably 20% by mass or more, and particularly preferably 30% by mass or more. In one embodiment, the content of (A) the epoxy resin can be set based on the content and thiol equivalent of (B) the thiol compound.

[0042] <(A-1) Epoxy resin containing a flexible skeleton>

[0043] In the present invention, from the viewpoint of suppressing the elastic modulus to a lower level and further increasing the elongation at break, the epoxy resin (A) preferably contains an epoxy resin (A-1) having a flexible skeleton. The epoxy resin (A-1) having a flexible skeleton refers to a curable resin having a flexible skeleton and an epoxy group. The flexible skeleton herein may be, for example, a saturated chain skeleton containing 6 or more (preferably 8 or more) skeleton atoms selected from carbon atoms and oxygen atoms in the main chain. The epoxy resin (A-1) having a flexible skeleton preferably has 1 to 5, more preferably 1 to 3, and particularly preferably 2 epoxy groups in one molecule. The epoxy resin (A-1) having a flexible skeleton may further have functional groups such as hydroxyl groups and amino groups.

[0044] As the epoxy resin (A-1) having a flexible skeleton, for example, an aromatic epoxy resin (A-1-1) having a flexible skeleton (having an aromatic ring) and a non-aromatic epoxy resin (A-1-2) having a flexible skeleton (not having an aromatic ring) can be cited. The epoxy resin (A-1) having a flexible skeleton can be used alone or in combination of two or more in any ratio.

[0045] (A-1-1) The aromatic epoxy resin having a flexible skeleton is an epoxy resin having at least one aromatic group (such as a phenylene group, etc.) and at least one saturated chain skeleton containing 6 or more (preferably 8 or more) skeleton atoms selected from carbon atoms and oxygen atoms in the main chain.

[0046] As the aromatic epoxy resin (A-1-1) having a flexible skeleton, for example, a modified bisphenol type epoxy resin having a flexible skeleton, a modified biphenyl type epoxy resin having a flexible skeleton, a modified novolac type epoxy resin having a flexible skeleton, a modified phenol aralkyl type epoxy resin having a flexible skeleton, etc. can be cited, and there is no particular limitation.

[0047] The modified bisphenol type epoxy resin having a flexible skeleton has, for example, a bisphenol ether skeleton such as a bisphenol A ether structure, a bisphenol AP ether structure, a bisphenol B ether structure, a bisphenol BP ether structure, a bisphenol C ether structure, a bisphenol E ether structure, a bisphenol F ether structure, a bisphenol TMC ether structure, etc.

[0048] (A-1-1) The aromatic epoxy resin having a flexible skeleton may be, for example, an epoxy resin represented by the formula (1):

[0049]

Chemical 1

[0050]

[0051] [In the formula, each R independently represents a single bond, -CR 1 2 -, -O-, -CO-, -S-, -SO-, or -SO 2 -, R 1Each independently represents a hydrogen atom, an alkyl group (preferably having 1 to 6 carbon atoms) or an aryl group (preferably having 6 to 14 carbon atoms), or two Rs bonded to the same carbon atom 1 bond together to form a cycloalkane ring (preferably having 3 to 8 carbon atoms), R 2 each independently represents an alkyl group (preferably having 1 to 6 carbon atoms) or an aryl group (preferably having 6 to 14 carbon atoms), X and Y each independently represent an alkylene group optionally having a hydroxyl group (preferably having 2 to 20 carbon atoms, more preferably having 2 to 10 carbon atoms), a each independently represents an integer of 0 or more, b each independently represents an integer of 2 or more, c represents an integer of 1 or more, and d each independently represents an integer of 0 to 3].

[0052] Alkyl refers to a straight-chain, branched-chain, and / or cyclic monovalent aliphatic saturated hydrocarbon group.

[0053] Examples of the alkyl group include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, neopentyl, sec-pentyl, tert-pentyl, cyclopentyl, cyclohexyl, etc., and preferably methyl. Aryl refers to a monovalent aromatic hydrocarbon group. Examples of the aryl group include phenyl, 1-naphthyl, 2-naphthyl, etc., and preferably phenyl. Cycloalkane ring refers to a cyclic aliphatic saturated hydrocarbon ring. Examples of the cycloalkane ring include cyclopentane ring, cyclohexane ring, cycloheptane ring, methylcyclohexane ring, dimethylcyclohexane ring, trimethylcyclohexane ring, etc. Alkylene refers to a straight-chain or branched-chain divalent aliphatic saturated hydrocarbon group. Examples of the alkylene group optionally having a hydroxyl group include -CH 2 -CH 2 -, -CH(CH 3 )-, -CH 2 -CH 2 -CH 2 -, -CH 2 -CH(CH 3 )-, -CH(CH 3 )-CH 2 -, -C(CH 3 ) 2 -, -CH 2 -CH 2 -CH 2 -CH 2 -, -CH 2 -CH 2 -CH(CH 3 )-, -CH 2 -CH(CH 3 )-CH 2 -, -CH(CH 3 )-CH 2 -CH 2 -, -CH2 -C(CH 3 ) 2 -、-C(CH 3 ) 2 -CH 2 -、-CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -、-CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -、-CH 2 -CH(CH 3 )-CH 2 -CH(CH 3 )-CH 2 -CH(CH 3 )-、-CH(CH 3 )-CH 2 -CH(CH 3 )-CH 2 -CH(CH 3 )-CH 2 -、-CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -、-CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -、-CH 2 -CH(CH 3 )-CH 2 -CH(CH 3 )-CH 2 -CH(CH 3 )-CH 2 -CH(CH 3 )-、-CH(CH 3 )-CH 2 -CH(CH 3 )-CH 2 -CH(CH 3 )-CH 2 -CH(CH3 )-CH 2 -,-CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -,-CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -and other alkylene groups having 2 to 10 carbon atoms; -CH 2 -CH(OH)-, -CH(OH)-CH 2 -,-CH 2 -CH(OH)-CH 2 -,-CH(CH 2 OH)-CH 2 -,-CH 2 -CH(CH 2 OH)-,-CH 2 -CH(CH 2 OH)-CH 2 -and other hydroxyalkylene groups having 2 to 10 carbon atoms.

[0054] In formula (1), each R is independently preferably -CR 1 -. R 1 Each is independently preferably a hydrogen atom or an alkyl group, more preferably a hydrogen atom or a methyl group. R 2 Each is independently preferably an alkyl group. Each a is independently preferably an integer from 0 to 20 (0 or an integer from 1 to 20), more preferably an integer from 0 to 10 (0 or an integer from 1 to 10). Each b is independently preferably an integer from 3 to 20, more preferably an integer from 3 to 10. c is preferably an integer from 1 to 20, more preferably an integer from 1 to 10, and further preferably an integer from 1 to 8. Each d is independently preferably 0 or 1, more preferably 0.

[0055] As specific examples of the flexible backbone-containing aromatic epoxy resin (A-1-1), epoxy resins represented by formulas (1A) to (1G) can be cited:

[0056]

Chemical 2

[0057]

[0058] [In the formula, R 3 , R 4 and R 5 each independently represent a hydrogen atom or a methyl group, x represents an integer from 1 to 10, and y each independently represents an integer from 1 to 10].

[0059] (A-1-2) The non-aromatic epoxy resin containing a flexible skeleton is an epoxy resin having a saturated aliphatic chain containing skeleton atoms selected from carbon atoms and oxygen atoms as a basic skeleton. As the aromatic epoxy resin containing a flexible skeleton, for example, alkane diol diglycidyl ethers such as ethylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether; polyalkylene glycol diglycidyl ethers such as polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, polybutylene glycol diglycidyl ether, etc. can be mentioned.

[0060] (A-1-2) The non-aromatic epoxy resin containing a flexible skeleton can be, for example, the epoxy resin represented by the formula (2):

[0061] [Chemical Formula 3]

[0062]

[0063] [In the formula, Z each independently represents an alkylene group optionally having a hydroxyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 10 carbon atoms), and e represents an integer of 1 or more].

[0064] In the formula (2), Z each independently preferably represents an alkylene group (preferably having 2 to 20 carbon atoms, more preferably 2 to 10 carbon atoms). e is preferably an integer from 1 to 20.

[0065] As commercially available products of the (A-1) epoxy resin containing a flexible skeleton, for example, "EP-4000S", "EP-4010S" (modified bisphenol type epoxy resin) manufactured by ADEKA Corporation; "YL7175-500", "YL7175-1000", "YL7410", "YX7105" (modified bisphenol type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "EXA-4850", "EXA-4850-150", "EXA-4816", "EXA-4822" (modified bisphenol type epoxy resin) manufactured by DIC Corporation; "EG-280" manufactured by Osaka Gas Chemical Co., Ltd.; "EX-830" (modified bisphenol type epoxy resin) manufactured by Nagase ChemteX Corporation; "YX7400" (polybutylene glycol diglycidyl ether) manufactured by Mitsubishi Chemical Corporation, etc. can be mentioned.

[0066] (A-1) The epoxy equivalent of the epoxy resin containing a flexible skeleton is not particularly limited, preferably 50 g / eq. or more, more preferably 100 g / eq. or more, further preferably 200 g / eq. or more, still further preferably 300 g / eq. or more, and particularly preferably 400 g / eq. or more. The lower limit of the epoxy equivalent of the epoxy resin containing a flexible skeleton is not particularly limited, preferably 5000 g / eq. or less, more preferably 2000 g / eq. or less, further preferably 1000 g / eq. or less, still further preferably 700 g / eq. or less, and particularly preferably 500 g / eq. or less. The epoxy equivalent is the mass of the resin for an average of 1 equivalent of epoxy groups. The epoxy equivalent can be measured in accordance with JIS K7236.

[0067] (A-1) The weight-average molecular weight (Mw) of the epoxy resin containing a flexible skeleton is preferably 100 to 5,000, more preferably 250 to 3,000, and further preferably 400 to 1,500. The weight-average molecular weight of the resin can be measured as a value in terms of polystyrene by gel permeation chromatography (GPC).

[0068] The content of the epoxy resin (A-1) containing a flexible skeleton in the resin composition is not particularly limited. When the non-volatile components in the resin composition are taken as 100% by mass, it is preferably 70% by mass or less, more preferably 60% by mass or less, further preferably 55% by mass or less, still further preferably 50% by mass or less, and particularly preferably 45% by mass or less. The lower limit of the content of the epoxy resin (A-1) containing a flexible skeleton in the resin composition is not particularly limited. When the non-volatile components in the resin composition are taken as 100% by mass, it is preferably 0.1% by mass or more, more preferably 1% by mass or more, further preferably 5% by mass or more, still further preferably 8% by mass or more, and particularly preferably 10% by mass or more.

[0069] <(A-2) Other optional epoxy resins>

[0070] In the present invention, the epoxy resin (A) may contain other optional epoxy resins (A-2) in addition to the epoxy resin (A-1) containing a flexible skeleton.

[0071] As the (A-2) other optional epoxy resins, for example, bis-o-cresol type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol AF type epoxy resin, dicyclopentadiene type epoxy resin, triphenol type epoxy resin, naphthol novolak type epoxy resin, phenol novolak type epoxy resin, tert-butyl-catechol type epoxy resin, naphthalene type epoxy resin, naphthol type epoxy resin, anthracene type epoxy resin, glycidylamine type epoxy resin, glycidyl ester type epoxy resin, cresol novolak type epoxy resin, phenol aralkyl type epoxy resin, biphenyl type epoxy resin, linear aliphatic epoxy resin, epoxy resin having a butadiene structure, alicyclic epoxy resin, heterocyclic epoxy resin, epoxy resin containing a spiro ring, cyclohexane type epoxy resin, cyclohexanedimethanol type epoxy resin, naphthalene ether type epoxy resin, trimethylol type epoxy resin, tetraphenylethane type epoxy resin, isocyanurate type epoxy resin, phenol phthalimide type epoxy resin, phenolphthalein type epoxy resin, etc. can be cited. The (A-2) other optional epoxy resins can be used alone as 1 kind, or 2 or more kinds can be used in combination.

[0072] As the (A-2) other optional epoxy resins of the resin composition, an epoxy resin having 2 or more epoxy groups in 1 molecule is preferably contained. With respect to 100% by mass of the (A-2) other optional epoxy resins, the proportion of the epoxy resin having 2 or more epoxy groups in 1 molecule is preferably 50% by mass or more, more preferably 60% by mass or more, and particularly preferably 70% by mass or more.

[0073] (A-2) The other optional epoxy resins can be classified into epoxy resins that are liquid at 20°C (hereinafter sometimes referred to as "liquid epoxy resins") and epoxy resins that are solid at 20°C (hereinafter sometimes referred to as "solid epoxy resins"). As the (A-2) other optional epoxy resins of the resin composition of the present invention, it may contain only liquid epoxy resins, or may contain only solid epoxy resins, or may contain a combination of liquid epoxy resins and solid epoxy resins.

[0074] As the liquid epoxy resin, a liquid epoxy resin having 2 or more epoxy groups in 1 molecule is preferred.

[0075] As the liquid epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, naphthalene type epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, phenol novolak type epoxy resin, alicyclic epoxy resin having an ester skeleton, cyclohexane type epoxy resin, cyclohexanedimethanol type epoxy resin, and epoxy resin having a butadiene structure are preferred.

[0076] As specific examples of the liquid epoxy resin, “HP4032”, “HP4032D”, “HP4032SS” (naphthalene-type epoxy resin) manufactured by DIC Corporation can be cited; “828US”, “828EL”, “jER828EL”, “825”, “Epicoat 828EL” (bisphenol A-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; “jER807”, “1750” (bisphenol F-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; “jER152” (phenol novolac-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; “630”, “630LSD”, “604” (glycidylamine-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; “ED-523T” (glycyl-type epoxy resin) manufactured by ADEKA Corporation; “EP-3950L”, “EP-3980S” (glycidylamine-type epoxy resin) manufactured by ADEKA Corporation; “EP-4088S” (dicyclopentadiene-type epoxy resin) manufactured by ADEKA Corporation; “ZX1059” (a mixture of bisphenol A-type epoxy resin and bisphenol F-type epoxy resin) manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.; “EX-721” (glycidyl ester-type epoxy resin) manufactured by Nagase ChemteX Corporation; “Celloxide 2021P” (alicyclic epoxy resin having an ester skeleton) manufactured by Daicel Corporation; “PB-3600” manufactured by Daicel Corporation, “JP-100”, “JP-200” (epoxy resin having a butadiene structure) manufactured by Nippon Soda Co., Ltd.; “ZX1658”, “ZX1658GS” (liquid 1,4-glycidylcyclohexane-type epoxy resin) manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., etc. They can be used alone, or two or more of them can be used in combination.

[0077] As the solid epoxy resin, a solid epoxy resin having 3 or more epoxy groups in one molecule is preferred, and an aromatic solid epoxy resin having 3 or more epoxy groups in one molecule is more preferred.

[0078] As the solid epoxy resin, a bisdimethylphenol-type epoxy resin, naphthalene-type epoxy resin, naphthalene-type tetrafunctional epoxy resin, naphthol novolac-type epoxy resin, cresol novolac-type epoxy resin, dicyclopentadiene-type epoxy resin, triphenol-type epoxy resin, naphthol-type epoxy resin, biphenyl-type epoxy resin, naphthalene ether-type epoxy resin, anthracene-type epoxy resin, bisphenol A-type epoxy resin, bisphenol AF-type epoxy resin, phenol aralkyl-type epoxy resin, tetraphenylethane-type epoxy resin, phenol phthalimide-type epoxy resin, phenolphthalein-type epoxy resin are preferred.

[0079] As specific examples of solid epoxy resins, there can be mentioned "HP4032H" (naphthalene-type epoxy resin) manufactured by DIC Corporation; "HP-4700", "HP-4710" (tetrafunctional naphthalene-type epoxy resin) manufactured by DIC Corporation; "N-690" (cresol novolak-type epoxy resin) manufactured by DIC Corporation; "N-695" (cresol novolak-type epoxy resin) manufactured by DIC Corporation; "HP-7200", "HP-7200HH", "HP-7200H", "HP-7200L" (dicyclopentadiene-type epoxy resin) manufactured by DIC Corporation; "EXA-7311", "EXA-7311-G3", "EXA-7311-G4", "EXA-7311-G4S", "HP6000" (naphthalene ether-type epoxy resin) manufactured by DIC Corporation; "EPPN-502H" (triphenol-type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "NC7000L" (naphthol novolak-type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "NC3000H", "NC3000", "NC3000L", "NC3000FH", "NC3100" (biphenyl-type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "ESN475V" (naphthalene-type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "ESN485" (naphthol-type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "ESN375" (dihydroxynaphthalene-type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "YX4000H", "YX4000", "YX4000HK", "YL7890" (bisdimethylphenol-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YL6121" (biphenyl-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YX8800" (anthracene-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YX7700" (phenol aralkyl-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "PG-100", "CG-500" manufactured by Osaka Gas Chemical Co., Ltd.; "YL7760" (bisphenol AF-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YL7800" (fluorene-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "jER1010" (bisphenol A-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "jER1031S" (tetraphenylethane-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "WHR991S" (phenol phthalimide-type epoxy resin) manufactured by Nippon Kayaku Co., Ltd., etc. They can be used individually, or two or more of them can be used in combination.

[0080] (A-2) The epoxy equivalent of other optional epoxy resins is preferably 50 g / eq. to 5,000 g / eq., more preferably 60 g / eq. to 2,000 g / eq., further preferably 70 g / eq. to 1,000 g / eq., and still further preferably 80 g / eq. to 500 g / eq. The epoxy equivalent is the mass of the resin for an average of 1 equivalent of epoxy groups. This epoxy equivalent can be measured in accordance with JIS K7236.

[0081] (A-2) The weight average molecular weight (Mw) of other optional epoxy resins is preferably 100 to 5,000, more preferably 250 to 3,000, and further preferably 400 to 1,500. The weight average molecular weight of the resin can be measured as a value in terms of polystyrene by gel permeation chromatography (GPC) method.

[0082] The content of (A-2) other optional epoxy resins in the resin composition is not particularly limited. When the non-volatile components in the resin composition are taken as 100% by mass, it is preferably 50% by mass or less, more preferably 40% by mass or less, further preferably 30% by mass or less, still further preferably 20% by mass or less, and particularly preferably 15% by mass or less. The lower limit of the content of (A-2) other optional epoxy resins in the resin composition is not particularly limited, and can be, for example, 0% by mass or more, 0.01% by mass or more, 0.1% by mass or more, 0.5% by mass or more, 1% by mass or more, 3% by mass or more, 5% by mass or more, etc. when the non-volatile components in the resin composition are taken as 100% by mass.

[0083] When the resin composition contains (A-2) other optional epoxy resins, the mass ratio of (A-2) other optional epoxy resins to (A-1) epoxy resin containing a flexible skeleton in the resin composition ((A-2) / (A-1)) can be preferably 2 or less, more preferably 1.5 or less, further preferably 1 or less, and particularly preferably 0.7 or less.

[0084] <(B) Thiol compound>

[0085] The resin composition of the present invention contains (B) thiol compound. When (B) thiol compound is used as a curing agent for (A) epoxy resin, it can be cured at a lower temperature and the reduction of magnetism can be inhibited.

[0086] (B) A thiol compound refers to an organic compound having a mercapto group (-SH). From the perspective of obtaining excellent epoxy curability, a thiol compound having two or more functional groups is preferred, and from the perspective of further increasing the crosslink density, a thiol compound having three or more functional groups is more preferred. When the number of functional groups is shown in the description of (B) thiol compounds, the number of mercapto groups (-SH) contained in one molecule is used as the basis. In addition, such a thiol compound is preferably a primary and / or secondary thiol compound from the perspective of improving reactivity.

[0087] (B) Among thiol compounds, there are also substances that contain not only a saturated hydrocarbon structure but also an unsaturated hydrocarbon structure. (B) Thiol compounds also include substances containing a linear, branched, and / or cyclic structure (such as an isocyanuric acid structure, a glycoluril structure, a benzene ring structure, etc.). In one embodiment, from the perspective of further improving impact resistance, a thiol compound that does not contain a cyclic structure (a substance containing a linear and / or branched chain and no cyclic structure) is preferred. (B) Thiol compounds can be non-aromatic thiol compounds (without an aromatic ring) or aromatic thiol compounds (containing an aromatic ring). In one embodiment, from the perspective of further improving impact resistance, non-aromatic thiol compounds (without an aromatic ring) are preferred. (B) Thiol compounds may have functional groups such as a hydroxyl group, a carboxyl group, or an amino group in addition to the mercapto group, and in one embodiment, it is preferably not to have them.

[0088] Examples of (B) thiol compounds include hydrocarbon thiol compounds, thiol compounds containing an ether structure, thiol compounds containing a thioether structure, thiol compounds containing an amine, thiol compounds containing an alcohol, thiol compounds containing a carboxylic acid ester structure, thiol compounds containing an isocyanurate structure, thiol compounds containing a carboxylic acid ester structure and an isocyanurate structure, thiol compounds containing a glycoluril structure, etc. (B) Thiol compounds can be used alone or in combination of two or more in any ratio.

[0089] Hydrocarbon thiol compounds refer to thiol compounds having a hydrocarbon as the basic skeleton, and examples include bifunctional hydrocarbon thiol compounds such as 1,4-butanedithiol, 1,6-hexanedithiol, 1,8-octanedithiol, 1,10-decanedithiol, 2,2-dimethylpropane-1,3-dithiol, 1,4-cyclohexanedithiol, 1,2-cyclohexanedithiol, m-xylene-α,α'-dithiol, p-xylene-α,α'-dithiol, etc.; trifunctional hydrocarbon thiol compounds such as 2-mercaptomethyl-1,3-propanedithiol, 2-ethyl-2-(mercaptomethyl)-1,3-propanedithiol, 2-mercaptomethyl-1,4-butanedithiol, 1,2,3-propanetrithiol, etc.; tetrafunctional hydrocarbon thiol compounds such as tetrakis(mercaptomethyl)methane, 2,2-bis(mercaptomethyl)-1,3-propanedithiol, etc.

[0090] A mercapto compound containing an ether structure refers to a mercapto compound having an ether structure, and examples thereof include bifunctional mercapto compounds containing an ether structure such as 3,6-dioxa-1,8-octanedithiol, 3,6,9-trioxaundecane-1,11-dithiol, 3,4-dimethoxybutane-1,2-dithiol, 2,3-dimercaptopropyl methyl ether, bis(2-mercaptoethyl) ether, bis[4-(2-mercaptoethyloxy)phenyl]methane, bis[4-(3-mercaptopropyloxy)phenyl]methane, 2,2-bis[4-(2-mercaptoethyloxy)phenyl]propane, 2,2-bis[4-(3-mercaptopropyloxy)phenyl]propane; trifunctional mercapto compounds containing an ether structure such as (2-mercaptoethyl)(2,3-dimercaptopropyl) ether, trimethylolpropane tris(2-mercaptoethyl) ether, trimethylolethane tris(2-mercaptoethyl) ether, trimethylolpropane tris(3-mercaptopropyl) ether, trimethylolethane tris(3-mercaptopropyl) ether, trimethylolpropane tris(4-mercaptobutyl) ether, trimethylolethane tris(4-mercaptobutyl) ether, glycerol tris(3-mercaptopropyl) ether, glycerol tris(4-mercaptobutyl) ether, trimethylolpropane tris(2-mercaptopropyl) ether, trimethylolethane tris(2-mercaptopropyl) ether, trimethylolpropane tris(3-mercaptobutyl) ether, trimethylolethane tris(3-mercaptobutyl) ether, glycerol tris(2-mercaptopropyl) ether, glycerol tris(3-mercaptobutyl) ether; tetrafunctional mercapto compounds containing an ether structure such as bis(2,3-dimercaptopropyl) ether, pentaerythritol tetrakis(2-mercaptoethyl) ether, pentaerythritol tetrakis(3-mercaptopropyl) ether, pentaerythritol tetrakis(4-mercaptobutyl) ether, pentaerythritol tetrakis(2-mercaptopropyl) ether, pentaerythritol tetrakis(3-mercaptobutyl) ether; polyfunctional mercapto compounds containing an ether structure with 5 or more functional groups such as dipentaerythritol hexa(3-mercaptopropyl) ether, dipentaerythritol hexa(2-mercaptopropyl) ether.

[0091] A thiol compound containing a thioether structure refers to a thiol compound having a thioether structure. Examples thereof include bifunctional thiol compounds containing a thioether structure such as bis(2-mercaptoethyl) sulfide, 3,6-dithia-1,8-octanedithiol, 3,6,9-trithiaundecane-1,11-dithiol, 1,4-dithiane-2,5-bis(methanethiol); trifunctional thiol compounds containing a thioether structure such as 4-(2-mercaptoethyl)-3,6-dithia-1,8-octanedithiol, 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol; tetrafunctional thiol compounds containing a thioether structure such as 1,2,6,7-tetramercapto-4-thiaheptane, 4,7-bis(mercaptomethyl)-3,6,9-trithiaundecane-1,11-dithiol, 5,7-bis(mercaptomethyl)-3,6,9-trithiaundecane-1,11-dithiol, 2,6-bis(mercaptomethyl)-3,5-dithiaheptane-1,7-dithiol, 3,5-bis(mercaptomethylthio)-2,6-dithiaheptane-1,7-dithiol; polyfunctional thiol compounds containing a thioether structure with 5 or more functional groups such as 1,2,9,10-tetramercapto-6-mercaptomethyl-4,7-dithiadodecane, 1,2,6,10,11-pentamercapto-4,8-dithioundecane, 1,2,9,13,14-pentamercapto-6-mercaptomethyl-4,7,11-trithiadecane, 1,2,6,10,14,15-hexamercapto-4,8,12-trithiapentadecane, etc.

[0092] A thiol compound containing an amine refers to a thiol compound having an amine structure (preferably a secondary amine structure or a tertiary amine structure) (optionally further having an ether structure or a thioether structure). Examples thereof include bifunctional thiol compounds containing an amine such as bis[4-(3-phenoxy-2-mercaptopropylamino)phenyl]methane, bis{4-[3-(4-methylphenoxy)-2-mercaptopropylamino]phenyl}methane, 1,4-bis(3-phenoxy-2-mercaptopropylamino)benzene, etc.

[0093] A thiol compound containing an alcohol refers to a thiol compound having a hydroxyl group (optionally further having an ether structure or a thioether structure). Examples thereof include bifunctional thiol compounds containing an alcohol such as 1,3-dimercapto-2-propanol, 2,3-dimercapto-1-propanol, 2,2-bis(mercaptomethyl)-1,3-propanediol; trifunctional thiol compounds containing an alcohol such as pentaerythritol tris(3-mercaptopropyl) ether, 3-mercapto-2,2-bis(mercaptomethyl)-1-propanol, etc.

[0094] A thiol compound containing a carboxylic acid ester structure refers to a thiol compound having a carboxylic acid ester structure (optionally further having an ether structure or a thioether structure), and examples thereof include bis(2-mercaptoethyl) succinate, bis(2-mercaptoethyl) phthalate, bis(3-mercaptopropyl) phthalate, bis(4-mercaptobutyl) phthalate, ethylene glycol bis(mercaptoacetate), ethylene glycol bis(3-mercaptopropionate), ethylene glycol bis(4-mercaptobutyrate), propylene glycol bis(3-mercaptopropionate), propylene glycol bis(4-mercaptobutyrate), diethylene glycol bis(3-mercaptopropionate), diethylene glycol bis(4-mercaptobutyrate), tetraethylene glycol bis(3-mercaptopropionate), 1,4-butanediol bis(mercaptoacetate), 1,4-butanediol bis(3-mercaptopropionate), 1,4-butanediol bis(4-mercaptobutyrate), 1,8-octanediol bis(3-mercaptopropionate), 1,8-octanediol bis(4-mercaptobutyrate), bis(1-mercaptoethyl) phthalate, bis(2-mercaptopropyl) phthalate, bis(3-mercaptobutyl) phthalate, ethylene glycol bis(2-mercaptopropionate), ethylene glycol bis(3-mercaptobutyrate), propylene glycol bis(2-mercaptopropionate), propylene glycol bis(3-mercaptobutyrate), diethylene glycol bis(2-mercaptopropionate), diethylene glycol bis(3-mercaptobutyrate), tetraethylene glycol bis(2-mercaptopropionate), 1,4-butanediol bis(2-mercaptopropionate), 1,4-butanediol bis(3-mercaptobutyrate), 1,8-octanediol bis(2-mercaptopropionate), 1,8-octanediol bis(3-mercaptobutyrate) and other bifunctional thiol compounds containing a carboxylic acid ester structure; bis(2-mercaptoethyl) thiomalate, trimethylolpropane tris(mercaptoacetate), trimethylolethane tris(mercaptoacetate), trimethylolpropane tris(3-mercaptopropionate), trimethylolethane tris(3-mercaptopropionate), trimethylolpropane tris(4-mercaptobutyrate), trimethylolethane tris(4-mercaptobutyrate), glycerol tris(3-mercaptopropionate), glycerol tris(4-mercaptobutyrate), trimethylolpropane tris(2-mercaptopropionate), trimethylolethane tris(2-mercaptopropionate), trimethylolpropane tris(3-mercaptobutyrate), trimethylolethane tris(3-mercaptobutyrate), glycerol tris(2-mercaptopropionate), glycerol tris(3-mercaptobutyrate) and other trifunctional thiol compounds containing a carboxylic acid ester structure; bis(2-mercaptoethyl) 2,3-dimercaptosuccinate, pentaerythritol tetra(mercaptoacetate), pentaerythritol tetra(3-mercaptopropionate), pentaerythritol tetra(4-mercaptobutyrate), pentaerythritol tetra(2-mercaptopropionate), pentaerythritol tetra(3-mercaptobutyrate) and other tetrafunctional thiol compounds containing a carboxylic acid ester structure; dipentaerythritol hexa(3-mercaptopropionate), dipentaerythritol hexa(2-mercaptopropionate) and other polyfunctional thiol compounds containing a carboxylic acid ester structure having 5 or more functional groups.

[0095] A thiol compound containing an isocyanurate structure refers to a thiol compound having an isocyanuric acid (i.e., 1,3,5-triazine-2,4,6(1H,3H,5H)-trione) structure (optionally further having an ether structure or a thioether structure), and examples thereof include trifunctional thiol compounds containing an isocyanurate structure such as tris(3-mercaptopropyl) isocyanurate, tris(2-mercaptopropyl) isocyanurate, tris(2-mercaptoethyl) isocyanurate, tris(4-mercaptobutyl) isocyanurate, etc.

[0096] A thiol compound containing a carboxylic acid ester structure and an isocyanurate structure refers to a thiol compound having a carboxylic acid ester structure and an isocyanuric acid structure (optionally further having an ether structure or a thioether structure), and examples thereof include trifunctional thiol compounds containing a carboxylic acid ester structure and an isocyanurate structure such as tris[2-(3-mercaptopropionyloxy)ethyl] isocyanurate, tris[2-(4-mercaptobutyryloxy)ethyl] isocyanurate, tris[2-(2-mercaptopropionyloxy)ethyl] isocyanurate, tris[2-(3-mercaptobutyryloxy)ethyl] isocyanurate, etc.

[0097] A thiol compound containing a glycoluril structure refers to a thiol compound having a glycoluril (i.e., tetrahydroimidazo[4,5-d]imidazole-2,5(1H,3H)-dione) structure, and examples thereof include bifunctional thiol compounds containing a glycoluril structure such as 1,3-bis(2-mercaptoethyl) glycoluril, 1,3-bis(3-mercaptopropyl) glycoluril, 1,4-bis(2-mercaptoethyl) glycoluril, 1,4-bis(3-mercaptopropyl) glycoluril, 1,6-bis(2-mercaptoethyl) glycoluril, 1,6-bis(3-mercaptopropyl) glycoluril, etc.; trifunctional thiol compounds containing a glycoluril structure such as 1,3,4-tris(2-mercaptoethyl) glycoluril, 1,3,4-tris(3-mercaptopropyl) glycoluril, etc.; tetrafunctional thiol compounds containing a glycoluril structure such as 1,3,4,6-tetrakis(2-mercaptoethyl) glycoluril, 1,3,4,6-tetrakis(3-mercaptopropyl) glycoluril, etc.

[0098] In one embodiment, from the viewpoint of further improving hydrolysis resistance, the thiol compound (B) preferably does not contain a thiol compound having a carboxylic acid ester structure.

[0099] In one embodiment, the thiol compound (B) can be a thiol compound that is solid at 25°C or a thiol compound that is liquid at 25°C. When the resin composition is used as a sealant or an adhesive, a thiol compound that is liquid at 25°C can be preferably used.

[0100] (B) The molecular weight of the thiol compound is not particularly limited, preferably 200 or more, more preferably 250 or more, further preferably 300 or more, and particularly preferably 350 or more. The upper limit of the molecular weight of the thiol compound (B) is not particularly limited, preferably 1,500 or less, more preferably 1,000 or less, further preferably 800 or less, and particularly preferably 700 or less.

[0101] (B) The thiol equivalent of the thiol compound is not particularly limited, preferably 1000 g / eq. or less, more preferably 500 g / eq. or less, further preferably 300 g / eq. or less, still more preferably 200 g / eq. or less, and particularly preferably 150 g / eq. or less. The lower limit of the thiol equivalent of the thiol compound (B) is not particularly limited, preferably 50 g / eq. or more, more preferably 70 g / eq. or more, further preferably 90 g / eq. or more, still more preferably 100 g / eq. or more, and particularly preferably 110 g / eq. or more. The thiol equivalent is the mass of the thiol compound per 1 equivalent of mercapto groups on average.

[0102] The ratio of the total number of mercapto groups of the thiol compound (B) in the resin composition to the total number of epoxy groups of the epoxy resin (A) (mercapto group / epoxy group) is preferably 0.1 or more, more preferably 0.3 or more, further preferably 0.5 or more, and particularly preferably 0.8 or more. The upper limit of the ratio of the total number of mercapto groups of the thiol compound (B) in the resin composition to the total number of epoxy groups of the epoxy resin (A) (mercapto group / epoxy group) is preferably 2.0 or less, more preferably 1.5 or less, further preferably 1.2 or less, and particularly preferably 1.0 or less.

[0103] The content of the thiol compound (B) in the resin composition is not particularly limited. When the non-volatile components in the resin composition are taken as 100% by mass, it is preferably 50% by mass or less, more preferably 40% by mass or less, further preferably 30% by mass or less, still more preferably 25% by mass or less, and particularly preferably 20% by mass or less. The lower limit of the content of the thiol compound (B) in the resin composition is not particularly limited. When the non-volatile components in the resin composition are taken as 100% by mass, it is preferably 0.1% by mass or more, more preferably 1% by mass or more, further preferably 2% by mass or more, still more preferably 5% by mass or more, and particularly preferably 7% by mass or more. In one embodiment, the content of the thiol compound (B) can be set based on the content and epoxy equivalent of the epoxy resin (A).

[0104] The mass ratio of (B) thiol compound to (A) epoxy resin in the resin composition ((B) thiol compound / (A) epoxy resin) is not particularly limited, preferably 0.1 or more, more preferably 0.15 or more, further preferably 0.2 or more, and particularly preferably 0.25 or more. The upper limit of the mass ratio of (B) thiol compound to (A) epoxy resin in the resin composition ((B) thiol compound / (A) epoxy resin) is not particularly limited, preferably 1.5 or less, more preferably 1 or less, further preferably 0.7 or less, and particularly preferably 0.5 or less.

[0105] <(C) Magnetic powder>

[0106] The resin composition of the present invention contains (C) magnetic powder. By containing (C) magnetic powder in the resin composition of the present invention, the specific magnetic permeability of its cured product can be improved.

[0107] (C) Magnetic powder can be either soft magnetic powder or hard magnetic powder. From the viewpoint of significantly obtaining the effects of the present invention, soft magnetic powder is preferred.

[0108] Examples of (C) magnetic powder include, for example, Fe-Mn ferrites, Fe-Mn-Zn ferrites, Mg-Zn ferrites, Mn-Zn ferrites, Mn-Mg ferrites, Cu-Zn ferrites, Mg-Mn-Sr ferrites, Ni-Zn ferrites, Ba-Zn ferrites, Ba-Mg ferrites, Ba-Ni ferrites, Ba-Co ferrites, Ba-Ni-Co ferrites, Y ferrites, iron oxide powders such as iron oxide powder (III) and magnetite; pure iron powders; iron alloy-based metal powders such as Fe-Si alloy powders, Fe-Si-Al alloy powders, Fe-Cr alloy powders, Fe-Cr-Si alloy powders, Fe-Ni-Cr alloy powders, Fe-Cr-Al alloy powders, Fe-Ni alloy powders, Fe-Ni-Mo alloy powders, Fe-Ni-Mo-Cu alloy powders, Fe-Co alloy powders, or Fe-Ni-Co alloy powders, etc. (C) Magnetic powder can be used alone as 1 type, or 2 or more types can be used in combination.

[0109] Among them, as (C) magnetic powder, at least 1 type selected from iron oxide powders and iron alloy-based metal powders is preferred. As the iron oxide powder, it preferably contains a ferrite containing at least 1 type selected from Ni, Cu, Mn, and Zn, and more preferably at least 1 type selected from Fe-Mn ferrites and Fe-Mn-Zn ferrites. In addition, as the iron alloy-based metal powder, it preferably contains an iron alloy-based metal powder containing at least 1 type selected from Si, Cr, Al, Ni, and Co.

[0110] As the (C) magnetic powder, commercially available products can be used, or two or more kinds can be used in combination. Specific examples of commercially available magnetic powders that can be used include M series such as "M05S" and "M05SWD" manufactured by Powdertech Co., Ltd.; "MZ05" manufactured by Powdertech Co., Ltd.; "PST-S" manufactured by Sanyo Special Steel Co., Ltd.; "AW2-08", "AW2-08PF20F", "AW2-08PF10F", "AW2-08PF3F", "Fe-3.5Si-4.5CrPF20F", "Fe-50NiPF20F", "Fe-80Ni-4MoPF20F" manufactured by Epson Atmix Corporation; "LD-M", "LD-MH", "KNI-106", "KNI-106GSM", "KNI-106GS", "KNI-109", "KNI-109GSM", "KNI-109GS" manufactured by JFE Chemical Corporation; "KNS-415", "BSF-547", "BSF-029", "BSN-125", "BSN-125", "BSN-714", "BSN-828", "S-1281", "S-1641", "S-1651", "S-1470", "S-1511", "S-2430" manufactured by Toda Kogyo Corporation; "JR09P2" manufactured by Nippon Heavy Chemical Industry Co., Ltd.; "Nanotek" manufactured by CIK Nanotech Co., Ltd.; "JEMK-S", "JEMK-H" manufactured by Kinsai Matech Co., Ltd.; "Yttrium iron oxide" manufactured by ALDRICH Corporation, etc.

[0111] The (C) magnetic powder is preferably spherical. The value obtained by dividing the length of the major axis of the magnetic powder by the length of the minor axis (aspect ratio) is preferably 2 or less, more preferably 1.5 or less, and still more preferably 1.2 or less. By using a spherical magnetic powder, magnetic loss can be reduced, and in addition, a resin composition having a desired and preferable viscosity can be obtained.

[0112] From the viewpoint of improving the specific magnetic permeability, the average particle diameter of the (C) magnetic powder is preferably 0.01 μm or more, more preferably 0.5 μm or more, and still more preferably 1 μm or more. The upper limit of the average particle diameter of the (C) magnetic powder is preferably 10 μm or less, more preferably 9 μm or less, and still more preferably 8 μm or less.

[0113] (C) The average particle diameter of the magnetic powder can be measured by a laser diffraction / scattering method based on the Mie scattering theory. Specifically, a particle size distribution of the magnetic powder can be created on a volume basis by a laser diffraction / scattering type particle size distribution measuring device, and the median diameter thereof can be used as the average particle diameter for measurement. As the measurement sample, a substance in which the magnetic powder is dispersed in water by ultrasound can be preferably used. As the laser diffraction / scattering type particle size distribution measuring device, “LA-500” manufactured by Horiba, Ltd., “SALD-2200” manufactured by Shimadzu Corporation, etc. can be used.

[0114] In one embodiment, from the viewpoints of adjusting the viscosity of the resin composition and further improving the moisture resistance and dispersibility, (C) the magnetic powder can be treated with a surface treatment agent. Examples of the surface treatment agent include vinyl silane-based coupling agents, (meth)acrylic acid-based coupling agents, fluorine-containing silane coupling agents, amino silane-based coupling agents, epoxy silane-based coupling agents, mercapto silane-based coupling agents, silane-based coupling agents, alkoxysilanes, organosilazane compounds, titanate-based coupling agents, etc. The surface treatment agent can be used alone as one kind, or two or more kinds can be used in any combination.

[0115] Examples of commercially available products of the surface treatment agent include “KBM1003” (vinyltriethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., “KBM503” (3-methacryloxypropyltriethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., “KBM403” (3-glycidoxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., “KBM803” (3-mercaptopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., “KBE903” (3-aminopropyltriethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., “KBM573” (N-phenyl-3-aminopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., “SZ-31” (hexamethyldisilazane) manufactured by Shin-Etsu Chemical Co., Ltd., “KBM103” (phenyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., “KBM-4803” (long-chain epoxy type silane coupling agent) manufactured by Shin-Etsu Chemical Co., Ltd., “KBM-7103” (3,3,3-trifluoropropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., etc.

[0116] From the viewpoint of improving the dispersibility of (C) the magnetic powder, the degree of surface treatment with the surface treatment agent preferably falls within a specified range. Specifically, 100 parts by mass of (C) the magnetic powder is preferably surface-treated with 0.01 part by mass to 5 parts by mass of the surface treatment agent, preferably surface-treated with 0.05 part by mass to 3 parts by mass, and preferably surface-treated with 0.1 part by mass to 2 parts by mass.

[0117] (C) Content of magnetic powder (volume %) From the viewpoints of increasing the relative permeability and reducing the loss factor, when the non-volatile components in the resin composition are taken as 100% by volume, it is preferably 0.1% by volume or more, more preferably 1% by volume or more, further preferably 5% by volume or more, still further preferably 10% by volume or more, and particularly preferably 14% by volume or more. The upper limit of the content of (C) magnetic powder (volume %) is not particularly limited. In one embodiment, from the viewpoint of functioning as a paste-like magnetic adhesive, when the non-volatile components in the resin composition are taken as 100% by mass, it is preferably 85% by volume or less, more preferably 70% by volume or less, further preferably 60% by volume or less, still further preferably 50% by volume or less, and particularly preferably 40% by volume or less.

[0118] (C) Content of magnetic powder (mass %) From the viewpoints of increasing the relative permeability and reducing the loss factor, when the non-volatile components in the resin composition are taken as 100% by mass, it is preferably 5% by mass or more, more preferably 20% by mass or more, further preferably 30% by mass or more, still further preferably 35% by mass or more, and particularly preferably 40% by mass or more. The upper limit of the content of (C) magnetic powder (mass %) is not particularly limited. In one embodiment, from the viewpoint of functioning as a paste-like magnetic adhesive, when the non-volatile components in the resin composition are taken as 100% by mass, it is preferably 90% by mass or less, more preferably 85% by mass or less, further preferably 80% by mass or less, still further preferably 77% by mass or less, and particularly preferably 75% by mass or less.

[0119] <(D) Stabilizer>

[0120] The resin composition of the present invention may contain (D) stabilizer as an optional component. (D) Stabilizer has the function of improving the storage stability of the resin composition (especially one-component resin composition).

[0121] Examples of (D) stabilizer include borate compounds, titanate compounds, aluminate compounds, zirconate compounds, isocyanate compounds, carboxylic acids, carboxylic anhydrides, etc. (D) Stabilizer can be used alone in one kind, or two or more kinds can be used in combination at any ratio.

[0122] Examples of the borate compound include trialkyl borates such as trimethyl borate, triethyl borate, tripropyl borate, triisopropyl borate, tributyl borate, tripentyl borate, trihexyl borate, tricyclohexyl borate, tris(2-ethylhexyl) borate, trioctyl borate, trinonyl borate, tridodecyl borate, tris(hexadecyl) borate, tris(octadecyl) borate; trialkenyl borates such as triallyl borate; triaryl borates such as triphenyl borate, tris(2-methylphenyl) borate, tris(3-methylphenyl) borate, tris(4-methylphenyl) borate, tris(2-ethylphenyl) borate, tris(3-ethylphenyl) borate, tris(4-ethylphenyl) borate, tris(3,5-dimethylphenyl) borate, tris(2,4-dimethylphenyl) borate; triaralkyl borates such as triphenylmethyl borate; amino group-containing borates such as triethanolamine borate, etc.

[0123] Examples of the titanate compound include tetraethyl titanate, tetrapropyl titanate, tetraisopropyl titanate, tetrabutyl titanate, tetraoctyl titanate, etc.

[0124] Examples of the aluminate compound include triethyl aluminate, tripropyl aluminate, triisopropyl aluminate, tributyl aluminate, trioctyl aluminate, etc.

[0125] Examples of the zirconate compound include tetraethyl zirconate, tetrapropyl zirconate, tetraisopropyl zirconate, tetrabutyl zirconate, etc.

[0126] Examples of the isocyanate compound include n-butyl isocyanate, isopropyl isocyanate, 2-chloroethyl isocyanate, phenyl isocyanate, p-chlorophenyl isocyanate, benzyl isocyanate, hexamethylene diisocyanate, 2-ethylphenyl isocyanate, 2,6-dimethylphenyl isocyanate, tolylene diisocyanate (e.g., 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate), 1,5-naphthalene diisocyanate, diphenylmethane-4,4'-diisocyanate, bitolylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, p-phenylene diisocyanate, bicycloheptane triisocyanate, etc.

[0127] Examples of the carboxylic acid include saturated aliphatic monocarboxylic acids such as formic acid, acetic acid, propionic acid, butyric acid, hexanoic acid, octanoic acid; unsaturated aliphatic monocarboxylic acids such as acrylic acid, methacrylic acid, crotonic acid; monohydric hydroxy acids such as glycolic acid, lactic acid; aliphatic aldehydo acids such as glyoxylic acid, gluconic acid; aliphatic polycarboxylic acids such as oxalic acid, malonic acid, succinic acid, maleic acid; aromatic monocarboxylic acids such as benzoic acid, p-toluic acid, phenylacetic acid, cinnamic acid, mandelic acid; aromatic polycarboxylic acids such as phthalic acid, trimesic acid; halogenated fatty acids such as monochloroacetic acid, dichloroacetic acid, etc.

[0128] Examples of the carboxylic anhydride include aliphatic polybasic acid anhydrides such as succinic anhydride, dodecenylsuccinic anhydride, maleic anhydride, hexahydrophthalic anhydride, and methyltetrahydrophthalic anhydride; and aromatic polybasic acid anhydrides such as phthalic anhydride, trimellitic anhydride, and pyromellitic dianhydride.

[0129] The content of the (D) stabilizer in the resin composition is not particularly limited. When the non-volatile components in the resin composition are regarded as 100% by mass, it is preferably 1% by mass or less, more preferably 0.5% by mass or less, and further preferably 0.3% by mass or less. The lower limit of the content of the (D) stabilizer in the resin composition is not particularly limited, and when the non-volatile components in the resin composition are regarded as 100% by mass, it can be, for example, 0% by mass or more, 0.001% by mass or more, preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and further preferably 0.1% by mass or more.

[0130] <(E) Dispersant>

[0131] The resin composition of the present invention may contain an (E) dispersant as an optional component.

[0132] Examples of the (E) dispersant include phosphate ester-based dispersants such as polyoxyethylene alkyl ether phosphate; polyoxyalkylene-based dispersants such as polyoxyethylene alkyl ether, polyoxyethylene alkyl ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkyl phenyl ether, polyoxyethylene alkylamine, and polyoxyethylene alkylamide; acetylene-based dispersants such as alkynediol; silicone-based dispersants such as polyether-modified polydimethylsiloxane, polyether-modified silicone, and polyester-modified polydimethylsiloxane; anionic dispersants such as sodium polyacrylate, sodium dodecylbenzenesulfonate, sodium laurate, ammonium polyoxyethylene alkyl ether sulfate, and sodium carboxymethyl cellulose; and cationic dispersants such as amino group-containing polyacrylate resins and amino group-containing polystyrene resins. The (E) dispersant may be used alone or in combination of two or more.

[0133] Examples of commercially available products of the phosphate ester-based dispersant include "RS-410", "RS-610", "RS-710", etc. of the "Fosfanol" series manufactured by Toho Chemical Industry Co., Ltd.

[0134] Examples of commercially available products of the polyoxyalkylene-based dispersant include "AKM-0531", "AFB-1521", "SC-0505K", "SC-1015F", "SC-0708A", and "HKM-50A", etc. of the "Marialim" series manufactured by NOF Corporation.

[0135] Examples of commercially available acetylene-based dispersants include "82", "104", "440", "465", "485" in the "Surfynol" series manufactured by Air Products and Chemicals Inc., and "Olefin Y", etc.

[0136] Examples of commercially available silicone-based dispersants include "BYK347", "BYK348", etc. manufactured by BYK Chemie GmbH.

[0137] Examples of commercially available anionic dispersants include "PN-411", "PA-111" manufactured by Ajinomoto Fine-Techno Co., Inc.; "A-550", "PS-1900" manufactured by Lion Corporation, etc.

[0138] Examples of commercially available cationic dispersants include "161", "162", "164", "182", "2000", "2001" manufactured by BYK Chemie GmbH; "PB-821", "PB-822", "PB-824" manufactured by Ajinomoto Fine-Techno Co., Inc.; "V-216", "V-220" manufactured by ISP Japan Corporation; "Solsperse 13940", "Solsperse 24000", "Solsperse 32000" manufactured by Lubrizol Corporation, etc.

[0139] The content of the (E) dispersant in the resin composition is not particularly limited. When the non-volatile components in the resin composition are taken as 100% by mass, it is preferably 1% by mass or less, more preferably 0.7% by mass or less, and further preferably 0.5% by mass or less. The lower limit of the content of the (E) dispersant in the resin composition is not particularly limited. When the non-volatile components in the resin composition are taken as 100% by mass, it can be, for example, 0% by mass or more, 0.001% by mass or more, 0.01% by mass or more, preferably 0.05% by mass or more, more preferably 0.1% by mass or more, and further preferably 0.2% by mass or more.

[0140] <(F) Curing Accelerator>

[0141] The resin composition of the present invention may contain an (F) curing accelerator as an optional component.

[0142] As the (F) curing accelerator, a latent curing accelerator is preferably used. The latent curing accelerator is an important component especially in the case of preparing a one-component resin composition, and has the function of not contributing to the curing of the (A) epoxy resin at room temperature (25°C) and promoting the curing of the (A) epoxy resin upon heating. The (F) curing accelerator can be used alone as one kind, or two or more kinds can be used in combination at any ratio.

[0143] The latent curing accelerator can be a liquid latent curing accelerator or a solid-dispersed latent curing accelerator, and more preferably a solid-dispersed latent curing accelerator.

[0144] The liquid latent curing accelerator refers to a liquid that is soluble in epoxy resin at room temperature (25 °C) and is a compound that functions as a curing accelerator for epoxy resin by heating. Examples of the liquid latent curing accelerator include, but are not limited to, ionic liquids.

[0145] Examples of the cation constituting the ionic liquid include ammonium-based cations such as imidazolium ions, piperidinium ions, pyrrolidinium ions, pyrazolium ions, guanidinium ions, pyridinium ions, and their hydrocarbon group (alkyl group, phenyl group, their combination, etc.) substituted bodies; phosphonium-based cations such as tetraalkylphosphonium ions; sulfonium-based cations such as trialkylsulfonium ions, etc.

[0146] In addition, examples of the anion constituting the ionic liquid include halide-based anions such as fluoride ions, chloride ions, bromide ions, and iodide ions; alkyl sulfate-based anions such as methanesulfonate ions; fluorine-containing compound-based anions such as trifluoromethanesulfonate ions, hexafluorophosphate ions, trifluoro tris(pentafluoroethyl)phosphate ions, bis(trifluoromethanesulfonyl)imide ions, trifluoroacetate ions, and tetrafluoroborate ions; phenol-based anions such as phenolate ions, 2-methoxyphenolate ions, and 2,6-di-tert-butylphenolate ions; acidic amino acid ions such as aspartate ions and glutamate ions; neutral amino acid ions such as glycinate ions, alaninate ions, and phenylalaninate ions; N-acyl amino acid ions such as N-benzoylalaninate ions, N-acetylphenylalaninate ions, N-acetylglycinate ions, and N-acetylglycinate ions; carboxylic acid-based anions such as formate ions, lactate ions, tartrate ions, hippurate ions, N-methylhippurate, and benzoate ions.

[0147] The solid-dispersed latent curing accelerator refers to a solid that is insoluble in epoxy resin at room temperature (25 °C) and becomes soluble in epoxy resin by heating and functions as a curing accelerator for epoxy resin.

[0148] Examples of the solid-dispersed latent curing accelerator include, but are not limited to, imidazole compounds that are solid at room temperature (25 °C) and solid-dispersed amine adduct-based latent curing accelerators.

[0149] Examples of imidazole compounds that are solid at normal temperature (25°C) include, but are not limited to, 2-heptadecylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-undecylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4-benzyl-5-hydroxymethylimidazole, 2,4-diamino-6-[2-(2-methyl-1-imidazolyl)ethyl]-1,3,5-triazine, 2,4-diamino-6-[2-(2-methyl-1-imidazolyl)ethyl]-1,3,5-triazine isocyanuric acid adduct, 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole isophthalate, 1-cyanoethyl-2-phenylimidazole isophthalate, N-(2-methylimidazol-1-ylethyl)urea, etc.

[0150] Suitable examples of the solid dispersion type amine adduct-based latent curing accelerator include at least one selected from compounds obtained by adding an epoxy adduct of an amine compound, a urea adduct of an amine compound, and a compound obtained by adding an isocyanate compound to a hydroxyl group of an epoxy adduct.

[0151] Examples of the epoxy compound used as one of the raw materials for producing the epoxy adduct of an amine compound include, but are not limited to, polyhydric phenols such as bisphenol A, bisphenol F, catechol, and resorcinol, or polyglycidyl ethers obtained by reacting polyhydric alcohols such as glycerol and polyethylene glycol with epichlorohydrin; glycidyl ether esters obtained by reacting hydroxycarboxylic acids such as p-hydroxybenzoic acid and β-hydroxynaphthoic acid with epichlorohydrin; polyglycidyl esters obtained by reacting polycarboxylic acids such as phthalic acid and terephthalic acid with epichlorohydrin; glycidylamine compounds obtained by reacting 4,4'-diaminodiphenylmethane, m-aminophenol, etc. with epichlorohydrin; polyfunctional epoxy compounds such as epoxidized phenol novolac resin, epoxidized cresol novolac resin, and epoxidized polyolefin, and monofunctional epoxy compounds such as butyl glycidyl ether, phenyl glycidyl ether, and glycidyl methacrylate.

[0152] The amine compound used as a raw material for manufacturing a latent curing accelerator of a solid dispersion type amine adduct system only needs to have one or more active hydrogens capable of undergoing an addition reaction with an epoxy group in the molecule and at least one functional group selected from primary amino groups, secondary amino groups, and tertiary amino groups in the molecule. Examples of such amine compounds include aliphatic amine compounds such as diethylenetriamine, triethylenetetramine, n-propylamine, 2-hydroxyethylaminopropylamine, cyclohexylamine, 4,4'-diamino-dicyclohexylmethane; aromatic amine compounds such as 4,4'-diaminodiphenylmethane, 2-methylaniline; nitrogen-containing heterocyclic compounds such as 2-ethyl-4-methylimidazole, 2-ethyl-4-methylimidazoline, 2,4-dimethylimidazoline, piperidine, piperazine, etc., but are not limited thereto.

[0153] In addition, among them, especially the compound having a tertiary amino group in the molecule is a raw material for giving a latent curing accelerator with excellent curing promoting ability. Examples of such compounds include amine compounds such as dimethylaminopropylamine, diethylaminopropylamine, di-n-propylaminopropylamine, dibutylaminopropylamine, dimethylaminoethylamine, diethylaminoethylamine, N-methylpiperazine; primary or secondary amines having a tertiary amino group in the molecule such as 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole; alcohols having a tertiary amino group in the molecule such as 2-dimethylaminoethanol, 1-methyl-2-dimethylaminoethanol, 1-phenoxymethyl-2-dimethylaminoethanol, 2-diethylaminoethanol, 1-butoxymethyl-2-dimethylaminoethanol, 1-(2-hydroxy-3-phenoxypropyl)-2-methylimidazole, 1-(2-hydroxy-3-phenoxypropyl)-2-ethyl-4-methylimidazole, 1-(2-hydroxy-3-butoxypropyl)-2-methylimidazole, 1-(2-hydroxy-3-butoxypropyl)-2-ethyl-4-methylimidazole, 1-(2-hydroxy-3-phenoxypropyl)-2-phenylimidazoline, 1-(2-hydroxy-3-butoxypropyl)-2-methylimidazoline, 2-(dimethylaminomethyl)phenol, 2,4,6-tris(dimethylaminomethyl)phenol, N-β-hydroxyethylmorpholine, 2-dimethylaminoethanethiol, 2-mercaptopyridine, 2-benzimidazole, 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, 4-mercaptopyridine, N,N-dimethylaminobenzoic acid, N,N-dimethylglycine, nicotinic acid, isonicotinic acid, methylpyridine, N,N-dimethylglycine hydrazide, N,N-dimethylpropionic acid hydrazide, nicotinic acid hydrazide, isonicotinic acid hydrazide, etc., and phenols, thiols, carboxylic acids, hydrazides, etc. having a tertiary amino group in the molecule.

[0154] When producing a latent curing accelerator by the addition reaction of an epoxide and an amine compound, a reactive hydrogen compound having two or more reactive hydrogens in the molecule may be further reacted. Examples of such reactive hydrogen compounds include polyhydric phenols such as bisphenol A, bisphenol F, bisphenol S, hydroquinone, catechol, resorcinol, pyrogallol, and phenol novolak resin; polyhydric alcohols such as trimethylolpropane; polycarboxylic acids such as adipic acid and phthalic acid; 1,2-dimercaptoethane, 2-mercaptoethanol, 1-mercapto-3-phenoxy-2-propanol, mercaptoacetic acid, anthranilic acid, lactic acid, etc., but are not limited thereto.

[0155] As the isocyanate compound used as a raw material for producing a solid dispersion type amine adduct-based latent curing accelerator, for example, monofunctional isocyanate compounds such as n-butyl isocyanate, isopropyl isocyanate, phenyl isocyanate, and benzyl isocyanate can also be used; polyfunctional isocyanate compounds such as hexamethylene diisocyanate, toluene diisocyanate, 1,5-naphthalene diisocyanate, diphenylmethane-4,4'-diisocyanate, isophorone diisocyanate, xylylene diisocyanate, p-phenylene diisocyanate, 1,3,6-hexamethylene triisocyanate, and bicycloheptane triisocyanate; further, compounds containing terminal isocyanate groups obtained by the reaction of these polyfunctional isocyanate compounds with reactive hydrogen compounds, etc. Examples of such compounds containing terminal isocyanate groups include addition compounds having terminal isocyanate groups obtained by the reaction of toluene diisocyanate with trimethylolpropane, addition compounds having terminal isocyanate groups obtained by the reaction of toluene diisocyanate with pentaerythritol, etc., but are not limited thereto.

[0156] In addition, examples of the urea compound used as a raw material for producing a solid dispersion type amine adduct-based latent curing accelerator include urea, thiourea, etc., but are not limited thereto.

[0157] The solid dispersion type amine adduct-based latent curing accelerator can be easily obtained, for example, by appropriately mixing the above-mentioned raw materials, reacting at a temperature from room temperature to 200 °C, cooling and curing, and then pulverizing, or reacting in a solvent such as methyl ethyl ketone, dioxane, or tetrahydrofuran, removing the solvent, and pulverizing the solid component.

[0158] Examples of commercially available latent curing accelerators as solid dispersion type amine adducts include, for example, "Amicure PN-FJ" (manufactured by Ajinomoto Fine-Techno Co., Inc.), "Amicure PN-23" (manufactured by Ajinomoto Fine-Techno Co., Inc.), "Amicure PN-H" (manufactured by Ajinomoto Fine-Techno Co., Inc.), "Hardener X-3661S" (manufactured by CCR Co., Ltd.), "Hardener X-3670S" (manufactured by CCR Co., Ltd.), "FXR-1081" (manufactured by T&K TOKA Co., Ltd.), "Fujicure FXR-1000" (manufactured by T&K TOKA Co., Ltd.), "Fujicure FXR-1030" (manufactured by T&K TOKA Co., Ltd.), "Novacure HX-3721" (manufactured by Asahi Kasei Corporation), "HX-3722" (manufactured by Asahi Kasei Corporation), "Novacure HX-3742" (manufactured by Asahi Kasei Corporation), and the like.

[0159] The content of the (F) curing accelerator in the resin composition is not particularly limited. When the non-volatile components in the resin composition are taken as 100% by mass, it is preferably 20% by mass or less, more preferably 10% by mass or less, and still more preferably 7% by mass or less. The lower limit of the content of the (F) curing accelerator in the resin composition is not particularly limited, and when the non-volatile components in the resin composition are taken as 100% by mass, it can be, for example, 0% by mass or more, 0.01% by mass or more, 0.1% by mass or more, preferably 0.5% by mass or more, more preferably 1% by mass or more, and still more preferably 2% by mass or more.

[0160] <(G) Organic Filler>

[0161] The resin composition of the present invention may further contain (G) an organic filler as an optional component.

[0162] (G) The organic filler exists in the resin composition in a particulate form. As the (G) organic filler, from the viewpoint of significantly obtaining the desired effects of the present invention, rubber particles are preferably used. The (G) organic filler can be used alone in one kind, or two or more kinds can be used in any ratio in combination.

[0163] As the rubber component contained in the rubber particles, silicone-based elastomers such as polydimethylsiloxane can be cited; olefin-based thermoplastic elastomers such as polybutadiene, polyisoprene, polychloroprene, ethylene-vinyl acetate copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-isobutene copolymer, acrylonitrile-butadiene copolymer, isoprene-isobutene copolymer, isobutene-butadiene copolymer, ethylene-propylene-diene terpolymer, ethylene-propylene-butene terpolymer, etc.; acrylic-based thermoplastic elastomers such as poly(propyl) (meth)acrylate, poly(butyl) (meth)acrylate, poly(cyclohexyl) (meth)acrylate, poly(octyl) (meth)acrylate, etc. Further, in the rubber component, silicone-based rubbers such as polyorganosiloxane rubber can be mixed. The glass transition temperature of the rubber component contained in the rubber particles is, for example, 0 °C or lower, preferably -10 °C or lower, more preferably -20 °C or lower, and further preferably -30 °C or lower.

[0164] (G) From the viewpoint of significantly obtaining the desired effects of the present invention, the organic filler is preferably a core-shell type rubber particle. The core-shell type rubber particle refers to a particulate organic filler containing a core particle containing a rubber component and one or more shell portions covering the core particle as exemplified above. Further, the core-shell type particle is preferably a core-shell type graft copolymer rubber particle containing a core particle containing a rubber component and a shell portion obtained by graft copolymerization with a monomer component capable of copolymerizing with the rubber component contained in the core particle. The core-shell type referred to herein does not necessarily mean a substance that can be clearly distinguished only into a core particle and a shell portion, but also includes a substance in which the boundary between the core particle and the shell portion is not clear, and the core particle may not be completely covered by the shell portion.

[0165] The rubber component is preferably contained in an amount of 40% by mass or more, more preferably 50% by mass or more, and further preferably 60% by mass or more in the core-shell type rubber particle. The upper limit of the content of the rubber component in the core-shell type rubber particle is not particularly limited, and from the viewpoint of sufficiently covering the core particle with the shell portion, it is, for example, 95% by mass or less, preferably 90%.

[0166] The monomer components forming the shell portion of the core-shell type rubber particle include, for example, (meth)acrylate esters such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, cyclohexyl (meth)acrylate, octyl (meth)acrylate, glycidyl (meth)acrylate, etc.; (meth)acrylic acid; N-substituted maleimides such as N-methyl maleimide, N-phenyl maleimide, etc.; maleimide; α,β-unsaturated carboxylic acids such as maleic acid, itaconic acid, etc.; aromatic vinyl compounds such as styrene, 4-vinyltoluene, α-methylstyrene, etc.; (meth)acrylonitrile, etc. Among them, (meth)acrylate esters are preferably included, and methyl (meth)acrylate is more preferably included.

[0167] Examples of commercially available core-shell rubber particles include, for example, "CHT" manufactured by Chail Industries; "B602" manufactured by UMG ABS; "Paraloid EXL-2602", "Paraloid EXL-2603", "Paraloid EXL-2655", "Paraloid EXL-2311", "Paraloid-EXL2313", "Paraloid EXL-2315", "Paraloid KM-330", "Paraloid KM-336P", "Paraloid KCZ-201" manufactured by Dow Chemical Japan; "Metablen C-223A", "Metablen E-901", "Metablen S-2001", "Metablen W-450A", "Metablen SRK-200" manufactured by Mitsubishi Rayon; "Kanekaes M-511", "Kanekaes M-600", "Kanekaes M-400", "Kanekaes M-580", "Kanekaes MR-01" manufactured by Kaneka, etc.

[0168] (G) The organic filler may be a dispersion in (A) epoxy resin. In the dispersion of (G) the organic filler in (A) epoxy resin, (G) the organic filler may be dispersed in the state of primary particles in (A) epoxy resin. In the dispersion of (G) the organic filler in (A) epoxy resin, the content of (G) the organic filler is preferably 10 to 40% by weight.

[0169] Examples of commercially available dispersions of (G) the organic filler in (A) epoxy resin include, for example, "Kanekaes MX120", "Kanekaes MX125", "Kanekaes MX130" (containing 25% by weight of a rubbery core-shell polymer (the rubber particle core is a styrene-butadiene copolymer)), "MX960", "MX965" (containing 25% by weight of a rubbery core-shell polymer containing silicone rubber (the rubber particle core is polydimethylsiloxane, etc.)) commercially available as a rubbery core-shell polymer-modified bisphenol A epoxy resin; "RKB-3040" (containing 29% by weight of a rubbery core-shell polymer (the rubber particle core is butadiene rubber)), "RKB-3040H" (containing 25% by weight of a rubbery core-shell polymer (the rubber particle core is butadiene rubber)) manufactured by Creha Trading, etc.

[0170] (G) The average particle diameter (average primary particle diameter) of the organic filler is not particularly limited, preferably 20 nm or more, more preferably 30 nm or more, and still more preferably 50 nm or more. The upper limit of the average particle diameter (average primary particle diameter) of the organic filler is not particularly limited, preferably 5,000 nm or less, more preferably 2,000 nm or less, and still more preferably 1,000 nm or less. The average particle diameter (average primary particle diameter) of the organic filler can be measured using a Zeta potential particle size distribution measuring device or the like.

[0171] The content of the (G) organic filler in the resin composition is not particularly limited. When the non-volatile components in the resin composition are taken as 100% by mass, it is preferably 20% by mass or less, more preferably 10% by mass or less, and still more preferably 5% by mass or less. The lower limit of the content of the (G) organic filler in the resin composition is not particularly limited, and can be, for example, 0% by mass or more, 0.01% by mass or more, 0.1% by mass or more, 1% by mass or more, 1.5% by mass or more when the non-volatile components in the resin composition are taken as 100% by mass.

[0172] <(H) Other additives>

[0173] As a non-volatile component, the resin composition of the present invention may further contain optional additives. Examples of such additives include curing agents other than thiol compounds such as phenolic curing agents, naphthol-based curing agents, acid anhydride-based curing agents, active ester-based curing agents, benzoxazine-based curing agents, cyanate ester-based curing agents, carbodiimide-based curing agents, imidazole-based curing agents; thermoplastic resins such as phenoxy resins, polyvinyl acetal resins, polyolefin resins, polysulfone resins, polyethersulfone resins, polyphenylene ether resins, polycarbonate resins, polyetheretherketone resins, polyester resins; organometallic compounds such as organic copper compounds, organic zinc compounds, organic cobalt compounds; colorants such as phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, titanium oxide, carbon black; polymerization inhibitors such as hydroquinone, catechol, pyrogallol, phenothiazine; leveling agents such as siloxanes; thickeners such as bentonite, montmorillonite; antifoaming agents such as silicone-based antifoaming agents, acrylic-based antifoaming agents, fluorine-based antifoaming agents, vinyl resin-based antifoaming agents; ultraviolet absorbers such as benzotriazole-based ultraviolet absorbers; adhesion improvers such as urea silanes; adhesion improvers such as silane coupling agents, triazole-based adhesion imparting agents, tetrazole-based adhesion imparting agents, triazine-based adhesion imparting agents; antioxidants such as hindered phenol-based antioxidants, hindered amine-based antioxidants; fluorescent brighteners such as stilbene derivatives; surfactants such as fluorine-based surfactants, silicone-based surfactants; flame retardants such as phosphorus-based flame retardants (e.g., phosphate compounds, phosphazene compounds, phosphine oxide compounds, red phosphorus), nitrogen-based flame retardants (e.g., melamine sulfate), halogen-based flame retardants, inorganic flame retardants (e.g., antimony trioxide), etc. The additives may be used singly or in combination of two or more in any ratio. (H) The content of other additives can be appropriately set by those skilled in the art.

[0174] <(I) Organic solvents>

[0175] In addition to the above-mentioned non-volatile components, as volatile components, the resin composition of the present invention may further contain an optional organic solvent. As the (I) organic solvent, as long as it can dissolve at least a part of the non-volatile components, known substances can be appropriately used, and the types thereof are not particularly limited. Examples of the (I) organic solvent include ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ester solvents such as methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, isopentyl acetate, methyl propionate, ethyl propionate, and γ-butyrolactone; ether solvents such as tetrahydropyran, tetrahydrofuran, 1,4-dioxane, diethyl ether, diisopropyl ether, dibutyl ether, and diphenyl ether; alcohol solvents such as methanol, ethanol, propanol, butanol, and ethylene glycol; ether ester solvents such as 2-ethoxyethyl acetate, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl ethylene glycol acetate, γ-butyrolactone, and methyl methoxypropionate; ester alcohol solvents such as methyl lactate, ethyl lactate, and methyl 2-hydroxyisobutyrate; ether alcohol solvents such as 2-methoxypropanol, 2-methoxyethanol, 2-ethoxyethanol, propylene glycol monomethyl ether, and diethylene glycol monobutyl ether (butyl carbitol); amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone; sulfoxide solvents such as dimethyl sulfoxide; nitrile solvents such as acetonitrile and propionitrile; aliphatic hydrocarbon solvents such as hexane, cyclopentane, cyclohexane, and methylcyclohexane; aromatic hydrocarbon solvents such as benzene, toluene, xylene, ethylbenzene, and trimethylbenzene, etc. The (I) organic solvent can be used alone or in combination of two or more in any ratio. When the (I) organic solvent is used, it can be used alone or in combination of two or more in any ratio. The smaller the amount of the (I) organic solvent, the more preferable it is (for example, when the non-volatile components in the resin composition are recorded as 100% by mass, it is 3% by mass or less, 1% by mass or less, 0.5% by mass or less, 0.1% by mass or less, 0.01% by mass or less), and it is particularly preferably not contained (0% by mass).

[0176] <Manufacturing method of resin composition>

[0177] The resin composition of the present invention can be produced, for example, by adding and mixing (A) an epoxy resin, (B) a thiol compound, (C) magnetic powder, (D) a stabilizer as required, (E) a dispersant as required, (F) a curing accelerator as required, (G) an organic filler as required, (H) other additives as required, and (I) an organic solvent as required in an arbitrary order and / or partially or entirely simultaneously in an arbitrary preparation container. Further, during the process of adding and mixing the respective components, the temperature can be appropriately set, and heating and / or cooling can be performed temporarily or continuously. Further, during the process of adding and mixing the respective components, stirring or oscillation can be performed. Further, when adding and mixing or thereafter, the resin composition can be stirred or oscillated using a stirring device or an oscillating device such as a mixer to be uniformly dispersed. Further, while stirring or oscillating, defoaming can be performed under a low-pressure condition such as under vacuum. The mixing temperature can be, for example, 10 to 40°C. The stirring speed during mixing can be, for example, 100 to 10,000 rpm. The mixing time can be, for example, 10 seconds to 10 minutes.

[0178] <Properties of the resin composition>

[0179] The resin composition of the present invention contains (A) an epoxy resin, (B) a thiol compound, and (C) magnetic powder. The cured product of the resin composition has a modulus of elasticity at 25°C of 500 MPa or less and an elongation at break of 30% or more, and thus a cured product having excellent impact resistance can be obtained. The impact resistance can be evaluated by, for example, the method of Test Example 5 below.

[0180] The cured product of the resin composition of the present invention has a modulus of elasticity at 25°C of 500 MPa or less. In one embodiment, from the viewpoint of further improving the impact resistance, the modulus of elasticity of the cured product of the resin composition of the present invention can preferably be 450 MPa or less, 400 MPa or less, more preferably 350 MPa or less, 300 MPa or less, further preferably 250 MPa or less, 200 MPa or less, particularly preferably 150 MPa or less, 100 MPa or less. The modulus of elasticity can be measured by, for example, the method of Test Example 1 below. It should be noted that regarding the modulus of elasticity, it is known that the modulus of elasticity can be controlled to a desired value by changing the selection of the compounding components and their contents.

[0181] The elongation at break of the cured product of the resin composition of the present invention at 25°C is 30% or more. In one embodiment, from the viewpoint of further improving impact resistance, the elongation at break of the cured product of the resin composition of the present invention at 25°C is preferably 35% or more, 40% or more, more preferably 45% or more, 50% or more, further preferably 55% or more, 60% or more, particularly preferably 65% or more, 70% or more. The elongation at break can be measured by the method of Test Example 2 below, for example. It should be noted that it is known that the elongation at break can be controlled to a desired value by changing the selection of the compounding components and their contents.

[0182] In one embodiment, the relative permeability (μ') of the cured product of the resin composition of the present invention at 23°C (measurement frequency 100 MHz) is preferably 1 or more, more preferably 1.3 or more, further preferably 1.6 or more, particularly preferably 2 or more. The relative permeability can be measured by the method of Test Example 3 below, for example.

[0183] In one embodiment, the viscosity of the resin composition of the present invention at 25°C is not particularly limited, and is preferably 0.001 Pa·s or more, more preferably 0.01 Pa·s or more, further preferably 0.1 Pa·s or more, still more preferably 1 Pa·s or more, particularly preferably 10 Pa·s or more. The lower limit of the viscosity of the resin composition of the present invention at 25°C is not particularly limited, and is preferably 1000 Pa·s or more, more preferably 500 Pa·s or more, further preferably 100 Pa·s or more, particularly preferably 50 Pa·s or more. The viscosity can be measured by the method of Test Example 4 below, for example.

[0184] The reaction peak temperature based on differential scanning calorimetry is preferably 150°C or lower, 140°C or lower, more preferably 130°C or lower, 120°C or lower, further preferably 110°C or lower, 100°C or lower, particularly preferably 95°C or lower, 90°C or lower, 85°C or lower, or 80°C or lower. By being in such a range, the resin composition can be cured at a lower temperature, and thus a decrease in magnetic force can be suppressed. As the lower limit of the reaction peak temperature, it can be, for example, 50°C or higher. Here, the reaction peak temperature based on differential scanning calorimetry is the temperature indicating the peak position on the lowest temperature side of the obtained differential scanning calorimetry curve (DSC curve) when differential scanning calorimetry is performed at a heating rate of 5°C / minute in the temperature range of 25°C to 300°C.

[0185] The curing temperature of the resin composition of the present invention can be set to a temperature at which it is judged that the curing reaction can proceed sufficiently, for example, with reference to the reaction start temperature or the reaction peak temperature of the resin composition based on differential scanning calorimetry (DSC). In one embodiment, since the resin composition of the present invention can be cured at a relatively low temperature, the curing temperature of the resin composition of the present invention can be, for example, 180 °C or lower, preferably 150 °C or lower, 140 °C or lower, more preferably 130 °C or lower, 120 °C or lower, further preferably 110 °C or lower, 100 °C or lower, and particularly preferably 95 °C or lower, 90 °C or lower. It should be noted that, in order to further suppress the decrease in magnetism, the lower the curing temperature, the more preferable. As the lower limit of the curing temperature, it can be, for example, 50 °C or higher, 60 °C or higher, 70 °C or higher, etc. In the above curing temperature, the curing time can be set to, for example, 10 minutes or longer, 20 minutes or longer, etc. The upper limit of the curing time can be set to 60 minutes or shorter, etc.

[0186] <Use of the resin composition>

[0187] The resin composition of the present invention can be used for various electronic components in various semiconductor devices (such as electrical products (such as computers, mobile phones, smartphones, tablet devices, wearable devices, digital cameras, medical devices, and televisions, etc.) and vehicles (such as motorcycles, automobiles, trains, ships, and airplanes, etc.)), and can be suitably used as, for example, an adhesive, a casting resin, a sealant, a caulking agent, a fiber-reinforcing resin, a coating agent, a paint, etc. Among them, it can be particularly suitably used as an adhesive or a sealant.

[0188] In particular, since the resin composition of the present invention can suppress the magnetic loss of magnets, it can be suitably used for electronic components equipped with magnets, and is suitable for, for example, uses where a magnet is bonded as an adherend (especially uses where a magnet is bonded to other members as an adherend); uses where members other than magnets are bonded to each other (especially uses where constituent members other than magnets are bonded to each other as adherends); uses in the bonding step of electronic components after mounting components containing magnets, etc.

[0189] Here, the magnet is not particularly limited and can be, for example, a known permanent magnet such as a ferrite magnet, an alnico magnet, a rare earth magnet (especially a neodymium magnet). In addition, it is known that a neodymium magnet has a strong tendency to shrink when heated and expand when cooled, but in one embodiment, the resin composition of the present invention can have excellent adhesion to a neodymium magnet, and thus can be particularly suitably used as an adhesive for bonding a neodymium magnet as an adherend.

[0190] As an electronic component equipped with a magnet, it can be, for example, an electric motor, particularly an electronic component of an electric motor containing a neodymium magnet. The resin composition of the present invention can be used as an adhesive for an electronic component of an electric motor equipped with a neodymium magnet, particularly an adhesive for bonding the magnet and the housing in an electric motor containing a neodymium magnet.

[0191] The resin composition of the present invention is used for final curing. Therefore, an electronic component using the resin composition of the present invention can contain a cured product of the resin composition of the present invention. In a specific embodiment, it can contain an electric motor containing a neodymium magnet and a cured product of the resin composition of the present invention. In addition, an electric motor containing a neodymium magnet using the resin composition of the present invention can contain a cured product of the resin composition of the present invention. Examples

[0192] Hereinafter, the present invention will be specifically described by way of examples. The present invention is not limited to these examples. It should be noted that "parts" and "%" indicating amounts hereinafter refer to "parts by mass" and "mass %" respectively, unless otherwise explicitly stated. In particular, the temperature condition in the case where the temperature is not specified is room temperature (25 °C).

[0193] First, the respective components were mixed according to the compounding compositions shown in Table 1 below to prepare the resin compositions of Examples 1 to 11 and Comparative Examples 1 to 4. Details are as described below.

[0194] <Example 1>

[0195] In a dedicated plastic container, 60 parts of an epoxy resin containing a flexible skeleton ("EXA-4850-150" manufactured by DIC Corporation, epoxy equivalent 450 g / eq), 40 parts of a dispersion of butadiene rubber particles in epoxy resin ("RKB-3040H" manufactured by Creha Trading Co., Ltd., bisphenol A / F type epoxy resin (25% dispersion of rubber-like core-shell polymer (core is butadiene rubber)), epoxy equivalent 223 g / eq), 39 parts of a thiol compound containing a carboxylic acid ester structure ("TMTP" manufactured by Yodo Chemical Industry Co., Ltd., trimethylolpropane tris(3-mercaptopropionate), thiol equivalent 140 g / eq), 110 parts of magnetic powder ("M05SWD" manufactured by Powdertech Co., Ltd.), 0.8 part of a stabilizer ("TEB" manufactured by Tokyo Chemical Industry Co., Ltd., triethyl borate), 1.1 part of a dispersant ("SC-1015F" manufactured by NOF Corporation), and 14 parts of an amine epoxy adduct-based curing accelerator ("PN-FJ" manufactured by Ajinomoto Fine-Techno Co., Inc.) of each material were measured.

[0196] Subsequently, using a rotation-revolution mixer AWATORI RENTARO (manufactured by Shinki Co., Ltd.; ARE-310), it was sufficiently mixed at 2000 rpm at room temperature of 25°C (confirmed that the magnetic powder was sufficiently dispersed and mixed with a scraper. The mixing time was about 30 seconds to about 1 minute). Further, using an automatic revolution stirring and degassing machine "HM-200W" manufactured by Kyoritsu Seiki Co., Ltd., degassing was performed under vacuum (pressure set to 0) at 1000 rpm for 2 minutes to obtain a resin composition.

[0197] <Example 2>

[0198] Instead of 60 parts of an epoxy resin containing a flexible skeleton (DIC Corporation's "EXA-4850-150"), 60 parts of an epoxy resin containing a flexible skeleton (Mitsubishi Chemical Corporation's "YX-7400", epoxy equivalent 440 g / eq) was used. The usage amount of the thiol compound containing a carboxylate structure (Denka Chemical Industry Co., Ltd.'s "TMTP") was changed from 39 parts to 40 parts, and the usage amount of the magnetic powder (Powdertech Co., Ltd.'s "M05SWD") was changed from 110 parts to 120 parts. Except for this, a resin composition was obtained in the same manner as in Example 1.

[0199] <Example 3>

[0200] The usage amount of the epoxy resin containing a flexible skeleton (DIC Corporation's "EXA-4850-150") was changed from 60 parts to 100 parts, 40 parts of a dispersion of butadiene rubber particles in epoxy resin (Kureha Trading Co., Ltd.'s "RKB-3040H") was not used, the usage amount of the thiol compound containing a carboxylate structure (Denka Chemical Industry Co., Ltd.'s "TMTP") was changed from 39 parts to 28 parts, and the usage amount of the magnetic powder (Powdertech Co., Ltd.'s "M05SWD") was changed from 110 parts to 105 parts. Except for this, a resin composition was obtained in the same manner as in Example 1.

[0201] <Example 4>

[0202] Instead of 110 parts of the magnetic powder (Powdertech Co., Ltd.'s "M05SWD"), 110 parts of the magnetic powder (Epson Atmix Corporation's "AW2-08PF3F") was used. Except for this, a resin composition was obtained in the same manner as in Example 1.

[0203] <Example 5>

[0204] The usage amount of the magnetic powder (Powdertech Co., Ltd.'s "M05SWD") was changed from 110 parts to 155 parts. Except for this, a resin composition was obtained in the same manner as in Example 1.

[0205] <Example 6>

[0206] The amount of magnetic powder (“M05SWD” manufactured by Powdertech Co., Ltd.) used was changed from 110 parts to 268 parts. Except for this, a resin composition was obtained in the same manner as in Example 1.

[0207] <Example 7>

[0208] The amount of magnetic powder (“M05SWD” manufactured by Powdertech Co., Ltd.) used was changed from 110 parts to 416 parts. Except for this, a resin composition was obtained in the same manner as in Example 1.

[0209] <Example 8>

[0210] Instead of 39 parts of a thiol compound having a carboxylic acid ester structure (“TMTP” manufactured by Yodo Chemical Industry Co., Ltd.), 38 parts of a thiol compound having an isocyanurate structure (“TMPIC” manufactured by Ajinomoto Fine-Techno Co., Inc., tris(3-mercaptopropyl) isocyanurate, thiol equivalent 117 g / eq) was used. Except for this, a resin composition was obtained in the same manner as in Example 1.

[0211] <Example 9>

[0212] Instead of 39 parts of a thiol compound having a carboxylic acid ester structure (“TMTP” manufactured by Yodo Chemical Industry Co., Ltd.), 33 parts of a thiol compound having a carboxylic acid ester structure (“PE-1” manufactured by Showa Denko K.K., pentaerythritol tetra(3-mercaptobutyrate), thiol equivalent 136 g / eq) was used. Except for this, a resin composition was obtained in the same manner as in Example 1.

[0213] <Example 10>

[0214] Instead of 1.1 parts of a dispersant (“SC-1015F” manufactured by NOF Corporation), 1.1 parts of a dispersant (“PB-821” manufactured by Ajinomoto Fine-Techno Co., Inc.) was used. Except for this, a resin composition was obtained in the same manner as in Example 1.

[0215] <Example 11>

[0216] 1.1 parts of a dispersant (“SC-1015F” manufactured by NOF Corporation) was not used. Except for this, a resin composition was obtained in the same manner as in Example 1.

[0217] <Comparative Example 1>

[0218] A resin composition was obtained in the same manner as in Example 1, except that 15 parts of a polyamine ("FXR-1081" manufactured by T&K TOKA Co., Ltd.) was used instead of 39 parts of a thiol compound containing a carboxylate structure ("TMTP" manufactured by Yonami Chemical Industry Co., Ltd.), and the amount of magnetic powder ("M05SWD" manufactured by Pawdatech Co., Ltd.) used was changed from 110 parts to 90 parts.

[0219] <Comparative Example 2>

[0220] A resin composition was obtained in the same manner as in Example 1 except that 39 parts of an allyl group-containing phenol (“MEH-8000H” manufactured by Meiwa Chemical Industry Co., Ltd., hydroxyl equivalent 141 g / eq) was used instead of 39 parts of a thiol compound containing a carboxylic acid ester structure (“TMTP” manufactured by Yodo Chemical Industry Co., Ltd.), the amount of a magnetic powder (“M05SWD” manufactured by Pawdatech Co., Ltd.) used was changed from 110 parts to 111 parts, 0.8 parts of a stabilizer (“TEB” manufactured by Tokyo Chemical Industry Co., Ltd., triethyl borate) and 1.1 parts of a dispersant (“SC-1015F” manufactured by NOF Corporation) were not used, and 0.4 parts of a phosphorus-based curing accelerator (“TBP-DA” manufactured by Hokko Chemical Co., Ltd., tetrabutylphosphonium decanoate) was used instead of 14 parts of an amine-epoxy adduct-based curing accelerator (“PN-FJ” manufactured by Ajinomoto Ficinno Co., Ltd.).

[0221] <Comparative Example 3>

[0222] In place of 39 parts of a thiol compound containing a carboxylate structure ("TMTP" manufactured by Yodo Chemical Industry Co., Ltd.), 35 parts of a phenol novolac type cyanate ester ("PT-30" manufactured by Ronza, functional group equivalent of 124 g / eq of Silanet) was used, the amount of magnetic powder ("M05SWD" manufactured by Pawdatech Co., Ltd.) used was changed from 110 parts to 105 parts, and no stabilizer ("TEB" manufactured by Tokyo Chemical Industry Co., Ltd., triethylborane) was used. A resin composition was obtained in the same manner as in Example 1, except that 0.8 parts of esters (manufactured by NOF Corporation) and 1.1 parts of a dispersant (“SC-1015F” manufactured by NOF Corporation), and 0.4 parts of a metal-based curing accelerator (manufactured by Tokyo Chemical Industry Co., Ltd., manganese (III) acetylacetonate (tris(2,4-pentanedione)manganese (III))) was used instead of 14 parts of an amine-epoxy adduct-based curing accelerator (manufactured by Ajinomoto Ficinno Co., Ltd.).

[0223] <Comparative Example 4>

[0224] A resin composition was obtained in the same manner as in Example 1 except that 39 parts of a thiol compound containing a carboxylate structure (“TMTP” manufactured by Yodo Chemical Industry Co., Ltd.) was not used, the amount of magnetic powder (“M05SWD” manufactured by Paudata Corporation) was changed from 110 parts to 79 parts, 0.8 parts of a stabilizer (“TEB” manufactured by Tokyo Chemical Industry Co., Ltd., triethyl borate) and 1.1 parts of a dispersant (“SC-1015F” manufactured by NOF Corporation) were not used, and 14 parts of an amine-epoxy adduct-based curing accelerator (“PN-FJ” manufactured by Ajinomoto Ficinno Co., Ltd.) was replaced with 2 parts of a phosphorus-based curing accelerator (“TBP-DA” manufactured by Hokko Chemical Co., Ltd., tetrabutylphosphonium decanoate).

[0225] <Test Example 1: Measurement of elastic modulus>

[0226] Each resin composition obtained in the examples and comparative examples was coated on a release PET film (NS-80A: manufactured by Toray Co., Ltd.) using a bar coater, and each was heated (set to a curing temperature of the reaction peak temperature ± 30°C and a curing time of 30 minutes or more (the same below): Examples 1 to 11 were 30 minutes at 80°C, Comparative Example 1 was 30 minutes at 100°C, Comparative Example 2 was 60 minutes at 180°C, Comparative Example 3 was 120 minutes at 200°C, and Comparative Example 4 was 60 minutes at 150°C) to obtain a cured product. The obtained cured product having a thickness of 100 μm was punched out with a dumbbell (trade name "Super Danbel Card (model: SDMK-5889-01)", manufactured by Danbel Co., Ltd.) to prepare a test piece for tensile strength measurement. The PET film was peeled off from the test piece. A tensile test was performed under the conditions of a temperature of 25° C., a humidity of 50%, and a tensile speed of 5 mm / min using a Tensilon universal testing machine (RTM-500 manufactured by Orientec Corporation) to measure the elastic modulus (MPa).

[0227] It should be noted that for each embodiment, DSC (differential scanning calorimetry) was measured before and after curing, and it was confirmed that the peak of the differential scanning calorimetry curve (DSC curve) at the curing reaction temperature before curing (peak near 60°C to 90°C) was not found in the cured product after curing. DSC was measured by heating from 25°C to 300°C at 5°C / min using a differential scanning calorimeter (DSC7000X, manufactured by Hitachi HiTech Co., Ltd.). In any of Examples 1 to 11, the reaction peak temperature was 90°C or less. Figure 1 This is a DSC chart showing differential scanning calorimetry curves (DSC curves) of the resin composition obtained in Example 1 before and after curing. Figure 1 In the figure, the solid line represents before curing, and the dotted line represents after curing.

[0228] <Test Example 2: Measurement of elongation at break>

[0229] Each of the resin compositions obtained in the examples and comparative examples was applied by bar coating on a release PET film (NS-80A: manufactured by Toray Industries, Inc.), and each was heated (Examples 1 to 11 for 30 minutes at 80°C, Comparative Example 1 for 30 minutes at 100°C, Comparative Example 2 for 60 minutes at 180°C, Comparative Example 3 for 120 minutes at 200°C, Comparative Example 4 for 60 minutes at 150°C) to obtain a cured product. The cured product with a thickness of 100 μm obtained was punched out with a dumbbell (trade name “Super Dumbbell Cutter (Model: SDMK-5889-01)”, manufactured by Dumbbell Co., Ltd.) to produce test pieces for tensile strength measurement. From the test pieces, the PET film was peeled off. Under the conditions of a temperature of 25°C, a humidity of 50%, and a tensile speed of 5 mm / minute, a tensile test was carried out using a tensilon universal testing machine (manufactured by Orientec Co., Ltd., RTM-500) to measure the elongation at break (%) at the breaking point.

[0230] <Test Example 3: Measurement of relative permeability>

[0231] Each of the resin compositions obtained in the examples and comparative examples was applied by bar coating on a release PET film (NS-80A: manufactured by Toray Industries, Inc.), and each was heated (Examples 1 to 11 for 30 minutes at 80°C, Comparative Example 1 for 30 minutes at 100°C, Comparative Example 2 for 60 minutes at 180°C, Comparative Example 3 for 120 minutes at 200°C, Comparative Example 4 for 60 minutes at 150°C) to obtain a cured product. From the test pieces, the PET film was peeled off. The cured product with a thickness of 400 μm obtained was cut into test pieces with a width of 10 mm and a length of 30 mm to produce test pieces for measurement. Using Agilent Technologies (manufactured by Agilent Technologies, Inc., “HP8362B”), the relative permeability (μ') was measured at room temperature of 23°C with the measurement frequency set in the range of 0.1 MHz to 500 MHz by the short-circuit strip line method. The relative permeability shown in Table 1 below is the relative permeability (μ') when the measurement frequency is 100 MHz.

[0232] <Test Example 4: Measurement of viscosity>

[0233] The temperature of each of the resin compositions obtained in the examples and comparative examples was maintained at 25°C (±2°C), and the viscosity (Pa·s) was measured using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd., “RE-85U”, 3°×R9.7 rotor) under the measurement conditions of 0.22 ml of the measurement sample and a rotation speed of 20 rpm.

[0234] <Test Example 5: Evaluation of impact resistance>

[0235] A fluororubber sheet (manufactured by AS ONE Corporation) with a thickness of 4 mm, cut to 60 mm × 100 mm, was further cut in half. A rectangle of 10 mm × 80 mm was cut out from the center of one of the two sheets. Inside the cut-out area, mold release agent DAIFREE (GA-9700, manufactured by Daikin Industries, Ltd.) was sprayed, and it was heated for 30 minutes under the curing conditions temperature.

[0236] After taking out the heated fluororubber sheet from the constant temperature bath and cooling it, the two fluororubber sheets were overlapped, and the periphery was fixed with a clamp. In the rectangular groove, each resin composition obtained in the examples and comparative examples was poured in such a way that the surface became flat, and each was heated (Examples 1 to 11: 30 minutes at 80°C, Comparative Example 1: 30 minutes at 100°C, Comparative Examples 2 and 3: 60 minutes at 180°C, Comparative Example 4: 60 minutes at 200°C), and cured.

[0237] After taking out from the constant temperature bath and cooling, the cured product was removed from the mold to obtain a test piece of 10 mm × 80 mm × 4 mm. This test piece was inserted 30 mm into the fixing part of an Izod impact tester (manufactured by Orientec Co., Ltd.), and at the position 45 mm from the fixing part, the test piece was impacted with a hammer to confirm the breakage or non-breakage of the test piece. The gap between the test piece and the fixing part of the impact test piece was not bonded. In addition, no cut (notch) was made on the test piece.

[0238] Regarding the results of the impact resistance test (N = 3), when each test was non-destructive, it was evaluated as "○", and when it was broken, it was evaluated as "×". As the final determination, among the 3 tests, when all 3 were non-destructive, it was recorded as "◎", when 2 were non-destructive, it was recorded as "〇", when only 1 was non-destructive, it was recorded as "△", and when all 3 were broken, it was recorded as "×".

[0239] The non-volatile components and their usage amounts of the resin compositions in the examples and comparative examples, as well as the measurement results and evaluation results of the test examples, are shown in Table 1 below.

[0240]

Table 1

[0241] 。

[0242] <Examination of Evaluation Results>

[0243] It can be seen that the cured products obtained from the resin compositions of Examples 1 to 11 have excellent impact resistance compared to the resin compositions of Comparative Examples 1 to 4. Specifically, in Examples 1 to 11 using a thiol compound, the elastic modulus was suppressed to be low, showing a high elongation at break point, and it can be seen that the impact resistance is excellent. In addition, in Comparative Examples 1 to 3 using other curing agents and Comparative Example 4 which is a homopolymer type of epoxy resin, it was confirmed that the elastic modulus and elongation at break point deteriorated and were not effective for impact resistance.

Claims

1. A resin composition comprising (A) an epoxy resin, (B) a thiol compound, and (C) a magnetic powder (A) The component contains (A-1) an epoxy resin having a flexible skeleton wherein The flexible skeleton refers to a saturated chain skeleton containing 6 or more skeleton atoms selected from carbon atoms and oxygen atoms in the main chain The elastic modulus of the cured product of the resin composition at 25°C is 500 MPa or less, and The elongation at break of the cured product of the resin composition at 25°C is 30% or more 2. The resin composition according to claim 1 wherein The elastic modulus of the cured product of the resin composition at 25°C is 450 MPa or less 3. The resin composition according to claim 1 wherein The elastic modulus of the cured product of the resin composition at 25°C is 100 MPa or less 4. The resin composition according to claim 1 wherein The elongation at break of the cured product of the resin composition at 25°C is 35% or more 5. The resin composition according to claim 1 wherein The elongation at break of the cured product of the resin composition at 25°C is 70% or more 6. The resin composition according to claim 1 wherein (A) The epoxy equivalent of the component is 50 g / eq. or more 7. The resin composition according to claim 1 wherein (A) The epoxy equivalent of the component is 5000 g / eq. or less 8. The resin composition according to claim 1 wherein (A) The epoxy equivalent of the component is 200 g / eq. to 1000 g / eq 9. The resin composition according to claim 8 wherein (A) The epoxy equivalent of the component is 500 g / eq. or less 10. The resin composition according to claim 1 wherein (B) The component is a thiol compound having 2 or more functional groups 11. The resin composition according to claim 1 wherein (B) The component is a thiol compound having 3 or more functional groups 12. The resin composition according to claim 1 wherein The ratio of the total number of mercapto groups of (B) the thiol compound to the total number of epoxy groups of (A) the epoxy resin (mercapto group / epoxy group) is 0.1 or more 13. The resin composition according to claim 1 wherein The ratio of the total number of mercapto groups of (B) the thiol compound to the total number of epoxy groups of (A) the epoxy resin (mercapto group / epoxy group) is 2.0 or less 14. The resin composition according to claim 1 wherein The ratio of the total number of mercapto groups of (B) the thiol compound to the total number of epoxy groups of (A) the epoxy resin (mercapto group / epoxy group) is 0.3 to 1.0 15. The resin composition according to claim 14 wherein The ratio of the total number of mercapto groups of (B) the thiol compound to the total number of epoxy groups of (A) the epoxy resin (mercapto group / epoxy group) is 0.5 or more 16. The resin composition according to claim 1 wherein (C) The content of the component is 5% by mass or more based on 100% by mass of the non-volatile components in the resin composition 17. The resin composition according to claim 1 wherein The content of component (C) is 90% by mass or less based on 100% by mass of the non-volatile components in the resin composition.

18. The resin composition according to claim 1, wherein the content of component (C) is 40% to 75% by mass based on 100% by mass of the non-volatile components in the resin composition.

19. The resin composition according to claim 1, which further comprises (F) a curing accelerator.

20. The resin composition according to claim 19, wherein the content of component (F) is 0.01% by mass or more based on 100% by mass of the non-volatile components in the resin composition.

21. The resin composition according to claim 19, wherein the content of component (F) is 2% by mass or more based on 100% by mass of the non-volatile components in the resin composition.

22. The resin composition according to claim 19, wherein the content of component (F) is 20% by mass or less based on 100% by mass of the non-volatile components in the resin composition.

23. The resin composition according to claim 19, wherein the content of component (F) is 7% by mass or less based on 100% by mass of the non-volatile components in the resin composition.

24. The resin composition according to claim 1, which further comprises a latent curing accelerator.

25. The resin composition according to claim 1, wherein the content of component (A-1) is 0.1% by mass or more based on 100% by mass of the non-volatile components in the resin composition.

26. The resin composition according to claim 1, wherein the content of component (A-1) is 10% by mass or more based on 100% by mass of the non-volatile components in the resin composition.

27. The resin composition according to claim 1, wherein the content of component (A-1) is 70% by mass or less based on 100% by mass of the non-volatile components in the resin composition.

28. The resin composition according to claim 1, wherein the content of component (A-1) is 45% by mass or less based on 100% by mass of the non-volatile components in the resin composition.

29. The resin composition according to claim 1, wherein component (A) comprises (A-2) other optional epoxy resins in addition to the epoxy resin (A-1) having a flexible skeleton.

30. The resin composition according to claim 29, wherein the content of component (A-2) is 0.01% by mass or more based on 100% by mass of the non-volatile components in the resin composition.

31. The resin composition according to claim 29, wherein the content of component (A-2) is 5% by mass or more based on 100% by mass of the non-volatile components in the resin composition.

32. The resin composition according to claim 29, wherein the content of component (A-2) is 50% by mass or less based on 100% by mass of the non-volatile components in the resin composition.

33. The resin composition according to claim 29, wherein the content of the component (A-2) is 15% by mass or less based on 100% by mass of the non-volatile components in the resin composition.

34. The resin composition according to claim 1, wherein the content of the component (A) is 1% by mass or more based on 100% by mass of the non-volatile components in the resin composition.

35. The resin composition according to claim 1, wherein the content of the component (A) is 30% by mass or more based on 100% by mass of the non-volatile components in the resin composition.

36. The resin composition according to claim 1, wherein the content of the component (A) is 99% by mass or less based on 100% by mass of the non-volatile components in the resin composition.

37. The resin composition according to claim 1, wherein the content of the component (A) is 50% by mass or less based on 100% by mass of the non-volatile components in the resin composition.

38. The resin composition according to claim 1, wherein the content of the component (B) is 0.1% by mass or more based on 100% by mass of the non-volatile components in the resin composition.

39. The resin composition according to claim 1, wherein the content of the component (B) is 5% by mass or more based on 100% by mass of the non-volatile components in the resin composition.

40. The resin composition according to claim 1, wherein the content of the component (B) is 50% by mass or less based on 100% by mass of the non-volatile components in the resin composition.

41. The resin composition according to claim 1, wherein the content of the component (B) is 20% by mass or less based on 100% by mass of the non-volatile components in the resin composition.

42. The resin composition according to claim 1, wherein the reaction peak temperature based on differential scanning calorimetry is 150 °C or less.

43. The resin composition according to claim 1, wherein the reaction peak temperature based on differential scanning calorimetry is 100 °C or less.

44. The resin composition according to claim 1, wherein the reaction peak temperature based on differential scanning calorimetry is 90 °C or less.

45. The resin composition according to claim 1, wherein the reaction peak temperature based on differential scanning calorimetry is 50 °C or more.

46. The resin composition according to claim 1, which is used as an adhesive.

47. The resin composition according to claim 46, which is used as an adhesive for bonding a neodymium magnet as an adherend.

48. The resin composition according to claim 1, which is used as a sealing material.

49. A cured product of the resin composition according to any one of claims 1 to 48.

50. An electric motor containing a neodymium magnet, which includes the cured product according to claim 49.

51. An electronic component, which includes the cured product according to claim 49.

52. An electronic component, which includes an electric motor containing a neodymium magnet and the cured product according to claim 49.

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