Composition, cured product, and article provided with cured product

Abstract

Provided is a composition containing: a (meth)acrylic polymer having (meth)acryloyl groups at both ends of a poly(meth)acrylate chain; a random copolymer containing alkyl (meth)acrylate and hydroxyalkyl (meth)acrylate as monomer units; and metal particles.

Description

Composition, cured product, and article comprising the cured product

[0001] The present disclosure relates to compositions, cured products, and articles comprising the cured products.

[0002] Electronic components such as processors and power modules, as well as batteries for electric vehicles, generate heat during use. To protect these components from heat, a means for efficiently dissipating the generated heat is required. Thermal interface materials (TIMs), also known as heat dissipation materials, are materials placed between a heat source and a heat dissipation component such as a heat sink. They reduce the thermal resistance between the heat source and the heat dissipation component and promote heat conduction from the heat source. Heat generated from the heat source is efficiently conducted to the cooling component via the TIM, making it easier for the heat to be dissipated from the heat dissipation component.

[0003] Patent Document 1 describes a composition containing a (meth)acrylic polymer having (meth)acryloyl groups at both ends of a poly(meth)acrylate chain and metal particles, and a cured product thereof.

[0004] International Publication No. 2024 / 009895

[0005] When a cured product of the above-described composition is used as a thermally conductive material, the cured product is required to have excellent adhesive properties to an adherend (such as a heat source or a heat dissipation member) in order to enhance thermal conductivity. Therefore, an object of the present disclosure is to provide a composition capable of forming a cured product with excellent adhesive properties.

[0006] A polymer other than a (meth)acrylic polymer having (meth)acryloyl groups at both ends of the poly(meth)acrylate chain may be added to a composition such as that described in Patent Document 1 for the purpose of adjusting viscosity, etc. The present inventors have discovered that by using a specific random copolymer in a composition together with a (meth)acrylic polymer having (meth)acryloyl groups at both ends of the poly(meth)acrylate chain, it is possible to form a cured product with excellent adhesion to an adherend (heat source or heat dissipation component). In some aspects, the present disclosure provides the following [1] to [7]. [1] A composition containing a (meth)acrylic polymer having (meth)acryloyl groups at both ends of the poly(meth)acrylate chain, a random copolymer containing alkyl (meth)acrylate and hydroxyalkyl (meth)acrylate as monomer units, and metal particles. [2] The composition described in [1], further containing a thiol compound. [3] The composition described in [1] or [2], further containing a silane compound. [4] The composition according to any one of [1] to [3], wherein the metal particles are silver particles. [5] The composition according to any one of [1] to [4], which is used to form a heat dissipation material. [6] A cured product of the composition according to any one of [1] to [5]. [7] An article comprising a heat source and the cured product according to [6], which is in thermal contact with the heat source.

[0007] According to one aspect of the present disclosure, there is provided a composition capable of forming a cured product having excellent adhesiveness.

[0008] 1 is a schematic cross-sectional view showing one embodiment of an article;FIG. 2 is a schematic cross-sectional view showing another embodiment of an article;FIG.

[0009] Hereinafter, embodiments of the present disclosure will be described in detail, but the present disclosure is not limited to the following embodiments.

[0010] In this specification, "(meth)acryloyl" means "acryloyl" and its corresponding "methacryloyl", and the same applies to similar expressions such as "(meth)acrylate" and "(meth)acrylic".

[0011] In this specification, the weight average molecular weight (Mw), number average molecular weight (Mn), and ratio of weight average molecular weight to number average molecular weight (Mw / Mn) refer to values ​​measured by gel permeation chromatography (GPC) under the following conditions and determined using polystyrene as a standard substance: Measuring instrument: HLC-8320GPC (product name, manufactured by Tosoh Corporation); Analytical column: TSKgel SuperMultipore HZ-H (three columns connected) (product name, manufactured by Tosoh Corporation); Guard column: TSKguardcolumn SuperMP(HZ)-H (product name, manufactured by Tosoh Corporation); Eluent: THF; Measurement temperature: 25°C.

[0012] [Composition] A composition according to one embodiment contains a (meth)acrylic polymer having (meth)acryloyl groups at both ends of a poly(meth)acrylate chain (hereinafter also referred to as "polymer A"), a random copolymer containing an alkyl (meth)acrylate and a hydroxyalkyl (meth)acrylate as monomer units (hereinafter also referred to as "polymer B"), and metal particles.

[0013] The composition according to one embodiment contains polymer A and polymer B together with metal particles, and thus the cured product of the composition has excellent adhesiveness.

[0014] The glass transition temperature (Tg) of polymer A may be 0° C. or lower, −10° C. or lower, −20° C. or lower, −30° C. or lower, or −40° C. or lower, from the viewpoint of providing a cured product with lower elasticity and excellent elongation. The Tg of polymer A may be −70° C. or higher, −60° C. or higher, or −55° C. or higher. In this specification, Tg refers to a value measured by differential scanning calorimetry.

[0015] Polymer A may be liquid at 23°C. In this case, the viscosity of polymer A at 23°C may be 1000 Pa·s or less, 900 Pa·s or less, or 800 Pa·s or less, from the viewpoint of facilitating application of the composition to a surface to be coated and further enhancing adhesion of the cured product to the surface to be coated. The viscosity of polymer A at 23°C may be 1 Pa·s or more, 50 Pa·s or more, 100 Pa·s or more, 200 Pa·s or more, 300 Pa·s or more, 400 Pa·s or more, or 500 Pa·s or more, from the viewpoint of facilitating application of the composition to a surface to be coated and further enhancing adhesion of the cured product to the surface to be coated.

[0016] In this specification, viscosity refers to a value measured in accordance with JIS Z8803, and specifically refers to a value measured using an E-type viscometer (for example, TV100-E manufactured by Toki Sangyo Co., Ltd.). The viscometer can be calibrated in accordance with JIS Z8809-JS14000.

[0017] From the viewpoint of providing a cured product with lower elasticity and excellent elongation, the Mw of polymer A is preferably 3,000 or more, 4,000 or more, 5,000 or more, 6,000 or more, 7,000 or more, 8,000 or more, 9,000 or more, 10,000 or more, 11,000 or more, 12,000 or more, 13,000 or more, 15,000 or more, 19,000 or more, 21,000 or more, 23,000 or more, or 25,000 or more. From the viewpoint of making it easier to adjust the viscosity of the composition, the Mw of polymer A is preferably 150,000 or less, 120,000 or less, 100,000 or less, 80,000 or less, 60,000 or less, or 40,000 or less.

[0018] The two (meth)acryloyl groups present at both ends of polymer A may each independently be an acryloyl group or a methacryloyl group. The poly(meth)acrylate chain contains a (meth)acrylic acid ester ((meth)acrylate) as a monomer unit. The (meth)acrylate as a monomer unit may have, for example, a hydrocarbon group, an organic group having an oxygen atom, an organic group having a nitrogen atom, or the like. The poly(meth)acrylate chain may have a side chain bonded to the (meth)acrylate as a monomer unit, and the structure of the side chain is not particularly limited.

[0019] In a (meth)acrylate having a hydrocarbon group, the hydrocarbon group may be linear or may have a ring (e.g., an aromatic ring). Examples of the hydrocarbon group include an alkyl group, an aryl group (e.g., a phenyl group, a toluyl group), and an aralkyl group (e.g., a benzyl group). The number of carbon atoms in the hydrocarbon group may be, for example, 1 or more and 18 or less. The (meth)acrylate having a hydrocarbon group may be an alkyl(meth)acrylate, an aryl(meth)acrylate, an aralkyl(meth)acrylate, or the like. Examples of alkyl (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 2-propylheptyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, dodecyl (meth)acrylate, and octadecyl (meth)acrylate. Examples of aryl (meth)acrylates include phenyl (meth)acrylate. Examples of aralkyl (meth)acrylates include benzyl (meth)acrylate.

[0020] In a (meth)acrylate having an organic group having an oxygen atom, the organic group having an oxygen atom may be, for example, a group having an alkoxy group, a group having a hydroxy group, a group having a carboxy group, a group having a glycidyl group, etc. Examples of a (meth)acrylate having an organic group having an oxygen atom include 2-methoxyethyl (meth)acrylate, 3-methoxybutyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, carboxy (meth)acrylate, and glycidyl (meth)acrylate.

[0021] In the (meth)acrylate having an organic group having a nitrogen atom, the organic group having a nitrogen atom may be, for example, a group having an amino group, a group having a nitrile group, etc. Examples of the (meth)acrylate having an organic group having a nitrogen atom include 2-aminoethyl (meth)acrylate and nitrile (meth)acrylate.

[0022] From the viewpoint of providing a cured product with better heat resistance, the content of polymer A may be 0.5 mass % or more, 1 mass % or more, or 3 mass % or more, and may be 15 mass % or less, 10 mass % or less, or 8 mass % or less, based on the total mass of the composition.

[0023] In addition to the polymer A, the composition may further contain another polymerizable compound other than the polymer A (details will be described later). From the viewpoint of providing a cured product with better heat resistance, the content of the polymer A is preferably 10 parts by mass or more, 20 parts by mass or more, 30 parts by mass or more, or 35 parts by mass or more relative to 100 parts by mass of the total of the polymer A and the other polymerizable compounds (hereinafter referred to as the "total content of polymerizable components"), and may be, for example, 80 parts by mass or less, 70 parts by mass or less, 60 parts by mass or less, or 50 parts by mass or less.

[0024] The composition may further contain another polymerizable compound copolymerizable with the above-described polymer A. The other polymerizable compound may be, for example, a compound having one (meth)acryloyl group. By further containing a compound having one (meth)acryloyl group in the composition, the physical properties of the cured product, such as thermal conductivity, can be adjusted. The other polymerizable compound may be a compound having, in addition to one (meth)acryloyl group, a hydrocarbon group, a group containing a polyoxyalkylene chain, a group containing a heterocycle, an alkoxy group, a phenoxy group, a group containing a siloxane bond, a halogeno group, a hydroxy group, a carboxy group, an amino group, or an epoxy group. The hydrocarbon group may be linear or branched, and may have a ring (aromatic or non-aromatic ring). The hydrocarbon group may be a chain or cyclic aliphatic hydrocarbon group, or may be an aromatic hydrocarbon group. An example of a chain aliphatic hydrocarbon group is an alkyl group. An example of a cyclic aliphatic hydrocarbon group is a cycloalkyl group. An example of an aromatic hydrocarbon group is a phenyl group.

[0025] The compound having a (meth)acryloyl group and an alkyl group may be an alkyl(meth)acrylate. The alkyl group in the alkyl(meth)acrylate (the alkyl group portion other than the (meth)acryloyl group) may be linear or branched. The number of carbon atoms in the alkyl group may be 1 or more, 3 or more, 5 or more, or 6 or more, and may be 30 or less, 25 or less, 20 or less, 15 or less, or 13 or less. The number of carbon atoms in the alkyl group may be, for example, 1 to 30, 3 to 20, or 5 to 15.

[0026] Examples of alkyl(meth)acrylates having a linear alkyl group include alkyl(meth)acrylates having a linear alkyl group with 1 to 6 carbon atoms, such as methyl(meth)acrylate, ethyl(meth)acrylate, propyl(meth)acrylate, butyl(meth)acrylate, pentyl(meth)acrylate, and n-hexyl(meth)acrylate; and alkyl(meth)acrylates having a linear alkyl group with 7 to 11 carbon atoms, such as n-heptyl(meth)acrylate, octyl(meth)acrylate, nonyl(meth)acrylate, decyl(meth)acrylate, and undecyl(meth)acrylate. and alkyl(meth)acrylates having a linear alkyl group having 12 to 30 carbon atoms, such as dodecyl(meth)acrylate (lauryl(meth)acrylate), tetradecyl(meth)acrylate, hexadecyl(meth)acrylate (cetyl(meth)acrylate), octadecyl(meth)acrylate (stearyl(meth)acrylate), docosyl(meth)acrylate (behenyl(meth)acrylate), tetracosyl(meth)acrylate, hexacosyl(meth)acrylate, and octacosyl(meth)acrylate.

[0027] Examples of alkyl(meth)acrylates having a branched alkyl group include alkyl(meth)acrylates having a branched alkyl group with 1 to 6 carbon atoms, such as s-butyl(meth)acrylate, t-butyl(meth)acrylate, isobutyl(meth)acrylate, isopentyl(meth)acrylate, and isoamyl(meth)acrylate; and alkyl(meth)acrylates having a branched alkyl group with 7 to 11 carbon atoms, such as isooctyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, isononyl(meth)acrylate, and isodecyl(meth)acrylate. (meth)acrylate, and alkyl (meth)acrylates having a branched alkyl group having 12 to 30 carbon atoms, such as isomyristyl (meth)acrylate, 2-propylheptyl (meth)acrylate, isoundecyl (meth)acrylate, isododecyl (meth)acrylate, isotridecyl (meth)acrylate, isopentadecyl (meth)acrylate, isohexadecyl (meth)acrylate, isoheptadecyl (meth)acrylate, isostearyl (meth)acrylate, and decyltetradecanyl (meth)acrylate.

[0028] Examples of the compound having a (meth)acryloyl group and a cyclic aliphatic hydrocarbon group (such as a cycloalkyl group) include cyclohexyl (meth)acrylate, 3,3,5-trimethylcyclohexyl (meth)acrylate, isobornyl (meth)acrylate, terpene (meth)acrylate, dicyclopentanyl (meth)acrylate, and dicyclopentenyl (meth)acrylate.

[0029] Examples of the compound having a (meth)acryloyl group and an aromatic hydrocarbon group include benzyl (meth)acrylate.

[0030] Examples of compounds having a (meth)acryloyl group and a group containing a polyoxyalkylene chain include polyethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, polypropylene glycol (meth)acrylate, methoxypolypropylene glycol (meth)acrylate, polybutylene glycol (meth)acrylate, and methoxypolybutylene glycol (meth)acrylate.

[0031] Examples of compounds having a (meth)acryloyl group and a group containing a heterocycle include N-acryloylmorpholine (ACMO) and tetrahydrofurfuryl (meth)acrylate.

[0032] An example of a compound having a (meth)acryloyl group and an alkoxy group is 2-methoxyethyl acrylate.

[0033] An example of a compound having a (meth)acryloyl group and a phenoxy group is phenoxyethyl (meth)acrylate.

[0034] Examples of compounds having a (meth)acryloyl group and a group containing a siloxane bond include silicone (meth)acrylates.

[0035] Examples of the compound having a (meth)acryloyl group and a halogeno group include trifluoromethyl (meth)acrylate, 2,2,2-trifluoroethyl (meth)acrylate, 1,1,1,3,3,3-hexafluoro-2-propyl (meth)acrylate, perfluoroethylmethyl (meth)acrylate, perfluoropropylmethyl (meth)acrylate, perfluorobutylmethyl (meth)acrylate, perfluoropentylmethyl (meth)acrylate, perfluorohexylmethyl (meth)acrylate, perfluoroheptylmethyl (meth)acrylate, perfluorooctylmethyl (meth)acrylate, perfluorononylmethyl (meth)acrylate, perfluorodecylmethyl (meth)acrylate, perfluoroundecylmethyl (meth)acrylate, perfluorododecylmethyl (meth)acrylate, perfluoro Examples of (meth)acrylates having a fluoro group include orotridecylmethyl (meth)acrylate, perfluorotetradecylmethyl (meth)acrylate, 2-(trifluoromethyl)ethyl (meth)acrylate, 2-(perfluoroethyl)ethyl (meth)acrylate, 2-(perfluoropropyl)ethyl (meth)acrylate, 2-(perfluorobutyl)ethyl (meth)acrylate, 2-(perfluoropentyl)ethyl (meth)acrylate, 2-(perfluorohexyl)ethyl (meth)acrylate, 2-(perfluoroheptyl)ethyl (meth)acrylate, 2-(perfluorooctyl)ethyl (meth)acrylate, 2-(perfluorononyl)ethyl (meth)acrylate, 2-(perfluorotridecyl)ethyl (meth)acrylate, and 2-(perfluorotetradecyl)ethyl (meth)acrylate.

[0036] Examples of the compound having a (meth)acryloyl group and a hydroxy group include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, and 12-hydroxylauryl (meth)acrylate, and hydroxyalkyl cycloalkane (meth)acrylates such as (4-hydroxymethylcyclohexyl)methyl (meth)acrylate.

[0037] Examples of the compound having a (meth)acryloyl group and a carboxy group include (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, monohydroxyethyl phthalate acrylate (e.g., "Aronix M5400" manufactured by Toagosei Co., Ltd.), and 2-acryloyloxyethyl succinate (e.g., "NK Ester A-SA" manufactured by Shin-Nakamura Chemical Co., Ltd.).

[0038] Examples of the compound having a (meth)acryloyl group and an amino group include N,N-dimethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, N,N-dimethylaminopropyl (meth)acrylate, and N,N-diethylaminopropyl (meth)acrylate.

[0039] Examples of the compound having a (meth)acryloyl group and an epoxy group include glycidyl (meth)acrylate, α-ethyl glycidyl (meth)acrylate, α-n-propyl glycidyl (meth)acrylate, α-n-butyl glycidyl (meth)acrylate, 3,4-epoxybutyl (meth)acrylate, 4,5-epoxypentyl (meth)acrylate, 6,7-epoxyheptyl (meth)acrylate, α-ethyl 6,7-epoxyheptyl (meth)acrylate, 3-methyl-3,4-epoxybutyl (meth)acrylate, 4-methyl-4,5-epoxypentyl (meth)acrylate, 5-methyl-5,6-epoxyhexyl (meth)acrylate, β-methylglycidyl (meth)acrylate, and α-ethyl β-methylglycidyl (meth)acrylate.

[0040] The compound having one (meth)acryloyl group may be a (meth)acrylic polymer having one (meth)acryloyl group at one end of a poly(meth)acrylate chain, such as "MM110C" manufactured by Kaneka Corporation.

[0041] The composition may contain one kind of the other polymerizable compounds described above, or may contain two or more kinds of them.

[0042] The content of the other polymerizable compounds may be 1% by mass or more, 2% by mass or more, 3% by mass or more, 4% by mass or more, or 5% by mass or more, and may be 15% by mass or less, 13% by mass or less, 11% by mass or less, or 9% by mass or less, based on the total mass of the composition.

[0043] The content of the other polymerizable compounds may be 30 parts by mass or more, 35 parts by mass or more, 40 parts by mass or more, or 45 parts by mass or more, and may be 90 parts by mass or less, 80 parts by mass or less, 70 parts by mass or less, or 60 parts by mass or less, relative to 100 parts by mass of the total content of the polymerizable components.

[0044] Polymer B is a random copolymer containing alkyl(meth)acrylate and hydroxyalkyl(meth)acrylate as monomer units. Note that what corresponds to polymer A does not correspond to polymer B. In the alkyl(meth)acrylate, the number of carbon atoms in the alkyl group may be 1 or more, 2 or more, or 3 or more, and may be 18 or less, 15 or less, 12 or less, 10 or less, 8 or less, 6 or less, or 5 or less. The alkyl group may be linear or branched.

[0045] As the alkyl (meth)acrylate, those alkyl (meth)acrylates that can be contained as other polymerizable compounds can be used. The alkyl (meth)acrylate as a monomer unit of polymer B preferably contains at least one selected from the group consisting of ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and isodecyl (meth)acrylate. It is particularly preferable that the alkyl (meth)acrylate contains butyl acrylate.

[0046] The Tg of the alkyl (meth)acrylate homopolymer may be 100° C. or lower, 50° C. or lower, 30° C. or lower, 10° C. or lower, 0° C. or lower, −10° C. or lower, −20° C. or lower, −30° C. or lower, or −40° C. or lower. The Tg of the alkyl (meth)acrylate homopolymer may be, for example, −100° C. or higher, or −80° C. or higher. When polymer B contains two or more types of alkyl (meth)acrylate, the Tg of the alkyl (meth)acrylate homopolymer means a value calculated based on the FOX formula.

[0047] The content of alkyl (meth)acrylate in polymer B may be 30% by mass or more, 50% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, or 85% by mass or more, and may be 98% by mass or less, 95% by mass or less, 90% by mass or less, or 88% by mass or less, based on the total mass of monomer units contained in polymer B.

[0048] In the hydroxyalkyl (meth)acrylate, the number of carbon atoms in the hydroxyalkyl group may be 1 or more, 2 or more, or 3 or more, and may be 18 or less, 15 or less, 12 or less, 10 or less, 8 or less, 6 or less, or 5 or less. In the hydroxyalkyl group, the hydroxy group may be bonded to a primary carbon of the alkyl group, or may be bonded to a secondary carbon of the alkyl group.

[0049] The hydroxyalkyl (meth)acrylate may be any of those described above as hydroxyalkyl (meth)acrylates that may be contained as other polymerizable compounds. The hydroxyalkyl (meth)acrylate as a monomer unit of polymer B preferably contains at least one selected from the group consisting of hydroxybutyl acrylate, hydroxypropyl acrylate, and hydroxyethyl acrylate. The hydroxyalkyl (meth)acrylate particularly preferably contains hydroxyethyl acrylate.

[0050] The content of hydroxyalkyl (meth)acrylate in polymer B may be 1% by mass or more, 5% by mass or more, 7% by mass or more, or 10% by mass or more, and may be 40% by mass or less, 30% by mass or less, 20% by mass or less, or 17% by mass or less, based on the total mass of monomer units contained in polymer B.

[0051] The mass ratio of the alkyl (meth)acrylate to the hydroxyalkyl (meth)acrylate (alkyl (meth)acrylate / hydroxyalkyl (meth)acrylate) contained in polymer B may be 50 / 50 or more, 60 / 40 or more, 70 / 30 or more, 80 / 20 or more, or 85 / 15 or more, and may be 99 / 1 or less, 98 / 2 or less, 97 / 3 or less, or 95 / 5 or less.

[0052] Polymer B may contain only alkyl (meth)acrylate and hydroxyalkyl (meth)acrylate as monomer units, or may contain other monomer units other than alkyl (meth)acrylate and hydroxyalkyl (meth)acrylate. As the other monomer units, those described above as compounds having a (meth)acryloyl group and a cyclic aliphatic hydrocarbon group, an aromatic hydrocarbon group, a group containing a polyoxyalkylene chain, a group containing a heterocycle, an alkoxy group, a phenoxy group, a group containing a siloxane bond, a halogeno group, a carboxy group, an amino group, or an epoxy group can be used.

[0053] The content of other monomer units in polymer B may be 0.1% by mass or more, and may be 20% by mass or less, 15% by mass or less, 10% by mass or less, or 5% by mass or less, based on the total mass of the monomer units contained in polymer B.

[0054] The Mw of polymer B may be 100,000 or more, 150,000 or more, 200,000 or more, or 250,000 or more. The Mw of polymer B may be 1,000,000 or less, 800,000 or less, 600,000 or less, 500,000 or less, or 400,000 or less.

[0055] The Mw / Mn of polymer B may be 1.0 or more, or 1.1 or more, and may be 2.5 or less, 2.2 or less, 2.0 or less, or 1.8 or less.

[0056] The content of polymer B may be 0.5% by mass or more, 0.8% by mass or more, 1.0% by mass or more, or 1.3% by mass or more, based on the total mass of the composition, and may be 20% by mass or less, 10% by mass or less, 7% by mass or less, or 5% by mass or less.

[0057] The content of polymer B may be 1 part by mass or more, 3 parts by mass or more, 7 parts by mass or more, or 10 parts by mass or more, and may be 30 parts by mass or less, 25 parts by mass or less, or 20 parts by mass or less, relative to 100 parts by mass of the total content of the polymerizable components.

[0058] The composition may further contain a thiol compound. When the composition contains a thiol compound, the heat resistance and elongation at break of the cured product can be further improved, and the tensile modulus of elasticity can be reduced. Furthermore, when the composition contains a silane compound together with the thiol compound, the adhesiveness of the cured product can be further improved. The thiol compound is a compound having one or more thiol groups. The thiol compound is preferably a polyfunctional thiol compound having two or more thiol groups. The number of thiol groups in the thiol compound may be 5 or less, or 4 or less.

[0059] The thiol group of the thiol compound may be a primary thiol group or a secondary thiol group. The primary thiol group is a thiol group bonded to a carbon atom bonded to one carbon atom and two hydrogen atoms, and the secondary thiol group is a thiol group bonded to a carbon atom bonded to two carbon atoms and one hydrogen atom. The thiol compound preferably has one or more secondary thiol groups, and more preferably has two or more secondary thiol groups.

[0060] The polyfunctional thiol compound may be, for example, a compound represented by the following formula (1), (2), or (3).

[0061] In formula (1), X １ , X ２ , X ３ and X ４ each independently represents a monovalent group having a thiol group or a hydrogen atom, and X １ , X ２ , X ３ and X ４ In formula (2), two or more of X are monovalent groups having a thiol group. ５ , X ６ and X ７ each independently represents a monovalent group having a thiol group or a hydrogen atom, and X ５ , X ６ and X ７ In formula (3), at least two of X are monovalent groups having a thiol group. ８ and X ９each independently represents a monovalent group having a thiol group, and R １ represents an alkylene group. １ may be an alkylene group having 2 to 10 carbon atoms. The monovalent group having a thiol group may be a group having a secondary thiol group represented by the following formula (11), or may be a group having a primary thiol group represented by the following formula (12) or (13). In formula (11), R ２ represents an alkylene group. ３ represents an alkylene group. ４ represents an alkylene group. ２ may be an alkylene group having 1 to 8 carbon atoms. ３ and R ４ may each independently be an alkylene group having 2 to 10 carbon atoms.

[0062] Examples of polyfunctional thiol compounds having a secondary thiol group include pentaerythritol tetrakis(3-mercaptobutyrate) represented by the following formula (1a) (e.g., Karenz MT PE1 manufactured by Resonac Corporation), 1,3,5-tris(2-(3-sulfanylbutanoyloxy)ethyl)-1,3,5-triazinane-2,4,6-trione represented by the following formula (2a) (e.g., Karenz MT NR1 manufactured by Resonac Corporation), and 1,4-bis(3-mercaptobutyryloxy)butane represented by the following formula (3a) (e.g., Karenz MT BD1 manufactured by Resonac Corporation).

[0063] Other examples of polyfunctional thiol compounds having a secondary thiol group include ethylene glycol bis(3-mercaptobutyrate), trimethylolethane tris(3-mercaptobutyrate), butanediol bis(3-mercaptobutyrate), pentaerythritol tri(3-mercaptobutyrate), trimethylolethane(3-mercaptobutyrate), trimethylolpropane tris(3-mercaptobutyrate), and dipentaerythritol hexakis(3-mercaptobutyrate).

[0064] Other examples of polyfunctional thiol compounds having a primary thiol group include pentaerythritol trippropanethiol, 1,2-ethanedithiol, 1,3-propanedithiol, 1,4-butanedithiol, 2,3-butanedithiol, 1,5-pentanedithiol, 1,6-hexanedithiol, 1,8-octanedithiol, 1,10-decanedithiol, 1,3-benzenedithiol, 1,4-benzenedithiol, 4,4'-thiobisbenzenethiol, 4,4'-biphenyldithiol, 1,5-dimercaptonaphthalene, 4,5 -bis(mercaptomethyl)-ortho-xylene, 1,3,5-benzenetrithiol, 1,4-butanediol bis(thioglycolate), dithioethythritol, 3,6-dioxa-1,8-octanedithiol, 3,7-dithia-1,9-nonanedithiol, bis(2-mercaptoethyl)sulfide, ethylene glycol bis(mercaptoacetate), ethylene glycol bis(3-mercaptopropionate), ethylene glycol bis(3-mercaptoisobutyrate), butanediol bis(mercaptoacetate), butane Diol bis(3-mercaptopropionate), butanediol bis(3-mercaptoisobutyrate), pentaerythritol tri(mercaptoacetate), pentaerythritol tri(3-mercaptopropionate), pentaerythritol tri(3-mercaptoisobutyrate), pentaerythritol tetrakis(mercaptoacetate), pentaerythritol tetrakis(3-mercaptopropionate), pentaerythritol tetrakis(3-mercaptoisobutyrate), trimethylolethane(mercaptoacetate) ester), trimethylolethane (3-mercaptopropionate), trimethylolethane (3-mercaptoisobutyrate), trimethylolpropane tris(mercaptoacetate), trimethylolpropane tris(3-mercaptopropionate), trimethylolpropane tris(3-mercaptoisobutyrate), dipentaerythritol hexakis(mercaptoacetate), dipentaerythritol hexakis(3-mercaptopropionate), dipentaerythritol hexakis(3-mercaptoisobutyrate), 1,4-bis(3-mercaptopropyloxy)butane, tris[(3-mercaptopropionyloxy)ethyl]isocyanurate, and tetraethylene glycol bis(3-mercaptopropionate).

[0065] The composition may contain one or more of the above thiol compounds.

[0066] The content of the thiol compound may be 0.01% by mass or more, or 0.02% by mass or more, and may be 2% by mass or less, 1% by mass or less, 0.5% by mass or less, 0.3% by mass or less, or 0.1% by mass or less, based on the total mass of the composition.

[0067] The composition may further contain a silane compound, which can adjust the viscosity of the composition, as well as the thermal conductivity, elongation at break, and tensile modulus of the cured product.

[0068] The silane compound may have an alkoxy group bonded to a silicon atom. The alkoxy group may be a methoxy group or an ethoxy group. The number of alkoxy groups bonded to a silicon atom may be 1 or more, 2 or more, or 3 or more, and may be 4 or less.

[0069] The silane compound may have a phenyl group, an epoxy group, a (meth)acryloyl group, an amino group, a ureido group, a mercapto group, an isocyanate group, etc. The silane compound preferably has an alkoxy group bonded to a silicon atom and at least one group selected from the group consisting of a phenyl group, an epoxy group, a (meth)acryloyl group, and an amino group, and more preferably has an alkoxy group bonded to a silicon atom and an epoxy group.

[0070] Examples of silane compounds having an alkoxy group and a phenyl group bonded to a silicon atom include phenyltrimethoxysilane and phenyltriethoxysilane. Examples of silane compounds having an alkoxy group and an epoxy group bonded to a silicon atom include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 3-glycidoxypropylmethyldiethoxysilane.

[0071] Examples of silane compounds having an alkoxy group and a (meth)acryloyl group bonded to a silicon atom include 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, and 3-(meth)acryloxypropylmethyldiethoxysilane.

[0072] In a silane compound having an alkoxy group and an amino group bonded to a silicon atom, the amino group is a primary amino group (—NH ２ ) or a secondary amino group (—NH—). Examples of silane compounds having an alkoxy group and an amino group bonded to a silicon atom include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, and N-phenyl-3-aminopropyltrimethoxysilane.

[0073] The content of the silane compound may be 0.01% by mass or more, 0.02% by mass or more, or 0.05% by mass or more, and may be 5% by mass or less, 3% by mass or less, 2% by mass or less, 1% by mass or less, or 0.5% by mass or less, based on the total mass of the composition.

[0074] The composition may further contain a polymerization initiator. The polymerization initiator may be, for example, a thermal polymerization initiator that generates radicals by heat, a photopolymerization initiator that generates radicals by light, etc. The polymerization initiator is preferably a thermal polymerization initiator.

[0075] When the composition contains a thermal polymerization initiator, a cured product of the composition can be obtained by applying heat to the composition. In this case, the composition may be a composition that is cured by heating preferably at 110°C or higher, more preferably 120°C or higher, and even more preferably 130°C or higher, and may be a composition that is cured by heating at, for example, 200°C or lower, 190°C or lower, or 180°C or lower. The heating time when heating the composition may be appropriately selected depending on the composition of the composition so that the composition is suitably cured. After the composition has been cured (first curing), it may be further heated to be cured (second curing). When the first curing is carried out by heating, the second curing may be carried out at a temperature different from that of the first curing.

[0076] Examples of the thermal polymerization initiator include azo compounds and organic peroxides. Examples of azo compounds include azobisisobutyronitrile, azobis-4-methoxy-2,4-dimethylvaleronitrile, azobiscyclohexanone-1-carbonitrile, and azodibenzoyl. Examples of organic peroxides include benzoyl peroxide, lauroyl peroxide, di-t-butyl peroxide, di-t-hexyl peroxide, di-t-butylperoxyhexahydroterephthalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, 1,1-t-butylperoxy-3,3,5-trimethylcyclohexane, t-butylperoxyisopropyl carbonate, t-butylperoxy-2-ethylhexyl monocarbonate, and t-butylperoxybenzoate. These may be used alone or in combination as the thermal polymerization initiator. From the viewpoint of providing a cured product with even better thermal conductivity, the thermal polymerization initiator may be a compound having a peroxy ester structure, such as 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexyl monocarbonate, or t-butylperoxybenzoate.

[0077] The one-minute half-life temperature of the thermal polymerization initiator may be 80°C or higher, 90°C or higher, 100°C or higher, 110°C or higher, 120°C or higher, 130°C or higher, 140°C or higher, 150°C or higher, 160°C or higher, or 165°C or higher. The one-minute half-life temperature of the thermal polymerization initiator may be 200°C or lower, 195°C or lower, 190°C or lower, 185°C or lower, 180°C or lower, 175°C or lower, or 170°C or lower. The one-minute half-life temperature of the thermal polymerization initiator refers to a set temperature at which, when a sample of the thermal polymerization initiator dissolved in benzene to a concentration of 0.10 mol / L is sealed in a nitrogen-purged glass tube and placed at a certain set temperature, it takes one minute for the thermal polymerization initiator in benzene to decompose and the concentration to be reduced by half.

[0078] The one-hour half-life temperature of the thermal polymerization initiator may be 50°C or higher, 60°C or higher, 70°C or higher, 80°C or higher, 90°C or higher, 95°C or higher, 100°C or higher, 105°C or higher, 110°C or higher, 115°C or higher, or 120°C or higher. The one-hour half-life temperature of the thermal polymerization initiator may be 150°C or lower, 140°C or lower, 130°C or lower, or 125°C or lower. The one-hour half-life temperature of the thermal polymerization initiator means a set temperature at which, when a sample of the thermal polymerization initiator dissolved in benzene to a concentration of 0.10 mol / L is sealed in a nitrogen-purged glass tube and placed at a certain set temperature, it takes one hour for the thermal polymerization initiator in benzene to decompose and the concentration to be reduced by half.

[0079] The content of the polymerization initiator is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, even more preferably 0.1 parts by mass or more, and particularly preferably 0.5 parts by mass or more, relative to 100 parts by mass of the total content of the polymerizable components, from the viewpoint of allowing the polymerization to proceed smoothly. The content of the polymerization initiator is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and even more preferably 3 parts by mass or less, relative to 100 parts by mass of the total content of the polymerizable components, from the viewpoint of ensuring that the molecular weight of the polymer in the cured product of the composition falls within a suitable range and suppressing decomposition products.

[0080] The composition may further contain an antioxidant from the viewpoint of improving the thermal reliability of the cured product. The antioxidant may be, for example, a phenol-based antioxidant, a benzophenone-based antioxidant, a benzoate-based antioxidant, a hindered amine-based antioxidant, a benzotriazole-based antioxidant, or the like, and is preferably a phenol-based antioxidant.

[0081] The phenolic antioxidant has, for example, a hindered phenol structure (hindered phenol ring). The hindered phenol structure (hindered phenol ring) may be, for example, a structure in which t-butyl groups are bonded to one or both of the ortho positions relative to the hydroxyl group on the phenol ring. The phenolic antioxidant may have one or more such hindered phenol rings, preferably two or more, more preferably three or more, and even more preferably four or more.

[0082] The content of the antioxidant may be 0.1 mass % or more, 0.2 mass % or more, or 0.3 mass % or more, and may be 5 mass % or less, 3 mass % or less, 1 mass % or less, or 0.7 mass % or less, based on the total mass of the composition.

[0083] The metal forming the metal particles may be, for example, silver, gold, copper, aluminum, etc. From the viewpoint of excellent thermal conductivity of the cured product, the metal particles are preferably silver particles. The metal content in the metal particles is preferably 90 mass% or more, more preferably 95 mass% or more, even more preferably 98 mass% or more, and particularly preferably 99 mass% or more, based on the total mass of the metal particles. The metal particles may be particles consisting essentially of metal (particles in which substantially 100 mass% of the particles are metal, or particles consisting only of metal and unavoidable impurities).

[0084] The thermal conductivity of the metal particles may be 200 W / (m·K) or more, 250 W / (m·K) or more, 300 W / (m·K) or more, 350 W / (m·K) or more, or 400 W / (m·K) or more, from the viewpoint of providing a cured product with better thermal conductivity.

[0085] The shape of the metal particles may be flaky, spherical, blocky, dendritic, plate-like, etc. From the viewpoint of achieving superior thermal conductivity in the cured product, the shape of the metal particles is preferably flaky. Two or more types of metal particles having different shapes may be used as the metal particles.

[0086] From the viewpoint of providing a cured product with superior thermal conductivity, the average particle size of the metal particles is preferably 1.0 μm or more, 3.0 μm or more, or 5.0 μm or more, and 16.0 μm or less, 14.0 μm or less, 12.0 μm or less, or 10.0 μm or less. The average particle size of the metal particles can be measured using a laser diffraction particle size distribution measuring device (laser diffraction method).

[0087] The BET specific surface area of ​​the metal particles is 0.08 m ２ / g or more, or 0.1m ２ / g or more, and ２ / g or less, 0.8m ２ / g or less, or 0.5m ２ / g or less.

[0088] The content of the metal particles may be 50% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, or 83% by mass or more, based on the total mass of the composition, from the viewpoint of providing a cured product with better thermal conductivity. The content of the metal particles is preferably 98% by mass or less, more preferably 95% by mass or less, even more preferably 90% by mass or less, and particularly preferably 87% by mass or less, based on the total mass of the composition, from the viewpoint of further improving the adhesiveness of the cured product.

[0089] The content of the metal particles may be 10% by volume or more, 20% by volume or more, 30% by volume or more, or 33% by volume or more, based on the total volume of the composition, from the viewpoint of providing a cured product with better thermal conductivity. The content of the metal particles is preferably 90% by volume or less, more preferably 70% by volume or less, even more preferably 50% by volume or less, and particularly preferably 40% by volume or less, based on the total volume of the composition, from the viewpoint of further improving the adhesiveness of the cured product.

[0090] The composition may further contain non-metallic particles. The non-metallic particles are particles other than the above-mentioned metal particles. The non-metallic particles may be composed of organic materials such as acrylic resin, styrene resin, urethane resin, polyimide resin, epoxy resin, etc., or inorganic materials such as silica (silicon dioxide) and glass. The non-metallic particles may function as gap fillers (spacers). The average particle size of the non-metallic particles may be, for example, 10 μm or more, or 20 μm or more, and may be 100 μm or less. The average particle size of the non-metallic particles can be measured by laser diffraction.

[0091] The content of the non-metallic particles may be 0.05% by weight or more, 0.1% by weight or more, or 0.15% by weight or more, based on the total weight of the composition, and may be 5% by weight or less, 3% by weight or less, 1% by weight or less, 0.5% by weight or less, or 0.3% by weight or less.

[0092] The composition may further contain other additives as needed. Examples of the other additives include thixotropic agents, surface treatment agents (excluding the above-mentioned silane compounds), dispersants, curing accelerators, colorants, crystal nucleating agents, heat stabilizers, foaming agents, flame retardants, vibration dampers, dehydrating agents, and flame retardant aids (e.g., metal oxides). The content of the other additives may be 0.1% by mass or more and 1% by mass or less, based on the total mass of the composition.

[0093] The composition is preferably liquid at 25°C. This allows it to be suitably applied to the surface of an adherend such as a heat source or cooling member, and further enhances adhesion to the coated surface. The composition may be solid at 25°C, and in this case, it is preferable that it becomes liquid upon heating (for example, at 50°C or higher).

[0094] The cured product of the above-mentioned composition has thermal conductivity, and therefore is suitable for applications such as heat dissipation materials, pressure sensitive adhesives, die attach materials, structural adhesives, battery binders, stress relief agents, sealants, coating agents, paints, etc., and is particularly suitable for use as a composition for forming a heat dissipation material. Similarly, the cured product of the above-mentioned composition has excellent adhesiveness, and is therefore suitable for each of the above-mentioned applications. Specifically, the cured product of the above-mentioned composition can be suitably used as a heat dissipation material for semiconductor components, and is particularly suitable for use in heat dissipation applications for semiconductor packages used in personal computers, servers, base stations, etc.

[0095] [Article] Next, an article including a cured product of the above-described composition (hereinafter simply referred to as "cured product") will be described. The article according to one embodiment includes a heat source and a cured product in thermal contact with the heat source. Below, an electronic component will be described as a more specific example of the article. FIG. 1 is a schematic cross-sectional view showing one embodiment of an electronic component including the cured product. The electronic component 1A shown in FIG. 1 includes a semiconductor chip 21 as a heat source and a heat sink 22 as a heat dissipation section.

[0096] The electronic component 1A includes a cured product 11 provided between a semiconductor chip 21 and a heat sink 22. The cured product 11 is a cured product of the composition described above.

[0097] Because the cured product 11 has thermal conductivity, it acts as a thermally conductive material (thermal interface material) in the electronic component 1A, conducting heat from the semiconductor chip 21 to the heat sink 22. The heat is then dissipated to the outside from the heat sink 22. Because the cured product 11 has excellent adhesive properties, it can effectively conduct heat generated from the semiconductor chip 21 to the heat sink 22.

[0098] The cured product 11 can also be obtained by disposing a liquid composition (composition set) between the semiconductor chip 21 and the heat sink 22 and then curing it. The curing means and curing conditions for the composition can be adjusted depending on the composition of the composition or the type of polymerization initiator.

[0099] 1, the cured product 11 is disposed so as to be in direct contact with the semiconductor chip 21 and the heat sink 22, but the cured product 11 need only be in thermal contact with the heat source, and in another embodiment, the cured product 11 may be disposed so as to be in contact with the heat source (semiconductor chip) via another member. Furthermore, the composition does not necessarily need to be disposed so as to be in direct contact with a heat dissipation member such as a heat sink, but may be disposed so as to be in thermal contact with the heat dissipation member.

[0100] Fig. 2 is a schematic cross-sectional view showing another embodiment of an electronic component including a cured material. The electronic component 1B shown in Fig. 2 is a processor including a semiconductor chip 21 as a heat source arranged on one surface of a substrate 23 via an underfill 24, a heat sink 22 as a heat dissipation section, and a heat spreader 25 provided between the semiconductor chip 21 and the heat sink 22. A first cured material 11 is provided between the semiconductor chip 21 and the heat spreader 25 so as to be in contact with the semiconductor chip 21. A second cured material 11 is provided between the heat spreader 25 and the heat sink 22.

[0101] The substrate 23, the underfill 24, and the heat spreader 25 may be made of materials commonly used in the art. For example, the substrate 23 may be a laminate substrate, the underfill 24 may be made of a resin such as an epoxy resin, and the heat spreader 25 may be a metal plate.

[0102] The first cured product 11 and the second cured product 11 are cured products of the above-mentioned composition. The first cured product 11 is in direct contact with the semiconductor chip 21, which is the heat source, while the second cured product 11 is in thermal contact with the semiconductor chip 21, which is the heat source, via the first cured product 11 and the heat spreader 25.

[0103] The first cured product 11 and the second cured product 11 have thermal conductivity and therefore function as a thermally conductive material (thermal interface material) in the electronic component 1B. That is, the first cured product 11 promotes thermal conduction from the semiconductor chip 21 to the heat spreader 25. The second cured product 11 also promotes thermal conduction from the heat spreader 25 to the heat sink 22. Then, the heat is dissipated from the heat sink 22 to the outside.

[0104] Since the first hardened material 11 and the second hardened material 11 also have excellent adhesive properties, the first hardened material 11 and the second hardened material 11 can more effectively conduct the heat generated from the semiconductor chip 21 to the heat spreader 25, and further can more effectively conduct the heat to the heat sink 22.

[0105] The first cured product 11 and the second cured product 11 can also be obtained by placing a liquid composition between the semiconductor chip 21 and the heat spreader 25, or between the heat spreader 25 and the heat sink 22, and then curing it.

[0106] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples in any way.

[0107] In the examples and comparative examples, the following components were used. Polymer A1: a (meth)acrylic polymer having (meth)acryloyl groups at both ends of a poly(meth)acrylate chain ("RC310C" manufactured by Kaneka Corporation, Mw: 30,000, viscosity at 23°C: 760 Pa·s, Tg: -44°C) Polymerizable compound 1: 2-ethylhexyl acrylate ("AEH" manufactured by Nippon Shokubai Co., Ltd.) Polymerizable compound 2: isodecyl acrylate ("FA-111A" manufactured by Resonac Corporation) Polymerizable compound 3: 4-hydroxybutyl acrylate (manufactured by Osaka Organic Chemical Industry Ltd.) Polymerizable compound 4: N-acryloylmorpholine ("ACMO" manufactured by KJ Chemicals Co., Ltd.) Polymerizable compound 5: 2-acryloyloxyethyl succinate ("NK Ester A-SA" manufactured by Shin-Nakamura Kogyo Co., Ltd.)

[0108] Polymer B1: a random copolymer containing butyl acrylate (Tg of homopolymer: -55°C) and hydroxyethyl acrylate as monomer units (manufactured by Resonac Corporation, butyl acrylate:hydroxyethyl acrylate (mass ratio) = 88:12, Mw = 330,000, Mw / Mn = 1.5); Polymer b1: a triblock copolymer in which a polymethyl methacrylate block, a poly-n-butyl acrylate block, and a polymethyl methacrylate block are bonded in this order (manufactured by Kuraray Co., Ltd., "CLARITY (registered trademark) LA3710", methyl methacrylate content based on the total mass of monomer units: 15 mass%, Mw: 150,000);

[0109] Thiol compound 1: 1,4-bis(3-mercaptobutyryloxy)butane (manufactured by Resonac Corporation, "Karenz MT BD1") Thiol compound 2: pentaerythritol tetrakis(3-mercaptobutyrate) (manufactured by Resonac Corporation, "Karenz MT PE1") Thiol compound 3: 1,3,5-tris(2-(3-sulfanylbutanoyloxy)ethyl)-1,3,5-triazinane-2,4,6-trione (manufactured by Resonac Corporation, "Karenz MT NR1")

[0110] Silane compound 1: phenyltrimethoxysilane ("KBM-103" manufactured by Shin-Etsu Chemical Co., Ltd.) Silane compound 2: 3-glycidoxypropyltrimethoxysilane ("KBM-403" manufactured by Shin-Etsu Chemical Co., Ltd.) Silane compound 3: 3-methacryloxypropyltrimethoxysilane ("KBM-503" manufactured by Shin-Etsu Chemical Co., Ltd.) Silane compound 4: N-phenyl-3-aminopropyltrimethoxysilane ("KBM-573" manufactured by Shin-Etsu Chemical Co., Ltd.)

[0111] Polymerization initiator 1: t-butylperoxy-2-ethylhexyl monocarbonate (manufactured by NOF Corporation, "Perbutyl E", 1-minute half-life temperature: 161.4°C, 1-hour half-life temperature: 119.3°C) Polymerization initiator 2: t-butyl peroxybenzoate (manufactured by NOF Corporation, "Perbutyl Z", 1-minute half-life temperature: 166.8°C, 1-hour half-life temperature: 124.7°C)

[0112] Antioxidant 1: Phenolic antioxidant ("Irganox 1010" manufactured by BASF Japan Ltd.)

[0113] Metal particle 1: scaly silver particles (“Silcoat AgC-2262” manufactured by Fukuda Metal Industry Co., Ltd., average particle size: 5.3 μm, BET specific surface area: 0.1 to 0.4 m ２ / g) Non-metallic particles 1: Gap filler (manufactured by Hayakawa Rubber Co., Ltd., "SD-BD", average particle size: 50 μm)

[0114] [Preparation of Compositions and Cured Products] Compositions of each Example and Comparative Example were obtained by mixing the components in the blending ratios shown in Tables 1 and 2. Each composition of each Example and Comparative Example was filled into a 10 cm × 10 cm × 0.5 mm mold (made of SUS plate), covered with a SUS plate, and then heated at 150°C for 90 minutes to cure, yielding cured products with a thickness of 0.5 mm.

[0115] [Viscosity of Composition] The viscosity of the composition was measured using an E-type viscometer (TV100-E, manufactured by Toki Sangyo Co., Ltd.) at a rotation speed of 1 rpm.

[0116] [Adhesion of Composition] An electronic component including a semiconductor chip on a copper substrate was prepared. Using a syringe, 0.36 g of the composition was applied to the surface of the semiconductor chip, resulting in a composition thickness of 50 μm. An adhesive was also applied around the semiconductor chip on the copper substrate. Next, a heat spreader was placed on the surface coated with the composition and adhesive, and pressure was applied in the loading direction under atmospheric conditions at a temperature of 25°C and a pressure of 0.1 MPa for 1 to 2 seconds. The composition was then cured by heating at 150°C for 90 minutes to obtain a package. The package was observed from the heat spreader side using an ultrasonic testing instrument (SAT), and an SAT image was obtained. From the SAT image, the adhesive area ratio ((b / a) × 100 [%]) of the adhesive area b between the cured composition and the heat spreader to the heat spreader area a was calculated and evaluated according to the following criteria. A: Adhesion area ratio is 95% or more. B: Adhesion area ratio is 90% or more but less than 95%. C: Adhesion area ratio is 60% or more but less than 90%. D: Adhesion area ratio is less than 60%.

[0117] [Heat resistance of cured product] A 0.5 mm thick cured product was cut into a 3 cm x 3 cm piece, and its weight (initial weight) was measured. The piece was then placed in a thermostatic bath at 150°C, removed after 1000 hours, and re-measured (weight after 1000 hours). The weight loss was calculated using the following formula: Weight loss (%) = {(initial weight - weight after 1000 hours) / initial weight} x 100

[0118] [Thermal Conductivity of Cured Product] A 0.5 mm thick cured product was cut into a 10 mm x 10 mm x 0.5 mm square and blackened with graphite spray. The thermal diffusivity was measured at 25°C using a xenon flash method ("LFA447 nanoflash" manufactured by NETZSCH-Geratebau GmbH, Selb / Bayern). The thermal conductivity of the cured product in the thickness direction was calculated based on the product of this value, the density measured by the Archimedes method, and the specific heat at 25°C measured with a differential scanning calorimeter ("DSC250" manufactured by TA Instruments) according to the following formula: Thermal conductivity λ (W / (m·K)) = α x ρ x Cp α: thermal diffusivity (m ２ / s) ρ: Density (kg / cm ３ ) Cp: specific heat (capacity) (kJ / (kg K))

[0119] [Elongation at break and tensile modulus of cured product] The elongation at break and tensile modulus of cured product at 25°C were measured using a tensile tester ("Autograph EZ-TEST EZ-S" manufactured by Shimadzu Corporation). Measurements were carried out on a cured product measuring 0.5 mm (thickness) × 5 mm (width) × 30 mm (length) at a chuck distance of 20 mm and a pulling rate of 5 mm / min in accordance with JIS K7161.

[0120] The physical properties of the compositions and cured products thereof in each of the Examples and Comparative Examples were measured, and the results are shown in Tables 1 and 2. In Tables 1 and 2, the "amount of metal particles (vol %)" means the content of metal particles 1 based on the total volume of the composition.

[0121]

[0122]

[0123] 1A, 1B...electronic component, 11...cured product of composition, 21...semiconductor chip (heat source), 22...heat sink, 23...substrate, 24...underfill, 25...heat spreader.

Claims

1. A composition comprising: a (meth)acrylic polymer having (meth)acryloyl groups at both ends of the poly(meth)acrylate chain; a random copolymer containing alkyl (meth)acrylate and hydroxyalkyl (meth)acrylate as monomer units; and metal particles.

2. The composition according to claim 1, further comprising a thiol compound.

3. The composition of claim 2, further comprising a silane compound.

4. The composition according to any one of claims 1 to 3, wherein the metal particles are silver particles.

5. The composition according to any one of claims 1 to 3, which is used to form a heat dissipating material.

6. A cured product of the composition according to any one of claims 1 to 3.

7. An article comprising: a heat source; and the cured product according to claim 6, in thermal contact with the heat source.

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