Thermosetting resin composition

Abstract

To provide a thermosetting resin composition excellent in heat dissipation and handleability.SOLUTION: A thermosetting resin composition comprising an epoxy resin (A) that is liquid at 25 °C., a curing agent (B), an inorganic filler (C), and a wetting and dispersing agent (D), wherein the inorganic filler (C) has maximum values at least in a particle diameter range of 0.7 μm to 3 μm and in a particle diameter range of 10 μm to 30 μm in a volume-based particle diameter frequency distribution measured by a laser diffraction / scattering method, A content of the inorganic filler (C) is 100 parts by weight to 300 parts by weight with respect to 100 parts by weight of a total amount of the epoxy resin (A) and the curing agent (B), the wetting and dispersing agent (D) is a polyether phosphate ester polymer having a number average molecular weight (Mn) of 1700 to 4000, and a content of the wetting and dispersing agent (D) is 2 parts by weight or more with respect to 100 parts by weight of the inorganic filler (C).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a thermosetting resin composition having excellent thermal conductivity. [Background technology]

[0002] In recent years, there has been a trend toward increasing heat generation due to the high-density packaging of electronic components. This heat generation causes problems such as reduced efficiency, and therefore high heat dissipation properties are required not only for the electronic components themselves but also for the laminate substrates on which they are mounted and the thermosetting resin compositions and other packaging materials.

[0003] As a mounting material with excellent heat dissipation properties, for example, a resin composition has been disclosed which contains an inorganic filler and an epoxy resin, and in which the frequency distribution of the volumetric particle size of the inorganic filler measured with a laser diffraction / scattering particle size distribution analyzer has maximum values ​​at least within the particle size range of 0.01 μm or more and less than 3.0 μm and within the particle size range of 3.0 μm or more and less than 10.0 μm, and the maximum particle size is less than 45 μm (Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2018-138634 Summary of the Invention [Problem to be solved by the invention]

[0005] The present inventors produced thermosetting resin compositions with reference to the invention described in Patent Document 1, and found that the obtained thermosetting resin compositions sometimes had high viscosity, or sometimes had low viscosity immediately after production but gradually increased in viscosity thereafter, and confirmed that further optimization of the thermosetting resin compositions was necessary from the viewpoint of handleability.

[0006] An object of the present invention is to provide a thermosetting resin composition that is excellent in heat dissipation properties and handleability. [Means for solving the problem]

[0007] As a result of extensive research to achieve the above object, the present inventors have found that the above problems can be solved by a thermosetting composition containing the following components. Specifically, the present invention includes the following inventions.

[0008] [1] A thermosetting resin composition comprising an epoxy resin (A) that is liquid at 25°C, a curing agent (B), an inorganic filler (C), and a wetting / dispersing agent (D), the inorganic filler (C) has a maximum value at least in a particle size range of 0.7 μm to 3 μm and a maximum value in a particle size range of 10 μm to 30 μm in a volume-based particle size frequency distribution measured by a laser diffraction / scattering method, and contains 25% to 80% particles having a particle size of 10 μm or less; the content of the inorganic filler (C) is 100 parts by weight to 300 parts by weight per 100 parts by weight of the total amount of the epoxy resin (A) and the curing agent (B), the wetting and dispersing agent (D) is a polyether phosphate ester polymer having a number average molecular weight (Mn) of 1700 to 4000, The thermosetting resin composition has a content of the wetting and dispersing agent (D) of 2 parts by weight or more per 100 parts by weight of the inorganic filler (C).

[0009] [2] The thermosetting resin composition according to [1], wherein 90% by weight or more of the total amount of the inorganic filler (C) is anhydrous magnesium carbonate. [Effects of the Invention]

[0010] According to the present invention, a thermosetting resin composition having excellent heat dissipation properties and easy handling can be provided. Therefore, the thermosetting resin composition of the present invention can be suitably used as a semiconductor packaging material, such as an interlayer filler for semiconductors. DETAILED DESCRIPTION OF THE INVENTION

[0011] In the present invention, when a range is expressed as "A to B", it means A or more and B or less, unless otherwise specified.

[0012] <Thermosetting resin composition> The thermosetting resin composition of the present invention contains an epoxy resin (A) that is liquid at 25°C, a curing agent (B), an inorganic filler (C), and a wetting / dispersing agent (D) (hereinafter, these may be referred to as component (A), component (B), component (C), and component (D), respectively).

[0013] <Epoxy resin (A) that is liquid at 25°C> As component (A), a known epoxy resin that is liquid at 25°C can be used. In the present invention, "liquid at 25°C" means that the viscosity at 25°C, measured using the measurement method described in the Examples section below, is 500 Pa·s or less. The viscosity of component (A), measured under the above conditions, is preferably 0.01 Pa·s to 100 Pa·s. When multiple epoxy resins are used in combination, the viscosity of the multiple epoxy resins when mixed together should be within the above range, and epoxy resins that are solid at 25°C can also be used in combination as long as the viscosity is within the above range.

[0014] Examples of epoxy resins of component (A) include epoxy resins such as bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol AD ​​type epoxy resins, naphthalene type epoxy resins, biphenyl type epoxy resins, alicyclic epoxy resins, dicyclopentadiene type epoxy resins, and phenol novolac type epoxy resins, as well as polyglycidyl ethers obtained by reacting polyhydric phenols such as catechol and resorcinol, or polyhydric alcohols such as glycerin and polyethylene glycol with epihalohydrin, glycidyl ether esters obtained by reacting hydroxycarboxylic acids such as p-oxybenzoic acid with epihalohydrin, polyglycidyl esters obtained by reacting polycarboxylic acids such as phthalic acid and terephthalic acid with epihalohydrin, and glycidylamine type epoxy resins obtained by reacting 4,4-diaminodiphenylmethane, m-aminophenol, or the like with epihalohydrin. Among these epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins, and glycidylamine type epoxy resins are preferred. These epoxy resins may be used alone or in combination of two or more.

[0015] <Curing agent (B)> Component (B) is not particularly limited as long as it does not impair performance after curing, and examples thereof include dihydrazide compounds, dicyandiamide, imidazole compounds, imidazole adduct compounds, amine adduct compounds, and modified aliphatic polyamine compounds. Examples of dihydrazide compounds include adipic acid dihydrazide, sebacic acid dihydrazide, isophthalic acid dihydrazide, maleic acid dihydrazide, dodecanedioic acid dihydrazide, and Amicure VDH and Amicure UDH manufactured by Ajinomoto Technofine Co., Ltd. Examples of imidazole compounds include 2-phenylimidazole and 2-phenyl-4-methyl-5-hydroxymethylimidazole. Examples of imidazole adduct compounds include Amicure PN-23 and Amicure PN-R manufactured by Ajinomoto Technofine Co., Ltd. Examples of amine adduct compounds include Amicure MY-24 and Amicure MY-R manufactured by Ajinomoto Technofine Co., Ltd., and the adduct compounds disclosed in JP-A-57-100127 and JP-A-2017-178981. Examples of modified aliphatic polyamine compounds include Fujicure FXE-1000 manufactured by T&K TOKA Corporation. Among these curing agents listed as component (B), imidazole adduct compounds and amine adduct compounds are preferred. These curing agents may be used alone or in combination of two or more.

[0016] The content of component (B) in the thermosetting resin composition of the present invention is, for example, 5 to 50 parts by weight, and preferably 10 to 40 parts by weight, per 100 parts by weight of component (A).

[0017] <Inorganic filler (C)> The primary purpose of component (C) is to improve thermal conductivity. For this reason, component (C) preferably has a thermal conductivity of 2 W / (m·K) or higher. Furthermore, since a high Mohs hardness may damage the commonly used SUS (stainless steel) manufacturing equipment used in the production of thermosetting resin compositions, component (C) preferably has a Mohs hardness of 5 or less.

[0018] Examples of inorganic fillers for component (C) include magnesium carbonate, boron nitride, fused silica, crystalline silica, glass filler, aluminum hydroxide, and magnesium hydroxide. Among these inorganic fillers, magnesium carbonate is preferred, and anhydrous magnesium carbonate (magnesium carbonate that is not a hydrate) is more preferred. These inorganic fillers may be used alone or in combination of two or more. When two or more types are used in combination, anhydrous magnesium carbonate preferably accounts for 90% by weight or more of the total amount of component (C), and more preferably 95% by weight or more of the total amount of component (C) is anhydrous magnesium carbonate.

[0019] Component (C) has a maximum value in at least (i) a particle size range of 0.7 μm to 3 μm and (ii) a particle size range of 10 μm to 30 μm in the volume-based particle size frequency distribution measured by laser diffraction / scattering. Furthermore, in the volume-based particle size frequency distribution measured by laser diffraction / scattering, particles with a particle size of 10 μm or less account for 25% to 80% of the particles. The maximum particle size is not particularly limited, but is, for example, less than 100 μm. These values ​​can be measured by the measurement method described in the Examples section below.

[0020] The content of component (C) in the thermosetting resin composition of the present invention is 100 to 300 parts by weight, preferably 150 to 300 parts by weight, per 100 parts by weight of the epoxy resin (A) and curing agent (B) combined.

[0021] <Wetting and dispersing agent (D)> The main purposes of component (D) are to suppress an increase in viscosity of the thermosetting resin composition due to high loading of component (C) and to suppress secondary aggregation of component (C) (suppression of viscosity increase over time).

[0022] More specifically, the polyether phosphate ester polymer in component (D) may be a mono- or diester of polyoxyethylene alkyl ether phosphate, a mono- or diester of polyoxyethylene alkylaryl ether phosphate, or an alkali metal salt (e.g., sodium salt), ammonium salt, or alkanolamine salt thereof. Furthermore, component (D) has a number-average molecular weight (Mn) of 1700 to 4000, preferably 1800 to 3700. The number-average molecular weight in the present invention refers to the polystyrene-equivalent molecular weight measured by gel permeation chromatography (GPC), as described in the Examples section below. Commercially available products of component (D) include, for example, BYK-W 9010, BYK-LP C 22144, and BYK-LP W 21483 (manufactured by BYK Japan), DA-375, AQ-320, AQ-330, ED152, ED153, and ED154 (manufactured by Kusumoto Chemicals Co., Ltd.).

[0023] The content of component (D) in the thermosetting resin composition of the present invention is usually 2 parts by weight or more, preferably 2 to 8 parts by weight, per 100 parts by weight of component (C).

[0024] <Other ingredients> The thermosetting resin composition of the present invention may contain, as needed, reactive diluents, non-reactive diluents, additives (for example, organic fillers, flame retardants, sizing agents, coupling agents, colorants, thixotropic agents, antistatic agents, antifoaming agents, wetting and dispersing agents other than component (D), etc.).

[0025] <Method for preparing thermosetting resin composition> The method for preparing the thermosetting resin composition of the present invention employs common stirring and mixing equipment and mixing conditions similar to those used in the preparation of conventional thermosetting resin compositions. Equipment that can be used includes a mixing roll, a dissolver, a planetary mixer, a kneader, an extruder, a revolutionary rotation stirring and degassing device, and the like. During mixing, the epoxy resin or the like may be heated to dissolve and / or reduce viscosity and improve stirring and mixing efficiency. Cooling may also be performed as needed to remove frictional heat, reaction heat, and the like. The stirring and mixing time may be determined as needed and is not particularly limited.

[0026] <Curing conditions> The epoxy resin composition of the present invention can be cured, for example, by heating, at a curing temperature of, for example, 60°C to 150°C, and preferably 80°C to 130°C.

[0027] <Characteristics of the thermosetting resin composition of the present invention> The thermosetting resin composition of the present invention has excellent thermal conductivity when cured as described above. Specifically, the thermal conductivity measured by the method described below is 0.5 W / (m·K) or higher, preferably 1.0 W / (m·K) to 3.0 W / (m·K). The thermosetting resin composition of the present invention also has excellent handleability. More specifically, the viscosity immediately after production (initial viscosity) and the viscosity stability over time are excellent. Specifically, the thermosetting resin composition of the present invention has an initial viscosity and a viscosity after storage at 25°C for 7 days of 500 Pa·s or less, and a viscosity increase ratio (the value obtained by dividing the viscosity after storage at 25°C for 7 days by the initial viscosity) of 2.0 times or less. The initial viscosity and the viscosity after storage at 25°C for 7 days can be measured by the measurement method described in the Examples section below. [Example]

[0028] The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to these examples. Measurements and evaluations of physical properties were carried out as follows.

[0029] (Measurement of the frequency distribution of particle size on a volume basis) For the inorganic filler used in preparing each resin composition, a sample of only the inorganic filler was prepared separately according to the blending ratio of the filler to the resin composition. The frequency distribution of the volumetric particle size of the sample was measured under the conditions described below using the laser diffraction / scattering particle size distribution analyzer described below, and the maximum particle size and the proportion of particles having a particle size of 10 μm or less were determined. Equipment used: Microtrac Bell Corporation "Microtrac HRA" Pretreatment: Place the sample in a beaker, dilute with ethanol, and then disperse it in an ultrasonic disperser for 2 minutes to use as the sample solution. Number of measurements: 2 ·Particle permeability: Transmission Particle refractive index: 1.72 Solvent: Ethanol Solvent refractive index: 1.36 ·Measurement upper limit: 704μm ·Measurement lower limit: 0.122μm

[0030] (Viscosity measurement) For each resin composition, values ​​were measured at a temperature of 25° C. and a rotation speed of 2 rpm using a B-type viscometer (manufactured by Toki Sangyo Co., Ltd., product name: VISCOMETER BHII, rotor number: No. 7). (Evaluation of initial viscosity) The initial viscosity of each resin composition was measured according to the viscosity measurement method described above, and the obtained values ​​were evaluated for initial viscosity based on the following evaluation criteria. ○: Viscosity is 500 Pa·s or less. ×: Viscosity is higher than 500 Pa·s. (Evaluation of stability over time) According to the viscosity measurement method described above, the viscosity of each resin composition was measured after storing it at 25° C. for 7 days. The obtained values ​​were evaluated for stability over time based on the following evaluation criteria. ○: Viscosity after storage at 25°C for 7 days is 500 Pa·s or less and the viscosity increase ratio is 2.0 times or less. ×: Viscosity after storage at 25°C for 7 days is higher than 500 Pa·s and / or the viscosity increase ratio is higher than 2.0 times.

[0031] (Measurement of thermal conductivity) For the cured product of each resin composition prepared in the examples, the thermal diffusivity, specific gravity, and specific heat were measured using the following equipment, and the thermal conductivity was calculated by multiplying these three measured values. (1) Thermal diffusivity: NETZSCH Japan Laser Flash Analyzer "LFA45MicroFlash" (2) Specific gravity: Alpha Mirage Electronic Specific Gravity Meter SD-200L (3) Specific heat: NETZSCH Japan Co., Ltd. "DSC404Fl Pegasus"

[0032] (Measurement of number average molecular weight) The polyether phosphate ester polymer (component (D)) was measured by GPC under the following conditions using polystyrene of known molecular weight as a standard substance. ·Equipment used: HLC-8320 (manufactured by Tosoh Corporation) Column: TSKgel SuperHZ4000 (Tosoh Corporation) Standard polystyrene: S-2750 / S-1750 / S-1030 / S-450 / S-170 / S-68 / S-34 / S-9.0 / S-3.3 / S-1.2 Solvent (carrier): THF (tetrahydrofuran) ·Flow rate: 0.350mL / min Column temperature: 40℃ Detector: RI ·Injection volume: 10μL Sample preparation: 10 mg of the compound to be measured was dissolved in 10 mL of THF. ·How to calculate number average molecular weight (Mn): The multimodal peaks obtained by the GPC measurement were treated as a single group, and the peaks corresponding to the organic solvent were excluded to calculate the number average molecular weight (Mn). Note that when calculating the number average molecular weight (Mn), the value was rounded to the nearest tenth, taking into account the accuracy of the GPC.

[0033] (Examples 1 to 8, Comparative Examples 1 to 9) Each component was weighed (parts by weight) according to Tables 1 and 2, and stirred and mixed using a revolutionary rotating stirring and degassing apparatus ("Kakuhunter SK-300TVS-A" (Shashin Kagaku Co., Ltd.)) to prepare the thermosetting resin compositions of each example and comparative example. The physical properties of the obtained thermosetting resin compositions were measured and evaluated by the methods described above. The results are shown in Tables 1 and 2.

[0034] [Table 1]

[0035] [Table 2]

[0036] The components in Tables 1 and 2 are as follows: In the tables, the amount of each component is indicated in parts by weight. <Component (A): Epoxy resin> Component (A-1): jER807 (bisphenol F type epoxy, manufactured by Mitsubishi Chemical Corporation) Component (A-2): DER331 (bisphenol A epoxy resin, manufactured by OLIN) Component (A-3): ADEKA Resin EP-4005 (polyglycidyl ether of propylene oxide adduct of bisphenol A, manufactured by ADEKA Corporation) <Component (B): Hardener> Ingredient (B-1): Dicyandiamide (manufactured by Nippon Carbide Industries Co., Ltd.) Component (B-2): Epoxy-amine adduct compound disclosed in JP-A-57-100127 (manufactured by Taoka Chemical Co., Ltd.) Ingredient (B-3): K-37Y (12-aminododecanoic acid, manufactured by PTI Japan Co., Ltd.) <Component (C): Inorganic filler> Ingredient (C-1): Magthermo MS-PS (anhydrous magnesium carbonate, average particle size 14 μm, mode diameter 19 μm, manufactured by Konoshima Chemical Co., Ltd.) Ingredient (C-2): Magthermo MS-PS (anhydrous magnesium carbonate, average particle size 19 μm, mode diameter 22 μm, manufactured by Konoshima Chemical Co., Ltd.) Ingredient (C-3): Magthermo MS-S (anhydrous magnesium carbonate, average particle size 1.7 μm, mode diameter 1.4 μm, manufactured by Konoshima Chemical Co., Ltd.) Ingredient (C-4): Magthermo MS-S (anhydrous magnesium carbonate, average particle size 1.3 μm, mode diameter 1.3 μm, manufactured by Konoshima Chemical Co., Ltd.) Ingredient (C-5): Aerosil 200 (fumed silica, manufactured by Nippon Aerosil Co., Ltd.) <Component (D): Wetting and dispersing agent> Component (D-1): BYK-LP W 21483 (polyether phosphate ester polymer, number average molecular weight (Mn) 1800, manufactured by BYK Japan) Component (D-2): DA-375 (polyether phosphate ester polymer, number average molecular weight (Mn) 3600, manufactured by Kusumoto Chemicals Co., Ltd.) Component (D-3): AQ-320 (polyether phosphate ester polymer, number average molecular weight (Mn) 3700, manufactured by Kusumoto Chemicals Co., Ltd.) Component (D-4): BYK-LP C 22144 (polyether phosphate ester polymer, number average molecular weight (Mn) 1500, manufactured by BYK Japan) Component (D-5): BYK-W 9010 (polyether phosphate ester polymer, number average molecular weight (Mn) 1400, manufactured by BYK Japan) Component (D-6): AQ-330 (polyether phosphate ester polymer, number average molecular weight (Mn) 4200, manufactured by Kusumoto Chemicals Co., Ltd.) Ingredient (D-7): NACURE 4000 (alkyl phosphate ester polymer, manufactured by Kusumoto Chemicals Co., Ltd.) Component (D-8): BYK-LP C 22147 (highly branched amine polymer, manufactured by BYK Japan) Component (D-9): BYK-LP C 22435 (highly branched amine polymer, manufactured by BYK Japan) Ingredient (D-10): DISPERBYK-2155 (highly branched amine polymer, manufactured by BYK Japan) Ingredient (D-11): DISPERBYK-2055 (acrylate polymer, manufactured by BYK Japan)

Claims

1. A thermosetting resin composition comprising an epoxy resin (A) that is liquid at 25°C, a curing agent (B), an inorganic filler (C), and a wetting / dispersing agent (D), the inorganic filler (C) has a maximum value at least in a particle size range of 0.7 μm to 3 μm and a maximum value in a particle size range of 10 μm to 30 μm in a volume-based particle size frequency distribution measured by a laser diffraction / scattering method, and contains 25% to 80% particles having a particle size of 10 μm or less; the content of the inorganic filler (C) is 100 parts by weight to 300 parts by weight per 100 parts by weight of the total amount of the epoxy resin (A) that is liquid at 25°C and the curing agent (B), the wetting and dispersing agent (D) is a polyether phosphate ester polymer having a number average molecular weight (Mn) of 1,700 to 4,000; The thermosetting resin composition has a content of the wetting and dispersing agent (D) of 2 parts by weight or more per 100 parts by weight of the inorganic filler (C).

2. 2. The thermosetting resin composition according to claim 1, wherein 90% by weight or more of the inorganic filler (C) is anhydrous magnesium carbonate.

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