Resin compositions and thixotropic modifier compositions

Abstract

A novel resin composition with excellent dispersibility and workability of fillers; a thixotropic modification composition is provided. [Solution] One embodiment of the resin composition of the present invention is a resin composition comprising a thermosetting resin, a filler, a base oil, and a thickener, which satisfies either of the following conditions (i) or (ii). Condition (i): The content of the thickener relative to the total amount of the resin composition is 0.50 to 1.10% by mass. Condition (ii): The total content of the base oil and the thickener relative to the total amount of the resin composition is 3.50 to 8.50% by mass.

Description

[Technical Field]

[0001] The present invention relates to resin compositions and thixotropic modifiers. [Background technology]

[0002] Electronic control units installed in automobiles and other vehicles are sealed and secured with a material called a encapsulant to protect the wiring board and the electronic components mounted on that wiring board.

[0003] Thermistor temperature sensors generally come in several types, including one in which a thermistor element, consisting of an oxide sintered body of a transition metal with electrodes, is connected to lead wires and then coated with a protective sealant, and another in which external lead wires made of long insulated wires are connected, inserted into a protective tube, and then sealed with resin.

[0004] By securing electronic components with a sealing material, damage due to vibration can be prevented, and the intrusion of water and corrosive gases can be prevented.

[0005] As sealing materials, resin compositions are widely used, which are made by mixing thermosetting resins such as epoxy resins with additives appropriate to the purpose using a kneading machine.

[0006] Generally, fillers are sometimes added to resin compositions to adjust physical properties such as thermal conductivity and thermal expansion. However, since fillers tend to aggregate and settle in resin compositions, it has been difficult to cure the resin composition while the fillers are dispersed.

[0007] A technique has been disclosed in which a dispersant having a predetermined molecular structure is used to improve the dispersibility of fillers (for example, Patent Document 1). In addition, a technique has been disclosed in which a thixotropic agent is incorporated into a resin composition (for example, Patent Document 2). [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2012-57178 [Patent Document 2] Japanese Patent Publication No. 2017-122187 [Overview of the project] [Problems that the invention aims to solve]

[0009] However, the technologies described in Patent Document 1 or Patent Document 2 do not consider the fluidity of the resin composition for use as a encapsulant before curing, resulting in poor workability during resin casting. Therefore, there is a need for a novel resin composition that offers excellent dispersibility of fillers in the cured resin after curing and good workability during resin casting.

[0010] In view of the above-mentioned problems, the present invention aims to provide a novel resin composition with excellent dispersibility and workability of fillers; a thixotropic modifier composition. [Means for solving the problem]

[0011] One aspect of the present invention is a resin composition. The resin composition comprises a thermosetting resin, a filler, a base oil, and a thickener, and satisfies either of the following conditions (i) or (ii). Condition (i): The content of the thickener relative to the total amount of the resin composition is 0.5 to 1.1% by mass. Condition (ii): The total content of the base oil and the thickener relative to the total amount of the resin composition is 3.5 to 8.5% by mass.

[0012] In the resin composition according to the above embodiment, it is preferable that the thermal conductivity of the filler is 20 W / mK or higher.

[0013] In the resin composition according to the above embodiment, it is preferable that the filler contains alumina.

[0014] In the resin composition of the above aspect, it is preferable that the thickener contains a urea compound.

[0015] In the resin composition of the above aspect, it is preferable that the urea compound is one or more selected from alicyclic, aromatic, and aliphatic.

[0016] In the resin composition of the above aspect, it is preferable that the thermosetting resin contains an epoxy resin.

[0017] In the resin composition of the above aspect, it is preferably used as a sealing material for electronic components.

[0018] Another aspect of the present invention is a composition for thixotropic modification. The composition for thixotropic modification includes a base oil and a thickener, and is added to a resin composition containing a thermosetting resin and a filler, and is used for modifying the thixotropy of the resin composition. The composition for thixotropic modification satisfies either of the following conditions (i) or (ii). Condition (i): After the composition for thixotropic modification is added to the resin composition, the content of the thickener with respect to the total amount of the composition for thixotropic modification and the resin composition is 0.50 to 1.10% by mass. Condition (ii): After the composition for thixotropic modification is added to the resin composition, the total content of the base oil and the thickener with respect to the total amount of the composition for thixotropic modification and the resin composition is 3.50 to 8.50% by mass.

Advantages of the Invention

[0019] According to the present invention, a novel resin composition and a composition for thixotropic modification can be provided.

Embodiments for Carrying Out the Invention

[0020] Hereinafter, embodiments of the disclosed technology will be described in detail. In this specification, the notation "a~b" in the description of a numerical range represents a to b, unless otherwise specified.

[0021] In the following, if the upper and lower limits are listed separately, it shall be assumed that a numerical range is substantially disclosed by combining any upper and lower limit.

[0022] The term "aromatic" is not particularly limited and, unless otherwise specified, includes heterocycles.

[0023] The following describes the resin composition, thixotropic modifier composition, components, content, and manufacturing method according to this embodiment.

[0024] 1.Resin composition The resin composition of this embodiment comprises a thermosetting resin, a filler, a base oil, and a thickener. The resin composition of this embodiment may also contain other components. Each component of the resin composition is described below. However, this embodiment is not limited to this.

[0025] 1-1.Thermosetting resin The thermosetting resin in this embodiment is not particularly limited, and examples include epoxy resins, phenolic resins, maleimide resins, etc. For applications in electronic components, it is preferable to include epoxy resin due to its high water resistance, chemical resistance, and electrical insulation properties. The epoxy resin is not particularly limited, and known and conventional polyfunctional epoxy resins having at least two epoxy groups in one molecule can be used.

[0026] Specifically, examples include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol E type epoxy resin, bisphenol S type epoxy resin, bisphenol AD ​​type epoxy resin, naphthalene type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, alicyclic epoxy resin, glycidyl ether type epoxy resin, glycidyl ester type epoxy resin, and glycidylamine type epoxy resin.

[0027] The thermosetting resins described above may be used individually or in combination of two or more types.

[0028] 1-2. Filler The filler in this embodiment is not particularly limited and includes inorganic fillers, organic fillers, and the like.

[0029] Examples of inorganic fillers include metal oxides such as fused silica, silica, alumina, titanium oxide, magnesium oxide, calcium oxide, zinc oxide, yttrium oxide, zirconium oxide, cerium oxide, and ytterbium oxide; metal hydroxides such as aluminum hydroxide and magnesium hydroxide; metal carbides such as silicon carbide, titanium carbide, and tungsten carbide; clay minerals such as talc and mica; fillers with a ferrovskite crystal structure such as barium titanate and strontium titanate; and metal nitrides such as boron nitride, silicon nitride, and aluminum nitride.

[0030] As organic fillers, fluororesins such as polytetrafluoroethylene (PTFE), tetrafluoroethylene / ethylene copolymer (ETFE), tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene / hexafluoropropylene copolymer (FEP), polychlorotrifluoroethylene (PCTFE), polyvinylidene fluoride (PVDF), and polyvinyl fluoride (PVF); hydrocarbon resins such as cycloolefin polymer (COP) and cycloolefin copolymer (COC); etc. can be used.

[0031] The filler is preferably one that has thermal conductivity, and more preferably one with a thermal conductivity of 20 W / mK or higher, 25 W / mK or higher, 30 W / mK or higher, 40 W / mK or higher, etc. Furthermore, the filler is preferably an inorganic filler, and more preferably one of magnesium oxide, boron nitride, silicon nitride, aluminum nitride, alumina, etc., and more preferably one that contains alumina.

[0032] These fillers may be used individually or in combination of two or more types.

[0033] 1-3. Base oil The base oil in this embodiment is not particularly limited. For example, mineral oil, synthetic oil, animal or vegetable oil, or mixtures thereof can be used as appropriate. Specific examples include base oils from groups 1 to 5 of the API (American Petroleum Institute) base oil categories. Here, the API base oil categories are a broad classification of base oil materials defined by the American Petroleum Institute to create guidelines for base oils.

[0034] The mineral oil in this embodiment is not particularly limited, and preferred examples include paraffinic or naphthenic mineral oils obtained by applying one or more refining methods, such as solvent delamination, solvent extraction, hydrocracking, solvent dewaxing, catalytic dewaxing, hydrorefining, sulfuric acid washing, and clay treatment, to a lubricating oil fraction obtained by atmospheric distillation and vacuum distillation of crude oil. These can be used individually or in combination.

[0035] The synthetic oil in this embodiment is not particularly limited, and poly-α-olefins (PAOs) or hydrocarbon-based synthetic oils (oligomers) can be given as preferred examples. PAOs are homopolymers or copolymers of α-olefins. For example, α-olefins are compounds with a CC double bond at the terminal, such as butene, butadiene, hexene, cyclohexene, methylcyclohexene, octene, nonene, decene, dodecene, tetradecene, hexadecene, octadecene, and eicosene. Examples of hydrocarbon-based synthetic oils (oligomers) include homopolymers or copolymers of ethylene, propylene, or isobutene. These compounds can be used individually or as mixtures of two or more. Furthermore, as long as the CC double bond is at the terminal, these compounds may have any of the possible isomer structures, including branched or linear structures. Two or more of these structural isomers or positional isomers of the double bond can also be used in combination. Of these olefins, those with 5 or fewer carbon atoms have a low flash point, and those with 31 or more carbon atoms have high viscosity and are not very practical; therefore, the use of linear olefins with 6 to 30 carbon atoms is more preferable.

[0036] In this embodiment, GTL (gas-to-liquid) synthesized by the Fischer-Tropsch process, a natural gas liquefaction technology, may be used as the base oil. Compared to mineral oil base oil refined from crude oil, GTL has extremely low sulfur and aromatic content and an extremely high paraffin content, resulting in excellent oxidation stability and very low evaporation loss, making it suitable for use as the base oil of the present invention.

[0037] 1-4. Thickener The thickener in this embodiment is not particularly limited and may include tricalcium phosphate, alkali metal soap, alkali metal complex soap, alkaline earth metal soap, alkaline earth metal complex soap, alkali metal sulfonate, alkaline earth metal sulfonate, other metal soaps, terephthalate metal salt, triurea monourethane, diurea, tetraurea, other polyurea compounds, or fluororesins such as clay, silica (silicon dioxide) such as silica aerogel, and polytetrafluoroethylene. One or more of these can be used in combination. Furthermore, any other substance that can impart a viscosity to a liquid substance can be used.

[0038] Among those mentioned above, it is preferable to include urea compounds such as diurea, tetraurea, and other polyureas as thickeners, with diurea being more preferable.

[0039] Urea compounds are obtained by reacting a polyisocyanate component with a monoamine or diamine component. Examples of polyisocyanate components include phenylenediisocyanate, tolylenediisocyanate, diphenyldiisocyanate, diphenylmethanediisocyanate, octadecanediisocyanate, decanediisocyanate, and hexanediisocyanate.

[0040] The monoamine component can be an aliphatic monoamine, an alicyclic monoamine, or an aromatic monoamine. Examples of aliphatic monoamines include hexylamine, octylamine, dodecylamine, hexadecylamine, octadecylamine, stearylamine, and oleylamine. Examples of alicyclic monoamines include cyclohexylamine. Examples of aromatic monoamines include aniline and p-toluidine.

[0041] Diamine components include aliphatic, alicyclic, or aromatic diamines. Examples include C2-C12 diamines such as ethylenediamine, trimethylenediamine, tetramethylenediamine, hexamethylenediamine, octamethylenediamine, and decamethylenediamine; alicyclic diamines such as diaminocyclohexane; and aromatic diamines such as phenylenediamine, benzidine, diaminostilbene, and tolidine.

[0042] The urea compound is preferably one or more selected from alicyclic, aromatic, and aliphatic compounds, and more preferably aromatic.

[0043] Aromatic urea compounds can be obtained by using aromatic diisocyanates as the polyisocyanate component and aromatic monoamines or aromatic diamines as the monoamine component.

[0044] As a thickener, a urea compound may be used alone, or a urea compound may be used in combination with one or more of the above-mentioned thickeners other than urea compounds.

[0045] 1-5. Other ingredients In addition to the above components, the resin composition of this embodiment may optionally contain various other components such as silane coupling agents, curing agents, curing accelerators, defoaming agents, mold release agents, colorants, dispersants, stress reducers, rust inhibitors, friction modifiers, wear inhibitors, antioxidants, oiliness agents, extreme pressure agents, solid lubricants, metal deactivators, metal-based detergents, non-metal-based detergents, and corrosion inhibitors.

[0046] 2. Content of each component of the resin composition The resin composition of this embodiment satisfies either condition (i) or (ii) below. Condition (i): The content of the thickener relative to the total amount of the resin composition is 0.50 to 1.10% by mass. Condition (ii): The total content of the base oil and the thickener relative to the total amount of the resin composition is 3.50 to 8.50% by mass.

[0047] By satisfying either condition (i) or (ii) above, the resin composition of this embodiment achieves appropriate fluidity and thixotropy, thereby improving workability before curing. Furthermore, after curing, the dispersibility of the filler can be improved.

[0048] The content of each component in the resin composition of this embodiment will be described below.

[0049] 2-1.Thermosetting resin The content of thermosetting resin in the resin composition is preferably 5.00% by mass or more, 8.00% by mass or more, 10.00% by mass or more, and preferably 50.00% by mass or less, 40.00% by mass or less, 30.00% by mass or less, when the total amount of the resin composition is 100.00% by mass.

[0050] 2-2. Fillers The filler content in the resin composition is preferably 30.00% by mass or more, 40.00% by mass or more, 50.00% by mass or more, and preferably 90.00% by mass or less, 80.00% by mass or less, 75.00% by mass or less, when the total amount of the resin composition is 100.00% by mass.

[0051] 2-3. Base oil The base oil content in the resin composition is preferably 1.00% by mass or more, 2.00% by mass or more, 3.00% by mass or more, and 20.00% by mass or less, 15.00% by mass or less, 10.00% by mass or less, when the total amount of the resin composition is 100.00% by mass.

[0052] 2-4. Thickeners The amount of thickener in the resin composition is preferably 0.30% by mass or more, 0.40% by mass or more, 0.50% by mass or more, and preferably 10.00% by mass or less, 5.00% by mass or less, 3.00% by mass, 1.50% by mass or less, 1.10% by mass or less, when the total amount of the resin composition is 100.00% by mass.

[0053] The total content of base oil and thickener in the resin composition is preferably 1.00% by mass or more, 2.00% by mass or more, 3.00% by mass or more, 3.50% by mass or more, etc., when the total amount of the resin composition is 100.00% by mass, and preferably 15.00% by mass or less, 10.00% by mass or less, 9.00% by mass or less, 8.50% by mass or less, etc.

[0054] 2-5. Other ingredients The content of other components in the resin composition may be adjusted as appropriate depending on the amount and type of thermosetting resin and filler added. For example, if the total amount of the resin composition is 100.00% by mass, then 0.50% by mass or more, 1.00% by mass or more, 1.50% by mass or more are preferred, and 25.00% by mass or less, 20.00% by mass or less, 15.00% by mass or less are preferred.

[0055] 3. Physical properties of resin compositions The resin composition of this embodiment has excellent fluidity during the pre-curing stage. More specifically, it is preferable that the viscosity measured under the following conditions is 25 Pa·s or less, 20 Pa·s or less, 19 Pa·s or less, etc. (Viscosity measurement conditions) Equipment: Discovery HR-2 (manufactured by T.A. Instruments Japan Co., Ltd.) Plate: φ25mm parallel plate Gap between plates: 0.4 mm Temperature: 25℃ Measurement method: Shear viscosity measurement Shear rate: 0.1 sec- 1 From 1,000 sec- 1 Increase to measure Shear rate of interest: 10 sec- 1

[0056] The resin composition of this embodiment has excellent thixotropy. Thixotropy refers to the property of a material whose viscosity decreases and deforms easily when force is applied, and whose viscosity increases again when left standing (at rest). A resin composition with excellent thixotropy suppresses the settling of the filler when left standing, and after heat curing, a resin cured product can be obtained in which the filler is uniformly dispersed.

[0057] In this embodiment, the thixotropy of the resin composition was evaluated by the following method. Specifically, among the viscosity measurement results described above, the shear rate was 1 sec- 1 Focusing on viscosity in the shear rate of 1 sec- 1 The viscosity in the shear rate is 10 sec- 1 The value obtained by dividing by the viscosity was calculated.

[0058] In order to improve the dispersibility of the filler in the resin after heat curing, the resin composition of this embodiment preferably has the above-mentioned thixotropy value of 1.0 or higher, 1.1 or higher, 1.2 or higher, etc., in the evaluation of thixotropy described above.

[0059] 4. Method for producing resin compositions The resin composition is obtained by mixing and dispersing the above-mentioned components.

[0060] 5. Uses of resin compositions The resin composition of this embodiment can be used in conventionally known applications. The cured products and electronic components obtained using the resin composition will be described below.

[0061] 5-1.Cured product The cured product is obtained by thermally curing the above-mentioned resin composition at 100°C for 3 hours.

[0062] The method for obtaining a cured product from a resin composition is not particularly limited and can be appropriately modified depending on the composition of the resin composition. As an example, in a thermistor temperature sensor, which is a type of electronic component, a thermistor element connected to an insulated wire is inserted into a protective case (case), and the resin composition is applied to the inside of the protective case (for example, by coating with an applicator). Subsequently, a drying step is performed to dry the resin composition as needed, and a step is performed to heat-cur the thermosetting resin and curing agent by heating (for example, by heating with an inert gas oven, hot plate, vacuum oven, vacuum press, etc.). The conditions for each step (for example, coating film thickness, drying temperature and time, heating temperature and time, etc.) can be appropriately modified depending on the composition of the resin composition and its application.

[0063] 5-2. Electronic Components The resin composition of this embodiment is suitable for use as a encapsulant for electronic components because it has excellent dispersibility and workability as a filler. More specifically, it can be suitably used as a encapsulant for thermistor temperature sensors, diodes, and the like.

[0064] The cured product made from the resin composition of this embodiment can be used as an adhesive for contact with circuits or as a encapsulant for casting applications. In particular, it can be used in electronic components such as underfill materials for semiconductor devices and encapsulants for thermistor temperature sensors.

[0065] 6. Compositions for Thixotropic Modification The thixotropic modifier composition of this embodiment comprises a base oil and a thickener. The thixotropic modifier composition of this embodiment may also contain other components. The explanation of each component of the thixotropic modifier composition is the same as described above in "1-3. Base Oil," "1-4. Thickener," and "1-5. Other Components," and is therefore omitted.

[0066] The thixotropic modification composition of this embodiment is added to a resin composition containing a thermosetting resin and a filler, and is used to modify the thixotropic properties of the resin composition.

[0067] The resin composition to which the thixotropic modifier of this embodiment is added may contain other components. The description of each component contained in the resin composition is the same as in "1-1. Thermosetting resin," "1-2. Filler," and "1-5. Other components" described above, and is therefore omitted.

[0068] The thixotropic modified composition of this embodiment satisfies either condition (i) or (ii) below. Condition (i): After the thixotropic modification composition is added to the resin composition, the amount of the thickener relative to the total amount of the thixotropic modification composition and the resin composition is 0.50 to 1.10% by mass. Condition (ii): After the thixotropic modifier composition is added to the resin composition, the total content of the base oil and the thickener relative to the total amount of the thixotropic modifier composition and the resin composition is 3.50 to 8.50% by mass.

[0069] By satisfying either condition (i) or (ii) above, the thixotropic modifier composition of this embodiment results in a resin composition to which the thixotropic modifier composition has been added exhibiting appropriate fluidity and thixotropy, thereby improving workability before curing. Furthermore, it is possible to improve the dispersibility of the filler after curing of the resin composition.

[0070] In other words, when the thixotropic modifier of this embodiment is added to a resin composition containing a thermosetting resin and a filler, the resin composition can be made to have excellent dispersibility and workability of the filler.

[0071] 7. Content of each component of the thixotropic modified composition The content of each component in the thixotropic modifier composition of this embodiment will be described below.

[0072] 7-1. Base oil The base oil content in the thixotropic modified composition is preferably 50.00% by mass or more, 60.00% by mass or more, 70.00% by mass or more, and preferably 99.00% by mass or less, 97% by mass or less, 95% by mass or less, when the total amount of the thixotropic modified composition is 100.00% by mass.

[0073] 7-2. Thickeners The amount of thickener in the resin composition is preferably 1.00% by mass or more, 3.00% by mass or more, 5.00% by mass or more, and preferably 25.00% by mass or less, 20.00% by mass or less, 15.00% by mass or less, when the total amount of the thixotropic modified composition is considered to be 100.00% by mass.

[0074] 8. Method for producing thixotropic modified compositions The method for producing the thixotropic modified composition is not particularly limited. For example, the above-mentioned components (base oil, thickener, and other components added as needed) may be mixed appropriately, and the mixing order is not particularly limited.

[0075] The components of thickeners, etc., may be obtained by blending the raw material components of the component into the base oil constituting the thixotropic modifier composition and reacting the raw material components. For example, a method may be employed in which a base oil, an isocyanate component, and an amine component are introduced into a kettle and the isocyanate component and amine component are reacted in the base oil to form a urea-based thickener, or a method may be employed in which a base oil, a carboxylic acid component, and a basic metal component are introduced into a kettle and the carboxylic acid component and basic metal component are reacted in the base oil to form a metal soap-based thickener. [Examples]

[0076] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited in any way by these examples.

[0077] <<Raw materials>> Resin compositions for Examples 1-6 and Comparative Examples 1-4 were prepared using the formulations listed in Table 1. The raw materials used in each example and comparative example are as follows.

[0078] <Resin composition> (thermosetting resin) • Epoxy resin A: Epoxy resin jER 811 (manufactured by Mitsubishi Chemical Corporation) • Epoxy resin B: ADEKA Resin EP-4005 (manufactured by ADEKA Corporation) (Filler) • Inorganic filler: HARMIC AE120-150 (manufactured by Nippon Steel Chemical & Material Co., Ltd.) (Hardening agent) • Acid anhydride A: Ricacid MH-700 (manufactured by Shin Nippon Rika Co., Ltd.) • Acid anhydride B: IPU-22AH (manufactured by Okamura Oil Co., Ltd.) (Curing accelerator A) • Phosphonium-based curing accelerator: U-CAT5003 (manufactured by Sunapro Co., Ltd.) (Curing accelerator B) • Imidazole-based curing accelerator: Cureazole 1B2MZ (manufactured by Shikoku Chemicals Co., Ltd.) (Silane coupling agent) • KBM-403 (manufactured by Shin-Etsu Chemical Co., Ltd.) (Antifoaming agent) • KS603 (manufactured by Shin-Etsu Chemical Co., Ltd.)

[0079] <Thixotropic Modifier Composition A> • Diurea thickener A Cyclic and aromatic ureas: Obtained by reacting 4,4'-diphenylmethane diisocyanate with aromatic amines and cyclohexylamines in a base oil. (Manufactured by Shell Lubricants Japan Co., Ltd.) • Base oil A Paraffinous mineral oil obtained by dewaxing solvent refining, belonging to Group 1 as classified by the American Petroleum Institute (API), with a kinematic viscosity of 99.82 mm² at 40°C. 2 (For viscosity index 98, / s) <Thixotropic Modification Composition B> • Diurea thickener B Aliphatic C8 urea: Obtained by reacting 4,4'-diphenylmethane diisocyanate and octylamine in base oil A. (Manufactured by Shell Lubricants Japan Ltd.) · Base oil A <Thixotropy-modifying composition C> · Diurea thickener C Aliphatic C8 & C18 urea: Obtained by reacting 4,4'-diphenylmethane diisocyanate, octylamine, and stearylamine in base oil A. (Manufactured by Shell Lubricants Japan Ltd.) · Base oil A <Thixotropy-modifying composition D> · Fatty acid amide wax Active ingredient of the thixotropy modifier contained in Disparon 6900-10X (manufactured by Kusumoto Chemicals, Ltd.) · Solvent Mixed solvent of xylene, ethanol, methanol, and IPA contained in Disparon 6900-10X (manufactured by Kusumoto Chemicals, Ltd.)

[0080] <<Measurement / Evaluation>> Evaluation tests were conducted on the resin compositions according to each example and comparative example. The evaluation results of each evaluation test are shown in Table 1.

[0081] <(1) Fluidity: Viscosity> The viscosity [Pa·s] of the resin compositions according to each example and comparative example immediately after preparation was measured under the following measurement conditions, and attention was paid to the viscosity at a shear rate of 10 sec- 1 Therein. (Measurement conditions for viscosity) Apparatus: Discovery HR-2 (manufactured by TA Instruments Japan Ltd.) Plate: φ25 mm parallel plate Gap between plates: 0.4 mm Temperature: 25 °C Measurement method: Shear viscosity measurement Shear rate: 0.1 sec -1 To 1,000 sec -1 And measured by increasing

[0082] <(2) Thixotropic> Of the viscosity measurement results mentioned above, the shear rate was 1 sec. -1 Focusing on viscosity in , when the shear rate is 1 sec -1 Viscosity at a shear rate of 10 seconds -1 The value obtained by dividing by the viscosity was calculated.

[0083] (3) Workability The values ​​from (1) and (2) above were multiplied to calculate a value, and the workability of the resin compositions of each example and comparative example was evaluated according to the evaluation criteria below. A: Less than 33 B: 33 or above, less than 55 C:55 or more

[0084] (4) Dispersibility of fillers Cured products were prepared from the resin compositions of each example and comparative example. The cross-section of the obtained cured products was observed, and the dispersibility of the filler was evaluated according to the following evaluation criteria. A: The percentage of the thickness of the resin layer without filler in the cross-section of the cured product is less than 10%. C: The percentage of the thickness of the resin layer without filler in the cross-section of the cured product is 10% or more.

[0085] [Table 1] [Industrial applicability]

[0086] The resin composition of the present invention is a novel resin composition that is excellent in terms of filler dispersibility and workability, and can therefore be used as a encapsulant for electronic components and the like.

Claims

1. A resin composition comprising a thermosetting resin, a filler, a base oil, and a thickener, A resin composition that satisfies either condition (i) or (ii) below. Condition (i): The content of the thickener relative to the total amount of the resin composition is 0.50 to 1.10% by mass. Condition (ii): The total content of the base oil and the thickener relative to the total amount of the resin composition is 3.50 to 8.50% by mass.

2. The resin composition according to claim 1, wherein the thermal conductivity of the filler is 20 W / mK or more.

3. The resin composition according to claim 1, wherein the filler contains alumina.

4. The resin composition according to claim 1, wherein the thickener comprises a urea compound.

5. The resin composition according to claim 4, wherein the urea compound is one or more selected from alicyclic, aromatic, and aliphatic compounds.

6. The resin composition according to claim 1, wherein the thermosetting resin includes an epoxy resin.

7. The resin composition according to claim 1, which is used as a encapsulant for electronic components.

8. It contains a base oil and a thickener. A thixotropic modifier composition, which is added to a resin composition comprising a thermosetting resin and a filler, and used to modify the thixotropic properties of the resin composition, A thixotropic modifier composition that satisfies either condition (i) or (ii) below. Condition (i): After the thixotropic modification composition is added to the resin composition, the amount of the thickener relative to the total amount of the thixotropic modification composition and the resin composition is 0.5 to 1.1% by mass. Condition (ii): After the thixotropic modifier composition is added to the resin composition, the total content of the base oil and the thickener relative to the total amount of the thixotropic modifier composition and the resin composition is 3.5 to 8.5% by mass.

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