Two-pack curable composition set, cured product, and electronic device

Abstract

To provide a two-pack curable composition set that prevents occurrence of cracks and enables maintenance of high thermal conductivity even under repeated exposure to high and low temperatures.SOLUTION: A two-pack curable composition set comprises a first agent including a vinyl-modified organopolysiloxane A and a second agent including a hydrosilyl-modified organopolysiloxane B, where at least one of the first agent and the second agent includes a reaction retarder C having an ethylenically unsaturated bond, and at least one of the first agent and the second agent includes an addition reaction catalyst D. A cured product obtained by mixing the first agent and the second agent in equal volumes is subjected to 1000 cycles of maintaining at 150°C for 30 minutes and then maintaining at -40°C for 30 minutes, such that a ratio C1000 / C0, which is a ratio of an Asker C hardness C1000 after the cycles to an Asker C hardness C0 before the cycles, is less than 2.0.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a two-component curing composition set, a cured product, and an electronic device. [Background technology]

[0002] As heat-generating electronic components, such as central processing units (CPUs) in personal computers, become smaller and more powerful, the amount of heat generated per unit area by these components has become extremely large. This amount of heat can reach approximately 20 times that of an iron. To prevent these heat-generating electronic components from breaking down over the long term, they must be cooled. Metal heat sinks and housings are used for cooling. However, when a heat-generating electronic component is placed directly in contact with a heat sink, microscopic air exists at the interface, which can impede heat conduction. Therefore, to efficiently transfer heat, a thermally conductive material is often placed between the heat-generating electronic component and the heat sink.

[0003] Thermally conductive materials include thermally conductive pads and sheets made by filling thermosetting resin with a thermally conductive filler and molding it into a sheet; thermally conductive grease made by filling a fluid resin with a thermally conductive filler and making it possible to spread it or make it into a thin film; and phase-change thermally conductive materials that soften or flow at the operating temperature of heat-generating electronic components.

[0004] Thermally conductive greases, for example, are made by adding thermally conductive powder to silicone. Such thermal greases are mainly classified into one-component and two-component types depending on the type of silicone used. Two-component types are further divided into condensation reaction types and addition reaction types. Thermally conductive greases containing two-component silicones are used as two-component curing composition sets containing two different compositions (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2023-064230 Summary of the Invention [Problem to be solved by the invention]

[0006] A two-component curing composition set is used, for example, by mixing the first and second components and then applying the mixture to a predetermined area. Hereinafter, the mixture of the first and second components will also be referred to simply as the "mixture." The curing reaction of the mixture begins upon mixing. For example, if the reaction between the first and second components is an addition reaction between a vinyl-modified organopolysiloxane and a hydrosilyl-modified organopolysiloxane, the addition reaction begins upon mixing. Ideally, once all of the reaction substrates have reacted, the physical properties of the mixture, such as hardness and dynamic viscoelasticity, will reach a certain value. The state in which the addition reaction between the vinyl-modified organopolysiloxane and the hydrosilyl-modified organopolysiloxane is complete is called a "cured product."

[0007] At this time, if unreacted components are produced in the mixture, unwanted side reactions may proceed or volatilization or oil bleeding may occur, so the first and second parts of a two-component curing composition set are usually designed so that the number of vinyl groups in the vinyl-modified organopolysiloxane matches the number of hydrosilyl groups in the hydrosilyl-modified organopolysiloxane. Specifically, a two-component curing composition set specified for use by mixing equal amounts of the first and second parts is designed so that, when equal amounts of the first and second parts are mixed according to the instructions, the number of vinyl groups in the vinyl-modified organopolysiloxane matches the number of hydrosilyl groups in the hydrosilyl-modified organopolysiloxane.

[0008] Unless otherwise specified, in this embodiment, the term "mixture" refers to a mixture in which the number of vinyl groups in the vinyl-modified organopolysiloxane and the number of hydrosilyl groups in the hydrosilyl-modified organopolysiloxane are the same. Even in cases in which the first agent contains a vinyl-modified organopolysiloxane and a hydrosilyl-modified organopolysiloxane and the second agent contains a vinyl-modified organopolysiloxane, the mixture should be mixed in such a way that the number of vinyl groups in the vinyl-modified organopolysiloxane and the number of hydrosilyl groups in the hydrosilyl-modified organopolysiloxane are the same as a result of mixing.

[0009] The mixture obtained as described above is used in contact with the heat-generating electronic components and the like, and is therefore subjected to high-temperature and low-temperature cycles (hereinafter simply referred to as "heat cycles"). If the mixture is exposed to heat cycles for a long period of time, cracks may occur in the mixture, and the thermal resistance value may increase at the cracked portions. Therefore, there is a need for the development of a two-component curing composition set that is less likely to crack even after heat cycles.

[0010] However, as the inventors of the present invention conducted further research, they discovered a new phenomenon in which the thermal resistance value decreases due to heat cycles, even though no cracks or the like appear to have occurred.

[0011] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a two-component curing composition set that does not cause cracks and can maintain high thermal conductivity even when repeatedly exposed to high and low temperatures, a cured product obtained from the two-component curing composition set, and an electronic device equipped with the cured product. [Means for solving the problem]

[0012] As a result of intensive research into achieving the above-mentioned object, the present inventors have found that the above-mentioned problems can be solved by a two-component curing composition set that includes a first part and a second part containing specified components, and in which a change in hardness when a cured product of an equivalent mixture of the first part and the second part is exposed to a heat cycle is within a specified range, and have thus completed the present invention.

[0013] That is, the present invention is as follows. [1] a first agent containing a vinyl-modified organopolysiloxane A; a second agent containing a hydrosilyl-modified organopolysiloxane B; At least one of the first agent and the second agent contains a reaction retarder C having an ethylenic double bond, At least one of the first agent and the second agent contains an addition reaction catalyst D, The cured product obtained by mixing equal volumes of the first agent and the second agent was subjected to a cycle of maintaining the temperature at 150°C for 30 minutes and then maintaining the temperature at -40°C for 30 minutes 1,000 times. The Asker C hardness C after the cycle was compared to the Asker C hardness C before the cycle. 1000 Ratio of C 1000 / C0 is less than 2.0, Two-component curing composition set. [2] Asker C hardness 1000 However, it is 20 to 85. [1] The two-component curing composition set according to [1]. [3] The Asker C hardness C0 is 20 to 60. The two-component curing composition set according to [1] or [2]. [4] the total weight of the reaction retarder C is 0.01 to 10 parts by weight when the total weight of the hydrosilyl-modified organopolysiloxane B contained in the first agent and the second agent is 100 parts by weight; The two-component curing composition set according to any one of [1] to [3]. [5] the total weight of the hydrosilyl-modified organopolysiloxane B contained in the first agent and the second agent is 50 to 200 parts by weight when the total weight of the vinyl-modified organopolysiloxane A is 100 parts by weight; The two-component curing composition set according to any one of [1] to [4]. [6] When at least one of the first agent and the second agent contains a reaction retarder C″ having an acetylenic triple bond, the total number of unsaturated bonds of the reaction retarder C″ contained in the first agent and the second agent is more than 0% and 70% or less of the total number of unsaturated bonds of the reaction retarder C and the reaction retarder C″ contained in the first agent and the second agent, The two-component curing composition set according to any one of [1] to [5]. [7] The first agent and the second agent do not contain a reaction retarder C″ having an acetylenic triple bond. The two-component curing composition set according to any one of [1] to [6]. [8] The first agent and / or the second agent contains a thermally conductive filler E. The two-component curing composition set according to any one of [1] to [7]. [9] The thermal resistance of the cured product obtained by mixing the first agent and the second agent in equal volumes is 3.0 cm at a thickness of 1.0 mm. 2 °C / W or less, The two-component curing composition set according to any one of [1] to [8].

[10] Used as a thermally conductive heat dissipation material, The two-component curing composition set according to any one of [1] to [9].

[11] [1] to [9], wherein the two-component curing composition set is obtained from a mixture of the first agent and the second agent. cured product.

[12] Used as a thermally conductive heat dissipation material,

[11] The cured product according to

[11] .

[13] An electronic component, the cured product according to

[12] , and a heat sink, the electronic component and the heat sink are in contact with each other via the cured product. electronic equipment. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a two-component curing composition set that does not cause cracks and can maintain high thermal conductivity even when repeatedly exposed to high and low temperatures, a cured product obtained from the two-component curing composition set, and an electronic device equipped with the cured product. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, an embodiment of the present invention (hereinafter referred to as "the present embodiment") will be described in detail. However, the present invention is not limited to the following embodiment, and various modifications are possible without departing from the gist of the present invention.

[0016] 1. Two-component curing composition set The two-component curing composition set of this embodiment comprises a first part containing a vinyl-modified organopolysiloxane A and a second part containing a hydrosilyl-modified organopolysiloxane B, wherein at least one of the first part and the second part contains a reaction retarder C having an ethylenic double bond, and at least one of the first part and the second part contains an addition reaction catalyst D. When a cycle of maintaining the first part and the second part at 150°C for 30 minutes and then maintaining them at -40°C for 30 minutes was repeated 1000 times, the Asker C hardness C after the cycles was compared to the Asker C hardness C before the cycles. 1000 Ratio of C 1000 / C0 is less than 2.0.

[0017] The present inventors measured the thermal resistance of mixtures (cured products) obtained by mixing the first and second parts of various two-component curing composition sets after subjecting them to heat cycles. As a result, they found that some cured products exhibited reduced thermal conductivity after the heat cycles, while others maintained high thermal conductivity, despite the fact that they appeared similar in appearance with no cracks or other defects.

[0018] Further investigation by the present inventors into this issue revealed that in mixtures with reduced thermal conductivity, unexpected side reactions occur even after the normal addition reaction (main reaction) between the vinyl-modified organopolysiloxane and the hydrosilyl-modified organopolysiloxane is nearly complete, causing the hardness of the cured product to change over a considerable period of time. This change in hardness of the cured product is thought to gradually reduce the adhesion between the cured product and the heat-generating component, resulting in a decrease in thermal conductivity at the interface between the cured product and the heat-generating component over time.

[0019] Therefore, the two-component curing composition set of this embodiment has little change in hardness of the cured product due to heat cycling. 1000 Ratio of C 1000 It is specified by / C0.

[0020] In this embodiment, the change in hardness when a cycle of maintaining the temperature at 150°C for 30 minutes and then maintaining the temperature at -40°C for 30 minutes is repeated 1000 times is defined as a heat cycle test generally used to evaluate the reliability of a two-component curing composition set.

[0021] As described above, in this embodiment, the ratio C 1000 / C0 defines the characteristic of suppressing unexpected side reactions. By limiting the increase in hardness when exposed to a heat cycle for a long period of time to a certain level, unexpected changes in the physical properties of the cured product of the two-component curing composition set can be suppressed, and a decrease in the adhesion of the cured product can be suppressed. As a result, a two-component curing composition set can be obtained that can maintain high thermal conductivity even when repeatedly exposed to high and low temperatures. Hereinafter, the characteristic of maintaining high thermal conductivity even when repeatedly exposed to high and low temperatures will be referred to as the "reliability" of the two-component curing composition set.

[0022] The compositions and mixture properties of the first and second agents will be described in detail below.

[0023] It is preferable that the number of vinyl groups in the vinyl-modified organopolysiloxane and the number of hydrosilyl groups in the hydrosilyl-modified organopolysiloxane contained in the first and second parts of the two-component curing composition set of this embodiment are approximately the same. More specifically, when the number of vinyl groups in vinyl-modified organopolysiloxane A is 100, the number of hydrosilyl groups in hydrosilyl-modified organopolysiloxane B is preferably 90 to 110, and more preferably 95 to 105. The number of vinyl groups in the vinyl-modified organopolysiloxane can be calculated by multiplying the vinyl group equivalent of the vinyl-modified organopolysiloxane by the amount used, and the number of hydrosilyl groups in hydrosilyl-modified organopolysiloxane B can be calculated by multiplying the hydrosilyl group equivalent of the hydrosilyl-modified organopolysiloxane by the amount used.

[0024] 1.1. Mixture of the first and second agents As described above, the hardening of the mixture begins when the first and second parts are mixed. In this embodiment, by controlling the hardness change and side reactions of the mixture, unexpected changes in physical properties when exposed to heat cycles can be suppressed, and high thermal conductivity can be maintained even when repeatedly exposed to high and low temperatures.

[0025] 1.1.1.Asker C hardness In this embodiment, the property of suppressing unexpected side reactions is achieved by the above ratio C 1000Specifically, when a cured product made by mixing equal volumes of the first and second agents is subjected to a cycle of 150°C for 30 minutes and then -40°C for 30 minutes, the Asker C hardness after the cycle is expressed as C0 / C0. 1000 Ratio of C 1000 / C0 is less than 2.0.

[0026] As mentioned above, the ratio C 1000 By setting / C0 to less than 2.0, it is possible to reliably suppress an increase in hardness of the cured product due to side reactions, which is a factor in reducing thermal conductivity due to heat cycles.

[0027] Therefore, the above ratio C 1000 / C0 is preferably 1.9 or less, 1.8 or less, 1.7 or less, or 1.6 or less. 1000 The lower limit of / C0 is not particularly limited, and the ratio C 1000 / C0 may be, for example, 0.5 or more, 0.6 or more, 0.7 or more, 0.8 or more, 0.9 or more, 1.0 or more, 1.1 or more, or 1.2 or more.

[0028] The Asker C hardness of the cured product of the mixture of the first and second parts can be measured by mixing equal volumes of the first and second parts, applying the mixture to a measuring jig with a smooth copper surface, and letting the mixture harden for one day (cured product).

[0029] More specifically, a mixture of equal volumes of the first and second agents is applied to a measuring jig with a smooth copper surface, and the mixture (cured product) is left to harden for one day, and the Asker C hardness C0 is measured. The cured product is then subjected to 1000 cycles of maintaining it at 150°C for 30 minutes and then at -40°C for 30 minutes, after which the Asker C hardness C0 is measured. 1000 The temperature rise and fall from -40°C to 150°C and from 150°C to -40°C should be within 5 minutes.

[0030] The Asker C hardness can be measured at 25° C. using an Asker C type spring hardness tester, and more specifically, can be measured by the method described in the Examples.

[0031] The value of the Asker C hardness C0 is not particularly limited, but is preferably 20-60, 30-58, 35-57, 37-55, 40-53, or 43-52.

[0032] Asker C hardness C above 1000 The value of is not particularly limited, but is preferably 20 to 85, 35 to 90, 40 to 88, 45 to 86, 50 to 85, 55 to 83, 60 to 80, or 65 to 78.

[0033] Asker C hardness C 1000 and the difference between Asker C hardness C0 (C 1000 -C0) is not particularly limited, but is preferably 0 to 45, 3 to 40, 5 to 38, 10 to 35, or 15 to 30 Pa.

[0034] Asker C hardness C0 and Asker C hardness C 1000 When the values ​​of and the difference between them are within the above ranges, the change in hardness when the first and second parts are mixed can be within a suitable range, and the reliability of the two-component curing composition set tends to be further improved.

[0035] Asker C hardness C0 and Asker C hardness C 1000 In order to bring the value of and the difference and ratio therebetween within the above ranges, for example, the type and content of each component of the first and second agents may be adjusted. For example, the above ratio C can be achieved by using a preferred reaction retarder C described below, controlling the content of reaction retarder C" contained in the first and second agents, adjusting the total weight of reaction retarders C relative to the total weight of hydrosilyl-modified organopolysiloxanes B, and / or the total weight of addition reaction catalysts D, and adjusting the total weight of hydrosilyl-modified organopolysiloxanes B relative to the total weight of vinyl-modified organopolysiloxanes A, etc.1000 / C0 can be less than 2.0.

[0036] 1.1.2.Thermal resistance value The two-component curing composition set of this embodiment is suitable for use as a thermally conductive heat-dissipating material such as thermally conductive grease. Therefore, when the first and second parts of the two-component curing composition set are mixed, it is preferable that the thermal resistance value is low. Specifically, for example, the thermal resistance value of a cured product obtained by mixing equal volumes of the first and second parts is 3.0 cm at a thickness of 1.0 mm. 2 The thermal resistance at a thickness of 1.0 mm is preferably 2.8 cm / W or less. 2 ·℃ / W or less, 2.5cm 2 ·℃ / W or less, 2.1cm 2 ·℃ / W or less, 2.0cm 2 ·℃ / W or less, 1.8cm 2 The lower limit of the thermal resistance at a thickness of 1.0 mm is not particularly limited, and for example, 2 ·℃ / W or more, 0.2cm 2 ·℃ / W or more, 0.5cm 2 °C / W or more, or 1.0 cm 2 ·°C / W or more.

[0037] The thermal resistance value of a 1.0 mm thick cured product of the mixture of the first and second parts can be measured by applying a mixture of equal volumes of the first and second parts to a measuring jig with a smooth copper surface and measuring the mixture (cured product) in a cured state after one day or more has elapsed, more specifically, by the method described in the Examples. In this embodiment, it is preferable that the number of vinyl groups in the vinyl-modified organopolysiloxane and the number of hydrosilyl groups in the hydrosilyl-modified organopolysiloxane contained in the mixture of equal volumes of the first and second parts are approximately the same.

[0038] In order to set the thermal resistance and thermal conductivity of the first and second agents within the above ranges, for example, the particle size and content of the thermally conductive filler contained in the first and second agents may be adjusted, or a filler with high thermal conductivity may be used.

[0039] 1.2. Ingredients of the first and second agents In the two-component curing composition set of this embodiment, the first component contains a vinyl-modified organopolysiloxane A, the second component contains a hydrosilyl-modified organopolysiloxane B, at least one of the first component and the second component contains a reaction retarder C having an ethylenic double bond, and at least one of the first component and the second component contains an addition reaction catalyst D.

[0040] The two-component curing composition set of this embodiment begins to cure when the first and second parts are mixed. Specifically, the vinyl-modified organopolysiloxane A and the hydrosilyl-modified organopolysiloxane B undergo an addition reaction in the presence of the addition reaction catalyst D, and the reaction retarder C controls the reaction rate of the addition reaction.

[0041] At least one of the first agent and the second agent preferably further contains a thermally conductive filler E, and may further contain other components. Components that may be contained in the first agent and the second agent will be described below.

[0042] 1.2.1. Vinyl-modified organopolysiloxane A Vinyl-modified organopolysiloxane A (hereinafter simply referred to as "organopolysiloxane A") is an organopolysiloxane having at least one vinyl group. Organopolysiloxane A may have a vinyl group on a side chain and / or at a terminal. Such organopolysiloxane has a structural unit represented by the following formula (a-1) or a terminal structure represented by formula (a-2). Organopolysiloxane A may have, for example, at least one of the structural unit represented by formula (a-1) and the terminal structure represented by formula (a-2), and a structural unit represented by formula (a-3).

[0043] [ka]

[0044] In formulas (a-1), (a-2), and (a-3), R represents any monovalent hydrocarbon group that may have a substituent. Examples of such monovalent hydrocarbon groups include, but are not limited to, alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, and dodecyl; cycloalkyl groups such as cyclopentyl and cyclohexyl; aryl groups such as phenyl, tolyl, xylyl, and naphthyl; aralkyl groups such as benzyl, 2-phenylethyl, and 2-phenylpropyl; and groups having a substituent in these groups. Examples of substituents that the monovalent hydrocarbon groups may have include halogen atoms, particularly fluorine and chlorine atoms.

[0045] Organopolysiloxane A may be used alone or in combination of two or more. The number of vinyl groups in organopolysiloxane A is preferably 2.0 or more on average per molecule. That is, when there is one type of organopolysiloxane A, it is preferable that the organopolysiloxane has two or more vinyl groups per molecule. When there are two or more types of organopolysiloxane A, it is preferable that the arithmetic average number of vinyl groups in each organopolysiloxane is 2.0 or more. By having 2.0 or more vinyl groups per molecule, the crosslink density can be adjusted, and the hardness change when the first and second parts are mixed tends to be in a more suitable range. There is no particular upper limit to the number of vinyl groups in organopolysiloxane A, and the number of vinyl groups may be, for example, 4.0 or less, 3.0 or less, or 2.5 or less on average per molecule. The average number of vinyl groups per molecule of organopolysiloxane A may be 2.0.

[0046] The average number of vinyl groups per molecule of organopolysiloxane A can be measured by NMR. Specifically, for example, measurement can be performed using an ECP-300NMR manufactured by JEOL Corporation, dissolving organopolysiloxane A in deuterated chloroform as a deuterated solvent. The average number of vinyl groups per molecule can be calculated by dividing the measurement result obtained in this manner by the average molecular weight of organopolysiloxane A.

[0047] Organopolysiloxane A preferably contains at least an organopolysiloxane having vinyl groups at both ends. Use of such an organopolysiloxane makes it possible to adjust the crosslink density, and tends to make it possible to keep the hardness change when the first and second parts are mixed within a more suitable range.

[0048] The viscosity of organopolysiloxane A at 25°C is preferably 30 to 500 mPa·s, 40 to 400 mPa·s, 50 to 300 mPa·s, 60 to 200 mPa·s, or 70 to 150 mPa·s. When the viscosity of organopolysiloxane A is 500 mPa·s or less, the crosslink density is improved and the handleability of the first part tends to be further improved. When the viscosity of organopolysiloxane A is 30 mPa·s or more, the mechanical strength, such as tensile strength, of the cured products of the first part and second part tends to be further improved.

[0049] Unless otherwise specified, when a numerical range is stated as 30 to 500 mPa·s, the range is inclusive, meaning 30 mPa·s or more and 500 mPa·s or less. The same applies hereinafter.

[0050] In this specification, the viscosity of organopolysiloxane at 25°C can be measured using a digital viscometer "DV-1" manufactured by Brookfield Corp. Using an RV spindle set and rotor No. 1, a container is used that can accommodate the rotor and that can hold organopolysiloxane up to the reference line, and the rotor is immersed in the organopolysiloxane, and the viscosity is measured at 25°C and 10 rpm.

[0051] The weight-average molecular weight of the vinyl-modified organopolysiloxane A is preferably 1,000 to 100,000, or may be 1,500 to 75,000, or 2,500 to 50,000. The weight-average molecular weight can be determined by gel permeation chromatography (GPC). The double bond group equivalent of the vinyl-modified organopolysiloxane A is preferably 0.1 to 1.0 mol / kg, or may be 0.15 to 0.8 mol / kg, or may be 0.2 to 0.6 mol / kg. The double bond group equivalent can be determined by NMR measurement. When the weight-average molecular weight or double bond group equivalent of the vinyl-modified organopolysiloxane A is within the above range, the mechanical strength, such as the tensile strength, of the mixture tends to be further improved, and cracking of the cured product tends to be further suppressed.

[0052] 1.2.2. Hydrosilyl-modified organopolysiloxane B Hydrosilyl-modified organopolysiloxane B (hereinafter simply referred to as "organopolysiloxane B") is an organopolysiloxane having at least two hydrosilyl groups. Organopolysiloxane B may have hydrosilyl groups on side chains and / or at terminals. Such organopolysiloxanes have a structural unit represented by the following formula (b-1) or a terminal structure represented by formula (b-2). Organopolysiloxane B may have, for example, at least one of the structural unit represented by formula (b-1) and the terminal structure represented by formula (b-2), and a structural unit represented by formula (b-3).

[0053] [ka]

[0054] In formulas (b-1), (b-2), and (b-3), R represents any monovalent hydrocarbon group which may have a substituent. That is, in organopolysiloxane B, any monovalent hydrocarbon group which may have a substituent is bonded to a side chain of the siloxane skeleton. Examples of such monovalent hydrocarbon groups include the same monovalent hydrocarbon groups that may be contained in vinyl-modified organopolysiloxane A.

[0055] The organopolysiloxane B may be used alone or in combination of two or more. For example, the organopolysiloxane B may be a hydrosilyl-modified organopolysiloxane B having hydrosilyl groups at both ends. x The hydrosilyl-modified organopolysiloxane B preferably contains at least x and hydrosilyl-modified organopolysiloxane B having hydrosilyl groups in the side chains. y It is more preferable to include

[0056] Organopolysiloxane B x Organopolysiloxane B has at least two hydrosilyl groups at both ends of the organopolysiloxane skeleton. x may further have a hydrosilyl group on the side chain. x may be an organopolysiloxane having hydrosilyl groups only at both ends.

[0057] Organopolysiloxane B y has at least two hydrogen atoms in the side chains of the organopolysiloxane skeleton, and the hydrogen atoms and silicon atoms form hydrosilyl groups. y Organopolysiloxane B may further have hydrosilyl groups at both ends of the organopolysiloxane skeleton. y The number of hydrosilyl groups in organopolysiloxane B is preferably more than 2.0 on average per molecule, more preferably 2.5 or more on average per molecule, and even more preferably 3.0 or more on average per molecule. yThere is no particular upper limit to the number of hydrosilyl groups, and the number of hydrosilyl groups per molecule may be, for example, 8.0 or less, 6.0 or less, or 5.0 or less on average.

[0058] The number of hydrosilyl groups in organopolysiloxane B is preferably 2.0 or more on average per molecule. That is, when there is one type of organopolysiloxane B, the organopolysiloxane preferably has two or more hydrosilyl groups per molecule. When there are two or more types of organopolysiloxane B, the arithmetic average number of hydrosilyl groups in each organopolysiloxane is preferably 2.0 or more.

[0059] The average number of hydrosilyl groups per molecule of organopolysiloxane B can be measured by NMR. Specifically, for example, measurement can be performed using an ECP-300NMR manufactured by JEOL Corporation, dissolving organopolysiloxane B in deuterated chloroform as a deuterated solvent. The average number of hydrosilyl groups per molecule can be calculated by dividing the measurement result thus obtained by the average molecular weight of organopolysiloxane B.

[0060] Organopolysiloxane B x The viscosity of organopolysiloxane B at 25°C is preferably 5 to 200 mPa·s, more preferably 30 to 150 mPa·s, and even more preferably 50 to 110 mPa·s. x If the viscosity of organopolysiloxane B is 100 mPa·s or less, the viscosity of the first and second agents tends to be lower. x When the viscosity is 5 mPa·s or more, the mechanical strength such as tensile strength of the cured product tends to be further improved.

[0061] Organopolysiloxane B y The viscosity of organopolysiloxane B at 25°C is preferably 1 to 150 mPa·s, 20 to 125 mPa·s, or 40 to 100 mPa·s. y If the viscosity of organopolysiloxane B is 100 mPa·s or less, the viscosity of the first and second agents tends to be lower. yWhen the viscosity is 1 mPa·s or more, the mechanical strength such as tensile strength of the cured product tends to be further improved.

[0062] Furthermore, the difference between the viscosity of organopolysiloxane A at 25°C and the viscosity of organopolysiloxane B at 25°C is preferably 20 to 50 mPa·s, 25 to 45 mPa·s, or 30 to 40 mPa·s. When the viscosity difference is within the above range, the homogeneity of the mixture of the first and second parts is further improved, which in turn further suppresses the occurrence of cracks during heat cycles and tends to maintain high thermal conductivity even when repeatedly exposed to high and low temperatures.

[0063] 1.2.3. Reaction retarder C The reaction retarder C is a component that inhibits the addition reaction of the vinyl-modified organopolysiloxane A and the hydrosilyl-modified organopolysiloxane B, and controls the curing rate when the first and second parts are mixed.

[0064] As described above, the two-component curing composition set is used by mixing the first and second components and then applying the mixture to a predetermined area. Therefore, if the reaction that begins when the first and second components are mixed is too fast, the reaction may progress partially before the first and second components are uniformly mixed, resulting in a mixture with partially different physical properties and resulting in a non-uniform composition. Furthermore, even if the first and second components are uniformly mixed, from a microscopic perspective, the rapid reaction may result in uneven crosslink density within the mixture. Furthermore, if the reaction that begins when the first and second components are mixed is too fast, the time between mixing the first and second components and applying the mixture to a predetermined area is shortened, resulting in poor handling.

[0065] From the above perspectives, the two-component curing composition set of this embodiment includes a reaction retarder C in at least one of the first and second parts. This makes the physical properties of the mixture uniform overall and reduces differences in crosslink density, further suppressing the occurrence of cracks during heat cycles. In addition, since it is possible to ensure time between mixing the first and second parts and applying them to the desired area, handling is also improved.

[0066] The reaction retarder C has an ethylenic double bond (hereinafter simply referred to as "double bond"). The reaction retarder C may be used alone or in combination of two or more kinds.

[0067] The mechanism by which the reaction retarder C delays the addition reaction is not particularly limited, but for example, in the first step, the unsaturated bond of the reaction retarder C coordinates to the addition reaction catalyst D in place of the vinyl group of the organopolysiloxane A. Then, in the second step, organopolysiloxane B coordinates to the addition reaction catalyst D to which the reaction retarder C has been coordinated. In the third step, the addition reaction catalyst D causes an addition reaction between the hydrosilyl group of organopolysiloxane B and the unsaturated bond of the reaction retarder C, resulting in detachment from the addition reaction catalyst D. In this way, the reaction retarder C delays the addition reaction of the vinyl-modified organopolysiloxane A and the hydrosilyl-modified organopolysiloxane B.

[0068] The molecular weight of reaction retarder C is preferably 20 to 800 g / mol, 50 to 700 g / mol, 70 to 600 g / mol, or 100 to 500 g / mol. Furthermore, the double bond group equivalent of reaction retarder C is preferably 1.0 to 20 mol / kg, 3.0 to 18 mol / kg, 5.0 to 16 mol / kg, or 7.0 to 14 mol / kg. When the molecular weight or double bond group equivalent of reaction retarder C is within the above range, the reaction retardation performance is improved, the physical properties of the mixture become uniform overall, differences in crosslink density are reduced, cracking during heat cycling is further suppressed, and handleability also tends to improve.

[0069] The reaction retarder C is not particularly limited as long as it has a double bond. The number of double bonds per molecule of the reaction retarder C is preferably 1 to 8, 1 to 6, or 1 to 5. The double bond is not particularly limited, but examples thereof include alkenyl group double bonds such as vinyl groups, allyl groups, and butenyl groups. The reaction retarder C is preferably an organopolysiloxane having an alkenyl group, and more preferably a cyclic organopolysiloxane having an alkenyl group.

[0070] When reaction retarder C is an organopolysiloxane, the number of silicon atoms contained in reaction retarder C is preferably 2 to 30, 3 to 20, 3 to 15, 3 to 8, or 3 to 6. The number of carbon atoms contained in reaction retarder C is preferably 6 to 60, 8 to 40, 9 to 30, 10 to 20, or 11 to 16.

[0071] The reaction retarder C preferably has a structure of the following formula (1): 1 and R 2 are each independently an alkyl group having 1 to 4 carbon atoms or an alkenyl group having 2 to 5 carbon atoms, preferably an alkyl group having 1 to 3 carbon atoms (methyl group, ethyl group, or propyl group) or an alkenyl group having 2 to 4 carbon atoms (vinyl group, allyl group, or butenyl group). In formula (1), p is an integer of 3 to 30, preferably 3 to 20, 3 to 15, 3 to 8, or 3 to 6. However, in formula (1), when multiple R 1 and R 2 At least one of R is an alkenyl group having 2 to 5 carbon atoms, preferably an alkenyl group having 2 to 4 carbon atoms, and more preferably a vinyl group. 1 and R 2 The number (total) of R is preferably 1 to p. 1 are each independently an alkyl group having 1 to 4 carbon atoms, and R 2 may each independently be an alkenyl group having 2 to 5 carbon atoms.

[0072] [ka]

[0073] The reaction retarder C is not particularly limited, but examples thereof include acyclic siloxanes such as 1,3-divinyl-1,1,3,3-tetramethyldisiloxane, and cyclic siloxanes such as 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane and 1,3,5,7-tetramethyl-1,3,5,7-tetrahexenylcyclotetrasiloxane. Among these, cyclic siloxanes are preferred, and 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane is preferred.

[0074] By using such a reaction retarder C, the reaction retardation performance is improved, the physical properties of the mixture become uniform overall, differences in crosslink density are reduced, the occurrence of cracks during heat cycles is further suppressed, and handleability also tends to improve.

[0075] The two-component curing composition set of the present embodiment may contain, as a reaction retarder component, a component other than the reaction retarder C having a double bond, but preferably does not contain a reaction retarder C″ having an acetylenic triple bond (hereinafter simply referred to as “triple bond”).

[0076] In this embodiment, compounds having a double bond and a triple bond in one molecule are defined as being included in the reaction retarder C". Specifically, in this embodiment, ene-yne ​​compounds such as 3-methyl-3-penten-1-yne and 3,5-dimethyl-3-hexen-1-yne are included in the reaction retarder C".

[0077] Similar to the mechanism for delaying the addition reaction of reaction retarder C described above, reaction retarder C" is thought to delay the addition reaction by having the unsaturated bond of reaction retarder C" coordinate to addition reaction catalyst D instead of the vinyl group of organopolysiloxane A. However, when reaction retarder C" is used, in the third step described above, a compound with a double bond that can again coordinate to addition reaction catalyst D in the first step is released. Compounds that can undergo two addition reactions with one unsaturated bond, such as reaction retarder C", can cause polymerization reactions, etc., so when reaction retarder C" is included as a reaction retarder component, it is presumed to be one of the factors that cause unnecessary side reactions to proceed. For this reason, it is preferable that reaction retarder C does not contain reaction retarder C".

[0078] The reaction retarder C" is not particularly limited as long as it has a triple bond. The number of triple bonds may be, for example, 1 to 4, 1 to 3, or 1 to 2. The triple bond is not particularly limited, but examples include alkynyl group triple bonds such as acetylene group, propynyl group, and butynyl group. The reaction retarder C" may be a hydrocarbon compound having an alkynyl group, or may be a cyclic hydrocarbon compound having an alkynyl group.

[0079] When the reaction retarder C" is a hydrocarbon compound, the number of carbon atoms contained in the reaction retarder C" may be, for example, 3 to 30, 4 to 20, 5 to 17, or 6 to 15. The hydrocarbon compound may contain atoms other than carbon and hydrogen, and may contain heteroatoms such as oxygen atoms and nitrogen atoms. The hydrocarbon compound may have a substituent containing a heteroatom, such as a hydroxy group or an alkoxy group.

[0080] The reaction retarder C" may be a cycloalkane having an alkynyl group having 2 to 5 carbon atoms, or may be a cycloalkane having an alkynyl group having 2 to 4 carbon atoms (acetylene group, propynyl group, or butynyl group). Such a cycloalkane preferably has a hydrocarbon ring structure consisting of 3 to 8, or 4 to 7, carbon atoms. In addition, such a cycloalkane may have a hydroxy group and / or an alkoxy group, or may have a hydroxy group.

[0081] Such reaction retarder C" is not particularly limited, but examples thereof include 1-ethynyl-1-cyclohexanol, 3-methyl-1-butyn-3-ol, 2-methyl-3-butyn-2-ol, 3,5-dimethyl-1-hexyn-3-ol, 2-phenyl-3-butyn-2-ol, bis(1,1-dimethylpropynyloxy)dimethylsilane, and methyltris(3-methyl-1-butyn-3-oxy)silane.

[0082] When the two-component curing composition set of this embodiment does not contain a reaction retarder C" or contains a reaction retarder C" having a triple bond, it is preferable that the total number of unsaturated bonds in the reaction retarder C" contained in the first and second parts is more than 0% and not more than 70% of the total number of unsaturated bonds in the reaction retarder C and reaction retarder C" contained in the first and second parts. By limiting the presence proportion of the reaction retarder C" within the above range, the occurrence of the above-mentioned polymerization reaction and the like resulting from the reaction retarder C" can be suppressed.

[0083] More specifically, the two-component curing composition set preferably does not contain 1-ethynyl-1-cyclohexanol, does not contain a cycloalkane having an alkynyl group having 2 to 5 carbon atoms, and may not contain a reaction retarder C″.

[0084] When the two-component curing composition set of this embodiment contains a reaction retarder C", the ratio of the total number of unsaturated bonds of the reaction retarder C" contained in the first and second parts to the total number of unsaturated bonds of the reaction retarder C and reaction retarder C" contained in the first and second parts is preferably 70% or less, 65% or less, 60% or less, 50% or less, 40% or less, or 30% or less. The lower limit of this ratio is not particularly limited, and the ratio may be more than 0%, 1% or more, 5% or more, or 10% or more.

[0085] Note that the total number of unsaturated bonds in reaction retarder C and reaction retarder C" contained in the first and second agents refers to the number of unsaturated bonds in reaction retarder C and / or reaction retarder C" when reaction retarder C and / or reaction retarder C" are contained in only one of the first and second agents; and refers to the sum of the number of unsaturated bonds in reaction retarder C1 and / or reaction retarder C1" and the number of unsaturated bonds in reaction retarder C2 and / or reaction retarder C2" when the first agent contains reaction retarder C1 and / or reaction retarder C1" and the second agent contains reaction retarder C2 and / or reaction retarder C2". The number of unsaturated bonds is the sum of double bonds and triple bonds.

[0086] Furthermore, the total number of unsaturated bonds in reaction retarder C" refers to the number of unsaturated bonds in reaction retarder C" when reaction retarder C" is contained in only one of the first and second agents; when the first agent contains reaction retarder C1" and the second agent contains reaction retarder C2", it refers to the sum of the number of unsaturated bonds in reaction retarder C1" and the number of unsaturated bonds in reaction retarder C2". When reaction retarder C" contains a double bond in addition to a triple bond, the number of unsaturated bonds in reaction retarder C" is the sum of the number of triple bonds and the number of double bonds.

[0087] Similarly, when the two-component curing composition set contains 1-ethynyl-1-cyclohexanol or a cycloalkane having an alkynyl group having 2 to 5 carbon atoms, the ratio of the total amount of the compounds contained in the first and second parts to the total number of unsaturated bonds of reaction retarder C and reaction retarder C″ contained in the first and second parts is preferably 70% or less, 65% or less, 60% or less, 50% or less, 40% or less, or 30% or less. There is no particular lower limit to this ratio, and this ratio may be more than 0%, 1% or more, 5% or more, or 10% or more.

[0088] The ratio of the total number of unsaturated bonds of the reaction retarder C contained in the first and second agents to the total number of unsaturated bonds of the reaction retarder C and reaction retarder C″ contained in the first and second agents is preferably 30% or more, 40% or more, 50% or more, 60% or more, 70% or more, 75% or more, 80% or more, 85% or more, 90% or more, 95% or more, 97% or more, or 99% or more. There is no particular upper limit to this ratio, and the ratio may be 100% or less, 99% or less, 95% or less, 90% or less, 85% or less, 80% or less, or 70% or less.

[0089] The number of unsaturated bonds in the reaction retarder C and the number of unsaturated bonds in the reaction retarder C″ can be measured by NMR measurement, IR measurement, LC-MS measurement, or the like.

[0090] 1.2.4. Addition reaction catalyst D The addition reaction catalyst D is not particularly limited as long as it catalyzes the addition reaction between the vinyl-modified organopolysiloxane A and the hydrosilyl-modified organopolysiloxane B. Examples of the addition reaction catalyst D include platinum compound catalysts, rhodium compound catalysts, and palladium compound catalysts. Among these, platinum compound catalysts are preferred. Use of such an addition reaction catalyst D makes it possible to keep the hardness change of the cured product of the mixture of the first and second parts within a suitable range, which tends to further improve the reliability of the two-component curing composition set.

[0091] The platinum compound catalyst is not particularly limited, but examples thereof include simple platinum, platinum compounds, and platinum-supported inorganic powders. The platinum compound is not particularly limited, but examples thereof include chloroplatinic acid, platinum-olefin complexes, platinum-alcohol complexes, platinum coordination compounds, etc. The platinum-supported inorganic powder is not particularly limited, but examples thereof include platinum-supported alumina powder, platinum-supported silica powder, and platinum-supported carbon powder.

[0092] The addition reaction catalyst D may be used alone or in combination of two or more. Furthermore, the addition reaction catalyst D may be blended alone when preparing the first and second agents, or may be blended in a pre-mixed state with other components, such as the vinyl-modified organopolysiloxane A and other organopolysiloxanes.

[0093] 1.2.5.Thermal Conductive Filler E The thermally conductive filler E is a filler having thermal conductivity. The thermal conductivity of the thermally conductive filler E is not particularly limited, but is, for example, 10 W / m·K or more. Examples of such thermally conductive fillers E include, but are not particularly limited to, aluminum oxide (hereinafter also referred to as "alumina"), aluminum nitride, silica (particularly crystalline silica), boron nitride, silicon nitride, silicon oxide, zinc oxide, aluminum hydroxide, metallic aluminum, magnesium oxide, diamond, carbon, indium, gallium, copper, silver, iron, nickel, gold, tin, metallic silicon, and the like.

[0094] The thermally conductive filler E preferably contains one or more selected from the group consisting of boron nitride, aluminum nitride, aluminum oxide, silicon nitride, silicon oxide, magnesium oxide, metallic aluminum, and zinc oxide, more preferably contains one or more selected from the group consisting of aluminum oxide, magnesium oxide, aluminum nitride, and metallic aluminum, and even more preferably contains aluminum oxide. This is because the thermally conductive filler has high thermal conductivity, high insulating properties, and is inexpensive. The thermally conductive filler E may be used alone or in combination of two or more.

[0095] The average particle size of the thermally conductive filler E is preferably 0.05 to 120 μm, more preferably 0.1 to 70 μm. When the average particle size of the thermally conductive filler E is within the above range, the fluidity of the first and second parts and the dispersibility and filling ability of the thermally conductive filler E tend to be further improved.

[0096] Furthermore, fillers with different average particle sizes may be mixed and used as the thermally conductive filler E. It is preferable to use a combination of two or more of the thermally conductive filler (E-1) having an average particle size of 30 to 100 μm, the thermally conductive filler (E-2) having an average particle size of 1.5 to 25 μm, and the thermally conductive filler (E-3) having an average particle size of 0.05 to 1.0 μm as the thermally conductive filler E, more preferably to use at least the thermally conductive filler (E-1) and the thermally conductive filler (E-2), and even more preferably to use all of the thermally conductive filler (E-1), the thermally conductive filler (E-2), and the thermally conductive filler (E-3).

[0097] The average particle size of thermally conductive fillers can be measured using, for example, a Shimadzu SALD-20 laser diffraction particle size analyzer. The evaluation sample is prepared by adding 50 ml of pure water and 5 g of the thermally conductive filler powder to be measured to a glass beaker, stirring with a spatula, and then dispersing in an ultrasonic cleaner for 10 minutes. The dispersed thermally conductive filler powder solution is then added dropwise to the sampler using a dropper. Once the absorbance stabilizes, measurements can be performed. The laser diffraction particle size analyzer calculates the particle size distribution from the light intensity distribution data of the diffraction / scattering holes detected by the sensor. The average particle size is calculated by multiplying the measured particle size value by the relative particle amount (difference %) and dividing by the total relative particle amount (100%). The average particle size is the average diameter of the particles and can be calculated as the cumulative weight average D50 (median diameter). Note that D50 is the particle size with the highest occurrence rate.

[0098] In this case, the content of the thermally conductive filler (E-1) relative to the total amount of the thermally conductive filler E is preferably 30 to 70% by weight or 40 to 60% by weight. The content of the thermally conductive filler (E-2) relative to the total amount of the thermally conductive filler E is preferably 10 to 50% by weight or 20 to 40% by weight. The content of the thermally conductive filler (E-3) relative to the total amount of the thermally conductive filler E is preferably 5 to 30% by weight or 10 to 20% by weight. By using the thermally conductive filler E as described above, the fluidity of the first and second parts and the dispersibility and filling properties of the thermally conductive filler E tend to be further improved.

[0099] 1.2.6.Other Ingredients In addition to the above components, the first and second agents may each contain additives such as a surfactant, a colorant, a silane coupling agent, a viscosity modifier, etc., as needed.

[0100] The surfactant may be a component that improves the wettability of the thermally conductive filler E with the vinyl-modified organopolysiloxane A and / or the hydrosilyl-modified organopolysiloxane B. From the viewpoint of further improving the wettability of the thermally conductive filler, the surfactant is preferably a copolymer having at least two of an anionic group, a cationic group, and a group having a siloxane skeleton.

[0101] The anionic group is not particularly limited, but examples thereof include a carboxy group, a phosphate group, a phenolic hydroxy group, and a sulfonic acid group. Among these, the anionic group is preferably at least one selected from the group consisting of a carboxy group, a phosphate group, and a phenolic hydroxy group, and is preferably a carboxy group.

[0102] The cationic group is not particularly limited, but examples thereof include a primary amino group, a secondary amino group, a tertiary amino group, and a quaternary ammonium cationic group. Of these, the anionic group is preferably a tertiary amino group.

[0103] The group having a siloxane skeleton is not particularly limited, but examples thereof include groups having an organopolysiloxane skeleton, and among these, the group having a siloxane skeleton is preferably a group having a polydimethylsiloxane skeleton.

[0104] The weight-average molecular weight of the surfactant is, for example, 20,000 to 150,000, 30,000 to 120,000, or 40,000 to 100,000. When the weight-average molecular weight of the surfactant is within the above range, the dispersibility of the thermally conductive filler E is improved, and the viscosity of the first and second agents tends to be reduced. The weight-average molecular weight can be determined by GPC (gel permeation chromatography).

[0105] The surfactant is, for example, a copolymer having (meth)acrylic monomer units α having a carboxy group, (meth)acrylic monomer units β having a tertiary amino group, and (meth)acrylic monomer units γ having a siloxane skeleton. Using such a copolymer tends to improve the dispersibility of the thermally conductive filler E and reduce the viscosity of the first and second agents. Note that "monomer" refers to a monomer having a polymerizable unsaturated bond before polymerization, and "monomer unit" refers to a repeating unit that constitutes part of the copolymer after polymerization and is derived from a specific monomer. Furthermore, (meth)acrylic includes acrylic and methacrylic, and (meth)acrylic monomers include (meth)acrylate and (meth)acrylamide.

[0106] Examples of the silane coupling agent include epoxy-based silane coupling agents such as 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane and 3-glycidoxypropylmethyldimethoxysilane; (meth)acrylic acid-modified silane coupling agents such as 3-methacryloxypropylmethyldimethoxysilane and 3-methacryloxytrimethoxysilane; and amino-based silane coupling agents such as N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane.

[0107] Examples of viscosity modifiers include polysiloxanes other than vinyl-modified organopolysiloxane A and hydrosilyl-modified organopolysiloxane B, synthetic rubber latex, urethane resin, hydroxyethyl cellulose, carboxymethyl cellulose, methyl cellulose, polyvinyl alcohol, polyethylene oxide, and dibenzylidene sorbitol.

[0108] 1.3. Composition of the first and second agents With regard to the compositions of the first and second agents, the first agent contains the vinyl-modified organopolysiloxane A1, the second agent contains the hydrosilyl-modified organopolysiloxane B2, and the compositions of the first and second agents can be adjusted as desired, as long as the vinyl-modified organopolysiloxane A, the hydrosilyl-modified organopolysiloxane B, and the addition reaction catalyst D are not all contained in a single agent.

[0109] In this specification, the vinyl-modified organopolysiloxane contained in the first agent is referred to as vinyl-modified organopolysiloxane A1, and the vinyl-modified organopolysiloxane contained in the second agent is referred to as vinyl-modified organopolysiloxane A2, and these are collectively referred to as vinyl-modified organopolysiloxane A. Furthermore, when there is no particular distinction between whether the vinyl-modified organopolysiloxane is contained in the first agent or the second agent, it is still referred to as vinyl-modified organopolysiloxane A. Therefore, when simply referring to "vinyl-modified organopolysiloxane A," this means that both the vinyl-modified organopolysiloxane A1 contained in the first agent and the vinyl-modified organopolysiloxane A2 contained in the second agent are described without any particular distinction.

[0110] Similarly, for the other ingredients, hydrosilyl-modified organopolysiloxane B, reaction retarder C, addition reaction catalyst D, and thermally conductive filler E, when it is clearly stated that they are contained in the first or second agent, "1" or "2" are written, respectively, and when they are referred to collectively or when there is no distinction made as to whether the ingredients are contained in the first or second agent, "1" and "2" are not written.

[0111] For example, the first agent may further contain other components, provided that the vinyl-modified organopolysiloxane A1, the hydrosilyl-modified organopolysiloxane B1, and the addition reaction catalyst D1 are not all contained in a single agent. Specifically, under the above conditions, the first agent may contain at least one of the hydrosilyl-modified organopolysiloxane B1, the reaction retarder C1, and the addition reaction catalyst D1.

[0112] Similarly, the second agent may further contain other components, provided that the vinyl-modified organopolysiloxane A2, the hydrosilyl-modified organopolysiloxane B2, and the addition reaction catalyst D2 are not all contained in a single agent. Specifically, the second agent may contain at least one of the vinyl-modified organopolysiloxane A2, the reaction retarder C2, and the addition reaction catalyst D2, under the above conditions.

[0113] The first and second agents each contain a vinyl-modified organopolysiloxane A and a hydrosilyl-modified organopolysiloxane B, but the first and second agents may contain both the vinyl-modified organopolysiloxane A and the hydrosilyl-modified organopolysiloxane B. That is, the first agent may contain a vinyl-modified organopolysiloxane A1 and a hydrosilyl-modified organopolysiloxane B1, and the second agent may contain a vinyl-modified organopolysiloxane A2 and a hydrosilyl-modified organopolysiloxane B2.

[0114] Furthermore, reaction retarder C and addition reaction catalyst D must be contained in at least one of the first and second agents. Therefore, if the first agent does not contain at least one of reaction retarder C1 and addition reaction catalyst D1, the second agent will contain either reaction retarder C or addition reaction catalyst D, whichever is not contained in the first agent. More specifically, if the first agent does not contain reaction retarder C1, the second agent will contain reaction retarder C2. If the first agent does not contain addition reaction catalyst D1, the second agent will contain addition reaction catalyst D2. Similarly, if the second agent does not contain at least one of reaction retarder C and addition reaction catalyst D, the first agent will contain either reaction retarder C or addition reaction catalyst D, whichever is not contained in the second agent.

[0115] The reaction retarder C and the addition reaction catalyst D may be contained in either the first or second part, but it is preferable that one part does not contain all of the hydrosilyl-modified organopolysiloxane B, the reaction retarder C, and the addition reaction catalyst D. In this case, side reactions of the reaction retarder C can be reliably suppressed, and the reliability of the two-component curing composition set can be further improved.

[0116] Furthermore, the reaction retarder C and the addition reaction catalyst D may be contained in a coexisting state in the first agent and / or the second agent. This allows the unsaturated bond of the reaction retarder C to be coordinated to the addition reaction catalyst D before the first agent and the second agent are mixed. Therefore, the effect of the reaction retarder C can be exerted more efficiently compared to when the unsaturated bond of the reaction retarder C is coordinated to the addition reaction catalyst D during mixing.

[0117] The vinyl-modified organopolysiloxane A and the hydrosilyl-modified organopolysiloxane B undergo an addition reaction in the presence of the reaction retarder C and the addition reaction catalyst D. Therefore, by appropriately adjusting the number of vinyl groups in the vinyl-modified organopolysiloxane A contained in the first and second parts, the number of hydrosilyl groups in the hydrosilyl-modified organopolysiloxane B contained in the first and second parts, the type and content of the reaction retarder C contained in the first and second parts, and the type and content of the addition reaction catalyst D contained in the first and second parts, it is possible to control the change in hardness of the cured product of the mixture of the first and second parts.

[0118] For example, from the viewpoint of keeping the hardness change of the cured product of the mixture of the first and second parts within a more suitable range, the total weight of the reaction retarder C is preferably 0.01 to 10 parts by weight, or 0.10 to 8.0 parts by weight, when the total weight of the hydrosilyl-modified organopolysiloxane B contained in the first and second parts is taken as 100 parts by weight.

[0119] From the same viewpoint, when the total weight of the vinyl-modified organopolysiloxane A contained in the first agent and the second agent is taken as 100 parts by weight, the total weight of the hydrosilyl-modified organopolysiloxane B is preferably 50 to 200 parts by weight, or 70 to 150 parts by weight.

[0120] From the same viewpoint, when the total weight of the hydrosilyl-modified organopolysiloxane B contained in the first and second agents is taken as 100 parts by weight, the total weight of the addition reaction catalyst D is preferably 0.1 to 30 parts by weight, more preferably 0.5 to 20 parts by weight, and even more preferably 1.0 to 10 parts by weight.

[0121] Furthermore, from the viewpoint of further improving thermal conductivity and mechanical properties such as tensile strength, the total weight of the thermally conductive filler E is preferably 400 to 3000 parts by weight, 600 to 2800 parts by weight, or 700 to 2600 parts by weight when the total weight of the vinyl-modified organopolysiloxane A and the hydrosilyl-modified organopolysiloxane B contained in the first agent and the second agent is taken as 100 parts by weight.

[0122] The total weight of the vinyl-modified organopolysiloxane A contained in the first and second agents refers to the weight of the vinyl-modified organopolysiloxane A1 contained in the first agent when the second agent does not contain vinyl-modified organopolysiloxane A2, and refers to the sum of the weight of the vinyl-modified organopolysiloxane A1 contained in the first agent and the weight of the vinyl-modified organopolysiloxane A2 contained in the second agent when the second agent contains vinyl-modified organopolysiloxane A2.

[0123] The total weight of the hydrosilyl-modified organopolysiloxane B contained in the first and second agents means the weight of the hydrosilyl-modified organopolysiloxane B2 contained in the second agent when the first agent does not contain hydrosilyl-modified organopolysiloxane B1, and means the sum of the weight of the hydrosilyl-modified organopolysiloxane B1 contained in the first agent and the weight of the hydrosilyl-modified organopolysiloxane B2 contained in the second agent when the first agent contains hydrosilyl-modified organopolysiloxane B1.

[0124] The total weight of the reaction retarder C contained in the first and second agents is the weight of the reaction retarder C when the reaction retarder C is contained in only one of the first and second agents, and is the sum of the weight of the reaction retarder C1 and the weight of the reaction retarder C2 when the first agent contains the reaction retarder C1 and the second agent contains the reaction retarder C2.

[0125] The total weight of the addition reaction catalyst D contained in the first and second agents is the weight of the addition reaction catalyst D when the addition reaction catalyst D is contained in only one of the first and second agents, and is the sum of the weight of the addition reaction catalyst D1 and the weight of the addition reaction catalyst D2 when the first agent contains the addition reaction catalyst D1 and the second agent contains the addition reaction catalyst D2.

[0126] The total weight of the thermally conductive filler E contained in the first and second agents is the weight of the thermally conductive filler E when the thermally conductive filler E is contained in only one of the first and second agents, and is the sum of the weight of the thermally conductive filler E1 and the weight of the thermally conductive filler E2 when the first agent contains the thermally conductive filler E1 and the second agent contains the thermally conductive filler E2.

[0127] By ensuring that the content of each component is within the above range, the hardness change of the cured product of the mixture of the first and second parts can be kept within a suitable range, which tends to further improve the reliability of the two-component curing composition set. In addition, the thermal conductivity of the mixture and the cured product can be further increased, and the cured product can be made less susceptible to cracking.

[0128] 1.3.1. Vinyl-modified organopolysiloxane A The content of organopolysiloxane A1 is preferably 60 to 99.5 wt %, or 70 to 99.0 wt %, based on the total of all components in the first agent other than thermally conductive filler E1. The content of organopolysiloxane A1 may be 75 wt % or more, 80 wt % or more, or 85 wt % or more, based on the total of all components in the first agent other than thermally conductive filler E1. When the content of vinyl-modified organopolysiloxane A1 is within the above range, the hardness change of the cured product of the mixture of the first and second agents and the mechanical properties such as tensile strength of the cured product tend to be within more suitable ranges.

[0129] When the first agent contains hydrosilyl-modified organopolysiloxane B1, the content of vinyl-modified organopolysiloxane A1 in the first agent may be 40 parts by weight or more, 50 parts by weight or more, 60 parts by weight or more, 70 parts by weight or more, 80 parts by weight or more, 85 parts by weight or more, or 90 parts by weight or more, and may be 99 parts by weight or less, 98 parts by weight or less, 95 parts by weight or less, 90 parts by weight or less, 80 parts by weight or less, 70 parts by weight or less, 60 parts by weight or less, or 50 parts by weight or less, relative to 100 parts by weight of the total of vinyl-modified organopolysiloxane A1 and hydrosilyl-modified organopolysiloxane B1.

[0130] The second agent may contain a vinyl-modified organopolysiloxane A2. The vinyl-modified organopolysiloxane A1 contained in the first agent and the vinyl-modified organopolysiloxane A2 contained in the second agent may be the same as or different from each other.

[0131] In the second agent, the content of the vinyl-modified organopolysiloxane A2 may be 0 parts by weight or more, 5 parts by weight or more, 10 parts by weight or more, 20 parts by weight or more, 30 parts by weight or more, 40 parts by weight or more, 50 parts by weight or more, or 60 parts by weight or more, relative to 100 parts by weight of the total of the vinyl-modified organopolysiloxane A2 and the hydrosilyl-modified organopolysiloxane B2, and may be 98 parts by weight or less, 95 parts by weight or less, 90 parts by weight or less, 80 parts by weight or less, 70 parts by weight or less, 60 parts by weight or less, 50 parts by weight or less, 40 parts by weight or less, 30 parts by weight or less, or 20 parts by weight or less.

[0132] 1.3.2. Hydrosilyl-modified organopolysiloxane B The total content of organopolysiloxane B2 is preferably 60 to 99.5 wt %, or 70 to 99.0 wt %, based on the total of all components other than thermally conductive filler E2 in the second part. The content of organopolysiloxane B2 may be 75 wt % or more, 80 wt % or more, or 85 wt % or more, based on the total of all components other than thermally conductive filler E2 in the second part. When the content of hydrosilyl-modified organopolysiloxane B2 is within the above range, the hardness change of the cured product of the mixture of the first and second parts, and the mechanical properties such as tensile strength of the cured product tend to be within more suitable ranges.

[0133] When the second agent contains vinyl-modified organopolysiloxane A2, the content of hydrosilyl-modified organopolysiloxane B2 in the second agent may be 40 parts by weight or more, 50 parts by weight or more, 60 parts by weight or more, 70 parts by weight or more, 80 parts by weight or more, 85 parts by weight or more, or 90 parts by weight or more, and may be 99 parts by weight or less, 98 parts by weight or less, 95 parts by weight or less, 90 parts by weight or less, 80 parts by weight or less, 70 parts by weight or less, 60 parts by weight or less, or 50 parts by weight or less, relative to 100 parts by weight of the total of vinyl-modified organopolysiloxane A2 and hydrosilyl-modified organopolysiloxane B2.

[0134] The first agent may contain a hydrosilyl-modified organopolysiloxane B1. The hydrosilyl-modified organopolysiloxane B1 contained in the first agent and the hydrosilyl-modified organopolysiloxane B2 contained in the second agent may be the same as or different from each other.

[0135] In the first agent, the content of the hydrosilyl-modified organopolysiloxane B1 may be 0 parts by weight or more, 5 parts by weight or more, 10 parts by weight or more, 20 parts by weight or more, 30 parts by weight or more, or 40 parts by weight or more, relative to 100 parts by weight of the total of the vinyl-modified organopolysiloxane A1 and the hydrosilyl-modified organopolysiloxane B1, and may be 90 parts by weight or less, 80 parts by weight or less, 70 parts by weight or less, 60 parts by weight or less, 50 parts by weight or less, 40 parts by weight or less, 30 parts by weight or less, 20 parts by weight or less, 10 parts by weight or less, 5 parts by weight or less, or 1 part by weight or less.

[0136] 1.3.3. Reaction retarder C The reaction retarder C1 that can be contained in the first part and the reaction retarder C2 that can be contained in the second part may be the same as or different from each other.

[0137] The content of the reaction retarder C1 is preferably 0 to 30 parts by weight, 0.03 to 20 parts by weight, 0.05 to 15 parts by weight, or 0.10 to 10 parts by weight per 100 parts by weight of the content of the vinyl-modified organopolysiloxane A1.

[0138] The content of the reaction retarder C2 is preferably 0 to 30 parts by weight, 0.03 to 20 parts by weight, 0.05 to 15 parts by weight, or 0.10 to 10 parts by weight per 100 parts by weight of the content of the hydrosilyl-modified organopolysiloxane B2.

[0139] The contents of reaction retarders C1 and C2 are preferably adjusted so that the total weight of reaction retarder C falls within the above-mentioned range when the total weight of hydrosilyl-modified organopolysiloxane B contained in the first and second agents is taken as 100 parts by weight.

[0140] By ensuring that the contents of the reaction retarders C1 and C2 are within the above ranges, the hardness change of the cured product of the mixture of the first and second parts can be kept within a suitable range, which tends to further improve the reliability of the two-component curing composition set.

[0141] 1.3.4. Addition reaction catalyst D The addition reaction catalyst D1 that can be contained in the first agent and the addition reaction catalyst D2 that can be contained in the second agent may be the same as or different from each other.

[0142] When the first agent contains the addition reaction catalyst D1, the content of the addition reaction catalyst D1 is preferably 0.1 to 30 parts by weight, more preferably 0.5 to 20 parts by weight, and even more preferably 1 to 10 parts by weight, per 100 parts by weight of the vinyl-modified organopolysiloxane A1.

[0143] When the second agent contains the addition reaction catalyst D2, the content of the addition reaction catalyst D2 is preferably 0.1 to 30 parts by weight, more preferably 0.5 to 20 parts by weight, and even more preferably 1 to 10 parts by weight, per 100 parts by weight of the content of the hydrosilyl-modified organopolysiloxane B2.

[0144] The contents of addition reaction catalysts D1 and D2 are preferably adjusted so that the total weight of addition reaction catalyst D falls within the above-mentioned range when the total weight of hydrosilyl-modified organopolysiloxane B contained in the first and second agents is taken as 100 parts by weight.

[0145] By ensuring that the contents of the addition reaction catalysts D1 and D2 are within the above ranges, the hardness change of the cured product of the mixture of the first and second parts can be kept within a suitable range, which tends to further improve the reliability of the two-component curing composition set.

[0146] 1.3.5.Thermal Conductive Filler E The thermally conductive filler E1 contained in the first agent and the thermally conductive filler E2 contained in the second agent may be the same or different.

[0147] The content of the thermally conductive filler E1 is preferably 400 to 3000 parts by weight, more preferably 600 to 2800 parts by weight, and even more preferably 700 to 2600 parts by weight, per 100 parts by weight of the vinyl-modified organopolysiloxane A1.

[0148] The content of the thermally conductive filler E2 is preferably 400 to 3000 parts by weight, more preferably 600 to 2800 parts by weight, and even more preferably 700 to 2600 parts by weight, per 100 parts by weight of the total of the hydrosilyl-modified organopolysiloxane B2.

[0149] When the contents of the thermally conductive fillers E1 and E2 are within the above ranges, the thermal conductivity of the resulting cured product tends to be improved, and the viscosity of the first and second parts tends to be reduced.

[0150] 1.3.6.Other Ingredients The additives contained in the first agent and the additives contained in the second agent may be the same or different.

[0151] When the first agent contains a surfactant, the content of the surfactant is, for example, 0.1 to 28 parts by weight, 0.2 to 25 parts by weight, 0.5 to 20 parts by weight, or 1.0 to 15 parts by weight per 100 parts by weight of the vinyl-modified organopolysiloxane A1. When the content of the surfactant is within the above range, the dispersibility of the thermally conductive filler E1 is further improved, and the viscosity of the first agent tends to be further reduced.

[0152] When the first agent contains a colorant, the content of the colorant is, for example, 0.001 to 0.2 parts by weight with respect to 100 parts by weight of the total amount of the first agent.

[0153] When the second agent contains a surfactant, the content of the surfactant is, for example, 0.1 to 28 parts by weight, 0.2 to 25 parts by weight, 0.5 to 20 parts by weight, or 1.0 to 15 parts by weight per 100 parts by weight of the content of the hydrosilyl-modified organopolysiloxane B2. When the content of the surfactant is within the above range, the dispersibility of the thermally conductive filler E2 is further improved, and the viscosity of the second agent tends to be further reduced.

[0154] When the second agent contains a colorant, the content of the colorant is, for example, 0.001 to 0.2 parts by weight with respect to 100 parts by weight of the total amount of the second agent.

[0155] 1.4.Applications The two-component curing composition set of the present embodiment can be suitably used as a thermally conductive heat-dissipating material such as thermally conductive grease.

[0156] 2.Cured product The cured product of this embodiment is obtained by mixing the first and second parts of the two-component curing composition set described above. More specifically, the cured product (crosslinked cured product) is obtained by an addition reaction between the vinyl groups of the vinyl-modified organopolysiloxane A and the hydrosilyl groups of the hydrosilyl-modified organopolysiloxane B in the mixture obtained by mixing the first and second parts.

[0157] After mixing the first and second parts, the mixture can be molded into a desired shape before curing to obtain a cured product having a desired shape. In addition, since the cured product of this embodiment contains a thermally conductive filler, it can be suitably used as a thermally conductive heat dissipation material.

[0158] To mix the first and second components, a mixer such as a roll mill, kneader, Banbury mixer, or line mixer is used. More specifically, examples include kneading methods using a universal mixer, hybrid mixer, Trimix (manufactured by Inoue Seisakusho), or static mixer. The preferred molding method is a doctor blade method, but depending on the viscosity of the resin, extrusion, pressing, or calendar roll methods may also be used. The reaction conditions for the addition reaction are not particularly limited, but are typically carried out at room temperature (e.g., 25°C) to 150°C for 0.1 to 24 hours.

[0159] The mixing ratio of the first agent and the second agent can be set appropriately depending on the type of the first agent and the second agent used and the purpose of use, but for example, the volume ratio of first agent:second agent may be 1.5:1.0 to 1.0:1.5, or may be 1.0:1.0.

[0160] 3.Electronic equipment The electronic device of this embodiment includes an electronic component, a cured product, and a heat sink, and the electronic component and the heat sink are in contact with each other via the cured product.

[0161] Here, the electronic component is not particularly limited, but examples thereof include heat-generating electronic components such as a motor, a battery pack, a circuit board mounted on an in-vehicle power supply system, a power transistor, a microprocessor, etc. Furthermore, the heat sink is not particularly limited, but examples thereof include a housing, particularly a metal housing, etc. [Example]

[0162] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0163] 1. Preparation of the first agent First parts I-1 to I-4 were prepared by mixing the following A1 component and C1 to E1 components according to the compounding ratios (parts by weight) shown in Table 1. The components were mixed using a hybrid mixer ARE-310 (trade name, manufactured by Thinky Corporation).

[0164] [A1: Vinyl-modified organopolysiloxane] RH-Vi100E (manufactured by Runhe Chemical Industry Co., Ltd., trade name), vinyl-modified organopolysiloxane, viscosity at 25°C: 105 mPa·s, average number of vinyl groups per molecule: 2, linear structure, vinyl group bonding positions: both terminals, double bond equivalent: 0.39 mol / kg, weight-average molecular weight: 11,000

[0165] [C1: Reaction retarder] C1: 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane (molecular weight: 344.6, double bond group equivalent: 11.6 mol / kg) C1": PA90 (trade name, manufactured by Elkem), a mixture of 1-ethynyl-1-cyclohexanol (molecular weight: 124.2, triple bond group equivalent: 8.1 mol / kg), polyorganosiloxane, and filler (1-ethynyl-1-cyclohexanol concentration: 10 mass%, triple bond group equivalent: 0.81 mol / kg)

[0166] [D1: Addition reaction catalyst] D1: Platinum complex polymethylvinylsiloxane solution (manufactured by Blue Star Silicones, product name: Silicolyse Catalyst 12070)

[0167] [E1: Thermally conductive filler] E1-1: DAW45S (product name, manufactured by Denka), spherical alumina, average particle size: 45 μm, thermal conductivity: 35 W / m K E1-2: DAW05 (product name, manufactured by Denka), spherical alumina, average particle size: 5 μm, thermal conductivity: 35 W / m·K E1-3: ASFP40 (product name, manufactured by Denka), ultrafine alumina, average particle size: 0.4 μm, thermal conductivity 35 W / m·K

[0168] [Table 1]

[0169] 2. Preparation of the second agent Second parts II-1 to II-8 were prepared by mixing components A2 to E2 shown below according to the compounding ratios (parts by weight) shown in Table 2. The components were mixed using a hybrid mixer ARE-310 (trade name, manufactured by Thinky Corporation).

[0170] [A2: Vinyl-modified organopolysiloxane] RH-Vi100E (manufactured by Runhe Chemical Industry, product name), vinyl-modified organopolysiloxane, viscosity at 25°C: 105 mPa·s, average number of vinyl groups per molecule: 2, linear structure, vinyl group bonding positions: both terminals

[0171] [B2: Hydrosilyl-modified organopolysiloxane] B2-1: RH-DH04 (manufactured by Runhe Chemical Industry, product name), hydrosilyl-modified organopolysiloxane, viscosity at 25°C: 70 mPa·s, average number of hydrosilyl groups per molecule: 2, linear structure, hydrosilyl group bonding positions: both terminals B2-2: RH-H33 (manufactured by Runhe Chemical Industry, trade name), hydrosilyl-modified organopolysiloxane, viscosity at 25°C: 60 mPa·s, average number of hydrosilyl groups per molecule: 3 or more, linear structure, hydrosilyl group bonding position: side chain

[0172] [C2: Reaction retarder] C2: 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane C2": PA90 (trade name, manufactured by Elkem), a mixture of 1-ethynyl-1-cyclohexanol, polyorganosiloxane, and filler

[0173] [D2: Addition reaction catalyst] D2: Platinum complex polymethylvinylsiloxane solution (manufactured by Blue Star Silicones, product name: Silicolyse Catalyst 12070)

[0174] [E2: Thermally conductive filler] E2-1: DAW45S (product name, manufactured by Denka), spherical alumina, average particle size: 45 μm, thermal conductivity: 35 W / m·K E2-2: DAW05 (manufactured by Denka, trade name), spherical alumina, average particle size: 5 μm, thermal conductivity 35 W / m K E2-3: ASFP40 (product name, manufactured by Denka), ultrafine alumina, average particle size: 0.4 μm, thermal conductivity 35 W / m·K

[0175] [Table 2]

[0176] 3. Evaluation (Measurement of thermal resistance value) The first and second components were mixed in a 1:1 volume ratio in the combination shown in Table 3, and the resulting mixture was applied to a measurement jig with a smooth copper surface measuring 2 cm wide and 4 cm deep, in an amount sufficient to cover the copper surface. The jig was then clamped in another jig with a copper surface of the same size, and any excess mixture (thermally conductive grease) was scraped off. The mixture was then adjusted to a width of 2 cm, a depth of 4 cm, and a thickness of 1 mm, and screwed in place. After leaving this for one day, a heater was inserted into the top of the jig, and thermocouples were inserted into the top and bottom surfaces to measure the initial thermal resistance.

[0177] The measuring jig on which the cured product was formed was subjected to a thermal shock test from -40°C to 150°C, and the thermal resistance value was then measured again. The holding time at -40°C and 150°C was 30 minutes, and the temperature increase and decrease from -40°C to 150°C and 150°C to -40°C were within 5 minutes, and 1000 cycles were performed. As with the measurement of the initial value, a heater and thermocouple were inserted and the thermal resistance value after the thermal shock test was measured. The results are shown in Table 3. No visible cracks were observed in the cured product of any of the samples.

[0178] (Asker C hardness measurement) The first and second components prepared above were placed in a 50 ml (1:1) cartridge in the combination shown in Table 3 and capped. The cartridge was then attached to a dispenser gun (product name "MixPac DMA50"), and a mixer (9.5 cm long, 12 blades) was attached to the cartridge's outlet to mix the first and second components at a 1:1 volume ratio. The mixture was then dispensed while mixing at a 1:1 volume ratio. The dispensed mixture was molded into a 1 mm thick sheet and cured at 25°C for 24 hours to obtain a cured product. This cured product was punched into 2 cm squares with a punching blade, and the Asker C hardness (Asker C hardness 1) of 12 stacked sheets was measured using an Asker C hardness tester. The Asker C hardness of the cured product after the thermal shock test was also measured in the same manner. The Asker C hardness was measured at 25°C using an Asker Rubber Hardness Tester Type C manufactured by Kobunshi Keiki Co., Ltd.

[0179] [Table 3] [Industrial Applicability]

[0180] The two-component curing composition set of this embodiment has industrial applicability as a material for thermally bonding a heat generating element and a heat sink, in particular, to a thermally conductive cured product obtained by mixing and curing the first and second parts.

Claims

1. a first agent containing a vinyl-modified organopolysiloxane A; a second agent containing a hydrosilyl-modified organopolysiloxane B, At least one of the first agent and the second agent contains a reaction retarder C having an ethylenic double bond, At least one of the first agent and the second agent contains an addition reaction catalyst D, The first agent and the second agent were mixed in equal volumes and the cured product was subjected to a cycle of maintaining the temperature at 150°C for 30 minutes and then maintaining the temperature at -40°C for 30 minutes 1000 times. The Asker C hardness C before the cycle was measured. 0 Asker C hardness C after the cycle 1000 Ratio C 1000 / C 0 is less than 2.0; Two-component curing composition set.

2. Asker C hardness C 1000 However, it is 20 to 85. The two-component curing composition set according to claim 1 .

3. Asker C hardness C 0 However, it is between 20 and 60. The two-component curing composition set according to claim 1 .

4. the total weight of the reaction retarder C is 0.01 to 10 parts by weight when the total weight of the hydrosilyl-modified organopolysiloxane B contained in the first agent and the second agent is 100 parts by weight; The two-component curing composition set according to claim 1 .

5. the total weight of the hydrosilyl-modified organopolysiloxane B contained in the first agent and the second agent is 50 to 200 parts by weight, relative to 100 parts by weight of the total weight of the vinyl-modified organopolysiloxane A; The two-component curing composition set according to claim 1 .

6. When at least one of the first agent and the second agent contains a reaction retarder C″ having an acetylenic triple bond, the total number of unsaturated bonds of the reaction retarder C″ contained in the first agent and the second agent is more than 0% and 70% or less of the total number of unsaturated bonds of the reaction retarder C and the reaction retarder C″ contained in the first agent and the second agent, The two-component curing composition set according to claim 1 .

7. The first agent and the second agent do not contain a reaction retarder C″ having an acetylenic triple bond. The two-component curing composition set according to claim 1 .

8. The first agent and / or the second agent contains a thermally conductive filler E. The two-component curing composition set according to claim 1 .

9. The thermal resistance of the cured product obtained by mixing the first agent and the second agent in equal volumes is 3.0 cm at a thickness of 1.0 mm. 2 ° C. / W or less, The two-component curing composition set according to claim 1 .

10. Used as a thermally conductive heat dissipation material, The two-component curing composition set according to any one of claims 1 to 9.

11. The two-component curing composition set according to any one of claims 1 to 9, wherein the two-component curing composition set is obtained from a mixture of the first component and the second component. cured product.

12. Used as a thermally conductive heat dissipation material, The cured product according to claim 11.

13. An electronic component, the cured product according to claim 12, and a heat sink, the electronic component and the heat sink are in contact with each other via the cured product. electronic equipment.

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