Two-component curing composition set, cured product, and electronic device

Abstract

The present invention provides a two-pack type curable composition set which comprises: a first agent that contains a copolymer A1, a vinyl-modified organopolysiloxane B1, a thermally conductive filler C1 and an addition reaction catalyst D1; and a second agent that contains a copolymer A2, a vinyl-modified organopolysiloxane B2, a thermally conductive filler C2 and a hydrosilyl-modified organopolysiloxane E2. With respect to this two-pack type curable composition set, the copolymer A1 and the copolymer A2 each have a (meth)acrylic monomer unit α that has a carboxy group, a (meth)acrylic monomer unit β that has a tertiary amino group, and a (meth)acrylic monomer unit γ that has a siloxane skeleton; and if the first agent and the second agent are mixed with each other in equal volumes, the time necessary for the mixture to achieve a loss tangent tanδ of less than 0.20 is 24 hours or less after the mixing.

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, for example, thermally conductive greases made by adding thermally conductive powder to room-temperature curing liquid silicone rubber. Room-temperature curing liquid silicone rubbers are primarily classified into one-component and two-component types, with the two-component type being further divided into condensation reaction and addition reaction types. Thermally conductive greases containing two-component liquid silicone rubbers are used as two-component curing composition sets containing two different compositions.

[0004] For example, Patent Document 1 describes that an addition reaction type silicone rubber composition containing an alkenyl group-containing organopolysiloxane, an organohydrogenpolysiloxane, a platinum catalyst, and an adhesion promoter is less susceptible to the effects of curing inhibitors and has excellent adhesion. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-22284 Summary of the Invention [Problem to be solved by the invention]

[0006] A two-component curing composition set is used by mixing two types of compositions and then applying them to a specified area, and the mixture hardens over time. Here, a low viscosity of the two types of compositions is desirable from the standpoint of ease of handling, such as application performance. On the other hand, when two types of compositions with low viscosity are used, there is a problem that the mixed composition will drip before hardening occurs if the application location is a vertical surface, or even if the application location is a horizontal surface and the coated member is used upright. Furthermore, if the viscosity of the two types of compositions is low, repeated thermal expansion and contraction of the mixed composition or its components during repeated heating and cooling cycles can cause the mixed composition or its components to flow out of the applied area (hereinafter referred to as "pump-out").

[0007] Therefore, the present invention has been made in consideration of the above-mentioned problems, and has an object to provide a two-component curing composition set that has low viscosity but excellent drip resistance and pump-out resistance, 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]

[0008] As a result of intensive research into achieving the above-mentioned object, the present inventors have found that the above-mentioned problem can be solved by a two-component curing composition set that contains specified components and, when the first and second parts are mixed in equal volumes, the loss tangent tanδ of the mixture falls within a specified range within a specified time, and have thus completed the present invention.

[0009] That is, the present invention is as follows. [1] a first agent containing a copolymer A1, a vinyl-modified organopolysiloxane B1, a thermally conductive filler C1, and an addition reaction catalyst D1; a second agent including a copolymer A2, a vinyl-modified organopolysiloxane B2, a thermally conductive filler C2, and a hydrosilyl-modified organopolysiloxane E2; the copolymer A1 and the copolymer A2 are copolymers 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, After mixing the first agent and the second agent in equal volumes, the time required for the loss tangent tanδ of the mixture, as measured at 25°C and a frequency of 1 Hz using a rotational rheometer, to become less than 0.20 is within 24 hours from the mixing. Two-component curing composition set. [2] the vinyl-modified organopolysiloxane B1 and the vinyl-modified organopolysiloxane B2 each independently have an average of 2.0 or more vinyl groups per molecule, The hydrosilyl-modified organopolysiloxane E2 has an average of more than 2.0 hydrosilyl groups per molecule. [1] The two-component curing composition set according to [1]. [3] the hydrosilyl-modified organopolysiloxane E2 comprises a hydrosilyl-modified organopolysiloxane E21 having hydrosilyl groups at both ends and a hydrosilyl-modified organopolysiloxane E22 having hydrosilyl groups in side chains; The two-component curing composition set according to [1] or [2]. [4] The vinyl-modified organopolysiloxane B1 and the vinyl-modified organopolysiloxane B2 each independently contain an organopolysiloxane having vinyl groups at both ends. The two-component curing composition set according to any one of [1] to [3]. [5] The number average molecular weight of the monomer unit γ is 1,500 to 50,000. The two-component curing composition set according to any one of [1] to [4]. [6] the content of the copolymer A1 in the first agent is 1 to 40 parts by weight per 100 parts by weight of the vinyl-modified organopolysiloxane B1; the content of the copolymer A2 in the second agent is 1 to 40 parts by weight per 100 parts by weight of the total of the vinyl-modified organopolysiloxane B2 and the hydrosilyl-modified organopolysiloxane E2; The two-component curing composition set according to any one of [1] to [5]. [7] The weight average molecular weight of the copolymer A1 and the copolymer A2 is independently 20,000 to 150,000. The two-component curing composition set according to any one of [1] to [6]. [8] In the copolymer A1 and the copolymer A2, the content of the monomer unit α, the monomer unit β, and the monomer unit γ is 100 parts by weight in total. the content of the monomer unit α is 0.08 to 6.0 parts by weight, the content of the monomer unit β is 0.02 to 4.0 parts by weight, the content of the monomer unit γ is 90.0 to 99.9 parts by weight; The two-component curing composition set according to any one of [1] to [7]. [9] The thermally conductive filler C1 and the thermally conductive filler C2 are each independently 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. The two-component curing composition set according to any one of [1] to [8].

[10] The storage modulus G0' of a mixture obtained by mixing equal volumes of the first agent and the second agent is measured by a rotational rheometer at 25 ° C. and a frequency of 1 Hz immediately after the mixing, compared with the storage modulus G1 measured in the same manner as above 15 hours after the mixing. 15 'Ratio of G 15 ' / G0' is between 100 and 1,500, The two-component curing composition set according to any one of [1] to [9].

[11] The first agent and the second agent are represented by the following formula: R 1 a R 2 b Si(OR 3 ) 4-(a+b) (R 1 are each independently an alkyl group having 1 to 15 carbon atoms, and R 2 are each independently a saturated or unsaturated monovalent hydrocarbon group having 1 to 8 carbon atoms, and R 3 are each independently an alkyl group having 1 to 6 carbon atoms, a is 1 to 3, b is 0 to 2, and a+b is 1 to 3. does not contain organosilane represented by The two-component curing composition set according to any one of [1] to

[10] .

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

[11] .

[13] [1] to

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

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

[13] The cured product according to

[13] .

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

[14] , 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]

[0010] According to the present invention, it is possible to provide a two-component curing composition set that has low viscosity but excellent drip resistance and pump-out resistance, a cured product obtained from the two-component curing composition set, and an electronic device equipped with the cured product. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 2 is a schematic diagram illustrating a method for testing dripping properties in the examples. [Figure 2] FIG. 2 is a schematic diagram illustrating a method for testing dripping properties in the examples. DETAILED DESCRIPTION OF THE INVENTION

[0012] 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.

[0013] 1. Two-component curing composition set The two-component curing composition set of this embodiment comprises: a first part containing copolymer A1, vinyl-modified organopolysiloxane B1, thermally conductive filler C1, and addition reaction catalyst D1; and a second part containing copolymer A2, vinyl-modified organopolysiloxane B2, thermally conductive filler C2, and hydrosilyl-modified organopolysiloxane E2, wherein copolymer A1 and copolymer A2 are copolymers 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, and wherein, after mixing equal volumes of the first and second parts, the loss tangent tanδ of the mixture, as measured using a rotational rheometer at 25°C and a frequency of 1 Hz, becomes less than 0.20 within 24 hours from mixing.

[0014] 1.1. First agent The first agent contains a copolymer A1, a vinyl-modified organopolysiloxane B1, a thermally conductive filler C1, and an addition reaction catalyst D1, and may further contain other components as necessary.

[0015] 1.1.1.Copolymer A1 Copolymer A1 contains (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 copolymer A1 not only improves the dispersibility of thermally conductive filler C1 but also reduces the viscosity of the first part. Furthermore, the curing rate when the first and second parts are mixed can be controlled within a suitable range, further improving the dripping resistance and / or pumping resistance of the two-component curing composition set. The dripping resistance and / or pumping resistance of the two-component curing composition set refers to the resistance of the mixture obtained by mixing the first and second parts of the two-component curing composition set, and the cured product thereof, to dripping and / or pumping.

[0016] The content of copolymer A1 is preferably 1 to 40 parts by weight (both inclusive, and the same applies hereinafter in this specification unless otherwise specified) per 100 parts by weight of the content of vinyl-modified organopolysiloxane B1, more preferably 2 to 30 parts by weight, even more preferably 3 to 20 parts by weight, and even more preferably 5 to 15 parts by weight. When the content of copolymer A1 is within the above range, the dispersibility of thermally conductive filler C1 is further improved, and the viscosity of the first agent tends to be further reduced.

[0017] The weight-average molecular weight of copolymer A1 is preferably 20,000 to 150,000, more preferably 30,000 to 120,000, and even more preferably 40,000 to 100,000. When the weight-average molecular weight of copolymer A1 is within the above range, the dispersibility of thermally conductive filler C1 is improved and the viscosity of the first agent tends to be reduced. The weight-average molecular weight can be determined by GPC (gel permeation chromatography).

[0018] Copolymer A1 will be described in more detail below. In this embodiment, "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. Furthermore, hereinafter, "(meth)acrylic monomer unit α" and the like will also be simply referred to as "monomer unit α" and the like.

[0019] In copolymer A1, the monomer units α, β, and γ may be contained randomly or in blocks. In copolymer A1, at least the monomer units α and γ are preferably contained as random copolymers. When the monomer units α and γ are contained as random copolymers, the viscosity of the first agent tends to be further reduced.

[0020] 1.1.1.1. (Meth)acrylic monomer unit α having a carboxy group The monomer unit α is a repeating unit having a carboxy group. When the copolymer A1 contains such a monomer unit, the dispersibility of the thermally conductive filler C1 is further improved.

[0021] The monomer unit α preferably further has an electron-withdrawing group bonded to the carboxy group. Such an electron-withdrawing group is not particularly limited as long as it has the effect of stabilizing the negative charge on the carboxy group. For example, the monomer unit α may be a unit derived from an acrylic monomer containing an electron-withdrawing substituent such as a halogen element on the carbon atom at the α-position of the carboxy group. The inclusion of such a monomer unit tends to further improve the dispersibility of the thermally conductive filler C1.

[0022] The monomer unit α preferably does not have an electron-donating group bonded to the carboxy group or has a group with low electron-donating properties. Such electron-donating groups are not particularly limited as long as they have the effect of destabilizing the negative charge on the carboxy group. For example, the monomer unit α may be a unit derived from an acrylic monomer that does not contain an electron-donating group, such as a methyl group, at the carbon atom at the α-position of the carboxy group. The inclusion of such a monomer unit tends to further improve the dispersibility of the thermally conductive filler C1.

[0023] Such (meth)acrylic monomers are not particularly limited, but examples thereof include acrylic acid, methacrylic acid, 2-acryloyloxyethyl succinic acid, 2-methacryloyloxyethyl succinic acid, etc. Among these, acrylic acid and 2-methacryloyloxyethyl succinic acid are preferred, and acrylic acid is more preferred. By including units derived from such monomers, affinity for the thermally conductive filler C1 is further improved, and the dispersibility of the thermally conductive filler C1 tends to be further improved. The monomer unit α may be used alone or in combination of two or more types.

[0024] The content of the monomer unit α is, for example, 0.05 to 20 parts by weight, preferably 0.08 to 6.0 parts by weight, more preferably 0.1 to 5.0 parts by weight, even more preferably 0.3 to 4.0 parts by weight, and even more preferably 0.5 to 3.0 parts by weight, relative to 100 parts by weight of the total of the monomer units α, β, and γ. Within the above range, the content of the monomer unit α may be 0.7 parts by weight or more, or 2.0 parts by weight or less. By having the content of the monomer unit α within the above range, the dispersibility of the thermally conductive filler C1 tends to be further improved, and the viscosity of the first agent tends to be further reduced. Furthermore, the curing rate when the first agent and the second agent are mixed tends to be within a more suitable range.

[0025] 1.1.1.2. (Meth)acrylic monomer units β having a tertiary amino group The monomer unit β is a repeating unit having a tertiary amino group. When the copolymer A1 contains such a monomer unit, the dispersibility of the thermally conductive filler C1 is further improved.

[0026] The monomer unit β preferably further has an electron-donating group bonded to the carbon atom adjacent to the nitrogen atom of the tertiary amino group. Such an electron-donating group is not particularly limited as long as it has the effect of stabilizing the positive charge on the tertiary amino group. The monomer unit β may be, for example, a unit derived from an acrylic monomer containing an electron-donating substituent, such as a methyl group, on the carbon atom at the α-position of the tertiary amino group. The inclusion of such a monomer unit tends to further improve the dispersibility of the thermally conductive filler C1.

[0027] The monomer unit β preferably does not have an electron-withdrawing group bonded to the carbon atom adjacent to the nitrogen atom in the tertiary amino group, or has a group with low electron-withdrawing properties. Such electron-withdrawing groups are not particularly limited as long as they have the effect of destabilizing the positive charge on the tertiary amino group. The monomer unit β may be, for example, a unit derived from an acrylic monomer that does not contain a substituent of an electron-withdrawing group such as a carboxyl group on the carbon atom at the α-position of the tertiary amino group. The inclusion of such a monomer unit tends to further improve the dispersibility of the thermally conductive filler C1.

[0028] Such (meth)acrylic monomers are not particularly limited, but examples thereof include dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, and 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate. Among these, dimethylaminoethyl methacrylate and 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate are preferred, and 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate is more preferred. By including units derived from such monomers, affinity for the thermally conductive filler C1 is further improved, and the dispersibility of the thermally conductive filler C1 tends to be further improved. The monomer unit β may be used alone or in combination of two or more types.

[0029] The content of the monomer unit β is, for example, 0.02 to 4.0 parts by weight, preferably 0.05 to 4.0 parts by weight, more preferably 0.07 to 3.0 parts by weight, even more preferably 0.08 to 2.0 parts by weight, and even more preferably 0.1 to 1.0 parts by weight, relative to 100 parts by weight of the total of the monomer units α, β, and γ. Within the above range, the content of the monomer unit β may be 0.3 parts by weight or more, or 0.8 parts by weight or less. When the content of the monomer unit β is within the above range, the dispersibility of the thermally conductive filler C1 is further improved, and the viscosity of the first agent tends to be further reduced.

[0030] 1.1.1.3. (Meth)acrylic monomer unit γ having a siloxane skeleton The monomer unit γ is a repeating unit having a siloxane skeleton. The presence of such a monomer unit in copolymer A1 increases the affinity or compatibility between copolymer A1 and vinyl-modified organopolysiloxane B1, further reducing the viscosity of the first part. Furthermore, the presence of monomer unit γ in copolymer A1 prevents the addition reaction catalyst D1 from being deactivated by reaction with monomer unit α. This allows the curing rate when the first and second parts are mixed to be within a suitable range, further improving the drip resistance and / or pump-out resistance of the two-part curing composition set.

[0031] Examples of the siloxane skeleton in the monomer unit γ include organopolysiloxane skeletons such as dialkylpolysiloxane, diphenylpolysiloxane, and alkylphenylpolysiloxane. The alkyl contained in the siloxane skeleton is not particularly limited, but examples thereof include methyl, ethyl, propyl, butyl, pentyl, and hexyl groups. The phenyl group contained in the siloxane skeleton is not particularly limited, but examples thereof include phenyl groups and substituted phenyl groups, specifically phenyl and benzyl groups. Examples of the substituent include methyl, ethyl, propyl, butyl, pentyl, and hexyl groups.

[0032] Such (meth)acrylic monomers are not particularly limited, but examples thereof include (meth)acrylic acid polysiloxanes in which the terminals of the siloxane skeletons are modified with (meth)acrylic acid, as described above. Specific examples include α-butyl-ω-(3-methacryloxypropyl)polydimethylsiloxane, etc. The monomer unit γ may be used alone or in combination of two or more.

[0033] The number average molecular weight of the monomer unit γ is preferably 1,500 to 50,000, more preferably 3,000 to 30,000, and even more preferably 4,000 to 20,000. When the number average molecular weight of the monomer unit γ is 1,500 or more, deactivation of the addition reaction catalyst D1 is further suppressed, and the dripping resistance and / or pump-out resistance of the two-component curing composition set tend to be further improved. When the number average molecular weight of the monomer unit γ is 50,000 or less, the viscosity of the first part tends to be further reduced. The number average molecular weight of the monomer unit γ can be determined by GPC (gel permeation chromatography).

[0034] The content of the monomer unit γ is, for example, 70.0 to 99.9 parts by weight, preferably 80.0 to 99.5 parts by weight, preferably 90.0 to 99.0 parts by weight, more preferably 93.0 to 98.8 parts by weight, and even more preferably 96.0 to 98.7 parts by weight, per 100 parts by weight of the total of the monomer units α, β, and γ. When the content of the monomer unit γ is within the above range, the dispersibility of the thermally conductive filler C1 tends to be further improved, and the viscosity of the first agent tends to be further reduced. Furthermore, the dripping resistance and / or pump-out resistance of the two-component curing composition set tends to be further improved.

[0035] The total content of the monomer units α, β, and γ in copolymer A1 is preferably 90% by weight or more, more preferably 95% by weight or more, even more preferably 99% by weight or more, and even more preferably 100% by weight, based on the total amount of copolymer A1. When this total content is within the above range, the dispersibility of the thermally conductive filler C1 tends to be further improved, and the viscosity of the first agent tends to be further reduced. The upper limit of the total content of the monomer units α, β, and γ is not particularly limited, and may be, for example, 100% by weight, 99% by weight, 98% by weight, or 95% by weight.

[0036] 1.1.1.4. Manufacturing method The method for producing copolymer A1 is not particularly limited, and any known polymerization method for (meth)acrylic monomers can be used. Examples of the polymerization method include radical polymerization and anionic polymerization. Among these, radical polymerization is preferred.

[0037] The thermal polymerization initiator used in radical polymerization is not particularly limited, but examples thereof include azo compounds such as azobisisobutyronitrile; and organic peroxides such as benzoyl peroxide, tert-butyl hydroperoxide, and di-tert-butyl peroxide. The photopolymerization initiator used in radical polymerization is not particularly limited, but examples thereof include benzoin derivatives. Furthermore, known polymerization initiators used in living radical polymerization such as ATRP and RAFT can also be used.

[0038] The polymerization conditions are not particularly limited and can be appropriately adjusted depending on the initiator and boiling point of the solvent used, and the types of other monomers.

[0039] The order of adding the monomers is not particularly limited. For example, when synthesizing a random copolymer, the monomers may be mixed to initiate polymerization, and when synthesizing a block copolymer, the monomers may be added sequentially to the polymerization system.

[0040] 1.1.2. Vinyl-modified organopolysiloxane B1 Vinyl-modified organopolysiloxane B1 (hereinafter also referred to simply as "organopolysiloxane B1") is an organopolysiloxane having at least one vinyl group. Organopolysiloxane B1 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 (b1-1) or a terminal structure represented by formula (b1-2). Organopolysiloxane B1 may have, for example, at least one of the structural unit represented by formula (b1-1) and the terminal structure represented by formula (b1-2), and a structural unit represented by formula (b1-3).

[0041] [ka]

[0042] In formulas (b1-1), (b1-2), and (b1-3), R represents any monovalent hydrocarbon group which may have a substituent. That is, in organopolysiloxane B1, any monovalent hydrocarbon group which may have a substituent is bonded to a side chain of the siloxane skeleton.

[0043] Such monovalent hydrocarbon groups are not particularly limited, and examples thereof include 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 the substituent in the monovalent hydrocarbon group include a halogen atom, particularly a fluorine atom or a chlorine atom.

[0044] The organopolysiloxane B1 is contained in the first part either alone or in combination of two or more. The number of vinyl groups in the organopolysiloxane B1 contained in the first part is preferably 2.0 or more on average per molecule. That is, when the first part contains one type of organopolysiloxane B1, the organopolysiloxane preferably has two or more vinyl groups per molecule. When the first part contains two or more types of organopolysiloxane B1, the arithmetic average number of vinyl groups in each organopolysiloxane is preferably 2.0 or more. By having 2.0 or more vinyl groups per molecule, the crosslink density can be adjusted, and the curing rate when the first part and the second part are mixed tends to be in a more suitable range. As a result, the drip resistance and / or pump-out resistance of the two-component curing composition set tends to be further improved. The upper limit of the number of vinyl groups in organopolysiloxane B1 is not particularly limited, and may be, for example, an average of 4.0, 3.0, or 2.5 per molecule, and the average number of vinyl groups in organopolysiloxane B1 per molecule may be 2.0.

[0045] The average number of vinyl groups per molecule of organopolysiloxane B1 can be measured by NMR. Specifically, for example, an ECP-300NMR manufactured by JEOL Corporation can be used to dissolve organopolysiloxane B1 in deuterated chloroform as a deuterated solvent. The average number of vinyl groups per molecule can be calculated by dividing the measurement result thus obtained by the average molecular weight of organopolysiloxane B1.

[0046] The organopolysiloxane B1 preferably contains at least an organopolysiloxane having vinyl groups at both ends. The use of such an organopolysiloxane tends to allow the crosslinking density to be adjusted, and the curing rate when the first and second parts are mixed tends to be within a more suitable range. As a result, the dripping resistance and / or pump-out resistance of the two-component curing composition set tends to be further improved. From the same perspective, the organopolysiloxane B1 preferably contains at least a polydimethylsiloxane having vinyl groups at both ends.

[0047] The viscosity of organopolysiloxane B1 at 25°C is preferably 30 to 500 mPa·s, more preferably 50 to 400 mPa·s, and even more preferably 70 to 300 mPa·s. If the viscosity of organopolysiloxane B1 is 500 mPa·s or less, the viscosity of the first agent tends to be further reduced. If the viscosity of organopolysiloxane B1 is 30 mPa·s or more, the mechanical strength of the cured product, such as the shear displacement and elongation at break, described below, tends to be further improved.

[0048] 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.

[0049] As will be described later, vinyl-modified organopolysiloxane B1 undergoes an addition reaction with hydrosilyl-modified organopolysiloxane E2 contained in the second part in the presence of addition reaction catalyst D1. By appropriately adjusting the numbers of vinyl groups and hydrosilyl groups in vinyl-modified organopolysiloxane B1 and hydrosilyl-modified organopolysiloxane E2 and their viscosities, it is possible to control the viscosity of the first and second parts, as well as the curing rate when the first and second parts are mixed.

[0050] The content of vinyl-modified organopolysiloxane B1 is preferably 60 to 99 wt %, more preferably 70 to 98 wt %, and even more preferably 80 to 95 wt %, based on the total of all components of the first agent other than thermally conductive filler C1. When the content of vinyl-modified organopolysiloxane B1 is within the above range, the viscosity of the first agent tends to be further reduced, and the curing speed when the first and second agents are mixed tends to be within a more suitable range.

[0051] 1.1.3.Thermal Conductive Filler C1 The thermally conductive filler C1 is a filler having thermal conductivity. The thermal conductivity of the thermally conductive filler C1 is not particularly limited, but may be, for example, 10 W / m·K or more, 20 W / m·K or more, or 30 W / m·K or more. The upper limit of the thermal conductivity of the thermally conductive filler C1 is not particularly limited, and may be, for example, 400 W / m·K or 300 W / m·K. Examples of such thermally conductive fillers C1 include, but are not limited to, aluminum oxide (hereinafter also referred to as "alumina"), aluminum nitride, silica, boron nitride, silicon nitride, zinc oxide, aluminum hydroxide, metallic aluminum, magnesium oxide, diamond, carbon, indium, gallium, copper, silver, iron, nickel, gold, tin, metallic silicon, and the like.

[0052] Among these, the first agent preferably contains, as the thermally conductive filler C1, 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 one or more selected from the group consisting of aluminum oxide, magnesium oxide, aluminum nitride, and metallic aluminum, and even more preferably aluminum oxide. This is because the thermally conductive filler has high thermal conductivity, high insulating properties, and is inexpensive. The thermally conductive filler C1 may be used alone or in combination of two or more.

[0053] The thermally conductive filler C1 has an average particle size of preferably 0.05 to 120 μm, more preferably 0.1 to 70 μm. When the average particle size of the thermally conductive filler C1 is within the above range, the fluidity of the first agent and the dispersibility and filling properties of the thermally conductive filler C1 tend to be further improved.

[0054] The thermally conductive filler C1 may be a mixture of fillers with different average particle sizes. As the thermally conductive filler C1, it is preferable to use a combination of two or more of the thermally conductive filler (C1-1) having an average particle size of 30 to 100 μm, the thermally conductive filler (C1-2) having an average particle size of 1.5 to 25 μm, and the thermally conductive filler (C1-3) having an average particle size of 0.05 to 1.0 μm. It is more preferable to use at least the thermally conductive filler (C1-1) and the thermally conductive filler (C1-2), and even more preferable to use all of the thermally conductive filler (C1-1), the thermally conductive filler (C1-2), and the thermally conductive filler (C1-3).

[0055] 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.

[0056] In this case, the content of the thermally conductive filler (C1-1) is preferably 30 to 70% by weight, more preferably 40 to 60% by weight, based on the total amount of the thermally conductive filler C1. The content of the thermally conductive filler (C1-2) is preferably 10 to 50% by weight, more preferably 20 to 40% by weight, based on the total amount of the thermally conductive filler C1. The content of the thermally conductive filler (C1-3) is preferably 5 to 30% by weight, more preferably 10 to 20% by weight, based on the total amount of the thermally conductive filler C1. The use of the thermally conductive filler C1 as described above tends to further improve the fluidity of the first agent and the dispersibility and filling ability of the thermally conductive filler C1. Note that the average particle size in this specification refers to D50 (median diameter).

[0057] The content of the thermally conductive filler C1 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 B1. When the content of the thermally conductive filler C1 is 400 parts by weight or more, the thermal conductivity of the resulting cured product tends to be further improved, while when it is 3000 parts by weight or less, the viscosity of the first agent tends to be further reduced.

[0058] 1.1.4. Addition reaction catalyst D1 The addition reaction catalyst D1 is not particularly limited as long as it catalyzes the addition reaction between the vinyl-modified organopolysiloxane B1 and the hydrosilyl-modified organopolysiloxane E2. Examples of the addition reaction catalyst D1 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 D1 can keep the curing rate when the first and second parts are mixed within a suitable range, and tends to further improve the drip resistance and / or pump-out resistance of the two-component curing composition set.

[0059] 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.

[0060] The addition reaction catalyst D1 may be used alone or in combination of two or more. Furthermore, when preparing the first agent, the addition reaction catalyst D1 may be blended alone or in a pre-mixed state with other components, such as the vinyl-modified organopolysiloxane B1 or other organopolysiloxanes.

[0061] The content of 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 content of vinyl-modified organopolysiloxane B1. When the content of addition reaction catalyst D1 is within the above range, the curing speed when the first and second parts are mixed can be set within a suitable range, and the dripping resistance and / or pump-out resistance of the two-component curing composition set tends to be further improved.

[0062] 1.1.5.Other Ingredients In addition to the above components, the first agent may contain additives such as a colorant and a reaction retarder, if necessary.

[0063] When the first agent contains a colorant, the content of the colorant is preferably 0.001 to 0.2 parts by weight relative to 100 parts by weight of the total amount of the first agent.

[0064] The reaction retarder is not particularly limited as long as it is a component that retards the reaction when the first and second agents are mixed, but examples include alkenyl alcohols, of which 1-ethynyl-1-cyclohexanol is preferred. When the first agent contains a reaction retarder, the content of the reaction retarder is preferably 0.1 to 20 parts by weight, more preferably 0.5 to 10 parts by weight, per 100 parts by weight of the vinyl-modified organopolysiloxane B1. The reaction retarder may not be contained in the first agent, but may be contained only in the second agent.

[0065] The first agent is a compound of the following formula: R 1 a R 2 b Si(OR 3 ) 4-(a+b) (R 1 are each independently an alkyl group having 1 to 15 carbon atoms, and R 2 are each independently a saturated or unsaturated monovalent hydrocarbon group having 1 to 8 carbon atoms, and R 3 are each independently an alkyl group having 1 to 6 carbon atoms, a is 1 to 3, b is 0 to 2, and a+b is 1 to 3. It is preferred that the organosilane does not contain an organosilane represented by the formula:

[0066] Although such organosilanes have been conventionally used to improve the wettability of thermally conductive fillers, they are preferably not included in the first part of the two-component curing composition set of this embodiment. According to this embodiment, the viscosity of the first part tends to be further reduced compared to when the above-described organosilanes are included. The reason for this is not entirely clear, but it is thought that when the first part contains an organosilane, copolymer A1 and the organosilane compete with each other as components for improving the wettability of thermally conductive fillers, thereby reducing the effect of copolymer A1.

[0067] R in the above formula 1Although not particularly limited, examples of R include a methyl group, an ethyl group, a propyl group, a hexyl group, a nonyl group, a decyl group, a dodecyl group, and a tetradecyl group. 1 is preferably an alkyl group having 6 to 12 carbon atoms.

[0068] R in the above formula 2 Examples of the alkyl group include, but are not limited to, alkyl groups such as methyl, ethyl, propyl, hexyl, and octyl; cycloalkyl groups such as cyclopentyl and cyclohexyl; alkenyl groups such as vinyl and allyl; aryl groups such as phenyl and tolyl; aralkyl groups such as 2-phenylethyl and 2-methyl-2-phenylethyl; and halogenated hydrocarbon groups such as 3,3,3-trifluoropropyl, 2-(perfluorobutyl)ethyl, 2-(perfluorooctyl)ethyl, and p-chlorophenyl.

[0069] R in the above formula 3 is not particularly limited, and is, for example, an alkyl group having 1 to 6 carbon atoms such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, or a hexyl group, and is preferably a methyl group or an ethyl group.

[0070] In the above formula, a is an integer of 1 to 3, and preferably 1. Furthermore, b is an integer of 0 to 2, and preferably 0. Furthermore, a+b is an integer of 1 to 3, and preferably 1.

[0071] The content of the organosilane in the first agent is preferably 1 part by weight or less, more preferably 0.1 part by weight or less, even more preferably 0.01 part by weight or less, and particularly preferably 0 part by weight (i.e., no organosilane) per 100 parts by weight of the thermally conductive filler C1. By keeping the organosilane content within the above range, the wettability of the thermally conductive filler tends to be effectively improved.

[0072] 1.1.6.Viscosity First agent: 25°C, shear rate: 10 s -1The viscosity in this range is preferably 20 to 160 Pa·s, more preferably 50 to 150 Pa·s, and even more preferably 70 to 140 Pa·s. A viscosity of 20 Pa·s or higher tends to further improve the drip resistance and / or pump-out resistance of the two-component curing composition set. Furthermore, a viscosity of 160 Pa·s or lower tends to provide better handleability and further improve the coatability of the mixed liquid obtained by mixing the first and second parts.

[0073] The first agent and the second agent described below were tested at 25°C and a shear rate of 10 s -1 The viscosity at 1000 kJ / s can be measured using a rotational rheometer "HANKE MARSIII" manufactured by Thermo Fisher Scientific. More specifically, parallel plates with a diameter of 35 mm were used, with a gap of 0.5 mm, a temperature of 25°C, and a shear rate of 10 s -1 The measurement can be performed under the following conditions.

[0074] 1.2. Second Agent The second agent contains a copolymer A2, a vinyl-modified organopolysiloxane B2, a thermally conductive filler C2, and a hydrosilyl-modified organopolysiloxane E2, and may contain other components as necessary.

[0075] 1.2.1.Copolymer A2 Specific examples and preferred embodiments of copolymer A2 are the same as those of copolymer A1 contained in the first agent, and therefore redundant explanations will be omitted. Copolymer A1 contained in the first agent and copolymer A2 contained in the second agent may be the same or different.

[0076] In the second agent, the content of copolymer A2 is preferably 1 to 40 parts by weight, more preferably 2 to 30 parts by weight, even more preferably 3 to 20 parts by weight, and even more preferably 5 to 15 parts by weight, per 100 parts by weight of the total of vinyl-modified organopolysiloxane B2 and hydrosilyl-modified organopolysiloxane E2. When the content of copolymer A2 is within the above range, the dispersibility of thermally conductive filler C2 is further improved, and the viscosity of the second agent tends to be further reduced.

[0077] 1.2.2. Vinyl-modified organopolysiloxane B2 Specific examples and preferred embodiments of the vinyl-modified organopolysiloxane B2 are the same as those of the vinyl-modified organopolysiloxane B1 contained in the first agent, and therefore redundant explanations will be omitted. The vinyl-modified organopolysiloxane B1 contained in the first agent and the vinyl-modified organopolysiloxane B2 contained in the second agent may be the same or different.

[0078] In the second agent, the content of vinyl-modified organopolysiloxane B2 is preferably 40 to 98 parts by weight, more preferably 45 to 95 parts by weight, and even more preferably 50 to 93 parts by weight, per 100 parts by weight of the total of vinyl-modified organopolysiloxane B2 and hydrosilyl-modified organopolysiloxane E2. Having the content of vinyl-modified organopolysiloxane B2 within the above range tends to make it possible to achieve a more suitable curing rate when the first agent and second agent are mixed. Within the above range, the content of vinyl-modified organopolysiloxane B2 may be 90 parts by weight or less, 80 parts by weight or less, or 70 parts by weight or less.

[0079] 1.2.3.Thermal Conductive Filler C2 Specific examples and preferred embodiments of the thermally conductive filler C2 are the same as those of the thermally conductive filler C1 contained in the first agent, and therefore, redundant explanations will be omitted. The thermally conductive filler C1 contained in the first agent and the thermally conductive filler C2 contained in the second agent may be the same or different.

[0080] The content of the thermally conductive filler C2 is preferably 400 to 3,000 parts by weight, more preferably 600 to 2,800 parts by weight, and even more preferably 700 to 2,600 parts by weight, per 100 parts by weight of the total of the vinyl-modified organopolysiloxane B2 and the hydrosilyl-modified organopolysiloxane E2. When the content of the thermally conductive filler C2 is 400 parts by weight or more, the thermal conductivity of the obtained cured product tends to be further improved, while when it is 3,000 parts by weight or less, the viscosity of the second agent tends to be further reduced.

[0081] 1.2.4. Hydrosilyl-modified organopolysiloxane E2 Hydrosilyl-modified organopolysiloxane E2 (hereinafter also referred to simply as "organopolysiloxane E2") is an organopolysiloxane having at least one hydrosilyl group. Organopolysiloxane E2 may have a hydrosilyl group on a side chain and / or at a terminal. Such organopolysiloxane has a structural unit represented by the following formula (e2-1) or a terminal structure represented by formula (e2-2). Organopolysiloxane E2 may have, for example, at least one of the structural unit represented by formula (e2-1) and the terminal structure represented by formula (e2-2), and a structural unit represented by formula (e2-3).

[0082] [ka] In formulae (e2-1), (e2-2), and (e2-3), R represents any monovalent hydrocarbon group which may have a substituent. That is, in organopolysiloxane E2, any monovalent hydrocarbon group which may have a substituent is bonded to a side chain of the siloxane skeleton.

[0083] Examples of such monovalent hydrocarbon groups include the same monovalent hydrocarbon groups that may be contained in the vinyl-modified organopolysiloxane B1.

[0084] The organopolysiloxane E2 is contained in the second agent either alone or in combination of two or more. For example, the second agent preferably contains, as organopolysiloxane E2, at least hydrosilyl-modified organopolysiloxane E22 having hydrosilyl groups in side chains, and more preferably contains hydrosilyl-modified organopolysiloxane E21 having hydrosilyl groups at both ends and the hydrosilyl-modified organopolysiloxane E22.

[0085] Organopolysiloxane E21 has at least two hydrosilyl groups at both ends of the organopolysiloxane skeleton. Organopolysiloxane E21 may further have hydrosilyl groups on side chains. Organopolysiloxane E21 may be an organopolysiloxane having hydrosilyl groups only at both ends.

[0086] Organopolysiloxane E22 has at least one hydrogen atom in a side chain of the organopolysiloxane skeleton, and this hydrogen atom and a silicon atom constitute a hydrosilyl group. Organopolysiloxane E22 may further have hydrosilyl groups at both ends of the organopolysiloxane skeleton. The number of hydrosilyl groups in organopolysiloxane E22 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. The upper limit of the hydrosilyl groups in organopolysiloxane E22 is not particularly limited, and may be, for example, 8.0, 6.0, or 5.0 on average per molecule.

[0087] The number of hydrosilyl groups in the organopolysiloxane E2 contained in the second agent is preferably more than 2.0 on average per molecule, and more preferably 2.5 or more on average per molecule. That is, when the second agent contains one type of organopolysiloxane E2, it is preferable that the organopolysiloxane has more than two (i.e., three or more) hydrosilyl groups per molecule. When the second agent contains two or more types of organopolysiloxane E2, it is preferable that the arithmetic average number of hydrosilyl groups in each organopolysiloxane is more than 2.0.

[0088] Because the number of hydrosilyl groups in organopolysiloxane E21 and organopolysiloxane E22 can be controlled separately as described above, by appropriately mixing the two, it tends to be possible to control the viscosity of the second part while also controlling its reactivity with the first part. In particular, when the second part contains organopolysiloxane E22, it tends to form a network structure when reacted with vinyl-modified organopolysiloxanes B1 and B2, resulting in a cured product with superior mechanical strength, such as shear displacement and elongation at break.

[0089] The average number of hydrosilyl groups per molecule of organopolysiloxane E2 can be measured by NMR. Specifically, for example, an ECP-300NMR (manufactured by JEOL) can be used to dissolve organopolysiloxane E2 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 E2.

[0090] The viscosity of organopolysiloxane E21 at 25°C is preferably 5 to 100 mPa·s, more preferably 10 to 80 mPa·s, and even more preferably 15 to 50 mPa·s. If the viscosity of organopolysiloxane E21 is 100 mPa·s or less, the viscosity of the second part tends to be further reduced. If the viscosity of organopolysiloxane E21 is 5 mPa·s or more, the mechanical strength of the cured product, such as the shear displacement and elongation at break, described below, tends to be further improved.

[0091] The viscosity of organopolysiloxane E22 at 25°C is preferably 1 to 100 mPa·s, more preferably 2 to 90 mPa·s, and even more preferably 3 to 80 mPa·s. When the viscosity of organopolysiloxane E22 is 100 mPa·s or less, the viscosity of the second part tends to be further reduced. When the viscosity of organopolysiloxane E22 is 1 mPa·s or more, the mechanical strength of the cured product, such as the shear displacement and elongation at break, described below, tends to be further improved. The viscosity of organopolysiloxane E22 at 25°C may be 50 mPa·s or less, or 20 mPa·s or less, within the above range. Alternatively, in another embodiment, the viscosity of organopolysiloxane E22 at 25°C may be 60 to 80 mPa·s, within the above range.

[0092] In the second agent, the content of hydrosilyl-modified organopolysiloxane E2 is preferably 2 to 60 parts by weight, more preferably 5 to 55 parts by weight, and even more preferably 7 to 50 parts by weight, per 100 parts by weight of the total of vinyl-modified organopolysiloxane B2 and hydrosilyl-modified organopolysiloxane E2. Having the content of hydrosilyl-modified organopolysiloxane E2 within the above range tends to make it possible to achieve a more suitable curing rate when the first agent and second agent are mixed. Within the above range, the content of hydrosilyl-modified organopolysiloxane E2 may be 10 parts by weight or more, 20 parts by weight or more, or 30 parts by weight or more.

[0093] The total content of the vinyl-modified organopolysiloxane B2 and the hydrosilyl-modified organopolysiloxane E2 is preferably 60 to 99% by weight, more preferably 70 to 98% by weight, and even more preferably 80 to 95% by weight, based on the total of all components other than the thermally conductive filler C1 in the second part. By keeping the content within the above range, the viscosity of the second part tends to be further reduced, and the curing rate when the first and second parts are mixed tends to be within a more suitable range.

[0094] 1.2.5. Reaction retarder F2 The reaction retarder F2 is an additive that is optionally added to control the reaction between the hydrosilyl group and the vinylsilyl group. In this embodiment, it is preferable that the first part contains the addition reaction catalyst D1 and the second part contains a reaction retarder. The reaction retarder F2 is not particularly limited as long as it is a component that delays the reaction when the first part and the second part are mixed, but examples thereof include alkenyl alcohols, and 1-ethynyl-1-cyclohexanol is particularly preferred. The use of such a reaction retarder F2 can keep the curing rate when the first part and the second part are mixed within a suitable range, which tends to further improve the drip resistance and / or pump-out resistance of the two-component curing composition set.

[0095] When the second part contains reaction retarder F2, the content of reaction retarder F2 is preferably 0.1 to 20 parts by weight, and more preferably 0.5 to 10 parts by weight, per 100 parts by weight of the total of vinyl-modified organopolysiloxane B2 and hydrosilyl-modified organopolysiloxane E2. By having the content of reaction retarder F2 within the above range, the curing rate when the first part and second part are mixed can be set within a suitable range, and the dripping resistance and / or pump-out resistance of the two-component curing composition set tends to be further improved.

[0096] 1.2.6.Other Ingredients In addition to the above components, the second agent may contain additives such as colorants as necessary. Specific examples, preferred embodiments, content, and other details of the colorants are the same as those of the first agent, and redundant explanations will be omitted. The additives contained in the first agent and the additives contained in the second agent may be the same or different.

[0097] The second agent is a compound of the following formula: R 1 a R 2 b Si(OR 3 ) 4-(a+b) (R 1 are each independently an alkyl group having 1 to 15 carbon atoms, and R2 are each independently a saturated or unsaturated monovalent hydrocarbon group having 1 to 8 carbon atoms, and R 3 are each independently an alkyl group having 1 to 6 carbon atoms, a is 1 to 3, b is 0 to 2, and a+b is 1 to 3. It is preferable that the second agent does not contain an organosilane represented by the following formula: By not containing the above organosilane, the viscosity of the second agent tends to be further reduced.

[0098] The specific aspects of the organosilane are the same as those of the organosilanes that are preferably not contained in the first agent, and the preferred content of the organosilane in the second agent is also the same as that in the first agent.

[0099] 1.2.7.Viscosity Second agent: 25°C, shear rate: 10 s -1 The viscosity in this range is preferably 20 to 150 Pa·s, more preferably 50 to 140 Pa·s, and even more preferably 70 to 130 Pa·s. A viscosity of 20 Pa·s or higher tends to further improve the drip resistance and / or pump-out resistance of the two-component curing composition set. Furthermore, a viscosity of 150 Pa·s or lower tends to provide better handleability and further improve the coatability of the mixed liquid obtained by mixing the first and second parts.

[0100] 1.3. Mixture of the first and second agents By mixing the first and second parts, curing begins. In this embodiment, by controlling the rate at which this curing progresses and the physical strength during curing, it is possible to reduce the viscosity of each of the first and second parts, while improving the dripping resistance and pump-out resistance when these parts are mixed and applied.

[0101] In this embodiment, the rate of cure and physical strength during cure are expressed in terms of loss tangent tan δ. Specifically, when equal volumes of the first and second parts are mixed and the loss tangent tan δ of the mixture is measured using a rotational rheometer at 25°C and a frequency of 1 Hz, it takes 24 hours from mixing for the loss tangent tan δ to become less than 0.20.

[0102] As described above, the first and second parts of the two-component curing composition set of this embodiment achieve a loss tangent tanδ of less than 0.20 within 24 hours, i.e., undergo a curing reaction at a predetermined rate. The thermally conductive grease obtained using such a two-component curing composition set has low viscosity, but begins to cure before dripping occurs when used upright, preventing dripping. Furthermore, the grease cures sufficiently in a short time, preventing pump-out. From the same perspective, the time required for the loss tangent tanδ to become less than 0.20 is preferably within 12 hours, more preferably within 8 hours, and even more preferably within 5 hours from mixing. The lower limit of the time required for the loss tangent tanδ to become less than 0.20 is not particularly limited, but may be 10 minutes or more, or 30 minutes or more.

[0103] Similarly, the rate of curing and the physical strength during curing may be expressed by the storage modulus G'. Specifically, the storage modulus G' measured in the same manner as above 15 hours after mixing of a mixture of equal volumes of the first and second parts is calculated by measuring the storage modulus G' at 25°C and a frequency of 1 Hz with a rotational rheometer immediately after mixing. 15 'Ratio of G 15 The ratio ' / G0' is preferably 100 to 1,500, more preferably 300 to 1,200, and even more preferably 600 to 1,000. 15 When ' / G0' is 100 or more, the curing speed when the first and second parts are mixed tends to be within a suitable range, and when it is 1,500 or less, the viscosity of the mixture immediately after mixing the first and second parts is not too low, which tends to further improve the dripping resistance and / or pump-out resistance of the two-component curing composition set.

[0104] The storage modulus G 15 The value of " is not particularly limited, but is preferably 100,000 to 1,000,000 Pa, more preferably 200,000 to 900,000 Pa, and even more preferably 300,000 to 800,000 Pa. The value of the storage modulus G0' is not particularly limited, but is preferably 100 to 3,000 Pa, more preferably 300 to 2,000 Pa, and even more preferably 500 to 1,200 Pa. Storage modulus G 15 When the values ​​of ' and storage modulus G0' are within the above ranges, the balance between the viscosity of the mixture immediately after mixing the first and second parts and the viscosity after curing can be further improved, and there is a tendency to be able to provide a two-component curing composition set that has lower viscosity yet is more excellent in drip resistance and pump-out resistance.

[0105] 1.4.Usage The two-component curing composition set of the present embodiment can be suitably used as a thermally conductive and heat-dissipating material such as thermally conductive grease.

[0106] 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 mixing the first and second parts in a mixture obtained by mixing the first and second parts, through an addition reaction between the vinyl groups of the vinyl-modified organopolysiloxanes B1 and B2 and the hydrosilyl groups of the hydrosilyl-modified organopolysiloxane E2.

[0107] 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.

[0108] 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.

[0109] 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.

[0110] 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.

[0111] 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]

[0112] 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.

[0113] 1. Copolymer synthesis 1.1. Raw materials ((Meth)acrylic monomer α having a carboxy group) Acrylic acid, manufactured by Toagosei

[0114] ((Meth)acrylic monomer β having a tertiary amino group) 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate, ADEKA Corporation "ADEKA STAB LA-82"

[0115] ((Meth)acrylic monomer γ having a siloxane skeleton) (γ-1)α-butyl-ω-(3-methacryloxypropyl)polydimethylsiloxane), JNC Corporation "Silaplane FM-0725" number average molecular weight 10,000 (γ-2)α-butyl-ω-(3-methacryloxypropyl)polydimethylsiloxane), JNC Corporation "Silaplane FM-0721" number average molecular weight 5000 (γ-3)α-butyl-ω-(3-methacryloxypropyl)polydimethylsiloxane), JNC Corporation "Silaplane FM-0711" number average molecular weight 1000

[0116] 1.2.Copolymer 1 Copolymer 1 was synthesized as follows. First, 1.5 parts by weight of acrylic acid, 0.5 parts by weight of 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate, and 98.0 parts by weight of α-butyl-ω-(3-methacryloxypropyl)polydimethylsiloxane (γ-1) were added to an autoclave equipped with a stirrer. Next, 0.05 parts by weight of azobisisobutyronitrile (manufactured by Tokyo Chemical Industry Co., Ltd.) was added as an initiator relative to 100 parts by weight of the total (meth)acrylic monomers, and 1,000 parts by weight of a mixed solution of toluene (special reagent grade) and isopropyl alcohol (special reagent grade) in a volume ratio of 7:3 was added as a solvent, and the atmosphere inside the autoclave was replaced with nitrogen. The autoclave was then heated in an oil bath at 65°C for 20 hours to carry out radical polymerization. After polymerization was completed, the mixture was degassed under reduced pressure at 120°C for 1 hour to obtain Copolymer 1.

[0117] The polymerization rate relative to 100% of the monomer charge was analyzed by gas chromatography and found to be 98% or more, suggesting that the ratio of each monomer unit in the copolymer was approximately the same as the monomer charge ratio.

[0118] The weight average molecular weight of the obtained copolymer 1 was determined as a weight average molecular weight converted into standard polystyrene using a GPC (gel permeation chromatography) method under the following measurement conditions. High-speed GPC equipment: Tosoh Corporation "HLC-8020" Columns: One Tosoh "TSK guardcolumn MP (x L)" 6.0 mm ID x 4.0 cm, and two Tosoh "TSK-GELMULTIPOREHXL-M" 7.8 mm ID x 30.0 cm (16,000 theoretical plates), for a total of three (total theoretical plate count: 32,000). Developing solvent: tetrahydrofuran Detector: RI (differential refractometer)

[0119] 1.3.Copolymers 2~11 Copolymers 2 to 11 were obtained by radical polymerization in the same manner as for copolymer 1, except that the mixing ratio of toluene and isopropyl alcohol was adjusted using the composition ratio of the (meth)acrylic monomers shown in Table 1 to control the solubility of the monomers and the weight-average molecular weight of the copolymer. The polymerization rates of the obtained copolymers 2 to 11 were all 98% or higher, and the ratios of each monomer unit contained in the copolymers were estimated to be similar to the monomer charging ratios. The weight-average molecular weights were also determined in the same manner as above.

[0120] The monomer compositions are shown in weight percent in Table 1. The weight ratio of α-butyl-ω-(3-methacryloxypropyl)polydimethylsiloxane was calculated based on its number average molecular weight.

[0121] [Table 1]

[0122] 2. Preparation of the first agent First agents I-1 to I-17 were prepared by mixing the following components A1 to D1 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).

[0123] [A1: Copolymer] A1-1 to A1-11: Copolymers 1 to 11 obtained by the above synthesis method (A1-1 to A1-11 correspond to Copolymers 1 to 11, respectively.)

[0124] [B1: Vinyl-modified organopolysiloxane] B1-1: 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

[0125] [C1: Thermally conductive filler] C1-1: DAW45S (product name, manufactured by Denka), spherical alumina, average particle size: 45 μm, thermal conductivity: 35 W / m·K C1-2: DAW05 (product name, manufactured by Denka), spherical alumina, average particle size: 5 μm, thermal conductivity: 35 W / m·K C1-3: ASFP40 (product name, manufactured by Denka), ultrafine alumina, average particle size: 0.4 μm, thermal conductivity 35 W / m·K C1-4: DMG60 (product name, manufactured by Denka), magnesium oxide, average particle size: 60 μm, thermal conductivity 60 W / m·K C1-5: AN-HF50LG (product name, manufactured by Combustion Synthesis Co., Ltd.), aluminum nitride, average particle size: 50 μm, thermal conductivity 170 W / m·K C1-6: Al-63μm (product name, manufactured by Hikari Materials Industry Co., Ltd.), metallic aluminum, average particle size: 63μm, thermal conductivity 240W / m·K

[0126] [D1: Addition reaction catalyst] D1-1: Platinum complex polymethylvinylsiloxane solution (manufactured by Blue Star Silicones, product name: Silicolyse Catalyst 12070)

[0127] [Table 2]

[0128] 3. Preparation of the Second Agent Second parts II-1 to II-19 were prepared by mixing the following components A2 to C2, E2, and F2 according to the blending ratios (parts by weight) shown in Table 3. The components were mixed using a hybrid mixer ARE-310 (trade name, manufactured by Thinky Corporation).

[0129] [A2: Copolymer] A2-1 to A2-11: Copolymers 1 to 11 obtained by the above synthesis method (A2-1 to A2-11 correspond to Copolymers 1 to 11, respectively.)

[0130] [B2: Vinyl-modified organopolysiloxane] B2-1: 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

[0131] [C2: Thermally conductive filler] C2-1: DAW45S (product name, manufactured by Denka), spherical alumina, average particle size: 45 μm, thermal conductivity: 35 W / m·K C2-2: DAW05 (product name, manufactured by Denka), spherical alumina, average particle size: 5 μm, thermal conductivity: 35 W / m·K C2-3: ASFP40 (product name, manufactured by Denka), ultrafine alumina, average particle size: 0.4 μm, thermal conductivity: 35 W / m·K C2-4: DMG60 (product name, manufactured by Denka), magnesium oxide, average particle size: 60 μm, thermal conductivity 60 W / m·K C2-5: AN-HF50LG (product name, manufactured by Combustion Synthesis Co., Ltd.), aluminum nitride, average particle size: 50 μm, thermal conductivity: 170 W / m·K C2-6: Al-63μm (product name, manufactured by Hikari Materials Industry Co., Ltd.), metallic aluminum, average particle size: 63μm, thermal conductivity 240W / m·K

[0132] [E2: Hydrosilyl-modified organopolysiloxane] E2-1: RH-LHC-3 (manufactured by Runhe Chemical Industry Co., Ltd., trade name), hydrosilyl-modified organopolysiloxane, viscosity at 25°C: 5 mPa·s, average number of hydrosilyl groups per molecule: 3 or more, linear structure, hydrosilyl group bonding position: side chain E2-2: RH-H45 (product name, manufactured by Runhe Chemical Industry Co., Ltd.), hydrosilyl-modified organopolysiloxane, viscosity at 25°C: 20 mPa·s, average number of hydrosilyl groups per molecule: 2, linear structure, hydrosilyl group bonding positions: both terminals

[0133] [F2: Reaction retarder] F2-1: PA90 (trade name, manufactured by Elkem), a mixture of 1-ethynyl-1-cyclohexanol, polyorganosiloxane, and filler

[0134] [Table 3]

[0135] 4. Characteristics of the first and second agents (viscosity) First and second agents at 25°C and a shear rate of 10 s -1 The viscosity at 1000 kJ / s was measured using a rotational rheometer "HANKE MARSIII" manufactured by Thermo Fisher Scientific. Specifically, parallel plates with a diameter of 35 mm were used, with a gap of 0.5 mm, a temperature of 25°C, and a shear rate of 10 s -1 The results are shown in Table 4.

[0136] (Dynamic viscoelasticity measurement) The first and second parts obtained above were mixed in equal volumes in the combination shown in Table 4 to obtain a mixture. The resulting mixture was kept at 25°C to allow the curing reaction to proceed, and the loss tangent tanδ was measured using a rotational rheometer (manufactured by Thermo Fisher Scientific, frequency 1 Hz). After mixing the first and second parts, the elastic modulus was measured over time, and the point at which the loss tangent tanδ became less than 0.20 was considered to be the point at which curing was complete, and this was measured as the curing time. The results are shown in Table 4. Note that if the loss tangent tanδ did not become less than 0.20 within 24 hours, this is indicated as "X" in Table 4.

[0137] In addition, in the dynamic viscoelasticity measurement, the storage modulus G 0′ immediately after mixing the first and second agents was measured. 15 'Ratio of G 15 ' / G0' was calculated, and the results are shown in Table 4.

[0138] 5. Evaluation (Drip resistance) The drip resistance of thermally conductive grease obtained from the first and second components was evaluated using the test method shown in Figures 1 and 2. First, as shown in Figure 1, 2 mm-thick shims 11 were placed at the four corners of an 80 mm x 80 mm glass plate 10. A mixture 12, obtained by mixing the first and second components in a 1:1 volume ratio as shown in Table 4, was applied in a circular pattern approximately in the center of the glass plate 10, and the glass plate was sandwiched between 80 mm x 80 mm glass plates 13. The amount of mixture 12 applied was determined so that the circular shape of the thermally conductive grease formed when sandwiched between the glass plates 10 and 13 would be 15 mm in diameter. After leaving the plate standing for 1 hour, the glass plates 10 and 13 were then fixed with clips 14 and placed vertically as shown in Figure 2. After leaving the plate standing for 24 hours at 25°C, the deviation of the thermally conductive cured product from its initial position was observed to evaluate drip resistance. Drip resistance was evaluated based on the following criteria. The results are shown in Table 4. ◯: After 24 hours, the thermally conductive cured product did not drip. ×: After 24 hours, the thermally conductive cured product dripped.

[0139] (Pump-out resistance) The first and second components were mixed in a 1:1 volume ratio as shown in Table 4, and the resulting mixture was applied to an aluminum plate measuring 60 mm square and 100 μm thick in four 0.03 cc dots. The plate was then sandwiched between glass plates, and the thermally conductive grease was adjusted to a 15 mm diameter circle. A 4 kg weight was then placed on the glass plate and left for one day. After that, both ends of the glass plate were secured with clips, and the outer periphery of the thermally conductive grease was marked with an oil-based marker. A thermal shock test was conducted from -40°C to 150°C to evaluate pump-out resistance. The holding time at -40°C and 150°C was 30 minutes, and the temperature rise and fall from -40°C to 150°C and 150°C to -40°C was within 5 minutes. 300 cycles were performed. Pump-out resistance was evaluated based on the following criteria. The results are shown in Table 4. Pump-out rate (%) = (diameter after thermal shock test - diameter before thermal shock test) / diameter before thermal shock test x 100 ○: Pump-out rate less than 5%. ×: Pump-out rate of 5% or more.

[0140] [Table 4]

[0141] As described above, the present invention relates to a composition comprising a first agent containing a copolymer A1, a vinyl-modified organopolysiloxane B1, a thermally conductive filler C1, and an addition reaction catalyst D1, and a second agent containing a copolymer A2, a vinyl-modified organopolysiloxane B2, a thermally conductive filler C2, and a hydrosilyl-modified organopolysiloxane E2, wherein the copolymer A1 and the copolymer A2 contain a (meth)acrylic monomer unit α having a carboxy group and a (meth)acrylic monomer unit α having a tertiary amino group. The two-part curing composition sets of Examples 1 to 2 and 4 to 14 were excellent in drip resistance and / or pump-out resistance, despite the low viscosity of the first and second parts. ...

[0142] On the other hand, Comparative Examples 3, 17, 21, 22, 26, and 27, in which the loss tangent tanδ did not become less than 0.20 within 24 hours after mixing the first and second parts, were evaluated as having poor drip resistance and / or pump-out resistance. Also, Comparative Examples 18, 23, and 28, in which either the first or second part did not contain a copolymer, and Comparative Examples 15, 16, 19, 20, 24, and 25, in which the copolymer did not contain any of the monomer unit α, monomer unit β, and monomer unit γ, had high viscosity of either the first or second part. [Industrial Applicability]

[0143] 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. [Explanation of symbols]

[0144] 10...glass plate, 11...shim, 12...mixture, 13...glass plate, 14...clip.

Claims

1. a first agent containing a copolymer A1, a vinyl-modified organopolysiloxane B1, a thermally conductive filler C1, and an addition reaction catalyst D1; a second agent containing a copolymer A2, a vinyl-modified organopolysiloxane B2, a thermally conductive filler C2, and a hydrosilyl-modified organopolysiloxane E2; the copolymer A1 and the copolymer A2 are copolymers 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, the time required for the loss tangent tanδ of the mixture, measured at 25°C and a frequency of 1 Hz using a rotational rheometer, to become less than 0.20 after mixing the first agent and the second agent in equal volumes, is within 24 hours from the mixing; In the copolymer A1, the total content of the monomer unit α, the monomer unit β, and the monomer unit γ is 90% by weight or more based on the total amount of the copolymer A1, In the copolymer A2, the total content of the monomer unit α, the monomer unit β, and the monomer unit γ is 90% by weight or more based on the total amount of the copolymer A2, In each of the copolymers A1 and A2, the content of the monomer units α, β, and γ is 100 parts by weight in total. the content of the monomer unit α is 0.08 to 6.0 parts by weight, the content of the monomer unit β is 0.02 to 4.0 parts by weight, the content of the monomer unit γ is 90.0 to 99.9 parts by weight, the number average molecular weight of the monomer unit γ is 1,500 to 50,000; The hydrosilyl-modified organopolysiloxane E2 contains at least a hydrosilyl-modified organopolysiloxane E22 having a hydrosilyl group in a side chain. Two-component curing composition set.

2. the vinyl-modified organopolysiloxane B1 and the vinyl-modified organopolysiloxane B2 each independently have an average of 2.0 or more vinyl groups per molecule, The hydrosilyl-modified organopolysiloxane E2 has an average of more than 2.0 hydrosilyl groups per molecule. The two-component curing composition set according to claim 1 .

3. The hydrosilyl-modified organopolysiloxane E2 further contains a hydrosilyl-modified organopolysiloxane E21 having hydrosilyl groups at both ends. The two-component curing composition set according to claim 1 .

4. the vinyl-modified organopolysiloxane B1 and the vinyl-modified organopolysiloxane B2 each independently contain an organopolysiloxane having vinyl groups at both ends; The two-component curing composition set according to claim 1 .

5. The number average molecular weight of the monomer unit γ is 3,000 to 30,000. The two-component curing composition set according to claim 1 .

6. the content of the copolymer A1 in the first agent is 1 to 40 parts by weight per 100 parts by weight of the vinyl-modified organopolysiloxane B1; the content of the copolymer A2 in the second agent is 1 to 40 parts by weight per 100 parts by weight of the total of the vinyl-modified organopolysiloxane B2 and the hydrosilyl-modified organopolysiloxane E2; The two-component curing composition set according to claim 1 .

7. The weight average molecular weights of the copolymer A1 and the copolymer A2 are each independently 20,000 to 150,000. The two-component curing composition set according to claim 1 .

8. In the copolymer A1 and the copolymer A2, the content of the monomer unit α, the monomer unit β, and the monomer unit γ is 100 parts by weight in total. the content of the monomer unit α is 0.1 to 5.0 parts by weight, the content of the monomer unit β is 0.05 to 4.0 parts by weight, the content of the monomer unit γ is 93.0 to 99.5 parts by weight; The two-component curing composition set according to claim 1 .

9. The thermally conductive filler C1 and the thermally conductive filler C2 are each independently 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. The two-component curing composition set according to claim 1 .

10. The storage modulus G of a mixture obtained by mixing the first agent and the second agent in equal volumes is measured using a rotational rheometer at 25°C and a frequency of 1 Hz immediately after the mixing. 0 ', the storage modulus G measured in the same manner as above 15 hours after the mixing 15 'Ratio of G 15 ' / G 0 ' is between 100 and 1,500, The two-component curing composition set according to claim 1 .

11. The first agent and the second agent are represented by the following formula: R 1 a R 2 b Si(OR 3 ) 4-(a+b) (R 1 are each independently an alkyl group having 1 to 15 carbon atoms, and R 2 are each independently a saturated or unsaturated monovalent hydrocarbon group having 1 to 8 carbon atoms, and R 3 are each independently an alkyl group having 1 to 6 carbon atoms, a is 1 to 3, b is 0 to 2, and a+b is 1 to 3. does not contain organosilane represented by The two-component curing composition set according to claim 1 .

12. Used as a thermally conductive heat dissipation material, The two-component curing composition set according to any one of claims 1 to 11.

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

14. Used as a thermally conductive heat dissipation material, The cured product according to claim 13.

15. An electronic component, the cured product according to claim 14, 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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