Thermally conductive silicone adhesive composition and thermally conductive composite

Abstract

The present invention provides a thermally conductive silicone adhesive composition having good handleability, exhibiting sufficient adhesive strength, and also having excellent storage stability of adhesive strength.　This thermally conductive silicone adhesive composition comprises (a) a linear or branched organopolysiloxane having an average degree of polymerization of 100-20,000, (b) a thermally conductive filler, (c) an organopolysiloxane containing a component having 0.05-0.15 mol / 100 g of an alkenyl group per molecule, (d) an adhesive component, and (e) an organic peroxide.　This thermally conductive composite has a thermally conductive adhesive member formed from the thermally conductive silicone adhesive composition on both surfaces of a reinforcing material.

Description

Thermally conductive silicone adhesive composition and thermally conductive composite

[0001] The present invention relates to a thermally conductive silicone adhesive composition and a thermally conductive composite.

[0002] Semiconductors such as transistors used in electronic devices and LED elements used as light sources for lighting, etc., are generating large amounts of heat as they become more powerful, faster, smaller, and more integrated. The resulting temperature rise in the device can cause malfunctions or even destruction. Therefore, many heat dissipation methods and heat dissipation materials have been proposed to suppress the temperature rise of semiconductors during operation.

[0003] Conventionally, in electronic devices, heat generated by semiconductors is dissipated to the outside via a thermally conductive material to a cooling component such as a heat sink or housing made of a metal plate with high thermal conductivity. Thermally conductive sheets with insulating properties are often used as the thermally conductive material. Screws and clips are used to fasten the cooling component to the semiconductor. The thermally conductive sheet between them is also fastened by pressure from the screws or clips. However, fastening methods using screws and clips require many parts and processes, resulting in very poor manufacturing efficiency. Furthermore, components such as screws and clips hinder the miniaturization and thinning of electronic devices themselves, which is a major disadvantage in terms of product design.

[0004] Therefore, a method has been considered in which adhesive properties are imparted to a thermally conductive sheet interposed between a cooling member and a semiconductor, thereby fixing the housing and semiconductor element. Specifically, an adhesive-coated thermally conductive sheet can be produced by applying an adhesive to both sides of the thermally conductive sheet. However, because the adhesive itself does not have thermal conductivity, the thermal conductivity of an adhesive-coated thermally conductive sheet is significantly reduced. For example, Patent Documents 1, 2, and 3 disclose thermally conductive adhesive tapes that use a thermally conductive filler in the adhesive. Patent Document 4 also discloses a thermally conductive silicone adhesive tape that uses silicone due to its heat resistance, cold resistance, and durability.

[0005] However, conventional adhesive tapes have poor adhesive strength compared to general adhesive materials, posing challenges in terms of screwless applications. Furthermore, single-layer adhesive tapes also have room for improvement in terms of workability, insulation, and strength. On the other hand, adhesive tapes are characterized by the fact that they can achieve better adhesive strength than conventional adhesive tapes by applying heat and pressure. However, in order to achieve sufficient adhesive strength, a heating process under high pressure is generally required, making them unsuitable for use on heat dissipation components that are sensitive to pressure.

[0006] On the other hand, some types of heat-curing adhesives that are not in sheet or tape form also have high adhesion to heat-dissipating components, providing high adhesive strength and heat dissipation performance. However, they have issues such as complicated application processes, inferior workability and reworkability compared to adhesive (bonding) sheets and tapes, and the risk of void contamination. Furthermore, refrigerated storage is often recommended for addition-curing adhesives to prevent deterioration of adhesive strength over time, which complicates quality control and leaves room for improvement. Furthermore, when it comes to adhesive (bonding) sheets and tapes, users are strongly demanding products that do not significantly deteriorate in performance even at temperatures of approximately 40°C, taking into account product transportation by sea and storage in outdoor warehouses.

[0007] JP 2014-034652 A JP 2014-062220 A JP 2002-121529 A JP 2008-260798 A

[0008] Therefore, an object of the present invention is to provide a thermally conductive silicone adhesive composition that is easy to handle, provides sufficient adhesive strength, and exhibits excellent storage stability of that adhesive strength, as well as to provide a thermally conductive composite that exhibits excellent strength and insulating properties.

[0009] As a result of extensive research into achieving the above-mentioned object, the inventors discovered that the following thermally conductive silicone adhesive composition could achieve the above-mentioned object, leading to the completion of the present invention. Specifically, the present invention provides the following thermally conductive silicone adhesive composition and a thermally conductive composite using said composition.

[0010] [1] A thermally conductive silicone adhesive composition comprising the following components (a) to (e): (a) 100 parts by mass of a linear or branched organopolysiloxane having an average degree of polymerization of 100 to 20,000, (b) 1,300 to 7,500 parts by mass of a thermally conductive filler, and (c) 150 to 600 parts by mass of an organopolysiloxane comprising a component (c-1) represented by the following general formula (1) and having an alkenyl group content per molecule of 0.05 to 0.15 mol / 100 g, and a component (c-2) represented by the following general formula (2): (In formula (1), R 1 are independently selected from alkyl groups having 1 to 10 carbon atoms, aryl groups having 6 to 10 carbon atoms, and aralkyl groups having 7 to 10 carbon atoms; R 2 are independently alkenyl groups having 2 to 8 carbon atoms. 0<a1≦10, 0<b1≦10, 0≦c1≦10, 0≦d1≦10, and 0≦e1≦10, provided that the range of 0.5≦a1 / (d1+e1)≦2.0 is satisfied. (In formula (2), R 1 are independently selected from alkyl groups having 1 to 10 carbon atoms, aryl groups having 6 to 10 carbon atoms, and aralkyl groups having 7 to 10 carbon atoms, and 0<a2≦10, 0≦c2≦10, 0≦d2≦1, and 0<e2≦10, provided that the ranges of 0.7≦a2 / e2≦2.5 are satisfied.) (d) An adhesive component represented by the following structural formula (3) and / or an adhesive component represented by the following structural formula (4): 0.5 to 20 parts by mass (In formula (3), R 6 is an alkyl group having 1 to 5 carbon atoms, and n is independently a number from 1 to 12. (In formula (4), R 6(e) organic peroxide: 1 to 40 parts by mass [2] The thermally conductive silicone adhesive composition according to [1], wherein component (b) is at least one selected from the group consisting of metals, metal oxides, and metal nitrides. [3] The thermally conductive silicone adhesive composition according to [1] or [2], wherein component (c-1) accounts for 10 to 60% by mass of the total amount of component (c). [4] The thermally conductive silicone adhesive composition according to any of [1] to [3], wherein component (a) is a linear or branched organopolysiloxane having two or more alkenyl groups per molecule. [5] The thermally conductive silicone adhesive composition according to any of [1] to [4], further comprising 1 to 40 parts by mass of component (f-1) represented by the following general formula (5) and / or component (f-2) represented by the following general formula (6), per 100 parts by mass of component (a). (In formula (5), R 3 are independently alkyl groups having 6 to 15 carbon atoms, and R 4 are independently alkyl groups having 1 to 5 carbon atoms, and R 5 are independently an alkyl group having 1 to 6 carbon atoms, m is a number from 1 to 3, and n is a number from 0 to 2, with the proviso that m+n is a number from 1 to 3. (In formula (6), R 5are independently an alkyl group having 1 to 6 carbon atoms, and p is a number from 5 to 100. [6] A thermally conductive composite having thermally conductive adhesive members formed from the thermally conductive silicone adhesive composition according to any one of [1] to [5] on both sides of a reinforcing material. [7] The thermally conductive composite according to [6], in which the thermal conductivity of the thermally conductive adhesive member is 2.0 W / m K or higher. [8] The thermally conductive composite according to [6] or [7], in which a thermally conductive adhesive member is laminated. [9] The thermally conductive composite according to any one of [6] to [8], in which the reinforcing material is a synthetic resin or glass cloth.

[10] The thermally conductive composite according to [9], in which the synthetic resin is one or more selected from aromatic polyimide resin, polyamide resin, polyamideimide resin, polyester resin, and fluororesin.

[11] The thermally conductive composite according to any one of [6] to

[10] , in which a substrate whose surface has been treated with a release agent is further laminated on the outermost layer of the thermally conductive adhesive member.

[12] The thermally conductive composite according to

[11] , wherein the release agent is a fluorine-modified silicone having a fluorine substituent bonded to the main chain.

[0011] The thermally conductive silicone adhesive composition of the present invention is easy to handle and can be easily mounted on heat-dissipating components. Furthermore, the thermally conductive silicone adhesive composition provides desirable thermal conductivity between a heat-generating element and a heat-dissipating component, and exhibits good adhesive strength, enabling strong fixation between the components. Furthermore, when thermocompression-bonding (bonding) the composition to a heat-dissipating component, a high-pressure curing process is not required; the composition cures by leaving it at high temperature for a certain period of time, achieving sufficient adhesive strength, making it suitable for bonding a wide range of heat-dissipating components. The composition also has excellent storage stability, suppressing deterioration in adhesive strength over time. Furthermore, by laminating thermally conductive adhesive layers formed from the thermally conductive silicone adhesive composition on both sides of a reinforcing layer to form a thermally conductive composite, it is possible to improve strength and insulating properties. Therefore, the thermally conductive silicone adhesive composition of the present invention is highly useful as a thermally conductive component that is interposed between a heat-generating element and a heat-dissipating component to transfer heat generated by the heat-generating element to the heat-dissipating component and secure the components together.

[0012] The present invention is described in detail below. The thermally conductive silicone adhesive composition of the present invention is characterized by comprising (a) a linear or branched organopolysiloxane having an average degree of polymerization of 100 to 20,000, (b) a thermally conductive filler, (c) an organopolysiloxane containing a component having an alkenyl group content per molecule of 0.05 to 0.15 mol / 100 g, (d) an adhesive component, and (e) an organic peroxide.

[0013] (a) Organopolysiloxane Component (a) is a linear or branched organopolysiloxane having an average degree of polymerization of 100 to 20,000, and is preferably an organopolysiloxane represented by the following average composition formula (7). (In formula (7), R is independently a monovalent hydrocarbon group having 1 to 10 carbon atoms, and x is a positive number of 1.98 to 2.02.)

[0014] In the above formula (7), R is independently a monovalent hydrocarbon group having 1 to 10 carbon atoms, preferably a monovalent hydrocarbon group having 1 to 8 carbon atoms. Examples of the monovalent hydrocarbon group include alkyl groups such as methyl, ethyl, propyl, and butyl; cycloalkyl groups such as cyclohexyl; alkenyl groups such as vinyl, allyl, butenyl, and hexenyl; aryl groups such as phenyl and tolyl; and chloromethyl and trifluoropropyl groups in which some or all of the hydrogen atoms bonded to the carbon atoms of these groups have been substituted with halogen atoms. Of these, methyl, vinyl, phenyl, and trifluoropropyl groups are preferred.

[0015] The organopolysiloxane of formula (7) above may or may not contain alkenyl groups per molecule. When the organopolysiloxane does not contain alkenyl groups, it is preferred that 50% or more of the total number of substituents R in the organopolysiloxane of formula (7) above be methyl groups, more preferably 80% or more, and particularly preferably all of the substituents R are methyl groups.

[0016] Furthermore, when the organopolysiloxane of formula (7) above contains alkenyl groups, it is preferable that the number of alkenyl groups contained in one molecule is at least 2, more preferably 2 to 20, and particularly preferably 2 to 10. With regard to the substituents R other than alkenyl groups, it is preferable that at least 50% of the total number of substituents R in the organopolysiloxane of formula (7) above be methyl groups, and more preferably at least 80% be methyl groups.

[0017] The (a) organopolysiloxane is preferably linear, but may have some branching as long as the rubber strength as a thermally conductive adhesive is not impaired. It may also be a mixture of two or more organopolysiloxanes with different molecular structures or degrees of polymerization. Furthermore, the organopolysiloxane has an average degree of polymerization of 100 to 20,000, preferably 200 to 10,000. The average degree of polymerization is the number-average degree of polymerization calculated in terms of polystyrene by gel permeation chromatography (GPC). [Measurement conditions] Developing solvent: tetrahydrofuran (THF) Flow rate: 0.6 mL / min Detector: differential refractive index detector (RI) Column: TSK Guard column Super H-H TSKgel Super H4000 (6.0 mm I.D. × 15 cm × 1) TSKgel Super H3000 (6.0 mm I.D. × 15 cm × 1) TSKgel Super H2000 (6.0 mm I.D. × 15 cm × 1) (all manufactured by Tosoh Corporation) Column temperature: 40°C Sample injection volume: 50 μL (THF solution with a concentration of 2.0% by mass)

[0018] The content of component (a) in the thermally conductive silicone adhesive composition of the present invention is preferably 1 to 25 mass %, and more preferably 5 to 20 mass %.

[0019] (b) Thermally Conductive Filler The thermally conductive filler (b) may be any known filler used in thermally conductive silicone compositions, preferably one or more selected from the group consisting of metals, metal oxides, and metal nitrides. Examples of known thermally conductive fillers include non-magnetic metals such as copper and aluminum, metal oxides such as alumina, silica, magnesia, red iron oxide, beryllia, titania, and zirconia, and metal nitrides such as aluminum nitride, silicon nitride, and boron nitride. The thermally conductive filler should have an average particle size of 0.1 to 70 μm, preferably 0.5 to 60 μm, and more preferably 1 to 50 μm. One type of thermally conductive filler may be used alone, or multiple types may be used in combination. Two or more types of particles with different average particle sizes may also be used. In the present invention, the average particle size is the volume average particle size, measured using a Microtrac particle size distribution analyzer MT3300EX (Nikkiso Co., Ltd.).

[0020] The thermally conductive filler may be subjected to various known surface treatments as long as the effects of the present invention, such as thermal conductivity, are not significantly impaired. Specific examples of such surface treatments include treatment with a coupling agent such as a silane or titanate coupling agent, and plasma treatment.

[0021] The amount of the thermally conductive filler is 1,300 to 7,500 parts by mass, preferably 2,000 to 6,000 parts by mass, per 100 parts by mass of component (a). If the amount of the thermally conductive filler exceeds 7,500 parts by mass, the thermally conductive adhesive member (thermally conductive adhesive layer) may become brittle, resulting in reduced workability. On the other hand, if the amount is less than 1,300 parts by mass, the desired thermal conductivity may not be achieved in the thermally conductive adhesive member (thermally conductive adhesive layer).

[0022] (c) Organopolysiloxane The organopolysiloxane of component (c) is an organopolysiloxane composed of the following components (c-1) and (c-2), and functions to impart cohesive force to the thermally conductive adhesive member (thermally conductive adhesive layer), impart workability, and obtain good adhesive strength in the thermally conductive adhesive member (thermally conductive adhesive layer) after curing.

[0023] (c-1) Component (c-1) is an organopolysiloxane represented by the following general formula (1) in which the alkenyl group content per molecule is 0.05 to 0.15 mol / 100 g. (In formula (1), R 1 are independently selected from alkyl groups having 1 to 10 carbon atoms, aryl groups having 6 to 10 carbon atoms, and aralkyl groups having 7 to 10 carbon atoms; R 2 are independently alkenyl groups having 2 to 8 carbon atoms. 0<a1≦10, 0<b1≦10, 0≦c1≦10, 0≦d1≦10, and 0≦e1≦10, provided that the range of 0.5≦a1 / (d1+e1)≦2.0 is satisfied.

[0024] (c-2) The component (c-2) is an organopolysiloxane represented by the following general formula (2). (In formula (2), R 1 are independently a group selected from an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, and an aralkyl group having 7 to 10 carbon atoms, and 0<a2≦10, 0≦c2≦10, 0≦d2≦10, and 0<e2≦10, provided that the range of 0.7≦a2 / e2≦2.5 is satisfied.

[0025] In formula (1), R 1 are independently a group selected from an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, and an aralkyl group having 7 to 10 carbon atoms. Specific examples include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, cyclohexyl, and heptyl; aryl groups such as phenyl, tolyl, xylyl, and naphthyl; aralkyl groups such as benzyl and phenethyl; and halogen-substituted alkyl groups such as chloromethyl, 3-chloropropyl, and 3,3,3-trifluoropropyl, with methyl and vinyl groups being particularly preferred.

[0026] R 2are independently an alkenyl group having 2 to 8 carbon atoms, and specific examples thereof include a vinyl group, an allyl group, a butenyl group, a pentenyl group, a hexenyl group, a cyclohexenyl group, and a heptenyl group, with a vinyl group being particularly preferred.

[0027] In formula (1), 0<a1≦10, preferably 1≦a1≦5. Also, 0<b1≦10, preferably 1≦b1≦5. Also, 0≦c1≦10, preferably 0≦c1≦5. Also, 0≦d1≦10, preferably 0≦d1≦5. And, 0≦e1≦10, preferably 1≦e1≦5. However, the range of 0.5≦a1 / (d1+e1)≦2.0 is satisfied, preferably 0.6≦a1 / (d1+e1)≦1.8, and more preferably 0.7≦a1 / (d1+e1)≦1.5. If a1 / (d1+e1) is less than 0.5, it becomes difficult to highly fill the thermally conductive filler of component (b), and the thermal conductivity of the thermally conductive adhesive member (thermally conductive adhesive layer) may decrease. Furthermore, if a1 / (d1+e1) exceeds 2.0, the cohesive force of the thermally conductive adhesive member (thermally conductive adhesive layer) may decrease, resulting in reduced workability.

[0028] The alkenyl group concentration per molecule of component (c-1) is 0.05 to 0.15 mol / 100 g, preferably 0.06 to 0.14 mol / 100 g, and more preferably 0.07 to 0.12 mol / 100 g. If the alkenyl group concentration per molecule is less than 0.05 mol / 100 g, it may be difficult to obtain sufficient adhesive strength in the thermally conductive adhesive member (thermally conductive adhesive layer), which is undesirable. If the concentration is more than 0.15 mol / 100 g, the thermally conductive adhesive member (thermally conductive adhesive layer) may become hard and brittle, which may reduce workability, which is undesirable.

[0029] In formula (2), R 1are independently selected from an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, and an aralkyl group having 7 to 10 carbon atoms, and satisfy 0 < a2 ≦ 10, preferably 1 ≦ a2 ≦ 5. Also, satisfy 0 ≦ c2 ≦ 10, preferably 0 ≦ c2 ≦ 5. Also, satisfy 0 ≦ d2 ≦ 10, preferably 0 ≦ d2 ≦ 5. And satisfy 0 < e2 ≦ 10, preferably 1 ≦ e2 ≦ 5. However, the range of 0.7 ≦ a2 / e2 ≦ 2.5 is satisfied, preferably 0.8 ≦ a2 / e2 ≦ 2.2, and more preferably 0.9 ≦ a2 / e2 ≦ 2.0 is satisfied.

[0030] If the a2 / e2 ratio is less than 0.8, it may be difficult to highly fill the thermally conductive filler (b) and the thermal conductivity of the thermally conductive adhesive member (thermally conductive adhesive layer) may decrease. If the a2 / e2 ratio is more than 2.5, the cohesive strength of the thermally conductive adhesive member (thermally conductive adhesive layer) may decrease and the desired adhesive strength may not be obtained.

[0031] R 1 Unless special properties such as solvent resistance are required, it is most preferable that all of the groups be methyl groups, for reasons of cost, availability, chemical stability, and environmental impact. When the organopolysiloxane of component (c) is solid, it can be used as a 50 to 70 mass % toluene solution. In this case, the kinematic viscosity at 25°C is 10 to 500 mm 2 / s, preferably 100 to 250 mm 2 The kinematic viscosity is a value measured at 25°C using a Cannon-Fenske viscometer according to JIS Z8803:2011.

[0032] Method for measuring the ratio of M units, T units, and Q units The trifunctional R units of the organopolysiloxane of the present invention are 1 SiO 3 / 2 Units (T units) and tetrafunctional SiO 4 / 2 At least one branched siloxane unit selected from the group consisting of monofunctional R 1 3SiO 1 / 2The ratio of the component (c-1) to the component (M unit), i.e., the value of a1 / (d1+e1) in the component (c-1) and the value of a2 / e2 in the component (c-2), is 29 It can be determined by Si-NMR. 29 There are no particular restrictions on the method for preparing a sample for Si-NMR, but for example, a sample can be prepared by dissolving 1 part by mass of organopolysiloxane in 3 parts by mass of deuterated chloroform.

[0033] The amount of organopolysiloxane (component (c)) is 150 to 600 parts by mass, preferably 170 to 550 parts by mass, and more preferably 200 to 500 parts by mass per 100 parts by mass of component (a). If the amount of component (c) added is less than 150 parts by mass, the thermally conductive adhesive member (thermally conductive adhesive layer) may not achieve the desired adhesive strength. If the amount exceeds 600 parts by mass, the thermally conductive adhesive member (thermally conductive adhesive layer) may become brittle and lack flexibility, resulting in reduced workability. Note that component (c) itself is a solid or viscous liquid at room temperature and can be used dissolved in a solvent. In this case, the amount added to the composition may be adjusted so that the resin content, excluding the solvent, falls within the above range.

[0034] The organopolysiloxane of component (c) is formed by combining the above-mentioned components (c-1) and (c-2). In this case, the amount of component (c-1) is preferably 10 to 60 mass% and more preferably 15 to 50 mass% relative to the total amount of component (c). When the proportion of component (c-1) is within this range, good adhesive strength can be obtained.

[0035] Component (d) is an adhesive component represented by the following structural formula (3) and / or (4), and the adhesive component has a triazine skeleton and an alkenyl group and a trialkoxy group. Component (d) not only exhibits good wettability with the adherend interface and functions to increase the adhesive strength of the thermally conductive adhesive member (thermally conductive adhesive layer), but also contributes to improving the storage stability of the adhesive strength of the thermally conductive adhesive member (thermally conductive adhesive layer) compared to known organohydrogenpolysiloxane-based adhesive components. (In formula (3), R 6is an alkyl group having 1 to 5 carbon atoms, and n is a number from 1 to 12. (In formula (4), R 6 is an alkyl group having 1 to 5 carbon atoms, and n is a number from 1 to 12.

[0036] In the above formulas (3) and (4), R 6 are independently monovalent hydrocarbon groups having 1 to 10 carbon atoms, preferably 1 to 4 carbon atoms, but do not contain aliphatic unsaturated bonds such as alkenyl groups. Examples of monovalent hydrocarbon groups include alkyl groups such as methyl, ethyl, propyl, and isopropyl; aryl groups such as phenyl, tolyl, xylyl, and naphthyl; and aralkyl groups such as benzyl, phenylethyl, and phenylpropyl. Among these, alkyl or aryl groups are preferred, and methyl is more preferred. In the above formulas (3) and (4), n is independently 1 to 12, preferably 1 to 10, and more preferably 1 to 8. When n is within this range, the desired adhesive strength of the thermally conductive adhesive member (thermally conductive adhesive layer) can be obtained.

[0037] The amount of component (d) is 0.5 to 20 parts by mass, preferably 1 to 15 parts by mass, per 100 parts by mass of component (a). If the amount of component (d) is less than 0.5 parts by mass, the wettability to the adherend may decrease, and the adhesive strength of the thermally conductive adhesive member (thermally conductive adhesive layer) may decrease. If the amount exceeds 20 parts by mass, the excess adhesive component may weaken the thermally conductive adhesive member (thermally conductive adhesive layer), resulting in a decrease in adhesive strength. The adhesive component may be used alone or in combination of two or more types.

[0038] (e) Organic Peroxide Component (e) is an organic peroxide that decomposes under specific conditions to generate free radicals, and functions to promote the curing of the thermally conductive adhesive member (thermally conductive adhesive layer) at high temperatures and increase the adhesive strength. The organic peroxide may be a conventionally known one, and is not particularly limited, and can be used alone or in appropriate combination of two or more. Examples of the peroxyketals include 1,1-di(t-butylperoxy)cyclohexane, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, and 2,2-di(4,4-di-(t-butylperoxy)cyclohexyl)propane; hydroperoxides such as p-menthane hydroperoxide and diisopropylbenzene hydroperoxide; dialkyl peroxides such as dicumyl peroxide and t-butylcumyl peroxide; diacyl peroxides such as dibenzoyl peroxide and disuccinic acid peroxide; peroxyesters such as t-butyl peroxyacetate and t-butyl peroxybenzoate; and peroxydicarbonates such as diisopropyl peroxydicarbonate. In particular, the use of peroxyketals, hydroperoxides, dialkyl peroxides, and peroxyesters having a relatively high decomposition temperature is preferred from the viewpoints of ease of handling and storage. These organic peroxides may be diluted with any organic solvent, hydrocarbon, liquid paraffin, inert solid, or the like.

[0039] The blending amount of component (e) is 1 to 40 parts by mass, preferably 5 to 30 parts by mass, per 100 parts by mass of component (a). If the amount of component (e) is less than 1 part by mass, the thermally conductive adhesive member (thermally conductive adhesive layer) may not be sufficiently cured when cured after being fixed to the heat dissipation member, resulting in a decrease in adhesive strength. If the amount of component (e) is more than 40 parts by mass, the thermally conductive adhesive member (thermally conductive adhesive layer) may be significantly affected by decomposition residues when cured, resulting in a decrease in adhesive strength.

[0040] (f) Surface Treatment Agent The thermally conductive silicone adhesive composition of the present invention may further contain a surface treatment agent (component (f)). Component (f) functions to uniformly disperse the thermally conductive filler (b) within the organopolysiloxane matrix (a) during preparation of the composition. Component (f) is an alkoxysilane compound (f-1) represented by the following general formula (5) and / or a dimethylpolysiloxane (f-2) represented by the following general formula (6). In other words, either component (f-1) or component (f-2) may be used alone or in combination.

[0041] (f-1) Alkoxysilane compounds represented by the following general formula (5): (In formula (5), R 3 are independently alkyl groups having 6 to 15 carbon atoms, and R 4 are independently alkyl groups having 1 to 5 carbon atoms, and R 5 are independently an alkyl group having 1 to 6 carbon atoms, m is a number from 1 to 3, and n is a number from 0 to 2, with the proviso that m+n is a number from 1 to 3.

[0042] (f-2) Dimethylpolysiloxane represented by the following general formula (6): (In formula (6), R 5 are independently alkyl groups having 1 to 6 carbon atoms, and p is a number from 5 to 100.

[0043] In the above general formula (5), R 3 Examples of the alkyl group represented by R include a hexyl group, an octyl group, a nonyl group, a decyl group, a dodecyl group, and a tetradecyl group. 3 When the number of carbon atoms in the alkyl group represented by the formula (I) is in the range of 6 to 15, the wettability of the above-mentioned component (b) is sufficiently improved, and the handleability of the composition becomes good.

[0044] R 4 is an alkyl group having 1 to 5 carbon atoms, preferably an alkyl group having 1 to 3 carbon atoms, and particularly preferably a methyl group.

[0045] R 5is an alkyl group having 1 to 6 carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, a propyl group, and a butyl group. Of these, a methyl group is most preferred.

[0046] The amount of component (f) is preferably 1 to 40 parts by mass, more preferably 2 to 35 parts by mass, and even more preferably 3 to 30 parts by mass, per 100 parts by mass of component (a). If the amount of component (f) is less than 1 part by mass, it will be difficult to highly fill component (b) into component (a). If the amount of component (f) is more than 40 parts by mass, the adhesive strength of the thermally conductive adhesive member (thermally conductive adhesive layer) may be significantly reduced.

[0047] Other Components In addition to the components (a) through (f) described above, the thermally conductive silicone adhesive composition of the present invention can also contain pigments and dyes for coloring, flame retardants, and various other additives for improving functionality, provided that the addition does not impair the objectives of the present invention.

[0048] Method for Producing the Composition The thermally conductive silicone adhesive composition of the present invention is prepared by uniformly mixing the above-mentioned components (a) to (e), optional component (f), and other components. The mixing method may be any conventionally known method. Preferably, components (a), (b), and (c) and optional components (component (f) and other components) are mixed together, and then components (d) and (e) are mixed.

[0049] Manufacturing Method of Thermally Conductive Adhesive Member (Thermal Conductive Adhesive Layer) The thermally conductive adhesive member (thermal conductive adhesive layer) of the thermally conductive composite of the present invention can be obtained by applying the thermally conductive silicone adhesive composition of the present invention to a substrate described below in the form of a thin film tape, molding it, and drying it. Drying conditions are 60 to 100°C for 5 to 20 minutes, preferably 70 to 90°C for 5 to 15 minutes. Drying conditions outside the above ranges may result in reduced thermal conductivity due to residual solvent, or the curing reaction of the composition may progress, making it difficult to adhere the dried thermally conductive adhesive member (thermal conductive adhesive layer) to the heat-dissipating component. The thermally conductive adhesive member (thermal conductive adhesive layer) of the present invention can be produced by placing the uncured thermally conductive silicone adhesive composition between the heat-dissipating component and the heat-generating component and subjecting it to a heat-curing treatment, thereby firmly bonding the two components. The cured thickness of the thermally conductive adhesive member (thermal conductive adhesive layer) is preferably 50 to 300 μm, more preferably 75 to 250 μm. If the thickness of the thermally conductive adhesive member (thermally conductive adhesive layer) is less than 50 μm, it is difficult to handle and the adhesive strength is reduced. On the other hand, if the thickness of the thermally conductive adhesive member (thermally conductive adhesive layer) is more than 300 μm, it is difficult to obtain the desired thermal conductivity. In addition, when coating and molding, it is possible to add a solvent such as toluene or xylene to adjust the viscosity.

[0050] The thermally conductive adhesive member (thermally conductive adhesive layer) of the present invention can have a separator film made of a substrate (e.g., polyethylene-laminated paper, PET film) surface-treated with a release agent. That is, both sides of the thermally conductive adhesive member (thermally conductive adhesive layer) may be protected with a release-treated film. By laminating a separator film to the thermally conductive adhesive member (thermally conductive adhesive layer), handling properties such as transport and cut-to-length performance can be improved. In this case, the peel strength of the separator film can be adjusted by varying the amount and type of release agent used and the film material. Examples of such separator films include polyethylene-laminated paper and PET film that have been subjected to a release treatment with a cured coating of a fluorine-modified silicone in which fluorine substituents, such as perfluoroalkyl groups or perfluoropolyether groups, are bonded to the main chain. The perfluoropolyether group can be represented by the following formulas (8) to (10): (p is 1 to 5, and q is 3 to 10)

[0051] As commercially available products of the fluorine-modified silicone, for example, X-70-201, X-70-258, X-41-3035 manufactured by Shin-Etsu Chemical Co., Ltd. can be used.

[0052] Examples of molding methods include, but are not limited to, methods in which a liquid material (thermally conductive silicone adhesive composition) is applied to a substrate (polyethylene-laminated paper, PET film, etc.) using a bar coater, knife coater, comma coater, spin coater, or the like.

[0053] The thermally conductive adhesive member (thermally conductive adhesive layer) of the present invention is in the form of a thin tape or sheet, can be easily placed in a desired location, and exhibits excellent thermal conductivity. Furthermore, when the above-mentioned separator films are provided on both sides of the thermally conductive adhesive member (thermally conductive adhesive layer), one separator film is peeled off and the adhesive is then attached to a heat-generating electronic component or a heat-dissipating component, and the remaining separator film is then peeled off and the adhesive is attached to a cooling component, etc., thereby bonding the cooling component and the heat-generating electronic component or the heat-dissipating component via the thermally conductive adhesive member (thermally conductive adhesive layer) (transfer method).

[0054] Furthermore, the thermally conductive adhesive member (thermally conductive adhesive layer) of the present invention provides good adhesion between components and enables strong fixation by heat generation by a heating element or by heat treatment after mounting. The heat treatment after mounting is performed at 130°C to 190°C for 15 to 90 minutes, preferably at 150°C to 170°C for 20 to 60 minutes. Since pressure is not particularly required during heating, it can also be applied to heat dissipation components that are sensitive to pressure.

[0055] Furthermore, the thermally conductive composite of the present invention is obtained by bonding a reinforcing material (reinforcing layer) described below to the thermally conductive adhesive member (thermally conductive adhesive layer) in order to reinforce its strength and insulating properties. More specifically, the thermally conductive composite of the present invention has thermally conductive adhesive members formed from the thermally conductive silicone adhesive composition of the present invention on both sides of the reinforcing material (reinforcing layer). The reinforcing material (reinforcing layer) in the present invention is preferably glass cloth or a synthetic resin film that is flexible and has high mechanical strength as well as excellent heat resistance and electrical insulation, and can be appropriately selected from known substrates.

[0056] The glass cloth preferably has a thickness of 10 μm or more and 50 μm or less and a weight of 45 g / m 2 More preferably, the thickness is 20 μm or more and 40 μm or less, and the weight is 30 g / m 2 The following is preferred. Glass cloth has a relatively low thermal conductivity, so a thinner thickness is preferable in consideration of thermal conductivity. However, if it is too thin, the strength decreases and the desired reinforcing effect cannot be obtained. Alternatively, moldability becomes poor, so a thickness within the above-mentioned range is preferred. The glass cloth may be pre-sealed with a silicone composition that forms a thermally conductive adhesive member (thermally conductive adhesive layer). Alternatively, the thermally conductive adhesive member (thermally conductive adhesive layer) may be directly attached without pre-sealing. In the latter case, thermocompression bonding is preferred because it makes it easier for the thermally conductive adhesive member (thermally conductive adhesive layer) to fill the holes in the cloth.

[0057] The synthetic resin film has a thickness of 2 to 30 μm, preferably in the range of 5 to 20 μm. If the synthetic resin film is thicker than 30 μm, the thermal conductivity of the thermally conductive composite of the present invention will be impaired. If it is thinner than 2 μm, the strength required as a reinforcing material (reinforcing layer) will be insufficient, and the withstand voltage characteristics will be deteriorated, resulting in insufficient electrical insulation performance. Furthermore, the synthetic resin film is preferably a film without holes that would reduce the withstand voltage characteristics. Examples of synthetic resins for the synthetic resin film include aromatic polyimides; polyamides; polyamideimides; polyesters such as polyethylene naphthalate; and fluororesins such as polytetrafluoroethylene (PTFE) and tetrafluoroethylene-perfluoroalkyl vinyl ether copolymers. When using the above-mentioned fluororesins as the synthetic resin, it is preferable to chemically etch the surface of the film using a metal sodium / naphthalene-based treatment solution to improve the adhesiveness of the thermally conductive composite. The synthetic resin film is preferably a heat-resistant film having a melting point of 200° C. or higher, preferably 250° C. or higher, so that its mechanical strength is not reduced by thermal deformation. An example of a synthetic resin film having heat resistance of a melting point of 250° C. or higher is Kapton (registered trademark) MT (trade name, manufactured by DuPont-Toray Co., Ltd.), which is an aromatic polyimide film.

[0058] Manufacturing Method of Thermally Conductive Composite Hereinafter, a manufacturing method of a thermally conductive composite having a thermally conductive adhesive member (thermally conductive adhesive layer) and a reinforcing material (reinforcing layer) according to the present invention will be described in detail. One example of a manufacturing method of a thermally conductive composite according to the present invention is a method in which the above-described thermally conductive adhesive member (thermally conductive adhesive layer) is laminated as an outer layer on both sides of a reinforcing material (reinforcing layer) by room-temperature compression bonding or thermocompression bonding. The lamination method is not particularly limited, and may be carried out as appropriate according to a conventionally known manufacturing method of a composite. In the case of room-temperature compression bonding, for example, a thermally conductive adhesive member (thermally conductive adhesive layer) previously formed on the separator film may be transferred to both sides of the reinforcing material (reinforcing layer). In the case of thermocompression bonding, a press jig is heated to 50 to 100°C and pressure-transfer is similarly carried out. In addition to press-compression bonding, roll-compression bonding and the like may also be used for compression bonding. Another example of a manufacturing method of a thermally conductive composite according to the present invention is a method in which a thermally conductive silicone adhesive composition diluted with a solvent is applied to both sides of a reinforcing material (reinforcing layer) and then dried.

[0059] When glass cloth is used as the reinforcing material (reinforcing layer), the glass cloth may be pre-sealed with the thermally conductive silicone adhesive composition described above. The thermally conductive silicone adhesive composition is applied to the glass cloth using a coating device such as a comma coater, knife coater, or kiss coater equipped with a drying oven, a heating oven, and a winding device. The composition is then continuously applied to the glass cloth, followed by drying and evaporation of the solvent, and then heat curing at 130 to 170°C, preferably 140 to 160°C, for 20 to 40 minutes, to obtain glass cloth sealed with the silicone composition. Alternatively, unsealed glass cloth may be used, and the thermally conductive adhesive member (thermally conductive adhesive layer) formed on the separator film may be transferred to the reinforcing material (reinforcing layer), thereby simultaneously laminating the thermally conductive adhesive member (thermally conductive adhesive layer). In this case, the transfer is preferably performed by heating the press jig to 50 to 100°C. Pressure bonding may be performed using press bonding or roll pressure bonding. If the transfer temperature is lower than 50°C, the thermally conductive adhesive member (thermally conductive adhesive layer) may not adhere well to the glass cloth, and the mesh of the cloth may not be filled, resulting in a decrease in insulation and thermal conductivity. Furthermore, if the temperature exceeds 100°C, there is a risk that the curing of the thermally conductive adhesive member (thermally conductive adhesive layer) may proceed. The overall thickness of the thermally conductive composite is preferably 100 to 450 μm, and more preferably 150 to 400 μm. As with the thermally conductive adhesive member (thermally conductive adhesive layer), the thermally conductive composite can be heated by a heating element or subjected to a heat treatment during mounting to provide good adhesion between the components and enable strong fixation of the two.

[0060] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples. The components (a) to (f) constituting the thermally conductive adhesive layer used in the following examples and comparative examples are as follows.

[0061] Component (a): (a-1) Dimethylpolysiloxane crude rubber having an average degree of polymerization of 7,000 (a-2) Dimethylpolysiloxane oil having an average degree of polymerization of 650 and vinyl groups at both ends

[0062] (b) Component: (b-1) Granular alumina having a volume average particle size of 1 μm (b-2) Granular aluminum nitride having a volume average particle size of 1 μm (b-3) Spherical alumina having a volume average particle size of 20 μm (b-4) Granular aluminum nitride having a volume average particle size of 20 μm (b-5) Spherical alumina having a volume average particle size of 45 μm

[0063] Component (c): (c-1) A toluene solution (50% by mass, kinematic viscosity 10 mm) of an organopolysiloxane resin represented by the following formula (1'), in which 0.08 mol / 100 g of alkenyl groups are bonded only to D units and the M / Q (molar ratio) is 0.9. 2 / s) (In formula (1'), R 1' is a methyl group, and R 2' is a vinyl group, and a1 ' is 1.8, and b1 ' is 1, and c1 ' is 1, and d1 ' is 1, and e1 ' is 1, and a1 ' / (d1 ' +e1 ' ) = 0.9)

[0064] (c-2) A toluene solution (60% by mass, kinematic viscosity 8 mm) of an organopolysiloxane resin represented by the following formula (2'), in which the molar ratio M / Q is 1.2 and all of the substituents bonded to the silicon atoms of the M units are methyl groups: 2 / s) (In formula (2'), R 1' are all methyl groups, and a2 ' is 1.2, and c2 ' is 0, and d2 ' is 0, and e2 ' is 1, and a2 ' / e2 ' = 1.2)

[0065] Component (d): (d-1): Adhesive component represented by the following structural formula (d-2): Adhesive component represented by the following structural formula (d-3): Adhesive component represented by the following structural formula (d-4): For comparative example

[0066] Component (e): 2,5-dimethyl-2,5-di(t-butylperoxy)hexane

[0067] Component (f): KBM-3103C (decyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd.)

[0068] The above components (a), (b), (c), and (f) were charged into a Shinagawa universal mixer in the amounts shown in Tables 1 and 2 and mixed for 60 minutes. Next, components (d) and (e) were added in the amounts shown in Tables 1 and 2 and mixed uniformly to obtain a thermally conductive silicone adhesive composition. However, in Comparative Example 1, component (d) was not added, and 5 parts by mass of KF-99P, a known organohydrogenpolysiloxane manufactured by Shin-Etsu Chemical Co., Ltd., was added as the adhesive component.

[0069] [Preparation of Thermally Conductive Adhesive Member (Thermal Conductive Adhesive Layer)] A fluorine-treated PET film (separator film) was prepared by subjecting the surface of a 38 μm-thick PET film (separator film) to a release treatment using a release agent (X-41-3035 (manufactured by Shin-Etsu Chemical Co., Ltd.)). An appropriate amount of toluene was added to the thermally conductive silicone adhesive composition obtained above to prepare a toluene solution. The toluene solution was applied to the PET film (separator film), and the toluene was volatilized at 80°C to form a thermally conductive adhesive member (thermal conductive adhesive layer). The PET film (separator film) was then laminated on top of the thermally conductive adhesive member (thermal conductive adhesive layer), obtaining a thermally conductive adhesive member (thermal conductive adhesive layer) with a thickness of 150 μm. The thickness is the thickness of the thermally conductive adhesive member (thermally conductive adhesive layer) only, and does not include the thickness of the separator films on both sides of the thermally conductive adhesive member (thermally conductive adhesive layer).

[0070] [Preparation of Thermally Conductive Composites] A reinforcing material (reinforcing layer) was laminated on the thermally conductive adhesive member (thermally conductive adhesive layer) obtained by the above method to prepare a tape-shaped thermally conductive composite. For thermally conductive composites using glass cloth as the reinforcing material (reinforcing layer), thermally conductive adhesive members (thermally conductive adhesive layers) were thermocompression bonded to both sides of a glass cloth (30 μm) at 70°C to prepare the thermally conductive composite. For thermally conductive composites using aromatic polyimide resin as the reinforcing material (reinforcing layer), thermally conductive adhesive members (thermally conductive adhesive layers) were thermocompression bonded to both sides of an aromatic polyimide resin (7.5 μm) at 70°C to prepare the thermally conductive composite. The overall thickness of the thermally conductive composite including the thermally conductive adhesive member (thermally conductive adhesive layer) and the reinforcing material (reinforcing layer) is shown in Tables 1 and 2. The thermally conductive composite was tape-shaped and measured 200 mm x 300 mm.

[0071] [Evaluation Method] (1) Handling Ease: When the thermally conductive adhesive member (thermally conductive adhesive layer) or the thermally conductive adhesive layer surface of the thermally conductive composite was attached to a heat dissipation member (aluminum heat sink), the desired adhesion was evaluated. The separator film on one side of the thermally conductive adhesive member (thermally conductive adhesive layer) or the thermally conductive composite was peeled off, and the thermally conductive adhesive member (thermally conductive adhesive layer) portion was attached to the aluminum heat sink. Then, when the other separator film was peeled off, the handling ease was evaluated based on whether the attached thermally conductive adhesive member (thermally conductive adhesive layer) or the thermally conductive composite was fixed without slipping from the heat sink. The results are shown in the table as ○ if the adhesive member was fixed without slipping, and × if slippage occurred.

[0072] (2) Thermal conductivity: The separator films on both sides of the thermally conductive adhesive member (thermally conductive adhesive layer) or the thermally conductive composite were peeled off, sandwiched between aluminum plates, and uniformly pressed together. After heating and curing at 150°C for 1 hour using a dryer, the thermal resistance was measured using the laser flash method (ASTM E1461). The thermal conductivity was calculated from the relationship between the thickness and the thermal resistance using a conventional method.

[0073] (3) Shear adhesive strength: A thermally conductive adhesive member (thermally conductive adhesive layer) or a thermally conductive composite having the thickness shown in the table was sandwiched between 10 mm x 10 mm aluminum plates, uniformly pressed, and then heated and cured in a dryer at 150 ° C for 1 hour. The shear adhesive strength of the obtained test piece to the aluminum plate at room temperature was measured using a Nordson 4000 Plus bond tester. After storing the molded thermally conductive adhesive member (thermally conductive adhesive layer) or thermally conductive composite at 40 ° C for one month, the shear adhesive strength to the aluminum plate was measured again using the same method, and the change in adhesive strength was calculated as a decrease rate to evaluate storage stability.

[0074] (4) Breakdown Voltage: Based on JIS K6249:2003, the breakdown voltage of the thermally conductive adhesive member (thermally conductive adhesive layer) or thermally conductive composite from which the separator films on both sides had been peeled off was measured in air.

[0075] (5) Tensile strength: After peeling off the separator films on both sides, the tensile strength of the thermally conductive adhesive member (thermally conductive adhesive layer) or the thermally conductive composite was measured using an autograph in accordance with JIS K6249:2003.

[0076]

[0077]

[0078] In Examples 1 to 10, the thermally conductive adhesive members (thermally conductive adhesive layers) or thermally conductive composites were formed into thin films using thermally conductive silicone adhesive compositions containing appropriate amounts of components (a) to (f). These compositions were easy to handle, could be easily mounted on adherends, and had good thermal conductivity. Furthermore, after heat curing, they exhibited good adhesive strength, and no significant decrease in adhesive strength was observed after storage at 40°C. In Comparative Example 1, the use of a known organohydrogenpolysiloxane as component (d) resulted in a significant decrease in adhesive strength after storage at 40°C. In Comparative Example 2, the amount of adhesive component (d) was less than 1 part by mass, resulting in decreased adhesive strength compared to Example 2. In Comparative Example 3, the amount of thermally conductive filler (b) exceeded 7,500 parts by mass, resulting in brittle thermally conductive adhesive members (thermally conductive adhesive layers), which reduced handleability and adhesive strength. In Comparative Example 4, the amount of the adhesive component (d) exceeded 20 parts by mass, making the thermally conductive adhesive member (thermally conductive adhesive layer) brittle and reducing the adhesive strength. In Comparative Example 5, the amount of the silicone resin (c) was less than 150 parts by mass, reducing the cohesive strength of the thermally conductive adhesive member (thermally conductive adhesive layer), resulting in reduced handleability and adhesive strength. In Comparative Example 6, the amount of the organic peroxide (e) was less than 1 part by mass, reducing the adhesive strength compared to Example 6. In Comparative Example 7, a composite was formed using the thermally conductive adhesive member (thermally conductive adhesive layer) of Comparative Example 1 and glass cloth, but as in Comparative Example 1, the adhesive strength significantly decreased after storage at 40°C.

Claims

1. A thermally conductive silicone adhesive composition containing the following components (a) to (e): (a) 100 parts by mass of a linear or branched organopolysiloxane having an average degree of polymerization of 100 to 20,000, (b) 1,300 to 7,500 parts by mass of a thermally conductive filler, and (c) 150 to 600 parts by mass of an organopolysiloxane comprising a component (c-1) represented by the following general formula (1) and having an alkenyl group content per molecule of 0.05 to 0.15 mol / 100 g, and a component (c-2) represented by the following general formula (2): (In formula (1), R 1 are independently selected from alkyl groups having 1 to 10 carbon atoms, aryl groups having 6 to 10 carbon atoms, and aralkyl groups having 7 to 10 carbon atoms; R 2 are independently alkenyl groups having 2 to 8 carbon atoms. 0<a1≦10, 0<b1≦10, 0≦c1≦10, 0≦d1≦10, and 0≦e1≦10, provided that the range of 0.5≦a1 / (d1+e1)≦2.0 is satisfied. (In formula (2), R 1 are independently selected from alkyl groups having 1 to 10 carbon atoms, aryl groups having 6 to 10 carbon atoms, and aralkyl groups having 7 to 10 carbon atoms, and 0<a2≦10, 0≦c2≦10, 0≦d2≦10, and 0<e2≦10, provided that the ranges of 0.7≦a2 / e2≦2.5 are satisfied.) (d) An adhesive component represented by the following structural formula (3) and / or an adhesive component represented by the following structural formula (4): 0.5 to 20 parts by mass (In formula (3), R 6 is an alkyl group having 1 to 5 carbon atoms, and n is independently a number from 1 to 12. (In formula (4), R 6 is an alkyl group having 1 to 5 carbon atoms, and n is independently a number from 1 to 12. (e) Organic peroxide: 1 to 40 parts by mass 2. The thermally conductive silicone adhesive composition according to claim 1, wherein component (b) is at least one selected from the group consisting of metals, metal oxides, and metal nitrides.

3. The thermally conductive silicone adhesive composition according to claim 1 or 2, wherein the proportion of component (c-1) relative to the total amount of component (c) is 10 to 60 mass %.

4. The thermally conductive silicone adhesive composition according to claim 1, wherein component (a) is a linear or branched organopolysiloxane containing two or more alkenyl groups per molecule.

5. The thermally conductive silicone adhesive composition according to claim 1, further comprising 1 to 40 parts by mass of a component (f-1) represented by the following general formula (5) and / or a component (f-2) represented by the following general formula (6) per 100 parts by mass of component (a): (In formula (5), R 3 are independently alkyl groups having 6 to 15 carbon atoms, and R 4 are independently alkyl groups having 1 to 5 carbon atoms, and R 5 are independently an alkyl group having 1 to 6 carbon atoms, m is a number from 1 to 3, and n is a number from 0 to 2, with the proviso that m+n is a number from 1 to 3. (In formula (6), R 5 are independently alkyl groups having 1 to 6 carbon atoms, and p is a number from 5 to 100.

6. A thermally conductive composite having thermally conductive adhesive members formed from the thermally conductive silicone adhesive composition of claim 1 on both sides of a reinforcing material.

7. The thermally conductive composite according to claim 6, wherein the thermal conductivity of the thermally conductive adhesive member is 2.0 W / m·K or more.

8. The thermally conductive composite according to claim 6, which is laminated with a thermally conductive adhesive member.

9. The thermally conductive composite according to claim 6, wherein the reinforcing material is a synthetic resin or glass cloth.

10. The thermally conductive composite according to claim 9, wherein the synthetic resin is at least one selected from the group consisting of aromatic polyimide resin, polyamide resin, polyamideimide resin, polyester resin and fluororesin.

11. The thermally conductive composite according to claim 6, wherein a substrate whose surface has been treated with a release agent is further laminated on the outermost layer of the thermally conductive adhesive member.

12. The thermally conductive composite according to claim 11, wherein the release agent is a fluorine-modified silicone having fluorine substituents attached to the main chain.

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