Thermally conductive silicone compositions and methods for producing thermally conductive silicone compositions

Abstract

Provided is a thermally conductive silicone composition having good contact and adhesion to a substrate such as a heat-generating body or a heat-dissipating body, having excellent heat-dissipating properties due to high thermal conductivity, and having anti-caking properties under discharge pressure while maintaining flexibility. The thermally conductive silicone composition includes: (A) an alkenyl group-containing diorganopolysiloxane having a viscosity of 500 mPa * s or more and 7,000 mPa * s or less at 25 DEG C in an amount of 1.0 parts by mass or more and 9.0 parts by mass or less; (B) an organopolysiloxane having a viscosity of 10,000 mPa * s or more and 200,000 mPa * s or less at 25 DEG C in an amount of 0.05 parts by mass or more and 1.0 parts by mass or less; (C) an organopolysiloxane having two or more hydrosilyl groups in one molecule; (D) a diorganopolysiloxane having no alkenyl group and having a viscosity of 500 mPa.s or less at 25 DEG C; (E) an addition reaction catalyst; and (F) a thermally conductive filler.

Description

Technical Field

[0001] The present invention relates to a thermally conductive silicone composition and a method for producing the thermally conductive silicone composition. Background Art

[0002] The thermally conductive silicone composition (such as a gap filler) is directly applied to a heat generating body or a heat dissipating body (such as a battery of an electric vehicle or a semiconductor of an electronic device), and has the function of transferring the heat emitted from these bodies to a heat dissipating member (such as a radiator). Effective heat transfer at the interface where the coating is formed requires close contact at the contact interface between the heat generating body, etc. and the gap filler. For example, a small amount of gap filler for electronic devices is applied to a circuit board with high precision with precise accuracy. This precision requires low unevenness in the amount of coating. One factor that causes uneven coating is a phenomenon called agglomeration. The term "agglomeration" in the present invention refers to the phenomenon that when the gap filler is discharged from the discharge device, the filler and the polymer are separated from each other, and only the filler component is gathered in the flow path. Preventing the occurrence of agglomeration is important both in terms of quality and productivity.

[0003] Generally, in gap fillers, thermally conductive fillers need to be included in the composition at a high relative content to obtain sufficient thermal conductivity. However, high filler content increases the viscosity of the gap filler and impairs the discharge performance. If a low viscosity polymer is used to ensure proper discharge performance, the relative number of organic functional groups in the polymer increases, resulting in poor compatibility with the filler. This poor compatibility causes the problem of agglomeration during gap filler discharge. Examples of methods for preventing agglomeration include surface treatment of the filler with a coupling agent. However, even if the amount of the coupling agent is increased, it is difficult to completely treat the filler surface and the compatibility cannot be significantly improved. Furthermore, if a high-viscosity polymer having a high molecular chain that is highly compatible with the filler is used, the viscosity of the gap filler increases, resulting in difficulty in discharging the gap filler.

[0004] PTL 1 discloses a precipitation prevention method for a silicone composition, in which a condensation reaction product of D-sorbitol and benzaldehyde is blended into a composition to produce a precipitation prevention silicone composition. However, the problem with this method is that high thermal conductivity cannot be maintained due to the high blending amount of the condensation reaction product relative to the filler (filler). In addition, PTL 1 solves the problem of long-term storage stability by preventing the separation of the polymer and the filler. PTL 2 discloses a resin composition having excellent thermal conductivity due to the uniform dispersion of aluminum nitride powder in the resin without forming aggregates. A flow modifier is included to improve its fluidity. Although PTL 2 improves fluidity, it does not disclose information on solving the agglomeration that occurs during long-term discharge under pressure. Citation List Patent Literature

[0005] PTL 1: Japanese Patent No. 2946104 PTL 2: Japanese Patent Application Laid-Open No. 10-204300 Summary of the invention Technical issues

[0006] The present invention provides a thermally conductive silicone composition and a method for producing the same, wherein the thermally conductive silicone composition has good contact and adhesion to a substrate such as a heat generating body or a heat dissipating body, has excellent heat dissipation properties due to high thermal conductivity, and has anti-caking properties under discharge pressure while maintaining flexibility. Solution to the problem

[0007] In the thermally conductive silicone composition of the present invention, a base polymer having high compatibility is used, a separation suppressing polymer is introduced, a diorganopolysiloxane is used to adjust the viscosity, and an appropriate amount of a thermally conductive filler is contained. As a result, the thermally conductive silicone composition exhibits high thermal conductivity, high discharge performance, and anti-caking properties under discharge pressure.

[0008] The thermally conductive silicone composition of the present invention comprises: Component (A) which is an alkenyl group-containing diorganopolysiloxane having a viscosity of 500 mPa·s or more and 7,000 mPa·s or less at 25° C., in an amount of 1.0 part by mass or more and 9.0 parts by mass or less (relative to 100 parts by mass of the entire composition); component (B) which is an organopolysiloxane having a viscosity of 10,000 mPa·s or more and 200,000 mPa·s or less at 25° C., in an amount of 0.05 parts by mass or more and 1.0 parts by mass or less (relative to 100 parts by mass of the entire composition); Component (C) which is an organopolysiloxane having two or more hydrosilyl groups in one molecule; Component (D) which is a diorganopolysiloxane having no alkenyl group and having a viscosity of 500 mPa·s or less at 25° C.; a component (E) which is an addition reaction catalyst; and Component (F), which is at least one or two or more thermally conductive fillers selected from metals, metal oxides, metal hydroxides, metal nitrides and metal carbides, wherein the content of component (F) is 85 parts by mass or more relative to 100 parts by mass of the overall thermally conductive silicone composition, The thermally conductive silicone composition has a mixed viscosity of 250 Pa·s or less at 25° C. The thermally conductive silicone composition may further include a component (G), wherein the component (G) is a coupling agent. The thermally conductive silicone composition may further include a component (H) which is a polydimethylsiloxane containing a silanol group.

[0009] The alkenyl-containing diorganopolysiloxane of component (A) may have a vinyl group (Vi) in a side chain, or may have at least one vinyl group (Vi) at each terminal. Preferably, the alkenyl-containing diorganopolysiloxane of component (A) is a linear dimethylpolysiloxane having one Vi group at each terminal and having a viscosity of 1,000 mPa·s or more and 1,200 mPa·s or less at 25°C.

[0010] Component (B) may be a non-functional dimethylpolysiloxane. The viscosity of component (B) at 25° C. is preferably 80,000 mPa·s or more and 120,000 mPa·s or less.

[0011] Component (C) is preferably a dimethylpolysiloxane having 12 to 18 hydrogen atoms bonded to silicon atoms only in the side chain, which has a viscosity at 25° C. of 150 mPa·s or more and 300 mPa·s or less.

[0012] The diorganopolysiloxane having no alkenyl group of component (D) is a nonfunctional siloxane and may have a trimethylsilyl group at the terminal. Component (D) is preferably a nonfunctional dimethylpolysiloxane having a viscosity of 30 mPa·s or more and 60 mPa·s or less at 25°C.

[0013] The addition reaction catalyst of component (E) is preferably a platinum-divinyltetramethyldisiloxane complex.

[0014] The thermally conductive filler of component (F) is preferably zinc oxide, amorphous aluminum oxide or spherical aluminum oxide.

[0015] Component (H) is preferably a linear dimethylpolysiloxane having one silanol group at each terminal, which has a viscosity at 25° C. of 30 mPa·s or more and 60 mPa·s or less.

[0016] The thermally conductive silicone composition is a two-component thermally conductive silicone composition comprising a first liquid and a second liquid that are separate from each other, the first liquid and the second liquid being mixed when in use (e.g., under pressure in a discharge device); The first liquid may contain components (A), (B), (D), (E), and (F); and The second liquid may contain components (B), (C), (D) and (F), but not component (E). The second liquid may further contain component (A). The first liquid and / or the second liquid may further contain a component (G) which is a coupling agent. The first liquid and / or the second liquid may further contain a component (H) which is a silanol group-containing polydimethylsiloxane.

[0017] When the total blended amount of the first liquid and / or the total blended amount of the second liquid is 100 parts by mass, the content of component (A) is preferably 2.5 parts by mass or more and 3.0 parts by mass or less. When the total blended amount of the first liquid and / or the total blended amount of the second liquid is 100 parts by mass, the content of component (B) is preferably 0.2 parts by mass or more and 0.4 parts by mass or less. When the total blended amount of the second liquid is 100 parts by mass, the content of component (C) is preferably 0.3 parts by mass or more and 0.5 parts by mass or less. When the total blended amount of the first liquid and / or the total blended amount of the second liquid is 100 parts by mass, the content of component (D) is preferably 4.5 parts by mass or more and 5.5 parts by mass or less. When the total blended amount of the first liquid is 100 parts by mass, the content of component (E) is preferably 0.15 parts by mass or more and 0.25 parts by mass or less. When the total blended amount of the first liquid and / or the total blended amount of the second liquid is 100 parts by mass, the content of zinc oxide as component (F) is preferably 4.0 parts by mass or more and 8.0 parts by mass or less. When the total blended amount of the first liquid and / or the total blended amount of the second liquid is 100 parts by mass, the content of amorphous aluminum oxide as component (F) is preferably 20.0 parts by mass or more and 40.0 parts by mass or less. When the total blended amount of the first liquid and / or the total blended amount of the second liquid is 100 parts by mass, the content of the spherical aluminum oxide as the component (F) is preferably 45.0 parts by mass or more and 65.0 parts by mass or less. When the total blended amount of the first liquid and / or the total blended amount of the second liquid is 100 parts by mass, the content of component (G) is preferably 0.4 parts by mass or more and 0.5 parts by mass or less. When the total blended amount of the first liquid and / or the total blended amount of the second liquid is 100 parts by mass, the content of component (H) is preferably 0.25 parts by mass or more and 0.35 parts by mass or less.

[0018] It is preferred that, in the thermally conductive silicone composition, the absence of aggregation in any of the first liquid, the second liquid, and the thermally conductive silicone composition is visually confirmed by the following agglomeration evaluation. Evaluation of caking: Using a dispenser (eg, MPP-3 manufactured by Musashi Engineering Inc.), discharge of a material volume of 0.03 cc and a waiting time of 0.20 seconds were repeated to discharge 1.0 kg of the material. The dispenser was then disassembled to visually inspect for aggregation.

[0019] The method for producing the two-component thermally conductive silicone composition of the present invention comprises: A first liquid production step of mixing 1.0 parts by mass or more and 9.0 parts by mass or less of component (A) (relative to 100 parts by mass of the entire composition), 0.05 parts by mass or more and 1.0 parts by mass or less of component (B) (relative to 100 parts by mass of the entire composition), component (D) and component (E), and then mixing component (F) to obtain a first liquid, wherein component (A) is an olefin-containing hydrocarbon having a viscosity of 500 mPa·s or more and 7,000 mPa·s or less at 25° C. diorganopolysiloxane, the component (B) is an organopolysiloxane having a viscosity of 10,000 mPa·s or more and 200,000 mPa·s or less at 25° C., the component (D) is a diorganopolysiloxane having no alkenyl group and having a viscosity of 500 mPa·s or less at 25° C., the component (E) is an addition reaction catalyst, and the component (F) is at least one or two or more thermally conductive fillers selected from metals, metal oxides, metal hydroxides, metal nitrides and metal carbides; and A second liquid production step of mixing component (B) in an amount of 0.05 parts by mass or more and 1.0 parts by mass or less (relative to 100 parts by mass of the entire composition), component (C), component (D) and component (F) to obtain a second liquid, wherein component (B) is an organopolysiloxane having a viscosity of 10,000 mPas or more and 200,000 mPas or less at 25° C., component (C) is an organopolysiloxane having two or more hydrosilyl groups in one molecule, component (D) is a diorganopolysiloxane having no alkenyl group and having a viscosity of 500 mPa·s or less at 25° C., and component (F) is at least one or two or more thermally conductive fillers selected from metals, metal oxides, metal hydroxides, metal nitrides and metal carbides. In the second liquid production step, before adding component (F), component (A) in an amount of 1.0 parts by mass or more and 9.0 parts by mass or less, which is an alkenyl group-containing diorganopolysiloxane having a viscosity of 500 mPa·s or more and 7,000 mPa·s or less at 25° C., may be mixed with other components. In the first liquid production step and / or the second liquid production step, component (G) which is a coupling agent may be mixed with other components before adding component (F). In the first liquid production step and / or the second liquid production step, component (H) which is a silanol group-containing polydimethylsiloxane may be mixed with other components before adding component (F). A method of producing a two-component thermally conductive silicone composition may include: A first liquid packaging step of filling the first liquid obtained in the first liquid production step into a predetermined first packaging material; and A second liquid packaging step of filling the second liquid obtained in the second liquid production step into a predetermined second packaging material.

[0020] The method for discharging the thermally conductive silicone composition of the present invention may include the following steps: introducing a first liquid from a first packaging material into a first liquid flow path of the dispenser; introducing a second liquid from the second packaging material into a second liquid flow path of the dispenser; introducing the first liquid and the second liquid at a predetermined ratio into a merged flow path in which the first liquid flow path and the second liquid flow path merge; and A mixed liquid of the first liquid and the second liquid contacting each other in the merging flow path is discharged from the nozzle of the dispenser onto the substrate. The above-mentioned term "predetermined ratio" refers to a mixing ratio of the first liquid and the second liquid set according to the specification of the thermally conductive silicone composition.

[0021] The method for producing the thermally conductive member of the present invention may include: the step of discharging the first liquid from the first liquid storage unit to the mixing unit; the step of discharging the second liquid from the second liquid storage unit to the mixing unit; a step of mixing the first liquid and the second liquid in a mixing unit to obtain a thermally conductive silicone composition; The step of discharging and applying the thermally conductive silicone composition to a substrate; and A step of curing the thermally conductive silicone composition applied to the substrate to obtain a thermally conductive member.

[0022] In the method for producing a thermally conductive member and the method for discharging a thermally conductive silicone composition, the discharge pressure for discharging the first liquid, the second liquid and the thermally conductive silicone composition onto the substrate may vary depending on the dispenser. However, the lower limit of the discharge pressure is, for example, 0.1 MPa, preferably 0.2 MPa to 0.8 MPa.

[0023] The heat dissipation member of the present invention may include a substrate and a thermally conductive member provided on a surface of the substrate, the thermally conductive member being obtained by curing the above-mentioned thermally conductive silicone composition.

[0024] The electric device or electronic device of the present invention may include the above-mentioned heat dissipation member.

[0025] (Function and Effect) (1) The thermally conductive silicone composition achieves good contact and adhesion with a substrate such as a heat sink, is excellent in heat dissipation properties due to high thermal conductivity, and can be used as a gap filler that prevents agglomeration while maintaining high discharge performance. (2) The thermally conductive silicone composition of the present invention can be used as a thermally conductive silicone composition that is less likely to clog a flow path even during long-term discharge. DETAILED DESCRIPTION

[0026] Hereinafter, a thermally conductive silicone composition, a method for producing the thermally conductive silicone composition, a method for producing a thermally conductive member, and a heat dissipation member according to the present invention will be described in detail.

[0027] Thermally Conductive Silicone Composition: The thermally conductive silicone composition may be any composition for forming a thermally conductive member. Examples of thermally conductive members include a heat generating body (such as an automotive battery), a gap filler or heat sink applied to a film covering a heat generating body, and a member cured and formed on a substrate, a circuit chip, a heat dissipation member, etc. for an electrical or electronic device. The thermally conductive silicone composition may be applied to the substrate in a liquid state before curing, and may be cured after application to provide a thermally conductive member. Alternatively, the thermally conductive silicone composition may be cured to obtain a thermally conductive member, which may then be applied to the substrate.

[0028] The temperature, procedure, etc. for curing the thermally conductive silicone composition are not limited and can be appropriately selected depending on the application of the cured product to be obtained, etc. The present invention provides a thermally conductive silicone composition that can exhibit sufficient performance, i.e., sufficient curability, adhesion to a substrate under discharge pressure, and anti-caking properties even when its use is limited to a normal temperature environment. However, in the case where such a high temperature environment is allowed, the thermally conductive silicone composition can be cured in a high temperature environment.

[0029] The curing method of the thermally conductive silicone composition is preferably an addition reaction type. The main reasons for this are, for example, as follows: the curing can be controlled over a wide temperature range from room temperature to about 150° C., the volume change and the amount of desorbed gas are low, and generally good compatibility with the thermally conductive filler is achieved. Generally, the higher the curing temperature, the faster the curing process. The present invention assumes that due to various restrictions depending on the application, some or all of the steps of applying the thermally conductive silicone composition, the curing step, and the subsequent steps need to be performed at room temperature. The addition reaction type allows the curing temperature to be appropriately set according to the restrictions.

[0030] Assuming that the curing method of the thermally conductive silicone composition according to the present invention is an addition reaction type, each component of the thermally conductive silicone composition will be described in detail below.

[0031] Component (A): Component (A) as the main component of the thermally conductive silicone composition is an alkenyl-containing diorganopolysiloxane. The alkenyl-containing diorganopolysiloxane preferably has a terminal Vi (vinyl group) to have a medium hardness after curing. The alkenyl-containing diorganopolysiloxane may have an OH group at its terminal. The viscosity and polymerization degree of component (A) are not particularly limited and may be selected according to the desired mixing viscosity of the thermally conductive silicone composition, etc., and the viscosity at 25° C. may be, for example, 500 mPa·s or more and 7,000 mPa·s or less. As the diorganopolysiloxane, one type thereof may be used alone, or two or more types thereof may be used in combination as appropriate. The diorganopolysiloxane is a main component of the thermally conductive silicone composition and has an average of at least two alkenyl groups bonded to a silicon atom in one molecule, preferably 2 to 50 alkenyl groups, more preferably 2 to 20 alkenyl groups. The amount of component (A) is in the range of 1.0 part by mass or more and 9.0 parts by mass or less, preferably 2 parts by mass or more and 4 parts by mass or less, relative to 100 parts by mass of the entire thermally conductive silicone composition. Component (A) is preferably contained in both the first liquid and the second liquid.

[0032] The molecular structure of component (A) is not particularly limited, and can be, for example, a linear structure, a partially branched linear structure, a branched structure, a cyclic structure or a branched cyclic structure. Among these, component (A) is preferably a substantially linear diorganopolysiloxane. Specifically, component (A) can be a linear diorganopolysiloxane in which the molecular chain is mainly composed of diorganosiloxane repeating units and in which the two ends of the molecular chain are end-capped with triorganosiloxy groups. Some or all ends of the molecular chain or a part of the side chain can be a silanol group.

[0033] The position of the alkenyl group bonded to the silicon atom in component (A) is not particularly limited, and component (A) may be a diorganopolysiloxane having alkenyl groups bonded to silicon atoms at both molecular chain ends. The diorganopolysiloxane having one alkenyl group at each end of the molecular chain has the advantage that the content of the alkenyl group serving as a reaction point for a crosslinking reaction is small, and the flexibility of the cured product (e.g., a gap filler) obtained after curing is enhanced.

[0034] The alkenyl group may be bonded to the silicon atom at a molecular chain terminal, bonded to the silicon atom at a non-terminal molecular chain site (in the middle of the molecular chain), or bonded to both. Component (A) may be a polymer composed of a single type of siloxane unit, or a copolymer composed of two or more types of siloxane units.

[0035] The viscosity of component (A) at 25° C. is 500 mPa·s or more and 7,000 mPa·s or less, preferably 1,000 mPa·s or more and 5,000 mPa·s or less, more preferably 1,000 mPa·s or more and 4,000 mPa·s or less, and even more preferably 1,000 mPa·s or more and 2,000 mPa·s or less. When the viscosity falls within the above range, appropriate fluidity of the resulting thermally conductive silicone composition can be obtained, and thus discharge performance is high, and thus productivity can be improved. In addition, the flexibility of the resulting thermally conductive member obtained by curing the thermally conductive silicone composition can be increased.

[0036] In order to adjust the viscosity (mixed viscosity) of the thermally conductive silicone composition obtained by mixing the liquid compositions before curing, two or more types of diorganopolysiloxanes having an alkenyl group and having different viscosities may also be used in combination.

[0037] Specifically, component (A) is represented by the following general formula (1) as an average composition formula: R 1 a SiO (4-a) / 2 …(1) (In formula (1), R 1 are the same as or different from each other and are each an unsubstituted or substituted monovalent hydrocarbon group having 1 to 18 carbon atoms, and a is 1.7 to 2.1, preferably 1.8 to 2.5, more preferably 1.95 to 2.05).

[0038] In one embodiment, the above R 1At least two or more of the monovalent hydrocarbon groups represented by are selected from alkenyl groups such as vinyl, allyl, propenyl, isopropenyl, butenyl, isobutenyl, hexenyl and cyclohexenyl. Groups other than these groups are substituted or unsubstituted monovalent hydrocarbon groups having 1 to 18 carbon atoms. Specifically, the above R 1 is selected from alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, neopentyl, hexyl, 2-ethylhexyl, heptyl, octyl, nonyl, decyl and dodecyl; cycloalkyl groups such as cyclopentyl, cyclohexyl and cycloheptyl; aryl groups such as phenyl, tolyl, xylyl, biphenyl and naphthyl; aralkyl groups such as benzyl, phenethyl, phenylpropyl and methylbenzyl; and halogen-substituted or cyano-substituted alkyl groups in which a part or all of the hydrogen atoms in the above hydrocarbon groups have been substituted with halogen atoms, cyano groups and the like, such as chloromethyl, 2-bromoethyl, 3,3,3-trifluoropropyl, 3-chloropropyl and cyanoethyl.

[0039] R to be selected 1 Examples of R preferably include vinyl, allyl, propenyl, isopropenyl, 2-methyl-1-propenyl, 2-methylallyl and 2-butenyl as the required two or more alkenyl groups. Vinyl is particularly preferred. 1 Preferred examples of include methyl and phenyl, of which methyl is particularly preferred. In addition, considering the physical properties and economic benefits of the cured product, it is preferred that R 1 70 mol % or more are methyl groups, and it is generally preferred that R 1 80 mol % or more of the groups are methyl groups.

[0040] Specific examples of the molecular structure of component (A) include dimethylpolysiloxane having two molecular chain ends terminated by dimethylvinylsiloxy groups; dimethylsiloxane-methylphenylsiloxane copolymer having two molecular chain ends terminated by dimethylvinylsiloxy groups; dimethylsiloxane-methylvinylsiloxane copolymer having two molecular chain ends terminated by dimethylvinylsiloxy groups; dimethylsiloxane-methylvinylsiloxane-methylphenylsiloxane copolymer having two molecular chain ends terminated by dimethylvinylsiloxy groups; dimethylsiloxane-methylvinylsiloxane copolymer having two molecular chain ends terminated by trimethylsiloxy groups; 1 / 2 The siloxane unit represented by the formula (CH3)3SiO 1 / 2 The siloxane units represented by the formula SiO 4 / 2Organopolysiloxanes composed of siloxane units represented by (where Vi represents a vinyl group); organopolysiloxanes in which some or all of the methyl groups in the above organopolysiloxanes are substituted by alkyl groups such as ethyl or propyl groups, aryl groups such as phenyl or tolyl groups, and halogenated alkyl groups such as 3,3,3-trifluoropropyl groups; and mixtures of two or more of these organopolysiloxanes. From the viewpoint of increasing the elongation at break of the cured product due to the increased molecular chain length, linear diorganopolysiloxanes having one vinyl group at each molecular chain end are preferred.

[0041] Component (A) may contain an alkenyl group-containing diorganopolysiloxane having at least one silanol group at a molecular chain terminal in an amount of 1.0 part by mass or more and 9.0 parts by mass or less. When the thermally conductive silicone composition of the present invention is stored as a two-component composition, the alkenyl-containing diorganopolysiloxane having a silanol group may be contained in the first liquid and / or the second liquid.

[0042] These diorganopolysiloxanes are commercially available or can be prepared by methods known to those skilled in the art.

[0043] Component (B): Component (B) is an organopolysiloxane. Component (B) may have a viscosity and a degree of polymerization which are not particularly limited and may be selected according to the desired mixed viscosity of the thermally conductive silicone composition, etc. For example, component (B) may have a viscosity of 10,000 mPa·s or more and 200,000 mPa·s or less at 25°C. Component (B) is an organopolysiloxane, and is a component that functions as a separation inhibitor for inhibiting the separation of the polymer and the filler under discharge pressure.

[0044] Component (B) may be any organohydrogenpolysiloxane. For example, component (B) may have the same structure as component (A), or may be a diorganopolysiloxane having no vinyl group.

[0045] The viscosity of component (B) at 25° C. is 10,000 mPa·s or more and 200,000 mPa·s or less, preferably 10,000 mPa·s or more and 150,000 mPa·s or less, more preferably 15,000 mPa·s or more and 100,000 mPa·s or less.

[0046] Component (C): Component (C) is an organopolysiloxane having two or more hydrosilyl groups in one molecule. Component (C) may function as a crosslinking agent. Component (C) may have a viscosity and a degree of polymerization which are not particularly limited and may be selected according to the desired mixed viscosity of the thermally conductive silicone composition. For example, component (C) may have a viscosity of 10 mPa·s or more and 10,000 mPa·s or less at 25°C. Component (C) may be a diorganopolysiloxane having three or more hydrosilyl groups bonded to silicon atoms in one molecule, and serves as a crosslinking agent for curing the thermally conductive silicone composition.

[0047] The number of hydrosilyl groups bonded to the silicon atom is not particularly limited as long as the number is 2 or more. The hydrogen content (H content) of component (C) is not particularly limited. In order to impart a practically sufficient elongation to a thermally conductive member obtained by curing the thermally conductive silicone composition, the hydrogen content (H content) of component (C) is preferably 0.01 mmol / g or more and 4.0 mmol / g or less, more preferably 0.3 mmol / g or more and 3.0 mmol / g or less, and even more preferably 1.0 mmol / g or more and 2.0 mmol / g or less.

[0048] As component (C), organohydrogenpolysiloxane may be used. Component (C) forms a cured product by an addition reaction with an alkenyl group, and may have a hydrogen atom (hydrosilyl group) bonded to at least one or more silicon atoms in a side chain in the molecule. Component (C) can act as a crosslinking agent. Component (C) acting as a crosslinking agent preferably has three or more hydrosilyl groups in one molecule, and may have at least one hydrosilyl group in the side chain of the molecule. Component (C) acting as a crosslinking agent is more preferably an organohydrogen polysiloxane with 5 or more hydrosilyl groups, and may have 10 or more and 18 or less hydrosilyl groups. The organohydrogen polysiloxane acting as a crosslinking agent has at least two hydrosilyl groups in its side chain. The number of hydrosilyl groups at the end of the molecular chain can be zero or more and two or less, and from an economic point of view, preferably two. The molecular structure of the organohydrogen polysiloxane can be any one of linear, cyclic, branched and three-dimensional network structures. The position of the silicon atom bonded to the hydrogen atom is not particularly limited, and may be at the end of the molecular chain, at a non-terminal molecular chain site (in the middle of the molecular chain) or in the side chain. There are no particular limitations on other conditions in the organohydrogenpolysiloxane, the type of organic group other than the hydrosilyl group, the bonding position, the degree of polymerization, the structure, etc. Two or more types of organohydrogenpolysiloxane may be used in combination.

[0049] In the above-mentioned thermally conductive silicone composition, the content of component (C) is preferably within such a range that the ratio of the number of hydrosilyl groups in component (C) to the number of alkenyl groups in components (A) and (B) falls within the range of 1 / 5 to 7, more preferably within the range of 1 / 2 to 2, and even more preferably within the range of 2 / 5 to 5 / 4. When the content of component (C) falls within the above-mentioned range, the thermally conductive silicone composition is fully cured, and the hardness of the overall cured product obtained by curing the composition falls within a more preferred range. As a result, when the cured product of the composition is used as a gap filler, cracks are less likely to occur. In addition to these, there is also the advantage that the cured product achieves both the desired degree of flexibility and adhesion.

[0050] The hydrosilyl group in component (C) may be present at the molecular chain end, may be present in the side chain, or may be present in both the molecular chain end and the side chain. It is preferred to use a mixture of an organohydrogenpolysiloxane having only one hydrosilyl group at each molecular chain end and an organohydrogenpolysiloxane having only a hydrosilyl group in the side chain of the molecular chain.

[0051] From the viewpoint of improving heat resistance, component (C) may contain an organohydrogenpolysiloxane having at least one aromatic group in the molecule. For economic reasons, the aromatic group is more preferably a phenyl group. An aromatic group-containing organohydrogenpolysiloxane and an aromatic group-free organohydrogenpolysiloxane may be used in combination.

[0052] The viscosity of component (C) at 25° C. is 10 mPa·s or more and 10,000 mPa·s or less, preferably 20 mPa·s or more and 5,000 mPa·s or less, more preferably 30 mPa·s or more and 2,000 mPa·s or less. In order to adjust the viscosity of the thermally conductive silicone composition as a final product, two or more types of organopolysiloxanes having two or more hydrosilyl groups and having different respective viscosities may also be used. The mixed viscosity of the thermally conductive silicone composition may be in the range of 10 Pa·s or more and 1,000 Pa·s or less, more preferably in the range of 20 Pa·s or more and 500 Pa·s or less, and even more preferably in the range of 30 Pa·s or more and 250 Pa·s or less.

[0053] In the thermally conductive silicone composition according to the present invention, the content of component (C) is preferably within a range such that the ratio of the number of hydrosilyl groups in component (C) to the number of alkenyl groups in components (A) and (B) falls within a range of 1 / 5 to 7. When the content of component (C) falls within the above range, the hardness of the cured product of the thermally conductive silicone composition becomes able to fall within an appropriate range.

[0054] Component (D): Component (D) is a diorganopolysiloxane containing no alkenyl group. Component (D) functions as a viscosity controller for the thermally conductive silicone composition. Component (D) has a viscosity of 500 mPa·s or less at 25°C.

[0055] The molecular structure of component (D) is not particularly limited, and component (D) is, for example, a linear, branched or cyclic diorganopolysiloxane, and preferably a linear diorganopolysiloxane.

[0056] Specific examples of component (D) include linear dimethylpolysiloxanes having both ends capped with trimethylsilyl groups and linear diethylpolysiloxanes having both ends capped with triethylsilyl groups. In particular, component (D) is preferably linear dimethylpolysiloxanes having both ends capped with trimethylsilyl groups.

[0057] Component (E): Component (E) is an addition reaction catalyst, and promotes the addition curing reaction between the alkenyl group bonded to the silicon atom in the above-mentioned component (A) and the hydrogen atom bonded to the silicon atom in the above-mentioned component (C). Such addition reaction catalysts are known to those skilled in the art. Examples of component (E) include platinum group metals such as platinum, rhodium, palladium, osmium, iridium and ruthenium, and catalysts in which any of the above metals is supported by a particulate support material (e.g., activated carbon, alumina and silica). Furthermore, specific examples of component (E) include platinum halides, platinum-olefin complexes, platinum-alcohol complexes, platinum-alcoholate complexes, platinum-vinylsiloxane complexes, dicyclopentadiene-platinum dichloride, cyclooctadiene-platinum dichloride, and cyclopentadiene-platinum dichloride.

[0058] In addition, from an economic point of view, the metal compound catalyst other than the above-mentioned platinum group metal can be used as component (E). Examples of iron catalysts for hydrosilylation include iron-carbonyl complex catalysts, iron catalysts with cyclopentadienyl as ligands, iron catalysts with terpyridine-based ligands or terpyridine-based ligands and a combination of bistrimethylsilylmethyl groups, iron catalysts with bisiminopyridine ligands, iron catalysts with bisiminoquinoline ligands, iron catalysts with aryl groups as ligands, iron catalysts with cyclic or acyclic olefin groups with unsaturated groups, and iron catalysts with cyclic or acyclic olefinic groups with unsaturated groups. Other examples of catalysts for hydrosilylation include cobalt catalysts, vanadium catalysts, ruthenium catalysts, iridium catalysts, samarium catalysts, nickel catalysts, and manganese catalysts.

[0059] The blending amount of component (E) is preferably in the range of 0.5 ppm or more and 1,000 ppm or less, more preferably 1 ppm or more and 500 ppm or less, still more preferably 1 ppm or more and 100 ppm or less in terms of the concentration of the catalyst metal element relative to the total mass of the thermally conductive silicone composition, although an effective amount thereof is used according to the curing temperature and curing time required depending on the application. If the blending amount is less than 0.5 ppm, the addition reaction will become very slow. If the blending amount exceeds 1,000 ppm, it is not economically preferred due to increased cost.

[0060] Component (F): The thermally conductive filler of component (F) is a filling material component that improves the thermal conductivity of the thermally conductive silicone composition. The thermally conductive filler of component (F) is at least one or more selected from metals, metal oxides, metal hydroxides, metal nitrides and metal carbides. In order to obtain a gap filler with high insulating properties for application to electronic substrates, etc., it is preferred to use a material with excellent insulating properties and thermal conductive properties as the thermally conductive filler of component (F).

[0061] Examples of thermally conductive fillers of component (F) include metal oxides such as aluminum oxide, zinc oxide, magnesium oxide, titanium oxide, silicon oxide, and beryllium oxide; metal hydroxides such as aluminum hydroxide and magnesium hydroxide; nitrides such as aluminum nitride, silicon nitride, and boron nitride; carbides such as boron carbide, titanium carbide, and silicon carbide; graphites such as graphite and black lead; metals such as aluminum, copper, nickel, and silver; and mixtures thereof. In particular, when the thermally conductive silicone composition requires electrical insulation, component (F) is preferably a metal oxide, a metal hydroxide, a nitride, or a mixture thereof, and may be an amphoteric hydroxide or an amphoteric oxide. Component (F) that can be used is preferably one or more types selected from aluminum hydroxide, boron nitride, aluminum nitride, zinc oxide, aluminum oxide, magnesium oxide, and magnesium hydroxide.

[0062] It should be noted that aluminum oxide, aluminum hydroxide, magnesium oxide, magnesium hydroxide, zinc oxide, aluminum nitride and boron nitride are insulating materials and have relatively good compatibility with components (A) and (B). In addition, they are industrially selectable varieties with a wide range of particle sizes, are easily available in resources, and are relatively cheap. Therefore, they are suitable as thermally conductive inorganic filling materials.

[0063] In the thermally conductive silicone composition of the present invention, at least one selected from aluminum oxide, aluminum hydroxide, magnesium oxide, magnesium hydroxide, zinc oxide, aluminum nitride, and boron nitride is more preferably used as component (F). When only one type thereof is used as component (F), aluminum oxide, aluminum hydroxide, or zinc oxide is preferably selected, and aluminum oxide is more preferably selected. Even when only one type is used, it is more preferred to combine two or more types of different shapes. For example, a combination of spherical aluminum oxide and amorphous aluminum oxide or a combination of spherical zinc oxide and amorphous zinc oxide may be used. As component (F), at least two types selected from aluminum oxide, aluminum hydroxide, magnesium oxide, magnesium hydroxide, zinc oxide, aluminum nitride and boron nitride are more preferably used. For example, a combination of spherical aluminum oxide, amorphous aluminum oxide and amorphous zinc oxide can be used.

[0064] The shape of the thermally conductive filler is not particularly limited, and may be, for example, a spherical shape, an amorphous shape, a fine powder, a fibrous shape, a flaky shape, etc. In order to blend the thermally conductive filler in an amount required to enhance the thermal conductivity of the thermally conductive member, the thermally conductive filler preferably has a spherical shape, and its average particle size may be 1 to 100 μm. Herein, the spherical shape may be not only a true spherical shape but also an ellipsoidal spherical shape. When spherical alumina is used as component (F), α-alumina obtained by high-temperature thermal spraying or hydrothermal treatment of hydrated alumina may be used.

[0065] In order to improve the filling rate of the thermally conductive filler, it is more preferable to use a spherical thermally conductive filler and a thermally conductive filler other than a spherical filler. When at least two or more thermally conductive fillers having different shapes are used in combination, the fillers can be stacked in an almost densely packed state, thereby obtaining an effect of improving thermal conductivity. When a spherical thermally conductive filler is used in combination with a thermally conductive filler other than a spherical filler (e.g., an amorphous thermally conductive filler), the thermal conductivity can be further improved.

[0066] The thermally conductive filler preferably has a thermal conductivity of 10 W / m·K or more. When the thermal conductivity is less than 10 W / m·K, the thermal conductivity of the thermally conductive silicone composition itself may be reduced. In particular, if the thermally conductive component requires electrical insulating properties, it is conceivable to select a non-conductive thermally conductive filler.

[0067] The thermally conductive filler may be blended in an amount required to improve the thermal conductivity of the thermally conductive member (e.g., 2.0 W / m·K or higher). For example, the content of component (F) may be 70 parts by mass or more and 95 parts by mass or less relative to 100 parts by mass of the entire thermally conductive silicone composition. When the content of component (F) falls within the above range, the thermally conductive silicone composition has sufficient thermal conductivity as a whole, is easy to mix when blended, and remains flexible even after curing. In addition, since the component (F) contained in such an amount does not excessively increase the specific gravity, the resulting composition is more suitable for forming a thermally conductive member that needs to have high thermal conductivity and reduced weight. If the content of component (F) is too small, it becomes difficult to fully increase the thermal conductivity of the cured product obtained by the thermally conductive silicone composition, and if the content of component (F) is too large, the resulting thermally conductive silicone composition becomes highly viscous, and there is a possibility that it becomes difficult to evenly apply the thermally conductive silicone composition. Therefore, this situation leads to problems such as an increase in the heat resistance value of the cured product of the composition and a decrease in the flexibility of the cured product.

[0068] The average particle size of component (F) is not particularly limited and may be in the range of 1 μm or more and 100 μm or less. If the average particle size is too small, the fluidity of the thermally conductive silicone composition decreases. If the average particle size is too large, there is a possibility that problems such as scratches of the coating equipment due to the filler being caught by the sliding part of the coating equipment may occur. Note that the average particle size of component (F) is defined as D50 (or median particle size), which is a 50% particle size in a volume-based cumulative particle size distribution measured by a laser diffraction particle size measuring device.

[0069] Component (G): Examples of the coupling agent of component (G) include silane coupling agents. Examples of the silane coupling agent include organic silicon compounds and organic siloxanes having an organic group having 3 or more carbon atoms and an alkoxy group bonded to a silicon atom in one molecule, the organic group including an epoxy group, an alkyl group, an aryl group, a vinyl group, a styryl group, a methacryloyl group, an acryl group, an amino group, an isocyanurate group, an ureide group, a mercapto group, an isocyanate group, and an acid anhydride. Examples of silane coupling agents are silane compounds, such as octyl trimethoxysilane, octyl triethoxysilane, decyl trimethoxysilane, decyl triethoxysilane, dodecyl trimethoxysilane, dodecyl triethoxysilane, vinyl trimethoxysilane, 3-glycidyloxypropyl trimethoxysilane, p-phenylene trimethoxysilane, 3-methacryloxypropyl trimethoxysilane, 3-acryloxypropyl trimethoxysilane, 3-aminopropyl trimethoxysilane, 3-aminopropyl triethoxysilane, tris-(trimethoxysilyl propyl) isocyanurate, 3-ureidopropyl trialkoxysilane, 3-mercaptopropyl methyl dimethoxysilane, 3-isocyanatopropyl triethoxysilane and 3-trimethoxysilyl propyl succinic anhydride. The silane compound may be a compound without a hydrosilyl group. One type thereof may be used alone, or two or more types thereof may be used in combination as appropriate. When the surface of the thermally conductive filler is treated with a silane coupling agent, the affinity with the silicone polymer may be improved, the viscosity of the composition may be reduced, and the filling properties of the thermally conductive filler may be improved. Therefore, when a larger amount of the thermally conductive filler is added, the thermal conductivity may be increased.

[0070] As the blending amount of the silane coupling agent relative to the thermally conductive filler, an effective amount according to the curing temperature or curing time required depending on the application is used. Relative to the amount of the thermally conductive filler, the general optimal amount is usually 0.5 weight % or more and 2 weight % or less. The standard of the required amount is calculated by the following expression. The silane coupling agent can be added in an amount of one to three times the standard of the required amount. The required amount of silane coupling agent (g) = the mass of thermal conductive filler (g) × the specific surface area of ​​thermal conductive filler (m 2 / g) / Specific minimum coverage area of ​​silane coupling agent (m 2 / g)

[0071] Component (H): Component (H) is a polydimethylsiloxane containing a silanol group. Component (H) exhibits a function of improving the disconnection property of the discharged liquid. The viscosity of component (H) is 10 mPa·s or more and 1,000 mPa·s or less at 25°C, more preferably 10 mPa·s or more and 500 mPa·s or less at 25°C.

[0072] A silanol group-containing organopolysiloxane having a viscosity of 10 mPa·s or more and 500 mPa·s or less at 25° C. is blended as component (H) to improve the storage stability of the thermally conductive silicone composition and also to improve the flexibility and pump-out resistance of a thermally conductive member obtained by curing the composition. Component (H) may be a compound having no alkenyl group or no hydrogen atom bonded to a silicon atom (having no hydrosilyl group). In addition, component (H) may be a linear organopolysiloxane having at least one silanol group at each molecular chain end. If component (H) has such a structure, the wire breaking property is improved accordingly.

[0073] Specific examples of component (H) include linear dimethylpolysiloxanes whose both terminals are blocked by dimethylhydroxysilyl groups and linear diethylpolysiloxanes whose both terminals are blocked by diethylhydroxysilyl groups. In particular, linear dimethylpolysiloxanes whose both terminals are blocked by dimethylhydroxysilyl groups are preferred.

[0074] In other components (eg, component (D)), silanol groups may be contained at an unavoidable amount level (eg, 0.001 parts by mass or less based on the total amount of the components), and when contained, the silanol groups do not account for the blending amount of component (H).

[0075] In the thermally conductive silicone composition, as another optional component other than the above-mentioned components (A) to (G), conventionally known additives for silicone rubber or gel can be used, as long as the purpose of the present invention is not damaged. Examples of such additives include organosilicon compounds, crosslinking agents, adhesive aids, pigments, dyes, curing inhibitors, heat resistance imparting agents, flame retardants, antistatic agents, conductivity imparting agents, air tightness improvers, radiation shielding agents, electromagnetic wave shielding agents, preservatives, stabilizers, organic solvents, plasticizers, fungicides, containing one hydrogen atom or alkenyl bonded to a silicon atom in one molecule and containing no other functional groups and containing an organopolysiloxane bonded to a silicon atom hydrogen atom. As these optional components, one type thereof can be used alone, or two or more types thereof can be used in combination as appropriate. The thermally conductive silicone composition of the present invention may contain any one or more selected from the following: octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), dodecamethylcyclohexasiloxane (D6), tetradecamethylcycloheptasiloxane (D7) and hexadecamethylcyclooctasiloxane (D8). The total content of (D4), (D5), (D6), (D7) and (D8) may be less than 0.1 parts by mass (i.e., less than 1,000 ppm) relative to 100 parts by mass of the total blending amount of the first liquid and / or the total blending amount of the second liquid.

[0076] Substrate: Here, the substrate may be at least one selected from glass, metal, ceramic, and resin. Preferred examples of metal substrates to which the thermally conductive silicone composition is bonded include those made of aluminum, magnesium, iron, nickel, titanium, stainless steel, copper, lead, zinc, molybdenum, and silicon. Preferred examples of ceramic substrates to which the thermally conductive silicone composition is bonded include those made of oxides, carbides, and nitrides such as aluminum oxide, aluminum nitride, alumina zirconia, zirconium oxide, zinc oxide, barium titanate, lead zirconate titanate, beryllium oxide, silicon nitride, and silicon carbide. Preferred examples of the resin substrate to which the cured thermally conductive silicone composition is bonded include resin substrates made of polyester, epoxy resin, polyamide, polyimide, ester resin, polyacrylamide, acrylonitrile-butadiene-styrene (ABS) resin, styrene resin, polypropylene, polyacetal, acrylic resin, polycarbonate (PC), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyether-ether ketone (PEEK), polymethyl methacrylate (PMMA), and silicone resin. In the case where a thermally conductive member obtained by curing a thermally conductive silicone composition is used as a gap filler for a battery cell, the battery cell case as a substrate to be bonded may have an iron surface at least partially coated with a cationic electrodeposition coating on the substrate surface, and the heat sink may have an aluminum surface. The thermally conductive silicone composition is injected and cured to fill the space between the aluminum surface and the iron surface coated therewith by cationic electrodeposition coating to provide a gap filler.

[0077] The electrical equipment and the electronic equipment are not particularly limited, and examples thereof include mobile phones, smart phones, tablet computers, smart watches, computers, semiconductor package substrates, electronic circuit substrates, LED package substrates, sensor substrates, imaging device substrates, liquid crystal substrates, and organic EL substrates.

[0078] Process for producing a thermally conductive silicone composition: The first production method is a method for obtaining a cured product of a two-component thermally conductive silicone composition. The first liquid contains the above-mentioned components (A), (B), (D), (E) and (F). The second liquid contains the above-mentioned components (B), (C), (D) and (F). The second liquid may further contain component (A). The first liquid and / or the second liquid may further contain the above-mentioned component (G). The first liquid and / or the second liquid may further contain the above-mentioned component (H).

[0079] In the first liquid production step, components (A), (B), (D) and (E) are mixed, and then component (F) is added to be mixed therewith. Component (A): diorganopolysiloxane containing alkenyl groups Viscosity: 500 mPa·s or more and 7,000 mPa·s or less at 25°C Amount: 1.0 parts by mass or more and 9.0 parts by mass or less relative to 100 parts by mass of the total amount of the first liquid Component (B): Organopolysiloxane Viscosity: 10,000 mPa·s or more and 200,000 mPa·s or less at 25°C Amount: 0.05 parts by mass or more and 1.0 parts by mass or less relative to 100 parts by mass of the total amount of the first liquid Component (D): diorganopolysiloxane having no alkenyl group Viscosity: 500 mPa·s or more at 25°C Amount: 0.1 parts by mass or more and 9.0 parts by mass or less relative to 100 parts by mass of the total amount of the first liquid Component (E): Addition reaction catalyst Amount: 0.01 parts by mass or more and 1.0 parts by mass or less relative to 100 parts by mass of the total amount of the first liquid Component (F): Thermally conductive filler Amount: 70.0 parts by mass or more and 95.0 parts by mass or less relative to 100 parts by mass of the total amount of the first liquid In the first liquid production step, components (A), (B), (D), (E), (G) and (H) may be mixed. In this case, components (G) and (H) are as follows: Component (G): coupling agent (SILANE 25013VP manufactured by Wacker Chemie AG) Amount: 0.01 parts by mass or more and 2.0 parts by mass or less relative to 100 parts by mass of the total amount of the first liquid Component (H): Polydimethylsiloxane containing silanol groups Viscosity: 10 mPa·s or more and 1,000 mPa·s or less at 25°C Amount: 0.01 parts by mass or more and 2.0 parts by mass or less relative to 100 parts by mass of the total amount of the first liquid

[0080] In the second liquid production step, components (A), (B), (C) and (D) are mixed, and then component (F) is added to be mixed therewith. Component (A): diorganopolysiloxane containing alkenyl groups Viscosity: 500 mPa·s or more and 7,000 mPa·s or less at 25°C Amount: 1.0 parts by mass or more and 9.0 parts by mass or less relative to 100 parts by mass of the total amount of the second liquid Component (B): Organopolysiloxane Viscosity: 10,000 mPa·s or more and 200,000 mPa·s or less at 25°C Amount: 0.05 parts by mass or more and 1.0 parts by mass or less relative to 100 parts by mass of the total amount of the second liquid Component (C): an organopolysiloxane having two or more hydrosilyl groups in one molecule Viscosity: 10 mPa·s or more and 10,000 mPa·s or less at 25°C Amount: 0.01 parts by mass or more and 10.0 parts by mass or less relative to 100 parts by mass of the total amount of the second liquid Component (D): diorganopolysiloxane having no alkenyl group Viscosity: 500 mPa·s or more at 25°C Amount: 0.1 parts by mass or more and 9.0 parts by mass or less relative to 100 parts by mass of the total amount of the second liquid Component (F): Thermally conductive filler Amount: 70.0 parts by mass or more and 95.0 parts by mass or less relative to 100 parts by mass of the total amount of the second liquid In the second liquid production step, components (A), (B), (C), (D), (G) and (H) may be mixed. In this case, components (G) and (H) are as follows: Component (G): coupling agent Amount: 0.01 parts by mass or more and 2.0 parts by mass or less relative to 100 parts by mass of the total amount of the second liquid Component (H): Polydimethylsiloxane containing silanol groups Viscosity: 10 mPa·s or more and 1,000 mPa·s or less at 25°C Amount: 0.01 parts by mass or more and 2.0 parts by mass or less relative to 100 parts by mass of the total amount of the second liquid

[0081] Method for producing a thermally conductive component: A method for producing a thermally conductive member is a method comprising: placing a first liquid and a second liquid in a two-component internal mixing type dispenser; applying a predetermined pressure to each of the first liquid and the second liquid to mix the first liquid and the second liquid at a predetermined ratio; and discharging a predetermined amount of the mixed liquid toward a substrate. Specifically, the production method comprises: the step of discharging the first liquid from the first liquid reservoir unit to the mixing unit; the step of discharging the second liquid from the second liquid reservoir unit to the mixing unit; a step of mixing the first liquid and the second liquid in a mixing unit to obtain a thermally conductive silicone composition (mixed liquid); The step of applying a thermally conductive silicone composition to a substrate; and A step of curing the thermally conductive silicone composition (mixed liquid) that has been applied to the substrate to obtain a thermally conductive member. Since the first liquid and the second liquid are used separately, there is no risk of agglomeration before the liquid under discharge pressure is discharged from the nozzle through the first liquid reservoir unit, the second liquid reservoir unit and the mixing unit.

[0082] Example: The present invention will be specifically described based on the examples, but the present invention is not limited to the following examples. The blending ratio of each component of the examples is shown in Table 1, and the evaluation results are shown in Table 3. The blending ratio of each component of the comparative example is shown in Table 2, and the evaluation results are shown in Table 4. The numerical values ​​of the blending ratios shown in Tables 1 and 2 are based on parts by mass. Note that the viscosity described herein refers to the value measured using a rotational viscometer (according to JIS K 7117-2) at 25°C and a shear rate of 10 / s.

[0083] The first liquid and the second liquid shown in the Examples and Comparative Examples were prepared. The first liquid and the second liquid are loaded into a dispenser (for example, a dispenser MPP-3 manufactured by Musashi Engineering Inc.) and discharged to the substrate. In the dispenser, the mixing ratio of the first liquid and the second liquid is set to a ratio of 1: 1. The discharge pressure of the dispenser is set to 0.5 MPa.

[0084] Mixed viscosity measurement method: The viscosity of the mixed liquid discharged from the dispenser was measured by a rotational viscometer (according to JIS K7117-2) at 25° C. and a shear rate of 10 / s. The viscosity is preferably 250 kPa or less.

[0085] Thermal conductivity measurement method: The mixed liquid discharged from the dispenser was compression molded into a cylindrical shape having a diameter of 30 mm and a height of 6 mm, and then cured at 23° C. for 24 hours to produce a columnar cured product. The thermal conductivity of the cured product was measured by a hot plate method according to ISO 22007-2 using a measuring device named TPS-500 manufactured by Kyoto Electronics Manufacturing Co., Ltd. A sensor was placed between two columnar cured products prepared as above, and the thermal conductivity was measured by the measuring device. The thermal conductivity is preferably 2.0 W / m·K or higher.

[0086] Hardness (ShoreOO) measurement method: The mixed liquid discharged from the dispenser was compression molded into a cylindrical shape having a diameter of 30 mm and a height of 6 mm, and then cured at 23° C. for 24 hours to produce a columnar cured product. The hardness of the cured product was measured using a hardness meter Shore OO manufactured by Teclock Co., Ltd., which is a machine based on the method measured according to JIS K 6253-3. ShoreOO is preferably between 30 and 80.

[0087] Agglomeration measurement method: Using a dispenser (MPP-3 manufactured by Musashi Engineering Inc.), a discharge volume of 0.03 cc of material and a waiting time of 0.20 seconds were repeated to discharge 1.0 kg of the material. The dispenser was then disassembled to check the occurrence of caking. The determination criteria A, B, and C were as follows. A: No aggregates were found. B: Aggregates of several millimeters in size were found, but no blockage in the flow path, C: Clogging occurs in the flow path.

[0088] Method for measuring initial discharge performance: Using a dispenser (MPP-3 manufactured by Musashi Engineering, Inc.), the discharge pressure was set to 0.5 MPa, and discharge was performed for 10 seconds. The amount of discharged material was checked to calculate the discharge amount per unit time. The measurement standards A, B, and C were as follows. A: 0.2cc / sec or greater, B: less than 0.2cc / sec and 0.1cc / sec or more, C: less than 0.1cc / second

[0089] Method for measuring the nature of disconnection: Using a dispenser filled with a thermally conductive silicone composition (MPP-3 manufactured by Musashi Engineering, Inc.), beads were applied to an area of ​​10 mm in width and 20 mm in length from a height of 2.5 mm above the aluminum plate. Beads were discharged onto 5 locations at 10-mm intervals, and the bead intervals at 4 locations were measured to calculate an average value. The closer the average value is to 10 mm, the better the wire breaking property, and the closer the average value is to 0 mm, the worse the wire breaking property. The evaluation results are divided into the following three categories. A (good): 6 mm or larger B (normal): 2 or more and less than 6 mm C (poor): less than 2mm

[0090] First Liquid: Based on the blending ratios in Tables 1 and 2, components (A), (B), (D), (E), (G) and (H) were each weighed and added together, and then kneaded at room temperature for 30 minutes using a planetary mixer. Component (F) was then added thereto and kneaded at room temperature for 15 minutes using a planetary mixer.

[0091] Second liquid: Based on the blending ratios in Tables 1 and 2, components (A), (B), (C), (D), (G) and (H) were each weighed and added together, and then kneaded at room temperature for 30 minutes using a planetary mixer. Component (F) was then added thereto and kneaded at room temperature for 15 minutes using a planetary mixer.

[0092] [Table 1]

[0093] [Table 2]

[0094] Components (A-1): Linear dimethyl polysiloxane having one alkenyl group at each end and a viscosity of 1,000 mPa·s (A-2): Linear dimethyl polysiloxane having one alkenyl group at each end and a viscosity of 500 mPa·s (A-3): Linear dimethyl polysiloxane having one alkenyl group at each end and a viscosity of 7,000 mPa·s (A-4): Linear dimethyl polysiloxane having one alkenyl group at each end and a viscosity of 100 mPa·s (B-1): Linear organopolysiloxane having a viscosity of 100,000 mPa·s (B-2): Linear organopolysiloxane having a viscosity of 200,000 mPa·s (B-3): Linear organopolysiloxane having a viscosity of 1,000,000 mPa·s (B-4): Linear organopolysiloxane having a viscosity of 10,000 mPa·s (C): dimethyl polysiloxane having 12 to 18 hydrogen atoms bonded to silicon atoms in the side chain and having a viscosity of 200 mPa·s (D-1): Linear dimethyl polysiloxane having no alkenyl group and a viscosity of 50 mPa·s (D-2): Linear dimethyl polysiloxane having no alkenyl group and a viscosity of 500 mPa·s (E): Platinum-divinyltetramethyldisiloxane complex (F-1): Amorphous zinc oxide (average particle size (D50): 0.6 μm, BET specific surface area: 4.1 m 2 / g) (F-2) Amorphous alumina (average particle size (D50): 3.9 μm, BET specific surface area: 0.9 m 2 / g) (F-3) Spherical alumina (average particle size (D50): 40 μm, BET specific surface area: 0.12 m 2 / g) (G): SILANE 25013VP, manufactured by Wacker Chemie AG (H): a linear diorganopolysiloxane having one silanol group at each end and a viscosity of 50 mPa·s

[0095] evaluate: Table 3 shows the evaluation results of Examples 1 to 15. In Example 1, a polymer having an appropriate viscosity is used as a base polymer, and a separation-inhibiting polymer having an appropriate viscosity is introduced. This formulation prevents agglomeration, and achieves good discharge performance, wire breaking properties, and high thermal conductivity. In Example 2, less separation inhibiting polymer was contained relative to Example 1. As a result, caking was reduced to a certain extent (to a degree not causing any problem in practical use), and the performance index was favorable. In Example 3, a polymer having a slightly higher viscosity is used as a base polymer, and a separation-inhibiting polymer having an appropriate viscosity is introduced. This formulation prevents agglomeration and achieves relatively good discharge performance, good wire breaking properties, and high thermal conductivity. In Example 4, a polymer having a slightly lower viscosity is used as a base polymer, and a separation-inhibiting polymer having an appropriate viscosity is introduced. This formulation prevents agglomeration to some extent, and achieves good discharge performance, good wire breaking properties, and high thermal conductivity. In Example 5, a polymer having an appropriate viscosity is used as a base polymer, and a separation-inhibiting polymer having a slightly higher viscosity is introduced. This formulation prevents agglomeration and achieves relatively good discharge performance, good wire breaking properties, and high thermal conductivity. In Example 6, a polymer having an appropriate viscosity is used as a base polymer, and a separation inhibiting polymer having a slightly lower viscosity is introduced. This formulation reduces agglomeration to some extent, and achieves good discharge performance, good wire breaking properties, and high thermal conductivity. In Example 7, a polymer having an appropriate viscosity is used as a base polymer, a separation suppressing polymer having an appropriate viscosity is introduced, and the amount of the base polymer is increased. This formulation prevents agglomeration and achieves relatively good discharge performance, good wire breaking properties, and high thermal conductivity. In Example 8, a polymer having an appropriate viscosity is used as the base polymer, a separation inhibiting polymer having an appropriate viscosity is introduced, and the amount of the base polymer is reduced. This formulation reduces agglomeration to some extent and achieves good discharge performance, good wire breaking properties, and high thermal conductivity. In Example 9, a polymer having an appropriate viscosity is used as a base polymer, a separation inhibiting polymer having an appropriate viscosity is introduced, and the amount of the separation inhibiting polymer is increased. This formulation prevents agglomeration and achieves relatively good discharge performance, good wire breaking properties, and high thermal conductivity. In Example 10, a polymer having an appropriate viscosity is used as a base polymer, a separation inhibiting polymer having an appropriate viscosity is introduced, and the amount of the separation inhibiting polymer is reduced. This formulation prevents agglomeration and achieves relatively good discharge performance, good wire breaking properties, and high thermal conductivity. In Example 11, a polymer having an appropriate viscosity was used as a base polymer, a separation suppressing polymer having an appropriate viscosity was introduced, and dimethyl oil having a slightly higher viscosity (500 mPa·s) was used to adjust the viscosity. This formulation prevented agglomeration and achieved relatively good discharge performance, good wire breaking properties, and high thermal conductivity. In Example 12, a polymer having an appropriate viscosity is used as a base polymer, a separation suppressing polymer having an appropriate viscosity is introduced, and the thermally conductive filler is adjusted to an amount of 85%. This formulation prevents agglomeration and achieves good discharge performance, good wire breaking properties, and high thermal conductivity. In Example 13, no base polymer is used in the second liquid, the amount of the base polymer introduced into the first liquid is increased, a polymer having an appropriate viscosity is used as the base polymer, and a separation-inhibiting polymer having an appropriate viscosity is introduced. This formulation prevents agglomeration and achieves relatively good discharge performance, good wire breaking properties, and high thermal conductivity. In Example 14, a polymer having an appropriate viscosity is used as a base polymer, a separation-inhibiting polymer having an appropriate viscosity is introduced, and the use of component (H) is omitted. The formulation prevents agglomeration and achieves good discharge performance and high thermal conductivity. However, not using component (H) results in poor disconnection properties. In Example 15, a polymer having an appropriate viscosity is used as the base polymer, a separation-inhibiting polymer having an appropriate viscosity is introduced, and the use of component (G) is omitted. The formulation prevents agglomeration and achieves good wire breaking properties and high thermal conductivity. However, not using component (G) results in less preferred discharge performance.

[0096] Table 4 shows the evaluation results of Comparative Examples 1 to 3. In Comparative Example 1, a polymer having a low viscosity was used as a base polymer, and a separation inhibiting polymer having an appropriate viscosity was introduced, resulting in the occurrence of agglomeration. However, the discharge performance was good and the thermal conductivity was high. In Comparative Example 2, a polymer having an appropriate viscosity was used as a base polymer, and a separation-inhibiting polymer having a high viscosity was introduced. Although this formulation prevented agglomeration, the discharge performance and wire breaking properties were poor. However, the thermal conductivity was high. In Comparative Example 3, a polymer with low viscosity was used as the base polymer, the filler amount was reduced, and a separation-inhibiting polymer with appropriate viscosity was introduced. This formulation prevented agglomeration and achieved good discharge performance and wire breaking properties. However, the thermal conductivity was low.

[0097] [Table 3]

[0098] [Table 4]

Claims

1. A thermally conductive silicone composition comprising: Component (A) which is an alkenyl group-containing diorganopolysiloxane having a viscosity of 500 mPa·s or more and 7,000 mPa·s or less at 25° C., in an amount of 1.0 parts by mass or more and 9.0 parts by mass or less; component (B) which is an organopolysiloxane having a viscosity of 10,000 mPa·s or more and 200,000 mPa·s or less at 25° C., in an amount of 0.05 parts by mass or more and 1.0 parts by mass or less; Component (C) which is an organopolysiloxane having two or more hydrosilyl groups in one molecule; Component (D) which is a diorganopolysiloxane having no alkenyl group and having a viscosity of 500 mPa·s or less at 25° C.; a component (E) which is an addition reaction catalyst; and Component (F), which is at least one or two or more thermally conductive fillers selected from metals, metal oxides, metal hydroxides, metal nitrides and metal carbides, wherein the content of component (F) is 85 parts by mass or more relative to 100 parts by mass of the bulk thermally conductive silicone composition, in: The thermally conductive silicone composition has a mixed viscosity of 250 Pa·s or less at 25° C.; and The organopolysiloxane of the component (C) is different from the components (A), (B) and (D). 2 . The thermally conductive silicone composition according to claim 1 , further comprising a component (H), wherein the component (H) is a polydimethylsiloxane containing a silanol group.

3. The thermally conductive silicone composition according to claim 1, wherein: The thermally conductive silicone composition is a two-component thermally conductive silicone composition comprising a first liquid and a second liquid separated from each other, wherein the first liquid and the second liquid are mixed when used; The first liquid contains the components (A), (B), (D), (E) and (F); and The second liquid contains the components (B), (C), (D) and (F), but does not contain the component (E). 4 . The thermally conductive silicone composition according to claim 3 , wherein the first liquid and / or the second liquid further contains a component (H), and the component (H) is a polydimethylsiloxane containing a silanol group.

5. The thermally conductive silicone composition according to claim 3 or 4, wherein in the thermally conductive silicone composition, in the following agglomeration evaluation, no aggregation is observed in any one of the first liquid, the second liquid, and the thermally conductive silicone composition: Evaluation of caking: Using the dispenser, a discharge volume of 0.03 cc of material and a waiting time of 0.20 seconds were repeated to discharge 1.0 kg of the material, and then the dispenser was disassembled to visually inspect for accumulation.

6. A method for producing a thermally conductive silicone composition, comprising: a first liquid production step of mixing 1.0 parts by mass or more and 9.0 parts by mass or less of component (A), 0.05 parts by mass or more and 1.0 parts by mass or less of component (B), component (D) and component (E), and then mixing component (F) to obtain a first liquid, wherein component (A) is an alkenyl group-containing diorganopolysiloxane having a viscosity of 500 mPa·s or more and 7,000 mPa·s or less at 25° C., component (B) is an organopolysiloxane having a viscosity of 10,000 mPa·s or more and 200,000 mPa·s or less at 25° C., component (D) is a non-functional diorganopolysiloxane having no alkenyl group and having a viscosity of 500 mPa·s or less at 25° C., component (E) is an addition reaction catalyst, and component (F) is at least one or two or more thermally conductive fillers selected from metals, metal oxides, metal hydroxides, metal nitrides and metal carbides; and a second liquid production step of mixing a component (B) in an amount of 0.05 parts by mass or more and 1.0 parts by mass or less, a component (C), a component (D) and a component (F) to obtain a second liquid, wherein the component (B) is an organopolysiloxane having a viscosity of 10,000 mPas or more and 200,000 mPas or less at 25° C., the component (C) is an organopolysiloxane having two or more hydrosilyl groups in one molecule, the component (D) is a non-functional diorganopolysiloxane having no alkenyl group and having a viscosity of 500 mPa·s or less at 25° C., and the component (F) is at least one or two or more thermally conductive fillers selected from metals, metal oxides, metal hydroxides, metal nitrides and metal carbides, wherein the organopolysiloxane of the component (C) is different from the components (A), (B) and (D).

7. The method for producing a thermally conductive silicone composition according to claim 6, wherein before adding the component (F) in the second liquid production step, the component (A) in an amount of 1.0 parts by mass or more and 9.0 parts by mass or less is mixed with other components, the component (A) being an alkenyl group-containing diorganopolysiloxane having a viscosity of 500 mPa·s or more and 7,000 mPa·s or less at 25°C.

8. The method for producing a thermally conductive silicone composition according to claim 6 or 7, wherein the component (H) is mixed with other components before adding the component (F) in the first liquid production step and / or the second liquid production step, and the component (H) is a polydimethylsiloxane containing a silanol group.

9. A method for producing a thermally conductive component, comprising: a step of discharging the first liquid according to claim 3 from the first liquid storage unit to the mixing unit; a step of discharging the second liquid according to claim 3 from the second liquid storage unit to the mixing unit; a step of mixing the first liquid and the second liquid in the mixing unit to obtain a thermally conductive silicone composition; The step of discharging and applying the thermally conductive silicone composition onto a substrate; as well as A step of curing the thermally conductive silicone composition applied to the substrate to obtain a thermally conductive member.

10. A method for producing a heat dissipation member, the heat dissipation member comprising: A substrate and a thermally conductive member provided on a surface of the substrate, the thermally conductive member being any one of a thermally conductive member obtained by curing the thermally conductive silicone composition according to claim 1 or 2, a thermally conductive member obtained by curing the thermally conductive silicone composition obtained by the method for producing a thermally conductive silicone composition according to claim 6 or 7, and a thermally conductive member obtained by the method for producing a thermally conductive element according to claim 9. 11 . A method for producing an electric device or an electronic device including a heat dissipation member, wherein the heat dissipation member is a heat dissipation member obtained by the method for producing a heat dissipation member according to claim 10 .

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