Polysiloxane composition

Abstract

This invention relates to a low-viscosity silicone composition having high thermal conductivity. It contains vinyl silicone oil, a thermal conductor, and a treatment agent. This composition can be used in the art of thermally conductive materials.

Description

[Technical Field]

[0001] The present invention relates to the technical field of thermally conductive silicone compositions. [Background technology]

[0002] Example 1 of Korean Published Patent No. 2021-0047752 discloses a thermally conductive composition comprising a silicone resin, alumina trihydrate (ATH), and isopropyltrioleyl titanate. Specifically, 16% by mass of silicone resin and 84% by mass of alumina trihydrate (ATH) were mixed. The alumina trihydrate consisted of a mixture of particles with a particle size of 5 μm and particles with a particle size of 50 μm, added in a mass ratio of 40:60. Next, 0.5 parts by mass of isopropyltrioleyl titanate was added to 100 parts by mass of alumina trihydrate as a base, and the mixture was uniformly mixed in a planetary mixer to obtain a thermally conductive composition for a heat dissipation pad.

[0003] Example 1 of Korean Registered Patent Publication No. 10-2218858 discloses a thermally conductive gap filler comprising an oil, a thermally conductive filler, a dispersant, and an antioxidant (mixing mass ratio: 8:108:1:0.3). The oil is a synthetic polyalphaolefin oil. The dispersant is a mixture of an organotitanium compound (bis(oleato-O)bis(propane-2-orato)titanium) and oleic acid (mixing mass ratio: organotitanium compound:oleic acid = 40-50:40-50).

[0004] Chinese Patent No. 1264932 discloses a method for modifying mica filler with titanate. A titanate solution is prepared using acetone as a diluent. The titanate solution and filler are mixed under high-speed stirring for 10 to 30 minutes, and the temperature is controlled to below 90°C.

[0005] Chinese Patent Application Publication No. 106118136 discloses a method for treating calcium carbonate with titanate and stearic acid. Example 3 discloses that calcium carbonate was first treated with titanate for 8 minutes, and then the filler was modified with stearic acid at 120°C for 15 minutes. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Korean Published Patent Publication No. 2021-0047752 [Patent Document 2] Korean Registered Patent No. 10-2218858 [Patent Document 3] Chinese Patent No. 1264932 Specification [Patent Document 4] Chinese Patent Application Publication No. 106118136 Specification [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] The object of the present invention is to obtain a treatment filler and a treatment method that can satisfy the requirement for a lower viscosity thermally conductive composition. Furthermore, the present invention aims to obtain a composition that simultaneously has low viscosity and high thermal conductivity at a high filler level. [Means for solving the problem]

[0008] A processed filler (CE) obtained by mixing component (C) a thermally conductive filler and component (E-2), Component (E-2) is given by the following general formula (2): (R 4 COO) m -Ti-OR 6 4-m (2) (In the formula, R 4 It is a hydrocarbon group containing 6 to 30 carbon atoms, and contains at least one carbon-carbon unsaturated group. Preferably, the number of carbon atoms is 6 to 24, more preferably 10 to 20, and even more preferably 16 to 20; preferably containing 1 to 3 ethylenic bonds, preferably containing 1 to 2 ethylenic bonds, and more preferably containing 1 ethylenic bond. R4 The COO⁻ is preferably an oleic acid group; R 6 is a hydrocarbon group containing 1 to 5 carbon atoms, preferably 1 to 4 carbon atoms, more preferably methyl, ethyl, ethylene, allyl, propyl, isopropyl, butyl, isobutyl; even more preferably propyl, isopropyl; m is 1 or 2, preferably m is 2) It is a titanate compound represented by and / or an oligomer with a polymerization degree of 2 to 5, The mixing conditions are 90 to 160 °C for 20 minutes or more; preferably 100 to 140 °C for 35 to 70 minutes; preferably 100 to 140 °C for 40 to 70 minutes; preferably 100 to 130 °C for 30 to 65 minutes; more preferably 115 to 125 °C for 35 to 60 minutes; even more preferably 118 to 122 °C for 35 to 60 minutes, particularly preferred temperatures are 95 °C, 98 °C, 105 °C, 110 °C, 112 °C, 116 °C, 128 °C, and particularly preferred times are 32 minutes, 38 minutes, 40 minutes, 42 minutes, 45 minutes, 50 minutes, 52 minutes, 55 minutes.

[0009] In the above-mentioned treated filler (CE), component (E-2) is used in an amount of 0.05 to 2.00% by mass, preferably 0.10 to 1.00% by mass, more preferably 0.15 to 0.60% by mass, even more preferably 0.20 to 0.45% by mass, calculated with the amount of the heat-conductive filler in component (C) as 100% by mass.

[0010] In the above-mentioned treated filler (CE), component (E-2) is one or more selected from the group consisting of diethyldioleoyl titanate, triethyloleoyl titanate, di-n-propyldioleoyl titanate, tri-n-propyloleoyl titanate, diisopropyldioleoyl titanate, triisopropyloleoyl titanate, dibutyldioleoyl titanate, tributyloleoyl titanate, preferably one or more selected from the group consisting of diisopropyldioleoyl titanate, triisopropyloleoyl titanate, and more preferably diisopropyldioleoyl titanate.

[0011] A method for treating component (C) a thermally conductive filler, This includes mixing component (C) with component (E-2), The mixing conditions are 90-160°C for 20 minutes or more; preferably 100-140°C for 35-70 minutes; preferably 100-140°C for 40-70 minutes; preferably 100-130°C for 30-65 minutes; more preferably 115-125°C for 35-60 minutes; even more preferably 118-122°C for 35-60 minutes, particularly 40, 45, 50, and 55 minutes.

[0012] According to the above method, under stirring conditions, component (C) thermally conductive filler is first subjected to nitrogen treatment, and then component (E-2) is added.

[0013] According to the above method, the nitrogen inactivation treatment time is 5 minutes or more, preferably 5 to 60 minutes, more preferably 5 to 30 minutes, and even more preferably 5 to 15 minutes.

[0014] According to the method described above, the temperature for nitrogen deactivation treatment is room temperature.

[0015] According to the method described above, component (E-2) was applied by spraying and / or atomization.

[0016] In the above-mentioned processed filler (CE), the amount of solvent used in the mixing step is calculated based on 100% by mass of the thermally conductive filler component (C), and is preferably 0.5% by mass or less, more preferably 0.2% by mass or less, and even more preferably 0.1% by mass or less.

[0017] The solvent is selected from methanol, ethanol, isopropanol, butanol, acetone, ethyl acetate, formaldehyde, toluene, phthalates, mineral oil, vegetable oil, animal oil, decamethylcyclopentasiloxane, octamethylcyclotetrasiloxane, and polydimethylsiloxane with a viscosity of less than 5 mPa·s.

[0018] The present invention Component (A) is an organopolysiloxane, preferably component (A-1) is an organopolysiloxane having two or more alkenyl groups per molecule; Component (B) is an organohydrogenpolysiloxane having two or more hydrogen atoms directly bonded to a silicon atom, wherein the number of moles of hydrogen atoms directly bonded to a silicon atom in component (B) is 0.1 to 5.0 times the number of moles of alkenyl groups derived from component (A-1); A processed filler (CE), wherein the filling amount of the processed filler (CE) is 0.80 or more, preferably 0.84 or more, preferably 0.88 or more, preferably 0.89 or more, and preferably 0.90 or more; Component (D) is an arbitrary component (D) having a platinum group metal element content of 0.1 to 1,000 ppm by mass relative to component (A-1), which is a platinum group metal-based curing catalyst. The present invention provides a composition containing the following:

[0019] Use of the above compositions in the field of caulking agents. Use of the above compositions in the field of potting.

[0020] In electronics, potting is the process of filling a complete electronic assembly with a solid or gelatinous compound to eliminate gaseous phenomena, withstand shocks and vibrations, and remove water, moisture, and corrosive substances.

[0021] In the above composition, if the thermal conductivity at 25°C according to DIN53019 is greater than 2.5 W / mk, preferably greater than 2.8 W / mk, and more preferably greater than 3.0 W / mk, and the shear rate is 1 (1 / s), then the initial viscosity of the mixed composition is 1000 Pa·s or less, preferably 500 Pa·s or less, more preferably 400 Pa·s or less, and even more preferably 300 Pa·s or less. In the above composition, if the thermal conductivity at 25°C according to DIN53019 is greater than 2.5 W / mk, preferably greater than 2.8 W / mk, and more preferably greater than 3.0 W / mk, and the shear rate is 10(1 / s), then the initial viscosity of the composition after mixing is 500 Pa·s or less, preferably 250 Pa·s or less, more preferably 200 Pa·s or less, even more preferably 150 Pa·s or less, and even more preferably 130 Pa·s or less.

[0022] A thermally conductive member comprising the above composition or a cured product thereof. A heat dissipation structure including the above-mentioned heat-conducting member. A heat dissipation structure including a heat dissipation component based on the above composition or its cured product, or a circuit board on which the heat dissipation component is mounted. The heat dissipation structure described above is an electrical / electronic device.

[0023] In this invention, the filling rate is calculated as the total amount of thermally conductive filler divided by the total mass of the composition. Generally, a filling rate of 0.88 or higher is considered a high filling rate.

[0024] In the above composition or method, component (C) thermally conductive filler is (C-1) aluminum hydroxide, with an average particle size of 0.1 μm or more and 4 μm or less, in a quantity of 10 to 25% by mass. For example, the average particle sizes of (C-1) are 0.8, 1.0, 1.2, 1.4, 1.6, 1.8, 2.0, 2.2, 2.4, 2.6, and 2.8 μm, and the content is 14% by mass, 16% by mass, 18% by mass, 20% by mass, 22% by mass, and 24% by mass; It is aluminum hydroxide (C-2) with an average particle diameter of 4 μm or more and 20 μm or less, and 18 to 37% by mass. For example, the average particle diameter of (C-2) is 6, 8, 10, 12, 14, 16, 18 μm, and the content is 20% by mass, 22% by mass, 24% by mass, 26% by mass, 28% by mass, 30% by mass, 32% by mass, 34% by mass, 36% by mass. It is aluminum hydroxide (C-3) with an average particle diameter of 80 μm or more and 100 μm or less, and 48 to 65% by mass. For example, the average particle diameter of (C-3) is 82, 84, 86, 88, 90, 92, 94, 96, 98 μm, and the content is 50% by mass, 52% by mass, 54% by mass, 56% by mass, 58% by mass, 60% by mass, 62% by mass, 64% by mass. It includes, and in (C-1), (C-2) and (C-3), the component (C) in the composition is calculated as 100% by mass.

[0025] In the above composition, the total amount of all aluminum hydroxides is calculated based on 100% by mass of the total amount of the thermal conductivity filler, and is greater than 95% by mass, preferably greater than 99% by mass, and more preferably greater than 99.9% by mass.

[0026] In the above composition, the total amount of all aluminum hydroxides is calculated based on 100% by mass of the total amount of the filler, and is greater than 95% by mass, preferably greater than 99% by mass, and more preferably greater than 99.9% by mass.

[0027] In the above composition, the density of the composition is 2.4 g / cm 3 or less, preferably 2.2 g / cm 3 or less, and more preferably 2.1 g / cm 3 or less.

[0028] In the above composition, the thermal conductivity of the composition is 3.1 W / mK or more, preferably 3.2 W / mK or more.

[0029] In the above composition, (C-1), (C-2), and (C-3) aluminum hydroxide are all amorphous. In the above composition, the amount of spherical filler is less than 10% by mass, preferably less than 1% by mass, calculated with the mass of the composition being 100% by mass. In the above composition, the amount of spherical alumina is less than 10% by mass, preferably less than 1% by mass, based on 100% by mass of the total weight of the composition.

[0030] In the above composition, the Al(OH)3 content in (C-1), (C-2), and (C-3) aluminum hydroxide is 99.1% by mass or more, preferably 99.5% by mass or more.

[0031] In the above composition, the Na2O content in (C-1), (C-2), and (C-3) aluminum hydroxide is 0.1% by mass or less, and preferably the total content of water-soluble Na2O and lattice-state Na2O is 0.1% by mass or less.

[0032] In the above composition, component (C) is 10-20% by mass of (C-1) aluminum hydroxide with an average particle size of 0.5 μm or more and 3 μm or less. (C-2) aluminum hydroxide, with an average particle size of 7 μm to 15 μm, 20-35% by mass, 50-60% by mass of (C-3) aluminum hydroxide with an average particle size of 85 μm to 95 μm. In (C-1), (C-2), and (C-3), component (C) is calculated as 100% by mass.

[0033] In the above composition, the surface-treated aluminum hydroxide is calculated as 90% by mass, preferably 95% by mass, and more preferably 99% by mass, with component (C) being 100% by mass.

[0034] In the above composition, the mass ratio of (C-1) / (C-3) is 0.2 to 0.4, preferably 0.22 to 0.38, for example 0.25, 0.27, 0.29, 0.31, 0.33, or 0.35. In the above composition, the mass ratio of (C-2) / (C-3) is 0.2 to 0.8, preferably 0.25 to 0.75, for example 0.3, 0.4, 0.5, 0.6, or 0.7.

[0035] In the above composition, the ratio of (C-2) / (C-1) average particle size is 8 to 12, preferably 9 to 11, more preferably 9.5 to 10.5, for example 9.6, 9.8, 10.0, 10.2, or 10.4. In the above composition, the ratio of (C-3) / (C-1) average particle size is 70 to 120, preferably 75 to 100, more preferably 80 to 99, for example 82, 84, 86, 88, 90, 92, 94, 96, 98. In the above composition, the ratio of (C-3) / (C-2) average particle size is 7.0 to 12.0, preferably 7.5 to 10, more preferably 8.0 to 9.9, for example 8.2, 8.4, 8.6, 8.8, 9.0, 9.2, 9.4, 9.6, and 9.8.

[0036] In the above composition, component (C) is (C-5) alumina with an average particle size of 1 μm or more and 10 μm or less, 20-50% by mass, (C-6) alumina with an average particle size of 30 μm to 95 μm, 50-80% by mass. This includes, where component (C) is calculated as 100% by mass.

[0037] The definition of average particle diameter refers to the volume-based value of the cumulative average particle diameter (D50 median diameter) measured with a BECKMAN COULTER LS 13 320 particle size distribution analyzer.

[0038] (C-1) The aluminum hydroxide sample is prepared by the solution method. 0.1 g of the (C-1) sample is placed in 10 ml of absolute ethanol and dispersed using ultrasound (100 w). Stirring is performed for 2 minutes to ensure complete dispersion of the aluminum hydroxide. Two to three drops of the sample solution are taken and placed in the sample cell of the particle size distribution analyzer. (C-2) and (C-3) aluminum hydroxide samples (or other thermally conductive fillers with an average particle size of 7 μm or more) are prepared by the dry powder method, and an appropriate amount of the dried sample is placed in the loading cylinder of the particle size analyzer. The loaded cylinder is then inserted into the detection port of the instrument.

[0039] In the present invention, the particle size distribution of the component in component (C) is unimodal, or its particle size satisfies a unimodal or nearly unimodal particle size distribution. In the present invention, a nearly unimodal particle size distribution means that, although there may be two or more peaks in the volume integral diagram of the measured sample, the volume integral area of ​​the main peak accounts for more than 80%, preferably more than 85%, more preferably more than 90%, and even more preferably more than 95% of the total volume integral area.

[0040] Spherical fillers are filler materials that are generally spherical in shape and are obtained from amorphous fillers that have been treated by chemical and / or physical treatments (including heat treatment).

[0041] Spherical alumina is a product obtained by heat-treating amorphous alumina, and its external shape is generally spherical.

[0042] Component (E-1) may be a treatment agent for component (C), where (E-1) is an alkoxysilane compound represented by the following formula (1); R 1 a R 2 b Si(OR 3 ) 4-a-b (1) In the formula, each R 1Each R independently represents an alkyl group having 1 to 24 carbon atoms, preferably 6 to 24 carbon atoms, more preferably 12 to 18 carbon atoms, and each R 2 Each R independently represents an unsubstituted or substituted hydrocarbon group having 1 to 10 carbon atoms, preferably methyl or ethyl, and each R 3 This independently represents an alkyl group having 1 to 6 carbon atoms, preferably methyl or ethyl. a represents an integer between 1 and 3, and b represents an integer between 0 and 2, where a + b is an integer between 1 and 3.

[0043] In the present invention, the mass ratio of component (C) to component (E-1) is 100 to 800, preferably 200 to 500, and more preferably 200 to 400. [Effects of the Invention]

[0044] As described above, the thermally conductive silicone composition of the present invention involves precisely adjusting and compounding a silicone composition containing a specific organopolysiloxane, a hydrogenpolysiloxane, and a thermally conductive filler so that the thermally conductive filler is densely packed into the substrate. This results in a thermal conductivity of 3.1 W / m·K or higher and a density of 2.4 g / cm³. 3 A thermally conductive silicone composition can be provided that yields a thermally conductive silicone cured product with high thermal conductivity, low viscosity, and light weight. Such a thermally conductive silicone cured product is particularly useful as a thermal conductive material interposed at the interface between the heat dissipation surface of a heat-generating electronic component and a heat dissipation member such as a heat sink or circuit board, for cooling electronic components by thermal conduction.

[0045] As described above, there is a need for the development of thermally conductive silicone cured products (thermally conductive resin molded products) that have high thermal conductivity, low viscosity, and are lightweight, as well as thermally conductive silicone compositions for forming these cured products.

[0046] As a result of diligent research to achieve the above objective, the inventors have precisely prepared and formulated a silicone composition containing a specific organopolysiloxane, a hydrogenpolysiloxane, and a thermally conductive filler, and by densely filling the substrate with the thermally conductive filler, a thermal conductivity of 3.1 W / m·K or higher and a density of 2.4 g / cm³ are achieved. 3 We discovered that a thermally conductive silicone cured product with high thermal conductivity, low viscosity, and lightweight properties can be obtained. This finding led to the completion of the present invention.

[0047] Specifically, the present invention is a thermally conductive silicone composition comprising the following:

[0048] Component (A): organopolysiloxane, preferably component (A-1): alkenyl group-containing organopolysiloxane.

[0049] Component (A) is an organopolysiloxane. Component (A) functions as the main component of the composition of the present invention. Generally, the main chain portion is usually composed of repeating basic diorganosiloxane units, but this molecular structure may include partially branched or cyclic structures. Nevertheless, from the viewpoint of the physical properties of the cured product, such as mechanical strength, the main chain is preferably a linear diorganopolysiloxane. Component (A-1) is an alkenyl group-containing organopolysiloxane having two or more silicon atom-bonded alkenyl groups per molecule. Component (A-1) functions as the main component of the composition of the present invention. Generally, the main chain portion is usually composed of repeating basic diorganosiloxane units, but this molecular structure may include a partially branched structure or a cyclic structure. Nevertheless, from the viewpoint of the physical properties of the cured product, such as mechanical strength, the main chain is preferably a linear diorganopolysiloxane.

[0050] Functional groups bonded to silicon atoms include unsubstituted or substituted monovalent hydrocarbon groups. Specific examples include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl, and dodecyl groups; cycloalkyl groups such as cyclopentyl, cyclohexyl, and cycloheptyl groups; aryl groups such as phenyl, tolyl, xylyl, naphthyl, and biphenylyl groups; aralkyl groups such as benzyl, phenylethyl, phenylpropyl, and methylbenzyl groups; and groups obtained by substituting some or all of the hydrogen atoms bonded to the carbon atoms of these groups with halogen atoms such as cyano, fluorine, chlorine, and bromine. Examples of such substituents include chloromethyl, 2-bromoethyl, 3-chloropropyl, 3,3,3-trifluoropropyl, chlorophenyl, fluorophenyl, cyanoethyl, and 3,3,4,4,5,5,6,6,6-nonafluorohexyl groups. Typical examples of functional groups include those having 1 to 10 carbon atoms, and particularly typical examples include those having 1 to 6 carbon atoms. Preferred examples of functional groups include unsubstituted or substituted alkyl groups having 1 to 3 carbon atoms, such as methyl, ethyl, propyl, chloromethyl, bromoethyl, 3,3,3-trifluoropropyl, and cyanoethyl groups; and unsubstituted or substituted phenyl groups, such as phenyl, chlorophenyl, and fluorophenyl groups. Furthermore, the functional groups bonded to the silicon atom do not all need to be the same. Furthermore, alkenyl groups typically have about 2 to 8 carbon atoms. Specific examples include vinyl groups, allyl groups, propenyl groups, isopropenyl groups, butenyl groups, hexenyl groups, and cyclohexenyl groups. Among these, lower alkenyl groups such as vinyl and allyl groups are preferred, with vinyl groups being particularly preferred. It is necessary that there are two or more alkenyl groups in one molecule, and in order to give the resulting cured product desirable flexibility, it is preferable that each alkenyl group is bonded only to the silicon atom at the end of the molecular chain. Component (A) organopolysiloxane has a viscosity at 25°C, preferably in the range of 10 to 100,000 mPa·s, particularly preferably 50 to 50,000 mPa·s, more preferably 50 to 20,000 mPa·s, and even more preferably 50 to 2,000 mPa·s. Component (A) organopolysiloxane is preferably polydimethylsiloxane. Component (A-1): The alkenyl group-containing organopolysiloxane has a viscosity at 25°C, preferably in the range of 10 to 100,000 mPa·s, particularly preferably 50 to 10,000 mPa·s, more preferably 50 to 1,000 mPa·s, and even more preferably 50 to 200 mPa·s. When the viscosity is 10 mPa·s or higher, the resulting composition has desirable storage stability. On the other hand, when the viscosity is 100,000 mPa·s or lower, the resulting composition has desirable extensibility. Component (A-1) the alkenyl group-containing organopolysiloxane is preferably a vinyl-terminated polydimethylsiloxane.

[0051] The organopolysiloxane of component (A) may be used alone, or two or more types with different viscosities may be used in combination. The alkenyl group-containing organopolysiloxane of component (A-1) may be used alone, or two or more types with different viscosities may be used in combination.

[0052] Optional component (B): Organohydrogenpolysiloxane

[0053] Component (B) is an organohydrogenpolysiloxane having at least two, preferably 2 to 100, hydrogen atoms (Si-H groups) directly bonded to silicon atoms per molecule. This component acts as a crosslinking agent for component (A-1). Specifically, through a hydrosilylation reaction promoted by a platinum group metal hardening catalyst, which will be described later as component (D), the Si-H groups in component (B) are added to the alkenyl groups in component (A-1), thereby forming a three-dimensional network structure with a crosslinking structure. Note that if the number of Si-H groups per molecule in component (B) is less than two, hardening will not occur. The organohydrogenpolysiloxane used can be, but is not limited to, the average structural formula (4) below: [ka]

[0054] In the formula, each R' independently represents an unsubstituted or substituted monovalent hydrocarbon group that does not contain a hydrogen atom or an aliphatic unsaturated bond, and at least two R' are hydrogen atoms; e represents an integer of 1 or more.

[0055] Examples of unsubstituted or substituted monovalent hydrocarbon groups in formula (4) that do not contain an aliphatic unsaturated bond as R' other than hydrogen include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl, and dodecyl; cycloalkyl groups such as cyclopentyl, cyclohexyl, and cycloheptyl; aryl groups such as phenyl, tolyl, xylyl, naphthyl, and biphenylyl; aralkyl groups such as benzyl, phenylethyl, phenylpropyl, and methylbenzyl; and groups obtained by substituting some or all of the hydrogen atoms bonded to the carbon atoms of these groups with halogen atoms such as cyano, fluorine, chlorine, and bromine. Examples of such substituents include chloromethyl, 2-bromoethyl, 3-chloropropyl, 3,3,3-trifluoropropyl, chlorophenyl, fluorophenyl, cyanoethyl, and 3,3,4,4,5,5,6,6,6-nonafluorohexyl groups. Typical examples of monovalent hydrocarbon groups include those having 1 to 10 carbon atoms, with particularly typical examples having 1 to 6 carbon atoms. Preferred examples of monovalent hydrocarbon groups include unsubstituted or substituted alkyl groups having 1 to 3 carbon atoms, such as methyl, ethyl, propyl, chloromethyl, bromoethyl, 3,3,3-trifluoropropyl, and cyanoethyl groups; and unsubstituted or substituted phenyl groups, such as phenyl, chlorophenyl, and fluorophenyl groups. Furthermore, it is not necessary for all R's to be the same.

[0056] The amount of component (B) is added such that, for every mole of alkenyl groups derived from component (A-1), the amount of Si-H groups derived from component (B) is 0.1 to 5.0 moles (i.e., the number of moles of hydrogen atoms directly bonded to silicon atoms is 0.1 to 5.0 times the number of moles of alkenyl groups derived from component (A-1)), preferably 0.3 to 2.0 moles, and more preferably 0.5 to 1.0 moles. If the amount of Si-H groups derived from component (B) is less than 0.1 moles per mole of alkenyl groups derived from component (A-1), hardening will not occur, or the strength of the hardened product will be insufficient, and in some cases the shape of the molded product may not be maintained, making it unhandling. On the other hand, if the amount exceeds 5.0 moles, the hardened product may lose its flexibility and become brittle.

[0057] The organopolysiloxane in component (B) may be used alone, or two or more types with different viscosities may be used in combination.

[0058] In the above composition, component (B) may include (B-1) and (B-2).

[0059] Component (B-1), the organic hydrogen-containing polysiloxane, is an organic hydrogen-containing polysiloxane having at least 3, preferably 3 to 100, hydrogen atoms (Si-H groups) directly bonded to silicon atoms in one molecule, with a hydrogen content of 0.5 to 4 mmol / g, preferably 0.8 to 3 mmol / g, more preferably 1.1 to 2.7 mmol / g, and even more preferably 1.5 to 2.3 mmol / g.

[0060] Component (B-2), the organic hydrogen-containing polysiloxane, is an organic hydrogen-containing polysiloxane having two hydrogen atoms (Si-H groups) directly bonded to a silicon atom in one molecule, with a hydrogen content of 0.01 to 1.5 mmol / g, preferably 0.1 to 1.2 mmol / g, more preferably 0.3 to 1.0 mmol / g, and even more preferably 0.4 to 0.8 mmol / g.

[0061] In the above composition, component (B) comprises (B-1) and (B-2), and the amount of component (B-1) is 0.5 to 3% by mass, preferably 1.5 to 2.5% by mass, calculated with component (A-1) being 100% by mass.

[0062] In the above composition, component (B) comprises (B-1) and (B-2), and the amount of component (B-2) is 10 to 50% by mass, preferably 20 to 40% by mass, calculated with component (A-1) being 100% by mass.

[0063] Ingredient (C): Thermally conductive filler

[0064] Thermally conductive fillers generally do not contain fumed silica or precipitated silica. In the composition of the present invention, the content of fumed silica and / or precipitated silica is less than 1% by mass, preferably less than 0.1% by mass, calculated based on 100% by mass of the total composition.

[0065] The thermally conductive filler is not particularly limited. Generally, materials considered thermally conductive fillers, such as non-magnetic metals like copper and aluminum, metal oxides like alumina, silica, magnesia, colcothar, beryllia, titania, and zirconia, metal nitrides like aluminum nitride, silicon nitride, and boron nitride, metal hydroxides like aluminum hydroxide and magnesium hydroxide, artificial diamond, and silicon carbide can be used. Furthermore, particle sizes of 0.1 to 200 μm can be employed. One or more of these materials may be used as a composite.

[0066] Preferably, component (C) thermally conductive filler is a metal oxide and / or metal hydroxide.

[0067] Component (C) must be blended in an amount of 800 to 4,000 parts by mass, preferably 900 to 2,000 parts by mass, and more preferably 900 to 1,500 parts by mass, per 100 parts by mass of component (A). If the blending amount is less than 800 parts by mass, the resulting composition will have poor thermal conductivity. If the blending amount exceeds 2,000 parts by mass, the kneading operability will be impaired, and the cured product will become extremely brittle.

[0068] Optional component (D): Platinum group metal curing catalyst

[0069] Component (D) is a platinum group metal-based hardening catalyst and is not particularly limited as long as it is a catalyst that promotes the addition reaction between the alkenyl group derived from component (A-1) and the Si-H group derived from component (B). Examples of catalysts include known catalysts used in hydrosilylation reactions. Specific examples include elemental platinum group metals such as platinum (including platinum black), rhodium, and palladium; platinum chloride, chloroplatinic acid, chloroplatinate salts, for example, H2PtCl4.nH2O, H2PtCl6.nH2O, NaHPtCl6.nH2O, KHPtCl6.nH2O, Na2PtCl6.nH2O, K2PtCl4.nH2O, PtCl4.nH2O, PtCl2, Na2HPtCl4.nH2O (wherein n is an integer from 0 to 6, preferably 0 or 6); alcohol-modified chloroplatinic acid (US 3,220,9 See Specification No. 72); complexes of chloroplatinic acid and olefins (see U.S. Patent Nos. 3,159,662, and 3,775,452); platinum group metals such as platinum black and palladium supported on a carrier such as alumina, silica, or carbon; rhodium-olefin complexes, chlorotris(triphenylphosphine)rhodium (Wilkinson catalyst); complexes of platinum chloride, chloroplatinic acid or chloroplatinate with vinyl group-containing siloxanes, especially vinyl group-free cyclic siloxanes; etc. Component (D) is used in an amount such that the content of platinum group metal elements is 0.1 to 1,000 ppm by mass relative to component (A-1). If the content is less than 0.1 ppm, sufficient catalytic activity cannot be obtained. If the content exceeds 1,000 ppm, not only does the cost increase, but the effect of promoting the addition reaction cannot be enhanced, and the catalyst remaining in the cured product may reduce the insulating properties.

[0070] Ingredient (E-1): Formula (1) R 1 a R 2 b Si(OR 3 ) 4-a-b (1) It is an alkoxysilane compound represented by, In the formula, each R 1Each R independently represents an alkyl group having 1 to 24 carbon atoms, preferably 6 to 24 carbon atoms, more preferably 12 to 18 carbon atoms, and each R 2 Each R independently represents an unsubstituted or substituted hydrocarbon group having 1 to 10 carbon atoms, preferably methyl or ethyl, and each R 3 A independently represents an alkyl group having 1 to 6 carbon atoms, a represents an integer from 1 to 3, and b represents an integer from 0 to 2, where a + b is an integer from 1 to 3.

[0071] R in equation (1) 1 Examples of alkyl groups represented by R include hexyl, octyl, nonyl, decyl, dodecyl, and tetradecyl groups. 1 When the number of carbon atoms in the alkyl group represented by satisfies the range of 6 to 15, the wettability of component (A) is sufficiently improved, resulting in excellent handling properties. Furthermore, low-temperature characteristics are also good. R 2Examples of unsubstituted or substituted hydrocarbon groups represented by include alkyl groups such as methyl, ethyl, vinyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl, and dodecyl; cycloalkyl groups such as cyclopentyl, cyclohexyl, and cycloheptyl; aryl groups such as phenyl, tolyl, xylyl, naphthyl, and biphenylyl; aralkyl groups such as benzyl, phenylethyl, phenylpropyl, and methylbenzyl; and groups obtained by substituting some or all of the hydrogen atoms bonded to the carbon atoms of these groups with halogen atoms such as cyano, fluorine, chlorine, and bromine. Examples of such substituents include chloromethyl group, 2-bromoethyl group, 3-chloropropyl group, 3,3,3-trifluoropropyl group, chlorophenyl group, fluorophenyl group, cyanoethyl group, and 3,3,4,4,5,5,6,6,6-nonafluorohexyl group. Typical examples of monovalent hydrocarbon groups include those having 1 to 10 carbon atoms, and particularly typical examples of monovalent hydrocarbon groups include those having 1 to 6 carbon atoms. Preferred examples of monovalent hydrocarbon groups include unsubstituted or substituted alkyl groups having 1 to 3 carbon atoms, such as methyl group, ethyl group, propyl group, chloromethyl group, bromoethyl group, 3,3,3-trifluoropropyl group, and cyanoethyl group; and unsubstituted or substituted phenyl groups, such as phenyl group, chlorophenyl group, and fluorophenyl group.

[0072] R 3 Examples of these groups include methyl, ethyl, propyl, butyl, and hexyl groups. Furthermore, a and b are not particularly limited as long as a is an integer from 1 to 3, b is an integer from 0 to 2, and a+b is an integer from 1 to 3. Preferably, a is 1 and b is 0.

[0073] Component (E-1) is preferably an alkoxysilane containing a C6-18 long-chain alkyl group; more preferably a trialkoxysilane containing a C6-18 long-chain alkyl group; even more preferably hexadecyltrimethoxysilane, hexadecyltriethoxysilane, tetradecyltrimethoxysilane, tetradecyltriethoxysilane, dodecyltrimethoxysilane, or dodecyltriethoxysilane.

[0074] The amount of component (E-1) is less than 1% by mass, more preferably less than 0.5% by mass, and even more preferably less than 0.1% by mass, relative to 100% by mass of component (C).

[0075] Component (F): Characterizing agent

[0076] As component (F), it is possible to add organopolysiloxanes represented by the following formula (3) with a viscosity of 10 to 100,000 mPa·s at 25°C: [ka]

[0077] In the formula, each R 5 'd' independently represents a monovalent hydrocarbon group having 1 to 10 carbon atoms and lacking aliphatic unsaturated bonds; 'd' represents an integer between 5 and 2,000.

[0078] Component (F) is used as a viscosity modifier, plasticizer, etc., as appropriate to impart properties to the thermally conductive silicone composition, but is not limited to these. These may be used individually or in combination of two or more. Each R 5 R independently represents an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms. 5Examples of substituents include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl, and dodecyl groups; cycloalkyl groups such as cyclopentyl, cyclohexyl, and cycloheptyl groups; aryl groups such as phenyl, tolyl, xylyl, naphthyl, and biphenylyl groups; aralkyl groups such as benzyl, phenylethyl, phenylpropyl, and methylbenzyl groups; and groups obtained by substituting some or all of the hydrogen atoms bonded to the carbon atoms of these groups with halogen atoms such as cyano, fluorine, chlorine, and bromine. Examples of such substituents include chloromethyl, 2-bromoethyl, 3-chloropropyl, 3,3,3-trifluoropropyl, chlorophenyl, fluorophenyl, cyanoethyl, and 3,3,4,4,5,5,6,6,6-nonafluorohexyl groups. Typical examples of monovalent hydrocarbon groups include those having 1 to 10 carbon atoms, and particularly typical examples include those having 1 to 6 carbon atoms. Preferred examples of monovalent hydrocarbon groups include unsubstituted or substituted alkyl groups having 1 to 3 carbon atoms, such as methyl, ethyl, propyl, chloromethyl, bromoethyl, 3,3,3-trifluoropropyl, and cyanoethyl groups; and unsubstituted or substituted phenyl groups, such as phenyl, chlorophenyl, and fluorophenyl groups. Methyl and phenyl groups are particularly preferred. From the viewpoint of the required viscosity, d is preferably an integer between 5 and 2,000, and particularly preferably an integer between 10 and 1,000. Furthermore, the viscosity at 25°C is preferably 10 to 100,000 mPa·s, and particularly preferably 100 to 10,000 mPa·s. When the viscosity is 10 mPa·s or higher, oil bleeding hardly occurs in the cured product of the resulting composition. When the viscosity is 100,000 mPa·s or lower, the resulting thermally conductive silicone composition has appropriate flexibility.

[0079] When component (F) is added to the thermally conductive silicone composition of the present invention, the amount added is not particularly limited and can be 10 to 100 parts by mass per 100 parts by mass of component (A). When the amount added is within this range, it becomes easy to fill with component (C) thermally conductive filler while maintaining the good fluidity and operability of the thermally conductive silicone composition before curing.

[0080] In the thermally conductive silicone composition of the present invention, the amount of component (F) is preferably less than 0.1 parts by mass, and more preferably less than 0.01 parts by mass, per 100 parts by mass of component (A). By doing so, oil leakage of the thermally conductive silicone composition and contamination of the substrate can be avoided.

[0081] Optional component (G): Reaction inhibitor

[0082] Component (G) can be an addition reaction inhibitor. Any known addition reaction inhibitor used in typical addition reaction curing silicone compositions can be used as the addition reaction inhibitor. Examples include acetylene compounds such as 1-ethynyl-1-hexanol and 3-butyne-1-ol, various nitrogen compounds, organophosphorus compounds, oxime compounds, and organochlorine compounds. When component (G) is included, the amount used is preferably 0.01 to 1 part by mass, more preferably 0.1 to 0.8 parts by mass, per 100 parts by mass of component (A-1). With such an amount, the curing reaction proceeds sufficiently and the molding efficiency is not impaired.

[0083] Other ingredients

[0084] The thermally conductive silicone composition of the present invention may further contain other components as needed. Examples of optional components that can be added include heat resistance improvers such as iron oxide and cerium oxide; viscosity modifiers such as silica; colorants; mold release agents; and the like. [Examples]

[0085] Embodiment Thermally conductive silicone cured product and method for manufacturing the same The thermally conductive silicone cured product (thermally conductive molded article) according to the present invention is a cured product of the thermally conductive silicone composition described above. The curing conditions for curing (molding) the thermally conductive silicone composition may be the same as those for known addition reaction curing type silicone rubber compositions. For example, the thermally conductive silicone composition will cure sufficiently even at room temperature, but may be heated if necessary. Preferably, the thermally conductive silicone composition is subjected to addition curing at 100 to 120°C for 8 to 120 minutes. Such a cured product (molded article) of the present invention has excellent thermal conductivity.

[0086] Thermal conductivity of molded products The thermal conductivity of the molded article of the present invention is preferably 3.1 W / m·K or higher, as measured at 25°C using the hot disk method. Articles with a thermal conductivity of 3.1 W / m·K or higher can be applied to heat-generating components with high heat output. Such thermal conductivity can be adjusted by adjusting the combination of the type and particle size of the thermally conductive filler.

[0087] Hardness of molded products The molded articles of the present invention are tested with a Zwick hardness tester. This hardness can be adjusted by changing the ratio of component (A-1) and component (B) to control the crosslinking density.

[0088] In accordance with DIN53019, the kinematic and static viscosity of the composition of the present invention were tested using an Anton Paar MCR302 apparatus.

[0089] The components (A) to (G) used in the following examples and comparative examples are shown below.

[0090] Ingredient (A): (A-1) Organopolysiloxane represented by the following formula (5) [ka]

[0091] (In the formula, X represents a vinyl group, and n represents the number at which the viscosity is 120 mPa·s.)

[0092] Ingredient (B): (B-1) This is a side-chain hydrogen polysiloxane represented by the following formula (6), with a hydrogen content of 1.7 mmol / g. [ka]

[0093] (B-2) Terminal hydrogen polysiloxane represented by formula (5) below [ka]

[0094] (In the formula, X represents hydrogen. The hydrogen content is 0.53 mmol / g.)

[0095] Ingredients (C): (C-1) Aluminum hydroxide with an average particle size of 1.5 μm (C-2) Aluminum hydroxide with an average particle size of 10 μm (C-3) Aluminum hydroxide with an average particle size of 90 μm

[0096] Ingredients (D): 5% by mass of chloroplatinate in a 2-ethylhexanol solution

[0097] Treatment agent Ea, component (E-2), is diethyl dioleyl titanate. Treatment agent Eb, isopropyl titanium triisostearate Treatment agent Ec, di-iso-butoxytitanium chelate (ethyl acetoacetate titanate), CAS: 83877-91-2 Treatment agent Ed, hexadecyltrimethoxysilane The treatment agents Eb, Ec, or Ed do not belong to component (E-2).

[0098] Ingredients (G): Ethinylmethidenecarbinol as an addition reaction inhibitor. The above materials are supplied by Wacker Chemie AG or purchased from the market.

[0099] Molding method After mixing, the compositions shown in Table 3 were obtained. The compositions shown in Table 3 were each poured into molds measuring 60 mm × 60 mm × 6 mm and molded using a press molding machine at 100°C for 60 minutes.

[0100] Evaluation method: Thermal conductivity: The compositions obtained from Tables 1 and 3 were poured into molds measuring 60 mm × 60 mm × 6 mm, and their thermal conductivity was measured. Under conditions of 100°C for 60 minutes, the compositions obtained in the following examples and the comparative examples in Table 3 were cured into 6 mm thick sheets. Two sheets from each composition were used to measure the thermal conductivity using a thermal conductivity meter (product name: TC3000E, manufactured by Xi'an Xiaxi Electronic Technology Co., Ltd.).

[0101] hardness: The compositions obtained in the following examples and comparative examples were cured into 6 mm thick sheets as described above. Two sheets obtained from each composition were stacked on top of each other, and the Shore hardness of 00 was obtained by measuring with a Zwick hardness tester.

[0102] Density: Measurements were performed using a Mettler Toledo ML204.

[0103] Table 1 Silicone Grease Composition [Table 1]

[0104] Table 2 shows the specific composition of "thermal conductive filler (C)" in Table 1.

[0105] Table 2 Thermally conductive fillers (C) [Table 2]

[0106] In Example 1, Comparative Example 2, Comparative Example 3, and Comparative Example 4, (a) Place the thermally conductive filler (C) in the reaction vessel and treat with nitrogen for 10-15 minutes under stirring conditions at 25°C. (b) Heat the heat-conductive filler (C) to 120°C within 5 to 10 minutes. (c) Mix the thermally conductive filler (C) with the treatment agents Ea, Eb, Ec, and Ed in a mass ratio of 249:1, and mix at 120°C for 10 minutes, 30 minutes, 40 minutes, and 60 minutes to obtain a premix of filler (C) and each treatment agent, i.e., treated filler (CE). (d) This premix and (A-1) are mixed again to obtain the thermally conductive silicone grease compositions of Example 1, Comparative Example 2, Comparative Example 3 and Comparative Example 4. In the process described above, the speed of the high-speed mixer was 1400 RPM. This method belongs to the premixing method.

[0107] In Comparative Example 5, under conditions of 25°C, treatment agent Ea was mixed with (A-1), and then the thermally conductive filler (C) was added to obtain the thermally conductive silicone grease composition of Comparative Example 5. Here, the mass ratio of thermally conductive filler (C) to treatment agent Ea was 249:1. This method belongs to the in-situ method.

[0108] In Table 1, the viscosities of the thermally conductive silicone grease compositions prepared in Example 1 were 113,300 mPa.s and 108,800 mPa.s, respectively, when using the premixes obtained after 40 and 60 minutes. The viscosities of these two products were significantly lower than those of the comparative examples using Eb, Ec, and Ed treatments. In particular, a homogeneous premix could not be obtained when mixing for a long time in Comparative Example 3. Even when Example 1 and Comparative Example 5 use the same treatment agent Ea, the viscosity of the thermally conductive silicone grease composition of Example 1 after 30 minutes of treatment is significantly lower than the viscosity of Comparative Example 5 obtained using the in-situ method.

[0109] Table 2 Thermally conductive gap filler compositions [Table 3]

[0110] As can be seen from the comparison between Example 1-1 and Comparative Example 5-1 in Table 3, even though the raw materials used in the two examples were exactly the same, the caulking product obtained in Example 1-1 (using a premix of (C) and Ea (processing time 60 minutes)) had a lower viscosity than the caulking product obtained in Comparative Example 5-1 (using the in-situ method).

Claims

1. A processed filler (CE) obtained by mixing component (C) a thermally conductive filler and component (E-2), Component (E-2) is given by the following general formula (2): (R ４ COO) ｍ -Ti-OR ６ ４－ｍ (2) (In the formula, R ４ This is a hydrocarbon group containing 6 to 30 carbon atoms, and includes at least one carbon-carbon unsaturated group. Preferably, the number of carbon atoms is 6 to 24, more preferably 10 to 20, and even more preferably 16 to 20; preferably containing 1 to 3 ethylenically bonded atoms, preferably containing 1 to 2 ethylenically bonded atoms, more preferably containing 1 ethylenically bonded atoms. R ４ COO- is preferably an oleic acid group; R ６ is a hydrocarbon group containing 1 to 5 carbon atoms, preferably 1 to 4 carbon atoms, more preferably methyl, ethyl, ethylene, allyl, propyl, isopropyl, butyl, isobutyl; even more preferably propyl, isopropyl; m is 1 or 2, preferably m is 2. A titanate compound and / or an oligomer with a degree of polymerization of 2 to 5, represented by The mixing conditions are 90 to 160°C for 20 minutes or more; preferably 100 to 140°C for 35 to 70 minutes; preferably 100 to 140°C for 40 to 70 minutes; preferably 100 to 130°C for 30 to 65 minutes; more preferably 115 to 125°C for 35 to 60 minutes; even more preferably 118 to 122°C for 35 to 60 minutes, and especially 40, 45, 50, and 55 minutes, for the processed filler (CE).

2. The treated filler (CE) according to claim 1, wherein component (E-2) is one or more selected from the group consisting of diethyl dioleyl titanate, triethyl oleyl titanate, di-n-propyl dioleyl titanate, tri-n-propyl oleyl titanate, diisopropyl dioleyl titanate, triisopropyl oleyl titanate, dibutyl dioleyl titanate, and tributyl oleyl titanate, preferably one or more selected from the group consisting of diisopropyl dioleyl titanate and triisopropyl oleyl titanate, and more preferably diisopropyl dioleyl titanate.

3. A method for treating component (C) a thermally conductive filler, This includes mixing component (C) with component (E-2), The mixing conditions are 90 to 160°C for 20 minutes or more; preferably 100 to 140°C for 35 to 70 minutes; preferably 100 to 140°C for 40 to 70 minutes; preferably 100 to 130°C for 30 to 65 minutes; more preferably 115 to 125°C for 35 to 60 minutes; even more preferably 118 to 122°C for 35 to 60 minutes, particularly 40, 45, 50, and 55 minutes. Processing method.

4. The method according to claim 3, wherein, under stirring conditions, the component (C) thermal conductive filler is first subjected to nitrogen treatment, and then the component (E-2) is added.

5. The method according to claim 3 or 4, wherein the nitrogen treatment time is 5 minutes or more, preferably 5 to 60 minutes, more preferably 5 to 30 minutes, and even more preferably 5 to 15 minutes.

6. A composition, Component (A) is an organopolysiloxane, preferably component (A-1) which is an organopolysiloxane having two or more alkenyl groups per molecule; Component (B) is an arbitrary component (B) which is an organohydrogenpolysiloxane having two or more hydrogen atoms directly bonded to a silicon atom, wherein the number of moles of hydrogen atoms directly bonded to a silicon atom in component (B) is 0.1 to 5.0 times the number of moles of alkenyl groups derived from component (A-1); A processed filler (CE) according to claim 1 or 2, wherein the filling amount of the processed filler (CE) is 0.80 or more, preferably 0.84 or more, preferably 0.88 or more, preferably 0.89 or more, and preferably 0.90 or more; Component (D) is an arbitrary component (D) that is a platinum group metal-based curing catalyst having a platinum group metal element content of 0.1 to 1,000 ppm by mass relative to component (A-1). A composition containing the following:

7. The aforementioned component (C) thermally conductive filler is 10 to 25% by mass of (C-1) aluminum hydroxide, having an average particle size of 0.1 μm or more and 4 μm or less. 18 to 37% by mass of (C-2) aluminum hydroxide, with an average particle size of 4 μm or more and 20 μm or less. 48-65% by mass of (C-3) aluminum hydroxide with an average particle size of 80 μm or more and 100 μm or less. A filler according to claim 1 or 2, comprising, in (C-1), (C-2), and (C-3), the component (C) in the composition being calculated as 100% by mass, a method according to any one of claims 3 to 5, or a composition according to claim 6.

8. A thermally conductive member comprising the composition according to claim 6 or 7 or a cured product thereof.

9. A heat dissipation structure comprising the heat conductive member described in claim 8.

10. A heat dissipation structure comprising a heat dissipation component based on the composition or cured product thereof according to claim 6 or 7, or a circuit board on which the heat dissipation component is mounted.

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