JP6394559B2 - Thermally conductive silicone grease composition - Google Patents

Description

  The present invention relates to a thermally conductive silicone grease composition, and more particularly to a thermally conductive silicone grease composition that is not only excellent in thermal conductivity but also does not cause cracking or misalignment during a cold cycle.

  Generally, since heat is generated during use of electric / electronic parts, heat removal is necessary to operate these parts properly. Conventionally, various heat conductive materials used for heat removal have been used. Proposed. In this case, there are two types of thermally conductive materials: (1) a sheet-like material that is easy to handle, and (2) a paste-like material called heat radiation grease.

  Of these, the sheet-like material (1) has the advantage of being easy to handle and excellent in stability, while the contact thermal resistance is inevitably increased. It will be inferior to the case. In addition, since a certain degree of strength and hardness is required to maintain the sheet shape, tolerances generated between the element and the housing cannot be absorbed, and the element may be destroyed by the stress.

  On the other hand, the heat dissipating grease (2) can be adapted not only for mass production of electrical and electronic products by using a dispensing device or printing device, but also has a low heat contact resistance for heat dissipation performance. There is an advantage of being excellent. However, when the viscosity of the heat-dissipating grease is lowered in order to obtain good dispensing performance and printing performance, the amount of thermally conductive inorganic filler is limited and sufficient heat conductivity cannot be ensured. Is not sufficient, or the grease for heat dissipation breaks or deviates during the cooling cycle assuming ON / OFF of the device, and the heat path is lost. As a result, the device may malfunction.

  Therefore, a specific organopolysiloxane, a thickener such as zinc oxide, alumina, aluminum nitride, boron nitride, and silicon carbide, an organopolysiloxane having at least one hydroxyl group directly bonded to a silicon atom in one molecule, and Grease-like silicone composition in which bleed of base oil is suppressed by combining alkoxysilane (Patent Document 1); liquid silicone, thermally conductive inorganic filler having a constant thermal conductivity and a Mohs hardness of 6 or more, and Thermally conductive silicone composition excellent in thermal conductivity and dispensing property comprising a combination of thermally conductive inorganic fillers having a constant thermal conductivity and a Mohs hardness of 5 or less (Patent Document 2); a specific base oil And a thermally conductive grease composition comprising a metal aluminum powder having an average particle size of 0.5 to 50 μm (Patent Document 3); Silicone grease composition with a high filling rate of aluminum nitride in silicone grease by mixing two different types of aluminum nitride powder (Patent Document 4); and increasing oil viscosity to suppress bleed-out A higher performance heat conductive silicone grease composition such as a silicone grease composition (Patent Document 5) has been proposed, but it can sufficiently cope with higher performance of electronic and electric parts used. Has not been obtained yet.

Japanese Patent Laid-Open No. 11-49958 JP-A-11-246884 JP 2000-63873 A JP 2000-169873 A JP 2003-301184 A

  Accordingly, an object of the present invention is to provide a thermally conductive silicone grease composition that not only has excellent thermal conductivity but also does not generate cracks or misalignment during a cooling / heating cycle.

  As a result of continual studies to achieve the above object, the present inventors have found that a specific organopolysiloxane, an aromatic-containing organic compound having an allyl group, an SP containing a higher SP value than the organopolysiloxane, and a specific organopolysiloxane. It has been found that by combining hydrogen polysiloxane and a heat conductive filler, a heat conductive silicone grease composition that not only has excellent thermal conductivity but also does not generate cracks or misalignment during a cold cycle can be obtained. The present invention has been reached.

（式中、Ｒ¹は同一又は異種の１価炭化水素基である。Ｘ¹、Ｘ²、Ｘ³はＲ¹又は−Ｒ²−ＳｉＲ¹ _a（ＯＲ³）_3-aで示される基であり、それぞれ異なっても良い。Ｒ¹は上記の通り、Ｒ²は酸素原子又は炭素数１〜４のアルキレン基、Ｒ³は炭素数１〜４のアルキル基、アルコキシアルキル基、アルケニル基又はアシル基であり、ａは１〜３の整数である。ｍ及びｎはそれぞれ１≦ｍ≦１，０００、０≦ｎ≦１，０００である。）
で示され、２５℃における粘度が０．００５〜１００ｍＰａ・ｓである３官能の加水分解性オルガノポリシロキサンであり、
アリル基を有する芳香族含有有機化合物（Ｂ）が、分子中にエポキシ基及びフェノール性水酸基から選ばれる有機基を有するＳＰ値が１０以上の化合物であり、
オルガノハイドロジェンポリシロキサン（Ｃ）が分子中にケイ素原子に結合した水素原子が３個以上存在するものであり、
熱伝導性無機充填材（Ｅ）が、金属系粉末、金属酸化物系粉末、金属水酸化物粉末及び金属窒化物粉末から選択される少なくとも１種である〔１〕記載の熱伝導性シリコーングリース組成物。
〔３〕
オルガノハイドロジェンポリシロキサン（Ｃ）は、ケイ素原子に結合した水素原子を１分子中に３個以上有するオルガノハイドロジェンポリシロキサンであり、前記（Ｂ）成分中のアリル基１個に対して、当該成分中のケイ素原子に結合した水素原子の個数が０．１〜１．０個となる量である〔１〕又は〔２〕記載の熱伝導性シリコーングリース組成物。
〔４〕
熱伝導性無機充填材（Ｅ）が、アルミニウム、銀、銅、ニッケル、酸化亜鉛、酸化アルミニウム、酸化ケイ素、酸化マグネシウム、窒化アルミニウム、窒化ホウ素、窒化ケイ素、及び金属ケイ素から選ばれる１種又は２種以上の組み合せである〔１〕〜〔３〕のいずれかに記載の熱伝導性シリコーングリース組成物。 That is, the present invention provides the following high thermal conductivity silicone grease composition.
[1]
(A) Organopolysiloxane: 20 to 90 parts by mass,
(B) Aromatic-containing organic compound having an allyl group: 40 to 5 parts by mass
(C) Organohydrogenpolysiloxane: 40-5 parts by mass,
(However, the total of the components (A), (B), and (C) is 100 parts by mass.)
(D) a catalyst selected from the group consisting of platinum and platinum compounds: catalytic amount,
(E) Thermally conductive inorganic filler having an average particle size of 0.5 to 100 μm: Contains 200 to 2,000 parts by mass with respect to a total of 100 parts by mass of the components (A), (B) and (C). The SP value of the organopolysiloxane (A) and the aromatic-containing organic compound (B) having an allyl group is (B)> (A) and (B) SP value of component) -SP value of component (A)> 2 and the viscosity of the heat conductive silicone grease composition is 50 to 1,000 Pa · s at 25 ° C. Grease composition.
[2]
Organopolysiloxane (A) is represented by the following general formula (1)

Wherein R ¹ is the same or different monovalent hydrocarbon group. X ¹ , X ² and X ³ are groups represented by R ¹ or —R ² —SiR ¹ _a (OR ³ ) _3-a There, even different from each good .R ¹ is of the street, R ² represents an oxygen atom or an alkylene group having 1 to 4 carbon atoms, R ³ is an alkyl group having 1 to 4 carbon atoms, an alkoxyalkyl group, an alkenyl group or an acyl A is an integer of 1 to 3. m and n are 1 ≦ m ≦ 1,000 and 0 ≦ n ≦ 1,000, respectively.
And a trifunctional hydrolyzable organopolysiloxane having a viscosity at 25 ° C. of 0.005 to 100 mPa · s,
The aromatic-containing organic compound (B) having an allyl group is a compound having an SP value of 10 or more having an organic group selected from an epoxy group and a phenolic hydroxyl group in the molecule,
The organohydrogenpolysiloxane (C) has three or more hydrogen atoms bonded to silicon atoms in the molecule,
The thermally conductive silicone grease according to [1], wherein the thermally conductive inorganic filler (E) is at least one selected from metal powder, metal oxide powder, metal hydroxide powder and metal nitride powder. Composition.
[3]
The organohydrogenpolysiloxane (C) is an organohydrogenpolysiloxane having 3 or more hydrogen atoms bonded to silicon atoms in one molecule, and for one allyl group in the component (B), The heat conductive silicone grease composition according to [1] or [2], wherein the number of hydrogen atoms bonded to silicon atoms in the component is 0.1 to 1.0.
[4]
The heat conductive inorganic filler (E) is one or two selected from aluminum, silver, copper, nickel, zinc oxide, aluminum oxide, silicon oxide, magnesium oxide, aluminum nitride, boron nitride, silicon nitride, and metal silicon The heat conductive silicone grease composition according to any one of [1] to [3], which is a combination of at least seeds.

  The thermally conductive silicone grease composition of the present invention not only has excellent thermal conductivity, but also does not generate cracks or misalignment during a cooling cycle, so it can remove heat from electrical and electronic components that generate heat during use. Is preferred.

  The (A) component organopolysiloxane constituting the thermally conductive silicone grease composition of the present invention is a liquid silicone having a viscosity at 25 ° C. of preferably 0.005 to 100 mPa · s.

  In the present invention, the viscosity of the organopolysiloxane of component (A) at 25 ° C. as measured by a B-type rotational viscometer is preferably in the range of 0.005 to 100 mPa · s as described above. More preferably, it is -50mPa * s. If the viscosity at 25 ° C. is less than 0.005 mPa · s, the resulting silicone grease composition will be separated during storage and the stability will be poor, and if it is greater than 100 mPa · s, mixing with the component (B) will occur. May be difficult.

（式中、Ｒ¹は同一又は異種の１価炭化水素基である。Ｘ¹、Ｘ²、Ｘ³はＲ¹又は−Ｒ²−ＳｉＲ¹ _a（ＯＲ³）_3-aで示される基であり、それぞれ異なっても良い。Ｒ¹は上記の通り、Ｒ²は酸素原子又は炭素数１〜４のアルキレン基、Ｒ³は炭素数１〜４のアルキル基、アルコキシアルキル基、アルケニル基又はアシル基であり、ａは１〜３の整数である。ｍ及びｎはそれぞれ１≦ｍ≦１，０００、０≦ｎ≦１，０００である。） The organopolysiloxane of component (A) preferably contains at least a trifunctional hydrolyzable organopolysiloxane represented by the following general formula (1).

Wherein R ¹ is the same or different monovalent hydrocarbon group. X ¹ , X ² and X ³ are groups represented by R ¹ or —R ² —SiR ¹ _a (OR ³ ) _3-a There, even different from each good .R ¹ is of the street, R ² represents an oxygen atom or an alkylene group having 1 to 4 carbon atoms, R ³ is an alkyl group having 1 to 4 carbon atoms, an alkoxyalkyl group, an alkenyl group or an acyl A is an integer of 1 to 3. m and n are 1 ≦ m ≦ 1,000 and 0 ≦ n ≦ 1,000, respectively.

（式中、Ｒ¹は独立に非置換又は置換の１価炭化水素基であり、Ｒ³は独立に炭素数１〜４のアルキル基、アルコキシアルキル基、アルケニル基又はアシル基であり、ｐは５〜１００の整数であり、ａは１〜３の整数である。）
で表され、好ましくは２５℃における粘度が０．００５〜１００ｍＰａ・ｓのオルガノポリシロキサンである。 More preferred organopolysiloxane (A) component for use in the present invention is represented by the following general formula (2):

Wherein R ¹ is independently an unsubstituted or substituted monovalent hydrocarbon group, R ³ is independently an alkyl group having 1 to 4 carbon atoms, an alkoxyalkyl group, an alkenyl group or an acyl group, and p is (It is an integer of 5-100, and a is an integer of 1-3.)
Preferably, it is an organopolysiloxane having a viscosity at 25 ° C. of 0.005 to 100 mPa · s.

In the present invention, the viscosity is measured with a Malcolm viscometer, and the maximum value recorded with a plotter is taken as the viscosity.
Rotor: A (10 rpm)
Measurement conditions: 25 ° C ± 0.5 ° C
It is the value measured by.

  Even if the organopolysiloxane (A) is highly filled with the heat conductive inorganic filler of the component (E) in order to obtain a highly heat conductive silicone grease composition, the composition of the present invention has fluidity. It also has the role of maintaining and imparting good handleability to the composition.

In the above formulas (1) and (2), R ¹ is independently an unsubstituted or substituted monovalent hydrocarbon group preferably having 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, and still more preferably 1 to 3 carbon atoms. Examples thereof include a linear alkyl group, a branched alkyl group, a cyclic alkyl group, an alkenyl group, an aryl group, an aralkyl group, and a halogenated alkyl group. Examples of the linear alkyl group include a methyl group, an ethyl group, a propyl group, a hexyl group, and an octyl group. Examples of the branched alkyl group include isopropyl group, isobutyl group, tert-butyl group, and 2-ethylhexyl group. Examples of the cyclic alkyl group include a cyclopentyl group and a cyclohexyl group. Examples of the alkenyl group include a vinyl group and an allyl group. Examples of the aryl group include a phenyl group and a tolyl group. Examples of the aralkyl group include 2-phenylethyl group and 2-methyl-2-phenylethyl group. Examples of the halogenated alkyl group include 3,3,3-trifluoropropyl group, 2- (nonafluorobutyl) ethyl group, and 2- (heptadecafluorooctyl) ethyl group. R ¹ is preferably a methyl group, a phenyl group, or a vinyl group.

R ³ is independently an alkyl group having 1 to 4 carbon atoms, an alkoxyalkyl group, an alkenyl group, or an acyl group. Examples of the alkyl group include linear alkyl groups, branched alkyl groups, and cyclic alkyl groups similar to those exemplified for R ¹ . Examples of the alkoxyalkyl group include a methoxyethyl group and a methoxypropyl group. As an acyl group, C2-C8 is preferable, for example, and an acetyl group, an octanoyl group, etc. are mentioned. R ³ is preferably an alkyl group, particularly preferably a methyl group or an ethyl group.
n and m are as described above, preferably n + m is 10 to 50, and p is an integer of 5 to 100, preferably 10 to 50. a is an integer of 1 to 3, and is preferably 3. In addition, it is preferable to have 1 to 6, or 3 or 6 OR ³ groups in the molecule.

  The viscosity at 25 ° C. of the organopolysiloxane (A) is usually 0.005 to 100 mPa · s, particularly preferably 0.005 to 50 mPa · s. When the viscosity is lower than 0.005 mPa · s, oil bleed tends to occur from the room temperature moisture-curing heat conductive silicone grease composition obtained, and it tends to sag. If the viscosity is greater than 100 mPa · s, the fluidity of the resulting thermally conductive silicone grease composition becomes poor, and there is a possibility that the dispensing property and the printability will deteriorate.

  Preferable specific examples of the organopolysiloxane (A) include the following.

  If the organopolysiloxane (A) is less than 20 parts by mass in a total of 100 parts by mass of the components (A), (B) and (C), the thermally conductive silicone composition thickens and cannot be discharged. If the amount exceeds 90 parts by mass, the viscosity becomes too low and the organopolysiloxane (A) bleeds. Therefore, it is used in the range of 20 to 90 parts by mass, preferably 30 to 80 parts by mass. It is a range.

The aromatic-containing organic compound having an allyl group as component (B) is preferably an organic compound having an organic group selected from an epoxy group and a phenolic hydroxyl group in the molecule.
In this case, the following epoxy resin is mentioned as a compound which has an epoxy group. As for molecular structure, molecular weight, etc., the viscosity at 25 ° C. is limited to 10 to 1,000,000 mPa · s. As such an epoxy compound, for example, bis (4-hydroxyphenyl) methane, 2,2′-bis (4-hydroxyphenyl) propane or a diglycidyl ether of this halide and a condensation polymer thereof (so-called bisphenol F) Type epoxy resin, bisphenol A type epoxy resin, etc.), diglycidyl ether of resorcin, 1,4-bis (2,3-epoxypropoxy) benzene, 4,4′-bis (2,3-epoxypropoxy) diphenyl ether, 1 , 2-dioxybenzene or resorcinol, epoxy glycidyl ether obtained by condensing polyphenol and epichlorohydrin, naphthalene ring-containing epoxy resin, biphenyl type epoxy resin, phenol aralkyl type epoxy resin, biphenyl aralkyl type epoxy And the like resin, in the ortho-position of the above-mentioned epoxy group having an allyl group.

In addition, a monoepoxy compound may be used in combination with the epoxy resin as appropriate, and examples of the monoepoxy compound include styrene oxide and phenyl glycidyl ether, which have an allyl group at the ortho position of these epoxy groups.
Moreover, the epoxy resin to be used is not necessarily limited to only one type, and two or more types can be used in combination.

  Examples of the phenol group-containing compound include bisphenol A, bisphenol F, trimethylol allyloxyphenol, and phenol resins such as phenol novolac resin having a low polymerization degree. The phenolic hydroxyl group has an allyl group at the ortho position. .

  (B) The compounding quantity of a component is 5-40 mass parts in the total of 100 mass parts of (A), (B), (C) component, Preferably it is the range of 10-30 mass parts. When there are too few (B) components, desired heat conductivity cannot be achieved, and when there are too many (B) components, it will become high viscosity and workability | operativity will deteriorate.

The organohydrogenpolysiloxane containing hydrogen atoms directly bonded to at least three silicon atoms in one molecule of the component (C) is a curing agent of the composition and is mixed with the components (A) and (B). Can be cured.
The number of silicon-bonded hydrogen atoms (SiH groups) in the organohydrogenpolysiloxane is 3 or more, preferably 3 to 50, and more preferably 4 to 30.

  As the group bonded to silicon atoms other than hydrogen atoms in the organohydrogenpolysiloxane, monovalent carbonization that excludes unsubstituted or substituted aliphatic unsaturated bonds having 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms. Examples include a hydrogen group, specifically, a linear alkyl group, a branched alkyl group, a cyclic alkyl group, an aryl group, an aralkyl group, and a halogenated alkyl group, and those exemplified in the above component (A) The same thing can be illustrated. The group bonded to a silicon atom other than a hydrogen atom is preferably a linear alkyl group or an aryl group, and particularly preferably a methyl group or a phenyl group.

  The viscosity of the organohydrogenpolysiloxane at 25 ° C. is not particularly limited, but is preferably in the range of 1 to 100,000 mPa · s, and particularly preferably in the range of 1 to 50,000 mPa · s. When the viscosity is within this range, it is easy to ensure handling workability of the composition, and it is easy to ensure good physical properties of the cured product of the composition. This viscosity is a value measured by a rotational viscometer.

  The molecular structure of the organohydrogenpolysiloxane is not particularly limited, and examples thereof include linear, branched, partially branched linear, cyclic, and dendritic (dendrimer). The organohydrogenpolysiloxane may be a single polymer having these molecular structures, a copolymer having these molecular structures, or a mixture thereof. The silicon atom-bonded hydrogen atom may exist only in one of the molecular chain terminal part and the molecular chain non-terminal part, or may exist in both of them.

Examples of the organohydrogenpolysiloxane of component (C) include molecular chain both ends dimethylhydrogensiloxy group-blocked, side chain methylhydrogensiloxy group dimethylpolysiloxane, molecular chain both ends trimethylsiloxy group blocked, sidechain methylhydro Gensiloxy group dimethylsiloxane / methylhydrogensiloxane copolymer, both ends of molecular chain dimethylhydrogensiloxy group blocked, side chain methylhydrogensiloxy group dimethylsiloxane / methylhydrogensiloxane copolymer, formula: (CH ₃ ) ₃ An organosiloxane copolymer comprising a siloxane unit represented by SiO _1/2 and a siloxane unit represented by the formula: (CH ₃ ) ₂ HSiO _1/2 and a siloxane unit represented by the formula: SiO _4/2 ; And a mixture of two or more of these That.
The organohydrogenpolysiloxane is basically composed of a siloxane skeleton and does not contain an alkoxy group.

  The amount of the organohydrogenpolysiloxane that is the component (C) is such that the amount of silicon atom-bonded hydrogen atoms (SiH groups) in the component (C) is 1 mol of allyl groups in the component (B). The amount is in the range of 0.05 to 0.5 mol, and is preferably in the range of 0.1 to 0.3 mol. When the content is such an amount, the composition can be cured sufficiently, without cracking or misalignment during thermal cycling, and can have an appropriate hardness that does not give thermal stress to electronic components. It is difficult to give stress to the heat dissipation element.

  In this case, the component (C) is 5 to 40 parts by mass, preferably 5 to 20 parts by mass, in a total of 100 parts by mass of the components (A), (B) and (C). -It is preferable in terms of balance between prevention of deviation and stress relaxation.

  The catalyst selected from the group consisting of platinum and platinum compounds as the component (D) is a component for promoting the addition reaction between the allyl group of the component (B) and the SiH group of the component (C). Examples of the component (D) include platinum alone, chloroplatinic acid, platinum-olefin complexes, platinum-alcohol complexes, platinum coordination compounds, and the like.

  The blending amount of the component (D) is not effective as a catalyst even if it is less than 0.1 ppm as platinum atoms with respect to the total mass of the components (B) and (C), and the effect increases even if it exceeds 500 ppm Since it is uneconomical, it is in the range of 0.1 to 500 ppm, preferably 0.1 to 400 ppm.

  In the present invention, it is preferable to use a control agent for the purpose of suppressing the catalytic activity of the component (D). The control agent suppresses the progress of the hydrosilylation reaction at room temperature and prolongs shelf life and pot life. As the control agent, known reaction control agents can be used, and acetylene compounds, various nitrogen compounds, organic phosphorus compounds, and the like can be used. Specifically, acetylene compounds such as 1-ethynyl-1-cyclohexanol and 3-butyn-1-ol, various nitrogen compounds such as triallyl isocyanurate and triallyl isocyanurate derivatives, and organophosphorus compounds such as triphenylphosphine Etc. can be illustrated.

  If the blending amount of the control agent is less than 0.01 parts by mass with respect to the total of 100 parts by mass of the components (B) and (C), sufficient shelf life and pot life may not be obtained, and 1.5 mass Since there exists a possibility that sclerosis | hardenability may fall when it is more than a part, the range of 0.01-1.5 mass part is preferable, and the range of 0.01-1.0 mass part is more preferable.

  In the present invention, when the SP values of the organopolysiloxane (A) and the non-silicone organic compound (B) are SP (A) and SP (B), respectively, SP (B)> SP (A), and SP (B) -SP (A)> 2, preferably SP (B) -SP (A) ≧ 2.5, more preferably SP (B) -SP (A) ≧ 3.

In this specification, the SP value is described by Toshinao Okitsu, “Adhesion”, Polymer Press, Vol. 40, No. 8 (1996) p342-350, ΔF of various atomic groups by Okitsu described in Table 1 below, It means the solubility parameter δ calculated by the following formula (3) using the Δv value. In the case of a mixed solvent or a copolymer, it means the solubility parameter δ calculated by the following formula (4).
δ = ΣΔF / ΣΔv (3)
δ _mix = φ ₁ δ ₁ + φ ₂ δ ₂ + ... φ _n δ _n (4)
In the formula, ΔF represents ΔF in Table 1 below, and Δv represents the molar volume Δv in Table 1 below. φ represents a volume fraction or a mole fraction, and φ ₁ + φ ₂ +... φ _n = 1.

For example, the SP value of heptane as a solvent is determined as follows.
Heptane has two —CH ₃ and five —CH ₂ — as atomic groups. The ΔF and Δv values are determined from Table 1 for each atomic group.
ΣΔF = 205 × 2 + 132 × 5 = 1070
ΣΔv = 31.8 × 2 + 16.5 × 5 = 146.1
Therefore, δ _hep of heptane can be obtained from the above equation (3) as follows.
δ _hep = ΣΔF / ΣΔv = 1070 / 146.1 = 7.32

Similarly, the bifunctional phenol resin of the following formula (i) has three groups of —CH ₂ —, two CH ₂ ═, two —CH═, two —OH (Arom), — It has 2 C ₆ H ₃ (Arom). The ΔF and Δv values are determined from Table 1 for each atomic group.
ΣΔF = 2594.0
ΣΔv = 241
Therefore, from the above formula (3), δ _{phOH of the} bifunctional phenol resin is obtained as follows.
δ _phOH = d * ΣΔF / ΣΔv = 1.15 * 2594.0 / 241 = 12.4

Similarly, the bifunctional epoxy resin represented by the following formula (ii) has, as atomic groups, 7 —CH ₂ —, ₂ > CH—, 2 CH ₂ =, 2 —CH═, —O— two (Epoxy), -O- (Arom, Lin) 2 pieces of, -C ₆ H ₃ a (Arom) to two chromatic. The ΔF and Δv values are determined from Table 1 for each atomic group.
ΣΔF = 2646.0
ΣΔv = 283
Therefore, from the above formula (3), δ _{epoxy of the} bifunctional phenolic resin is obtained as follows.
δ _epoxy = d * ΣΔF / ΣΔv = 1.20 * 2646.0 / 283 = 11.2

  From the Science Chronology, Vol. 84, Article 54 (410), the thermal conductivity of silicone is 0.16 W / mK, and the epoxy resin (Bisphenol A) is 0.21 W / mK.

When the polyorganosiloxane of component (A) and the organic compound of component (B) are mixed, they are separated if the difference in SP value is greater than 2. Surfaces of metals, metal oxides, and metal nitrides have hydroxyl groups or amino groups on the surfaces due to the influence of oxygen and moisture in the atmosphere. By this surface functional group, the aromatic-containing organic compound having an allyl group having a high SP value has a strong interaction with the thermally conductive inorganic filler. The organic compound of the component (B) having a high SP value is intentionally cross-linked by an aromatic-containing organic compound having an allyl group between the islands of the thermally conductive inorganic filler floating in the silicone matrix. By doing so, it has come to exhibit heat dissipation characteristics that were not found in conventional silicone heat conductive heat dissipation grease.
Aromatic-containing organic compounds having an allyl group and a thermally conductive inorganic filler even when the grease is misaligned or deformed by imparting thermosetting properties to the aromatic-containing organic compound having an allyl group Since the heat path is maintained, it can be expected that the heat conduction characteristics do not change.

  The component (E) is a filler that imparts thermal conductivity to the thermally conductive silicone grease composition of the present invention.

The heat conductive inorganic filler (E) used in the present invention needs to have an average particle size of 0.5 to 100 μm. Even if the average particle diameter is smaller than 0.5 μm or larger than 100 μm, the grease becomes non-uniform and has a high viscosity, so that it is particularly preferably 1 to 20 μm. In the present invention, the average particle diameter is a mass average value D ₅₀ (or median diameter) measured by a laser diffraction method.

  Examples of the thermally conductive inorganic filler of the component (E) include metal powder, metal oxide powder, metal hydroxide powder, and metal nitride powder. Specifically, aluminum, silver, copper, nickel Zinc oxide, aluminum oxide, silicon oxide, magnesium oxide, aluminum nitride, boron nitride, silicon nitride, metal silicon, or one or a combination of two or more thereof are preferred.

  The blending amount of component (E) is based on 100 parts by mass of (A) component organopolysiloxane, (B) component-containing aromatic compound having an allyl group, and (C) component organohydrogenpolysiloxane. It is necessary to be in the range of 200 to 2,000 parts by mass, and preferably in the range of 700 to 1,500 parts by mass. If the amount is less than 200 parts by mass, not only a sufficient thermal conductivity cannot be obtained, but also the strength as grease cannot be maintained, so that it becomes easy to shift. If it is larger than 2,000 parts by mass, the grease cannot be maintained.

  When producing the thermally conductive silicone grease composition of the present invention, the (A), (B), (C) component, (E) component and other components are added to produce a trimix, twin mix, planetary mixer ( All are registered trademarks of the mixer manufactured by Inoue Seisakusho Co., Ltd., Ultramixer (registered trademark of the mixer manufactured by Mizuho Industry Co., Ltd.), Hibis Disper Mix (registered trademark of the mixer manufactured by Special Machine Industries Co., Ltd.), etc. Mix using a mixer. If necessary, you may heat to 50-170 degreeC.

In the present invention, the grease viscosity (viscosity of the thermally conductive silicone grease composition) is 50 to 1,000 Pa · s, preferably 100 to 500 Pa · s at 25 ° C.
If the viscosity is too low, the filler is heavily settled and requires mixing and stirring before use. If the viscosity is too high, precise ejection becomes difficult.
The grease viscosity is a value measured with model number PC-1TL (rotation speed: 10 rpm) manufactured by Malcolm Corporation.

In addition, the hardness when the thermally conductive silicone grease composition of the present invention is heated at 150 ° C. for 120 minutes is 5 to 75, particularly 10 to 60 as measured by Asker C. ) Can prevent cracking and misalignment.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in full detail, this invention is not limited by this. The tests according to Examples and Comparative Examples conducted for clarifying the superiority of the present invention are as follows.

[Viscosity of organopolysiloxanes and allyl-containing aromatic compounds]
Using a Brookfield type rotational viscometer, 25 ± 0.5 ° C., rotor No. The measurement was performed at 4, 10 rpm.

[Grease viscosity]
The viscosity of the thermally conductive silicone grease composition was measured at 25 ° C. using model number PC-1TL (rotation speed: 10 rpm) manufactured by Malcolm Corporation.

〔Thermal conductivity〕
The thermal conductivity was measured at 25 ° C. using TPA-501 manufactured by Kyoto Electronics Industry Co., Ltd.

[Crack / Deviation]
1.0 g of a thermally conductive silicone grease composition shown in Examples and Comparative Examples was sandwiched with a 1 mm spacer between the glass plate and the aluminum plate. After putting this test piece in a dryer at 150 ° C. for 2 hours to cure the silicone grease composition, it was put into a cooling cycle of −45 ° C./30 minutes to 125 ° C./30 minutes and 250 times later. The condition of the grease was observed.

Ａ−２：オルガノシラン（ＳＰ値８．２，粘度３ｍＰａ・ｓ）

Ａ−３：オルガノポリシロキサン（ＳＰ値８．１，粘度８０ｍＰａ・ｓ）

In addition, (A)-(E) component in a table | surface is as follows.
Organopolysiloxane (A) A-1: Organopolysiloxane (SP value 8.0, viscosity 30 mPa · s)

A-2: Organosilane (SP value 8.2, viscosity 3 mPa · s)

A-3: Organopolysiloxane (SP value 8.1, viscosity 80 mPa · s)

Ｂ−２：アリル基含有ビスフェノールＦ型エポキシ樹脂（ＳＰ値１１．２，粘度１８，０００ｍＰａ・ｓ）

Ｂ−３：エピコート６３０（ＳＰ値１４．６，粘度２５０ｍＰａ・ｓ）

B-1: Allyl group-containing bisphenol F type phenol resin (SP value 13.5, viscosity 25,000 mPa · s) as the aromatic-containing organic compound (B) having an allyl group

B-2: Allyl group-containing bisphenol F type epoxy resin (SP value 11.2, viscosity 18,000 mPa · s)

B-3: Epicoat 630 (SP value 14.6, viscosity 250 mPa · s)

Ｃ−２：オルガノハイドロジェンポリシロキサンＤ４

Ｃ−３：オルガノハイドロジェンポリシロキサンＤ１６

Ｃ−４：オルガノハイドロジェンポリシロキサンＤ２５

Ｃ−５：オルガノハイドロジェンポリシロキサンＤ２

Ｃ−６：オルガノハイドロジェンポリシロキサンＭ２

(C) Component: Organohydrogenpolysiloxane represented by the following formula C-1: Organohydrogenpolysiloxane D3

C-2: Organohydrogenpolysiloxane D4

C-3: Organohydrogenpolysiloxane D16

C-4: Organohydrogenpolysiloxane D25

C-5: Organohydrogenpolysiloxane D2

C-6: Organohydrogenpolysiloxane M2

(E) component:
E-1: Zinc oxide powder (average particle size 1.1 μm)
E-2: Aluminum powder (average particle size 10 μm)
E-3: Alumina powder (average particle size 1.0 μm)
E-4: Alumina powder (average particle size 10 μm)

In addition, [PL-5 (Shin-Etsu Chemical Co., Ltd.)] was used as a reaction catalyst between the allyl group of component (D) and the organohydrogenpolysiloxane, which was a dimethylvinylsilyl end-capped dimethylpolysiloxane solution of a platinum-divinyltetramethyldisiloxane complex. Industrial Co., Ltd.)].
DICY (dicyandiamide) was used as the catalyst of the comparative example in Table 3.

  The particle size of the thermally conductive inorganic filler is a volume-based cumulative average diameter measured by Microtrac MT3300EX, a particle size analyzer manufactured by Nikkiso Co., Ltd.

  The results of Tables 2 and 3 show that the thermally conductive silicone grease composition of the present invention is not only excellent in thermal conductivity, but also does not generate cracks or misalignment during the cooling and heating cycle. -It demonstrates that it is excellent in removing heat from electronic components.

  The thermally conductive silicone grease composition of the present invention not only has excellent thermal conductivity, but also does not generate cracks or misalignment during a cooling cycle, so it can remove heat from electrical and electronic components that generate heat during use. Is preferred.

Claims (4)

(A) Organopolysiloxane: 20 to 90 parts by mass,
(B) Aromatic-containing organic compound having an allyl group: 40 to 5 parts by mass
(C) Organohydrogenpolysiloxane: 40-5 parts by mass,
(However, the total of the components (A), (B), and (C) is 100 parts by mass.)
(D) a catalyst selected from the group consisting of platinum and platinum compounds: catalytic amount,
(E) Thermally conductive inorganic filler having an average particle size of 0.5 to 100 μm: Contains 200 to 2,000 parts by mass with respect to a total of 100 parts by mass of the components (A), (B) and (C). The SP value of the organopolysiloxane (A) and the aromatic-containing organic compound (B) having an allyl group is (B)> (A) and (B) SP value of component) -SP value of component (A)> 2 and the viscosity of the heat conductive silicone grease composition is 50 to 1,000 Pa · s at 25 ° C. Grease composition. Organopolysiloxane (A) is represented by the following general formula (1)

Wherein R ¹ is the same or different monovalent hydrocarbon group. X ¹ , X ² and X ³ are groups represented by R ¹ or —R ² —SiR ¹ _a (OR ³ ) _3-a There, even different from each good .R ¹ is of the street, R ² represents an oxygen atom or an alkylene group having 1 to 4 carbon atoms, R ³ is an alkyl group having 1 to 4 carbon atoms, an alkoxyalkyl group, an alkenyl group or an acyl A is an integer of 1 to 3. m and n are 1 ≦ m ≦ 1,000 and 0 ≦ n ≦ 1,000, respectively.
And a trifunctional hydrolyzable organopolysiloxane having a viscosity at 25 ° C. of 0.005 to 100 mPa · s,
The aromatic-containing organic compound (B) having an allyl group is a compound having an SP value of 10 or more having an organic group selected from an epoxy group and a phenolic hydroxyl group in the molecule,
The organohydrogenpolysiloxane (C) has three or more hydrogen atoms bonded to silicon atoms in the molecule,
The thermally conductive silicone grease according to claim 1, wherein the thermally conductive inorganic filler (E) is at least one selected from a metal powder, a metal oxide powder, a metal hydroxide powder, and a metal nitride powder. Composition.   The organohydrogenpolysiloxane (C) is an organohydrogenpolysiloxane having 3 or more hydrogen atoms bonded to silicon atoms in one molecule, and for one allyl group in the component (B), The thermally conductive silicone grease composition according to claim 1 or 2, wherein the number of hydrogen atoms bonded to silicon atoms in the component is 0.1 to 1.0.   The heat conductive inorganic filler (E) is one or two selected from aluminum, silver, copper, nickel, zinc oxide, aluminum oxide, silicon oxide, magnesium oxide, aluminum nitride, boron nitride, silicon nitride, and metal silicon The thermally conductive silicone grease composition according to any one of claims 1 to 3, which is a combination of at least species.