JP2017002179A - Thermally conductive silicone putty composition - Google Patents

Abstract

SOLUTION: A thermal conductive silicon putty composition contains following components (A) to (D): (A) organopolysiloxane represented by the formula (1), RSiO(1), where Ris one or more kind of groups selected from a group of saturated or unsaturated monovalent hydrocarbon group having 1 to 18 carbon atoms and the a is 1.8≤a≤2.2, and having kinetic viscosity at 25°C of 10 to 100,000 mm/s; (B) organopolysiloxane raw rubber having absolute viscosity at 25°C when xylene soluble organopolysiloxane of 30 mass% is dissolved into xylene of 5,000 to 40,000 mPa s; (C) an aluminum hydroxyl powder having average particle diameter of 0.5 to 10 μm; and (D) one or more kind of inorganic compound powder selected from an aluminum powder, a zinc oxide powder, an alumina powder, a boron nitride powder, an aluminum nitride powder and having average particle powder of 0.5 to 100 μm.EFFECT: A composition has large enhancement of lag resistance even with flowability.SELECTED DRAWING: None

Description

  The present invention relates to a thermally conductive silicone putty composition having excellent misalignment resistance.

Generally, since heat is generated during use of electric / electronic parts, heat removal is necessary to properly operate the electric parts, and various heat conductive materials for heat removal have been proposed. This heat conductive material is roughly classified into two types: 1) a sheet-like material that is easy to handle, and 2) a paste-like material.
The sheet-like material is easy to handle and has the advantage of excellent stability, but the contact heat resistance is increased in nature, so the heat dissipation performance is inferior to the paste-like material. In addition, a certain degree of strength / hardness is required to maintain the sheet shape, the tolerance generated between the element and the casing cannot be absorbed, and the element may be destroyed by the stress.
On the other hand, the paste-like material can be applied to mass production by using a coating device or the like, and has excellent heat radiation performance because of low contact thermal resistance. However, when mass-produced by screen printing or the like, the viscosity of the paste should be low, but in that case, the paste will be displaced due to the thermal shock of the element (pump-out phenomenon), and slow heating is not sufficient, As a result, the device sometimes malfunctions.
In addition, the following technologies have been proposed as past technologies, but none of them has achieved sufficient performance.

Japanese Patent No. 3948642 Japanese Patent No. 3195277 JP 2000-169873 A JP 2006-143978 A JP 2004-210856 A JP 2005-162975 A Japanese Patent No. 5300408

  This invention is made | formed in view of the said situation, and it aims at providing the heat conductive silicone putty composition excellent in the shift | offset | difference resistance.

  As a result of intensive studies to achieve the above object, the present inventor has mixed a specific organopolysiloxane and a certain proportion of aluminum hydroxide having a relatively small particle size in the thermally conductive silicone putty composition. It has been found that when mixed as described above, the slip resistance is drastically improved while having fluidity.

（式中、Ｒ²は炭素数１〜６のアルキル基、Ｒ³は炭素数１〜１８の飽和又は不飽和の一価炭化水素基の群の中から選択される１種もしくは２種以上の基、ｂは５〜１２０の整数である。）
で表される片末端３官能の加水分解性オルガノポリシロキサンを成分（Ａ）１００質量部に対し１〜５０質量部含むことを特徴とする〔１〕記載の熱伝導性シリコーンパテ組成物。
〔３〕
成分（Ａ）、（Ｂ）、（Ｅ）を分散又は溶解する溶剤（Ｆ）を成分（Ａ）１００質量部に対し１〜１００質量部含むことを特徴とする〔１〕又は〔２〕の熱伝導性シリコーンパテ組成物。
〔４〕
前記成分（Ｆ）は、沸点８０〜２６０℃のイソパラフィン系溶剤であることを特徴とする〔１〕〜〔３〕のいずれかに記載の熱伝導性シリコーンパテ組成物。 Accordingly, the present invention provides the following thermally conductive silicone putty composition.
[1]
A thermally conductive silicone putty composition comprising the following components (A) to (D).
(A) The following general formula (1)
R ¹ _a SiO _{(4-a) / 2} (1)
[Wherein, R ¹ is one or more groups selected from the group of saturated or unsaturated monovalent hydrocarbon groups having 1 to 18 carbon atoms, and a is 1.8 ≦ a ≦ 2. 2. ]
An organopolysiloxane having a kinematic viscosity of 10 to 100,000 mm ² / s at 25 ° C. represented by: 100 parts by mass,
(B) When 30 mass% of xylene-soluble organopolysiloxane is dissolved in xylene, an organopolysiloxane raw rubber having an absolute viscosity at 25 ° C of 5,000 to 40,000 mPa · s: 1 to 50 parts by mass;
(C) Aluminum hydroxide powder having an average particle size of 0.5 to 10 μm: 10 to 200 parts by mass,
(D) One or more inorganic compound powders selected from aluminum powder, zinc oxide powder, alumina powder, boron nitride powder and aluminum nitride powder having an average particle size of 0.5 to 100 μm: 500 to 3,000 mass Department.
[2]
(E) The following general formula (2)

Wherein R ² is an alkyl group having 1 to 6 carbon atoms, R ³ is one or more selected from the group of saturated or unsaturated monovalent hydrocarbon groups having 1 to 18 carbon atoms. Group b is an integer from 5 to 120.)
1 to 50 parts by mass of the trifunctional hydrolyzable organopolysiloxane represented by the formula (1) with respect to 100 parts by mass of the component (A).
[3]
1 to 100 parts by mass of the solvent (F) for dispersing or dissolving the components (A), (B) and (E) with respect to 100 parts by mass of the component (A) Thermally conductive silicone putty composition.
[4]
The heat conductive silicone putty composition according to any one of [1] to [3], wherein the component (F) is an isoparaffin solvent having a boiling point of 80 to 260 ° C.

  Although the heat conductive silicone putty composition of the present invention has fluidity, a significant improvement in misalignment resistance is recognized.

Hereinafter, the present invention will be described in more detail.
The organopolysiloxane of the component (A) has a kinematic viscosity at 25 ° C. represented by the following general formula (1) of 10 to 100,000 mm ² / s.
R ¹ _a SiO _{(4-a) / 2} (1)
[Wherein, R ¹ is one or more groups selected from the group of saturated or unsaturated monovalent hydrocarbon groups having 1 to 18 carbon atoms, and a is 1.8 ≦ a ≦ 2. 2. ]

In the above formula (1), R ¹ is one or more groups selected from the group of saturated or unsaturated monovalent hydrocarbon groups having 1 to 18 carbon atoms. Such groups include, for example, methyl groups, ethyl groups, propyl groups, hexyl groups, octyl groups, decyl groups, alkyl groups such as dodecyl groups, tetradecyl groups, hexadecyl groups, octadecyl groups, cyclopentyl groups, cyclohexyl groups, etc. An alkenyl group such as a cycloalkyl group, a vinyl group and an allyl group; an aryl group such as a phenyl group and a tolyl group; an aralkyl group such as a 2-phenylethyl group and a 2-methyl-2-phenylethyl group; Examples thereof include halogenated hydrocarbon groups such as trifluoropropyl group, 2- (perfluorobutyl) ethyl group, 2- (perfluorooctyl) ethyl group, and p-chlorophenyl group. From the viewpoint of the consistency required for the silicone grease composition, a is preferably in the range of 1.8 to 2.2, and particularly preferably 1.9 to 2.1.

Further, if the kinematic viscosity at 25 ° C. of the organopolysiloxane used in the present invention is lower than 10 mm ² / s, oil bleeding tends to occur when it is made into a putty composition, and if it is higher than 100,000 mm ² / s, the putty composition Dispensability when made into a product becomes poor, so that it is necessary to be 10 to 100,000 mm ² / s at 25 ° C., and particularly preferably 30 to 10,000 mm ² / s. The kinematic viscosity of the organopolysiloxane is a value of 25 ° C. measured with an Ostwald viscometer.

  The organopolysiloxane raw rubber of component (B) is soluble in xylene, and has an absolute viscosity of 5,000 to 40,000 mPa · s at 25 ° C. when dissolved in 30% by mass in xylene. The structure itself is represented by the general formula (1) as in the case of the component (A). However, the degree of polymerization of siloxane is larger than that of component (A), and is generally called silicone raw rubber.

  When dissolved at 30% by mass in xylene, if the absolute viscosity at 25 ° C. is less than 5,000 mPa · s, the resistance to misalignment will be poor, and if it is greater than 40,000 mPa · s, the dispensing property will be poor. The range is 40,000 mPa · s, preferably 10,000 to 35,000 mPa · s.

  Further, when the content of the component (B) is less than 1 part by mass, misalignment resistance is deteriorated, and when it is greater than 50 parts by mass, the handleability is deteriorated, so the range of 1 to 50 parts by mass, more preferably 5 The range of -30 mass parts is good. The viscosity of 30% by mass dissolved in xylene is a value of 25 ° C. measured with a BH tachometer.

  The aluminum hydroxide powder in the component (C) of the present invention improves the displacement resistance of the silicone heat dissipation putty of the present invention. The aluminum hydroxide powder used in the present invention has poor fluidity and handling properties when the average particle size is smaller than 0.5 μm, and misalignment resistance is worse when it is larger than 10 μm. The range is 10 μm, and preferably 1 to 5 μm.

  In the present invention, the average particle diameter is a volume average particle diameter, and can be measured with a laser diffraction / scattering particle size distribution measuring instrument Microtrac MT3300EX (hereinafter the same).

  Moreover, when the compounding amount of the component (C) is less than 10 parts by mass, misalignment resistance is deteriorated, and when it is greater than 200 parts by mass, the fluidity is deteriorated and the handleability is deteriorated. The amount is preferably 30 to 100 parts by mass.

  The aluminum hydroxide powder used in the present invention may be hydrophobized with an organosilane, an organosilazane, an organopolysiloxane, an organic fluorine compound or the like if necessary. As the hydrophobizing method, a generally known method may be used. For example, aluminum hydroxide powder and organosilane or a partial hydrolyzate thereof are mixed into a trimix, twin mix, planetary mixer (all registered with a mixer manufactured by Inoue Mfg. Co., Ltd.). Trademark), Ultramixer (registered trademark of Mizuho Kogyo Co., Ltd. mixer), Hibis Dispermix (registered trademark of Special Kikai Kogyo Co., Ltd. mixer) and the like. If necessary, you may heat to 50-150 degreeC. For mixing, a solvent such as toluene, xylene, petroleum ether, mineral spirit, isoparaffin, isopropyl alcohol, ethanol or the like may be used. In that case, it is preferable to remove the solvent using a vacuum apparatus or the like after mixing.

  The inorganic compound powder used in component (D) must have high thermal conductivity, and one or two selected from aluminum powder, zinc oxide powder, alumina powder, boron nitride powder, and aluminum nitride powder. More than seeds can be used. The surface of these inorganic compound powders may be subjected to a hydrophobic treatment with an organosilane, an organosilazane, an organopolysiloxane, an organic fluorine compound or the like, if necessary.

  The average particle size of the inorganic compound powder of component (D) is in the range of 0.5 to 100 μm because the filling rate of the obtained grease composition cannot be increased even if it is smaller than 0.5 μm or larger than 100 μm. Is preferably in the range of 1 to 50 μm.

  When the blending amount of the inorganic compound powder as the component (D) is less than 500 parts by mass in the heat conductive silicone putty composition, the thermal conductivity of the resulting composition is deteriorated and is greater than 3,000 parts by mass. Since the fluidity is poor and the handling is poor, the range of 500 to 3,000 parts by mass is preferable. More preferably, it is 1,000-2,500 mass parts.

（式中、Ｒ²は炭素数１〜６のアルキル基、Ｒ³は炭素数１〜１８の飽和又は不飽和の一価炭化水素基の群の中から選択される１種もしくは２種以上の基、ｂは５〜１２０の整数である。） As the component (E), a one-terminal trifunctional hydrolyzable organopolysiloxane represented by the following general formula (2) is used.

Wherein R ² is an alkyl group having 1 to 6 carbon atoms, R ³ is one or more selected from the group of saturated or unsaturated monovalent hydrocarbon groups having 1 to 18 carbon atoms. Group b is an integer from 5 to 120.)

  The organopolysiloxane of the general formula (2) is used to treat the surface of the thermally conductive inorganic fillers of the components (C) and (D), but it only helps to increase the powder filling. Furthermore, the powder surface is less likely to agglomerate by covering the powder surface, and the effect is maintained even at high temperatures, so that the heat resistance of the thermally conductive silicone putty composition is improved.

In the above formula (2), R ² includes, for example, an alkyl group having 1 to 6 carbon atoms such as a methyl group, an ethyl group, and a propyl group, and a methyl group and an ethyl group are particularly preferable. R ³ is one or more groups selected from the group of saturated or unsaturated monovalent hydrocarbon groups having 1 to 18 carbon atoms. Examples of such groups include methyl groups, ethyl groups, and the like. Group, propyl group, hexyl group, octyl group, decyl group, dodecyl group, tetradecyl group, hexadecyl group, octadecyl group and other alkyl groups, cyclopentyl group, cyclohexyl group and other cycloalkyl groups, vinyl group, allyl group and other alkenyl groups Aryl groups such as phenyl group and tolyl group, aralkyl groups such as 2-phenylethyl group and 2-methyl-2-phenylethyl group, 3,3,3-trifluoropropyl group, 2- (perfluorobutyl) ethyl Group, a halogenated hydrocarbon group such as 2- (perfluorooctyl) ethyl group, p-chlorophenyl group, and the like, and a methyl group is particularly preferable. B of General formula (2) is an integer of 5-120, Preferably it is an integer of 10-90.

  When the addition amount of the organopolysiloxane of the general formula (2) is less than 1 part by mass with respect to 100 parts by mass of the component (A), the desired putty composition cannot be obtained, and from 50 parts by mass. If it is large, the resistance to misalignment is deteriorated, so the range is 1 to 50 parts by mass, preferably 3 to 30 parts by mass.

Moreover, you may add a component (F) to this heat conductive silicone putty composition as needed.
By adding the component (F), the heat conductive silicone putty becomes soft, so that the dispensing property is improved. In addition, after application, the component (F) is volatilized depending on the operating temperature of the device to be applied, etc., so that the shift resistance is not affected.

  The solvent as the component (F) is not particularly limited as long as it can disperse or dissolve the components (A), (B), and (E). For example, toluene, xylene, acetone, methyl ethyl ketone, cyclohexane, n- Examples include hexane, n-heptane, butanol, IPA, and isoparaffin. In particular, from the viewpoint of the environment, it is preferable to use an isoparaffin solvent. When the boiling point of the isoparaffinic solvent is less than 80 ° C., the volatilization becomes too fast, causing a problem in storage stability. If the boiling point exceeds 260 ° C., the solvent tends to remain in the thermally conductive silicone putty composition, and defects such as voids are generated, resulting in deterioration of the thermal characteristics. Therefore, the boiling point range of 80 to 260 ° C. It is desirable to be within.

  When the amount of the solvent is less than 1 part by mass with respect to 100 parts by mass of the component (A), dispense applicability deteriorates, and when it exceeds 100 parts by mass, it becomes difficult to volatilize after application. It is preferable that it is -100 mass parts, More preferably, it is 5-60 mass parts.

  In order to produce the thermally conductive silicone grease composition of the present invention, each of the above components is mixed with Trimix, Twin Mix, Planetary Mixer (all registered trademarks of a mixer manufactured by Inoue Seisakusho Co., Ltd.), Ultra Mixer (Mizuho Industry ( Mixing is performed for 30 minutes to 4 hours in a mixing machine such as a registered trademark of a mixer manufactured by Kogyo Co., Ltd., Hibis Disper Mix (registered trademark of a mixer manufactured by Tokushu Kika Kogyo Co., Ltd.). If necessary, you may heat to 50-150 degreeC.

  The heat conductive heat dissipation putty composition according to the present invention is also characterized in that it can be dispensed. The container used for dispensing is not particularly limited, and is generally filled in what is called a syringe or cartridge that is commercially available, and is applied to a desired location with air or mechanical pressure during use. The

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in full detail, this invention is not limited by this. In order to clarify the superiority of the present invention, specific examples will be shown and proved.

The test relating to the present invention was performed as follows.
〔Thermal conductivity〕
The thermal conductivity was measured at 25 ° C. using TPS-2500S manufactured by Kyoto Electronics Industry Co., Ltd.
(Particle size measurement)
The particle size measurement is a volume-based cumulative average diameter measured by Microtrack MT3300EX, which is a particle size analyzer manufactured by Nikkiso Co., Ltd.
[Displacement]
A 1 mm spacer is provided, and a thermally conductive silicone putty composition is sandwiched between two slide glass plates so as to form a circle having a diameter of 1.5 cm, and the test piece is tilted 90 degrees with respect to the ground. It was placed in a thermal shock tester (model number: TSE-11-A) manufactured by ESPEC Co., Ltd. set so as to alternately repeat at 100 ° C. and 100 ° C. (each 15 minutes), and a 100 cycle test was conducted. After 100 cycles, how much the thermally conductive silicone putty composition shifted from its original location was measured.
<Standard>
If it is 1 mm or less, it can be said that the displacement resistance is excellent.
[Dispensing]
30g of heat conductive silicone putty composition is put into a 30cc syringe (trade name: Optimum) manufactured by Nordson Co., Ltd., and removed for 10 minutes at 2,000 rpm in a centrifuge (trade name: HL-7) manufactured by Kokusan Co., Ltd. I worried. Thereafter, dispensing was performed at a pressure of 0.4 MPa for 5 seconds without attaching the needle. Dispensing was performed 5 times, and the average of the dispense weight was defined as the discharge amount.
<Standard>
When it exceeds 0.5 g, it can be said that the dispensing property is excellent.

[Examples 1 to 5, Comparative Examples 1 to 10]
As shown in Tables 1, 2, and 3, each component was charged into a planetary mixer (the number in the table indicates g) and uniformly mixed at 25 ° C. for 30 minutes to prepare a heat conductive putty composition. The various tests mentioned above were done using the obtained composition. The results are also shown in Tables 1, 2, and 3. In addition, the used components (A) to (F) are as shown below.

Ingredient (A)
(A-1)
A linear dimethylpolysiloxane having a kinematic viscosity of 1,000 mm ² / s, both ends of which are blocked with trimethylsilyl groups.
(A-2)
A linear dimethylpolysiloxane having a kinematic viscosity of 5,000 mm ² / s, both ends of which are blocked with trimethylsilyl groups.
(A-3)

Ingredient (B)
(B-1)
A dimethylpolysiloxane raw rubber having a vinyl group at both ends having an absolute viscosity of 11,000 mPa · s at 25 ° C. when dissolved in 30% by mass in xylene.
(B-2)
A dimethylpolysiloxane raw rubber having a hydroxy group at both ends having an absolute viscosity of 33,000 mPa · s at 25 ° C. when dissolved in 30% by mass in xylene.
(B-3)
A dimethylpolysiloxane raw rubber having a vinyl group at both ends having an absolute viscosity at 25 ° C. of 4,500 mPa · s when dissolved in 30% by mass in xylene. <For comparative example>
(B-4)
A dimethylpolysiloxane raw rubber having a hydroxy group at both ends, having an absolute viscosity of 41,000 mPa · s at 25 ° C. when dissolved in 30% by mass in xylene. <For comparative example>

Ingredient (C)
Aluminum hydroxide powder (C-1) average particle size 1.0 μm, irregular shape (C-2) average particle size 2.5 μm, irregular shape (C-3) average particle size 14.5 μm, irregular shape <For Comparative Example >
(C-4) Average particle size 0.4 μm, irregular shape <for comparative example>

Ingredient (D)
(D-1) Aluminum powder (average particle size: 30 μm)
(D-2) Zinc oxide powder (average particle size: 1.0 μm)
(D-3) Alumina powder (average particle size: 15.7 μm)
(D-4) Boron nitride powder (average particle size: 2.0 μm)
(D-5) Aluminum nitride powder (average particle size: 6.8 μm)

Ingredient (E)
(E-1)

Ingredient (F)
(F-1)
IP solvent 2028 (an isoparaffin solvent having a boiling point of 210 to 254 ° C., trade name of Idemitsu Kosan Co., Ltd.)

Claims (4)

A thermally conductive silicone putty composition comprising the following components (A) to (D).
(A) The following general formula (1)
R ¹ _a SiO _{(4-a) / 2} (1)
[Wherein, R ¹ is one or more groups selected from the group of saturated or unsaturated monovalent hydrocarbon groups having 1 to 18 carbon atoms, and a is 1.8 ≦ a ≦ 2. 2. ]
An organopolysiloxane having a kinematic viscosity of 10 to 100,000 mm ² / s at 25 ° C. represented by: 100 parts by mass,
(B) When 30 mass% of xylene-soluble organopolysiloxane is dissolved in xylene, an organopolysiloxane raw rubber having an absolute viscosity at 25 ° C of 5,000 to 40,000 mPa · s: 1 to 50 parts by mass;
(C) Aluminum hydroxide powder having an average particle size of 0.5 to 10 μm: 10 to 200 parts by mass,
(D) One or more inorganic compound powders selected from aluminum powder, zinc oxide powder, alumina powder, boron nitride powder and aluminum nitride powder having an average particle size of 0.5 to 100 μm: 500 to 3,000 mass Department. (E) The following general formula (2)

Wherein R ² is an alkyl group having 1 to 6 carbon atoms, R ³ is one or more selected from the group of saturated or unsaturated monovalent hydrocarbon groups having 1 to 18 carbon atoms. Group b is an integer from 5 to 120.)
The thermally conductive silicone putty composition according to claim 1, comprising 1 to 50 parts by mass of a trifunctional hydrolyzable organopolysiloxane represented by the formula (100) with respect to 100 parts by mass of the component (A).   The heat conduction according to claim 1 or 2, comprising 1 to 100 parts by mass of the solvent (F) for dispersing or dissolving the components (A), (B) and (E) with respect to 100 parts by mass of the component (A). Silicone putty composition.   The thermally conductive silicone putty composition according to any one of claims 1 to 3, wherein the component (F) is an isoparaffin solvent having a boiling point of 80 to 260 ° C.