WO2008066051A1

WO2008066051A1 - Thermally conductive resin composition

Info

Publication number: WO2008066051A1
Application number: PCT/JP2007/072875
Authority: WO
Inventors: Takayuki Miyashita; Takashi Usami
Original assignee: Polyplastics Co., Ltd.
Priority date: 2006-11-29
Filing date: 2007-11-20
Publication date: 2008-06-05
Also published as: CN101547975A; JP2008133382A; CN101547975B; JP5122116B2

Abstract

Disclosed is an insulating material having high thermal conductivity, which is excellent in moldability and abrasion characteristics. Specifically disclosed is an insulating material obtained by adding 10-200 parts by weight of a fibrous titanium oxide (B) having a thermal conductivity of not less than 3 W/m•K and an aspect ratio of not less than 10, and 10-400 parts by weight of one or more plate-like, spherical or amorphous thermally conductive fillers (C) having a thermal conductivity of not less than 2 W/m•K to 100 parts by weight of a liquid crystalline polymer (A) (provided that the total addition amount of the components (B) and (C) is 30-500 parts by weight per 100 parts by weight of the liquid crystalline polymer (A)). The thermal conductivity of the composition is set at not less than 0.8 W/m•K.

Description

Technical Field of Thermally Conductive Resin Composition

The present invention relates to an insulating heat conductive resin composition having excellent moldability and wear characteristics. More specifically, the present invention relates to a heat used for various automobile parts, electric and electronic parts and the like that require heat dissipation. The present invention relates to a liquid crystalline polymer composition having excellent conductivity. Background art

Liquid crystalline polymers that can form an anisotropic molten phase are known as materials that are superior in dimensional accuracy and vibration damping properties among thermoplastic resins, and that generate very little burrs during molding. In the past, taking advantage of these characteristics, liquid crystal polymer compositions reinforced with glass fibers have been widely used as materials for various electric and electronic parts. However, in recent years, these components have become lighter, thinner, and shorter, and heat radiation inside the components has become a problem, and there has been a demand for materials that impart heat dissipation.

For this reason, a method has been proposed in which alumina having a specific particle diameter is added to a thermoplastic resin to improve moldability and thermal conductivity (Japanese Patent Laid-Open No. 2 0 0 2-1 4 6 1 8 7 Although this method improves moldability, the Mohs hardness of alumina is high, so the extruder, the screw of the molding machine, the cylinder, and the molding die are severely worn during kneading with the resin and during molding. There was a problem of mixing.

On the other hand, a method for imparting thermal conductivity by blending graphite in a liquid crystalline polymer has been proposed (Japanese Patent Laid-Open No. 2 0 06-2 5 7 1 7 4). Although there is no wear such as squealing, there is a problem that it cannot be used in fields where electrical insulation is required because electrical conductivity is imparted simultaneously with thermal conductivity.

In addition, it has been proposed to add a thermal conductive filler having an aspect of 5 or more to a thermoplastic resin (Japanese Patent Application Laid-Open No. 2000-061 1994). Only PBO (polybenzazole) fibers are used, and other fibrous thermal conductive fillers have not been studied, and fibrous fillers alone are used in large quantities to improve thermal conductivity. There was a problem that the fluidity was remarkably lowered when added to.

In addition, it has been proposed that amorphous titanium oxide is added to a thermoplastic resin to improve light reflectivity and light shielding property and to be used as a photocatalyst (Japanese Patent Laid-Open No. 2 0 0 4-7 5 7 7 0 No. 2 and Japanese Laid-Open Patent Publication No. 2 0 3-2 5 3 1 3 0) have not been studied for improving thermal conductivity. Disclosure of the invention

An object of the present invention is to solve the above-mentioned drawbacks of the prior art and to provide a highly heat-conductive material that is insulating and excellent in moldability and wear characteristics.

In view of the above-mentioned problems, the present inventors diligently searched for and studied a liquid crystalline polymer composition having excellent moldability and wear characteristics and high thermal conductivity. As a result, specific fibers were obtained for the liquid crystalline polymer. The present invention has been completed by finding that it is extremely effective to combine a sheet-like heat conductive filler with a specific plate-like / spherical / indeterminate heat-conductive filler.

That is, the present invention

(A) For 100 parts by weight of liquid crystalline polymer,

(B) Thermal conductivity 3 WZm · K or more, 10 to 200 parts by weight of fibrous titanium oxide with an aspect ratio of 10 or more,

(C) Thermal conductivity 2 WZm · K or more plate shape · Spherical shape · Indeterminate shape Add one or more heat conductive fillers 10 to 400 parts by weight,

The total addition amount of the components (B) and (C) is 30 to 500 parts by weight with respect to 100 parts by weight of the (A) liquid crystalline polymer, and the thermal conductivity is at least 0.8 W / m · K. Insulating heat conductive resin composition.

The above composition has a thermal conductivity of 0.8 W / m · K or more. Detailed Description of the Invention

Hereinafter, the present invention will be described in detail. The liquid crystalline polymer (A) used in the present invention refers to a melt processable polymer having a property capable of forming an optically anisotropic molten phase. The properties of the anisotropic molten phase can be confirmed by a conventional polarization inspection method using an orthogonal polarizer. More specifically, the anisotropic molten phase can be confirmed by observing a molten sample placed on a Leitz hot stage at a magnification of 40 times in a nitrogen atmosphere using a Leit _Z polarization microscope. . When a liquid crystalline polymer applicable to the present invention is examined between crossed polarizers, polarized light is normally transmitted even in a molten stationary state, and optically anisotropic.

The liquid crystalline polymer (A) is not particularly limited, but is preferably an aromatic polyester or an aromatic polyester amide, and the aromatic polyester or the aromatic polyester amide is contained in the same molecular chain. Partially included polyesters are also in that range. These are preferably at least about 2.0 d 1 / g, more preferably from 2.0 to 10 O dl / g when dissolved in pentafluorophenol at a concentration of 0.1 wt% at 60 ° C. Those having logarithmic viscosity (I.V.) are used.

The aromatic polyester or aromatic polyester amide as the liquid crystalline polymer (A) applicable to the present invention is particularly preferably at least selected from the group consisting of aromatic hydroxycarboxylic acids, aromatic hydroxyamines and aromatic diamines. Aromatic polyesters and aromatic polyester amides having one or more compounds as constituents.

More specifically,

(1) A polyester mainly composed of one or more aromatic hydroxycarboxylic acids and derivatives thereof;

(2) Primarily (a) One or more aromatic hydroxycarboxylic acids and their derivatives, and (b) One or two derivatives of aromatic dicarboxylic acids and alicyclic dicarboxylic acids. And (c) a polyester comprising at least one or more of aromatic diol, alicyclic diol, aliphatic diol and derivatives thereof. Stealth;

(3) Mainly (a) one or more aromatic hydroxycarboxylic acid derivatives and (b) one or two aromatic hydroxyamines, aromatic diamines and their derivatives. And (c) a polyester amide comprising one or more of aromatic dicarboxylic acid, alicyclic dicarboxylic acid and derivatives thereof;

(4) Mainly (a) one or more aromatic hydroxycarboxylic acids and derivatives thereof; and (b) one or more aromatic hydroxyamines, aromatic diamines and derivatives thereof. (C) one or more of aromatic dicarboxylic acids, alicyclic dicarboxylic acids and derivatives thereof, and (d) at least one of aromatic diols, alicyclic diols, aliphatic diols and derivatives thereof. Examples thereof include polyester amides composed of two or more species. Furthermore, you may use a molecular weight modifier together with said structural component as needed.

Preferable examples of specific compounds constituting the liquid crystalline polymer (A) applicable to the present invention include aromatic hydroxycarboxylic acids such as p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid, , 6-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 4, 4'-dihydroxybifenenole, hydroxyquinone, resorcin, compounds represented by the following general formula (I) and the following general formula (II), etc. Aromatic diols; terephthalic acid, isophthalic acid, 4,4′-diphenyldicarboxylic acid, 2,6-naphthalenedicarboxylic acid and aromatic dicarboxylic acids such as compounds represented by the following general formula (III); p-aminophenol And aromatic amines such as p-phenylenediamine.

(However, X: Anorekiren (C 1 through C 4), alkylidene, - 0 -, - SO-, - S0 2 -, _s -, -CO - from group _{selected, Y: - (CH 2)} n - ( n = 1 to 4),-0 (CH ₂ ) _n 0- (group selected from n = l to 4))

Particularly preferred liquid crystalline polymers (A) to which the present invention is applied include aromatic compounds containing p-hydroxybenzoic acid, 6-hydroxy-1-naphthoic acid, 4,4, -dihydroxybiphenyl, and terephthalic acid as main structural unit components. A polyester. Next, (B) fibrous titanium oxide used in the present invention, its thermal conductivity is important. If the thermal conductivity is low, improvement in the thermal conductivity of the resin composition with filler added can hardly be expected. Therefore, the thermal conductivity of fibrous titanium oxide is 3 W / m · K or more, preferably lOWZm · K or higher. The aspect ratio is also important. If the ratio is too small, it is difficult to develop the heat transfer path in the resin composition, and there is a problem that the heat conductivity of the resin composition is not improved. The pect ratio should be 10 or more, preferably 15 or more. Fibrous titanium oxide satisfies the above-mentioned conditions, does not give adverse effects such as decomposition to the liquid crystalline polymer, and has no electrical conductivity. As a fibrous thermal conductive filter of the component (B) in the present invention, Used selectively.

In addition, the amount of fibrous titanium oxide added is too small. If the amount added is too small, the heat transfer path in the resin composition will not develop, so that sufficient heat conductivity will not be exhibited. Although the entanglement becomes intense and the thermal conductivity increases, the molding flow There are problems such as a problem that the mobility is remarkably reduced, a problem that the pressure in the extruder rises during kneading and the kneading property is extremely deteriorated, a fiber breaks due to thickening of the resin composition, and a problem that the thermal conductivity is rather lowered. Therefore, the amount of (B) fibrous titanium oxide added is 10 to 200 parts by weight, preferably 20 to 150 parts by weight, more preferably 20 to 100 parts by weight with respect to 100 parts by weight of (A) liquid crystalline polymer. Most preferably, it is 30 to 100 parts by weight.

Next, the (C) plate-like / spherical / indeterminate thermally conductive filler used in the present invention is added. The reason for adding the plate-like / spherical / indeterminate thermally conductive filler is as follows: (B) Fibrous oxidation Titanium alone increases the heat conduction in the fiber direction, but the improvement in the heat conductivity in the perpendicular direction is reduced. Therefore, by adding a filler that spreads in two or more dimensions of plate, spherical, and irregular shapes. It is possible to give uniform thermal conductivity as a resin composition, and adding only a large amount of fibrous titanium oxide causes a significant decrease in fluidity as described above. It is difficult to obtain resin yarns and compositions having high thermal conductivity. For this reason, the thermal conductivity of a plate-like, spherical, and amorphous heat-conducting filler is as important as that of fibrous titanium oxide. The heat conductivity is low and it becomes difficult to transfer the heat transferred by the fibrous heat conductive filler, and the heat transfer at that portion becomes rate limiting. Therefore, the thermal conductivity of the plate-like / spherical / indeterminate thermal conductive filler is 2 WZm · K or more, preferably 3 W / m · K or more.

In addition, the amount of addition of the plate-shaped 'spherical' amorphous heat conductive filler is too small. However, if the amount added is too small, the heat transfer path in the resin composition will not develop, so that sufficient heat conductivity will not be exhibited. On the other hand, if the amount is too large, the fiber breaks due to the increase in the viscosity of the resin composition, but rather the problem that the thermal conductivity decreases, the problem that the internal pressure of the extruder increases during kneading, and the kneadability deteriorates significantly occurs. Therefore, the amount of (C) plate-like 'spherical' amorphous heat conductive filler added is 10 to 400 parts by weight with respect to 100 parts by weight of (A) liquid crystalline polymer, preferably 20 to: L00 Parts by weight, more preferably 30 to 80 parts by weight.

As the (C) plate-like / spherical / indeterminate thermally conductive filler that can be used in the present invention, any material that satisfies the above conditions can be used. Specific substances include talc, anhydrous magnesium carbonate, magnesium oxide, aluminum Mina, silica, beryllia, boron nitride, silicon carbide, and aluminum nitride can be used. Among these, talc, magnesium carbonate anhydrous, and magnesium oxide are preferred from the standpoint of filler hardness, toxicity, and economy. .

If the total amount of (B) fibrous titanium oxide and (C) plate-like, spherical, and amorphous heat-conducting fillers is too small, the thermal conductivity will not improve. Since the internal pressure increases and the kneadability is extremely deteriorated, the total addition amount is 30 to 100 parts by weight of 100 parts by weight of the (A) liquid crystalline polymer while satisfying the addition amounts of the components (B) and (C). 500 parts by weight, preferably 50 to 250 parts by weight, more preferably 50 to 200 parts by weight.

Next, anhydrous magnesium carbonate used as component (C). Generally, magnesium carbonate exists as a trihydrate, and it is known that its crystal water is released at 100 ° C. For this reason, when general magnesium carbonate is mixed into the resin, problems such as foaming and resin decomposition occur due to the release of crystal water, and kneading cannot be performed. However, anhydrous magnesium carbonate used in the present invention is obtained by treating a general magnesium carbonate existing as a trihydrate with high temperature and high pressure to form anhydrous crystals, and there is no such problem. Anhydrous magnesium carbonate produced by such a method is generally available as high-purity magnesite M S L (manufactured by Kamijima Chemical Co., Ltd.).

Next, magnesium oxide used as the component (C) can be used as it is, but it is preferable to use phosphorus-containing coated magnesium oxide in order to improve the heat and moisture resistance. The phosphorus-containing coated magnesium oxide used in the present invention is the one in which a compound that forms a double oxide is present on the surface of the magnesium oxide and the surface is coated with the double oxide by melting at a high temperature. is there. Specifically, the compound that forms the double oxide is wet-added to the magnesium oxide powder and then mixed and stirred, or the compound that forms the double oxide is present on the surface of the magnesium oxide. It can be produced by firing at a temperature equal to or higher than the melting point of the coating material.

The compounds used to form double oxides are aluminum compounds, ironated One or more compounds selected from the group consisting of a compound, a key compound and a titanium compound are preferred. The form of the compound is not limited, but nitrate, sulfate, chloride, oxynitrate, oxysulfate, oxychloride, hydroxide, oxide, etc. are used. Specific examples of this compound include fumed silica, aluminum nitrate, iron nitrate and the like.

The method for producing a phosphorus-containing coated magnesium oxide is the following: surface treatment with a phosphorous compound is performed on magnesium oxide having a coating layer made of magnesium oxide or a double oxide produced by the above method, and magnesium phosphate is applied to the surface. A coating layer is formed from the compound.

Examples of the phosphorus compound used for this surface treatment include phosphoric acid, phosphate, and acidic phosphate ester. These may be used alone or in combination of two or more. ,. Examples of the phosphate include sodium phosphate, potassium phosphate, and ammonium phosphate, and examples of the acidic phosphate ester include isopropenoreaside phosphate, methenoreaside phosphate, ethenoreaside phosphate, and propinoreaside phosphate. Butyl acid phosphate, lauryl acid phosphate, stearyl acid phosphate, 2-ethylenohexanoyl acid phosphate, oleino rare acid, phosphate and the like. Of these, isopropyl acid phosphate is preferred because a coating layer having excellent water resistance can be easily formed.

As a specific method for the surface treatment of a phosphorus-containing coated magnesium oxide with a phosphorus compound, a predetermined amount of a phosphorus compound is added to magnesium oxide having a coating layer made of magnesium oxide or a double oxide, for example, 5 to 5 After stirring for 60 minutes, firing is performed at a temperature of 300 ° C or higher for 0.5 to 5 hours.

Phosphorus-containing coated magnesium oxide produced by such a method is generally available as Cool Filler CF2-1OOA (Tateho Chemical Industry Co., Ltd.). Next, in the present invention, it is preferable to further add (D) an alkoxysilane compound from the viewpoint of improving heat resistance. The effect is particularly remarkable when phosphorus-containing coated magnesium oxide is used as component (C). The alkoxysilane compound used in the present invention may be at least one selected from the group consisting of aminoalkoxysilane, vinylalkoxysilane, epoxyalkoxysilane, mercaptoalkoxysilane and arylalkoxysilane.

As an aminoalkoxysilane, any silane compound having one or more amino groups in one molecule and having two or three alkoxy groups can be used, for example, y-aminopropyl. Trimethoxysilane, aminopropyltriethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyljetoxysilane, Ν- (β-aminoethyl) —γ-aminobutyl pilltrimethoxysilane, Ν-phenol γ And monoaminopropyltrimethoxysilane. As the vinylalkoxysilane, any silane compound having one or more bur groups in one molecule and having two or three alkoxy groups is effective. For example, burtrimethoxysilane, vinyltriethoxysilane, vinyltris ( β-methoxyxoxy) silane and the like. Epoxyalkoxysilane is effective as long as it is a silane compound having one or more epoxy groups in one molecule and two or three alkoxy groups, such as γ-glycidoxyprovir. Examples include trimethoxysilane, β- (3,4-epoxy hexyl) ethyltrimethylsilane, γ-glycidoxy pill triethoxysilane, and the like. As the mercaptoalkoxysilane, any silane compound having one or more mercapto groups in one molecule and having two or three alkoxy groups can be used! /, But any of them can be used. For example, γ-mercaptopropyl trimethoxysilane 7-mercaptopropyltriethoxysilane and the like. As the arylalkoxysilane, any silane compound having one or more aryl groups in one molecule and having two or three alkoxy groups is effective. For example, one diallylaminopropyl Examples include trimethoxysilane, γ-arylaminopropyltrimethoxysilane, and y-arylthiopropyltrimethoxysilane. For the purpose of the present invention, among the alkoxysilane compounds, aminoalkoxysilane is most preferable. In the present invention, the amount of the alkoxysilane compound added is important. If the amount of the alkoxysilane compound is small, the mechanical properties after the PCT are remarkably deteriorated. Therefore, the addition amount of the alkoxysilane compound is 0.1 to 5 parts by weight, preferably 0.4 to 4 parts by weight with respect to 100 parts by weight of (A) liquid crystalline polymer.

In addition, the high thermal conductive resin composition of the present invention is within the object range of the present invention, in order to improve performance such as mechanical strength, heat resistance, dimensional stability (deformation resistance, warpage), and electrical properties. (B), (C) Inorganic or organic fillers other than the components may be blended, and for this purpose, fibrous, granular, or plate-like fillers are used.

In addition, known substances generally added to thermoplastic resins, that is, flame retardants, colorants such as dyes and pigments, stabilizers such as antioxidants and UV absorbers, lubricants, crystallization accelerators, crystal nucleating agents Can be used as the composition of the present invention.

Molded products obtained by injection molding, extrusion molding, blow molding, etc. using the heat conductive resin composition of the present invention thus obtained have high moisture and heat resistance, chemical resistance, dimensions. Shows stability, flame retardancy, and excellent heat dissipation. Taking advantage of this advantage, it can be suitably used for components that radiate internally generated heat, such as heat exchangers, heat sinks, and optical pick-ups.

Other applications include, for example, LEDs, sensors, connectors, sockets, terminal blocks, printed circuit boards, motor parts, ECU cases and other electrical / electronic parts, lighting parts, TV parts, rice cooker parts, microwave oven parts, irons, etc. It can be used for home / office electrical product parts such as parts, copier-related parts, printer-related parts, facsimile-related parts, heaters, and air conditioner parts. Example

EXAMPLES Next, although an Example and a comparative example demonstrate this invention concretely, this invention is not limited to these. In addition, the method of the physical-property measurement in an Example is as follows.

(1) Thermal conductivity Thermal conductivity was measured by a hot disk method using a sample in which disk-shaped molded products having a diameter of 30 mra and a thickness of 2 mm were stacked.

(2) Injection moldability

Under the conditions of a cylinder temperature of 370 ° C and an injection speed of 15 m / min, a rod-shaped molded product with a width of 5 mm, a thickness of 0.3 mm and a maximum flow distance of 70 mm was molded, and the flow distance was measured to determine the injection moldability.

(3) Moisture and heat resistance

Using 80x10x 4mm IS standard test piece, perform pressure tacker test for 48 hours under the condition of 121 ° C, humidity 100%, 2 atm, and measure the bending strength according to I SO 1 78 The retention rate relative to the initial value was obtained. Examples 1-6, Comparative Examples 1-5

Liquid crystal polymer, heat conductive filler, and alkoxysilane compound are mixed in the composition shown in Table 1 using a twin screw extruder (TEX30 α type, manufactured by Nippon Steel) to form pellets, then injected The above-mentioned specimens were molded using a molding machine, and various evaluations were performed. The results are shown in Table 1.

In addition, each component used and the alkoxysilane compound addition method are as follows.

(Ii) Liquid crystalline polymer (LCP)

Polyplastics Co., Ltd. S 950, thermal conductivity 0.45W / m

(B) Fibrous titanium oxide

Acicular titanium oxide; manufactured by Ishihara Sangyo Co., Ltd. F T L _ 300, fiber diameter 0.27 m, fiber length 5.15 μm, thermal conductivity 20 W / m · K

(C) Plate, Spherical, Amorphous heat conductive filler

Talc ： Crown talc PP manufactured by Matsumura Sangyo Co., Ltd., plate shape, average particle size 8μπι, thermal conductivity 3.2W / m · K

Anhydrous magnesium carbonate; high purity magnesite MS L (anhydrous magnesium carbonate synthetic product) manufactured by Kamishima Chemical Industry Co., Ltd., irregular shape, average particle size 8 / m, thermal conductivity 15WZ m · K Phosphorus-containing coated magnesium oxide; manufactured by Tateho Chemical Co., Ltd. CF2-100A, spherical, average particle size 27μπι, maximum particle size ΙΟΟμπκ Thermal conductivity 35WZm · Κ

Titanium oxide; manufactured by Sakai Chemical Industry Co., Ltd. T I T ONE SR—1, amorphous, average particle size 0.25 μm, thermal conductivity 20W / m · K

(D) Aminosilane compound

3-Aminoprovir triethoxysilane

* 1; Cannot be kneaded due to increased resin pressure during kneading, and cannot be evaluated.

Claims

The scope of the claims

1. (A) 100 parts by weight of liquid crystalline polymer

(C) Thermal conductivity 2 W / m · K or more plate shape · Spherical shape · Indeterminate shape Add one or more heat conductive fillers 10 to 400 parts by weight,

The total addition amount of the components (B) and (C) is 30 to 500 parts by weight with respect to 100 parts by weight of the (A) liquid crystalline polymer, and the thermal conductivity is at least 0.8 W / m · K. An insulating thermal conductive resin composition.

2. Additive amount of component (B) is 20 to 100 parts by weight, (C) component is added 20 to L00 parts by weight, and (B) and (C) component is added in total 50 to The insulating heat conductive resin composition according to claim 1, wherein the amount is 200 parts by weight.

3. The insulating heat conduction according to claim 1 or 2, wherein the (C) plate-like / spherical / indeterminate thermally conductive filler is at least one selected from talc, anhydrous magnesium carbonate and magnesium oxide. Resin composition.

4. The insulating heat conductive resin composition according to claim 3, wherein the magnesium oxide is a phosphorus-containing coated magnesium oxide.

5. The thermal conductive resin composition according to claim 4, further comprising (D) an alkoxysilane compound in an amount of 0.:! To 5 parts by weight based on 100 parts by weight of the (A) liquid crystalline polymer.