JPH09176368A - Synthetic resin composition having high thermal conductivity and high thermal conductivity improver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a synthetic resin composition, having a high thermal conductivity and useful especially as an encapsulant for electronic materials by blending a synthetic resin with magnesium hydroxide having specific properties and a high thermal conductivity improver in respective specific proportions. SOLUTION: This synthetic resin composition having a high thermal conductivity is obtained by blending (A) 100 pts.wt. synthetic resin with (B) 0-400 pts.wt. magnesium hydroxide having <=3.0×10<-3> strain in the <101> direction in an X-ray diffractometry and <=20m<2> /g specific surface area according to the BET method, (C) 0-400 pts.wt. fibrous magnesium hydroxide having >=2.5 ratio of the length/diameter and >=1μm length and <=20m<2> /g specific surface area according to the BET method and (D) 0-100 pts.wt. high thermal conductivity improver. The total amount of the blended components (B) and (C) is 50-400 pts.wt. Either or both of the surfaces of the components (B) and (C) are preferably treated with a surface treating agent. Furthermore, both the components (B) and (C) are thermal conductivity improving agents.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a synthetic resin composition having excellent thermal conductivity and a thermal conductivity improver used therefor. More specifically, the present invention relates to a synthetic resin composition having high thermal conductivity in which a specific proportion of magnesium hydroxide having a specific property is blended, and a thermal conductivity improver comprising the specific magnesium hydroxide. Since the synthetic resin composition of the present invention has high thermal conductivity, it is advantageously used, for example, as an electronic material sealant.

[0002]

2. Description of the Related Art Conventionally, silica has been used as a thermal conductivity improver for synthetic resins. However, silica has low thermal conductivity, and when it is used as a sealant for electronic materials such as semiconductor elements, it cannot cope with the increase in the amount of heat generated due to higher power consumption and higher speed. Beryllia and alumina were used to solve this thermal problem. In the case of beryllia, its use is restricted due to its toxicity. Alumina has a thermal conductivity 10 times or more that of silica, but has a high hardness, so that it has a drawback that the molding machine and the mold are worn during molding.

Recently, magnesium oxide, which has a low hardness and a thermal conductivity three times that of alumina, has been attracting attention as a thermal conductivity improver. However, magnesium oxide has a drawback that it is gradually attacked by water or water vapor and converted into magnesium hydroxide, and excellent physical properties are lost. In order to solve this, magnesium oxide having low hydration and high thermal conductivity was developed (Japanese Patent Laid-Open No. 171928/1994).
issue). However, there is a problem in that the physical properties of the synthetic resin are deteriorated when the magnesium oxide is blended in a high amount, and there is a demand for the development of a higher thermal conductivity improver.

[0004]

SUMMARY OF THE INVENTION The first object of the present invention is to provide a high thermal conductivity improver comprising magnesium hydroxide which, when incorporated into a synthetic resin, imparts high thermal conductivity with little deterioration in the physical properties of the resin. To provide.

A second object of the present invention is to provide a synthetic resin composition having high thermal conductivity. A third object of the present invention is to provide an electronic material sealant having high thermal conductivity.

[0006]

According to the present invention, the object of the present invention is: (a) 100 parts by weight of a synthetic resin (a component), and (b) the <101> direction in the X-ray diffraction method. 0 to 400 parts by weight of magnesium hydroxide (component b) having a strain of 3.0 × 10 ⁻³ or less and a specific surface area by BET method of 20 m ² / g or less, (c) electron microscope, optical microscope or visually 0 to 400 weight of fibrous magnesium hydroxide (component c) having a determined length / diameter ratio of 2.5 or more, a length of 1 μm or more and a BET specific surface area of 20 m ² / g or less. Parts, and (d) 0 to 100 parts by weight of the high thermal conductivity improving aid (d component), and 50 to 400 parts by weight of the b component and the c component in total. This is achieved by the high thermal conductive synthetic resin composition.

According to the present invention, the object is that the strain in the <101> direction in the X-ray diffraction method is 3.0 × 10 ⁻³ or less and the specific surface area by the BET method is 20 m ² / g or less. This is achieved by a high thermal conductivity improver for synthetic resins, which comprises magnesium hydroxide.

Further, according to the present invention, the object is a length / diameter ratio of 2.5 or more determined by an electron microscope, an optical microscope or visual observation, a length of 1 μm or more, and a BET method. This is achieved by a high thermal conductivity improver for synthetic resins, which comprises fibrous magnesium hydroxide having a specific surface area of 20 m ² / g or less.

Hereinafter, the present invention will be described in more detail. Magnesium hydroxide used as a high thermal conductivity modifiers in the present invention has two types, the distortion of the <101> direction in one X-ray diffraction method 3.0 × 10 ^- by ³ or less and the BET method It is magnesium hydroxide (component b) having a specific surface area of 20 m ² / g or less. This component b has high thermal conductivity when the strain by the X-ray diffraction method is 3.0 × 10 ⁻³ or less, preferably 2.6 × 10 ⁻³ or less, and the value of the specific surface area by the BET method. There 20 m ² / g or less, preferably of 1 to 10 m ² / g, the compatibility with the resin, dispersibility, forming or processing property becomes good, good resultant molded article appearance, mechanical strength, etc. It is preferable because the physical properties of are improved.

Another type of magnesium hydroxide (component c) of the present invention has a fibrous morphology and has a length / diameter ratio of 2.5 or more, preferably determined by electron microscope, optical microscope or visual observation, preferably. 5 to 100, and the length is 1 μm or more,
It is preferably 5 to 10,000 μm, and the specific surface area by the BET method is 20 m ² / g or less, preferably 1 to 10 m ^2.
/ G. The component c has a higher thermal conductivity as the length / diameter ratio is larger, and a component having a length and a specific surface area in the above range has better compatibility with a resin, dispersibility, moldability or workability, The obtained molded article is preferable because it has an excellent appearance and various physical properties such as mechanical strength are improved.

The synthetic resin composition of the present invention comprises (b) 0 to 400 parts by weight of magnesium hydroxide of the above-mentioned component b, and (c) the above-mentioned c to 100 parts by weight of the synthetic resin (a component).
0 to 400 parts by weight, preferably 0 to 200 parts by weight, of the component fibrous magnesium hydroxide, and (d) 0 to 100 parts by weight of the thermal conductivity improving aid (d component) are added, and the b component and the c component are blended. Is added in a total amount of 50 to 400 parts by weight.

The synthetic resin of the component a used in the present invention is
Synthetic resin or rubber means, for example, polyethylene, copolymers of ethylene with other α-olefins, copolymers of ethylene with vinyl acetate, ethyl acrylate or methyl acrylate, polypropylene, polypropylene and other α. -Copolymers with olefins, polybutene-1,
Thermoplastic resins such as polystyrene, styrene and acrylonitrile, polyvinyl acetate, polyacrylate, polymethacrylate, polyurethane, polyester, polyether, polyamide; thermosetting of phenolic resin, melamine resin, epoxy resin, unsaturated polyester resin, alkyd resin, etc. Resins; and synthetic rubbers such as ethylene propylene diene rubber (EPDM), SBR, NBR, butadiene rubber, butyl rubber, isobutyl rubber, urethane rubber, acrylic rubber, chloroprene rubber, chlorosulfonated polyethylene, silicone rubber, and fluororubber. .

The components b and c of the present invention can be surface-treated with a surface-treating agent when blended with a resin. Examples of such a surface treatment agent include higher fatty acids such as oleic acid and stearic acid or alkali metal salts thereof, vinylethoxysilane, vinyl-tris (2-methethoxy) silane, γ-methacryloxypropyltrimethoxysilane, γ-aminopropyl. Silane coupling agents such as trimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane; isopropyltriisostearoyl titanate, Titanate cups such as isopropyl tris (dioctyl pyrophosphate) titanate, isopropyl tri (N-aminoethyl-aminoethyl) titanate, isopropyl tridecylbenzenesulfonyl titanate Aluminum-based coupling agents such as acetoalkoxyaluminum diisopropylate; Mono- or diesters of orthophosphoric acid and oleyl alcohol, Mono- or diesters of orthophosphoric acid and stearyl alcohol, and their acid or alkali metal salts And partial phosphoric acid esters such as The surface treatment agent is usually used in a proportion of 0.1 to 10 parts by weight per 100 parts by weight of the component b or the component c.

As described above, the synthetic resin composition of the present invention contains 0 to 100 parts by weight of the thermal conductivity improving aid (d component) based on 100 parts by weight of the synthetic resin (a component). You can Even if the thermal conductivity improver is added to the synthetic resin by itself, it has little effect of improving the thermal conductivity of the synthetic resin. However, when this auxiliary agent is used in combination with the b component and / or the c component, the thermal conductivity is further improved. Sex is improved.

As the thermal conductivity improving aid of the component d, a fibrous or chain-like inorganic substance is used, which may be a natural product or a synthetic product. Specific examples of these auxiliaries include, as the fibrous inorganic substance, for example, basic magnesium sulfate, carbon fiber, wollastonite, aluminum borate,
Examples of potassium titanate, sepiolite, and xonotlite, and examples of chain-like inorganic substances include acetylene black.

In preparing the synthetic resin composition of the present invention, there is no particular limitation on the method of blending the respective components with the synthetic resin, and any means can be used as long as they can be mixed uniformly. it can. For example, the above components and other additives may be mixed in advance and then melt-kneaded by an open roll, a single-screw or twin-screw extruder, a Banbury mixer, or the like. There is no particular restriction on the molding method of the obtained resin composition, and examples thereof include injection molding, extrusion molding, blow molding, press molding, rotational molding, calender molding, and sheet forming molding.

Further, various additives, reinforcing agents, fillers and the like which are usually added can be added to the high heat conductive synthetic resin composition of the present invention.
Antioxidant, flame retardant aid, UV absorber, light stabilizer, metal deactivator, cross-linking agent, colorant, curing agent, lubricant, nucleating agent,
Foaming agent, deodorant, lithopone, clay, wood powder, glass fiber, ferrite, carbon black, talc, mica,
Examples include additives such as calcium carbonate, red phosphorus, tin and inorganic salts thereof, metal fibers, metal powders, reinforcing agents, and fillers.

The high heat conductive synthetic resin composition of the present invention can be molded into a high heat conductive molded product, but it also has a flame retardant effect due to the action of the components b and c. Thus, the molded article obtained from the synthetic resin composition of the present invention maintains excellent physical properties with less deterioration in physical properties,
In particular, since it has excellent high thermal conductivity, it is more advantageous to use it as a sealant for electronic materials such as semiconductors.
In the case of this electronic material encapsulant, the synthetic resin may be one that is usually used as an electronic material encapsulant.
An epoxy resin is shown as a typical example of such a synthetic resin.

[0019]

The present invention will be described below in detail with reference to examples. In the examples, "parts" means parts by weight. In the examples, thermal conductivity, BET specific surface area, tensile strength, and strain in the X-ray diffraction method were measured by the following methods and means. Thermal conductivity: Kyoto Electronics Manufacturing Co., Kemtherm QTM-
Measured using D3. BET specific surface area: "Catalyst" (Vol.2, No.4, 473
Page, 1960, Tokuji Takagi). Tensile strength: Silicone rubber was measured according to JIS K6301, and polypropylene was measured according to JIS K7113.

Strain in <101> direction in X-ray diffraction: sin δ / λ on the horizontal axis and β cos δ / λ on the vertical axis according to the following relational expression :
Was plotted, and the strain (η) was obtained by multiplying the crystal grain size (ε) from the reciprocal of the intercept and the gradient by ½.

[0021]

[Equation 1]

Where λ: wavelength of X-ray used, Cu-K
1.542Å in α line θ: Black angle β: True half width, unit: radian The above β was determined by the following method. (101) plane and (2
The diffraction profile of the (02) plane as an X-ray source is 35K
It was measured using a Cu-Kα ray generated under the conditions of V and 15 mA. The measurement conditions are gonio speed 1/4 ° / min, chart speed 10 mm / min, slit width in the order of divergence slit, receiving slit, and scattering slit, and 1 ° -0.3 for the (101) plane.
mm-1 °, 2 ° -0.3mm for (202) plane
It was measured under the condition of -2 °. About the obtained profile,
The width (B0) at half the height from the background to the diffraction peak was measured. Kα1, Kα2 for 2θ
From the relationship of the split width (δ) of (101) and (2
The δ for 2θ of the 02) plane was read. Then, B was determined from the relationship between δ / B0 and B / B0 based on the values of B0 and δ. High-purity silicon (Purity 99.999
%), Slit width 1/2 ° -0.3 mm-1 /
Each diffraction profile was measured at 2 °, and the half value width (b) was determined. This was plotted against 2θ, and a graph showing the relationship between b and 2θ was created. B / B is calculated from b corresponding to 2θ of the (101) and (202) planes, and b / B and β / B
Β was obtained from the relationship.

[Examples 1 to 5] The respective amounts of the respective components shown in Tables 1 and 2 below were adjusted to 2 by a twin-screw kneading extruder.
The mixture was kneaded at a temperature of 30 ° C., and the kneaded product was compression-molded at 230 ° C. to prepare a test piece having thermal conductivity, and injection molding was carried out to prepare a test piece for a tensile test. The thermal conductivity and tensile strength of the obtained test piece were measured by the methods described above. The results are shown in Tables 1 and 2.
However, the magnesium hydroxide of the component b has a strain in the <101> direction of 2.1 × 10 ⁻³ and a specific surface area by the BET method of 5.
It was 3 m ² / g and was surface-treated by a Henschel mixer with 1 part by weight of stearic acid per 100 parts by weight of this powder. On the other hand, the fibrous magnesium hydroxide of the component c has a length / diameter ratio of 5 to 35, a length of 10 to 30 μm,
A BET specific surface area of 3.6 m ² / g was used. As the polypropylene, BC-6 manufactured by Mitsubishi Chemical Corporation was used. In Tables 1 and 2, "DLTP" is dilaurylthiodipropionate, "Ir1010" is Irganox 1010 (antioxidant), and its component is pentaerythrityl tetrakis [3- (3. , 5-
Di-tert-butyl-4-hydroxyphenyl) propionate]. Further, acetylene black manufactured by Denki Kagaku Kogyo Co., Ltd. was used.

[0024]

[Table 1]

[0025]

[Table 2]

[Comparative Examples 1 to 4] Molded products were obtained in the same manner as in Examples 1 to 5 with the compounding compositions shown in Table 3 below. Table 3 shows the results. However, the strain in the <101> direction of the conventional magnesium hydroxide was 4.63 × 10 ⁻³ and the specific surface area by the BET method was 21 m ² / g. The hydration property of low-hydrated magnesium oxide [Increase amount of Ig-loss (wt.%) After immersion in warm water of 100 ° C. for 2 hours] is 0.81.

[0027]

[Table 3]

[Examples 6 to 10] Molded products were obtained in the same manner as in Examples 1 to 5 with the compounding compositions shown in Table 4 below. Table 3 shows the results. Fluorosilicone rubber is used as the silicone rubber, dicumyl peroxide is used as the silicone polymer crosslinking agent, and the vulcanization conditions are press 200 kgf / cm.
At 150 ° C. for 15 minutes. The other compounding ingredients are shown in Example 1.
The same as ~ 5.

[0029]

[Table 4]

[Comparative Examples 5 and 6] Molded products were obtained in the same manner as in Examples 6 to 10 with the compounding compositions shown in Table 5 below.
Table 5 shows the results.

[0031]

[Table 5]

[Examples 11 to 13] An epoxy resin (Epicoat 828), a curing agent (Ricacid MH-700) and a curing accelerator (BDMA) were mixed, and then the compounding agents shown in Table 6 were mixed and the mixture was vacuumed. After defoaming with a pump, it was cast and cured. The curing conditions are pre-curing: 110 ° C., 1 hour,
Post-curing: 150 ° C., 2 hours. After curing, Example 1
Molded articles were obtained in the same manner as in ~ 5, and the thermal conductivity was measured. Table 6 shows the results.

[0033]

[Table 6]

[0034]

According to the present invention, there is provided a thermal conductivity improver comprising magnesium hydroxide having a specific property capable of imparting high thermal conductivity to a synthetic resin. In addition, when it is compounded with a resin, physical properties are less deteriorated and a molded product with high thermal conductivity can be obtained, which can be particularly advantageously used as an electronic material sealing agent.

Claims (6)

[Claims] 1. A ratio of 100 parts by weight of (a) a synthetic resin (a component) to (b) a strain in the <101> direction of an X-ray diffraction method of 3.0 × 10 ⁻³ or less and a BET method. 0 to 400 parts by weight of magnesium hydroxide (b component) having a surface area of 20 m ² / g or less, (c) a length / diameter ratio determined by an electron microscope, an optical microscope or visual observation of 2.5 or more, and a length of 0 to 400 parts by weight of fibrous magnesium hydroxide (c component) having a specific surface area of 20 m ² / g or less by BET method and (d) a high thermal conductivity improving aid (d component) 0 ˜100 parts by weight and a total of 50 to 400 parts by weight of the b component and the c component are blended. 2. The synthetic resin composition according to claim 1, wherein one or both of the magnesium hydroxide (b component) and the fibrous magnesium hydroxide (c component) are surface-treated with a surface treatment agent. 3. The synthetic resin composition according to claim 1, wherein the high thermal conductivity improving aid (component d) is a fibrous or chain-like inorganic substance. 4. High thermal conductivity for synthetic resin made of magnesium hydroxide having a strain in the <101> direction of not more than 3.0 × 10 ⁻³ in the X-ray diffraction method and having a specific surface area of not more than 20 m ² / g according to the BET method. Sex improver. 5. The length / diameter ratio determined by an electron microscope, an optical microscope or visually is 2.5 or more, and the length is 1 μm.
m or more and the specific surface area by BET method is 20 m ² /
A high thermal conductivity improver for synthetic resins, which is composed of fibrous magnesium hydroxide of g or less. 6. An electronic material sealant molded from the synthetic resin composition according to claim 1.