WO2007043695A9 - Thermally conductive resin composition - Google Patents

Abstract

Disclosed is a material having a high thermal conductivity, which is excellent in moldability, wet heat resistance and wear characteristics. Specifically, 50-500 parts by weight of a magnesite containing no crystal water is blended per 100 parts by weight of a polyarylene sulfide resin.

Description

 Description Thermally conductive resin composition Technical Field

 The present invention relates to a heat conductive resin composition excellent in injection moldability and extrusion moldability, and excellent in heat and moisture resistance and wear characteristics. Background art

 Polyphenylene sulfide (hereinafter may be abbreviated as PPS) Polyarylene sulfide represented by resin (hereinafter may be abbreviated as PAS) Resin has high heat resistance, mechanical properties, chemical resistance, dimensions Because of its stability and flame retardancy, it is widely used for electrical / electronic equipment parts materials, automotive equipment parts materials, chemical equipment parts materials, etc. In recent years, these parts have become lighter, thinner, and smaller, and heat radiation inside the parts has become a problem, and there has been a demand for materials with heat dissipation.

 For this reason, a method has been proposed in which alumina with a specific particle size is added to PPS resin to improve moldability and thermal conductivity (JP—A 2002-146 1 8 7). Although the moldability is improved, the Mohs hardness of alumina is high, so there is a problem that the extruder, the screw of the molding machine, the cylinder and the molding die are severely worn and mixed with the metal during kneading with the resin and molding. there were.

 On the other hand, a method has been proposed in which graphite is added to PPS resin to impart thermal conductivity (JP—A 2003—4 1 1 1 9). However, this method has the problem of wear such as screw due to filler. Although it does not occur, it has the problem that it cannot be used in fields where electrical insulation is required because it provides electrical conductivity as well as thermal conductivity.

Therefore, as a thermal conductive filler for resin addition, magnesium oxide, which is insulating but has a relatively high thermal conductivity and has a Mohs hardness lower than that of alumina, is used to improve its moisture resistance. Coated fillers have been proposed (JP— A 2 0 0 3— 3 4 5 2 3). However, when this filler is used, the humidity resistance at room temperature is improved, but the humidity resistance under high temperature and high humidity (humidity heat resistance) is inferior, so the pressure Kunker test (hereinafter sometimes abbreviated as PCT) In such tests, there was a problem that magnesium oxide was changed to magnesium hydroxide, causing whitening of the resin, expansion, and a significant decrease in mechanical properties. Disclosure of the invention

 The present invention provides a material having high heat conductivity excellent in moldability, heat and humidity resistance and wear characteristics.

 As a result of intensive investigations, the present inventors have found that by adding a magnesium-free magnetite to PAS resin, moldability, heat-and-moisture resistance and wear characteristics are improved, and the present invention is completed. It came.

The present invention provides to polyarylene sulfide Huai de resin 100 parts by weight, and crystal water does not contain a formula MgC0 ₃ heat transfer conductive resin composition obtained by blending 50 to 500 parts by weight of Magunesai bets indicated by. Detailed Description of the Invention

 Hereinafter, the present invention will be described in detail. The PAS resin used in the present invention is mainly composed of-(Ar-S)-(where Ar is an arylene group) as a repeating unit. Examples of arylene groups include p-phenylene group, m-phenylene group, o-phenylene group, substituted phenyl group, p, p'-diphenylene sulfone group, p, p '— Biphenylene group, p' p '— diphenylene group, p, p' — diphenylene carbonyl group, naphthalene group, etc. can be used. In this case, in the arylene sulfide group composed of the above-mentioned arylene group, in addition to the polymer using the same repeating unit, that is, the homopolymer, in terms of the processability of the composition, Copolymers containing heterogeneous repeat units may be preferred.

As the homopolymer, those having a p-phenylene sulfide group as a repeating unit and using a p-phenylene group as an arylene group are particularly preferably used. As the copolymer, among the arylene sulfide groups composed of the above-mentioned arylene groups, two or more different combinations can be used. Among them, p-phenylene sulfide group and m-sulfide group can be used.組 み 合 わ せ Combinations containing nylene sulfide groups are particularly preferred. In this, 70 moles of p-phenylene sulfide group. / ₀ or more, preferably 80 mol. /. The above-mentioned materials are appropriate from the viewpoint of physical properties such as heat resistance, fluidity (formability), and mechanical properties.

 Further, among these PAS resins, a high molecular weight polymer having a substantially linear structure obtained by condensation polymerization from a monomer mainly composed of a bifunctional halogen aromatic compound can be particularly preferably used. In addition to the PAS resin in the form of a structure, when polycondensation is performed, a small amount of a monomer such as a polyhaloaromatic compound having three or more halogen substituents is used to partially form a branched structure or a crosslinked structure. Polymers can also be used, and relatively low molecular weight linear structure polymers are heated at high temperatures in the presence of oxygen or an oxidant to increase melt viscosity by oxidative crosslinking or thermal crosslinking, thereby improving molding processability. Polymers or mixtures thereof can also be used.

The PAS resin used in the present invention is mainly composed of the linear PAS resin (the viscosity at 310 ° C * slipping rate lOOOsec- ¹ is 10 to 300 Pa · s), and a part thereof to 30 wt%, preferably 2 ˜25 wt%) force ;, mixed system with branched or cross-linked PAS resin having relatively high viscosity (300 to 3000 Pa · s, preferably 500 to 2000 Pa · s). In addition, the PAS resin used in the present invention is preferably obtained by purifying by-product impurities and the like by performing acid cleaning, hot water cleaning, organic solvent cleaning (or a combination thereof) after polymerization.

 The melt viscosity of the PAS resin used in the present invention is not particularly limited. However, from the viewpoint of formability, the melt viscosity at 310 ° C · slipping rate lOOOsec is 20 to 1200 Pa · s, preferably 200 to 1000 Pa · s. Particularly when used for injection molding, those having a melt viscosity of 20 to 200 Pa · s are preferred, and when used for extrusion molding, those having a melt viscosity of 200 to 1000 Pa · s are preferred.

Next, Magunesai preparative represented by the chemical formula MgC0 ₃ containing no crystal water used in the present invention is a material different from what is conventionally referred to as magnesium carbonate. The substance conventionally called magnesium carbonate is (3-5) MgC0 _3. Mg (0H) _2. (3- 7) basic salt containing water of crystallization of H ₂ 0, is that arsenide Dorokishi magnesium carbonate. This magnesium hydroxide carbonate releases its crystal water when heated at around 100 ° C and decomposes violently at around 330 ° C, the PAS resin kneading temperature, causing problems such as PAS resin foaming and decomposition. Generated and cannot be kneaded. The Magunesai bets formula MgC0 ₃ containing no crystal water, natural products, but synthetic products are present, because of the possible degradation problems during kneading for impurities that are natural products are included, using a synthetic ho Uga is preferred.

 A synthetic product is obtained by treating the above-mentioned magnesium hydroxide carbonate under high temperature and high pressure, and does not cause trouble due to crystal water or impurities.

 Magnesite produced by such a method is generally available as high-purity magnesi 卜 M S L, M S HP (Makishima Chemical Co., Ltd.).

 In addition, in the present invention, the amount of magnesi rice cake added is important. If the amount added is too small, the desired thermal conductivity will not be exhibited, and conversely if the amount added is too large, the moldability will deteriorate. Therefore, the added amount of magnetite is 50 to 500 parts by weight, preferably 100 to 400 parts by weight with respect to 100 parts by weight of the PAS resin.

In addition, the particle size distribution of the magnetite is also important. If the average particle size is too small, when kneaded with a resin, there is a problem that the viscosity is severely increased and the moldability is remarkably lowered. On the other hand, if it is too high, the thermal conductivity is improved, but problems such as deterioration of mechanical properties, molding failure due to clogging of the mold gate during injection molding, and deterioration of surface properties during extrusion molding occur. Therefore, the average particle as a diameter _3~50 μ ιπ, preferably 5~25 μ ιτι.

 Next, the alkoxysilane compound used in the present invention may be at least one selected from the group consisting of an aminoalkoxysilane, a vinylenoalkoxysilane, an epoxyalkoxysilane, a mercaptoalkoxysilane, and an arylalkoxysilane.

Any aminoalkoxysilane may be used as long as it is a silane compound having one or more amino groups in one molecule and having two or three alkoxy groups. For example, γ-butylaminopropyltrimethoxysilane, _γ —aminopropyltriethoxysilane, γ—aminopropylmethyldimethoxysilane, γ—aminopropylmesyl Examples include tiljetoxysilane, N- (jS-aminoethyl) 1 γ-aminomino trimethylsilane, N-phenyl 1 γ-aminopropyl trimethoxysilane, and the like.

 As the butyl alkoxysilane, any silane compound having one or more bur groups in one molecule and having two or three alkoxy groups is effective. For example, vinyltrimethyoxysilane, bitriethoxysilane. , Vinyl tris

 (i3—Methoxysoxy) Silane etc. can be burned.

 As the epoxyalkoxysilane, any silane compound having one or more epoxy groups in one molecule and having two or three alkoxy groups is effective. For example, γ-glycidoxypropyltrimethoxysilane , Β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyl ligatoxysilane, and the like.

 As the mercaptoalkoxylane, any silane compound having one or more mercapto groups and two or three alkoxy groups in one molecule is effective. For example, γ-mercaptoprovir trimethoxysilane, γ —Mercaptopropyl triethoxysilane and the like.

 As the arylalkoxysilane, any silane compound having one or more allyl groups and two or three alkoxy groups in one molecule is effective. For example, γ-diaryl Examples include aminopropyltrimethoxysilane, γ-arylaminopropyltrimethoxysilane, and γ-arylthiopropyltrimethoxysilane.

 In the present invention, among the above alkoxysilane compounds, aminoalkoxysilane is most preferable.

In the present invention, the addition amount of the alkoxysilane compound 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 0.5 to 4 parts by weight with respect to 100 parts by weight of the PAS resin. In addition, the thermally conductive resin composition of the present invention is within the scope of the present invention and is inorganic or organic for improving performance such as mechanical strength, heat resistance, dimensional stability (deformation resistance, warpage), and electrical properties. Machine fillers may be blended, and for this purpose, fibrous, powdery, or plate-like fillers are used.

 Examples of the fibrous filler include inorganic fibrous materials such as glass fiber, asbestos fiber, boron fiber, and titanic acid lithium fiber. A particularly typical fibrous filler is glass fiber. High melting point organic fiber materials such as polyamide, fluororesin, and acryl resin can also be used.

 On the other hand, the granular fillers include quartz powder, glass beads, glass powder, calcium silicate, aluminum silicate, kaolin, talc, clay, diatomaceous earth, silicates such as wollastonite, iron oxide, titanium oxide, zinc oxide. Metal oxides such as calcium carbonate, metal carbonates such as calcium carbonate, and metal sulfates such as calcium sulfate and barium sulfate.

 Examples of the plate-like filler include My strength and glass flakes.

 These inorganic fillers can be used alone or in combination of two or more.

 In addition, known substances generally added to thermoplastic resins, that is, flame retardants, colorants such as dyes and pigments, stabilizers such as antioxidants and ultraviolet absorbers, lubricants, crystallization accelerators, crystal nucleating agents, etc. In addition, those appropriately added according to the required performance can also 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, dimensional stability and difficulty. Shows flammability 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 pickups.

Other applications include, for example, LEDs, sensors, connectors, sockets, terminal blocks, printed circuit boards, motor parts, ECU cases, etc., electrical and electronic parts, lighting parts, TV parts, rice cooker parts, microwave oven parts, irons, etc. Parts, copier-related parts, printer-related parts, facsimile-related parts, heaters, air conditioner parts, etc. Can be used for household electrical appliance parts. Example

 Next, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited to these. In addition, the method of the physical-property measurement in an Example is as follows.

 (1) Thermal conductivity

 The thermal conductivity was measured by the hot disk method using a sample of disk-shaped molded products with a diameter of 30 mm and a thickness of 2 mm.

 (2) Injection moldability

For a resin composition using a PAS resin with a melt viscosity (310 ° C · shear rate lOOOsec— ¹ ) of less than 200 Pa · s suitable for injection molding, with a cylinder temperature of 320 ° C and an injection pressure of lOOMPa, a width of 20 A rod-shaped molded product with a thickness of 1 sleep was formed, and the flow distance was measured and evaluated as injection moldability.

 (3) Extrudability

 Melting viscosity suitable for extrusion (310 ° C. Resin composition using PAS resin with shear rate lOOOsec— of 200 Pa · s or more, cylinder temperature 330 ° C, outer diameter 6.3 mm, Using pipes with an inner diameter of 5.7 mm, the pipe was extruded at an extrusion rate of 20 ccZmin and the take-off speed was lOm / min. .

 (4) Moist heat resistance

 Using 80X10X 4mm ISO standard test piece, perform pressure cooker test for 48 hours under the condition of 121 ° C, humidity 100%, 2 atm, and the bending strength of the test piece according to ISO 1 78 Measurements were made to determine the retention rate relative to the initial value.

 (5) Wear resistance test

80X 10X 4mm ISO standard test specimen and φ10X L20mm SUS 30 4 cylinder as the mating material, the surface of SUS 304 cylinder is contacted with 80X 4mm surface of IS〇 standard test specimen, load 10kgf The speed of the ISO standard test piece and the S US 304 cylinder after reciprocating the ISO standard test piece 20,000 times under the condition of speed S cm Zsec stroke 5 cm The amount was measured, and the difference from the weight before the test was evaluated as the amount of wear.

Examples 1-4, Comparative Examples 1-3

Polyphenylene sulfide resin, thermal conductive filler, and alkoxysilane compound with melt viscosity (310 ° C · shear rate lOOOsec- ¹ ) of less than 200 Pa · s in the composition shown in Table 1 are twin-screw extrusion A pellet was formed by kneading using a machine (TEX 30 α type, manufactured by Nippon Steel Works), and the above-mentioned test pieces were formed with an injection molding machine and subjected to various evaluations. The results are shown in Table 1.

Examples 5-8, Comparative Examples 4-5

 A twin-screw extruder with a composition shown in Table 2 consisting of a polyphenylene sulfide resin, a thermal conductive filler and an alkoxysilane compound with a melt viscosity (310 ° C 'slip rate lOOOsec-') of 200 Pa · s or more. (Tex 30 model manufactured by Nippon Steel Works) was used for kneading to form pellets, and the above test pieces were molded using an injection molding machine, and various evaluations were performed. Moreover, the above-mentioned extrusion moldability was evaluated. The results are shown in Table 2.

 The components used are as follows.

Polyphenylene sulfide resin (PPS resin)

 • P P S-1, Kureha Fortron W202 A (melt viscosity (310. C. shear rate lOOOsec— ') 25 Pa. S)

• PPS— 2 ； Kureha Fortron W 2 20 A (melt viscosity (310.C · shear rate lOOOsec " ¹ ) 220Pa · s)

• PPS-3; Kureha Fortron W540 (melt viscosity (310.C. shear rate lOOOsec- ¹ ) 600Pa.s)

Thermally conductive filler

• 7 Ira one 1; Magunesai bets (manufactured by Konoshima Chemical Co. high purity Magunesai preparative MS L, formula MgC0 _3, average particle size 8 m)

'Fila 1 2; Magnesia 卜 (High purity magnesite MSK P, chemical formula MgC0 ₃ , average particle size 22μιπ, manufactured by Kamishima Chemical Co., Ltd.)

-Filler 1 (Comparative product); Magnesium carbonate (Magnetium GP-30 manufactured by Kamishima Chemical Co., Ltd., chemical formula 4MgC0 ₃ 'Mg (OH) ₂ · 4 Η ₂ 0, average particle size 9 m) 'Fila Ichi 4 (Comparative); Alumina (Electrochemical Industry Co., Ltd. Spherical Alumina AL2 03- 05)

 -Filler 1 (Comparative); Silica coated magnesium oxide (Cool filler CF 2_ 100, average particle size 27μιη, maximum particle size ΙΟΟμιη, manufactured by Tateho Chemical Co., Ltd.)

.Alkoxysilane compounds; _γ -aminopropyl triethoxysilane

Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Weight part 100 100 100 100 100 100 100 F Q. Filler 1 65 65 300

 Filler 2 邰 300

 "

 Filler 3 ¾ Sato 65

 Filler 4 Weight part 300 Filler 5 parts by weight 300 Alkoxysilane Weight part 0.5 3 3 Thermal conductivity W / m-K 0.5 0.6 1.9 2.0 * 1 1.8 1.7 Moisture and heat resistance retention% 58 82 51 81 * 1 41 32 Injection moldability mm 208 196 31 51 * 1 76 42

ISO test piece wear mg 0.1 0.1 0.1 0.1 * 1 24 12

 s US wear mg 0.2 0.2 0.8 0.9 * 1 610 79

* 1: Foaming and resin decomposition occur during extrusion kneading, and cannot be kneaded

2

 * 1: Foaming and resin decomposition occur during extrusion kneading, and cannot be kneaded

Claims

The scope of the claims 1. Polyarylene one to sulfide resin 100 parts by weight, the heat conductive resin sets Narubutsu comprising a Magunesai Bok represented by crystal water does not contain a chemical formula MgC0 ₃ were blended 50 to 500 parts by weight.  2. The thermally conductive resin composition according to claim 1, further comprising 0.1 to 5 parts by weight of an alkoxysilane compound (100 parts by weight of polyarylene sulfide resin).  3. The high thermal conductive resin composition according to claim 1 or 2, wherein the polyarylene sulfide resin has a melt viscosity (310 ° C, shear rate lOOOOsec—20 to 1200 Pa · s). 4. The high thermal conductive resin composition according to claim 1 or 2, wherein the polyarylene sulfide resin has a melt viscosity (310 ° C 'shear rate l OOOsec- ¹ ) of 200 to 1000 Pa · s.  5. The heat conductive resin composition according to any one of claims 1 to 4, wherein the average particle size of magnesai rice cake is 3 to 50 µηι.