WO2012086673A1

WO2012086673A1 - Thermally conductive resin composition

Info

Publication number: WO2012086673A1
Application number: PCT/JP2011/079600
Authority: WO
Inventors: 卓也下拂; 大樹舩岡; 小林　幸治
Original assignee: 東洋紡績株式会社
Priority date: 2010-12-24
Filing date: 2011-12-21
Publication date: 2012-06-28
Also published as: JPWO2012086673A1; JP5906741B2

Abstract

The present invention is capable of providing a thermally conductive resin composition, which contains 70-20 parts by volume of (A) a polyester resin that has a melt viscosity at 200˚C under a load of 10 kgf of 5-2,000 dPa·s and 30-80 parts by volume of (B) a thermally conductive filler, and which is capable of increasing the filling density of the filler, while maintaining good molding fluidity. In addition, the present invention is capable of providing a thermally conductive resin composition having good filler dispersibility by using a filler that is surface-treated with a coupling agent, and also capable of providing a thermally conductive resin composition having good wet heat resistance by using a filler that has a particle diameter frequency within a specific range.

Description

Thermally conductive resin composition

The present invention relates to a thermally conductive resin composition that enables high filler filling while maintaining good molding fluidity, and further has good filler dispersibility and good heat-and-moisture resistance. More specifically, the present invention relates to a heat conductive resin composition having excellent injection moldability and high heat conductivity, further having good filler dispersibility, and good moisture and heat resistance, containing a polyester resin having a very low melt viscosity and a heat conductive filler. .

In recent years, problems of heat generation such as personal computer and display housings, electronic device materials, and interior and exterior of automobiles have been highlighted, and materials having high thermal conductivity are required. When a thermoplastic resin composition is used for these applications, since plastic has a lower thermal conductivity than an inorganic material such as a metal material, it may be a problem that it is difficult to release generated heat. In order to solve such problems, attempts have been widely made to obtain a highly thermally conductive resin composition by highly filling an inorganic compound having high thermal conductivity into a thermoplastic resin. Examples of the inorganic compound having high thermal conductivity include graphite, carbon fiber, metallic silicon, magnesium, aluminum, aluminum nitride, boron nitride, zinc oxide, magnesia, and alumina, and usually 30% by volume or more, and further 50 volume. It is necessary to mix | blend in resin with the high content of more than%. In this filler high-filling technology, what often becomes a problem is formability and filler dispersion.
However, if a high thermal conductivity thermoplastic resin is to be molded by a commonly used injection molding method, the resin that has flowed into the mold is cooled and solidified at a high speed because of its high thermal conductivity, and the gate portion in the mold After solidifying, there is a problem that the resin cannot be allowed to flow into the mold at all. In order to solve this, special molds such as a combination of hot runners and specially shaped gates are required when injection molding high thermal conductivity thermoplastic resin, making it impossible to mold with general purpose molds. There is an obstacle to the spread.
Further, the filler dispersion state is important in physical properties such as kneading and heat conductivity of the heat conductive thermoplastic resin. For example, if the wettability between the resin and the filler is poor and a void (air layer) is formed at the interface, or if aggregates of the filler are formed, the strand becomes unstable and the filler cannot be highly filled, resulting in high thermal conductivity. Inhibits rate. Or when the dispersion state of a filler is non-uniform | heterogenous, problems, such as a heat conductivity worsening compared with a theoretical value, will arise.

In order to solve such a problem relating to moldability, a method of adding a liquid organic compound at room temperature in order to improve the injection moldability of a thermoplastic resin highly filled with a filler is exemplified (for example, see Patent Document 1). . However, in such a method, there is a problem that a liquid organic compound bleeds out during injection molding and contaminates the mold.

On the other hand, in order to solve the problem relating to moldability, an invention was made to improve molding fluidity and improve injection moldability by using a resin capable of greatly delaying the solidification rate during cooling in the mold ( For example, see Patent Document 2). However, although this invention has been improved in terms of molding fluidity at the time of injection molding, it is necessary to set the injection molding temperature high, and the filler filling rate is limited to about 60% by volume, and the filler can be used sufficiently. This is a problem in that high thermal conductivity cannot be achieved without high filling. The reason why such a problem occurs is that the wettability between the resin and the filler is not sufficient, so that it is difficult to achieve a high filler filling due to problems such as breakage of strands during kneading, or 60% by volume. There is a problem that injection molding becomes difficult because the melt viscosity of the resin composition is remarkably increased due to the above high filler filling, and both high filler filling and good injection moldability have not been achieved.

On the other hand, in order to solve such a problem related to the filler dispersion state, a method of improving the fluidity of the filler by mixing a fluidity modifier in order to disperse uniformly in the resin without forming filler aggregates is exemplified. (For example, see Patent Document 3). Such filler surface modification improves the dispersibility in the resin and improves the thermal conductivity, but it has not been achieved in the problem of high filler filling.
Further, depending on the type of filler, the hygroscopicity is high, and the heat and moisture resistance of the resin composition containing the filler may be a problem.

Japanese Patent No. 3948240 JP 2009-91440 A Japanese Patent No. 3714502

The present invention has been made against the background of the problems of the prior art. That is, an object of the present invention is to provide a highly thermally conductive resin composition that achieves both high filler filling and good injection moldability, and further has good filler dispersibility and good wet heat resistance.

As a result of intensive studies, the present inventors have found that the above problems can be solved by the following means, and have reached the present invention. That is, the present invention has the following configuration.
[1] It comprises 70 to 20 parts by volume of a polyester resin (A) having a melt viscosity of 5 to 2000 dPa · s at 200 ° C. under a load of 10 kgf, and 30 to 80 parts by volume of a heat conductive filler (B). A thermally conductive resin composition.
[2] 80 mol% or more of the dicarboxylic acid component constituting the polyester resin (A) is terephthalic acid and / or naphthalenedicarboxylic acid, and 40 mol% of the diol component constituting the polyester resin (A). The heat conductive resin composition according to [1], wherein the above is 1,4-butanediol.
[3] Of the dicarboxylic acid component constituting the polyester resin (A), 80 mol% or more is naphthalenedicarboxylic acid, and among the diol components constituting the polyester resin (A), 40 mol% or more is 1,4. The heat conductive resin composition according to [1], which is butanediol.
[4] The thermally conductive resin composition according to any one of [1] to [3], wherein 2 mol% or more of the diol component of the polyester resin (A) is a polyalkylene ether glycol. .
[5] The heat conductive resin composition according to [4], wherein the polyalkylene ether glycol is polytetramethylene glycol having a number average molecular weight of 400 to 4000.
[6] The heat conductive filler (B) is composed of one type or two or more types of fillers, and when the total particle frequency of all fillers is 100%, the particle frequency with a particle size of 1 to 10 μm is 10 to 40. %, And the frequency of particles having a particle diameter of 10 to 100 μm is 50 to 85%. The heat conductive resin composition according to any one of [1] to [5].
[7] The thermal conductive resin composition according to any one of [1] to [6], wherein the thermal conductivity of the thermal conductive filler (B) alone is 10 W / m · K or more. .
[8] The heat conductive resin composition according to any one of [1] to [7], wherein the heat conductive filler (B) is surface-treated with a coupling agent.
[9] When the heat conductive filler (B) is composed of one kind or two or more kinds of fillers and the total particle frequency of all fillers is 100%, the particle frequency of 1 to 10 μm in particle size is 10 to 20 %, And the frequency of particles having a particle diameter of 10 to 100 μm is 70 to 85%. The heat conductive resin composition according to any one of [1] to [8].

The particle frequency of the filler will be described below.
In the present invention, the heat conductive filler is sometimes simply referred to as a filler.

The greatest feature of the present invention is that the resin properties are made to have an ultra-low melt viscosity and the crystallization speed is significantly delayed, thereby greatly improving the wettability with the filler and enabling a high filler filling. . And a favorable melt viscosity can be maintained for the molding process after filler high filling, and coexistence with high filler filling and the outstanding moldability is realizable. Furthermore, by using a filler that has been surface-treated with a coupling agent, it is possible to suppress filler aggregation and achieve good dispersibility, thereby further improving the thermal conductivity. Further, by using a filler having a particle frequency of the particle size of the filler in a specific range, even if the filler is hygroscopic, it is possible to realize good wet heat resistance by reducing the filler surface area.

The present invention is described in detail below.
The polyester resin (A) used in the present invention needs to have a melt viscosity of 5 to 2000 dPa · s at 200 ° C. When the melt viscosity is higher than 2000 dPa · s, the melt viscosity of the resin composition after the high filler filling is remarkably increased, and good injection moldability cannot be obtained. By using a polyester resin having a melt viscosity of 2000 dPa · s or less, preferably 1000 dPa · s or less, good injection moldability can be obtained even after high filler filling. Further, the melt viscosity at 200 ° C. is preferably low, but considering the mechanical strength of the heat conductive resin composition, the lower limit is required to be 5 dPa · s or more, preferably 20 dPa · s or more, more preferably 100 dPa. · S or more, more preferably 200 dPa · s or more.

The polyester resin (A) preferably contains 80 mol% or more of terephthalic acid and / or naphthalenedicarboxylic acid as the dicarboxylic acid component, assuming that the total amount of dicarboxylic acid components is 100 mol%. More preferably, it is 90 mol% or more, More preferably, it is 95 mol% or more. If it is less than 80 mol%, the mechanical strength and heat resistance tend to decrease.
Naphthalenedicarboxylic acid is preferred as the dicarboxylic acid component from the viewpoints of heat resistance and mechanical strength, and from the viewpoint of better compatibility between high filler filling and good molding fluidity.
The methyl ester derivative may be used as the dicarboxylic acid component. Naphthalenedicarboxylic acid is preferably 2,6-naphthalenedicarboxylic acid or a methyl ester derivative thereof, among its isomers, in consideration of the reactivity and the three-dimensional structure of the polymer chain.

The polyester resin (A) preferably contains 40 mol% or more of 1,4-butanediol as a glycol component, assuming that the total amount of diol components is 100 mol%. More preferably, it is 50 mol% or more. If it is less than 40 mol%, the crystallinity is too low, and blocking, moldability and heat resistance are problematic. The upper limit is preferably 80 mol% or less, more preferably 70 mol% or less. If it exceeds 80 mol%, the crystallization rate becomes too fast, so that the wettability with the filler deteriorates, the strand breakage or the like tends to occur due to the floating of the filler, and it tends to be difficult to achieve high filler filling.

In order to maintain good injection moldability even after high filler filling, it is desirable that the melt viscosity of the resin before blending the filler is low, and it is desirable to copolymerize polyalkylene ether glycol for that purpose.
Examples of the polyalkylene ether glycol include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, poly (ethylene oxide / propylene oxide) copolymer, poly (ethylene oxide / tetrahydrofuran) copolymer, poly (ethylene oxide / propylene oxide / tetrahydrofuran). ) Copolymer and the like, and when the total amount of diol components of the polyester resin (A) is 100%, the polyalkylene ether glycol is preferably 2 mol% or more, more preferably 5 mol% or more. More preferably, it is 10 mol% or more, particularly preferably 20 mol% or more, and most preferably 30 mol% or more. The upper limit is preferably 60% by mole or less, more preferably 50% by mole or less in consideration of handling properties such as heat resistance and blocking.

Polytetramethylene glycol is desirable as the polyalkylene ether glycol. The number average molecular weight of polytetramethylene glycol is preferably 400 or more, more preferably 500 or more, still more preferably 600 or more, particularly preferably 700 or more, and the upper limit is preferably 4000 or less, more preferably 3500 or less, More preferably, it is 3000 or less. When the number average molecular weight of polytetramethylene glycol is less than 400, hydrolysis resistance may be lowered. On the other hand, when it exceeds 4000, the compatibility with the polyester portion composed of butylene terephthalate and / or butylene naphthalate units is lowered, and it may be difficult to copolymerize in a block form.

The polyester resin of the present invention can be produced by a known method. For example, after the esterification reaction of the above dicarboxylic acid and diol component at 150 to 250 ° C., the pressure is reduced at 230 to 300 ° C. under reduced pressure. The desired polyester can be obtained by condensation. Alternatively, the target polyester can be obtained by performing a transesterification reaction at 150 ° C. to 250 ° C. using a derivative such as dimethyl ester of the above dicarboxylic acid and a diol component, followed by polycondensation at 230 ° C. to 300 ° C. under reduced pressure. Can do.

In producing the polyester resin (A), it is preferable to add an antioxidant for the purpose of suppressing thermal deterioration, oxidative deterioration, etc., and it may be added before, during or after the reaction. For example, known hindered phenol-based, phosphorus-based, and thioether-based antioxidants can be used.
These antioxidants can be used alone or in combination. The addition amount is preferably 0.1% by mass or more and 5% by mass or less with respect to the polyester resin (A). If it is less than 0.1% by mass, the effect of preventing thermal deterioration may be poor. If it exceeds 5 mass%, other physical properties may be adversely affected.

Also, a known copolymerizable component can be used for the polyester resin (A) as long as the reactivity and mechanical properties and chemical properties of the obtained copolymer are not impaired. The component includes a divalent or higher aromatic carboxylic acid having 8 to 22 carbon atoms, a divalent or higher aliphatic carboxylic acid having 4 to 12 carbon atoms, and a divalent or higher alicyclic carboxylic acid having 8 to 15 carbon atoms. Carboxylic acids such as acids and their ester-forming derivatives, aliphatic compounds having 2 to 20 carbon atoms and compounds having two or more hydroxyl groups in the molecule, aromatic compounds having 6 to 40 carbon atoms, Examples thereof include compounds having two or more hydroxyl groups in the molecule, and ester-forming derivatives thereof.

Specifically, as carboxylic acids, in addition to terephthalic acid and naphthalenedicarboxylic acid, for example, isophthalic acid, bis (p-carboxyphenyl) methaneanthracene dicarboxylic acid, 4,4′-diphenyldicarboxylic acid, 1,2-bis (Phenoxy) ethane-4,4′-dicarboxylic acid, adipic acid, sebacic acid, azelaic acid, dodecanedioic acid, maleic acid, trimesic acid, trimellitic acid, pyromellitic acid, 1,3-cyclohexanedicarboxylic acid, 1, Examples thereof include carboxylic acids such as 4-cyclohexanedicarboxylic acid and decahydronaphthalenedicarboxylic acid or derivatives having ester-forming ability thereof. Examples of the hydroxyl group-containing compounds include 1,4-butanediol, ethylene glycol, 1,3 -Propanediol, 1,2-propanedioe 1,6-hexanediol, neopentyl glycol, cyclohexanedimethanol, 2,2'-bis (4-hydroxyphenyl) propane, 2,2'-bis (4-hydroxycyclohexyl) propane, hydroquinone, glycerin, pentaerythritol Or derivatives having an ester forming ability thereof.

In addition, oxyacids such as p-oxybenzoic acid and p-hydroxyethoxybenzoic acid and ester-forming derivatives thereof, and cyclic esters such as ε-caprolactone can be used.
The copolymerization amount of the above components is preferably 20% by mass or less, more preferably 15% by mass or less, and still more preferably 10% by mass or less.

Furthermore, in the present invention, by adding a polyfunctional compound selected from the group of an epoxy compound having at least two reactive groups, an organic carboxylic acid and / or an anhydride thereof, an oxazoline compound, an isocyanate compound, and the like, This copolymer can be obtained in a relatively short time, and is useful from the viewpoint of the thermal stability of the block copolymer.

The method for adding the polyfunctional compound is not particularly limited, and a normal method is used. For example, a method of adding at an arbitrary stage before the end of polycondensation, a method of adding in an inert gas atmosphere after the end of polycondensation, an addition after taking out the copolymer into pellets, flakes, or powders And a method of melt mixing with an extruder or a kneader.

The heat conductive filler (B) blended in the heat conductive resin composition of the present invention is not particularly limited. In consideration of the effect of improving the thermal conductivity of the composition, it is preferable that the thermal conductivity of the single component is 10 W / m · K or more. If it is less than 10 W / m · K, the effect of improving the thermal conductivity of the composition is poor. The thermal conductivity of the single substance is more preferably 15 W / m · K or more, further preferably 20 W / m · K or more, particularly preferably 30 W / m · K or more. The upper limit of the thermal conductivity of the heat conductive filler (B) alone is not particularly limited, and it is preferably as high as possible. Generally, it is preferably 3000 W / m · K or less, more preferably 2500 W / m · K or less. Used.

The heat conductive filler (B) can contain one kind or two or more kinds of fillers. The term “two or more types of fillers” means that two or more types differing in at least one of the material type, shape, average particle size, particle size distribution, and surface treatment agent of the filler.

As for the shape of the heat conductive filler (B), various shapes can be applied. For example, particles, particles, nanoparticles, agglomerated particles, wires, rods, needles, plates, irregular shapes, rugby balls, hexahedrons, composite particles in which large particles and fine particles are combined, Various shapes can be exemplified. Further, these heat conductive fillers (B) may be natural products or synthesized ones. In the case of a natural product, there are no particular limitations on the production area and the like, which can be selected as appropriate.

One type or two or more types of thermally conductive fillers (B) are represented as B ′, B ″, B ′ ″..., And the total of these masses is 100% by mass. When the particle frequency with a particle size of 1 to 10 μm is obtained by (Equation 1) and the particle frequency with a particle size of 10 to 100 μm is obtained by (Equation 2), 1 of the thermally conductive filler (B) It is preferable that the particle frequency of a particle size of ˜10 μm is 10 to 40% and the particle frequency of a particle size of 10 to 100 μm is 50 to 85%. More preferably, the particle frequency of 1 to 10 μm is 10 to 40%, the particle frequency of 10 to 100 μm is 50 to 80%, and more preferably 1 to 10 μm. The particle frequency of 15 to 35% and a particle size of 10 to 100 μm is 55 to 78%, particularly preferably a particle frequency of 1 to 10 μm and a particle frequency of 20 to 30% and a particle size of 10 to 100 μm. The particle frequency is 60 to 75%.
It is preferable that the particle frequency of the filler satisfies these ranges, so that the filler filling rate and the thermal conductivity can be improved efficiently as compared with the case where the same charge amount does not satisfy these ranges.

In addition to the filler filling rate and thermal conductivity, in order to satisfy the heat and moisture resistance, the thermal conductive filler (B) is composed of one kind or two or more kinds of fillers, and the total particle frequency of all fillers is 100. %, The particle frequency with a particle size of 1 to 10 μm is preferably 10 to 20%, and the particle frequency with a particle size of 10 to 100 μm is preferably 70 to 85%. More preferably, the particle frequency of 1 to 10 μm is 10 to 18%, and the particle frequency of 10 to 100 μm is 70 to 83%.
When the particle frequency satisfies these ranges, even if the filler is hygroscopic, it is possible to reduce the filler surface area to such an extent that the heat and moisture resistance can be satisfied.
In general, when the filler is hygroscopic, the cause is a functional group on the surface. Therefore, if the amount of functional groups on the surface is reduced, the hygroscopicity is improved. In many cases, the amount of surface functional groups depends on the size of the surface area. Therefore, it is possible to improve the hygroscopic property and further the heat and moisture resistance by controlling the surface area by controlling the particle diameter and particle frequency.

When the type of filler used is one (Equation 1), up to the term B ′ in (Equation 2), similarly up to B ″ in the case of two types, up to B ′ ″ in the case of three types, etc. The sum of particle frequencies up to the term corresponding to the number of types shall be considered.
However, the particle size and particle frequency handled in (Equation 1) and (Equation 2) indicate the particle size and particle frequency of the heat conductive filler alone before blending with the resin. That is, regardless of the shape of the heat conductive filler (B), in the case of an aggregate, the particle size and particle frequency of the aggregate are targeted. Moreover, when the aspect ratios of the fillers are different, such as a wire shape, a rod shape, a needle shape, a plate shape, a rugby ball shape, and a hexahedron shape, the average value of the major axis and the minor axis is targeted. However, this is not the case when it is an aggregate. When none of these applies, the average particle size per particle and the particle frequency are targeted. In addition, the average particle diameter and particle frequency in this invention shall be measured using particle size distribution measuring apparatuses, such as a laser scattering particle size distribution analyzer.

(Formula 1)
{(Mixing ratio of heat conductive filler B ′ [mass%]) / 100 × (particle frequency of 1 to 10 μm of heat conductive filler B ′ [%]) / 100
+ (Mixing ratio of heat conductive filler B ″ [% by mass]) / 100 × (particle frequency of 1 to 10 μm of heat conductive filler B ″ [%]) / 100
+ (Mixing ratio of heat conductive filler B ′ ″ [% by mass]) / 100 × (particle frequency of 1 to 10 μm of heat conductive filler B ′ ″ [%]) / 100
+ ...} × 100
(Formula 2)
{(Mixing ratio of heat conductive filler B ′ [mass%]) / 100 × (particle frequency of heat conductive filler B ′ of 10 to 100 μm [%]) / 100
+ (Mixing ratio of heat conductive filler B ″ [mass%]) / 100 × (particle frequency of 10 to 100 μm of heat conductive filler B ″ [%]) / 100
+ (Mixing ratio of heat conductive filler B ′ ″ [% by mass]) / 100 × (particle frequency of heat conductive filler B ′ ″ of 10 to 100 μm [%]) / 100
+ ...} × 100

Specific examples of the thermally conductive filler (B) exhibiting electrical insulation include metal oxides such as aluminum oxide (alumina), magnesium oxide (magnesia), silicon oxide, beryllium oxide, zinc oxide, copper oxide, and cuprous oxide. Metal nitride such as boron nitride, aluminum nitride, silicon nitride, metal carbide such as silicon carbide, metal carbonate such as magnesium carbonate, diamond, and other insulating carbon materials, aluminum hydroxide, magnesium hydroxide, etc. The metal hydroxide can be exemplified.

Among them, since it has excellent electrical insulation properties, metal nitrides such as boron nitride, aluminum nitride, and silicon nitride, metal oxides such as aluminum oxide, magnesium oxide, beryllium oxide, and zinc oxide, metal carbonates such as magnesium carbonate, Metal hydroxides such as aluminum hydroxide and magnesium hydroxide, and insulating carbon materials such as diamond can be more preferably used. Of these, aluminum oxide (alumina), magnesium oxide (magnesia), and zinc oxide are preferable because wettability with the resin is relatively good, and aluminum oxide (alumina) and magnesium oxide (magnesia) are more preferable. is there. These can be used alone or in combination.

Specific examples of the heat conductive filler (B) exhibiting electrical conductivity include carbon materials such as graphite and carbon fiber, and metal materials such as metal silicon, aluminum, and magnesium. These can be used alone or in combination.

The average particle size of the heat conductive filler (B) used in the present invention is preferably 1 to 100 μm. The thickness is more preferably 1.5 to 80 μm, further preferably 2 to 70 μm.
When two types of fillers having different average particle diameters are used, considering the closest packing in the resin, the thermal conductivity of the resin composition, the problem of aggregate formation, and the ease of handling, The average particle size is preferably 1 to 20 μm, and the average particle size of the filler having a large particle size is preferably 20 to 100 μm. When the filler surface area is small, the average particle size of the filler having a large particle size is preferably 30 μm or more, more preferably from the viewpoint of being hardly affected by the poor wettability with the resin and hardly forming an aggregate. 40 μm or more.

These heat conductive fillers (B) improve the adhesiveness at the interface between the polyester resin and the inorganic compound (compound constituting the filler), facilitate the workability, and improve the dispersibility in the resin. Therefore, it is preferable that the surface treatment is performed with a coupling agent. The coupling agent is not particularly limited, and conventionally known ones such as a silane coupling agent, a titanate coupling agent, an aluminate coupling agent, and a phosphate ester coupling agent can be used. Among these, a silane coupling agent is preferably used because it hardly reduces the physical properties of the resin.
The surface treatment method of the inorganic compound is not particularly limited, and a normal treatment method can be used.
The following can be illustrated as such a surface-treated heat conductive filler. Silane coupling treated magnesia such as RF-10C-SC and RF-50-SC manufactured by Ube Materials Co., Ltd., and aluminate coupling treated magnesia such as MCA-10 and MCA- manufactured by Sankyo Seimitsu Co., Ltd. 50, such as MCP-10 and MCP-50 manufactured by Sankyo Seimitsu Co., Ltd. as Magnesia Phosphate Coupling Co., Ltd. MCT-10, MCT-50 manufactured by Sankyo Seiko Co., Ltd. MCT9SA-10, MCT9SA-50, etc. can be used.
By improving the dispersibility of the filler, the thermal conductivity of the resin composition is further improved, which is preferable.

The polyester resin (A) and the heat conductive filler (B) in the heat conductive resin composition of the present invention are 70 to 20 parts by volume of the polyester resin (A) and 30 to 80 parts by volume of the heat conductive filler (B). Contained. The viewpoint that the impact resistance and molding processability of the resulting resin composition are improved and the kneading with the resin during melt kneading tends to be easier as the content of (A) is larger, and (B) In order to achieve both of them in consideration of the viewpoint that thermal conductivity tends to improve as the amount increases, the content is preferably (A) 60 to 20 parts by volume and (B) 40 to 80 parts by volume, More preferred are (A) 50-25 parts by volume and (B) 50-75 parts by volume, still more preferred (A) 40-30 parts by volume and (B) 60-70 parts by volume.

In the heat conductive resin composition of the present invention, the blending ratio of the polyester resin (A) and the heat conductive filler (B) is expressed in volume parts, but when the resin composition is produced, (A), ( B) Based on each specific gravity, it mix | blends on a mass basis. (A) is based on the specific gravity of the resin alone, and (B) is based on the specific gravity of the filler chemical species alone. In this way, the compounding amount is expressed in volume parts because the thermal conductivity, which is an important characteristic of the resin composition obtained according to the present invention, means that the volume ratio is large, not the mass ratio of the heat conductive filler in the composition. Because it has.
Also when the heat conductive resin composition which concerns on this invention contains components other than a polyester resin (A) and a heat conductive filler (B), a compounding quantity is determined similarly.
Since the heat conductive resin composition according to the present invention has very good dispersibility of the heat conductive filler (B) in the polyester resin (A), there are almost no voids (air layer) in the resin composition. Therefore, whether or not the heat conductive filler (B) is filled according to the blending ratio can be confirmed based on the specific gravity of (A) and (B) by measuring the specific gravity of the obtained heat conductive resin composition. I can do it.
The heat conductive resin composition according to the present invention preferably occupies 90% by volume or more in total of the polyester resin (A) and the heat conductive filler (B). The total of (A) and (B) in the thermally conductive resin composition is more preferably 95% by volume or more, and still more preferably 97% by volume or more.

In order to make the heat conductive resin composition of the present invention higher performance, a heat stabilizer such as a phenol-based stabilizer, a sulfur-based stabilizer and a phosphorus-based stabilizer is added alone or in combination of two or more. It is preferable to do. Furthermore, as necessary, generally well-known stabilizers, lubricants, mold release agents, plasticizers, flame retardants other than phosphorus, flame retardant aids, ultraviolet absorbers, light stabilizers, pigments, dyes, charging An inhibitor, a conductivity imparting agent, a dispersant, a compatibilizing agent, an antibacterial agent and the like may be added alone or in combination of two or more.

The method for producing the thermally conductive resin composition of the present invention is not particularly limited. For example, it can be produced by drying the components and additives described above and then melt-kneading them in a melt-kneader such as a single-screw or twin-screw extruder. Moreover, when a compounding component is a liquid, it can also manufacture by adding to a melt kneader on the way using a liquid supply pump etc.

As a method of melt-kneading the filler and the polyester resin, it is possible to add and knead the filler separately. For example, one series of side feeds can be used, and a dry blend of a part of the resin and filler can be put into the original feed, and the remaining filler can be put into the side feed and kneaded continuously. Alternatively, use two series of side feeds, add resin to the original feed, add part of the filler to the side feed close to the original feed, and the remaining filler to the side feed far from the original feed, and knead continuously. May be. Alternatively, the resin (A) and a part of the filler may be kneaded, once taken out as pellets, etc., mixed with the remaining filler, and then kneaded again.

The method for molding the heat conductive resin composition of the present invention is not particularly limited. For example, a molding method generally used for thermoplastic resins, for example, injection molding, blow molding, extrusion molding, vacuum molding, press molding. Calendar molding can be used. Among these, it is preferable to perform injection molding by an injection molding method because the molding cycle is short, the production efficiency is excellent, and the composition has good fluidity at the time of injection molding.

The composition of the present invention exhibits good thermal conductivity as shown in the examples, and is 0.7 W / m · K or more, preferably 1 W / m · K or more, more preferably 2.0 W / m · K or more. It is possible to obtain a molded body.

The composition thus obtained can be used in various forms such as resin films, resin molded products, resin foams, paints and coating agents, electronic materials, magnetic materials, catalyst materials, structural materials, optical materials, medical materials. It can be widely used for various applications such as materials, automobile materials, and building materials. The high thermal conductive thermoplastic resin composition obtained in the present invention has a complicated shape because a general plastic molding machine such as an injection molding machine or an extrusion molding machine that is widely used at present can be used. Molding into products is easy. In particular, since it has excellent properties such as excellent moldability and high thermal conductivity, it is very useful as a resin for a casing of a mobile phone, a display, a computer or the like having a heat source inside.

The high thermal conductive resin composition of the present invention can be suitably used for injection molded products such as home appliances, OA equipment parts, AV equipment parts, automotive interior / exterior parts, and the like. In particular, it can be suitably used as an exterior material in home appliances and office automation equipment that generate a lot of heat.

Furthermore, in an electronic device having a heat source inside but difficult to forcibly cool by a fan or the like, it is suitably used as an exterior material for these devices in order to dissipate the heat generated inside to the outside. Among these, as preferred devices, small or portable electronic devices such as portable computers such as notebook computers, PDAs, cellular phones, portable game machines, portable music players, portable TV / video devices, portable video cameras, etc. It is very useful as a resin for housings, housings, and exterior materials. It can also be used very effectively as a resin for battery peripherals in automobiles and trains, a resin for portable batteries of home appliances, a resin for power distribution parts such as a breaker, and a sealing material for motors.

The high thermal conductive resin composition of the present invention has better molding processability and impact resistance than conventional well-known compositions, and has useful properties for parts or casings in the above applications. It is.

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to the examples. In addition, each measured value described in the Example is measured by the following method.

(Melt viscosity)
The melt viscosity was measured using a flow tester (CFT-500C type) manufactured by Shimadzu Corporation. A resin sample dried to a moisture content of 0.1% or less is filled in a cylinder at the center of a heating body set to 200 ° C. After 1 minute of filling, a load (10 kgf) is applied to the sample via a plunger, and the bottom of the cylinder The melted sample was extruded from the die (hole diameter: 1.0 mm, thickness: 10 mm), the plunger descending distance and the descending time were recorded, and the melt viscosity was calculated. When the melting point of the resin exceeded 185 ° C., the load was measured at 50 kgf.

(Particle frequency)
One type or two or more types of thermally conductive fillers (B) are represented as B ′, B ″, B ′ ″..., And the total of these masses is 100% by mass. The particle frequency with a particle size of 1 to 10 μm was obtained from (Equation 1) and the particle frequency with a particle size of 10 to 100 μm was obtained from (Equation 2).
(Formula 1)
{(Mixing ratio of heat conductive filler B ′ [mass%]) / 100 × (particle frequency of 1 to 10 μm of heat conductive filler B ′ [%]) / 100
+ (Mixing ratio of heat conductive filler B ″ [% by mass]) / 100 × (particle frequency of 1 to 10 μm of heat conductive filler B ″ [%]) / 100
+ (Mixing ratio of heat conductive filler B ′ ″ [% by mass]) / 100 × (particle frequency of 1 to 10 μm of heat conductive filler B ′ ″ [%]) / 100
+ ...} × 100
(Formula 2)
{(Mixing ratio of heat conductive filler B ′ [mass%]) / 100 × (particle frequency of heat conductive filler B ′ of 10 to 100 μm [%]) / 100
+ (Mixing ratio of heat conductive filler B ″ [mass%]) / 100 × (particle frequency of 10 to 100 μm of heat conductive filler B ″ [%]) / 100
+ (Mixing ratio of heat conductive filler B ′ ″ [% by mass]) / 100 × (particle frequency of heat conductive filler B ′ ″ of 10 to 100 μm [%]) / 100
+ ...} × 100

(Production example: Polyester resin (A1))
In a reaction vessel equipped with a stirrer, a thermometer, and a condenser for distillation, 194 parts by mass of dimethyl terephthalate, 100 parts by mass of 1,4-butanediol, and polytetramethylene glycol “PTMG2000” having a number average molecular weight of 2000 (Mitsubishi Chemical) 800 parts by mass and 0.25 part by mass of tetrabutyl titanate were added, and an esterification reaction was performed at 170 to 220 ° C. for 2 hours. After completion of the esterification reaction, the temperature was raised to 255 ° C., while the pressure in the system was slowly reduced to 665 Pa at 255 ° C. over 60 minutes. Further, a polycondensation reaction was performed at 133 Pa or less for 30 minutes to obtain a polyester resin (A1). The composition of this polyester resin (A1) was terephthalic acid // 1,4-butanediol / PTMG2000 = 100 // 60/40 mol%, the melting point was 140 ° C., and the melt viscosity was 350 dPa · s.

(Production examples: polyester resins (A2) to (A5), (C1) to (C3))
The polyester resins (A2) to (A5) and (C1) to (C3) were synthesized by the same method as the polyester resin (A1). Each composition and physical property value are shown below. Polyesters (C1) to (C3) were used as raw materials for the comparative examples.
(A2): terephthalic acid // 1,4-butanediol / PTMG2000 = 100 // 70/30 mol%, melting point 157 ° C., melt viscosity 500 dPa · s.
(A3): 2,6-naphthalenedicarboxylic acid // 1,4-butanediol / PTMG2000 = 100 // 40/60 mol%, melting point 140 ° C., melt viscosity 250 dPa · s.
(A4): 2,6-naphthalenedicarboxylic acid // 1,4-butanediol / PTMG2000 = 100 // 60/40 mol%, melting point 160 ° C., melt viscosity 500 dPa · s.
(A5): 2,6-naphthalenedicarboxylic acid // 1,4-butanediol / PTMG2000 = 100 // 70/30 mol%, melting point 185 ° C., melt viscosity 650 dPa · s.
(C1): terephthalic acid // 1,4-butanediol / PTMG2000 = 100 // 80/20 mol%, melting point 178 ° C., melt viscosity 2200 dPa · s.
(C2): terephthalic acid // 1,4-butanediol / PTMG1000 = 100 // 85/15 mol%, melting point 191 ° C., melt viscosity 4000 dPa · s.
(C3): 2,6-naphthalenedicarboxylic acid // 1,4-butanediol / PTMG1000 = 100 // 75/25 mol%, melting point 189 ° C., melt viscosity 6500 dPa · s.

Polyester resins (A1) to (A5) have a melt viscosity at 200 ° C. of 5 to 2000 dPa · s, while polyester resins (C1) to (C3) have a melt viscosity at 200 ° C. of more than 2000 dPa · s. is there.

The heat conductive filler used for the Example and the comparative example is as follows. Those not described regarding the surface treatment are untreated fillers.
(B1): Alumina (LS-210B manufactured by Nippon Light Metal Co., Ltd., single body thermal conductivity 20-40 W / m · K, average particle size 3.2 μm, volume resistivity 10 ¹² to 10 ¹⁴ Ω · cm, specific gravity 3.98, Particle frequency: [1-10 μm] 95%, [10-100 μm] 0%, [Others] 5%)
(B2): Alumina (Nippon Light Metal Co., Ltd. LS-110F, thermal conductivity 20 alone ~ 40W / m · K, the average particle diameter of 1.1 .mu.m, a volume resistivity ^{^{10 12 ~ 10 14 Ω · cm}} , a specific gravity 3.98, Particle frequency: [1-10 μm] 60%, [10-100 μm] 0%, [Others] 40%)
(B3): Alumina (Nippon Light Metal Co., Ltd. V325F, single body thermal conductivity 20 to 40 W / m · K, average particle size 12 μm, volume resistivity 10 ¹² to 10 ¹⁴ Ω · cm, specific gravity 3.98, Particle frequency: [1-10 μm] 35%, [10-100 μm] 55%, [Others] 10%)
(B4): Magnesia (RF-50-C manufactured by Ube Materials Co., Ltd., single unit thermal conductivity 42 to 60 W / m · K, average particle size 56.6 μm, volume resistivity 10 ¹⁷ Ω · cm, specific gravity 3.58, Particle frequency: [1-10 μm] 0%, [10-100 μm] 95%, [Others] 5%)
(B4a): Magnesia (RF-50-C manufactured by Ube Materials Co., Ltd., single unit thermal conductivity 42 to 60 W / m · K, average particle size 56.3 μm, volume resistivity 10 ¹⁷ Ω · cm, specific gravity 3.58, particle frequency: [1-10 μm] 0%, [10-100 μm] 86%, [others] 14%)
(B5): Magnesia (RF-10C-C manufactured by Ube Materials Co., Ltd., single unit thermal conductivity 42-60 W / m · K, average particle size 6.6 μm, volume resistivity 10 ¹⁷ Ω · cm, specific gravity 3.58, Particle frequency: [1-10 μm] 60%, [10-100 μm] 35%, [Others] 5%)
(B5a): Magnesia (RF-10C-C manufactured by Ube Materials Co., Ltd., single unit thermal conductivity 42 to 60 W / m · K, average particle size 6.6 μm, volume resistivity 10 ¹⁷ Ω · cm, specific gravity 3.58, particle frequency: [1-10 μm] 60%, [10-100 μm] 39%, [others] 1%)
(B5b): Magnesia (RF-10C-C manufactured by Ube Materials Co., Ltd., single unit thermal conductivity 42 to 60 W / m · K, average particle size 10.7 μm, volume resistivity 10 ¹⁷ Ω · cm, specific gravity 3.58, particle frequency: [1-10 μm] 43%, [10-100 μm] 50%, [others] 7%)
(B6): Silane coupling-treated magnesia (RF-10C-SC manufactured by Ube Materials Co., Ltd., single body thermal conductivity 42 to 60 W / m · K, average particle size 7.4 μm, volume resistivity 10 ¹⁷ Ω・ Cm, specific gravity 3.58, particle frequency: [1-10 μm] 58%, [10-100 μm] 40%, [others] 2%)
(B6a): Silane coupling-treated magnesia (RF-10C-SC manufactured by Ube Materials Co., Ltd., single unit thermal conductivity 42 to 60 W / m · K, average particle size 12.5 μm, volume resistivity 10 ¹⁷ Ω (Cm, specific gravity 3.58, particle frequency: [1-10 μm] 36%, [10-100 μm] 58%, [others] 6%)
(B7): Silane coupling-treated magnesia (RF-50-SC manufactured by Ube Materials Co., Ltd., single unit thermal conductivity 42 to 60 W / m · K, average particle size 53.6 μm, volume resistivity 10 ¹⁷ Ω (Cm, specific gravity 3.58, particle frequency: [1-10 μm] 0%, [10-100 μm] 86%, [others] 14%)
(B8): aluminate coupling treatment magnesia (Sankyo Seiko Co. MCA-10, the thermal conductivity by itself 42 ~ 60W / m · K, the average particle diameter of 11.9, a volume resistivity ^{10 17} Omega · cm, specific gravity 3.58, particle frequency: [1-10 μm] 36%, [10-100 μm] 59%, [others] 5%)
(B9): Aluminate coupling-treated magnesia (MCA-50 manufactured by Sankyo Seimitsu Co., Ltd., single unit thermal conductivity 42-60 W / m · K, average particle size 61.8 μm, volume resistivity 10 ¹⁷ Ω · cm, specific gravity 3.58, particle frequency: [1-10 μm] 0%, [10-100 μm] 86%, [others] 14%)
(B10): Phosphate ester-treated magnesia (MCP-10 manufactured by Sankyo Seimitsu Co., Ltd., thermal conductivity 42 to 60 W / m · K alone, average particle size 15.2 μm, volume resistivity 10 ¹⁷ Ω (Cm, specific gravity 3.58, particle frequency: [1-10 μm] 29%, [10-100 μm] 62%, [others] 9%)
(B11): Phosphate ester coupling treated magnesia (MCP-50 manufactured by Sankyo Seimitsu Co., Ltd., single unit thermal conductivity 42-60 W / m · K, average particle size 51.9 μm, volume resistivity 10 ¹⁷ Ω (Cm, specific gravity 3.58, particle frequency: [1-10 μm] 0%, [10-100 μm] 90%, [others] 10%)
(B12): Titanate coupling-treated magnesia (MCT-10 manufactured by Sankyo Seimitsu Co., Ltd., thermal conductivity 42 to 60 W / m · K alone, average particle size 15.8 μm, volume resistivity 10 ¹⁷ Ω · cm , Specific gravity 3.58, particle frequency: [1-10 μm] 28%, [10-100 μm] 62%, [others] 10%)
(B13): Titanate coupling-treated magnesia (Sankyo Seimitsu Co., Ltd. MCT-50, single unit thermal conductivity 42 to 60 W / m · K, average particle size 49.6 μm, volume resistivity 10 ¹⁷ Ω · cm Specific gravity 3.58, particle frequency: [1-10 μm] 0%, [10-100 μm] 95%, [others] 5%)
(B14): Titanate coupling-treated magnesia (manufactured by Sankyo Seimitsu Co., Ltd. MCT9SA-10, thermal conductivity of 42 to 60 W / m · K alone, average particle size of 14.7 μm, volume resistivity of 10 ¹⁷ Ω · cm , Specific gravity 3.58, particle frequency: [1-10 μm] 31%, [10-100 μm] 61%, [others] 8%)
(B15): Titanate coupling-treated magnesia (Sankyo Seimitsu Co., Ltd. MCT9SA-50, single body thermal conductivity 42-60 W / m · K, average particle size 51.3 μm, volume resistivity 10 ¹⁷ Ω · cm , Specific gravity 3.58, particle frequency: [1-10 μm] 0%, [10-100 μm] 90%, [others] 10%)

Example 1
After mixing the polyester resin (A1) polymerized by the above method and the mixture of the heat conductive fillers (B1) and (B2) in the ratio shown in Table 1, the tabletop type manufactured by Toyo Seiki Co., Ltd. preheated to 180 ° C. The kneader Laboplast Mill 20C200 was charged and kneaded at 20 rpm for 10 minutes.

(Examples 2 to 32, Comparative Examples 1 to 7)
Kneading was carried out in the same manner as in Example 1 except that the types and blending amounts of the polyester resin and the heat conductive filler were changed as shown in Tables 1 to 6. The examples and comparative examples were kneaded at 200 ° C. using polyester resins (A5) and (C1) to (C3) having a relatively high melting point or melt viscosity.

[Evaluation methods]
As described below, the kneaded state, the dispersed state, the heat and humidity resistance, the thermal conductivity, the specific gravity, and the injection moldability were determined.

(Preparation of sheet sample for evaluation)
Sheet samples used for various measurements were prepared using a heat press machine SA-302-I manufactured by Tester Sangyo Co., Ltd. The resin composition was placed in a mold having a predetermined thickness, melted at 190 ° C. for 2 minutes, applied with a load of 100 kgf / cm ² , and then cooled in water after 1 minute to obtain a sheet sample with a predetermined thickness. . In the case of a composition using a resin having a melting point of 185 ° C. or higher, it was melted at 200 ° C.

(Kneaded state)
The kneading state of the resin and filler was determined as follows, and ○ was judged good and Δ or x was judged as poor kneading. Δ is caused by the fact that the resin composition contains a large amount of voids, and is substantially synonymous with the fact that high filling is not achieved.
○: The resin and the filler are uniformly mixed, and the charged amount of the filler and the actually measured filling rate agree within a range of ± 5%.
Δ: Although uniform at first glance, the charged amount of filler and the actually measured filling rate are outside the range of ± 5%.
X: Resin and filler are completely separated and not mixed.

(Distributed state)
Within the range of 10 cmφ near the center of the 0.5 mm thick sheet obtained by heat press, the number of filler aggregates present on the sheet surface that can be visually confirmed is counted, and the dispersion state is determined as follows. It was. If the kneading state is ◯ or Δ, it is practical as a heat conductive resin composition. The better the dispersion state in this evaluation (the smaller the number of filler aggregates), the more the thermal conductivity can be improved.
○: The number of filler aggregates is 2 or less Δ: The number of filler aggregates is 3 or more and 14 or less ×: The number of filler aggregates is 15 or more

(Moisture and heat resistance)
A sheet sample having a thickness of 1 mm obtained by heat pressing was cut into a size of 10 mm × 50 mm to prepare a sample. This was put into a high-temperature and high-humidity tank, and the expansion coefficient of the sample under the condition of 85 ° C. × 85% Rh was observed. The length, width, and thickness (mm) before the high temperature and high humidity tank were added and after 1000 hours had elapsed after the high temperature and high humidity tank were supplied, respectively, and the expansion rate (%) in each direction was calculated. Furthermore, those products were taken and the volume expansion coefficient (%) was calculated. At this time, the expansion rate before charging the high-temperature and high-humidity tank is 100%. A constant pressure caliper was used for the measurement.
The smaller the volume expansion coefficient, the better. When the volume expansion coefficient is 130% or less, the deterioration of brittleness is small and good. If the expansion rate exceeds 130%, the brittleness deteriorates, so use under high humidity is not preferable.

(Thermal conductivity)
Specific heat was measured using DS Instruments 2920 manufactured by TA Instruments. 10.0 mg of the resin composition was put in an aluminum pan, heated from room temperature to 200 ° C. at a temperature rising temperature of 10 ° C./min, held for 5 minutes after reaching 200 ° C., and then cooled at 10 ° C./min. Similarly, 26.8 mg of sapphire as a reference material was placed in an aluminum pan and measured under the same conditions. Furthermore, the empty aluminum pan which has not put the sample as a blank was measured on the same conditions. Heat of each DSC curve at 23 ° C
The value of Flow was read, and the specific heat capacity was calculated by the following formula 3.
Cp is the specific heat of the sample, C′p is the specific heat of the reference material (sapphire) at 23 ° C., h is the difference between the DSC curve of the empty container and the sample, H is the difference of the DSC curve of the empty container and the reference material (sapphire), m is the sample Mass (g) and m ′ represent mass (g) of the reference material (sapphire).
(Formula 3)
Cp = (h / H) × (m ′ / m) × C′p
The specific gravity was measured using an automatic hydrometer DH100 manufactured by Toyo Seiki Co., Ltd. A sheet having a thickness of 0.5 mm obtained by heat pressing was sampled to a size of 10 mm × 10 mm, and the specific gravity was measured by an underwater substitution method.
The thermal diffusivity is measured by ai-phase.
It measured using Mobile1. The thermal diffusivity in the thickness direction of the kneaded resin composition processed into a sheet having a thickness of 0.5 mm with a heat press was measured.
The thermal conductivity was calculated from the specific heat, specific gravity, and thermal diffusivity obtained by the above method according to the following formula.
(Formula 4)
Thermal conductivity (W / m · K) = specific gravity × specific heat (J / g · K) × thermal diffusivity (m ² / sec)

(Injection moldability)
The injection moldability was judged as follows, and ○ was judged as good moldability and X was judged as poor moldability.
○: Injection molding is possible at a mold temperature of 180 to 280 ° C.
×: Injection molding is not possible at a mold temperature of 180 to 280 ° C. (Short shots of specimens occur.)

The respective formulations and results are shown in Tables 1 to 6. From Tables 1 to 6, it can be seen that the composition of the present invention exhibits particularly excellent thermal conductivity compared to the composition outside the range of the present invention, and a resin composition with high thermal conductivity excellent in injection moldability can be obtained. Recognize.

Uses a polyester resin whose dicarboxylic acid component is naphthalenedicarboxylic acid and uses a thermally conductive filler with a particle frequency of 1 to 10 μm and a particle frequency of 10 to 40 μm and a particle frequency of 10 to 100 μm of 50 to 85%. It can be seen that the compositions of Examples 3, 7, 8, 11, and 12 obtained excellent results in all of the kneaded state, thermal conductivity, and injection moldability.

Compared to the compositions of Examples 13 to 19 using the heat conductive filler surface-treated with the coupling agent, the compositions of Examples 20 and 21 using the heat-conductive filler with an untreated surface are heat conductive. Although it is practical as a resin composition, it turns out that the dispersion state of a filler is inferior.

Compared to the compositions of Examples 22-29 using thermal conductive fillers with a particle frequency of 1-20 μm particle size of 10-20% and a particle frequency of 10-100 μm particle size of 70-85% It can be seen that the compositions of Examples 30 to 31 using a non-thermally conductive filler are practical as a thermally conductive resin composition, but have poor wet heat resistance.

The heat conductive resin composition of the present invention enables high filler filling, and also has high heat conductivity, but also has excellent molding fluidity during injection molding, high filler filling and good injection. It is a thermoplastic resin composition with high thermal conductivity that has both moldability and industrial utility value.

Claims

Heat conduction characterized by containing 70 to 20 parts by volume of a polyester resin (A) having a melt viscosity of 5 to 2000 dPa · s at 200 ° C. under a load of 10 kgf and 30 to 80 parts by volume of a heat conductive filler (B). Resin composition.
80 mol% or more of the dicarboxylic acid component constituting the polyester resin (A) is terephthalic acid and / or naphthalenedicarboxylic acid, and 40 mol% or more of the diol component constituting the polyester resin (A) is 1 The heat conductive resin composition according to claim 1, which is 1,4-butanediol.
80 mol% or more of the dicarboxylic acid component constituting the polyester resin (A) is naphthalenedicarboxylic acid, and 40 mol% or more of the diol component constituting the polyester resin (A) is 1,4-butanediol. The thermally conductive resin composition according to claim 1, wherein:
The heat conductive resin composition according to any one of claims 1 to 3, wherein 2 mol% or more of the diol component of the polyester resin (A) is polyalkylene ether glycol.
The heat conductive resin composition according to claim 4, wherein the polyalkylene ether glycol is polytetramethylene glycol having a number average molecular weight of 400 to 4000.
When the heat conductive filler (B) is composed of one kind or two or more kinds of fillers, and the total particle frequency of all fillers is 100%, the particle frequency of 1 to 10 μm in particle diameter is 10 to 40%, and 6. The thermally conductive resin composition according to claim 1, wherein the frequency of particles having a particle diameter of 10 to 100 μm is 50 to 85%.
The thermal conductive resin composition according to any one of claims 1 to 6, wherein the thermal conductivity of the thermal conductive filler (B) alone is 10 W / m · K or more.
The heat conductive resin composition according to any one of claims 1 to 7, wherein the heat conductive filler (B) is surface-treated with a coupling agent.
When the heat conductive filler (B) is composed of one kind or two or more kinds of fillers, and the total particle frequency of all fillers is 100%, the particle frequency of 1 to 10 μm in particle diameter is 10 to 20%, and The thermally conductive resin composition according to any one of claims 1 to 8, wherein the frequency of particles having a particle diameter of 10 to 100 µm is 70 to 85%.