JP7044484B2 - Thermally conductive composition - Google Patents

Description

The present invention relates to a thermally conductive composition containing a thermoplastic resin and a metal oxide, which is useful for, for example, containers, tableware, heat dissipation members and various other uses.

Compared to general ceramic tableware and containers, thermoplastic resin tableware and containers have the advantage that they can be easily molded by injection molding or the like and are not easily broken. Further, it has been proposed to add various fillers to the thermoplastic resin for the purpose of preventing odor, improving moldability, physical properties and the like as described below.

Patent Document 1 describes a synthetic resin (A), one or more elements selected from the group consisting of titanium, aluminum, magnesium, calcium, and silicon, and zinc, for the purpose of solving the problem of odor of a resin container. A synthetic resin container containing oxide aggregate particles (B) containing and as a main component is described.

Patent Document 2 describes a polyolefin resin composition containing 80 to 20 parts by mass of a polyolefin resin and 20 to 80 parts by mass of an inorganic filler for the purpose of preventing the sheet from sagging during vacuum forming of the polyolefin resin. , Metal oxides and the like are also mentioned as specific examples of the inorganic filler.

Patent Document 3 describes a polyester resin having a specific composition and physical properties for the purpose of improving the mechanical properties of the polyester resin, reducing the calorific value of combustion at the time of disposal, and facilitating disposal. It is also described that a filler such as a metal oxide may be blended in an amount of 10 to 70% by mass.

Patent Document 4 describes a thermoplastic resin composition containing 1 to 60% by mass of an inorganic filler for the purpose of increasing the rigidity, heat resistance, alkali resistance and surface appearance of resin tableware. Metal oxides and the like are also mentioned as specific examples of the filler.

Japanese Unexamined Patent Publication No. 3-20875 Japanese Unexamined Patent Publication No. 52-15542 Japanese Unexamined Patent Publication No. 6-172620 Japanese Unexamined Patent Publication No. 2006-137867

When advancing the commercialization of tableware and containers made of thermoplastic resin, the present inventors have a feeling of warmth and coldness of the contents of dishes and the like in the tableware and containers made of thermoplastic resin as compared with the tableware and containers made of ceramics. I focused on the fact that it is hard to feel and there is a sense of discomfort when enjoying meals such as hot dishes and cold drinks, and that the feeling of weight and stability when held by hand is insufficient. Such a point has not been examined at all in Patent Documents 1 to 4.

For example, in the synthetic resin container of Patent Document 1, the blending amount of oxide aggregate particles (B) containing zinc as a main component and one or more elements selected from the group consisting of titanium, aluminum, magnesium, calcium and silicon. Is 0.1 to 20% by mass, and with such a small blending amount, it is difficult to feel the warmth and coldness of the contents, and the feeling of weight and stability is insufficient. Further, since the oxide aggregate particles (B) in Patent Document 1 are simply blended to solve the problem of odor, a blending amount exceeding 20% by mass is not required.

In the polyolefin resin composition of Patent Document 2, the blending amount of the inorganic filler is tentatively 20 to 80 parts by mass, but the inorganic filler blended in the examples is only talc and kaolin, and heat conduction. Highly acidic metal oxides are not actually blended. Further, in the specific example of the inorganic filler described in Patent Document 2, talc, kaolin and the like having a relatively good kneadability with a resin and a metal oxide having a poor kneadability with a resin are listed together. It is clear that the range of the blending amount of the inorganic filler having a large blending amount of, for example, about 50 to 80 parts by mass means the range when talc, kaolin, etc., which have relatively good kneadability with the resin, are used. Is. Even if talc or kaolin is blended as in the examples of Patent Document 2, the feeling of warmth and coldness of the contents is hard to feel, and the feeling of weight and stability is insufficient. Further, since the inorganic filler in Patent Document 2 is blended to prevent the sheet from sagging during vacuum forming, that is, to improve the moldability by vacuum forming, a large amount of metal oxide having poor kneadability is blended. On the contrary, there is no way to adopt an aspect that lowers the formability.

In the polyester resin composition of Patent Document 3, the blending amount of the filler is tentatively 10 to 70% by mass, but the filler blended in the examples is only talc and calcium carbonate, and has thermal conductivity. High metal oxides are not actually compounded. Further, in the specific example of the filler described in Patent Document 3, the filler having a relatively good kneadability with the resin and the filler having a poor kneadability are listed together as in Patent Document 2. It is clear that the range of the blending amount having a large blending amount of, for example, about 50 to 70% by mass means the range when talc, calcium carbonate or the like having a relatively good kneadability with the resin is used. Even if talc or calcium carbonate is blended as in the examples of Patent Document 3, the feeling of warmth and coldness of the contents is hard to feel, and the feeling of weight and stability is insufficient. Further, since one of the purposes of Patent Document 3 is ease of disposal, there is no way to adopt a mode in which a large amount of metal oxide, which is not always preferable from the viewpoint of disposal, is blended.

In the thermoplastic resin composition of Patent Document 4, the blending amount of the inorganic filler is tentatively 1 to 60% by mass, but only talc and mica blended in the examples have high thermal conductivity. No metal oxide is actually compounded. Further, in the specific example of the inorganic filler described in Patent Document 4, the one having a relatively good kneadability with the resin and the one having a poor kneadability are listed together as in Patent Document 2, and therefore the inorganic filler is listed. It is clear that the range of the blending amount of the agent having a large blending amount of, for example, about 50 to 60% by mass means the range when talc, mica, or the like having a relatively good kneadability with the resin is used. Even if talc or mica is blended as in the examples of Patent Document 4, the feeling of warmth and coldness of the contents is hard to feel, and the feeling of weight and stability is insufficient. Further, since one of the purposes of Patent Document 4 is to improve the surface appearance, there is no way to adopt an aspect in which a large amount of a metal oxide having poor kneadability is blended and the appearance may be adversely affected.

As described above, Patent Documents 1 to 4 do not suggest that a large amount of metal oxide having high thermal conductivity is blended, and the resin molded body containing the filler of Patent Documents 1 to 4 is used for tableware and the like. Even if it is used in a container, it is difficult to feel the warmth and coldness of the contents, and the feeling of weight and stability is insufficient.

Further, it is difficult to mix a large amount of a metal oxide having poor kneadability with a resin by a conventional method, and some ingenuity is required to improve the kneadability.

The present invention has been made to solve the problems of the prior art described above. That is, an object of the present invention is that the kneadability of the resin thermoplastic resin and the metal oxide is improved and a large amount of the metal oxide can be blended. It is an object of the present invention to provide a heat conductive composition which is easy to feel and has a sufficient feeling of weight and stability, and a suitable use of the composition.

As a result of diligent studies to solve the above problems, the present inventors have remarkably kneaded the resin thermoplastic resin (A) and the metal oxide (B) when a specific amount of the modified polyolefin wax (C) is blended. It was found that the composition was improved, and further, it was found that the obtained composition was suitable for various specific uses, and the present invention was completed. That is, the present invention is specified by the following matters.

[1] A modified polyolefin-based wax containing a thermoplastic resin (A) and a metal oxide (B) selected from the group consisting of an ethylene-based resin and a propylene-based resin, and having an acid value of 60 to 100 mg-KOH / g. A thermally conductive composition containing 0.1 to 20 parts by mass of (C) with respect to 100 parts by mass of the thermoplastic resin (A).

[2] The said, which contains 10 to 50 parts by mass of the thermoplastic resin (A) and 50 to 90 parts by mass of the metal oxide (B) (total 100 parts by mass of the thermoplastic resin (A) and the metal oxide (B)). The thermally conductive composition according to [1].
[3] The heat conduction according to the above [1] or [2], wherein the thermoplastic resin (A) is a propylene resin selected from the group consisting of a propylene / ethylene block copolymer and a propylene / ethylene random copolymer. Sex composition.
[4] The thermoplastic resin (A) is a propylene / ethylene block copolymer having a decan-soluble portion of 8% by weight or more and 35% by weight or less at room temperature (25 ° C.) and / or an ethylene content of 1.9 to 1.9. The heat conductive composition according to any one of the above [1] to [3], which is a 5.4% by mass propylene / ethylene random copolymer.
[ 5 ] The melt flow rate ( MFR) measured at 230 ° C. under a load of 2.16 kg according to ASTM D1238E of the thermoplastic resin (A) is 11 to 100 g / 10 minutes. The thermally conductive composition according to any one.
[ 6 ] The thermally conductive composition according to any one of the above [1] to [ 5 ], wherein the modified polyolefin wax (C) is a polyethylene wax or a polypropylene wax.
[ 7 ] The heat conductive composition according to any one of the above [1] to [ 6 ], wherein the heat conductivity of the heat conductive composition is 0.5 to 5 W / mK.

[ 8 ] A container containing the thermally conductive composition according to any one of the above [1] to [ 7 ].
[ 9 ] Tableware containing the thermally conductive composition according to any one of the above [1] to [ 7 ].
[ 10 ] A heat radiating member containing the heat conductive composition according to any one of the above [1] to [ 7 ].
" 11 " A water-related structural material containing the thermally conductive composition according to any one of the above [1] to [ 7 ].
[ 12 ] An electronic device housing containing the thermally conductive composition according to any one of the above [1] to [ 7 ].
[ 13 ] A timepiece exterior material containing the heat conductive composition according to any one of the above [1] to [ 7 ].
[ 14 ] A tumbler containing the thermally conductive composition according to any one of the above [1] to [ 7 ].
[ 15 ] Daily miscellaneous goods containing the thermally conductive composition according to any one of the above [1] to [ 7 ].

In the present invention, since a specific amount of the modified polyolefin wax (C) is blended, the kneadability of the resin thermoplastic resin (A) and the metal oxide (B) is remarkably improved, and as a result, the thermoplastic resin (A) is blended. ) Can be blended with a relatively large amount of the metal oxide (B), the thermal conductivity of the composition is dramatically improved, and the mass is also increased. When such a heat conductive composition is used, for example, for tableware and containers, the feeling of warmth and coldness of the contents such as dishes can be sufficiently transmitted, and meals such as hot dishes and cold drinks can be enjoyed, and even by hand. The feeling of weight and stability when holding it is also sufficient. Since such a heat conductive composition has excellent heat conductivity, it is also suitable for use as a heat radiating member (for example, a heat radiating sheet). It is also suitable for applications such as water-related structural materials, electronic device housings, watch exterior materials, tumblers, and daily miscellaneous goods.

It is a photograph which shows the state of the test piece after the flame retardant test about Example 2 and Comparative Example 2.

<Thermoplastic resin (A)>
The type of the thermoplastic resin (A) used in the present invention is not particularly limited, and for example, various thermoplastic resins such as polyolefin-based resins and polyester-based resins can be used. Two or more kinds of thermoplastic resins may be used in combination. Of these, polyolefin-based resins and polyester-based resins are preferable, and polyolefin-based resins are more preferable.

Specific examples of the polyolefin-based resin include ethylene-based resin and propylene-based resin. In particular, a propylene-based resin is preferable. The propylene-based resin may be a propylene homopolymer or a copolymer of propylene and another α-olefin. In particular, a copolymer of propylene and another α-olefin is preferable. This copolymer may be a block copolymer or a random copolymer.

Specific examples of other α-olefins to be copolymerized with propylene include ethylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1 -Ethylene, 1-hexadodecene, 1-octadodecene, 1-eicosene, 4-methyl-1-pentene, 2-methyl-1-butene, 3-methyl-1-butene , 3,3-dimethyl-1-butene , Diethyl-1-butene, trimethyl-1-butene, 3-methyl-1-pentene, ethyl-1-pentene, propyl-1-pentene, dimethyl-1-pentene, methylethyl-1-pentene, diethyl-1- Hexen, trimethyl-1-pentene, 3-methyl-1-hexene, dimethyl-1-hexene, 3,5,5-trimethyl-1-hexene, methylethyl-1-heptene, trimethyl-1-heptene, ethyl Examples thereof include ethylene such as -1-octene and methyl-1-nonene and α-olefins having 4 to 20 carbon atoms. Of these, ethylene and α-olefins having 4 to 8 carbon atoms are preferable, and ethylene, 1-hexene and 1-octene are more preferable.

Suitable specific examples of the copolymer of propylene and other α-olefins include a propylene / ethylene copolymer, a propylene / 1-butene copolymer, a propylene / 1-pentene copolymer, and a propylene / 1-hexene. Examples thereof include a copolymer, a propylene / 1-octene copolymer, and a propylene / ethylene / 1-butene copolymer. Of these, a propylene / ethylene copolymer is particularly preferable.

As the thermoplastic resin (A) such as a polyolefin resin, the melt flow rate (MFR) measured at 230 ° C. under a load of 2.16 kg according to ASTM D1238E is preferably 11 to 100 g / 10 minutes, more preferably 20. ~ 90g / 10 minutes.

When the thermoplastic resin (A) is a propylene / ethylene block copolymer, the amount of the room temperature decan-soluble portion of the propylene / ethylene block copolymer is preferably 8% by weight or more and 35% by weight or less, more preferably 8% by weight. % Or more and 28% by weight or less. The ultimate viscosity [η] of the room temperature decane-soluble portion is preferably 1.0 dl / g or more and 10.0 dl / g or less. The amount of ethylene in the room temperature decane-soluble portion is preferably 33 mol% or more and 48 mol% or less, and more preferably 37 mol% or more and 43 mol% or less.

The melting point measured by a differential scanning calorimeter (DSC) according to JIS K7121 of a thermoplastic resin (A) such as a polyolefin resin is preferably 130 to 170 ° C, more preferably 130 to 165 ° C, and particularly preferably 135. It is ~ 160 ° C.

When the thermoplastic resin (A) is a propylene homopolymer, the preferred MFR is as described above, and the preferred melting point is 155 to 170 ° C, more preferably 158 to 165 ° C.

When the thermoplastic resin (A) is a propylene / ethylene random copolymer, the amount of ethylene in the propylene / ethylene random copolymer is preferably 1.9 to 5.4% by mass, more preferably 2.0 to 4 It is .8% by mass. The crystal melting point measured by a differential scanning calorimeter (DSC) according to JIS K7121 of a propylene / ethylene random copolymer is preferably usually 130 to 150 ° C, more preferably 130 to 145 ° C, and particularly preferably 135. It is ~ 145 ° C.

The propylene / ethylene block copolymer and the propylene / ethylene random copolymer may be used alone or in combination of two or more kinds. For example, two or more kinds of copolymers can be mixed for MFR adjustment.

The propylene / ethylene block copolymer can be produced, for example, by polymerizing propylene with an olefin polymerization catalyst containing a solid titanium catalyst component and an organic metal compound catalyst component, and further copolymerizing propylene and ethylene. As the solid titanium catalyst component, a known solid titanium catalyst component containing, for example, titanium, magnesium, halogen and, if necessary, an electron donor can be used. As the organometallic compound catalyst component, for example, an organoaluminum compound, a complex alkylated product of a Group 1 metal and aluminum, an organometallic compound of a Group 2 metal, or the like can be used, and an organoaluminum compound is particularly preferable.

The room temperature n-decane-insoluble portion constituting the propylene / ethylene block copolymer is mainly composed of the propylene polymer component. On the other hand, the portion soluble in room temperature n-decane is mainly composed of a propylene / ethylene copolymer rubber component. Therefore, a propylene / ethylene block copolymer can be obtained by continuously carrying out the following two polymerization steps (polymerization step 1 and polymerization step 2).

[Polymerization step 1]
A step of polymerizing propylene in the presence of a solid titanium catalyst component to produce a propylene polymer component (propylene polymer manufacturing step).
[Polymerization step 2]
A step of copolymerizing propylene and ethylene in the presence of a solid titanium catalyst component to produce a propylene-ethylene copolymer rubber component (copolymer rubber manufacturing step).

The propylene / ethylene block copolymer is preferably produced by such a production method, and it is more preferable that the polymerization step 1 is performed in the first stage and the polymerization step 2 is performed in the second stage. Further, each polymerization step (polymerization step 1, polymerization step 2) can be performed using two or more polymerization tanks. The content of the decan-soluble portion in the block copolymer may be adjusted, for example, by the polymerization time (residence time) of steps 1 and 2.

As the propylene / ethylene random copolymer, for example, a titanium-based Ziegler catalyst or a metallocene catalyst may be used as the polymerization catalyst. Further, when producing a block or a random copolymer, a chain transfer agent typified by hydrogen gas can be introduced. The MFR can be increased by increasing the amount of the chain transfer agent introduced with respect to the amount of the raw material monomer, and the MFR can be decreased by decreasing the amount.

The thermoplastic resin (A) used in the present invention may be a thermoplastic resin composition containing a plurality of types of resins. In this case, preferred embodiments include a polyolefin compound containing a crystalline olefin polymer (A-1) and an ethylene / α-olefin copolymer (A-2). More preferably, the crystalline olefin polymer (A-1) is a polypropylene compound which is a propylene-based polymer.

The component (A-1) is not particularly limited as long as it is a crystalline olefin polymer, but it is preferably a propylene-based polymer. Examples of such a propylene-based polymer and the component (A-2) described later include components disclosed in JP-A-2010-190407 and International Publication No. 2014/046086. More specifically, examples of the component (A-1) include the above-mentioned propylene homopolymer and block copolymer. When the component (A-1) is a propylene-based polymer, the preferable MFR and melting point are the same as described above.

The component (A-2) may be a copolymer using at least ethylene and another α-olefin, and may be a copolymer using a non-conjugated polyene. Specific examples thereof include an ethylene / α-olefin random copolymer and an ethylene / α-olefin / non-conjugated polyene copolymer.

The ethylene / α-olefin random copolymer is preferably a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms, and preferably exhibits properties as an elastomer. Specific examples of the α-olefin having 3 to 20 carbon atoms include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene, 1-decene, and 1 -Dodecene, 1-tetradecene, 1-hexadecene, 1-eikosen can be mentioned. These α-olefins can be used alone or in combination. Among these, propylene, 1-butene, 1-hexene and 1-octene are particularly preferable. The molar ratio of ethylene to α-olefin (ethylene / α-olefin) is preferably 95/5 to 70/30, more preferably 90/10 to 75/25. The ethylene / α-olefin copolymer has an MFR of preferably 0.1 g / 10 min or more, more preferably 0.5 to 5 g / 10 min at 230 ° C. and a load of 2.16 kg.

The ethylene / α-olefin / non-conjugated polyene copolymer is preferably an elastomer component which is a copolymer of ethylene, an α-olefin having 3 to 20 carbon atoms, and a non-conjugated polyene. Specific examples of the α-olefin having 3 to 20 carbon atoms include the same as described above. Specific examples of non-conjugated polyethylene include 5-ethylidene-2-norbornene, 5-propylidene-5-norbornene, dicyclopentadiene, 5-vinyl-2-norbornene, 5-methylene-2-norbornene, and 5-isopropyridene-. Acyclic diene such as 2-norbornene and norbornadiene; 1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, 5-methyl-1,5-heptadiene, 6-methyl Chain non-conjugated diene such as -1,5-heptadiene, 6-methyl-1,7-octadien, 7-methyl-1,6-octadien; triene such as 2,3-diisopropylidene-5-norbornene Can be mentioned. Among these, 1,4-hexadiene, dicyclopentadiene and 5-ethylidene-2-norbornene are preferable. The molar ratio of ethylene, α-olefin and non-conjugated polyene (ethylene / α-olefin / non-conjugated polyene) is preferably 90/5/5 to 30/45/25, more preferably 80/10/10 to 40. / 40/20. The ethylene / α-olefin / non-conjugated polyene random copolymer preferably has an MFR of 0.05 g / 10 min or more, more preferably 0.1 to 10 g / 10 min at 230 ° C. and a load of 2.16 kg. Specific examples of the ethylene / α-olefin / non-conjugated polyene random copolymer include ethylene / propylene / diene ternary copolymer (EPDM).

The total of the (A-1) component, the (A-2) component and the (B) component of the polyolefin compound is 100 parts by mass, and the total of the (A-1) component and the (A-2) component is usually 15 to 50. It is by mass, preferably 15 to 40 parts by mass, and more preferably 15 to 30 parts by mass. The mass ratio of the component (A-1) to the component (A-2) is usually 100/0 to 0/100, preferably 90/10 to 10/90, and more preferably 80/20 to 20/80. .. The content of the metal oxide (B) is usually 50 to 85 parts by mass, preferably 60 to 85 parts by mass, and more preferably 70 to 85 parts by mass.

In addition to the above-mentioned ethylene / α-olefin copolymer as the component (A-2), for example, a hydrogenated block copolymer such as a styrene-based thermoplastic elastomer or another elastic polymer may be used. ..

As described above, as the thermoplastic resin (A) of the present invention, a polyolefin-based resin is preferable, and a polypropylene-based resin is particularly preferable, but other resins such as the polyester-based resin described above are not impaired as long as the object of the present invention is not impaired. May be included. The content of the other resin in 100% by weight of the heat-possible resin (A) is preferably 5% by weight or less, more preferably 2% by weight or less, particularly preferably 1% by weight or less, and most preferably 0% by weight. Is.

The blending amount of the thermoplastic resin (A) is 10 to 50 parts by mass, preferably 15 to 40 parts by mass, based on a total of 100 parts by mass of the thermoplastic resin (A) and the metal oxide (B).

<Metal oxide (B)>
The type of the metal oxide (B) used in the present invention is not particularly limited, and any metal oxide having higher thermal conductivity than the thermoplastic resin (A) may be used. For example, various metal oxides such as magnesium oxide, aluminum oxide, titanium oxide, and ferrite can be used. Two or more kinds of metal oxides may be used in combination. Of these, magnesium oxide, aluminum oxide, and titanium oxide are preferable from the viewpoint of excellent thermal conductivity, and magnesium oxide is more preferable from the viewpoint of white color, easy coloring, and low cost. Further, the metal oxide (B) is preferably water-resistant. It is preferable that the metal oxide (B) does not substantially contain the metal hydroxide and its hydrate or the hydrate of the metal oxide. Specifically, the content of the metal hydroxide and its hydrate or the hydrate of the metal oxide in 100% by weight of the entire metal oxide (B) is preferably 1% by weight or less, more preferably 0. It is .5% by weight or less, particularly preferably 0.3% by weight or less.

The thermal conductivity of the metal oxide (B) is preferably 1 to 500 W / mK, more preferably 3 to 100 W / mK, and particularly preferably 5 to 80 W / mK.

The average particle size of the metal oxide (B) is preferably 0.1 to 100 μm, more preferably 0.1 to 50 μm, and particularly preferably 0.1 to 10 μm.

Further, the heat conductive metal oxide (B) preferably has a small aspect ratio from the viewpoint of uniformity of heat conduction and the like. Specifically, the aspect ratio is preferably less than 1.2, more preferably less than 1.1.

The blending amount of the metal oxide (B) is preferably 50 to 90 parts by mass, more preferably 60 to 85 parts by mass, based on a total of 100 parts by mass of the thermoplastic resin (A) and the metal oxide (B). be. If this blending amount is less than 50 parts by mass, sufficient thermal conductivity may not be obtained, or a desired level of thermal conductivity cannot be obtained. On the other hand, if this compounding amount exceeds 90 parts by mass, there is a problem that the moldability is deteriorated. It can be seen from the results of Examples 1 to 4 described later that the thermal conductivity tends to increase sharply when the content ratio of the metal oxide (B) is within the above range. It is considered that this is because when the metal oxides are preferably in a well-dispersed state, the contact ratio between the metal oxides is increased, so that the structure is similar to that of a continuous layer, and the thermal conductivity is efficiently increased.

The mass ratio (B / A) of the thermoplastic resin (A) to the metal oxide (B) is preferably 1 to 9, more preferably 1.2 to 4, particularly preferably 1.4 to 4, and most preferably. It is 1.5-4.

<Modified polyolefin wax (C)>
The modified polyolefin wax (C) used in the present invention is an essential component for facilitating kneading the metal oxide (B) having a high content in the thermoplastic resin (A). By using this modified polyolefin wax (C), it is considered that agglomeration of the metal oxide (B) in the thermoplastic resin (A) is suppressed, so that kneading becomes easy.

The type of the modified polyolefin wax (C) is not particularly limited, but modified polyethylene wax and modified polypropylene wax are preferable, and modified polyethylene wax is more preferable.

The modified polyolefin wax (C) can be produced by a known method. For example, there are a method of adding an unsaturated carboxylic acid compound to a low molecular weight ethylene polymer in a solvent-free or solvent by a radical reaction, a method of adding in the presence of Lewis acid, and a method of adding at a high temperature. Be done. The reaction temperature is 20 ° C. to 300 ° C., particularly preferably 120 ° C. to 250 ° C. Since the melting point of the low molecular weight ethylene polymer is about 120 ° C., it is preferable to set the reaction temperature to 120 ° C. or higher in order to make the reaction system uniform.

The unsaturated carboxylic acid compound is not particularly limited as long as it has a reactive double bond and has a carboxylic acid group or a group that can be derived from the group. For example, known unsaturated carboxylic acids and derivatives thereof. For example, anhydrides, esters, acid halides, amides, imides and the like can be used.

Examples of the unsaturated carboxylic acid include unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, crotonic acid and isocrotonic acid, and maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, norbornenedicarboxylic acid and nagic. Examples thereof include unsaturated dicarboxylic acids such as acid TM (endosys-bicyclo [2.2.1] hept-5-ene-2,3-dicarboxylic acid. Modification having a carboxylic acid group by using an unsaturated carboxylic acid. A hydrocarbon resin can be obtained. As the unsaturated carboxylic acid anhydride, the above-mentioned unsaturated dicarboxylic acid anhydride can be used. Specific examples thereof include maleic anhydride, itaconic acid anhydride, citraconic acid anhydride, and tetrahydro. Examples thereof include phthalic acid anhydride and nagic acid anhydride TM (endosis-bicyclo [2.2.1] hept-5-ene-2,3-dicarboxylic acid anhydride). By using an unsaturated carboxylic acid anhydride. , A modified hydrocarbon resin having an anhydrous carboxylic acid group can be obtained. Particularly, anhydrous maleic acid is preferable.

As the ester of the unsaturated carboxylic acid, the alkyl ester of the unsaturated carboxylic acid, the hydroxyalkyl ester, and the glycidyl ester can be used. Specific examples thereof include monomethyl maleate, dimethyl maleate, glycidyl maleate, hydroxyl (meth) acrylate, hydroxypropyl (meth) acrylate, and glycidyl (meth) acrylate. By using an ester of unsaturated carboxylic acid, a modified hydrocarbon resin having a carboxylic acid ester group can be obtained.

Specific examples of the unsaturated carboxylic acid halide include malenyl chloride, dichloromaleic anhydride (C ₄ Cl ₂ O ₃ ) and the like. By using an unsaturated carboxylic acid halide, a modified hydrocarbon resin having a halogen atom-containing carboxylic acid group can be obtained. Specific examples of the unsaturated carboxylic acid amide include sulamide, phthalamide, maleamide and the like. By using the amide of unsaturated carboxylic acid, a modified hydrocarbon resin having an amide group can be obtained. Specific examples of the unsaturated carboxylic acid imide include maleimide, phthalimide, and sulimide. By using an unsaturated carboxylic acid imide, a modified hydrocarbon resin having an imide group can be obtained.

The acid value of the modified polyolefin wax (C) is preferably 1 to 100 mg-KOH / g, more preferably 10 to 90 mg-KOH / g.

The polystyrene-equivalent number average molecular weight (Mn) measured by gel permeation chromatography (GPC) of the modified polyolefin wax (C) is preferably 400 to 20000.

The blending amount of the modified polyolefin wax (C) is preferably 0.1 to 20 parts by mass, more preferably 0.3 to 15 parts by mass, and particularly preferably 0. It is 3 to 10 parts by mass.

<Other ingredients>
As a preferred embodiment, an embodiment in which the reinforcing fiber (F) is contained in the heat conductive composition of the present application can be mentioned. In the polyolefin compound containing the reinforcing fiber (F), the reinforcing fiber (F) mainly exerts an effect of improving mechanical properties such as strength. The reinforcing fiber (F) is not limited to the mode of combining with the component (A-1) and the component (A-2), and can be combined with various thermoplastic resins (A) as long as the object of the present invention is not impaired. Is. Specific examples of the reinforcing fiber (F) include glass fiber, carbon fiber, magnesium sulfate fiber, polyester fiber, nylon fiber, kenaf fiber, bamboo fiber, and jude fiber. Among these, glass fiber and carbon fiber are preferable. The reinforcing fiber (F) has an aspect ratio larger than 1. Specifically, it is 1.1 or more, preferably 1.2 or more, more preferably 1.2 to 10, particularly preferably 1.3 to 8, and most preferably 1.4 to 5.

The thermally conductive composition of the present invention may contain a filler other than the reinforcing fiber (F). Such fillers include inorganic fillers such as talc, mica, calcium carbonate, magnesium hydroxide, ammonium phosphate salts, silicates, carbonates, carbon black; organic fillers such as wood flour, cellulose, rice flour, starch and corn starch. ; Can be mentioned. Among these, talc is most preferable from the viewpoint of balance of price, performance, handleability, supply stability and the like.

Further, the heat conductive composition of the present invention includes various additives such as plasticizers, lubricants, antioxidants, ultraviolet absorbers, heat stabilizers, pigments, dyes, antistatic agents and antibacterial agents depending on the intended use. Agents, flame retardants, coupling agents, dispersants and the like can be blended within a range that does not impair the object of the present invention.

The thermally conductive resin composition of the present invention may be in the form of an oil spread containing known oils. However, it is preferable that the oil is not substantially contained, especially in applications such as housings of electronic devices and home appliances, furniture, and building materials, which will be described later, which are often touched by human hands. Specifically, the oil content in 100% by weight of the entire thermoplastic resin composition is preferably 5% by weight or less, more preferably 2% by weight or less, particularly preferably 1% by weight or less, and most preferably 0% by weight. Is.

<Thermal conductive composition>
The thermally conductive composition of the present invention can be produced by blending the above-mentioned components (A) and (B) and, if necessary, any component. The components may be sequentially blended in any order or may be mixed at the same time. Further, a multi-step mixing method may be adopted in which some components are mixed and then other components are mixed.

As a method of blending each component, for example, a method of mixing or melt-kneading each component simultaneously or sequentially using a mixing device such as a Banbury mixer, a single-screw extruder, a twin-screw extruder, or a high-speed twin-screw extruder is used. Can be mentioned.

The thermally conductive composition of the present invention thus obtained is excellent in thermal conductivity. Specifically, the thermal conductivity is usually 0.5 to 5 W / mK, preferably 0.6 to 5 W / mK, more preferably 0.6 to 3 W / mK, and particularly preferably 0.6 to 2. It is 5 W / mK, most preferably 0.6 to 2 W / mK.

The thermally conductive composition of the present invention is also excellent in flame retardancy, and may exhibit excellent flame retardancy without using a flame retardant in combination. The reason why the thermally conductive composition of the present invention is excellent in flame retardancy is not clear, but the present inventors speculate as follows.

The heat conductive composition of the present invention has excellent heat conductivity, and for example, heat energy is easily dispersed even when exposed to a flame, so that a rapid temperature rise is unlikely to occur, and therefore the oxidation reaction of the thermoplastic resin (A) occurs. It is considered unlikely to occur. Further, since the dispersion of the thermoplastic resin (A) and the metal oxide (B) is good, the thermoplastic resin (A) is unlikely to be unevenly distributed, which is also a factor that the oxidation reaction of the thermoplastic resin (A) is unlikely to occur. Conceivable.

The flame retardancy of the heat conductive composition of the present invention can be evaluated by, for example, the method described in ISO3795 standard or a method according to the method.

<Molded body>
The method for molding the thermally conductive composition of the present invention is not particularly limited, and various known methods can be used. Above all, it is preferable to apply it to an injection molding method having a high degree of freedom in shape.

The molded product obtained from the heat conductive composition of the present invention can be used in various fields such as household products, where high heat conductivity is required. Specific examples thereof include containers for storing foods and tableware such as forks, knives, spoons and plates. These can be easily molded by injection molding and have high thermal conductivity, so that it is easy to feel the warmth and coldness of the contents, and it is very useful as tableware and containers to replace ceramics in that a feeling of weight can be obtained. It can also be applied to other applications that use ceramics, such as daily miscellaneous goods such as lampshades and vases, structural materials for specific acoustic speakers (luxury speakers, etc.), and water-related products such as washbasins and toilet bowls. .. In addition to applications that use ceramics, taking advantage of the features that can give a sense of weight and stability, for example, applications such as plastic models and other models and toys, furniture applications such as desks and chairs, musical instrument applications such as piano keys, tiles, and artificial marble substitutes. It can also be used for building applications such as products and building materials. Further, it may be suitable as a filament of a 3D printer by utilizing the feeling of heat and moldability.

In addition, various containers such as bottles and jars that take advantage of features such as design, stability, and tactile sensation can be mentioned. In particular, containers for cosmetics (cosmetics, cosmetic creams, etc.), shampoos (including body shampoos, etc.), and beauty-related products such as conditioners, which tend to have a high impact on the commercial value of these performances, are suitable examples. You can. More specifically, containers having a shape such as a container with a lid (including an airless container), a compact (for cosmetics), a pallet (for cosmetics), and a bottle can be mentioned. In recent years, plastic containers such as polyolefin, which are lightweight and have excellent impact resistance, are mostly used for such applications, but for visual and tactile sensations (including thermal conductivity and weight). It is a material that is not suitable for producing a high-class feeling. Containers such as ceramics are suitable for producing a high-class feeling, but this has major problems such as limitation of the degree of freedom in terms of design and mass production, and low impact resistance. Since these containers using the composition of the present invention can apply the same molding method as conventional plastic products, they are not only excellent in productivity and design, but also shock resistant compared to ceramics. Since it has excellent properties and has the same weight and thermal conductivity as ceramics, it can be considered to be suitable for the above-mentioned applications.

Further, the molded product obtained from the heat conductive composition of the present invention is also useful as a heat radiating member in applications requiring high heat conductivity. For example, it is very useful as a heat radiating member such as an electronic component that requires high thermal conductivity and a heat radiating sheet in various electronic devices such as notebook computers and mobile devices. Further, if the heat conductive composition of the present invention is applied to a part or all of the housings of various electronic devices such as notebook computers and mobile devices and used in combination with a heat dissipation sheet, the heat dissipation performance of the electronic devices is further enhanced. Can be expected. Further, the heat conductive composition of the present invention is used for a part of the housing of various electronic devices such as a notebook computer and a mobile device, and the other part, for example, a place where a hand often comes into contact during operation. Can also manufacture a housing that can reduce the possibility of developing low-temperature burns and the like during long-term operation by using a material having a reduced metal oxide content or a material containing no metal oxide. Such a housing can be manufactured, for example, by installing a plurality of resin injection gates in a mold for molding the housing and injecting resins having different compositions for each gate.

For other uses, it is also useful as a substitute material for metal housings by taking advantage of its excellent thermal conductivity, flexibility in shape during molding, and high impact strength. For example, it can be expected to be applied to the exterior materials of home appliances such as watches, wristwatch housings and belts, furniture parts (for example, metal handles), washing machines and refrigerators.

Hereinafter, the present invention will be described in more detail by way of examples. However, the present invention is not limited thereto. The materials used in the examples are as follows.

<Thermoplastic resin (A)>
"B-PP": Propylene / ethylene block copolymer (room temperature decane-soluble part (rubber content) = 23% by mass, room temperature decane-soluble part ethylene amount = 40 mol%, room temperature decane-soluble part limit Viscosity [η] = 2.5 dl / g, MFR (230 ° C., 2.16 kg) = 63 g / 10 minutes)
"R-PP": Propylene / ethylene random copolymer (ethylene amount = 2.7% by mass, MFR (230 ° C., 2.16 kg) = 60 g / 10 minutes)

The amount of room-temperature decane-soluble part of the above-mentioned propylene / ethylene block copolymer (b-PP), the amount of ethylene in the room-temperature decane-soluble part, the extreme viscosity [η] and MFR of the room-temperature decane-soluble part, and propylene / ethylene random. The ethylene content and MFR of the copolymer (r-PP) were measured by the following methods.

(1) Amount of decane-soluble part at room temperature First, 5 g of the sample is precisely weighed, placed in a 1,000 ml eggplant-shaped flask, and 1 g of BHT (dibutylhydroxytoluene, phenolic antioxidant) is added to the rotor and the rotor. 700 ml of n-decane was added. Next, a cooler was attached to the eggplant-shaped flask, and the flask was heated in an oil bath at 135 ° C. for 120 minutes while operating the rotor to dissolve the sample in n-decane. Next, the contents of the flask were poured into a 1,000 ml beaker, and the solution in the beaker was allowed to cool for 8 hours or more until it reached room temperature (25 ° C.) while stirring with a stirrer, and the precipitate was collected by wire mesh. .. The filtrate was filtered through filter paper and poured into 2,000 ml of methanol contained in a 3,000 ml beaker, and the solution was left at room temperature (25 ° C.) for 2 hours or more with stirring with a stirrer. Next, the obtained precipitate was collected by filtration with a wire mesh, air-dried for 5 hours or more, dried at 100 ° C. for 240 to 270 minutes in a vacuum dryer, and the n-decane soluble portion at 25 ° C. was recovered. The content (x) of the n-decane soluble part at 25 ° C. is x (mass%) = 100 × C / A, where Ag is the sample weight and Cg is the weight of the recovered n-decane soluble part. expressed.

(2) Amount of ethylene in the room temperature decan-soluble part
¹³ Measured by a conventional method by C-NMR.

(3) Extreme viscosity of decane-soluble part at room temperature [η]
Measured with decalin at 135 ° C.

(4) Amount of ethylene in r-PP
¹³ Measured by a conventional method by C-NMR.

(5) Melt flow rate (MFR)
According to ASTM D1238E, the measurement was performed under the conditions of a temperature of 230 ° C. and a load of 2.16 kg.

<Metal oxide (B)>
Magnesium oxide (manufactured by Konoshima Chemical Co., Ltd., trade name Starmag PSF-WR, average particle size = 1.1 μm, thermal conductivity = 45-60 W / mK)

<Modified polyolefin wax (C)>
Modified polyolefin wax (manufactured by Mitsui Chemicals, Inc., trade name: High Wax 1105A, acid value = 60 mg-KOH / g, number average molecular weight (Mn) = 1500, density = 940, crystallinity 60%, melting point 104 ° C., melt viscosity (140 ° C) = 150)

The acid value and number average molecular weight (Mn) of the above-mentioned modified polyolefin wax were measured by the following methods.

(1) Acid value Measured according to JIS K5902.

(2) Number average molecular weight (Mn)
GPC analysis was performed under the following conditions to measure the number average molecular weight (Mn) of the polymer.
Equipment: Alliance GPC 2000 type (trade name, manufactured by Waters)
Column: TSKgel GMH6-HT x 2 TSKgel GMH6-HTL x 2 (Product name, both manufactured by Tosoh, inner diameter 7.5 mm x length 30 cm)
Column temperature: 140 ° C
Mobile phase: Orthodichlorobenzene (containing 0.025% dibutylhydroxytoluene)
Detector: Differential refractometer Flow rate: 1.0 mL / min Sample concentration: 0.15% (w / v)
Injection volume: 0.5 mL
Sampling time interval: 1 second Column calibration: Monodisperse polystyrene (manufactured by Tosoh)

[Examples 1 to 4]
Each component was blended at the blending ratio (part by mass) shown in Table 1 to obtain a thermally conductive composition. Specifically, first, as a modified polyolefin wax (C), the propylene / ethylene block copolymer (b-PP) or the propylene / ethylene random copolymer (r-PP) as the thermoplastic resin (A) is used. High wax and magnesium oxide as a heat conductive metal oxide (B) are kneaded using a kneading device (Laboplast Mill (manufactured by Toyo Seiki Co., Ltd.)) at 200 ° C. and 60 to 80 rpm, and the pellet is cut into strands. A thermally conductive composition in the form of a polymer was obtained.

The compositions of Examples 1 to 4 obtained as described above were injection-molded to obtain a molded product (dish-shaped tableware having a diameter of about 20 cm and a thickness of about 4 cm). This injection molding was performed under the conditions of a molding temperature of 220 to 240 ° C., a mold temperature of 80 ° C., an injection time-holding pressure time: 1 to 2 seconds (primary filling time of 14 seconds), and a cooling time of 16 seconds.

Further, the injection square plate of the heat conductive composition of the present invention obtained under the same conditions can be used, for example, for building materials, furniture constituent materials, water-related members, housings for home appliances, electronic devices (personal computers, smartphones, etc.). As a housing, heat dissipation sheet, housing for precision machinery such as acoustic equipment (speakers, etc.), parts such as plastic models and toys, design containers such as gardening containers and vases, and various applications (sample materials, etc.) such as cosmetic containers. Can be utilized.

[Comparative Examples 1 and 2]
Under the conditions shown in Table 1 (no modified polyolefin wax (C) was used), kneading was attempted under various conditions including 200 ° C. using a tabletop kneader PBV-0.1 manufactured by Irie Shokai. , I couldn't knead enough.

The thermal conductivity of the molded products of Examples 1 to 4 and the kneadability of the thermally conductive compositions of Examples 1 to 4 and Comparative Examples 1 and 2 were evaluated by the following methods. The results are shown in Table 1.

(Thermal conductivity)
The thermal conductivity of the thermally conductive composition was carried out by the constant information thermal flow meter method. Specifically, a measuring instrument GH-1 manufactured by ULVAC Riko Co., Ltd. was used, and the measurement was performed at a temperature of 30 ° C. according to ASTM E1530.

(Kneading property)
The kneadability was evaluated according to the following criteria at the stage of melting and mixing using a kneader under the conditions of a kneader rotation speed of 60 to 80 rpm and a heating temperature of 200 ° C.
"○": Sufficiently mixed.
"×": It was not possible to knead.

[Example 5]
First, as a molding material, a thermally conductive composition of Example 1 containing a metal oxide (B) and a resin composition (CPD) having the same composition as that of Example 1 except that the metal oxide (B) is not contained. I prepared. Then, the melt of the resin composition (CPD) containing no metal oxide (B) is injected from the injection gate near the center of the mold of the smartphone housing, and the metal oxide (B) is injected from the other gates. The melt of the heat conductive composition of Example 1 containing the above was injected, molded and cooled to form a housing component. In the obtained housing parts, the central portion, which is easily touched by a hand when used as a smartphone, has low thermal conductivity, and the upper and lower portions have high thermal conductivity.

(Flame retardance)
A flame retardant test was conducted using the test pieces obtained from the heat conductive compositions obtained in Example 2 and Comparative Example 2 by applying the conditions of the ISO3795 standard mutatis mutandis. As the test piece, a melt press molding apparatus and a predetermined mold were used, and a test piece molded into a size of 200 mm × 100 mm × 2 mm by a conventional method was used. Specifically, the heat conductive composition was melted at 190 ° C. for 6 minutes, pressed and molded for 4 minutes, and cooled for 5 minutes using a water cooling device (10 ° C.). FIG. 1 is a photograph showing the state of the test piece after the test. As shown in FIG. 1, the test piece of Example 2 hardly changed, but the test piece of Comparative Example 2 was greatly deformed by combustion.

The heat conductive composition of the present invention can be used as a molded material in various fields such as household goods and electronic parts described in detail above, and in particular, a container, tableware, a heat radiating member, a water-related structural material, and an electronic device. It can be suitably used as a material for a housing, a watch exterior material, a tumbler, and daily miscellaneous goods.

Claims (15)

A modified polyolefin wax (C) containing a thermoplastic resin (A) and a metal oxide (B) selected from the group consisting of an ethylene resin and a propylene resin and having an acid value of 60 to 100 mg-KOH / g. A thermally conductive composition containing 0.1 to 20 parts by mass of the thermoplastic resin (A) with respect to 100 parts by mass. Claim 1 contains 10 to 50 parts by mass of the thermoplastic resin (A) and 50 to 90 parts by mass of the metal oxide (B) (100 parts by mass of the thermoplastic resin (A) and the metal oxide (B) in total). The heat conductive composition according to the above. The heat conductive composition according to claim 1 or 2, wherein the thermoplastic resin (A) is a propylene resin selected from the group consisting of a propylene / ethylene block copolymer and a propylene / ethylene random copolymer. The thermoplastic resin (A) is a propylene / ethylene block copolymer having a decan-soluble portion of 8% by weight or more and 35% by weight or less at room temperature (25 ° C.) and / or an ethylene content of 1.9 to 5.4. The heat conductive composition according to any one of claims 1 to 3, which is a mass% propylene / ethylene random copolymer. The present invention according to any one of claims 1 to 4 , wherein the melt flow rate (MFR) measured at 230 ° C. under a load of 2.16 kg according to ASTM D1238E of the thermoplastic resin (A) is 11 to 100 g / 10 minutes. Thermally conductive composition. The thermally conductive composition according to any one of claims 1 to 5 , wherein the modified polyolefin wax (C) is a modified polyethylene wax or a modified polypropylene wax. The heat conductive composition according to any one of claims 1 to 6 , wherein the heat conductive composition has a thermal conductivity of 0.5 to 5 W / mK. A container containing the thermally conductive composition according to any one of claims 1 to 7 . Tableware containing the thermally conductive composition according to any one of claims 1 to 7 . A heat radiating member containing the heat conductive composition according to any one of claims 1 to 7 . A water-related structural material containing the thermally conductive composition according to any one of claims 1 to 7 . An electronic device housing containing the heat conductive composition according to any one of claims 1 to 7 . A watch exterior material containing the heat conductive composition according to any one of claims 1 to 7 . A tumbler comprising the thermally conductive composition according to any one of claims 1 to 7 . Daily miscellaneous goods containing the heat conductive composition according to any one of claims 1 to 7 .

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