JP2013203949A - Composition including polyamide resin, polyolefin resin and inorganic compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composition including a polyamide resin and an inorganic compound, which is improved in heat conductivity, compared with a compound obtained only by blending an inorganic compound having high heat conductivity such as magnesium oxide to a polyamide resin.SOLUTION: A composition includes a polyamide resin (A), a polyolefin resin (B) and an inorganic compound (C). The polyolefin resin (B) includes an acid-denatured polyolefin resin (B1) and a non-acid denatured polyolefin resin (B2), and the acid denaturation rate of the polyolefin resin (B) is 0.1-0.4 mass%. The inorganic compound (C) is at least one selected from the group consisting of aluminum oxide, magnesium oxide, boron nitride, aluminum nitride and calcium silicate whisker. The content of the polyolefin resin (B) is less than 50 vol.% relative to the total volume of the polyamide resin (A) and the polyolefin resin (B).

Description

  The present invention relates to a composition comprising a polyamide resin, a polyolefin resin and an inorganic compound.

  Polyamide resins typified by polyamide 6 and polyamide 66 are widely used as general-purpose engineer plastics because of their excellent properties and ease of melt molding. The polyamide resin has a high thermal conductivity such as magnesium oxide. Citations 1 and 2 disclose that thermal conductivity is improved by blending an inorganic compound.

JP-A-1-213356 JP-A-3-79666

  However, in a composition in which an inorganic compound having a high thermal conductivity such as magnesium oxide is simply blended with a polyamide resin, the thermal conductivity may not be sufficient. There is a need for compositions containing compounds.

  Accordingly, an object of the present invention is to provide a composition comprising a polyamide resin and an inorganic compound, which have improved thermal conductivity, compared to a composition in which an inorganic compound having a high thermal conductivity such as magnesium oxide is blended with a polyamide resin. Is to provide.

  The present inventors have found that a composition containing a polyamide resin, a specific polyolefin resin, and a specific inorganic compound can achieve the above-described problem.

That is, the present invention is a composition comprising a polyamide resin (A), a polyolefin resin (B) and an inorganic compound (C),
The polyolefin resin (B) includes an acid-modified polyolefin resin (B1) and a non-acid-modified polyolefin resin (B2),
The acid modification rate of the polyolefin resin (B) is 0.1% by mass or more and 0.4% by mass or less,
The inorganic compound (C) is at least one selected from the group consisting of aluminum oxide, magnesium oxide, boron nitride, aluminum nitride, and calcium silicate whisker,
The composition comprises less than 50% by volume of the polyolefin resin (B) based on the total volume of the polyamide resin (A) and the polyolefin resin (B).

  According to the present invention, it is possible to provide a composition comprising a polyamide resin and an inorganic compound that have improved thermal conductivity as compared with a composition in which a polyamide resin is simply blended with an inorganic compound having high thermal conductivity such as magnesium oxide. it can.

It is the photograph which observed the torn surface of the test piece of Example 1 with the scanning electron microscope. It is the photograph which observed the torn surface of the test piece of Comparative Examples 1-4 with the scanning electron microscope.

The present invention is a composition comprising a polyamide resin (A), a polyolefin resin (B) and an inorganic compound (C),
The polyolefin resin (B) includes an acid-modified polyolefin resin (B1) and a non-acid-modified polyolefin resin (B2),
The acid modification rate of the polyolefin resin (B) is 0.1% by mass or more and 0.4% by mass or less,
The inorganic compound (C) is at least one selected from the group consisting of aluminum oxide, magnesium oxide, boron nitride, aluminum nitride, and calcium silicate whisker,
It is a composition containing less than 50 volume% of polyolefin resin (B) with respect to the whole volume of the said polyamide resin (A) and the said polyolefin resin (B).

[Polyamide resin (A)]
The polyamide resin (A) used in the present invention has an amide bond (—CONH—) in the main chain, and is made from lactam, aminocarboxylic acid, nylon salt composed of diamine and dicarboxylic acid, or diamine and dibutyl oxalate as raw materials. Can be obtained by polymerization or copolymerization by a known method such as melt polymerization, solution polymerization or solid phase polymerization.

  Examples of the lactam include ε-caprolactam, ω-enantolactam, ω-laurolactam, α-pyrrolidone, α-piperidone and the like. These can use 1 type (s) or 2 or more types. Among these, ε-caprolactam and / or ω-laurolactam are preferable.

  Examples of the aminocarboxylic acid include 6-aminocaproic acid, 7-aminoheptanoic acid, 9-aminononanoic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid. These can use 1 type (s) or 2 or more types. Among these, at least one selected from the group consisting of 6-aminocaproic acid, 11-aminoundecanoic acid and 12-aminododecanoic acid is preferable.

  Examples of diamines include ethylene diamine, tetramethylene diamine, pentamethylene diamine, hexamethylene diamine, peptamethylene diamine, octamethylene diamine, nonamethylene diamine, decamethylene diamine, undecamethylene diamine, dodecane methylene diamine, tridecane diamine, and tetradecane diamine. , Pentadecanediamine, hexadecanediamine, heptadecanediamine, octadecanediamine, nonadecanediamine, eicosanediamine, 2-methyl-1,8-octanediamine, 2,2,4 / 2,4,4-trimethylhexamethylenediamine, etc. Aliphatic diamine, 1,3- / 1,4-cyclohexyldiamine, bis (4-aminocyclohexyl) methane, bis (4-aminocyclohexyl) propane, bis (3 Methyl-4-aminocyclohexyl) methane, (3-methyl-4-aminocyclohexyl) propane, 1,3- / 1,4-bisaminomethylcyclohexane, 5-amino-2,2,4-trimethyl-1-cyclo Cycloaliphatic diamines such as pentanemethylamine, 5-amino-1,3,3-trimethylcyclohexanemethylamine, bis (aminopropyl) piperazine, bis (aminoethyl) piperazine, norbornanedimethyleneamine, m / p-xyl Examples thereof include aromatic diamines such as range amines. These can use 1 type (s) or 2 or more types. Among these, hexamethylene diamine, nonane diamine and / or 2-methyl-1,8-octane diamine are preferable.

  Dicarboxylic acids include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecane Aliphatic dicarboxylic acids such as dionic acid, hexadecanedioic acid, octadecanedioic acid, eicosandioic acid, 1,3- / 1,4-cyclohexanedicarboxylic acid, dicyclohexanemethane-4,4′-dicarboxylic acid, norbornane dicarboxylic acid And alicyclic dicarboxylic acids such as isophthalic acid, terephthalic acid, and aromatic dicarboxylic acids such as 1,4- / 1,8- / 2,6- / 2,7-naphthalenedicarboxylic acid. These can use 1 type (s) or 2 or more types. Among these, oxalic acid and / or adipic acid are preferable.

  These lactam, aminocarboxylic acid, diamine and dicarboxylic acid, or a polyamide resin single polymer composed of diamine and dibutyl oxalate, or a copolymer thereof can be used alone or in the form of a mixture.

  As a single polymer of polyamide resin, for example, polycaprolactam (polyamide 6), polyundecanoic acid lactam (polyamide 11), polylauryl lactam (polyamide 12), polyethylene adipamide (polyamide 26), polytetramethylene succinamide (Polyamide 44), polytetramethylene glutamide (polyamide 45), polytetramethylene adipamide (polyamide 46), polytetramethylene azelamide (polyamide 49), polytetramethylene sebamide (polyamide 410), polytetramethylene Dodecamide (polyamide 412), polypentamethylene succinamide (polyamide 54), polypentamethylene glutamide (polyamide 55), polypentamethylene adipamide (polyamide 56), polypentamethylene Ramide (polyamide 59), polypentamethylene sebacamide (polyamide 510), polypentamethylene dodecamide (polyamide 512), polyhexamethylene succinamide (polyamide 64), polyhexamethylene glutamide (polyamide 65), polyhexa Methylenediaminoadipamide (polyamide 66), polyhexamethylene azelamide (polyamide 69), polyhexamethylene sebamide (polyamide 610), polyhexamethylene dodecamide (polyamide 612), polynonamethylene adipamide (polyamide 96) ), Polynonamethylene azelamide (polyamide 99), polynonamethylene sebamide (polyamide 910), polynonamethylene dodecamide (polyamide 912), polydecamethylene adipamide (polyamide 106), Ridecamemethylene amide (polyamide 109), polydecamethylene decanamide (polyamide 1010), polydecamethylene dodecamide (polyamide 1012), polydodecamethylene adipamide (polyamide 126), polydodecamethylene azeamide (polyamide 129) And homopolymers such as polydodecamethylene sebacamide (polyamide 1210), polydodecamethylene dodecamide (polyamide 1212), polyamide 92, polyamide 102, polyamide 122, polyamide 62, and the like.

  Examples of the copolymer of the polyamide resin using lactam, aminocarboxylic acid, diamine, dicarboxylic acid and / or dibutyl oxalate include, for example, caprolactam / hexamethylenediaminoadipic acid copolymer (polyamide 6/66), caprolactam / Hexamethylene diamino azelaic acid copolymer (polyamide 6/69), caprolactam / hexamethylene diamino sebacic acid copolymer (polyamide 6/610), caprolactam / hexamethylene diaminoundecanoic acid copolymer (polyamide 6/611), caprolactam / Hexamethylene diaminododecanoic acid copolymer (polyamide 6/612), caprolactam / aminoundecanoic acid copolymer (polyamide 6/11), caprolactam / lauryl lactam copolymer (polyamide 6/12) Caprolactam / hexamethylenediaminoadipic acid / lauryllactam (polyamide 6/66/12), caprolactam / hexamethylenediaminoadipic acid / hexamethylenediaminosebacic acid (polyamide 6/66/610), and caprolactam / hexamethylenediaminoadipic acid / Examples include hexamethylene diaminododecanedicarboxylic acid (polyamide 6/66/612), polyamide 92/62, polyamide 102/62, polyamide 122/62, and the like. These can use 1 type (s) or 2 or more types.

  Among these, polyamide 6, polyamide 12, polyamide 66, polyamide 6/66 copolymer (copolymer of polyamide 6 and polyamide 66, hereinafter the copolymer is also described), polyamide 6/69 copolymer, Polyamide 6/610 copolymer, polyamide 6/611 copolymer, polyamide 6/612 copolymer, polyamide 6/12 copolymer, polyamide 6/66/12 copolymer, polyamide 6 / IPD6 copolymer and It is preferably at least one selected from the group consisting of polyamide MXD6, polyamide 6, polyamide 12, polyamide 66, polyamide 6/66 copolymer, polyamide 6/12 copolymer, polyamide 6 / IPD6 copolymer And at least one selected from the group consisting of polyamide 6/66/12 copolymers Ri preferably, polyamide 6, more preferably the group consisting of polyamide 66 and polyamide 6/66 copolymer is at least one selected from the viewpoint of moldability, the polyamide 6 is particularly preferred.

  According to JIS K-6920, the relative viscosity of the polyamide resin (A) measured in 96% sulfuric acid in a polyamide resin concentration of 1% by mass and a temperature of 25 ° C. is 1.5 or more and 5.0 or less. It is preferable that it is 1.7 or more and 4.5 or less. If the relative viscosity of the polyamide resin is less than the above value, the mechanical properties of the obtained molded product may be lowered. On the other hand, when the above value is exceeded, the viscosity at the time of melting increases, and it may be difficult to mold the molded product. Furthermore, from the viewpoint of the productivity of the polyamide resin composition of the present invention and the moldability of the molded product, it is more preferably 1.7 or more and 3.0 or less.

  Further, the amount of water extracted from the polyamide resin (A) measured according to the method for measuring the content of low molecular weight substances specified in JIS K-6920 is not particularly limited. It is preferable that the amount be 5% by mass or less because there is a possibility that the productivity may be deteriorated due to adhesion to manufacturing equipment, or the appearance may be deteriorated due to adhesion to product pellets.

  The particle shape of the polyamide resin (A) is not particularly limited, but from the viewpoint of uniformly mixing the polyolefin resin (B), the inorganic compound (C) and other additives, a powder shape having an average particle size of 1 mm or less is preferable. . In addition, there is no restriction | limiting in particular as the method of making it into a powder form, However, Freezing grinding | pulverization is preferable from a viewpoint of the productivity of powder.

  The terminal adjustment of the polyamide resin (A) is produced by polymerization or copolymerization by a conventional method, for example, a known method such as melt polymerization, solution polymerization or solid phase polymerization in the presence of a terminal adjusting agent. . Alternatively, it is produced by melt-kneading in the presence of amines after polymerization. Alternatively, it is produced by melt-kneading in the presence of a terminal adjusting agent after polymerization. As described above, the terminal adjusting agent can be added at any stage during the polymerization, or at any stage during the melt kneading after the polymerization, but in consideration of the fluidity and moldability of the polyamide resin composition, It is preferable to add at this stage.

  In adjusting the terminal of the polyamide resin (A), one or more of monoamine, diamine, monocarboxylic acid, and dicarboxylic acid can be added as appropriate. For example, alicyclic such as aliphatic monoamines such as methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, decylamine, stearylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, cyclohexylamine, dicyclohexylamine Aromatic monoamines such as monoamine, aniline, toluidine, diphenylamine, and naphthylamine, aliphatic diamines such as hexamethylenediamine, nonamethylenediamine, decamethylenediamine, and dodecamethylenediamine, cycloaliphatic diamines such as cyclohexanediamine, methylcyclohexanediamine, and isophoronediamine Aromatic diamines such as diamine, m- / p-phenylenediamine, m- / p-xylylenediamine, acetic acid, propionic acid, butyric acid, Acid, caproic acid, caprylic acid, lauric acid, tridecylic acid, myristic acid, palmitic acid, stearic acid, pivalic acid, isobutyric acid and other aliphatic monocarboxylic acids, cyclohexanecarboxylic acid and other alicyclic monocarboxylic acids, benzoic acid Aromatic monocarboxylic acids such as toluic acid, α- / β-naphthalenecarboxylic acid, methylnaphthalenecarboxylic acid, phenylacetic acid, adipic acid, trimethyladipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedicarboxylic acid , Aliphatic dicarboxylic acids such as dodecane dicarboxylic acid, alicyclic dicarboxylic acids such as 1,3-cyclopentanedicarboxylic acid, 1,3- / 1,4-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, 1,4- Aromatic dicals such as / 2,6- / 2,7-naphthalenedicarboxylic acid It is phosphate and the like.

[Polyolefin resin (B)]
The polyolefin resin (B) used in the present invention includes an acid-modified polyolefin resin (B1) and a non-acid-modified polyolefin resin (B2), and the acid modification rate of the polyolefin resin (B) is 0.1% by mass or more. 0.4% by mass or less.

  The acid modification rate of the polyolefin resin (B) is based on the total mass of the polyolefin resin (B). For example, the polyolefin resin (B) is acid-modified polyolefin resin (B1) having an acid modification rate of 10% by mass. When 50% by mass and 50% by mass of the polyolefin resin (B2) not acid-modified are contained, the acid modification rate of the polyolefin resin (B) is 5% by mass.

  From the viewpoint of thermal conductivity, the acid modification rate of the polyolefin resin (B) is preferably 0.1% by mass to 0.4% by mass, more preferably 0.1% by mass to 0.3% by mass, More preferably, the content is 15% by mass or more and 0.2% by mass or less.

  Further, the polyolefin resin (B) is contained in an amount of less than 50% by volume, preferably from 10% by volume to less than 50% by volume, from the viewpoint of thermal conductivity, with respect to the total volume of the polyamide resin (A) and the polyolefin resin (B). More preferably, it contains 20 volume% or more and 49 volume% or less, More preferably, it contains 30 volume% or more and 45 volume% or less.

  From the viewpoint of thermal conductivity, the polyolefin resin (B) has a total volume of 50 volumes including the total volume of the polyolefin resin (B), the acid-modified polyolefin resin (B1) and the non-acid-modified polyolefin resin (B2). % To 100% by volume, more preferably 75% to 100% by volume, and still more preferably 90% to 100% by volume.

  From the viewpoint of thermal conductivity, the polyolefin resin (B) preferably contains 40% by volume or more and 100% by volume or less of the acid-modified polyolefin resin (B1) with respect to the total volume of the polyolefin resin (B). More preferably, it is contained in an amount of not less than 50% by volume and not more than 75% by volume, and more preferably not less than 40% by volume and not more than 60% by volume.

  On the other hand, from the viewpoint of thermal conductivity, the polyolefin resin (B) preferably contains 60% by volume or less of the non-acid-modified polyolefin resin (B2) with respect to the total volume of the polyolefin resin (B), and is 30% by volume. More preferably, it is contained in an amount of 60% by volume or less, more preferably 40% by volume or more and 60% by volume or less.

  The ratio of the acid-modified polyolefin resin (B1) and the non-acid-modified polyolefin resin (B2) (acid-modified polyolefin resin (B1): non-acid-modified polyolefin resin (B2)) is from the viewpoint of thermal conductivity. 40:60 to 90:10, preferably 40:60 to 75:25, and more preferably 40:60 to 60:40.

  The particle shape of the polyolefin resin (B) is not particularly limited. From the viewpoint of uniformly mixing the polyamide resin (A), the inorganic compound (C), and other additives, a powder shape having an average particle size of 1 mm or less is preferable. .

  From the viewpoint of thermal conductivity, the polyolefin resin of the acid-modified polyolefin resin (B1) and the non-acid-modified polyolefin resin (B2) are preferably the same.

(1) Acid-modified polyolefin resin (B1)
Examples of the polyolefin resin used for the acid-modified polyolefin resin (B1) include high density polyethylene (HDPE), medium density polyethylene (MDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), and ultra high molecular weight. Polyethylene (UHMWPE), polypropylene (PP), ethylene / propylene copolymer (EPR), ethylene / butene copolymer (EBR), ethylene / vinyl acetate copolymer (EVA), saponified ethylene / vinyl acetate copolymer (EVOH), ethylene / acrylic acid copolymer (EAA), ethylene / methacrylic acid copolymer (EMAA), ethylene / methyl acrylate copolymer (EMA), ethylene / methyl methacrylate copolymer (EMMA), Ethylene / ethyl acrylate copolymer (EEA) etc. It is below. These may be used alone or in combination of two or more.

  From the viewpoint of thermal conductivity and impact resistance, the polyolefin resin used for the acid-modified polyolefin resin (B1) is high density polyethylene (HDPE), medium density polyethylene (MDPE), low density polyethylene (LDPE), linear low At least one selected from the group consisting of density polyethylene (LLDPE), ultra high molecular weight polyethylene (UHMWPE), polypropylene (PP), ethylene / propylene copolymer (EPR) and ethylene / butene copolymer (EBR) Preferably, at least one selected from the group consisting of polypropylene (PP), ethylene / propylene copolymer (EPR) and ethylene / butene copolymer (EBR) is more preferable.

  Examples of the acid used for the acid-modified polyolefin resin (B1) include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, mesaconic acid, citraconic acid, glutaconic acid, and cis-4-cyclohexene-1. , 2-dicarboxylic acid, endobicyclo- [2.2.1] -5-heptene-2,3-dicarboxylic acid and other carboxyl groups and metal salts thereof (Na, Zn, K, Ca, Mg), maleic anhydride Acid anhydride groups such as itaconic anhydride, citraconic anhydride, endobicyclo- [2.2.1] -5-heptene-2,3-dicarboxylic anhydride, glycidyl acrylate, glycidyl methacrylate, glycidyl ethacrylate And compounds containing functional groups such as epoxy groups such as glycidyl itaconate and glycidyl citraconic acid. These may be used alone or in combination of two or more. From the viewpoint of availability, at least one selected from the group consisting of maleic anhydride, itaconic anhydride and citraconic anhydride is preferred, and maleic anhydride and / or itaconic anhydride is more preferred.

  As the acid-modified polyolefin resin (B1) used in the present invention, from the viewpoint of thermal conductivity, polypropylene (PP) modified with maleic anhydride, ethylene / propylene copolymer (EPR) modified with maleic anhydride, and anhydrous At least one selected from the group consisting of an ethylene / butene copolymer (EBR) modified with maleic acid is preferred.

(2) Polyolefin resin that is not acid-modified (B2)
The non-acid-modified polyolefin resin (B2) is the same as the polyolefin resin used for the acid-modified polyolefin resin (B1).

[Inorganic compound (C)]
The inorganic compound (C) used in the present invention is at least one selected from the group consisting of aluminum oxide, magnesium oxide, boron nitride, silicon nitride, aluminum nitride, and calcium silicate whisker. From the viewpoint, at least one selected from the group consisting of magnesium oxide, boron nitride, and aluminum nitride is preferable.

  The average particle size of the inorganic compound (C) is not particularly limited, but is preferably 0.1 μm or more and 200 μm or less, more preferably 1 μm or more and 150 μm or less, and more preferably 5 μm or more and 100 μm or less from the viewpoint of physical properties such as impact resistance. Further preferred. Also, the particle shape is not particularly limited, but from the viewpoint of productivity, moldability, and thermal conductivity, a granular material, particularly a rounded granular material having a small specific surface area is preferable.

Although the specific surface area of an inorganic compound (C) does not have a restriction | limiting in particular, 5 m < ² > / g or less is preferable and 1 m < ² > / g or less is more preferable.

  The purity of the inorganic compound (C) is not particularly limited, but is preferably 70% by mass or more, more preferably 80% by mass or more, still more preferably 90% by mass or more, from the viewpoint of electrical insulation and thermal conductivity. A mass% or more is particularly preferred.

The apparent specific gravity of the inorganic compound (C) is not particularly limited, but is preferably 0.1 g / cm ³ or more from the viewpoint of handling during production (measures against scattering).

  The inorganic compound (C) is preferably surface-treated from the viewpoint of dispersion in the composition. Examples of the surface treatment agent include silane compounds, chromium compounds, titanium compounds, and the like. A surface treatment agent of a titanium compound and / or a titanium compound is preferable.

  As the surface treatment agent for the silane compound, an aminosilane coupling agent and / or a vinylsilane coupling agent is preferable, and an aminosilane coupling agent excellent in adhesion to the sizing agent is more preferable. For example, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β -(Aminoethyl) -γ-aminopropyltriethoxysilane, γ-aminodithiopropyltrihydroxysilane, γ- (polyethyleneamino) propyltrimethoxysilane, N-β- (aminopropyl) -γ-aminopropylmethyldimethoxysilane N- (trimethoxysilylpropyl) -ethylenediamine, γ-dibutylaminopropyltrimethoxysilane, and the like. These can use 1 type (s) or 2 or more types.

  As surface treatment agents for titanium-based compounds, isopropyl triisostearoyl titanate, isopropyl tri (N-aminoethyl) titanate, isopropyl tris (dioctyl pyrophosphate) titanate, tetraisopropyl bis (dioctyl phosphite) titanate, tetraisopropyl titanate, tetra Butyl titanate, tetraoctyl bis (ditridecyl phosphite) titanate, isopropyl trioctanoyl titanate, isopropyl tridodecyl benzene sulfonyl titanate, isopropyl tri (dioctyl phosphate) titanate, bis (dioctyl pyrophosphate) ethylene titanate, isopropyl dimethacrylisostearoyl titanate , Tetra (2,2-diallyloxymethyl-1-butyl Bis (ditridecylphosphite) titanate, isopropyl tricumylphenyl titanate, bis (dioctyl pyrophosphate) oxy acetate titanate, and isopropyl isostearoyl diacryl titanate. These can use 1 type (s) or 2 or more types.

  Among these, from the group consisting of N-β- (aminoethyl) γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) γ-aminopropylmethyldimethoxysilane, and γ-aminopropyltriethoxysilane). At least one selected is preferred.

  As the inorganic compound (C) used in the present invention, surface-treated magnesium oxide is preferable from the viewpoint of selective dispersion in the polyamide resin (A), and the surface is treated with an aminosilane coupling agent and / or a vinylsilane coupling agent. Treated magnesium oxide is more preferred, and magnesium oxide surface-treated with an aminosilane coupling agent is even more preferred.

[Composition]
The composition of the present invention is a composition comprising a polyamide resin (A), a polyolefin resin (B) and an inorganic compound (C),
The polyolefin resin (B) includes an acid-modified polyolefin resin (B1) and a non-acid-modified polyolefin resin (B2),
The acid modification rate of the polyolefin resin (B) is 0.1% by mass or more and 0.4% by mass or less,
The inorganic compound (C) is at least one selected from the group consisting of aluminum oxide, magnesium oxide, boron nitride, aluminum nitride, and calcium silicate whisker,
The composition comprises less than 50% by volume of the polyolefin resin (B) based on the total volume of the polyamide resin (A) and the polyolefin resin (B).

  The content of the polyamide resin (A) in the composition is preferably 30% by volume or more and 70% by volume or less with respect to the total volume of the composition, from the viewpoint of manufacturability and thermal conductivity of the composition. More preferably, it is contained in an amount of 50% by volume or less, more preferably 35% by volume or more and 45% by volume or less.

  The content of the polyolefin resin (B) in the composition is preferably 10% by volume or more and 50% by volume or less with respect to the total volume of the composition, from the viewpoint of manufacturability and thermal conductivity of the composition. More preferably, the content is 40% by volume or less, and more preferably 20% by volume or more and 30% by volume or less.

  The content of the inorganic compound (C) in the composition is preferably 1% by volume or more and 70% by volume or less, and 20% by volume with respect to the total volume of the composition, from the viewpoint of the manufacturability and thermal conductivity of the composition. More preferably, it is contained in an amount of 50% by volume or less, more preferably 30% by volume or more and 40% by volume or less.

  In the composition of the present invention, from the viewpoint of thermal conductivity, the polyamide resin (A) forms a continuous layer in the composition, and the inorganic compound (C) contains an inorganic compound (C ) Is preferably contained in an amount of 50% by volume or more, more preferably 70% by volume or more and 100% by volume or less, and still more preferably 90% by volume or more and 100% by volume or less.

  In the composition of the present invention, various additives, modifiers, reinforcing materials such as heat stabilizers, antioxidants, UV absorption, etc., which are usually blended within the range that does not impair the properties of the composition of the present invention. Agents, weathering agents, fillers, plasticizers, foaming agents, antiblocking agents, tackifiers, sealability improvers, anti-clouding agents, mold release agents, crosslinking agents, foaming agents, flame retardants, colorants (pigments, dyes Etc.), inorganic reinforcing materials such as coupling agents and glass fibers.

  The composition of the present invention can contain a thermoplastic resin other than the polyamide resin and the polyolefin resin within a range not impairing the properties of the composition of the present invention.

  Other thermoplastic resins include polyether resins such as polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyphenylene oxide (PPO), polyphenylene sulfide (PPS), polymethacrylonitrile, acrylonitrile / styrene copolymer. Examples thereof include a blend (AS), a methacrylonitrile / styrene copolymer, and an acrylonitrile / butadiene / styrene copolymer (ABS).

  There is no restriction | limiting in particular in the manufacturing method of the composition of this invention, Usually, the following manufacturing methods can be mentioned. A method using a mixer such as a cylindrical mixer, a method using a twin screw extruder, a single screw extruder, a multi screw extruder, a Banbury mixer, a roll mixer, a kneader or the like, a combination of a mixer and an extruder The manufacturing method etc. can be mention | raise | lifted.

[Molding]
Examples of the method of making the composition of the present invention into a molded article include injection molding, extrusion molding, hollow molding, press molding, roll molding, foam molding, vacuum / pressure molding, stretch molding, etc., among these, A method by injection molding is preferred.

  Examples of the molded product formed by molding the polyamide resin composition of the present invention include injection molded products, hollow bodies, films, sheets, and fibers, and injection molded products are preferable.

  Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples. However, the present invention is not limited to the following examples as long as the gist of the present invention is not exceeded. The various evaluation methods and materials used are shown below.

[Evaluation method]
(1) Thermal conductivity The obtained composition was press-molded into a molded body of 25 mm × 25 mm and 3 mm thickness by a 250 ° C. vacuum press. The surface of the obtained molded body was smoothed with sandpaper (# 240), and silicon grease KS613 manufactured by Shin-Etsu Chemical Co., Ltd. was applied to both sides thereof. This molded body was used as a test piece.
The thermal conductivity of the test piece at 50 ° C. was measured by a steady-state heat flow meter method based on ASTM E1530, using GH-1 which is a thermal conductivity measuring device manufactured by ULVAC Riko.

(2) Observation of phase structure The block-shaped composition obtained by Brabender was cut into a 5 mm x 5 mm x 15 mm rectangular parallelepiped, immersed in liquid nitrogen for 2 minutes, then ruptured with pliers. It was immersed in P-xylene at 135 ° C. for 1 hour and taken out. The taken out was used as a test piece. Silver was vapor-deposited on the fracture surface of the specimen, and the phase structure of the fracture surface of the specimen was observed using a scanning electron microscope JSM-6390LV (hereinafter sometimes referred to as SEM) manufactured by JEOL DATUM.

[material]
(1) Polyamide resin (A)
According to JIS K-6920, the relative viscosity measured under the conditions of 96% by mass of sulfuric acid, polyamide concentration of 1% by mass and temperature of 25 ° C. is 2.5 or more and 2.7 or less, measured according to JIS K-6920. Polyamide 6 having a water extract of 0.1 or less and a measured density of 1.14 kg / m ³ according to ISO 1183. (Hereafter, it may be called PA6.)

(2) Polyolefin resin (B)
(2-1) Acid-modified polyolefin resin (B1)
P553A manufactured by Mitsubishi Chemical Corporation, which is a maleic anhydride-modified polypropylene, was used. (Hereinafter, it may be referred to as modified PP.) According to ISO 1183, the measured density was 0.89 kg / m ³ . Further, the modified PP is dissolved in P-xylene, acetone is added, and reprecipitation is performed to remove maleic anhydride that has not reacted with polypropylene in the modified PP, and the modified PP obtained by reprecipitation. Is dissolved in P-xylene by heating, and 0.05N (normal) potassium hydroxide (KOH) in methanol is added to saponify the modified PP. The amount of potassium hydroxide used for saponification was calculated by titration with a 0.05N (normal) hydrochloric acid (HCl) 2-propanol solution, and the graft amount was determined to be 0.36% by mass.

(2-2) Non-acid-modified polyolefin resin (B2)
J704UG, a non-acid-modified polypropylene manufactured by Prime Polymer, was used. (Hereinafter, it may be referred to as unmodified PP.) According to ISO 1183, the measured density was 0.91 kg / m ³ .

(3) Inorganic compound (C)
RF50AC manufactured by Ube Materials Co., Ltd., which is magnesium oxide having an average particle size of 50 μm and surface-treated with an aminosilane coupling agent, was used. In accordance with JIS R2205, the measured density was 3.58 kg / m ³ . (Hereinafter, it may be referred to as MgO-1.)
RF50SC manufactured by Ube Materials Co., Ltd., which is magnesium oxide having an average particle diameter of 50 μm and surface-treated with a vinylsilane coupling agent, was used. In accordance with JIS R2205, the measured density was 3.58 kg / m ³ . (Hereafter, it may be called MgO-2.)

[Example 1]
Brabender equipped with premixed 20.6 g PA6, 5.37 g modified PP and 5.49 g unmodified PP, and fitted with R-40 type rotor manufactured by Toyo Seiki Seisakusho Co., Ltd. It was introduced from the feed port of the mold biaxial kneader. The cylinder temperature was 250 ° C. and the rotation speed was 60 rpm. After melt-kneading for 3 minutes from the charging, 53.2 g of MgO-1 was charged from the feed port, and further kneaded for 3 minutes to obtain a composition.

Each blending mass of PA6, modified PP, unmodified PP, and MgO-1 is obtained by multiplying the total volume of the composition by 45 cm ³ by the blending ratio shown in Table 1 to obtain each blending volume. Multiply the reciprocal of each density.

  Further, the acid modification rate of the polyolefin resin (B) was obtained by multiplying the ratio of the modified PP to the total mass of the modified PP and the unmodified PP by the modification rate of the modified PP, and is shown in Table 1.

  The obtained composition was evaluated by the above evaluation method, the results of thermal conductivity are shown in Table 1, and the observation results of the phase structure are shown in FIG.

[Comparative Examples 1 to 9]
Each mass was calculated | required by the method similar to Example 1 so that it might become a combination and ratio shown in Table 1, and the composition was obtained by the method similar to Example 1. FIG. Further, the acid modification rate of the polyolefin resin (B) was determined in the same manner as in Example 1, and is shown in Table 1.

  The obtained composition was evaluated by the above evaluation method, and the results of thermal conductivity are shown in Table 1.

  There was no significant difference in the observation results of the phase structures of Comparative Examples 1 to 4. A representative example is shown in FIG.

By immersing in xylene at 135 ° C. for 1 hour, the polyolefin resin (B) is dissolved in xylene at 135 ° C., and a recess can be formed on the fracture surface of the test piece. As shown in FIG. 1 and FIG. The internal phase structure is observed by SEM.
In the phase structure of the fracture surface of the test piece of Example 1, most of the recesses had a length of the longer side (distance between phases) of about several tens to several hundreds μm, whereas Comparative Examples 1 to 4 As for the phase structure of the fracture surface of the test piece, most of the recesses were about several μm as shown in FIG.

Claims (5)

A composition comprising a polyamide resin (A), a polyolefin resin (B) and an inorganic compound (C);
The polyolefin resin (B) includes an acid-modified polyolefin resin (B1) and a non-acid-modified polyolefin resin (B2),
The acid modification rate of the polyolefin resin (B) is 0.1% by mass or more and 0.4% by mass or less,
The inorganic compound (C) is at least one selected from the group consisting of aluminum oxide, magnesium oxide, boron nitride, aluminum nitride, and calcium silicate whisker,
A composition comprising less than 50% by volume of the polyolefin resin (B) based on the total volume of the polyamide resin (A) and the polyolefin resin (B). The composition according to claim 1, wherein the inorganic compound (C) is surface-treated. The composition according to claim 1 or 2, wherein a polyolefin resin of the acid-modified polyolefin resin (B1) and the non-acid-modified polyolefin resin (B2) are the same. The composition according to claim 2 or 3, wherein the inorganic compound (C) is surface-treated magnesium oxide. The composition according to claim 4, wherein the inorganic compound (C) is magnesium oxide surface-treated with an aminosilane coupling agent and / or a vinylsilane coupling agent.

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