JP6207916B2 - Thermoplastic elastomer composition - Google Patents

Description

  The present invention relates to a heat radiating member for electric and electronic parts, for example, a thermoplastic elastomer composition used for a heat radiating sheet, a housing, a sealing material, and the like, and a molded body obtained by thermoforming the thermoplastic elastomer composition. About.

  In recent years, the current value handled by many electric and electronic components has increased dramatically, such as the evolution of solar cells, LEDs, and hybrid electric vehicles, and the increased capacity of CPUs. With the progress of miniaturization and miniaturization, measures to dissipate Joule heat generated in large quantities from small parts are becoming very important.

  As one of the heat dissipation measures for these heating elements, a method using a flexible material with high thermal conductivity called heat dissipation rubber or heat dissipation sheet is known. For example, heat transfer efficiency between the heating element and a cooling component There is a method of sandwiching a flexible heat dissipation material as a spacer. In the first place, a material in which a filler having a relatively high thermal conductivity is contained in silicone rubber has been used for such applications. However, the silicone resin itself is expensive and low molecular weight siloxane contained in the resin is used. Since there is a problem that it diffuses and adheres to electrode contacts and the like and becomes insulating silicon dioxide, causing contact failure, improvement is required.

  In Patent Document 1, for example, 1 to 20% by mass of styrene elastomer (SEBS) as the A component, 1 to 20% by mass of paraffin oil as a rubber softener as the B component, and an average particle size of 10 as the C component. A thermally conductive sheet is disclosed that adds ˜80 μm granular metal hydroxide.

  Patent Document 2 discloses a high heat containing a processing aid including polytetrafluoroethylene and a filler selected from aluminum oxide, magnesium oxide and graphite in at least one elastomer selected from polyurethane elastomer, polyester elastomer and polyamide elastomer. A conductive resin composition is disclosed.

WO09 / 133930 pamphlet JP 2003-82225 A

  Patent Document 1 discloses that magnesium hydroxide is preferable because it can impart flame retardancy in addition to thermal conductivity, but in reality, it tends to cause a bleed phenomenon of a rubber softener and has a heat aging resistance. There is a problem that it is inferior.

  The resin composition described in Patent Document 2 has a problem that it is inferior in heat and humidity resistance, and there is no description or suggestion about an acrylic elastomer. Therefore, it is not known what effect can be obtained when a similar filler is used in an acrylic elastomer.

  Therefore, as a prior art of a heat conductive elastomer composition, a flexible heat conductive composition containing an elastomer other than silicone rubber and acrylic elastomer and a heat conductive filler such as metal hydroxide or metal oxide is Although it is known, there is no known heat conductive filler that is excellent in moisture resistance and heat aging resistance in combination with an acrylic elastomer.

  An object of the present invention is to provide a thermoplastic elastomer composition having good thermal conductivity and excellent in moisture resistance and heat aging resistance, and a molded article obtained using the composition.

The present invention
[1] A thermoplastic elastomer composition comprising (meth) acrylic elastomer (component A) and 40 to 300 parts by volume of a heat conductive filler (component B) with respect to 100 parts by volume of component A. the volume average particle diameter measured by a laser diffraction particle size distribution analyzer and B Ri 0.1~500μm der further vinyl copolymer having an average of two or more epoxy groups in one molecule (component C), component a 100 mass ing contain 0.1 to 30 parts by weight with respect to parts, the thermoplastic elastomer composition, and (2) above [1] obtained by heat molding the thermoplastic elastomer composition according moldings relates.

  The thermoplastic elastomer composition of the present invention has an effect that it has good thermal conductivity as a material of a molded body and is excellent in moisture resistance and heat aging resistance.

  The thermoplastic elastomer composition of the present invention contains a (meth) acryl elastomer (component A) and a thermally conductive filler (component B) having a specific particle size.

  The (meth) acrylic elastomer (component A) preferably comprises two or more (meth) acrylic monomers and, if necessary, other copolymerizable vinyl monomers as constituent components. It can be obtained by increasing the molecular weight.

  Examples of the (meth) acrylic monomer include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, phenyl (meth) acrylate, (meth) 2-ethylhexyl acrylate, cyclohexyl (meth) acrylate, (meth) acrylic acid, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, glycidyl (meth) acrylate, methoxyethyl (meth) acrylate, Examples thereof include ethoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, phenoxyethyl (meth) acrylate, and the like. In this specification, unless otherwise specified, an alkyl group name without a subscript includes isomers such as n-, iso-, sec-, tert-, etc. And both acrylic.

  The amount of the (meth) acrylic monomer is preferably 20% by mass or more, more preferably 50% by mass or more, and still more preferably 80% by mass or more in the constituent components.

  Other copolymerizable vinyl monomers include styrene, α-methylstyrene, vinyl acetate, ethylene, propylene, butadiene, isoprene, maleic anhydride, etc. Among these, styrene, α-methylstyrene and Ethylene is preferred, and these vinyl monomers may be used in combination within a range that does not impair the object of the present invention (preferably 30% by mass or less, more preferably 20% by mass or less, and further preferably 10% by mass or less). Good.

  Examples of the monomer polymerization method for obtaining the (meth) acryl elastomer include a radical polymerization method, a living anion polymerization method, a living radical polymerization method, and the like. Examples of the polymerization form include a solution polymerization method, an emulsion polymerization method, a suspension polymerization method, and a bulk polymerization method.

  Component A is preferably a block copolymer composed of a hard segment and a soft segment. A block copolymer comprising two or more blocks constituting a hard segment and one or more blocks constituting a soft segment. A polymer is more preferable, and a triblock copolymer having two blocks constituting a hard segment on both sides of one block constituting a soft segment is further preferred. The proportion of the triblock copolymer in component A is preferably 60% by mass or more, and more preferably 70% by mass or more. Component A may contain a diblock copolymer and a multiblock copolymer in addition to the triblock copolymer.

  In order for the component A to exhibit the properties as a thermoplastic elastomer, it is preferable to have a hard segment having a glass transition temperature of room temperature or higher.

  The glass transition temperature of the block constituting the hard segment is preferably 20 to 200 ° C, more preferably 30 to 180 ° C, and even more preferably 50 to 150 ° C from the viewpoint of maintaining toughness in the normal temperature range of the composition. If the glass transition temperature of the block constituting the hard segment is too low, the resulting composition may have insufficient heat resistance, and it is difficult to obtain raw materials for blocks having a glass transition temperature exceeding 200 ° C.

  The vinyl monomer constituting the hard segment is preferably one or more of (meth) acrylic monomers. Such (meth) acrylic monomers include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, phenyl (meth) acrylate, (meth) acrylic. 2-ethylhexyl acid, cyclohexyl (meth) acrylate, (meth) acrylic acid, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, glycidyl (meth) acrylate, methoxyethyl (meth) acrylate, ( Examples include ethoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, phenoxyethyl (meth) acrylate, and the like. In these, from a viewpoint of economical efficiency, methyl methacrylate, ethyl methacrylate, and butyl methacrylate are preferable, and methyl methacrylate is more preferable.

  The vinyl monomer constituting the hard segment preferably contains the (meth) acrylic monomer, but does not impair the object of the present invention (preferably 30% by mass or less, more preferably 20%). Or less, more preferably 10% by weight or less), and other monomers may be contained. Moreover, it can also be set as a hard segment by high molecular weight by a polymerization reaction.

  Examples of the copolymerizable vinyl monomer include ethylene, propylene, α-olefin, styrene, α-methylstyrene, acrylonitrile, parahydroxystyrene, vinyl alcohol, acrylic acid, methacrylic acid, acrylamide, methacrylamide, and methyl vinyl ether. , Vinyl benzoate, maleic acid, N-cyclohexylmaleimide and the like. Among these, styrene, α-methylstyrene and ethylene are preferable.

  The glass transition temperature of the block constituting the soft segment is preferably −100 to 19 ° C., more preferably −80 to 10 ° C., and further preferably −70 to 0 ° C. If the glass transition temperature of the block constituting the soft segment is too high, the resulting composition may be insufficient in flexibility, and it is difficult to obtain raw materials for blocks having a glass transition temperature lower than −100 ° C.

  The vinyl monomer constituting the soft segment is preferably one or more of acrylic monomers. As such an acrylic monomer, ethyl acrylate, butyl acrylate, methoxyethyl acrylate, ethoxyethyl acrylate, benzyl acrylate, phenylethyl acrylate and the like are preferable because of high reactivity with the transesterification catalyst.

  Moreover, as an acrylic monomer which comprises the soft segment for the glass transition temperature of a soft segment to be 19 degrees C or less, acrylate acrylate, n-butyl acrylate, acrylate sec-butyl, acrylate acrylate At least one selected from the group consisting of hexyl, ethyl hexyl acrylate, n-heptyl acrylate, n-octyl acrylate, and phenylethyl acrylate is preferable, and it is difficult to be compatible with the hard segment and has a phase separation structure. From an easy viewpoint, at least one selected from the group consisting of n-propyl acrylate, n-butyl acrylate, n-hexyl acrylate, n-heptyl acrylate and n-octyl acrylate is more preferable, and acrylic acid n-Butyl is more preferred.

  The vinyl monomer constituting the soft segment preferably contains the acrylic monomer, but does not impair the object of the present invention (preferably 30% by mass or less, more preferably 20% by mass or less). And more preferably 10% by mass or less), and other monomers may be contained.

  As a method for measuring the glass transition temperature of a polymer, differential scanning calorimetry (DSC), dynamic viscoelasticity measurement, thermal expansion measurement (TMA) and the like are known. In the present invention, a hard segment and a soft segment are used. In block copolymers containing both, dynamic viscoelasticity measurement is a common method that can accurately measure both hard segment and soft segment values. A method for determining the glass transition temperature from the peak of the dielectric loss tangent Tan δ is known. Therefore, the glass transition temperature measured by dynamic viscoelasticity measurement is used for the glass transition temperature of the hard segment and the soft segment in the present invention.

  The mass ratio of the hard segment to the soft segment in component A (hard segment / soft segment) is preferably 10/90 to 70/30 from the viewpoint of imparting appropriate flexibility to component A, and 15/85 to 60/40. Is more preferable.

  Examples of commercially available products that can be used as Component A include Clarity from Kuraray Co., Ltd., Nanostrength from Arkema, and Nabster from Kaneka.

  The weight average molecular weight of Component A is preferably 20,000 or more, more preferably 30,000 or more, and further preferably 40,000 or more, from the viewpoint of mechanical properties such as tensile strength. Further, from the viewpoint of easy handling and maintaining a melt viscosity suitable for production of a molded article such as injection molding, it is preferably 1 million or less, more preferably 800,000 or less, and further preferably 700,000 or less. From these viewpoints, the weight average molecular weight of Component A is preferably 20,000 to 1,000,000, more preferably 30,000 to 800,000, and still more preferably 40,000 to 700,000.

  Further, in the relationship between the weight average molecular weight (Mw) and the number average molecular weight (Mn), Mw / Mn is preferably 1 to 5, and more preferably 1.1 to 3.

  In the present invention, the component A may be one having a higher molecular weight than the polymerization average molecular weight of the component A in the raw material stage by a transesterification catalyst, a radical polymerization initiator, or the like. In this case, the distribution of the weight average molecular weight is broad or multimodal (having two or more peaks), and the weight average molecular weight is the average molecular weight.

  The A hardness of Component A is preferably 5 to 90, more preferably 10 to 80, from the viewpoint of the flexibility of the composition. In addition, A hardness means the durometer type A hardness prescribed | regulated to JISK6253. If the durometer type A hardness exceeds 90, the measurement accuracy will drop, so a comparison is also made using the durometer type D hardness, but the relative comparison that the value of the A hardness is higher is harder If it is the purpose of the above, it may be evaluated by A hardness.

  The flow start temperature of component A is preferably 80 ° C. or higher from the viewpoint of heat resistance of the composition, and preferably 220 ° C. or lower from the viewpoint of thermoplasticity (fluidity) of the composition. From these viewpoints, the flow start temperature of component A is preferably 80 to 220 ° C, and more preferably 100 to 200 ° C.

  Since component A has low moisture permeability, it has an action of suppressing moisture absorption of component B, and the greater the amount, the better the moisture resistance of the thermoplastic elastomer composition, so the content of component A is the content of the thermoplastic elastomer composition. 10 mass% or more is preferable, 20 mass% or more is more preferable, and 30 mass% or more is more preferable.

  Component B is a thermally conductive filler, which not only enhances thermal conductivity, but also improves releasability.

  As the thermally conductive filler, when the thermoplastic elastomer composition of the present invention is used as a member constituting the insulating layer, the insulating thermal conductivity is prevented from the viewpoint of preventing the volume resistivity of the thermoplastic elastomer composition from being lowered. Fillers are preferred. Insulating thermal conductive fillers include inorganic oxides such as alumina, magnesium oxide, beryllium oxide, titanium oxide, metal hydroxides such as aluminum hydroxide and magnesium hydroxide, boron nitride, silicon nitride, aluminum nitride, etc. Nitrides, carbides such as silicon carbide, insulating carbon-based materials such as diamond, silica powders such as quartz and quartz glass, and the like.

  Moreover, when using the thermoplastic elastomer composition of this invention as an electrically-conductive member, an electroconductive heat conductive filler is preferable from a viewpoint which has heat conductivity and electroconductivity. Examples of the conductive thermally conductive filler include metals such as copper, silver, iron, aluminum, nickel, and titanium, metal alloys composed of two or more of these, and carbon-based materials such as graphite and carbon.

  On the other hand, the thermally conductive filler is preferably an inorganic oxide and / or a metal hydroxide, more preferably an inorganic oxide, from the viewpoint of toughness and hardness (thermal expansion coefficient). Examples of the inorganic oxide include alumina, magnesium oxide, beryllium oxide, titanium oxide and the like. Examples of the metal hydroxide include aluminum hydroxide and magnesium hydroxide.

  The inorganic oxide and the metal hydroxide are preferably coated with an organic substance and / or an inorganic substance from the viewpoint of the moisture resistance of the thermoplastic elastomer composition and the dispersibility of the thermally conductive filler. Examples of the heat conductive filler to be blended in the thermoplastic elastomer composition of the present invention include aluminum hydroxide surface-coated with an organic coupling agent and / or magnesia clinker deactivated by firing at 1600 ° C. or higher. Magnesium oxide whose surface is coated with an inorganic substance and / or an organic substance is preferred. The coating layer made of the organic coupling agent is hardly peeled off from the surface of the aluminum hydroxide powder, and the coating layer made of the inorganic substance and / or the organic matter is also hardly peeled off from the surface of the magnesium oxide powder. Become a layer.

  In the composition of the present invention, the thermally conductive filler having a coating layer made of an inorganic material and / or an organic material improves dispersibility, so that the mechanical properties of the molded body are improved, but it is severe that the effect of the coating is greatly manifested. This is the case where the moisture resistance test of the molded product is performed under the conditions, and in the case of the thermally conductive filler having the coating layer, there is almost no difference in mechanical strength after the moisture resistance test, whereas the thermal conductive filler system without the coating layer Then, a difference that the molded product cannot keep its shape may appear. Since the acrylic elastomer itself has low moisture permeability, moisture does not penetrate into the molded product in a normal moisture resistance test, and there is no difference due to filler, but under severe conditions where moisture penetrates deep into the molded product, If there is no filler, water may enter the interface between the filler and the acrylic resin, causing the molded product to collapse.

As the aluminum hydroxide, a soda component (Na ₂ O) content as low as possible (for example, a content of less than 0.4% by mass) is preferable. Aluminum hydroxide with a small content of soda has a high decomposition temperature, a low hygroscopic property, and a high insulating property. Examples of the organic coupling agent used for coating the aluminum hydroxide include titanate esters such as tetraisopropyl titanate, tetrabutyl titanate, tetra (2-ethylhexyl) titanate, tetrastearyl titanate, and γ- Examples thereof include a silicon compound (silane coupling agent) having two groups of a Si (OR) ₃ portion such as methacryloxypropyltrimethoxysilane and an organic functional group such as a vinyl group, amino group, and epoxy group. The coupling agent may contain two or more of the organic functional groups in one molecule, and two or more of the coupling agents may be used in combination.

  The inert magnesia clinker can be produced, for example, by the following method.

An alkaline substance such as caustic soda is added to a magnesium-containing raw material such as seawater and bitter juice to prepare a magnesium hydroxide slurry.
The magnesium slurry is filtered and dried, for example, under conditions of 120 ° C. × 10 hours.
The dried product (magnesium hydroxide) is calcined at 600 to 1000 ° C. to obtain light-burned magnesia. The firing temperature in the calcination is preferably 1200 ° C. or less from the viewpoint of preventing a significant decrease in the activity of the resulting magnesium oxide.
The light-burned magnesia is fired by a rotary kiln or the like, preferably at 1600 ° C. or higher, more preferably 1800-2100 ° C. to obtain a magnesia clinker. The firing temperature is preferably 1600 ° C. or higher from the viewpoint of inactivation of magnesium oxide, ie, loss of reactivity with acid and water vapor, and large crystallization. Burning the magnesium oxide at 1600 ° C. or higher to obtain a surface-inactive magnesia clinker is called death firing. Here, the magnesia clinker means a mass obtained by melting the magnesia component by the dead burning. As described above, the magnesia clinker inactivated and large crystallized by dead burning has excellent moisture resistance and thermal conductivity.

  Examples of the inorganic substance used for the surface coating of the magnesia clinker include an aluminum compound, a silicon compound, a titanium compound, and the like, and two or more of the inorganic substances may be used in combination. Examples of the inorganic substance include ceramic compounds such as oxides, nitrides and borides, salts such as nitrates, sulfates and chlorides, hydroxides, and the like.

  Examples of the organic substance used for the surface coating of the magnesia clinker include the organic coupling agent, silane coupling agent, and organic synthetic resin used for the aluminum hydroxide coating. Two or more organic substances may be mixed and used.

  The magnesia clinker is improved in moisture resistance and dispersibility by the surface coating of the inorganic and / or organic matter.

  The smaller the particle size of the thermally conductive filler is preferable because it can cope with a thinner sheet shape. On the other hand, the larger the particle size, the smaller the surface area per volume, so the fluidity during melt flow is improved. preferable. From these viewpoints, the volume average particle diameter of the thermally conductive filler measured by a laser diffraction particle size distribution meter is 0.1 to 500 μm, preferably 0.5 to 100 μm, more preferably 1.0 to 60 μm. It is known that the particle size can be measured by various measurement principles such as image analysis based on electron microscope observation, Coulter counter, centrifugal sedimentation type, laser diffraction type, etc. It is also known that there are differences in the numerical values obtained by the principle. In the present invention, the average particle diameter measured by a laser diffraction particle size distribution analyzer and analyzed on a volume basis is defined as a representative value of the filler, but the particle diameter values measured by other measurement principles are based on common general technical knowledge. It can be used after conversion.

  The specific gravity of the thermally conductive filler means true specific gravity, and is preferably 1 or more, and more preferably 2 or more, from the viewpoint of thermal conductivity. Further, from the viewpoint of dispersibility, 10 or less is preferable, and 4 or less is preferable. From these viewpoints, the specific gravity of the thermally conductive filler is preferably 1 to 10 and more preferably 2 to 4 from the viewpoints of dispersibility and thermal conductivity.

  The water absorption rate by the moisture absorption test of the heat conductive filler used in the present invention is desirably less than 1.5% by mass from the viewpoint of preventing the deterioration of the thermoplastic elastomer.

  The smaller the content of component B in the thermoplastic elastomer composition of the present invention, the higher the melt fluidity of the composition, and the higher the content, the higher the thermal conductivity of the composition. From these viewpoints, the content of component B in the thermoplastic elastomer composition of the present invention is 40 to 300 parts by volume, preferably 50 to 200 parts by volume, more preferably 60 to 100 parts by volume with respect to 100 parts by volume of component A. 150 parts by volume.

  Component B is a filler, and the effect tends to appear mainly based on the surface area rather than the mass of component B. In this sense, the ratio of component A to component B is more volume than mass part. The tendency of the effect can be reflected more well if it is defined in the section. When the specific gravity of each of component A and component B is known, the mass part can be converted into the volume part by the specific gravity. The volume part of the heat conductive filler can be calculated from the true specific gravity.

  It is known that when a filler is added to an elastomer, the hardness is increased. However, in the combination of Component A and Component B of the present invention, when the particle size and volume part of Component B are limited to the above ranges, the composition The surface hardness of the object is not so great and flexibility can be maintained.

  The thermoplastic elastomer composition of the present invention preferably contains a vinyl copolymer (component C) from the viewpoint of improving heat aging resistance. It is thought that the vinyl copolymer may also have an effect of increasing the dispersibility of Component B.

The monomer unit constituting Component C is a monomer containing 50 mass% or more of two embodiments, that is, the first embodiment: a monomer unit (monomer unit c1) having an SP value of 17.5 to 25.0. Unit and second aspect: monomer unit containing at least 50% by mass of at least one monomer unit (monomer unit c2) selected from the group consisting of (meth) acrylic monomers, styrene and styrene derivatives (When the monomer unit c2 is composed of two or more types of monomer units, it means that the total amount is 50% by mass or more)
The monomer units c1 and c2 are common in that the affinity with the component A is good. The first embodiment and the second embodiment are separated for convenience, and some monomers are common to both. That is, (meth) acrylic monomers, styrene and styrene derivatives having an SP value of 17.5 to 25.0 correspond to any of the embodiments.

  In the first embodiment, the SP value for specifying the monomer unit c1 is widely known as a Solubility Parameter. The SP value (δ) in the present invention is determined by the following estimation formula.

VanKrevelen's formula
[VanKrevelen] Solubilityparameter: δ
δ = (Ecoh / V) 0.5
Ecoh = ΣEcoh, i
Unit: (J / cm ³ ) 0.5
Physical property values required for estimation
V: molar volume of constituent repeating unit (CRU) [cm ³ / mol]
Physical quantities calculated by group contribution method
Ecoh: molar cohesive energy of Hoftyzer & VanKrevelen [J / mol]
Group parameters
Ecoh, i: Group parameter for i-th molar cohesive energy [J / mol]

  As monomer units having an SP value of 17.5 to 25.0 (the values in parentheses are SP values), styrene (18.82), α-methylstyrene (19.55), methyl methacrylate (18.54), n-butyl acrylate (18.12) ), Ethyl acrylate (18.83), methyl acrylate (19.13), methoxyethyl acrylate (19.43), vinyl acetate (19.13) and the like.

  For example, olefins having an SP value of less than 17.5, such as ethylene and propylene, are not suitable as the main monomer unit of component C in the present invention. Examples of olefins having an SP value of less than 17.5 (the values in parentheses are SP values) include ethylene (16.00) and propylene (17.04).

  From the viewpoint of affinity with Component A, the SP value of the monomer unit c1 is 17.5 or more, preferably 17.8 or more, more preferably 18.0 or more. Moreover, it is 25.0 or less, Preferably it is 23.0 or less, More preferably, it is 22.0 or less, More preferably, it is 21.0 or less, More preferably, it is 20.0 or less. From these viewpoints, the SP value of the monomer unit c1 is 17.5 to 25.0, preferably 17.8 to 23.0, more preferably 18.0 to 22.0, still more preferably 18.0 to 21.0, and still more preferably. 18.0 to 20.0.

  When the proportion of the monomer unit c1 is 50% by mass or more in the monomer unit of the component C, the affinity with the component A is good and the dispersibility of the component B in the component A is better. Become. The proportion of the monomer unit c2 is more preferably 60% by mass or more, further preferably 70% by mass or more, and more preferably 80% by mass or more.

  In the present invention, even a monomer unit whose SP value is difficult to specify can be used as the main monomer unit of Component C as long as it is a (meth) acryl monomer, styrene, or a styrene derivative.

  Therefore, the second embodiment of the monomer unit of component C includes at least one monomer unit (monomer unit c2) selected from the group consisting of (meth) acrylic monomers, styrene and styrene derivatives. It is a waste.

  Suitable (meth) acrylic monomers as the monomer unit c2 include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, and cyclohexyl (meth) acrylate. , Hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, glycidyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, (meth ) Phenoxyethyl acrylate and the like are exemplified, and among these, from the viewpoint of affinity with Component A, alkyl (1-6) esters of (meth) acrylic acid and glycidyl (meth) acrylate are preferred. Since glycidyl (meth) acrylate has a strong hydrogen bond, it is difficult to specify the SP value, but it has a high affinity with Component A and is preferable as the monomer unit c2.

  Styrene derivatives are substituted with substituents such as lower alkyl groups having 1 to 4 carbon atoms, lower alkoxy groups having 1 to 4 carbon atoms, carboxyl groups, and halogen atoms at the alpha, ortho, meta, or para positions of styrene. Means the compound formed. The molecular weight (atomic weight) of the substituent is preferably 60 or less, more preferably 50 or less, and still more preferably 40 or less. Specific examples of the styrene derivative include α-methylstyrene and p-chlorostyrene.

  However, among the monomer unit c2 whose SP value is specified, that is, (meth) acrylic monomer, styrene and styrene derivatives, the SP value deviates from the SP value required for the monomer unit c1 of the first embodiment. Those having an SP value of less than 17.5 and more than 25.0 have low affinity with component A, and are excluded from the monomer unit c2 in the second embodiment. For example, those having an SP value of the monomer unit of less than 17.5 include alkyl esters of (meth) acrylic monomers having an alkyl group having 8 or more carbon atoms.

  When the proportion of the monomer unit c2 is 50% by mass or more in the monomer unit of the component C, the affinity with the component A is good, and the dispersibility of the component B in the component A is better. Become. The proportion of the monomer unit c2 is more preferably 60% by mass or more, further preferably 70% by mass or more, and more preferably 80% by mass or more.

  Hereinafter, in the present specification, unless otherwise specified, component C includes both component C of the first embodiment containing monomer unit c1 and component C of the second embodiment containing monomer unit c2. Applicable.

  The monomer unit constituting Component C preferably contains 10 to 90% by mass of (meth) acrylic monomer and 10 to 90% by mass of styrene or a styrene derivative. More preferably, it contains 15 to 80% by mass (more preferably 20 to 70% by mass) of (meth) acrylic monomer and 20 to 85% by mass (more preferably 30 to 80% by mass) of styrene or a styrene derivative. Since such a component C has a (meth) acryl monomer having a high affinity with the component A and styrene or a styrene derivative having a high affinity with the component B as constituent units, it is used as a compatibilizer for both AB components. It is preferable because it can work effectively.

  Component C preferably has solubility in tetrahydrofuran (THF) from the viewpoint of affinity with Component A, and is preferably a vinyl copolymer. Specifically, having solubility in THF means that the solubility in THF at 25 ° C. is 5% by mass or more. The solubility is more preferably 10% by mass or more, and further preferably 15% by mass or more.

  The more epoxy groups that component C has, the better the affinity with component B, and the smaller the epoxy group, the better the compatibility with component A and the better the dispersibility of component B. It has an average of 2 or more, more preferably 2.5 to 20, more preferably 3 to 10 epoxy groups.

  From the viewpoint of improving the dispersibility of Component B, the epoxy value of Component C is preferably 0.5 to 5 meq / g, and more preferably 0.7 to 3 meq / g.

  Examples of commercially available products that can be used as component C include Alfon UG series manufactured by Toagosei Co., Ltd., Marproof G series manufactured by NOF Corporation, and Jonkrill ADR series manufactured by BASF.

  Component C needs to maintain compatibility with Component A, but if the weight average molecular weight of Component C exceeds 100,000, the compatibility with Component A decreases. On the other hand, if it is less than 1000, the compatibility with the component A becomes too high. From these viewpoints, the weight average molecular weight of Component C is preferably 1000 or more, more preferably 3000 or more, and further preferably 5000 or more. Moreover, 100,000 or less is preferable, 80,000 or less is more preferable, and 60,000 or less is more preferable. The weight average molecular weight of Component C is preferably 1,000 to 100,000, more preferably 3,000 to 80,000, and even more preferably 5,000 to 60,000.

  The number average molecular weight of component C is preferably 500 to 50,000, more preferably 1000 to 40,000, and still more preferably 2000 to 30,000 from the viewpoint of compatibility with component A as described above.

  The content of the component C is preferably 0.1 parts by mass or more with respect to 100 parts by mass of the component A, from the viewpoint of improving the strength and heat aging resistance of the composition molded body. From the viewpoint of preventing deterioration in heat aging resistance due to residual, 30 parts by mass or less is preferable. From these viewpoints, the content of Component C is preferably 0.1 to 30 parts by mass, more preferably 0.2 to 20 parts by mass, still more preferably 0.2 to 15 parts by mass, and more preferably 0.3 to 10 parts by mass with respect to 100 parts by mass of Component A. Part by mass is more preferable.

  From the viewpoint of improving heat resistance, the thermoplastic elastomer composition of the present invention preferably further contains a thermoplastic resin (component D) having a functional group capable of reacting with an epoxy group. Component D is preferably crystalline in order to cause phase separation with Component A, and is preferably a crystalline thermoplastic resin having a high melting point from the viewpoint of imparting heat resistance. In the present invention, when the component C is used in combination with the system in which the component A, the component B, and the component D are used in combination, there is an effect of chemically increasing the compatibility between the component A and the component D. There is a tendency for strength to increase.

  From the viewpoint of improving the heat resistance of the composition, the melting point of the thermoplastic resin is preferably 100 ° C. or higher, more preferably 180 ° C. or higher, and further preferably 200 ° C. or higher. From the viewpoint of ease of production, 350 ° C. or lower is preferable, 300 ° C. or lower is more preferable, and 280 ° C. or lower is further preferable. From these viewpoints, the melting point of the thermoplastic resin is preferably 100 to 350 ° C, more preferably 180 to 300 ° C, and further preferably 200 to 280 ° C. The crystalline thermoplastic resin generally refers to a thermoplastic resin whose melting point is observed in a differential scanning calorimeter (DSC), and the melting point value is DSC. Although it also has a glass transition temperature, the glass transition temperature can be measured by DSC, but the dynamic viscoelasticity measurement can obtain a more precise value.

  In the present invention, examples of the functional group capable of reacting with an epoxy group include a hydroxyl group, a carboxyl group, an acid anhydride group, an amide group, an amino group, and the like. It has a seed or two or more kinds in the main chain or side chain of the thermoplastic resin.

  The thermoplastic resin having a functional group capable of reacting with an epoxy group can react with component C to be cross-linked to improve the heat resistance of the composition, and is effective in improving the dispersibility of component B. When components A, B and C are used in combination, the dispersibility of B is excellent, so that the melt viscosity is low, and the effects of increasing the heat resistance and strength of the composition are manifested.

  Specific examples of component D include nylon 6, nylon 6,6, nylon 12, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyethylene naphthalate, polypropylene, polyethylene, polymethyl methacrylate, polystyrene, polymethacrylstyrene ( MS), polymers such as acrylonitrile-butadiene-styrene (ABS) resin, acrylonitrile-styrene (AS) resin, polyacetal resin (POM), polyphenylene oxide resin (PPO), polyvinyl chloride (PVC), and the like. From the viewpoint of compatibility (high melting point) and incompatibility with component A, aromatic polyester and / or polyamide is preferred. As the aromatic polyester, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate and the like are preferable, and as the polyamide, nylon 6, nylon 6,6 and the like are preferable. Although it is preferable to use a plurality of these in combination, polyethylene terephthalate and / or polybutylene terephthalate are more preferable.

  When Component D is polyester, hydroxyl groups and carboxyl groups exist as functional groups at the molecular ends. In the present invention, the abundances of hydroxyl groups and carboxyl groups at the molecular ends of the polyester used as component D in the present invention are not particularly limited, and general ones can be used. For example, component D is polyester. In this case, the acid value that is an index of the amount of the carboxyl group is preferably 0.1 to 100 meq / kg. More specifically, the acid value is preferably 0.1 meq / kg or more, more preferably 1 meq / kg or more, further preferably 3 meq / kg or more, and further preferably 5 meq / kg or more. Further, it is preferably 100 meq / kg or less, more preferably 80 meq / kg or less, further preferably 70 meq / kg or less, and further preferably 60 meq / kg or less. The acid value of the polyester resin was determined by dissolving 200 mg of a sufficiently dried sample in 10 ml of hot benzyl alcohol, cooling the solution, adding 10 ml of chloroform and phenol red, and adding 1/25 normal alcoholic potash solution (KOH Titration with methanol solution) and measurement. The hydroxyl value of the polyester is calculated by measuring the end group concentration which is the sum of the hydroxyl end group and the carboxyl end group of the polyester, and subtracting the acid value (carboxyl end group concentration) therefrom. The terminal group concentration is measured as the sum of the carboxyl terminal groups derived from succinic acid and the carboxyl groups of the polyester itself (= total acid value) by binding succinic acid to the hydroxyl terminal of the polyester. Calculated by hydroxyl value = total acid value−acid value.

When component D is polyamide, the molecular end functional groups are generally carboxyl groups and amino groups. In the present invention, the abundances of carboxyl groups and amino groups at the molecular terminals of the polyamide used as component D in the present invention are not particularly limited and general ones can be used, but when component D is polyamide, The terminal amino group concentration is preferably 10 to 200 μmol / g. More specifically, the terminal amino group concentration is preferably 10 μmol / g or more, more preferably 15 μmol / g or more, further preferably 20 μmol / g or more, and further preferably 30 μmol / g or more. Further, it is preferably 200 μmol / g or less, more preferably 190 μmol / g or less, further preferably 180 μmol / g or less, and further preferably 170 μmol / g or less. The terminal amino group concentration and terminal carboxyl group concentration are determined from the integrated value of the characteristic signal corresponding to each terminal group by ¹ H-NMR.

  The content of Component D is preferably 10 parts by mass or more with respect to 100 parts by mass of Component A from the viewpoint of heat resistance, and is preferably 400 parts by mass or less from the viewpoint of flexibility. From these viewpoints, the content of Component C is preferably 10 to 400 parts by mass, more preferably 20 to 300 parts by mass, and still more preferably 30 to 250 parts by mass with respect to 100 parts by mass of Component A.

  The composition of the present invention preferably contains an aliphatic carboxylic acid metal salt (component E) as a dispersant for improving the dispersibility of component B.

  As the aliphatic carboxylic acid metal salt, a metal salt of a saturated or unsaturated fatty acid having 12 to 25 carbon atoms is preferable. The fatty acid is preferably a saturated fatty acid. Examples of the metal salt include sodium salt, potassium salt, magnesium salt, aluminum salt, calcium salt, zinc salt and the like, and divalent or trivalent metal salts are preferable. From these viewpoints, as the aliphatic carboxylic acid metal salt, aluminum stearate and calcium stearate are more preferable.

  The content of Component E is preferably 0.001 part by mass or more and more preferably 0.005 part by mass or more with respect to 100 parts by mass of Component B from the viewpoint of dispersibility of Component B. Moreover, from a viewpoint of suppressing discoloration, 10 mass parts or less are preferable, and 5 mass parts or less are more preferable. From these viewpoints, the content of Component E is preferably 0.001 to 10 parts by mass and more preferably 0.01 to 5 parts by mass with respect to 100 parts by mass of Component B.

  The thermoplastic elastomer composition of the present invention preferably further contains a transesterification catalyst. By blending the transesterification catalyst, the tensile strength at break of the resulting composition is improved. Specifically, in the tensile test, the tensile product (product of strength and elongation) is large, and the balance between strength and elongation becomes better. The reason for such an effect is that the molecular weight of component A can be increased by the transesterification catalyst, and in some cases, a partial crosslink is formed. It is presumed that the transesterification catalyst acts as a cross-linking agent, and that the composition becomes tougher by increasing the molecular weight of component A, which is the main component of the composition.

  A general polyester polymerization catalyst can be used as the esterification catalyst as a reaction catalyst for increasing the molecular weight of component A and partially crosslinking. Examples of such catalysts include antimony catalysts such as antimony trioxide, tin catalysts such as butyltin, octyltin, and stannoxane, titanium catalysts such as titanium aminates and titanium alkoxides, zirconium acetylacetonates, zirconium alkoxides, and the like. And zirconium-based catalysts. Among these, a titanium-based catalyst and a zirconium-based catalyst are preferable, and a titanium-based catalyst is more preferable.

  Specific examples of the titanium catalyst include titanium alkoxides such as tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, tetraoctyl titanate, titanium acetylacetonate, titanium tetraacetylacetonate, titanium ethylacetoacetate, titanium phosphate compound , Organic solvent-soluble chelate compounds such as titanium octylene glycolate, titanium ethyl acetoacetate, titanium lactate ammonium salt, titanium lactate, titanium triethanolaminate, titanium tributanol aminate, titanium diethanolaminate, titanium aminoethylamino ethanol And water-soluble chelate compounds such as rate, and the like. Among these, water-soluble chelate compounds are preferred, and more preferred is tita. It is alkanol aminate

  The content of Component F is preferably 0.01 parts by mass or more and more preferably 0.1 parts by mass or more with respect to 100 parts by mass of Component A. Further, the content of the transesterification catalyst is preferably 10 parts by mass or less, and more preferably 5 parts by mass or less from the viewpoint of suppressing a decrease in thermoplasticity of the composition obtained by crosslinking of Component A. The content of Component F is preferably 0.01 to 10 parts by mass and more preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of Component A.

  The thermoplastic elastomer composition of the present invention may contain a thermal stabilizer from the viewpoint of suppressing changes in the properties of the composition of the present invention under heating conditions.

  Examples of the heat stabilizer include phosphorus-containing compounds, hydrazide compounds, organic sulfur-based antioxidants, phenol-based antioxidants, amine-based antioxidants, and other chelating agents with other transesterification catalysts (component F). Thus, compounds that reduce the activity of the catalyst can also be used. In this invention, since the tolerance with respect to the heat aging of a thermoplastic elastomer improves remarkably, a phosphorus containing compound and a hydrazide compound are preferable from a viewpoint which the freedom degree of use conditions becomes larger. These may be used in combination. The content of the heat stabilizer is preferably 0.01 to 15 parts by mass and more preferably 0.05 to 10 parts by mass with respect to 100 parts by mass of the total amount of component A and component B. Thermal aging mainly includes two phenomena, the first is a decrease in strength due to an increase in the proportion of low molecular weight components produced by thermal decomposition, and the second is free radicals produced by thermal decomposition. This is a decrease in elongation caused by the formation of active site crosslinks.

  The thermoplastic elastomer composition of the present invention includes acrylic rubber, silicone-modified acrylic rubber, butyl rubber, crosslinked rubber such as silicone-modified butyl rubber, acrylic rubber-g-methyl methacrylate, MAS (acrylic rubber-g-methyl methacrylate / styrene). Further, it may contain a graft copolymer such as MBS (butadiene rubber-g-methyl methacrylate / styrene), a block copolymer other than acrylic, such as a polyester block copolymer.

  Other additives include lubricants such as heavy metal deactivators and fatty acid esters; light stabilizers such as benzotriazole compounds, benzophenone compounds, benzoate compounds and hindered phenol compounds; hydrolysis of carbodiimide compounds and oxazoline compounds Inhibitors; Plasticizers such as phthalate compounds, polyester compounds, (meth) acryl oligomers, process oils; Inorganic foaming agents such as sodium bicarbonate and ammonium bicarbonate; Organics such as nitro compounds, azo compounds, and sulfonyl hydrazides Fillers such as carbon black, calcium carbonate, talc, glass fiber; flame retardants such as tetrabromophenol, ammonium polyphosphate, melamine cyanurate, magnesium hydroxide and aluminum hydroxide; silane coupling agents, tita Over preparative based coupling agents, compatibilizers, such as aluminate-based coupling agent or an acid-modified polyolefin resin; other pigments or dyes.

  The thermoplastic elastomer composition of the present invention comprises at least a (meth) acrylic elastomer (component A), a heat conductive filler (component B), a vinyl copolymer (component C), and, if necessary, a thermoplastic resin (component). D), a raw material component containing an aliphatic carboxylic acid metal salt (component E), a transesterification catalyst (component F), a heat stabilizer, other additives and the like can be obtained by a method of heating and kneading with an extruder or a kneader. preferable.

  When using a transesterification catalyst to increase the molecular weight of the (meth) acrylic elastomer (component A), it is preferable to use a heat stabilizer in combination to further stabilize the characteristics of the composition. It is preferable that the stabilizer is added after the component A has a high molecular weight (for example, after a raw material other than the heat stabilizer is kneaded for about 0.5 to 15 minutes at a kneading temperature of 180 to 350 ° C.). . If the heat stabilizer is added too early, component A may not be sufficiently high in molecular weight.

  Examples of the extruder include a single screw extruder, a parallel screw twin screw extruder, and a conical screw twin screw extruder. In the present invention, from the viewpoint of excellent mixing ability (the resulting mixture has good dispersibility), a twin screw extruder is preferable, and a co-rotating twin screw extruder is more preferable.

  The die attached to the discharge part of the extruder can be selected arbitrarily. For example, a strand die suitable for pellet production, a T die suitable for sheet or film production, a pipe die, a profile extrusion die, etc. Can be mentioned.

  Moreover, the extruder may be provided with a vent for venting gas connected to an air release portion or a decompression device, or may be provided with a plurality of raw material inlets.

  The kneader means a batch-type mixer capable of controlling the temperature, and examples include a Banbury mixer, a Brabender plastograph, and a lab plast mill.

  Each component may be charged into the extruder or kneader all at once, separately, or dividedly. However, the introduction of the heat stabilizer is as described above.

  From the viewpoint of moldability, the heat kneading temperature is preferably 170 ° C. or higher, more preferably 180 ° C. or higher, and further preferably 190 ° C. or higher. Further, from the viewpoint of preventing thermal deterioration during heating and kneading, 350 ° C. or lower is preferable, 310 ° C. or lower is more preferable, and 300 ° C. or lower is further preferable.

  The heating and kneading time depends on the heating temperature, the type and concentration of each component, and cannot be determined unconditionally. However, the heating and kneading time is appropriately determined in consideration of the quality variation control and productivity of the obtained thermoplastic elastomer composition. It is preferable. A typical heating and mixing time when using an extruder is, for example, 0.5 to 20 minutes, preferably 0.7 to 15 minutes, and more preferably 1 to 10 minutes.

  A molded body is obtained by appropriately heat-molding the thermoplastic elastomer composition of the present invention according to a conventional method. The use of the molded product obtained by thermoforming the thermoplastic elastomer composition of the present invention is not particularly limited, and general styrene elastomers, polyolefin elastomers, polyurethane elastomers, polyamide elastomers, acrylic elastomers And polyester elastomers can be used.

  Since the molded product obtained by molding the thermoplastic elastomer composition of the present invention has excellent heat resistance, for example, for applications that require heat resistance of 100 ° C. or higher (120 ° C. or higher, 130 ° C. or higher depending on the design) Can also be suitably used.

  The temperature at the time of heat molding is preferably 180 ° C. or higher from the viewpoint of fluidity of the composition and molding processability resulting from it, from the viewpoint of preventing thermal decomposition of the (meth) acrylic component of component A in the composition, 350 degrees C or less is preferable. From these viewpoints, the temperature during the heat molding is preferably 180 to 350 ° C, more preferably 200 to 320 ° C.

  Any molding machine capable of melt-molding the composition can be used as an apparatus used for producing a molded article using the thermoplastic elastomer composition of the present invention. Examples thereof include a kneader, an extrusion molding machine, an injection molding machine, a press molding machine, a blow molding machine, and a mixing roll.

  The molded body obtained by thermoforming the thermoplastic elastomer composition of the present invention preferably has an A hardness of 20 to 100, more preferably 20 to 90, which is an index of flexibility.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to this.

[Production of vinyl copolymer C3]
The oil jacket temperature of a 1 liter pressurized stirred tank reactor equipped with an oil jacket was maintained at 200 ° C. On the other hand, a monomer mixture composed of 74 parts by mass of styrene, 20 parts by mass of glycidyl methacrylate, 6 parts by mass of n-butyl acrylate, 15 parts by mass of xylene and 0.5 parts by mass of ditertiary butyl peroxide (DTBP) as a polymerization initiator The raw material tank was charged. Continuous supply from the raw material tank to the reactor at a constant supply rate (48 g / min, residence time: 12 minutes), and the reaction liquid is continuously supplied from the outlet of the reactor so that the liquid content in the reactor is constant at approximately 580 g. Extracted. At that time, the internal temperature of the reactor was maintained at about 210 ° C.
After 36 minutes have passed since the temperature inside the reactor has stabilized, the extracted reaction solution is continuously removed by a thin-film evaporator maintained at a reduced pressure of 30 kPa and a temperature of 250 ° C. The free copolymer C3 was recovered. About 7 kg of vinyl copolymer C3 was recovered over 180 minutes.

[Production of vinyl copolymers C1 and C2]
The vinyl copolymer was prepared in the same manner as the vinyl copolymer C3, except that a monomer mixture composed of a monomer having the composition shown in Table 3-1, 15 parts by mass of xylene, and 0.3 parts by mass of DTBP was used. C1 and C2 were produced.

Examples 1-34 and Comparative Examples 1-3 (Examples 1-13 are reference examples)
Raw material components were charged into a batch kneader (Plastograph manufactured by Brabender) heated to 200 ° C. at a composition ratio shown in Tables 5 to 8, and the raw material was melt-kneaded at a rotational speed of a rotor rotational speed of 100 r / min. The kneading time was 13 to 18 minutes. When the kneading torque reached the maximum value, the entire kneaded material in a molten state was taken out and cooled at room temperature to obtain a composition.

  The detail of the used resin raw material is shown to Tables 1-4.

  In addition, the physical property of each raw material component of Tables 1-3 was measured with the following method. Production of the raw material sheet was carried out in the same manner as the production of a press sheet of the composition described later. However, the press temperature was adjusted according to the raw material (a temperature at which a small amount of raw material was raised in advance and the temperature at which flow was visually confirmed was grasped).

[A hardness]
Measured according to JIS K 6253-3 “Durometer hardness”.

[Weight average molecular weight (Mw) and number average molecular weight (Mn)]
From a gel permeation chromatograph (hereinafter also referred to as GPC), THF is used as a solvent and is determined from polystyrene conversion.

(Glass transition temperature (Tg))
Using a dynamic viscoelasticity measuring device (RSAIII manufactured by TA Instruments Co., Ltd.), heat the test piece in the temperature range of -100 to 280 ° C, the heating rate of 5 ° C / min, and the frequency of 10Hz. The peak temperature of loss tangent (Tanδ) measured at the time is observed, and this temperature is defined as the glass transition temperature (Tg). A test piece having a thickness of 2 mm, a width of 12 mm, and a length of 30 mm is used.
In an elastomer having a plurality of blocks (soft segment and hard segment), a plurality of loss tangent peaks are usually observed. In this case, the peak on the low temperature side is derived from the soft segment, and the peak on the high temperature side is It comes from the hard segment.

[Flow start temperature]
A test piece of 12mm width x 30mm length is cut from the press sheet, and the dynamic viscoelasticity measuring device (TA Instruments RSA-II type) torsion mode (10gf load), frequency 10Hz, heating rate Measure the viscoelastic properties of each sample at 5 ° C / min and temperature 0-280 ° C.
The inflection point of the obtained storage modulus or the temperature at which measurement becomes impossible is defined as the flow start temperature. Although the inflection point of the storage elastic modulus appears near the glass transition temperature, it does not flow and therefore does not correspond to the flow start temperature.

[Melting point]
Place about 10mg of sample in an aluminum pan and crimp the aluminum lid. Install the aluminum pan in the instrument measuring section of the differential scanning calorimeter (Perkin Elmer DSC8000) and measure it in air at a heating rate of 20 ° C / min.

[Volume average particle diameter]
The thermally conductive filler ultrasonically dispersed in deionized water is measured with an LA-500 laser diffraction particle size distribution meter manufactured by Horiba, Ltd., and analyzed on a volume basis to calculate the average particle size.

[Water absorption rate]
Place 10g of thermal conductive filler in a petri dish, leave it in a thermostat at 90 ° C x 90% RH, measure the mass change after 48 hours with an electronic balance, and use the following formula to calculate the mass change rate (water absorption rate) ) Is calculated.

[Average number of epoxy groups per molecule (Fn)]
Calculated from the following formula.
Average number of epoxy groups (Fn) = a × b / 100c
In the above formula, a, b and c are as follows.
a: Ratio (% by mass) of vinyl monomer units having an epoxy group contained in the copolymer
b: number average molecular weight of copolymer c: molecular weight of vinyl monomer having epoxy group

[Epoxy value]
This is the number of milliequivalents of epoxy groups contained in 1 g of sample (equivalent number of epoxy groups contained in 1 kg of sample), which corresponds to the epoxy index of JISK7236.

  The compositions obtained in Examples and Comparative Examples were press-molded to produce Plate A having a thickness of 2 mm × width of 200 mm × length of 200 mm.

[Press molding conditions]
Press molding machine: 40ton electric hydraulic molding machine Heating temperature: Upper mold 200-240 ° C, Lower mold 200-240 ° C
Heating time: 5 minutes Pressing pressure: 5MPa
Cooling time: 2 minutes

  Using plate A, the following characteristics were evaluated. The results are shown in Tables 5-8.

(1) Flexibility <A hardness>
Measure according to JIS K 6253-3 durometer hardness except for the following conditions.
Measurement time: 1 second after the needle contacts the sample Load: 5kg

(2) Heat aging resistance <Tensile strength retention>
The test piece is used by punching plate A into No. 3 dumbbell type described in JIS K 6251. Using a tensile tester having a thermostatic chamber at the tensile test site, the test piece after leaving the test piece for 48 hours at 130 ° C. and the test piece before leaving at 130 ° C. for a tensile speed of 500 mm / min Perform a tensile test at The tensile strength retention is calculated from the following formula. 70% or more is preferable, and 80% or more is more preferable.

(3) Elastic modulus retention at high temperatures <Storage modulus>
The sample is allowed to stand at 23 ° C. for 48 hours, and then the storage elastic modulus is measured under the following conditions. It is preferred that the value of the storage modulus at 200 ° C. exceeds 1.0 × 10 ⁴ Pa (> 10 ⁴ ).
Measurement mode: shear Use jig: Torsion plate Frequency: 10Hz
Temperature increase rate: 5 ℃ / min
Measurement temperature: -100 to 280 ° C
Sample shape: 12mm x 30mm x 2mm
Measuring instrument: ARES-RDS (manufactured by TA Instruments)

(4) Moisture resistance <Tensile strength retention>
After leaving the test piece for 168 hours in a constant temperature and humidity chamber at 80 ° C. and 95% RH, the tensile strength retention is measured in the same manner as in the evaluation of heat aging resistance. 70% or more is preferable.

(5) Thermal conductivity <Thermal conductivity>
The thermal diffusivity is measured by the laser flash method (temperature 19-30 ° C).
Measure specific heat with DSC (conforms to JIS K 7123).
Measure specific gravity by underwater substitution method (conforms to JIS K 7112).
Based on the measurement result, the thermal conductivity is calculated from the following formula.
Thermal conductivity = thermal diffusivity x specific heat x specific gravity Sample: Disk with φ = 15mm, thickness = 1.0mm

  From the above results, it can be seen that in Examples 1 to 33, all have excellent flexibility as a molded body, and are excellent in heat aging resistance, elastic retention at high temperatures, moisture resistance and thermal conductivity. .

  On the other hand, in Comparative Examples 1 and 2, since component B is not blended or is blended in a small amount, it lacks thermal conductivity. Comparative Example 3 in which component B was excessively blended could not be melt kneaded.

  The thermoplastic elastomer composition of the present invention can be used for heat radiating members of electric and electronic parts, for example, heat radiating sheets, housings, sealing materials and the like.

Claims (15)

A thermoplastic elastomer composition comprising (meth) acrylic elastomer (component A) and 40 to 300 parts by volume of a heat conductive filler (component B) with respect to 100 parts by volume of component A, the component B laser the volume average particle diameter determined by the diffraction type particle size distribution meter Ri 0.1~500μm der further vinyl copolymer having an average of two or more epoxy groups in one molecule (component C), relative to component a 100 parts by weight ing contain 0.1 to 30 parts by weight of Te, a thermoplastic elastomer composition.   The thermoplastic elastomer composition according to claim 1, wherein Component B is an insulating filler.   The thermoplastic elastomer composition according to claim 1 or 2, wherein Component B is an inorganic oxide and / or a metal hydroxide.   The thermoplastic elastomer composition according to claim 3, wherein the inorganic oxide and / or metal hydroxide is coated with an organic material and / or an inorganic material.   The (meth) acryl elastomer (component A) is composed of a hard segment having a glass transition temperature determined by dynamic viscoelasticity measurement of 20 to 200 ° C. and a soft segment having a glass transition temperature of −100 to 19 ° C. The thermoplastic elastomer composition according to any one of claims 1 to 4, which is a block copolymer.   The (meth) acryl elastomer (component A) is a block copolymer comprising two or more blocks constituting a hard segment and one or more blocks constituting a soft segment. A thermoplastic elastomer composition.   The thermoplastic elastomer composition according to any one of claims 1 to 6, wherein the (meth) acryl elastomer (component A) has a weight average molecular weight of 20,000 to 1,000,000. Furthermore, 10 to 400 parts by mass of a thermoplastic resin (component D) having a melting point of 100 to 350 ° C. and having a functional group capable of reacting with an epoxy group is contained with respect to 100 parts by mass of component A. The thermoplastic elastomer composition according to any one of 1 to 7 . A vinyl copolymer (component C) is a monomer unit containing 50% by mass or more of a monomer unit (monomer unit c1) having an SP value of 17.5 to 25.0, or a (meth) acrylic monomer, styrene and styrene The thermoplastic elastomer according to any one of claims 1 to 8, wherein the thermoplastic elastomer is composed of monomer units containing at least 50% by mass of at least one monomer unit (monomer unit c2) selected from the group consisting of derivatives. Composition. Vinyl copolymer monomer units constituting the (Component C), (meth) comprises 10 to 90 wt% of acrylic monomers, styrene or a styrene derivative are those containing 10 to 90 wt%, to any one of claims 1 to 9 The thermoplastic elastomer composition as described. The thermoplastic elastomer composition according to any one of claims 1 to 10 , wherein the vinyl copolymer (component C) has a weight average molecular weight of 1,000 to 100,000. The thermoplastic elastomer composition according to any one of claims 8 to 11 , wherein the thermoplastic resin (component D) is an aromatic polyester and / or a polyamide. The thermoplastic elastomer composition according to any one of claims 1 to 12 , further comprising 0.001 to 10 parts by mass of an aliphatic carboxylic acid metal salt (component E) based on 100 parts by mass of component B. Furthermore, the thermoplastic elastomer composition according to any one of claims 1 to 13 , wherein the transesterification catalyst (component F) is contained in an amount of 0.01 to 10 parts by mass with respect to 100 parts by mass of the component A. Molded article obtained by heat molding the claims 1-14 thermoplastic elastomer composition according to any one.