JP5474460B2 - Thermally conductive resin composition and thermal conductive sheet using the same - Google Patents

Description

  The present invention relates to a heat conductive resin composition and a heat conductive sheet using the same.

  In recent years, with the increase in speed and functionality of electrical and electronic devices, semiconductor devices such as integrated circuits (ICs), central processing elements (CPUs), light emitting diodes (LEDs), large scale integrated circuits (LSIs), and power transistors Electronic components such as these tend to be highly integrated and dense. However, when electronic components are highly integrated and densified, power consumption increases, and there is a problem that the amount of heat generated increases as power consumption increases. As described above, the heat generated inside the electric device or the electronic device may cause problems such as deterioration, malfunction, failure or breakage of the electronic component.

  In order to suppress the occurrence of defects in the electronic component as described above, a method of removing heat from the electronic component or equalizing the temperature by eliminating a temperature difference in the same component or in the apparatus is used. For example, heat is transferred from an electronic component that is a heat source to a cooling component such as a heat sink, and at the same time, the cooling component such as a heat sink to which heat is transmitted is forcibly cooled by a cooling fan or the like to remove the heat. The method is used.

  In addition, if there is no space to install a cooling fan, such as a small electronic device such as a notebook personal computer, or an electronic component that is highly integrated and densified, apply silicone grease. A method of dissipating heat is used.

  However, when silicone grease is used, not only is it difficult to uniformly apply silicone grease, but there is a problem that parts are contaminated by the protrusion after application. Moreover, since silicone grease is inferior in cushioning properties, there is a problem that use is limited when a high load is applied.

  By the way, in recent years, the use of a heat conductive sheet in place of silicone grease is increasing. The heat conductive sheet is used by being sandwiched between an electronic component or the like as a heat source and a cooling component such as a heat sink. As a result, both can be brought close to each other and heat can be efficiently transferred from the electronic component to the cooling component.

  As the heat conductive sheet, for example, a heat conductive sheet in which a filler having relatively high heat conductivity is mixed with silicone rubber is used. The heat conductive sheet is required to have various performances in addition to the heat conductivity. For example, since it is often mounted in contact with an electronic substrate, insulation is required to prevent failure due to energization of the electronic substrate. Moreover, when a heat conductive sheet is used for the internal parts of electric equipment and electronic equipment with high power consumption, heat resistance and flame retardance are required from the viewpoint of safety.

  Patent Document 1 discloses a heat conductive material in which aluminum hydroxide is blended with synthetic rubber. Patent Document 2 discloses a heat dissipating composition in which aluminum hydroxide that is a thermal conductivity imparting agent and a softening agent that is made of paraffinic oil are blended with a styrene thermoplastic elastomer.

JP 2000-150740 A JP 2004-146106 A

  However, the heat conductive sheet made of silicone rubber has the advantage that it is easier to handle than silicone grease, but the silicone rubber as a raw material is expensive and the number of processing steps such as a curing step increases. Therefore, there is a problem that the cost becomes high. In addition, since low molecular weight siloxane is contained in the silicone rubber, the low molecular weight siloxane bleeds out from the heat conductive sheet during use of the electronic component, and the bleed out low molecular weight siloxane adheres to the electrode contacts and the like. There is a problem of producing silicon dioxide. The generated silicon dioxide may cause a contact failure or the like, and the contact failure or the like may induce malfunction of electronic equipment or electrical equipment.

  Since the heat conductive material disclosed in Patent Document 1 has a structure in which oil oozes out on the surface, the oil oozed out on the surface may contaminate electronic components and the like. Moreover, since it has innumerable bubbles inside the heat conducting material, the flame retardancy is not sufficient.

  The heat dissipating composition disclosed in Patent Document 2 has low thermal conductivity. In addition, there is room for studying flame retardancy and insulation.

  The present invention has been made in view of the above circumstances, and without impairing the insulating properties, the heat conductive resin composition having excellent heat conductivity and heat resistance and flame retardancy, and heat conduction using the same It aims at providing a sex sheet.

  As a result of intensive studies to solve the above problems, the present inventors have found that a copolymer containing a conjugated diene monomer unit and a vinyl aromatic monomer unit, a polyphenylene ether resin and / or a modified polyphenylene ether resin, The present invention has found that the above-mentioned problems can be solved by using a thermally conductive resin composition comprising a rubber softener, a metal hydroxide, and a fluororesin and / or a fluororesin-modified product. It came to complete.

That is, the present invention is as follows.
[1]
(A) 0.9 to 10% by mass of a copolymer containing a conjugated diene monomer unit and a vinyl aromatic monomer unit;
(B) 0.1 to 10% by mass of polyphenylene ether resin and / or modified polyphenylene ether resin,
(C) 1 to 20% by mass of a rubber softener,
(D) 70 to 95% by mass of a metal hydroxide, and (E) 0.01 to 5% by mass of a fluororesin and / or a fluororesin-modified product, and
The heat conductive resin composition whose mass ratio ((A) / (B)) of the said (A) component and the said (B) component is 90 / 10-50 / 50.
[2]
The component (D) includes a first metal hydroxide having an average particle diameter of 20 μm or more and a second metal hydroxide having an average particle diameter of less than 20 μm, and the first metal hydroxide The heat conductive resin composition of [1], wherein the mass ratio of the second metal hydroxide is 100/1 to 100/80.
[3]
The heat conductive resin composition according to [1] or [2], wherein the Na ₂ O concentration in the component (D) is 0.2% by mass or less.
[4]
Furthermore, (F) Thermal conductivity as described in any one of [1] to [3], including at least one selected from the group consisting of a silane coupling agent, an aluminum coupling agent, and a titanate coupling agent. Resin composition.
[5]
The component (A) is a hydrogenated copolymer obtained by hydrogenating a copolymer containing a conjugated diene monomer unit and a vinyl aromatic monomer unit, and / or a conjugated diene monomer unit. The thermal conductive resin according to any one of the above [1] to [4], which is a modified hydrogenated copolymer obtained by introducing a functional group into a copolymer containing a vinyl aromatic monomer unit and adding hydrogen Composition.
[6]
The heat conductive resin composition according to any one of [1] to [5], wherein the content of the vinyl aromatic monomer unit in the component (A) is 30% by mass or more and 90% by mass or less.
[7]
The heat conductive resin composition according to any one of [1] to [6], wherein a hydrogenation rate of a double bond based on the conjugated diene monomer unit of the component (A) is 10% or more.
[8]
The said (A) component is a heat conductive resin composition as described in any one of said [1]-[7] containing the random copolymer containing a conjugated diene monomer unit and a vinyl aromatic monomer unit.
[9]
The heat conductive resin composition according to any one of [1] to [8], wherein the component (B) is dispersed in a matrix of the component (A).
[10]
The heat conductive sheet formed by forming the heat conductive resin composition in any one of said [1]-[9] in a sheet form.
[11]
(A) A step of obtaining a master batch by melt-kneading a copolymer containing a conjugated diene monomer unit and a vinyl aromatic monomer unit and (B) a polyphenylene ether resin and / or a modified polyphenylene ether resin. When,
The master batch and at least (C) a rubber softener, (D) a metal hydroxide, and (E) a fluororesin and / or a fluororesin-modified product are melt-kneaded to obtain a heat conductive resin composition. A process for producing a thermally conductive resin composition.

  ADVANTAGE OF THE INVENTION According to this invention, the heat conductive resin composition excellent in heat conductivity, heat resistance, and a flame retardance, and a heat conductive sheet can be provided, without impairing insulation.

4 is a TEM photograph of the thermally conductive resin composition of Example 2.

  Hereinafter, a mode for carrying out the present invention (hereinafter simply referred to as “the present embodiment”) will be described in detail. The following embodiments are examples for explaining the present invention, and are not intended to limit the present invention to the following contents. The present invention can be implemented with appropriate modifications within the scope of the gist thereof.

  The thermally conductive resin composition according to this embodiment includes (A) a copolymer containing 0.9 to 10% by mass of a conjugated diene monomer unit and a vinyl aromatic monomer unit, and (B) a polyphenylene ether resin. And / or 0.1 to 10% by mass of a modified polyphenylene ether resin, (C) 1 to 20% by mass of a softening agent for rubber, (D) 70 to 95% by mass of a metal hydroxide, (E) a fluororesin and / or The fluororesin-modified product is contained in an amount of 0.01 to 5% by mass, and the mass ratio ((A) / (B)) between the component (A) and the component (B) is 90/10 to 50/50.

  The thermally conductive resin composition of the present embodiment includes (A) a copolymer containing a conjugated diene monomer unit and a vinyl aromatic monomer unit. A monomer that can be used as a conjugated diene monomer unit is a diolefin having a pair of conjugated double bonds (two double bonds linked so as to be conjugated). Examples of the conjugated diene monomer include 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, and 2-methyl. Examples include -1,3-pentadiene and 1,3-hexadiene. Among these, 1,3-butadiene and 2-methyl-1,3-butadiene (isoprene) are preferably used from the viewpoints of polymerizability and physical properties. These conjugated diene monomers may be used alone or in combination of two or more.

  A monomer that can be used as a vinyl aromatic monomer unit refers to a compound having a vinyl group and an aromatic ring. Examples of the vinyl aromatic monomer include styrene, α-methylstyrene, p-methylstyrene, divinylbenzene, 1,1-diphenylethylene, N, N-dimethyl-p-aminoethylstyrene, and N, N- Examples include diethyl-p-aminoethylstyrene. Among these, styrene, α-methylstyrene, and divinylbenzene are preferably used from the viewpoints of polymerizability and physical properties. These vinyl aromatic monomers may be used alone or in combination of two or more.

  The component (A) is not particularly limited as long as it is a copolymer obtained by copolymerizing at least a conjugated diene monomer and a vinyl aromatic monomer, and a known one can also be used. Further, a polymer obtained by adding hydrogen to a copolymer containing the conjugated diene monomer unit and the vinyl aromatic monomer unit (hereinafter referred to as “hydrogenated copolymer”); A polymer obtained by introducing a functional group into a copolymer containing a monomer unit and a vinyl aromatic monomer unit (hereinafter referred to as a “modified copolymer”); and the conjugated diene monomer unit and vinyl. A polymer obtained by adding hydrogen to a copolymer having a functional group introduced into a copolymer containing an aromatic monomer unit (hereinafter referred to as “modified hydrogenated copolymer”) may be used. Among these, a hydrogenated copolymer and / or a modified hydrogenated copolymer are preferable from the viewpoint of processability, heat resistance and compatibility, and from the viewpoint that a large amount of metal hydroxide can be blended. Specifically, styrene elastomer such as styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), styrene-butadiene-butylene-styrene block copolymer (SBBS). Styrene-ethylene-butadiene-styrene block copolymer (SEBS), styrene-ethylene-propylene-styrene block copolymer (SEPS), styrene- (ethylene-ethylene / propylene) -styrene block copolymer (SEEPS), etc. Examples thereof include a modified copolymer and a modified hydrogenated copolymer obtained by introducing a functional group into a hydrogenated copolymer, a styrene-based elastomer, or a hydrogenated copolymer. Thus, the component (A) is preferably a hydrogenated copolymer and / or a modified hydrogenated copolymer from the viewpoint that a large amount of metal hydroxide can be blended, and a random copolymer such as styrene-butadiene. A hydrogenated copolymer containing a polymer and / or a modified hydrogenated copolymer is more preferable. The hydrogenated copolymer and the modified hydrogenated copolymer will be described later.

  (A) Content of the vinyl aromatic monomer unit in a component becomes like this. Preferably it is 30-90 mass%, More preferably, it is 45-90 mass%, More preferably, it is 45-86 mass%. If the content of the vinyl aromatic monomer unit is within the above range, more excellent flexibility can be obtained. In addition, content of a vinyl aromatic monomer unit can be measured using a nuclear magnetic resonance apparatus (NMR).

  In the component (A), the content of the polymer block composed of vinyl aromatic monomer units is preferably 40% by mass or less. If the content of the polymer block composed of vinyl aromatic monomer units is 40% by mass or less, more excellent flexibility and blocking resistance can be obtained.

  Moreover, when it is desired to further improve the blocking resistance of the thermally conductive resin composition, the content of the polymer block composed of vinyl aromatic monomer units in the component (A) is 10 to 40% by mass. It is preferably 13 to 37% by mass, more preferably 15 to 35% by mass.

  Moreover, when it is desired to further improve the flexibility of the heat conductive resin composition, the content of the polymer block composed of vinyl aromatic monomer units in the component (A) may be less than 10% by mass. Preferably, it is 8 mass% or less, and it is preferable that it is 5 mass% or less.

  The content of the polymer block composed of vinyl aromatic monomer units in the component (A) is determined by a method of oxidatively decomposing a hydrogenated copolymer with t-butyl hydroperoxide using osmium tetroxide as a catalyst (IM). (The method described in KOLTHOFF, et al., J. Polym. Soi. 1, 429 (1946)). The polymer component consisting of about 30 or less vinyl aromatic monomer units is excluded) and can be determined from the following formula:

  Content (% by mass) of polymer block composed of vinyl aromatic monomer units = {(Vinyl aromatic monomer in copolymer containing conjugated diene monomer unit and vinyl aromatic monomer unit Mass of polymer block consisting of units) / (mass of copolymer containing conjugated diene monomer unit and vinyl aromatic monomer unit)} × 100

  The block ratio of the vinyl aromatic monomer unit in the component (A) is preferably 40% by mass or less, more preferably 20% by mass or less, and still more preferably 18% by mass. If the block ratio is within the above range, further excellent flexibility can be obtained. In addition, a block rate here means the ratio of the polymer block amount which consists of a vinyl aromatic monomer unit with respect to the total vinyl aromatic monomer unit amount contained in (A) component.

  Furthermore, it is preferable that (A) component contains 5 mass% or more of vinyl aromatic monomer units other than the polymer block which consists of a vinyl aromatic monomer unit. That is, the average polymerization degree of the component (A) is less than 30, and the content of the vinyl aromatic monomer polymer component that is not regarded as a polymer block composed of vinyl aromatic monomer units is 5% by mass or more. Is preferred. If the content of the vinyl aromatic monomer unit other than the polymer block composed of the vinyl aromatic monomer unit is 5% by mass or more, the heat resistance of the component (A) can be improved. Furthermore, since crystallization of portions other than the polymer block composed of vinyl aromatic monomer units can be inhibited, excellent flexibility can be imparted to the thermally conductive resin composition. And since it can suppress crystallization of (A) component, it becomes possible to mix | blend a filler in large quantities.

(A) The weight average molecular weight (Mw) of the copolymer containing a conjugated diene monomer unit and a vinyl aromatic monomer unit is preferably 5 × 10 ^{4 to} 100 × 10 ⁴ , more preferably 8 × 10. ^{It is 4} to 80 × 10 ⁴ , more preferably 9 × 10 ⁴ to 30 × 10 ⁴ . When the content of the polymer block composed of vinyl aromatic monomer units is 10 to 40% by mass, the weight average molecular weight is preferably 10 × 10 ⁴ to 50 × 10 ⁴ , more preferably 13 × 10 ⁴ to 40 × 10 ^4, more preferably from ^{15 × 10 4 ~30 × 10 4} . If the weight average molecular weight is 5 × 10 ⁴ or more, good toughness is obtained, and if it is 100 × 10 ⁴ or less, good flexibility is obtained. Furthermore, if the weight average molecular weight is in the range of 5 × 10 ^{4 to} 100 × 10 ⁴ , the content of low molecular weight components is small, so that volatile components can be suppressed.

  (A) The molecular weight distribution (Mw / Mn) of the copolymer containing a conjugated diene monomer unit and a vinyl aromatic monomer unit is preferably 1.01 to 8.0, and more preferably 1.1 to 8.0. 6.0, more preferably 1.1 to 5.0. If the molecular weight distribution is within the above range, good moldability can be obtained. In addition, the shape of the molecular weight distribution of the copolymer containing the (A) conjugated diene monomer unit and the vinyl aromatic monomer unit measured by GPC is not particularly limited, and is a polymodal having two or more peaks. It may have a molecular weight distribution or may have a monomodal molecular weight distribution with one peak.

  (A) Weight average molecular weight (Mw) and molecular weight distribution [Mw / Mn; weight average molecular weight (Mw) number average molecular weight (Mn) of a copolymer containing a conjugated diene monomer unit and a vinyl aromatic monomer unit ))] Is a calibration curve (created using the standard molecular weight of standard polystyrene) obtained by measuring the molecular weight of the peak of chromatogram measured by gel permeation chromatography (GPC) from the measurement of commercially available standard polystyrene. Can be obtained.

  The hydrogenated copolymer and the modified hydrogenated copolymer used as the component (A) preferably have a hydrogenation rate of 10% or more, more preferably 75% or more, and still more preferably 85% or more. By setting the hydrogenation rate to 10% or more, it is possible to suppress a decrease in flexibility, strength, and elongation due to thermal deterioration (oxidation deterioration). Furthermore, if the hydrogenation rate is 85% or more, more preferably 90% or more, and still more preferably 95% or more, more excellent heat resistance can be obtained. Further, when the hydrogenation rate is 75% or more, more preferably 85% or more, and still more preferably 90% or more, more excellent weather resistance can be obtained. In the case where the copolymer containing the (A) conjugated diene monomer unit and the vinyl aromatic monomer unit is subjected to a crosslinking reaction, the hydrogenation rate is 98% or less from the viewpoint of crosslinking density and physical properties. Preferably, it is 95% or less, more preferably 90% or less.

  Here, the hydrogenation rate refers to the hydrogenation rate of double bonds based on the conjugated diene monomer unit before adding hydrogen of each of the hydrogenated copolymer and the modified hydrogenated copolymer. That is, a copolymer containing a conjugated diene monomer unit before addition of hydrogen and a vinyl aromatic monomer unit (hereinafter referred to as “pre-hydrogenation copolymer”), and hydrogen are added. A conjugated diene possessed by a functional group introduced into a copolymer containing a previous conjugated diene monomer unit and a vinyl aromatic monomer unit (hereinafter referred to as a “modified hydrogenated copolymer”). The ratio of the hydrogenated double bond of each of the hydrogenated copolymer and the modified hydrogenated copolymer to the double bond of the monomer unit. The hydrogenation rate can be measured using a nuclear magnetic resonance apparatus (NMR).

  The hydrogenation rate of the aromatic double bond based on the vinyl aromatic monomer unit in the hydrogenated copolymer and the modified hydrogenated copolymer is not particularly limited, preferably 50% or less, more preferably 30% or less, more preferably 20% or less. The hydrogenation rate of the aromatic double bond is determined based on the hydrogenated copolymer and the modified hydrogenated copolymer with respect to the aromatic double bond contained in each of the copolymer before hydrogenation and the copolymer before modification hydrogenation. Refers to the percentage of each hydrogenated double bond.

(A) The copolymer containing a conjugated diene monomer unit and a vinyl aromatic monomer unit preferably has at least one structure selected from the following formulas (A) to (E). Moreover, the mixture which contains the following structure in multiple types and arbitrary ratios may be sufficient.
(I) B
(B) B-A
(C) B-A-B
(D) (BA) _m -Z
(E) (BA) _n -Z-A _p

  In the formulas (A) to (E), B represents a random copolymer block of conjugated diene monomer units and vinyl aromatic monomer units (hereinafter referred to as “block B”), and A represents vinyl. This represents a polymer block composed of aromatic monomer units (hereinafter referred to as “block A”). m represents an integer of 2 or more, and n and p each represents an integer of 1 or more. Z represents a coupling agent residue. Here, the coupling residue refers to a plurality of copolymers of a conjugated diene monomer unit and a vinyl aromatic monomer unit between block AA, block BB, or block AB. It means a residue after coupling of a coupling agent composed of a polyhalogen compound, an acid ester, or the like used for bonding between them. The coupling residue Z is, for example, m-valent in the formula (d) and n + p-valent in the formula (e).

  In the above formulas (a) to (e), the vinyl aromatic monomer units in the block B may be distributed uniformly or in a tapered shape. That is, the arrangement of the vinyl aromatic monomer unit may be any of a head-head structure, a tail-tail structure, and a head-tail structure. In the block B, a plurality of portions where the vinyl aromatic monomer units are uniformly distributed and / or a portion where the units are distributed in a tapered shape may exist. m should just be an integer greater than or equal to 2, Preferably it is an integer of 2-10. n and p should just be an integer greater than or equal to 1, respectively, Preferably it is an integer of 1-10. By making the block B a random structure of a conjugated diene monomer unit and a vinyl aromatic monomer unit, the crystal part in the component (A) can be reduced or eliminated as much as possible. A large amount can be mixed.

  The modified copolymer is obtained by introducing a functional group into a copolymer containing a conjugated diene monomer unit and a vinyl aromatic monomer unit. The modified hydrogenated copolymer is obtained by hydrogenating the above modified copolymer. Examples of the functional group include a hydroxyl group, a carboxyl group, a carbonyl group, a thiocarbonyl group, an acid halide group, an acid anhydride group, a carboxylic acid group, a thiocarboxylic acid group, an aldehyde group, a thioaldehyde group, a carboxylic acid ester group, Epoxy group, thioepoxy group, sulfide group, isocyanate group, isothiocyanate group, amide group, sulfonic acid group, sulfonic acid ester group, phosphoric acid group, phosphoric acid ester group, amino group, imino group, nitrile group, pyridyl group, quinoline Group, halogenated silicon group, silanol group, alkoxysilane group, halogenated tin group, alkoxytin group, and phenyltin group. Among these, from the viewpoint of compatibility and adhesiveness, preferably a hydroxyl group, an amino group, an epoxy group, a silanol group, a carboxyl group, an acid anhydride group, a carboxylic acid group, and an alkoxysilane group, more preferably a hydroxyl group, an amino group. Groups, epoxy groups, and acid anhydride groups. The functional group contained in the modified hydrogenated copolymer preferably has at least one functional group selected from the above functional group group.

  Examples of the modified copolymer include maleic anhydride-modified styrene-butadiene-styrene block copolymer, epoxy-modified styrene-butadiene-styrene block copolymer, amino-modified styrene-butadiene-styrene block copolymer, and carboxy-modified styrene. -Butadiene-styrene block copolymer, maleic anhydride-modified styrene-isoprene-styrene block copolymer, epoxy-modified styrene-isoprene-styrene block copolymer, amino-modified styrene-isoprene-styrene block copolymer, carboxy-modified styrene -Isoprene-styrene block copolymer, maleic anhydride-modified styrene-butadiene random copolymer, amino-modified styrene-butadiene random copolymer, epoxy-modified styrene-butadiene copolymer Dam copolymers, and carboxy-modified styrene - random copolymers of butadiene and the like. Among these, from the viewpoint of compatibility and adhesiveness, maleic anhydride-modified styrene-butadiene-styrene block copolymer, maleic anhydride-modified styrene-isoprene-styrene block copolymer, maleic anhydride-modified styrene-butadiene. Random copolymers are preferred.

  Examples of the modified hydrogenated copolymer include maleic anhydride-modified styrene- (ethylene / butylene) -styrene copolymer), amino-modified styrene- (ethylene / butylene) -styrene copolymer, and epoxy-modified styrene- (ethylene. / Butylene) -styrene copolymer, carboxy-modified styrene- (ethylene / butylene) -styrene copolymer, maleic anhydride-modified styrene-butadiene-butylene-styrene block copolymer), amino-modified styrene-butadiene-butylene-styrene Block copolymer, epoxy-modified styrene-butadiene-butylene-styrene block copolymer, carboxy-modified styrene-butadiene-butylene-styrene block copolymer, maleic anhydride modified styrene-ethylene-propylene-styrene block copolymer, amino Modified styrene-ethylene-propylene-styrene block copolymer, epoxy-modified styrene-ethylene-propylene-styrene block copolymer, carboxy-modified styrene-ethylene-propylene-styrene block copolymer, maleic anhydride modified styrene- (ethylene- Ethylene / propylene) -styrene block copolymer, epoxy-modified styrene- (ethylene-ethylene / propylene) -styrene block copolymer, amino-modified styrene- (ethylene-ethylene / propylene) -styrene block copolymer, carboxy-modified styrene -(Ethylene-ethylene / propylene) styrene block copolymer, maleic anhydride-modified styrene-butadiene random copolymer hydrogenated product, amino-modified styrene-butadiene random copolymer Containing additives, epoxy-modified styrene - hydrogenated product of a random copolymer of butadiene, and carboxy-modified styrene - hydrogenated product of random copolymers of butadiene and the like. Among these, from the viewpoint of compatibility, adhesiveness, and processability, maleic anhydride-modified styrene- (ethylene / butylene) -styrene copolymer), maleic anhydride-modified styrene-ethylene-propylene-styrene block copolymer A hydrogenated product of a random copolymer of maleic anhydride-modified styrene-butadiene is preferred.

  The modified hydrogenated copolymer contains at least one functional group selected from the above functional group group at the end of polymerization of the copolymer containing a conjugated diene monomer unit and a vinyl aromatic monomer unit. It can be obtained by reacting a modifier. For example, a modifying agent containing a functional group is added to a living terminal of a copolymer containing a conjugated diene monomer unit and a vinyl aromatic monomer unit obtained using an organolithium compound as a polymerization catalyst, and a modified water is added. After obtaining the copolymer before addition, a modified hydrogenated copolymer can be obtained by adding hydrogen.

  As another method for obtaining a modified hydrogenated copolymer, a hydrogenated copolymer obtained by reacting an organic alkali metal compound such as an organolithium compound (metalation reaction) with the hydrogenated copolymer to add an organic alkali metal. For example, a method obtained by adding a modifier containing a functional group to the coalescence reaction can be used.

  The component (A) preferably has no crystallization peak in the temperature range of −50 to 100 ° C. in the differential scanning calorimetry (DSC method). Here, the absence of a crystallization peak in the temperature range of −50 to 100 ° C. means that no peak due to crystallization appears in this temperature range, or even when a peak due to crystallization is observed. This refers to the case where the crystallization peak heat quantity in crystallization is less than 3 J / g. Thus, it becomes possible to mix | blend a filler in a larger quantity by making the crystal | crystallization part of a hydrogenated copolymer and / or a modification | denaturation hydrogenated copolymer as small as possible, or making a crystal part not exist. That is, since the filler cannot enter the crystal portion, the smaller the crystal portion, the larger the amount of filler can be.

  It is preferable that at least one peak of loss tangent (tan δ) in the dynamic viscoelastic spectrum of the component (A) exists at −30 to 80 ° C., more preferably −20 to 70 ° C., and still more preferably −20. ~ 50 ° C. When at least one tan δ peak exists in the range of −30 to 80 ° C., the flexibility and toughness are excellent. In addition, the peak of tan δ existing in the range of −30 to 80 ° C. is a peak due to the block B. The loss tangent (tan δ) in the dynamic viscoelastic spectrum can be measured by a dynamic viscoelasticity measuring apparatus.

  The microstructure (ratio of cis, trans, vinyl bond) of the conjugated diene part of the component (A) is not particularly limited, and can be arbitrarily changed by using a polar compound or the like described later.

  In general, when 1,3-butadiene is used as the conjugated diene monomer, the 1,2-vinyl bond content is preferably 5 to 80%, more preferably 10 to 100% of the conjugated diene moiety. ~ 60%. When isoprene is used as the conjugated diene monomer, or when 1,3-butadiene and isoprene are used in combination, the total content of 1,2-vinyl bonds and 3,4-vinyl bonds is preferably 3 to 75. %, More preferably 5 to 60%. The total content of 1,2-vinyl bond and 3,4-vinyl bond (however, when 1,3-butadiene is used as the conjugated diene monomer, the content of 1,2-vinyl bond) Hereinafter referred to as “vinyl bond content”. The vinyl bond content based on the conjugated diene monomer unit can be measured using a nuclear magnetic resonance apparatus (NMR).

  The difference between the maximum value and the minimum value of the vinyl bond content in each molecular chain in the component (A) is preferably less than 10%, more preferably 8% or less, and even more preferably 6% or less. The vinyl bonds in the component (A) may be distributed uniformly or in a tapered shape. That is, the vinyl bond (double bond) sequence generated by the polymerization of the conjugated diene monomer may be any of a head-head structure, a tail-tail structure, and a head-tail structure. The difference between the maximum value and the minimum value of the vinyl bond content is determined by the polymerization conditions, that is, the type of vinyl content modifier, the added amount of the vinyl content modifier, and the polymerization temperature of the conjugated diene monomer. Maximum and minimum vinyl bond content determined.

  The difference between the maximum value and the minimum value of the vinyl bond content in each molecular chain in the component (A) is, for example, during polymerization of the conjugated diene monomer or between the conjugated diene monomer and the vinyl aromatic monomer. It can control by the superposition | polymerization temperature at the time of superposition | polymerization. Specifically, in the case where the kind and addition amount of a vinyl amount adjusting agent such as a tertiary amine compound and an ether compound are constant, the vinyl bond content incorporated in each molecular chain during polymerization is determined by the polymerization temperature. For example, when polymerized isothermally, a polymer in which vinyl bonds are uniformly dispersed in each molecular chain is obtained. On the other hand, in the polymerization carried out at a high temperature, a copolymer having a high vinyl bond content is obtained at the beginning of the polymerization reaction, that is, when the polymerization temperature is low, and the latter half of the polymerization reaction, that is, the polymerization temperature is increased. Polymers having a difference in vinyl bond content in each molecular chain are obtained, such that a copolymer having a low vinyl bond content is obtained at high temperatures. By adding hydrogen to a copolymer containing a conjugated diene monomer unit and a vinyl aromatic monomer unit having a structure in which the vinyl bond content in each molecular chain is different, vinyl in each molecular chain is added. Hydrogenated copolymers and modified hydrogenated copolymers having different bond contents are obtained.

  A copolymer containing a conjugated diene monomer unit and a vinyl aromatic monomer unit can be obtained, for example, by anion living polymerization using an initiator such as an organic alkali metal compound in a hydrocarbon solvent. The hydrocarbon solvent is not particularly limited, and examples thereof include aliphatic hydrocarbons such as n-butane, isobutane, n-pentane, n-hexane, n-heptane, and n-octane, cyclohexane, cycloheptane, and methylcycloheptane. And alicyclic hydrocarbons such as benzene, toluene, xylene and ethylbenzene.

  The initiator is not particularly limited as long as it is an organic alkali metal compound generally known to have anionic polymerization activity with respect to a conjugated diene monomer and a vinyl aromatic monomer. Examples thereof include an aliphatic hydrocarbon alkali metal compound having 1 to 20 carbon atoms, an aromatic hydrocarbon alkali metal compound having 1 to 20 carbon atoms, and an organic amino alkali metal compound having 1 to 20 carbon atoms. Examples of the alkali metal contained in the initiator include lithium, sodium, and potassium. In addition, 1 type, or 2 or more types of alkali metals may be contained in 1 molecule.

  Specifically, n-propyllithium, n-butyllithium, sec-butyllithium, tert-butyllithium, n-pentyllithium, n-hexyllithium, benzyllithium, phenyllithium, tolyllithium, diisopropenylbenzene and sec -Reaction product of -butyllithium, further reaction product of divinylbenzene, sec-butyllithium and a small amount of 1,3-butadiene. Further, 1- (t-butoxy) propyllithium disclosed in US Pat. No. 5,708,092 and a lithium compound in which 1 to several molecules of isoprene monomer are inserted to improve its solubility, British Patent 2 Siloxy group-containing alkyllithium such as 1- (t-butyldimethylsiloxy) hexyllithium disclosed in US Pat. No. 5,241,239, amino group-containing alkyl disclosed in US Pat. No. 5,527,753 Aminolithiums such as lithium, diisopropylamid lithium and hexamethyldisilazide lithium can also be used.

  When an organic alkali metal compound is used as a polymerization initiator and a conjugated diene monomer and a vinyl aromatic monomer are copolymerized, a vinyl bond (1,2 bond resulting from the conjugated diene monomer incorporated in the copolymer) Alternatively, a tertiary amine compound or an ether compound is added as an adjusting agent in order to adjust the content of 3 or 4 bonds) or to adjust the random copolymerizability between the conjugated diene monomer and the vinyl aromatic monomer. be able to.

  The method of copolymerizing a conjugated diene monomer and a vinyl aromatic monomer using an organic alkali metal compound as a polymerization initiator may be batch polymerization, continuous polymerization, or a combination thereof. . From the viewpoint of adjusting the molecular weight distribution to a preferable appropriate range, a continuous polymerization method is preferable. Although superposition | polymerization temperature is not specifically limited, Usually, it is 0-180 degreeC, Preferably it is 30-150 degreeC. The time required for the polymerization varies depending on the conditions, but is usually within 48 hours, preferably 0.1 to 10 hours. Moreover, it is preferable to superpose | polymerize in inert gas atmosphere, such as nitrogen gas. The polymerization pressure is not particularly limited as long as the polymerization pressure is in a range sufficient to maintain the monomer and solvent in a liquid phase within the above polymerization temperature range.

  At the end of the polymerization, the coupling reaction may be performed by adding a necessary amount of a coupling agent having two or more functional groups. It does not specifically limit as a coupling agent more than bifunctional group, A well-known thing can be used. Examples of the bifunctional coupling agent include dihalogen compounds such as dimethyldichlorosilane and dimethyldibromosilane, and acid esters such as methyl benzoate, ethyl benzoate, phenyl benzoate, and phthalates.

Examples of the polyfunctional coupling agent having three or more functional groups include polyhydric alcohols having three or more valences, polyepoxy compounds such as epoxidized soybean oil and diglycidyl bisphenol A, the formula R _(4-n) SiX _n (however, , R is a hydrocarbon group having 1 to 20 carbon atoms, X is a halogen, and n is an integer of 3 or 4, and a tin halide compound. Examples of the silicon halide compound include methylsilyl trichloride, t-butylsilyl trichloride, silicon tetrachloride, and bromides thereof. Examples of the tin halide compound include polyvalent halogen compounds such as methyltin trichloride, t-butyltin trichloride, and tin tetrachloride. Moreover, dimethyl carbonate, diethyl carbonate, etc. can also be used.

  In this embodiment, as a modifier used to obtain a modified hydrogenated copolymer having at least one functional group selected from the group consisting of a hydroxyl group, an amino group, an epoxy group, a silanol group, and an alkoxysilane group. For example, the denaturant described in Japanese Patent Publication No. 4-39495 is mentioned.

The hydrogenation catalyst used for producing the hydrogenated copolymer and the modified hydrogenated copolymer is not particularly limited, and for example, the catalysts shown in the following (a) to (c) are used.
(A) A supported heterogeneous hydrogenation catalyst in which a metal such as Ni, Pt, Pd, or Ru is supported on carbon, silica, alumina, diatomaceous earth, or the like.
(B) A so-called Ziegler type hydrogenation catalyst using an organic acid salt such as Ni, Co, Fe, Cr or a transition metal salt such as acetylacetone salt and a reducing agent such as organic aluminum.
(C) Homogeneous hydrogenation catalysts such as so-called organometallic complexes such as organometallic compounds such as Ti, Ru, Rh and Zr.

  Specific examples of the hydrogenation catalyst include Japanese Patent Publication No. 42-8704, Japanese Patent Publication No. 43-6636, Japanese Patent Publication No. 63-4841, Japanese Patent Publication No. 1-337970, Japanese Patent Publication No. 1-53851, The hydrogenation catalyst described in Japanese Utility Model Publication No. 2-9041 can be used. Preferred hydrogenation catalysts include mixtures with titanocene compounds and / or reducing organometallic compounds. Examples of the titanocene compound include compounds described in JP-A-8-109219, and specific examples thereof (substitution) such as biscyclopentadienyl titanium dichloride and monopentamethylcyclopentadienyl titanium trichloride. Examples thereof include compounds having at least one ligand having a cyclopentadienyl structure, an indenyl structure, and a fluorenyl structure. Examples of the reducing organometallic compound include organoalkali metal compounds such as organolithium, organomagnesium compounds, organoaluminum compounds, organoboron compounds, and organozinc compounds.

  The reaction temperature of the hydrogenation reaction is usually 0 to 200 ° C, preferably 30 to 150 ° C. The pressure of hydrogen used for the hydrogenation reaction is preferably 0.1 to 15 MPa, more preferably 0.2 to 10 MPa, and still more preferably 0.3 to 5 MPa. The reaction time of the hydrogenation reaction is usually 3 minutes to 10 hours, preferably 10 minutes to 5 hours. Note that the hydrogenation reaction can be any of a batch process, a continuous process, or a combination thereof.

  In the reaction solution after completion of the hydrogenation reaction, the catalyst residue can be removed if necessary, and the hydrogenated copolymer and the modified hydrogenated copolymer can be separated from the solvent. Examples of the separation method include, for example, a polar solvent that is a poor solvent for a hydrogenated copolymer such as acetone or alcohol and a modified hydrogenated copolymer in a solution of the hydrogenated copolymer and the modified hydrogenated copolymer. A method of precipitating and recovering the hydrogenated copolymer and the modified hydrogenated copolymer, or adding a solution of the hydrogenated copolymer and the modified hydrogenated copolymer into hot water with stirring, and steaming. There are a method of removing the solvent by stripping and recovering, or a method of distilling off the solvent by directly heating a solution of the hydrogenated copolymer and the modified hydrogenated copolymer.

  Stabilizers such as various phenol stabilizers, phosphorus stabilizers, sulfur stabilizers and amine stabilizers may be added to the hydrogenated copolymer and the modified hydrogenated copolymer.

  Examples of the phenolic stabilizer include 2,6-di-t-butyl-4-methylphenol, n-octadecyl-3- (4′-hydroxy-3 ′, 5′-di-t-butylphenyl) propionate, Tetrakis- [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane], tris- (3,5-di-t-butyl-4-hydroxybenzyl) isocyanate Nurate, 4,4′-butylidene-bis- (3-methyl-6-tert-butylphenol), 3,9-bis [2- {3- (3-tert-butyl-4-hydroxy-5-methylphenyl) Propionyloxy} -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane, triethylene glycol-bis [3- (3-tert-butyl-5-methyl-4) -Hydroxyphenyl) propionate], 1,6-hexanediol-bis- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 2,4-bis- (n-octylthio)- 6- (4-Hydroxy-3,5-di-t-butylanilino) 1,3,5-triazine, pentaerythrityl tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate 2,2-thio-diethylenebis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], N, N′-hexamethylenebis (3,5-di-t-butyl -4-hydroxy-hydrocinnamamide), 3,5-di-t-butyl-4-hydroxybenzylphosphonate-diethyl ester, 1,3,5-trimethyl-2,4,6-tris (3,5- Di-t-butyl-4-hydroxybenzyl) benzene, a mixture of bis (3,5-di-t-butyl-4-hydroxybenzylphosphonate ethyl) calcium and polyethylene wax (50%), octylated diphenylamine, 2, 4-bis [(octylthio) methyl] -o-cresol, isooctyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, butyric acid, 3,3-bis (3-t-butyl -4-hydroxyphenyl) ethylene ester, 1,1,3-tris- (2-methyl-4-hydroxy-5-t-butylphenyl) butane, 1,3,5-tris (4-t-butyl-3) -Hydroxy-2,6-dimethylbenzyl) isocyanurate, 2-t-butyl-6- (3'-t-butyl-5'-methyl-2'-hydroxybenzyl) -4-methylphenyl acrylate, and 2- [1- (2-hydroxy-3,5-di -t- pentylphenyl) - ethyl] -4,6-di -t- pentylphenyl acrylate.

  Phosphorus stabilizers include tris (nonylphenyl) phosphite, tris (mixed mono- and di-nonylphenyl) phosphite, diphenyl mono (2-ethylhexyl) phosphite, diphenyl monotridecyl phosphite, diphenyl isodecyl -Phosphite, diphenyl-isooctyl phosphite, diphenylnonylphenyl phosphite, triphenyl phosphite, tris (tridecyl) phosphite, triisodecyl phosphite, tris (2,4-di-t-butylphenyl) phosphite Tetraphenyldipropylene glycol diphosphite, tetraphenyltetra (tridecyl) pentaerythritol tetraphosphite, 1,1,3-tris (2-methyl-4-di-tridecylphosphite-5 -Butylphenyl) butane, 4,4'-butylidenebis (3-methyl-6-tert-butyl-di-tridecylphosphite), 2,2'-methylenebis (4,6-di-tert-butylphenol) octylphos Phyto, 4,4′-isopropylidene-diphenol alkyl (C12-C15) phosphite, cyclic neopentanetetrayl bis (2,4-t-butylphenyl phosphite), cyclic neopentanetetrayl bis (2,6 -Di-t-butyl-4-methylphenyl phosphite), cyclic neopentanetetrayl bis (nonylphenyl phosphite), cyclic neopentanetetrayl bis (octadecyl phosphite), bis (nonylphenyl) pentaerythritol diphosphite Bis (2,6-di-t-butyl-4-methylphenyl) Intererythritol diphosphite, pentaerythritol diphosphite mixture, dibutyl hydrogen phosphite, distearyl pentaerythritol diphosphite, hydrogenated bisphenol A pentaerythritol phosphite polymer, tetrakis (2,4-di-t- Butylphenyl) -4,4′-biphenylene-diphosphonate, bis [2,4-bis (1,1-dimethylethyl) -6-methylphenyl] ethyl ester phosphite, and 6-[(3-t- Butyl-4-hydroxy-5-methyl) propoxy] -2,4,8,10-tetra-t-butyldibenz [d, f] [1,3,2] -dioxaphosphine.

  Sulfur stabilizers include dilauryl thiodipropionate, distearyl thiodipropionate, dimyristyl thiodipropionate, ditridecyl-3,3′-thiodipropionate, pentaerythritol tetrakis- (3-dodecylthio). Propionate), dilauryl thiodipropionate, and tetrakis [methylene-3- (dodecylthio) propionate] methane.

  Examples of the amine stabilizer include phenyl-α-naphthylamine, 4,4′-dimethoxydiphenylamine, 4,4′-bis (α, α-dimethylbenzyl) diphenylamine, and 4-isopropoxydiphenylamine.

  Content of the said (A) component is 0.9-10 mass% with respect to the heat conductive resin composition whole quantity of this embodiment, Preferably it is 2-10 mass%, More preferably, it is 4-10 mass. %. When content of (A) component exceeds 10 mass%, it exists in the tendency for heat conductivity and a flame retardance to fall. Further, when the content of the component (A) is less than 0.9% by mass, sufficient moldability cannot be obtained.

  The heat conductive resin composition of this embodiment contains (B) polyphenylene ether resin. Examples of (B) polyphenylene ether resins include poly (2,6-dimethyl-1,4-phenylene ether), poly (2-methyl-6-ethyl-1,4-phenylene ether), and poly (2-methyl). -6-phenyl-1,4-phenylene ether) and poly (2,6-dichloro-1,4-phenylene ether). Further, a copolymer of 2,6-dimethylphenol and other phenols (for example, a copolymer of 2,3,6-trimethylphenol as described in JP-B-52-17880, 2- A polyphenylene ether copolymer such as a copolymer with methyl-6-butylphenol can also be used. Among these, from the viewpoint of compatibility, poly (2,6-dimethyl-1,4-phenylene ether), a copolymer of 2,6-dimethylphenol and 2,3,6-trimethylphenol, or these Mixtures are preferred.

  The manufacturing method of polyphenylene ether resin is not specifically limited, A well-known method can be used. For example, U.S. Pat. No. 3,306,874, U.S. Pat. No. 3,306,875, U.S. Pat. No. 3,257,357 and U.S. Pat. No. 3,257,358, JP-A-50-51197, JP-B-52-17880. And a production method described in JP-B 63-152628.

  The component (B) may be a modified polyphenylene ether resin in which all or part of the component is modified. The modified polyphenylene ether resin as used herein includes at least one carbon-carbon double bond or triple bond and at least one carboxylic acid group, acid anhydride group, amino group, hydroxyl group or glycidyl group in the molecular structure. A polyphenylene ether resin modified with at least one modifying compound.

  The modification reaction of the polyphenylene ether resin is not particularly limited, and examples thereof include the methods shown in the following (d) to (f).

(D) A method in which the polyphenylene ether resin is reacted with the modifying compound at a temperature in the range of 100 ° C. or higher and lower than the glass transition temperature of the polyphenylene ether resin without melting the polyphenylene ether resin.
(E) A method in which a polyphenylene ether resin is melt kneaded and reacted with a modifying compound at a temperature in the range of the glass transition temperature of the polyphenylene ether resin to 360 ° C. or less.
(F) A method of reacting a polyphenylene ether resin with a modifying compound in a solution at a temperature lower than the glass transition temperature of the polyphenylene ether resin.

  The modification reaction can be performed in the presence or absence of a radical initiator. Among these, the method (d) or (e) is preferable from the viewpoints of workability and handling properties after completion of the reaction.

  Examples of the modifying compound having at least one carbon-carbon double bond and a carboxylic acid group or an acid anhydride group in the molecular structure include maleic acid, fumaric acid, chloromaleic acid, cis-4-cyclohexene-1,2 -Dicarboxylic acid, these acid anhydrides, etc. are mentioned. Among these, from the viewpoint of compatibility, fumaric acid, maleic acid, and maleic anhydride are preferable, and fumaric acid and maleic anhydride are more preferable. Further, a compound in which one or two of the two carboxyl groups of the unsaturated dicarboxylic acid is an ester can also be used.

  Examples of the modified compound having at least one carbon-carbon double bond and glycidyl group in the molecular structure include allyl glycidyl ether, glycidyl acrylate, glycidyl methacrylate, and epoxidized natural oil. Among these, glycidyl acrylate and glycidyl methacrylate are preferable.

Examples of the modified compound having at least one carbon-carbon double bond and a hydroxyl group in the molecular structure include general formulas C _n such as allyl alcohol, 4-penten-1-ol, 1,4-pentadien-3-ol and the like. Unsaturated alcohol represented by H _2n-3 OH (n is a positive integer), general formula C _n H _2n-5 OH, C _n H _2n-7 OH (n is a positive integer) Alcohol etc. are mentioned.

  The various modifying compounds may be used alone or in combination of two or more.

  The amount of the modifying compound added when producing the modified polyphenylene ether resin is preferably 0.1 to 10 parts by mass, more preferably 0.3 to 5 parts by mass with respect to 100 parts by mass of the polyphenylene ether resin. preferable.

  The amount of the radical initiator in producing the modified polyphenylene ether resin using the radical initiator is preferably 0.001 to 1 part by mass with respect to 100 parts by mass of the polyphenylene ether resin.

  The addition rate of the modifying compound to the modified polyphenylene ether resin is preferably 0.01 to 5% by mass, more preferably 0.1 to 3% by mass. In the modified polyphenylene ether resin, the unreacted modified compound and / or polymer of the modified compound may remain if the amount is less than 1% by mass.

  Although the number average molecular weight of (B) component is not specifically limited, From a heat resistant and workable viewpoint, it is preferable that it is 1000 or more, It is more preferable that it is 1500-50000, It is further that it is 1500-30000. preferable. Here, the number average molecular weight of the component (B) is a polystyrene-reduced number average molecular weight measured using GPC.

  The reduced viscosity ηsp / C (0.5 g / dL, chloroform solution, measured at 30 ° C.) of the component (B) is preferably in the range of 0.20 to 0.70 dL / g from the viewpoint of workability. More preferably, it is in the range of 30 to 0.60 dl / g.

  (B) The compounding quantity of a component is 0.1-10 mass% with respect to the heat conductive resin composition whole quantity of this embodiment, Preferably it is 1-10 mass%, More preferably, it is 2-10 mass%. It is. When the blending amount of the component (B) exceeds 10% by mass, flexibility and workability tend to decrease. Further, if the blending amount is less than 0.1% by mass, the effect of improving heat resistance cannot be obtained.

  Furthermore, mass ratio ((A) / (B)) of (A) component and (B) component is 90 / 10-50 / 50, Preferably it is 80 / 20-60 / 40. If the said mass ratio is in the said range, the heat resistance of a heat conductive resin composition can be improved easily, without reducing a softness | flexibility and workability.

  (B) The polyphenylene ether resin and / or the modified polyphenylene ether resin is compatible with the vinyl aromatic monomer unit in the component (A). Therefore, by adding the component (B) to the component (A), it becomes possible to increase the softening temperature of the phase of the vinyl aromatic monomer unit in the component (A), and the heat conductive resin composition Heat resistance can be improved.

  The thermally conductive resin composition of this embodiment comprises (B) a polyphenylene ether resin and / or a modified polyphenylene in a copolymer matrix containing (A) a conjugated diene monomer unit and a vinyl aromatic monomer unit. It is preferable that the ether resin is in a uniformly dispersed state. (A) A copolymer comprising a conjugated diene monomer unit and a vinyl aromatic monomer unit, and (B) a composite of a polyphenylene ether resin and / or a modified polyphenylene ether resin has the above morphology. (A) The softening temperature derived from the phase of the vinyl aromatic monomer in the copolymer containing the conjugated diene monomer unit and the vinyl aromatic monomer unit can be easily increased to the high temperature side. And a decrease in performance such as tensile properties can be suppressed. The morphology of the composite can be observed with a transmission electron microscope (TEM) by preparing an ultrathin section with an ultramicrotome after staining the sample with osmium tetroxide.

  The component (A) is preferably a hydrogenated copolymer and / or a modified hydrogenated copolymer containing a random copolymer of styrene-butadiene. Since hydrogenated copolymers and / or modified hydrogenated copolymers including random styrene-butadiene copolymers have excellent flexibility, (A) conjugated diene monomer units and vinyl aromatic units Not only can the amount of (B) polyphenylene ether resin and / or modified polyphenylene ether resin blended with the copolymer containing the monomer unit can be increased, but also a large amount of (D) metal hydroxide described later. Can do. Thereby, while being able to acquire the heat resistance improvement effect easily, heat conductivity can be improved easily.

  (A) The processing temperature at the time of melt-kneading the copolymer containing the conjugated diene monomer unit and the vinyl aromatic monomer unit and (B) the polyphenylene ether resin and / or the modified polyphenylene ether resin is the above ( B) It is preferably higher than the melting point or softening temperature of the polyphenylene ether resin and / or modified polyphenylene ether resin, for example, 250 ° C or higher, more preferably 270 ° C or higher, and further preferably 280 ° C or higher.

The thermally conductive resin composition of this embodiment contains (C) a rubber softener.
(C) The softening agent for rubber is not particularly limited and may be any softening agent generally used in rubber compositions, and known ones can also be used. Examples of the (C) rubber softener include mineral oil softeners, vegetable oil softeners, sub factices, fatty acids and fatty acid salts, synthetic organic compounds, and synthetic oils. Among these, mineral oil-based softeners are preferable from the viewpoint of processability. Examples of the mineral oil softener include paraffinic process oil, naphthenic process oil, aromatic process oil, paraffin / wax, liquid paraffin, and the like. Among these, paraffinic process oil is more preferable from the viewpoints of low temperature characteristics, contamination resistance, aging resistance, and the like.

The kinematic viscosity at 40 ° C. of the paraffinic process oil is not particularly limited, but is preferably 100 mm ² / sec or more, more preferably 100 to 10000 mm ² / sec, and even more preferably 200 to 5000 mm from the viewpoint of physical properties and heat aging characteristics. ² / sec. Examples of the paraffinic process oil include “NA Solvent (trade name)” manufactured by Nippon Oil and Fats, “Diana (trademark) process oils PW-90 and PW-380” manufactured by Idemitsu Kosan Co., Ltd., and “IP-solvent 2835 (commercial product) manufactured by Idemitsu Petrochemical. Name) ", and" Neothiozole (trade name) "manufactured by Sanko Chemical Industry.

  The component (C) preferably has a flash point of 170 to 300 ° C. from the viewpoint of safety. The flash point can be measured according to ASTM D-92. The component (C) preferably has a weight average molecular weight of 100 to 5000 from the viewpoints of physical properties and processability. The weight average molecular weight is a polystyrene-reduced weight average molecular weight measured using GPC.

  (C) Content of the rubber softener is 1 to 20% by mass, preferably 2 to 15% by mass, and more preferably 6 to 12% by mass with respect to the total amount of the heat conductive resin composition of the present embodiment. %. (C) If the content of the rubber softener is 20% by mass or less, not only the bleeding out of the rubber softener can be suppressed, but also the adverse effect on flame retardancy can be suppressed. Moreover, if content of (C) rubber | gum softener is 1 mass% or more, the heat conductive resin composition which has sufficient softness | flexibility can be obtained.

  (D) The metal hydroxide is not particularly limited as long as it is a metal hydroxide, and examples thereof include aluminum hydroxide, magnesium hydroxide, calcium hydroxide, and zinc hydroxide. These metal hydroxides may be used alone or in combination of two or more. Among the above metal hydroxides, aluminum hydroxide is particularly preferable. The endothermic amount of aluminum hydroxide is about 1.97 kJ / g, and it has a large endothermic amount compared to about 1.31 kJ / g of magnesium hydroxide and about 0.93 kJ / g of calcium hydroxide. Therefore, a sufficient flame retardant effect can be obtained. Furthermore, since aluminum hydroxide has a relatively high thermal conductivity and can act as a thermally conductive filler, not only flame retardancy but also thermal conductivity can be easily obtained. .

In addition, (D) metal hydroxide may contain a trace amount of impurity components (components other than metal hydroxide) derived from raw materials and the like. Examples of aluminum hydroxide include aluminum hydroxide obtained by a carbon dioxide gas method obtained by dissolving bauxite in an alkaline aqueous solution and introducing carbon dioxide, or obtained by adding seed crystals by dissolving bauxite in an alkaline aqueous solution. Aluminum hydroxide or the like obtained by the Bayer method can be used. Therefore, depending on such a production method, aluminum hydroxide may usually contain other components such as SiO ₂ , Fe ₂ O ₃ , Na ₂ O and the like. In this embodiment, the aluminum hydroxide includes aluminum hydroxide containing a trace amount of impurities (usually the content of aluminum hydroxide is 99% by mass or more) in addition to pure aluminum hydroxide.

  (D) The compounding quantity of a component is 70 mass% or more and 95 mass% or less with respect to the heat conductive resin composition whole quantity of this embodiment, Preferably it is 75 mass% or more, More preferably, it is 80 mass% or more. is there. When the blending amount of the component (D) is 70% by mass or more, a sufficient thermal conductivity effect and flame retardancy effect can be obtained. If it is 95 mass% or less, favorable workability can be obtained.

  (D) As for the compounding quantity of a component, 50-90 volume% is preferable with respect to the heat conductive resin composition of this embodiment, More preferably, it is 55-90 volume%, More preferably, it is 60-90 volume%. . If content of (D) component is 50 volume% or more, sufficient thermal conductivity effect and a flame-retardant effect can be acquired. Moreover, if content of (D) component is 90 volume% or less, while being able to suppress the viscosity raise of a heat conductive resin composition, it can suppress that a heat conductive sheet becomes hard.

  The component (D) preferably contains a metal hydroxide having an average particle size of 20 μm or more (hereinafter referred to as “first metal hydroxide”). By including a metal hydroxide having an average particle size of 20 μm or more, sufficient thermal conductivity can be obtained. The average particle diameter of the first metal hydroxide is preferably 25 μm or more, more preferably 30 μm or more.

  Furthermore, the component (D) preferably contains a metal hydroxide having an average particle size of less than 20 μm (hereinafter referred to as “second metal hydroxide”). That is, it is more preferable that the thermally conductive resin composition of this embodiment contains two or more kinds of metal hydroxides having different average particle diameters. By including two or more kinds of metal hydroxides having different average particle diameters, not only thermal conductivity but also flame retardancy can be improved. The average particle size of the second metal hydroxide is preferably 15 μm or less, more preferably 10 μm or less.

  The component (D) is a mass ratio of the first metal hydroxide having an average particle diameter of 20 μm or more and the second metal hydroxide having an average particle diameter of less than 20 μm (first metal hydroxide / first 2) is preferably 100/1 to 100/80, more preferably 100/10 to 100/50, and still more preferably 100/20 to 100/50. If the mass ratio between the first metal hydroxide and the second metal hydroxide is within the above range, sufficient thermal conductivity and flame retardancy can be obtained.

  The average particle diameter is a volume-based particle diameter measured using a laser diffraction / scattering particle size distribution measuring apparatus. The average particle size is usually measured by dispersing metal hydroxide in water or ethanol so that the concentration is 1% or less. At this time, if it cannot be dispersed, a surfactant may be used, and it may be appropriately dispersed by a homogenizer or ultrasonic waves.

(D) Na ₂ O concentration in the component is not particularly limited, and preferably not more than 0.2 mass%. More preferably, it is 0.1 mass% or less, More preferably, it is 0.05 mass% or less. If the Na ₂ O concentration in the metal hydroxide is 0.2% by mass or less, the insulation can be improved. The content of Na ₂ O can be determined by fluorescent X-ray spectroscopy. Here, the concentration of Na ₂ O wherein each of the metal hydroxide used as the two or more as (D) a metal hydroxide may be in the numerical range. In this case, it is most preferred that concentration of Na ₂ O all aluminum hydroxide is above range, concentration of Na ₂ O at least one aluminum hydroxide improves to some extent even insulation only in the numerical range Can be made.

  The component (D) may be appropriately subjected to pretreatment such as surface treatment with a coupling agent, fatty acid, fatty acid metal salt, fatty acid ester or the like. Examples of the coupling agent include a silane coupling agent, a titanate coupling agent, an aluminum coupling agent, and a zirconium coupling agent described later. These coupling agents may be used alone or in combination of two or more. Examples of fatty acids include stearic acid, oleic acid, lauric acid, ricinoleic acid, palmitic acid, and myristic acid. Examples of the fatty acid metal salt include zinc stearate, barium stearate, calcium stearate, and magnesium stearate. Examples of fatty acid esters include glycerin fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, and polyoxyethylene fatty acid esters.

  The heat conductive resin composition of this embodiment contains (E) a fluororesin and / or a fluororesin modified material. Examples of the fluororesin include polytetrafluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-ethylene copolymer, polyvinylidene fluoride, poly Examples include chlorotrifluoroethylene, ethylene-chlorofluoroethylene copolymer, tetrafluoroethylene-perfluorodioxole copolymer, polyvinyl fluoride, and tetrafluoroethylene-propylene copolymer. Among these, polytetrafluoroethylene and tetrafluoroethylene-perfluoroalkyl vinyl ether copolymers are preferable from the viewpoint of processability.

  Examples of the fluororesin-modified products include polytetrafluoroethylene acrylic-modified products, polytetrafluoroethylene ester-modified products, polytetrafluoroethylene epoxy-modified products, and polytetraethylene silane-modified products. Among these, from the viewpoint of processability, an acrylic modified product of polytetrafluoroethylene (PTFE) is preferable.

  (E) Content of fluororesin and / or fluororesin modified material is 0.01-5 mass% with respect to the heat conductive resin composition whole quantity, Preferably it is 0.1-2 mass%, More preferably Is 0.3-1.5 mass%. Here, the content of the fluororesin and / or the modified fluororesin is, for example, when the thermally conductive resin composition contains both the fluororesin and the modified fluororesin, the total amount thereof, and only the fluororesin is contained. When it contains, it means the total amount of the fluororesin, and when it contains only the fluororesin modified product, it means the total amount of the fluororesin modified product. (E) If the content of fluororesin and / or modified fluororesin is within the above range, flame retardancy, mechanical properties, and sheet formability (viscosity and roll adhesion) can be significantly improved in a balanced manner. it can.

  It is preferable that the heat conductive resin composition of this embodiment further includes one or more selected from the group consisting of (F) a silane coupling agent, an aluminum coupling agent, and a titanate coupling agent. By blending these coupling agents, the dispersibility of the component (B) in the component (A) can be further improved. As a result, the thermal conductivity can be further improved.

  Examples of the silane coupling agent include γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, γ-glycidoxy-propyltrimethoxysilane, β- (3,4). -Epoxy-cyclohexyl) ethyltrimethoxysilane, vinyltriethoxysilane, vinyl-tris (2-methoxyethoxy) silane, γ-mercaptopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane , Γ-methacryloxypropyltrimethoxysilane, N- (3-triethoxysilylpropyl) urea, methyltrimethoxysilane, octadecyltriethoxylarane, vinyltriacetoxysilane, γ-chloropropyltrimethoxysilane, hexamethyldisilazaza , Γ-anilinopropyltrimethoxysilane, octadecyldimethyl [3- (trimethoxysilyl) propyl] ammonium chloride, γ-chloropropylmethyldimethoxysilane, methyltrichlorosilane, polyalkylene oxide silanes, and perfluoroalkyltrimethoxysilane And the like. Examples of the aluminum coupling agent include acetoalkoxyaluminum diisopropylate. Examples of titanate coupling agents include isopropyl triisostearoyl titanate, isopropyl tri (N-aminoethyl-aminoethyl) titanate, isopropyl tris (dioctyl pyrophosphate) titanate, tetraisopropyl bis (dioctyl phosphite) titanate, tetraisopropyl Titanate, tetrabutyl 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 dimethacryl Isostearoyl titanate, tetra (2,2-diallylthio Shimechiru-1-butyl) bis (ditridecylphosphite) titanate, isopropyl tricumylphenyl titanate, bis (dioctyl pyrophosphate) oxy acetate titanate, and the like isopropyl isostearoyl diacryl titanate. These coupling agents may be used alone or in combination of two or more.

  The total content of component (F) is preferably 0.01 to 10% by mass, more preferably 0.1 to 8% by mass, and preferably 0.2 to More preferably, it is 5 mass%. When the total content of the coupling agent is within the above range, the dispersibility of the component (C) in the heat conductive resin composition can be improved, and the mechanical properties and the heat conductivity can be improved. In particular, when the total content of the coupling agent is 0.01% by mass or more, the addition effect of the coupling agent is sufficiently obtained, and when it is 10% by mass or less, the flame retardancy can be further improved. .

  The heat conductive resin composition of the present embodiment may contain a tackifier if necessary as long as the purpose of the present embodiment is not impaired. There is no limitation in particular as a tackifier which can be used, A conventionally well-known thing can be used. For example, rosin resin (gum rosin, tall oil rosin, wood rosin, modified rosin resin (hydrogenated rosin, disproportionated rosin, polymerized rosin, maleated rosin, etc.), rosin ester (rosin / glycerin ester, hydrogenated rosin / Glycerin ester, rosin / pentaerythritol ester, hydrogenated rosin / pentaerythritol ester, perhydrogenated rosin / glycerin ester, stabilized rosin / pentaerythritol ester, etc.), petroleum resin (hydrocarbon (aliphatic petroleum, Aromatic petroleum, dicyclopentadiene, thermal reaction type, aromatic modified aliphatic petroleum, etc.), aliphatic petroleum resin (C5 series), aromatic petroleum resin (C9 series), copolymer petroleum resin ( C5 / C9), alicyclic petroleum resins (hydrogenated, dicyclopentadiene, etc.), terpene resins (α Pinene, β-pinene, d-limonene, aromatic modification, phenol-modified terpene, polyterpene, hydrogenated terpene, etc.), pure monomer resins (styrene / α-methylstyrene, α-methylstyrene / vinyltoluene, styrene, etc.) (Meth) acrylic resins), coumarone / indene resins, phenolic resins, xylene resins, and the like. Particularly preferred are rosin resins (rosin resins, modified rosin resins), terpene resins (terpene resins), and petroleum resins. (Petroleum resin, aliphatic petroleum resin, aromatic petroleum resin, copolymer petroleum resin, alicyclic petroleum resin) These tackifiers may be used alone or in combination of two or more. May be used.

  Although the compounding quantity of a tackifier can be suitably changed according to the target adhesive force, Preferably, it is 1-20 mass% with respect to the heat conductive resin composition whole quantity of this embodiment, More preferably, it is 2 -15% by mass, more preferably 6-12% by mass.

  The heat conductive resin composition of this embodiment can mix | blend suitably the various components mix | blended in a normal resin composition as needed. For example, rubber softeners other than the mineral oil softeners, plasticizers, anti-aging agents, antioxidants, crosslinking agents, thermoplastic resins and / or rubbers other than the above, fillers other than the above metal hydroxides, the above Flame retardants other than metal hydroxides.

  Examples of rubber softeners other than the mineral oil softeners include vegetable oil softeners such as castor oil, linseed oil, rapeseed oil and coconut oil, waxes such as beeswax, carnauba wax and lanolin, tall oil, , Linoleic acid, palmitic acid, stearic acid, lauric acid and the like.

  Examples of the plasticizer include dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), diheptyl phthalate (DHP), dioctyl phthalate (DOP), diisononyl phthalate (DINP), and phthalate. Examples include diisodecyl acid (DIDP), butyl benzyl phthalate (BBP), dilauryl phthalate (DLP), and dicyclohexyl phthalate (DCHP).

  Examples of the antiaging agent include amines, phenols, imidazoles, carbamic acid metal salts, and waxes. These antioxidants may be used alone or in combination of two or more.

  Examples of the antioxidant include aldehydes, amines, and phenols.

  Examples of the crosslinking agent include organic peroxides, sulfur vulcanizing agents, epoxies, isocyanates, and di (meth) acrylates.

  Examples of the thermoplastic resin other than the above include polyethylene, polypropylene, (meth) acrylic resin, polystyrene, and the like. Examples of the rubber include isoprene rubber, styrene-butadiene rubber, butadiene rubber, and styrene-isoprene-butadiene rubber.

  Examples of the filler other than the metal hydroxide include carbon black, silica, aluminum oxide, magnesium oxide, zinc oxide, clay, carbon fiber, graphite fine powder, glass fiber, boron nitride, silicon carbide, boron carbide, aluminum nitride, Aluminum, copper, etc. are mentioned.

  Examples of flame retardants other than the metal hydroxides include nitrogen flame retardants (such as triazines), PPE (polyphenylene ether), silicone flame retardants, aromatic carboxylic acids and their metal salts, boron compounds, and zinc compounds. Can be mentioned.

  The heat conductive resin composition of the present embodiment is prepared by using each of the above-described blending components, for example, a pressure kneader, a Banbury mixer, an internal mixer, a lab plast mill, a mix lab, an extruder (a twin screw extruder), and the like. It can be prepared by mechanical kneading. In this case, a pressure kneader, a Banbury mixer, and a twin screw extruder are particularly preferable.

  The thermally conductive resin composition of the present embodiment includes (1) (A) a copolymer containing a conjugated diene monomer unit and a vinyl aromatic monomer unit, (B) a polyphenylene ether resin and / or a modification. Polyphenylene ether resin 0. And (2) the master batch, at least (C) a softening agent for rubber, (D) a metal hydroxide, and (E) a fluororesin and / or a fluororesin. Preferably, the modified product is manufactured by a manufacturing method including a step of melt-kneading and obtaining a heat conductive resin composition.

  First, (A) a copolymer containing a conjugated diene monomer unit and a vinyl aromatic monomer unit and (B) a polyphenylene ether resin and / or a modified polyphenylene ether resin are previously melt-kneaded, Make a batch. (B) Polyphenylene ether resin and / or modified polyphenylene ether resin can be easily prepared in a copolymer matrix containing (A) conjugated diene monomer unit and vinyl aromatic monomer unit by melt-kneading in advance. Can be uniformly dispersed. The method of melt kneading is not particularly limited, and the same method as described above can be used. In addition, as a shape of a masterbatch, there exist a sheet form, a ribbon form, and a pellet form, but it is preferable that it is a pellet form from a viewpoint of the ease of handling in a post process.

  Next, the master batch is melt-kneaded with at least (C) a softening agent for rubber, (D) a metal hydroxide, and (E) a fluororesin and / or a fluororesin-modified product. The method of melt kneading is not particularly limited, and the same method as described above can be used. Thereby, a heat conductive resin composition can be obtained.

  The thermally conductive resin composition of the present embodiment can be processed into a sheet shape according to the application, and can be made into a thermally conductive sheet (sometimes referred to as “film” or the like). The method for processing into a sheet is not particularly limited, and the sheet can be processed by extrusion molding, press molding, calendar molding, or the like. For example, when it is desired to process into a sheet having a thickness of less than 3 mm, and when it is continuously formed and wound into a roll, extrusion molding or calendar molding is preferable. Further, when it is desired to process a sheet having a thickness of 3 mm or more, it is difficult to wind it into a roll, and therefore press molding is preferable.

  When processing into a sheet form by extrusion molding or calendering, the obtained heat conductive sheet can be wound up as a roll with a release film or a transfer adhesive film in between. Moreover, the magnitude | size of a sheet | seat width is not specifically limited, A sheet | seat width can be determined according to a use. When using extrusion molding, for example, there is a method of forming a sheet by extruding it to a T-die while kneading each component with an extruder, and winding the obtained sheet together with a release film or a transfer type adhesive film by a sheet take-up device. Can be mentioned. The extrusion conditions at this time vary depending on the blending of the heat conductive resin composition or the desired sheet width. For example, the set temperature of the extruder is 90 to 190 ° C., the screw rotation speed is 5 to 80 rpm, L / D (screw length to diameter ratio) is preferably 20 or more.

Further, the heat conductive sheet may be formed by mixing the above-described blending components with an organic solvent or the like and uniformly dispersing the mixture and then applying and drying the support. That is, a mixed solution obtained by mixing and uniformly dispersing the above-mentioned blending components with an organic solvent is impregnated into a fibrous sheet such as cloth, paper, glass cloth, and the organic solvent is volatilized and dried. By this, you may manufacture a heat conductive sheet as a composite of a fibrous sheet and a heat conductive resin composition. Furthermore, you may press the heat conductive sheet obtained by said method with a calender roll or a press. In this way, by further pressing the heat conductive sheet formed as a composite of the fibrous sheet and the heat conductive resin composition with a calendar roll or a press, the thickness of the heat conductive sheet can be adjusted, Since the inside of the fibrous sheet as a support can be sufficiently impregnated with the heat conductive resin composition, the heat conductivity can be improved. The processing conditions for the press vary depending on the desired thickness, size, etc. In the case of a calendar roll, the set temperature is preferably 80 to 120 ° C. and the linear pressure is 10 to 800 kgf / cm. The temperature is preferably 80 to 120 ° C. and the load is 10 to 160 kg / cm ² .

  The heat conductive sheet of the present embodiment obtained as described above can have a heat conductivity of 1.0 W / m · K or more. The thermal conductivity can be measured according to ASTM (American Society for Testing and Materials) D5470.

  Furthermore, as a preferable aspect of the heat conductive sheet of this embodiment, the V-0 standard of UL94 standard (Underwriters Laboratories Inc. standard number 94) can be satisfied. The UL94 standard is a standard related to a plastic material flammability test for equipment and instrument parts, and is classified as a material having high flame retardancy by satisfying this standard.

  The metal hydroxide contained in the thermally conductive resin composition of this embodiment decomposes and releases water when the temperature rises above a certain temperature. For example, aluminum hydroxide has the property of decomposing at 200 ° C. or higher to release water. That is, when the heat conductive sheet using the heat conductive resin composition of the present embodiment burns, the metal hydroxide contained in the heat conductive resin composition decomposes and releases water. Is extinguished by. Therefore, the heat conductive sheet of this embodiment can have excellent flame retardancy.

  The thermally conductive sheet of this embodiment can be used for electronic components, semiconductor devices, display devices, and the like. Specifically, for example, a CPU of a computer, a liquid crystal backlight, a plasma display panel, an LED element, an organic EL element, a secondary battery or its peripheral device, also a radiator of a motor, a Peltier element, an inverter, and (high) power A transistor etc. are mentioned.

  The heat conductive sheet of the present embodiment is used by being sandwiched between a heat generating component that is a heat generating source such as an electronic component or a semiconductor device and a cooling component such as a heat radiating plate or a heat sink. In this way, heat can be efficiently conducted from the heat-generating component to the cooling component by way of the heat conductive sheet, thus reducing the thermal deterioration of electronic components, semiconductor devices, display devices, etc. It becomes possible. As a result, it is possible not only to reduce failures of electronic parts, semiconductor devices, display devices, etc., but also to extend the life.

  In particular, LED-related parts such as LED backlights and LED lightings tend not only to generate a large amount of heat with high power in recent years, but also to cause heat non-uniformity. In order to solve such a problem, it is necessary to efficiently dissipate and equalize heat. For example, by sticking the heat conductive sheet of the present embodiment between the back side of the LED substrate and a heat radiating member such as an aluminum chassis, the heat generated in the LED substrate can be efficiently conducted to the heat radiating member. .

  Based on an Example, this invention is demonstrated concretely. In addition, this invention is not limited to these Examples, It can change suitably as needed.

  First, materials used in the examples will be described. A hydrogenated copolymer (polymer 1) of a conjugated diene monomer and a vinyl aromatic monomer was produced by the following method. About other materials, the commercially available thing was used as it was.

[Preparation of polymer 1 (hydrogenated copolymer of conjugated diene monomer and vinyl aromatic monomer)]
A hydrogenation catalyst was prepared according to the following procedure (i). Next, according to the following reaction procedures (ii) to (viii), (A) a copolymer of a conjugated diene monomer and a vinyl aromatic monomer was polymerized and hydrogenated. During the polymerization reaction, the inside of the reaction vessel was kept at 70 ° C., and during the hydrogenation reaction, the inside of the reaction vessel was kept at 65 ° C.

(I) 1 L of dried and purified cyclohexane was charged into a hydrogenation catalyst adjusting reaction vessel purged with nitrogen, and 100 mmol of bis (η5-cyclopentadienyl) titanium dichloride was added. With sufficient stirring, an n-hexane solution containing 200 mmol of trimethylaluminum was added and reacted at room temperature for about 3 days, and used as a hydrogenation catalyst.

(Ii) 10 parts by mass of cyclohexane was added to a stirring apparatus and jacketed tank reactor with an internal volume of 10 L, and adjusted to 70 ° C.

(Iii) Next, 0.0076 parts by mass of n-butyllithium and N, N, N ′, N′-tetramethylethylenediamine (TMEDA) are added so as to be 0.4 mol with respect to 1 mol of n-butyllithium. did.

(Iv) As a first-stage reaction, a cyclohexane solution containing 8 parts by mass of styrene (monomer concentration: 22% by mass) was added over about 3 minutes, and reacted for 30 minutes after the addition was completed.

(V) As a second-stage reaction, a cyclohexane solution (monomer concentration of 22% by mass) containing 48 parts by mass of 1,3-butadiene and 36 parts by mass of styrene is continuously put into a reaction vessel at a constant rate over 60 minutes. The mixture was fed and reacted for 30 minutes after the addition.

(Vi) As a third-stage reaction, a cyclohexane solution containing 8 parts by mass of styrene (monomer concentration: 22% by mass) is added over about 3 minutes, and the reaction is performed for 30 minutes after the addition is completed. A copolymer of vinyl aromatic monomers was obtained.

(Vii) To the obtained copolymer of conjugated diene monomer and vinyl aromatic monomer, 100 mass ppm of the hydrogenation catalyst prepared in (i) is added in terms of titanium, and the hydrogen pressure is 0.7 MPa. The hydrogenation reaction was performed at a temperature of 65 ° C.

(Viii) After completion of the hydrogenation reaction, methanol is added, then octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate as a stabilizer, conjugated diene monomer and vinyl aroma A hydrogenated copolymer (polymer 1) containing a random copolymer of styrene-butadiene was added by adding 0.3% by mass to the copolymer of the group monomer.

The resulting polymer 1 had a weight average molecular weight of 16.5 × 10 ⁴ , a molecular weight distribution of 1.2, and a hydrogenation rate of 99%. As a result of dynamic viscoelasticity measurement, the peak temperature of tan δ was at −15 ° C. As a result of DSC measurement, there was no crystallization peak. Furthermore, the content of the vinyl aromatic unit determined from the pre-hydrogenation copolymer obtained after the third stage reaction is 52% by mass, the content of the polymer block composed of vinyl aromatic is 16% by mass, 1, The vinyl bond content in the 3-butadiene part was 21% by mass. The weight average molecular weight and molecular weight distribution were measured using “HLC-8220GPC” manufactured by Tosoh Corporation.
GPC; Equipment: Tosoh HLC-8220GPC
Data processing: Tosoh GPC-8020
Column: TSKgel SuperHZM-M (4.6 mmID × 15 cm), TSKgel SuperHZ2000 (4.6 mmID × 15 cm)
Solvent: tetrahydrofuran (THF)
Composition: Polystyrene equivalent dynamic viscoelasticity; manufactured by TS Instruments Japan, solid viscoelasticity analyzer “RSA III”
DSC: manufactured by PerkinElmer, "DSC-7"

Polymer 2: “Septon 4033” manufactured by Kuraray (styrene- (ethylene-ethylene / propylene) -styrene copolymer)
Polymer 3: “Clayton FG1901X” (maleic anhydride modified styrene- (ethylene / butylene) -styrene copolymer) manufactured by Kraton Polymer Japan
Polyphenylene ether resin; manufactured by Asahi Kasei Plastics Singapore, polyphenylene ether (PPE) powder (product code: Zylon (trademark) (S202A) (chemical name: poly (2,6-dimethyl-1,4-phenylene oxide))
Rubber softener: “Diana Process Oil (trademark) PW-380” (paraffinic process oil), manufactured by Idemitsu Kosan
Metal hydroxide: Aluminum hydroxide (manufactured by Nippon Light Metal) (Table 2 shows the average particle size and Na ₂ O content.)
Fluororesin-modified product: Acrylic-modified polytetrafluoroethylene (Mitsubishi Rayon, “METABBRENE (trademark) A-3800”) (Methyl methacrylate / butyl acrylate copolymer, tetrafluoroethylene polymer mixture)
Silane coupling agent: “KBE-403” (3-glycidoxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd.
Aluminum coupling agent: “Preneact AL-M” (acetoalkoxyaluminum diisopropylate) manufactured by Ajinomoto Fine-Techno

[Manufacturing method of master batch]
Using the compounding composition shown in Table 1, polymer 1 and polyphenylene ether resin were pelletized while performing melt extrusion at a cylinder set temperature of 280 ° C. using a twin screw extruder “PCM-30” (manufactured by Ikekai Tekko), and master A batch was made.

[Method for Producing Thermal Conductive Sheet of Comparative Example 1]
The composition shown in Table 2 was mixed for 5 minutes at 150 ° C. using a lab plast mill (Toyo Seiki, “Roller Mixer R60”) to prepare each thermally conductive resin composition. Each obtained heat conductive resin composition was knead | mixed at 150 degreeC using the 3-inch roll kneader, and shape | molded in the sheet form. Furthermore, it press-molded with the press heated at 170 degreeC, and obtained the heat conductive sheet of length 220mm x width 120mm, 0.3mm thickness, 0.5mm thickness, and 1.0mm thickness, respectively.

[Methods for producing thermally conductive sheets of Examples 1 to 10, 12 and Comparative Examples 2 and 3]
With the blending composition shown in Table 2, each masterbatch and each material were mixed at 150 ° C. for 5 minutes using a lab plast mill (manufactured by Toyo Seiki Co., Ltd.) to prepare each thermally conductive resin composition. Each obtained heat conductive resin composition was knead | mixed at 150 degreeC using the 3-inch roll kneader, and shape | molded in the sheet form. Furthermore, it press-molded with the press heated at 170 degreeC, and obtained the heat conductive sheet of length 220mm x width 120mm, 0.3mm thickness, 0.5mm thickness, and 1.0mm thickness, respectively. As an example, the morphology of the sample of Example 2 was examined by imaging with a transmission electron microscope (TEM). Specifically, after the sample was stained with osmium tetroxide, an ultrathin section was prepared with an ultramicrotome and imaged with a transmission electron microscope (TEM; magnification: 50,000 times). A TEM photograph of the thermally conductive resin composition of Example 2 is shown in FIG. According to FIG. 1, it was confirmed that the polyphenylene ether resin was uniformly dispersed in the matrix of the polymer 1 by the polyphenylene ether resin entering the phase of the vinyl aromatic monomer of the polymer 1.

[Methods for producing thermally conductive sheets of Examples 11 and 13 and Comparative Examples 4 and 5]
With the blending composition shown in Table 3, each material was melt-kneaded using a twin screw extruder “ZSK-25” (manufactured by Werner & Frederer) to obtain pellets of each thermally conductive resin composition. The obtained pellets of each heat conductive resin composition were single-screw extruder (manufactured by Toyo Seiki Seisakusho, Lab Plast Mill model: 50M, screw model: D2020) and 120 mm wide T-die (Toyo Seiki Seisakusho). Manufactured) to obtain thermally conductive sheets 220 mm long × 120 mm wide, 0.3 mm thick, 0.5 mm thick and 1.0 mm thick.

  Using the obtained thermal conductive sheet, the softening temperature, flame retardancy, thermal conductivity, dielectric breakdown strength, flex resistance, and molding stability were measured.

<Average particle size>
The average particle diameter of aluminum hydroxide was measured using a laser diffraction / scattering particle size distribution analyzer “LA-910” (manufactured by Horiba Seisakusho). The sample was dispersed in the dispersion medium by applying ultrasonic waves for 1 minute.

<Na ₂ O content>
The Na ₂ O content in aluminum hydroxide was measured by fluorescent X-ray spectroscopy (manufactured by Rigaku Corporation, fluorescent X-ray analyzer “System 3270E”).

<Softening temperature>
The softening temperature of each heat conductive sheet having a thickness of 1.0 mm was measured using a thermomechanical analyzer (TMA) (TA Instruments, “TMA / Q400”). The measurement was performed in the penetration mode.

<Flame retardance>
Based on UL94 standard, the combustibility of each 0.3 mm thick heat conductive sheet was measured.

<Thermal conductivity>
In accordance with ASTM (American Society for Testing and Materials) D5470, the thermal conductivity of each thermal conductive sheet was measured using a resin material thermal resistance measurement device (manufactured by Hitachi, Ltd., “PMFA038-1”). The measurement temperature was 30 ° C.

<Dielectric breakdown strength>
In accordance with JIS C2110, the dielectric breakdown strength of each thermally conductive sheet was measured by a short time method at 23 ° C. in oil. The test electrode was Φ25 cylinder / Φ25 cylinder, and the thickness of the test piece was 1.0 mm.

<Flexibility>
Each thermally conductive sheet having a length of 155 mm, a width of 25 mm, and a thickness of 0.5 mm was bent three times at an angle of 180 °, and then the presence or absence of cracks in the bent portion was visually observed. The evaluation was “◯” for “no cracks in the bent part to minute”, “Δ” for “large number of cracks in the bent part”, and “×” for “partially fractured bent part”.

<Molding stability>
Using a single screw extruder (manufactured by Toyo Seiki Seisakusho, Labo Plast Mill model: 50M, screw model: D2020) and 120 mm wide T-die (manufactured by Toyo Seiki Seisakusho) The lip thickness of the T die was adjusted to 1.0 mm, and sheet molding was performed. The appearance of the obtained sheet and the presence or absence of foaming were visually confirmed to evaluate the molding stability. “No foaming” was evaluated as “◯”, “No foaming” was evaluated as “Δ”, and “Foaming” was evaluated as “X”.

  As shown in Table 2, in Examples 1 to 3, the softening temperature was higher than that of Comparative Example 1 by blending the polyphenylene ether resin. Moreover, it was confirmed that the flame retardancy is improved by blending the fluororesin-modified product. Furthermore, the thermal conductivity was good without impairing the insulating properties.

  Although the comparative example 3 contained much polyphenylene ether resin, the softening temperature became low. This is because the blending amount of the polyphenylene ether resin is too large, making it difficult to uniformly mix the hydrogenated copolymer of the conjugated diene monomer unit and the vinyl aromatic monomer unit with the polyphenylene ether resin. Is considered to be due to incompleteness.

  In Examples 4 and 5, it was confirmed that the dispersibility of aluminum hydroxide was further improved and the thermal conductivity was improved by adding a coupling agent.

In Example 6, although concentration of Na ₂ O is an example containing more than 0.2 mass% of aluminum hydroxide, and reduced flame retardancy.

  Example 7 does not contain aluminum hydroxide having an average particle diameter of less than 20 μm, and the average particle diameter of aluminum hydroxide is 20 μm or more. In contrast, in Example 2 and the like, the average particle diameter is It was confirmed that bending resistance and molding stability were further improved by containing aluminum hydroxide having a mean particle size of 20 μm or more.

  Example 10 is an example in which the mass ratio of aluminum hydroxide having an average particle diameter of 20 μm or less and aluminum hydroxide having an average particle diameter of 20 μm or more is 100/100. Etc., it was confirmed that the bending resistance, molding stability, and flame retardancy were further improved.

  In Example 11, a sufficient heat resistance improvement effect was not obtained. Further, the bending resistance and molding stability were lowered. Example 11 is an example in which the master batch was not formed in the production process of the resin composition. However, in Example 2, the heat resistance, the bending resistance and the molding stability were further improved. Was confirmed.

  As shown in Table 4, also in Examples 12 and 13, heat resistance is improved by adding a polyphenylene ether resin, and flame retardancy is further improved by adding a modified fluororesin. Was confirmed.

  The heat conductive resin composition of the present invention is a heat conductive resin composition excellent in high heat conductivity, high insulation, bending resistance and molding stability, flame retardant and excellent in environmental properties. Can be used as a heat conductive member. In particular, it can be suitably used as a heat conductive sheet. The heat conductive sheet of the present invention is conventionally provided by, for example, providing it between a heat generation component that is a heat generation source in various electronic components, semiconductor devices, or display devices and a cooling component that is a heat dissipation component such as a heat sink. In comparison, it can be suitably used for applications that require high thermal conductivity, high insulation, and flame retardancy.

Claims (10)

(A) 0.9 to 10% by mass of a copolymer containing a conjugated diene monomer unit and a vinyl aromatic monomer unit;
(B) 0.1 to 10% by mass of polyphenylene ether resin and / or modified polyphenylene ether resin,
(C) 1 to 20% by mass of a rubber softener,
(D) 70 to 95% by mass of a metal hydroxide, and (E) 0.01 to 5% by mass of a fluororesin and / or a fluororesin-modified product, and
Wherein component (A) and (B) the mass ratio of the component ((A) / (B)) is, Ri 90 / 10-50 / 50 der,
The component (A) is a hydrogenated copolymer obtained by hydrogenating a copolymer containing a conjugated diene monomer unit and a vinyl aromatic monomer unit, and / or a conjugated diene monomer unit. vinyl aromatic monomer units and a copolymer obtained by adding hydrogen to introduce a functional group into the modified hydrogenated copolymer der Ru thermally conductive resin composition comprising a.   The component (D) contains a first metal hydroxide having an average particle diameter of 20 μm or more and a second metal hydroxide having an average particle diameter of less than 20 μm, and the first metal hydroxide The heat conductive resin composition of Claim 1 whose mass ratio of a thing and a said 2nd metal hydroxide is 100/1-100/80. Wherein (D) Na ₂ O concentration in the component, thermally conductive resin composition according to claim 1 or 2 0.2 mass% or less.   Furthermore, (F) Thermal conductivity of any one of Claims 1-3 containing at least 1 sort (s) chosen from the group which consists of a silane coupling agent, an aluminum coupling agent, and a titanate coupling agent. Resin composition. Content of the said vinyl aromatic monomer unit in the said (A) component is 30 mass% or more and 90 mass% or less, The heat conductive resin composition of any one of Claims 1-4 . The thermally conductive resin composition according to any one of claims 1 to 5 , wherein a hydrogenation rate of a double bond based on the conjugated diene monomer unit of the component (A) is 10% or more. Wherein component (A), the thermally conductive resin composition according to any one of claims 1 to 6 including the random copolymer block of a conjugated diene monomer units and vinyl aromatic monomer units. The thermally conductive resin composition according to any one of claims 1 to 7 , wherein the component (B) is dispersed in a matrix of the component (A). The heat conductive sheet formed by forming the heat conductive resin composition of any one of Claims 1-8 in a sheet form. (1) (A) A copolymer containing a conjugated diene monomer unit and a vinyl aromatic monomer unit, and (B) a polyphenylene ether resin and / or a modified polyphenylene ether resin are melt-kneaded, and a master batch Obtaining
(2) The masterbatch, at least (C) a rubber softener, (D) a metal hydroxide, and (E) a fluororesin and / or a fluororesin-modified product are melt-kneaded to obtain a heat conductive resin composition. Obtaining a product;
The manufacturing method of the heat conductive resin composition of any one of Claims 1-8 containing these.