JP4496438B2 - Thermally conductive hot melt composition - Google Patents

Description

The present invention relates to a heat conductive hot melt composition containing a heat conductivity imparting agent that is excellent in heat conductivity, fluidity, and heat resistance and can be directly melt coated on a heat generator or a heat radiator.

In recent years, with higher integration, higher density, and higher frequency in the electronic field and semiconductor field, power consumption is also increasing, efficiently dissipating the generated heat and reducing the temperature rise of electronic component elements. It has become an important issue. In addition, portable computers and other electronic devices are becoming smaller, thinner, and lighter, and the demand for thermal conductivity of electronic components is increasing along with large devices.

In the automotive field, hybrid vehicles and electric vehicles are attracting attention due to the integration of electronic components and especially environmental problems in recent years, and the drive voltage is also increasing. For this reason, many power devices such as power ICs and semiconductor switching devices (transistors) are used in electrical junction boxes and the like provided in automobiles. A printed circuit board on which electronic components (resistors, capacitors, diodes, transistors, etc.) and ICs (integrated circuits) are mounted is also built in, and it is required to dissipate the heat generated from these components more efficiently. In the building materials field, there is a tendency for comfortable indoor spaces such as floor heating, wall heating, ceiling heating, etc., and there is a tendency for demand for thermal conductivity to increase, such as the use of technology using heat dissipation materials. .

Conventionally, various heat sinks, heat sinks, housings, etc. are heated in order to remove the heat generated by the display devices of these electronic component elements and electronic devices, or to eliminate the temperature difference in the same component or device. Although the sheet-like heat conductive composition to convey is used, the process previously processed into a sheet form is required. Further, in the case of a sheet, a gap is easily formed at the time of pasting, and a technique is required for the pasting work. Furthermore, there is a problem that the thermal conductivity is lowered when the adhesion to the heating element or the heat sink is insufficient. In addition, heat-dissipating materials using silicone as a composition are widely used as a publicly known technology, but problems such as low-molecular weight silicone contained in silicone evaporate and adhere to contacts of electronic parts, etc., resulting in poor contacts. Has been pointed out.

The performance required for these thermally conductive compositions includes thermal conductivity, flexibility, adhesion, durability, heat resistance, flame retardancy, etc., in order to impart a particularly higher thermal conductivity effect. Must be highly filled with a heat transfer agent. However, if the heat conductivity-imparting agent is highly filled, the melt viscosity of the heat conductive composition itself is increased, and the flowability at the time of molding is deteriorated, so that productivity is lowered and there is a problem in practical use for electronic parts and the like. . In addition, it is possible to improve the apparatus for pumping through a pump and mold a heat conductive composition having a high melt viscosity, but it is not only necessary to cost the improvement of the apparatus, There is a concern that the product value may be reduced due to the contamination of the apparatus due to the wear of the apparatus due to the load on the product. As described above, there is a problem in terms of both the process and the productivity, and a novel thermally conductive composition is desired.

Various thermal conductive compositions have been proposed. For example, the thermal conductivity at 25 ° C. is 0.5 W / mk or more, the average diameter is 0.1 μm to 5 μm, and the average length is 0.5 μm. A thermally conductive filler in which fine zinc oxide is bonded to the surface thereof at a ratio of 30% by volume to 90% by volume, and the elongated matrix having an average aspect ratio of 5 to 500, and an average aspect ratio of 5 to 500; There is a disclosure (Patent Document 1) of a heat conductive resin composite whose thermal conductivity is improved by dispersing it in a resin that becomes a thermal conductive resin composite, but the heat conductive resin composite does not have a function as an adhesive. In addition, since it does not have both thermal conductivity and fluidity performance, it does not meet its purpose as an actual product. Further, there is disclosed a high thermal conductive resin compound or sheet containing spherical or non-spherical alumina particles and a manufacturing method thereof (Patent Document 2 or Patent Document 3). Since a process is required, it cannot be directly melt-coated on an electronic component. In addition, there is a disclosure (Patent Document 4) of a thermally conductive composition that is highly filled with aluminum hydroxide having a wide particle size distribution and imparts thermal conductivity and flame retardancy, but the fluidity during molding is improved. It cannot be directly applied to electronic components. Furthermore, it is feared that it is easy to react with water. Although there is a disclosure (Patent Document 5) of a heat conductive hot melt adhesive composition containing a heat conductivity-imparting agent, improvement in fluidity of the heat conductive composition containing the heat conductivity-imparting agent is shown. Not.
JP 2007-254637 A JP 2007-277405 A JP 2007-277406 A JP 2003-313431 A JP 2007-262392 A

The present invention solves the above problems and provides a heat conductive hot melt adhesive that is excellent in high heat conductivity, fluidity, and heat resistance and can be directly melt coated on a heating element or a heat radiating element.

As a result of intensive studies to solve the above problems, the present inventor has found that a thermally conductive hot melt adhesive composition in which a thermal conductivity imparting agent having an average particle size of 5 to 80 μm is dispersed in a thermoplastic resin composition. It has been found that a product can achieve its purpose, and the present invention has been completed. The present invention is shown below.

[1] It contains (D) a thermal conductivity imparting agent having an average particle size of 5 to 80 μm having a particle size distribution containing 0 to 40 vol% of a particle size of less than 2 μm, and the thermal conductivity is 0.4 W / mK or more. (A) 100 to 300 parts by weight of a styrene-based elastomer, (B) 100 to 300 parts by weight of a tackifier, (C) 20 to 500 parts by weight of a plasticizer, and (D) magnesium carbonate and / or water. An adhesive comprising a thermally conductive hot melt adhesive composition containing 1500 to 10,000 parts by weight of magnesium oxide and 0.5 to 30 parts by weight of (E) polyphenylene ether resin and / or modified polyphenylene ether resin.

According to the present invention, when a hot melt adhesive composition containing a thermal conductivity imparting agent having an average particle size of 5 to 80 μm and having a thermal conductivity of 0.4 W / mK or more in a more preferable filling range is used, Since it is excellent in conductivity, fluidity and heat resistance and can be directly applied to a heating element or a heat dissipation element, productivity can be improved. Furthermore, when the heat conductive hot melt adhesive composition of the present invention is used, the burden on the apparatus can be reduced, and a product with higher quality value can be provided.

Next, an embodiment of the present invention will be described.

The thermal conductivity imparting agent (D) of the present invention has an average particle diameter of 5 to 80 μm, preferably 7 to 50 μm, and a thermal conductivity hot melt having a thermal conductivity of 0.4 K / mK or more. Any adhesive composition may be used. When the average particle size of the heat conductivity imparting agent is less than 5 μm, the fluidity of the heat conductive hot melt adhesive composition is lowered, and when it exceeds 80 μm, the dispersibility is lowered and the desired heat conductive hot melt adhesive is obtained. It is difficult to obtain an agent composition. The heat conductive hot melt adhesive composition of the present invention may have a heat conductivity of at least 0.4 W / mK, and preferably 0.5 W / mK or more. If it is less than 0.4 W / mK, the heat radiation from the heating element and the heating effect are practically insufficient.

The (D) thermal conductivity-imparting agent of the present invention may be one containing 0 to 40 vol%, preferably 0 to 20 vol%, having a particle size distribution of less than 2 μm. . When the particle size of less than 2 μm is included exceeding 40 vol%, the surface area of the heat conductivity imparting agent in the heat conductive hot melt adhesive composition is increased, and the flow of the heat conductive hot melt adhesive composition is increased. Sex is reduced.

The thermal conductivity imparting agent (D) of the present invention has an average particle size of 5 to 80 μm, and the thermal conductivity of the thermally conductive hot melt adhesive composition containing the thermal conductivity imparting agent is 0.4 W / mK. What is necessary is just to use the thermal conductivity imparting agent as described above. Metal oxide, metal nitride, metal carbide, metal hydroxide, silica, calcined organic polymer, nitrogen carbide, carbon, metal powder having these properties Such as body. For example, magnesium carbonate, magnesium hydroxide, calcium carbonate, kaolin clay, calcium silicate, calcium oxide, magnesium oxide, zinc oxide, alumina, aluminum nitride, aluminum borate whisker, boron nitride, crystalline silica, amorphous silica, carbonized Silicon, carbon black, graphite, aluminum, copper, silver and the like can be mentioned, and these may be used alone or in combination of two or more. Preferably, magnesium carbonate, magnesium hydroxide, magnesium oxide, and alumina are used, and at least one of these groups may be used.

Furthermore, the thermal conductivity imparting agent (D) of the present invention preferably has an aspect ratio of 1 to 5, good flowability even when the filling amount is high, and the thermal conductive hot melt adhesive of the present invention. The thermal conductivity of the composition is 0.4 W / mK or more, and the desired thermal conductivity can be imparted. The aspect ratio is more preferably 1 to 3. If the aspect ratio exceeds 5, the dispersibility in the heat conductive hot melt adhesive composition becomes insufficient, and the heat conductive hot melt adhesion The fluidity of the agent composition decreases.

The (D) thermal conductivity imparting agent of the present invention may be 200 to 10,000 parts by weight with respect to 100 parts by weight of the (A) thermoplastic resin. Furthermore, the blending amount of the thermal conductivity imparting agent (D) is particularly preferably 200 to 10,000 parts by weight when the aspect ratio is less than 1.5, and 200 to 3000 parts by weight when the aspect ratio is 1.5 or more. . (D) If the blending amount of the thermal conductivity imparting agent is less than 200 parts by weight, the thermal conductivity tends to be insufficient. Further, when the aspect ratio is less than 1.5 and the blending amount exceeds 10,000 parts by weight, when the aspect ratio is 1.5 or more and the blending amount exceeds 3000 parts by weight, the heat conductive hot melt adhesive is hard. And there is a tendency for the adhesiveness to decrease.

The heat conductive hot melt adhesive composition of the present invention may have a heat conductivity of 0.4 W / mK or more. For example, (A) a thermoplastic resin, (B) a tackifier as an embodiment of the first composition , (C) a plasticizer, (D) a thermal conductivity imparting agent, (E) a composition containing an engineering plastic, and (F) an acid anhydride-modified thermoplastic resin as an embodiment of the second composition, ( Examples include, but are not limited to, B) a tackifier, (C) a plasticizer, (D) a thermal conductivity imparting agent, and (G) a reaction curable composition containing an epoxy resin.

The (A) thermoplastic resin of the present invention is not particularly limited, and any conventionally known substance that can be used as the thermoplastic resin of the present invention may be used, and examples thereof include styrene-based elastomers. The styrenic elastomer has a polystyrene block derived from styrene and a rubber intermediate block capable of imparting rubber elasticity. For example, styrene-butadiene-styrene triblock copolymer (SBS), styrene-isoprene. -Styrene triblock copolymer (SIS), SBS hydrogenated product (SEBS), SIS hydrogenated product (SEPS) styrene-ethylene / ethylenepropylene-styrene block copolymer (SEEPS), maleic anhydride modified styrene -Ethylenebutylene-styrene block copolymer (MAH-SEBS), maleic anhydride modified styrene-ethylenepropylene-styrene block copolymer (MAH-SEPS), maleic anhydride modified styrene-isoprene-styrene block copolymer (MAH) -S S), maleic acid-modified styrene anhydride - butadiene - mentioned styrene block copolymer (MAH-SBS), but these may be used alone or in combination of two or more. Preferably, SEBS, SEPS, SEEPS, MAH-SEBS, and MAH-SEPS are used, and at least one of these groups may be used.

Styrenic elastomers can provide elasticity, cohesive force, and adhesion to a coating substrate as a sealing material for electronic parts, building materials, etc., among them, if the average molecular weight of the styrene elastomer is 30000-500000 The purpose of imparting elasticity and cohesive force can be achieved. Furthermore, it is more preferable that the average molecular weight of the styrene elastomer is 60,000 to 300,000 as imparting coating stability, heat resistance, durability, adhesion to the coating substrate or adhesion.

Styrenic elastomers can provide vibration resistance in addition to elasticity, cohesive strength, and adhesion to coating base materials as sealing materials for automobile parts and the like. Among them, styrene elastomers have an average molecular weight of 30,000 to 500,000. If there is, the purpose of imparting elasticity and cohesive force can be achieved. Furthermore, it is more preferable that the average molecular weight of the styrenic elastomer is 100,000 to 300,000 as imparting coating stability, heat resistance, durability, adhesion to the coating substrate or adhesion.

The (B) tackifier of the present invention is not particularly limited, and any conventionally known substance that can be used as the tackifier of the present invention may be used. For example, rosin resins (gum rosin, tall oil rosin, wood rosin, Hydrogenated rosin, disproportionated rosin, polymerized rosin, maleated rosin, rosin glycerin ester, hydrogenated rosin glycerin ester, etc.), terpene phenol resin, terpene resin (mainly α-pinene, β-pinene, dipentene, etc.), Aromatic hydrocarbon-modified terpene resin, petroleum resin (aliphatic, alicyclic, aromatic, etc.), coumarone / indene resin, styrene resin (styrene, substituted styrene, etc.), phenolic resin (alkylphenol resin) Rosin-modified phenolic resin, etc.), xylene resin, etc., which can be used alone or in combination of two or more. It only has to be.

The plasticizer (C) of the present invention may be any component having a function of reducing the melt viscosity of the heat conductive composition, and may be a conventionally known substance that can be used as the plasticizer of the present invention. Liquid oils such as liquid paraffin, paraffinic, naphthenic, and aromatic, liquid rubber such as liquid polyisoprene, ester plasticizer, vegetable oil, liquid polybutene, paraffin wax, microcrystalline wax, polyethylene wax, polypropylene wax, Examples include acid anhydride-modified polybutene, acid anhydride-modified liquid polyisoprene, acid anhydride-modified polyethylene wax, acid anhydride-modified polypropylene wax, and the like. These may be used alone or in combination. Preferably, at least one selected from the group of liquid paraffin, process oil, and liquid polybutene having a large effect of improving fluidity may be used. In order to improve the adhesive strength of the adhesive, one kind selected from the group of acid anhydride-modified polybutene, acid anhydride-modified liquid polyisoprene, acid anhydride-modified polyethylene wax, and acid anhydride-modified polypropylene wax is used. do it.

The (E) engineering plastic of the present invention may be a conventionally known material that can be used as the engineering plastic of the present invention. For example, polyphenylene ether resin, modified polyphenylene ether resin, polyphenylene sulfide resin, polybutylene terephthalate resin, polycarbonate Resins etc. are mentioned, and these may be used alone or in combination of two or more.

For example, the (E) engineering plastic of the present invention may be a known polyphenylene ether resin having a number average molecular weight of 1000 or more, such as poly (2,6-dimethyl-1,4 phenylene ether), poly (2- Methyl-6-ethyl-1,4-phenylene ether), poly (2,6 diphenyl-1,4-phenylene ether), poly (2-methyl-6-phenylene-1,4-phenylene ether), poly (2, 6-dichloro-1,4-phenylene ether) and the like, and polyphenylene ether copolymers such as copolymers of 2,6-dimethylphenol and monohydric phenols. These may be used alone or in combination of two or more. Use it. The modified polyphenylene ether resin is a resin obtained by blending a styrene resin and a nylon resin in order to impart processing performance to the polyphenylene ether resin. Commercially available products are Zylon 500H manufactured by Asahi Kasei Kogyo Co., Ltd., Japan GE Plastics. SA-120 manufactured by Susu Co., Ltd.

Further, by using a polyphenylene ether resin or a modified polyphenylene ether resin as the engineering plastic (E) of the present invention, the non-adhesive polyphenylene ether resin or modified polyphenylene ether resin is compatible with the styrene phase of the high molecular weight styrene block copolymer. Therefore, the heat conductive hot melt adhesive composition of the present invention reduces the wettability of the styrene phase to the adherend at high temperatures, imparts releasability, and improves the heat resistance of the styrenic block copolymer. The temperature at which the determined styrene phase is softened can be raised to impart heat resistance. Therefore, if the heat distortion temperature or glass transition point of the polyphenylene ether resin or modified polyphenylene ether resin to be added is higher than 90 to 100 ° C., which is the glass transition temperature of the styrene resin, the purpose of imparting heat resistance can be achieved. However, in order to easily obtain heat resistance with a small addition amount, it is desirable that the heat distortion temperature is 120 ° C. or higher. Especially when heat resistance of 80 ° C. or higher is desired, the heat distortion temperature is 150 ° C. or higher. By using those, it is possible to easily obtain peelability and heat resistance with a small addition amount. For example, a commercially available polyphenylene ether resin or modified polyphenylene ether resin having a heat distortion temperature of 120 ° C. or higher can be used as the engineering plastic of the present invention.

The (F) acid anhydride-modified thermoplastic resin of the present invention may be a conventionally known substance that can be used as the acid anhydride-modified thermoplastic resin of the present invention, and 0.5 to 5% by mass of acid anhydride is used. Examples thereof include modified styrene block copolymers. For example, maleic anhydride-modified styrene-ethylenebutylene-styrene block copolymer (hereinafter referred to as “maleic anhydride-modified SEBS”), maleic anhydride-modified styrene-ethylenepropylene-styrene block copolymer (hereinafter referred to as “maleic anhydride-modified SEPS”). ), Maleic anhydride modified styrene-isoprene-styrene block copolymer (hereinafter referred to as “maleic anhydride modified SIS”), maleic anhydride modified styrene-butadiene-styrene block copolymer (hereinafter referred to as “maleic anhydride modified SBS”). These may be used singly or in combination of two or more. The maleic anhydride-modified styrene block copolymer is obtained by grafting to a styrenic block copolymer using an acid or acid anhydride containing an unsaturated group in the presence of a radical generator. As a production method, an acid anhydride, a radical generator, and a styrene block copolymer are added to an organic solvent and reacted while heating or stirring, or after mixing the above three raw materials uniformly with a high-speed stirrer, sufficient Known methods such as a method of melt-kneading with a single-screw or multi-screw extruder having kneading ability are used. If the addition amount of the acid anhydride is less than 0.5% by mass, the reactivity tends to be low and sufficient heat resistance tends not to be obtained, and if it exceeds 5% by mass, the acid anhydride is converted into a styrene block copolymer. Difficult to add. Specific examples of maleic anhydride-modified SEBS include Kraton Polymer Japan Co., Ltd., trade name Clayton FG1924X, Asahi Kasei Co., Ltd., trade name Tuftec M1943. Specific examples of maleic anhydride-modified SBS include Asahi Kasei Co., Ltd., trade name TUFPRENE 912 and the like.

The (G) epoxy resin of this invention should just use the conventionally well-known substance which can be used as an epoxy resin of this invention, and the monomer, oligomer, and polymer which have 2-10 epoxy groups in 1 molecule are mentioned. It is done. For example, bisphenol type epoxy resin, orthocresol novolak type epoxy resin, phenol novolak type epoxy resin, alicyclic epoxy resin, biphenyl type epoxy resin, stilbene type epoxy resin, naphthol type epoxy resin, triphenolmethane type epoxy resin, and these These may be used alone or in combination of two or more. The epoxy resin of the present invention is more preferably an epoxy resin having an epoxy equivalent of 100 to 5,000 g / equivalent, more preferably 150 to 1,000 g / equivalent. For example, trade names “Epicoat 828”, “Epicoat 1001”, and “Epicoat 1004” manufactured by Japan Epoxy Resin Co., Ltd. may be mentioned. When the number of epoxy groups in one molecule is less than 2, there is a tendency that the reactivity is low and sufficient heat resistance cannot be obtained. When the number of epoxy groups in one molecule exceeds 10, the pot life and storage stability tend to be adversely affected.

The content ratio of each component of the heat conductive hot melt adhesive composition of the present invention is, for example, in the range of (B) tackifier 100 to 300 parts by weight with respect to (A) 100 parts by weight of the thermoplastic resin. (C) The plasticizer is preferably set in the range of 20 to 500 parts by weight and (E) engineering plastics in the range of 0.5 to 30 parts by weight. With this content ratio, particularly good adhesiveness and heat dissipation are exhibited at the actual use temperature of room temperature to 80 ° C., and it is particularly easy to perform separation by softening and melting even at a temperature slightly exceeding 120 ° C. Moreover, if the blending amount of the (B) tackifier is less than 100 parts by weight, the tackiness becomes insufficient, and if it exceeds 300 parts by weight, the blending balance with other components is lost, and the intended effect cannot be obtained. . Further, if the blending amount of the plasticizer (C) is less than 20 parts by weight, the coating property tends to deteriorate, and if it exceeds 500 parts by weight, it softens / melts during actual use or oozes out. Or Further, when the blending amount of (E) engineering plastic is less than 0.5 parts by weight, the heat distortion temperature or the glass transition point is not increased, and the desired heat resistance cannot be obtained. At the same time, the releasability from each substrate is remarkably lowered, which is not preferable. On the other hand, if it exceeds 30 parts by weight, the softening point of the blend becomes too high, and it is not suitable for the purpose of use. In the adhesive composition, the more preferable content ratio is (B) in the range of 100 to 300 parts by weight of the tackifier with respect to 100 parts by weight of the thermoplastic resin, and (C) the plasticizer 30. Within the range of ˜400 parts by weight, (E) 1-25 parts by weight of engineering plastic.

The heat conductive hot melt adhesive composition of the present invention can be appropriately blended with an anti-aging agent or the like according to the use form, mode or application.

Examples of the anti-aging agent include various substances such as aldehydes, amines and phenols, and these may be used alone or in combination of two or more. Preferably hindered phenol, 1,1-bis- (4-hydroxyphenyl) -cyclohexane, dilauryl thiodibrovionate, tetrakis- [methylene-3- (3 ', 5'-di-tert-butyl-4' -Hydroxyphenyl) propionate] methane, tris (mixed mono- and di-nonylphenyl) phosphite, zinc di-n-butyl dithiocarbamate, and one or more selected from these groups may be used.

And the content rate of an anti-aging agent is 100 weight of (A) thermoplastic resin and (F) acid anhydride modified thermoplastic resin from a viewpoint of the anti-aging improvement of the heat conductive hot melt adhesive composition of this invention. It is preferably set in the range of 0.2 to 10 parts by weight with respect to parts.

The method for producing the heat conductive hot melt adhesive composition of the present invention is not particularly limited as long as it is a method capable of producing a heat conductive hot melt adhesive composition having a target performance, and a known method is applied. be able to. For example, the above-described components and optional additive components may be melt mixed using a heat kneader such as a roll, a Banbury mixer, a plastic bender, a kneader, a high shear mixer, a single screw extruder, a twin screw extruder, etc. A heat conductive hot melt adhesive in which the heat conductivity imparting agent is kneaded and uniformly dispersed in the heat conductive hot melt adhesive composition can be easily produced.

When using a conventional heat conductive composition as an adhesive for electronic parts, semiconductor devices, etc., the heat conductive composition is melted in a hot melt tank and is pumped to a hose via a gear pump. It is discharged from a melt shot gun or nozzle to a target location such as an electronic component or a semiconductor device. When the molten heat conductive composition is pumped to the hose via the gear pump, if the heat conductive composition has a high melt viscosity, the pressure loss in the hose increases, and the heat conductive composition is released to the hot melt tank. Alternatively, a certain amount of melt does not flow to the shotgun or nozzle, and the desired discharge amount cannot be obtained, making coating difficult.

The heat conductive hot melt adhesive composition of the present invention is a conventional pump because it melts in a hot melt tank, flows uniformly uniformly due to its own weight, and can be discharged using a gear pump. Or it can carry out without applying a great load to a hose. Moreover, since there is no release to a hot melt tank, it is not necessary to improve the apparatus. Furthermore, since the discharge property is stable and good, a constant discharge amount is obtained, the coating performance is good, and the productivity in electronic parts, semiconductor devices, automobile parts, building materials, etc. is improved.

In addition, the heat conductive hot melt adhesive composition of the present invention is a plunger pump, a pneumatic feed pump even when it is difficult to pump the hose with the gear pump described above due to its own weight. By changing to an extruder pump or the like, stable pumping can be performed and discharge can be performed. There is no great load on the hose due to the change of the pump, the stability at the time of coating is good, and the productivity in electronic parts, semiconductor devices, automobile parts, building materials, etc. is improved.

In addition, a heat conductive composition containing a conventional heat conductivity-imparting agent has a high viscosity on the composition or a high hardness of the heat conductivity-imparting agent. There is. The heat conductive hot melt adhesive composition of the present invention is economical because the load on the apparatus is small and the wear is difficult due to the selection of the (D) heat conductivity imparting agent.

The heat conductive hot melt adhesive composition of the present invention releases heat generated efficiently by being sandwiched between a heat generating part of an electronic component or a semiconductor device and a heat radiating component or a heat radiating plate as an adhesive. It is possible to reduce thermal deterioration of components, semiconductor devices, and display devices, reduce failures, and extend the life. An electronic component, a semiconductor device, etc. are mentioned, It does not specifically limit. For example, the heat conduction of the present invention between a secondary battery and a radiator in a hybrid electric vehicle or the like as a CPU (central processing element), a plasma display panel, an organic EL element, a secondary battery, etc., or a peripheral device thereof. The hot-melt adhesive composition can be used to control the temperature and stabilize the battery characteristics. Further, a radiator of an electric motor, a Peltier element, an inverter, a (high) power transistor, and the like can be used.

The heat conductive hot melt adhesive composition of the present invention can also be used for a plasma display panel. Since a plasma display panel tends to generate heat due to discharge or heat nonuniformity due to a large panel, a structure for radiating and soaking heat is necessary. The plasma display panel has a relatively large area, and a temperature difference in the panel is likely to occur depending on the color and brightness of light emission. If this temperature difference is large, there is a risk that the glass panel will break, and soaking is necessary to eliminate this temperature difference. Since the heat conductive hot melt adhesive composition of the present invention has heat conductivity and tackiness, it is suitable for bonding a plasma display panel and a heat sink. In addition, the plasma display panel and the heat sink are not completely flat, and there are slight irregularities, so that flexibility is required to improve adhesion. The heat conductive hot melt adhesive composition of the present invention is excellent in tackiness, flexibility, adhesion, flame retardancy, and durability in addition to heat conductivity, heat resistance, and adhesiveness. Also suitable for use in display panels.

The heat conductive hot melt adhesive composition of the present invention can be used for automobiles and parts thereof. The automobile needs to have a structure that dissipates heat generated by the discharge of power ICs such as electric junction boxes and semiconductor switching power elements, and battery modules of electric cars and hybrid cars. Heating elements (power ICs, semiconductor switching power elements, battery modules) can be dissipated by connecting to a radiator (chassis) that is in contact with the outside air. Structurally, the thermal conductivity becomes poor due to the separation of the connecting part due to vibrations or the like during actual use, and as a result, failure of the parts may occur. Since the heat conductive hot melt adhesive composition of the present invention has both adhesiveness and flexibility in addition to heat conductivity, it is very suitable as a material for interposing a heating element and a heat dissipation element that are parts of an automobile. Yes.

The method for sandwiching the heat conductive hot melt adhesive composition of the present invention between the heat generator and the heat radiator is not particularly limited, and a known method can be applied. For example, a method of adhering a heat generating body by sticking a heat conductive hot melt adhesive composition sheet prepared by an extruder or a solvent method to a heat radiator, a method of adhering a heat radiator by sticking a sheet prepared by the above method to a heat generator, A method in which a heat conductive hot melt adhesive composition is melted and applied directly to a radiator and a heating element is bonded. A heat conductive hot melt adhesive composition is melted and applied directly to a heat generator. There is a method of bonding. The method of manufacturing and bonding the sheet is divided into two stages, that is, a process of manufacturing the sheet and a process of bonding, and thus is not efficient in terms of productivity and time. The adhesion method in which melt coating is directly applied to the heat generator or the heat radiator is particularly preferable from the viewpoint of continuous productivity and shortening of production time because the number of steps is small.

The heat conductive hot melt adhesive composition of the present invention can be melt coated using a known apparatus, and the shape at the time of melt coating is appropriately changed depending on the material and shape of the object to be coated. It is possible and is not particularly limited, and a known shape can be applied. For example, it may be formed in a stripe shape, a sheet shape, a spiral spray shape, a curtain spray shape, a dot shape, or the like.

Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. However, this is merely an example, and the present invention is not limited thereto unless it exceeds the gist.

The evaluation methods used in the examples and comparative examples are as follows.

Thermal conductivity: A rapid thermal conductivity meter QTM-500 manufactured by Kyoto Electronics Industry Co., Ltd. was used as an apparatus measured by the probe method. The test piece used was a press sheet having a width of 70 mm, a length of 150 mm, and a thickness of 20 mm. The measurement environment temperature was 20.0 ± 1.0 ° C.

Average particle diameter, ratio of particle diameter of 2 μm or less: Laser diffraction scattering apparatus (microtrack method) was used. When the cumulative curve was obtained by determining the particle size of the fine particles containing secondary aggregates with the total volume of the powder population as 100%, the particle size at the point where the cumulative curve was 50% was measured as the average particle size.

Heat resistance: Evaluated by SAFT (shear bond failure temperature) test. A test piece was prepared by applying a hot melt adhesive to a glass plate to a thickness of 1 mm. The test condition is that the test piece is 25 mm in width and 25 mm in length, and is bonded to an aluminum plate by reciprocating a 2 kg roller. A 500 g load is applied to the bonded pieces in this manner, the temperature is raised at a pace of 2 ° C./5 minutes, and the drop temperature is measured. The measurement was performed from room temperature to 180 ° C. 90 ° C. or higher was defined as “good” and less than 90 ° C. was defined as “bad”.

Self-weight: 10 ml of a granular heat conductive hot melt adhesive composition is placed in a 20 ml glass bottle and allowed to stand in a thermostatic bath at 200 ° C. for 2 hours, and then the state of the hot melt adhesive in the glass bottle is observed. The shape of the granular hot-melt adhesive is broken, and what is almost in a molten state is "good", the bulk of the hot-melt adhesive in the glass bottle is reduced, but the granular shape is partially The remaining ones that were not in the molten state were evaluated as “good” as being slightly good, and those that were not changed in a granular shape were determined as “not good” as being defective.

Coating property: After the adhesive composition is melted in a 200 ° C. melting tank, it is melt coated in a 3 mm diameter bead shape on a glass surface with a pneumatic feed pump. A sample having good dischargeability when melt-coated was defined as “good” and a sample having difficulty in discharge was defined as “impossible”.

The components used in Examples and Comparative Examples are as follows.
Component (A) -1: Thermoplastic resin (manufactured by Kuraray Co., Ltd., trade name: Septon 2007, styrene / ethylene / propylene / ethylene copolymer, styrene addition content 30 mass%), component (A) -2 : Thermoplastic resin (manufactured by Kraton Polymer Japan Co., Ltd., trade name: Kraton FG-1924, styrene-ethylene-butylene-styrene block copolymer, styrene addition content 13 mass%), Component (B): Tackifying resin ( Yashara Chemical Co., Ltd., trade name: Clearon P-150), Component (C): Plasticizer (manufactured by Idemitsu Kosan Co., Ltd., trade name: Process Oil PW-90, paraffin oil), Component (D) -1 : Thermal conductivity-imparting agent (manufactured by Kamishima Chemical Industry Co., Ltd., magnesium hydroxide, average particle diameter 7.8 μm, ratio 15% of 2 μm or less), component (D) -2: heat transfer Conductivity-imparting agent (manufactured by Kamishima Chemical Industry Co., Ltd., magnesium hydroxide, average particle diameter 20.0 μm, 5% ratio of 2 μm or less), component (D) -3: thermal conductivity-imparting agent (Kamishima Chemical Industry Co., Ltd. ), Magnesium carbonate, average particle size 6.0 μm, ratio of 2 μm or less 0%), component (D) -4: thermal conductivity imparting agent (manufactured by Kamishima Chemical Co., Ltd., magnesium carbonate, average particle size 21.). 0 [mu] m, 2 [mu] m ratio 0%), Component (D) -5: Thermal conductivity imparting agent (Showa Denko KK, trade name: AS-50, aluminum oxide, average particle size 10.0 [mu] m, 2 [mu] m or less. Ratio 8%), component (D) -6: thermal conductivity imparting agent (manufactured by Kamishima Chemical Industry Co., Ltd., trade name: electrofused magnesia A25, magnesium oxide, average particle diameter 25.0 μm, ratio of 2 μm or less 12% ), Component (D) -7: Thermal conductivity-imparting agent (Sui Co., Ltd.) Trade name: SGP25, graphite, average particle size 25.0 μm, ratio 5% of 2 μm or less), component (D) -8: thermal conductivity imparting agent (manufactured by Kamishima Chemical Co., Ltd., magnesium hydroxide, Average particle diameter 2.8 μm, ratio 25% of 2 μm or less), Component (D) -9: Thermal conductivity imparting agent (Furukawa Electronics Co., Ltd., trade name: FAN-f80, aluminum nitride, average particle diameter 80 μm, 2% or less 1%), component (E): engineering plastic (manufactured by GE Plastics Japan, trade name: SA-120, polyphenylene ether)

Examples 1-33, Comparative Examples 1-4
Using an adhesive composition obtained by blending the above components in the proportions shown in Table 1 below, the thermal conductivity, melt viscosity, heat resistance, fluidity, and coatability were evaluated according to the above methods. The obtained results are shown in Table 1.

From the above results, Examples 1 to 33 had heat conductivity of 0.4 W / mK or more, good weight, good heat resistance, and good coatability. In Comparative Examples 1 and 3, the thermal conductivity was good, but the self-weight and coating properties were reduced. In Comparative Example 2, the thermal conductivity was insufficient. In Comparative Example 4, good results were obtained in terms of thermal conductivity, self-weight, and coatability, but the heat resistance was lowered and the intended performance could not be obtained. If the composition and blending amount described in the present invention are appropriately used, a product with higher quality and desired performance can be obtained.

The present invention relates to an adhesive comprising the thermally conductive hot melt adhesive composition of the present invention. For example, the thermally conductive hot melt adhesive composition of the present invention is used as the adhesive or an electronic component, By providing a semiconductor device or display device, and between a heat generator such as an automobile and its parts, building materials, and a heat radiator, the high-performance device capable of withstanding a higher load than before is configured. Related to the use.

Claims (1)

It comprises (D) a thermal conductivity imparting agent having an average particle size of 5 to 80 μm having a particle size distribution containing 0 to 40 vol% of a particle size of less than 2 μm, and has a thermal conductivity of 0.4 W / mK or more. (A) 100 to 300 parts by weight of a styrene-based elastomer, (B) 100 to 300 parts by weight of a tackifier, (C) 20 to 500 parts by weight of a plasticizer, and (D) magnesium carbonate and / or magnesium hydroxide 1500. An adhesive comprising a thermally conductive hot melt adhesive composition containing -10,000 parts by weight and (E) 0.5-30 parts by weight of a polyphenylene ether resin and / or a modified polyphenylene ether resin.