JP6168851B2 - Heat radiation resin molding - Google Patents

Description

  The present invention relates to a heat-dissipating resin molded body that improves heat dissipation characteristics of electronic / electrical parts and the like, and more particularly, to a heat-dissipating resin molded body that can improve heat dissipation by contacting an object that requires heat dissipation. Is.

  In recent years, in the field of electronic devices such as personal computers, mobile phones, digital cameras, projectors, optical disk devices, information terminals, etc., composite functions, high performance, miniaturization, thinning, weight reduction, etc. have progressed, and the amount of signals handled Due to the increase in processing speed and the increase in processing speed, the heat generated from electronic components tends to increase. Also, in the electrical field such as automobiles and lighting, especially when only automobiles are viewed, the number of electronic components mounted on the vehicle is increasing, and with downsizing and higher performance, etc. The amount of heat generated by parts is increasing. When the calorific value of the electronic component increases, the temperature inside the electronic component or device rises, and the heat may reduce the function of the electronic component or device, cause malfunction, or damage. For this reason, heat dissipation design for heat countermeasures to dissipate the heat generated in various electronic components more efficiently is a very important issue, and the development of materials that exhibit high heat dissipation characteristics for heat sources such as electronic components It is being advanced.

  By the way, as a heat dissipation material exhibiting heat dissipation characteristics, metal materials and ceramic materials having high thermal conductivity have been conventionally used in electronic component housings, etc., but further miniaturization, weight reduction, high performance, etc. of components have been used. Therefore, light weight and high moldability are required. Therefore, as a material that meets these requirements, an alternative to a resin material that has a high degree of freedom in shape selection and is inexpensive is in progress. However, general-purpose resins themselves have low thermal conductivity. For this reason, attempts have been made to increase the thermal conductivity of resin compositions by, for example, Patent Document 1 and Patent Document 2 by filling a resin with a high thermal conductivity filling material to form a composite material. Yes.

JP 2009-007552 A JP 2003-120688 A

  However, the resin molded products described in Patent Document 1 and Patent Document 2 are inventions regarding a heat conductive resin in which a high thermal conductivity filling material is filled into the resin to increase the heat conductivity. Although the molded product itself has a high thermal conductivity, it may not be used as a heat dissipation design unless other characteristics other than the thermal conductivity are satisfied. Therefore, in order to satisfy other characteristics other than the thermal conductivity, heat dissipation is improved by bringing a molded body of heat conductive resin with increased thermal conductivity into contact with the molded body to be radiated (hereinafter referred to as heat dissipation object). Measures can be considered. At this time, if the surface of the heat conductive resin molded body in contact with the heat radiation object is rough, the contact area between the heat radiation object and the heat conductive resin molded body is small, and the heat radiation object and the heat conductive resin molded body The gap acts as a heat insulating layer, impeding heat conduction.

  Then, this invention is made | formed in view of the said situation, and makes it a subject to provide the thermal radiation resin molded object which makes a thermal radiation object contact and enables heat dissipation improvement.

The heat-dissipating resin molding of the invention of claim 1 contains a thermoplastic resin as a synthetic organic resin , a thermally conductive filler, and basic magnesium sulfate or calcium titanate having an old Mohs hardness of 5 or less as an inorganic short fiber. A molded article obtained by molding a resin composition, wherein the molded article has a surface roughness of 10-point average roughness Rz of less than 6 μm.
Here, the ten-point average roughness Rz is the highest peak measured by extracting only the reference length (L) from the roughness curve in the direction of the average line and measuring in the direction of the vertical magnification from the average line of the extracted portion. Calculate the sum of the absolute value of the altitude (Yp) of the top of the mountain from the first to the fifth and the average of the absolute value of the altitude (Yv) of the bottom from the lowest valley to the fifth. The value is expressed in terms of (μm), and is a value measured according to JIS B 0601 (1994). The average at this time is a value of an arithmetic average (also referred to as an arithmetic average). In the present invention, the average is a value of an arithmetic average (also referred to as an arithmetic average).

  Here, the old Mohs hardness is indicated by an index of the hardness of the mineral with the hardness defined as 1 to 10, and specifically, the standard material is rubbed with a sample material for measuring the hardness, and the hardness is determined by the presence or absence of scratches. Measure the thickness. The new Mohs hardness is the old Mohs hardness divided into 15 levels.

  The heat-radiating resin molding of the invention of claim 2 is such that the inorganic short fibers of the resin composition are in the range of an average fiber diameter of 0.1 μm to 1.0 μm and an average fiber length of 3 μm to 30 μm. It is.

  In the heat-dissipating resin molded body of the invention of claim 3, the blending ratio of the inorganic short fibers of the resin composition is in the range of 1% by weight to 50% by weight with respect to the whole resin composition.

In the heat-dissipating resin molded body of the invention of claim 4, the resin composition further contains reinforcing fibers, and the blending ratio of the inorganic short fibers of the resin composition is such that the thermoplastic resin , the thermally conductive filler, and the It is within the range of 1 to 30 parts by weight with respect to 100 parts by weight of the total content with the reinforcing fibers.

  The heat-dissipating resin molded body of the invention of claim 5 is the structure of claim 4, wherein the blending ratio of the inorganic short fibers of the resin composition is within the range of 5% by weight to 10% by weight in the whole resin composition. There is something. In addition, the above-mentioned various numerical values are not required to be strict, but are approximate, and are naturally approximate values including errors due to measurement and the like, and do not deny errors of several percent.

The heat-dissipating resin molded body according to the invention of claim 1 is a molded body obtained by molding a resin composition containing a thermoplastic resin , a thermally conductive filler, and an inorganic short fiber as an organic synthetic resin . The surface roughness is less than 6 μm in terms of 10-point average roughness Rz.
Here, the present inventors have conducted extensive experimental research on a resin composition capable of forming a molded product having high heat dissipation, and as a result, in a resin composition containing a thermoplastic resin as an organic synthetic resin and a thermally conductive filler. By adding inorganic short fibers, the surface roughness of the molded body obtained from the resin composition is improved and adhesion to the heat dissipation object is increased, thereby increasing heat conduction from the heat dissipation object, thereby increasing the heat dissipation object. The present invention has been completed by finding that the heat radiation from the heat is improved.
That is, according to the heat-dissipating resin molded body of the present invention, the blended inorganic short fibers improve the surface roughness of the molded body to be less than 6 μ in terms of the 10-point average roughness Rz, resulting in a smooth surface. Property is obtained, and the adhesiveness to the heat dissipation object is improved. Therefore, heat can be efficiently conducted from the heat dissipation object by bringing it into contact with the heat dissipation object, and heat dissipation is further enhanced by the high thermal conductivity of the heat conductive filler.

  According to the heat radiating resin molded body according to the present invention, the old Mohs hardness of the inorganic short fibers is 5 or less. Thus, by disposing soft inorganic short fibers having a small hardness in the resin composition, it is possible to obtain a heat-dissipating resin molded body having good surface smoothness. Therefore, good adhesion to the object to be radiated can be easily obtained, and heat can be radiated by conducting heat from the object to be radiated more efficiently.

  According to the heat radiating resin molded body of the invention of claim 2, the inorganic short fibers of the resin composition have an average fiber diameter in the range of 0.1 μm to 1.0 μm and an average fiber length of 3 μm to 30 μm. By defining the average fiber diameter and the average fiber length within this range, in addition to the effect of the first aspect, a heat radiation resin molded body having a smooth surface can be obtained more reliably.

  According to the heat-radiating resin molded body of the invention of claim 3, the inorganic short fibers are blended in a blending ratio within the range of 1% by weight to 50% by weight in the entire resin composition, and the inorganic short fibers are in the above range. In addition to the effect of Claim 1 or Claim 2, the heat dissipation resin molding with high surface smoothness is stably obtained by mix | blending inside.

According to the heat-dissipating resin molded body according to the invention of claim 4, the resin composition further contains reinforcing fibers, and the blending ratio of the inorganic short fibers is the thermoplastic resin , the thermally conductive filler, and the reinforcing fibers. With respect to the total amount of 100 parts by weight, the amount is in the range of 1 to 30 parts by weight. Thereby, in addition to the effect of Claim 1 or Claim 2, when the reinforcement fiber is contained, the molded object which is excellent in surface smoothness is obtained stably.

  According to the heat-radiating resin molded body of the invention of claim 5, the blending ratio of the inorganic short fibers is in the range of 5% by weight to 10% by weight in the entire resin composition. Thereby, in addition to the effect of Claim 4, when the fibrous fillers, such as a reinforced fiber, are contained, the molded object which is excellent in surface smoothness is obtained more stably.

FIG. 1 is a schematic view when a resin composition is prepared using an extruder as a melt kneader. FIG. 2 is an explanatory diagram for explaining a measurement method for heat dissipation. FIG. 3 is a characteristic diagram showing the relationship between the surface roughness of the molded body and the heat dissipation in comparison between Example 1 and Comparative Example 1.

Embodiments of the present invention will be described below.
The heat-dissipating resin molded body according to the present embodiment is obtained by molding a resin composition containing an organic synthetic resin, a thermally conductive filler, and inorganic short fibers.

Conventionally, as a thermally conductive resin material, additives other than resin, for example, when a large amount of filler such as a thermally conductive filler is added in order to improve heat dissipation, the moldability decreases due to a decrease in fluidity, and the molded body It is difficult to obtain smooth surface. Therefore, it was unsuitable for making it heat-dissipate in close contact with the heat dissipation object.
Therefore, in the present invention, the surface roughness of the molded body is improved by blending the inorganic short fibers while ensuring the desired thermal conductivity with the thermally conductive filler, that is, excellent adhesion to the heat dissipation object. It is possible to secure.

  Here, as the inorganic short fiber capable of improving the surface roughness in the molded body, basic magnesium sulfate, potassium titanate, etc., which exhibit insulation properties can be used, and these are relatively easily available and inexpensive. And the specific gravity is small. Moreover, these can be used individually by 1 type or in combination of 2 or more types, However, It is preferable to use basic magnesium sulfate and potassium titanate. This is because these are short inorganic fibers having an old Mohs hardness of 5 or less. In addition, these inorganic short fibers may be subjected to surface treatment such as stearic acid-based coupling by a supercritical CVD (chemical vapor deposition) method or the like. Furthermore, it is also possible to use an anhydride having no hydrate by heat treatment at 300 ° C. to 600 ° C.

The inorganic short fibers preferably have an average fiber diameter of 0.1 μm to 1.0 μm and an average fiber length of 3 μm to 30 μm.
When the average fiber diameter exceeds 1.0 μm, the filling rate is reduced and the uniform dispersibility is deteriorated, and the fluidity and molding processability at the time of molding are lowered, and the surface roughness of the surface of the heat-dissipating resin molded body is deteriorated. . On the other hand, inorganic short fibers having an average fiber diameter of less than 0.1 μm are relatively difficult to produce and are difficult to obtain, and moreover, fibers tend to aggregate and are difficult to disperse uniformly, or may be molded. Sometimes it breaks easily and lacks stability.

On the other hand, if the average fiber length is longer than 30 μm, uniform dispersibility is lacking due to a decrease in filling rate or entanglement between fibers, and fluidity and molding processability at the time of molding are reduced, resulting in a surface roughness of the surface of the heat-dissipating resin molded body. It gets worse. On the other hand, inorganic short fibers having an average fiber length of less than 3 μm are relatively difficult to produce and difficult to obtain, and the fibers tend to agglomerate, making it difficult to uniformly disperse them.
Therefore, by using inorganic short fibers having an average fiber diameter of 0.1 μm to 1.0 μm and an average fiber length of 3 μm to 30 μm, it is possible to form a heat dissipation resin molded body having a high surface smoothness.

Such inorganic short fibers are preferably blended at a blending ratio in the range of 1% by weight to 50% by weight in the entire resin composition. By setting the blending ratio of the inorganic short fibers within this range, a molded article having a surface roughness of less than 10-point average roughness Rz 6 μm can be stably obtained.
In particular, when blending fibrous reinforcing fibers described later in the resin composition, the blending ratio of the inorganic short fibers is 1 weight with respect to 100 parts by weight of the total amount of the organic synthetic resin, the heat conductive filler, and the reinforcing fibers. By making it within the range of 30 parts by weight to 30 parts by weight, it is possible to achieve both the reinforcement of the heat-dissipating resin molding and the heat dissipation. Furthermore, when arranging such fibrous fillers such as reinforcing fibers in the resin composition, the blending ratio of the inorganic short fibers is still more preferably in the range of 5 wt% to 10 wt% in the entire resin composition. preferable.

Examples of the organic synthetic resin of such resin composition according to the present embodiment, positive Riechiren (PE) resin, polypropylene (PP) resin, polyvinyl chloride (PVC) resins, polyvinylidene chloride (PVDC) resin, polystyrene (PS) resin, polyvinyl acetate (PVAc) resin, an acrylic (PMMA) resin, acrylonitrile styrene (AS) tree butter, Po Li polytetrafluoroethylene (PTFE) resin, polysulfone (PSF) resin, polyethersulfone ( PES) resin, polysulfone (PSF) resin, polyarylate (PAR) resin, liquid crystal polymer (LCP) resin, amorphous polyarate (PAR) resin, polyetheretherketone (PEEK) resin, thermoplastic polyimide (PI) resin, polyamide Imide (PAI) resin, Aramid (AR) tree Polyamide resins such as ABS resin and polyamide (PA) resin, polyacetal (POM) resin, polycarbonate (PC) resin, modified polyphenylene ether (PPE) resin, polybutylene terephthalate (PBT) resin, polyethylene terephthalate (PET) resin, Examples thereof include thermoplastic resins such as polyphenylene sulfide (PPS) resin and cyclic polyolefin (COP) resin, and these can be used alone or in combination of two or more.
In particular, polyphenylene sulfide (PPS) resin has high heat resistance, mechanical properties, chemical resistance, dimensional stability, and flame retardancy. Can be widely used for chemical equipment parts materials.

  The blending ratio of the organic synthetic resin is preferably in the range of 20% by weight to 70% by weight in the entire resin composition. When the blending ratio of the organic synthetic resin is less than 20% by weight, it becomes brittle and the strength is insufficient. On the other hand, when it exceeds 70% by weight, the blending amount of the heat conductive filler in the entire resin composition is small and sufficient. This is because heat dissipation cannot be obtained.

  Furthermore, the heat conductive filler blended in the resin composition according to the present embodiment may be insulating or conductive. Examples of the insulating heat conductive filler include boron nitride and aluminum nitride. Nitrogen compounds such as silicon nitride, metal oxides such as aluminum oxide, magnesium oxide, zinc oxide, silicon oxide, beryllium oxide, copper oxide and cuprous oxide, and metal hydroxides such as magnesium hydroxide and aluminum hydroxide In addition, carbon compounds such as magnesite (magnesium carbonate), silicon carbide and diamond, ceramics such as silica, talc, mica, kaolin, bentonite and pyroferrite, titanium boride, calcium titanate and the like can be used.

  Among these, nitrogen compounds such as boron nitride and aluminum nitride are preferable, and boron nitride is particularly preferable from the viewpoints of thermal conductivity, warpage of a molded product, and the like. This boron nitride is composed of c-BN (cubic structure), w-BN (wurtzite structure), h-BN (hexagonal structure), r-BN (rhombohedral structure), t-BN (turbulent layer). Any structure such as (structure) may be used, but a hexagonal structure type having a structure similar to graphite is preferable. By using boron nitride having a hexagonal crystal structure, it is possible to reduce wear of a molding machine or a mold used when obtaining a molded body. In addition, there are spherical and scaly forms of boron nitride, and any of them can be used in the present invention. When a scaly thing is used, it has excellent insulating properties and good mechanical properties. Can be obtained.

In addition, as the conductive heat conductive filler, carbon such as graphite, carbon black, graphite, carbon fiber (especially, coal pitch type (Pitch), PAN type is preferable), carbon nanotube (CNT), carbon nanofiber (CNF), etc. Compounds, metal fibers such as silver, copper, nickel, aluminum, stainless steel, titanium, SUS, or metal powder, metal oxides such as tin oxide and zinc oxide, and metal compounds such as ferrites can be used.
Among these, carbon compounds such as carbon fibers are preferable because they are inexpensive and can effectively improve thermal conductivity and conductivity.

  These thermally conductive fillers can be used singly or in combination of two or more, but the insulating or conductive electrical characteristics are selected according to the use of the resin composition. In addition, about the shape of a heat conductive filler, the thing of various shapes can be used, for example, fiber shape, plate shape, scale shape, rod shape, granular shape, rod shape, tube shape, curved plate shape, needle shape, curved plate Shape, needle shape and the like. Moreover, these heat conductive fillers may be subjected to surface treatment such as silane coupling treatment, titanate coupling treatment, epoxy treatment, urethane treatment, oxidation treatment and the like. By such surface treatment being performed, adhesion and affinity with the resin interface are improved, and workability such as kneading is easy. In addition, it is also possible to use an insulating filler in which insulation is imparted to the conductive filler by coating the conductive filler with silica, and this can be used as a thermally conductive filler.

The blending ratio of the heat conductive filler is preferably in the range of 5% by weight to 50% by weight in the entire resin composition. When the blending ratio of the heat conductive filler is less than 5% by weight, the resin composition has a low thermal conductivity and sufficient heat dissipation cannot be obtained. The specific gravity of the product increases, the fluidity decreases, the molding processability deteriorates, and the amount of inorganic short fibers is less than the amount of thermally conductive filler, improving the surface roughness of the heat-dissipating resin molding This is because it is not possible to obtain.
In particular, in the present embodiment, by blending the inorganic short fibers, a molded article having a good surface smoothness with a surface roughness of less than Rz 6 μm can be obtained even when the thermally conductive filler is highly filled. Therefore, it is possible to obtain excellent thermal conductivity from the object to be radiated.

Moreover, in the resin composition concerning this Embodiment, in order to improve intensity | strength and rigidity, it is also possible to mix | blend fillers, such as a reinforced fiber. Examples of the reinforcing fiber appropriately blended in the resin composition according to the present embodiment include glass fiber (chopped fiber, milled fiber, etc.) aramid fiber, PBO fiber (Zylon), carbon fiber, boron fiber, polyethylene fiber (Dyneema). Nylon fiber, kenaf, hemp, flax, alumina fiber, silica fiber, potassium titanate fiber, carbide fiber such as silicon carbide, nitride fiber such as silicon nitride, etc. alone or in combination be able to.
In addition, it is preferable that the mixture ratio of a reinforced fiber shall be 50 weight% or less in the whole resin composition. If it exceeds 50% by weight, the blending amount of the heat conductive filler and the inorganic short fibers in the entire resin composition of the heat radiating resin molded body is reduced, and sufficient heat dissipation cannot be obtained.

  The resin composition according to the present embodiment is usually obtained by melting and kneading these raw material components in various known melt kneaders, pelletized, and resin molding material, mainly as a material for injection molding. It is provided, and is formed into a desired shape by a known molding method such as injection molding to obtain a heat radiation resin molded body. In addition, before melt-kneading, if necessary, the raw material components are mixed by mixing means such as a Henschel mixer, V-type blender, mechanochemical device, extrusion mixer, static mixer, dynamic mixer, tumbler, super mixer, plast mill, etc. It is also possible to do. Also, the preparation of the resin composition is preferably a melt-kneading method in terms of industrial cost, but is not limited to this, and for example, it is prepared by a solution mixing method in which a solution such as hydrocarbon is added and mixed. Is also possible.

Here, as the melt kneader, a single-screw or multi-screw extruder, a Banbury mixer, a kneader, a roll, a feeder ruder, a brabender, or the like can be used. In particular, as the extruder, a single-screw type or twin-screw type extruder can be used, and preferably has a vent capable of degassing moisture in the raw material and volatile gas generated from the resin, and a good kneading state This is a bent type twin screw extruder.
In addition, the method of supplying the raw material components to these melt-kneaders is not particularly limited, and each raw material component can be supplied individually, or each raw material component may be supplied in a batch, You may divide and mix into a hopper or a side feeder and supply them sequentially.

In particular, in the case of blending components that are easily destroyed by melt-kneading, for example, glass fibers, etc., if raw materials are supplied all at once to a melt-kneader such as a biaxial extruder, Components that are easily destroyed are finely crushed by shearing during kneading extrusion and the function of the components is reduced, so that components other than those that are easily destroyed are supplied to the hopper upstream of the melt-kneader, and components that are easily destroyed after the middle stream It is desirable to add side feed that is supplied to the side feeder of the melt kneader and kneaded. As a result, it is possible to maintain the size and shape of components that are easily broken, such as glass fibers, and to obtain characteristics such as sufficient strength and rigidity in the molded body after molding.
The resin extruded by a melt kneader such as an extruder is directly cut into pellets, or after forming a strand, the strand is cut with a pelletizer or the like to be pelletized.

  Further, as the molding method, a molding method generally used for the resin composition, for example, injection molding, extrusion molding, blow molding, press molding, compression molding, hollow molding such as gas assist, vacuum molding, calendar molding, Atypical molding, rotational molding, transfer molding, film molding, foam molding (including supercritical fluid), sheet molding, thermoforming, laminate molding, and the like can be used, and melt molding such as injection molding is particularly preferable. According to the injection molding method of pouring into the mold at high pressure, fibrous compounded components such as inorganic short fibers and reinforcing fibers tend to be oriented parallel to the injection direction, preventing the filler from floating on the surface of the molded body. It is easy to obtain a molded body having a smooth surface. In addition, it is also possible to control the orientation of the compounding components by applying a magnetic field, an electric field, an ultrasonic wave, or the like during the molding process.

  Furthermore, as a molding form of the heat radiating resin molded body, various forms such as a resin molded product, a resin film, a resin sheet, and the like are made in accordance with the heat radiating object in order to make the heat radiating object improved by contacting with the heat radiating object. It can be illustrated. By forming a heat-dissipating resin molded body with improved surface roughness and excellent surface smoothness in these molding forms, it is possible to improve adhesion to a heat-dissipating object, and to efficiently transmit and dissipate heat. .

  The heat-radiating resin molded body of the resin composition formed in this way is improved in surface roughness due to the addition of inorganic short fibers while ensuring high thermal conductivity by the thermally conductive filler. A smooth surface property of an average roughness Rz of less than 6 μm is obtained, and an excellent surface appearance is obtained. Therefore, when the surface roughness is improved, when it is joined to the object to be radiated, the contact area with the object to be radiated becomes large and the adhesiveness is increased, thereby causing a contact thermal resistance or a gap with the object to be radiated. The heat insulating property is reduced, the heat of the object to be radiated is easily conducted, and the heat radiating property to lower the temperature of the object by the heat dissipation is increased.

And the heat radiating resin molded body of the present embodiment with improved heat dissipation as described above is an electronic material, a magnetic material, a catalyst material, a structure material, as a heat radiating material for releasing heat of electronic parts and the like to the outside. Various uses such as optical materials, medical materials, automotive materials, building materials, for example, heat sinks that diffuse heat by joining to heat sources, heat dissipation fins, home appliances, OA equipment parts, AV equipment parts, precision Equipment, housings for automobile interior and exterior parts (for example, housings for personal computers and mobile phones, housings for semiconductor elements such as power transistors and diodes, in-vehicle ECUs, housings for light emitting elements such as LEDs, housings for motor cores, etc.) Casing (for example, fan motor casing, secondary battery case, personal computer or mobile phone casing), chassis, heat sink, Projection plates (for example, backlights for liquid crystal display devices, scanner lamps for facsimile devices or scanner devices, reflectors for automobile headlamps, etc.), heat exchangers, substrates (for example, substrates for mounting electronic components, optical pickup bases, etc.) , Separators, thermoelectric conversion elements, fans, packings, panels, and other injection molded products.
In particular, since the resin composition of the present embodiment is a resin, it is easy to mold a complex shape, has high processability, and is light in material, so it is molded from such a resin composition. In the heat-dissipating resin molded body, the degree of freedom of the applicable product shape is high as compared with the metal material, and the cost and weight can be reduced.

  Incidentally, specific product parts that can use the heat-dissipating resin molded body formed from the resin composition of the present embodiment include, for example, personal computers, game machines, VTRs, TVs, irons, air conditioners, air purifiers, negative ions, and the like. Generators, vacuum cleaners, refrigerators, irons, hair dryers and other beauty equipment, lighting equipment, rice cookers, microwave ovens, microwave cooking pots, cooking utensils such as heat-resistant dishes, and portable information terminals ( So-called PDAs), electronic dictionaries, electronic books, mobile TVs, compact discs, laser discs (registered trademark), recording media (CD, MD, DVD, next-generation high-density discs, hard disks, IC cards, smart media, memory sticks, etc.) Drives / readers, optical cable ferrules, coils, sealing elements such as semiconductor elements and resistors, terminal blocks, Electrical / electronic parts such as lint boards, circuit boards, chips, thermal heads, sensors, connectors, sockets, relay parts, coil bobbins, optical pickups, oscillators, LSIs, CPUs, computer-related parts, LED lighting, lamp sockets, lamps Lighting fixture parts such as reflectors and lamp housings, display devices such as CRTs, liquid crystals, plasmas, projectors, organic ELs, audio back panels, acoustic product parts such as stereos and speakers, printers, copiers, scanners, fax machines, separations Copier / printer-related parts such as nails and heater holders, pachinko and slot machine-related parts, machine parts such as impellers, fan gears, gears, bearings, motor parts and cases, and power distribution parts such as breakers , Automotive mechanical parts, Automotive parts such as engine parts, engine compartment parts, lamp reflectors, lamp housings, instrument panels, center console panels, deflectors, lamps, car stereos, car navigation, car audio visuals, auto mobile computer parts, etc. Vehicle parts, aircraft / spacecraft parts, sensor parts, telephone (cell phones, landline phones, etc.), communication equipment parts such as modems, optical cameras, digital cameras, typewriters, etc. -Product parts such as recording equipment, parabolic antennas, and power tools.

Next, examples of the heat-dissipating resin molded body according to the embodiment of the present invention will be specifically described with reference to FIGS. 1 to 3.
The resin composition forming the heat-dissipating resin molded body of this example uses polyphenylene sulfide (PPS: “MA510” manufactured by DIC Corporation) as an organic synthetic resin, and boron nitride (momentive Materials Performance Japan GK “PT110S”) and glass fiber (flat glass fiber: “CSG3PA-830S” manufactured by Nitto Boseki Co., Ltd.) Fiber diameter major axis 27 μm, minor axis 4 μm, fiber Table 1 using basic magnesium sulfate ("Moss Heidi" fiber diameter 0.5 to 1.0 µm, fiber length 10 to 30 µm, manufactured by Ube Materials Co., Ltd.) as inorganic short fibers. As shown, Example 1 and Example 2 were blended and prepared.

The preparation method will be described in more detail with reference to FIG. 1. Polyphenylene sulfide (PPS) 1 as an organic synthetic resin, boron nitride 2 as a heat conductive filler, and basic magnesium sulfate 3 as an inorganic short fiber are premixed. The mixed mixture is put into a hopper 21 upstream of a vent type twin-screw extruder (“PCM30 type” manufactured by Ikegai Co., Ltd.) 20 and melt-kneaded. Further, the glass fibers 4 as reinforcing fibers are independently vented. In addition to the side feeder 22 on the downstream side of the twin screw extruder 20, the feed is halfway fed and melted and kneaded, and then the strand is extruded, and the strand is air-cooled and then cut using a hot cutter 23 to obtain the resin composition pellets 10. Prepared.
Next, the resin composition pellets 10 were injection molded to form a heat-dissipating resin molded body 40 (FIG. 2). The shape of the heat-dissipating resin molded body 40 was a flat plate shape having a width of 80 mm, a length of 80 mm, and a thickness of 5 mm for evaluating heat dissipation described below.

And the measurement of surface roughness and the heat dissipation were performed using the said flat plate-shaped heat radiation resin molding 40. FIG.
For the measurement of the surface roughness, the surface roughness (10-point average roughness: Rz) was measured using a surface roughness shape measuring instrument (“Surfcom 1400D” manufactured by Tokyo Seimitsu Co., Ltd.). The measurement length was 4.0 mm, the cutoff wavelength was 0.8 mm, and the measurement speed was 0.15 mm / s.

  As shown in FIG. 2, the heat dissipation is measured by placing an aluminum plate 32 having a width of 80 mm, a length of 80 mm, and a thickness of 5 mm on the heater 31 and having the same shape as the heat dissipation resin molded body 40. To stabilize by heating to 120 ° C. On the aluminum plate 32 heated to 120 ° C., the heat-dissipating resin molded body 40 is placed, and on the heat-dissipating resin molded body 40, an aluminum plate having the same shape as that of the heat-dissipating resin molded body 40 has a width of 80 mm, a length of 80 mm, and a thickness of 5 mm. 33 is quickly placed, the heater 31 is turned off to stop heating, and then the upper surface of the aluminum plate 33 placed on the heat radiating resin molded body 40 is the opposite surface to the contact surface with the heat radiating resin molded body 40. The side temperature was measured over time. FIG. 3 shows the characteristics of the temperature change with time. Thereby, it is possible to know the heat radiation effect of the heat radiating resin molded body 40 when the heat radiating resin molded body 40 is joined to the aluminum plate 32 which is a heat radiating object.

  Here, for comparison, for comparison, without using basic magnesium sulfate as an inorganic short fiber, polyphenylene sulfide (PPS) as an organic synthetic resin, boron nitride as a thermally conductive filler, and reinforcing fiber A molded product of the resin composition of Comparative Example 1 produced by the same production procedure as in the above Examples was also used at the blending ratio shown in Table 1 using the glass fiber as. About the measurement of surface roughness, it carries out using the heat-radiation resin molding of Example 1 and Example 2, and the molding of the resin composition of Comparative Example 1, and about the measurement of heat dissipation, it is Example 1. The heat-dissipating resin molded body and the molded body of the resin composition of Comparative Example 1 were used.

  In addition, the numerical value of Table 1 shows each compounding component of the resin composition of an Example and a comparative example by a weight part. As shown in Table 1, in Example 1 and Example 2, the blending amounts of the organic synthetic resin and the thermally conductive filler are the same, and the blending ratio of the reinforcing fibers and the inorganic short fibers is the same, but the blending ratio is the same. In Example 1, the blending ratio of the inorganic short fibers was 10% by weight in the entire resin composition, and in Example 2, the blending ratio of the inorganic short fibers was 5% by weight in the entire resin composition. Further, in Comparative Example 1, the blending amount of the organic synthetic resin and the heat conductive filler is the same as in Example 1 and Example 2, and the reinforcing fiber is blended into this, and the blending amount of the reinforcing fiber in the entire resin composition is carried out. The total amount of Example 1 and Example 2 was the same.

Hereinafter, the measurement results will be described.
In the heat-dissipating resin molded bodies of Example 1 and Example 2, as shown in Table 1, the surface roughness (Rz) of ten-point average roughness is 2.0 μm in Example 1, and the surface in Example 2 is The roughness (Rz) is 2.9 μm, which is smaller than the surface roughness (Rz) of 6.0 μm of Comparative Example 1, and even if the total amount of filler and fibers in the molded body is the same, the inorganic short In the example in which the fibers are arranged, the surface smoothness is improved and a smooth surface is obtained.

As for the heat dissipation, in Example 1 and Comparative Example 1, as shown in the characteristic diagram of FIG. 3, the temperature from the aluminum plate 32 of the object to be radiated in Example 1 compared to Comparative Example 1 is shown. Quickly descended greatly. That is, it was found that Example 1, which has a small surface roughness (Rz) of 10-point average roughness and high surface smoothness, exhibits high heat dissipation due to good adhesion to a heat dissipation object.
In Table 1, the thermal conductivity is measured using a hot disk method (unsteady surface heat source method, ISO / CD 22007-) using a hot disk method thermophysical property measuring apparatus (manufactured by Kyoto Electronics Industry Co., Ltd., TPA-501). When measured by 2), Example 1 was 3.2 (W / m · k), and Example 2 also showed the same thermal conductivity as 3.2 (W / m · k). And the comparative example 1 was 3.3 (W / m * k) and the thermal conductivity substantially the same as Example 1 and Example 2. FIG.
Therefore, the heat radiating resin molded body of the present embodiment itself has the same high thermal conductivity as that of the conventional resin molded body according to Comparative Example 1 in which the inorganic short fibers are not blended. Improved surface smoothness allows more heat to be dissipated from the heat dissipation object.

As described above, in the heat-dissipating resin molded body of the embodiment of the present invention, polyphenylene sulfide as an organic synthetic resin and boron nitride as a heat conductive filler, a base having an old Mohs hardness of 5 or less as an inorganic short fiber By incorporating the functional magnesium sulfate, a molded body having a small surface roughness and excellent surface smoothness can be obtained. For this reason, when bonded to a heat dissipation object, the contact area with the heat dissipation object is improved and the adhesion is improved, thereby reducing the contact thermal resistance and reducing the heat insulation generated in the gap with the heat dissipation object. By doing so, the heat from the object to be radiated is easily conducted, and the heat radiation property to dissipate the heat from the object to be radiated becomes high.
In particular, as shown in Table 1, in Example 2, the total amount of the thermally conductive filler and the reinforcing fiber is 55% by weight, and the component other than the organic synthetic resin component has a high filling amount. Regardless, the incorporation of inorganic short fibers resulted in a heat-dissipating resin molded body having a small surface roughness and excellent surface smoothness, and high thermal conductivity due to the thermally conductive filler.

  In addition, according to the heat radiating resin molded body formed from the resin composition of the present embodiment, the surface roughness is small, the smoothness of the surface of the molded body is high, and there are few surface irregularities. For example, when the surface of the molded body is rubbed against another member, the convex portion is worn or the stress concentrates on the base of the convex portion, and the convex portion is damaged and the resin powder is peeled off. be able to. Also, if there are many irregularities on the surface, when a molded body containing a thermally conductive filler with good electrical conductivity is used for an electronic substrate in an electronic device, it peels off due to damage to the convex portion on the electronic substrate. The resin powder may cause an electrical short circuit, but in the heat-dissipating resin molded body formed from the resin composition of the present embodiment, the above electrical It is also possible to prevent a situation where a short circuit occurs.

  Furthermore, when carrying out the present invention, it is possible to have a structure reinforced with glass fibers as reinforcing fibers, such as a heat-dissipating resin molded body formed from the resin composition of this example. High strength, toughness and rigidity can be obtained.

  In the compounding composition of the resin composition in the heat-dissipating resin molded body of the above example, the example embodied as an injection molding material has been described. However, the present invention is not limited to this example. The blending ratio of the organic synthetic resin, the heat conductive filler, the inorganic short fiber, and the reinforcing fiber can be variously changed.

  In addition, the resin composition in the heat-dissipating resin molded body of the present invention includes a dispersant, a flame retardant, an antioxidant, a heat stabilizer, an ultraviolet light inhibitor, a weathering agent, a light stabilizer, a plasticizer, and the like as necessary. Various stabilizers, thickeners, lubricants, release agents, flame retardants, coupling agents, nucleating agents, light diffusing agents, foaming agents, antistatic agents, crosslinking agents, anti-coloring agents, pigments, dyes, coloring agents, etc. It is also possible to add other additives.

And when implementing this invention, it is not limited to the said Example about the structure of another part of a thermal radiation resin molding, a component, a mixing | blending, a manufacturing method, etc.
It should be noted that the numerical values given in the embodiments and examples of the present invention are not all critical values, and certain numerical values are values determined from manufacturing cost, easy manufacturing, etc. Since it indicates a preferable preferable value, even if the numerical value is slightly changed within the allowable value, its implementation is not denied.

1 PPS (organic synthetic resin)
2 Boron nitride (thermally conductive filler)
3 Basic magnesium sulfate (inorganic short fiber)
4 Glass fiber (reinforced fiber)
10 Resin composition (pellet)
40 Heat dissipation resin molding

Claims (5)

A molded product obtained by molding a resin composition containing a thermoplastic resin as an organic synthetic resin , a thermally conductive filler, and basic magnesium sulfate or calcium titanate having an old Mohs hardness of 5 or less as an inorganic short fiber,
The heat-radiating resin molded body, wherein the surface roughness of the molded body is less than 6 μm in terms of 10-point average roughness Rz.   The inorganic short fibers of the resin composition have an average fiber diameter in the range of 0.1 µm to 1.0 µm and an average fiber length in the range of 3 µm to 30 µm. Heat dissipation resin molding.   The heat dissipation resin molding according to claim 1 or 2, wherein a blending ratio of the inorganic short fibers in the resin composition is in a range of 1 wt% to 50 wt% in the entire resin composition. body. The resin composition further contains reinforcing fibers, and the blending ratio of the inorganic short fibers is 1 to 30 parts by weight with respect to 100 parts by weight of the total amount of the thermoplastic resin , the thermally conductive filler, and the reinforcing fibers. The heat-radiating resin molded body according to claim 1 or 2 , wherein the heat-radiating resin molded body is within a range of parts by weight.   5. The heat-dissipating resin molded body according to claim 4, wherein a blending ratio of the inorganic short fibers in the resin composition is in a range of 5 wt% to 10 wt% in the entire resin composition.

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