JP2014093427A - Heat sink - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat sink that maintains a mechanical characteristic, prevents bleed-out, ensures molding with satisfactory processability, is lightweight and excellent in heat dissipation.SOLUTION: In a heat sink containing molded body formed from molding a thermoplastic resin composition. The thermoplastic resin composition containing (A) thermoplastic resin, (B) filler of heat conductivity of not lower than 5 W/(m K), and (C) rosin. The thermoplastic resin (A) is (A1) polyamide resin, (A2) aliphatic polyester resin, or (A3) semi-aromatic polyester resin. The volume ratio (A/B) of the thermoplastic resin (A) to filler (B) is 80/20 to 25/75. The content of (C) rosin with respect to 100 parts by mass of the total of thermoplastic resin (A) and filler (B) is 0.3 to 5 parts by mass. The acid number of the rosin (C) is 60 mgKOH/g or greater.

Description

  The present invention relates to a heat sink that is lightweight and excellent in heat dissipation characteristics.

In recent years, miniaturization and weight reduction have been promoted in the field of portable electronic devices such as PDAs, mobile phones, and personal computers. Along with this, a heat countermeasure that effectively dissipates heat generated in various electronic components to the outside has become a very important issue, and heat sinks are used to cool CPUs, semiconductor power devices, and the like.
In recent years, LED devices have been developed, and the light emission efficiency has been greatly improved. As a result, the demand for LED devices in lighting applications such as LED bulbs has increased rapidly. Generally, if there is resistance when electricity flows through an electronic device, a part of the electric energy is converted into heat energy at that portion, and heat is generated. Also in the LED device, the LED element itself becomes a resistance, and heat is generated simultaneously with light emission. Since the LED element is vulnerable to heat, it is known that when the temperature exceeds a prescribed temperature, the light emission efficiency is lowered and the life of the LED element is affected. For this reason, in an apparatus using an LED device, the temperature of the LED element must be kept below a standard value. Many devices have a design in which an LED device is housed in a housing, and since the heat dissipation efficiency to the outside of the device system is poor, a design to dissipate the generated heat is required. A heat sink is also used as a countermeasure against them.

Common heat sinks are made by using a metal material with high thermal conductivity such as copper, aluminum, aluminum alloy, etc., and are made in a shape with a plurality of fins arranged in parallel on a flat heat receiving surface, or patent literature As described in FIG. 1, a fin shape is provided in the casing portion and the casing itself is used as a heat sink.
However, such a metal heat sink has a problem that the product itself becomes heavy and the processing cost becomes high. Based on such a background, in order to reduce the weight of the device and improve the degree of freedom in designing the member, it is desired that the resin is excellent in heat conduction and molded by injection molding.
Generally, a resin has a lower thermal conductivity than a metal or the like, and sufficient heat dissipation cannot be obtained as it is. As a method for improving the heat dissipation of the resin, a method of blending a filler having excellent thermal conductivity is generally used, and a large amount of a highly thermally conductive filler is blended in order to develop high thermal conductivity. However, a resin composition containing a large amount of a high thermal conductive filler has a high melt viscosity at the time of melting, so that the workability at the time of injection molding is greatly reduced.

In the resin composition containing the filler as described above, as a method for improving flowability and improving moldability, the resin composition may be aliphatic hydrocarbon, polyolefin wax, higher fatty acid, aliphatic alcohol. It is known that fatty acid amides, metal soaps, fatty acid esters and the like are added as lubricants, and conventionally known plasticizers are added. Patent Document 2 discloses that a rosin acid derivative such as rosinamide or rosin acid ester is added as a resin processability improver.
However, in order to further improve the moldability, increasing the amount of these lubricants, plasticizers, and processability improvers may decrease the mechanical properties of the resulting molded article or bleed out. . In addition, even when these lubricants, plasticizers, and processability improvers are added, sufficient molding processability cannot be obtained in a resin composition having a large amount of filler.

JP 2009-4130 A Japanese Patent Laid-Open No. 10-251443

  In view of the prior art, an object of the present invention is to provide a heat sink that is lightweight and excellent in heat dissipation, that is mechanically maintained, has no bleed-out, and is molded with good workability.

  As a result of intensive studies to solve the above problems, the present inventors have determined that a thermoplastic resin composition contains a specific thermoplastic resin, a thermally conductive filler, and a rosin having an acid value of 60 mgKOH / g or more. The present inventors have found that the above problems can be solved by molding a product, and have reached the present invention.

That is, the gist of the present invention is as follows.
(1) A heat sink including a molded body formed by molding a thermoplastic resin composition, wherein the thermoplastic resin composition has a thermal conductivity of thermoplastic resin (A), 5 W / (m · K) or more. Containing a filler (B) and rosin (C), the thermoplastic resin (A) is a polyamide resin (A1), an aliphatic polyester resin (A2) or a semi-aromatic polyester resin (A3), and a thermoplastic resin ( The volume ratio (A / B) of A) to the filler (B) is 80/20 to 25/75, and the rosin (C) with respect to 100 parts by mass of the total of the thermoplastic resin (A) and the filler (B) ) Is 0.3 to 5 parts by mass, and the acid value of rosin (C) is 60 mgKOH / g or more.
(2) The heat sink according to (1), wherein the polyamide resin (A1) is polyamide 6 or polyamide 66.
(3) The heat sink according to (1), wherein the aliphatic polyester resin (A2) is polylactic acid.
(4) The heat sink according to (1), wherein the semi-aromatic polyester resin (A3) is polybutylene terephthalate or polyethylene terephthalate.
(5) The filler (B) is flaky graphite having an average particle size of 30 μm or more, flaky boron nitride having an average particle size of 15 μm or more having a hexagonal crystal structure, talc having an average particle size of 15 μm or more, and an average particle size of 30 μm. The heat sink according to any one of (1) to (4), which is at least one selected from the above aluminum oxide and magnesium oxide having an average particle size of 30 μm or more.

  According to the present invention, by including a molded body formed by molding a resin composition containing a specific thermoplastic resin, a thermally conductive filler, and a rosin having an acid value of 60 mgKOH / g or more, It is possible to provide a heat sink that is excellent in characteristics, does not bleed out, and is lightweight and excellent in heat dissipation with good moldability.

FIG. 1 is a structural example of a heat sink of the present invention. FIG. 2 is a structural example of the heat sink of the present invention. FIG. 3 is a structural example of an LED bulb using the heat sink of the present invention as a housing. FIG. 4 is an evaluation model used for the heat dissipation evaluation of the example.

Hereinafter, the present invention will be described in detail.
The heat sink of this invention contains the molded object formed by shape | molding the thermoplastic resin composition containing a thermoplastic resin (A), a filler (B), and rosin (C).

  In the present invention, polyamide resin (A1), aliphatic polyester resin (A2), or semi-aromatic polyester resin (A3) is used as the thermoplastic resin (A).

  The polyamide resin (A1) used in the present invention is a homopolyamide or copolyamide having an amide bond, and a mixture thereof. A homopolyamide or copolyamide having an amide bond can be obtained by polymerizing lactam, aminocarboxylic acid, diamine, or dicarboxylic acid.

  Specific examples of the polyamide resin (A1) include polycapramide (polyamide 6, nylon 6), polytetramethylene adipamide (nylon 46), polyhexamethylene adipamide (polyamide 66, nylon 66), polycoupleramide / polyhexamethylene Adipamide copolymer (nylon 6/66), polyundecamide (nylon 11), polycapramide / polyundecamide copolymer (nylon 6/11), polydodecamide (nylon 12), polycapramide / polydodecamide copolymer (nylon 6/12), Polyhexamethylene sebamide (nylon 610), polyhexamethylene dodecamide (nylon 612), polyundecamethylene adipamide (nylon 116), polyhexamethylene isophthalamide (nylon 6I), polyhex Methylene terephthalamide (nylon 6T), polyhexamethylene terephthalamide / polyhexamethylene isophthalamide copolymer (nylon 6T / 6I), polycapramide / polyhexamethylene terephthalamide copolymer (nylon 6 / 6T), polycoupleramide / polyhexamethylene isophthalamide copolymer (Nylon 6 / 6I), polyhexamethylene adipamide / polyhexamethylene terephthalamide copolymer (nylon 66 / 6T), polyhexamethylene adipamide / polyhexamethylene isophthalamide copolymer (nylon 66 / 6I), polytrimethylhexa Methylene terephthalamide (nylon TMDT), polybis (4-aminocyclohexyl) methane dodecamide (nylon PACM12), polybis (3- Til-4-aminocyclohexyl) methane dodecamide (nylon dimethyl PACM12), polymetaxylylene adipamide (nylon MXD6), polynonamethylene terephthalamide (nylon 9T), polydecamethylene terephthalamide (nylon 10T), polyundeca Examples include methylene terephthalamide (nylon 11T), polydodecamethylene terephthalamide (nylon 12T), and mixtures and copolymers thereof. Among these, polyamide 6 and polyamide 66 are preferable from the viewpoint of economy.

  Examples of the aliphatic polyester (A2) used in the present invention include polycondensates from aliphatic dicarboxylic acids and aliphatic diols, polycondensates of aliphatic hydroxycarboxylic acids, and the like. Etc. are not particularly limited.

  Specific examples of the aliphatic polyester (A2) include polybutylene sebacate, polybutylene succinate, polybutylene succinate / adipate, polypropylene sebacate, polypropylene succinate, polypropylene succinate / adipate, polylactic acid, polyglycolic acid and the like Among these, polylactic acid is preferred from the viewpoints of the environmental aspect that the raw material is derived from plants, heat resistance, and moldability.

Examples of the polylactic acid used in the present invention include poly (L-lactic acid), poly (D-lactic acid), a mixture of poly (L-lactic acid) and poly (D-lactic acid), poly (L-lactic acid) and poly (L A copolymer with D-lactic acid), a stereo complex, and the like. Among these, polylactic acid mainly composed of poly (L-lactic acid) is preferably used from the viewpoint of heat resistance and moldability.
Polylactic acid is preferably derived from plants such as corn, and more preferably from non-edible plants, since it can reduce environmental burden.

  The melting point of polylactic acid mainly composed of poly (L-lactic acid) varies depending on the optical purity, but in the present invention, the mechanical strength, impact resistance and heat resistance of the molded product obtained by molding the resin composition are improved. In consideration, it is preferably 160 ° C. or higher. In order to set the melting point to 160 ° C. or higher, the proportion of poly (D-lactic acid) may be less than about 3 mol%.

The weight average molecular weight of polylactic acid is preferably 50,000 to 300,000, more preferably 100,000 to 300,000, and further preferably 120,000 to 200,000. When the weight average molecular weight is less than 50,000, it is difficult to obtain practical strength and durability. On the other hand, when the weight average molecular weight exceeds 300,000, the fluidity is low, and melt extrusion tends to be difficult.
The weight average molecular weight of polylactic acid is calculated by a method of analyzing by gel permeation chromatography (GPC).

  Polylactic acid is produced by a known melt polymerization method or by further adding a solid phase polymerization method thereto.

A cross-linked or branched structure may be introduced into the polylactic acid. By introducing a cross-linked or branched structure, the heat resistance of polylactic acid can be improved.
Examples of methods for introducing a crosslinked structure include a method of adding a peroxide, a method of using a peroxide and a radical polymerizable compound in combination, a method of irradiating radiation, a method of using a polyfunctional compound as a crosslinking agent, and the like. . Examples of the peroxide used for introducing a crosslinked structure include dibutyl peroxide and bis (butylperoxy) diisopropylbenzene. Examples of the radical polymerizable compound include glycidyl dimethacrylate, ethylene glycol dimethacrylate, and polyethylene glycol diester. Examples of the polyfunctional compound include ethylene-vinyl alcohol copolymer, partially saponified polyvinyl alcohol, and cellulose diacetate.
Examples of the method for introducing a branched structure include a method in which a tri- or higher functional monomer is copolymerized with L-lactic acid or D-lactic acid, and a method in which a macromonomer is graft-polymerized to polylactic acid. Examples of the tri- or higher functional monomer used for introducing a branched structure include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, malic acid, glyceric acid, citric acid, tartaric acid, and the like. It will not specifically limit if it is a compound which can couple | bond with the asymmetric carbon which exists in a lactic acid resin, alpha-olefins, such as 1-hexene, etc. are mentioned.

  The semi-aromatic polyester (A3) used in the present invention is a semi-aromatic polyester obtained by polycondensation of a dicarboxylic acid compound and a dihydroxy compound, polycondensation of an oxycarboxylic acid compound or polycondensation of a mixture of these three components. Even if it is any of homopolyester and copolyester, the effect of this invention can be show | played.

  Specific examples of the semi-aromatic polyester (A3) include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, and polycyclohexylenedimethylene terephthalate. Among these, polybutylene terephthalate and polyethylene terephthalate are preferable in terms of moldability and economy.

The polybutylene terephthalate used in the present invention is a polymer obtained by a polycondensation reaction between terephthalic acid or an ester-forming derivative thereof and 1,4-butanediol or an ester-forming derivative thereof.
Polybutylene terephthalate may be copolymerized with terephthalic acid or its ester-forming derivative, isophthalic acid, naphthalenedicarboxylic acid, adipic acid, sebacic acid, dodecanedioic acid, oxalic acid or its ester-forming derivative, etc. 1,4-butanediol or ester-forming derivatives thereof, ethylene glycol, propylene glycol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, decamethylene glycol, cyclohexanedimethanol, cyclohexanediol, molecular weight 400 ˜6000 polyethylene glycol, poly-1,3-propylene glycol, polytetramethylene glycol or ester-forming derivatives thereof may be copolymerized.

The polyethylene terephthalate used in the present invention is mainly composed of terephthalic acid and ethylene glycol.
Polyethylene terephthalate is used as an acid component other than terephthalic acid, for example, aromatic dicarboxylic acids such as isophthalic acid, 5-sodium sulfoisophthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4′-diphenyldicarboxylic acid, and diphenylsulfonedicarboxylic acid. Acids; aromatic polycarboxylic acids such as trimellitic acid and pyromellitic acid and their anhydrides; copolymerized with aliphatic dicarboxylic acids such as oxalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, decanedicarboxylic acid May be.
Polyethylene terephthalate is an alcohol component other than ethylene glycol, for example, propylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4. -Aliphatic diols such as butanediol, 2,3-butanediol, diethylene glycol, 1,5-pentanediol, neopentyl glycol, triethylene glycol and polyethylene glycol; aliphatic polyhydric alcohols such as trimethylolpropane and pentaerythritol; Alicyclic diols such as 1,4-cyclohexanedimethanol and 1,4-cyclohexanediethanol; aromatic diols such as ethylene oxide adducts of bisphenol A and bisphenol S; 4-hydroxybenzoic acid, ε-ca Hydroxycarboxylic acid may be copolymerized in such Rorakuton.
The copolymer component is preferably used within a range that does not impair the properties of polyethylene terephthalate, and is preferably less than 5 mol% with respect to 100 mol% each of the acid component and alcohol component constituting polyethylene terephthalate. If it exceeds 5 mol%, the mechanical properties may be impaired or the fluidity may be lowered.

The thermoplastic resin composition used for this invention contains a filler (B) with the said thermoplastic resin (A). The filler (B) has thermal conductivity, and it is necessary that the thermal conductivity is 5 W / (m · K) or more. The filler (B) may be either conductive or insulating.
The thermal conductivity of the thermally conductive filler can be measured using the sintered product. As specific examples of the filler (B) (the representative value of thermal conductivity (unit: W / (m · K)) is indicated in parentheses), talc (5 to 10), aluminum oxide (36) , Magnesium oxide (60), zinc oxide (25), magnesium carbonate (15), silicon carbide (160), aluminum nitride (170), boron nitride (210), silicon nitride (40), carbon (10 to several hundreds) , Inorganic fillers such as graphite (10 to several hundred), silver (427), copper (398), aluminum (237), titanium (22), nickel (90), tin (68), iron (84), Examples thereof include metallic fillers such as stainless steel (15). These may be used alone or in combination of two or more. Of these, graphite and boron nitride are preferably used because of their high thermal conductivity when blended with the thermoplastic resin (A). Moreover, it is preferable to use a talc, magnesium oxide, and aluminum oxide from the point of economical efficiency.

  Examples of the form of graphite include sphere, powder, fiber, needle, scale, whisker, microcoil, and nanotube. Among these, scaly graphite is more preferable because it can increase the heat conduction efficiency when blended with the thermoplastic resin (A). The scale-like graphite has higher thermal conductivity as the average particle size is larger. However, the mechanical properties tend to decrease, and the mechanical properties and thermal conductivity are uniform without causing agglomeration due to poor dispersion. In order to mold the molded body with good workability, the average particle size of the scaly graphite is preferably 1 μm or more, more preferably 10 μm or more, and further preferably 30 μm or more, It is especially preferable that it is 30-200 micrometers.

  Examples of the form of talc include a plate shape, a scale shape, a scale shape, and a flake shape. Among these, scaly talc and lamellar talc are more preferable because they are easily oriented in the surface direction when formed into a molded body, and as a result, the thermal conductivity can be increased. For the same reason as described above, the average particle size of the scaly talc is preferably 1 μm or more, more preferably 5 μm or more, further preferably 15 μm or more, and particularly preferably 15 to 70 μm. preferable.

  Examples of the form of boron nitride include a plate shape, a scale shape, and a flake shape. Among these, scaly boron nitride is more preferable because it is easily oriented in the surface direction when formed into a molded body, and as a result, the thermal conductivity can be increased. For the same reason as described above, the average particle size of the flaky boron nitride is preferably 1 μm or more, more preferably 5 μm or more, further preferably 15 μm or more, and 15 to 70 μm. Particularly preferred. The crystal system of boron nitride is not particularly limited, and boron nitride having any crystal structure such as hexagonal system, cubic system, and the like is applicable. Of these, boron nitride having a hexagonal crystal structure is preferable because of its high thermal conductivity.

  Examples of the form of magnesium oxide include a spherical shape, a fiber shape, a spindle shape, a rod shape, a needle shape, a cylindrical shape, and a column shape. Among these, spherical magnesium oxide is more preferable because it can improve the moldability. The average particle diameter of the spherical magnesium oxide is preferably 1 μm or more, more preferably 10 μm or more, further preferably 30 μm or more, and particularly preferably 30 to 80 μm for the same reason as described above. preferable.

  Examples of the form of aluminum oxide include a spherical shape, a fiber shape, a spindle shape, a rod shape, a needle shape, a cylindrical shape, and a column shape. Among these, spherical aluminum oxide is more preferable because it can improve the moldability. The average particle diameter of the spherical aluminum oxide is preferably 1 μm or more, more preferably 10 μm or more, further preferably 30 μm or more, and particularly preferably 30 to 80 μm for the same reason as described above. preferable.

  The filler (B) used in the present invention may be subjected to a surface treatment with a silane coupling agent or a titanium coupling agent in order to improve adhesion with the thermoplastic resin (A). Examples of silane coupling agents include γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropyldimethoxymethylsilane, and the like. Aminosilane-based coupling agents; epoxysilane-based coupling agents such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, etc. Examples of the titanium coupling agent include isopropyl tristearoyl titanate, isopropyl tridodecylbenzenesulfonyl titanate, and tetraisopropyl bis (dioctyl phosphite) titanate. These may be used alone or in combination of two or more.

  In the thermoplastic resin composition used in the present invention, the volume ratio (A / B) between the thermoplastic resin (A) and the filler (B) needs to be 80/20 to 25/75, 70/30 to 30/70 is more preferable, and 65/35 to 35/65 is even more preferable. By setting the capacity ratio (A / B) within this range, molding processability can be improved while improving characteristics such as mechanical characteristics and thermal characteristics.

  The thermoplastic resin composition used in the present invention needs to contain rosin (C) in addition to the thermoplastic resin (A) and the filler (B). By containing rosin (C), the thermoplastic resin composition can improve molding processability, and in particular, even when a large amount of filler (B) is contained, the particle size is also large. Even when the filler (B) is used, it can have excellent molding processability, and the obtained molded product can maintain mechanical characteristics and does not bleed out.

The rosin (C) in the present invention is a diterpenic acid compound called resin acid (rosin acid). Examples of rosin (C) include natural rosin, modified rosin, and polymerized rosin.
Natural rosin is a mixture of resin acids collected from Pinaceae plants. The main component of the resin acid is abietic acid, and further includes neoabietic acid, dehydroabietic acid, parastrinic acid, pimaric acid, isopimaric acid, sandaracopimaric acid, levopimaric acid, and the like.
Modified rosin is a modified natural rosin such as hydrogenated rosin such as dihydroabietic acid and tetrahydroabietic acid, disproportionated rosin such as dehydroabietic acid and dihydroabietic acid, acrylic acid, maleic acid and fumaric acid. Examples thereof include acid-modified rosin obtained by modifying natural rosin with an acid or the like, and esters thereof.
The polymerized rosin is a product obtained by reacting natural rosins or modified rosins, and examples thereof include dimerized products and trimerized products.

  In the present invention, the acid value of rosin (C) needs to be 60 mgKOH / g or more, preferably 100 mgKOH / g or more, more preferably 180 mgKOH / g or more, and 200 mgKOH / g or more. More preferably. When the acid value of rosin (C) is less than 60 mgKOH / g, molding processability may not be improved.

The content of rosin (C) needs to be 0.3 to 5 parts by mass with respect to 100 parts by mass in total of the thermoplastic resin (A) and the filler (B), and 0.5 to It is preferably 3 parts by mass.
When the content of rosin (C) is less than 0.3 parts by mass, molding processability may not be improved. On the other hand, when the content of rosin (C) exceeds 5 parts by mass, the resulting molded body machine The mechanical characteristics may be significantly reduced and the heat resistance may be significantly reduced.

  The softening temperature of rosin (C) is preferably 110 ° C. or higher, and more preferably 120 ° C. or higher. By using rosin (C) having a softening temperature of 110 ° C. or higher, decomposition of rosin (C) itself during molding can be suppressed, and rosin (C) can be prevented from bleeding out from the molded body. Moreover, the heat resistance fall of a molded object can also be suppressed.

  The thermoplastic resin composition used for the heat sink of the present invention can be blended with a fibrous filler in order to further improve various properties such as mechanical strength and heat resistance. Specific examples of the fibrous filler include glass fiber, aramid fiber, carbon fiber, metal fiber, silica fiber, silica / alumina fiber, zirconia fiber, boron nitride fiber, silicon nitride fiber, boron fiber, potassium titanate fiber, and kenaf. And natural fibers represented by These fibrous fillers may be used alone or in combination of two or more. In addition, the method of mixing these with a thermoplastic resin composition is not specifically limited.

Although the heat sink of this invention can be used conveniently for a lighting fixture member, when it is used outdoors, such as a road light, it is preferable to have a weather resistance. In order to impart weather resistance to the resin, a weathering agent is generally added.
The weathering agent absorbs or blocks ultraviolet rays to prevent photodegradation of the resin, or captures radicals generated by ultraviolet rays or heat to suppress polymer degradation. An agent, an ultraviolet absorber, an antioxidant and the like can be preferably used. These may be used singly, but when a plurality of these are combined, a synergistic effect is exhibited and a better weather resistance change can be obtained.

  As the ultraviolet blocking agent, inorganic fine particles coated with cerium oxide can be suitably used. Inorganic fine particles coated with cerium oxide are those in which cerium oxide fine particles crystallize on the surface of the base pigment, and silica, talc and mica having a refractive index of 1.5 to 1.6 are suitable as the base pigment. Can be used for The average particle diameter is 1 to 3 μm for silica base and talc base, and 2 to 4 μm for mica base. The cerium oxide fine particles crystallized on the surface of the base pigment are fine particles excellent in ultraviolet blocking properties, and have an average particle size of 0.03 to 0.05 μm. The inorganic fine particles thus configured can play the role of an ultraviolet blocking agent because ultraviolet rays are converted into a low amount of heat energy and released without being absorbed even when irradiated with ultraviolet rays. Further, when amorphous silica obtained by crystallizing cerium oxide fine particles on the surface of the base pigment is further coated with amorphous silica, the stability as an ultraviolet blocking agent is further improved. As the ultraviolet blocking agent, for example, trade name Seriguard S-3018-02 manufactured by Nippon Inorganic Chemical Co., Ltd. can be suitably used.

Examples of the light stabilizer include hindered amine compounds, copper compounds, and / or potassium halides.
Specific examples of hindered amine compounds include 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, bis- (2,2,6,6-tetramethyl-4-piperidyl) adipate, bis- (2 , 2,6,6-tetramethyl-4-piperidyl) suberate, bis- (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis- (2,2,6,6-tetramethyl- 4-piperidyl) phthalate, bis- (2,2,6,6-tetramethyl-4-piperidyl) terephthalate, bis- (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, bis- ( 1,2,2,6,6-pentamethyl-4-piperidyl) terephthalate, N, N′-bis- (2,2,6,6-tetramethyl-4-piperidyl) adipamide, N, N′- Su- (2,2,6,6-tetramethyl-4-piperidyl) -1,3-benzenedicarboxamide, bis- (1,2,2,6,6-pentamethyl-4-piperidyl) -n- Butyl (3,5-di-t-butyl-4-hydroxybenzyl) malonate, bis- (2,2,6,6-tetramethyl-4-piperidyl) -n-butyl (3,5-di-t- Butyl-4-hydroxybenzyl) malonate, tetra- (2,2,6,6-tetramethyl-4-piperidyl) ester of butanetetracarboxylic acid, 1- [2- [3- (3,5-di-t -Butyl-4-hydroxyphenyl) propionyloxy] ethyl] -4- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy] 2,2,6,6-tetramethylpiperidine, Poly [[6 -(1,1,3,3-tetramethylbutyl) imino-1,3,5-triazine-2,4-diyl] [(2,2,6,6-tetramethylpiperidyl) imino] hexamethylene [( 2,2,6,6-tetramethyl-4-piperidyl) imino]], tetrakis (1,2,2,6,6-pentamethyl-4-piperidyl) 1,2,3,4-butanetetracarboxylate, Tetrakis (2,2,6,6-tetramethyl-4-piperidyl) 1,2,3,4-butanetetracarboxylate, dimethyl-1- (2-hydroxyethyl) -4-hydroxy-2,2 succinate , 6,6-tetramethylpiperidine, 1,2,3,4-butanetetracarboxylic acid and 2,2,6,6-tetramethyl-4-piperidinol and β, β, β ′, β′-tetramethyl- 3,9- [2,4 , 8,10-tetraoxaspiro (5,5) undecane] diethanol, 1,2,3,4-butanetetracarboxylic acid and 1,2,2,6,6-pentamethyl-4-piperidinol and a condensate with β, β, β ′, β′-tetramethyl-3,9- [2,4,8,10-tetraoxaspiro (5,5) undecane] diethanol, and the like, and bis- (2 , 2,6,6-tetramethyl-4-piperidyl) sebacate and N, N′-bis- (2,2,6,6-tetramethyl-4-piperidyl) -1,3-benzenedicarboxamide are preferred. Used for. These may be used alone or in combination of two or more. As the hindered amine compound, for example, trade name Sanol LS-770 manufactured by Organic Synthesis Co., Ltd., trade name Nyrostub S-EED manufactured by Clariant Japan, etc. can be preferably used.
Examples of the copper compound include cuprous chloride, cupric chloride, cuprous bromide, cupric bromide, cuprous iodide, copper acetate, copper propionate, copper benzoate, copper adipate, Examples include copper terephthalate, copper isophthalate, copper sulfate, copper phosphate, copper borate, copper nitrate, copper stearate, and copper complex salts coordinated to chelating agents. Of these, cuprous iodide is preferred. Can be used. In addition, these copper compounds may be used independently and may mix 2 or more types.
Specific examples of the potassium halide include potassium iodide, potassium bromide, and potassium chloride. Among these, potassium iodide can be preferably used. Moreover, these potassium halides may be used independently and may mix 2 or more types.
In the present invention, as a combination of the copper compound and potassium halide, a combination of cuprous iodide and potassium iodide can be most suitably used for improving weather resistance.

Examples of the ultraviolet absorber include benzotriazole-based, benzophenone-based, salicylic acid phenyl ester-based, triazine-based, and cyanoacrylate-based ultraviolet absorbers.
Examples of the benzotriazole ultraviolet absorber include 2- (5-methyl-2hydroxyphenyl) benzotriazole, 2- [2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] -2H-benzotriazole 2- (2′-hydroxy-5′-t-octylphenyl) benzotriazole, 2,2-methylenebis [4- (1,1,3,3-tetramethylenebutyl) -6- (2H-benzotriazole- 2-yl) phenol] and the like. As the benzotriazole-based ultraviolet absorber, for example, trade name Tinupin-900 manufactured by BASF can be suitably used.
Examples of benzophenone-based ultraviolet absorbers include 2-hydroxy-4-octoxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxy-4′-chlorobenzophenone, 2,2-dihydroxy-4-methoxybenzophenone, 2,2-dihydroxy-4,4′-dimethoxybenzophenone and the like can be mentioned. As the benzophenone ultraviolet absorber, for example, trade name ADK STAB 1413 manufactured by Asahi Denka Co., Ltd. can be suitably used.
Examples of the salicylic acid phenyl ester ultraviolet absorber include para-t-butylphenyl salicylic acid ester and para-octylphenyl salicylic acid ester.
Examples of triazine ultraviolet absorbers include 2,4-diphenyl-6- (2-hydroxy-4-methoxyphenyl) -1,3,5-triazine, 2,4-diphenyl-6- (2-hydroxy-4-). Ethoxyphenyl) -1,3,5-triazine, 2,4-diphenyl-6- (2-hydroxy-4-propoxyphenyl) -1,3,5-triazine, 2,4-diphenyl-6- (2- Hydroxy-4-butoxyphenyl) -1,3,6-triazine, 2,4-diphenyl-6- (2-hydroxy-4-hexyloxyphenyl) -1,3,5-triazine, 2,4-diphenyl- 6- (2-hydroxy-4-octyloxyphenyl) -1,3,5-triazine, 2,4-diphenyl-6- (2-hydroxy-4-dodecyloxyphenyl) -1,3 5-triazine, 2,4-diphenyl-6- (2-hydroxy-4-butoxyethoxy) -1,3,5-triazine and the like. As the triazine-based ultraviolet absorber, for example, Siasorb UV-1164 manufactured by Sun Chemical Co., Ltd. can be suitably used.
Examples of the cyanoacrylate ultraviolet absorber include ethyl-2-cyano-3,3-diphenyl acrylate, 2-ethylhexyl-2-cyano-3,3-diphenyl acrylate, and the like. As the cyanoacrylate-based ultraviolet absorber, for example, the product name ubinal N-539, 3035, 3039 manufactured by BASF can be preferably used.

Examples of the antioxidant include hindered phenol-based, phosphite-based, and thioether-based antioxidants.
Specific examples of the hindered phenol antioxidant include triethylene glycol-bis-3- (3′-t-butyl-4′-hydroxy-5-methylphenyl) propionate, 1,3,5-tris (3 ', 5'-di-t-butyl-4'-hydroxybenzoyl) isocyanurate, 1,3,5-trimethyl-2,4,6-tris (3', 5'-di-t-butyl-4 ' -Hydroxy-benzyl) benzene, hexamethylene glycol-bis-[[beta]-(3,5-di-t-butyl-4-hydroxy-phenyl) propionate], 6- (4'-hydroxy-3 ', 5'- Di-t-butylanilino) -2,4-bis-octyl-thio-1,3,5-triazine, tetrakis [methylene-3 (3 ′, 5′-di-t-butyl-4′-hydroxy-phenyl) Propionate Tan, 2,2'-thio [diethyl-bis-3 (3 ", 5" -di-t-butyl-4 "-hydroxyphenyl) propionate], n-octadecyl-3- (4'-hydroxy-3 ' , 5′-di-t-butylphenol) propionate, N, N′-hexamethylene-bis-3- (3 ′, 5′-di-t-butyl-4′-hydroxy-propamide), 1,3,5 -Tris (3 ', 5'-di-t-butyl-4'-hydroxybenzyl) isocyanurate, 3', 5'-di-t-butyl-4'-hydroxy-benzylphosphoric acid dimethyl ester, bis ( 3,5-di-t-butyl-4-hydroxybenzylphosphoric acid) monomethyl ester and the like, N, N'-hexamethylene-bis-3- (3 ', 5'-di-t -Butyl-4'-hydroxy -Propamide) can be used preferably, alone or in combination of two or more, and as hindered phenol-based antioxidants, for example, Irganox 1098 manufactured by BASF, Irganox 1010, etc. are preferably used. it can.
Examples of the phosphite antioxidant include triphenyl phosphite, trioctadecyl phosphite, tridecyl phosphite, trinonylphenyl phosphite, diphenylisodecyl phosphite, bis (2,6-di-t-butyl-4- Methylphenyl) pentaerythritol diphosphite, bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite, tris (2,4-di-t-butylphenyl) phosphite, distearyl pentaerythritol diphosphite Phyto, tetra (tridecyl-4,4′-isopropylidene diphenyl diphosphite, 2,2-methylenebis (4,6-di-t-butylphenyl) octyl phosphite, etc. As phosphite antioxidants For example, the product name ADEKA manufactured by Asahi Denka Co., Ltd. Stub PEP-36 can be preferably used.
Examples of the thioether-based antioxidants include distereal β, β′-thiobutyrate, lauryl stearyl thiodipropionate, dimyristyl thiodipropionate, dilauryl thiodipropionate, distearyl thiodipropionate, tetrakis [methylene-3- (Dodecylthio) propionate] methane and the like. As the thioether-based antioxidant, for example, trade name ADK STAB AO-412S manufactured by Asahi Denka Co., Ltd. can be suitably used.

A flame retardant, a crystal nucleating agent, a compatibilizing agent, a pigment, a lubricant, a release agent, an antistatic agent and the like may be added to the resin composition used in the present invention as long as the effects of the present invention are not impaired.
Flame retardants include halogen flame retardants, inorganic flame retardants such as aluminum hydroxide, magnesium hydroxide and antimony trioxide, phosphinates and diphosphinates and their polymers, melamine polyphosphate, melamine cyanurate, red Phosphorus, phosphoric acid ester, condensed phosphoric acid ester, phosphazene compound and the like can be mentioned.
Examples of the crystal nucleating agent include sorbitol compounds, benzoic acid, metal salts of the compounds, and phosphate ester metal salts.
Examples of the compatibilizer include ionomer compatibilizers, oxazoline compatibilizers, elastomer compatibilizers, reactive compatibilizers, and copolymer-based compatibilizers.
As the pigment, both organic and inorganic pigments can be used. When the heat sink of the present invention is used in an LED lighting device, white is often preferred, and a white pigment is added to a resin composition for molding the heat sink. Examples of the white pigment include zinc oxide and aluminum oxide exemplified as the filler (B), as well as titanium oxide, barium sulfate, calcium carbonate, zinc sulfide, zinc sulfate and the like. Titanium oxide is preferable because the optical properties of the film are improved. Titanium oxide is preferably a rutile type having a high refractive index and good light stability, and the particle diameter is preferably 0.05 to 2.0 μm, more preferably 0.05 to 0.5 μm. . Titanium oxide may be surface-treated with a metal oxide such as alumina, silica, zinc oxide and zirconium oxide, an organic acid such as stearic acid, and a surface treatment agent such as a silane coupling agent and a titanium coupling agent.
These additives may be used alone or in combination of two or more. In addition, the method of mixing these in this invention is not specifically limited.

  The thermoplastic resin composition used in the present invention comprises a thermoplastic resin (A), a filler (B), and rosin (C), and various additives as required, and a general extruder. For example, it can be manufactured by melt-kneading using a single screw extruder, a twin screw extruder, a roll kneader, or a Brabender. At this time, it is effective to use a static mixer or a dynamic mixer together. In order to improve the kneading state, it is preferable to use a twin screw extruder. Although it does not specifically limit as an addition method of a filler (B), In the extruder, the method of adding from a hopper or using a side feeder is mentioned.

The heat sink of this invention contains the molded object formed by shape | molding the said thermoplastic resin composition. The molding is performed using a generally known melt molding method such as injection molding, compression molding, extrusion molding, transfer molding, or sheet molding.
The housing for the LED lighting device as the heat sink of the present invention is preferably molded using an injection molding method from the viewpoint of moldability. Although it does not specifically limit as an injection molding machine, For example, a screw in-line type injection molding machine and a plunger type injection molding machine are mentioned. The resin composition heated and melted in the cylinder of the injection molding machine is weighed for each shot, injected into the mold in a molten state, cooled and solidified in a predetermined shape, and then taken out from the mold as a molded body. It is. The resin temperature at the time of injection molding needs to be not less than the melting point of the resin composition, and is preferably less than (melting point + 100 ° C.).

The shape of the heat sink of the present invention is not particularly limited, but is preferably a shape having a large surface area in order to increase heat dissipation efficiency, and specifically, a plate shape, a cylindrical shape, a curved surface shape, a fin shape, and a housing shape. Is mentioned.
The heat sink of the present invention includes a molded body formed by molding a thermoplastic resin composition, and even if all of the molded body is molded from a thermoplastic resin composition, a part thereof is thermoplastic. The resin composition may be molded and other parts may be made of other materials. For example, in order to increase heat dissipation efficiency, a metal such as copper or aluminum, a ceramic such as alumina or aluminum nitride, A high heat conductive material made of carbon or the like may be joined. The method of joining the molded body of the thermoplastic resin composition and the high thermal conductive material is not particularly limited. However, when the thermoplastic resin composition is molded with the adhesive or the like, or when the thermoplastic resin composition is molded, the mold is heated. For example, an insert molding method in which a conductive material is placed and a resin is poured.

  EXAMPLES Next, although an Example demonstrates this invention concretely, this invention is not limited by these. In the following examples and comparative examples, various physical properties were measured and evaluated by the following methods.

(1) Acid value The rosin (C) was measured according to the method described in JIS standard K5902.

(2) Softening temperature It measured according to the method of JIS-7206: 1999.

(3) Density The density was measured at 20 ° C. using an electronic hydrometer (manufactured by Kyoto Electronics Industry Co., Ltd.).

(4) Bar flow flow length An injection molding machine (manufactured by Nissei Plastic Industry Co., Ltd .: NEX110-12E) equipped with a fully dried resin composition and a bar flow test mold (spiral shape) having a width of 20 mm and a thickness of 1 mm is used. It was used for injection molding 10 times, and the average was taken as the bar flow flow length. The cylinder temperature and mold temperature were the temperatures shown in the table, and the injection pressure was 150 MPa.

(5) Melt viscosity About the pellet of the resin composition, the melt viscosity at the temperature described in a table | surface was measured using the descent | fall type flow tester (made by Shimadzu Corporation). An orifice having a diameter of 1 mm and a length of 10 mm was used.

(6) Bending strength A sufficiently dried resin composition is injection-molded under the temperature conditions described in the table using an injection molding machine (manufactured by Nissei Plastic Industry Co., Ltd .: NEX110-12E) and described in ISO standard 3167. A multi-purpose specimen A type was prepared. Using the obtained test piece, measurement was performed according to the method described in ISO standard 178.

(7) Thermal conductivity Thermal conductivity λ was calculated by the following equation as the product of thermal diffusivity α, density ρ and specific heat Cp determined by the following method.
λ = α ・ ρ ・ Cp
λ: thermal conductivity (W / (m · K))
α: Thermal diffusivity (m ² / sec)
ρ: Density (g / m ³ )
Cp: Specific heat (J / g · K)
The thermal diffusivity α was measured using a laser flash method thermal constant measuring device TC-7000 (manufactured by ULVAC-RIKO) in the resin flow direction and thickness direction of the test piece prepared in (6) above. The density ρ was measured using an electronic hydrometer ED-120T (manufactured by Mirage Trading Co.). The specific heat Cp was measured using a differential scanning calorimeter DSC-7 (manufactured by Perkin Elmer) under the condition of a temperature rising rate of 10 ° C./min.

(8) Weather resistance Using the carbon arc lamp sunshine weather meter according to JIS standard B7753 (Suga Test Instruments, model “S80DHB”, irradiance: 255 W / m ² , wavelength: 300 to 700 nm) above (6 ) Was subjected to a weather resistance test (temperature: 63 ± 3 ° C., humidity: 65 ± 5% RH (no spraying), spraying condition: sprayed every 120 minutes for 8 minutes), and exposed for 500 hours The test piece was later taken out and dried in a vacuum dryer at 100 ° C. for 12 hours, and then the bending strength was measured according to the above (6). Assuming that the bending strength of the test piece not subjected to the weather resistance test is S0 and the bending strength of the test piece subjected to the weather resistance test is S1, the bending strength retention rate is calculated according to the following formula, and the weather resistance is evaluated. did.
Bending strength retention rate (%) = [S1 / S0] × 100

(9) Moldability The sufficiently dried resin composition was injection molded using an injection molding machine (Nissei Resin Co., Ltd .: NEX110-12E), and the heat sink (heat receiving surface: 36 mm × 36 mm) having the structure shown in FIG. , Fin: width 36 mm × height 20 mm × thickness 4 mm, number of fins: 5), and the appearance at that time was visually observed.
○: A portion not filled with resin was not seen.
(Triangle | delta): Although resin was not filled partially, the heat dissipation evaluation of following (11) was possible.
X: The resin was not partially filled, and could not be subjected to the heat dissipation evaluation of the following (11).

(10) Bleed-out property After preparing 100 heat sinks in (9) above, the presence or absence of deposits on the surface of the molded body and the mold surface was visually observed.
○: No deposits were observed in any of them.
X: A deposit was observed in any of the cases.

(11) Heat dissipation With respect to the heat sink produced in (9) above, a ceramic heater 6 is installed on the heat receiving surface 5 as shown in FIG. 4, and the heater surface temperature after applying a predetermined voltage for 20 minutes is measured with a K-type thermocouple. Then, heat dissipation was evaluated. The lower the surface temperature, the better the heat dissipation. The ceramic heater 6 has a power consumption of 3 W, and between the heat receiving surface 5 and the ceramic heater 6, in order to reduce the contact thermal resistance, heat conductive grease (Ceramic Grease AS-04, manufactured by ArcicSilver) A conductivity of 5.1 W / mK) was applied thinly. In addition, the manufactured heat sink had a portion not filled with resin, and the heat dissipation evaluation test could not be performed as x.

The raw materials used in Examples and Comparative Examples of the present invention are shown below.
(1) Polyamide resin (A1)
PA6: Polyamide 6 obtained by polymerization of ε-caprolactam (relative viscosity 1.9, density 1.13 g / cm ³ )
PA66: polyamide 66 obtained by polymerization of hexamethylenediamine and adipic acid (relative viscosity 2.8, density 1.14 g / cm ³ )

(2) Aliphatic polyester resin (A2)
PLA1: Polylactic acid (manufactured by Nature Works, PLA6251D, melting point 165 ° C., density 1.24 g / cm ³ )
PLA2: Polylactic acid (Unitika Ltd., Terramac TE-7003, melting point 165 ° C., density 1.25 g / cm ³ )

(3) Semi-aromatic polyester resin (A3)
PBT: polybutylene terephthalate (Wintech Polymer Co., Ltd., DURANEX 500FP, density 1.31 g / cm ³ )
PET: Polyethylene terephthalate (Unitika, SA-1206, density 1.35 g / cm ³ )

(4) Other resins / PP: Polypropylene (Nippon Polypro, SA08, density 0.9 g / cm ³ )

(5) Filler (B)
GrA: scaly graphite (manufactured by Nippon Graphite Industries Co., Ltd., average particle size 40 μm, thermal conductivity 100 W / (m · K), density 2.25 g / cm ³ )
GrB: scaly graphite (manufactured by Nippon Graphite Industry Co., Ltd., average particle size 130 μm, thermal conductivity 100 W / (m · K), density 2.25 g / cm ³ )
TC: scaly talc (manufactured by Nippon Talc Co., Ltd., average particle size 23 μm, thermal conductivity 5-10 W / (m · K), density 2.70 g / cm ³ )
AL: spherical aluminum oxide (manufactured by Micron, average particle size 50 μm, thermal conductivity 36 W / (m · K), density 3.98 g / cm ³ )
MgO: spherical magnesium oxide (manufactured by Tateho Chemical Co., Ltd., average particle size 30 μm, thermal conductivity 50 W / (m · K), density 3.58 g / cm ³ )
BN: Hexagonal scaly boron nitride (manufactured by Electrochemical Co., Ltd., average particle size 15 μm, thermal conductivity 210 W / (m · K), density 2.26 g / cm ³ )

(6) Rosin (C)
C1: maleated rosin (manufactured by Arakawa Chemical Industries, Marquide No. 31, acid value 188 mgKOH / g, softening temperature 141 ° C.)
C2: maleated rosin (Arakawa Chemical Industries, Marquide No. 33, acid value 317 mgKOH / g, softening temperature 153 ° C.)
C3: Maleinized rosin (manufactured by Arakawa Chemical Industries, Marquide 3002, acid value 107 mgKOH / g, softening temperature 170 ° C.)
C4: maleated rosin (Arakawa Chemical Industries, Pine Crystal KE-604, acid value 237 mg KOH / g, softening temperature 129 ° C.)
C5: maleated rosin (manufactured by Arakawa Chemical Industries, Marquide No. 8, acid value 38 mgKOH / g, softening temperature 133 ° C.)
C6: Rosin ester (Arakawa Chemical Industries, Superester S-100, acid value 3 mgKOH / g, softening temperature 100.5 ° C.)

(7) Plasticizer / HB: p-hydroxybenzoic acid alkyl ester (manufactured by Kao Corporation, Exepearl HD-PB, liquid)
ADF: low molecular weight styrene-acrylic oligomer (BASF, JONCRYL ADF-1300, solid)

(8) Fiber reinforcing material / GF: Glass fiber (Owens Corning, average fiber diameter 10 μm, average fiber length 3 mm, density 2.50 g / cm ³ )

(9) Flame retardant / FRB: Brominated flame retardant (IC-2, F-2400)
Sb: antimony trioxide (Nippon Seiko Co., Ltd., PATOX-M)
FRP: phosphorus flame retardant (Clariant, Exolit OP1230)

(10) Weathering agent / WRA: hindered amine light stabilizer (manufactured by Organic Synthesis Co., Ltd., Sanol LS-770)
-WRB: hindered phenol antioxidant (manufactured by BASF, Irganox 1098)
・ WRC: Cuprous iodide (manufactured by Nippon Chemical Industry Co., Ltd.)
・ WRD: Potassium iodide (Mitsui Chemicals Fine)

(11) Pigment / Ti: Titanium oxide (manufactured by Ishihara Sangyo Co., Ltd., Type PF-728, average particle size 0.21 μm, density 4.5 g / cm ³ )

Example 1
In the main hopper of a twin screw extruder (TEM 26SS manufactured by Toshiba Machine Co., Ltd., screw diameter 26 mm), 33 parts by mass of polyamide 6 (PA6) resin, 67 parts by mass of flake graphite (GrA), and 2 parts by mass of rosin (C4) Was melt-kneaded at 260 ° C., extruded into a strand shape, cooled and solidified, and then cut into a pellet shape to obtain a resin composition.
Next, this resin composition was injection molded at a cylinder temperature of 280 ° C. and a mold temperature of 100 ° C. using an injection molding machine (manufactured by Nissei Plastic Industry Co., Ltd .: NEX110-12E). Was molded. The evaluation results of the obtained molded body are shown in Table 1. During the kneading and injection molding operations, no generation of volatile gases was observed.

Examples 2-32 and Comparative Examples 1-16
A resin composition and a molded body were obtained in the same manner as in Example 1 except that the resin composition and the molding conditions were changed as shown in Tables 1 to 3. Glass fiber was supplied from the middle by a side feeder. The evaluation result of the obtained molded object is shown to Tables 1-3.

  As shown in Tables 1 and 2, the resin composition used in the present invention has a long bar flow flow length, a low melt viscosity, and excellent molding processability. The bleed-out property was good and the heat dissipation property was excellent while maintaining the target characteristics (bending strength). Moreover, in Examples 11-14, 18, and 19, since a weathering agent was included, it was excellent in weather resistance.

On the other hand, as shown in Table 3, in Comparative Examples 1, 3, and 8, since the resin composition does not contain rosin (C) or the content of rosin (C) is small, the bar flow flow length is short, Since the melt viscosity is high and the molding processability is inferior, the obtained heat sink is not partially filled with resin, and the heat dissipation is also reduced. It was not obtained.
In Comparative Example 4, since the rosin (C) was contained in an amount more than that specified in the present invention, the obtained molded product had low strength and was missing when taken out from the mold.
In Comparative Examples 5 to 6, since the acid value of the rosin (C) used was low, the bar flow flow length was short, the melt viscosity was high, and the molding processability was poor.
In Comparative Example 7, since the amount of the filler (B) was larger than the amount specified in the present invention, the moldability was remarkably lowered, and a molded body was not obtained.
In Comparative Example 9, since the amount of the filler (B) was smaller than the amount specified in the present invention, the obtained heat sink had low heat dissipation.
In Comparative Examples 10 to 13, when a plasticizer was used instead of rosin (C), there was no problem in molding processability, but the obtained molded body had low bending strength, and the surface of the molded body and There were deposits on the mold surface and the bleed-out property was poor.
In Comparative Examples 14 to 15, polypropylene was used as the thermoplastic resin, but the effect of improving workability by blending rosin was not observed for polypropylene.

1 Heat sink (fin)
2 Translucent cover 3 LED mounting board 4 Heat sink (frame)
5 Heat-receiving surface 6 Ceramic heater

Claims (5)

  A heat sink including a molded body formed by molding a thermoplastic resin composition, wherein the thermoplastic resin composition has a thermoplastic resin (A), a filler having a thermal conductivity of 5 W / (m · K) or more ( B) and rosin (C), and the thermoplastic resin (A) is a polyamide resin (A1), an aliphatic polyester resin (A2) or a semi-aromatic polyester resin (A3), and the thermoplastic resin (A) The volume ratio (A / B) with the filler (B) is 80/20 to 25/75, and the rosin (C) is contained with respect to 100 parts by mass in total of the thermoplastic resin (A) and the filler (B). A heat sink, wherein the amount is 0.3 to 5 parts by mass, and the acid value of rosin (C) is 60 mgKOH / g or more.   The heat sink according to claim 1, wherein the polyamide resin (A1) is polyamide 6 or polyamide 66.   The heat sink according to claim 1, wherein the aliphatic polyester resin (A2) is polylactic acid.   The heat sink according to claim 1, wherein the semi-aromatic polyester resin (A3) is polybutylene terephthalate or polyethylene terephthalate. The filler (B) is flaky graphite having an average particle size of 30 μm or more, flaky boron nitride having an average particle size of 15 μm or more having a hexagonal crystal structure, talc having an average particle size of 15 μm or more, and oxidation having an average particle size of 30 μm or more. The heat sink according to claim 1, wherein the heat sink is at least one selected from aluminum and magnesium oxide having an average particle diameter of 30 μm or more.

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