JP6079490B2 - Thermoplastic resin composition for heat dissipation electric / electronic parts and heat dissipation electric / electronic parts comprising the same - Google Patents

Description

  The present invention relates to a thermoplastic resin composition for heat-dissipating electric / electronic parts and a heat-dissipating electric / electronic part formed by melt-molding the same.

  In recent years, there has been an increase in ubiquitous compatible devices capable of operating home electric / electronic devices from outside. Such an electric / electronic device is used in a situation where the connector is always connected and idling current for the remote power source continues to flow, and thus heat is always generated in the electrode portion. When an electric / electronic device is operated and goes into operation while going out, a larger current consumption flows. Even in such a case, a countermeasure is required to prevent an excessive heating phenomenon from occurring due to the heat generated by the connector.

  In recent electric and electronic devices, power consumption of electric and electronic components mounted therein has increased with higher functionality and higher performance, and as a result, temperature rise of the device has become a problem. In particular, portable electronic devices typified by mobile phones are required to be further reduced in size, thickness, and functionality. Therefore, metal heat sinks and fans used in personal computers are used due to space constraints. It is difficult to provide such a heat dissipation structure. Since the surface area of the casing of the portable electronic device is small and sufficient heat dissipation efficiency cannot be obtained, the temperature of the casing rises when the heat generation amount of the electric / electronic component is large. If the temperature of the housing rises while using the portable electronic device, the user may feel uncomfortable or may get a low temperature burn.

  In recent years, improvements in terms of materials have been proposed for the above problems.

  For example, Patent Document 1 discloses an electric wire with a connector formed by using a resin composition that is electrically insulating and has a thermal conductivity of 0.8 W / m · K or more inside and outside the connector. The claim includes at least one resin selected from polyvinyl chloride, chlorinated polyethylene, EPDM, polyester, polyphenylene sulfide (PPS), polyamide (PA), and liquid crystal polymer (LCP), alumina, aluminum hydroxide, water A resin composition containing at least one filler selected from magnesium oxide, boron nitride, and talc is described, but no specific example using these materials is shown. In addition, a molded product obtained from such a resin composition has low mechanical strength, and has a problem of low drop resistance and scratch resistance when used for electric / electronic parts.

  Patent Document 2 discloses a flame-retardant polyamide molding composition containing a thermoplastic and partially crystalline polyamide resin, magnesium hydroxide and glass fiber, and polyamide 6 or polyamide 6/66 copolymer. A specific example using is shown. Although such a composition is presumed to have excellent thermal conductivity, a better surface appearance is desired for use in the exterior of electric / electronic parts. In addition, it is easy to crystallize in the mold, and it is necessary to fill with high pressure at the time of injection molding, so the length of burrs generated on the fixed and movable split surfaces (parting line: PL) of the mold increases. There was also concern.

  Patent Document 3 discloses a flame-retardant polyamide molding composition containing a polyamide resin that is at least partially crystalline, a semi-aromatic amorphous polyamide, magnesium hydroxide, and glass fibers. Specific examples using nylon and nylon 6T / 6I copolymer are shown. Although such a composition is also presumed to be a material having excellent thermal conductivity, there is a concern that the filling rate is low when injection molding of complicated and thin-walled electric / electronic parts due to poor fluidity during injection molding. Moreover, since it is necessary to fill with high pressure at the time of injection molding, there is also a concern that the burr length becomes large. Furthermore, since the fluidity at the time of injection molding is poor, the weld strength is also low, and there are also problems with drop resistance and scratch resistance.

JP 2009-59649 A JP-A-6-234913 JP 2002-129209 A

  The present invention is excellent in thermal conductivity, mechanical strength and fluidity at the time of injection molding, can reduce burrs during injection molding, and can dissipate heat and heat and can obtain electrical and electronic parts with excellent surface appearance It is an object of the present invention to provide a thermoplastic resin composition for electric / electronic parts.

In the present invention, the total of (A), (B), and (C) is 100% by weight, (A) 25-45% by weight polyamide resin, (B) 25-74% by weight magnesium hydroxide, and (C) glass. A thermoplastic resin composition for heat-dissipating electrical and electronic parts having a thermal conductivity of 1 W / m · K or more measured by a heat flow meter method, comprising 1 to 40% by weight of a fiber, comprising the following (I) It is a thermoplastic resin composition for heat-dissipating electrical / electronic parts, characterized by satisfying all of (III) to (III).
(I) The polyamide resin extracted from the thermoplastic resin composition for heat-dissipating electric / electronic parts has a relative viscosity of 1.5 to 2.8 at 25 ° C. in a 98% sulfuric acid solution of 0.01 g / ml.
(II) Melting | fusing point of the thermoplastic resin composition for said heat dissipation electrical / electronic components is 200-300 degreeC.
(III) The difference between the melting point and the cooling crystallization temperature of the thermoplastic resin composition for heat-dissipating electrical / electronic parts is 45 to 70 ° C.

  The thermoplastic resin composition for heat-dissipating electrical / electronic parts of the present invention is excellent in thermal conductivity, mechanical strength and fluidity during injection molding, and can reduce burrs during injection molding. The thermoplastic resin composition for heat-dissipating electric / electronic parts of the present invention can provide a heat-dissipating electric / electronic part having an excellent surface appearance. Furthermore, by melt-molding the thermoplastic resin composition for heat-dissipating electrical and electronic parts of the present invention, it has excellent filling rate, mold release, surface appearance, drop resistance, and scratch resistance in the thin parts of molded products, and a wide range of injections. It becomes possible to provide a heat-dissipating electrical / electronic component with less burr over pressure conditions.

It is a perspective view of the connector molded article used in an Example and a comparative example. It is the schematic which shows the manufacturing method of the connector molded article used by an Example and a comparative example. (I) is a schematic front view showing the arrangement of a connector molded product, a sprue and a runner, and (II) is a schematic side view thereof.

  Hereinafter, the present invention will be described in more detail.

  The thermoplastic resin composition for heat-dissipating electrical / electronic parts of the present invention (hereinafter sometimes referred to as “thermoplastic resin composition”) comprises (A) a polyamide resin, (B) magnesium hydroxide, and (C ) Glass fiber is blended.

  The (A) polyamide resin used in the present invention is a resin composed of a polymer having an amide bond, and is mainly composed of amino acids, lactams or diamines and dicarboxylic acids. By blending the polyamide resin with the thermoplastic resin composition of the present invention, a thermoplastic resin composition having excellent heat resistance, mechanical strength, and fluidity during injection molding can be obtained. By applying this thermoplastic resin composition to heat-dissipating electrical / electronic parts (hereinafter sometimes referred to as “electrical / electronic parts”), the filling rate, drop resistance, and scratch resistance of the molded product thin-walled parts Can be increased.

  Typical examples of the raw material of the polyamide resin include amino acids such as 6-aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid and paraaminomethylbenzoic acid; lactams such as ε-caprolactam and ω-laurolactam; tetramethylenediamine , Pentamethylenediamine, hexamethylenediamine, 2-methylpentamethylenediamine, nonamethylenediamine, decamethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2,2,4- / 2,4,4-trimethylhexamethylenediamine , Aliphatic diamines such as 5-methylnonamethylenediamine; aromatic diamines such as metaxylylenediamine and paraxylylenediamine; 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexa 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, bis (4-aminocyclohexyl) methane, bis (3-methyl-4-aminocyclohexyl) methane, 2,2-bis (4- Alicyclic diamines such as aminocyclohexyl) propane, bis (aminopropyl) piperazine, aminoethylpiperazine; aliphatic dicarboxylic acids such as adipic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid; terephthalic acid, isophthalic acid, Aromatic dicarboxylic acids such as 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, 5-sodium sulfoisophthalic acid, 2,6-naphthalenedicarboxylic acid, hexahydroterephthalic acid, hexahydroisophthalic acid; cyclohexane Alicyclic dicals such as dicarboxylic acids Such as phosphate, and the like. In the present invention, two or more polyamide homopolymers or copolymers derived from these raw materials may be blended.

  In the present invention, a particularly useful polyamide resin is a polyamide resin having a melting point of 200 to 300 ° C. and excellent in heat resistance. Here, the melting point is a temperature difference of 20 ° C./min from a molten state in a nitrogen atmosphere using a differential scanning calorimeter (DSC) and held for 2 minutes. It is defined as the temperature of the endothermic peak that appears when the temperature is raised at a temperature rate. When a plurality of polyamide resins having different melting points are used in combination, the melting point of the polyamide resin having the highest melting point is preferably 200 to 300 ° C. By blending a polyamide resin having a melting point of 200 ° C. or higher, the heat resistance of the thermoplastic resin composition can be improved. For example, when an electrode is connected to an electrical / electronic component such as a connector and electricity is applied for a long period of time, it may generate heat up to around 200 ° C., but by using a thermoplastic resin composition with high heat resistance, Thermal deterioration of electronic components can be suppressed, and drop resistance after long-time use can also be improved. The melting point of the polyamide resin is more preferably 220 ° C. or higher. On the other hand, by setting the melting point of the polyamide resin having the highest melting point to 300 ° C. or less, the deterioration of the polyamide resin and the dehydration reaction of magnesium hydroxide can be suppressed during melt-kneading and injection molding. By suppressing the formation of cavities in electric / electronic parts produced by injection molding, the filling rate and thermal conductivity of the molded product can be further improved. The melting point of the polyamide resin is more preferably 280 ° C. or less.

  Specific examples of the polyamide resin include polycaproamide (polyamide 6), polyhexamethylene adipamide (polyamide 66), polypentamethylene adipamide (polyamide 56), polytetramethylene adipamide (polyamide 46). Polyhexamethylene sebacamide (polyamide 610), polypentamethylene sebacamide (polyamide 510), polytetramethylene sebacamide (polyamide 410), polyhexamethylene dodecamide (polyamide 612), polyundecanamide (polyamide 11) ), Polydodecanamide (polyamide 12), polycaproamide / polyhexamethylene adipamide copolymer (polyamide 6/66), polycaproamide / polyhexamethylene terephthalamide copolymer (polyamide 6 / 6T), polyhexene Methylene adipamide / polyhexamethylene terephthalamide copolymer (polyamide 66 / 6T), polyhexamethylene adipamide / polyhexamethylene isophthalamide copolymer (polyamide 66 / 6I), polyhexamethylene adipamide / polyhexamethylene isophthalamide / Polycaproamide copolymer (polyamide 66 / 6I / 6), polyhexamethylene terephthalamide / polyhexamethylene isophthalamide copolymer (polyamide 6T / 6I), polyhexamethylene terephthalamide / polydecanamide copolymer (polyamide 6T / 12), Polyhexamethylene adipamide / polyhexamethylene terephthalamide / polyhexamethylene isophthalamide copolymer (polyamide 66 / 6T / 6I), polymetaxylylene Adipamide (polyamide MXD6), polymetaxylylene sebamide (polyamide MXD10), polyparaxylylene adipamide (polyamide PXD6), polyparaxylylene sebacamide (polyamide PXD10), polyhexamethylene terephthalamide / poly-2 -Methylpentamethylene terephthalamide copolymer (polyamide 6T / M5T), polyhexamethylene terephthalamide / polypentamethylene terephthalamide copolymer (polyamide 6T / 5T), polypentamethylene terephthalamide / polypentamethylene adipamide copolymer (5T / 56) ), Polynonamethylene terephthalamide (polyamide 9T), polynonamethylene terephthalamide / poly 2-methyl-1,8-octamethylene terephthalamide copolymer (poly Amide 9T / M8T), polydecamethylene terephthalamide (polyamide 10T), polydecamethylene terephthalamide / polyhexamethylene adipamide copolymer (polyamide 10T / 66), polydecamethylene terephthalamide / polyhexamethylene dodecamide copolymer (polyamide) 10T / 612), polydodecamethylene terephthalamide (polyamide 12T), and copolymers thereof. Here, “/” represents a copolymer and the same applies hereinafter. It is also practically preferable to blend two or more of these polyamide resins depending on the required properties such as mechanical properties, fluidity, releasability, surface appearance and heat resistance.

  Among these, polyamide 6/66, polyamide 66 / 6I, polyamide 66 / 6I / 6, polyamide 6T / 6I, polyamide 6T / 12, polyamide 66 / 6T / 6I, polyamide MXD6, polyamide 6T / M5T, polyamide 9T / M8T Polyamide 10T / 66 and polyamide 10T / 612 are mechanical strength, fluidity during injection molding, shear rate dependence of melt viscosity, mold release during molding, surface appearance of molded product, heat resistance (after heating It is preferably used because the characteristics of (drop resistance) can be expressed in a well-balanced manner. Polyamide 66 / 6I, polyamide 66 / 6I / 6, and polyamide MXD6 are more preferably used, and polyamide 66 / 6I / 6 is most preferably used.

  It is preferable that 70 to 100% by weight of polyamide 66 / 6I / 6 is contained in a total of 100% by weight of the polyamide resin. If the content of polyamide 66 / 6I / 6 in the polyamide resin is 70% by weight or more, mechanical strength, fluidity during injection molding, dependence of melt viscosity on shear rate, mold release during molding, surface appearance Moreover, the characteristics of drop resistance can be expressed in a more balanced manner. 80% by weight or more is more preferable.

  Although there is no restriction | limiting in particular in the polymerization degree of these polyamide resins, It is preferable that relative viscosity is 1.5-2.8. The relative viscosity here refers to a value measured using an Ostwald viscometer in a 98% concentrated sulfuric acid solution having a polyamide resin concentration of 0.01 g / ml at 25 ° C. When a plurality of polyamide resins are used in combination, the relative viscosity of the entire polyamide resin is preferably 1.5 to 2.8. When the relative viscosity is 1.5 or more, the mechanical strength of the thermoplastic resin composition can be further increased, and the drop resistance and scratch resistance of the molded product are further improved. 1.7 or more is more preferable. On the other hand, if the relative viscosity is 2.8 or less, the melt viscosity of the thermoplastic resin composition can be suppressed to an appropriate range, the fluidity can be further improved, and the burr of the molded product at the time of injection molding can be further reduced. Moreover, even when used for thin-walled and complex-shaped electric / electronic parts, the strength of the weld portion is particularly high, and the drop resistance is further improved. 2.4 or less is more preferable.

As the magnesium hydroxide (B) used in the present invention, magnesium hydroxide having a high purity containing 80% by weight or more of an inorganic substance represented by the chemical formula Mg (OH) ₂ is preferable. By adding magnesium hydroxide to the thermoplastic resin composition of the present invention, it is possible to impart thermal conductivity and shear viscosity dependence of melt viscosity to the thermoplastic resin composition, and to improve the mold release property at the time of molding. it can. From the point of further improving the thermal conductivity, the dependence of melt viscosity on the shear rate, and the releasability, the inorganic material represented by Mg (OH) ₂ is contained by 80% by weight or more, the CaO content is 5% by weight or less, and the chlorine content is 1% by weight. High purity magnesium hydroxide is more preferable, and high purity magnesium hydroxide containing 98% by weight or more of Mg (OH) ₂ , 0.1% by weight or less of CaO, and 0.1% by weight or less of chlorine is further included. preferable.

  The shape of magnesium hydroxide used in the present invention may be any of particles, flakes, and fibers, but particles and flakes are preferred from the viewpoint of feedability and dispersibility during extrusion melt kneading. The particle size is not particularly limited, but was measured by a laser diffraction method from the viewpoint of further improving the mechanical strength, thermal conductivity, dependence of melt viscosity on shear rate, and releasability of the thermoplastic resin composition. The average particle size is preferably in the range of 0.1 to 10 μm, more preferably in the range of 0.3 to 4 μm.

  Examples of magnesium hydroxide include vinyl silane compounds such as vinyl triethoxysilane and vinyl trichlorosilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, and β- (3,4-epoxycyclohexyl). Epoxysilane compounds such as ethyltrimethoxysilane, aminosilane compounds such as γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, The surface treatment may be performed with a long-chain fatty acid such as stearic acid, oleic acid, montanic acid, stearyl alcohol, or a long-chain aliphatic alcohol. In particular, magnesium hydroxide surface-treated with an epoxy silane compound and / or an amino silane compound is preferably used because it can further increase the mechanical strength of the thermoplastic resin composition.

  (C) Glass fiber used for this invention does not have a restriction | limiting in particular, A well-known thing can be used. By blending the glass fiber with the thermoplastic resin composition of the present invention, the mechanical strength, releasability and heat resistance can be enhanced. Glass fibers include chopped strands, roving strands, milled fibers and the like cut to a predetermined length, and any of them may be used. Although there is no restriction | limiting in particular in a fiber diameter, a thing of 4-11 micrometers is preferable. When the fiber diameter is 4 μm or more, the filling rate into the thin part of the molded product can be increased. On the other hand, if it is 11 μm or less, the number of glass fibers in the thermoplastic resin composition can be increased, and the reinforcing effect by the glass fibers can be easily obtained, so that the mechanical strength can be increased. Here, the fiber diameter of the glass fiber refers to the number average value of the fiber diameters of the respective glass fibers, and can be determined by the following method. Using a SEM (scanning electron microscope), observe the cross section of the glass fiber (the plane perpendicular to the length direction of the fiber), measure the maximum and minimum diameters, and calculate the average value of the fibers of each glass fiber. The diameter. By calculating the number average value of the fiber diameters of 10 glass fibers selected at random, the fiber diameter of the glass fibers can be obtained. When the chopped strand is used, the fiber length is not particularly limited, but glass fiber having a strand length of 3 mm, which has high workability for extrusion kneading, is preferably used. When using a roving strand, it can be combined by a known technique in which the roving strand is directly fed into an extruder. Two or more of these glass fibers may be used in combination.

  The glass fiber is preferably surface-treated with a known coupling agent (for example, silane coupling agent, titanate coupling agent, etc.) or other surface treatment agent, and the mechanical strength of the thermoplastic resin composition Can be further improved. Examples of the silane coupling agent include amino silane, epoxy silane, and acrylic silane.

  Moreover, it is preferable that the glass fiber is coat | covered with the sizing agent (binding agent), and can improve the workability | operativity at the time of melt-kneading. Furthermore, the effect which improves the mechanical strength of a thermoplastic resin composition more may be expressed. Examples of the bundling agent (binding agent) include urethane resins, epoxy resins, acrylic acid resins, amino resins, vinyl acetate resins, polyolefin resins, and the like.

  In the thermoplastic resin composition of the present invention, the blending amount of (A) polyamide resin, (B) magnesium hydroxide, and (C) glass fiber is 100% by weight of the total of (A), (B), and (C). (A) 25 to 45% by weight of polyamide resin, (B) 25 to 74% by weight of magnesium hydroxide, and (C) 1 to 40% by weight of glass fiber.

  (A) When the blending amount of the polyamide resin is less than 25% by weight, the mechanical strength of the resulting thermoplastic resin composition, the fluidity at the time of injection molding, the surface appearance of the molded product is lowered, and the drop resistance of the molded product is reduced. Scratch resistance is also reduced. 30 weight% or more is more preferable. On the other hand, when the compounding amount of the polyamide resin is more than 45% by weight, the thermal conductivity and releasability of the obtained thermoplastic resin composition are deteriorated. More preferred is 40% by weight or less.

  (B) When the compounding quantity of magnesium hydroxide is less than 25 weight%, the thermal conductivity of the obtained thermoplastic resin composition and the shear rate dependence of melt viscosity will become small. 30 weight% or more is more preferable. On the other hand, if the blending amount of magnesium hydroxide is more than 74% by weight, good pellets cannot be collected by melt kneading. 60 weight% or less is more preferable.

  (C) If the glass fiber content is less than 1% by weight, the resulting thermoplastic resin composition has low mechanical strength, releasability, and heat resistance, and the drop resistance and scratch resistance of the molded product also decrease. 10 weight% or more is more preferable. On the other hand, when the blending amount of the glass fiber is more than 40% by weight, the thermal conductivity, the fluidity at the time of injection molding, and the surface appearance are deteriorated. 35% by weight or less is more preferable.

  The thermoplastic resin composition of the present invention needs to have a thermal conductivity of 1 W / m · K or more measured by a heat flow meter method. When the thermal conductivity of the thermoplastic resin composition is less than 1 W / m · K, for example, when electricity is applied to an electrical / electronic component such as a connector made of the thermoplastic resin composition of the present invention, Since the generated heat is not easily dissipated into the air through the thermoplastic resin composition, the electrical / electronic parts are thermally deteriorated. For this reason, after use for a long time, for example, cracking when dropped is likely to occur, and drop resistance is reduced. Here, the thermal conductivity of the thermoplastic resin composition means that a square plate molded product (50 mm × 50 mm × thickness 3 mm, film gate) is produced by injection molding the thermoplastic resin composition. Thermal conductivity obtained by measuring with a heat flow meter method thermal conductivity measuring device (manufactured by Rigaku Corporation, GH-1S) using a test piece having a thickness of 2 mm by cutting the surface to a depth of 0.5 mm. Point to. The thermal conductivity is more preferably 1.2 W / m · K or more. For example, by blending a specific amount of (B) magnesium hydroxide and (C) glass fiber as described above, a thermoplastic resin composition satisfying the above thermal conductivity can be obtained.

The thermoplastic resin composition of the present invention needs to satisfy all of the following (I) to (III).
(I) The relative viscosity at 25 ° C. of a 98% sulfuric acid solution of 0.01 g / ml of the polyamide resin extracted from the thermoplastic resin composition is 1.5 to 2.8.
(II) Melting | fusing point of the said thermoplastic resin composition is 200-300 degreeC.
(III) The difference between the melting point and the cooling crystallization temperature of the thermoplastic resin composition is 45 to 70 ° C.

Regarding (I), the relative viscosity of a polyamide resin extracted from a thermoplastic resin composition at 25 ° C. in a 98% sulfuric acid solution of 0.01 g / ml is that of the polyamide resin blended in the thermoplastic resin composition described above. Approximately equal to relative viscosity. When a plurality of polyamide resins are used in combination, the relative viscosity of the entire blended polyamide resin is substantially equal. When the relative viscosity is less than 1.5, the mechanical strength of the resulting thermoplastic resin composition is lowered, and the drop resistance and scratch resistance of the molded product are lowered. Further, since the melt viscosity in the high shear rate region is lowered, if the molding is performed at a pressure equal to or higher than the lower limit for product removal, for example, even if the lower limit pressure is +10 kgf / cm ² , the burr length is increased. 1.7 or more is more preferable. On the other hand, if the relative viscosity is larger than 2.8, the flowability at the time of injection molding of the thermoplastic resin composition obtained and the shear rate dependence of the melt viscosity are lowered, and burrs are likely to occur at the time of injection molding. 2.4 or less is more preferable. For example, a thermoplastic resin composition satisfying the above (I) can be obtained by blending a polyamide resin having a desired relative viscosity.

  Here, the relative viscosity of the polyamide resin extracted from the thermoplastic resin composition is measured by the following method. 10 g of pellets of the thermoplastic resin composition are immersed in 100 mL of hexafluoroisopropanol (HFIP) and stirred for 24 hours, and then filtered through a glass filter to collect the filtrate. Thereafter, the solvent (HFIP) in the filtrate is removed by evaporation, and the remaining polyamide resin is recovered and vacuum-dried at 80 ° C. for 24 hours or more. Using the dried product, the relative viscosity (ηr) is measured using an Ostwald viscometer in 98% concentrated sulfuric acid having a resin concentration of 0.01 g / ml at 25 ° C.

  Regarding (II), the melting point of the thermoplastic resin composition is a temperature difference from a molten state to 20 ° C. at a temperature lowering rate of 20 ° C./min using a differential scanning calorimeter (DSC) and held for 2 minutes. Is defined as the temperature of the endothermic peak that appears when the temperature is raised at a rate of temperature increase of 20 ° C./min. However, when two or more endothermic peaks are detected, the highest temperature peak is taken as the melting point. The melting point of the thermoplastic resin composition is approximately equal to the melting point of the polyamide resin having the highest melting point blended in the thermoplastic resin composition. When the melting point of the thermoplastic resin composition is lower than 200 ° C., the heat resistance of the thermoplastic resin composition is low. For example, when an electrode is connected to an electrical / electronic component such as a connector and electricity is applied for a long time, it may generate heat up to around 200 ° C. Is greatly reduced. The melting point is preferably 220 ° C. or higher. On the other hand, when the melting point exceeds 300 ° C., during the melt kneading and injection molding, the deterioration of the polyamide resin and the dehydration reaction of magnesium hydroxide proceed, and there are cavities in the molded product produced by injection molding of the thermoplastic resin composition. As a result, the filling rate and thermal conductivity of the molded product are lowered. Moreover, since mechanical strength falls, fall tolerance and scratch resistance fall. The melting point is preferably 270 ° C. or lower. For example, a thermoplastic resin composition satisfying the above (II) can be obtained by blending a polyamide resin having a desired melting point.

  Here, the melting point of the thermoplastic resin composition is measured by the following method. Using a differential scanning calorimeter (Seiko Instruments, Robot DSC-RDC220), about 5 mg of a pellet of the thermoplastic resin composition is sampled and measured under a nitrogen atmosphere. The temperature of the endothermic peak that appears when the temperature is lowered from a molten state to 20 ° C. at a temperature lowering rate of 20 ° C./min and held for 2 minutes and then heated at a temperature rising rate of 20 ° C./min is defined as the melting point.

  Regarding (III), the temperature-falling crystallization temperature of the thermoplastic resin composition is included in the thermoplastic resin composition at a rate of temperature increase of 20 ° C./min under a nitrogen atmosphere using a differential scanning calorimeter (DSC). The temperature is defined as the temperature of the exothermic peak that appears when the temperature is lowered to 20 ° C. at a temperature lowering rate of 20 ° C./minute after the temperature is raised to the melting point of the polyamide resin + 30 ° C. and held for 2 minutes. However, when two or more exothermic peaks are detected, the lowest temperature peak is defined as the temperature-falling crystallization temperature. When the difference between the melting point of the thermoplastic resin composition and the cooling crystallization temperature is less than 45 ° C., it is easy to crystallize in the mold at the time of injection molding, and the molded product filling rate becomes low. Moreover, since it is necessary to fill with high pressure at the time of injection molding, the length of the burr is also increased. Furthermore, since it is easy to crystallize in the mold at the time of injection molding, the weld strength is low in the case of a complicated molded product, and it is easy to crack when dropped. Moreover, the surface appearance also deteriorates. The difference between the melting point of the thermoplastic resin composition and the cooling crystallization temperature is more preferably 48 ° C. or higher. On the other hand, if the difference between the melting point of the thermoplastic resin composition and the temperature-falling crystallization temperature is larger than 70 ° C., the releasability from the mold at the time of injection molding is deteriorated. The difference between the melting point of the thermoplastic resin composition and the cooling crystallization temperature is more preferably 65 ° C. or less.

  Here, the temperature drop crystallization temperature of the thermoplastic resin composition is measured by the following method. Using a differential scanning calorimeter (Seiko Instruments, Robot DSC-RDC220), about 5 mg of a pellet of the thermoplastic resin composition is sampled and measured under a nitrogen atmosphere. When the temperature was raised to the melting point of the polyamide resin contained in the thermoplastic resin composition + 30 ° C. at a rate of temperature rise of 20 ° C./minute and held for 2 minutes, then the temperature was lowered to 20 ° C. at a rate of temperature drop of 20 ° C./minute. The temperature of the exothermic peak that appears is defined as the cooling crystallization temperature. For example, a thermoplastic resin composition satisfying the above (III) can be obtained by blending (B) magnesium hydroxide and (C) glass fibers with the above-mentioned specific amounts in the above-mentioned (A) polyamide resin. .

  Moreover, it is preferable that the thermoplastic resin composition of this invention is 20-55 J / g of temperature-fall crystallization heat amount of the polyamide resin converted from the temperature-fall crystallization heat amount of a thermoplastic resin composition. If it is 20 J / g or more, the releasability from the mold at the time of injection molding can be further improved. More preferably, it is 30 J / g or more. On the other hand, if it is 55 J / g or less, the fluidity and surface appearance during injection molding will be better. 50 J / g or less is more preferable. For example, by blending (B) magnesium hydroxide and (C) glass fiber with the above-mentioned specific amounts into the above-mentioned (A) polyamide resin, a thermoplastic resin composition satisfying the above-mentioned temperature-falling crystallization heat quantity is obtained. Can do.

Here, the cooling crystallization heat quantity of the polyamide resin converted from the cooling crystallization heat quantity of the thermoplastic resin composition is determined by the following method. The total heat quantity of the exothermic peak that appears when measuring the temperature-falling crystallization temperature of the thermoplastic resin composition in (III) is defined as the temperature-falling crystallization heat quantity (J / g) of the thermoplastic resin composition. Further, the amount of polyamide resin recovered in the method for measuring the relative viscosity of the polyamide resin in (I) was measured, and this value × 10 was determined as the polyamide resin content (% by weight) contained in the thermoplastic resin composition. Define. The temperature decrease crystallization heat amount (J / g) of the polyamide resin converted from the temperature decrease crystallization heat amount of the thermoplastic resin composition is calculated by the following formula.
(Cooling crystallization heat amount of polyamide resin converted from cooling crystallization heat amount of thermoplastic resin composition) = 100 × (Cooling crystallization heat amount of thermoplastic resin composition) / (Polyamide contained in thermoplastic resin composition) Resin content)

  The thermoplastic resin composition of the present invention has a thermal conductivity, mechanical properties, and injection molding according to the blending amount regulations of (A), (B) and (C) and the regulations of (I), (II) and (III). The balance of fluidity, melt viscosity dependence on shear rate, releasability, surface appearance, and heat resistance is highly expressed.

In particular, the thermoplastic resin composition of the present invention is greatly dependent on the shear rate of the melt viscosity, and has a low melt viscosity in a high shear rate region (around 1216 sec ⁻¹ ) corresponding to the shear rate during injection molding. In the low shear rate region (around 24 sec ⁻¹ ), the melt viscosity is high. This feature can be obtained, for example, by blending (B) magnesium hydroxide and (C) glass fiber with the above-mentioned specific amount into the above-mentioned (A) polyamide resin. In injection molding, the lower the melt viscosity in the high shear rate region, the lower the pressure can be filled, so the burr length generated on the fixed and movable split surfaces (parting line: PL) of the mold. Can be reduced. Furthermore, in injection molding, resin is filled at a low shear rate at the flow end of the molded product, but the higher the melt viscosity in the low shear rate region, the smaller the burr length. Therefore, the thermoplastic resin composition of the present invention having a low melt viscosity in the high shear rate region and a high melt viscosity in the low shear rate region can significantly reduce the burr length. In addition, when removing a molded product at a pressure higher than the molding lower limit pressure (minimum filling pressure), the burr length is unlikely to increase even if pressure is applied too much. Therefore, a wide process window at the time of molding can be taken.

The melt viscosity at 1216 sec ⁻¹ (high shear rate region) of the thermoplastic resin composition of the present invention is preferably 250 Pa · s or less, and more preferably 200 Pa · s or less. The ratio of the melt viscosity at the melt viscosity and 1216 sec ^-1 (high shear rate region) in 24sec thermoplastic resin composition of the present invention ¹ (low shear rate region) is preferably 3.5 or more, 3 More preferably, it is 8 or more. For example, a thermoplastic resin composition satisfying the above-mentioned melt viscosity ratio can be obtained by blending (B) magnesium hydroxide and (C) glass fibers with the above-mentioned specific amounts in the above-mentioned (A) polyamide resin. it can.

  You may mix | blend components other than said (A) (B) (C) with the thermoplastic resin composition of this invention as needed in the range which does not impair the characteristic.

  For example, you may mix | blend thermoplastic resins other than (A) polyamide resin as needed in the range which does not impair the characteristic. (A) As thermoplastic resins other than polyamide resin, for example, polyester resin, polyphenylene sulfide resin, polyphenylene oxide resin, polycarbonate resin, polylactic acid resin, polyacetal resin, polysulfone resin, tetrafluoropolyethylene resin, polyetherimide resin, Polyamideimide resin, polyimide resin, polyethersulfone resin, polyetherketone resin, polythioetherketone resin, polyetheretherketone resin, polyethylene resin, polypropylene resin, styrene resin such as polystyrene resin and ABS resin, polyalkylene oxide resin, etc. Is mentioned. It is also possible to mix two or more of such thermoplastic resins. When such a thermoplastic resin is used, the blending amount is not particularly limited, but is preferably 0.1 to 400 parts by weight with respect to 100 parts by weight in total of (A), (B), and (C).

  Moreover, you may mix | blend a rubbery polymer with the thermoplastic resin composition of this invention as needed in the range which does not impair the characteristic. A rubbery polymer refers to a polymer having a glass transition temperature lower than room temperature, in which some of the molecules are constrained to each other by covalent bonds, ionic bonds, van der Waals forces, entanglements, etc. . Examples of rubber polymers include polybutadiene, polyisoprene, random copolymers and block copolymers of styrene / butadiene, hydrogenated products of the block copolymers, acrylonitrile / butadiene copolymers, and butadiene / isoprene copolymers. Diene rubbers such as polymers, ethylene / propylene random copolymers and block copolymers, ethylene / butene random copolymers and block copolymers, ethylene / α-olefin copolymers, ethylene / acrylic acid esters Ethylene / unsaturated carboxylic acid ester copolymer such as ethylene / methacrylic acid ester, acrylic acid ester / butadiene copolymer such as butyl acrylate / butadiene copolymer, ethylene / fatty acid vinyl such as ethylene / vinyl acetate copolymer Copolymer, ethylene / Propylene / ethylidene norbornene copolymer, ethylene / propylene / non-conjugated diene terpolymer such as ethylene / propylene / hexadiene copolymer, butylene / isoprene copolymer, chlorinated polyethylene, polyamide elastomer, polyester elastomer, etc. A thermoplastic elastomer etc. are mentioned. Among these, from the viewpoint of compatibility with the (A) polyamide resin, an ethylene / unsaturated carboxylic acid ester copolymer is preferably used. As unsaturated carboxylic acid ester, (meth) acrylic acid ester is mentioned, Preferably it is ester of (meth) acrylic acid and alcohol. Specific examples of (meth) acrylic acid esters include methyl (meth) acrylate, ethyl (meth) acrylate, (meth) acrylic acid-2-ethylhexyl, stearyl (meth) acrylate, and the like.

  The rubbery polymer preferably has a reactive functional group from the viewpoint of reactivity with the (A) polyamide resin. Examples of the reactive functional group include an epoxy group, an acid anhydride group, an amino group, a carboxyl group, a carboxyl metal salt, an oxazoline group, a hydroxyl group, an isocyanate group, a mercapto group, and a sulfonic acid group. You may have 2 or more types of these. Among these, an epoxy group, an acid anhydride group, an amino group, a carboxyl group, a carboxyl metal salt, and an oxazoline group are preferably used because of high reactivity and few side reactions such as decomposition and crosslinking. As a method for introducing a reactive functional group into a rubbery polymer, there are usually known techniques, and there is no particular limitation. For example, a monomer having a reactive functional group and a raw material for the rubbery polymer are used. A method of copolymerizing with a monomer, a method of grafting a compound having a reactive functional group onto a rubbery polymer, or the like can be used.

  It is also possible to blend two or more kinds of such rubbery polymers. When such a rubbery polymer is used, the blending amount thereof is not particularly limited, but is preferably 0.1 to 400 parts by weight with respect to 100 parts by weight as a total of (A), (B) and (C).

  Moreover, you may mix | blend the inorganic filler other than (C) glass fiber with the thermoplastic resin composition of this invention as needed in the range which does not impair the characteristic. (C) As inorganic fillers other than glass fiber, for example, carbon fiber, titanium oxide, potassium titanate whisker, zinc oxide whisker, aluminum borate whisker, alumina fiber, silicon carbide fiber, ceramic fiber, asbestos fiber, and stone fiber fiber , Fibrous inorganic fillers such as metal fibers, Wollastonite, zeolite, sericite, kaolin, mica, clay, pyrophyllite, bentonite, asbestos, talc, alumina silicate and other metal silicates, alumina, silicon oxide, magnesium oxide , Metal oxides such as zirconium oxide and iron oxide, carbonates such as calcium carbonate, magnesium carbonate and dolomite, metal sulfates such as calcium sulfate and barium sulfate, metal hydroxides such as calcium hydroxide and aluminum hydroxide, glass Beads, ceramic bi 'S, non-fibrous inorganic fillers such as boron nitride and silicon carbide and the like, which may be hollow. These inorganic fillers may be pretreated with a coupling agent such as an isocyanate compound, an organic silane compound, an organic titanate compound, an organic borane compound, or an epoxy compound. Two or more kinds of such inorganic fillers can be used in combination. When such an inorganic filler is used, the blending amount thereof is not particularly limited, but is preferably 0.1 to 400 parts by weight with respect to 100 parts by weight in total of (A), (B) and (C).

  Moreover, you may mix | blend various additives with the thermoplastic resin composition of this invention as needed in the range which does not impair the characteristic. Examples of various additives include crystal nucleating agents, anti-coloring agents, antioxidants (heat stabilizers), weathering agents, mold release agents, plasticizers, lubricants, dye-based colorants, pigment-based colorants, antistatic agents. And flame retardants and foaming agents. Two or more of these may be blended. Although there is no restriction | limiting in particular in the compounding quantity, It is preferable to mix | blend 0.01-20 weight part with respect to a total of 100 weight part of (A), (B), and (C).

  As the antioxidant (heat stabilizer), a hindered phenol compound, a hindered amine compound, a hydroquinone compound, a phosphorus compound, and a substituted product thereof, copper halide, iodide compound and the like are preferably used. In particular, hindered phenol compounds and phosphorus compounds are preferably used.

  Specific examples of the hindered phenol compound include triethylene glycol-bis [3-t-butyl- (5-methyl-4-hydroxyphenyl) propionate], N, N′-hexamethylene bis (3,5-di- -T-butyl-4-hydroxy-hydrocinnamide), N, N'-hexamethylenebis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionamide], tetrakis [methylene-3- ( 3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane, pentaerythrityltetrakis [3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] 1,3,5-tris (3,5-di-t-butyl-4-hydroxybenzyl) -s-triazine-2,4,6- (1H, 3H 5H) -trione, 1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane, 4,4'-butylidenebis (3-methyl-6-t-butylphenol), n- Octadecyl-3- (3,5-di-t-butyl-4-hydroxy-phenyl) propionate, 3,9-bis [2- (3- (3-t-butyl-4-hydroxy-5-methylphenyl) Propionyloxy) -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane, 1,3,5-trimethyl-2,4,6-tris- (3,5 -Di-t-butyl-4-hydroxybenzyl) benzene and the like. Among them, amide type polymer hindered phenol type is preferable, and specifically, N, N′-hexamethylenebis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionamide] is preferable. Used.

  Specific examples of phosphorus compounds include bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol-di-phosphite, bis (2,4-di-t-butylphenyl) pentaerythritol- Di-phosphite, bis (2,4-di-cumylphenyl) pentaerythritol-di-phosphite, tris (2,4-di-t-butylphenyl) phosphite, tetrakis (2,4-di-t-butyl) Phenyl) -4,4′-bisphenylene phosphite, di-stearyl pentaerythritol-di-phosphite, triphenyl phosphite and the like; 3,5-di-butyl-4-hydroxybenzyl phosphonate Examples include diethyl ester.

  As the weathering agent, resorcinol compounds, salicylate compounds, benzotriazole compounds, benzophenone compounds, hindered amine compounds, and the like are preferably used.

  As the release agent, aliphatic alcohol, aliphatic amide, aliphatic bisamide, ethylene bisstearylamide, higher fatty acid ester, and the like are preferably used.

  As the plasticizer, octyl p-oxybenzoate, N-butylbenzenesulfonamide and the like are preferably used.

  As the dye-based colorant, nigrosine, aniline black and the like are preferably used.

  As the pigment-based colorant, cadmium sulfide, phthalocyanine, carbon black and the like are preferably used.

  Antistatic agents include alkyl sulfate type anionic antistatic agents, quaternary ammonium salt type cationic antistatic agents, nonionic antistatic agents such as polyoxyethylene sorbitan monostearate, and betaine amphoteric antistatic agents. Preferably used.

  Flame retardants include hydroxides such as melamine cyanurate and aluminum hydroxide, ammonium polyphosphate, aluminum phosphinate, melamine polyphosphate, zinc borate, red phosphorus, brominated polystyrene, brominated polyphenylene oxide, brominated polycarbonate, A brominated epoxy resin or a combination of these brominated flame retardants and antimony trioxide is preferably used.

  As a method for producing the thermoplastic resin composition of the present invention, production in a molten state, production in a solution state, and the like can be used, and production in a molten state can be preferably used from the viewpoint of productivity. For production in a molten state, melt kneading using an extruder, a Banbury mixer, a kneader, a mixing roll, or the like can be used, and melt kneading using an extruder that can be continuously produced can be preferably used from the viewpoint of productivity. Examples of the extruder include a multi-screw extruder such as a single-screw extruder, a twin-screw extruder, and a four-screw extruder, a twin-screw single-screw composite extruder, and the like. A plurality of these extruders may be combined. From the viewpoint of improving kneadability, reactivity, and productivity, a multi-screw extruder such as a twin-screw extruder or a four-screw extruder is preferable, and a twin-screw extruder is more preferable.

  Examples of the melt-kneading method using a twin-screw extruder include, for example, (A) polyamide resin, (B) magnesium hydroxide, (C) glass fiber and, if necessary, components other than (A), (B) and (C) Are premixed and supplied to a twin-screw extruder in which the cylinder temperature is set to be equal to or higher than the melting point of the polyamide resin (A) and melt kneaded. There is no particular limitation on the mixing order of the raw materials, a method in which all the raw materials are melt-kneaded by the above method, a method in which some raw materials are melt-kneaded by the above-described method, and the remaining raw materials are blended and melt-kneaded Any method such as a method of mixing the remaining raw materials using a side feeder during melt kneading of some raw materials may be used. (A) Polyamide resin, (B) Magnesium hydroxide and, if necessary, other components other than (A), (B) and (C), the root of the extruder (the side where the raw material is supplied is upstream, the side where the molten resin is discharged is A method is preferably used in which the glass fiber is introduced from the middle of the extruder and melt-kneaded using a side feeder after being melted and kneaded after being introduced from the downstream side (position of the upstream end portion of the screw). Moreover, the method of removing the gas which generate | occur | produces by exposing to a vacuum state in the middle of an extruder is also used preferably.

  The thermoplastic resin composition of the present invention can be melt-molded by an ordinary molding method (injection molding, extrusion molding, press molding, blow molding, injection press molding, etc.). Among these, from the viewpoint of mass productivity, it is preferable to mold by injection molding or injection press molding, and most preferable to mold by injection molding.

  The thermoplastic resin composition of the present invention is preferably used for heat-dissipating electrical / electronic parts.

  Since the thermoplastic resin composition of the present invention is excellent in fluidity at the time of injection molding, it is possible to increase the filling rate even when molding thin and complicated electrical / electronic parts as shown in FIG. 1, for example. It is possible to reduce molding defects. In addition, the thermoplastic resin composition of the present invention is excellent in fluidity at the time of injection molding and shear rate dependence of melt viscosity, so that there are few burrs at the time of injection molding and a wide process window at the time of injection molding can be taken. Even when a thin-walled and complex-shaped electrical / electronic component as shown in FIG. 1 is molded, molding defects can be reduced. In addition, since the thermoplastic resin composition of the present invention is excellent in releasability from a mold, the releasability of thin and complex-shaped electric / electronic parts as shown in FIG. 1 is also good. Furthermore, by using the thermoplastic resin composition of the present invention, an electric / electronic component having excellent surface appearance can be obtained.

  The thermoplastic resin composition of the present invention is excellent in mechanical strength and fluidity at the time of injection molding, and has a reasonably large difference between the melting point and the cooling crystallization temperature. Even when used in electrical / electronic parts, the strength of the molded product, particularly the strength of the welded portion, is high, and it is possible to suppress cracking when dropped and to impart drop resistance. In addition, since the thermoplastic resin composition of the present invention is excellent in thermal conductivity and heat resistance (melting point), for example, an electrode is connected to a connector molded product as shown in FIG. 1 made of the thermoplastic resin composition of the present invention. Even if electricity is passed through, the generated heat is transferred to the thermoplastic resin composition and dissipated into the air, so the thermal degradation of the connector molded product is suppressed, and cracking when dropped after prolonged use can also be suppressed. . Further, for example, even if the electrode is inserted into and removed from the connector molded article made of the thermoplastic resin composition of the present invention as shown in FIG.

  Examples of the heat dissipating electrical / electronic components of the present invention include connectors, relay cases, relay bases, relay spools, switches, coils, sensors, various gears, LED lamps, sockets, resistors, coil bobbins, capacitors, variable capacitor cases, Optical pickup, oscillator, various terminal boards, transformer, plug, printed circuit board, tuner, speaker, microphone, headphones, small motor, magnetic head base, power module, semiconductor, liquid crystal, FDD carriage, FDD chassis, motor brush holder, Electronic components such as parabolic antennas, thermal protectors, computer-related parts, generators, motors, transformers, current transformers, voltage regulators, rectifiers, inverters, relays, power contacts, switches, circuit breakers, knife switches H, other poles, electrical equipment parts such as electrical parts cabinets, VTR parts, TV parts, irons, hair dryers, rice cooker parts, microwave oven parts, acoustic parts, audio / laser discs (registered trademark) / compact discs, etc. For audio equipment, lighting parts, refrigerator parts, air conditioner parts, typewriter parts, word processor parts, personal computer parts, personal computer cases, mobile phone parts, mobile phone cases, smartphone parts, smart phone cases, battery parts, battery cases, etc. Representative home / office electrical product parts, office computer-related parts, telephone-related parts, facsimile-related parts, copier-related parts, cleaning jigs, oilless bearings, stern bearings, submersible bearings, and other motor parts , Machines represented by lighters, typewriters, etc. Various valves such as electric parts such as continuous electric parts, microscope parts, binocular parts, camera parts, watch parts, etc., electrical parts related to optical equipment and precision machinery, alternator terminals, alternator connectors, IC regulators, light dimmer potentiometer bases, exhaust gas valves, etc. Peripheral electrical parts, fuel-related, cooling system, brake system, wiper system, exhaust system, various pipes, hoses, tubes, air intake nozzle snorkel, intake manifold, fuel pump, fuel tank, engine coolant joint, carburetor main Body, carburetor spacer, exhaust gas sensor, cooling water sensor, oil temperature sensor, brake pad wear sensor, throttle position sensor, crankshaft position sensor, air flow Meter, brake pad wear sensor, battery peripheral parts, thermostat base for air conditioner, heating hot air flow control valve, brush holder for radiator motor, water pump impeller, turbine vane, wiper motor related parts, distributor, starter switch, starter relay , Transmission wire harness, Transmission oil pan, Transmission oil filter, Window washer nozzle, Air conditioner panel switch board, Fuel related electromagnetic valve coil, Wire harness connector, SMJ connector, PCB connector, Door grommet connector, Fuse connector, etc. Connectors, horn terminals, electrical component insulation plates, step motor low -, Lamp socket, lamp reflector, lamp housing, brake piston, solenoid bobbin, engine oil pan, engine oil filter, ignition device case, torque control lever, safety belt parts, register blade, washer lever, window regulator handle, window regulator handle Knob, passing light lever, sun visor bracket, instrument panel, airbag peripheral parts, door pad, pillar, console box, various motor housings, roof rail, fender, garnish, roof panel, hood panel, trunk lid, door mirror stay, spoiler , Hood louver, wheel cover, wheel cap, grill apron cover frame, lamp It can be used for electrical parts around automobiles and vehicles such as zel, door handle, door molding, rear finisher, wiper, etc., especially useful for connectors, relays, switches, personal computer cases, mobile phone cases, battery cases, etc. It is.

  Hereinafter, the effects of the present invention will be described more specifically with reference to examples. In addition, this invention is not limited to the following Example.

The polyamide resin (A) used in the examples and comparative examples is as follows. The relative viscosity of the polyamide resin (A) was measured using an Ostwald viscometer in 98% concentrated sulfuric acid having a resin concentration of 0.01 g / ml at 25 ° C.
(A-1): Polyamide 66 / 6I / 6 (= 76/17/7% by weight) resin having a melting point of 228 ° C., a density of 1.13 g / cm ³ , and a relative viscosity of 2.00.
(A-2): Polyamide 66 / 6I / 6 (= 76/17/7% by weight) resin having a melting point of 228 ° C., a density of 1.13 g / cm ³ and a relative viscosity of 2.70.
(A-3): Polyamide 66 / 6I / 6 (= 76/17/7% by weight) resin having a melting point of 228 ° C., a density of 1.13 g / cm ³ , and a relative viscosity of 1.60.
(A-4): Polyamide 66 / 6I / 6 (= 76/17/7% by weight) resin having a melting point of 228 ° C., a density of 1.13 g / cm ³ , and a relative viscosity of 3.00.
(A-5): Polyamide 66 / 6I / 6 (= 76/17/7% by weight) resin having a melting point of 228 ° C., a density of 1.13 g / cm ³ , and a relative viscosity of 1.40.
(A-6): Polyamide 6/66 (= 20/80 wt%) resin having a melting point of 225 ° C., a density of 1.13 g / cm ³ , and a relative viscosity of 2.00.
(A-7): Polyamide 66 / 6I (= 70/30 wt%) resin having a melting point of 220 ° C., a density of 1.13 g / cm ³ , and a relative viscosity of 2.00.
(A-8): Polyamide MXD6 resin having a melting point of 240 ° C., a density of 1.22 g / cm ³ , and a relative viscosity of 2.00.
(A-9): Polyamide 10T / 612 (= 91/9 wt%) resin having a melting point of 295 ° C., a density of 1.10 g / cm ³ , and a relative viscosity of 2.00.
(A-10): Polyamide 6 resin having a melting point of 222 ° C., a density of 1.13 g / cm ³ , and a relative viscosity of 2.00.
(A-11): Polyamide 6/66 (= 95/5 wt%) resin having a melting point of 215 ° C., a density of 1.13 g / cm ³ and a relative viscosity of 2.00.
(A-12): Polyamide 6/66 (= 95/5 wt%) resin having a melting point of 215 ° C., a density of 1.13 g / cm ³ , and a tree relative viscosity of 3.40.
(A-13): Polyamide 6/66 (= 80/20 wt%) resin having a melting point of 190 ° C., a density of 1.13 g / cm ³ and a relative viscosity of 2.00.
(A-14): Polyamide 6/66 (= 10/90 wt%) resin having a melting point of 244 ° C., a density of 1.13 g / cm ³ , and a relative viscosity of 2.00.
(A-15): Polyamide 6T / 6I resin (Ms Chemie Japan Co., Ltd., Grivory G21). No melting point or temperature drop crystallization temperature was observed.
(A-16): Polyamide 6/66/610 (= 40/35/35 wt%) resin having a melting point of 153 ° C., a density of 1.13 g / cm ³ , and a relative viscosity of 2.00.
(A-17): Polyamide 6T / M5T / 6I (= 32/48/20 wt%) resin having a melting point of 264 ° C., a density of 1.14 g / cm ³ , and a relative viscosity of 2.00.
(A-18): Polyamide 6T / 66 (= 65/35 wt%) resin having a melting point of 310 ° C., a density of 1.14 g / cm ³ and a relative viscosity of 2.00.

Magnesium hydroxide (B) used in Examples and Comparative Examples is as follows.
(B-1): Magnesium hydroxide having a density of 2.36 g / cm ³ , an inorganic content of 99.7% by weight represented by Mg (OH) ₂ , and an average particle diameter of 0.83 μm measured by a laser diffraction method “KISUMA” (registered trademark) 5EU ”(manufactured by Kyowa Chemical Industry Co., Ltd.)

The glass fiber (C) used for the Example and the comparative example is as follows.
(C-1): Glass fiber “T-275H” having a fiber diameter of 10.5 μm and a density of 2.55 g / cm ³ (manufactured by Nippon Electric Glass Co., Ltd.).

Components other than (A), (B), and (C) used in Examples and Comparative Examples are as follows.
(D-1): Red phosphorus “NOVAEXCEL (registered trademark) 140” (manufactured by Rin Chemical Industry Co., Ltd.).
(E-1): Thermal stabilizer “IR1098” (N, N′-hexamethylenebis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionamide]) (manufactured by BASF).

  Evaluation in Examples and Comparative Examples was performed by the following methods.

(1) Evaluation of Relative Viscosity of Polyamide Resin Extracted from Thermoplastic Resin Composition 10 g of the thermoplastic resin composition pellets obtained in Examples and Comparative Examples were immersed in 100 mL of hexafluoroisopropanol (HFIP) for 24 hours. After stirring, the filtrate was recovered by filtration through a glass filter. Thereafter, the solvent (HFIP) in the filtrate was removed by evaporation, and the remaining polyamide resin was recovered and vacuum-dried at 80 ° C. for 24 hours or more. Using the dried product, the relative viscosity (ηr) was measured using an Ostwald viscometer in 98% concentrated sulfuric acid having a resin concentration of 0.01 g / ml at 25 ° C.

(2) Evaluation of melting point and temperature-falling crystallization temperature of thermoplastic resin composition About 5 mg of the pellets of the thermoplastic resin composition obtained in Examples and Comparative Examples were sampled, and a differential scanning calorimeter (manufactured by Seiko Instruments Inc., Using a robot DSC-RDC 220), the melting point and the crystallization temperature were measured under a nitrogen atmosphere. The temperature lowering crystallization temperature of the thermoplastic resin composition was 20 ° C./min. At a rate of temperature increase of 20 ° C./min. The temperature was the temperature of the exothermic peak that appeared when the temperature was lowered to ° C. However, when two or more exothermic peaks were detected, the peak with the lowest temperature was defined as the temperature-falling crystallization temperature. Further, the melting point of the thermoplastic resin composition is determined by using a differential scanning calorimeter to lower the temperature from the molten state to 20 ° C. at a temperature lowering rate of 20 ° C./min and hold it for 2 minutes, and then the temperature rising rate of 20 ° C./min The temperature of the endothermic peak that appears when the temperature is raised at. However, when two or more endothermic peaks were detected, the peak with the highest temperature was taken as the melting point.

(3) Evaluation of temperature-down crystallization heat amount of polyamide resin converted from temperature-down crystallization heat amount of thermoplastic resin composition Total heat amount of exothermic peak that appears when temperature-down crystallization temperature of thermoplastic resin composition is evaluated in (2) Was defined as the temperature drop crystallization heat (J / g) of the thermoplastic resin composition. In (1), the amount of polyamide resin recovered from the thermoplastic resin composition was measured, and this value × 10 was defined as the polyamide resin content (% by weight) contained in the thermoplastic resin composition. Here, the temperature decrease crystallization heat amount (J / g) of the polyamide resin calculated from the temperature decrease crystallization heat amount of the thermoplastic resin composition was calculated by the following formula.
(Cooling crystallization heat amount of polyamide resin converted from cooling crystallization heat amount of thermoplastic resin composition) = 100 × (Cooling crystallization heat amount of thermoplastic resin composition) / (Polyamide contained in thermoplastic resin composition) Resin content)

(4) Evaluation of thermal conductivity with test pieces Using the injection molding machine (Sumitomo Heavy Industries, Ltd., SG75H-MIV), the pellets of the thermoplastic resin compositions obtained in Examples and Comparative Examples were used. Set the cylinder temperature (melting point + 50 ° C.) and mold temperature described in Table 1 and Table 3, injection molding under the conditions of the lower limit pressure (minimum filling pressure) +10 kgf / cm ² , a square plate molded product (50 mm × 50 mm × A 3 mm thick, film gate) was prepared, and both surfaces of this molded product were cut to a depth of 0.5 mm to obtain a test piece having a thickness of 2 mm, and a heat flow meter method thermal conductivity measuring device (Rigaku Corporation) The thermal conductivity was measured by GH-1S). It shows that it is excellent in thermal conductivity, so that this value is high.

(5) Evaluation of tensile strength with test pieces The pellets of the thermoplastic resin compositions obtained in Examples and Comparative Examples were used with an injection molding machine (SG75H-MIV, manufactured by Sumitomo Heavy Industries, Ltd.). Set the cylinder temperature (melting point + 50 ° C.) and mold temperature shown in Table 1 and Table 3 and injection mold under the conditions of the lower limit pressure (minimum filling pressure) +10 kgf / cm ² to produce ASTM No. 1 dumbbell, Autograph AG Using -2000C (manufactured by Shimadzu Corporation), the tensile strength was measured by performing a tensile test in an atmosphere of 23 ° C. and 50% RH in accordance with ASTM-D638.

(6) Evaluation of flexural modulus of test piece About ASTM No. 1 dumbbell produced by the method described in (5), using Tensilon RTA1T (manufactured by Orientec Co., Ltd.), according to ASTM-D790, 23 ° C., 50% A bending test was performed in an RH atmosphere to measure the flexural modulus.

(7) Evaluation of impact strength with test pieces The pellets of the thermoplastic resin compositions obtained in Examples and Comparative Examples were used with an injection molding machine (SG75H-MIV, manufactured by Sumitomo Heavy Industries, Ltd.). Set the cylinder temperature (melting point + 50 ° C.) and mold temperature described in Table 1 and Table 3, injection molding under the conditions of the lower limit pressure (minimum filling pressure) +10 kgf / cm ^{2, and} an Izod impact test piece with 1/8 inch notch. The Izod impact test was performed in an atmosphere of 23 ° C. and 50% RH according to ASTM-D256, and the impact strength was measured.

(8) Evaluation of melt viscosity Using Capillograph 1C (manufactured by Toyo Seiki Co., Ltd.), the temperature was set to the same temperature as the cylinder temperature (melting point + 50 ° C.) in the injection molding described in Table 1 and Table 3, and the length was 10 mm and the diameter. using 1mm capillary, after being pelleted for 5 minutes melt retention of the thermoplastic resin composition obtained in examples and Comparative examples, the melt viscosity was measured at a shear rate of 24 sec ^-1 and 1216 sec ^-1.

(9) Evaluation of releasability with test pieces Using the injection molding machine (Sumitomo Heavy Industries, Ltd., SG75H-MIV), the pellets of the thermoplastic resin compositions obtained in Examples and Comparative Examples were used. Forming when 100 shots of ASTM No. 1 dumbbell were continuously formed under the conditions of the cylinder temperature (melting point + 50 ° C.) and mold temperature described in Tables 1 and 3 and the lower limit pressure (minimum filling pressure) +10 kgf / cm ^2. The product was evaluated by the number of pieces attached to the mold. In addition, when it was stuck to the mold and did not release, after removing the molded product, a mold release spray (Daikin Industry Co., Ltd., Die Free GA-7500) was applied to the mold and injection molding was resumed. . The smaller the value, the better the releasability.

(10) Evaluation of glossiness with test pieces The pellets of the thermoplastic resin compositions obtained in the examples and comparative examples were prepared using an injection molding machine (SG75H-MIV, manufactured by Sumitomo Heavy Industries, Ltd.). Set the cylinder temperature (melting point + 50 ° C.) and mold temperature described in Table 1 and Table 3 and use a mirror-finished 80 mm × 80 mm × thickness 1 mm mold, lower limit pressure (minimum filling pressure) +10 kgf / cm ² A square plate was produced by injection molding under the conditions described above. Next, based on JIS-Z-8741, the glossiness at an incident angle of 60 ° C. was measured using a digital variable gloss meter (UGV-5D, manufactured by Suga Test Instruments Co., Ltd.). It shows that it is excellent in glossiness, so that this value is high.

(11) Evaluation of flame retardancy with test pieces Using pellets of thermoplastic resin compositions obtained in Examples and Comparative Examples, an injection molding machine (Sumitomo Heavy Industries, Ltd., SG75H-MIV) Set to cylinder temperature (melting point + 50 ° C.) and mold temperature described in Table 1 and Table 3, injection molding under conditions of lower limit pressure (minimum filling pressure) +10 kgf / cm ² , 1/16 inch (1.6 mm) Thickness test specimens were obtained. Using the above-mentioned combustion test piece, flame retardancy was evaluated according to the evaluation standard defined in the UL94 vertical test. Flame retardancy falls and ranks in the order of V-0>V-1> V-2. Moreover, the material which was inferior in combustibility, did not reach said V-2, and did not correspond to said flame retardance rank was made into the outside of specification.

(12) Evaluation of filling rate of connector molded product The pellets of the thermoplastic resin compositions obtained in the examples and comparative examples were prepared using an injection molding machine (SG75H-MIV, manufactured by Sumitomo Heavy Industries, Ltd.). The connector molded product 1 shown in FIG. 1 was injection molded under the conditions of the cylinder temperature (melting point + 50 ° C.) and the mold temperature described in Table 1 and the mold temperature, and the lower limit pressure (minimum filling pressure) +10 kgf / cm ² . The connector molded product 1 has a terminal pitch (Lp) shown in FIG. 1 of 2 mm, a minimum thickness part (Lt) (partition wall part 3) of the product of 1 mm, and external dimensions of 10 mm width × 3 mm height × 40 mm length. This is a connector-type long molded product. Resin was filled from a pin gate G1 (gate diameter: 1 mm) placed on the short surface 2 on one side of the connector molded product 1 to obtain a connector molded product 1.

The specific gravity of the molded product was measured with a specific gravity measuring device (manufactured by Shimadzu Corporation, AUW320 / SMK-401), and the average value of 10 pieces was taken as the specific gravity of the molded product. The theoretical specific gravity was calculated based on the density of each compounding material, and the molded product filling rate (%) was calculated from the following formula. In addition, it shows that it is excellent in the filling rate to a thin part, so that this value is high.
Molded product filling ratio = (molded product specific gravity / theoretical specific gravity) × 100

(13) Evaluation of burr length of connector molded product (process window evaluation during molding)
Cylinder temperatures (melting points) described in Tables 1 and 3 were used for the pellets of the thermoplastic resin compositions obtained in Examples and Comparative Examples using an injection molding machine (SG75H-MIV, manufactured by Sumitomo Heavy Industries, Ltd.). + 50 ° C.), and set the mold temperature, the lower limit pressure (minimum filling pressure) + 10kgf / cm ² and lower pressure (minimum filling pressure) + 40kgf / cm ² conditions were injection molded connector molded article 1 shown in FIG. 1 . At this time, the length of the burr C generated at the flow end of the connector molded product 1 injection molded from the pin gate G1 via the sprue A and the runner B shown in FIG. The smaller the burr length, the better, and the burr length when injection molding is performed at the lower limit pressure (minimum filling pressure) +10 kgf / cm ² and the burr length when injection molding is performed at the lower limit pressure (minimum filling pressure) +40 kgf / cm ^2. The smaller the difference, the larger the process window at the time of molding because a similar molded product can be collected even if it is appropriately injection molded.

(14) Evaluation of releasability of connector molded product The pellets of the thermoplastic resin compositions obtained in Examples and Comparative Examples were used with an injection molding machine (SG75H-MIV, manufactured by Sumitomo Heavy Industries, Ltd.). 1 and 20 are continuously formed into the connector molded product 1 shown in FIG. 1 under the conditions of the cylinder temperature (melting point + 50 ° C.) and mold temperature described in Table 3 and the lower limit pressure (minimum filling pressure) +10 kgf / cm ² . The number of molded products stuck to the mold was evaluated. In addition, when it was stuck to the mold and did not release, after removing the molded product, a mold release spray (Daikin Industry Co., Ltd., Die Free GA-7500) was applied to the mold and injection molding was resumed. . The smaller the number, the better the releasability.

(15) Evaluation of surface appearance of connector molded product The pellets of the thermoplastic resin compositions obtained in the examples and comparative examples were prepared using an injection molding machine (Sumitomo Heavy Industries, Ltd., SG75H-MIV). 1 and the cylinder temperature described in Table 3 (melting point + 50 ° C.), mold temperature, injection molding of the connector molded product 1 shown in FIG. 1 under the condition of the lower limit pressure (minimum filling pressure) +10 kgf / cm ² , The clarity of the ceiling surface 4 of the obtained molded product was observed with the naked eye and evaluated according to the following criteria.
○: The reflected image of the fluorescent lamp is clearly observed up to the outline.
Δ: The reflected image of the fluorescent lamp is observed although it is unclear.
X: The reflected image of a fluorescent lamp cannot be observed.

(16) Evaluation of Drop Resistance of Connector Molded Product The connector molded product 1 shown in FIG. 1 is injection-molded by the method described in (12), the connector electrode is inserted into the obtained molded product, and it is repeatedly dropped from a height of 1 m. The number of drops until the molded product was broken was measured. The evaluation was performed immediately after molding and after 20,000 hours had passed since the 100 V voltage was applied to the connector electrode and heat was applied. The larger the number of drops, the better the drop resistance.

(17) Evaluation of scratch resistance The amount of dust caused by rubbing when the connector molded product 1 shown in FIG. 1 is injection-molded by the method described in (12) and the connector electrode is repeatedly inserted and removed 10,000 times. Was measured. The smaller the amount of dust, the better the scratch resistance.

Examples 1-11, Comparative Examples 1-15
Each component is premixed with the composition shown in Table 1 and Table 3, and while performing nitrogen flow, the screw diameter is 30 mm, the screw is two screws with two threads, L / D = 35 in the same direction rotation Using a fully meshed twin screw extruder (manufactured by Nippon Steel Works, TEX-30α), set the cylinder temperature as shown in Table 1 and Table 3, and melt kneading at a screw speed of 200 rpm and a discharge rate of 20 kg / h. The strand-shaped molten resin was discharged from the discharge port (L / D = 35). The screw configuration at that time is provided with three kneading zones starting from the positions of L / D = 7, 16, 25, and the length Lk / D of each kneading zone is Lk / D = 3.0 in order. 3.0 and 3.0. Furthermore, the reverse screw zone was provided in the downstream of each kneading zone, and length Lr / D of each reverse screw zone was Lr / D = 0.5, 0.5, 0.5 in order. Further, the ratio (%) of the total length of the kneading zone to the total length of the screw was calculated by (total length of kneading zone) / (total length of screw) × 100, and was 26%. In addition, a side feeder is installed at the position of L / D = 23, and (C) All raw materials except glass fiber are melted at the root of the extruder (position of L / D = 1) (upstream on the side where the raw material is supplied) When the resin discharge side is downstream, the position of the upstream end of the screw is 0%, and the position of the downstream end of the screw is 100%, the position is 3%). During fiber extrusion (L / D = 23 position) (Raw material supply side is upstream, molten resin discharge side is downstream, screw upstream end position is 0%, screw downstream When the position of the side end portion is 100%, the position is 66%. A vent vacuum zone was provided at a position of L / D = 30, and volatile components were removed at a gauge pressure of −0.1 MPa. The molten resin discharged from the 4 mmφ × 2 hole passing through the die head was drawn into a strand shape, passed through a cooling bath, cooled, and cut while being taken out by a pelletizer to obtain a pellet of a thermoplastic resin composition. . The pellets were vacuum-dried at 80 ° C. for 24 hours or more, and then evaluated as described above. Various evaluation results are shown in Tables 1 to 4.

The thermoplastic resin compositions of Examples 1 to 11 have a low melt viscosity in a high shear rate region (1216 sec ⁻¹ ) corresponding to the shear rate at the time of injection molding, and are excellent in fluidity at the time of injection molding. Even when a connector molded product having a large number of thin portions as shown is molded, the filling rate can be increased and molding defects can be reduced.

In addition, the thermoplastic resin compositions of Examples 1 to 11 have a large melt viscosity dependency on the shear rate. As described above, the melt viscosity is low in the high shear rate region (1216 sec ⁻¹ ), but the low shear rate region ( At 24 sec ⁻¹ ), the melt viscosity is high and the burr length can be remarkably suppressed. In addition, when removing the product above the lower limit pressure, the burr length is unlikely to increase even if pressure is applied too much, that is, the same molded product can be collected even if it is appropriately injection molded. Can be taken widely.

  Moreover, since the thermoplastic resin composition of Examples 1-11 is excellent also in the mold release property from a metal mold | die, it is excellent in continuous productivity also in complicated molded articles like a connector. When the polyamide resin used in Examples 1 to 11 is used as a base resin, it is generally known that the releasability from the mold is poor (Comparative Example 14). By blending a specific amount of magnesium oxide and glass fiber, releasability is expressed.

  Moreover, since the thermoplastic resin composition of Examples 1-11 shows high glossiness, the connector molded article excellent in the surface external appearance can be obtained.

  In addition to the high strength, rigidity and impact resistance, the thermoplastic resin compositions of Examples 1 to 11 are excellent in fluidity at the time of injection molding and have a reasonably large difference between the melting point and the cooling crystallization temperature. Even in complicated connector molded products, the weld part has high strength and excellent drop resistance.

  Furthermore, even if electricity is passed through the connector electrode, the generated heat is transmitted to the thermoplastic resin composition and dissipated into the air, so that deterioration of the connector molded product is suppressed, and the drop resistance after long-time use is excellent.

  In addition, since the thermoplastic resin compositions of Examples 1 to 11 have high strength, rigidity, and impact resistance, the amount of scraping caused by rubbing when the connector electrode is inserted and removed is small, and the scratch resistance is excellent.

Since Comparative Example 1 is a thermoplastic resin composition using a polyamide resin having a high relative viscosity, the melt viscosity in the high shear rate region (1216 sec ⁻¹ ) is high, the fluidity during connector molding is poor, and the filling It can be seen that the rate is low. It can also be seen that the length of the burr is increased because the connector is filled at a high pressure during molding. Furthermore, it can be seen that the weld strength is low and the drop resistance is low due to poor fluidity during connector molding.

Since Comparative Example 2 is a thermoplastic resin composition using a polyamide resin having a low relative viscosity, it can be seen that the strength, rigidity and impact resistance are low, and the drop resistance and scratch resistance of the connector molded product are low. Also, since the melt viscosity in the high shear rate region (1216 sec ⁻¹ ) is low, the filling rate of the connector molded product is high. However, when the molding is performed at a pressure lower than the lower limit for product removal, the melt viscosity in the high shear rate region is low. Therefore, it can be seen that the burr length increases even if the lower limit pressure is +10 kgf / cm ² .

It can be seen that Comparative Examples 3 to 4 and 7 are thermoplastic resin compositions having a small difference between the melting point and the temperature-falling crystallization temperature, and thus are easily crystallized in the mold and have a low filling rate. It can also be seen that the length of the burr increases because it is necessary to fill the connector with high pressure. Further, since a small shear rate dependence of melt viscosity, the difference between the burr length is greater that occurs when molded at lower pressure + 10 kgf / cm ² and lower pressure + 40 kgf / cm ^2, that narrow process window during molding Recognize. Furthermore, since it is easy to crystallize, it can be seen that the weld strength is low and the drop resistance is low. It can also be seen that the surface appearance is insufficient.

  In Comparative Example 5, the polyamide resin used in Comparative Example 4 is replaced with a high molecular weight type having a high relative viscosity. It can be seen that the high molecular weight type increases the difference between the melting point and the cooling crystallization temperature but increases the melt viscosity, resulting in poor fluidity during connector molding and a low filling rate. It can also be seen that the length of the burr increases because it is necessary to fill the connector at a higher pressure during molding. Moreover, since the fluidity at the time of injection molding becomes further poor, it can be seen that the weld strength is lowered and the drop resistance is also lowered. Moreover, although the surface appearance is improved as compared with Comparative Examples 3 and 4, it can be seen that it is still insufficient.

  Comparative Example 6 is a thermoplastic resin composition having a low melting point using a polyamide resin having a high copolymerization ratio, but it can be seen that releasability from the mold is remarkably deteriorated. It can also be seen that when electricity is applied to the connector electrode for a long time, the thermoplastic resin composition partially deteriorates and the drop resistance after long-time use is greatly reduced.

  Comparative Examples 8 and 9 are thermoplastic resin compositions to which a part of semi-aromatic non-crystalline polyamide is added. However, since the melt viscosity is high, the fluidity at the time of molding a connector is poor, and the melting point and the temperature-falling crystallization It can be seen that since the temperature difference is small, it is easy to crystallize in the mold, the filling rate is low, and the weld strength and drop resistance are also low. It can also be seen that the length of the burr is increased because the connector is filled at a high pressure.

  Comparative Example 10 is a thermoplastic resin composition (melting point and cooling crystallization temperature higher than 70 ° C.) that does not show a cooling crystallization temperature, but it can be seen that the releasability from the mold is extremely poor.

  Comparative Example 11 is a thermoplastic resin composition having a large difference between the melting point and the cooling crystallization temperature, but it can be seen that the releasability from the mold is extremely poor.

  Comparative Example 12 is a thermoplastic resin composition using a polyamide resin having a high melting point, but a large amount of gas derived from the decomposition of the polyamide resin and magnesium hydroxide was generated during melt kneading. As a result, the strength and impact resistance are low, and it is understood that the drop resistance and scratch resistance of the connector molded product formed by molding the thermoplastic resin composition are low.

  Comparative Example 13 was an example in which the amount of polyamide resin and glass fiber was small and the amount of magnesium hydroxide was increased, but good pellets could not be collected by melt-kneading.

  Comparative Example 14 is a thermoplastic resin composition having a small amount of magnesium hydroxide and a large amount of glass fiber. However, since the melt viscosity is high, the fluidity at the time of molding a connector is poor, and the filling rate is low. . It can also be seen that the length of the burr is increased because the connector is filled at a high pressure during molding. Moreover, it turns out that a mold release property is also bad compared with an Example. Furthermore, due to the low thermal conductivity, when electricity is passed through the connector electrode for a long time, the generated heat cannot be dissipated into the air, and the thermoplastic resin composition partially deteriorates, It can be seen that the drop resistance decreases.

  Comparative Example 15 is a thermoplastic resin composition that does not contain glass fiber, but the strength and impact resistance of the thermoplastic resin composition is low, so it is understood that the drop resistance and scratch resistance of the connector molded product are low. .

1: Connector molded product 2: Short surface 3: Partition wall 4: Ceiling surface G1: Pin gate Lp: Inter-terminal pitch
Lt: Minimum thickness part
A: Sprue B: Runner C: Bali

Claims (6)

(A) Polyamide resin 25-45 wt%, (B) Magnesium hydroxide 25-74 wt%, and (C) Glass fibers 1-40, where the total of (A), (B), and (C) is 100 wt%. A thermoplastic resin composition for heat-dissipating electrical / electronic parts having a thermal conductivity of 1 W / m · K or more, as measured by a heat flow meter method, comprising the following weights (I) to (III): A thermoplastic resin composition for heat-dissipating electrical / electronic parts, characterized by satisfying all of the above.
(I) The polyamide resin extracted from the thermoplastic resin composition for heat-dissipating electric / electronic parts has a relative viscosity of 1.5 to 2.8 at 25 ° C. in a 98% sulfuric acid solution of 0.01 g / ml.
(II) Melting | fusing point of the thermoplastic resin composition for said heat dissipation electrical / electronic components is 200-300 degreeC.
(III) The difference between the melting point and the cooling crystallization temperature of the thermoplastic resin composition for heat-dissipating electrical / electronic parts is 45 to 70 ° C. 2. The heat-dissipating electrical / electronic component according to claim 1, wherein the heat-dissipating crystallization heat amount of the polyamide resin converted from the heat-dissipating crystallization heat amount of the thermoplastic resin composition for heat-dissipating electrical / electronic components is 20 to 55 J / g. Thermoplastic resin composition. The thermoplastic resin composition for heat-dissipating electrical / electronic parts according to claim 1 or 2, wherein the (A) polyamide resin comprises a polyamide 66 / 6I / 6 copolymer, 66 / 6I copolymer and / or MXD6. object. The thermoplastic resin composition for heat-dissipating electrical and electronic parts according to claim 3, comprising 70 to 100% by weight of polyamide 66 / 6I / 6 copolymer in 100% by weight of the (A) polyamide resin. A heat-dissipating electrical / electronic component obtained by melt-molding the thermoplastic resin composition for heat-dissipating electrical / electronic component according to claim 1. The heat dissipating electrical / electronic component according to claim 5, which is a connector, a relay, a switch, a personal computer casing, a mobile phone casing or a battery casing.

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