Resin composition and molded article thereof

Abstract

To provide: a resin composition which can provide a molding which shows little deformation, has excellent toughness and, even when it comes in contact with an article having a plating layer on its surface, causes little separation of the plating of the counterpart article; and a molding thereof.SOLUTION: A resin composition comprises 55 to 80 mass% of all aromatic polyester amide having the following constituent units (I) to (V) and 20 to 45 mass% of whiskers.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a resin composition and a molded article thereof. [Background technology]

[0002] Liquid crystalline polymers such as wholly aromatic polyesters are widely used as high-performance engineering plastics because they have a good balance of excellent fluidity, mechanical strength, heat resistance, chemical resistance, electrical properties, etc. For example, Patent Document 1 describes a liquid crystalline polyester resin composition having a predetermined monomer composition.

[0003] A connector is a component that connects various types of electric wires, and is known to have a structure in which contacts (male terminals) are inserted into a connector (female connector) provided on one side of a board, penetrating the board from the other side. The connector holds female terminals inside. The connector has contact insertion holes into which the contacts are inserted, and the contacts are introduced into the contact insertion holes of the connector to connect with the female terminals. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 5-170902 Summary of the Invention [Problem to be solved by the invention]

[0005] However, vibrations during insertion of the contacts into the contact insertion holes or during use after installation in a vehicle or other vehicle can cause the contact surface to come into contact with the inner periphery of the contact insertion hole and wear away the plating layer on the contact surface. If the peeled plating layer accumulates inside the connector, it could cause a short circuit. There is also concern that the contact insertion hole itself could be worn away and damaged by contact with the contact. In addition, when a liquid crystalline polymer is molded, the outside of the molded product is rapidly cooled, solidifying before crystallization progresses, resulting in a small shrinkage rate, while the inside is slowly cooled, solidifying in a more crystallized state, resulting in a large shrinkage rate. As a result, there is a difference in shrinkage rate between the inside and outside of the molded product, which can cause the molded product to deform. In particular, when at least a portion of the cross-sectional shape of the molded product is a shape with a partial opening on the entire periphery (for example, a U-shape (a rectangular shape with one side open, also known as a "U-shape"), an L-shape, an E-shape, etc.), so-called inward collapse deformation is likely to occur in that portion. Furthermore, it is desirable that the resin composition for connectors give molded articles with excellent toughness to prevent breakage due to vibrations during vehicle running, etc.

[0006] An object of the present invention is to provide a resin composition that can give a molded article that has little deformation and excellent toughness, and that causes little plating peeling from the mating article even when it comes into contact with an article having a plated layer on its surface, and a molded article made from the resin composition. [Means for solving the problem]

[0007] The present invention has the following aspects. [1] A polymer comprising a wholly aromatic polyester amide and whiskers, the wholly aromatic polyester amide comprising the following structural units (I) to (V): TIFF0007799388000001.tif102170 (Ar1 and Ar2 in structural units (III) and (IV) each independently represent a divalent aromatic group.) A resin composition, wherein, relative to all structural units of the wholly aromatic polyesteramide, the content of structural unit (I) is 40 mol% or more and 70 mol% or less, the content of structural unit (II) is more than 0 mol% and 8 mol% or less, the content of structural unit (III) is 12.5 mol% or more and 27.5 mol% or less, the content of structural unit (IV) is 7.5 mol% or more and 22.5 mol% or less, the content of structural unit (V) is 1 mol% or more and 9 mol% or less, the total content of structural units (I) to (V) is 100 mol%, the content of wholly aromatic polyesteramide is 55 to 80 mass% relative to the total amount of the resin composition, and the content of whiskers is 20 to 45 mass% relative to the total amount of the resin composition. [2] The resin composition according to [1], wherein the whiskers comprise one or more selected from potassium titanate whiskers, calcium silicate whiskers, calcium carbonate whiskers, zinc oxide whiskers, aluminum borate whiskers, silicon nitride whiskers, silicon trinitride whiskers, basic magnesium sulfate whiskers, barium titanate whiskers, silicon carbide whiskers, and boron whiskers. [3] The resin composition according to [1] or [2], wherein the whiskers have an average fiber diameter of 0.1 to 15 μm. [4] The resin composition according to any one of [1] to [3], wherein the whiskers have an average fiber length of 1 to 200 μm. [5] The resin composition according to any one of [1] to [4], wherein the content of the plate-like, fibrous or granular inorganic filler is less than 20 mass % based on the total amount of the resin composition. [6] The resin composition according to any one of [1] to [5], which is used for manufacturing connector parts. [7] Use of the resin composition according to any one of [1] to [6] for producing a connector part. [8] A molded article comprising the resin composition according to any one of [1] to [6]. [9] The molded product according to [8], which is a connector part.

[10] The molded product according to [9], which is for an in-vehicle connector.

[11] A molded product according to [9] or

[10] , which has one or more through holes for inserting contacts, and the surface roughness Ra of the inner surface of the one or more through holes is 1.25 μm or less. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a resin composition that can give a molded article that has little deformation and excellent toughness, and that causes little plating peeling from the mating article even when it comes into contact with an article having a plated layer on its surface, and a molded article made from the resin composition. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view showing an example of a configuration of a connector. [Figure 2] 2A is a cross-sectional view taken along line AA of the connector part 1 of FIG. 1, and FIG. 2B is a bottom view thereof. [Figure 3] 2 is a perspective view showing an example of an electrical connector (IGBT connector) including a plurality of connectors 100 of FIG. 1. FIG. [Figure 4] 1A and 1B are diagrams showing a 0.6 mm pitch connector molded in an example, where the numerical values ​​in the diagram are in mm. (a) is a plan view, (b) is a front view, and (c) is an AA cross-sectional view. [Figure 5] 1A and 1B are diagrams showing measurement points in the measurement of warpage of a 0.6 mm pitch connector carried out in an example, where (a) is a perspective view of the 0.6 mm pitch connector, and (b) is a conceptual diagram showing the measurement points. [Figure 6] 1 is a schematic diagram showing the shape of a molded article for evaluating inward collapse deformation in an example, where (a) is a perspective view and (b) is a front view, and A and B represent the interior angles at one end of the molded article. DETAILED DESCRIPTION OF THE INVENTION

[0010] An embodiment of the present invention will be described in detail below. The present invention is not limited to the following embodiment, and can be carried out by making appropriate modifications within the scope that does not impair the effects of the present invention.

[0011] [Resin composition] The resin composition according to this embodiment (hereinafter also simply referred to as "resin composition") contains wholly aromatic polyesteramide and whiskers. (fully aromatic polyester amide) The wholly aromatic polyesteramide contains the following structural units (I) to (V) as essential components, with the structural unit (I) content being 40 mol% to 70 mol%, the structural unit (II) content being greater than 0 and 8 mol% or less, the structural unit (III) content being 12.5 mol% to 27.5 mol%, the structural unit (IV) content being 7.5 mol% to 22.5 mol%, and the structural unit (V) content being 1 mol% to 9 mol%, with the total content of structural units (I) to (V) being 100 mol%. TIFF0007799388000002.tif102170In the formula, Ar1 and Ar2 each independently represent a divalent aromatic group.

[0012] The structural unit (I) is derived from 4-hydroxybenzoic acid (hereinafter also referred to as "HBA"). The wholly aromatic polyesteramide contains 40 mol % or more and 70 mol % or less of the structural unit (I) relative to all structural units. If the content of the structural unit (I) is less than 40 mol % or more than 70 mol %, at least one of a low melting point and heat resistance tends to be insufficient. From the viewpoint of achieving both a low melting point and heat resistance, the content of the structural unit (I) is preferably 45 to 70 mol %, more preferably 50 to 70 mol %, even more preferably 50 to 68 mol %, still more preferably 55 to 68 mol %, and particularly preferably 55 to 65 mol %.

[0013] The structural unit (II) is derived from 6-hydroxy-2-naphthoic acid (hereinafter also referred to as "HNA"). The wholly aromatic polyesteramide contains more than 0 and 8 mol% or less of the structural unit (II) relative to all structural units. If the structural unit (II) is not contained or if the structural unit (II) content exceeds 8 mol%, at least one of the low melting point and heat resistance tends to be insufficient. From the viewpoint of achieving both a low melting point and heat resistance, the content of the structural unit (II) is preferably 0.1 to 8 mol%, more preferably 1 to 8 mol%, even more preferably 1.5 to 7.5 mol%, still more preferably 2 to 7.5 mol%, and particularly preferably 2 to 7 mol%.

[0014] In the structural unit (III), Ar1 represents a divalent aromatic group. Examples of the divalent aromatic group include p-phenylene, m-phenylene, o-phenylene, substituted phenylene, biphenyl-4,4'-diyl, naphthalene-2,6-diyl, naphthalene-2,7-diyl, naphthalene-1,6-diyl, and naphthalene-1,4-diyl. The structural unit (III) is derived from an aromatic dicarboxylic acid. For example, the structural unit (III) is derived from 1,4-phenylenedicarboxylic acid (hereinafter also referred to as "TA"), 1,3-phenylenedicarboxylic acid (hereinafter also referred to as "IA"), 2,6-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 4,4'-dicarboxybiphenyl, etc., as well as alkyl-, alkoxy-, or halogen-substituted derivatives thereof, and ester-forming derivatives thereof, such as ester derivatives and acid halides. The structural unit (III) is preferably derived from one or more selected from 1,4-phenylenedicarboxylic acid, 1,3-phenylenedicarboxylic acid, and 2,6-naphthalenedicarboxylic acid, and more preferably derived from 1,4-phenylenedicarboxylic acid (TA).

[0015] The structural unit (III) preferably has at least one structure selected from the following formulae (III-a) to (III-c), and more preferably has the structure of formula (III-a). TIFF0007799388000003.tif48170

[0016] The wholly aromatic polyesteramide contains 12.5 mol% or more and 27.5 mol% or less of the structural unit (III) relative to all structural units. If the content of the structural unit (III) is less than 12.5 mol% or more than 27.5 mol%, at least one of a low melting point and heat resistance tends to be insufficient. From the viewpoint of achieving both a low melting point and heat resistance, the content of the structural unit (III) is preferably 13 to 27 mol%, more preferably 14 to 26 mol%, even more preferably 15.5 to 25.5 mol%, still more preferably 15 to 25 mol%, and particularly preferably 15 to 23 mol%.

[0017] In the structural unit (IV), Ar2 represents a divalent aromatic group. Examples of the divalent aromatic group include p-phenylene, m-phenylene, o-phenylene, substituted phenylene, biphenyl-4,4'-diyl, biphenyl-3,3'-diyl, biphenyl-3,4'-diyl, naphthalene-2,6-diyl, naphthalene-2,7-diyl, naphthalene-1,6-diyl, and naphthalene-1,4-diyl. The structural unit (III) is derived from an aromatic diol. For example, structural unit (IV) is derived from 4,4'-dihydroxybiphenyl (hereinafter also referred to as "BP"), 1,4-dihydroxybenzene, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 4,4'-dihydroxybiphenyl, 3,3'-dihydroxybiphenyl, 3,4'-dihydroxybiphenyl, 4,4'-dihydroxybiphenyl ether, etc., as well as ester-forming derivatives thereof such as alkyl, alkoxy, or halogen-substituted derivatives, and acylated derivatives thereof. The structural unit (IV) is preferably derived from one or more selected from 4,4'-dihydroxybiphenyl, 1,4-dihydroxybenzene, and 2,6-dihydroxynaphthalene, and more preferably derived from 4,4'-dihydroxybiphenyl (BP).

[0018] The structural unit (IV) preferably has at least one structure selected from the following formulae (IV-a) to (IV-c), and more preferably has the structure of formula (IV-a). TIFF0007799388000004.tif42170

[0019] The wholly aromatic polyesteramide contains 7.5 mol% or more and 22.5 mol% or less of the structural unit (IV) relative to all structural units. If the content of the structural unit (IV) is less than 7.5 mol% or more than 22.5 mol%, at least one of a low melting point and heat resistance tends to be insufficient. From the viewpoint of achieving both a low melting point and heat resistance, the content of the structural unit (IV) is preferably 8 to 22 mol%, more preferably 8 to 21 mol%, even more preferably 8.5 to 21.5 mol%, still more preferably 9 to 21 mol%, and particularly preferably 10 to 20 mol%.

[0020] The structural unit (V) is derived from p-aminophenol or N-acetyl-p-aminophenol. The wholly aromatic polyesteramide contains 1 mol % or more and 9 mol % or less of the structural unit (V) relative to all structural units. If the content of the structural unit (V) is less than 1 mol % or more than 9 mol %, at least one of a low melting point and heat resistance tends to be insufficient. From the viewpoint of achieving both a low melting point and heat resistance, the content of the structural unit (V) is preferably 1.5 to 9 mol %, more preferably 1.5 to 8.5 mol %, even more preferably 2 to 8 mol %, still more preferably 2 to 7.5 mol %, and particularly preferably 2.5 to 7.5 mol %.

[0021] From the viewpoint of high rigidity and high fluidity, the wholly aromatic polyesteramide is configured so that it contains the structural units (I) to (V) in total at 100 mol % of all the structural units.

[0022] Next, the properties of wholly aromatic polyesteramide will be described. Wholly aromatic polyesteramide exhibits optical anisotropy when melted. The fact that wholly aromatic polyesteramide exhibits optical anisotropy when melted means that it is a liquid crystalline polymer.

[0023] In this embodiment, the fact that the wholly aromatic polyesteramide is a liquid crystalline polymer is an essential factor for the wholly aromatic polyesteramide to have both thermal stability and easy processability, and to provide molded articles with excellent heat resistance and moldability. Although some wholly aromatic polyesteramides composed of the above structural units (I) to (V) do not form an anisotropic molten phase depending on the structural components and the sequence distribution in the polymer, the polymer used in this embodiment is limited to wholly aromatic polyesteramides that exhibit optical anisotropy when melted.

[0024] The melt anisotropy can be confirmed by a conventional polarization inspection method using crossed polarizers. More specifically, melt anisotropy can be confirmed by melting a sample placed on a Linkam hot stage using an Olympus polarizing microscope and observing it at 150x magnification under a nitrogen atmosphere. Liquid crystal polymers are optically anisotropic and transmit light when inserted between crossed polarizers. If a sample is optically anisotropic, polarized light will transmit even when it is in a molten, static liquid state, for example.

[0025] Nematic liquid crystalline polymers exhibit a significant decrease in viscosity above their melting point, and therefore, the fact that they exhibit liquid crystallinity at or above their melting point is generally an indicator of their processability. The melting point of the wholly aromatic polyesteramide is preferably as high as possible from the viewpoint of heat resistance, but considering the thermal degradation during melt processing of the polymer and the heating capacity of the molding machine, a preferable guideline is 350°C or less. From the viewpoints of heat resistance and moldability, the melting point of the wholly aromatic polyesteramide is more preferably 310 to 350°C, even more preferably 315 to 345°C, and still more preferably 320 to 340°C.

[0026] The "melting point" refers to the melting point Tm2 measured by a differential scanning calorimeter. The melting point Tm2 is determined by measuring the peak top temperature (melting point Tm1) of the endothermic peak observed when heating from room temperature at a heating rate of 20°C / min (first run) according to a method based on JIS K-7121 (1999), holding the sample at (melting point Tm1 + 40)°C for 2 minutes, cooling to room temperature at a heating rate of 20°C / min, and then heating again from room temperature at a heating rate of 20°C / min (second run). The melting point Tm2 is the peak top temperature of the endothermic peak observed in the second run.

[0027] The wholly aromatic polyesteramide preferably has a melt viscosity of 1000 Pa·s or less at a temperature 10 to 30°C higher than the melting point of the wholly aromatic polyesteramide and at a shear rate of 1000 / sec. By ensuring that the melt viscosity is 1000 Pa·s or less, fluidity is easily ensured during molding of the resin composition, and excessive filling pressure is less likely to occur. From the viewpoints of fluidity and moldability, the melt viscosity of the wholly aromatic polyesteramide is more preferably 4 to 500 Pa·s, even more preferably 4 to 250 Pa·s, and even more preferably 5 to 100 Pa·s. In this specification, melt viscosity refers to the melt viscosity measured in accordance with ISO 11443.

[0028] The melt viscosity measured at a "cylinder temperature 10 to 30°C higher than the melting point" means a melt viscosity measured at any cylinder temperature 10 to 30°C higher than the melting point Tm2 as described above, selected appropriately depending on the composition of the wholly aromatic polyesteramide, and the melt viscosity measured over the entire temperature range 10 to 30°C higher than the melting point Tm2 does not have to be within the above range. The melt viscosity can be adjusted by adjusting the final polymerization temperature during melt polymerization of the liquid crystalline polymer.

[0029] Next, a method for producing wholly aromatic polyesteramide will be described. The wholly aromatic polyesteramide of this embodiment is polymerized using a direct polymerization method, a transesterification method, or the like. For the polymerization, a melt polymerization method, a solution polymerization method, a slurry polymerization method, a solid-state polymerization method, or a combination of two or more of these methods is used, and a melt polymerization method or a combination of a melt polymerization method and a solid-state polymerization method is preferably used.

[0030] In the polymerization, an acylating agent for the polymerizable monomer or a monomer whose terminal is activated as an acid chloride derivative can be used. Examples of the acylating agent include fatty acid anhydrides such as acetic anhydride.

[0031] Various catalysts can be used in these polymerizations, and representative examples include metal salt catalysts such as potassium acetate, magnesium acetate, stannous acetate, tetrabutyl titanate, lead acetate, sodium acetate, antimony trioxide, and tris(2,4-pentanedionato)cobalt(III), and organic compound catalysts such as 1-methylimidazole and 4-dimethylaminopyridine.

[0032] In this embodiment, the molecular weight of the resin obtained by melt polymerization can be increased by further subjecting it to solid-phase polymerization.

[0033] (whiskers) The resin composition contains whiskers. Surprisingly, the inventors' research has revealed that by using whiskers as a filler added to the resin composition, a molded article made from the resin composition is less likely to peel off the plating of an article having a plated layer on its surface, even when the molded article comes into contact with the other article. In addition, it has been found that even when the molded article has at least a cross-sectional shape with a partial opening (e.g., a U-shape, an L-shape, an E-shape, etc.), inward collapse deformation is unlikely to occur. Whiskers refer to whisker-like (needle-shaped) inorganic compounds. Examples of whiskers include needle-shaped single-crystal inorganic compound whiskers, such as potassium titanate whiskers, calcium silicate whiskers (wollastonite), calcium carbonate whiskers, zinc oxide whiskers, aluminum borate whiskers, silicon nitride whiskers, silicon trinitride whiskers, basic magnesium sulfate whiskers, barium titanate whiskers, silicon carbide whiskers, and boron whiskers. One or more selected from these can be used. In terms of availability, it is preferable to include one or more selected from potassium titanate whiskers, calcium silicate whiskers (wollastonite), calcium carbonate whiskers, zinc oxide whiskers, and aluminum borate whiskers, and it is more preferable to include potassium titanate whiskers and / or calcium silicate whiskers (wollastonite).

[0034] The whiskers preferably have an average fiber length of 1 to 200 μm. By setting the average fiber length of the whiskers within the range of 1 to 200 μm, a resin composition can be obtained that provides a molded article with less plating peeling from the mating part. From the viewpoints of maintaining high rigidity and mechanical strength and further suppressing plating peeling from the mating part, the average fiber length of the whiskers is more preferably 5 to 200 μm, and even more preferably 10 to 150 μm. In one embodiment, the average fiber length of the whiskers can be 1 to 50 μm, preferably 5 to 40 μm, and more preferably 10 to 20 μm. In one embodiment, the average fiber length of the whiskers can be more than 50 μm and not more than 200 μm, preferably 80 to 150 μm, and more preferably 100 to 150 μm. In one embodiment, whiskers having an average fiber length of 1 to 50 μm, preferably 5 to 40 μm, more preferably 10 to 20 μm, and whiskers having an average fiber length of more than 50 μm but not more than 200 μm, preferably 80 to 150 μm, more preferably 100 to 150 μm, can be used in combination.

[0035] The average fiber length is measured by importing a stereomicroscope image of 100 whiskers from a CCD camera into a PC and then processing the image using an image measuring device. This process is repeated 10 times, and the average value of the measured values ​​when the number of whiskers reaches 1,000 is adopted. The average fiber length of the whiskers in a resin composition can be obtained by heating the resin composition at 600°C for 2 hours, incinerating it, and measuring the residue using the above method.

[0036] The whiskers preferably have an average fiber diameter of 0.1 to 15 μm. By setting the average fiber diameter of the whiskers within the range of 0.1 to 15 μm, it is possible to obtain a resin composition that provides a molded article with less plating peeling from the mating article. It is also possible to obtain a resin composition that provides a molded article that is less susceptible to inward collapse deformation. From the viewpoints of maintaining high rigidity and mechanical strength and further suppressing plating peeling from the mating part, the average fiber diameter of the whiskers is more preferably 0.3 to 10 μm, and even more preferably 0.4 to 9 μm. In one embodiment, the average fiber diameter of the whiskers can be 1 to 15 μm, preferably 3 to 10 μm, and more preferably 5 to 10 μm. In one embodiment, the average fiber diameter of the whiskers can be set to 0.1 to 1 μm, preferably 0.1 to 0.8 μm, and more preferably 0.1 to 0.5 μm. In one embodiment, whiskers having an average fiber diameter of 1 to 15 μm, preferably 3 to 10 μm, more preferably 5 to 10 μm, and whiskers having an average fiber diameter of 0.1 to 1 μm, preferably 0.1 to 0.8 μm, more preferably 0.1 to 0.5 μm can be used in combination.

[0037] The average fiber diameter is determined by measuring 30 whiskers with a scanning electron microscope and using the average value. The average fiber diameter of the whiskers in the resin composition is obtained by heating the resin composition at 600°C for 2 hours, incinerating it, and measuring the residue using the method described above.

[0038] From the viewpoint of obtaining a resin composition that provides a molded article with less plating peeling from a mating part, the whiskers preferably have an average aspect ratio of 10 to 50, more preferably 10 to 40. The average aspect ratio is a value calculated by dividing the average fiber length by the average fiber diameter.

[0039] (Content) The content of the wholly aromatic polyesteramide in the entire resin composition is 55 to 80% by mass. By setting the content of the wholly aromatic polyesteramide within the range of 55 to 80% by mass, the excellent fluidity, rigidity, mechanical strength, heat resistance, chemical resistance, electrical properties, etc., possessed by the liquid crystal polymer can be fully exhibited. From the viewpoints of heat resistance, high rigidity, and high fluidity, the content of the wholly aromatic polyesteramide in the resin composition is preferably 55 to 75% by mass, more preferably 58 to 70% by mass, and even more preferably 60 to 68% by mass.

[0040] The whisker content is 20 to 45% by mass of the total resin composition. By setting the whisker content within the range of 20 to 45% by mass, it is possible to obtain a resin composition that maintains excellent heat resistance, high rigidity, and high fluidity, while providing a molded article that, even when in contact with an article having a plated layer on its surface, causes little plating peeling from the mating article. It is also possible to obtain a resin composition that provides a molded article that is less susceptible to inward collapse and deformation. From the viewpoints of excellent heat resistance, high rigidity, and high fluidity, and further suppressing plating peeling from the mating part, the whisker content is preferably 25 to 45% by mass, more preferably 30 to 40% by mass, and even more preferably 32 to 38% by mass.

[0041] (mold release agent) The resin composition preferably contains a mold release agent. The mold release agent is not particularly limited as long as it is a commonly available agent, and examples thereof include fatty acid esters, fatty acid metal salts, fatty acid amides, and low-molecular-weight polyolefins, with pentaerythritol fatty acid esters (e.g., pentaerythritol tetrastearate) being preferred.

[0042] The amount of the release agent in the resin composition is preferably in the range of 0.1 to 3% by mass. When the amount of the release agent is 0.1% by mass or more, the mold releasability during molding is improved, and it is easy to obtain a molded product with less plating peeling even when it comes into contact with an article having a plated layer on its surface. When the amount of the release agent is 3% by mass or less, mold deposits (i.e., matter adhering to the mold during molding; hereinafter also referred to as "MD") are easy to reduce.

[0043] (Other additives) The resin composition may contain various powdery, granular, plate-like or fibrous inorganic or organic fillers depending on the intended use. Examples of powdery inorganic fillers include carbon black, graphite, silica, quartz powder, glass beads, glass balloons, glass powder, calcium silicate, aluminum silicate, kaolin, clay, diatomaceous earth, metal oxides such as iron oxide, titanium oxide, zinc oxide, antimony trioxide, and alumina, metal carbonates such as calcium carbonate and magnesium carbonate, metal sulfates such as calcium sulfate and barium sulfate, as well as ferrite, silicon carbide, silicon nitride, boron nitride, and various metal powders.

[0044] Examples of plate-like inorganic fillers include mica, glass flakes, talc, various metal foils, etc. Examples of organic fillers include heat-resistant, high-strength synthetic fibers such as aromatic polyester fibers, liquid crystal polymer fibers, aromatic polyamide fibers, and polyimide fibers.

[0045] Examples of the fibrous inorganic filler include fibrous fillers (amorphous fibers or polycrystalline fibers) such as glass fibers, milled glass fibers, carbon fibers, and alumina fibers.

[0046] These inorganic and organic fillers can be used alone or in combination of two or more. When using a filler, a sizing agent or a surface treatment agent can be used if necessary. The amount of filler blended is preferably less than 20% by mass, more preferably 10% by mass or less, and even more preferably 5% by mass or less, of the total resin composition. The composition may also be configured to contain no inorganic or organic fillers.

[0047] In particular, from the viewpoint of providing a resin composition that gives a molded product that is less likely to suffer inward collapse deformation in at least a portion of its cross-sectional shape, even if that portion has an open shape (e.g., a U-shape, an L-shape, an E-shape, etc.), the content of the plate-like filler is preferably 10% by mass or less, more preferably 5% by mass or less, and the composition may also be such that it does not contain any plate-like filler. Furthermore, from the viewpoint of providing a resin composition that produces a molded article with little plating peeling even when it comes into contact with an article having a plating layer on its surface, the content of the fibrous filler in the total resin composition is preferably 10 mass% or less, more preferably 5 mass% or less, and the resin composition may also be configured to contain no fibrous filler.

[0048] The resin composition may contain other resins besides the liquid crystalline polymer, and additives such as antioxidants, stabilizers, pigments, crystal nucleating agents, etc. The content of other resins and additives in the resin composition is preferably 20 mass % or less.

[0049] The melt viscosity of the resin composition is preferably 1000 Pa·s or less at a temperature 10 to 30°C higher than the melting point of the wholly aromatic polyesteramide and at a shear rate of 1000 / sec. By making the melt viscosity of the resin composition 1000 Pa·s or less, fluidity is easily ensured and excessive filling pressure is less likely to occur. From the viewpoint of ensuring fluidity and moldability, the melt viscosity of the resin composition is more preferably 4 to 500 Pa·s, even more preferably 4 to 250 Pa·s, and even more preferably 5 to 100 Pa·s.

[0050] The method for producing the resin composition is not particularly limited, and the resin composition can be prepared by a conventionally known method. For example, the resin composition is prepared by blending the components and melt-kneading them using a single-screw or twin-screw extruder.

[0051] [Application] The resin composition according to this embodiment has heat resistance, high mechanical strength, high rigidity, and high fluidity, and thus can be processed into various three-dimensional molded articles, fibers, films, and the like. For example, it can be preferably used in the production of connectors, CPU sockets, relay switch components, bobbins, actuators, noise reduction filter cases, electronic circuit boards, or heating fuser rolls for office automation equipment. In particular, this resin composition can produce molded articles that exhibit minimal plating peeling even when in contact with articles having a plated surface. Therefore, it is preferably used in the production of components that rub against articles having a plated surface during production or use, such as connector components (in-vehicle connector components) installed in automobiles. Furthermore, this resin composition can produce molded articles that are resistant to inward deformation, and therefore it is preferably used in the production of molded articles in which at least a portion of the cross-sectional shape is partially open around the entire periphery (e.g., U-shaped, L-shaped, E-shaped).

[0052] [Molded products] The molded article according to the present embodiment can be obtained by molding the resin composition. The molding method is not particularly limited, and a general molding method can be used. Examples of general molding methods include injection molding, extrusion molding, compression molding, blow molding, vacuum molding, foam molding, rotational molding, gas injection molding, and inflation molding.

[0053] The molded article preferably has a surface roughness Ra of 1.25 μm or less. By keeping the surface roughness Ra at 1.25 μm or less, peeling of the plating on the mating part can be reduced even when the molded article comes into contact with an article having a plated layer on its surface. From the viewpoint of reducing peeling of the plating on the mating part, the surface roughness Ra is more preferably 1.20 μm or less, and even more preferably 1.15 μm or less. Methods for reducing the surface roughness Ra include adjusting the composition and content of the whiskers, as well as adjusting the molding conditions. The surface roughness Ra is a value measured in accordance with JIS B 0601:1994.

[0054] In order to prevent damage due to deformation even when the molded article is subjected to strong vibrations during use, such as in an on-board connector, the bending strain of the molded article measured in accordance with ASTM D790 is preferably 2.0% or more, and more preferably 2.2% or more.

[0055] Molded articles obtained by molding the resin composition exhibit minimal deformation and excellent toughness, making them suitable for a variety of applications. For example, the molded articles can be connectors, CPU sockets, relay switch components, bobbins, actuators, noise-reducing filter cases, electronic circuit boards, or heating and fusing rolls for office automation equipment. In particular, because the plating of the molded articles is minimal even when they come into contact with articles having a plated layer on their surfaces, they can be used as components whose surfaces rub against those of articles having a plated surface during manufacture or use, such as automotive connector components (e.g., IGBT connectors) installed in automobiles.

[0056] (connector parts) Fig. 1 shows an example of the configuration of a connector (female connector) 100 including a connector part 1 and a female terminal 20. Fig. 2 shows (a) a cross-sectional view of the connector part 1 of Fig. 1 taken along line AA, and (b) a bottom view. The connector part 1 is an injection-molded product of the above-mentioned resin composition, and functions as a housing for the female terminal 20. The connector part 1 is a box-shaped body having a cavity 2 that accommodates the female terminal 20. The connector part 1 includes the cavity 2, a side wall 3 that surrounds the cavity 2, and a bottom floor 4 that is continuous with the side wall 3 and is provided on the side where a contact (male terminal: not shown) is inserted. The contact is inserted into the connector 100 from the direction of the arrow in FIG. 1(b). As shown in Figure 2(a), the portion of the connector part 1 that forms the cavity 2 downward from the upper end has a rectangular (U-shaped) cross section with at least one side open. Conventionally, when a molded product having such a shape is formed using a liquid crystalline polymer, the difference in shrinkage rate between the resin on the outside and inside of the molded product can cause the side wall 3 to collapse inward, resulting in a small interior angle A or B. However, because the connector part 1 is formed using the resin composition described above, it is less likely to collapse inward. As shown in FIG. 2(b), the lower end of the connector component 1 forms a bottom floor 4, which has contact insertion holes 5 for inserting contacts. The contact insertion holes 5 are through-holes formed in a funnel shape with an opening diameter that widens outward so that contacts (not shown) can be easily guided into the connector 100 from the direction of the arrow in FIG. 1(b). The contact insertion holes 5 are formed so that the maximum opening diameter (the opening diameter at the outermost part) is larger than the maximum diameter of the contacts, and the minimum opening diameter (the opening diameter at the innermost part) is approximately the same as the diameter of the contacts. The contact insertion holes 5 shown in FIG. 2(b) have a rectangular planar shape, but may have other shapes (for example, a circular shape).

[0057] As described above, the maximum opening diameter of the contact insertion hole 5 (the opening diameter at the end on the entrance side where the contact is inserted) is larger than the diameter of the contact. This allows the contact to be easily inserted into the contact insertion hole 5. The minimum opening diameter of the contact insertion hole 5 (the opening diameter at the end on the contact exit side, i.e., the side where the contact enters the connector 100) is approximately the same as the diameter of the contact. This allows the contact inserted into the contact insertion hole 5 to be easily guided into the connector. For example, when the actual dimensions of the contact are approximately 0.5 mm x 0.7 mm, the maximum opening diameter of the contact insertion hole 5 can be 0.65 mm x 0.85 mm. The minimum opening diameter of the contact insertion hole 5 can be 0.50 mm x 0.70 mm.

[0058] In conventional connector components, when the inner surface of the contact insertion hole comes into contact with a contact, particularly when the inner surface of the portion with the smallest opening diameter (e.g., X in Figure 2(b)) comes into contact with the contact, the plating layer formed on the surface of the contact can be scraped off. In contrast, the connector component of this embodiment is formed using the above-mentioned resin composition, so plating peeling can be suppressed even when it comes into contact with a contact. In addition, because it has heat resistance, high strength, and high rigidity, it can prevent damage even when used at high temperatures, such as in the engine compartment of an automobile.

[0059] The connector component 1 has one or more through holes (contact insertion holes 5) for inserting contacts, and the surface roughness Ra of the inner surface of the one or more through holes is preferably 1.25 μm or less. By setting the surface roughness Ra to 1.25 μm or less, peeling of the plating on the contact can be reduced even when the contact comes into contact with a contact having a plating layer on its surface. From the viewpoint of reducing peeling of the plating on the contact, the surface roughness Ra is more preferably 1.20 μm or less, and even more preferably 1.15 μm or less. Methods for reducing the surface roughness Ra include adjusting the whisker composition and content, as well as adjusting the molding conditions. The surface roughness Ra is a value measured in accordance with JIS B 0601:1994.

[0060] FIG. 3 is a perspective view showing an example of an electrical connector 200 using the connector 100. The electrical connector 200 having the structure shown in FIG. 3 is also called an IGBT connector, and includes an outer housing 30 composed of components such as a back plate, a cap housing, and a plug housing, and six connectors 100 housed within the outer housing 30. The number of housed connectors 100 is selected appropriately depending on the application. The electrical connector 200 is soldered to a substrate (not shown). The substrate typically has a substantially rectangular contact insertion hole penetrating through the thickness direction, and the contacts are introduced into the contact insertion hole of the substrate from the side opposite the female connector (connector 100), via a guide connector or the like as necessary, and then penetrate the substrate and introduced into the female connector (connector 100) to connect with the female terminals 20. [Example]

[0061] The present invention will be explained in more detail below by showing examples, but the present invention is not limited to these examples.

[0062] (Method of producing wholly aromatic polyesteramide) A polymerization vessel equipped with a stirrer, a reflux column, a monomer inlet, a nitrogen inlet, and a pressure reduction / outlet line was charged with the following raw material monomers, a fatty acid metal salt catalyst, and an acylating agent, and nitrogen substitution was initiated. (I) 4-hydroxybenzoic acid 1380 g (60 mol%) (HBA) (II) 6-Hydroxy-2-naphthoic acid 157g (5 mol%) (HNA) (III-a) 1,4-phenylenedicarboxylic acid 484 g (17.5 mol%) (TA) (IV) 4,4'-dihydroxybiphenyl 388g (12.5 mol%) (BP) (V) N-acetyl-p-aminophenol 126 g (5 mol%) (APAP) Potassium acetate catalyst 110mg Acetic anhydride 1659g

[0063] After the raw materials were charged, the reaction system temperature was raised to 140°C and allowed to react at 140°C for 1 hour. The temperature was then raised further to 340°C over 4.5 hours, and the pressure was then reduced to 10 Torr (i.e., 1330 Pa) over 15 minutes. Melt polymerization was carried out while distilling off acetic acid, excess acetic anhydride, and other low-boiling components. After the stirring torque reached a predetermined value, nitrogen was introduced to change the pressure from reduced to normal pressure to pressurized. The product was discharged from the bottom of the polymerization vessel and pelletized to obtain pelleted prepolymer. The resulting prepolymer was heat-treated (solid-state polymerization) at 300°C for 2 hours under a nitrogen stream to obtain the desired wholly aromatic polyesteramide. The resulting wholly aromatic polyesteramide had a melting point of 336°C and a melt viscosity of 20 Pa·s.

[0064] (Method of producing wholly aromatic polyester) A polymerization vessel equipped with a stirrer, a reflux column, a monomer inlet, a nitrogen inlet, and a pressure reduction / outlet line was charged with the following raw material monomers, a fatty acid metal salt catalyst, and an acylating agent, and nitrogen substitution was initiated. (I) 4-hydroxybenzoic acid 1040 g (48 mol%) (HBA) (II) 6-Hydroxy-2-naphthoic acid 89g (3 mol%) (HNA) (III-a) 1,4-phenylenedicarboxylic acid 547 g (21 mol%) (TA) (III-b) 1,3-phenylenedicarboxylic acid: 91 g (3.5 mol%) (IA) (IV) 4,4'-dihydroxybiphenyl 716g (24.5 mol%) (BP) Potassium acetate catalyst 110mg Acetic anhydride 1644g

[0065] After the raw materials were charged, the reaction temperature was raised to 140°C and allowed to react at 140°C for 1 hour. The temperature was then raised further to 360°C over 5.5 hours, and the pressure was then reduced to 5 Torr (i.e., 667 Pa) over 20 minutes. Melt polymerization was carried out while distilling off acetic acid, excess acetic anhydride, and other low-boiling components. After the stirring torque reached a predetermined value, nitrogen was introduced to change the pressure from reduced to normal pressure to pressurized. The product was discharged from the bottom of the polymerization vessel and pelletized to obtain pelletized wholly aromatic polyester. The melting point of the resulting wholly aromatic polyester was 355°C and the melt viscosity was 10 Pa·s.

[0066] The melt viscosity and melting point of the obtained wholly aromatic polyesteramide and wholly aromatic polyester were measured by the methods described below.

[0067] [Measurement of physical properties of liquid crystalline polymers] The melt viscosity and melting point of the liquid crystal polymer are measured as follows. (melt viscosity) The melt viscosity of the liquid crystalline polymer was measured using a capillary rheometer (Capillograph, manufactured by Toyo Seiki Seisakusho Co., Ltd.) at the following cylinder temperature and shear rate of 1000 / sec in accordance with ISO 11443. An orifice with an inner diameter of 1 mm and a length of 20 mm was used for the measurement. Cylinder temperature: 350℃ (fully aromatic polyesteramide) 370℃ (fully aromatic polyester)

[0068] (Melting Point) Using a differential scanning calorimeter (DSC, manufactured by PerkinElmer), the liquid crystalline polymer was measured at a temperature increase rate of 20°C / min from room temperature to observe the endothermic peak temperature (Tm1). After that, the polymer was held at a temperature of (Tm1+40)°C for 2 minutes, cooled to room temperature at a temperature decrease rate of 20°C / min, and then measured again at a temperature increase rate of 20°C / min to measure the endothermic peak temperature.

[0069] [Example 1] 69.7% by mass of wholly aromatic polyesteramide, 30% by mass of potassium titanate whiskers (manufactured by Otsuka Chemical Co., Ltd., "TISMOH N-102", average fiber diameter 0.45 μm, average fiber length 15 μm, average aspect ratio 33), and 0.3% by mass of lubricant (pentaerythritol tetrastearate, manufactured by Emery Oleochemicals Japan Co., Ltd., "LOXIOL VPG861") were melt-kneaded using a twin-screw extruder (manufactured by The Japan Steel Works, Ltd., TEX30α type) at a cylinder temperature of 350°C to obtain resin composition pellets of Example 1.

[0070] [Examples 2 to 6, Comparative Examples 1 to 6] Resin composition pellets were obtained in the same manner as in Example 1, except that the materials and contents shown in Table 1 were used.

[0071] Comparative Example 7 59.7% by mass of wholly aromatic polyester, 40% by mass of potassium titanate whiskers (manufactured by Otsuka Chemical Co., Ltd., "TISMOH N-102", average fiber diameter 0.45 μm, average fiber length 15 μm, average aspect ratio 33), and 0.3% by mass of lubricant (pentaerythritol tetrastearate, manufactured by Emery Oleochemicals Japan Co., Ltd., "LOXIOL VPG861") were melt-kneaded using a twin-screw extruder (manufactured by The Japan Steel Works, Ltd., TEX30α type) at a cylinder temperature of 370°C to obtain resin composition pellets of Comparative Example 7.

[0072] The calcium silicate whiskers, talc, mica, silica and glass fibers shown in Table 1 were used as follows. Calcium silicate whiskers (wollastonite, manufactured by IMERYS, "NYGLOS 8", average fiber diameter 8 μm, average fiber length 130 μm, average aspect ratio 16) Talc: Matsumura Sangyo Co., Ltd., "Crown Talc PP", median diameter 14.6 μm Mica: Yamaguchi Mica, "AB-25S", median diameter 25.0 μm Silica: Denka Co., Ltd., "FB-5SDC", median diameter 5.0 μm Glass fiber: Nippon Electric Glass Co., Ltd., "ECS03T-786", average fiber diameter 10 μm, average fiber length 3 mm

[0073] [Measurement and evaluation of physical properties of resin composition] The resin compositions obtained in the examples and comparative examples were measured for melt viscosity, flexural strength, flexural modulus, flexural strain, deflection temperature under load, and surface roughness Ra by the following methods. Furthermore, moldability (minimum connector filling pressure), deformation (inward collapse deformation), and gold plating chipping were evaluated according to the following criteria. The results are shown in Table 1.

[0074] (melt viscosity) The melt viscosity of the resin composition was measured using a capillary rheometer (Capillograph, manufactured by Toyo Seiki Seisakusho, Ltd.) at the following cylinder temperature and shear rate of 1000 / sec in accordance with ISO 11443. An orifice with an inner diameter of 1 mm and a length of 20 mm was used for the measurement. Cylinder temperature: 350°C (Examples 1 to 6, Comparative Examples 1 to 6) 370°C (Comparative Example 7)

[0075] (surface roughness Ra) The pellets of the examples and comparative examples were molded using a molding machine ("SE100DU" manufactured by Sumitomo Heavy Industries, Ltd.) under the following molding conditions to obtain test pieces (12.5 mm x 120 mm x 0.8 mm thick, two-point side gate, thin-walled weld evaluation type with a weld formed in the center). The surface roughness Ra of the ejector pin side surface of this test piece was measured in accordance with JIS B 0601:1994. The measurement conditions were as follows: [Test piece molding conditions] Cylinder temperature: 350°C (Examples 1 to 6, Comparative Examples 1 to 6) 370°C (Comparative Example 7) Mold temperature: 80℃ Injection speed: 33mm / sec [Measurement conditions] Measuring equipment: KEYENCE laser microscope VK-9500 Measurement magnification: 20x, pitch 0.1μm, distance 30~40μm Measurement location: The upper center of the weld when the test piece is placed with the gate facing up Center line average roughness (Ra)

[0076] (bending test) The resin pellets obtained in the examples and comparative examples were molded under the following molding conditions using a molding machine ("SE100DU" manufactured by Sumitomo Heavy Industries, Ltd.) to prepare bending test pieces measuring 130 mm x 13 mm x 0.8 mm. Using these test pieces, bending strength, bending modulus, and bending strain were measured in accordance with ASTM D790. [Molding conditions] Cylinder temperature: 350°C (Examples 1 to 6, Comparative Examples 1 to 6) 370°C (Comparative Example 7) Mold temperature: 90℃ Injection speed: 33mm / sec Holding pressure: 50MPa

[0077] (heat deflection temperature) The resin pellets obtained in the examples and comparative examples were molded using a molding machine ("SE100DU" manufactured by Sumitomo Heavy Industries, Ltd.) under the following molding conditions to obtain test pieces of 4 mm x 10 mm x 80 mm. The deflection temperature under load was measured using these test pieces according to the method in accordance with ISO 75-1, 2. The bending stress used was 1.8 MPa. [Molding conditions] Cylinder temperature: 350°C (Examples 1 to 6, Comparative Examples 1 to 6) 370°C (Comparative Example 7) Mold temperature: 90℃ Injection speed: 33mm / sec Holding pressure: 50MPa

[0078] (Fluidity: Connector minimum filling pressure) The resin pellets obtained in the examples and comparative examples were molded using a molding machine ("SE30DUZ" manufactured by Sumitomo Heavy Industries, Ltd.) under the following molding conditions to obtain a 0.6 mm pitch connector as shown in Figure 4. Figure 4(a) is a plan view, Figure 4(b) is a side view, and Figure 5(c) is an AA cross-sectional view. The molded product (0.6 mm pitch connector) had a basic thickness of 0.6 mm, a total length of 57.2 mm, a terminal pitch of 0.3 mm, a terminal pitch of 0.3 mm, and the number of poles was 90 pins x 2 rows (180 pins in total). [Molding conditions] Cylinder temperature: 350°C (Examples 1 to 6, Comparative Examples 1 to 6) 370°C (Comparative Example 7) Mold temperature: 80℃ Injection speed: 200mm / sec Holding pressure: 50MPa

[0079] When injection molding the 0.6 mm pitch connector in Figure 4, the minimum injection filling pressure required to obtain a good molded product (i.e., moldability with excellent reproducibility of the mold shape) was measured and evaluated according to the following criteria. The lower the minimum filling pressure, the better the fluidity can be evaluated. 2 (Good): Minimum filling pressure is 100 MPa or less 1 (bad): Minimum filling pressure exceeds 100 MPa

[0080] (Plating chipping) The resin pellets obtained in the examples and comparative examples were molded using a molding machine ("SE100DU" manufactured by Sumitomo Heavy Industries, Ltd.) under the following molding conditions to obtain test pieces measuring 100 mm x 100 mm x 3 mm. A spherical metal part (made of SUS) with a radius of 2 mm and gold-plated on the surface (average thickness of about 20 μm) was placed on this test piece with a load of 50 g, and then slid horizontally (TD direction) for 20 mm at a speed of 10 mm / s, and visually evaluated whether the plating layer on the surface of the metal part was scraped off. [Molding conditions] Cylinder temperature: 350°C (Examples 1 to 6, Comparative Examples 1 to 6) 370°C (Comparative Example 7) Mold temperature: 90℃ Injection speed: 33mm / sec Holding pressure: 50MPa 2 (Good): The plating layer is not scraped off. 1 (bad): Part of the plating layer has been scraped off

[0081] (Warpage deformation: Connector warpage) For the 0.6 mm pitch connectors shown in FIG. 4, which were produced using the resin pellets obtained in the examples and comparative examples, the distance between the line connecting the points on both ends of the connector fixing surface and the point in the center of the connector was measured as shown in FIG. 5, and the average of the measured values ​​for 10 connectors was taken as the warpage. 2 (Good): The difference in warpage is 0.3 mm or less 1 (Poor): The difference in warpage exceeds 0.3 mm

[0082] (Inner collapse deformation evaluation) The resin pellets obtained in the examples and comparative examples were molded using a molding machine (Sumitomo Heavy Industries, Ltd., "SE30DUZ") under the following molding conditions to obtain liquid crystal polymer molded articles (10 mm x 5 mm x 5 mm, thickness: 0.5 mm) with a cross-sectional shape perpendicular to the longitudinal direction that is a square (U-shaped) with one side open, as shown in Figures 6(a) and 6(b). Corner A (gate side) and corner B (opposite gate side) shown in Figure 6(b) were measured using an image dimension measuring instrument IM-6020 manufactured by Keyence Corporation. The sum A + B of corner A and corner B was calculated as the inward collapse deformation and evaluated according to the following criteria. [Molding conditions] Cylinder temperature: 350°C (Examples 1 to 6, Comparative Examples 1 to 6) 370°C (Comparative Example 7) Mold temperature: 90℃ Injection speed: 100mm / sec 2 (Good): 175° or more 1 (bad): Less than 175°

[0083] [Table 1] [Explanation of symbols]

[0084] 1 Connector parts 2 cavities 3 side wall 4 Substrate 5 Contact insertion hole 20 female terminal 30 outer housing 100 Connector (female connector) 200 Electrical Connectors

Claims

1. Contains wholly aromatic polyester amide and whiskers, The wholly aromatic polyester amide contains the following structural units (I) to (V): (Ar in structural units (III) and (IV) １ , Ar ２ each independently represents a divalent aromatic group. With respect to all structural units of the wholly aromatic polyesteramide, the content of structural unit (I) is 40 mol% or more and 70 mol% or less, the content of structural unit (II) is more than 0 and 8 mol% or less, the content of structural unit (III) is 12.5 mol% or more and 27.5 mol% or less, the content of structural unit (IV) is 7.5 mol% or more and 22.5 mol% or less, the content of structural unit (V) is 1 mol% or more and 9 mol% or less, and the total content of structural units (I) to (V) is 100 mol%; the content of the wholly aromatic polyester amide is 55 to 80 mass% based on the total amount of the resin composition, The whisker content is 20 to 45% by mass based on the total amount of the resin composition, A resin composition, wherein the content of the plate-like filler is 5% by mass or less based on the total composition.

2. 2. The resin composition according to claim 1, wherein the whiskers comprise one or more selected from potassium titanate whiskers, calcium silicate whiskers, calcium carbonate whiskers, zinc oxide whiskers, aluminum borate whiskers, silicon nitride whiskers, silicon trinitride whiskers, basic magnesium sulfate whiskers, barium titanate whiskers, silicon carbide whiskers, and boron whiskers.

3. 3. The resin composition according to claim 1, wherein the whiskers have an average fiber diameter of 0.1 to 15 μm.

4. The resin composition according to any one of claims 1 to 3, wherein the whiskers have an average fiber length of 1 to 200 µm.

5. A resin composition described in any one of claims 1 to 4, wherein the content of amorphous fibrous, polycrystalline fibrous or granular inorganic filler is less than 20 mass% relative to the total amount of the resin composition.

6. The resin composition according to claim 1 , which is used for producing a connector part.

7. Use of the resin composition according to any one of claims 1 to 6 for producing a connector part.

8. A molded article comprising the resin composition according to any one of claims 1 to 6.

9. The molded article according to claim 8, which is a connector part.

10. The molded article according to claim 9, which is for an on-vehicle connector.

11. 11. The molded product according to claim 9, having one or more through holes for inserting contacts, wherein the surface roughness Ra of the inner surface of the one or more through holes is 1.25 μm or less.

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