Polyamide resin composition

Abstract

Provided is a polyamide resin composition that can achieve high rigidity, low warpage, and good surface appearance in a molded product. [Solution] A resin composition is provided which comprises a polyamide resin (A) and glass fibers (B), wherein the polyamide resin (A) comprises a crystalline polyamide resin (A-1) and an amorphous polyamide resin (A-2) having an MVR of 50 ml / 10 min or more as measured in accordance with ISO 1133 at a temperature of 275°C under a load of 5 kg, and the glass fibers (B) comprise glass fibers (B-1) with a non-circular cross section, and the total content of the glass fibers (B) is 40 mass % or more and 80 mass % or less.

Description

Technical Field

[0001] The present invention relates to a polyamide resin composition.

Background Art

[0002] A polyamide resin can achieve high rigidity and the like by blending glass fibers. However, since glass fibers have the property of orienting in the resin flow direction, anisotropy in strength may occur and cause warping. As a technique for realizing low warpage, a technique of blending glass fibers having a flat cross-section has been proposed (see, for example, Patent Documents 1 and 2). Further, as a technique for realizing high vibration resistance characteristics, a glass fiber-reinforced polyamide resin composition in which an aliphatic polyamide and polymetaxylylene adipamide are used in combination with glass fibers having a specific cross-sectional area has been proposed (see, for example, Patent Document 3).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the prior art, it has been difficult in some cases to realize good surface appearance when forming a molded product while maintaining high rigidity and low warpage. An object of the present invention is to provide a polyamide resin composition capable of realizing high rigidity, low warpage, and good surface appearance in a molded product.

Means for Solving the Problems

[0005] Specific means for solving the above problems are as follows. It contains polyamide resin (A) and glass fiber (B). The polyamide resin (A) contains a crystalline polyamide resin (A-1) consisting of one type and an amorphous polyamide resin (A-2). The glass fiber (B) contains a glass fiber (B-1) with a non-circular cross-section, and it is a polyamide resin composition in which the total content of the glass fiber (B) is 40% by mass or more and 80% by mass or less.

Effect of the Invention

[0006] According to the present invention, it is possible to provide a polyamide resin composition capable of realizing high rigidity, low warpage, and good surface appearance in a molded product.

Mode for Carrying Out the Invention

[0007] In this specification, the content of each component in the composition means the total amount of the plurality of substances present in the composition when there are a plurality of substances corresponding to each component in the composition, unless otherwise specified.

[0008] [Polyamide Resin Composition] The polyamide resin composition of this embodiment contains polyamide resin (A) and glass fiber (B). The polyamide resin (A) contains a crystalline polyamide resin (A-1) and an amorphous polyamide resin (A-2) having an MVR of 50 ml / 10 minutes or more measured at a temperature of 275°C and a load of 5 kg based on ISO1133. The glass fiber (B) contains a glass fiber (B-1) with a non-circular cross-section, and the total content of the glass fiber (B) is 40% by mass or more and 80% by mass or less. By blending the crystalline polyamide resin (A-1) and the specific amorphous polyamide resin (A-2) with the non-circular cross-section glass fiber (B-1) at a specific content rate, when a molded product is formed, it is possible to realize good surface appearance while maintaining high rigidity and low warpage.

[0009] Polyamide Resin (A) The polyamide resin composition contains, as the polyamide resin, at least one type of crystalline polyamide resin (A-1) and at least one type of amorphous polyamide resin (A-2) having an MVR of 50 ml / 10 min or more measured at a temperature of 275 °C and a load of 5 kg based on ISO 1133. By combining the crystalline polyamide resin (A-1) and the amorphous polyamide resin (A-2) having a specific MVR value, it is possible to achieve a good surface appearance while maintaining high rigidity and low warpage in the molded product.

[0010] Crystalline polyamide resin (A-1) The crystalline polyamide resin (A-1) in this specification means a polyamide resin that exhibits a distinct endothermic peak due to melting in a differential scanning calorimeter (DSC) analysis under a temperature increase condition of 10 °C / min. Specifically, it means a polyamide resin having a heat of fusion of more than 1 cal / g.

[0011] Examples of the crystalline polyamide resin (A-1) include aliphatic polyamide resins composed of aliphatic diamines and aliphatic dicarboxylic acids, and aliphatic polyamide resins composed of lactams or aminocarboxylic acids. The crystalline polyamide resin (A-1) is preferably an aliphatic polyamide resin.

[0012] Examples of the monomer components constituting the aliphatic polyamide resin include combinations of aliphatic diamines having 2 to 20 carbon atoms, preferably 4 to 12 carbon atoms, and aliphatic dicarboxylic acids having 2 to 20 carbon atoms, preferably 6 to 12 carbon atoms, lactams or aminocarboxylic acids having 6 to 12 carbon atoms, and the like.

[0013] Examples of the aliphatic diamine include ethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, peptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, undecamethylenediamine, dodecamethylenediamine, tridecanediamine, tetradecanediamine, pentadecanediamine, hexadecanediamine, heptadecanediamine, octadecanediamine, nonadecanediamine, eicosanediamine, etc. Examples of the aliphatic dicarboxylic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, octadecanedioic acid, eicosanedioic acid, etc.

[0014] Examples of the combination of the aliphatic diamine and the aliphatic dicarboxylic acid include the combination of hexamethylenediamine and adipic acid, the combination of hexamethylenediamine and sebacic acid, the combination of hexamethylenediamine and dodecanedioic acid, etc. Equimolar salts of these combinations are preferably used.

[0015] Examples of the lactam include ε-caprolactam, enanthlactam, undecanelactam, dodecanelactam, α-pyrrolidone, α-piperidone, etc. Examples of the aminocarboxylic acid include 6-aminocaproic acid, 7-aminoheptanoic acid, 9-aminononanoic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid. From the viewpoint of polymerization production, at least one selected from the group consisting of ε-caprolactam, undecanelactam, and dodecanelactam is preferable.

[0016] The monomer components constituting the aliphatic polyamide resin may be used alone or in combination of two or more. Here, the combination of the aliphatic diamine and the aliphatic dicarboxylic acid is regarded as one monomer component in the form of the combination of one aliphatic diamine and one aliphatic dicarboxylic acid.

[0017] The crystalline polyamide resin (A-1) is preferably selected from the group consisting of polyamide 6, polyamide 66, polyamide 6 / 66, polyamide 6 / 12, polyamide 610, polyamide 612, polyamide 6 / 66 / 12, polyamide 11 and polyamide 12 from the viewpoint of productivity, and polyamide 6 and / or polyamide 66 is more preferable. The crystalline polyamide resin (A-1) may be contained alone or in combination of two or more. When two or more crystalline polyamide resins are contained, the total content of the other crystalline polyamide resins with respect to the crystalline polyamide resin having the largest content is, for example, 25% by mass or less, preferably 5% by mass or less.

[0018] The relative viscosity of the crystalline polyamide resin (A-1) is not particularly limited, but according to JIS K 6810, for the crystalline polyamide resin (A-1) with a concentration of 1% in 98% sulfuric acid, the relative viscosity measured at 25°C is preferably 1.8 or more and 5.0 or less.

[0019] The content of the crystalline polyamide resin (A-1) in the total amount of the polyamide resin composition is preferably, for example, 20% by mass or more and less than 60% by mass, more preferably 30% by mass or more and 50% by mass or less, from the viewpoints of mechanical properties and surface appearance.

[0020] Amorphous polyamide resin (A-2) The amorphous polyamide resin (A-2) in the present specification means a polyamide resin in which crystallization hardly occurs or the crystallization rate is very small. Specifically, it means a polyamide resin that does not show a distinct endothermic peak due to melting in a differential scanning calorimeter (DSC) analysis under a temperature rising condition of 10°C / min, which means that the heat of fusion of crystallization is 1 cal / g or less. Also, the amorphous polyamide resin (A-2) has an MVR of 50 ml / 10 min or more, preferably 60 ml / 10 min or more, measured at a temperature of 275°C and a load of 5 kg based on ISO1133. When the MVR is less than 50 ml / 10 min, it may be difficult to achieve a good surface appearance in the molded body. The upper limit of MVR is, for example, 200 ml / min, preferably 100 ml / min. When two or more types of amorphous polyamide resins are included, these are mixed and the MVR of the entire amorphous polyamide resin is measured. When the MVR measured at a temperature of 275°C and a load of 5 kg based on ISO 1133 is 50 ml / 10 min or more, the entire amorphous polyamide resin can be made into amorphous polyamide resin (A-2). The measurement of MVR is preferably carried out as described above. However, when the MVR of each amorphous polyamide resin and its mixing ratio are known, the average value calculated by summing the values obtained by multiplying each MVR by its mixing ratio can be used as the MVR of the entire amorphous polyamide resin.

[0021] The amorphous polyamide resin (A-2) is preferably a polyamide resin having a structure that inhibits crystallization, and examples thereof include aliphatic polyamides having a branched structure or polyamides having functional groups such as alicyclic or aromatic groups in the main chain or side chain. Further, from the viewpoint of inhibiting crystallization, it is more preferably a copolymer. The amorphous polyamide resin (A-2) is preferably a copolymer polyamide resin containing at least two components of an aromatic monomer component, and more preferably has a glass transition temperature of 100°C or higher determined by the peak temperature of the loss elastic modulus at absolute dryness obtained by measuring dynamic viscoelasticity. The polymerization method of the amorphous polyamide is not particularly limited as long as it is a known method.

[0022] Examples of the dicarboxylic acid constituting the amorphous polyamide resin (A-2) include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,4-phenylenedioxydiacetic acid, 1,3-phenylenedioxydiacetic acid, dibenzoic acid, 4,4'-oxydibenzoic acid, diphenylmethane-4,4'-dicarboxylic acid, diphenylsulfone-4,4'-dicarboxylic acid, 4,4'-biphenyldicarboxylic acid; and alicyclic dicarboxylic acids such as 1,3-cyclopentanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid.

[0023] Examples of the diamine constituting the amorphous polyamide resin (A-2) include alicyclic diamines such as cyclohexanediamine, methylcyclohexanediamine, and isophoronediamine; and aromatic diamines such as p-phenylenediamine, m-phenylenediamine, p-xylenediamine, m-xylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, and 4,4'-diaminodiphenylether.

[0024] Specific examples of the amorphous polyamide resin (A-2) include polycondensates of isophthalic acid / terephthalic acid / hexamethylenediamine / bis(3-methyl-4-aminocyclohexyl)methane, polycondensates of terephthalic acid / 2,2,4-trimethylhexamethylenediamine / 2,4,4-trimethylhexamethylenediamine, polycondensates of isophthalic acid / bis(3-methyl-4-aminocyclohexyl)methane / ω-laurolactam, polycondensates of isophthalic acid / terephthalic acid / hexamethylenediamine (polyamide 6T / 6I), polycondensates of isophthalic acid / 2,2,4-trimethylhexamethylenediamine / 2,4,4-trimethylhexamethylenediamine, polycondensates of isophthalic acid / terephthalic acid / 2,2,4-trimethylhexamethylenediamine / 2,4,4-trimethylhexamethylenediamine, polycondensates of isophthalic acid / bis(3-methyl-4-aminocyclohexyl)methane / ω-laurolactam, and the like. Among these, the amorphous polyamide resin (A-2) is preferably a copolymer having an aromatic ring, such as polyamide 6T / 6I, because it inhibits the crystallization of the crystalline polyamide resin.

[0025] Specifically, the amorphous polyamide resin (A-2) preferably comprises 40 to 95 mol% of terephthalic acid component units and 5 to 60 mol% of isophthalic acid component units, and an aliphatic diamine. Preferred combinations of monomer components constituting the amorphous polyamide resin (A-2) include equimolar salts of hexamethylenediamine and terephthalic acid and equimolar salts of hexamethylenediamine and isophthalic acid. The amorphous polyamide resin (A-2) preferably contains, in an amount of 60% by mass or more and 99% by mass or less, units derived from monomer components composed of an aliphatic diamine, isophthalic acid, and terephthalic acid, and contains, in an amount of 1% by mass or more and 40% by mass or less, units of an aliphatic polyamide component.

[0026] The relative viscosity of the amorphous polyamide resin (A-2) is not particularly limited, but preferably, for the amorphous polyamide resin (A-2) with a concentration of 1% in 98% sulfuric acid, the relative viscosity measured at a temperature of 25°C is 1.5 to 4.0, more preferably 1.8 to 3.0, in accordance with JIS K 6810.

[0027] From the viewpoints of mechanical properties and surface appearance, the content of the amorphous polyamide resin (A-2) in the total amount of the polyamide resin composition is preferably 0.5% by mass or more and 30% by mass or less, more preferably 0.5% by mass or more and 20% by mass or less, still more preferably 3% by mass or more and 25% by mass or less, still more preferably 3% by mass or more and 20% by mass or less, and even more preferably 3% by mass or more and 8% by mass or less. The polyamide resin composition may contain the amorphous polyamide resin alone or in combination of two or more.

[0028] Glass fiber (B) The polyamide resin composition contains at least glass fiber (B-1) with a non-circular cross-section as the glass fiber (B), and the total content of the glass fiber (B) is 40% by mass or more and 80% by mass or less. Thereby, in the molded product, a good surface appearance can be realized while maintaining high rigidity and low warpage.

[0029] Glass fiber (B-1) with a non-circular cross-section The glass fiber (B-1) with a non-circular cross-section is not particularly limited as long as its cross-section is non-circular. A non-circular cross-section means that in a cross-section perpendicular to the length direction of the glass fiber, among two points on the outer periphery of the cross-section, there are a major axis connecting the two points with the maximum distance and a minor axis connecting the two points with the maximum distance between two points where a straight line perpendicular to the major axis intersects the outer periphery of the cross-section, and the shape where the lengths of the major axis and the minor axis are different. The ratio of the major axis to the minor axis of the glass fiber only needs to be greater than 1. From the perspective of mechanical properties, for example, it is 1.2 or more and 10 or less, preferably 1.5 or more and 6 or less, and more preferably 1.7 or more and 4.5 or less.

[0030] As the cross-sectional shape of the glass fiber (B-1) with a non-circular cross-section, generally, a shape like a spindle shape, an oval shape, a semi-circular shape, an arc shape, a rectangular shape, a parallelogram shape or a similar shape thereof is used. In practical use, from the perspectives of fluidity, mechanical properties, and low warpage, a spindle shape, an oval shape or a rectangular shape is preferable. For specific examples of the cross-sectional shape of the glass fiber (B-1) with a non-circular cross-section, reference can be made to, for example, the description in Japanese Patent Laid-Open No. 62-268612.

[0031] The thickness of the glass fiber (B-1) with a non-circular cross-section is not particularly limited. The minor axis of the glass fiber (B-1) with a non-circular cross-section is usually 0.5 μm or more and 25 μm or less, and the major axis is 1.25 μm or more and 300 μm or less. For the glass fiber (B-1) with a non-circular cross-section, glass fibers with a fiber length of usually 1 mm or more and 15 mm or less, preferably 1.5 mm or more and 12 mm or less, and more preferably 2 mm or more and 6 mm or less are used. The aspect ratio obtained by dividing the fiber length by the average value of the major axis and the minor axis of the glass fiber (B-1) with a non-circular cross-section is usually 10 or more, and from the perspectives of rigidity, mechanical strength, and fluidity, it is preferably 15 or more and 100 or less.

[0032] Examples of the glass constituting the glass fiber (B-1) with a non-circular cross-section include those having a composition such as A glass, C glass, or E glass. From the perspective of the thermal stability of the polyamide resin, E glass is preferred. Further, the glass fiber (B-1) with a non-circular cross-section may be surface-treated with a silane coupling agent, a titanium coupling agent, or other high-molecular or low-molecular surface treatment agents. By being surface-treated, the dispersibility and adhesion in the polyamide resin are improved. Also, from the perspective of improving the adhesion to the resin, the glass fiber (B-1) with a non-circular cross-section is preferably converged with a converging material. The converging material is not particularly limited, and from the perspective of compatibility with the polyamide resin, it is preferably a urethane resin and / or an acrylic resin.

[0033] From the perspectives of high rigidity, low warpage, and good surface appearance, the content of the glass fiber (B-1) with a non-circular cross-section in the total amount of the polyamide resin composition is preferably 15% by mass or more and 70% by mass or less, and more preferably 20% by mass or more and 65% by mass or less.

[0034] Glass fiber (B-2) with a circular cross-section In addition to the glass fiber (B-1) with a non-circular cross-section as the glass fiber, the polyamide resin composition may further contain a glass fiber (B-2) with a circular cross-section. The glass fiber (B-2) with a circular cross-section is a glass fiber having a circular cross-section perpendicular to the length direction of the glass fiber. The average fiber diameter of the glass fiber (B-2) with a circular cross-section is, for example, 4 μm or more and 15 μm or less, and more preferably 6 μm or more and 13 μm or less. When the average fiber diameter is within the above range, the mechanical properties and dimensional stability of the molded body tend to be further improved. The average fiber diameter of the glass fiber (B-2) with a circular cross-section can be measured according to JIS R3420.

[0035] As the glass fiber (B-2) with a circular cross-section, those having a fiber length of usually 1 mm or more and 15 mm or less, preferably 1.5 mm or more and 12 mm or less, and more preferably 2 mm or more and 6 mm or less are used. The aspect ratio obtained by dividing the fiber length by the average fiber diameter of the glass fiber with a circular cross-section is usually 10 or more, and preferably 15 or more and 100 or less from the viewpoints of rigidity, mechanical strength, and fluidity.

[0036] Examples of the glass constituting the glass fiber with a circular cross-section include those having a composition such as A glass, C glass, and E glass. From the viewpoint of the thermal stability of the polyamide resin, E glass is preferred. Further, the glass fiber with a circular cross-section may be surface-treated with a silane coupling agent, a titanium coupling agent, or other high-molecular or low-molecular surface treatment agents. By being surface-treated, the dispersibility and adhesion in the polyamide resin are improved. Further, from the viewpoint of improving the adhesiveness with the resin, the glass fiber with a circular cross-section is preferably converged with a converging material. The converging material is not particularly limited, and from the viewpoint of compatibility with the polyamide resin, it is preferably a urethane resin and / or an acrylic resin.

[0037] When the polyamide resin composition contains the glass fiber (B-2) with a circular cross-section, the content of the glass fiber (B-2) with a circular cross-section in the total amount of the polyamide resin composition is preferably 5% by mass or more and less than 40% by mass, and more preferably 10% by mass or more and 35% by mass or less from the viewpoints of high rigidity, low warpage, and good surface appearance. Further, the content ratio (B-2 / B-1) of the glass fiber (B-2) with a circular cross-section to the glass fiber (B-1) with a non-circular cross-section is preferably 0.1 or more and 1.2 or less, and more preferably 0.3 or more and 1.0 or less from the viewpoints of high rigidity, low warpage, and good surface appearance.

[0038] In the polyamide resin composition, other components, for example, functional additives such as plasticizers, impact-resistant materials, heat-resistant materials, foaming agents, weather-resistant agents, crystal nucleating agents, crystallization accelerators, mold release agents, lubricants, antistatic agents, flame retardants, flame retardant aids, pigments, dyes, etc., can be appropriately blended within a range that does not impair the effects of the present invention.

[0039] The polyamide resin composition is produced by melt-kneading a crystalline polyamide resin (A-1), an amorphous polyamide resin (A-2), and a glass fiber (B-1) with a non-circular cross-section in a predetermined amount using a single-screw or twin-screw extruder, a Banbury mixer, or the like. By molding the obtained polyamide resin composition, a desired molded article can be obtained. As the molding method, an extrusion molding method, a blow molding method, an injection molding method, or the like can be adopted.

[0040] Since the molded article containing the polyamide resin composition of the present embodiment exhibits a good surface appearance, it is suitably used for various applications such as automotive parts, those requiring designability, and housings. Further, for the molded article obtained by injection molding the polyamide resin composition, the glossiness (gloss value) measured in accordance with ASTM D-523 is preferably 65% or more, and more preferably 70% or more.

[0041] The polyamide resin composition of the present embodiment provides high rigidity, low warpage, and good surface appearance in molded articles. (Mechanical properties) In the molded article containing the polyamide resin composition of the present embodiment, the tensile strength measured at 23 °C in accordance with ISO 527-1,2 is preferably 265 MPa or more. In the molded article containing the polyamide resin composition of the present embodiment, the tensile modulus measured at 23 °C in accordance with ISO 527-1,2 is preferably 20 GPa or more. In the molded article containing the polyamide resin composition of the present embodiment, the Charpy impact strength measured at 23 °C in accordance with ISO 179-1 is preferably 20 kJ / m 2 is. The tensile strength and the tensile modulus can be measured by the following method. An ISO standard TYPE-A test piece is produced by injection molding and used for obtaining mechanical property data. For the tensile strength and the tensile modulus, they are measured at 23 °C using an Instron tensile tester model 5567 in accordance with ISO 527-1,2. The Charpy impact strength can be measured by the following method. In accordance with ISO179-1, using Yasuda Seiki Charpy impact tester No. 258-PC, at 23°C, an edgewise impact test is conducted using a test piece with a V-notch thickness of 4 mm. (n = 10)

[0042] (Flowability) In the molded article containing the polyamide resin composition of the present embodiment, the flow length measured under the following conditions is preferably 85 mm or more. Using PS-40E manufactured by Nissei Plastic Industrial Co., Ltd. (screw diameter 26 mm, clamping force 40 tons), the flow length is measured from the molded product obtained using a spiral flow type mold for evaluating fluidity with a cavity size of width w = 15 mm and thickness t = 1 mm. The molding conditions are a molding temperature of 290°C, a mold temperature of 80°C, and an injection pressure of 100 MPa.

[0043] (Surface appearance (glossiness) (gloss)) In the molded article containing the polyamide resin composition of the present embodiment, the glossiness (gloss value) measured under the following conditions is preferably 65% or more, more preferably 70% or more. Using SE100D-C160S manufactured by Sumitomo Heavy Industries, Ltd. (screw diameter 28 mm, clamping force 100 tons), a flat plate of 100 mm × 70 mm × thickness 2 mm is created. The molding conditions are a molding temperature of 290°C, a mold temperature of 80°C, an injection speed of 80 mm / sec, and a cooling time of 15 seconds. The obtained test piece is measured for glossiness (gloss value) at an incident angle of 60° in accordance with ASTM D-523 using a color computer SM-5-IS-2B manufactured by Suga Test Instruments Co., Ltd.

[0044] (Warpage deformation) In the molded article containing the polyamide resin composition of the present embodiment, low warpage can be evaluated by the following method. Using the SE100D-C160S manufactured by Sumitomo Heavy Industries, Ltd. (screw diameter 28 mm, clamping force 100 tons), a D-1 type mold of 60 mm × 60 mm × thickness 1t in accordance with ISO294-3 is created. The molding conditions are: molding temperature 290°C, mold temperature 80°C, injection speed 97 mm / sec, injection pressure 60 MPa, and cooling time 15 seconds. Immediately after molding, the gate is cut, and after leaving it in a moisture-proof container for 48 hours, a weight is placed on the specified corner on the surface plate, and the maximum gap with the surface plate is taken as the warpage deformation amount. When the obtained deformation amount is 3 mm or more, it is regarded as having warpage deformation, and when it is less than 3 mm, it is regarded as having no warpage deformation.

Example

[0045] Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to these examples. The resin and the physical property evaluation methods of the molded products used in the examples and comparative examples are shown below.

[0046] [Mechanical properties] ISO standard TYPE-A test pieces were produced by injection molding and used for obtaining mechanical property data. For the tensile strength and tensile modulus of elasticity, in accordance with ISO527-1,2, a tensile testing machine type 5567 manufactured by Instron was used for measurement at 23°C.

[0047] [Charpy impact strength] In accordance with ISO179-1, using a Charpy impact tester No. 258-PC manufactured by Yasuda Seiki Co., Ltd., an edgewise impact test was conducted at 23°C using a test piece with a thickness of 4 mm with an A-notch. (n = 10)

[0048] [Flowability] Using PS-40E manufactured by Nissei Plastic Industrial Co., Ltd. (screw diameter 26 mm, clamping force 40 tons), the flow length was measured from a molded product obtained using a spiral flow type mold for evaluating fluidity with a cavity size of width w = 15 mm and thickness t = 1 mm. The molding conditions were: molding temperature 290°C, mold temperature 80°C, and injection pressure 100 MPa.

[0049] [Glossiness (gloss)] A flat plate of 100 mm × 70 mm × 2 mm thickness was created using SE100D-C160S manufactured by Sumitomo Heavy Industries, Ltd. (screw diameter 28 mm, clamping force 100 tons). The molding conditions were a molding temperature of 290 °C, a mold temperature of 80 °C, an injection speed of 80 mm / sec, and a cooling time of 15 seconds. The obtained test piece was measured for glossiness (gloss value) at an incident angle of 60° using a Color Computer SM-5-IS-2B manufactured by Suga Test Instruments Co., Ltd. in accordance with ASTM D-523.

[0050] [Warp deformation] An ISO294-3 D-1 type mold of 60 mm × 60 mm × 1t thickness was created using SE100D-C160S manufactured by Sumitomo Heavy Industries, Ltd. (screw diameter 28 mm, clamping force 100 tons). The molding conditions were a molding temperature of 290 °C, a mold temperature of 80 °C, an injection speed of 97 mm / sec, an injection pressure of 60 MPa, and a cooling time of 15 seconds. Immediately after molding, the gate was cut, and after being left in a moisture-proof container for 48 hours, a weight was placed on the specified corner on the surface plate, and the maximum gap with the surface plate was taken as the warp deformation amount. When the obtained deformation amount was 3 mm or more, it was regarded as having warp deformation, and when it was less than 3 mm, it was regarded as having no warp deformation.

[0051] · Polyamide resin (A) · Crystalline polyamide resin (A-1) PA6-1: For a crystalline polyamide resin with a concentration of 1% in 96% sulfuric acid, in accordance with JIS K 6810, the relative viscosity measured at 25 °C was 2.43 - 2.51, and it was polyamide 6 composed of caprolactam with 6 carbon atoms. PA6-2: For a crystalline polyamide resin with a concentration of 1% in 96% sulfuric acid, in accordance with JIS K 6810, the relative viscosity measured at 25 °C was 2.16 - 2.25, and it was polyamide 6 composed of caprolactam with 6 carbon atoms. · Amorphous polyamide resin · An amorphous polyamide resin (A-2) with an MVR measured at a temperature of 275 °C and a load of 5 kg based on ISO1133 of 50 ml / 10 min or more. PA6T / 6I-1: Grivory G16 (manufactured by EMS-CHEMIE (Japan)) with an MVR of 100 ml / 10 min measured at a temperature of 275 °C and a load of 5 kg based on ISO 1133 PA6T / 6I-2: Grivory G21 (manufactured by EMS-CHEMIE (Japan)) with an MVR of 25 ml / 10 min measured at a temperature of 275 °C and a load of 5 kg based on ISO 1133

[0052] · Glass fiber GF1: Glass fiber with a non-circular cross-section (CSG3PA-820S manufactured by Nitto Boseki Co., Ltd.) Ratio of major axis to minor axis 4, fiber diameter 7 × 28 μm GF2: Glass fiber with a circular cross-section (CS 3DE-456S manufactured by Nitto Boseki Co., Ltd.) Average fiber diameter 6 μm GF3: Glass fiber with a circular cross-section (ECS 03T-249 manufactured by Nippon Electric Glass Co., Ltd.) Average fiber diameter 13 μm

[0053] · PA6 black MB Black masterbatch containing a dye component and a pigment component based on polyamide 6 (UBE NYLON 1013MBC manufactured by Ube Industries, Ltd.)

[0054] · Molding aid - 2 Pentolite (manufactured by Koei Chemical Industry Co., Ltd.) · Molding aid - 2 LICOWAX OP POWDER (manufactured by Clariant Japan Ltd.)

[0055] · Heat-resistant agent CuI, KI mixture (weight ratio 1:6) CuI Cuprous iodide F (manufactured by Ise Chemical Industry Co., Ltd.) KI Potassium iodide powder (Mitsui Fine Chemicals Co., Ltd.)

[0056] Examples 1 to 9, Comparative Examples 1 to 8 The polyamide resin and glass fiber described in Table 1 were melt-kneaded with a TEX44HCT twin-screw kneader to produce the target polyamide resin composition pellets. Next, various test pieces were manufactured using the obtained pellets, and various physical properties were evaluated. The results obtained are shown in Table 1. In Table 1, "-" means not blended.

[0057]

Table 1

[0058] As is clear from the results in Table 1, it can be seen that when a molded article is formed using the polyamide resin composition of the present invention, high rigidity, low warpage, and good surface appearance can be achieved.

[0059] The disclosure of Japanese Patent Application No. 2016-018653 (filing date: February 3, 2016) is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards described in this specification are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard were specifically and individually indicated to be incorporated by reference.

Claims

1. comprising a polyamide resin (A) and glass fibers (B), wherein the polyamide resin (A) comprises a crystalline polyamide resin (A-1) and an amorphous polyamide resin (A-2) having an MVR of 50 ml / 10 min or more and 200 ml / min or less as measured at a temperature of 275 ° C. and a load of 5 kg based on ISO 1133, wherein the glass fibers (B) comprise glass fibers (B-1) having a non-circular cross section and glass fibers (B-2) having a circular cross section, wherein the total content of the glass fibers (B) is 40% by mass or more and 80% by mass or less based on the total amount of the polyamide resin composition, wherein the content ratio (B-2 / B-1) of the glass fibers (B-2) having a circular cross section to the glass fibers (B-1) having a non-circular cross section is 0.3 or more and 1.0 or less, wherein the content of the amorphous polyamide resin (A-2) is 0.5% by mass or more and 8% by mass or less based on the total amount of the polyamide resin composition, wherein the amorphous polyamide resin (A-2) contains polyamide 6T / 6I, a polyamide resin composition.

2. The polyamide resin composition according to claim 1, wherein the glass fibers (B-1) having a non-circular cross section have a ratio of the major axis to the minor axis in a cross section perpendicular to the longitudinal direction of 1.2 or more and 10 or less.

3. The polyamide resin composition according to claim 1 or 2, wherein the average fiber diameter of the glass fibers (B-2) having a circular cross section is 4 μm or more and 15 μm or less.

4. The polyamide resin composition according to any one of claims 1 to 3, wherein the crystalline polyamide resin (A-1) is selected from the group consisting of polyamide 6, polyamide 66, polyamide 6 / 66, polyamide 6 / 12, polyamide 610, polyamide 612, polyamide 6 / 66 / 12, polyamide 11, and polyamide 12.

5. The polyamide resin composition according to any one of claims 1 to 4, wherein the crystalline polyamide resin (A-1) contains polyamide 6.

6. The polyamide resin composition according to any one of claims 1 to 5, wherein the content of the glass fibers (B-1) having a non-circular cross section is 5% by mass or more and 70% by mass or less based on the total amount of the polyamide resin composition.

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

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