Molded article

Abstract

To provide a molded article having superior impact resistance and chemical resistance.SOLUTION: A molded article composed of a thermoplastic resin composition, wherein the thermoplastic resin composition has a sea-island structure, and in an SEM image obtained by observing a cross section of the molded article by SEM, when island portions of a specific area in the sea-island structure are defined as island portions I, a most frequent value of aspect ratio of the island portions I is less than 1.90, and the ratio of the number of the island portions I having an aspect ratio more than 1.95 and 2.25 or less to the total number of the island portions I is 17.0% or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a molded article. [Background technology]

[0002] Resin molded products are used as housings for a variety of products.

[0003] Products with plastic housings are used in a wide variety of environments, including everyday environments, outdoor environments exposed to wind and rain, and high-temperature environments.

[0004] Resins have their own unique characteristics, such as whether they are crystalline or amorphous, heat resistance, and self-extinguishing properties, and are used as housing materials for various products due to their characteristics and economical efficiency.

[0005] Products that use housings often require impact resistance and chemical resistance.

[0006] For example, Patent Document 1 discloses a resin composition containing (a) a polyphenylene ether resin, (b) a hydrogenated block copolymer and / or a modified product of the hydrogenated block copolymer, and (c) an olefin polymer composed of olefins other than propylene, in which component (a) forms a continuous phase, a specific block in component (b) has a glass transition temperature of −65°C or lower, and component (c) has a brittle temperature of −50°C or lower. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2022-108192 Summary of the Invention [Problem to be solved by the invention]

[0008] As products become smaller and more complex, products using plastic housings (e.g., batteries) are increasingly being used in combination with other products (e.g., chargers).

[0009] In order to easily and accurately combine a product using a resin housing with another product, for example, a thin-walled portion may be provided on the resin housing. Then, for example, the product using the resin housing can be slid onto the other product using the thin-walled portion as a guide.

[0010] Because the thin-walled parts of the housing are thinner than the surrounding areas, residual strain from injection molding the housing remains strong, and if chemicals come into contact with the thin-walled parts, chemical cracks may occur in the thin-walled parts.

[0011] Therefore, an object of the present invention is to provide a molded article having excellent impact resistance and chemical resistance. [Means for solving the problem]

[0012] As a result of extensive research, the present inventors have found that the above-mentioned problems can be solved by using a thermoplastic resin composition having a specific sea-island structure.

[0013] That is, the present invention is as follows. [1] A molded article made of a thermoplastic resin composition, The thermoplastic resin composition has an island-sea structure, In an SEM image obtained by observing a cross section of the molded product using a scanning electron microscope (SEM), The area of ​​the sea-island structure is 0.0008 μm 2 More than 0.08μm 2 When the following island portion is designated as island portion I, the most frequent aspect ratio of island portion I is less than 1.90, A molded article, wherein the ratio of the number of island portions I having an aspect ratio of more than 1.95 and not more than 2.25 to the total number of island portions I is 17.0% or less. [2] The molded product according to [1], wherein the ratio of the number of island portions I having an aspect ratio of 1.35 or less to the total number is 10.0% or more. [3] The molded product according to [1] or [2], wherein the ratio of the number of island portions I having an aspect ratio of more than 1.65 and not more than 1.95 to the total number is 20.0% or less. [4] The observation range of the SEM image is within a range of 5 μm × 5 μm, and the average area of ​​each island portion I of the sea-island structure obtained by contour extraction analysis of the binarized image of the SEM image is 0.1000 μm 2 The molded article according to any one of [1] to [3] below. [5] The molded article according to any one of [1] to [4], wherein the thermoplastic resin composition contains a polyphenylene ether resin (A), a styrene elastomer (B), and an olefin polymer (C). [6] The molded article according to [5], wherein the styrene-based elastomer (B) is two types of styrene-based elastomers. [7] The molded article according to [5] or [6], wherein the styrene-based elastomer (B) is at least one selected from the group consisting of hydrogenated block copolymers and modified products of the hydrogenated block copolymers. [8] The molded article according to any one of [5] to [7], wherein the olefin polymer (C) is an olefin polymer other than polypropylene. [9] The molded article according to any one of [5] to [8], wherein the thermoplastic resin composition further contains a flame retardant (D).

[10] The molded article according to [9], wherein the flame retardant (D) is a phosphate ester-based flame retardant.

[11] The molded article according to any one of [1] to

[10] , wherein the thickness of the thickest part of the molded article is 6 mm or less.

[12] The molded article according to any one of [1] to

[11] , which is a housing for a secondary battery.

[13] The molded article according to any one of [1] to

[12] , which is a case for a portable secondary battery, wherein the weight of the portable secondary battery is 200 g or more.

[14] The molded article according to any one of [1] to

[13] , which is a housing for a portable secondary battery and has a thin-walled portion at a portion where the portable secondary battery is attached to a device that uses the portable secondary battery.

[15] The molded product according to

[14] , wherein the thickness of the thin-walled portion is 1 mm or more and 10 mm or less. [Effects of the Invention]

[0014] According to the present invention, a molded article having excellent impact resistance and chemical resistance can be provided. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a perspective view that schematically shows an example of a molded product having a thin-walled portion. [Figure 2] FIG. 2 is a cross-sectional view showing a typical example of a corner portion of a molded product. [Figure 3] FIG. 3 is a schematic diagram showing an example of a procedure for preparing a test piece for cross-sectional observation. [Figure 4] FIG. 4 is a diagram illustrating the configuration of the extruder used in the examples. [Figure 5] FIG. 5 is a perspective view schematically showing a flat plate and a test piece for sea-island structure analysis in the examples. [Figure 6] FIG. 6 is a perspective view schematically showing the test piece of FIG. 5 and a small piece for observing the sea-island structure. [Figure 7] FIG. 7 is an SEM image of the TD direction test piece of Example 11. [Figure 8] FIG. 8 is an SEM image of the MD test piece of Example 11. [Figure 9] FIG. 9 is an SEM image of the TD direction test piece of Comparative Example 3. [Figure 10] FIG. 10 is an SEM image of the MD test piece of Comparative Example 3. [Figure 11A] 11A and 11B show the image analysis program used in the examples. [Figure 11B]11A and 11B show the image analysis program used in the examples. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, a mode for carrying out the present invention (hereinafter simply referred to as "the present embodiment") will be described in detail. The following present embodiment is an example for explaining the present invention, and is not intended to limit the present invention to the following content. The present invention can be carried out by appropriately modifying it within the scope of its gist.

[0017] In this embodiment, observation of the sea-island structure by SEM, image analysis, image processing, and area calculation are performed by the methods described in the Examples.

[0018] In this specification, the thickness of a molded product may be referred to as a wall thickness. Also, a portion of a molded product that is thinner than the surrounding area may be referred to as a thin-walled portion.

[0019] In the present invention, two or more embodiments can be combined in any manner.

[0020] Unless otherwise specified, the materials, components, compounds and resins described herein may be used alone or in combination of two or more.

[0021] In this specification, unless otherwise specified, numerical ranges are intended to include the upper and lower limits. For example, 0.0008 to 0.08 μm 2 is 0.0008 μm 2 More than 0.08μm 2 It means the following:

[0022] (molded product) The molded article of the present embodiment is a molded article made of a thermoplastic resin composition, The thermoplastic resin composition has an island-sea structure, In an SEM image obtained by observing a cross section of the molded product using an SEM, The area of ​​the sea-island structure is 0.0008 μm 2More than 0.08μm 2 When the following island portion is designated as island portion I, the most frequent aspect ratio of island portion I is less than 1.90, In the molded article, the ratio of the number of island portions I having an aspect ratio of more than 1.95 and not more than 2.25 to the total number of island portions I is 17.0% or less, thereby providing excellent impact resistance and chemical resistance.

[0023] [Sea-island structure] The thermoplastic resin composition has an island-in-a-sea structure. Therefore, a molded article made of the thermoplastic resin composition also has an island-in-a-sea structure. The components constituting the sea portion and the island portion in the island-in-a-sea structure are not particularly limited.

[0024] The sea-island structure of the thermoplastic resin composition and the molded article is observed by SEM.

[0025] The shape of the island portions is not particularly limited, and examples of the shape of the island portions include a shape stretched by shear stress during injection molding, an irregular shape, and a circular shape.

[0026] In this embodiment, in an SEM image obtained by observing the cross section of a molded product using an SEM, among the island portions present in the sea-island structure, an area of ​​0.0008 μm 2 More than 0.08μm 2 The following island part is called island part I. Of the island parts in the sea-island structure, the area is 0.0008 μm 2 Islands and areas less than 0.08 μm 2 Island portions exceeding 1.95 are excluded. The most frequent aspect ratio of the island portion I is less than 1.90. In this embodiment, the most frequent aspect ratio of the island portion I is only less than 1.90, and there is no most frequent aspect ratio in the range exceeding 1.95.

[0027] In this embodiment, the island portions in the sea-island structure have an area of ​​0.0008 μm 2 Islands and areas less than 0.08 μm 2 Islands exceeding 0.0008 μm are excluded. 2The island portion having an area of ​​less than 0.08 μm corresponds to the island portion having an area of ​​less than 300 pixels in the examples described later. 2 The island portion exceeding 30,000 pixels corresponds to the island portion exceeding 30,000 pixels in the embodiment described below.

[0028] The aspect ratio of the island portion I is calculated by calculating a circumscribing rectangle for the island portion I from analysis of three SEM images of a test piece cut out in accordance with paragraphs

[0038] to

[0043] described below, and then calculating the aspect ratio of the island portion I using the following formula. Aspect ratio = "Length of the long side of the bounding rectangle" / "Length of the short side of the bounding rectangle"

[0029] A histogram is created from the calculated aspect ratios of the island portions I in increments of 0.10. In the molded product of this embodiment, the most frequent aspect ratio in this histogram is less than 1.90. In this embodiment, when the most frequent aspect ratio of the island portions I is less than 1.90, the island portions I are more finely dispersed in the sea portion, making it more difficult for chemicals to penetrate, and further improving chemical resistance. In one embodiment, the most frequent aspect ratio of the island portions I is 1.80 or less, 1.70 or less, 1.60 or less, 1.50 or less, or 1.40 or less. In another embodiment, the most frequent aspect ratio of the island portions I is 1.00 or more, 1.10 or more, 1.20 or more, 1.30 or more, 1.40 or more, or 1.50 or more.

[0030] In this embodiment, from the viewpoint of achieving excellent chemical resistance and impact resistance of the molded article, the ratio of island portions I having an aspect ratio of greater than 1.95 and less than or equal to 2.25 (hereinafter referred to as "ratio A") to the total number of island portions I is 17.0% or less. When ratio A is 17.0% or less, the elastomer component is uniformly and finely dispersed, and when chemicals penetrate from the surface to the interior of the molded article, their penetration is hindered by the elastomer component, causing them to bypass the elastomer multiple times. This delay or inhibition of chemical penetration is presumably responsible for improved chemical resistance. Furthermore, while a strong impact on a molded article typically causes cracks to propagate, resulting in cracks in products using the molded article, in this embodiment, the elastomer is finely dispersed, and the cracks propagate in a direction that tears the sea portion (e.g., PPE) rather than tearing the highly tough elastomer component. This presumably contributes to improved impact resistance, as the cracks bypass the elastomer multiple times. Preferably, the ratio A is 16.0% or less or 15.0% or less. The ratio A is, for example, 0% or more.

[0031] In one embodiment, the proportion of island portions I having an aspect ratio of 1.35 or less (hereinafter referred to as "proportion B") is 10.0% or more of the total number of island portions I. This results in the elastomer component being uniformly and finely dispersed, and chemicals penetrating from the surface to the interior of the molded article are inhibited by the elastomer component, causing the chemicals to bypass the elastomer multiple times, thereby improving chemical resistance.

[0032] In one embodiment, the proportion of island portions I having an aspect ratio of more than 1.65 and not more than 1.95 (hereinafter referred to as "proportion C") is 20% or less of the total number of island portions I. This results in the elastomer component being uniformly and finely dispersed, and chemicals penetrating from the surface to the interior of the molded article are prevented from penetrating by the elastomer component, causing the chemicals to bypass the elastomer multiple times, thereby improving chemical resistance.

[0033] In one embodiment, if the island portions I satisfy the following two conditions, the molded article will have better chemical resistance and impact resistance. Condition 1: Ratio A is 17.0% or less and Ratio B is 10.0% or more; Condition 2: Proportion C is 20% or less.

[0034] The ratio B is, for example, 100% or less.

[0035] The ratio C is more preferably 18.0% or less. The ratio C is, for example, 0% or more.

[0036] Furthermore, from the viewpoint of improving chemical resistance, the ratio A / ratio B is preferably 1.5 or less, more preferably 1.2 or less, even more preferably 1.1 or less, and most preferably 1.0 or less. The ratio A / ratio B is, for example, 0 or more.

[0037] In this embodiment, the observation range of the SEM image is within a range of 5 μm × 5 μm, and the average area of ​​each island portion I of the sea-island structure obtained by contour extraction analysis of the binarized SEM image is 0.1000 μm 2 The average area of ​​the island portions I is 0.0500 μm or less, which further improves chemical resistance. 2 Less than 0.0100 μm is more preferable. 2 More preferably, 0.0060 μm or less 2 Less than 0.0040 μm is more preferable. 2 The most preferable average area of ​​the island portion I is, for example, 0.0010 μm 2 That's all.

[0038] The cross section for observing the sea-island structure is a cross section in which the flow direction (also called MD direction) is perpendicular to the cross section to be observed. If the MD direction and TD direction are unknown due to the product shape, etc., they can be determined by following steps 1 to 6 below. This procedure is explained with reference to Figure 3. Step 1: A small piece to be observed (small piece 10 in FIG. 3B) is cut out from any location of the molded product (molded product 1 in FIG. 3A). Step 2: Divide the small piece into two equal parts (in Figure 3B, small piece 10 is divided into two equal parts, the front and the back, by the dashed line). At this time, both of the divided small pieces (small pieces 11 and 12 in Figure 3C) contain the surface of the original molded product. Step 3: Using a cryomicrotome, cut parallel to the surface at a point 3 μm to 8 μm from the outer surface of the small piece 12 to expose a surface (surface 14 D in Figure 3) for observing the extension direction of the island portion I using SEM. Step 4: The sample with the exposed surface for observing the elongation direction (small piece 12 in Figure 3E) and ruthenium tetroxide (RuO4) are placed in a sealed container for 5 minutes, and the surface for observing the elongation direction (surface 14 in Figure 3E) is stained by exposing it to the sublimating ruthenium. Step 5: The surface prepared in step 4 for observing the extension direction is observed by SEM to confirm the extension direction in which the island portion (island portion 20 F in FIG. 3) is extended. Step 6: Cut the other unprocessed sample (piece 11 in Figure 3C) at a position parallel to the direction perpendicular to the elongation direction confirmed in Step 5 (the dashed line in Figure 3F). Place the sample in a sealed container with ruthenium tetroxide (RuO4) for 5 minutes, expose the sample to the sublimating ruthenium, and stain and observe the cross section (the surface to be observed) to measure the aspect ratio.

[0039] The area in the molded product where the sea-island structure was observed was within a range of 5 μm deep from the surface of the molded product.

[0040] There are no particular restrictions on the location from which the small pieces are cut out of the molded article. For example, in the case of a molded article having a gate, to properly evaluate chemical resistance, if the gate position is 0.0 and the position of the flow end is 10.0, then the small pieces are cut out from a location between 4.0 and 9.5.

[0041] The distance from the gate to the end of the flow can be determined by simulating using flow analysis software or by gradually increasing the amount of resin filled during injection molding to check the resin filling behavior and then determining the distance.

[0042] If there are multiple flow ends, the flow end with the longest distance from the gate portion to the flow end is selected.

[0043] When there are a plurality of flow ends that are the same distance from the gate portion to the flow end, the flow end that has a thin wall portion between the gate portion and the flow end is selected.

[0044] In this embodiment, the thermoplastic resin composition preferably contains a polyphenylene ether resin (A), a styrene elastomer (B), and an olefin polymer (C). When the thermoplastic resin composition contains these three components, the sea portion of the sea-island structure is the polyphenylene ether resin (A), and the island portions are the styrene elastomer (B) and the olefin polymer (C).

[0045] The molded article of this embodiment is characterized by having the above-described morphology.

[0046] Such a morphology can be obtained by appropriately controlling the composition of the thermoplastic resin composition, molding conditions, etc. Specifically, for example, increasing the injection speed decreases the most frequent aspect ratio of the island portions I. For example, increasing the emissivity decreases the most frequent aspect ratio of island portion I. For example, lowering the mold temperature reduces the most frequent aspect ratio of island portion I. For example, lowering the cylinder temperature, especially in the front and middle portions, reduces the most frequent aspect ratio of island portion I. For example, when the peak injection pressure is increased, the most frequent aspect ratio of the island portion I becomes smaller.

[0047] Next, the thermoplastic resin composition constituting the molded article of this embodiment will be described.

[0048] [Thermoplastic resin] Examples of thermoplastic resins include polyamide-based resins, polyester-based resins, polyacetal-based resins, polycarbonate-based resins, polyacrylic-based resins, polyphenylene ether-based resins (including modified polyphenylene ethers obtained by blending or graft-polymerizing polyphenylene ethers with other resins), polyarylate-based resins, polysulfone-based resins, polyphenylene sulfide-based resins, polyethersulfone-based resins, polyketone-based resins, polyphenylene ether ketone-based resins, polyimide-based resins, polyamideimide-based resins, polyetherimide-based resins, polyurethane-based resins, polyolefin-based resins (for example, α-olefin (co)polymers), and ionomers.

[0049] The thermoplastic resin is preferably a crystalline resin having a melting point in the range of 100°C or more and 350°C or less, an amorphous resin having a glass transition temperature in the range of 50°C or more and 250°C or less, or a combination thereof.

[0050] The melting point of a crystalline resin refers to the peak-top temperature of the endothermic peak that appears when the temperature is increased from 23°C at a rate of 10°C / min using a differential scanning calorimeter (DSC). If two or more endothermic peaks appear, it refers to the peak-top temperature of the endothermic peak with the highest temperature. The enthalpy of this endothermic peak is preferably 10 J / g or higher, and more preferably 20 J / g or higher. Furthermore, when measuring, it is desirable to first heat the sample to a temperature condition of at least 20°C above the melting point to melt the resin, and then cool it to 23°C at a rate of 10°C / min.

[0051] The glass transition temperature (Tg) of an amorphous resin is the peak-top temperature at which the storage modulus drops significantly and the loss modulus reaches its maximum when measured using a dynamic viscoelasticity measuring device at a heating rate of 2°C / min from 23°C and an applied frequency of 10 Hz. If two or more loss modulus peaks appear, the peak-top temperature refers to the peak-top temperature of the highest-temperature peak. To improve measurement accuracy, measurements should be taken at least once every 20 seconds. There are no particular restrictions on the method for preparing samples for measurement. However, to eliminate the effects of molding distortion, it is desirable to use cut pieces of hot-press molded products. Furthermore, from the perspective of thermal conduction, it is desirable for the size (width and thickness) of the cut pieces to be as small as possible.

[0052] The thermoplastic resin may be a homopolymer or a copolymer.

[0053] As the thermoplastic resin, the above-mentioned resins modified with at least one compound selected from unsaturated carboxylic acids, acid anhydrides thereof and derivatives thereof can also be used.

[0054] As the thermoplastic resin, from the viewpoints of chemical resistance, impact resistance, moldability, designability, and mechanical properties, one or more resins selected from the group consisting of polyolefin-based resins, polyamide-based resins, polyester-based resins, polystyrene-based resins, polyacetal-based resins, polyacrylic-based resins, polyphenylene ether-based resins, and polyphenylene sulfide-based resins are preferred.

[0055] In the present embodiment, the thermoplastic resin composition preferably contains polyphenylene ether (A), a styrene-based elastomer (B), and an olefin-based polymer (C), which improves chemical resistance and impact resistance after molding and allows the composition to exhibit more excellent properties under various environmental conditions.

[0056] (Polyphenylene ether (A)) Examples of the polyphenylene ether (A) in this embodiment include poly(2,6-dimethyl-1,4-phenylene ether), poly(2-methyl-6-ethyl-1,4-phenylene ether), poly(2-methyl-6-phenyl-1,4-phenylene ether), and poly(2,6-dichloro-1,4-phenylene ether). Further examples include polyphenylene ether copolymers such as copolymers of 2,6-dimethylphenol and other phenols (e.g., copolymers of 2,6-dimethylphenol and 2,3,6-trimethylphenol and copolymers of 2,6-dimethylphenol and 2-methyl-6-butylphenol, as described in Japanese Patent Publication No. 52-017880). Among these, poly(2,6-dimethyl-1,4-phenylene ether), copolymers of 2,6-dimethylphenol and 2,3,6-trimethylphenol, and mixtures thereof are preferred from the viewpoint of mechanical strength.

[0057] The method for producing the polyphenylene ether (A) used in the present invention is not particularly limited, and known methods can be used, such as the production method described in Patent Document 1.

[0058] The lower limit of the reduced viscosity of the polyphenylene ether (A) (measured in a 0.5 g / dL chloroform solution at 30°C using an Ubbelohde viscometer) is preferably 0.30 dL / g or more, more preferably 0.35 dL / g or more, and even more preferably 0.38 dL / g or more. The upper limit of the reduced viscosity of the polyphenylene ether is preferably 0.80 dL / g or less, more preferably 0.75 dL / g or less, and even more preferably 0.55 dL / g or less. The combination of the lower and upper limits of the reduced viscosity of the polyphenylene ether is preferably 0.30 dL / g or more and 0.80 dL / g or less, more preferably 0.35 dL / g or more and 0.75 dL / g or less, and even more preferably 0.38 dL / g or more and 0.55 dL / g or less. When the reduced viscosity of the polyphenylene ether (A) is 0.30 dL / g or more and 0.80 dL / g or less, the impact resistance and heat resistance are further improved.

[0059] The polyphenylene ether (A) usable in the present invention may be a fully or partially modified polyphenylene ether (A1). The modified polyphenylene ether (A1) refers to a polyphenylene ether (A1-1) modified with at least one modifying compound having at least one carbon-carbon double bond or triple bond and at least one carboxylic acid group, acid anhydride group, amino group, hydroxyl group, or glycidyl group in its molecular structure.

[0060] The modified polyphenylene ether (A1) is expected to react with adhesives used in assembling multiple molded products or joining them with other materials, and is therefore preferable from the viewpoint of bonding strength and wettability.

[0061] Examples of methods for producing the modified polyphenylene ether (A1) include: (1) a method of reacting the polyphenylene ether with a modifying compound without melting it at a temperature in the range of 100°C or higher and lower than the glass transition temperature of the polyphenylene ether, in the presence or absence of a radical initiator; (2) a method of melt-kneading and reacting the polyphenylene ether with a modifying compound at a temperature in the range of higher than the glass transition temperature of the polyphenylene ether and lower than 360°C, in the presence or absence of a radical initiator; and (3) a method of reacting the polyphenylene ether with a modifying compound in a solution, in the presence or absence of a radical initiator, at a temperature lower than the glass transition temperature of the polyphenylene ether. Any of these methods is acceptable, but methods (1) and (2) are preferred.

[0062] Next, at least one modified compound having at least one carbon-carbon double bond or triple bond and at least one carboxylic acid group, acid anhydride group, amino group, hydroxyl group, or glycidyl group in its molecular structure will be specifically described.

[0063] Examples of modified compounds having a carbon-carbon double bond, a carboxylic acid group, and an acid anhydride group in the molecule include maleic acid, fumaric acid, chloromaleic acid, cis-4-cyclohexene-1,2-dicarboxylic acid, and their acid anhydrides. Fumaric acid, maleic acid, and maleic anhydride are particularly preferred, with fumaric acid and maleic anhydride being particularly preferable. These unsaturated dicarboxylic acids in which one or two carboxyl groups are esterified can also be used.

[0064] Examples of modified compounds having both a carbon-carbon double bond and a glycidyl group in the molecule include allyl glycidyl ether, glycidyl acrylate, glycidyl methacrylate, epoxidized natural fats and oils, etc. Among these, glycidyl acrylate and glycidyl methacrylate are particularly preferred.

[0065] Modified compounds having both a carbon-carbon double bond and a hydroxyl group in the molecule include compounds represented by the general formula C, such as allyl alcohol, 4-penten-1-ol, and 1,4-pentadiene-3-ol. n H 2n-3 Unsaturated alcohols of formula C n H 2n-5 O.H., C. n H 2n-7 Examples include unsaturated alcohols such as OH (n is a positive integer).

[0066] The amount of the modifying compound added when producing the modified polyphenylene ether (A1) is preferably from 0.1 to 10 parts by mass, more preferably from 0.3 to 5 parts by mass, per 100 parts by mass of polyphenylene ether. The amount of the radical initiator used when producing the modified polyphenylene ether is preferably from 0.001 to 1 part by mass, per 100 parts by mass of polyphenylene ether.

[0067] The addition rate of the modifying compound in the modified polyphenylene ether (A1) is preferably from 0.01% by mass to 5% by mass, more preferably from 0.1% by mass to 3% by mass. Unreacted modifying compound and / or a polymer of the modifying compound may remain in the modified polyphenylene ether (A1).

[0068] To stabilize the polyphenylene ether (A), various known stabilizers may be blended into the resin composition. Examples of stabilizers include metal stabilizers such as zinc oxide and zinc sulfide; and organic stabilizers such as hindered phenol stabilizers, phosphorus stabilizers, and hindered amine stabilizers. The content of the stabilizer is preferably less than 5 parts by mass per 100 parts by mass of the polyphenylene ether (A).

[0069] [Polyphenylene ether (A) content] In the resin composition of this embodiment, when the total amount of the polyphenylene ether (A), the styrene-based elastomer (B), and the olefin-based polymer (C) is taken as 100 parts by mass, the amount of the polyphenylene ether (A) is preferably 30 parts by mass or more and 95 parts by mass or less, more preferably 40 parts by mass or more and 90 parts by mass or less, and even more preferably 50 parts by mass or more and 85 parts by mass or less. By making the content of the polyphenylene ether (A) 30 parts by mass or more, it is possible to improve the elastic modulus and obtain a molded article having the rigidity required for a housing. On the other hand, by making the content of the polyphenylene ether (A) 95 parts by mass or less, it is possible to obtain a molded article having excellent impact resistance and chemical resistance.

[0070] (Styrene-based elastomer (B)) The styrene elastomer (B) is not particularly limited, and its structure may be a random copolymer or a block copolymer, with the styrene elastomer (B) preferably being a block copolymer.

[0071] Block copolymer styrene elastomers offer excellent flexibility and elasticity. They consist of polystyrene (PS) segments that make up hard segments and soft segments, and come in several varieties depending on their composition. There are no particular limitations on the type of block copolymer; typical examples include SBS (S: styrene, B: butadiene) and SIS (I: isoprene), as well as SEBS (E: ethylene, B: butylene) and SEPS (P: propylene), which are modified with water. Among these, SBS and SEBS are the preferred styrene elastomers for this application due to their balance of flexibility and modulus. The inclusion of an appropriate amount of styrene elastomer (B) enhances the compatibility of the individual components, contributing to improved impact resistance of molded products.

[0072] The styrene-based elastomer (B) is a hydrogenated block copolymer obtained by hydrogenating at least a portion of a block copolymer comprising at least one polymer block A mainly composed of styrene and at least one polymer block B mainly composed of a conjugated diene compound. The styrene-based elastomer may contain blocks other than the polymer block A and the polymer block B, but is preferably composed of only the polymer block A and the polymer block B, and more preferably composed of only one type of polymer block A and one type of polymer block B.

[0073] From the viewpoint of improving drop impact resistance and other performance, the styrene-based elastomer (B) more preferably contains a plurality of types of styrene-based elastomers (B). In one embodiment, the styrene-based elastomer (B) contains two types of styrene-based elastomers.

[0074] In one embodiment, the styrene-based elastomer (B) is at least one selected from the group consisting of hydrogenated block copolymers and modified products of the hydrogenated block copolymers.

[0075] --Polymer Block A-- Examples of polymer block A include a styrene homopolymer block and a copolymer block of styrene and a conjugated diene compound. Among these, a styrene homopolymer block refers to a block containing more than 50% by mass of styrene units, preferably 70% by mass or more, more preferably 80% by mass or more, and may contain 100% by mass or less of styrene units.

[0076] Examples of the conjugated diene compound constituting the polymer block A include the conjugated diene compounds described below, such as butadiene, isoprene, 1,3-pentadiene, and 2,3-dimethyl-1,3-butadiene. Of these, butadiene, isoprene, and combinations thereof are preferred, and butadiene is more preferred. In polymer block A, the distribution of styrene, conjugated diene compounds, etc. in the molecular chain of the polymer block may be random, tapered (where the monomer component increases or decreases along the molecular chain), partially block-like, or any combination thereof.

[0077] When two or more polymer blocks A are present in the styrene-based elastomer (B) component, the polymer blocks A may have the same structure or different structures.

[0078] The number average molecular weight (Mn) of the polymer block A is preferably 8,000 or more, more preferably 10,000 or more, and even more preferably 40,000 or more and 100,000 or less, from the viewpoints of improving dispersibility in the resin composition and improving impact resistance when stress is concentrated.

[0079] --Polymer Block B-- Examples of the polymer block B mainly composed of a conjugated diene compound include a homopolymer block of a conjugated diene compound, a random copolymer block of a conjugated diene compound and a vinyl aromatic compound, etc. Among these, a homopolymer block of a conjugated diene compound and a copolymer block of a conjugated diene compound and a vinyl aromatic compound containing more than 50% by mass (preferably 70% by mass or more) of conjugated diene compound units are preferred. Here, in the polymer block B, "mainly composed of a conjugated diene compound" means that the polymer block B before hydrogenation contains more than 50% by mass of conjugated diene compound units, preferably 70% by mass or more, more preferably 80% by mass or more, and may contain 100% by mass or less of conjugated diene compound units.

[0080] The conjugated diene compound is not particularly limited, but examples thereof include butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, etc. Among these, butadiene, isoprene, and a combination thereof are preferred, and butadiene is more preferred.

[0081] Examples of vinyl aromatic compounds include styrene, α-methylstyrene, vinyltoluene, p-tert-butylstyrene, and diphenylethylene, with styrene being preferred.

[0082] In the polymer block B, the distribution of the conjugated diene compound, vinyl aromatic compound, etc. in the molecular chain of the polymer block may be random, tapered (where the monomer component increases or decreases along the molecular chain), partially block-like, or any combination thereof.

[0083] When two or more polymer blocks B are present in the styrene-based elastomer (B) component, the polymer blocks B may have the same structure or different structures.

[0084] The hydrogenation rate relative to the ethylenic double bonds in the conjugated diene compound units in the polymer block B is preferably 30% or more, more preferably 70% or more, and even more preferably 90% or more, from the viewpoint of obtaining even better rigidity, chemical resistance, impact resistance, and impact resistance under concentrated stress. The hydrogenation rate can be measured using a nuclear magnetic resonance (NMR) spectrometer.

[0085] The total ratio of 1,2-vinyl bonds and 3,4-vinyl bonds to the ethylenic double bonds in the conjugated diene compound units in polymer block B is preferably 35% or more, more preferably 45% or more, and even more preferably 65% ​​or more and 90% or less, from the viewpoints of increasing the compatibility of polymer block B with olefinic components and improving impact resistance under stress concentration. In this specification, the total amount of 1,2-vinyl bonds and 3,4-vinyl bonds (total amount of vinyl bonds) refers to the ratio of the total amount of 1,2-vinyl bonds and 3,4-vinyl bonds in the conjugated diene compound units in the conjugated diene compound-containing polymer block before hydrogenation to the total amount of 1,2-vinyl bonds, 3,4-vinyl bonds, and 1,4-conjugated bonds. The total amount of vinyl bonds can be measured using an infrared spectrophotometer and calculated according to the method described in Analytical Chemistry, Volume 21, No. 8, August 1949.

[0086] The number average molecular weight (Mn) of the polymer block B is preferably 30,000 or more and 100,000 or less, more preferably 40,000 or more and 90,000 or less, from the viewpoint of obtaining even better rigidity, impact resistance, and chemical resistance.

[0087] From the viewpoint of obtaining even better rigidity, impact resistance, and chemical resistance, the glass transition temperature of the polymer block B after hydrogenation is preferably −85° C. or higher and 0° C. or lower, more preferably −40° C. or higher and −10° C. or lower. In this specification, the glass transition temperature of the block copolymer and the glass transition temperature of the polymer block in the block copolymer can be measured, for example, using a dynamic viscoelasticity measuring device using a film-form sample in a tensile mode, at a temperature scan rate of 3° C. / min, a frequency of 1 Hz, and in a nitrogen atmosphere.

[0088] The structure of the hydrogenated block copolymer in the styrene-based elastomer (B), where polymer block A is defined as "A" and polymer block B is defined as "B", may be, for example, an AB type, an ABA type, a BA-BA type, an (AB-)nX type (where n is an integer of 1 or more, and X is a reaction residue of a polyfunctional coupling agent such as silicon tetrachloride or tin tetrachloride, or a residue of an initiator such as a polyfunctional organolithium compound), or an ABABA type.

[0089] Regarding the block structure, it is preferred that polymer block B is a homopolymer block of a conjugated diene compound or a copolymer block of a conjugated diene compound containing more than 50% by mass (preferably 70% by mass or more) of conjugated diene compound units and a vinyl aromatic compound, and that polymer block A is a homopolymer block of a vinyl aromatic compound or a copolymer block of a vinyl aromatic compound containing more than 50% by mass (preferably 70% by mass or more) of a vinyl aromatic compound and a conjugated diene compound.

[0090] The molecular structure of the hydrogenated block copolymer in the styrene-based elastomer is not particularly limited, and may be, for example, linear, branched, radial, or any combination thereof.

[0091] The content of styrene units in the styrene elastomer component before hydrogenation is not particularly limited, but from the viewpoint of the heat resistance and mechanical strength of the composition, it is preferably from 10 to 70% by mass, more preferably from 20 to 60% by mass, even more preferably from 30 to 50% by mass, and particularly preferably from 40 to 50% by mass. In addition to using one type of styrene elastomer having a vinyl aromatic compound unit content within these ranges, two or more types of styrene elastomers having different vinyl aromatic compound unit contents can also be used in combination.

[0092] The total proportion of 1,2-vinyl bonds and 3,4-vinyl bonds relative to the ethylenic double bonds in the conjugated diene compound units contained in the styrene-based elastomer (B) component is preferably 35% or more, more preferably 45% or more, and even more preferably 65% ​​or more, and preferably 90% or less. A total proportion of 1,2-vinyl bonds and 3,4-vinyl bonds of 35% or more improves compatibility with olefin-based polymers, which is preferable. A total proportion of 1,2-vinyl bonds and 3,4-vinyl bonds of less than 90% improves the impact resistance of the resin composition. Methods for controlling the total proportion of 1,2-vinyl bonds and 3,4-vinyl bonds within a certain range include, but are not limited to, adding a 1,2-vinyl bond amount regulator or adjusting the polymerization temperature during the production of the styrene-based elastomer.

[0093] "The sum of 1,2-vinyl bonds and 3,4-vinyl bonds relative to the double bonds in the conjugated diene compound units" refers to the sum of 1,2-vinyl bonds and 3,4-vinyl bonds relative to the double bonds (ethylenic double bonds) in the conjugated diene compound units in the block copolymer before hydrogenation of the hydrogenated block copolymer. For example, the block copolymer before hydrogenation can be measured using an infrared spectrophotometer and calculated using the Hampton method. It can also be calculated using NMR from the block copolymer after hydrogenation.

[0094] In the styrene-based elastomer (B) component, the hydrogenation rate of the ethylenic double bonds (double bonds in the conjugated diene compound units) in the block copolymer is preferably 30% or more, more preferably 70% or more, and even more preferably 90% or more, from the viewpoint of obtaining even better rigidity, chemical resistance, impact resistance, and impact resistance under stress concentration.

[0095] A styrene-based elastomer having such a hydrogenation rate can be easily obtained, for example, by controlling the amount of hydrogen consumed in the hydrogenation reaction of the ethylenic double bonds of the block copolymer to fall within the range of the desired hydrogenation rate.

[0096] From the viewpoints of rigidity, impact resistance, and chemical resistance, the molecular weight peak of the styrene elastomer (B) component after hydrogenation, as calculated using standard polystyrene standards, as determined by GPC measurement, is preferably from 10,000 to 500,000, more preferably from 30,000 to 400,000, even more preferably from 50,000 to 350,000, and particularly preferably from 70,000 to 300,000. When the styrene elastomer (B) has a sufficient molecular weight, it becomes possible to maintain the sea-island structure defined in the present application, which improves chemical resistance when strong shear stress is generated.

[0097] The method for controlling the molecular weight peak of the styrene-based elastomer within the range is not particularly limited, but for example, a method of adjusting the amount of catalyst in the polymerization step can be mentioned.

[0098] In this specification, the molecular weight peak can be measured using a Showa Denko Gel Permeation Chromatography System 21 under the following conditions. In this measurement, one Showa Denko KG, one Showa Denko K-800RL, and one Showa Denko K-800R columns connected in series are used. The column temperature is 40°C, the solvent is chloroform, the solvent flow rate is 10 mL / min, and the sample concentration is 1 g of hydrogenated block copolymer / 1 L of chloroform solution. Furthermore, a calibration curve is created using standard polystyrene (molecular weights of standard polystyrene: 3,650,000, 2,170,000, 1,090,000, 681,000, 204,000, 52,000, 30,200, 13,800, 3,360, 1,300, and 550). Furthermore, the UV (ultraviolet) wavelength of the detector is set to 254 nm for both the standard polystyrene and the hydrogenated block copolymer.

[0099] The molecular weight distribution (Mw / Mn) of the styrene-based elastomer component (B) before hydrogenation is preferably 1.01 or more and 1.50 or less, more preferably 1.03 or more and 1.40 or less, from the viewpoint of obtaining even better rigidity, impact resistance, and chemical resistance.

[0100] As a method for producing the hydrogenated block copolymer in the styrene-based elastomer (B), a known production method can be used, and for example, the method described in Patent Document 1 can be mentioned.

[0101] [Content of styrene-based elastomer (B)] In the resin composition of this embodiment, when the total amount of the polyphenylene ether (A), styrene-based elastomer (B), and olefin-based polymer (C) is 100 parts by mass, the amount of the styrene-based elastomer (B) is preferably 5 parts by mass or more and 50 parts by mass or less, more preferably 10 parts by mass or more and 40 parts by mass or less, and even more preferably 12 parts by mass or more and 30 parts by mass or less. By making the amount of the styrene-based elastomer (B) 5 parts by mass or more, a molded article having excellent impact resistance and chemical resistance can be obtained. On the other hand, by making the amount of the styrene-based elastomer (B) 50 parts by mass or less, a molded article having excellent rigidity can be obtained.

[0102] (Olefin polymer (C)) The olefin polymer (C) is not particularly limited, and examples thereof include a homopolymer of an olefin monomer and a copolymer of two or more types of monomers including an olefin monomer.

[0103] From the viewpoint of impact resistance, the olefin polymer (C) is preferably, for example, a homopolymer of an olefin monomer other than propylene, or a copolymer of two or more monomers including an olefin monomer other than propylene, and in particular, a copolymer of ethylene and an α-olefin other than ethylene is more preferred.

[0104] From the viewpoint of the impact resistance, chemical resistance, tracking resistance, and rigidity of the resin composition, it is preferred that the monomer units constituting the olefin polymer (C) do not contain a propylene unit.

[0105] In this specification, "olefin polymer composed of olefins other than propylene" and "not containing propylene units" include cases where propylene is contained as a structural unit to an extent that does not impair the effects of the invention, and for example, means that the content of propylene units in all structural units constituting the olefin polymer (C) is 1.0 mass% or less, preferably 0.1 mass% or less.

[0106] Examples of the olefin polymer (C) include copolymers of ethylene and one or more C4-C20 α-olefins. Among these, copolymers of ethylene and one or more C4-C8 α-olefins are preferred, copolymers of ethylene and one or more comonomers selected from the group consisting of 1-butene, 1-hexene, 4-methyl-1-pentene, and 1-octene are even more preferred, and copolymers of ethylene and 1-butene are particularly preferred. Using such copolymers as the olefin polymer (C) tends to result in resin compositions with higher impact properties and chemical resistance. Two or more ethylene-α-olefin copolymers may be used as the olefin polymer (C).

[0107] The content of ethylene-derived structural units in the olefin polymer (C) is preferably 5% by mass or more and 95% by mass or less, more preferably 30% by mass or more and 90% by mass or less, based on the total amount of the olefin polymer, from the viewpoint of low-temperature curing resistance and flexibility of the resin composition.

[0108] The content of structural units derived from an α-olefin other than ethylene in the olefin polymer (C) is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 20% by mass or more, based on the total amount of the olefin polymer, from the viewpoints of low-temperature curing resistance and flexibility of the resin composition. Also, from the viewpoint of rigidity of the resin composition, it is preferably 50% by mass or less, more preferably 48% by mass or less.

[0109] The brittle temperature of the olefin polymer (C) is -50°C or lower, and from the viewpoint of obtaining even better impact resistance and chemical resistance, it is preferably -60°C or lower, more preferably -70°C or lower. The brittle temperature can be measured in accordance with ASTM D746.

[0110] The density of the olefin polymer (C) measured in accordance with JIS K7112 (density at the raw material stage before kneading) is 0.80 g / cm from the viewpoint of chemical resistance of the resin composition. 3 More preferably, 0.84 g / cm 3 More preferably, 0.86 g / cm 3 The density of the olefin polymer (C) is 0.80 g / cm 3 As a method for controlling the above, for example, a method of adjusting by controlling the content ratio of ethylene units can be mentioned.

[0111] The melt flow rate (MFR, measured in accordance with ASTM D-1238 at 190°C under a load of 2.16 kgf, density at the raw material stage before kneading) of the olefin polymer (C) is preferably 0.1 g / 10 min or more and 100.0 g / 10 min or less, more preferably 0.5 g / 10 min or more and 50.0 g / 10 min or less, even more preferably 1.0 g / 10 min or more and 30.0 g / 10 min or less, still more preferably 1.0 g / 10 min or more and 10.0 g / 10 min or less, and most preferably 1.5 g / 10 min or more and 5.0 g / 10 min or less, from the viewpoints of morphology stabilization due to dispersion of the olefin polymer (C) in the resin composition and the chemical resistance and impact resistance of the resin composition.

[0112] The method for controlling the melt flow rate of the olefin polymer (C) to 0.1 g / 10 min or more and 100.0 g / 10 min or less is not particularly limited, and examples thereof include a method of adjusting the polymerization temperature and polymerization pressure when producing the olefin polymer (C), and a method of adjusting the molar ratio of the concentration of a monomer such as ethylene or an α-olefin to the concentration of hydrogen in the polymerization system.

[0113] The olefin polymer (C) may be, for example, an olefin polymer rubber made of an olefin other than polypropylene.

[0114] The torsional rigidity of the olefin polymer (C) is preferably 1 MPa or more and 30 MPa or less, more preferably 1 MPa or more and 25 MPa or less, from the viewpoint of imparting sufficient impact resistance to the composition. The torsional rigidity of the olefin polymer (C) can be measured in accordance with ASTM D1043.

[0115] From the viewpoint of imparting sufficient impact resistance to the composition, the Shore A of the olefin polymer (C) is preferably from 30 to 110, more preferably from 40 to 100, and even more preferably from 50 to 90. The Shore A of the olefin polymer (C) can be measured in accordance with JIS K6253.

[0116] The method for preparing the olefin polymer (C) is not particularly limited, and examples thereof include a method using a catalyst (e.g., a titanium-, metallocene-, or vanadium-based catalyst) that can easily produce a highly molecular weight α-olefin polymer under commonly used processing conditions. Among these, methods using a metallocene catalyst and a titanium chloride catalyst are preferred from the viewpoint of stability of structure control. The known methods described in JP-A-6-306121 and JP-A-7-500622 can be used to produce ethylene-α-olefin copolymers.

[0117] [Content of olefin polymer (C)] In the resin composition of this embodiment, when the total amount of the polyphenylene ether (A), the styrene-based elastomer (B), and the olefin-based polymer (C) is taken as 100 parts by mass, the amount of the olefin-based polymer (C) is preferably 1.0 part by mass or more and 30.0 parts by mass or less, more preferably 3.0 parts by mass or more and 20.0 parts by mass or less, and even more preferably 4.0 parts by mass or more and 10.0 parts by mass or less. By setting the content of the olefin-based polymer (C) to 1.0 part by mass or more, a molded article with excellent chemical resistance and impact resistance can be obtained. On the other hand, by setting the amount of the olefin-based polymer (C) to 30.0 parts by mass or less, a decrease in the elastic modulus can be suppressed, and a molded article with the rigidity required for a housing can be obtained.

[0118] (Flame retardant (D)) The thermoplastic resin composition may further contain a flame retardant (D) in addition to the polyphenylene ether resin (A), the styrene elastomer (B), and the olefin polymer (C).

[0119] The flame retardant (D) is not particularly limited, and examples thereof include phosphate ester flame retardants, phosphinic acid flame retardants, aromatic halogen flame retardants, and silicone flame retardants.

[0120] The phosphate ester flame retardant is not particularly limited, and may be any phosphate ester compound (phosphate ester compound, condensed phosphate ester compound, etc.) having the effect of improving the flame retardancy of a resin composition, such as triphenyl phosphate, phenyl bis dodecyl phosphate, phenyl bis neopentyl phosphate, phenyl-bis(3,5,5'-trimethyl-hexyl phosphate), ethyl diphenyl phosphate, 2-ethyl-hexyl di(p-tolyl) phosphate, bis-(2-ethylhexyl)-p-tolyl phosphate, tritolyl phosphate, bis-(2-ethylhexyl)phenyl phosphate, tri-(nonylphenyl) phosphate, di(dodecyl) phosphate, bis(2-ethylhexyl)phenyl phosphate, tri-(nonylphenyl) phosphate, Examples of suitable phosphates include bisphenol A bis(diphenyl phosphate), diphenyl-(3-hydroxyphenyl)phosphate, bisphenol A bis(dicresyl phosphate), resorcinol bis(diphenyl phosphate), resorcinol bis(dixylenyl phosphate), 2-naphthyl diphenyl phosphate, 1-naphthyl diphenyl phosphate, and di(2-naphthyl)phenyl phosphate. Other examples include the phosphate ester compounds described in Patent Document 1.

[0121] In the resin composition of this embodiment, when the total amount of the polyphenylene ether (A), the styrene-based elastomer (B), and the olefin-based polymer (C) is 100 parts by mass, the amount of the flame retardant (D) is preferably 1.0 part by mass or more and 50.0 parts by mass or less, more preferably 5.0 parts by mass or more and 40.0 parts by mass or less, and even more preferably 10.0 parts by mass or more and 30.0 parts by mass or less. By setting the content of the flame retardant (D) to 1.0 part by mass or more, a molded article with excellent flame retardancy can be obtained. On the other hand, by setting the amount of the flame retardant to 50.0 parts by mass or less, a molded article with excellent impact resistance and chemical resistance can be obtained.

[0122] [Other additives (E)] The thermoplastic resin composition of this embodiment may contain other additives (E) commonly used in resin compositions, provided that the effects of the molded article of this embodiment are not impaired. Examples of other additives (E) include thermoplastic resins other than polyphenylene ether (A), styrene-based elastomer (B) block copolymers of vinyl aromatic compounds and conjugated diene compounds, fillers, antioxidants, metal deactivators, heat stabilizers, fluorine-based polymers, plasticizers (e.g., low-molecular-weight polyethylene, epoxidized soybean oil, polyethylene glycol, fatty acid esters), weather resistance improvers, light resistance improvers, nucleating agents for polyolefins, slip agents, colorants, mold release agents, and flame retardant aids.

[0123] Examples of fillers include glass fibers, carbon fibers, calcium silicate fibers, potassium titanate fibers, aluminum borate fibers, glass flakes, calcium carbonate, talc, kaolin, mica, hydrotalcite, zinc carbonate, calcium hydrogen phosphate, wollastonite, zeolite, boehmite, magnesium oxide, calcium silicate, sodium aluminosilicate, magnesium silicate, ketjen black, acetylene black, furnace black, carbon nanotubes, graphite, brass, copper, silver, aluminum, nickel, iron, calcium fluoride, montmorillonite, swellable fluoromica, apatite, and milled fibers.

[0124] The colorant may be either an inorganic material or an organic material. Examples of colorants include carbon black (acetylene black, lamp black, thermal black, furnace black, channel black, ketjen black, gas black, oil black, etc.), graphite, titanium black, black iron oxide, etc. Among these, carbon black is preferred in terms of dispersibility, color development, cost, etc.

[0125] Non-black pigments include various inorganic pigments and organic pigments described below.

[0126] Examples of inorganic pigments include white pigments such as calcium carbonate, titanium oxide, zinc oxide, and zinc sulfide; yellow pigments such as cadmium yellow, yellow lead, titanium yellow, zinc chromate, yellow ochre, and yellow iron oxide; red pigments such as red pigments, umber, red iron oxide, and cadmium red; blue pigments such as iron blue, ultramarine, and cobalt blue; and green pigments such as chrome green.

[0127] Examples of organic pigments include azo pigments, azomethine pigments, methine pigments, indanthrone pigments, anthraquinone pigments, pyranthrone pigments, flavanthrone pigments, benzenethrone pigments, phthalocyanine pigments, quinophthalone pigments, perylene pigments, perinone pigments, dioxazine pigments, thioindigo pigments, isoindolinone pigments, isoindoline pigments, pyrrulepyrrole pigments, and quinacridone pigments.

[0128] (Method of producing resin composition) The resin composition of the present embodiment can be produced by melt-kneading the above-mentioned polyphenylene ether (A), styrene-based elastomer (B), olefin-based polymer (C), and, if necessary, flame retardant (D) and other additives (E).

[0129] A preferred method for producing the resin composition of the present embodiment is a production method including the following steps (1-1) and (1-2). (1-1): A step of melt-kneading polyphenylene ether (A) and styrene-based elastomer (B) to obtain a kneaded mixture. (1-2): A step of adding the styrene-based elastomer (B), the olefin-based polymer (C), and, if necessary, the flame retardant (D) and other additives (E) to the kneaded product obtained in the step (1-1), and melt-kneading the mixture.

[0130] In step (1-1), the polyphenylene ether (A) may be added in its entirety or in part. The styrene-based elastomer (B) may be added in its entirety or in part. Among these, step (1-1) is preferably a step in which the entire polyphenylene ether (A) and, if necessary, the entire or part styrene-based elastomer (B) are melt-kneaded to obtain a kneaded mixture.

[0131] In step (1-2), the styrene elastomer (B), the olefin polymer (C), and, if necessary, the flame retardant (D) and other additives (E) may be added in their entirety or in part. When a portion of them is added in step (1-2), the styrene elastomer (B), the olefin polymer (C), and, if necessary, the flame retardant (D) and other additives (E) may be added in their entirety in steps (1-1) and (1-2). Step (1-2) is preferably a step in which the entirety of the styrene elastomer (B), the olefin polymer (C), and, if necessary, the flame retardant (D) and other additives (E) is added to the kneaded product obtained in step (1-1), and the mixture is melt-kneaded. In this production method, by adding the styrene elastomer (B), the olefin polymer (C), and, if necessary, the flame retardant (D) and other additives (E) in step (1-2) during melt-kneading (particularly by adding the entire amounts of the styrene elastomer (B), the olefin polymer (C), and, if necessary, the flame retardant (D) in step (1-2)), the styrene elastomer (B), the olefin polymer (C), and, if necessary, the flame retardant (D) are efficiently dispersed in the polyphenylene ether (A), and a resin composition having even more excellent chemical resistance and impact resistance can be obtained.

[0132] The melt kneader suitably used for melt-kneading each component in the method for producing the resin composition of this embodiment is not particularly limited, and examples thereof include extruders such as single-screw extruders and multi-screw extruders such as twin-screw extruders, rolls, kneaders, Brabender plastographs, Banbury mixers, and the like, but from the viewpoint of kneading properties, twin-screw extruders are particularly preferred. Specific examples of twin-screw extruders include the ZSK series manufactured by Coperion, the TEM series manufactured by Toshiba Machine Co., Ltd., and the TEX series manufactured by The Japan Steel Works, Ltd. The type and specifications of the extruder are not particularly limited, and may be known.

[0133] Hereinafter, preferred embodiments will be described in which an extruder such as a single-screw extruder or a multi-screw extruder such as a twin-screw extruder is used.

[0134] The L / D (effective barrel length / inner barrel diameter) of the extruder is preferably 20 or more, more preferably 30 or more, and is preferably 75 or less, more preferably 60 or less.

[0135] The configuration of the extruder is not particularly limited, and for example, the extruder can include a first raw material supply port on the upstream side in the direction in which the raw materials flow, a first vacuum vent downstream of the first raw material supply port, a second raw material supply port downstream of the first vacuum vent, a first liquid addition pump downstream of the second raw material supply port, a second vacuum vent downstream of the first liquid addition pump, and a second liquid addition pump downstream of the second vacuum vent.

[0136] The method for supplying the raw material through the second raw material supply port is not particularly limited, and may involve simply adding the raw material through the upper opening of the raw material supply port, or adding the raw material through the side opening using a forced side feeder. In particular, from the viewpoint of stable supply, adding the raw material through the side opening using a forced side feeder is preferred.

[0137] The melt-kneading temperature is not particularly limited, and is, for example, 200°C or higher and 370°C or lower.

[0138] The screw rotation speed during melt-kneading is not particularly limited, and is, for example, 100 rpm or more and 1200 rpm or less.

[0139] When adding a liquid raw material, the liquid raw material can be added by directly feeding the liquid raw material into the cylinder system using a liquid addition pump or the like in the extruder cylinder part. The liquid addition pump is not particularly limited, and examples thereof include a gear pump and a flange-type pump, with a gear pump being preferred. In this case, from the viewpoint of reducing the load on the liquid addition pump and improving the operability of the raw material, it is preferable to heat the parts that serve as the flow path for the liquid raw material, such as a tank for storing the liquid raw material, the piping between the tank and the liquid addition pump, and the piping between the pump and the extruder cylinder, using a heater or the like to reduce the viscosity of the liquid raw material.

[0140] The molded product in this embodiment may be a single product, or may be a combination of multiple molded products such as a case and a cover. The molded product may be either a closed type or an open type, but when used with components housed inside, a closed type is preferable.

[0141] The shape of the contact area between the case and cover in a sealed type is not particularly limited, and it may be a flat surface or an interlocking type with a thin-walled portion (also called a "rib") inserted. Furthermore, the sealability may be improved by fitting an O-ring to the contact area, or by joining the case and cover with adhesive, laser welding, ultrasonic welding, or infrared welding.

[0142] The shape of the molded article is not particularly limited, and may be, for example, a box shape, a polygonal prism shape, a cylinder shape, a sphere shape, or a combination of these shapes.

[0143] The size of the molded product is not particularly limited, but the sum of the length, width, and height of the smallest rectangular prism that can accommodate the molded product is preferably 100 mm or more, more preferably 200 mm or more, even more preferably 300 mm or more, even more preferably 400 mm or more, and most preferably 500 mm or more.

[0144] As the molded product becomes larger, the distance from the gate to the end of the flow becomes longer, and the shear strain generated in the resin increases due to the decrease in resin temperature during molding, resulting in a more favorable morphology and improved chemical resistance.

[0145] The thickness of the thickest part of the molded article is preferably 0.5 mm or more and 10 mm or less, more preferably 1 mm or more and 8 mm or less, and even more preferably 2 mm or more and 6 mm or less.

[0146] If the molded product has corners, the maximum thickness is the distance between the outer surface and the inner surface at the point where the distance is greatest (for example, thickness 3 of the thick portion in FIG. 2).

[0147] By ensuring that the maximum thickness of the molded article is within the above range, strong shear strain is generated in the resin during injection molding, making it possible to achieve a more desirable morphology and further improving chemical resistance.

[0148] The molded product may have a fitting portion for attaching it to another device or combining an additional part. The fitting method is not particularly limited, but examples thereof include snap fitting and sliding fitting.

[0149] The shape of the parts that slide to fit together is not particularly limited, but by providing a plurality of thin-walled parts 2 as shown in Fig. 1, they can be aligned and assembled by sliding in the desired direction. In a method of providing thin-walled parts in this way, the thickness of the thin-walled parts is preferably 0.5 mm to 10 mm, more preferably 1 mm to 10 mm, more preferably 1 mm to 8 mm, and even more preferably 2 mm to 6 mm, from the viewpoint of chemical resistance.

[0150] When a molded product is produced by injection molding, the type of gate may be, for example, a film gate, a side gate, a pin gate, a submarine gate, etc. Preferred gates are the side gate and the pin gate.

[0151] When a side gate is selected, the cross-sectional area of ​​the gate is not particularly limited. The cross-sectional area of ​​the gate is preferably, for example, 0.1 to 5 times the cross-sectional area of ​​the runner. The cross-sectional area of ​​the gate is more preferably 3 times or less, even more preferably 2 times or less, and particularly preferably 1 time or less, the cross-sectional area of ​​the runner.

[0152] The molded product of this embodiment may have a thin-walled portion (rib structure). In the molded product, the thin-walled portion (rib structure) can (1) function as a guide, (2) limit the insertion direction, or (3) determine the insertion direction when the molded product is attached to another device or when additional parts are combined. In addition, the thin-walled portion (rib structure) in the molded product can also reinforce other thin-walled portions of the molded product.

[0153] It is generally known that when resin molded products are produced by injection molding, strong shear strain increases molding distortion and reduces chemical resistance. See, for example, Chapter 11, "Chemical Resistance," in the "Modified PPE Resin Zylon Handbook," published by Asahi Kasei Corporation. In contrast, the molded product of this embodiment can be suitably applied to gate types, which have a shape that generates strong shear strain.

[0154] Although the application of the present invention is not particularly limited, a case for a secondary battery is suitable due to its high chemical resistance and excellent impact resistance. For portable secondary batteries, which are carried and used in various environments, a molded article having excellent impact resistance and chemical resistance is particularly useful.

[0155] When the molded article of the present invention is used as a case for a secondary battery, the weight of the secondary battery is, for example, 300 g or more, preferably 500 g or more, more preferably 1 kg or more, even more preferably 2 kg or more, and still more preferably 3 kg or more. The weight of the secondary battery is, for example, 30 kg or less, preferably 15 kg or less.

[0156] In this specification, the term "secondary battery" refers to a secondary battery product (finished product) that includes a secondary battery casing (a molded article in this embodiment) and necessary components such as a battery cell and a circuit board, and is also called a secondary battery module. In this specification, the term "portable secondary battery" refers to a secondary battery that is typically carried or used while being carried.

[0157] In one embodiment, the molded article is a casing for a portable secondary battery. In another embodiment, the molded article is a casing for a portable secondary battery, and the portable secondary battery weighs 200 g or more.

[0158] In one embodiment, the molded article is a housing for a portable secondary battery, and has a thin-walled portion at a portion where the portable secondary battery is attached to a device that uses the portable secondary battery, such as an automobile, an electric vehicle, a hybrid electric vehicle, an electrically assisted bicycle, an e-bike, or a wheelchair.

[0159] The molded article is not particularly limited, and examples thereof include automobile parts, interior and exterior parts of electrical equipment, and other parts.

[0160] Examples of automotive parts include, but are not limited to, exterior parts such as bumpers, fenders, door panels, various moldings, emblems, engine hoods, wheel caps, roofs, spoilers, and various aero parts; interior parts such as instrument panels, console boxes, and trim; secondary battery case parts mounted on automobiles, electric vehicles, hybrid electric vehicles, electrically assisted bicycles, E-bikes, wheelchairs, and the like; lithium ion secondary battery parts and their casings; and the like.

[0161] The interior and exterior parts of electrical equipment are not particularly limited, and examples thereof include parts used in cabinets and chassis of various computers and their peripheral devices, junction boxes, various connectors, other office automation equipment, televisions, videos, various disc players, etc., refrigerators, vacuum cleaners, air conditioners, cordless cleaners, liquid crystal projectors, electric machine tools, secondary battery housings, and secondary battery charger housings.

[0162] Other parts include electric wires and cables obtained by applying a coating to metal conductors or optical fibers, fuel cases for solid methanol batteries, fuel cell water pipes, water cooling tanks, boiler exterior cases, ink-related parts and components for inkjet printers, furniture (chairs, etc.), chassis, water pipes, and joints.

[0163] Although the flame retardancy of the thermoplastic resin constituting the present invention is not particularly limited, from the viewpoint of safety, it is preferable that the molded article be made of a resin having flame retardancy. More specifically, it is preferable that the flame retardancy be V-2 or higher, more preferably V-1 or higher, in the UL94 flammability test established by Underwriters Laboratories Limited Liability Company (hereinafter referred to as UL).

[0164] (Method of manufacturing molded products) A molded article can be produced by molding the resin composition of this embodiment. The method for producing the molded article is not particularly limited, and examples thereof include injection molding, extrusion molding, extrusion profile molding, blow molding, and compression molding. In order to more effectively obtain the effects of the present invention, injection molding is preferred. In order to achieve the morphology of this embodiment, a higher injection pressure is preferred during injection molding. In particular, it is preferred to use a high molecular weight styrene-based elastomer for the island component and to mold the elastomer at a high injection pressure.

[0165] The injection speed in injection molding is preferably, for example, 5 mm / sec or more and 200 mm / sec or less, and more preferably 10 mm / sec or more and 150 mm / sec or less.

[0166] A preferred injection rate for injection molding is, for example, 100 mm 3 / sec or more 500000mm 3 / sec or less, and 10000mm 3 / sec or more 70000mm 3 / sec or less is more preferable.

[0167] The mold temperature for injection molding is preferably, for example, 20°C or higher and 150°C or lower, and more preferably 50°C or higher and 100°C or lower.

[0168] The preferred cylinder temperature for injection molding (particularly the front and middle portions) is 200°C or higher and 400°C or lower. The cylinder temperature for the front portion is more preferably 270°C or higher and 350°C or lower. The cylinder temperature for the middle portion is more preferably 260°C or higher and 340°C or lower.

[0169] The peak injection pressure of the injection molding is preferably 20 MPa or more and 200 MPa or less, and more preferably 60 MPa or more and 180 MPa or less. [Example]

[0170] The present invention will be described in detail below with reference to specific examples and comparative examples, but the present invention is not limited to the following examples.

[0171] Polyphenylene ether (A) The reduced viscosity (η sp / c: 0.5g / dL chloroform solution) 0.51dL / g polyphenylene ether

[0172] Styrene-based elastomer (B) (B-1) SEBS: TSRC, product name "TAIPOL6151" (styrene unit ratio of all constituent monomer units: 32% by mass, mass average molecular weight: 260,000)

[0173] (B-2) An unmodified block copolymer was synthesized using polystyrene as polymer block A and polybutadiene as polymer block B. The physical properties of the resulting block copolymer are shown below. The polystyrene content was measured using an ultraviolet spectrophotometer. The number average molecular weight (Mn) and molecular weight peak were determined using GPC (mobile phase: chloroform, standard: polystyrene). The molecular weight distribution (Mw / Mn) was calculated by dividing the weight average molecular weight (Mw) determined by a conventional method using GPC (mobile phase: chloroform, standard: polystyrene) by the above-mentioned number average molecular weight (Mn). The total vinyl bond content was measured using an infrared spectrophotometer and calculated according to the method described in Analytical Chemistry, Volume 21, No. 8, August 1949. The hydrogenation rate was measured using a nuclear magnetic resonance (NMR) spectrometer. The mixing ratio was determined from the peak area ratio during GPC measurement. (B-2) is a mixture of (B-2-1) and (B-2-2) shown below (mixing ratio (B-2-1):(B-2-2)=30:70). (B-2-1): Polystyrene content in block copolymer before hydrogenation: 30% by mass, molecular weight peak of block copolymer after hydrogenation: 125,000, number average molecular weight (Mn) of polystyrene block: 18,750, number average molecular weight (Mn) of polybutadiene block: 87,500, molecular weight distribution (Mw / Mn) of block copolymer before hydrogenation: 1.10, total of 1,2-vinyl bonds and 3,4-vinyl bonds relative to double bonds in polybutadiene units: 40%, hydrogenation rate of polybutadiene moieties constituting polybutadiene block: 35%, glass transition temperature of polybutadiene block after hydrogenation: -80°C. (B-2-2): Polystyrene content in block copolymer before hydrogenation: 30% by mass, molecular weight peak of block copolymer after hydrogenation: 65,000, number average molecular weight (Mn) of polystyrene block: 19,500, number average molecular weight (Mn) of polybutadiene block: 45,500, molecular weight distribution (Mw / Mn) of block copolymer before hydrogenation: 1.10, total of 1,2-vinyl bonds and 3,4-vinyl bonds relative to double bonds in polybutadiene units: 40%, hydrogenation rate of polybutadiene moieties constituting polybutadiene block: 35%, glass transition temperature of polybutadiene block after hydrogenation: -80°C.

[0174] (B-3) Polystyrene content in block copolymer before hydrogenation: 30% by mass, molecular weight peak of block copolymer after hydrogenation: 53,000, number average molecular weight (Mn) of polystyrene block: 8,000, number average molecular weight (Mn) of polybutadiene block: 37,000, molecular weight distribution (Mw / Mn) of block copolymer before hydrogenation: 1.10, 1,2-vinyl bond content (total vinyl bond content) in polybutadiene block before hydrogenation: 40%, hydrogenation rate relative to the polybutadiene portion constituting the polybutadiene block: 35%, glass transition temperature of polybutadiene block after hydrogenation: -80°C.

[0175] (B-4) An unmodified block copolymer was synthesized using polystyrene as polymer block A and polybutadiene as polymer block B. The physical properties of the resulting block copolymer are shown below. A block copolymer having a BABA block structure was synthesized by a known method, with polymer block A consisting of polystyrene and polymer block B consisting of polybutadiene. The synthesized block copolymer was hydrogenated by a known method. The polymer was not modified. The physical properties of the resulting unmodified hydrogenated block copolymer are shown below. Polystyrene content in the block copolymer before hydrogenation: 44% by mass; number average molecular weight (Mn) of the block copolymer after hydrogenation: 95,000; number average molecular weight (Mn) of the polystyrene block: 41,800; number average molecular weight (Mn) of the polybutadiene block: 53,200; molecular weight distribution (Mw / Mn) of the block copolymer before hydrogenation: 1.06; total of 1,2-vinyl bonds and 3,4-vinyl bonds relative to double bonds in the polybutadiene unit: 75%; hydrogenation rate relative to the polybutadiene portion constituting the polybutadiene block: 99%; glass transition temperature of the polybutadiene block after hydrogenation: -15°C.

[0176] (B-5) SEBS: TSRC, product name "TAIPOL6152" (styrene unit ratio of all constituent monomer units: 27% by mass, mass average molecular weight: 70,000)

[0177] [Olefin polymer (C)] (C-1) Ethylene-butene copolymer Product name: "Tafmer DF640" Mitsui Chemicals, Inc., MFR: 3.6 g / 10 min (measurement method: ASTM D1238, measurement conditions: 190°C, 2.16 kgf), brittle temperature (measurement method: ASTM D746): less than -70°C, density (measurement method: ASTM D1505): 0.864 g / cm 3 (C-2) Ethylene-butene copolymer Product name: "Tafmer DF610" Mitsui Chemicals, MFR: 1.2 g / 10 min (measurement method: ASTM D1238, measurement conditions: 190 °C, 2.16 kgf), brittle temperature (measurement method: ASTM D746): less than -70 °C, density (measurement method: ASTM D1505): 0.862 g / cm3 (C-3) Propylene homopolymer (melting point: 165°C, MFR: 0.4g / 10min (measurement method: ASTM D1238, measurement conditions: 230°C, 2.16kgf))

[0178] Flame retardant (D) (D-1) Phosphate ester flame retardant Product name "E890" Daihachi Chemical Industry Co., Ltd. (D-2) Phosphinates Product name: "Exolit OP1230" Clariant Japan

[0179] Other additives (E) Nippon Talc Co., Ltd., product name "Talc MS" (average particle size (D50) measured by laser diffraction method = 14 μm)

[0180] [Manufacturing Examples 1 to 10] Samples of each resin composition containing each component according to the formulations in Table 1 were prepared.

[0181] A twin-screw extruder (ZSK-25, manufactured by Coperion) was used as a melt kneader for producing pellets of the resin composition. The L / D of the extruder was set to 35.

[0182] The twin-screw extruder was configured to include a first raw material supply port on the upstream side in the direction in which the raw materials flow, a first vacuum vent downstream of the first raw material supply port, a second raw material supply port downstream of the first vacuum vent, a liquid addition pump downstream of the second raw material supply port, and a second vacuum vent downstream of the liquid addition pump.

[0183] The twin-screw extruder was configured to include a first raw material supply port on the upstream side in the direction in which the raw materials flow, a first vacuum vent downstream of the first raw material supply port, a second raw material supply port downstream of the first vacuum vent, a liquid addition pump downstream of the second raw material supply port, and a second vacuum vent downstream of the liquid addition pump.

[0184] The barrel temperature of the twin-screw extruder was set to 320°C from the first raw material supply port to the first vacuum vent, and 280°C downstream of the second raw material supply port, and pellets of the resin composition were produced under the conditions of a screw rotation speed of 300 rpm and an extrusion rate of 15 kg / h. The configuration of the twin-screw extruder is shown in Figure 4.

[0185] [Table 1]

[0186] C1 to C12 in Fig. 4 represent the cylinder blocks of the extruder. By exchanging the cylinder blocks, it is possible to provide a raw material supply port, a vacuum vent, and a liquid addition pump connection port at any cylinder position.

[0187] (Examples 1 to 21, Comparative Examples 1 to 13) The resin compositions of Production Examples 1 to 10 were injection molded under the conditions described below and shown in Tables 2 to 4 to obtain molded articles.

[0188] (1) Analysis of sea-island structure (1-1) Preparation of test specimens The resin composition pellets obtained in the Production Example were dried for 2 hours at 100°C. A 120mm x 80mm x 3mm flat plate (reference numeral 30 in Figures 5A and 5B) was produced from the dried resin composition pellets using an injection molding machine (model: SE180EV (cylinder diameter: 36mm) manufactured by Sumitomo Heavy Industries, Ltd.) The gate (reference numeral 50 in Figures 5A and 5B) was a 5mm wide side gate. The molding conditions (cylinder temperature, mold temperature, injection rate (molding speed), peak pressure up to the switching position, and holding pressure) were adjusted to create several types of test pieces. The samples created are summarized in Tables 2 to 4 for each molding condition. Two types of test pieces (test piece 40 in Figure 5A and test piece 41 in Figure 5B) were cut out from this flat plate. Test piece 1 (hereinafter referred to as "TD direction test piece"): A rectangular piece (80 mm × 12.5 mm × 3 mm, reference numeral 40 in Figure 5A) was cut from the center of the flat plate so that its longitudinal direction was perpendicular to the flow direction (the direction of reference numeral 60 in Figure 5A). Test piece 2 (hereinafter referred to as "MD test piece"): A rectangular piece (80 mm × 12.5 mm × 3 mm, reference numeral 41 in Figure 5B) was cut from the center of the flat plate so that the longitudinal direction was parallel to the flow direction (the direction of reference numeral 60 in Figure 5B).

[0189] (1-2) Observation image acquisition Small pieces (small pieces 70 and 71) measuring 12.5 mm × 12.5 mm × 3 mm were cut from the center of the TD test specimen (specimen 40 in Figure 6A) and MD test specimen (specimen 41 in Figure 6B) prepared in (1-1). The surfaces to be observed were then cryo-cut using a cryomicrotome. The small pieces cut from the surfaces to be observed were then placed in a sealed container with ruthenium tetroxide (RuO4) for 5 minutes, and stained by exposure to the sublimating ruthenium. SEM images were acquired from the samples prepared in this way. The observation area was a region 3 μm from the surface of the center of the gate side at a magnification of 30,000x and an accelerating voltage of 1.0 kV. Images of 2560 × 1920 pixels were obtained in BMP file format. As examples of the observation images, the TD test specimen and MD test specimen of Example 11 are shown in Figures 7 and 8, respectively. 9 and 10 show the observed images of the TD and MD test pieces of Comparative Example 3, respectively.

[0190] (1-3) Calculating the aspect ratio The images acquired in (1-2) were analyzed using Python and the open-source library "OpenCV." The analysis program is shown in Figures 11A and 11B. The image analysis procedure is as follows: steps 1 to 7. Step 1: The imaging information and scale at the bottom of the retrieved image (for example, Figures 7 to 10) were trimmed. Step 2: The image from step 1 was grayscaled and converted to monochrome. Step 3: The image from step 2 was subjected to a "Bilateral Filter" to reduce noise in the image. Step 4: The image from step 3 was binarized. The threshold value for the binarization was determined using the Otsu binarization algorithm. Step 5: The sea-island structure was determined using the "findContours" function for the image from step 4. At this time, the settings for the "findContours" function were set to mode: "RETR_TREE" and method: "CHAIN_APPROX_SIMPLE". Step 6: In the image from Step 5, each island portion I was covered with a rectangle of the smallest size, and the aspect ratio was calculated from the long side / short side of the circumscribing rectangle. In this process, island components with an area of ​​300 pixels or less were excluded from the calculation to remove noise. Step 7: Steps 1 to 6 were performed on three observation samples cut out from three TD test pieces or three MD test pieces formed under the same molding conditions, and the aspect ratio of the island portion I was calculated.

[0191] (1-4) Calculating the area of ​​the island The area of ​​the island was calculated using the following procedure. When determining the sea-island structure in step 5 of Step 1:(1-3), the number of pixels in the area that constitutes the island portion I (hereinafter referred to as "S") was also calculated using the "findContours" function in "OpenCV." Step 2: The pixels that make up the island part I, which is usually irregular in shape, are rearranged into a square to make it easier to calculate the area. 1 / 2 It was converted into a square and treated. Step 3: Using the scale displayed on the image, the length of one side of one pixel (square) (= P) was determined. Specifically, a 1 μm scale was displayed at the bottom of the SEM image, the number of pixels equivalent to 1 μm was calculated, and the length of one side of one pixel, P (μm), was calculated. Step 4: The area of ​​the square created in Step 2, i.e., the specific island portion I, was calculated using the following formula. Formula: Area of ​​island I (μm 2 )=(S 1 / 2 ×P) 2

[0192] (1-5) Specific aspect ratio Based on the results of (1-3), the following classification was made: N: total number of island parts I n1: Total number of island parts I with aspect ratios greater than 1.95 and less than or equal to 2.25 n2: Total number of island parts I with aspect ratio of 1.35 or less n3: Total number of island parts I with aspect ratios greater than 1.65 and less than or equal to 1.95

[0193] Using the obtained N, n1, n2, and n3, the ratio A, ratio B, and ratio C were calculated as follows. Percentage A (%): (n1 / N) x 100 Percentage B (%): (n2 / N) x 100 Ratio C(%):(n3 / N)×100 was calculated.

[0194] From the obtained ratio A and ratio B, "ratio A / ratio B" was calculated.

[0195] A histogram was created for the aspect ratios obtained from (1-3) in increments of 0.10, and the most frequent aspect ratio of island I was determined from the histogram.

[0196] The average area of ​​the island part I (unit: μm) was calculated using the programs shown in FIGS. 11A and 11B for the area obtained in (1-4). 2 ) was calculated.

[0197] [evaluation] Test pieces were molded as described below using pellets of the resin compositions of the Examples and Comparative Examples. The test pieces were then subjected to the following tests and measurements to evaluate their impact resistance and chemical resistance. However, for Comparative Example 7, surface peeling occurred after molding, so impact resistance and chemical resistance were not evaluated.

[0198] (1) Charpy impact test The obtained resin composition pellets were dried at 100°C for 2 hours. Test specimens in accordance with ISO-15103 were prepared from the dried resin composition pellets using a Toshiba Machine Co., Ltd. EC75SXII injection molding machine (cylinder temperature set at 300°C, mold temperature set at 80°C). Next, in accordance with ISO-179, a notch was made in the center of the above test specimen to prepare a notched Charpy impact test specimen. The notched Charpy impact strength of the notched Charpy impact test specimen was measured in accordance with ISO179 1eA as an impact resistance evaluation.

[0199] (2) Puncture impact test The obtained resin composition pellets were dried for 2 hours at 100° C. A 60 mm × 60 mm × 2 mm flat plate (gate: 5 mm wide side gate) was produced from the dried resin composition pellets using an injection molding machine (model: SE50D) manufactured by Sumitomo Heavy Industries, Ltd., with a cylinder temperature set to 300° C. and a mold temperature set to 80° C. Using this flat plate, a puncture impact test was carried out in accordance with JIS K7211-2:2006 in a 23°C environment, and the energy at break (unit: J) was measured. The condition of the test piece after the test and the chart at the time of the test were also checked, and the behavior was selected from the following based on "3.10 Mechanical behavior of materials during impact breakage tests" in JIS K7211-2:2006. YD: Yielding caused by deep drawing (zero slope at maximum impact force). YS: Yielding (zero slope at maximum impact force) caused by a stable crack (at least partially). YU: Yielding caused by an unstable crack (slope is zero at maximum impact force). NY: Non-surrender behavior.

[0200] (3) Flexural modulus The obtained resin composition pellets were dried at 100°C for 2 hours. Test specimens in accordance with ISO-15103 were prepared from the dried resin composition pellets using an EC75SXII injection molding machine manufactured by Toshiba Machine Co., Ltd. (cylinder temperature set at 300°C, mold temperature set at 80°C). The flexural modulus of the obtained test specimens was then measured in accordance with ISO 178.

[0201] (4) Glossiness The obtained resin composition pellets were dried for 2 hours at 100° C. A 60 mm × 60 mm × 2 mm flat plate (gate: 5 mm wide side gate) was produced from the dried resin composition pellets in an injection molding machine (SE50D) with a cylinder temperature of 300° C. and a mold temperature of 80° C. The 60 degree gloss (%) of the central part of the obtained test piece was measured using a gloss meter (IG320 manufactured by HORIBA) in accordance with JIS-K7150.

[0202] (5) Chemical resistance test The test piece prepared in (1-1) is placed on the x-axis in the horizontal direction and the y-axis in the vertical direction. 2 The specimen was attached to the curved surface of a parabolic bending bar, which was expressed by the equation =6x(x≧0, y≧0), using a jig so that there was no gap between the bar and the specimen. The position of the bending bar on its vertical cross section where x=0, y=0 was the position of the measurement starting point end of the specimen, and the position where x>0 and y>0 was the position of the measurement terminal end of the specimen.

[0203] After attaching the test specimen to the bending bar as described above, petroleum benzine (Kanto Chemical Co., Ltd., standard: Grade 1) or CRC5-56 (Kure Industries Co., Ltd.) was applied to the surface of the test specimen and left at 23°C and 50% RH for 48 hours. If cracks appeared on the surface of the test specimen after 48 hours, the critical position at which the crack occurred (the position where the x value in the x-axis direction of the bending bar was the largest) was read. The critical position was read by transcribing the x-axis coordinate of the bending bar onto the test specimen while it was attached to the bending bar. After removing the test specimen from the bending bar, the presence of a crack of the specified size was confirmed and the position of the crack was read by comparing it with the transcribed scale (the critical position is the position corresponding to the x-axis coordinate of the bending bar, not the periphery length of the test specimen). The critical strain was then calculated from the test specimen thickness and the critical position at which the crack occurred using the following equation: (Critical strain) = d x 31 / 2 / {2×(3+50.8x) 3 / 2}×100 d: thickness of test piece (mm) x: Position along the x axis (mm) The calculated critical strains (%) are shown in Tables 2 to 4. In Tables 2 to 4, the upper critical strains show the results of tests using petroleum benzine, and the lower critical strains show the results of tests using CRC5-56.

[0204] The cracks are those that are 200 μm or larger and parallel to the short side of the test piece, and can be seen when observing the surface of the test piece using a microscope such as VHX-5000 (manufactured by Keyence Corporation).

[0205] (6) Flame retardancy Of the resin composition pellets obtained, only samples containing a flame retardant were subjected to flame retardancy evaluation. Ten test pieces (1.5 mm thick) for UL94 vertical flame test were prepared from the resin composition pellets to be evaluated using an injection molding machine (SE50D) with a cylinder temperature of 300°C and a mold temperature of 80°C. Flame retardancy was evaluated based on the UL94 vertical flame test method, and the samples were classified into flame retardancy classes of V-0, V-1, V-2, and HB based on the UL94 standard. The evaluation results are shown in Tables 3 and 4. In Tables 2 and 3, pellets not subject to evaluation are marked with "-" to indicate that they were not evaluated.

[0206] [Table 2]

[0207] [Table 3]

[0208] [Table 4] [Industrial Applicability]

[0209] According to the present invention, a molded article having excellent impact resistance and chemical resistance can be provided. [Explanation of symbols]

[0210] 1: Molded product 2: Thin-walled section 3: Thickness of the thickest part 10: Small piece 11, 12: Pieces obtained by dividing piece 10 into two equal pieces 13: Cut surface 14: Surface for observing the extension direction of the island part 20: Island part 30: Flat plate 40: TD direction test piece 41:MD direction test piece 50: Gate 60:Flow direction 70: Small piece for observation in TD direction test piece 71: Small piece for observation in MD direction test piece

Claims

1. A molded article made of a thermoplastic resin composition, The thermoplastic resin composition has an island-sea structure, In an SEM image obtained by observing a cross section of the molded product using a scanning electron microscope (SEM), The area of ​​the sea-island structure is 0.0008 μm ２ 0.08 μm or more ２ When the following island portion is designated as island portion I, the most frequent aspect ratio of island portion I is less than 1.90, A molded article, wherein the ratio of the number of island portions I having an aspect ratio of more than 1.95 and not more than 2.25 to the total number of island portions I is 17.0% or less.

2. 2. The molded product according to claim 1, wherein the ratio of the number of island portions I having an aspect ratio of 1.35 or less to the total number is 10.0% or more.

3. 3. The molded product according to claim 1, wherein the ratio of the number of island portions I having an aspect ratio of more than 1.65 and not more than 1.95 to the total number is 20.0% or less.

4. The observation range of the SEM image is within a range of 5 μm × 5 μm, and the average value of the area of ​​each island portion I of the sea-island structure obtained by contour extraction analysis of the image obtained by binarizing the SEM image is 0.1000 μm ２ 3. The molded article according to claim 1 or 2, wherein:

5. The molded article according to claim 1 , wherein the thermoplastic resin composition contains a polyphenylene ether resin (A), a styrene elastomer (B), and an olefin polymer (C).

6. The molded article according to claim 5 , wherein the styrene-based elastomer (B) comprises two types of styrene-based elastomers.

7. 6. The molded article according to claim 5, wherein the styrene-based elastomer (B) is at least one selected from the group consisting of hydrogenated block copolymers and modified products of the hydrogenated block copolymers.

8. The molded article according to claim 5, wherein the olefin polymer (C) is an olefin polymer other than polypropylene.

9. The molded article according to claim 5 , wherein the thermoplastic resin composition further contains a flame retardant (D).

10. The molded article according to claim 9, wherein the flame retardant (D) is a phosphate ester-based flame retardant.

11. 2. The molded product according to claim 1, wherein the thickness of the thickest part of the molded product is 6 mm or less.

12. The molded article according to claim 1 , which is a housing for a secondary battery.

13. 2. The molded article according to claim 1, which is a housing for a portable secondary battery, the portable secondary battery having a weight of 200 g or more.

14. 2. The molded article according to claim 1, which is a housing for a portable secondary battery and has a thin-walled portion at a portion where the portable secondary battery is attached to a device that uses the portable secondary battery.

15. The molded product according to claim 14, wherein the thin-walled portion has a thickness of 1 mm or more and 10 mm or less.

Images