Polycarbonate resin composition, process for its preparation, masterbatch pellets and molded articles

Abstract

A polycarbonate resin composition comprising: 50 to 90 mass% of polycarbonate resin (A); 2 to 30 mass% of acrylonitrile-butadiene-styrene copolymer resin (B); 5 to 40 mass% of at least one basic magnesium sulfate (C) selected from fibrous basic magnesium sulfate (C-1) and fan-shaped basic magnesium sulfate (C-2); 0.1 to 8 mass% of fatty acid metal salt (D); and 1 to 20 mass% of an elastomer (E).

Description

Technical area

[0001] The present invention relates to a polycarbonate resin composition, a process for its production, masterbatch pellets and a molded article. Background technology

[0002] Polycarbonate resins have excellent mechanical properties and thermal properties and are therefore widely used in various fields such as OA devices, electronic and electrical equipment, and automobiles. However, polycarbonate resin is difficult to process due to its high melt viscosity and, being a non-crystalline resin, has poor chemical resistance. Therefore, it is known to add a polyolefin resin to the polycarbonate resin to improve the chemical resistance of the polycarbonate resin. Many resin compositions have been proposed to which a compatibilizer, such as an elastomer or a filler, is added to improve the compatibility between the two components with different properties and to impart practical mechanical properties.

[0003] For example, JP 2000-7904 A discloses a method of adding a glass fiber as an inorganic filler to a resin composition containing a polycarbonate resin, a styrene-based resin, and a thermoplastic elastomer to obtain a molded article for OA equipment parts having excellent vibration-damping properties without impairing the properties of the polycarbonate-based resin.

[0004] Document CN 107722592 A describes a fiber-free, high-gloss, halogen-free, flame-retardant PC / ABS-reinforced composition suitable for hot stamping and a manufacturing process therefor, which belongs to the technical field of high polymer materials. The composition contains the following components in parts by weight: 50-80 parts PC resin, 5-15 parts ABS resin, 8-15 parts of a halogen-free phosphonolipid flame retardant, 5-20 parts magnesium sulfate, 1-4 parts of a compatibilizer, 2-5 parts of a toughener, 0.3-0.8 parts of an anti-drip agent, 0.3-0.8 parts of a lubricant, and 0.2-0.4 parts of an antioxidant. Brief description of the inventionTechnical problem

[0005] However, a molded article obtained by curing a polycarbonate resin composition containing glass fibers exhibits insufficient impact resistance. Furthermore, the commonly used glass fibers have a large fiber diameter, which can impair the external appearance of the molded article.

[0006] Therefore, fibrous basic magnesium sulfate has attracted attention as a filler that has a smaller fiber diameter than glass fibers, exhibits a reinforcing effect, and can impart an excellent external appearance to the molded article. Fibrous basic magnesium sulfate is a biosoluble and safe filler. However, fibrous basic magnesium sulfate is weakly basic, and if added to a polycarbonate resin that is weak to a base, the polycarbonate resin will be hydrolyzed. In this case, a problem arises in that even kneading is impossible.

[0007] Therefore, it is an object of the present invention to provide a polycarbonate resin composition which is kneadable and moldable without hydrolysis, has excellent processability, and can obtain a molded product having good mechanical properties and good appearance, a process for its production, masterbatch pellets, and a molded article. Solution to the problem

[0008] As a result of intensive studies to achieve the above object, the present inventors have found that even when fibrous basic magnesium sulfate is added to the polycarbonate resin, kneading is possible without hydrolysis of the polycarbonate resin and processability is also improved by containing an acrylonitrile-butadiene-styrene copolymer resin, a fatty acid metal salt, and an elastomer in predetermined ratios, thereby completing the present invention.

[0009] That is, the present invention relates to a polycarbonate resin composition comprising: 50 to 90 mass% of polycarbonate resin (A); 2 to 30 mass% of acrylonitrile-butadiene-styrene copolymer resin (B); 5 to 40 mass% of at least one basic magnesium sulfate (C) selected from fibrous basic magnesium sulfate (C-1) and fan-shaped basic magnesium sulfate (C-2); 0.1 to 8 mass% of fatty acid metal salt (D); and 1 to 20 mass% of an elastomer (E).

[0010] Furthermore, the present invention relates to a process for producing a polycarbonate resin composition, the process comprising: a first step of melt-kneading 2 to 50 mass % of acrylonitrile-butadiene-styrene copolymer resin (B), 40 to 70 mass % of at least one basic magnesium sulfate (C) selected from fibrous basic magnesium sulfate (C-1) and fan-shaped basic magnesium sulfate (C-2), 0.1 to 5 mass % of fatty acid metal salt (D), and 1 to 50 mass % of an elastomer (E) to obtain masterbatch pellets; and a second step of melt-kneading 10 to 60 mass % of the masterbatch pellets and 40 to 90 mass % of polycarbonate resin (A) to produce a polycarbonate resin composition.

[0011] Furthermore, the present invention provides masterbatch pellets for producing a polycarbonate resin composition by kneading with a diluent containing polycarbonate resin (A), the masterbatch pellets containing 2 to 50 mass% of acrylonitrile-butadiene-styrene copolymer resin (B), 40 to 70 mass% of at least one basic magnesium sulfate (C) selected from fibrous basic magnesium sulfate (C-1) and fan-shaped basic magnesium sulfate (C-2), 0.1 to 5 mass% of fatty acid metal salt (D), and 1 to 50 mass% of an elastomer (E).

[0012] Furthermore, the present invention relates to a molded article which is a product molded from the polycarbonate resin composition. Advantageous effects of the invention

[0013] The present invention provides a polycarbonate resin composition which is kneadable and moldable without hydrolysis, has excellent processability, and can obtain a molded article having good mechanical properties and good external appearance, a process for its production, masterbatch pellets, and a molded article. Description of Embodiments 1. Polycarbonate resin composition

[0014] The polycarbonate resin composition of the present invention contains: 50 to 90 mass % of polycarbonate resin (A); 2 to 30 mass % of acrylonitrile-butadiene-styrene copolymer resin (hereinafter also referred to as ABS resin) (B); 5 to 40 mass % of at least one basic magnesium sulfate (C) selected from fibrous basic magnesium sulfate (C-1) and fan-shaped basic magnesium sulfate (C-2); 0.1 to 8 mass % of at least one fatty acid metal salt (D); and 1 to 20 mass % of an elastomer (E).

[0015] The polycarbonate resin and ABS resin have an affinity, which is why they are mixed and dispersed. This is believed to be a factor that suppresses the hydrolysis of the polycarbonate resin. That is, in the polycarbonate resin composition of the present invention, an interface is created between the ABS resin and the basic magnesium sulfate, and an interfacial tension related to a mutual cohesive force is generated at the interface. The attractive force acts to fix the elastomer at the interface, thereby preventing direct contact of the basic magnesium sulfate with the polycarbonate resin. It is believed that the above result makes it possible to knead and mold the polycarbonate resin composition without causing hydrolysis of the polycarbonate resin. The individual components are described below. (A) Polycarbonate resin

[0016] The polycarbonate resin is not particularly limited, and aliphatic polycarbonate and aromatic polycarbonate, for example, can be used. Aromatic polycarbonate is preferred. A commercially available polycarbonate resin can be used, or a synthetic resin can be used as appropriate.

[0017] The method for synthesizing the polycarbonate resin is not particularly limited and can be suitably selected depending on the intended use. Examples include a method for synthesizing a dihydric phenol and a carbonate precursor by a solution method or a melt method. In addition, a molecular weight modifier, a branching agent, and a catalyst can be used as needed.

[0018] Beispiele für das zweiwertige Phenol sind Bisphenol A [2,2-Bis(4-hydroxyphenyl)propan], Hydrochinon, 2,2-Bis(4-hydroxyphenyl)pentan, 2,4'-Dihydroxydiphenylmethan, Bis(2-hydroxyphenyl)methan, Bis(4-hydroxyphenyl)methan, Bis(4-hydroxy-5-nitrophenyl)methan, 1,1-Bis(4-hydroxyphenyl)ethan, 3,3-Bis(4-hydroxydiphenyl)pentan, 2,2'-Dihydroxydiphenyl, 4,4'-Dihydroxydiphenyl, 2,6-Dihydroxynaphthalin, Bis(4-hydroxyphenyl)sulfon, Bis(3,5-diethyl-4-hydroxyphenyl)sulfon, 2,2-Bis(3,5-Dimethyl-4-hydroxyphenyl)propan, 2,4'-Dihydroxydiphenylsulfon, 5'-Chlor-2,4'-dihydroxydiphenylsulfon, Bis(4-hydroxyphenyl)diphenylether, 4,4'-Dihydroxy-3,3'-dichlorphenylether, 4,4'-Dihydroxy-2,5-dichlordiphenylether, Bis(4-dihydroxy-5-propylphenyl)methan, Bis(4-dihydroxy-2,6-dimethyl-3-methoxyphenyl)methan, 1,1-Bis(4-hydroxy-2-ethylphenyl)ethan, 2,2-Bis(3-phenyl-4-hydroxyphenyl)propan, Bis(4-hydroxyphenyl)cyclohexylmethan und 2,2-Bis(4-hydroxyphenyl)-1-phenylpropan.These can be used individually or in combinations of two or more. Among them, bis(4-hydroxyphenyl)alkane-based compounds are preferred, with bisphenol A being particularly preferred due to its easy commercial availability.

[0019] The carbonate precursor is not particularly limited and can be appropriately selected depending on the intended use. Examples include carbonyl halide, carbonate, and haloformate. Specific examples include phosgene, diphenyl carbonate, dihaloformate of dihydric phenol, and mixtures thereof.

[0020] The melt flow rate (MFR) of the polycarbonate resin can be appropriately selected depending on the intended use, but is preferably 2 to 25 g / 10 minutes, and more preferably 2 to 10 g / 10 minutes. When the melt flow rate of the polycarbonate resin is 2 g / 10 minutes or more, a polycarbonate resin composition with good molding processability can be obtained. Furthermore, when the melt flow rate is 25 g / 10 minutes or less, sufficient impact resistance can be imparted to the molded article.

[0021] The content of the polycarbonate resin is in the range of 50 to 90 mass%, preferably 55 to 75 mass%, based on the total amount of the polycarbonate resin composition. When the content of the polycarbonate resin is 50 mass% or more, a molded article with high impact resistance derived from the polycarbonate resin can be obtained. On the other hand, when the content of the polycarbonate resin is 90 mass% or less, a sufficient reinforcing effect can be achieved due to the filler, and a desired flexural modulus can be imparted to the molded article. (B) Acrylonitrile-butadiene-styrene copolymer resin (ABS resin)

[0022] ABS resin can be obtained by either a grafting process or a polymer blending process. The composition of ABS resin is not particularly limited and generally consists of approximately 5 to 50% acrylonitrile, 5 to 40% butadiene, and 95 to 50% styrene.

[0023] ABS resin can be used singly or in combination with two or more. The melt flow rate (MFR) of ABS resin can be appropriately selected depending on the intended use, but is preferably 5 to 60 g / 10 minutes, and more preferably 10 to 60 g / 10 minutes.

[0024] The content of the ABS resin is in the range of 2.0 to 30 mass%, preferably in the range of 2 to 25 mass%, and more preferably in the range of 5 to 20 mass%, based on the total amount of the polycarbonate resin composition. When the content of the ABS resin is 2.0 mass% or more, hydrolysis of the polycarbonate resin by basic magnesium sulfate can be suppressed. On the other hand, when the content of the ABS resin is 20 mass% or less, a molded article with the desired impact resistance can be obtained. Furthermore, from the viewpoint of suppressing hydrolysis of the polycarbonate resin, the ratio of ABS resin to basic magnesium sulfate (ABS resin / basic magnesium sulfate) is preferably 0.4 to 1.0. (C) Basic magnesium sulfate

[0025] Basic magnesium sulfate can be obtained by hydrothermal synthesis, for example, using magnesium hydroxide and magnesium sulfate extracted from seawater as raw materials. Either fibrous basic magnesium sulfate or fan-shaped basic magnesium sulfate can be used as the basic magnesium sulfate, although fibrous basic magnesium sulfate is particularly preferred. (C-1) Fibrous basic magnesium sulfate

[0026] The average major axis of the fibrous basic magnesium sulfate is generally in the range of 5 to 100 µm, preferably in the range of 10 to 60 µm. Furthermore, the average minor axis of the fibrous basic magnesium sulfate is generally in the range of 0.1 to 5.0 µm, preferably in the range of 0.2 to 2.0 µm, and more preferably in the range of 0.2 to 1.0 µm.

[0027] Typically, the glass fiber used as a filler has an average fiber diameter (average minor axis) of at least about 10 µm. Fibrous basic magnesium sulfate has a smaller average fiber diameter (average minor axis) than glass fibers and therefore has a smoother appearance.

[0028] The fibrous basic magnesium sulfate generally has an average aspect ratio (average major axis / average minor axis) of 2 or more, preferably 5 or more, and more preferably in the range of 5 to 80. The average major axis and average minor axis of fibrous basic magnesium sulfate can be calculated from the average values of the major axis and minor axis of 100 particles measured from a magnified image of a scanning electron microscope (SEM). Furthermore, the fibrous basic magnesium sulfate may be an aggregate or a conjugate of a plurality of fibrous particles. (C-2) Fan-shaped basic magnesium sulfate

[0029] Fan-shaped basic magnesium sulfate is a particle obtained by joining and bonding a portion of a plurality of fibrous basic magnesium sulfate particles into a fan shape. For example, the average particle length is 2 to 100 μm, the average particle width is 1 to 40 μm, and the average aspect ratio is approximately 1 to 100. The average particle length refers to the dimension in the longitudinal direction of the particles, and the average particle width refers to the maximum dimension in the short direction of the particles. The longitudinal direction of the particles is the direction in which the particle length is maximum, and the short direction of the particles is the direction orthogonal to the longitudinal direction. Furthermore, the average aspect ratio is defined as the average particle length / average particle width.

[0030] Each fibrous basic magnesium sulfate constituting the fan-shaped basic magnesium sulfate has an average fiber length of 2 to 100 µm, an average fiber diameter of 0.1 to 5 µm, and an average aspect ratio of 1 to 1000. For example, the plurality of fibrous basic magnesium sulfates are bundled at one end and expanded at the other end. Furthermore, the plurality of fibrous basic magnesium sulfates may be bundled at any position in the longitudinal direction and expanded at both ends. Such a fan-shaped basic magnesium sulfate can be produced and confirmed by the methods described, for example, in JP 4-36092 B and JP 6-99147 B.

[0031] Furthermore, the fan-shaped basic magnesium sulfate does not necessarily have to be in a state where individual fibrous basic magnesium sulfates are confirmed; in some cases, fibrous basic magnesium sulfates may be interconnected in the longitudinal direction. If the fibrous basic magnesium sulfate is confirmed to have the above shape and further having an average fiber length, average fiber diameter, and average aspect ratio within a predetermined range, it can be regarded as the fan-shaped basic magnesium sulfate used in the present invention.

[0032] The content of basic magnesium sulfate is in the range of 5 to 40 mass%, preferably in the range of 5 to 30 mass%, and more preferably in the range of 10 to 20 mass%, based on the total amount of the polycarbonate resin composition. When the content of basic magnesium sulfate is 5 mass% or more, the reinforcing effect of basic magnesium sulfate is exhibited and a desired flexural modulus can be imparted to the molded article. When the content of basic magnesium sulfate is 40 mass% or less, a polycarbonate resin composition with good processability can be obtained. (D) Fatty acid metal salts

[0033] The polycarbonate resin composition of the present invention contains a fatty acid metal salt, whereby basic magnesium sulfate is suitably distributed in the olefin polymer.

[0034] The fatty acid of the fatty acid metal salt preferably has a carbon atom number in the range of 12 to 22 and can be a saturated fatty acid or an unsaturated fatty acid. Examples of the saturated fatty acid are lauric acid, tridecylic acid, myristic acid, pentadecylic acid, palmitic acid, margaric acid, stearic acid, nonadecylic acid, arachidic acid, and behenic acid. Examples of the unsaturated fatty acid are myristoleic acid, palmitoleic acid, oleic acid, elaidic acid, vaccenic acid, gadoleic acid, and erucic acid. Examples of the metal salt are magnesium salt, calcium salt, aluminum salt, lithium salt, and zinc salt. Particularly preferred is at least one component selected from the group consisting of magnesium stearate, calcium stearate, and aluminum stearate.

[0035] The contents of the fatty acid metal salt are in the range of 0.1 to 8 mass%, preferably in the range of 0.1 to 7 mass%, more preferably in the range of 0.5 to 6 mass%, based on the total amount of the polycarbonate resin composition. When the contents of the fatty acid metal salt are 0.1 mass% or more, the effect of adding these compounds is exhibited. In contrast, when the contents of the fatty acid metal salt are 8 mass% or less, a polycarbonate resin composition with good thermal stability can be obtained. The polycarbonate resin composition contains a fatty acid metal salt. (E) Elastomer

[0036] A styrene-based thermoplastic elastomer is preferably used as the elastomer. The styrene-based thermoplastic elastomer is preferably a block copolymer represented by the following formula (e1) or (e2). Xk−Y−Xn Xm−Yn

[0037] In the above formula, X represents an aromatic vinyl polymer block. In formula (e1), the degree of polymerization at both ends of the molecular chain may be the same or different. Furthermore, Y is selected from a butadiene polymer block, an isoprene polymer block, a butadiene / isoprene copolymer block, a hydrogenated butadiene polymer block, a hydrogenated isoprene polymer block, a hydrogenated butadiene / isoprene copolymer block, a partially hydrogenated butadiene polymer block, a partially hydrogenated isoprene polymer block, and a partially hydrogenated butadiene / isoprene copolymer block. k, m, and n are integers greater than or equal to 1.

[0038] Specific examples thereof are styrene-ethylene / butylene-styrene copolymer, styrene-ethylene / propylene-styrene copolymer, styrene-ethylene / ethylene / propylene-styrene copolymer, styrene-butadiene-butene-styrene copolymer, styrene-butadiene-styrene copolymer, styrene-isoprene-styrene copolymer, hydrogenated styrene-butadiene diblock copolymer, hydrogenated styrene-isoprene diblock copolymer, styrene-butadiene diblock copolymer and styrene-isoprene diblock copolymer, and among them, styrene-ethylene / butylene-styrene copolymer, styrene-ethylene / propylene-styrene copolymer, styrene-ethylene / ethylene / propylene-styrene copolymer and styrene-butadiene-butene-styrene copolymer are the most preferred.

[0039] The content of the X component in the block copolymer is 40 to 80 mass%, preferably 40 to 75 mass%, and more preferably 40 to 70 mass%. When the content of the X component is 40 mass% or more, the molded article can be imparted with suitable rigidity and impact resistance. On the other hand, when the content of the X component is 80 mass% or less, a molded article with a desired impact resistance can be obtained.

[0040] The weight-average molecular weight of the styrene-based thermoplastic elastomer is preferably 250,000 or less, more preferably 200,000 or less, and even more preferably 150,000 or less. When the weight-average molecular weight is 250,000 or less, there is no possibility of lower molding processability or impaired dispersibility in the polycarbonate resin composition. Furthermore, the lower limit of the weight-average molecular weight is not particularly limited, but is preferably 40,000 or more, and more preferably 50,000 or more.

[0041] The weight-average molecular weight is a value measured by the following method. That is, the molecular weight is measured with respect to polystyrene by a gel permeation chromatograph, and the weight-average molecular weight is calculated. The melt flow rate (230°C, 2.16 kg) of the styrene-based thermoplastic elastomer is preferably 0.1 to 10 g / 10 min, more preferably 0.15 to 9 g / 10 min, and particularly preferably 0.2 to 8 g / 10 min. When the melt flow rate of the styrene-based thermoplastic elastomer is in the range of 0.1 to 10 g / 10 min, a molded article with sufficient toughness can be obtained.

[0042] The elastomer content is in the range of 1 to 20 mass%, preferably in the range of 1 to 15 mass%, and more preferably in the range of 1 to 12 mass%, based on the total amount of the polycarbonate resin composition. When the elastomer content is 2 mass% or more, the effect of adding the elastomer can be achieved. On the other hand, when the elastomer content is 20 mass% or less, the molded article can be imparted with appropriate rigidity and long-term creep resistance.

[0043] Furthermore, the polycarbonate resin composition of the present invention may contain other components as long as the effects of the present invention are not impaired. Examples of other components include antioxidants, UV absorbers, pigments, antistatic agents, copper deterioration inhibitors, flame retardants, neutralizing agents, foaming agents, plasticizers, nucleating agents, bubble inhibitors, and crosslinking agents. The content of the other components is preferably 1 mass% or less, more preferably 0.5 mass% or less, based on the total amount of the polycarbonate resin composition. 2. Process for producing a polycarbonate resin composition

[0044] A method for producing the polycarbonate resin composition is described. A method for producing the polycarbonate resin composition of the present invention comprises: a first step of melt-kneading 2 to 50 mass % of ABS resin (B), 40 to 70 mass % of at least one basic magnesium sulfate (C) selected from fibrous basic magnesium sulfate (C-1) and fan-shaped basic magnesium sulfate (C-2), 0.1 to 5 mass % of at least one component (D) selected from a fatty acid metal salt, and 1 to 50 mass % of an elastomer (E) to obtain masterbatch pellets; and a second step of melt-kneading 10 to 60 mass % of the masterbatch pellets and 40 to 90 mass % of polycarbonate resin (A) to produce a polycarbonate resin composition.

[0045] In the first step, ABS resin (B), at least one basic magnesium sulfate (C) selected from fibrous basic magnesium sulfate (C-1) and fan-shaped basic magnesium sulfate (C-2), at least one fatty acid metal salt (D), and an elastomer (E) are melt-kneaded to obtain masterbatch pellets containing the elastomer and basic magnesium sulfate.

[0046] Kneading these masterbatch pellets with the polycarbonate resin causes the ABS resin and the polycarbonate resin to mix and disperse, creating an interface between the ABS resin and the basic magnesium sulfate. Interfacial tension creates an attractive force, fixing the elastomer at the interface, thereby suppressing hydrolysis of the polycarbonate resin.

[0047] The melt-kneading method is not particularly limited in either the first or second step, and examples include a method using a single-screw extruder, a twin-screw extruder, a Banbury mixer, a kneader, or a kneading roller. The melt-kneading temperature in the first step is preferably 160 to 260°C, more preferably 180 to 240°C, and the melt-kneading temperature in the second step is preferably 230 to 280°C, more preferably 240 to 260°C.

[0048] Each percentage among "2 to 50 mass % of ABS resin (B), 40 to 70 mass % of at least one basic magnesium sulfate (C) selected from fibrous basic magnesium sulfate (C-1) and fan-shaped basic magnesium sulfate (C-2), 0.1 to 5 mass % of at least one fatty acid metal salt (D), and 1 to 50 mass % of an elastomer (E)" in the first step is a percentage in the preparation of the masterbatch pellets. By adjusting the ratio between the masterbatch pellets prepared in the above percentage and the polycarbonate resin (A) in the second step, the percentages of the ABS resin (B), the basic magnesium sulfate (C), at least one fatty acid metal salt (D), and the elastomer (E) in the polycarbonate resin composition can be adjusted.

[0049] In the first step, the method for obtaining the masterbatch pellets is not particularly limited, and the masterbatch pellets can be obtained by melt-kneading and then forming into pellets by a known method.

[0050] Furthermore, in the second step, the shape of the polycarbonate resin composition obtained by melt kneading is not limited, and the molding process can be carried out to obtain any shape, such as a strand shape, a sheet shape, a flat plate shape, or a pellet shape. Regarding the molding in a later step, a pellet shape is preferred from the viewpoint of easy feeding to the molding machine. 3. Masterbatch (MB) pellets

[0051] Masterbatch pellets are described below. The masterbatch pellets of the present invention are a raw material for producing a polycarbonate resin composition by kneading with a diluent containing polycarbonate resin (A).

[0052] The masterbatch pellets according to the invention contain 2 to 50 mass% of ABS resin (B), 40 to 70 mass% of at least one basic magnesium sulfate (C) selected from fibrous basic magnesium sulfate (C-1) and fan-shaped basic magnesium sulfate (C-2), 0.1 to 5 mass% of at least one component (D) selected from a fatty acid metal salt and a fatty acid, and 1 to 50 mass% of an elastomer (E). Preferably, the masterbatch pellets according to the invention contain 2 to 45 mass% of ABS resin (B), 55 to 70 mass% of at least one basic magnesium sulfate (C) selected from fibrous basic magnesium sulfate (C-1) and fan-shaped basic magnesium sulfate (C-2), 0.1 to 4.5 mass% of at least one fatty acid metal salt (D), and 1 to 45 mass% of an elastomer (E).More preferably, the masterbatch pellets of the present invention contain 2 to 40 mass% of ABS resin (B), 60 to 70 mass% of at least one basic magnesium sulfate (C) selected from fibrous basic magnesium sulfate (C-1) and fan-shaped basic magnesium sulfate (C-2), 0.5 to 4 mass% of at least one component (D) selected from a fatty acid metal salt and a fatty acid, and 2 to 40 mass% of an elastomer (E).

[0053] Details of the ABS resin (B), the basic magnesium sulfate (C), the at least one fatty acid metal salt (D), and the elastomer (E) are as described above and will therefore not be described in detail. Furthermore, the method for preparing the masterbatch pellets is the same as the first step of the above-described method for preparing the polycarbonate resin composition. The diluent is not particularly limited as long as it is a resin containing the above-described polycarbonate resin (A). 4. Molded body

[0054] The molded article will be described below. The molded article of the present invention can be produced by molding the polycarbonate resin composition of the present invention. Examples of the method for molding the polycarbonate resin composition include: a method of preparing the polycarbonate resin composition by the above method and molding the polycarbonate resin composition; and a method of mixing the masterbatch pellets and the diluted pellets and directly molding the mixture by a molding machine. In addition, examples of the molding machine used for molding include a roll molding machine such as a calendar molding machine, a vacuum molding machine, an extrusion molding machine, an injection molding machine, a blow molding machine, and a compression molding machine.

[0055] The molded article of the present invention has excellent properties in terms of high Izod impact strength. Izod impact strength is a measure of resistance to impact stress. The Izod impact strength value in the present specification can be defined as the result measured by a method illustrated in examples described later. Specifically, it is the result of a measurement by the method according to JIS K7110 using an Izod impact tester.

[0056] Furthermore, the molded article according to the invention is also characterized by a high flexural modulus. The flexural modulus is a parameter that represents the difficulty of deforming the molded article and can be defined as the result measured by the method presented in the examples described later. Specifically, it is the result of the measurement according to the method according to JIS K7171 using a dynamic universal testing machine.

[0057] The molded article of the present invention is obtained by molding the polycarbonate resin composition obtained by using fibrous basic magnesium sulfate having a small average fiber diameter (average minor axis) or fan-shaped basic magnesium sulfate in which a portion of a plurality of fibrous basic magnesium sulfates are connected in a fan shape as a filler. Therefore, the molded article of the present invention has the advantage of excellent appearance compared to the case where glass fibers having a large average fiber diameter (average minor axis) are used as the filler, and is therefore suitable for an exterior portion visible to the public.

[0058] In the following, the present invention will be described in more detail with reference to examples, which, however, are not intended to limit the subject matter of the present invention, and the present invention is not limited to these examples.

[0059] The measurement method used in the present examples is presented. (Melt Flow Rate (MFR))

[0060] A melt flow rate test was conducted according to JIS K7210 using a Melt Flow Indexer (G-01, manufactured by Toyo Seiki Seisakusho Co., Ltd.), and the melt flow rate (MFR) was evaluated. The higher the MFR value, the better the processability. (Izod impact strength (Izod))

[0061] The Izod impact strength was evaluated by conducting a test according to JIS K7110 using an Izod impact tester (manufactured by MYS-TESTER Co., Ltd.). The hammer impact energy was 2.75 J. (Flexural modulus (FM))

[0062] A 3-point bending test was performed using a dynamic universal testing machine (manufactured by Imada Co., Ltd.), and the flexural modulus was evaluated from the obtained force-deflection curve using the method according to JIS K7171. The distance between the support points was 40 mm, and the loading rate was 10 mm / min. <Herstellung einer Harzzusammensetzung>

[0063] The components used in the examples and comparative examples are shown below.

[0064] Polycarbonate resin (A): [MFR (temperature of 240°C, load of 5000 kg): 4.5 g / 10 minutes]

[0065] ABS resin (B): [MFR (temperature of 220°C, load of 5000 kg): 18 g / 10 minutes]

[0066] Fibrous basic magnesium sulfate (C-1): (MOS-HIGE A-1, manufactured by Ube Material Industries Ltd., average major axis: 15 µm, average minor axis: 0.5 µm)

[0067] Fan-shaped basic magnesium sulfate (C-2): (average particle length of 33.0 µm, average particle width of 6.0 µm, average aspect ratio of 5.5) Fatty acid metal salt (D): Magnesium stearate

[0068] Elastomer (E): Styrene-Ethylene-Butylene-Styrene (SEBS, Tough Tech H1043, manufactured by Asahi Kasei Corporation)

[0069] Fiber optic (F): Chopped GF (ECS03 T-511, manufactured by Nippon Electric Glass Co., Ltd., fiber major diameter: 3 mm, fiber minor diameter: 13 µm) Milled GF (PF E-001, manufactured by Nitto Boseki Co., Ltd., fiber minor diameter: 10 µm) (Example 1)

[0070] 25.3 mass% ABS resin (B), 59.1 mass% fibrous basic magnesium sulfate particles (C-1), 1.8 mass% fatty acid metal salt (D), and 13.8 mass% elastomer (E) were mixed, and the resulting mixture was melt-kneaded at 240°C for 2 minutes. A melt-kneading extruder, Labplast Mill Roller Mixer (R60, capacity of 60cc, manufactured by Toyo Seiki Co., Ltd.), was used for melt-kneading, with the shaft rotation speed being 120 rpm. The resulting melt-kneaded product was formed into a sheet by hot pressing (temperature of 240°C) and then cut into masterbatch pellets.

[0071] 24.7 mass% of the masterbatch pellets and 75.3 mass% of the polycarbonate resin (A) were mixed. Then, a twin-screw melt-kneading extruder (L / D = 25, manufactured by Imoto Machinery Co., Ltd.) was used to perform melt-kneading at 260°C and 50 rpm to obtain the polycarbonate resin composition of Example 1. (Example 2)

[0072] Masterbatch pellets were obtained in the same manner as in Example 1, except that 22.8 mass% of ABS resin (B), 53.1 mass% of fibrous basic magnesium sulfate particles (C-1), 1.6 mass% of fatty acid metal salt (D), and 22.5 mass% of elastomer (E) were used.

[0073] The polycarbonate resin composition of Example 2 was obtained in the same manner as in Example 1, except that 27.5 mass% of the masterbatch pellets and 72.5 mass% of the polycarbonate resin (A) were used. (Example 3)

[0074] Masterbatch pellets were obtained in the same manner as in Example 1, except that 19.7 mass% of ABS resin (B), 46.2 mass% of fibrous basic magnesium sulfate particles (C-1), 1.4 mass% of fatty acid metal salt (D), and 32.7 mass% of elastomer (E) were used.

[0075] The polycarbonate resin composition of Example 3 was obtained in the same manner as in Example 1, except that 31.8 mass% of the masterbatch pellets and 68.2 mass% of the polycarbonate resin (A) were used. (Example 4)

[0076] Masterbatch pellets were obtained in the same manner as in Example 1, except that 25.3 mass% of ABS resin (B), 59.1 mass% of fan-shaped basic magnesium sulfate particles (C-2), 1.8 mass% of fatty acid metal salt (D), and 13.8 mass% of elastomer (E) were used.

[0077] The polycarbonate resin composition of Example 4 was obtained in the same manner as in Example 1, except that 24.7 mass% of the masterbatch pellets and 75.3 mass% of the polycarbonate resin (A) were used. (Example 5)

[0078] The polycarbonate resin composition of Example 5 was obtained in the same manner as in Example 1, except that 22.8 mass% of ABS resin (B), 53.1 mass% of fan-shaped basic magnesium sulfate particles (C-2), 1.6 mass% of fatty acid metal salt (D), and 22.5 mass% of elastomer (E) were used to prepare masterbatch pellets, and 27.5 mass% of the obtained masterbatch pellets and 72.5 mass% of polycarbonate resin (A) were mixed. (Example 6)

[0079] The polycarbonate resin composition of Example 6 was obtained in the same manner as in Example 1, except that 19.7 mass% of ABS resin (B), 46.2 mass% of fan-shaped basic magnesium sulfate particles (C-2), 1.4 mass% of fatty acid metal salt (D), and 32.7 mass% of elastomer (E) were used to prepare masterbatch pellets, and 31.8 mass% of the obtained masterbatch pellets and 68.2 mass% of polycarbonate resin (A) were mixed. (Comparison example 1)

[0080] Masterbatch pellets were obtained in the same manner as in Example 1, except that 27.3 mass% of ABS resin (B), 64.2 mass% of fibrous basic magnesium sulfate particles (C-1), 1.9 mass% of fatty acid metal salt (D), and 6.6 mass% of elastomer (E) were used.

[0081] The polycarbonate resin composition of Comparative Example 1 was obtained in the same manner as in Example 1, except that 22.9 mass% of the obtained masterbatch pellets and 77.1 mass% of polycarbonate resin (A) were used. (Comparison example 2)

[0082] Polycarbonate resin (A) was used individually. (Comparison example 3)

[0083] 80 mass % polycarbonate resin (A) and 20 mass % glass fiber (F) (chopped GF) were mixed. The resulting mixture was melt-kneaded using a twin-screw melt-kneading extruder to obtain the polycarbonate resin composition of Comparative Example 2. The melt-kneading was carried out in the same manner as in Example 1, except that the temperature was changed to 280°C. (Comparison example 4)

[0084] 80 mass% polycarbonate resin (A) and 20 mass% fibrous basic magnesium sulfate particles (C-1) were mixed. Then, as in Example 1, melt-kneading was attempted using a twin-screw melt-kneading extruder; however, the kneading failed. (Comparison example 5)

[0085] 84.7 mass% of polycarbonate resin (A), 14.9 mass% of fibrous basic magnesium sulfate particles (C-1), and 0.4 mass% of fatty acid metal salt (D) were mixed. Then, as in Example 1, melt-kneading was attempted using a twin-screw melt-kneading extruder; however, the kneading failed. (Comparison example 6)

[0086] 79.0 mass% polycarbonate resin (A), 6.3 mass% ABS resin (B), and 14.7 mass% fibrous basic magnesium sulfate particles (C-1) were mixed. Then, as in Example 1, melt-kneading was attempted using a twin-screw melt-kneading extruder; however, the kneading failed.

[0087] From the results of Comparative Examples 4 to 6, it is clear that the kneading process itself is impossible when the fibrous basic magnesium sulfate particles (C-1) are contained and ABS resin (B) and / or fatty acid metal salt (D) are not contained. (Comparison example 7)

[0088] The polycarbonate resin composition of Comparative Example 7 was obtained in the same manner as in Example 3 except that the fibrous basic magnesium sulfate particles (C-1) were replaced with the same amount of glass fibers (F) (chopped GF). (Comparison example 8)

[0089] The polycarbonate resin composition of Comparative Example 8 was obtained in the same manner as in Example 3 except that the fibrous basic magnesium sulfate particles (C-1) were replaced with the same amount of glass fibers (F) (milled GF). (Comparison example 9)

[0090] 27.3 mass% of ABS resin (B), 64.2 mass% of fan-shaped basic magnesium sulfate particles (C-2), 1.9 mass% of magnesium stearate (D), and 6.6 mass% of elastomer (E) were used to prepare masterbatch pellets, and kneading was attempted in the same manner as in Comparative Example 1 except that 22.9 mass% of the obtained masterbatch pellets and 77.1 mass% of polycarbonate resin (A) were mixed; however, the kneading failed.

[0091] Table 1 below summarizes the contents (mass%) of polycarbonate resin (A), ABS resin (B), basic magnesium sulfate particles (C), fatty acid metal salt (D), elastomer (E), and glass fiber (F) of the polycarbonate resin compositions obtained in Examples 1 to 6 and Comparative Examples 1 to 9. [Table 1] (A) (B) (C) (D) (E) (F) (C-1) (C-2) Example 1 75,3 6,26 14,6 0,44 3,4 Example 2 72,5 6,26 14,6 0,44 6,2 Example 3 68,2 6,26 14,7 0,44 10,4 Example 4 75,3 6,26 14,6 0,44 3,4 Example 5 72,5 6,26 14,6 0,44 6,2 Example 6 68,2 6,26 14,7 0,44 10,4 Comparison example 1 77,1 6,26 14,7 0,44 1,5 Comparison example 2 100,0 Comparison example 3 80,0 20,0 Comparison example 4 80,0 20,0 Comparison example 5 84,7 14,9 0,4 Comparison example 6 79,0 6,3 14,7 Comparison example 7 68,2 6,26 0,44 10,4 14,7 Comparison example 8 68,2 6,26 0,44 10,4 14,7 Comparison example 9 77,1 6,26 14,7 0,44 1,5 <bewertungsverfahren>

[0092] The polycarbonate resin compositions obtained in Examples 1 to 6 and Comparative Examples 1 to 9 were extruded into strand-like compositions and then cut to obtain polycarbonate resin composition pellets. The melt flow rate of the polycarbonate resin composition pellets was measured by the above-mentioned method.

[0093] Furthermore, the above polycarbonate resin composition pellets were injection-molded using a small injection molding machine (C. Mobile0813, manufactured by Shinko Sellbic Co., Ltd.) to produce a molded article (length 50 mm, width 5 mm, thickness 2 mm). Using the obtained molded article as a test specimen, the impact strength, flexural modulus, and strength were measured according to the method described above.

[0094] In addition, the external appearance of each specimen was visually observed to check whether a filler was detected on the surface. The case where the filler was not detected was marked as "◯", and the case where the filler was detected was marked as "×".

[0095] The results obtained are summarized in Table 2 below together with the above measurement results. [Table 2] MFR (g / 10 min) Impact strength FM (GPa) Appearance Izod (kJ / m 2 ) Example 1 13,8 20,3 4,25 O Example 2 16,7 13,7 4,31 ◯ Example 3 21,3 18,6 4,38 ◯ Example 4 10,5 23,3 3,91 ◯ Example 5 9,2 10,7 3,70 ◯ Example 6 10,2 9,2 3,69 ◯ Comparison example 1 45,8 1,3 4,59 ◯ Comparison example 2 4,5 87,8 2,16 ◯ Comparison example 3 4,1 11,8 4,83 × Comparison example 7 34,3 2,9 3,60 × Comparison example 8 25,2 1,9 2,70 ◯

[0096] As shown in Table 2 above, the polycarbonate resin compositions (Examples 1 to 3) containing polycarbonate resin, ABS polymer, fibrous basic magnesium sulfate, fatty acid metal salt, and elastomer in a predetermined amount exhibit significantly improved melt flow rate values compared with the polycarbonate resin alone (Comparative Example 2) and the polycarbonate resin composition containing only glass fiber (Comparative Example 3).

[0097] A molded article produced using the polycarbonate resin composition of Examples 1 to 6 exhibits excellent impact strength (Izod) and flexural modulus (FM), and also has good external appearance. In contrast, a molded article produced using a polycarbonate resin composition in which the elastomer content was low (Comparative Example 1) exhibits poor impact strength (Izod), and a molded article produced using only a polycarbonate resin (Comparative Example 2) has a low flexural modulus (FM).

[0098] As shown in Comparative Examples 7 and 8, a molded article produced using a polycarbonate resin composition containing glass fibers instead of fibrous basic magnesium sulfate exhibits poor impact strength (Izod) and low flexural modulus (FM). When chopped GF is used as a filler, defects in the external appearance of the resulting molded article occur (Comparative Examples 3 and 7).

[0099] In Comparative Example 9, in which the content of the elastomer (E) was small, the polycarbonate resin was hydrolyzed by fan-shaped basic magnesium sulfate, and the kneading failed.

[0100] It was demonstrated that the polycarbonate resin composition containing polycarbonate resin, ABS polymer, basic magnesium sulfate, fatty acid metal salt and elastomer in predetermined amounts is kneadable and moldable without hydrolysis, has excellent processability and is capable of providing a molded article with good mechanical properties and good external appearance.< / bewertungsverfahren>

Claims

[1] A polycarbonate resin composition comprising: 50 to 90 mass% of polycarbonate resin (A); 2 to 30 mass% of acrylonitrile-butadiene-styrene copolymer resin (B); 5 to 40 mass% of at least one basic magnesium sulfate (C) selected from fibrous basic magnesium sulfate (C-1) and fan-shaped basic magnesium sulfate (C-2); 0.1 to 8 mass% of fatty acid metal salt (D); and 1 to 20 mass% of an elastomer (E). [2] A process for producing a polycarbonate resin composition, the process comprising: a first step of melt-kneading 2 to 50 mass% of acrylonitrile-butadiene-styrene copolymer resin (B), 40 to 70 mass% of at least one basic magnesium sulfate (C) selected from fibrous basic magnesium sulfate (C-1) and fan-shaped basic magnesium sulfate (C-2), 0.1 to 5 mass% of fatty acid metal salt (D), and 1 to 50 mass% of an elastomer (E) to obtain masterbatch pellets; and a second step of melt-kneading 10 to 60 mass% of the masterbatch pellets and 40 to 90 mass% of the polycarbonate resin (A) to prepare the polycarbonate resin composition. [3] Masterbatch pellets for producing a polycarbonate resin composition by kneading with a diluent containing polycarbonate resin (A), the masterbatch pellets comprising: 2 to 50 mass% of acrylonitrile-butadiene-styrene copolymer resin (B); 40 to 70 mass% of at least one basic magnesium sulfate (C) selected from fibrous basic magnesium sulfate (C-1) and fan-shaped basic magnesium sulfate (C-2); 0.1 to 5 mass% of fatty acid metal salt (D); and 1 to 50 mass% of an elastomer (E). [4] A molded article which is a product molded from the polycarbonate resin composition according to claim 1.