Resin composition

Abstract

A resin composition containing an ABS resin having properties equivalent to or superior to those of conventional resins is provided. [Solution] According to one aspect of the present invention, there is provided a resin composition comprising an acrylonitrile-butadiene-styrene copolymer (ABS resin), a first higher fatty acid or a salt thereof having 12 to 14 carbon atoms, and a second higher fatty acid or a salt thereof having 16 to 18 carbon atoms, wherein the content of the first higher fatty acid or a salt thereof is less than 5000 ppm and the content of the second higher fatty acid or a salt thereof is less than 12000 ppm.

Description

[Technical Field]

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

[0002] Acrylonitrile-butadiene-styrene copolymers (ABS resins) are used in a wide range of applications due to their excellent balance of impact resistance, heat resistance, moldability, and appearance (see Patent Document 1). Such ABS resins are produced, for example, by emulsion polymerization. In this process, potassium salts of beef tallow fatty acids and the like are used as emulsifiers. However, in recent years, there has been a demand for using biomass raw materials to reduce the environmental impact, and there is a growing need to develop ABS resins that use other emulsifiers but have properties that are equal to or better than conventional ABS resins. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 09-110943 Summary of the Invention [Problem to be solved by the invention]

[0004] In view of the above circumstances, the present invention provides a resin composition containing an ABS resin having properties equal to or superior to those of conventional resins. [Means for solving the problem]

[0005] According to one aspect of the present invention, there is provided a resin composition comprising an acrylonitrile-butadiene-styrene copolymer (ABS resin), a first higher fatty acid or a salt thereof having from 12 to 14 carbon atoms, and a second higher fatty acid or a salt thereof having from 16 to 18 carbon atoms, wherein the content of the first higher fatty acid or the salt thereof is less than 5000 ppm and the content of the second higher fatty acid or the salt thereof is less than 12000 ppm.

[0006] According to such an aspect, a resin composition containing an ABS resin having properties equivalent to or better than those of the conventional ones can be provided.

Embodiments for Carrying Out the Invention

[0007] <Resin Composition> The resin composition of the present embodiment contains an acrylonitrile-butadiene-styrene copolymer (ABS resin), a first higher fatty acid having 12 to 14 carbon atoms or a salt thereof, and a second higher fatty acid having 16 to 18 carbon atoms or a salt thereof.

[0008] <<ABS Resin>> The ABS resin is a general term for resins obtained by copolymerization using acrylonitrile, butadiene, and styrene as raw material monomers, and the ratio of each component can be arbitrarily set. In addition to or instead of styrene, monomers such as α-methylstyrene, vinyltoluene, dimethylstyrene, chlorostyrene, vinylnaphthalene, etc. can be used as the raw material monomers. In addition to or instead of acrylonitrile, monomers such as methacrylonitrile, ethacrylonitrile, fumaronitrile, etc. can be used.

[0009] Furthermore, in addition to or instead of butadiene, monomers such as acrylic rubber mainly composed of butyl (meth)acrylate, chlorinated polyethylene, and ethylene-propylene-diene rubber (EPDM), which is an ethylene-based rubber, can be used. In addition to acrylonitrile, butadiene, and styrene, other monomers can be used as the raw material monomers. Examples of such other monomers include (meth)acrylate esters such as methyl methacrylate. Therefore, in this specification, the term "ABS-based resin" is a concept that encompasses not only acrylonitrile-butadiene-styrene copolymer (ABS resin), but also acrylonitrile-ethylene-propylene-diene-styrene copolymer (AES resin), acrylonitrile-styrene-acrylic acid ester copolymer (ASA resin), acrylonitrile-chlorinated polyethylene-styrene copolymer (ACS resin), methyl methacrylate-acrylonitrile-butadiene-styrene copolymer (MABS resin: transparent ABS resin), etc.

[0010] As the ABS resin, any resin can be used as long as it contains ABS resin as the main component, and for example, ABS resin blends, ABS resin alloys, etc. can be used. Examples of resins containing ABS resin as a main component include PC / ABS resin blends, which are blends of polycarbonate (PC) and ABS resin. Furthermore, for the purpose of improving the heat resistance of ABS resins and improving the compatibility of PC / ABS resin blends and polyamide / ABS resin blends, these may be blended with, for example, a styrene-N-phenylmaleimide-maleic anhydride copolymer.

[0011] <<First higher fatty acid or salt thereof>> The first higher fatty acid or a salt thereof has 12 to 14 carbon atoms. Such a first higher fatty acid or a salt thereof is a component that affects, for example, the fluidity (melt mass flow rate: MFR) and heat resistance (weight loss temperature) of the resin composition. The first higher fatty acid may be either a saturated fatty acid or an unsaturated fatty acid, but is preferably a saturated fatty acid.

[0012] Examples of salts of the first higher fatty acid include alkali metal salts, ammonium salts, and lower amine salts. Among these, alkali metal salts are preferred as salts of the first higher fatty acid, and sodium salts or potassium salts are more preferred. The first higher fatty acid or its salt may be either an anhydride or a hydrate. The first higher fatty acid or its salt is preferably at least one selected from lauric acid (dodecanoic acid), tridecanoic acid, myristic acid (tetradecanoic acid), and salts thereof, and more preferably at least one selected from lauric acid, myristic acid, and salts thereof.

[0013] The content of the first higher fatty acid or its salt is less than about 5000 ppm, preferably from about 10 ppm to less than 5000 ppm, more preferably from about 50 ppm to 4000 ppm, even more preferably from about 100 ppm to 3000 ppm, particularly preferably from about 300 ppm to 2000 ppm, and most preferably from about 500 ppm to 1000 ppm, which makes it easy to improve the fluidity and heat resistance of the resin composition. Hereinafter, in this specification, when the higher fatty acid is a salt or a hydrate, the content of the higher fatty acid or its salt is expressed as a value converted into the higher fatty acid which is a free acid. In this specification, the content of each higher fatty acid or salt thereof means the proportion of each higher fatty acid or salt thereof in the entire resin composition, unless otherwise specified.

[0014] <<Second higher fatty acid or its salt>> The second higher fatty acid or a salt thereof has 16 to 18 carbon atoms. Such a second higher fatty acid or a salt thereof is a component that affects, for example, the fluidity and molding processability (mold fouling resistance) of the resin composition. The second higher fatty acid may be either a saturated fatty acid or an unsaturated fatty acid. Examples of salts of the second higher fatty acid include alkali metal salts, ammonium salts, and lower amine salts. Among these, alkali metal salts are preferred as salts of the second higher fatty acid, and sodium salts or potassium salts are more preferred. The second higher fatty acid or its salt may be either anhydrous or hydrated.

[0015] The second higher fatty acid or its salt is preferably at least one selected from palmitic acid, stearic acid, palmitoleic acid (hexadecenoic acid), oleic acid (octadecenoic acid), linoleic acid, linolenic acid, and salts thereof, and more preferably at least one selected from palmitic acid, stearic acid, oleic acid, linoleic acid, and salts thereof. The content of the second higher fatty acid or its salt is less than about 12,000 ppm, preferably about 500 ppm to 10,000 ppm, more preferably about 1,000 ppm to 8,000 ppm, even more preferably about 1,500 ppm to 6,000 ppm, and particularly preferably about 2,000 ppm to 4,000 ppm, which is likely to improve the flowability and moldability of the resin composition.

[0016] The second higher fatty acid or its salt preferably contains linoleic acid or its salt, which can further improve the molding processability of the resin composition. In this case, the content of linoleic acid or a salt thereof is preferably about 10 ppm or more, more preferably about 50 ppm to 1000 ppm, even more preferably about 100 ppm to 900 ppm, particularly preferably about 200 ppm to 800 ppm, and most preferably about 350 ppm to 700 ppm, which allows for good adjustment of the moldability of the resin composition.

[0017] No. 1 The higher fatty acid or its salt preferably includes myristic acid or its salt. Millis By including tin acid or a salt thereof, the heat resistance of the resin composition can be further improved. In this case, the content of myristic acid or a salt thereof is preferably about 10 ppm to 2000 ppm, more preferably about 50 ppm to 1700 ppm, even more preferably about 100 ppm to 1400 ppm, particularly preferably about 150 ppm to 1100 ppm, and most preferably about 200 ppm to 800 ppm, which allows the heat resistance of the resin composition to be suitably adjusted.

[0018] The first higher fatty acid or its salt and the second higher fatty acid or its salt preferably include a plant-derived higher fatty acid or its salt. By using a plant-derived higher fatty acid or its salt, carbon dioxide emissions can be reduced, thereby reducing the environmental load. Whether or not the first higher fatty acid or its salt and the second higher fatty acid or its salt contain a plant-derived higher fatty acid or its salt, and / or the content thereof, is specified in ASTM D6866. 14 It can be determined by measuring the biomass using C isotope measurement.

[0019] Furthermore, the plant-derived higher fatty acid or salt thereof preferably comprises a higher fatty acid or salt thereof prepared from at least one type of vegetable oil such as palm oil, palm olein, palm kernel oil, olive oil, rapeseed oil, sesame oil, cottonseed oil, soybean oil, sunflower oil, safflower oil, rice bran oil, corn oil, coconut oil, or linseed oil, and more preferably comprises a higher fatty acid or salt thereof prepared from at least one type of vegetable oil such as palm oil, palm olein, or palm kernel oil. Specifically, plant-derived higher fatty acids or salts thereof can be obtained by appropriately mixing higher fatty acids or salts thereof prepared from two or more types of vegetable oils, or by adding a desired higher fatty acid or salt thereof to a higher fatty acid or salt thereof prepared from at least one type of vegetable oil. By using such a first higher fatty acid or a salt thereof and a second higher fatty acid or a salt thereof, the type and content of the higher fatty acid or a salt thereof contained in the resin composition can be easily adjusted to within the desired range.

[0020] <Method of manufacturing resin composition> The resin composition of the present embodiment can be produced, for example, as follows. That is, first, a latex of a rubber-like polymer is obtained by emulsion polymerization. Next, to this latex, monomers such as a vinyl cyanide monomer and an aromatic vinyl monomer are added all at once, batchwise or continuously to carry out emulsion graft polymerization with the rubber-like polymer, thereby obtaining a latex of graft copolymer (A). Next, the graft copolymer (A) is precipitated (salted out) from this latex and recovered. Thereafter, the graft copolymer (A) is mixed with a copolymer (B) of monomers such as a vinyl cyanide monomer and an aromatic vinyl monomer.

[0021] <<Graft copolymer (A)>> Examples of the rubbery polymer contained in the graft copolymer (A) include polymers of conjugated diene monomers such as butadiene, isoprene, dimethylbutadiene, chloroprene, and cyclopentadiene; polymers of non-conjugated diene monomers such as 2,5-norbornadiene, 4-ethylidenenorbornadiene, and 1,4-cyclohexadiene; and, if necessary, copolymers exhibiting rubbery elasticity obtained by copolymerizing aromatic vinyl monomers such as styrene, α-methylstyrene, and vinyltoluene; vinyl cyanide monomers such as acrylonitrile and methacrylonitrile; acrylic acid ester monomers such as methyl acrylate, 2-ethylhexyl acrylate, and octyl acrylate; methacrylic acid ester monomers such as methyl methacrylate, ethyl methacrylate, and butyl methacrylate; and olefin monomers such as ethylene, propylene, 1-butene, isobutylene, and 2-butene. In one embodiment, the rubbery polymer is preferably polybutadiene.

[0022] By using emulsion polymerization to prepare the rubbery polymer, the particle size, particle size distribution, etc. can be strictly controlled. During this emulsion polymerization, various surfactants such as anionic surfactants, nonionic surfactants, and amphoteric surfactants can be used as emulsifiers, but it is preferable to use a mixture of higher fatty acids containing the first higher fatty acid or a salt thereof and the second higher fatty acid or a salt thereof. The volume average particle size of the rubbery polymer is preferably about 250 nm to 400 nm, more preferably about 300 nm to 500 nm. A mixture of rubbery polymers with different average particle sizes may also be used.

[0023] Such rubbery polymers can be produced by first obtaining a rubbery polymer having a small particle size (e.g., a volume average particle size of 100 nm or less) by emulsion polymerization and then enlarging the small particle size rubbery polymer. Examples of enlarging methods include a method in which small particle size rubbery polymers are coagulated and enlarged by applying shear force using a Manton-Gaulin homogenizer or the like, or a method in which an acidic substance such as an inorganic acid, an organic acid, or an acid group-containing copolymer is added to a latex to chemically enlarge the rubbery polymer. Rubbery polymers produced by such methods are characterized by a broad particle size distribution. Alternatively, rubbery polymers can be produced by emulsion polymerization using a small amount of emulsifier under conditions that reduce the particle number, resulting in enlargement. Rubbery polymers produced by such methods are characterized by a narrow particle size distribution.

[0024] The particle size of the rubber polymer can be measured by diluting the rubber polymer latex with pure water and using a laser diffraction scattering particle size distribution analyzer (Model LS230, manufactured by COULTER). The particle size distribution of the graft copolymer (A) can be measured by stirring 1 g of the graft copolymer (A) in 100 g of dimethylformamide (DMF) for 24 hours, diluting the mixture with more DMF to an appropriate concentration (the concentration that provides the highest sensitivity when measuring with a measuring instrument), and then using a laser diffraction / scattering particle size distribution measuring instrument.

[0025] Examples of the aromatic vinyl monomer used in the graft copolymer (A) include styrene, α-methylstyrene, chlorostyrene, butylstyrene, vinyltoluene, and divinylstyrene. On the other hand, examples of the vinyl cyanide monomer used in the graft copolymer (A) include acrylonitrile, methacrylonitrile, and ethacrylonitrile. Furthermore, examples of vinyl-based monomers that can be copolymerized with these and that are used as needed in the graft copolymer (A) include (meth)acrylic acid ester monomers such as methyl (meth)acrylate and butyl (meth)acrylate, and maleimide-based monomers such as n-methylmaleimide and n-phenylmaleimide. In one embodiment, the graft copolymer (A) is preferably an acrylonitrile-butadiene-styrene copolymer (ABS resin).

[0026] The graft copolymer (A) is preferably obtained by emulsion graft polymerization of 30 to 90 parts by mass of a mixture of monomers in the presence of 10 to 70 parts by mass of the rubbery polymer. By adjusting the amount of the rubbery polymer to fall within the above range, the appearance of the molded article can be improved, and the impact resistance and productivity of the resin composition can be improved. The monomer mixture preferably contains 10% by mass or more and 40% by mass or less of a vinyl cyanide monomer, 60% by mass or more and 90% by mass or less of an aromatic vinyl monomer, and 0% by mass or more and 30% by mass or less of a monomer copolymerizable therewith. During emulsion graft polymerization, it is preferred to add, to the rubber polymer latex, a mixture of monomers as well as, for example, a polymerization initiator, an emulsifier, a chain transfer agent, and the like.

[0027] As the polymerization initiator, for example, at least one of organic hydroperoxides such as cumene hydroperoxide and diisopropylbenzene hydroperoxide, organic peroxyesters such as t-butyl peroxyacetate, t-hexyl peroxybenzoate and t-butyl peroxybenzoate, persulfates such as potassium persulfate and ammonium persulfate, and diazo compounds such as azobisbutyronitrile can be used. In addition to these polymerization initiators, a reducing agent such as iron ions, a secondary reducing agent such as sodium formaldehyde sulfoxylate, and a chelating agent such as tetrasodium ethylenediaminetetraacetate can also be combined.

[0028] As the emulsifier, various surfactants such as anionic surfactants, nonionic surfactants, and amphoteric surfactants can be used, but it is preferable to use a mixture of higher fatty acids containing the above-mentioned first higher fatty acid or a salt thereof and the second higher fatty acid or a salt thereof. In the latter case, the content of the first higher fatty acid or its salt in the mixture is preferably about 5% to 40% by mass, more preferably about 10% to 35% by mass, and even more preferably about 15% to 30% by mass, while the content of the second higher fatty acid or its salt in the mixture is preferably about 60% to 95% by mass, more preferably about 65% to 90% by mass, and even more preferably about 70% to 85% by mass. Examples of chain transfer agents that can be used include n-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, α-methylstyrene dimer, ethyl thioglycolate, limonene, and terpinolene.

[0029] The amount of emulsifier used in emulsion graft polymerization is preferably about 0.1 to 10 parts by mass, more preferably about 0.5 to 7.5 parts by mass, and even more preferably about 1 to 5 parts by mass, per 100 parts by mass of the rubber-like polymer. The precipitating agent used for precipitating (salting out) the graft copolymer (A) may be, for example, at least one selected from the group consisting of sulfuric acid, acetic acid, and magnesium sulfate. The temperature in the emulsion graft polymerization is not particularly limited, but is preferably about 30°C or higher and 90°C or lower, more preferably about 40°C or higher and 80°C or lower, and even more preferably about 50°C or higher and 70°C or lower.

[0030] The graft copolymer (A) can be recovered by, for example, (i) dehydrating the slurry (latex after adding the precipitating agent) using a centrifugal dehydrator or a press dehydrator, and then drying using a flash dryer or the like, or (ii) simultaneously dehydrating and drying using a compression dehydrator or an extruder or the like. The bulk density of the graft copolymer (A) was measured by placing a thoroughly dried graft copolymer (A) in a cylindrical container with a volume of 100 cm 3 In this specification, the bulk density is measured in accordance with JIS K 6721:1977.

[0031] The content of the rubbery polymer in the graft copolymer (A) is preferably about 40% by mass or more and about 70% by mass or less, and more preferably about 45% by mass or more and about 65% by mass or less. In this case, the impact resistance of the graft copolymer (A) can be improved. The content of the rubbery polymer in the graft copolymer (A) can be adjusted, for example, by changing the ratio of the aromatic vinyl monomer and the vinyl cyanide monomer used relative to the rubbery polymer during emulsion graft polymerization. The constituent units of the graft copolymer (A), excluding the rubber polymer, preferably contain aromatic vinyl monomer units in an amount of about 65% to 85% by mass and vinyl cyanide monomer units in an amount of about 15% to 35% by mass, which can further improve the impact resistance and chemical resistance of the graft copolymer (A).

[0032] The graft copolymer (A) is preferably in the form of particles. The graft copolymer (A) is a rubber-like polymer particle formed by graft copolymerization of an aromatic vinyl monomer, a vinyl cyanide monomer, or the like. It is a component that is insoluble in organic solvents such as methyl ethyl ketone (MEK) and toluene and can be separated by centrifugation. Such particles are also called gel components. The graft copolymer (A) may form an occlusion structure in which particulate aromatic vinyl-vinyl cyanide copolymer is encapsulated inside particles of the rubbery polymer. In the resin composition obtained by melt-blending the graft copolymer (A) and the copolymer (B), the gel fraction exists as a dispersed phase in the form of particles in the continuous phase of the copolymer (B).

[0033] The volume average particle size of the graft copolymer (A), i.e., the volume average particle size of the gel fraction, is preferably about 0.1 μm or more and 1 μm or less, more preferably about 0.15 μm or more and 0.5 μm or less, which increases the impact resistance of the graft copolymer (A) and tends to improve the appearance of molded articles. In this specification, the volume-average particle size is a value calculated from an image analysis of particles dispersed in a continuous phase after ultrathin sections are cut from pellets of a resin composition obtained by melt-blending graft copolymer (A) and copolymer (B) and observing the pellets with a transmission electron microscope (TEM). The volume-average particle size can be adjusted, for example, by the particle size of the rubbery polymer used in emulsion graft polymerization. The particle size of the rubbery polymer can also be adjusted by the method of adding an emulsifier or the amount of water used during emulsion polymerization.

[0034] The graft ratio of the graft copolymer (A) is preferably about 10% by mass or more and 100% by mass or less, and more preferably about 20% by mass or more and 70% by mass or less. In this case, the impact resistance of the graft copolymer (A) can be further improved. In this specification, the graft ratio is a value calculated based on the gel fraction (G) and the rubber polymer content (RC) of the graft copolymer (A) by the formula: graft ratio (% by mass) = [(G-RC) / RC] × 100. The graft ratio represents the amount of aromatic vinyl-vinyl cyanide copolymer bound to rubbery polymer particles by grafts and the amount of aromatic vinyl-vinyl cyanide copolymer encapsulated in the particles per unit mass of the rubbery polymer. The graft ratio can be adjusted, for example, during emulsion graft polymerization, by setting the ratio of monomer to rubbery polymer, the type and amount of polymerization initiator, the amount of chain transfer agent, the amount of emulsifier, polymerization temperature, charging method (lump sum / multistage / continuous), monomer addition rate, etc.

[0035] The degree of swelling of the graft copolymer (A) in toluene is preferably about 5 to 20 times. This further improves the impact resistance of the graft copolymer (A) and tends to improve the appearance of molded articles. In this specification, the degree of swelling in toluene represents the degree of crosslinking of rubbery polymer particles, and is a value calculated by dissolving the graft copolymer (A) in toluene, separating the insoluble matter by centrifugation or filtration, and then calculating the ratio of the mass of the graft copolymer (A) in a state swollen with toluene to the mass of the dried graft copolymer (A) after removing the toluene by vacuum drying. The degree of swelling in toluene is affected by, for example, the degree of crosslinking of the rubber-like polymer used in emulsion graft polymerization, and this can be adjusted by selecting a polymerization initiator and / or an emulsifier during emulsion polymerization of the rubber-like polymer, setting the polymerization temperature, adding a polyfunctional monomer such as divinylbenzene, or the like.

[0036] <<Copolymer (B)>> The copolymer (B) is a copolymer comprising an aromatic vinyl monomer, a vinyl cyanide monomer, and, if necessary, a vinyl monomer copolymerizable therewith. Examples of the aromatic vinyl monomer used in the copolymer (B) include styrene, α-methylstyrene, and vinyltoluene. On the other hand, examples of the vinyl cyanide monomer used in the copolymer (B) include acrylonitrile, methacrylonitrile, and ethacrylonitrile. Furthermore, examples of vinyl-based monomers that can be copolymerized with these and that are used as needed in the copolymer (B) include (meth)acrylic acid ester monomers such as methyl (meth)acrylate and butyl (meth)acrylate, and maleimide-based monomers such as n-methylmaleimide and n-phenylmaleimide. In one embodiment, the copolymer (B) is preferably an acrylonitrile-styrene copolymer (AS resin or SAN resin).

[0037] The copolymer (B) preferably contains 10% by mass or more and 40% by mass or less of a vinyl cyanide monomer, 60% by mass or more and 90% by mass or less of an aromatic vinyl monomer, and 0% by mass or more and 30% by mass or less of a vinyl monomer copolymerizable therewith. By setting the content of the vinyl cyanide monomer within the above range, the moldability of the resin composition is improved, and the chemical resistance, impact resistance, and heat resistance can be improved. Furthermore, by setting the content of the aromatic vinyl monomer within the above range, the moldability of the resin composition is improved, and the impact resistance and chemical resistance can be improved. Furthermore, by setting the content of the copolymerizable vinyl monomer within the above range, the balance of moldability, impact resistance, heat resistance, etc. of the resin composition can be improved.

[0038] The resin composition preferably comprises 10 to 50 parts by mass of graft copolymer (A) and 50 to 90 parts by mass of copolymer (B), and the rubber polymer content in the resin composition is 3 to 35% by mass.More preferably, the resin composition comprises 15 to 45 parts by mass of graft copolymer (A) and 55 to 85 parts by mass of copolymer (B), and the rubber polymer content in the resin composition is 5 to 30% by mass. By setting the content of the graft copolymer (A) and the content of the rubber-like polymer in the resin composition within the above ranges, the impact strength of the resin composition can be improved, and the moldability and rigidity can be enhanced, resulting in a molded product with a good appearance.

[0039] The resin composition is preferably used in the form of pellets obtained by melt-kneading the graft copolymer (A) and the copolymer (B) in an extruder or the like. Suitable extruders include, for example, twin-screw extruders, single-screw extruders, multi-screw extruders, and continuous kneaders equipped with twin rotors. A combination of these extruders can also be used. The extruder has, for example, a kneading section for melt-kneading the graft copolymer (A) and the copolymer (B), and at least one devolatilizing section. The graft copolymer (A) and the copolymer (B) fed to the extruder are first melted in the kneading section and kneaded to a uniform composition. The kneading section is configured by combining mixing elements such as kneading disks. From the viewpoint of kneading efficiency, it is preferable to use an element downstream of the kneading section that has the effect of pushing the molten resin back upstream to fill the kneading section. Examples of such elements include a reverse lead full flight, a reverse offset kneading element, and a seal ring.

[0040] The resin composition melt-kneaded in the kneading section is conveyed in a molten state to a devolatilizing section, where volatile components are devolatilized through a vacuum vent. The devolatilized molten resin composition is extruded in the form of strands through a multi-hole die and cut by a cold cut method, an in-air hot cut method, an underwater hot cut method, or the like to obtain a resin composition in the form of pellets. As a method of devolatilization extrusion, a water injection devolatilization method in which water is added before the devolatilization section is preferred because it has excellent devolatilization efficiency. For example, a method in which the graft copolymer (A) and the copolymer (B) are melt-kneaded in a kneading section, and then a further kneading section is provided to uniformly knead and disperse water in the molten resin composition, and volatile components are devolatilized together with water in a downstream devolatilization section can be mentioned. Similarly, it is preferable that the kneading section where water is added and kneaded is also filled up. The amount of water added is preferably about 0.05% by mass or more and 2% by mass or less based on the resin composition.

[0041] The cylinder temperatures of the kneading section and the devolatilizing section of the extruder are not particularly limited, but are preferably about 150° C. or higher and 280° C. or lower, more preferably about 170° C. or higher and 260° C. or lower, and even more preferably about 190° C. or higher and 240° C. Setting the cylinder temperature high makes it easier to increase the efficiency of devolatilizing volatile components from the resin composition. The pressure in the devolatilization section is preferably set to about 10 mmHg or less when no water is added, and to about 40 mmHg or less when water is added. Here, the volatile components include monomers derived from the graft copolymer (A) and the copolymer (B), substances derived from the solvent components, substances derived from the monomer components produced by thermal decomposition, and substances derived from higher fatty acids or salts thereof added as emulsifiers. During kneading, additives such as lubricants, pigments, dyes, antioxidants and ultraviolet absorbers, and reinforcing agents such as glass fibers and talc may be added to the resin composition as needed.

[0042] In the above-described method for producing a resin composition, the amount of the higher fatty acid remaining in the resin composition can be adjusted by changing at least one of, for example, the type and ratio of the higher fatty acid in the emulsifier to be added, the amount of emulsifier to be added, the precipitation conditions of the graft copolymer (A), the blending ratio of the graft copolymer (A) to the copolymer (B), and the extrusion conditions of the resin composition.

[0043] <Characteristics of resin composition> The gel content of the resin composition (100% by mass) is preferably about 15% by mass or more and 24% by mass or less, and more preferably about 16% by mass or more and 21% by mass or less. By setting the gel content of the resin composition within the above range, the impact resistance of the resin composition can be increased, and the flowability can be improved, resulting in improved moldability. The gel content can be adjusted by the compounding ratio of the graft copolymer (A) and the copolymer (B). In this specification, the gel content is a value calculated by dissolving a resin composition having a mass W in methyl ethylene ketone (MEK), centrifuging the solution at 20,000 rpm using a centrifuge to precipitate the insoluble matter, removing the supernatant by decantation to obtain the insoluble matter, and vacuum drying the solution to obtain the dried insoluble matter having a mass S, using the formula: gel content (mass %) = (S / W) × 100.

[0044] The resin composition has a Charpy impact strength of 26 kJ / m, measured at 23°C using a notched test piece in accordance with JIS K 7111-1:2012. 2 It is preferable that the concentration is about 26.5 kJ / m or more. 2 More than 32.5kJ / m 2 It is more preferable that the concentration is about 27 kJ / m or less. 2 More than 32kJ / m 2 It is more preferable that the concentration is about 27.5 kJ / m or less. 2 More than 31.5kJ / m 2 It is particularly preferable that the concentration is about 28 kJ / m or less. 2 More than 31kJ / m 2 It is most preferable that the Charpy impact strength is about the following: A resin composition having such a Charpy impact strength can be evaluated as having high toughness.

[0045] The resin composition preferably has a Vicat softening temperature measured in accordance with JIS K 7206:1999 of about 100° C. or higher, and more preferably about 101° C. or higher and 105° C. or lower. A resin composition having such a Vicat softening temperature can be evaluated as having excellent heat resistance. Furthermore, the resin composition preferably has a deflection temperature under load measured at a stress of 1.8 MPa using the flatwise method in accordance with JIS K 7191-1, -2:2015 of about 78°C or higher, and more preferably about 79°C or higher and 83°C or lower. A resin composition having such a deflection temperature under load can also be evaluated as having excellent heat resistance.

[0046] The resin composition preferably has a melt mass-flow rate (MFR) of about 15.5 g / 10 min or less, more preferably about 10.5 g / 10 min to 15 g / 10 min, even more preferably about 10.6 g / 10 min to 14.5 g / 10 min, particularly preferably about 10.7 g / 10 min to 14 g / 10 min, and most preferably about 10.8 g / 10 min to 13.5 g / 10 min, as measured at 220°C and a load of 10 kg in accordance with JIS K 7210:1999. Resin compositions with such a melt mass-flow rate can be evaluated as having excellent fluidity and good moldability.

[0047] The resin composition preferably has a 1% mass loss temperature (Td(1%)) in a nitrogen atmosphere of about 345° C. or higher, more preferably about 346° C. or higher and 355° C. or lower, even more preferably about 347° C. or higher and 354° C. or lower, particularly preferably about 348° C. or higher and 353° C. or lower, and most preferably about 349° C. or higher and 353° C. A resin composition with such a 1% mass loss temperature can also be evaluated as having excellent heat resistance. The nitrogen content of the nitrogen atmosphere is preferably about 95% by volume or more, more preferably about 97% by volume or more, even more preferably about 99% by volume or more, and may be 100% by volume. Furthermore, it may be provided in the following aspects.

[0048] (1) A resin composition comprising an acrylonitrile-butadiene-styrene copolymer (ABS resin), a first higher fatty acid or a salt thereof having 12 to 14 carbon atoms, and a second higher fatty acid or a salt thereof having 16 to 18 carbon atoms, wherein the content of the first higher fatty acid or the salt thereof is less than 5,000 ppm, and the content of the second higher fatty acid or the salt thereof is less than 12,000 ppm.

[0049] (2) The resin composition according to (1) above, wherein the content of the first higher fatty acid or its salt is 10 ppm or more.

[0050] (3) The resin composition according to (1) or (2) above, wherein the second higher fatty acid or its salt includes linoleic acid or its salt.

[0051] (4) The resin composition according to (3) above, wherein the content of the linoleic acid or a salt thereof is 10 ppm or more.

[0052] (5) In the resin composition described in any one of (1) to (4) above, the second higher fatty acid or its salt includes myristic acid or its salt, and the content of the myristic acid or its salt is 10 ppm or more and 2000 ppm or less.

[0053] (6) In the resin composition described in any one of (1) to (5) above, the first higher fatty acid or its salt and the second higher fatty acid or its salt comprise a plant-derived higher fatty acid or its salt.

[0054] (7) The resin composition according to any one of (1) to (6) above, which has a Vicat softening temperature of 100° C. or higher as measured in accordance with JIS K 7206:1999.

[0055] (8) The resin composition according to any one of (1) to (7) above, wherein the melt mass-flow rate (MFR) measured in accordance with JIS K 7210:1999 at a temperature of 220°C and a load of 10 kg is 15.5 g / 10 min or less.

[0056] (9) The resin composition according to any one of (1) to (8) above, wherein the 1% mass loss temperature (Td(1%)) in a nitrogen atmosphere is 345° C. or higher. Of course, this is not the case.

[0057] Finally, while various embodiments of the present disclosure have been described, they are presented as examples and are not intended to limit the scope of the invention. The novel embodiments may be embodied in various other forms, and various omissions, substitutions, and modifications may be made without departing from the spirit of the invention. Such embodiments and modifications are intended to be included within the scope and spirit of the invention, as well as within the scope of the inventions and their equivalents as defined in the claims. [Example]

[0058] The resin composition will be described in more detail below based on examples, but is not limited to these examples. 1. Preparation of Higher Fatty Acid Mixture A mixture of higher fatty acids shown in Table 1 below was prepared. The higher fatty acid mixture (A) is animal-based (derived from semi-hardened beef tallow). The higher fatty acid mixtures (B) and (C) are plant-based. The higher fatty acid mixture (D) is a plant-based mixture in which high-purity myristic acid and lauric acid are mixed with the higher fatty acid mixture (B) to adjust the composition ratio.

[0059] [Table 1]

[0060] 2. Manufacturing of emulsifiers [Emulsifier (A)] 599 parts by mass of ion-exchanged water and 21 parts by mass of potassium hydroxide were added to an autoclave and dissolved with stirring, and the temperature was raised to 60° C. After the temperature was raised, 100 parts by mass of a mixture of higher fatty acids (A) was added and stirred until uniform, thereby producing an emulsifier (A). [Emulsifier (B)] Emulsifier (B) was produced in the same manner as emulsifier (A), except that higher fatty acid mixture (B) was used instead of higher fatty acid mixture (A), the amount of ion-exchanged water was 597 parts by mass, and the amount of potassium hydroxide was 23 parts by mass.

[0061] [Emulsifier (C)] Emulsifier (C) was produced in the same manner as emulsifier (A), except that higher fatty acid mixture (C) was used instead of higher fatty acid mixture (A), the amount of ion-exchanged water was 598 parts by mass, and the amount of potassium hydroxide was 21 parts by mass. [Emulsifier (D)] Emulsifier (D) was produced in the same manner as emulsifier (A), except that higher fatty acid mixture (D) was used instead of higher fatty acid mixture (A), the amount of ion-exchanged water was 597 parts by mass, and the amount of potassium hydroxide was 23 parts by mass. The composition of higher fatty acids and formulation of each of the emulsifiers (A) to (D) are shown in Table 2 below.

[0062] [Table 2]

[0063] 3. Production of polybutadiene (rubber-like polymer) [Polybutadiene (1) latex] First, 151 parts by mass of ion-exchanged water was added to an autoclave, and while stirring, 15 parts by mass of emulsifier (A), 0.08 parts by mass of divinylbenzene (crosslinking agent), 0.2 parts by mass of t-dodecyl mercaptan (chain transfer agent), 0.1 parts by mass of potassium persulfate (polymerization initiator), 0.3 parts by mass of potassium chloride, and 0.001 parts by mass of tetrasodium ethylenediaminetetraacetate tetrahydrate (chelating agent) were added and dissolved.

[0064] After that, 100 parts by mass of butadiene was added, and the temperature was raised to 60°C and polymerization was carried out for 10 hours. Then, the temperature was raised to 70°C and polymerization was carried out for an additional 5 hours. After the polymerization was completed, the pressure was released to remove the remaining butadiene, and a latex of small particle size polybutadiene was obtained. This polybutadiene latex was agglomerated using a Manton-Gaulin homogenizer (pressure agglomeration agglomeration machine) to obtain a polybutadiene (1) latex. The obtained latex of polybutadiene (1) had a solid content of 39% by mass, and the volume average particle diameter of polybutadiene (1) was 340 nm.

[0065] [Polybutadiene (2) latex] A latex of polybutadiene (2) was produced in the same manner as the latex of polybutadiene (1), except that emulsifier (B) was used instead of emulsifier (A). The obtained latex of polybutadiene (2) had a solid content of 38 mass %, and the volume average particle diameter of polybutadiene (1) was 337 nm.

[0066] [Polybutadiene (3) latex] First, 71 parts by mass of ion-exchanged water was added to an autoclave, and while stirring, 0.7 parts by mass of emulsifier (B), 1 part by mass of potassium rosinate (emulsifier), 0.4 parts by mass of β-naphthalenesulfonic acid formalin condensate sodium salt (dispersant: "Demol NL" manufactured by Kao Corporation), 0.5 parts by mass of t-dodecyl mercaptan (chain transfer agent), 1 part by mass of potassium carbonate, 0.02 parts by mass of sodium hydrogen carbonate, 0.5 parts by mass of potassium persulfate (polymerization initiator), and 0.005 parts by mass of tetrasodium ethylenediaminetetraacetate tetrahydrate (chelating agent) were added and dissolved.

[0067] After that, 100 parts by mass of butadiene was added, and the temperature was raised to 60°C and polymerization was carried out for 25 hours. Next, the temperature was raised to 66°C and polymerization was carried out for 10 hours, and then the temperature was raised to 70°C and polymerization was carried out for 15 hours. After completion of the polymerization, the pressure was released and residual butadiene was removed to obtain a latex of polybutadiene (3). The obtained latex of polybutadiene (3) had a solid content of 57% by mass, and the volume average particle diameter of polybutadiene (3) was 315 nm.

[0068] [Polybutadiene (4) latex] A latex of polybutadiene (4) was produced in the same manner as the latex of polybutadiene (1), except that emulsifier (C) was used instead of emulsifier (A). The obtained latex of polybutadiene (4) had a solid content of 38% by mass, and the volume average particle diameter of polybutadiene (4) was 335 nm.

[0069] [Polybutadiene (5) latex] A latex of polybutadiene (5) was produced in the same manner as the latex of polybutadiene (1), except that emulsifier (D) was used instead of emulsifier (A). The obtained latex of polybutadiene (5) had a solid content of 37% by mass, and the volume average particle diameter of polybutadiene (5) was 338 nm. The polymerization charge amounts for producing the latexes of the polybutadienes (1) to (5) are shown in Table 3 below.

[0070] [Table 3]

[0071] 4. Preparation of graft ABS resin (graft copolymer (A)) [Production of Grafted ABS Resin (A1)] First, 100 parts by mass of polybutadiene (1) latex was added to an autoclave, and then 4 parts by mass of acrylonitrile, 9 parts by mass of styrene, 0.1 parts by mass of t-dodecyl mercaptan (chain transfer agent), and 48 parts by mass of ion-exchanged water were added while stirring, and the mixture was heated. After the temperature reached 50°C, 0.06 parts by mass of ferrous sulfate (reducing agent), 0.2 parts by mass of tetrasodium ethylenediaminetetraacetate tetrahydrate (chelating agent), and 4 parts by mass of sodium formaldehyde sulfoxylate dihydrate (secondary reducing agent: Rongalit dihydrate) were added to initiate polymerization. 40 minutes after the temperature reached 50°C, an additional 0.06 parts by mass of ferrous sulfate (reducing agent), 0.2 parts by mass of tetrasodium ethylenediaminetetraacetate tetrahydrate (chelating agent), and 4 parts by mass of sodium formaldehyde sulfoxylate dihydrate (secondary reducing agent: Rongalit dihydrate) were added.

[0072] Furthermore, a mixture of 0.1 parts by mass of diisopropylbenzene hydroperoxide (polymerization initiator: NOF Corporation's "Percumyl P"), 0.2 parts by mass of t-butyl peroxyacetate (polymerization initiator: Arkema Yoshitomi Co., Ltd.'s "Lupasol-70"), 3 parts by mass of emulsifier (A), 9 parts by mass of acrylonitrile, 21 parts by mass of styrene, 0.4 parts by mass of t-dodecyl mercaptan (chain transfer agent), and 13 parts by mass of ion-exchanged water was continuously added over 4 hours from the start of polymerization. After the addition was completed, the polymerization was completed by stirring for 2 hours at a temperature of 70° C. Magnesium sulfate and sulfuric acid (precipitating agents) were added to this latex to cause precipitation (salting out), thereby obtaining a graft ABS resin (A1).

[0073] [Graft ABS resin (A2)] Graft ABS resin (A2) was produced in the same manner as graft ABS resin (A1), except that polybutadiene (2) latex was used instead of polybutadiene (1) latex and emulsifier (B) was used instead of emulsifier (A). [Graft ABS resin (A3)] Graft ABS resin (A3) was produced in the same manner as graft ABS resin (A1), except that polybutadiene (3) latex was used instead of polybutadiene (1) latex and emulsifier (B) was used instead of emulsifier (A).

[0074] [Graft ABS resin (A4)] Graft ABS resin (A4) was produced in the same manner as graft ABS resin (A1), except that polybutadiene (4) latex was used instead of polybutadiene (1) latex, emulsifier (C) was used instead of emulsifier (A), and calcium chloride was used as the precipitating agent. [Graft ABS resin (A5)] Graft ABS resin (A5) was produced in the same manner as graft ABS resin (A1), except that polybutadiene (5) latex was used instead of polybutadiene (1) latex and emulsifier (D) was used instead of emulsifier (A). The polymerization charge amounts for producing each of the graft ABS resins (A1) to (A5) are shown in Table 4 below.

[0075] [Table 4]

[0076] 5. Production of resin composition (Reference example) A pellet-shaped resin composition was produced by blending 30 parts by mass of the graft ABS resin (A1) and 70 parts by mass of AS resin (copolymer (B): manufactured by Denka Co., Ltd., "AS-EXS") and melt-kneading the mixture using a twin-screw extruder at a temperature of 220°C. In order to remove any remaining volatile matter, devolatilization was carried out through a vacuum vent and by pouring water for devolatilization.

[0077] Example 1 A pellet-shaped resin composition of Example 1 was produced in the same manner as in Reference Example, except that the graft ABS resin (A2) was used instead of the graft ABS resin (A1). Example 2 A pellet-shaped resin composition of Example 2 was produced in the same manner as in Reference Example, except that the graft ABS resin (A3) was used instead of the graft ABS resin (A1).

[0078] (Comparative Example 1) A pellet-shaped resin composition of Comparative Example 1 was produced in the same manner as in Reference Example, except that the graft ABS resin (A4) was used instead of the graft ABS resin (A1) and the water injection and devolatilization were omitted. (Comparative Example 2) A pellet-shaped resin composition of Comparative Example 2 was produced in the same manner as in Reference Example, except that the graft ABS resin (A5) was used instead of the graft ABS resin (A1).

[0079] 5. Measurement and Evaluation 5-1. Measurement of residual amount of higher fatty acids The amount of higher fatty acids remaining in each resin composition was measured using the following procedure. The freeze-pulverized resin composition was extracted with ethanol for 1.5 hours using an Exfat extraction device. The extract was then concentrated and filtered through a membrane filter to obtain a measurement sample. This was measured using a Shimadzu LC-10 CLASS-VP (detector: RID-10A, column: YMC ODS-A, mobile phase: MeOH: 1000 mL / H2O (0.5% H3PO4 / H2O): 80 mL). 5-2. Charpy impact strength measurement The Charpy impact strength was measured at 23°C using a notched test piece in accordance with JIS K 7111-1:2012.

[0080] 5-3. Measurement of Vicat softening temperature The Vicat softening temperature was measured in accordance with JIS K 7206:1999. 5-4. Measurement of deflection temperature under load The deflection temperature under load was measured in accordance with JIS K 7191-1, -2:2015 using the flatwise method at a stress of 1.8 MPa.

[0081] 5-5.Melt mass-flow rate (MFR) measurement The melt mass flow rate (MFR) was measured in accordance with JIS K 7210:1999 under conditions of a temperature of 220°C and a load of 10 kg. 5-6. Measurement of heating mass loss temperature The heating mass loss temperature was determined as the temperature at which a 1% mass loss occurred when simultaneous thermogravimetry / differential thermal analysis (TG / DTA) was performed in a nitrogen atmosphere at a heating rate of 10°C / min.

[0082] 5-7. Evaluation of mold fouling Mold fouling was evaluated by visually inspecting the degree of mold fouling caused by adhesion of low molecular weight components from the resin during injection molding of the molded product, according to the following criteria. A: No stains were observed even after 1,500 shots or more. B: Staining occurred after 1500 or more shots but less than 1000 shots. C: Staining occurred after less than 1000 shots. These results are shown in Table 5 below.

[0083] [Table 5]

[0084] The results shown in Table 5 show that the resin compositions of each example have properties equivalent to or superior to those of the resin composition of the reference example, which was produced using conventional animal-based (semi-hardened beef tallow-derived) higher fatty acids.

Claims

1. A resin composition comprising: The composition contains an acrylonitrile-butadiene-styrene copolymer (ABS resin), a first higher fatty acid or a salt thereof having 12 to 14 carbon atoms, and a second higher fatty acid or a salt thereof having 16 to 18 carbon atoms, The content of the first higher fatty acid or a salt thereof is 5 ppm or more and 3000 ppm or less, The content of the second higher fatty acid or a salt thereof is 2000 ppm or more and 10000 ppm or less, A resin composition, wherein the second higher fatty acid or its salt contains linoleic acid or its salt, and the content of the linoleic acid or its salt is 100 ppm or more and 700 ppm or less.

2. The resin composition according to claim 1, the first higher fatty acid or a salt thereof includes myristic acid or a salt thereof, The resin composition has a content of the myristic acid or a salt thereof of 10 ppm or more and 2000 ppm or less.

3. The resin composition according to claim 1, A resin composition, wherein the first higher fatty acid or its salt and the second higher fatty acid or its salt comprise a plant-derived higher fatty acid or its salt.

4. The resin composition according to claim 1, A resin composition having a Vicat softening temperature of 100°C or higher as measured in accordance with JIS K 7206:1999.

5. The resin composition according to claim 1, A resin composition having a melt mass-flow rate (MFR) of 15.5 g / 10 min or less, measured in accordance with JIS K 7210:1999 at a temperature of 220°C and a load of 10 kg.

6. The resin composition according to claim 1, A resin composition having a 1% mass loss temperature (Td (1%)) of 345°C or higher in a nitrogen atmosphere.

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