resin composition

Abstract

The present invention provides a resin composition containing an ABS-based resin having properties equivalent to or better than those of conventional resins. [Solution] According to one aspect of the present invention, a resin composition is provided which 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, wherein the content of the first higher fatty acid or salt thereof is less than 5000 ppm, and the content of the second higher fatty acid or salt thereof is less than 12000 ppm.

Description

[Technical Field]

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

[0002] Acrylonitrile-butadiene-styrene copolymer (ABS resin) is used in a wide range of applications due to its excellent balance of impact resistance, heat resistance, moldability, and appearance (see Patent Document 1). Such ABS resin is manufactured, for example, by emulsion polymerization. In this process, potassium salts of beef tallow fatty acids are used as emulsifiers. However, in recent years, there has been a growing demand to reduce environmental impact by using biomass raw materials. Therefore, there is an increasing need to develop ABS resins that possess properties equivalent to or better than conventional resins, while still utilizing other emulsifiers. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 09-110943 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] In view of the above circumstances, the present invention aims to provide a resin composition containing an ABS-based resin having properties equivalent to or better than those of conventional resins. [Means for solving the problem]

[0005] According to one aspect of the present invention, a resin composition is provided which 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, wherein the content of the first higher fatty acid or salt thereof is less than 5000 ppm, and the content of the second higher fatty acid or salt thereof is less than 12000 ppm.

[0006] According to such an aspect, it is possible to provide a resin composition containing an ABS resin having properties equivalent to or higher than those of the conventional resin.

Mode 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 resin is a concept that includes 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), and the like.

[0010] As for the ABS resin, any resin can be used as long as it has ABS resin as its main component. For example, ABS resin blends and ABS resin alloys can be used. Examples of resins primarily composed of ABS resin include PC / ABS resin blends, which are made by blending polycarbonate (PC) and ABS resin. Furthermore, to improve the heat resistance of ABS resins and the compatibility of PC / ABS resin blends and polyamide / ABS resin blends, these may be blended with, for example, styrene-N-phenylmaleimide-maleic anhydride copolymer.

[0011] <<First higher fatty acid or its salt>> The first higher fatty acid or its salt has 12 to 14 carbon atoms. Such first higher fatty acids or their salts are components that affect, 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 or unsaturated fatty acid, but a saturated fatty acid is preferred.

[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 the salt of the first higher fatty acid, and sodium salts or potassium salts are more preferred. Furthermore, the first higher fatty acid or its salt may be in either anhydrous or hydrated form. As such first higher fatty acid or its salt, at least one selected from lauric acid (dodecanoic acid), tridecanoic acid, myristic acid (tetradecanoic acid) and their salts is preferable, and at least one selected from lauric acid, myristic acid and their salts is more preferable.

[0013] The content of the first higher fatty acid or its salt is about less than 5000 ppm, preferably about 10 ppm or more and less than 5000 ppm, more preferably about 50 ppm or more and 4000 ppm or less, still more preferably about 100 ppm or more and 3000 ppm or less, particularly preferably about 300 ppm or more and 2000 ppm or less, and most preferably about 500 ppm or more and 1000 ppm or less. In this case, it is 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 shall be the value converted to the higher fatty acid which is a free acid. Also, in this specification, unless otherwise specified, the content of each higher fatty acid or its salt means the proportion in the whole resin composition of each higher fatty acid or its salt.

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

[0015] As such a second higher fatty acid or its salt, at least one selected from palmitic acid, stearic acid, palmitoleic acid (hexadecenoic acid), oleic acid (octadecenoic acid), linoleic acid, linolenic acid, and their salts is preferable, and at least one selected from palmitic acid, stearic acid, oleic acid, linoleic acid, and their salts is more preferable. The content of the second higher fatty acid or its salt is preferably less than 12000 ppm, more preferably from 500 ppm to 10000 ppm, still more preferably from 1000 ppm to 8000 ppm, further more preferably from 1500 ppm to 6000 ppm, and particularly preferably from 2000 ppm to 4000 ppm. In this case, it is easy to improve the fluidity and molding processability of the resin composition.

[0016] The second higher fatty acid or its salt preferably contains linoleic acid or its salt. By containing linoleic acid or its salt, the molding processability of the resin composition can be further improved. In this case, the content of linoleic acid or its salt is preferably at least 10 ppm, more preferably from 50 ppm to 1000 ppm, still more preferably from 100 ppm to 900 ppm, further more preferably from 200 ppm to 800 ppm, and particularly preferably from 350 ppm to 700 ppm. Thereby, the molding processability of the resin composition can be adjusted well.

[0017] The second higher fatty acid or its salt preferably contains myristic acid or its salt. By containing palmitic acid or its salt, the heat resistance of the resin composition can be further improved. In this case, the content of myristic acid or its salt is preferably 10 ppm to 2000 ppm, more preferably 50 ppm to 1700 ppm, even more preferably 100 ppm to 1400 ppm, particularly preferably 150 ppm to 1100 ppm, and most preferably 200 ppm to 800 ppm. This allows for a suitable adjustment of the heat resistance of the resin composition.

[0018] The first higher fatty acid or its salt and the second higher fatty acid or its salt preferably include higher fatty acids or their salts derived from plants. By using higher fatty acids or their salts derived from plants, carbon dioxide emissions can be reduced, thereby lowering the environmental burden. Whether the first higher fatty acid or its salt and the second higher fatty acid or its salt include, and / or their content, higher fatty acids or their salts of plant origin are as defined in ASTM D6866. 14 This can be determined by measuring the biomass content using the 1C isotope assay method.

[0019] Furthermore, the plant-derived higher fatty acids or salts thereof preferably include higher fatty acids or salts thereof prepared from at least one of the following vegetable oils: 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, and linseed oil, and more preferably include higher fatty acids or salts thereof prepared from at least one of the following vegetable oils: palm oil, palm olein, and palm kernel oil. Specifically, higher fatty acids derived from plants or their salts can be obtained by appropriately mixing higher fatty acids or their salts prepared from two or more vegetable oils, or by adding a desired higher fatty acid or its salt to a higher fatty acid or its salt prepared from at least one vegetable oil. By using such a first higher fatty acid or its salt and a second higher fatty acid or its salt, the type and content of higher fatty acids or their salts contained in the resin composition can be easily adjusted to the desired range.

[0020] <Method for producing resin compositions> The resin composition of this embodiment can be manufactured, for example, as follows. Specifically, first, a rubbery polymer latex is obtained by emulsion polymerization. Next, monomers such as vinyl cyanide monomers and aromatic vinyl monomers are added to this latex all at once, in batches, or sequentially, and emulsion graft polymerization is carried out on the rubbery polymer to obtain a graft copolymer (A) latex. Next, the graft copolymer (A) is precipitated (salted out) from this latex and recovered. Subsequently, the graft copolymer (A) is mixed with a copolymer (B) of monomers such as vinyl cyanide monomers and aromatic vinyl monomers.

[0021] <<Graft copolymer (A)>> Examples of rubbery polymers included in the graft copolymer (A) include polymers of conjugated diene monomers such as butadiene, isoprene, dimethylbutadiene, chloroprene, and cyclopentadiene; polymers of unconjugated diene monomers such as 2,5-norbornadiene, 4-ethylidenenorbornene, 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 rubbery polymers, it is possible to precisely control their particle size, particle size distribution, and other properties. 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 diameter of the rubbery polymer is preferably between 250 nm and 400 nm, and more preferably between 300 nm and 500 nm. Furthermore, multiple types of rubbery polymers with different average particle diameters may be mixed and used.

[0023] Such rubbery polymers can be produced by first obtaining a rubbery polymer with a small particle size (for example, a volume-average particle size of 100 nm or less) by emulsion polymerization, and then enlarging this small-particle-size rubbery polymer. Methods for enlarging in this case include, for example, applying shear force to the small-particle-size rubbery polymer using a Manton-Gorin homogenizer to cause aggregation and enlargement, or chemically enlarging the rubbery polymer by adding an acidic substance such as an inorganic acid, organic acid, or an acid group-containing copolymer to latex. Rubbery polymers produced by such methods are characterized by a broad particle size distribution. Furthermore, rubbery polymers can be produced, for example, by using a method that involves emulsion polymerization and enlargement under conditions that reduce the number of particles by using a small amount of emulsifier. Rubbery polymers produced by this method are characterized by a narrow particle size distribution.

[0024] The particle size of rubbery polymers can be measured by diluting the latex of the rubbery polymer with pure water and using a laser diffraction scattering particle size distribution analyzer (COULTER LS230). Furthermore, the particle size distribution of graft copolymer (A) can be measured by stirring 1 g of graft copolymer (A) in 100 g of dimethylformamide (DMF) for 24 hours, then adding more DMF to dilute it to an appropriate concentration (the concentration with the best sensitivity for measurement using the measuring instrument), and finally using a laser diffraction scattering particle size distribution analyzer.

[0025] Examples of aromatic vinyl monomers used in the graft copolymer (A) include styrene, α-methylstyrene, chlorostyrene, butylstyrene, vinyltoluene, and divinylstyrene. On the other hand, examples of vinyl cyanide monomers used in the graft copolymer (A) include acrylonitrile, methacrylonitrile, and ethacrylonitrile. Furthermore, vinyl monomers that can be copolymerized with these and used as needed in the graft copolymer (A) include, for example, (meth)acrylic acid ester monomers such as methyl (meth)acrylate and butyl (meth)acrylate, and maleimide 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 monomer mixture in the presence of 10 to 70 parts by mass of the above-mentioned rubbery polymer. By setting the amount of rubbery polymer within the above range, the appearance of the molded product can be improved, as well as the impact resistance and productivity of the resin composition. The monomer mixture preferably contains 10% to 40% by mass of vinyl cyanide monomers, 60% to 90% by mass of aromatic vinyl monomers, and 0% to 30% by mass of monomers copolymerizable with these. In emulsion graft polymerization, it is preferable to add a mixture of monomers, as well as, for example, a polymerization initiator, emulsifier, chain transfer agent, etc., to the latex of the rubbery polymer.

[0027] As polymerization initiators, at least one of the following can be used: 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. In addition to these polymerization initiators, reducing agents such as iron ions, secondary reducing agents such as sodium formaldehyde sulfoxylate, and chelating agents such as tetrasodium ethylenediaminetetraacetate can also be combined.

[0028] 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. In the latter case, the content of the first higher fatty acid or its salt in the mixture is preferably about 5% by mass or more and 40% by mass or less, more preferably about 10% by mass or more and 35% by mass or less, and even more preferably about 15% by mass or more and 30% by mass or less. On the other hand, the content of the second higher fatty acid or its salt in the mixture is preferably about 60% by mass or more and 95% by mass or less, more preferably about 65% by mass or more and 90% by mass or less, and even more preferably about 70% by mass or more and 85% by mass or less. 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, terpinolene, and the like.

[0029] The amount of emulsifier added when performing emulsion graft polymerization is preferably 0.1 parts by mass to 10 parts by mass, more preferably 0.5 parts by mass to 7.5 parts by mass, and even more preferably 1 part by mass to 5 parts by mass, per 100 parts by mass of the rubbery polymer. Furthermore, examples of precipitating agents used for precipitation (salting out) of the graft copolymer (A) include at least one selected from the group consisting of sulfuric acid, acetic acid, and magnesium sulfate. The temperature in emulsion graft polymerization is not particularly limited, but is preferably between 30°C and 90°C, more preferably between 40°C and 80°C, and even more preferably between 50°C and 70°C.

[0030] The graft copolymer (A) can be recovered by, for example, (i) dewatering the slurry (latex after the addition of a precipitating agent) using a centrifugal dewatering machine or press dewatering machine and then drying it with an air-flow dryer or the like, or (ii) simultaneously dewatering and drying using a compression dewatering machine or extruder or the like. Furthermore, the bulk density of the graft copolymer (A) was measured by placing the thoroughly dried graft copolymer (A) in a cylindrical container at 100 cm³. 3 This can be done by filling the container and measuring its mass. In this specification, the measurement of bulk density shall be performed in accordance with JIS K 6721:1977.

[0031] The content of the rubbery polymer in the graft copolymer (A) is preferably 40% to 70% by mass, and more preferably 45% to 65% by mass. In this case, the impact resistance of the graft copolymer (A) can be increased. The content of the rubbery polymer in the graft copolymer (A) can be adjusted, for example, by the ratio of aromatic vinyl monomers and vinyl cyanide monomers used to the rubbery polymer during emulsion graft polymerization. Furthermore, it is preferable that the constituent units of the graft copolymer (A), excluding the rubbery polymer, consist of approximately 65% ​​to 85% by mass of aromatic vinyl monomer units and approximately 15% to 35% by mass of vinyl cyanide monomer units. This configuration can further improve the impact resistance and chemical resistance of the graft copolymer (A).

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

[0033] The volume-average particle diameter of the graft copolymer (A), i.e., the volume-average particle diameter of the gel portion, is preferably about 0.1 μm to 1 μm, and more preferably about 0.15 μm to 0.5 μm. In this case, the impact resistance of the graft copolymer (A) is increased, and the appearance of the molded product tends to be good. In this specification, the volume-average particle size is calculated from image analysis of particles dispersed in a continuous phase, obtained by cutting ultrathin sections from pellets of a resin composition obtained by melt-blending graft copolymer (A) and copolymer (B), and observing them 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 be adjusted by the method of adding emulsifiers and the amount of water used during emulsion polymerization.

[0034] The grafting rate of the graft copolymer (A) is preferably 10% by mass or more and 100% by mass or less, and more preferably 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 grafting rate is a value calculated based on the gel content (G) and rubbery polymer content (RC) of the graft copolymer (A) using the formula: grafting rate (mass%) = [(G-RC) / RC] × 100. The graft ratio represents the amount of aromatic vinyl-vinyl cyanide copolymer and aromatic vinyl-vinyl cyanide copolymer contained in each unit mass of the rubbery polymer particles, which are bonded by grafts. The graft ratio can be adjusted, for example, during emulsion graft polymerization by setting the ratio of monomers to rubbery polymers, the type and amount of polymerization initiator, the amount of chain transfer agent, the amount of emulsifier, the polymerization temperature, the charging method (all at once / multi-stage / continuous), and the monomer addition rate.

[0035] The degree of toluene swelling of the graft copolymer (A) is preferably between 5 and 20 times. This further enhances the impact resistance of the graft copolymer (A) and makes it easier to obtain a good appearance for the molded product. In this specification, the degree of toluene swelling represents the degree of crosslinking of the rubbery polymer particles and is a value calculated from the ratio of the mass of the graft copolymer (A) in the toluene-swollen state to the mass of the dry state after removing the toluene by vacuum drying, after dissolving the graft copolymer (A) in toluene and separating the insoluble matter by centrifugation or filtration. Furthermore, the degree of toluene swelling is affected, for example, by the degree of crosslinking of the rubbery polymer used in emulsion graft polymerization. This can be adjusted by selecting the polymerization initiator and / or emulsifier during emulsion polymerization of the rubbery polymer, setting the polymerization temperature, and adding polyfunctional monomers such as divinylbenzene.

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

[0037] Copolymer (B) preferably contains 10% to 40% by mass of a vinyl cyanide monomer, 60% to 90% by mass of an aromatic vinyl monomer, and 0% to 30% by mass of a vinyl monomer copolymerizable with these. By setting the content of vinyl cyanide monomers within the above range, the moldability of the resin composition can be improved, as well as chemical resistance, impact resistance, and heat resistance. Furthermore, by setting the content of aromatic vinyl monomers within the above range, the moldability of the resin composition can be improved, as well as its impact resistance and chemical resistance. Furthermore, by setting the content of copolymerizable vinyl monomers 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 content of rubbery polymer in the resin composition is preferably 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 content of rubbery polymer in the resin composition is preferably 5% to 30% by mass. By setting the content of the graft copolymer (A) and the content of the rubbery polymer in the resin composition to the above ranges, the impact strength of the resin composition can be improved, as well as the moldability and rigidity can be enhanced, and the appearance of the molded product can be improved.

[0039] The resin composition is preferably used in pellet form by melt-kneading a graft copolymer (A) and 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 with twin rotors. Multiple of these extruders can also be used in combination. The extruder has, for example, a kneading section for melting and kneading graft copolymer (A) and copolymer (B), and at least one defoliation section. The graft copolymer (A) and copolymer (B) supplied to the extruder are first melted in the kneading section and kneaded to a uniform composition. The kneading section is composed of a combination of mixing elements such as kneading discs. Downstream of the kneading section, it is preferable to use an element that pushes the molten resin back to the upstream side, thereby filling the kneading section, from the viewpoint of kneadability. Examples of such elements include reverse lead full flight, reverse offset kneading, and seal rings.

[0040] The resin composition, melt-kneaded in the mixing section, is transported in a molten state to the defoliation section, where volatile components are defoliated by vacuum venting. The defoliated molten resin composition is extruded in a strand shape from a porous die and cut using methods such as cold cutting, air hot cutting, or underwater hot cutting to obtain pellet-shaped resin compositions. As a method of devolatilization extrusion, the water-injection devolatilization method, in which water is added before the devolatilization section, is preferred because it has excellent devolatilization efficiency. For example, one method is to melt-knead the graft copolymer (A) and copolymer (B) in the kneading section, then provide another kneading section to uniformly knead and disperse water in the molten resin composition, and then devolatilize the volatile components together with the water in the downstream devolatilization section. It is also preferable that the kneading section where water is added and mixed is filled to a similar state. The amount of water added is preferably 0.05% by mass or more and 2% by mass or less relative to the resin composition.

[0041] The cylinder temperature of the kneading and devolatilization sections of the extruder is not particularly limited, but is preferably between 150°C and 280°C, more preferably between 170°C and 260°C, and even more preferably between 190°C and 240°C. Setting a higher cylinder temperature makes it easier to increase the devolatilization efficiency of volatile components from the resin composition. Furthermore, it is preferable to set the pressure in the devolatilization section to approximately 10 mmHg or less if water is not added, and approximately 40 mmHg or less if water is added. Here, volatile components include monomers derived from graft copolymer (A) and copolymer (B), substances derived from solvent components, substances derived from monomer components produced by thermal decomposition, and substances derived from higher fatty acids or their salts added as emulsifiers. During the mixing process, additives such as lubricants, pigments, dyes, antioxidants, and UV absorbers, as well as reinforcing agents such as glass fibers and talc, may be added to the resin composition as needed.

[0042] In the method for producing the resin composition as described above, the remaining amount of the higher fatty acid 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 added emulsifier, the addition amount of the emulsifier, the precipitation conditions of the graft copolymer (A), the blending ratio of the graft copolymer (A) and the copolymer (B), the extrusion conditions of the resin composition, and the like.

[0043] <Properties of the resin composition> The gel content contained in 100% by mass of the resin composition 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 contained in the resin composition within the above range, the impact resistance of the resin composition can be enhanced, and the fluidity can be improved to enhance the molding processability. The gel content can be adjusted by the blending ratio of the graft copolymer (A) and the copolymer (B). In this specification, the gel content is obtained by dissolving a resin composition of mass W in methyl ethyl ketone (MEK), centrifuging at 20000 rpm using a centrifuge to precipitate the insoluble matter, removing the supernatant by decantation to obtain the insoluble matter, and calculating from the mass S of the dried insoluble matter after vacuum drying, the gel content (mass%) = (S / W) × 100.

[0044] The resin composition, in accordance with JIS K 7111-1:2012, has a Charpy impact strength measured at 23°C using a notched test piece of 26 kJ / m 2 or more, preferably 2 26.5 kJ / m 2 or more and 32.5 kJ / m 2 or less, more preferably 2 27 kJ / m 2 or more and 32 kJ / m 2 or less, even more preferably 2 27.5 kJ / m 2 or more and 31.5 kJ / m 2 or less, particularly preferably 2 28 kJ / m 2 or more and 31 kJ / m 2 or less, and most preferably. The 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 of approximately 100°C or higher, and more preferably between 101°C and 105°C, as measured in accordance with JIS K 7206:1999. Resin compositions with such Vicat softening temperatures can be evaluated as having excellent heat resistance. Furthermore, the resin composition preferably has a load deflection temperature of approximately 78°C or higher, and more preferably between 79°C and 83°C, as measured by the flatwise method at a stress of 1.8 MPa in accordance with JIS K 7191-1, -2:2015. Resin compositions with such load deflection temperatures can also be evaluated as having excellent heat resistance.

[0046] The resin composition preferably has a melt mass flow rate (MFR) of approximately 15.5 g / 10 min or less, measured at a temperature of 220°C and a load of 10 kg in accordance with JIS K 7210:1999, more preferably between 10.5 g / 10 min and 15 g / 10 min, even more preferably between 10.6 g / 10 min and 14.5 g / 10 min, particularly preferably between 10.7 g / 10 min and 14 g / 10 min, and most preferably between 10.8 g / 10 min and 13.5 g / 10 min. 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%)) of approximately 345°C or higher under a nitrogen atmosphere, more preferably 346°C to 355°C, even more preferably 347°C to 354°C, particularly preferably 348°C to 353°C, and most preferably 349°C to 353°C. Resin compositions 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 95% by volume or more, more preferably 97% by volume or more, even more preferably 99% by volume or more, and may also be 100% by volume. Furthermore, they may be provided in the following embodiments.

[0048] (1) A resin composition comprising 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, wherein the content of the first higher fatty acid or salt thereof is less than 5000 ppm, and the content of the second higher fatty acid or salt thereof is less than 12000 ppm.

[0049] (2) A 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) A resin composition according to (1) or (2) above, wherein the second higher fatty acid or salt thereof comprises linoleic acid or a salt thereof.

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

[0052] (5) A resin composition according to any one of (1) to (4) above, wherein the second higher fatty acid or salt thereof comprises myristic acid or a salt thereof, and the content of myristic acid or a salt thereof is 10 ppm or more and 2000 ppm or less.

[0053] (6) A resin composition according to any one of (1) to (5) above, wherein the first higher fatty acid or a salt thereof and the second higher fatty acid or a salt thereof include a higher fatty acid or a salt thereof derived from a plant.

[0054] (7) A resin composition according to any one of (1) to (6) above, wherein the Vicat softening temperature measured in accordance with JIS K 7206:1999 is 100°C or higher.

[0055] (8) A 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) A resin composition according to any one of (1) to (8) above, wherein the 1% mass loss temperature (Td(1%)) under a nitrogen atmosphere is 345°C or higher. Of course, this is not always the case.

[0057] Finally, while various embodiments relating to this disclosure have been described, these are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be implemented in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims and their equivalents. [Examples]

[0058] The resin compositions will be described in more detail below based on the examples, but are not limited to these examples. 1. Preparation of a mixture of higher fatty acids A mixture of higher fatty acids, as shown in Table 1 below, was prepared. The mixture of higher fatty acids (A) is of animal origin (derived from semi-hardened beef tallow). The mixtures of higher fatty acids (B) and (C) are plant-derived. Furthermore, the mixture of higher fatty acids (D) is a plant-derived mixture obtained by adding high-purity myristic acid and lauric acid to mixture (B) and adjusting the composition ratio.

[0059] [Table 1]

[0060] 2. Manufacturing of emulsifiers [Emulsifier (A)] 599 parts by mass of deionized water and 21 parts by mass of potassium hydroxide were added to an autoclave and dissolved while stirring, and the temperature was raised to 60°C. After raising the temperature, 100 parts by mass of the mixture of higher fatty acids (A) was added and stirred until homogenized to produce emulsifier (A). [Emulsifier (B)] Emulsifier (B) was prepared in the same manner as emulsifier (A), except that mixture (B) of higher fatty acids was used instead of mixture (A), the amount of deionized water was 597 parts by mass, and the amount of potassium hydroxide was 23 parts by mass.

[0061] [Emulsifier (C)] Emulsifier (C) was manufactured in the same manner as emulsifier (A), except that mixture (C) of higher fatty acids was used instead of mixture (A), the amount of deionized water was 598 parts by mass, and the amount of potassium hydroxide was 21 parts by mass. [Emulsifier (D)] Emulsifier (D) was manufactured in the same manner as emulsifier (A), except that mixture (D) of higher fatty acids was used instead of mixture (A), the amount of deionized water was 597 parts by mass, and the amount of potassium hydroxide was 23 parts by mass. The composition of the higher fatty acids in each emulsifier (A) to (D) and the formulation of the emulsifiers 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 deionized 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] Subsequently, 100 parts by mass of butadiene were added, and the temperature was raised to 60°C for 10 hours of polymerization. Then, the temperature was raised to 70°C for a further 5 hours of polymerization. After polymerization was complete, the pressure was removed to remove the remaining butadiene, and a small particle size polybutadiene latex was obtained. This polybutadiene latex was enlarged using a Manton-Gorin homogenizer (pressure-induced flocculation and enlargement machine) to obtain polybutadiene (1) latex. The obtained polybutadiene (1) latex had a solid content of 39% by mass and a volume-average particle size of 340 nm.

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

[0066] [Polybutadiene(3) latex] First, 71 parts by mass of deionized water were 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-naphthalene sulfonic acid formalin condensate sodium salt (dispersant: Kao Corporation, "Demol NL"), 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 bicarbonate, 0.5 parts by mass of potassium persulfate (polymerization initiator), and 0.005 parts by mass of ethylenediaminetetraacetate tetrahydrate (chelating agent) were added and dissolved.

[0067] Subsequently, 100 parts by mass of butadiene were added, and the temperature was raised to 60°C for 25 hours of polymerization. Then, the temperature was raised to 66°C for 10 hours of polymerization, and further raised to 70°C for 15 hours of polymerization. After polymerization was complete, the pressure was removed to remove the remaining butadiene and obtain polybutadiene (3) latex. The obtained polybutadiene (3) latex had a solid content of 57% by mass and a volume-average particle size of 315 nm.

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

[0069] [Polybutadiene (5) latex] Polybutadiene (5) latex was manufactured in the same manner as polybutadiene (1) latex, except that emulsifier (D) was used instead of emulsifier (A). The obtained polybutadiene (5) latex had a solid content of 37% by mass and a volume-average particle size of 338 nm. The polymerization rates for each polybutadiene (1) to (5) used in the production of latex are shown in Table 3 below.

[0070] [Table 3]

[0071] 4. Manufacturing of grafted ABS resin (grafted copolymer (A)) [Manufacturing of grafted ABS resin (A1)] First, 100 parts by mass of polybutadiene (1) latex was added to an autoclave, and while stirring, 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 deionized water were added and the temperature was raised. After reaching 50°C, polymerization was started by adding 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). Forty minutes after reaching 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: manufactured by Nippon Oil & Fats Co., Ltd., "Parkmyl P"), 0.2 parts by mass of t-butyl peroxyacetate (polymerization initiator: manufactured by Arkema Yoshitomi Co., Ltd., "Lupazol-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 complete, the mixture was stirred at 70°C for 2 hours to complete the polymerization. Magnesium sulfate and sulfuric acid (precipitating agent) were added to this latex to precipitate (salt-out) and obtain grafted ABS resin (A1).

[0073] [Grafted ABS resin (A2)] Grafted ABS resin (A2) was manufactured in the same manner as grafted ABS resin (A1), except that polybutadiene (2) latex was used instead of polybutadiene (1) latex, and emulsifier (B) was used instead of emulsifier (A). [Grafted ABS resin (A3)] Grafted ABS resin (A3) was manufactured in the same manner as grafted 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] [Grafted ABS resin (A4)] Grafted ABS resin (A4) was manufactured in the same manner as grafted 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 a precipitant. [Grafted ABS resin (A5)] Grafted ABS resin (A5) was manufactured in the same manner as grafted 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 rates used when manufacturing each grafted ABS resin (A1) to (A5) are shown in Table 4 below.

[0075] [Table 4]

[0076] 5. Manufacturing of resin compositions (Reference example) A pelletized resin composition was produced by blending 30 parts by mass of grafted ABS resin (A1) and 70 parts by mass of AS resin (polymer (B): manufactured by Denka Co., Ltd., "AS-EXS") and melt-kneading them at a temperature of 220°C using a twin-screw extruder. In order to remove residual volatile matter, defloration was performed by vacuum venting and water injection defloration.

[0077] (Example 1) The pelletized resin composition of Example 1 was manufactured in the same manner as the Reference Example, except that grafted ABS resin (A2) was used instead of grafted ABS resin (A1). (Example 2) The pelletized resin composition of Example 2 was manufactured in the same manner as the Reference Example, except that grafted ABS resin (A3) was used instead of grafted ABS resin (A1).

[0078] (Comparative Example 1) A pelletized resin composition of Comparative Example 1 was manufactured in the same manner as the Reference Example, except that grafted ABS resin (A4) was used instead of grafted ABS resin (A1) and the water defoliation process was omitted. (Comparative Example 2) A pelletized resin composition of Comparative Example 2 was manufactured in the same manner as the Reference Example, except that grafted ABS resin (A5) was used instead of grafted ABS resin (A1).

[0079] 5. Measurement and Evaluation 5-1. Measurement of residual amount of higher fatty acids The amount of residual higher fatty acids in each resin composition was measured using the following procedure. The freeze-dried resin composition was extracted with ethanol for 1.5 hours using an Exfat extractor. The extract was then concentrated and filtered through a membrane filter to obtain the measurement sample. This sample 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. Measurement of Charpy impact strength Charpy impact strength was measured at 23°C using notched specimens 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 load deflection temperature The temperature of deflection under load was measured using the flatwise method at a stress of 1.8 MPa, in accordance with JIS K 7191-1, -2:2015.

[0081] 5-5. Measurement of Melt Mass Flow Rate (MFR) The melt mass flow rate (MFR) was measured in accordance with JIS K 7210:1999 under conditions of 220°C and 10 kg load. 5-6. Measurement of the temperature at which the mass decreases during heating. The heating mass loss temperature was defined as the temperature at which 1% of the mass was lost, measured by simultaneous thermogravimetric / differential thermal analysis (TG / DTA) under a nitrogen atmosphere at a heating rate of 10°C / min.

[0082] 5-7. Evaluation of mold fouling properties Mold fouling was evaluated visually during injection molding of molded products, based on the degree of mold contamination caused by the adhesion of low molecular weight components from the resin, according to the following criteria. A: No dirt was generated even after more than 1500 shots. B: Dirt appeared after more than 1500 shots but less than 1000 shots. C: Dirt appeared after less than 1000 shots. These results are shown in Table 5 below.

[0083] [Table 5]

[0084] The results shown in Table 5 indicate that the resin compositions of each example have properties equivalent to or better than those of the reference example resin composition produced using conventional animal-derived (semi-cured beef tallow-derived) higher fatty acids.

Claims

1. A resin composition, It 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. The content of the first higher fatty acid or its salt is less than 5000 ppm, A resin composition having a content of less than 12,000 ppm of the second higher fatty acid or its salt.

2. In the resin composition according to claim 1, A resin composition having a content of 10 ppm or more of the first higher fatty acid or its salt.

3. In the resin composition according to claim 1, The resin composition comprises linoleic acid or a salt thereof, wherein the second higher fatty acid or salt thereof is linoleic acid or a salt thereof.

4. In the resin composition according to claim 3, A resin composition having a linoleic acid or salt thereof content of 10 ppm or more.

5. In the resin composition according to claim 1, The second higher fatty acid or its salt includes myristic acid or its salt. A resin composition in which the content of myristic acid or its salt is 10 ppm or more and 2000 ppm or less.

6. In the resin composition according to claim 1, A resin composition comprising the first higher fatty acid or salt thereof and the second higher fatty acid or salt thereof, which are plant-derived higher fatty acids or salts thereof.

7. In 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.

8. In 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 under conditions of 220°C and 10 kg load, in accordance with JIS K 7210:1999.

9. In the resin composition according to claim 1, A resin composition having a 1% mass loss temperature (Td(1%)) of 345°C or higher under a nitrogen atmosphere.

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