Recycled ABS resin composition

Abstract

To provide a recycled ABS resin composition having excellent strength, toughness, and impact resistance.SOLUTION: Provided is a recycled ABS resin composition, comprising a recycled ABS resin (a) and a hydrogenated block copolymer (x). The hydrogenated block copolymer (x) is a block copolymer having a polymer block S composed mainly of vinyl aromatic monomer units and a polymer block B composed mainly of conjugated diene monomer units. On the conjugated diene portion constituting the hydrogenated block copolymer (x), 30 mol % or more is hydrogenated. The hydrogenated block copolymer (x) contains 30 to 100 mass % of a modified hydrogenated block copolymer (b*) in which at least one molecule of a heteroatom-containing functional group is chemically bonded to a polymer graft chain, a polymer end, or a coupling agent residue. The mass ratio of the recycled ABS resin (a) to the hydrogenated block copolymer (x), (a) / (x), is 99 / 1 to 80 / 20.SELECTED DRAWING: None

Description

[Technical Field]

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

[0002] In general, vinyl aromatic resins, such as polystyrene resins and ABS resins (acrylonitrile / butadiene / styrene copolymers), are excellent in moldability, rigidity, impact resistance, etc., and are inexpensive and have a low specific gravity, making them economically advantageous. Therefore, they are widely used in a variety of fields, such as for automotive interior materials, housings for home appliances and office automation equipment, and everyday goods. Among the above-mentioned vinyl aromatic resins, ABS resins, which have an excellent balance of impact resistance, rigidity, chemical resistance, etc., are widely used as materials for main components of durable consumer goods, mainly for various injection-molded products such as home appliances, miscellaneous goods, and automobile parts.

[0003] In recent years, there has been a growing trend towards recycling as part of a circular economy, with a view to reducing the burden on the global environment. Recycling of home appliances is also being promoted, and the Home Appliance Recycling Law is promoting the recycling of materials in particular for four items: air conditioners, televisions, refrigerators, and washing machines. ABS resin is used in large quantities in the four types of home appliances mentioned above, and a large amount of ABS resin is recovered from these waste products. On the other hand, ABS resin is also widely used in automobile interior parts, and ABS resin is recovered after scrapping of automobiles.

[0004] There are three main ways to recycle plastic waste: the first is thermal recycling, which involves burning the plastic to recover thermal energy; the second is chemical recycling, which involves chemically breaking it down and converting it into oil or monomer raw materials for recovery; and the third is material recycling, which involves crushing the waste, remelting it, and reprocessing it into molding materials for reuse in various molded products. Of these recycling methods, material recycling has attracted attention from the perspective of effective resource utilization with minimal environmental impact, and various companies are conducting research and development into it.

[0005] Resin molded products commonly used in various industrial products, such as home appliances and automobiles, are made from a wide variety of resin materials, including polyolefin resins such as polypropylene, ABS resins, and polyamide resins. When these industrial products are discarded, a mixture of different resins, known as shredder dust, is generated as resin residue. These are generally mixtures of different resins, and cannot be used as is in the original molded resin parts due to quality or mechanical properties.

[0006] On the other hand, recent remarkable technological innovations in material recycling have made it possible to separate polyolefin resins such as polypropylene, which have a low specific gravity, from polystyrene and ABS-based resins, which have a specific gravity slightly above 1, by gravity separation, and further to separate polystyrene and ABS-based resin by electrostatic separation, which takes advantage of the difference in polarity, and recover the resulting ABS-based resin as recycled material.

[0007] However, recycled ABS resins sorted and recovered in this way usually deteriorate over time. Furthermore, since it is difficult to sort and recover ABS resins with 100% purity, the sorted and recovered ABS resins often contain small amounts of incompatible resins, such as polystyrene resins and polyamides. Furthermore, paints and plating applied to ABS resin substrates are difficult to completely remove from the ABS resin, so small amounts of these contaminants may be present. Therefore, recycled ABS resins are significantly inferior to virgin ABS resins in terms of quality and mechanical properties as molding materials for durable consumer goods, and are therefore often reluctantly sent for thermal recycling. Therefore, many challenges remain in material recycling.

[0008] Concerning the above-mentioned problems, particularly the problem of deterioration in the physical properties of recycled ABS resins, attempts to improve the problem have been studied (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-231119 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-126995 Summary of the Invention [Problem to be solved by the invention]

[0010] However, ABS resins are highly polar because they are copolymerized with acrylonitrile as a monomer component, and because they have low compatibility with common olefin-based elastomers and styrene-based elastomers, it is difficult to modify recycled ABS resins using these elastomers, and there is a problem in that they do not achieve mechanical properties that are practically usable.

[0011] Therefore, an object of the present invention is to provide a recycled ABS resin composition excellent in strength, toughness, and impact resistance, which will enable recycled ABS resins, which have been difficult to recycle in the past, to be used in applications where virgin ABS resins are used, as a high-value recycled ABS resin composition. [Means for solving the problem]

[0012] The present inventors have conducted extensive research to solve the above-mentioned problems associated with conventional recycled ABS resins, and as a result have found that the above-mentioned problems associated with conventional techniques can be solved by blending a hydrogenated block copolymer having a specific structure with a recycled ABS resin, thereby completing the present invention. That is, the present invention is as follows.

[0013] [1] Recycled ABS resin (a), a hydrogenated block copolymer (x); A recycled ABS resin composition comprising: The hydrogenated block copolymer (x) is a block copolymer having at least one polymer block S mainly composed of vinyl aromatic monomer units and at least one polymer block B mainly composed of conjugated diene monomer units, 30 mol % or more of the conjugated diene moiety constituting the hydrogenated block copolymer (x) is hydrogenated, The hydrogenated block copolymer (x) is the hydrogenated block copolymer (x) contains 30% by mass or more and 100% by mass or less of a modified hydrogenated block copolymer (b*) in which at least one molecule of a heteroatom-containing functional group is chemically bonded to a polymer graft chain, a polymer end, or a coupling agent residue; The mass ratio of the recycled ABS resin (a) to the hydrogenated block copolymer (x) is (a) / (x)=99 / 1~80 / 20, Recycled ABS resin composition. [2] Further containing virgin ABS resin (a*), the mass ratio of the recycled ABS resin (a) to the virgin ABS resin (a*) is (a) / (a*)=100 / 0 to 20 / 80; The recycled ABS resin composition according to [1] above. [3] The recycled ABS resin composition according to [1] or [2], wherein the hydrogenated block copolymer (x) has a vinyl aromatic monomer unit content of 15% by mass to 50% by mass and a conjugated diene monomer unit content of 85% by mass to 50% by mass. [4] The modified hydrogenated block copolymer (b*) At least one functional group is present at the polymer end and / or at the coupling agent residue. The recycled ABS resin composition according to any one of [1] to [3] above. [5] The recycled ABS resin composition according to [4], wherein the modified hydrogenated block copolymer (b*) has a functional group at at least one polymer terminal, and the functional group is any one selected from the group consisting of a primary amino group, a secondary amino group, and an epoxy group. [6] The recycled ABS resin (a) is are recovered from consumer waste and / or industrial waste, The recycled ABS resin composition according to any one of [1] to [5] above. [7] The recycled ABS resin (a) is The material is recovered from molded articles such as housings or mechanical parts that constitute any one selected from the group consisting of home appliances, information devices, communication devices, and automobiles. The recycled ABS resin composition according to any one of [1] to [5] above. [Effects of the Invention]

[0014] According to the present invention, a recycled ABS resin composition having excellent strength, toughness, and impact resistance can be provided. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, an embodiment of the present invention (hereinafter referred to as "the present embodiment") will be described in detail. It should be noted that the following embodiments are merely examples for explaining the present invention, and are not intended to limit the present invention to the following content, and the present invention can be implemented in various modified forms within the scope of its gist.

[0016] [Recycled ABS resin composition] Recycled ABS resin (a), a hydrogenated block copolymer (x); A recycled ABS resin composition comprising: The hydrogenated block copolymer (x) is a block copolymer having at least one polymer block S mainly composed of vinyl aromatic monomer units and at least one polymer block B mainly composed of conjugated diene monomer units, 30 mol % or more of the conjugated diene moiety constituting the hydrogenated block copolymer (x) is hydrogenated, The hydrogenated block copolymer (x) is the hydrogenated block copolymer (x) contains 30% by mass or more and 100% by mass or less of a modified hydrogenated block copolymer (b*) in which at least one molecule of a heteroatom-containing functional group is chemically bonded to a polymer graft chain, a polymer end, or a coupling agent residue; The mass ratio of the recycled ABS resin (a) to the hydrogenated block copolymer (x) is (a) / (x)=99 / 1 to 80 / 20. Preferably, the mass ratio of the recycled ABS resin (a) to the hydrogenated block copolymer (b) is (a) / (b) in the range of 98 / 2 to 85 / 15, and more preferably (a) / (b) in the range of 97 / 3 to 88 / 12.

[0017] The recycled ABS resin composition of this embodiment, having the above-described structure, exhibits excellent strength, toughness, and impact resistance. Furthermore, by modifying the recycled ABS resin (a) with the specific hydrogenated block copolymer (x), the mechanical properties of the recycled ABS resin are comparable to those of virgin ABS resin, enabling it to be effectively used as an industrial component. This allows for the efficient use of petrochemical resources, contributing to a circular economy from the perspective of protecting the global environment.

[0018] The recycled ABS resin composition of this embodiment is primarily composed of ABS (acrylonitrile / butadiene / styrene) resin. Here, "primarily composed of ABS resin" means that the recycled ABS resin content in the composition of this embodiment is 80% by mass or more. In addition, in this specification, the expression "mainly composed of" is used to describe the proportion of a monomer unit in a polymer, which means that the content of a specific monomer unit is 60% by mass or more, preferably 80% by mass or more, and more preferably 90% by mass or more.

[0019] (Recycled ABS resin (a)) The recycled ABS resin (a) constituting the recycled ABS resin composition of the present embodiment is preferably a material recovered from consumer waste and / or industrial waste, or a material recovered from molded articles such as housings or mechanical parts constituting any one selected from the group consisting of household electrical appliances, information devices, communication devices, and automobiles, and contains ABS resin recovered from these various used products. Recycled ABS resin (a) is defined as a resin containing at least 1% by mass of unintentional impurities derived from used products, excluding intentional additives such as stabilizers.

[0020] Recent advances in recycling technology have been remarkable, and in addition to the conventional gravity separation method, in which materials are placed in water and separated based on differences in specific gravity, an electrostatic separation method that utilizes differences in electrical properties has been established. By utilizing this technology, it is possible to accurately separate low-polarity polystyrene resin from relatively high-polarity ABS resin, even though their specific gravities are relatively close (1.04-1.05 for polystyrene resin and 1.05-1.08 for ABS resin). After crushing and pulverizing the collected products, the recycled ABS resin (a) used in this embodiment is preferably made to have an ABS resin purity of 80% by mass or more by applying the specific gravity separation method, electrostatic separation method, or the like, more preferably 85% by mass or more, even more preferably 90% by mass or more, and even more preferably 95% by mass or more.

[0021] Although it is technically possible to improve the purity of the ABS resin in the recycled ABS resin (a) by investing time and money, economic efficiency must also be emphasized for use in an actual industrial product. Therefore, it is preferable to arbitrarily set the purity of the ABS resin in the recycled ABS resin (a) depending on the properties and quality required by the reuse destination. Furthermore, the recycled ABS resin composition of this embodiment contains, in addition to the recycled ABS resin (a), an unused virgin ABS resin (a*) described below. This compensates for the low purity of the ABS resin shown in the recycled ABS resin (a), and also compensates for the mechanical properties that have deteriorated over time.

[0022] The recycled ABS resin (a) preferably has a content of foreign resins and foreign matter of 20% by mass or less, more preferably 15% by mass or less, even more preferably 10% by mass or less, and even more preferably 5% by mass or less. The types and contents of these foreign resins and foreign substances tend to be affected in the recovered products. For example, when the recycled ABS resin (a) is derived from an automobile, it tends to contain trace amounts of polyamide resin, polypropylene resin, plating material, paint, etc. It also tends to contain inorganic substances such as talc and glass fiber. On the other hand, when the recycled ABS resin (a) is derived from home appliances, it tends to contain additives such as flame retardants in addition to other resins such as polystyrene resin and polycarbonate / ABS resin alloy. These are just examples, and the foreign resins and foreign materials are not particularly limited.

[0023] Furthermore, AES resins in which ethylene rubber is used instead of butadiene rubber to improve light resistance, and ASA resins in which acrylate rubber is used instead of butadiene rubber, are also included in the recycled ABS resin (a) that constitutes the recycled ABS resin composition of this embodiment, and can be suitably used as constituent materials of the recycled ABS resin composition of this embodiment. Furthermore, alloy materials of ABS resin with polycarbonate resin or acrylic resin are also included in the recycled ABS resin (a) constituting the recycled ABS resin composition of this embodiment, and can be suitably used as a constituent material of the recycled ABS resin composition of this embodiment.

[0024] (Virgin ABS resin (a*)) The recycled ABS resin composition of this embodiment may further contain a virgin ABS resin (a*) in addition to the recycled ABS resin (a) as long as it does not deviate from the spirit of the present invention. Virgin ABS resin (a*) is defined as resin that has never been used as a molded product and is composed only of the base polymer ABS resin and intentional additives for the purposes of stabilizers and functionality. It is defined as resin with a purity of 100% by mass, excluding impurities derived from the manufacturing process, such as residual solvents and emulsifiers. The content of virgin ABS resin in the recycled ABS resin composition of this embodiment is preferably a mass ratio of recycled ABS resin (a) to virgin ABS resin (a*) of (a) / (a*) = 100 / 0 to 20 / 80, but in view of the spirit of the present invention, the use ratio of recycled ABS resin (a) is preferably higher, preferably closer to 100 mass%. Specifically, (a) / (a*) is more preferably 100 / 0 to 50 / 50, and even more preferably 100 / 0 to 70 / 30. The monomer composition ratio (composition ratio of acrylonitrile / butadiene / styrene) of the recycled ABS resin (a) and the virgin ABS resin (a*) may be the same or different. Generally, the mechanical properties of recycled ABS resins deteriorate over time, so it is preferable that the melt flow rate of the virgin ABS resin (a*) be lower than that of the recycled ABS resin.

[0025] The virgin ABS resin (a*) encompasses all so-called ABS resins that have been distributed on the market up until now, and there are no particular limitations on the manufacturer or brand. Commercially available ABS resins include, but are not limited to, "Cevian (registered trademark)" manufactured by Daicel, "Toyolac (registered trademark)" manufactured by Toray, "Clarastic (registered trademark)" manufactured by Nippon A&L, "Techno ABS (registered trademark)" manufactured by Techno UMG, "Polylac (registered trademark)" manufactured by Chimei Industries, and "Terlan (registered trademark)" manufactured by Ineos.

[0026] The virgin ABS resin (a*) may be a neat polymer that does not contain functional secondary materials such as colorants, lubricants, fillers, or flame retardants, or may be a so-called compound grade that contains functional secondary materials.Furthermore, it may be a functional ABS resin that has been imparted with improved heat resistance by copolymerizing a comonomer such as maleimide, or an ABS resin copolymerized with a (meth)acrylic monomer, and these are all included in the virgin ABS resin (a*). Furthermore, the above-mentioned AES resins using ethylene rubber and ASA resins using acrylate rubber are also included in the virgin ABS resin (a*). Furthermore, alloy materials of ABS resin with polycarbonate resin or acrylic resin are also included in the virgin ABS resin (a*). Any known method can be used to produce the ABS resin, and the ABS resin may be produced by either emulsion polymerization or solution polymerization.

[0027] (Hydrogenated Block Copolymer (x)) The recycled ABS resin composition of this embodiment contains a hydrogenated block copolymer (x). The hydrogenated block copolymer (x) is a block copolymer having at least one polymer block S mainly composed of vinyl aromatic monomer units and at least one polymer block B mainly composed of conjugated diene monomer units, in which 30 mol % or more of the conjugated diene portion is hydrogenated. The hydrogenated block copolymer (x) contains 30% by mass or more and 100% by mass or less of a modified hydrogenated block copolymer (b*) in which at least one molecule of a heteroatom-containing functional group is chemically bonded to a polymer graft chain, a polymer end, or a coupling agent residue. That is, the hydrogenated block copolymer (x) used in the recycled ABS resin composition of this embodiment contains 30% by mass or more of the modified hydrogenated block copolymer (b*), and when the content is 100% by mass, the hydrogenated block copolymer (x) is the same as the modified hydrogenated block copolymer (b*).When the content of the modified hydrogenated block copolymer (b*) is less than 100% by mass, the hydrogenated block copolymer (x) contains unmodified hydrogenated block copolymer (b). The hydrogenated block copolymer (x) has a polymer block S mainly composed of vinyl aromatic monomer units and a polymer block B mainly composed of conjugated diene monomer units, and may have two or more of either polymer block or both of these blocks.

[0028] From the viewpoint of the balance between rigidity and impact strength of a molded article of the recycled ABS resin composition of this embodiment, the hydrogenated block copolymer (x) preferably has a vinyl aromatic monomer unit content of 15 to 50 mass % and a conjugated diene monomer unit content of 50 to 85 mass %. More preferably, the content of the vinyl aromatic monomer unit is 25 to 50% by mass, and the content of the conjugated diene monomer unit is 50 to 75% by mass. More preferably, the content of the vinyl aromatic monomer unit is 28 to 42 mass % and the content of the conjugated diene monomer unit is 58 to 72 mass %.

[0029] In the hydrogenated block copolymer (x), 30 mol % or more of the conjugated diene portion is hydrogenated. Hydrogenation of the conjugated diene moiety converts it to an olefin structure, dramatically improving thermal stability during processing. By increasing the hydrogenation rate of the conjugated diene moiety of the hydrogenated block copolymer (x) to 30 mol% or more, recycled ABS resin compositions with an excellent balance of mechanical properties tend to be obtained. The hydrogenation rate can be determined by known analytical methods, and for example, infrared absorption spectroscopy, 1H-NMR, etc. can be suitably used.

[0030] The hydrogenated block copolymer (x) has a hydrogenation rate of the conjugated diene moiety of 30 mol% or more, preferably 40 mol% or more, more preferably 50 mol% or more, even more preferably 60 mol% or more, and still more preferably 70 mol% or more. The upper limit of the hydrogenation rate is not particularly limited, but is preferably 100 mol % or less. When the hydrogenation rate of the conjugated diene portion of the hydrogenated block copolymer (x) is 30 mol % or more, the thermal stability during processing is significantly improved, and a recycled ABS resin composition having desirable mechanical properties tends to be obtained. The hydrogenation rate of the conjugated diene portion of the hydrogenated block copolymer (x) can be controlled within the above-mentioned range by adjusting the type and amount of the hydrogenation catalyst, the amount of hydrogen supplied in the hydrogenation step, and the hydrogenation step time.

[0031] From the viewpoint of the mechanical properties of the recycled ABS resin composition of this embodiment, the polymer block S mainly composed of vinyl aromatic monomer units constituting the hydrogenated block copolymer (x) is preferably a polymer block containing 90 mass% or more of vinyl aromatic monomer units. The polymer block mainly composed of conjugated diene monomer units constituting the hydrogenated block copolymer (x) may be a conjugated diene polymer block composed solely of conjugated diene monomer units, or may be a copolymer block of conjugated diene monomer units and vinyl aromatic monomer units. In the case of the copolymer block, various copolymer block structures can be used, such as a uniform random structure or a tapered structure (in which the composition ratio of the monomers changes along the chain).

[0032] The hydrogenated block copolymer (x) may be a combination of two or more block copolymers having different average molecular weights, or a combination of two or more block copolymers having different copolymerization ratios of vinyl aromatic monomer units and conjugated diene monomer units. The hydrogenated block copolymer (x) may contain other polymerizable monomer units other than the vinyl aromatic monomer units and the conjugated diene monomer units, as necessary.

[0033] The vinyl aromatic monomer units constituting the hydrogenated block copolymer (x) can be formed using a vinyl aromatic compound. The vinyl aromatic compound may be any compound having an aromatic ring and a vinyl group in the molecule, including, but not limited to, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, o-ethylstyrene, p-ethylstyrene, p-tert-butylstyrene, 2,4-dimethylstyrene, 1,3-dimethylstyrene, α-methylstyrene, α-methyl-p-methylstyrene, vinylnaphthalene, vinylanthracene, and 1,1-diphenylethylene. These vinyl aromatic compounds may be used alone or in combination of two or more. Among these, styrene is preferred from the industrial and economical viewpoints.

[0034] The conjugated diene monomer units constituting the hydrogenated block copolymer (x) can be formed using a conjugated diene compound. The conjugated diene compound may be a diolefin having a pair of conjugated double bonds, including, but not limited to, 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, and 1,3-hexadiene. These conjugated diene compounds may be used alone or in combination of two or more. Among these, from the industrial and economical viewpoints, 1,3-butadiene and isoprene are preferred, and 1,3-butadiene is more preferred.

[0035] The mass ratio of the vinyl aromatic monomer units to the conjugated diene monomer units in the hydrogenated block copolymer (x) is preferably vinyl aromatic monomer units / conjugated diene monomer units=15 / 85 to 50 / 50, more preferably 25 / 75 to 50 / 50, and even more preferably vinyl aromatic monomer units / conjugated diene monomer units=28 / 72 to 42 / 58. When the ratio of each monomer unit is within the above range, the recycled ABS resin composition of this embodiment tends to provide a molded article with a better balance between rigidity and impact strength.

[0036] When the mass proportion of vinyl aromatic monomer units in the hydrogenated block copolymer (x) is in the range of 15 mass % or more and 35 mass % or less, the resulting recycled ABS resin composition tends to exhibit high impact strength, although the elastic modulus is slightly low, and tends to be comparable to the performance of the virgin ABS resin (a*) alone. On the other hand, when the mass proportion of the vinyl aromatic monomer units in the hydrogenated block copolymer (x) is in the range of more than 35 mass % to 50 mass %, it tends to be possible to obtain a recycled ABS resin composition that has a good balance of mechanical properties while maintaining the elastic modulus of the original recycled ABS resin (a). As described above, it is preferable to select the mass proportion of the vinyl aromatic monomer units in the hydrogenated block copolymer (x) in consideration of the final use and the important physical properties.

[0037] The contents of the vinyl aromatic monomer unit and the conjugated diene monomer unit in the hydrogenated block copolymer (x) can be determined by the method described in the Examples below. The content of these monomer units can be controlled by adjusting the amount and ratio of each monomer added in the polymerization step of the hydrogenated block copolymer (x).

[0038] The hydrogenated block copolymer (x) is not particularly limited, but examples thereof include block copolymers having block structures represented by the following general formulas (1) to (5). SB...(1) S-(BS) n …(2) B-(SB) n …(3) S-(BSB) n …(4) (SB) n X …(5) Here, S represents a polymer block mainly composed of vinyl aromatic monomer units, and B represents a polymer block mainly composed of hydrogenated conjugated diene monomer units. Furthermore, n represents any integer from 1 to 6. Each n in (2) to (5) may be independently the same or different. X represents a coupling agent residue.

[0039] The general formulae (1) to (4) are linear hydrogenated block copolymers, and (5) is a branched (also called star-shaped) hydrogenated block copolymer with the B moiety as the bond center, and either can be suitably used. Furthermore, when the recycled ABS resin composition of this embodiment is used in durable consumer goods and other applications that require mechanical properties above a certain level, it is preferable to select a hydrogenated block copolymer (x) that has at least one polymer block S mainly composed of vinyl aromatic monomer units, and it is more preferable to select a hydrogenated block copolymer (x) that has at least two polymer blocks S. In this specification, the "polymer block mainly composed of vinyl aromatic monomer units" may be simply referred to as the "polymer block S."

[0040] <Peak molecular weight and molecular weight distribution of hydrogenated block copolymer (x)> The hydrogenated block copolymer (x) preferably has at least one peak molecular weight in the range of 20,000 to 250,000 in the molecular weight distribution curve measured by gel permeation chromatography (GPC), which tends to further improve the mechanical properties of the recycled ABS resin composition of this embodiment. From the same viewpoint, the peak molecular weight of the hydrogenated block copolymer (x) is more preferably in the range of 30,000 to 150,000, and even more preferably in the range of 35,000 to 100,000. The peak molecular weight of the hydrogenated block copolymer (x) can be measured by the method described in the Examples below.

[0041] Furthermore, with regard to the molecular weight distribution of the hydrogenated block copolymer (x), simple anionic polymerization results in a polymer with a unimodal molecular weight distribution and a narrow distribution in which the molecular weights are relatively uniform. However, it is also possible to obtain a hydrogenated block copolymer (x) with an intentionally broadened molecular weight distribution by, for example, associating the polymerization active ends of some of the polymers with a coupling agent or the like described below, or by combining polymers with different molecular weights.

[0042] <Content and Molecular Weight of Polymer Block S in Hydrogenated Block Copolymer (x)> The content of polymer block S mainly composed of vinyl aromatic monomer units in hydrogenated block copolymer (x) can be determined by calculating the mass ratio of polymer block S components (excluding vinyl aromatic hydrocarbon monomer polymer components having an average degree of polymerization of approximately 30 or less) obtained by a method of oxidatively decomposing a block copolymer with tert-butyl hydroperoxide using osmium tetroxide as a catalyst (the method described in I. M. Kolthoff, et al., J. Polym. Sci. 1, 429 (1946)). Furthermore, the molecular weights (Mn and Mv) of polymer block S can be determined by measuring the polymer block S components obtained by the above method using gel permeation chromatography (GPC). This method is referred to herein as the "osmium tetroxide method."

[0043] The content of polymer block S in the hydrogenated block copolymer (x) can also be determined by a method using a nuclear magnetic resonance (NMR) spectrometer (the method described in Y. Tanaka, et al., RUBBER CHEMISTRY and TECHNOLOGY 54, 685 (1981)) using the block copolymer before and after hydrogenation as samples. In this specification, this analytical method is referred to as the "NMR method."

[0044] In this case, when the content of polymer block S mainly composed of vinyl aromatic monomer units measured by the osmium tetroxide method using a block copolymer before hydrogenation is defined as (Os), there is a correlation shown in the following formula (F) between the content of polymer block S mainly composed of vinyl aromatic monomer units measured by the NMR method using a block copolymer after hydrogenation (defined as (Ns)). (Os)=-0.012(Ns)2+1.8(Ns)-13.0...(F) Therefore, when the content of the polymer block S in the hydrogenated block copolymer (x) is determined by the NMR method, the value of (Os) determined by the above formula (F) can be used as the content of the polymer block S mainly composed of vinyl aromatic monomer units as defined in this embodiment.

[0045] (Modified hydrogenated block copolymer (b*)) The hydrogenated block copolymer (x) contains 30% by mass or more and 100% by mass or less of a modified hydrogenated block copolymer (b*) having at least one molecule of a heteroatom-containing functional group chemically bonded to a polymer graft chain, a polymer end, or a coupling agent residue. Generally, heteroatoms refer to all elements other than carbon and hydrogen in hydrocarbon compounds. Typical examples of heteroatoms in hydrocarbon-based organic compounds include oxygen, nitrogen, boron, sulfur, phosphorus, silicon, the halogens, and tin. In general, a functional group is an atomic group in which there is a charge imbalance between covalently bonded atoms, and generally, an atomic group containing the above-mentioned heteroatom is covalently bonded to a hydrogenated block copolymer.

[0046] The use of hydrogenated block copolymer (x) containing 30% to 100% by mass of modified hydrogenated block copolymer (b*) in the recycled ABS resin composition of this embodiment results in a modification effect due to the development of affinity between the ABS resin, which is the main component of the recycled ABS resin (a), and the target ABS resin (a) through hydrogen bonding with acrylonitrile, one of the monomer components. Furthermore, covalent bonds are formed by hydrogen bonding or grafting between hydrogenated block copolymer (x) and polar impurities, such as plating components and paint components, and polar resins, such as polyamides, contained as impurities in the recycled ABS resin (a). This reinforces the interfaces between the different resins and polar impurities through chemical or hydrogen bonding, and the compatibilization of these components significantly improves mechanical properties. Incorporation of the modified hydrogenated block copolymer (b*) into the recycled ABS resin composition of the present embodiment not only serves to reinforce the ABS resin, but also to achieve the effect of compatibilizing other resins, foreign matter, and the like. Furthermore, when a filler is contained as a compounding material in the recycled ABS resin composition of this embodiment, the graft reaction with the filler tends to have the effect of promoting the dispersion of the filler.

[0047] The amount of functional groups bonded to the modified hydrogenated block copolymer (b*) is generally 0.01% by mass or more and 10% by mass or less, preferably 0.01% by mass or more and 8.0% by mass or less, more preferably 0.05% by mass or more and 6.0% by mass or less, and even more preferably 0.05% by mass or more and 4.0% by mass or less, relative to 100% by mass of the hydrogenated block copolymer (x). By setting the amount of functional groups to be added in a range of 0.01% by mass to 10% by mass, the recycled ABS resin composition of this embodiment tends to exhibit its maximum effect in improving impact resistance.

[0048] The hydrogenated block copolymer (x) contains 30% by mass or more and 100% by mass or less of a modified hydrogenated block copolymer (b*) in which at least one molecule of a heteroatom-containing functional group is chemically bonded to a polymer graft chain, a polymer end, or a coupling agent residue. The hydrogenated block copolymer (x) must contain 30% by mass or more of the modified hydrogenated block copolymer (b*). By containing 30% by mass or more of the modified hydrogenated block copolymer (b*), it tends to be possible to obtain a high modifying effect on the recycled ABS resin (a). The content of the modified hydrogenated block copolymer (b*) in the hydrogenated block copolymer (x) is more preferably 40% by mass or more, more preferably 50% by mass or more, even more preferably 60% by mass or more, still more preferably 70% by mass or more, still more preferably 80% by mass or more, particularly preferably 90% by mass or more, and most preferably 100% by mass.

[0049] Examples of functional groups containing a heteroatom include, but are not limited to, a hydroxyl group, a carboxyl group, a carbonyl group, a thiocarbonyl group, an acid halide group, an acid anhydride group, a carboxylic acid group, a thiocarboxylic acid group, an aldehyde group, a thioaldehyde group, a carboxylic acid ester group, an amide group, a sulfonic acid group, a sulfonate ester group, a phosphoric acid group, a phosphoric acid ester group, an amino group, an imino group, a nitrile group, a pyridyl group, a quinoline group, an epoxy group, a thioepoxy group, a sulfide group, an isocyanate group, an isothiocyanate group, a silicon halide group, a silanol group, an alkoxy silicon group, a tin halide group, a boronic acid group, a boron-containing group, a boronate salt group, an alkoxytin group, and a phenyltin group, and may be atomic groups containing at least one of these functional groups.

[0050] In particular, an atomic group having at least one functional group selected from the group consisting of an acid anhydride group, a carboxylic acid group, a hydroxyl group, an epoxy group, an amino group, an amide group, a silanol group, and an alkoxysilane group is preferred, more preferably an atomic group having at least one functional group selected from the group consisting of an acid anhydride group, a carboxylic acid group, a hydroxyl group, an epoxy group, an amino group, and an amide group, and even more preferably an atomic group having at least one functional group selected from the group consisting of an acid anhydride group, a carboxylic acid group, and a hydroxyl group. When an acid anhydride is bonded to a block copolymer in the functional group formation step, the acid anhydride may react with moisture in the air, etc., and some of the acid anhydride may be formed as a carboxylic acid group, but the amount of such a carboxylic acid group is not particularly limited.

[0051] The modified hydrogenated block copolymer (b*) preferably has a functional group at least at one end of the polymer and / or at one coupling agent residue, from the viewpoint of improving compatibility with ABS resins and obtaining a high modifying effect.

[0052] From the viewpoint of improving compatibility with ABS-based resins and obtaining a high modifying effect, it is particularly preferred that the modified hydrogenated block copolymer (b*) has a functional group at at least one polymer end, and that the functional group is any one selected from the group consisting of a primary amino group, a secondary amino group, and an epoxy group.

[0053] <Method for producing hydrogenated block copolymer (x)> The hydrogenated block copolymer (x) can be produced by known techniques. A typical example of the prior art is a method of block copolymerizing a conjugated diene compound and a vinyl aromatic compound in a hydrocarbon solvent using an anionic initiator such as an organolithium compound, etc. For example, the copolymer can be produced by the methods described in Japanese Patent Publication Nos. 19286 / 1961, 17979 / 1968, 2423 / 1973, 36957 / 1974, 49567 / 1982, and 11446 / 1983.

[0054] [Polymerization solvent] The hydrogenated block copolymer (x) can be obtained by block copolymerizing a vinyl aromatic compound and a conjugated diene compound in a hydrocarbon solvent. The hydrocarbon solvent used in producing the hydrogenated block copolymer (x) may be any conventionally known hydrocarbon solvent, including, but not limited to, aliphatic hydrocarbons such as n-butane, isobutane, n-pentane, n-hexane, n-heptane, and n-octane; alicyclic hydrocarbons such as cyclopentane, methylcyclopentane, cyclohexane, methylcyclohexane, cycloheptane, and methylcycloheptane; and aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene. These hydrocarbon solvents may be used alone or in combination of two or more. Among these, when an organolithium initiator is used, n-hexane and cyclohexane are generally used, and cyclohexane is most commonly used industrially and is therefore preferably used.

[0055] [Polymerization initiator] The polymerization initiator is not particularly limited, but suitable examples include polymerization initiators that exhibit anionic polymerization activity toward conjugated diene compounds and vinyl aromatic compounds, such as alkali metal compounds, such as aliphatic hydrocarbon alkali metal compounds, aromatic hydrocarbon alkali metal compounds, and organic amino alkali metal compounds.

[0056] The alkali metal used in the alkali metal compound is not particularly limited, but examples thereof include lithium, sodium, and potassium. Suitable alkali metal compounds include, but are not limited to, aliphatic and aromatic hydrocarbon lithium compounds having 1 to 20 carbon atoms, including compounds containing one lithium atom per molecule, and dilithium compounds, trilithium compounds, and tetralithium compounds containing multiple lithium atoms per molecule.

[0057] Examples of such alkali metal compounds include, but are not limited to, n-propyllithium, n-butyllithium, sec-butyllithium, tert-butyllithium, hexamethylenedilithium, butadienyldilithium, isoprenyldilithium, a reaction product of diisopropenylbenzene with sec-butyllithium, and a reaction product of divinylbenzene with sec-butyllithium and a small amount of 1,3-butadiene.

[0058] Organic alkali metal compounds disclosed in foreign patents such as U.S. Pat. No. 5,708,092, British Patent No. 2,241,239, and U.S. Pat. No. 5,527,753 can also be used. These can be used alone or in combination of two or more. Among these, n-butyllithium is most preferred.

[0059] [Polymerization process] In the polymerization process of the hydrogenated block copolymer (x), the content of the vinyl aromatic monomer unit and the content of the conjugated diene monomer unit in the finally obtained hydrogenated block copolymer (x) can be controlled by adjusting the charging ratio of the vinyl aromatic compound and the conjugated diene compound, which are the polymerization raw materials.

[0060] Suitable polymerization processes for the hydrogenated block copolymer (x) include, for example, a process in which a polymerization initiator is added during the polymerization, a process in which a small amount of a polyfunctional monomer having two or more reactive sites is added to cause a partial coupling reaction, or a process in which an alcohol, water, or the like is added in an amount less than the number of reactive sites during the polymerization, and then the monomer is again supplied to continue the polymerization. By appropriately selecting such a process, a hydrogenated block copolymer (x) containing multiple components with different molecular weights can be produced. On the other hand, by adding an alcohol such as ethanol in a molar equivalent amount smaller than the number of moles of the polymerization initiator to the polymerization system during the polymerization to terminate the polymerization of a part of the polymer, it is also possible to obtain a hydrogenated block copolymer (x) which is a mixture of polymers having different molecular weights.

[0061] Examples of methods for producing a copolymer block comprising vinyl aromatic monomer units and conjugated diene monomer units include a method in which a mixture of a vinyl aromatic compound and a conjugated diene compound is continuously supplied to a polymerization system and polymerized, and a method in which a vinyl aromatic compound and a conjugated diene compound are copolymerized using a polar compound or a randomizer.

[0062] Furthermore, the polar compound or randomizer also has the effect of increasing the proportion of vinyl bonds in the conjugated diene when the conjugated diene compound is polymerized alone. The vinyl bond content of the hydrogenated block copolymer (x) can be controlled by using a Lewis base, for example, a compound such as an ether or an amine, as a vinylating agent. The desired vinyl bond content can be controlled by adjusting the amount of vinyl bond used.

[0063] The vinylating agent is not limited to the following, but examples thereof include ether compounds and tertiary amine compounds.

[0064] The ether-based compound as the vinylating agent is not limited to the following, but examples thereof include ethers such as tetrahydrofuran, diethylene glycol dimethyl ether, and diethylene glycol dibutyl ether. Furthermore, examples of tertiary amine compounds include, but are not limited to, pyridine, N,N,N',N'-tetramethylethylenediamine, tributylamine, tetramethylpropanediamine, 1,2-dipiperidinoethane, and bis[2-(N,N-dimethylamino)ethyl]ether. These may be used alone or in combination of two or more. The tertiary amine compound is preferably a compound having two amines, and among them, compounds having an intramolecularly symmetric structure are more preferred, and N,N,N',N'-tetramethylethylenediamine, bis[2-(N,N-dimethylamino)ethyl]ether, and 1,2-dipiperidinoethane are even more preferred.

[0065] The hydrogenated block copolymer (x) can be produced in the presence of an alkali metal alkoxide in order to control the vinyl bond content. The alkali metal alkoxide is a compound represented by the general formula MOR (where M is an alkali metal and R is an alkyl group). The use of the alkali metal alkoxide makes it possible to obtain a hydrogenated block copolymer (x) having a high vinyl bond content.

[0066] The alkali metal in the alkali metal alkoxide is preferably sodium or potassium from the viewpoints of a high vinyl bond content, a narrow molecular weight distribution, a high polymerization rate, and a high block rate. Examples of the alkali metal alkoxide include, but are not limited to, sodium alkoxides, lithium alkoxides, and potassium alkoxides having an alkyl group with 2 to 12 carbon atoms, preferably sodium alkoxides or potassium alkoxides having an alkyl group with 3 to 6 carbon atoms, and more preferably sodium t-butoxide, sodium t-pentoxide, potassium t-butoxide, and potassium t-pentoxide. Among these, the sodium alkoxides sodium t-butoxide and sodium t-pentoxide are more preferred.

[0067] When the polymerization step of the hydrogenated block copolymer (x) is carried out in the coexistence of a vinylating agent, an organolithium compound, and an alkali metal alkoxide, it is preferable that the molar ratio of the vinylating agent to the organolithium compound (vinylating agent / organolithium compound) and the molar ratio of the alkali metal alkoxide to the organolithium compound (alkali metal alkoxide / organolithium compound) are as follows: Vinylating agent / organolithium compound molar ratio: 0.2 to 3.0 Alkali metal alkoxide / organolithium compound molar ratio: 0.01 to 0.3

[0068] The molar ratio of vinylating agent / organolithium compound is preferably 0.2 or more from the viewpoint of a high vinyl bond content and a high polymerization rate, and is preferably 3.0 or less from the viewpoint of obtaining a narrow molecular weight distribution and high hydrogenation activity. The molar ratio of alkali metal alkoxide / organolithium compound is preferably 0.01 or more from the viewpoints of a high vinyl bond content, a high polymerization rate, and a high block ratio, and is preferably 0.3 or less from the viewpoints of a narrow molecular weight distribution and high hydrogenation activity. This improves the polymerization rate, increases the vinyl bond content of the target hydrogenated block copolymer (x), narrows the molecular weight distribution, and tends to improve the block ratio. As a result, by controlling the vinyl bond content of the hydrogenated block copolymer (x), it is possible to inhibit crystallization resulting from the polyethylene structure of the hydrogenated conjugated diene block portion, thereby enabling the copolymer to exhibit flexible, elastic properties. Furthermore, in addition to functioning as a compatibilizer, it is also possible to meet various required properties depending on the application, such as impact resistance, flexibility, and transparency.

[0069] The optimum polymerization temperature in the polymerization step of the hydrogenated block copolymer (x) varies depending on the polymer structure, but in the case of anionic polymerization using a polymerization initiator, it is generally in the range of -10°C to 150°C, preferably 10°C to 100°C. The time required for polymerization is usually within 48 hours, preferably in the range of 0.1 to 10 hours. It is also preferable to replace the atmosphere of the polymerization system with an inert gas such as nitrogen gas. The polymerization pressure is not particularly limited as long as it is within a pressure range sufficient to maintain the monomer and polymerization solvent in a liquid phase within the above-mentioned polymerization temperature range. Furthermore, it is preferable to take care to prevent impurities such as water, oxygen, carbon dioxide gas, etc., which may inactivate the polymerization initiator and the living polymer from being unintentionally mixed into the polymerization system.

[0070] When obtaining a hydrogenated block copolymer (x) containing a random copolymer block, it is preferable to employ a method in which a mixture of a vinyl aromatic compound and a conjugated diene compound is continuously supplied to a polymerization system and polymerized, and / or a method in which a polar compound or a randomizing agent is used to copolymerize a vinyl aromatic compound and a conjugated diene compound.

[0071] When an organic alkali metal is used as a polymerization initiator in the production of the hydrogenated block copolymer (x), the polymerization reaction is generally terminated by adding, as a polymerization terminator, a compound containing a hydroxy group or a carboxy group, such as ethanol or a fatty acid, which is capable of providing active hydrogen, in an amount equimolar to the organolithium compound used as the polymerization initiator. On the other hand, in producing the hydrogenated block copolymer (x) that constitutes the recycled ABS resin composition of this embodiment, preferred methods include using a coupling reaction in which a heteroatom-containing coupling agent is used to bond two or more molecules to terminate the polymerization reaction, or using a heteroatom-containing modifier, particularly a modifier that can form an amino group, as a polymerization terminator to introduce a functional group into the polymerization terminal and terminate the polymerization reaction, to produce the modified hydrogenated block copolymer (b*).

[0072] The method of using a modifying agent capable of forming an amino group at the polymer terminal as a polymerization terminator will be described in detail later in the section entitled "Modification Step."

[0073] The coupling reaction at the time of terminating the polymerization can be carried out by adding a coupling agent exemplified below to the polymerization system. Furthermore, by adjusting the amount of coupling agent added, only a portion of the polymers in the polymerization system can be coupled, allowing uncoupled polymers and coupled polymers to coexist, thereby producing a hydrogenated block copolymer (x) having two or more peaks in the molecular weight distribution. Furthermore, coupling agents generally contain heteroatoms, and functional groups containing heteroatoms derived from the coupling agent residues in the polymer chains exhibit a modifying effect even after the coupling reaction. Therefore, hydrogenated block copolymers produced using coupling reactions can also be considered modified hydrogenated block copolymers (b*) if the presence of coupling agent residues can be confirmed.

[0074] The coupling agent that can be suitably used in the production of the hydrogenated block copolymer (x) is not particularly limited, but examples thereof include any coupling agent having two or more functionalities. Specific examples include silane compounds containing an amino group, such as tetraglycidyl meta-xylenediamine, tetraglycidyl-1,3-bisaminomethylcyclohexane, tetraglycidyl-p-phenylenediamine, tetraglycidyldiaminodiphenylmethane, diglycidylaniline, diglycidylorthotoluidine, γ-glycidoxyethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxybutyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltripropoxysilane, and γ-glycidoxypropyltributoxysilane. Other coupling agents include, for example, 1-[3-(triethoxysilyl)-propyl]-4-methylpiperazine, 1-[3-(diethoxyethylsilyl)-propyl]-4-methylpiperazine, 1-[3-(trimethoxysilyl)-propyl]-3-methylimidazolidine, 1-[3-(diethoxyethylsilyl)-propyl]-3-ethylimidazolidine, 1-[3-(triethoxysilyl)-propyl]-3-methylhexahydropyrimidine, 1-[3-(dimethoxymethylsilyl)-propyl]-3-methylhexahydropyrimidine, 1-[3-(dimethoxymethylsilyl)-propyl]-3-methylhexahydropyrimidine, 1-[3-(triethoxysilyl)-propyl]-3-methylhexahydropyrimidine, 1-[3-(triethoxysilyl)-propyl]-3-methylhexahydropyrimidine, 1-[3-(triethoxymethyl ...

[0033] Examples of silane compounds containing a silyl group include 1-(2-ethoxyethyl)-3-[3-(trimethoxysilyl)-propyl]-imidazolidine, 2-(2-ethoxyethyl)-3-[3-(trimethoxysilyl)-propyl]-tetrahydropyrimidine, 2-(2-ethoxyethyl)-3-[3-(trimethoxysilyl)-propyl]-tetrahydropyrimidine, 2-(2-ethoxyethyl)-3-[3-(trimethoxysilyl)-propyl]-tetrahydropyrimidine, and 2-(2-ethoxyethyl)-3-[3-(trimethoxysilyl)-propyl]-tetrahydropyrimidine.

[0075] Other coupling agents include, for example, γ-glycidoxypropyltriphenoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylethyldimethoxysilane, γ-glycidoxypropylethyldiethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropylmethyldipropoxysilane, γ-glycidoxypropylmethyldibutoxysilane, γ-glycidoxypropylmethyldiphenoxysilane, γ-glycidoxypropyldimethylmethoxysilane, γ-glycidoxypropyldiethylethoxysilane, γ-glycidoxypropyldimethylethoxysilane, γ-glycidoxypropyldimethylphenoxysilane, γ-glycidoxypropyldiethylmethoxysilane, γ-glycidoxypropyldimethylethoxysilane, γ-glycidoxypropyldimethylphenoxysilane, γ-glycidoxypropyldiethylmethoxysilane, γ-glycidoxypropyldimethylphenyl ... Examples of silane compounds containing a glycidoxy group include silane compounds such as bis(γ-glycidoxypropyl)methyldiisopropeneoxysilane, bis(γ-glycidoxypropyl)dimethoxysilane, bis(γ-glycidoxypropyl)diethoxysilane, bis(γ-glycidoxypropyl)dipropoxysilane, bis(γ-glycidoxypropyl)dibutoxysilane, bis(γ-glycidoxypropyl)diphenoxysilane, bis(γ-glycidoxypropyl)methylmethoxysilane, bis(γ-glycidoxypropyl)methylethoxysilane, bis(γ-glycidoxypropyl)methylpropoxysilane, bis(γ-glycidoxypropyl)methylbutoxysilane, and bis(γ-glycidoxypropyl)methylphenoxysilane tris(γ-glycidoxypropyl)methoxysilane.

[0076] Other coupling agents include silane compounds containing a methacryloxy group, such as γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-methacryloxymethyltrimethoxysilane, γ-methacryloxyethyltriethoxysilane, bis(γ-methacryloxypropyl)dimethoxysilane, and tris(γ-methacryloxypropyl)methoxysilane.

[0077] Further, other coupling agents include, for example, β-(3,4-epoxycyclohexyl)ethyl-trimethoxysilane, β-(3,4-epoxycyclohexyl)ethyl-triethoxysilane, β-(3,4-epoxycyclohexyl)ethyl-tripropoxysilane, β-(3,4-epoxycyclohexyl)ethyl-tributoxysilane, β-(3,4-epoxycyclohexyl)ethyl-triphenoxysilane, β-(3,4-epoxycyclohexyl)propyl-trimethoxysilane, β-(3,4-epoxycyclohexyl)ethyl-methyldimethoxysilane, β-(3,4-epoxycyclohexyl)ethyl-ethyldimethoxysilane, β-(3,4-epoxycyclohexyl)ethyl-ethyldiethoxysilane, β-(3,4-epoxycyclohexyl)ethyl-methyldiethoxysilane, β-(3,4-epoxycyclohexyl)ethyl-methyldipropoxy Examples of silane compounds containing an epoxycyclohexyl group include silane, β-(3,4-epoxycyclohexyl)ethyl-methyldibutoxysilane, β-(3,4-epoxycyclohexyl)ethyl-methyldiphenoxysilane, β-(3,4-epoxycyclohexyl)ethyl-dimethylmethoxysilane, β-(3,4-epoxycyclohexyl)ethyl-diethylethoxysilane, β-(3,4-epoxycyclohexyl)ethyl-dimethylethoxysilane, β-(3,4-epoxycyclohexyl)ethyl-dimethylpropoxysilane, β-(3,4-epoxycyclohexyl)ethyl-dimethylbutoxysilane, β-(3,4-epoxycyclohexyl)ethyl-dimethylphenoxysilane, β-(3,4-epoxycyclohexyl)ethyl-diethylmethoxysilane, and β-(3,4-epoxycyclohexyl)ethyl-methyldiisopropeneoxysilane. Other coupling agents include, for example, 1,3-dimethyl-2-imidazolidinone, 1,3-diethyl-2-imidazolidinone, N,N'-dimethylpropylene urea, and N-methylpyrrolidone.

[0078] When the coupling agent is added to the polymerization active terminal of the hydrogenated block copolymer to obtain the modified hydrogenated block copolymer (b*), the structure of the living terminal of the hydrogenated block copolymer is not particularly limited. However, from the viewpoint of the mechanical strength of the recycled ABS resin composition of this embodiment, the living terminal is preferably a polymer block mainly composed of vinyl aromatic monomer units. The amount of the coupling agent used is preferably 0.05 equivalents or more and 1 equivalent or less, and more preferably 0.1 equivalents or more and 1 equivalent or less, relative to 1 equivalent of the living end of the hydrogenated block copolymer. The coupling agents may be used alone or in any combination of two or more.

[0079] It is also possible to produce a modified hydrogenated block copolymer (b*) having both a functional group containing a heteroatom and an amino group by using a coupling agent having a functional group containing a heteroatom and a modifying agent capable of forming an amino group at the polymer terminal, taking into consideration the molar amount of the organolithium compound. When a modifying agent capable of forming an amino group at the polymer terminal is not used, and when no heteroatom remains in the polymer molecular chain after the coupling reaction among the above coupling agents, the copolymer is not treated as a modified hydrogenated block copolymer (b*). The heteroatom-containing functional group is expected to exhibit interactions such as hydrogen bonding with the recycled ABS resin (a). For example, when a coupling reaction is carried out using tetraglycidyl-1,3-bisaminomethylcyclohexane, which is four-functional and has a tertiary amino group and an epoxy group, it can be easily estimated from a molecular weight distribution curve obtained by GPC that an average of 0.8 unreacted coupling residues are present, assuming that the ratio of the number average molecular weight Mn of the uncoupled polymer to the number average molecular weight Mn of the coupled polymer is 3.2 times.

[0080] [Hydrogenation process] The hydrogenated block copolymer (x) is produced by a step of hydrogenating some or all of the double bonds in the conjugated diene monomer units of the block copolymer obtained in the polymerization step. Catalysts used in hydrogenation reactions include, but are not limited to, supported heterogeneous catalysts in which a metal such as Ni, Pt, Pd, or Ru is supported on a support such as carbon, silica, alumina, or diatomaceous earth; so-called Ziegler-type catalysts that use an organic salt or acetylacetone salt of Ni, Co, Fe, Cr, or the like with a reducing agent such as organoaluminum; so-called organic complex catalysts such as organometallic compounds of Ru, Rh, etc.; and homogeneous catalysts that use a titanocene compound and an organolithium, organoaluminum, organomagnesium, or the like as a reducing agent. Among these, from the viewpoints of economy, polymer colorability, and adhesive strength, homogeneous catalyst systems that use a titanocene compound and an organolithium, organoaluminum, organomagnesium, or the like as a reducing agent are preferred.

[0081] The hydrogenation method is not limited to the following, but examples thereof include the methods described in Japanese Patent Publication Nos. 42-8704 and 43-6636, and preferably the methods described in Japanese Patent Publication Nos. 63-4841 and 63-5401. Specifically, a hydrogenated block copolymer solution can be obtained by hydrogenating the copolymer in an inert solvent in the presence of a hydrogenation catalyst. The hydrogenation reaction is not particularly limited, but is preferably carried out after the deactivation step of the active terminals of the polymer described above, from the viewpoint of exhibiting high hydrogenation activity. The hydrogenation step can be carried out by a batch process, a continuous process, or a combination thereof.

[0082] In the hydrogenation step, some of the conjugated bonds of the vinyl aromatic monomer units may be hydrogenated. The hydrogenation rate of conjugated bonds in all vinyl aromatic monomer units is preferably 30 mol % or less, more preferably 10 mol % or less, and even more preferably 3 mol % or less. Considering that the mechanical properties are expressed by forming a microphase-separated structure, it is preferable that the vinyl aromatic monomer units are not hydrogenated and are close to 0 mol %.

[0083] [Denaturation process] The hydrogenated block copolymer (x) contains at least 30% by mass of the modified hydrogenated block copolymer (b*) which is produced by introducing a functional group through a modification step. The modified hydrogenated block copolymer (b*) and the unmodified hydrogenated block copolymer (b) may be the same or different in the ratio of vinyl aromatic monomer units to conjugated diene monomer units, hydrogenation rate, molecular weight, etc.

[0084] Known methods can be applied as the modification method. In the polymerization step, a modification method (called terminal modification) may be carried out by using a compound having a functional group as a polymerization initiator and / or polymerization terminator, or a modification method (called main chain modification) may be carried out by adding an unsaturated compound having a functional group to the hydrogenated block copolymer after the polymerization step using a single-screw or twin-screw extruder with or without using a radical generator. To introduce a functional group using a polymerization initiator, polymerization is generally carried out using the above-mentioned organic amino alkali metal compound.

[0085] Specific methods for introducing functional groups into hydrogenated block copolymers include, for example, melt-kneading using an extruder or reacting by dissolving, dispersing, and mixing in a solvent. This is called a grafting reaction or main chain modification. In addition, in the process of polymerizing the hydrogenated block copolymer (x), it is also possible to use a method of polymerization using a monomer having a functional group, or a method of terminating the polymerization by modifying with a compound having a functional group instead of alcohols, which are commonly used for polymerization termination reactions. This is called terminal modification.

[0086] Modifiers that form functional groups in polymers, specifically those that can form carboxylic acid groups or dicarboxylic acid anhydride groups or that contain these functional groups, include, but are not limited to, maleic acid, maleic anhydride, maleic anhydride imide, fumaric acid, itaconic acid, acrylic acid, methacrylic acid, glycidyl methacrylate, and crotonic acid. By using these, it is possible to form polymer graft chains mainly on the main chain of the hydrogenated block copolymer, and by adjusting the amount added and the addition reaction conditions, it is possible to prepare a modified block copolymer having multiple functional groups.

[0087] On the other hand, a terminally modified hydrogenated block copolymer having a functional group at the terminal can be obtained by adding a modifier capable of forming an amino group or a modifier containing an amino group, as exemplified below, to the polymerization system. The degree of modification can be controlled by adjusting the amount of the modifying agent capable of forming an amino group or the modifying agent containing an amino group added.

[0088] Modifiers capable of forming an amino group or modifiers containing an amino group include, but are not limited to, tetraglycidyl meta-xylenediamine, tetraglycidyl-1,3-bisaminomethylcyclohexane, ε-caprolactone, δ-valerolactone, 4-methoxybenzophenone, γ-glycidoxyethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyldimethylphenoxysilane, bis(γ-glycidoxypropyl)methylpropoxysilane, 1,3-dimethyl-2-imidazolidinone, 1,3-diethyl-2-imidazolidinone, N,N'-dimethylpropyleneurea, and N-methylpyrrolidone.

[0089] The amount of the modifier added to the hydrogenated block copolymer (x) can be measured by a known analytical method. A typical method is, for example, titration using sodium methoxide in the case of maleic anhydride modification.

[0090] The melt flow rate (ISO1133 temperature 230°C, load 2.16 kgf) of the hydrogenated block copolymer (x) is preferably 0.01 to 50 g / 10 min, more preferably 0.03 to 20 g / 10 min, and even more preferably 0.05 to 10 g / 10 min, from the viewpoint of the processability and mechanical properties of the recycled ABS resin composition of this embodiment. The hydrogenated block copolymer (x) is preferably domain-dispersed in the recycled ABS resin (a), and a low MFR of about 0.1 g / 10 min tends to be useful in terms of expressing physical properties, assuming that the copolymer is kneaded in a twin-screw extruder.

[0091] (Other additives that can be blended into recycled ABS resin compositions) The recycled ABS resin composition of the present embodiment may contain any compounding agent or additive within the scope of the present invention and within the scope of the present invention. Examples of compounding agents and additives include those commonly used in compounding resins and rubbery polymers, and include, but are not limited to, inorganic fillers such as calcium carbonate, magnesium carbonate, silica, zinc oxide, and carbon black; higher alcohols such as stearyl alcohol; higher fatty acids such as palmitic acid, stearic acid, and behenic acid; higher fatty acid metal salts such as zinc stearate, calcium stearate, magnesium stearate, magnesium behenate, and hydrogenated magnesium ricinoleate; lubricants and release agents such as fatty acid amides such as erucic acid amide and ethylene bisstearylamide; organic polysiloxanes such as paraffin oil, process oil, dimethyl silicone, and methylphenyl silicone; softeners and plasticizers such as mineral oil; hindered phenol-based and phosphorus-based heat stabilizers and antioxidants; hindered amine-based light stabilizers; benzotriazole-based ultraviolet absorbers; halogen-based and phosphorus-based flame retardants; reinforcing agents such as organic fibers, glass fibers, carbon fibers, and metal whiskers; and colorants such as organic pigments, inorganic pigments, and organic dyes.

[0092] (Method of manufacturing recycled ABS resin composition) The method for producing the recycled ABS resin composition of this embodiment is not particularly limited, but may include, for example, pelletizing recycled ABS resin (a) recovered from a product using an extruder or the like, combining the recycled ABS resin (a) with hydrogenated block copolymer (x) essentially containing modified hydrogenated block copolymer (b*), and dry-blending the pellets at room temperature, with or without a tumbler or Henschel mixer as needed. The resulting mixture is then fed into a twin-screw extruder hopper, melt-kneaded in the twin-screw extruder, and the melted ABS resin composition is extruded from a die in the form of strands, which are then pelletized again through a cooling bath to obtain a pelletized ABS resin composition. The heat-melt kneading is not particularly limited as long as it is a kneader for a thermoplastic resin that can be heated and melted. For example, kneaders such as a kneader, a Banbury mixer, a roll, a ribbon blender, a single-screw extruder, or a twin-screw extruder can be suitably used. In addition to the strand cutting method using a cooling bath, other methods such as hot cutting and underwater cutting can also be preferably used depending on the purpose.

[0093] (mass ratio of recycled ABS resin to hydrogenated block copolymer (x)) In the recycled ABS resin composition of this embodiment, the mass ratio of the recycled ABS resin (a) to the hydrogenated block copolymer (x) is (a) / (x)=99 / 1 to 80 / 20, preferably (a) / (x)=97 / 3 to 85 / 15, and more preferably 96 / 4 to 90 / 10. By using the above mass ratio, it is possible to obtain a recycled ABS resin composition that has impact strength and other properties close to those of the original virgin ABS resin and has a balance of mechanical properties that makes it suitable for practical use. [Example]

[0094] Hereinafter, the present embodiment will be described in more detail with reference to specific examples and comparative examples, but the present invention is not limited to the following examples and comparative examples in any way.

[0095] [Recycled ABS resin (a), virgin ABS resin (a*)] The recycled ABS resins (a) used were automobile-derived recycled ABS resin (a)-1 and home appliance-derived recycled ABS resin (a)-2, both of which were manufactured and sold by Kansai Chemical Industry Co., Ltd. and produced using both gravity separation and electrostatic separation techniques. On the other hand, virgin ABS resin (a*) was obtained from "Polylac PA-757", an ABS resin manufactured and sold by Chi Mei Industrial Co., Ltd., and used as virgin ABS resin (a*)-3. The melt flow rate of Polylac PA-757 was 23 g / 10 min under the conditions of ISO1133 temperature 220°C and load 10 kgf.

[0096] [Identification of impurities contained in recycled ABS resin (a) and calculation of the purity of ABS resin] Approximately 0.2 g of the obtained recycled ABS resin (a) of unknown composition was precisely weighed and dissolved in 10 mL of chloroform in a centrifuge tube. The solution was then centrifuged to separate it into (1) an upper insoluble layer, (2) a soluble layer, and (3) a precipitated insoluble layer. In the upper insoluble layer (1), in addition to ABS gel rubber, thermoplastic resins insoluble in chloroform, such as polyolefins and polyamides, were separated. The matrix components of the ABS resin were mainly separated from the soluble matter (2). The precipitated insoluble matter (3) was mainly separated as inorganic matter. After carrying out the necessary pretreatment for each of these separated components, the impurity components were identified and quantified using ATR-IR spectroscopy and 1H-NMR, and by using internal standards, etc. as necessary. In this way, information on the purity and impurity components of the ABS resin was obtained. Table 1 below shows the properties (purity, impurities, melt flow rate) of various ABS resins.

[0097] [Table 1]

[0098] [Hydrogenated block copolymer (x)] Of the hydrogenated block copolymers (x), only the hydrogenated block copolymer (b*)-1 below was produced according to the production example shown below. The other hydrogenated block copolymers (b*)-2 to 4 and (b)-5 to 7 used were various brands of Tuftec (registered trademark) and Asaprene (registered trademark) manufactured and sold by Asahi Kasei Corporation. The melt flow rate of the hydrogenated block copolymer (x) was measured in accordance with standard ISO1133 at a temperature of 230°C and a load of 2.16 kgf. The actual hydrogenation rate (mol %) of each of the Tuftec (registered trademark) and Asaprene (registered trademark) products is listed in Table 2 below as 30 or more (selective hydrogenation). Furthermore, even in the case of fully hydrogenated products, it is difficult to achieve an actual hydrogenation rate of 100 mol %, so the actual measured hydrogenation rates were 97 mol % for each.

[0099] (Production of hydrogenation catalyst) The hydrogenation catalyst was prepared as follows. 1 L of dried and purified cyclohexane was placed in a nitrogen-purged reaction vessel, and 100 mmol of bis(cyclopentadienyl)titanium dichloride was added. With thorough stirring, an n-hexane solution containing 200 mmol of trimethylaluminum was added, and the mixture was allowed to react at room temperature for approximately 3 days to obtain a hydrogenation catalyst.

[0100] (Production of hydrogenated block copolymer) The following hydrogenated block copolymer (b*)-1 was produced according to the following production example. <Production Example: Hydrogenated Block Copolymer (b*)-1> A predetermined amount of cyclohexane was placed in a jacketed tank reactor, and the temperature inside the reactor was adjusted to 65°C under a nitrogen gas atmosphere. Next, 0.17 parts by mass of n-butyllithium and 0.30 parts by mass of tetramethylmethylenediamine were added. Subsequently, a cyclohexane solution containing 20 parts by mass of styrene at a concentration of 25% by mass was fed into the reactor over about 10 minutes, after which the reaction was continued for 15 minutes. Subsequently, a cyclohexane solution containing 58 parts by mass of 1,3-butadiene and 22 parts by mass of styrene at a concentration of 25% by mass was supplied to the reactor over 30 minutes. After the reaction, the temperature inside the reactor was adjusted to 65°C and the reaction was continued for 10 minutes. Subsequently, 0.2 equivalents of tetraglycyl-1,3-bisaminomethylcyclohexane (CAS number: 65992-66-7, molecular weight: 366.5) was added as a coupling agent relative to n-butyllithium, and the mixture was reacted at 80° C. for 5 minutes.

[0101] Thereafter, in order to completely terminate the polymerization, 0.4 equivalents of ethanol relative to n-butyllithium was added to the reactor to terminate the polymerization reaction. Next, the hydrogenation catalyst was added to the obtained polymer solution in an amount of 80 ppm in terms of titanium per 100 parts by mass of the polymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.5 MPa and a temperature of 75° C. The hydrogenation rate was adjusted by adjusting the amount of hydrogen supplied to the reactor. After the hydrogenation reaction was completed, 0.25 parts by mass of octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate was added as an antioxidant to 100 parts by mass of the block copolymer.

[0102] Subsequently, the polymer solution was concentrated to a certain extent by heating and reducing the pressure, and then fed to a twin-screw extruder equipped with a degassing function, and the hydrogenated block copolymer (b*)-1 was recovered. The hydrogenated block copolymer (b*)-1 thus obtained had a styrene content of 42% by mass, a butadiene content of 58% by mass, and a hydrogenation rate of 75% by mole. The hydrogenated block copolymer (b*)-1 was a mixture of the S1-S / B1 structure and the (S1-S / B1)X structure formed by coupling of the S1-S / B1 structure. Molecular weight measurement by GPC, which will be described later, revealed that the weight-average molecular weight of the S1-S / B1 structure was 46,000 and the weight-average molecular weight of the (S1-S / B1)X structure was 157,000, indicating that the block copolymer had these two peak molecular weights. The ratio of these molecular weights is 157,000 ÷ 46,000 = approximately 3.4. The coupling agent used, tetraglycol-1,3-bisaminomethylcyclohexane, has four epoxy groups per molecule, which suggests a difference from the above molecular weight ratio, that is, an average of 0.6 coupling agent residues, and indicates that the compound has an epoxy group with an oxygen atom as a heteroatom. The hydrogenated block copolymer (b*)-1 is a modified hydrogenated block copolymer having an epoxy group in the coupling agent residue as a functional group. The concentration of the coupling agent containing a functional group in the modified hydrogenated block copolymer (b*)-1 was calculated from its molecular weight and was found to be about 0.15%.

[0103] Table 2 below shows the characteristics of each hydrogenated block copolymer (type of heteroatom contained, type of functional group containing the heteroatom, amount of styrene, amount of butadiene, hydrogenation rate (for Tuftec or Asaprene products, type of complete hydrogenation or selective hydrogenation), weight average molecular weight, peak molecular weight, number of molecular weight peaks, and melt flow rate.

[0104] [Table 2]

[0105] (Molecular weight measurement by GPC) The GPC apparatus and measurement conditions used in the examples are described below. GPC equipment: Tosoh HLC-8420 Column: Four TSKgel SuperHZM-N columns connected in series Column temperature: 40℃ Fluid flow rate: 0.6 mL / min Detector: Refractometer (RI) Solvent: tetrahydrofuran

[0106] The sample for GPC measurement was prepared by dissolving about 10 mg of the polymer to be measured for molecular weight in 20 mL of tetrahydrofuran and filtering to remove insoluble matter.

[0107] The measurement method is described below. First, a calibration curve was created using nine standard polystyrene samples with known molecular weights. The highest molecular weight standard polystyrene had a weight average molecular weight (Mw) of 1,090,000, and the lowest molecular weight was 1,050. Next, measurement samples were prepared using each block polymer whose molecular weight was to be measured, as described above.

[0108] After confirming that the temperature inside the tank containing the column had become constant, the solution sample was injected and the measurement was started. After the measurement was completed, the obtained molecular weight distribution curve was statistically processed to calculate the weight average molecular weight (Mw) and number average molecular weight (Mn). The molecular weight distribution (Mw / Mn) was calculated by dividing the obtained weight average molecular weight (Mw) by the number average molecular weight (Mn). The peak molecular weight and the number of molecular weight peaks were determined from the above molecular weight distribution curve.

[0109] [Production of recycled ABS resin composition] Recycled ABS resin compositions were produced by the following method using recycled ABS resins (a)-1 and -2 shown in Table 1, virgin ABS resin (a*)-3 (Polylac PA-757), and hydrogenated block copolymers (b*)-1 to -4 and (b)-5 to -7 shown in Table 2.

[0110] The production was carried out using the following equipment: Twin-screw extruder TEX-30αII manufactured by Japan Steel Works Screw diameter 30mm, L / D=36

[0111] First, since the recycled ABS resin (a) had an irregular shape as it was coarsely crushed and was a mixture of white, black, gray, etc., it was homogenized and pelletized using the twin-screw extruder. The thus obtained homogenized recycled ABS resin (a) was dry-blended at room temperature in the form of pellets with the virgin ABS resin (a*), hydrogenated block copolymer (b), and (b*) in the composition ratios shown in the table below, and then melt-kneaded in the twin-screw extruder. The cylinder temperature was set to 220°C. Pellets of the recycled ABS resin composition were obtained by the strand cutting method.

[0112] [Characteristics of recycled ABS resin composition] The ABS resin compositions of the examples and comparative examples were evaluated for various properties as follows.

[0113] (mechanical properties) <Preparation of various test pieces using an injection molding machine> For the tensile test, bending test, and Charpy impact strength test, test specimens were prepared using an ISO test specimen mold with the following molding machine. Injection molding machine: Nissei Plastic Industrial Co., Ltd. FNX110III hybrid type Clamping pressure: 110 tons, cylinder temperature: 230°C, mold temperature: 60°C Test pieces for each test were injection molded and then cured for 24 hours in a constant temperature room at a room temperature of 23°C and a humidity of 50%, after which various characteristics were evaluated.

[0114] <Evaluation standards and conditions for mechanical properties> The detailed evaluation conditions for each mechanical property are as follows: The values in the table are the average values for each n number. Tensile test: Using a Minebea TG-5kN tension and compression testing machine, the test was carried out in accordance with ISO 527-1 at a tension speed of 50 mm / min in a thermostatic chamber at 23°C with an n number of 6. Bending test: Using a Minebea TG-5kN tension and compression testing machine, the test was carried out in accordance with ISO178 at a compression rate of 2 mm / min in a constant temperature room at 23°C with an n number of 4. Charpy impact test: In accordance with ISO 179, both notched and unnotched specimens were tested in a constant temperature room at 23°C, with an n value of 10 for each specimen. If the specimen did not break into two or more pieces after the test, it was marked as NB.

[0115] [Reference Examples 1 to 3, Examples 1 to 28, Comparative Examples 1 to 16] Various recycled ABS resin compositions were obtained by combining the recycled ABS resin (a) shown in Table 1 with, as needed, a virgin ABS resin (a*), and various unmodified hydrogenated block copolymers (b) and modified hydrogenated block copolymers (b*) shown in Table 2.

[0116] Subsequently, various test pieces were molded using the injection molding machine. Before injection molding, the samples were pre-dried at 90°C for 2 hours. The blending compositions and evaluations of the physical properties of the recycled ABS resin compositions obtained in each example are shown in Tables 3 to 6 below.

[0117] [Table 3]

[0118] [Table 4]

[0119] [Table 5]

[0120] [Table 6]

[0121] The physical property values shown in Reference Examples 1 and 3 were obtained by the inventors themselves through evaluation of the recycled ABS resin (a)-1 derived from automobiles and the recycled ABS resin (a)-2 derived from home appliances. The physical property values shown in Reference Example 2 were obtained by the inventors themselves through evaluation of Polylac PA-757 alone, which was used as the virgin ABS resin (a*)-3. In order to improve the accuracy of the evaluation, the catalog values for virgin ABS resin were not referred to, and the evaluation was carried out side by side at the same time using the same evaluation equipment as in each example. Comparing the results of Reference Examples 1 to 3, it was found that the virgin ABS resin (a*)-3 was superior in terms of the balance of mechanical properties such as rigidity and impact strength. It was found that recycled ABS resin is difficult to reuse on its own because it contains other resins and foreign matter and its physical properties deteriorate significantly over time, and even if it could be reused, its uses would be significantly limited.

[0122] Furthermore, from the results of the Examples in Tables 3 to 6, it was confirmed that the effect of improving the properties can be obtained by blending the modified hydrogenated block copolymer (b*) containing heteroatoms as the hydrogenated block copolymer (x) with the recycled ABS resin (a).

[0123] Among the modified hydrogenated block copolymers (b*), it was confirmed that the modification effect was more pronounced when a hydrogenated block copolymer modified with epoxy groups derived from coupling agent residues or a hydrogenated block copolymer modified with a terminal secondary amine was used than when a hydrogenated block copolymer modified with maleic anhydride was used, as is evident from a comparison of Example 4 with Examples 6 and 8 in Table 3.

[0124] Furthermore, we confirmed that adding even 1% by mass of modified hydrogenated block copolymer (b*) to a recycled ABS resin composition can improve its properties. This is evidenced by the fact that Example 9 in Table 4 shows good practical physical properties. Example 9 uses a hydrogenated block copolymer modified with a terminal secondary amine. It was revealed that even at a small blend amount, this modified hydrogenated block copolymer (b*) had a better balance of properties and a modifying effect than Reference Example 1, which used only recycled ABS resin (a). In other words, it was found that when a hydrogenated block copolymer modified with a terminal secondary amine was blended, the secondary amino group significantly contributed to improving the physical properties of the recycled ABS resin composition.

[0125] Furthermore, even when the modified hydrogenated block copolymer (b*) was added in an amount of 20 mass% of the recycled ABS resin composition, which is the upper limit of the range of the present invention, a modifying effect was obtained. This is evident from the fact that practically satisfactory physical properties were obtained in Example 10 in Table 4. However, considering that the amount added was a high content of 20 mass% in the recycled ABS-based resin composition, no corresponding improvement in properties was observed. Example 10 had a low flexural modulus, and the flexural modulus tended to decrease in proportion to the amount of modified hydrogenated block copolymer (b*) added. This revealed that there is little benefit to adding modified hydrogenated block copolymer (b*) in an amount exceeding 20 mass% in the recycled ABS-based resin composition.

[0126] On the other hand, it was revealed that blending a heteroatom-free unmodified hydrogenated block copolymer (b) with a recycled ABS resin (a) did not provide any modifying effect, resulting in a lower Charpy impact strength than that of the recycled ABS resin alone, and that increasing the blending amount further reduced the Charpy impact strength (unnotched). This is evident from the fact that Comparative Examples 1 to 6 in Table 3 have a worse balance of properties than Reference Example 1, and Comparative Examples 9 to 14 in Table 5 have a worse balance of properties than Reference Example 3, and that increasing the blending amount of unmodified hydrogenated block copolymer (b) reduced the Charpy impact strength.

[0127] Furthermore, although a modifying effect can be achieved by using the modified hydrogenated block copolymer (b*) in combination with the unmodified hydrogenated block copolymer (b), it was found that, if the same amount of hydrogenated block copolymer is added, a higher modifying effect can be obtained when the entire amount is modified hydrogenated block copolymer (b*). This is evident from the fact that Examples 25 to 28 have a better balance of properties than Examples 23 and 24 in Table 6.

[0128] In Comparative Examples 7 and 8 in Table 4 and Comparative Examples 15 and 16 in Table 6, recycled ABS resin (a) was blended with virgin ABS resin, without blending a hydrogenated block copolymer. These examples showed a greater improvement in properties than when only recycled ABS resin (a) was used, but the improvement was lower than when a similar amount of recycled ABS resin was used and blended with a hydrogenated block copolymer. This is evident in Table 4 by comparing Comparative Example 7 with Examples 11 and 12, and Comparative Example 8 with Examples 13 and 14. This is also evident in Table 6 by comparing Comparative Example 15 with Examples 25 and 26, and Comparative Example 16 with Examples 27 and 28.

[0129] The recycled ABS resin composition of the present invention has been found to have significantly improved impact strength compared to the recycled ABS resin alone. Although recycled resin recovered from the market is subject to deterioration over time and the inclusion of foreign matter, it has been confirmed that it is fully suitable for practical product design. [Industrial Applicability]

[0130] The recycled ABS resin composition of the present invention contributes significantly to the realization of carbon neutrality, while also contributing significantly to resource conservation through the effective use of waste plastics and reducing the burden on the global environment. Furthermore, it has great potential for industrial application as a material for a wide range of ABS resin molded products, including home appliances, automobiles, and daily necessities.

Claims

1. A recycled ABS resin (a), a hydrogenated block copolymer (x); A recycled ABS resin composition comprising: The hydrogenated block copolymer (x) is a block copolymer having at least one polymer block S mainly composed of vinyl aromatic monomer units and at least one polymer block B mainly composed of conjugated diene monomer units, 30 mol % or more of the conjugated diene moiety constituting the hydrogenated block copolymer (x) is hydrogenated, The hydrogenated block copolymer (x) is the hydrogenated block copolymer (x) contains 30% by mass or more and 100% by mass or less of a modified hydrogenated block copolymer (b*) in which at least one molecule of a heteroatom-containing functional group is chemically bonded to a polymer graft chain, a polymer end, or a coupling agent residue; The mass ratio of the recycled ABS resin (a) to the hydrogenated block copolymer (x) is (a) / (x)=99 / 1 to 80 / 20; Recycled ABS resin composition.

2. Further containing a virgin ABS resin (a*), The mass ratio of the recycled ABS resin (a) to the virgin ABS resin (a*) is (a) / (a*)=100 / 0 to 20 / 80; The recycled ABS resin composition according to claim 1.

3. The hydrogenated block copolymer (x) has a vinyl aromatic monomer unit content of 15% by mass to 50% by mass and a conjugated diene monomer unit content of 85% by mass to 50% by mass. The recycled ABS resin composition according to claim 1.

4. The modified hydrogenated block copolymer (b*) is At least one functional group is present at the polymer end and / or at the coupling agent residue. The recycled ABS resin composition according to claim 1.

5. The modified hydrogenated block copolymer (b*) has a functional group at at least one polymer terminal, and the functional group is any one selected from the group consisting of a primary amino group, a secondary amino group, and an epoxy group; The recycled ABS resin composition according to claim 4.

6. The recycled ABS resin (a) is recovered from consumer waste and / or industrial waste, The recycled ABS resin composition according to claim 1.

7. The recycled ABS resin (a) is The material is recovered from molded articles such as housings or mechanical parts that constitute any one selected from the group consisting of home appliances, information devices, communication devices, and automobiles. The recycled ABS resin composition according to claim 1.

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