Recycled flame-retardant styrene resin composition and molded article

Abstract

The object of the present invention is to provide a recycled flame-retardant styrene resin composition that reduces environmental impact by using recycled recovered styrene resin, and that has excellent flame retardancy, thermal stability, and light resistance. [Solution] The present invention is a recycled flame-retardant styrene resin composition comprising a recovered styrene resin (A) and a NOR-type hindered amine compound (B).

Description

Technical Field

[0001] The present invention relates to a recycled flame-retardant styrenic resin composition and a molded article containing the recycled flame-retardant styrenic resin composition.

Background Art

[0002] Styrenic resins are widely used in a wide range of applications because they are excellent in moldability, dimensional stability, and impact resistance. Among them, polystyrene-based resin compositions imparted with flame retardancy are used in a wide variety of applications including home appliances, OA equipment, packaging containers, and heat insulation materials, and are used for members that require design properties such as exterior parts and transparent parts.

[0003] In recent years, due to problems such as environmental issues and resource depletion, the recycling of materials has been demanded, and the recycling of materials has been promoted, and material recycling has been carried out. On the other hand, due to the deterioration and coloring of styrenic resins, the improvement of the quality and functionality of material recycled products has hardly been carried out.

[0004] For example, Patent Documents 1 to 3 disclose flame-retardant styrenic resins containing NOR-type hindered amine compounds in styrenic resins. Further, Patent Document 4 discloses a recycled resin composition in which a resin fluidity modifier and a phosphorus-based flame retardant are blended in a recovered styrenic resin.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

[0006] However, while Patent Documents 1-3 describe the effectiveness of thinning and flame retarding styrene resins, there are no examples of using recycled styrene resins (or recovered styrene resins), and there is no description whatsoever regarding the effects or characteristics of such recycled materials. Furthermore, Patent Document 4 states that although flame retardancy and fluidity are excellent, the thermal stability is insufficient due to degraded products and impurities contained in the recycled styrene resin, resulting in problems such as molding defects and burning. In addition, there was a problem that the light resistance was greatly impaired due to degraded products in the recycled styrene resin.

[0007] Therefore, the object of the present invention is to provide a recycled flame-retardant styrene resin composition that reduces environmental impact by using recycled recovered styrene resin (A), and has excellent flame retardancy, thermal stability, and light resistance. [Means for solving the problem]

[0008] As a result of diligent research to solve the above problems, the inventors of the present invention have found that by using a recycled flame-retardant styrene resin containing a recovered styrene resin (A) and a NOR-type hindered amine compound (B), it is possible to reduce the environmental impact, achieve excellent flame retardancy, and have good thermal stability and light resistance, thus completing the present invention.

[0009] In other words, the present invention is as follows. [1] A recycled flame-retardant styrene resin composition comprising a recovered styrene resin (A) and a NOR-type hindered amine compound (B).

[0010] [2] Preferably, the content of the NOR-type hindered amine compound (B) is 0.1 to 5.0 parts by mass per 100 parts by mass of the recovered styrene resin (A).

[0011] [3] Preferably, the recovered styrene resin (A) makes up 50% or more of the total.

[0012] [4] Preferably, the recovered styrene resin (A) contains 0.1 to 30 parts by mass of a flame retardant (C) per 100 parts by mass.

[0013] [5] Furthermore, it is preferable that the flame retardant (C) is a phosphorus-based flame retardant.

[0014] [6] A molded article characterized by containing the recycled flame-retardant styrene resin composition described in any one of the above items [1] to [5]. [Effects of the Invention]

[0015] According to the present invention, it is possible to provide a recycled flame-retardant styrene resin composition that reduces environmental impact by using recycled recovered styrene resin, and has excellent flame retardancy, thermal stability, and light resistance. [Modes for carrying out the invention]

[0016] The embodiments of the present invention (hereinafter referred to as "this embodiment") will be described in detail below, but the present invention is not limited to the following description and can be implemented in various ways within the scope of its gist.

[0017] [Recycled flame-retardant styrene resin composition] This embodiment is characterized by a recycled flame-retardant styrene resin composition comprising a recovered styrene resin (A) and a NOR-type hindered amine compound (B). This makes it possible to provide a recycled flame-retardant styrene resin composition that exhibits excellent flame retardancy, thermal stability, and light resistance compared to the recovered styrene resin (A).

[0018] <Recovered styrene resin (A): Component (A)> The recycled flame-retardant styrene resin composition of this embodiment contains, as an essential component, recovered styrene resin (A). In the recycled flame-retardant styrene resin composition of this embodiment, the recovered styrene resin (A) is a pre-consumer material such as factory-recovered products, a post-consumer material such as market-recovered products, and may also include long-term stock pellets and off-spec pellets. Furthermore, the recovered styrene resin (A) can be a flame-retardant styrene resin containing a phosphorus-based flame retardant, and may also contain liquid paraffin, stabilizers, colorants, etc., and can be used in products where other resins are laminated. Pre-consumer materials are materials collected and reused from scraps and defective products generated during the production process of styrene resin products, as well as styrene resin products that were left unsold or discarded before shipment after their quality assurance period had expired. Post-consumer materials are materials that have been shipped to the market and collected and reused after consumers have finished using them. In this invention, from the viewpoint of manufacturing products with a low environmental impact and promoting green purchasing and improved recycling rates, it is preferable that the "recovered styrene resin (A)" in the styrene resin composition is a post-consumer material. Specific examples of recovered styrene resin (A) suitable as a post-consumer material include expanded polystyrene, extruded sheets, containers, packaging materials, cases for recording media such as CDs and MDs, bobbins, hangers and other miscellaneous goods, and plastic parts for electrical and office automation equipment. The recovered styrene resin (A) may be mixed with unused styrene resin depending on the application. From the viewpoint of resource recovery, it is preferable that the recycled flame-retardant styrene resin composition contains 50% by mass or more of the recovered styrene resin, and more preferably 60% by mass or more. Furthermore, examples of recovered styrene resin (A) include styrene resin recovered from home appliances and other items collected under the Home Appliance Recycling Law, resin recovered from resin products marked as PS, etc., and recovered items that are clearly polystyrene, such as expanded polystyrene. If necessary, a sorting process for recovered styrene resin (A) may be performed to separate the recovered styrene resin (A) from the recovered material using known methods such as specific gravity and IR sorting.

[0019] The recovered styrene-based resin (A) that can be used in this embodiment is preferably a resin obtained by polymerizing a styrene monomer with one or more vinyl monomers and rubbery polymers (a) that can copolymerize with the styrene monomer as needed. In other words, the recovered styrene-based resin (A) is preferably a polymer having styrene monomer units, and more preferably a polymer (for example, a rubber-modified styrene-based resin and / or a styrene-based copolymer resin) that essentially contains styrene monomer units and optionally contains monomer units of other vinyl monomers and / or rubbery polymers (a) copolymerizable with the styrene monomer units. Furthermore, the recovered styrene-based resin (A) that can be used in this embodiment preferably contains 70% by mass or more of styrene monomer units relative to the total recovered styrene-based resin (A). Therefore, the recovered styrene-based resin (A) in this embodiment preferably contains one or more selected from the group consisting of polymers containing styrene monomer units, rubber-modified styrene-based resins and styrene-based copolymer resins. The preferred composition of the recovered styrene resin (A) in this embodiment is not particularly limited, but specifically, examples include a rubber-modified styrene resin in which particles of the rubbery polymer (a) are dispersed in a polymer matrix containing polystyrene, a polystyrene polymer (such as a polystyrene and / or polystyrene-unsaturated carboxylic acid polymer), or a styrene copolymer resin.

[0020] <Polystyrene> In this embodiment, the polystyrene usable as the recovered styrene-based resin (A) is a (single) polymer obtained by polymerizing styrene monomers, and generally available ones can be appropriately selected and used. Examples of styrene monomers constituting polystyrene include, in addition to styrene, α-methylstyrene, α-methyl-p-methylstyrene, ο-methylstyrene, m-methylstyrene, p-methylstyrene, vinyltoluene, ethylstyrene, isobutylstyrene, and styrene derivatives such as t-butylstyrene or bromostyrene and indene. Styrene is particularly preferred from an industrial standpoint. One or more of these styrene monomers can be used. Polystyrene may further contain monomer units other than the above-mentioned styrene monomer units, as long as it does not impair the effects of the present invention, but it typically consists of styrene monomer units.

[0021] <<Rubber-modified styrene resin>> In this embodiment, the rubber-modified styrene resin that can be used as the recovered styrene resin (A) is a styrene resin matrix in which particles of a rubbery polymer (a) are dispersed, and it can be produced by polymerizing a styrene monomer in the presence of the rubbery polymer (a).

[0022] In addition to styrene, the styrene monomers constituting the rubber-modified styrene resin of this embodiment include, for example, α-methylstyrene, α-methylp-methylstyrene, ο-methylstyrene, m-methylstyrene, p-methylstyrene, vinyltoluene, ethylstyrene, isobutylstyrene, and styrene derivatives such as t-butylstyrene or bromostyrene and indene. Styrene is particularly preferred. One or more of these styrene monomers can be used.

[0023] The rubber-like polymer (a) contained in the rubber-modified styrene resin of this embodiment may, for example, contain a resin containing styrene monomer units obtained from the above-mentioned styrene monomer inside the rubber-like polymer (a), and / or may have a resin containing styrene monomer units grafted onto the surface of the rubber-like polymer (a).

[0024] As the rubbery polymer (a), for example, rubber components such as polybutadiene, polyisoprene, natural rubber, polychloroprene, styrene-butadiene copolymer, and acrylonitrile-butadiene copolymer can be used. Furthermore, the rubber component may also contain polystyrene and / or polystyrene-unsaturated carboxylic acid polymers. Among these, polybutadiene or styrene-butadiene copolymer is preferred as the rubbery polymer (a). Both high-cis polybutadiene with a high cis content and low-cis polybutadiene with a low cis content can be used for the polybutadiene. Furthermore, both random and block structures can be used for the styrene-butadiene copolymer. One or more of these rubbery polymers (a) can be used. Saturated rubber obtained by hydrogenating butadiene-based rubber can also be used.

[0025] Examples of such rubber-modified styrene resins include HIPS (high-impact polystyrene), ABS resin (acrylonitrile-butadiene-styrene copolymer), AAS resin (acrylonitrile-acrylic rubber-styrene copolymer), and AES resin (acrylonitrile-ethylene propylene rubber-styrene copolymer).

[0026] When the rubber-modified styrene resin is a HIPS resin, among these rubbery polymers (a), high-cis polybutadiene composed of 90 mol% or more cis-1,4 bonds is particularly preferred. In the high-cis polybutadiene, it is preferable that vinyl-1,2 bonds be composed of 6 mol% or less, and particularly preferable that they be composed of 3 mol% or less.

[0027] Furthermore, the content of isomers of the constituent units of the above-mentioned isis-polybutadiene that have a cis-1,4 structure, a trans-1,4 structure, or a vinyl-1,2 structure can be calculated by measuring with an infrared spectrophotometer and processing the data using the Morello method.

[0028] Furthermore, the above-mentioned high-cis polybutadiene can be easily obtained by polymerizing 1,3-butadiene using a known production method, for example, a catalyst containing an organoaluminum compound and a cobalt or nickel compound.

[0029] The content of the rubber-like polymer (a) in the rubber-modified styrene resin is preferably 3 to 20% by mass, and more preferably 5 to 15% by mass, based on 100% by mass of the total amount of the rubber-modified styrene resin. If the content of the rubber-like polymer (a) is less than 3% by mass, the impact resistance of the styrene resin may decrease. Also, if the content of the rubber-like polymer (a) exceeds 20% by mass, the flame retardancy may decrease.

[0030] In this disclosure, the content of the rubbery polymer (a) contained in the rubber-modified styrene resin is a value calculated using pyrolysis gas chromatography.

[0031] The average particle size of the rubbery polymer (a) contained in the rubber-modified styrene resin is preferably 0.5 to 4.0 μm, and more preferably 0.8 to 3.5 μm, from the viewpoint of impact resistance and flame retardancy.

[0032] In this disclosure, the average particle size of the rubbery polymer (a) contained in the rubber-modified styrene resin can be measured by the following method. Ultrathin sections with a thickness of 75 nm were prepared from a rubber-modified styrene resin stained with osmium tetroxide, and photographs were taken at a magnification of 10,000x using an electron microscope. In the photograph, the black-stained particles are the rubbery polymer (a). From the photograph, the following formula (N1) was derived: Average particle size=ΣniDri 3 / ΣniDri 2 (N1) (In the above formula (N1), ni is the number of rubbery polymer (a) particles with particle size Dri, and particle size Dri is the particle size calculated as the equivalent circle diameter from the area of ​​the particles in the photograph.) The area-average particle diameter is calculated and used as the average particle diameter of the rubbery polymer (a). This measurement is performed by scanning a photograph at a resolution of 200 dpi and measuring it using the particle analysis software of the image analysis device IP-1000 (manufactured by Asahi Kasei Corporation).

[0033] The reduced viscosity of the rubber-modified styrene resin (which is an indicator of the molecular weight of the rubber-modified styrene resin) is preferably in the range of 0.50 to 0.85 dL / g, and more preferably in the range of 0.55 to 0.80 dL / g. If it is less than 0.50 dL / g, the impact strength may decrease, and if it exceeds 0.85 dL / g, the moldability may decrease due to a decrease in fluidity.

[0034] In this disclosure, the reduced viscosity of the rubber-modified styrene resin is the value measured in a toluene solution at 30°C and a concentration of 0.5 g / dL.

[0035] The method for producing rubber-modified styrene resins is not particularly limited, but they can be produced by bulk polymerization (or solution polymerization) in which styrene monomers (and a solvent) are polymerized in the presence of a rubbery polymer (a), or by bulk-suspension polymerization in which the reaction transitions to suspension polymerization, or by emulsion graft polymerization in which styrene monomers are polymerized in the presence of a rubbery polymer (a) latex. In bulk polymerization, the resin can be produced by continuously supplying a mixed solution of the rubbery polymer (a), styrene monomers, and optionally an organic solvent, organic peroxide, and / or chain transfer agent to a polymerization apparatus configured by connecting a fully mixed reactor or a tank reactor and multiple tank reactors in series.

[0036] <<Styrene-based copolymer resin>> In this embodiment, the styrene copolymer resin usable as the recovered styrene-based resin (A) is a resin containing styrene monomer units and other monomers copolymerizable with the styrene monomers (for example, unsaturated carboxylic acid monomer units). For example, when the other monomers are unsaturated carboxylic acid monomer units, the styrene copolymer resin according to the present invention preferably contains 69 to 98% by mass, more preferably 74 to 96% by mass, and even more preferably 77 to 92% by mass, when the total content of styrene monomer units and unsaturated carboxylic acid monomer units is 100% by mass. By setting the content to 69% by mass or more, the fluidity of the resin can be improved. On the other hand, by setting the content of styrene monomer units to 98% by mass or less, it becomes difficult to have a desired amount of unsaturated carboxylic acid monomer units, which are an example of other monomers, and it becomes difficult to obtain the effects of these monomer units described later.

[0037] In this embodiment, the unsaturated carboxylic acid monomer includes one or more selected from the group consisting of unsaturated carboxylic acid monomers and unsaturated carboxylic acid ester monomers.

[0038] In the preferred styrene copolymer resin of this embodiment, unsaturated carboxylic acid monomer units play a role in improving heat resistance. When the total content of styrene monomer units, unsaturated carboxylic acid monomer units, and unsaturated carboxylic acid ester monomer units in the styrene copolymer resin is set to 100% by mass, the content of unsaturated carboxylic acid monomer units is preferably 2 to 16% by mass, more preferably 4 to 14% by mass, and even more preferably 8 to 13% by mass. By setting the content to 2% by mass or more, the dispersibility of component (B) is improved and the heat resistance can be further improved. On the other hand, by setting the content to 16% by mass or less, when the recycled flame-retardant styrene-based resin composition of this embodiment is used as a masterbatch, excellent dispersibility with respect to the styrene-based resin is exhibited, flame retardancy can be improved, and the molded appearance, resin fluidity, and mechanical properties are further improved.

[0039] Generally, styrene-methacrylic acid-methyl methacrylate copolymer resins, which are one form of the styrene-based copolymer resin in the present invention, are almost always produced by radical polymerization on an industrial scale. However, in this embodiment, various alcohols can be added to the polymerization system to suppress the gelation reaction in the defoliation step.

[0040] Unsaturated carboxylic acid ester monomers can be used to suppress the dehydration reaction of unsaturated carboxylic acid monomers through intermolecular interactions and to improve the mechanical strength of resins. Furthermore, unsaturated carboxylic acid ester monomers also contribute to improving resin properties such as weather resistance and surface hardness.

[0041] In this embodiment, when the total content of styrene monomer units, unsaturated carboxylic acid monomer units, and unsaturated carboxylic acid ester monomer units is set to 100% by mass, the content of unsaturated carboxylic acid ester monomer units is preferably 0 to 15% by mass, more preferably 1 to 12% by mass, and even more preferably 2 to 10% by mass. By setting the content to 15% by mass or less, the fluidity of the resin can be improved and water absorption can be suppressed. Furthermore, by setting the lower limit of the content of unsaturated carboxylic acid ester monomer units to 0% by mass, heat resistance can be improved and costs can be reduced, but from the above viewpoint, the content of unsaturated carboxylic acid ester monomer units can also be greater than 0% by mass.

[0042] Furthermore, when an unsaturated carboxylic acid monomer and an unsaturated carboxylic acid ester monomer unit are bonded adjacent to each other, a de-alcoholization reaction may occur under certain conditions when a high-temperature, high-vacuum defloration apparatus is used, forming a six-membered cyclic acid anhydride. The styrene copolymer resin of this embodiment may contain this six-membered cyclic acid anhydride, but it is preferable to have as little of the generated six-membered cyclic acid anhydride as possible, as it reduces fluidity.

[0043] In this embodiment, the content of styrene monomer units (e.g., styrene monomer units), unsaturated carboxylic acid monomer units (e.g., methacrylic acid monomer units), and unsaturated carboxylic acid ester monomer units (e.g., methyl methacrylate monomer units) in the styrene copolymer resin is determined by proton nuclear magnetic resonance ( 1 It can be determined from the integral ratio of the spectrum measured with a 1H-NMR detector.

[0044] In this embodiment, the styrene copolymer resin may further contain monomer units other than styrene monomer units and, as an example of other monomers, unsaturated carboxylic acid monomers (e.g., unsaturated carboxylic acid monomer units and unsaturated carboxylic acid ester monomer units), to the extent that it does not impair the effects of the present invention. However, the styrene copolymer resin in the present invention is preferably typically composed of styrene monomer units, unsaturated carboxylic acid monomer units, and / or unsaturated carboxylic acid ester monomer units.

[0045] The styrene monomer constituting the styrene copolymer resin of this embodiment is not particularly limited, but examples include styrene, α-methylstyrene, α-methyl-p-methylstyrene, ο-methylstyrene, m-methylstyrene, p-methylstyrene, vinyltoluene, ethylstyrene, isobutylstyrene, t-butylstyrene, bromostyrene, indene, and other styrene derivatives. From an industrial standpoint, styrene is preferred as the styrene monomer. These styrene monomers can be used individually or in combination of two or more.

[0046] The unsaturated carboxylic acid monomers constituting the styrene copolymer resin of this embodiment are not particularly limited, but examples include methacrylic acid, acrylic acid, maleic anhydride, maleic acid, fumaric acid, itaconic acid, etc. Methacrylic acid is preferred as the unsaturated carboxylic acid monomer because it has a significant effect in improving heat resistance and is liquid at room temperature, making it easy to handle. These unsaturated carboxylic acid monomers can be used individually or in combination of two or more.

[0047] The unsaturated carboxylic acid ester monomers constituting the styrene copolymer resin of this embodiment are not particularly limited, but examples include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, and cyclohexyl (meth)acrylate. Methyl (meth)acrylate is preferred as the (meth)acrylate monomer because it has little effect on the reduction of heat resistance. These unsaturated carboxylic acid ester monomers can be used individually or in combination of two or more.

[0048] Suitable styrene-based copolymer resins for this embodiment include styrene-methacrylic acid copolymer, styrene-methyl methacrylate copolymer, styrene-methacrylic acid-methyl methacrylate copolymer, styrene-acrylic acid copolymer, styrene-methyl acrylate copolymer, styrene-acrylic acid-methyl acrylate copolymer, styrene-methyl methacrylate-butyl methacrylate copolymer, styrene-butyl methacrylate copolymer, or styrene-maleic anhydride copolymer.

[0049] In this embodiment, the weight-average molecular weight (Mw) of the styrene copolymer resin is preferably 100,000 to 350,000, more preferably 120,000 to 300,000, and even more preferably 140,000 to 240,000. When the weight-average molecular weight (Mw) is 100,000 to 350,000, a resin with a better balance of mechanical strength and fluidity is obtained, and the inclusion of gel material is also reduced. The weight-average molecular weight (Mw) is a value obtained using gel permeation chromatography on a standard polyethylene basis.

[0050] In this embodiment, there are no particular limitations on the polymerization method of the styrene-based alkoxy group polymer resin, but for example, a bulk polymerization method or a solution polymerization method can be suitably employed as a radical polymerization method. The polymerization method mainly comprises a polymerization step of polymerizing the polymerization raw material (monomer component) and a defoliation step of removing volatile components such as unreacted monomers and polymerization solvents from the polymerization product.

[0051] The following describes an example of a polymerization method for styrene copolymer resins that can be used in this embodiment.

[0052] When polymerizing polymerization raw materials to obtain styrene copolymer resins, the polymerization raw material composition typically contains a polymerization initiator and a chain transfer agent.

[0053] Polymerization initiators used in the polymerization of styrene copolymer resins include organic peroxides, such as peroxyketals like 2,2-bis(t-butylperoxy)butane, 1,1-bis(t-butylperoxy)cyclohexane, and n-butyl-4,4-bis(t-butylperoxy)valerate; dialkyl peroxides like di-t-butylperoxide, t-butylcumylperoxide, and dicumylperoxide; diacyl peroxides like acetylperoxide and isobutyrylperoxide; peroxydicarbonates like diisopropylperoxydicarbonate; peroxyesters like t-butylperoxyacetate; ketone peroxides like acetylacetone peroxide; and hydroperoxides like t-butylhydroperoxide. Of these, 1,1-bis(t-butylperoxy)cyclohexane is preferred from the viewpoint of decomposition rate and polymerization rate.

[0054] Examples of chain transfer agents used in the polymerization of styrene copolymer resins include α-methylstyrene linear dimer, n-dodecyl mercaptan, t-dodecyl mercaptan, and n-octyl mercaptan.

[0055] As a polymerization method for styrene copolymer resins, solution polymerization using a polymerization solvent can be employed as needed. Examples of polymerization solvents that can be used include aromatic hydrocarbons, such as ethylbenzene and dialkyl ketones, such as methyl ethyl ketone. These may be used individually or in combination of two or more. Other polymerization solvents, such as aliphatic hydrocarbons, can be further mixed with aromatic hydrocarbons as long as they do not reduce the solubility of the polymerization product. It is preferable to use these polymerization solvents in an amount not exceeding 25 parts by mass per 100 parts by mass of total monomers. If the amount of polymerization solvent exceeds 25 parts by mass per 100 parts by mass of total monomers, the polymerization rate tends to decrease significantly, and the mechanical strength of the resulting resin tends to decrease greatly. Adding 5 to 20 parts by mass per 100 parts by mass of total monomers before polymerization is preferable in terms of quality uniformity and polymerization temperature control.

[0056] In this embodiment, the apparatus used in the polymerization step for obtaining the styrene-based copolymer resin is not particularly limited and may be appropriately selected according to the polymerization method of the styrene-based resin. For example, when bulk polymerization is employed, one or a plurality of connected polymerization apparatuses of a completely mixed reactor can be used. Also, there is no particular limitation on the devolatilization step. When bulk polymerization is adopted, polymerization is advanced until the unreacted monomer finally becomes preferably 50% by mass or less, more preferably 40% by mass or less, and the volatile components such as such unreacted monomers are removed by a known method for devolatilization treatment. More specifically, for example, ordinary devolatilization apparatuses such as a flash drum, a twin-screw devolatilizer, a thin-film evaporator, an extruder, etc. can be used, but a devolatilization apparatus with less residence part is preferred. The temperature of the devolatilization treatment is usually about 190 to 280 °C, and from the viewpoint of suppressing the formation of a six-membered ring acid anhydride due to the adjacency of an unsaturated carboxylic acid monomer (for example, methacrylic acid) and an unsaturated carboxylic acid ester monomer (for example, methyl methacrylate), 190 to 260 °C is more preferred. The pressure of the devolatilization treatment is usually about 0.13 to 4.0 kPa, preferably 0.13 to 3.0 kPa, and more preferably 0.13 to 2.0 kPa. As the devolatilization method, for example, a method of removing volatile components by reducing the pressure under heating and a method of removing through an extruder or the like designed for the purpose of removing volatile components are desirable.

[0057] <NOR-type hindered amine compound (B): Component (B)> The recycled flame-retardant styrene-based resin composition of this embodiment essentially contains a NOR-type hindered amine compound (B). The content of the NOR-type hindered amine compound (B) is 0.1 to 5% by mass, preferably 0.3 to 3% by mass, and more preferably 0.5 to 2.0% by mass, based on 100% by mass of component (A). If the content is 0.1% by mass or more, the flame retardancy, thermal stability, and hue of the recovered styrene resin can be improved. Component (B) may be added as is as an additive, but components already contained in the recovered styrene resin (A) can also be used as the NOR-type hindered amine compound (B) of this embodiment. Furthermore, materials already containing the NOR-type hindered amine compound (B), such as post-consumer materials, can also be used as the NOR-type hindered amine compound (B) of this embodiment. In that case, it is not necessary to add component (B) or other styrene resins (for example, recovered styrene resin (A) or unused styrene resin) to achieve the predetermined content of component (B).

[0058] Furthermore, component (B) can improve thermal stability by stabilizing radical decomposition products from the recovered styrene resin (A). It also has the effect of inactivating impurities and suppressing photo-oxidative degradation. Moreover, when used in combination with a flame retardant, the flame retardancy is enhanced by a synergistic effect, allowing for flame retardancy with a smaller amount. In particular, when used in combination with a phosphorus-based flame retardant, thermal stability and hue can be improved. On the other hand, such effects are not observed in N-methyl type hindered amine compounds or NH type hindered amine compounds.

[0059] The NOR-type hindered amine compound (B) used in this embodiment is not particularly limited as long as it has an N-alkoxyl group (>N-OR) structure. Specific examples include, for instance, NOR-type hindered amine compounds described in Japanese Patent Publication No. 2002-507238, International Publication No. 2005 / 082852, International Publication No. 2008 / 003605, etc., which are preferred examples.

[0060] Furthermore, the NOR-type hindered amine compound (B) is preferably of the polymer type. A polymer type generally refers to an oligomeric or polymeric compound. The polymer type reduces mold deposits during molding and offers superior flame retardancy and heat resistance.

[0061] The above-mentioned oligomeric or polymeric NOR-type hindered amine compound (B) preferably has 2 to 100 repeating units, and more preferably 5 to 80.

[0062] Specific examples of NOR-type hindered amine compounds (B) include the following compounds: 1-cyclohexyloxy-2,2,6,6-tetramethyl-4-octadecylaminopiperidine; 2,2,6,6-tetramethyl-4-piperidyl)sebacate; 2,4-bis[(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidine-4-yl)butylamino]-6-(2-hydroxyethylamino)-s-triazine; bis(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidine-4-yl)adipate; An oligomeric compound formed by the condensation of 4,4'-hexamethylenebis(amino-2,2,6,6-tetramethylpiperidine) and 2,4-dichloro-6-[(1-octyloxy-2,2,6,6-tetramethylpiperidine-4-yl)butylamino]-s-triazine, which is terminally capped with 2-chloro-4,6-bis(dibutylamino)-s-triazine; 4,4'-hexamethylenebis(amino-2,2,6,6-tetramethylpiperidine) and 2-chloro-4,6-bis(dibutylamino)-s-triazine An oligomeric compound which is a condensation product with 2,4-dichloro-6-[(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidine-4-yl)butylamino]-s-triazine; 2,4-bis[(1-cyclohexyloxy-2,2,6,6-piperidine-4-yl)-6-chloro-s-triazine; peroxidized 4-butylamino-2,2,6,6-tetramethylpiperidine, 2,4,6-trichloro-s-triazine, cyclohexane, and N,N'-ethane-1,2-diylbis(1,3-propanediamine) Reaction products with (N,N',N'''-Tris{2,4-bis[(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidine-4-yl)n-butylamino]-s-triazine-6-yl}-3,3'-ethylenediiminodipropylamine); bis(1-undecanoxy-2,2,6,6-tetramethylpiperidine-4-yl) carbonate; 1-undecyloxy-2,2,6,6-tetramethylpiperidine-4-one; bis(1-stearyloxy-2,2,6,6-tetramethylpiperidine-4-yl) carbonate.

[0063] The NOR-type hindered amine compound (B) in this embodiment may be a commercially available product, for example, FlamestabNOR116FF, TINUVIN NOR371, TINUVIN XT850FF, TINUVIN XT855FF, TINUVIN PA123 from BASF, and LA-77Y, LA-81, FP-T80 from ADEKA Corporation. In this embodiment, the NOR-type hindered amine compound (B) may be used alone or in combination of two or more types.

[0064] <Flame retardant (C): (C) component> In this embodiment, the recycled flame-retardant styrene resin composition or the recovered styrene resin (A) may contain a flame retardant (C). The content of the flame retardant (C) is preferably 0.1 to 30% by mass, more preferably 2 to 20% by mass, and even more preferably 3 to 15% by mass, based on the total recycled flame-retardant styrene resin composition (100% by mass). If the content is greater than 30% by mass, the impact resistance decreases. Preferred flame retardants are phosphorus-based flame retardants and / or bromine-based flame retardants that can be expected to have a flame-retardant synergistic effect with the NOR-type hindered amine compound (B). Furthermore, when used in combination with a phosphorus-based flame retardant, thermal stability, hue, and light resistance can be improved. In particular, when the phosphorus-based flame retardant is a phosphonic acid ester compound and / or a phosphinic acid compound, the hue improvement effect is significant. Component (C) may be added as is as an additive, but it can also be used if it is contained in the recovered styrene resin.

[0065] -Phosphorus-based flame retardant- The phosphorus-based flame retardant is not particularly limited, and can be obtained by conventionally known methods or is a commercially available product. Preferably, it is a phosphate ester compound, a phosphazene compound, a phosphonic acid compound (including, for example, phosphonic acid ester compounds), or a phosphinic acid compound (including, for example, phosphinate compounds), which may be used individually or in combination of two or more. Among these, phosphate ester compounds, phosphonic acid ester compounds, or phosphinic acid compounds that have good compatibility with styrene resins are most preferred.

[0066] Phosphorus-based flame retardants, especially those with a phosphorus content of 3.0% by mass or more, exhibit a synergistic effect in flame retardancy with NOR-type hindered amine compounds (B), allowing for high flame retardancy with a small amount of additive. A phosphorus content of 3.0% by mass or more refers to a phosphorus compound containing 3.0% by mass or more of the element phosphorus in the phosphorus-based flame retardant. The phosphorus-based flame retardant preferably has a phosphorus content of 3.0% by mass or more, and more preferably 7.0% by mass or more and 30% by mass or less, relative to the total phosphorus-based flame retardant. When the phosphorus content is 3.0% by mass or more, it exhibits a synergistic effect with the NOR-type hindered amine compound (B) on flame retardancy, and flame retardancy can be obtained with a small amount of additive. This is effective for low dielectric constant and low dielectric loss tangent, and changes under the usage environment can also be minimized. Furthermore, the phosphorus content can be measured by the absorbance photometry method to determine the amount of phosphorus atoms contained in the phosphorus-based flame retardant.

[0067] Furthermore, as a phosphorus-based flame retardant, it is preferable to use a flame retardant that is liquid at 150°C to 300°C, i.e., has a melting point of 300°C or lower, which allows for good dispersion in the recycled flame-retardant styrene-based resin composition. If a phosphorus-based flame retardant that is solid during melt mixing (for example, a phosphorus-based flame retardant with no melting point) is used, the phosphorus-based flame retardant will not be in a liquid state during melt mixing, and therefore will not be uniformly dispersed in component (A), which may lead to a decrease in physical properties or a decrease in flame retardancy.

[0068] --Phosphate ester compounds-- As phosphate ester compounds, aromatic phosphate ester compounds are preferred. Examples include monomeric phosphate ester compounds such as trimethyl phosphate (TMP), triethyl phosphate (TEP), triphenyl phosphate (TPP), tricresyl phosphate (TCP), trixylenyl phosphate (TXP), and cresyl diphenyl phosphate (CDP), and aromatic condensed phosphate ester compounds which are reaction products of phosphorus oxychloride, a divalent phenolic compound, and phenol (or alkylphenol), such as resorcinol bis-dixylenyl phosphate, resorcinol bis-diphenyl phosphate, bisphenol A bis-diphenyl phosphate (BADP), bisphenol A bis-dicresyl phosphate, biphenol bis-diphenyl phosphate, and biphenol bis-dixylenyl phosphate. Among these, triphenyl phosphate (TPP), tricresyl phosphate (TCP), resorcinol bis-dixlenyl phosphate, resorcinol bis-diphenyl phosphate, bisphenol A bis-diphenyl phosphate (BADP), biphenol bis-diphenyl phosphate, and biphenol bis-dixlenyl phosphate are preferred, more preferably triphenyl phosphate (TPP), resorcinol bis-dixlenyl phosphate, and resorcinol bis-diphenyl phosphate are preferred, and even more preferably resorcinol bis-dixlenyl phosphate is preferred.

[0069] Furthermore, the phosphate ester compound is preferably a condensed phosphate ester compound of the condensation type, from the viewpoint of heat resistance and reduction of mold deposits during molding, and in particular, an aromatic condensed phosphate ester compound represented by the following chemical formula (1) is preferred. [ka] (In the above chemical formula (1), R 1 ~R 5Each of these is independently a hydrogen atom, a C1-C10 alkyl group, a C3-C20 cycloalkyl group, a C6-C20 aryl group, a C1-C10 alkoxy group, or a halogen atom, and R 1 ~R 5 (These values ​​may be the same or different. n is an integer between 0 and 30, preferably between 0 and 10.) Examples of the alkyl groups mentioned above include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, 2-butyl group, 3-butyl group, amyl group, 3-amyl group, hexyl group, 2-ethylhexyl group, n-octyl group, nonyl group, decyl group, and the like. Examples of the above-mentioned cycloalkyl groups include cyclohexyl groups. Examples of the aryl groups mentioned above include phenyl group, cresyl group, xylyl group, 2,6-xylyl group, 2,4,6-trimethylphenyl group, butylphenyl group, and nonylphenyl group. Examples of the alkoxy groups mentioned above include methoxy groups, ethoxy groups, propoxy groups, and butoxy groups. Examples of the halogen atoms mentioned above include fluorine atoms, chlorine atoms, and bromine atoms.

[0070] Furthermore, among the above-mentioned phosphate ester compounds, from the viewpoint of achieving both flame retardancy and transparency, phosphate ester compounds represented by the following compounds (1-1), (1-2), or (1-3) are preferred, compounds (1-2) or (1-3) are more preferred, and compound (1-2) is even more preferred. For compound (1-2) (resorcinol bis-dixylenyl phosphate), for example, PX-200 from Daihachi Chemical Industry Co., Ltd. can be used, and for compound (1-3) (resorcinol bis-diphenyl phosphate), for example, CR-733S from Daihachi Chemical Industry Co., Ltd. can be used. [ka]

[0071] -Phosphazene compounds- Examples of phosphazene compounds include 1,1,3,3,5,5-hexa(methoxy)cyclotriphosphazene, 1,1,3,3,5,5-hexa(ethoxy)cyclotriphosphazene, 1,1,3,3,5,5-hexa(n-propoxy)cyclotriphosphazene, 1,1,3,3,5,5-hexa(iso-propoxy)cyclotriphosphazene, 1,1,3,3,5,5-hexa(n-butoxy)cyclotriphosphazene, 1,1,3,3,5,5-hexa(iso-butoxy)cyclotriphosphazene, and 1,1,3,3,5,5-hexa(phenoxy) Cyclotriphosphazene, 1,1,3,3,5,5-Hexa(p-tolyloxy)cyclotriphosphazene, 1,1,3,3,5,5-Hexa(m-tolyloxy)cyclotriphosphazene, 1,1,3,3,5,5-Hexa(o-tolyloxy)cyclotriphosphazene, 1,1,3,3,5,5-Hexa(4-ethylphenoxy)cyclotriphosphazene, 1,1,3,3,5,5-Hexa(4-n-propylphenoxy)cyclotriphosphazene, 1,1 ,3,3,5,5-Hexa(4-t-butylphenoxy)cyclotriphosphazene, 1,1,3,3,5,5-Hexa(4-t-octylphenoxy)cyclotriphosphazene, 1,1,3,3,5,5-Hexa(2,3-dimethylphenoxy)cyclotriphosphazene, 1,1,3,3,5,5-Hexa(2,4-dimethylphenoxy)cyclotriphosphazene, 1,1,3,3,5,5-Hexa(2,5-dimethylphenoxy)cyclotriphosphazene, 1,1,3,3,5,5-Hexa(2,6-dimethylphenoxy)cyclotriphosphazene, 1, 3,5-Tris(methoxy)-1,3,5-Tris(phenoxy)cyclotriphosphazene, 1,3,5-Tris(ethoxy)-1,3,5-Tris(phenoxy)cyclotriphosphazene, 1,3,5-Tris(n-propoxy)-1,3,5-Tris(phenoxy)cyclotriphosphazene, 1,3,5-Tris(iso-propoxy)-1,3,5-Tris(phenoxy)cyclotriphosphazene, 1,3,5-Tris(n-butoxy)-1,3,5-Tris(phenoxy)cyclotriphosphazene, 1,3,5-Tris(iso-butoxy)-1,3,5-Tris(phenoxy)cyclotriphosphazene, 1,3,5-Tris(methoxy)-1,3,5-Tris(p-tolyloxy)cyclotriphosphazene, 1,3,5-Tris(methoxy)-1,3,5-Tris(m-tolyloxy)cyclotriphosphazene, 1,3,5-Tris(methoxy)-1,3,5-Tris(o-tolyloxy)cyclotriphosphazene, 1,3,5-Tris(ethoxy)-1,3,5-Tris(p-tolyloxy)cyclotriphosphazene Sphazene, 1,3,5-tris(ethoxy)-1,3,5-tris(m-tolloxy)cyclotriphosphazene, 1,3,5-tris(ethoxy)-1,3,5-tris(o-tolloxy)cyclotriphosphazene, 1,3,5-tris(n-propoxy)-1,3,5-tris(p-tolloxy)cyclotriphosphazene, 1,3,5-tris(n-propoxy)-1,3,5-tris(m-tolloxy)cyclotriphosphazene, 1,3,5- Tris(n-propoxy)-1,3,5-tris(o-tolyloxy)cyclotriphosphazene, 1,3,5-tris(iso-propoxy)-1,3,5-tris(p-tolyloxy)cyclotriphosphazene, 1,3,5-tris(n-butoxy)-1,3,5-tris(p-tolyloxy)cyclotriphosphazene, 1,3,5-tris(iso-butoxy)-1,3,5-tris(p-tolyloxy)cyclotriphosphazene, 1,3,5-tris(meth Examples include tris(4-t-butylphenoxy)cyclotriphosphazene, tris(methoxy)-1,3,5-tris(4-t-octylphenoxy)cyclotriphosphazene, tris(n-propoxy)-1,3,5-tris(4-t-butylphenoxy)cyclotriphosphazene, and tris(n-propoxy)-1,3,5-tris(4-t-octylphenoxy)cyclotriphosphazene.

[0072] Among these, preferably, 1,1,3,3,5,5 - hexakis(methoxy)cyclotriphosphazene, 1,1,3,3,5,5 - hexakis(ethoxy)cyclotriphosphazene, 1,1,3,3,5,5 - hexakis(phenoxy)cyclotriphosphazene, 1,1,3,3,5,5 - hexakis(p - tolyloxy)cyclotriphosphazene, 1,3,5 - tris(methoxy)-1,3,5 - tris(phenoxy)cyclotriphosphazene, 1,3,5 - tris(ethoxy)-1,3,5 - tris(phenoxy)cyclotriphosphazene; more preferably, 1,1,3,3,5,5 - hexakis(ethoxy)cyclotriphosphazene, 1,1,3,3,5,5 - hexakis(phenoxy)cyclotriphosphazene, 1,3,5 - tris(ethoxy)-1,3,5 - tris(phenoxy)cyclotriphosphazene; still more preferably, 1,1,3,3,5,5 - hexakis(phenoxy)cyclotriphosphazene.

[0073] - phosphonate - Examples of the phosphonate include those represented by the following chemical formula (2).

Chemical formula

[0074] Specific examples of phosphonic acid esters represented by the above chemical formula (2) include the compounds represented by the following formulas (2-1) to (2-8). [ka]

[0075] -Phosphinic acid compounds- Examples of phosphinic acid compounds include 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and 10-benzyl-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide. For example, Sanko Co., Ltd.'s HCA can be used as 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, and Sanko Co., Ltd.'s BCA can be used as 10-benzyl-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide.

[0076] -Phosphinate compounds- Furthermore, in this embodiment, the content of the phosphinate compound is preferably 70% by mass or more relative to 100% by mass of the total amount of the flame retardant (C). Therefore, relative to 100% by mass of the total amount of the flame retardant (C), known flame retardants other than the phosphinate compound and / or optional additives described later (antioxidants, UV inhibitors, etc.) may be included in an amount of 30% by mass or less. In this embodiment, the phosphinate compound is represented by the following general formula (i), and preferably contains at least one phosphinate selected from phosphinates and diphosphinates, and more preferably the phosphinates account for 70% by mass or more of the total phosphinate compound (100% by mass). The following general formula (i): [ka] [In the above formula (i), R i1 and R i2 Each of these is independently either unsubstituted or has one or more hydrogen atoms substituted R i3A linear or branched alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an aralkyl group having 6 to 14 carbon atoms, which may be substituted by: The substituent R i3 This is expressed by the following formula (ii): [ka] In the above formula (ii), R ii1 Each of these is independently a linear or branched alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms, and * represents a bond with another atom. M i is at least one selected from the group consisting of calcium ions, magnesium ions, aluminum ions, zinc ions, bismuth ions, manganese ions, sodium ions, potassium ions, and protonated nitrogen bases, p + is M i It represents the ion valency, and is a positive integer from 1 to 3, m i1 n is a positive integer between 1 and 3. - |p| represents a negative integer of -1, -2, or -3, and r is a positive integer of 1 to 3. + ×r|=|n - xm i1 | is also R i1 and R ii1 If there are multiple instances of each, each R i1 and R ii1 They may be the same or different. Therefore, the phosphinate compound in this embodiment may contain known flame retardants other than phosphinates represented by general formula (i) in an amount of 30% by mass or less relative to the total amount of the phosphinate compound (100% by mass). In the above formula (i), M i The ion value of "p + The absolute value of the product of " and "r" is "n - " and "m i1 It is equal to the absolute value of the product of and . In (i) above, p + 1 or 2 is preferred. i11 or 2 is preferred. - For -1 or -2, r is preferably 1 or 2.

[0077] In this embodiment, preferred phosphinate compounds are represented by the following general formula (iii). [ka] [In the above formula (iii), R 11 and R 12 Each is independently a linear or branched alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms, M 1 is at least one selected from the group consisting of calcium ions, magnesium ions, aluminum ions, zinc ions, bismuth ions, manganese ions, sodium ions, potassium ions, and protonated nitrogen bases, a + is M 1 It represents the ion valency, and is an integer from 1 to 3, m 1 a is an integer between 1 and 3, and a = m 1 That is. R 11 and R 12 If there are multiple instances of each, each R 11 and R 12 They may be the same or different.

[0078] In this embodiment, preferred diphosphinates are those represented by the following general formula (iv). [ka] [In the above formula (iv), R 21 and R 22 Each is independently a linear or branched alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms, L 23 This is a linear or branched alkylene group having 1 to 10 carbon atoms, an arylene group having 6 to 10 carbon atoms, an alkylarylene group having 6 to 14 carbon atoms, or an arylalkylene group having 6 to 14 carbon atoms, M 2b is at least one selected from the group consisting of calcium ions, magnesium ions, aluminum ions, zinc ions, bismuth ions, manganese ions, sodium ions, potassium ions, and protonated nitrogen bases, + is M 2 It represents the ion valency, and is an integer from 1 to 3, m 2 b is an integer between 1 and 3, q ​​is an integer of 1 or 2, and b × q = 2m 2 That is. R 21 and R 12 If there are multiple instances of each, each R 21 and R 22 They may be the same or different. At least one is selected from the group consisting of ].

[0079] In the above formulas (i), (ii), (iii), and (iv), examples of linear or branched alkyl groups having 1 to 6 carbon atoms include linear alkyl groups such as methyl, ethyl, propyl, butyl, amyl, or hexyl groups, and branched alkyl groups such as isopropyl, isobutyl, s-butyl, t-butyl, isoamyl, or t-amyl groups. In the above formulas (i), (ii), (iii), and (iv), the aryl group having 6 to 10 carbon atoms may have a monocyclic or fused ring structure. Examples include the phenyl group or the naphthyl group. In formula (iv) above, a linear or branched alkylene group having 1 to 10 carbon atoms can be a group obtained by removing one hydrogen atom from the linear or branched alkyl group having 1 to 6 carbon atoms. In the above formula (iv), the arylene group having 6 to 10 carbon atoms is a group obtained by removing one hydrogen atom from the above aryl group having 6 to 10 carbon atoms. In formula (i) above, the aralkyl group having 6 to 14 carbon atoms can be a benzyl group, a phenylethyl group, a phenylpropyl group, a phenylbutyl group, a methylphenyl group, an ethylphenyl group, a propylphenyl group, a butylphenyl group, a methylnaphthyl group, an ethylnaphthyl group, or a tert-butylnaphthyl group. In formula (iv) above, examples of alkylarylene groups having 6 to 14 carbon atoms include methylphenylene group, ethylphenylene group, tert-butylphenylene group, methylnaphthylene group, ethylnaphthylene group, and tert-butylnaphthylene group. In the above formula (iv), examples of arylalkylene groups having 6 to 14 carbon atoms include phenylmethylene, phenylethylene, phenylpropylene, and phenylbutylene groups. In the above equation (iii), R 11 and R 12 Each of these is preferably independently a linear alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms. In the above formula (iii), M 1 Calcium, magnesium, aluminum, or zinc are preferred. Also, a is M 1 This represents the ionic charge, which is 2 or 3. In the above equation (iv), R 21 and R 22 Each of these is preferably independently a linear alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms. In the above equation (iv), L 23 Each of these is preferably independently a linear alkylene group having 1 to 6 carbon atoms or an arylene group having 6 to 10 carbon atoms. In the above equation (iv), M 2 Calcium, magnesium, aluminum, or zinc are preferred. Also, b is M 2 This represents the ionic charge, which is 2 or 3. Phosphinate compounds have excellent electrical properties, making them suitable for flame-retardant materials requiring insulation. They also have excellent hydrolytic properties, making them suitable for use in high-temperature and high-humidity environments, and they are highly recyclable.

[0080] The phosphinates used in this embodiment are primarily monomeric compounds, produced in aqueous solution using phosphinic acid and metal carbonates, metal hydroxides, or metal oxides. However, depending on the reaction conditions and environment, polymeric phosphinates with a condensation degree of 1 to 3 may also be included.

[0081] Such phosphinates are not particularly limited, but include, for example, calcium dimethylphosphinate, magnesium dimethylphosphinate, aluminum dimethylphosphinate, zinc dimethylphosphinate, calcium ethylmethylphosphinate, magnesium ethylmethylphosphinate, aluminum ethylmethylphosphinate, zinc ethylmethylphosphinate, calcium diethylphosphinate, magnesium diethylphosphinate, aluminum diethylphosphinate, zinc diethylphosphinate, calcium methyl-n-propylphosphinate, magnesium methyl-n-propylphosphinate, aluminum methyl-n-propylphosphinate, zinc methyl-n-propylphosphinate, calcium methanedi(methylphosphinate), magnesium methanedi(methylphosphinate), aluminum methanedi(methylphosphinate), zinc methanedi(methylphosphinate), calcium benzene-1,4-(dimethylphosphinate), calcium benzene-1,4- Examples include magnesium (dimethylphosphinate), aluminum benzene-1,4-(dimethylphosphinate), zinc benzene-1,4-(dimethylphosphinate), calcium methylphenylphosphinate, magnesium methylphenylphosphinate, aluminum methylphenylphosphinate, zinc methylphenylphosphinate, calcium diphenylphosphinate, magnesium diphenylphosphinate, aluminum diphenylphosphinate, and zinc diphenylphosphinate. Preferably, the answer is calcium dimethylphosphinate, aluminum dimethylphosphinate, zinc dimethylphosphinate, calcium ethylmethylphosphinate, aluminum ethylmethylphosphinate, aluminum ethylbutylphosphinate, aluminum dibutylphosphinate, zinc ethylmethylphosphinate, calcium diethylphosphinate, aluminum diethylphosphinate, and zinc diethylphosphinate, and more preferably, aluminum diethylphosphinate. Examples of commercially available phosphinate compounds (b) include, but are not limited to, Exolit® OP1230, OP1240, OP1311, OP1312, OP930, and OP935 manufactured by Clariant Japan.

[0082] In this embodiment, the phosphinate compound is preferably in granular form. When the phosphinate compound is in granular form, the average particle size of the phosphinate compound is preferably 100 μm or less, more preferably 50 μm or less, and even more preferably 20 μm or less, from the viewpoint of improving the mechanical strength and appearance of the molded article obtained by molding the flame-retardant resin composition of this embodiment, and it is preferable to use a powder of the phosphinate compound ground to this particle size. Preferably, it is more than 0.5 μm and 20 μm, and more preferably more than 1 μm and 20 μm or less. Using a powder with a preferred particle size is particularly preferable because it not only exhibits high flame retardancy but also significantly increases impact strength. The average particle size of granular phosphinate compounds is measured based on volume-based particle size measured using a laser diffraction / scattering particle size distribution analyzer. Furthermore, the value is measured using a 3% isopropanol aqueous solution as the dispersion medium for the phosphinate compound. Specifically, using a LA-910 laser diffraction / scattering particle size distribution analyzer (manufactured by Horiba, Ltd.), a blank measurement is performed using a 3% isopropanol aqueous solution as the dispersion medium. Then, the sample is added to achieve a specified transmittance (95% to 70%) and measured. The dispersion of the sample in the dispersion medium is achieved by irradiating it with ultrasound for one minute. In this embodiment, the preferred content of the phosphorus-based flame retardant in the styrene-based composition can be the same as the preferred content of flame retardant (C).

[0083] - Bromone-based flame retardant - The bromine-based flame retardant in this embodiment can be any bromine-based flame retardant (brominated flame retardant) commonly used in this field, and among these, commonly used examples include brominated bisphenol A or brominated bisphenol S compounds (for example, brominated bisphenol A compounds, brominated bisphenol S compounds, brominated phenyl ethers, brominated bisphenol A carbonate oligomers, brominated bisphenol A epoxy resins), brominated phenyl ethers, brominated bisphenol A carbonate oligomers, brominated bisphenol A epoxy resins, brominated styrene compounds, brominated phthalimide compounds, brominated benzene compounds, brominated cycloalkane compounds, and brominated isocyanurates. These bromine-based flame retardants may be used individually or in combination of two or more.

[0084] Brominated bisphenol A compounds or brominated bisphenol S compounds include compounds in which 1 to 8 brome atoms are bonded to the benzene ring of a bisphenol A residue or a bisphenol S residue. Examples include tetrabrombisphenol A, tetrabrombisphenol A bis(2-hydroxyethyl ether), tetrabrombisphenol A bis(allyl ether), tetrabrombisphenol A bis(2-bromethyl ether), tetrabrombisphenol A bis(3-bromopropyl ether), tetrabrombisphenol A bis(2,3-dibromopropyl ether), tetrabrombisphenol S, tetrabrombisphenol S bis(2-hydroxyethyl ether), and tetrabrombisphenol S bis(2,3-dibromopropyl ether).

[0085] Examples of commercially available brominated bisphenol A or brominated bisphenol S include "FR-1524" from Bromochem Far East Co., Ltd., "Great Lakes BA-50", "Great Lakes BA-50P", "Great Lakes BA-59", "Great Lakes BA-59P", and "Great Lakes PE-68" from Great Lakes Chemical Co., Ltd., "Saytex RB-100" from Albemarle Co., Ltd., "Fireguard 2000", "Fireguard 3000", "Fireguard 3100", and "Fireguard 3600" from Teijin Chemicals Limited, "Nonnen PR-2" from Marubishi Yuka Kogyo Co., Ltd., "Flamecut 121R" from Tosoh Corporation, and "Firecut P-680" from Suzuyu Chemical Co., Ltd.

[0086] Brominated phenyl ethers are compounds in which one or more bromine atoms are bonded to a phenyl ether group, and examples include bis(tribromphenoxy)ethane, hexabrom diphenyl ether, octabrom diphenyl ether, decabrom diphenyl ether, and polydibromphenyl oxide.

[0087] Examples of commercially available brominated phenyl ether flame retardants include "FR-1210" and "FR-1208" from Bromochem Far East Co., Ltd., "Great Lakes FF-680," "Great Lakes DE-83," "Great Lakes DE-83R," and "Great Lakes DE-79" from Great Lakes Chemical Co., Ltd., and "Saytex 102E" and "Saytex 111" from Albemarle Co., Ltd.

[0088] The above-mentioned brominated bisphenol A system is preferably a compound having the chemical structure represented by the following chemical formula (3), and may include oligomers or polymers. [ka] (In the chemical formula (3) above, * represents a bonding bond.)

[0089] An example of a compound represented by the above chemical formula (3) is a brominated bisphenol A carbonate oligomer, which is shown in the following chemical formula (3-1) [ka] It is preferable that the polymer has the group shown by . Note that an oligomer refers to one with a degree of polymerization of 1 to 10. Note that in the above chemical formula (3-1), * represents a bond.

[0090] Examples of polymers of the group represented by the above chemical formula (3-1) include the flame retardants represented by the following compounds (3-2) or (3-3). [ka]

[0091] Examples of commercially available flame retardants of the above compound (3-1) include "Fireguard 7000" and "Fireguard 7500" from Teijin Chemicals Ltd. Furthermore, commercially available flame retardants of the above compound (3-2) include "Great Lakes BC-52" and "Great Lakes BC-58" from Great Lakes Chemical Co., Ltd.

[0092] An example of a brominated bisphenol A-based epoxy resin, which is represented by the above chemical formula (3), is the compound shown in the following chemical formula (4). [ka]

[0093] As for commercially available flame retardants of the above chemical formula (4), the degree of polymerization (m 3There are various products depending on the product, including Bromochem Far East Co., Ltd.'s "F-2300", "F-2300H", "F-2400", and "F-2400H", Dainippon Ink and Chemicals, Inc.'s "Plasarm EP-16", "Plasarm EP-30", "Plasarm EP-100", and "Plasarm EP-500", and Sakamoto Pharmaceutical Co., Ltd.'s "SR-T1000", "SR-T2000", "SR-T5000", and "SR-T20000", among others.

[0094] Furthermore, examples of brominated bisphenol A epoxy resins include compounds in which both terminal epoxy groups of formula (4) above are blocked with a blocking agent, and compounds in which one terminal epoxy group is blocked with a blocking agent. The blocking agent is not limited to compounds that perform ring-opening addition of epoxy groups, but examples include phenols, alcohols, carboxylic acids, amines, and isocyanates that contain a brome atom. Among these, brominated phenols are preferred in that they improve the flame retardant effect, and examples include dibromophenol, tribromophenol, pentabromophenol, ethyldibromophenol, propyldibromophenol, butyldibromophenol, and dibrom cresol.

[0095] Examples of flame retardants in which the epoxy groups at both ends of the polymer are sealed with a blocking agent include the flame retardants shown in the following compounds (4-1) or (4-2). [ka]

[0096] Examples of commercially available flame retardants of the above compound (4-1) or (4-2) include DIC Corporation's "Plasarm EC-14," "Plasarm EC-20," and "Plasarm EC-30," Toto Chemical Co., Ltd.'s "TB-60" and "TB-62," and Sakamoto Pharmaceutical Co., Ltd.'s "SR-T3040" and "SR-T7040."

[0097] Furthermore, examples of flame retardants in which only one terminal epoxy group of the polymer is blocked with a blocking agent include the flame retardants shown in the following compounds (4-3) or (4-4). [ka]

[0098] Examples of commercially available flame retardants of the above compound (4-3) or (4-4) include "Plaserm EPC-15F" from DIC Corporation and "E5354" from Yuka Shell Epoxy Co., Ltd.

[0099] Brominated styrene flame retardants include brominated styrene monomers with the following chemical formula (5), in which 1 to 5 bromine atoms are bonded to the benzene ring of the styrene skeleton. [ka] and polymers of the chemical formula (5), that is, polymers having repeating units of the following chemical formula (5a) [ka] Examples include polymers, which are preferred.

[0100] Specific examples of brominated styrene-based materials include bromostyrene and brominated polystyrene. Commercially available brominated polystyrene-based flame retardants include "Great Lakes PDBS-10" and "Great Lakes PDBS-80" from Great Lakes Chemical Co., Ltd. Although manufactured using a different method than the aforementioned flame retardants, "Pyrocheck 68PB" from Ferro Co., Ltd. can also be cited as an example of a brominated polystyrene-based flame retardant.

[0101] Brominated phthalimide flame retardants are compounds in which 1 to 4 brom atoms are bonded to the benzene ring of a phthalimide group, such as monobromophthalimide, dibromophthalimide, tribromophthalimide, tetrabromophthalimide, ethylenebis(monobromophthalimide), ethylenebis(dibromophthalimide), ethylenebis(tribromophthalimide), and ethylenebis(tetrabromophthalimide) of the following chemical formula (6). [ka] Examples of commercially available flame retardants include "Saytex BT-93" and "Saytex BT-93W" from Albemarle Co., Ltd.

[0102] Brominated benzenes are compounds consisting of a group in which one or more bromine atoms are bonded to a benzene ring, and examples include tetrabrombenzene, pentabrombenzene, hexabrombenzene, bromophenylallyl ether, pentabromtoluene, 1,1-bis(pentabromphenyl)ethane, 1,2-bis(pentabromphenyl)ethane, and poly(pentabrombenzyl acrylate). A commercially available flame retardant is "Saytex 8010" from Albemarle Co., Ltd.

[0103] Brominated cycloalkanes include brominated hydrocarbons in which 1 to 6 brome atoms are bonded to a cycloalkane (cyclic aliphatic hydrocarbon) having 6 to 12 carbon atoms. Examples of cycloalkanes include cyclohexane and cyclododecane, and examples of brominated cycloalkanes include pentabromcyclohexane, hexabromcyclohexane, tetrabromcyclododecane, pentabromcyclododecane, and hexabromcyclododecane. Examples of commercially available hexabromcyclododecane include "FR-1206" from Bromochem Far East Co., Ltd., "Saytex HBCD" from Albemarle Co., Ltd., "Great LakesCD-75P" from Great Lakes Chemical Co., Ltd., "Firecut P-880M" from Suzuyu Chemical Co., Ltd., and "Piroguard SR-103" from Daiichi Kogyo Seiyaku Co., Ltd.

[0104] Examples of brominated isocyanurates include compounds in which a brominated alkyl group, in which a brome atom is bonded to an alkyl group (chain aliphatic hydrocarbon group) having 2 to 6 carbon atoms, is bonded to an isocyanuric acid residue, and compounds in which a brominated phenoxy group, in which 1 to 5 brome atoms are bonded to a phenoxy group, is bonded to an isocyanuric acid residue. Specific examples include tris(monobromopropyl) isocyanurate, tris(2,3-dibromopropyl) isocyanurate, tris(tribromopropyl) isocyanurate, tris(tetrabromopropyl) isocyanurate, tris(pentabromopropyl) isocyanurate, tris(heptabromopropyl) isocyanurate, tris(octabromobutyl) isocyanurate, tris(monobromphenoxy) isocyanurate, tris(dibromphenoxy) isocyanurate, tris(tribromphenoxy) isocyanurate, tris(pentabromphenoxy) isocyanurate, tris(ethylmonobromphenoxy) isocyanurate, and tris(propyldibromphenoxy) isocyanurate. Examples of commercially available brominated isocyanurates include "Taik-6B" from Nippon Chemical Corporation and "Firecut P-660" from Suzuyu Chemical Co., Ltd.

[0105] In addition to the commonly used bromine-based flame retardants mentioned above, those listed in the literature and in the catalogs of bromine-based flame retardant manufacturers can also be used. Examples of such bromine-based flame retardants include brominated phenols, brominated phenoxytriazines, brominated alkanes, brominated maleimides, and brominated phthalates.

[0106] Brominated phenols are compounds in which 1 to 5 brom atoms are bonded to a phenol group, and examples include monobromophenol, dibromophenol, tribromophenol, tetrabromophenol, and pentabromophenol.

[0107] Brominated phenoxytriazine compounds are compounds in which 1 to 5 brom atoms are bonded to a phenoxy group, and 1 to 3 of these brominated phenoxy groups are bonded to a triazine ring. Examples include mono(tribromphenoxy)triazine, bis(monobromphenoxy)triazine, bis(tribromphenoxy)triazine, tris(dibromphenoxy)triazine, and tris(tribromphenoxy)triazine. A commercially available flame retardant is "Piroguard SR-245" from Daiichi Kogyo Seiyaku Co., Ltd.

[0108] Brominated alkanes are compounds in which a bromine atom is bonded to an alkane (a chain-like aliphatic hydrocarbon) having 2 to 6 carbon atoms. Examples of such alkanes include ethane, propane, butane, pentane, and hexane. Examples of brominated alkanes include dibromoethane, tetrabromoethane, monobromopropane, tribromopropane, hexabromopropane, octabromopropane, tetrabromobutane, hexabromobutane, octabromobutane, tribromopentane, pentabromopentane, octabromopentane, dibromohexane, tribromohexane, tetrabromohexane, hexabromohexane, and octabromohexane.

[0109] Brominated maleimide compounds are compounds in which 1 to 5 bromine atoms are bonded to a phenylmaleimide group, and examples include monobromphenylmaleimide, dibromphenylmaleimide, tribromphenylmaleimide, and pentabromphenylmaleimide.

[0110] Examples of brominated phthalates include compounds in which 1 to 4 brom atoms are bonded to phthalic anhydride, such as monobrom phthalic anhydride, dibrom phthalic anhydride, tribrom phthalic anhydride, and tetrabrom phthalic anhydride.

[0111] Furthermore, while it is common practice to use flame retardant additives such as antimony trioxide in combination to further enhance flame retardancy, the addition of these flame retardant additives does not affect the effects of the present invention in any way. The amount of flame retardant additive added is usually 0.5 to 10 parts by mass per 100 parts by mass of polystyrene, but the preferred amount is 1 to 7 parts by mass in relation to physical properties, etc. In this embodiment, the preferred content of the bromine-based flame retardant in the styrene-based composition can be the same as the preferred content of flame retardant (C).

[0112] <Optional addition ingredients> In addition to the components (A) to (C) described above, the recycled flame-retardant styrene resin composition of this embodiment may contain, as necessary, conventionally known additives, processing aids, and other optional additives, provided that the effects of the present invention are not impaired. Examples of such additives and processing aids include antioxidants, weathering agents, lubricants, antistatic agents, and fillers.

[0113] Examples of the above-mentioned antioxidants include phenolic compounds, phosphorus compounds, and thioether compounds.

[0114] Examples of the above-mentioned phenolic antioxidants include 2,6-di-tert-butyl-p-cresol, 2,6-diphenyl-4-octadecyloxyphenol, distearyl(3,5-di-tert-butyl-4-hydroxybenzyl)phosphonate, 1,6-hexamethylenebis[(3,5-di-tert-butyl-4-hydroxyphenyl)propionamide], 4,4'-thiobis(6-tert-butyl-m-cresol), 2,2'-methylenebis(4-methyl-6-tert-butylphenol), and 2,2'-methylene Bis(4-ethyl-6-tert-butylphenol), 4,4'-butylidenebis(6-tert-butyl-m-cresol), 2,2'-ethylidenebis(4,6-di-tert-butylphenol), 2,2'-ethylidenebis(4-sec-butyl-6-tert-butylphenol), 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 1,3,5-tris(2,6-dimethyl-3-hydroxy-4-tert-butylbenzyl)isocyanurate, 1,3,5-tris(3 ,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene, 2-tert-butyl-4-methyl-6-(2-acryloyloxy-3-tert-butyl-5-methylbenzyl)phenol, stearyl [3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate methyl ]methane, thiodiethylene glycol bis[(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 1,6-hexamethylene bis[(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], bis[3,3-bis(4-hydroxy-3-tert-butylphenyl)butyric acid] glycol ester, bis[2-tert-butyl-4-methyl-6-(2-hydroxy-3-tert-butyl-5-methylbenzyl)phenyl] terephthalate, 1,3,5-tris[(3,Examples include 5-di-tert-butyl-4-hydroxyphenyl)propionyloxyethyl]isocyanurate, 3,9-bis[1,1-dimethyl-2-{(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy}ethyl]-2,4,8,10-tetraoxaspiro[5,5]undecane, and triethylene glycol bis[(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate]. These may be used individually or in combination of two or more.

[0115] Examples of the phosphorus-based antioxidants mentioned above include tris(2,4-di-tert-butylphenyl) phosphite, trisnonylphenyl phosphite, tris[2-tert-butyl-4-(3-tert-butyl-4-hydroxy-5-methylphenylthio)-5-methylphenyl] phosphite, tridecyl phosphite, octyldiphenyl phosphite, di(decyl)monophenyl phosphite, di(tridecyl)pentaerythritol diphosphite, and di(nonylphenyl)pentaerythritol Litol diphosphite, bis(2,4-tert-butylphenyl)pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, bis(2,4,6-tri-tert-butylphenyl)pentaerythritol diphosphite, bis(2,4-dicumylphenyl)pentaerythritol diphosphite, tetra(tridecyl)isopropylidene diphenol diphosphite, tetra(tridecyl)-4,4'-n- Butylidenebis(2-tert-butyl-5-methylphenol) diphosphite, hexa(tridecyl)-1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane triphosphite, tetrakis(2,4-di-tert-butylphenyl) biphenylenediphosphonite, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 2,2'-methylenebis(4,6-tert-butylphenyl)-2-ethylhexylphosphate Examples include 2,2'-methylenebis(4,6-tert-butylphenyl)-octadecyl phosphite, 2,2'-ethylidenebis(4,6-di-tert-butylphenyl)fluorophosphite, tris(2-[(2,4,8,10-tetrakis-tert-butyldibenzo[d,f][1,3,2]dioxaphosphine-6-yl)oxy]ethyl)amine, and phosphites of 2-ethyl-2-butylpropylene glycol and 2,4,6-tri-tert-butylphenol. These may be used individually or in combination of two or more.

[0116] Examples of the thioether-based antioxidants mentioned above include dialkylthiodipropionates such as dilauryl thiodipropionate, dimyristyl thiodipropionate, and distearyl thiodipropionate, as well as pentaerythritol tetra(β-alkylmercaptopropionate esters). These may be used individually or in combination of two or more.

[0117] As the above weather-resistant agent, ultraviolet absorbers can be used. Examples of such ultraviolet absorbers include 2-hydroxybenzophenones such as 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, and 5,5'-methylenebis(2-hydroxy-4-methoxybenzophenone); 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole, and 2-(2'-hydroxy-3'-tert-butylphenyl) 2-(2'-hydroxyphenyl)benzotriazoles such as 2-(2'-hydroxyphenyl)benzotriazole, 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-dicumylphenyl)benzotriazole, 2,2'-methylenebis(4-tert-octyl-6-(benzotriazolyl)phenol), and 2-(2'-hydroxy-3'-tert-butyl-5'-carboxyphenyl)benzotriazole; phenyl salicylate Benzoates such as resorcinol monobenzoate, 2,4-di-tert-butylphenyl-3,5-di-tert-butyl-4-hydroxybenzoate, 2,4-di-tert-amylphenyl-3,5-di-tert-butyl-4-hydroxybenzoate, and hexadecyl-3,5-di-tert-butyl-4-hydroxybenzoate; substituted oxanilides such as 2-ethyl-2'-ethoxyoxanilide and 2-ethoxy-4'-dodecyloxanilide; and ethyl-α-cyano-β,β-diphenylacrylate. Examples include cyanoacrylates such as methyl-2-cyano-3-methyl-3-(p-methoxyphenyl)acrylate; and triaryltriazines such as 2-(2-hydroxy-4-octoxyphenyl)-4,6-bis(2,4-di-tert-butylphenyl)-s-triazine, 2-(2-hydroxy-4-methoxyphenyl)-4,6-diphenyl-s-triazine, and 2-(2-hydroxy-4-propoxy-5-methylphenyl)-4,6-bis(2,4-di-tert-butylphenyl)-s-triazine. These may be used individually or in combination of two or more.

[0118] As the above lubricant, fatty acid amides, fatty acid esters, fatty acids, fatty acid metal salts, etc., can be used.

[0119] Examples of the above-mentioned aliphatic amide lubricants include stearamide, oleamide, erucamide, behenamide, ethylenebisstearate, ethylenebisoleamide, ethylenebiserucamide, and ethylenebislauramide. These may be used individually or in combination of two or more.

[0120] The above aliphatic ester lubricants include methyl laurate, methyl myristate, methyl palmitate, methyl stearate, methyl oleate, methyl erucate, methyl behenate, butyl laurate, butyl stearate, isopropyl myristate, isopropyl palmitate, octyl palmitate, octyl coconut fatty acid ester, octyl stearate, octyl beef tallow fatty acid ester, lauryl laurate, stearyl stearate, behenyl behenate, cetyl myristate, esters of montanic acid and ethylene glycol, esters of montanic acid and glycerin, and mon Examples include esters of tanic acid and butylene glycol, esters of montanic acid and trimethylolethane, esters of montanic acid and trimethylolpropane, esters of montanic acid and pentaerythritol, glycerin monostearate, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan sesquioleate, sorbitan trioleate, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate, and polyoxyethylene sorbitan trioleate. These may be used individually or in combination of two or more.

[0121] Among the fatty acid-based lubricants mentioned above, saturated fatty acids specifically include lauric acid (dodecanoic acid), isodecanoic acid, tridecylic acid, myristic acid (tetradecanoic acid), pentadecylic acid, palmitic acid (hexadecanoic acid), margaric acid (heptadecanoic acid), stearic acid (octadecanoic acid), isostearic acid, tubercurostearic acid (nonadecanoic acid), 2-hydroxystearic acid, arachidic acid (eicosanoic acid), behenic acid (docosanoic acid), lignoceric acid (tetradocosanoic acid), cerotic acid (hexadocosanoic acid), montanic acid (octadocosanoic acid), melissic acid, etc., with lauric acid, palmitic acid, stearic acid, behenic acid, 12-hydroxystearic acid, and montanic acid being particularly noteworthy.

[0122] Among the fatty acid-based lubricants mentioned above, specific examples of unsaturated fatty acids include myristoleic acid (tetradecenoic acid), palmitoleic acid (hexadecenoic acid), oleic acid (cis-9-octadecenoic acid), elaidic acid (trans-9-octadecenoic acid), ricinoleic acid (octadecadienoic acid), vaccenic acid (cis-11-octadecenoic acid), linoleic acid (octadecadienoic acid), linolenic acid (9,11,13-octadecatrienoic acid), elestearic acid (9,11,13-octadecatrienoic acid), gadoleic acid (eicosanic acid), erucic acid (docosanoic acid), nervonic acid (tetradocosanoic acid), etc. These may be used individually or in combination of two or more.

[0123] Examples of the above-mentioned fatty acid metal salt lubricants include lithium salts, calcium salts, magnesium salts, and aluminum salts of the fatty acids in the above-mentioned fatty acid lubricants. These may be used individually or in combination of two or more.

[0124] As the above-mentioned antistatic agents, cationic, anionic, nonionic, amphoteric, and fatty acid partial esters such as glycerin fatty acid monoesters can be used. Specifically, alkyltrimethylammonium salts, dialkyldimethylammonium salts, benzalkonium salts, N,N-bis(2-hydroxyethyl)-N-(3-dodecyloxy-2-hydroxypropyl)methylammonium mesosulfate, (3-laurylamidopropyl)trimethylammonium methylsulfate, stearamidopropyldimethyl-2-hydroxyethylammonium nitrate, stearamidopropyldimethyl-2-hydroxyethylammonium phosphate, cationic polymers, alkyl sulfonates, alkylbenzene sulfonates, alkyldiphenyl ether disulfonate sodium, alkyl nitrate esters, phosphorus Examples include alkyl acid ester salts, alkyl phosphate amine salts, monoglyceride stearate, pentaerythritol fatty acid esters, sorbitan monopalmitate, sorbitan monostearate, diglycerin fatty acid esters, alkyldiethanolamine, alkyldiethanolamine fatty acid monoesters, alkyldiethanolamide, polyoxyethylene dodecyl ether, polyoxyethylene alkylphenyl ether, polyethylene glycol monolaurate, polyoxyethylene alkylamine, polyoxyethylene alkylamide, polyether block copolymer, cetyl betaine, hydroxyethylimidazoline sulfate, and the like. These may be used individually or in combination of two or more.

[0125] Examples of fillers that can be used include talc, calcium carbonate, barium sulfate, carbon fiber, mica, wollastonite, and whiskers.

[0126] In this embodiment, the recycled flame-retardant styrene resin composition used as the recycled flame retardant masterbatch and the composition containing the recycled flame retardant masterbatch may also contain the above-mentioned additives and processing aids, as well as other optional additives such as blocking inhibitors, colorants, blooming inhibitors, surface treatment agents, antibacterial agents, and eye discharge inhibitors (eye discharge inhibitors such as silicone oil described in Japanese Patent Application Publication No. 2009-120717, monoamide compounds of higher aliphatic carboxylic acids, and monoester compounds obtained by reacting higher aliphatic carboxylic acids with monovalent to trivalent alcohol compounds). The total content of optional additives such as additives and processing aids may be 0.05 to 5% by mass in the recycled flame-retardant styrene resin composition.

[0127] The recycled flame-retardant styrene resin composition of this embodiment may consist substantially only of components (A) to (C) and optional additives. Alternatively, it may consist only of components (A) to (C), or only of components (A) to (C) and optional additives.

[0128] "Substantially consisting only of components (A) to (C) and optional additives" means that 95 to 100% (preferably 98 to 100% by mass) (A to C) of the recycled flame-retardant styrene resin composition is either components (A) to (C) or components (A) to (C) and optional additives.

[0129] Furthermore, the recycled flame-retardant styrene resin composition of this embodiment may contain unavoidable impurities in addition to components (A) to (C) and optional additives, as long as the effects of the present invention are not impaired.

[0130] <Recycling method for recycled flame-retardant styrene resin composition> For recovered styrene resin (A) from home appliances and office equipment, the recovered styrene resin is sorted from the recovered products and crushed to the extent necessary for recompounding. The crushed recovered styrene resin is then washed, dewatered, and dried. If the recovered styrene resin (A) is of a suitable size for pellets or compounding, crushing is not performed, and if it is not contaminated, the washing process is also unnecessary. The recovered styrene resin (A) obtained in this way is mixed with predetermined amounts of NOR-type hindered amine compound (B) and flame retardant (C) as needed, dry-blended, and then the mixture is put into a hopper and melt-kneaded to produce pellets. For example, methods include using a high-speed agitator such as a Henschel mixer, a batch-type kneader such as a Banbury mixer, a single-shaft or twin-shaft continuous kneader, a roll mixer, etc., either individually or in combination. The heating temperature during kneading is usually selected in the range of 180 to 260°C. During the melting and mixing process, foreign matter is removed using a mesh or similar device, and metal is removed using magnets or metal detectors. The recycling method for the recycled flame-retardant styrene resin composition in this embodiment includes a step (II) of preparing a molten compound by melting and kneading the recovered styrene resin (A) at a temperature range of 180 to 260°C. A preferred example of the recycling method for the recycled flame-retardant styrene resin composition in this embodiment includes a step (I) of separating the recovered styrene resin (A) from the recovered product, and a step (II) of preparing a molten compound by melting and kneading the separated recovered styrene resin (A) at a temperature range of 180 to 260°C. The method may also include a step (III) of blending the NOR-type hindered amine compound (B) in an amount of 0.3 to 3.5% by mass of the entire molten compound. Furthermore, the method may also include a step (IV) of blending the flame retardant (C) in an amount of 1 to 25% by mass of the entire molten compound. After step (II), the method may further include a step (V) of removing foreign matter of 20 μm or larger using a sieve or mesh. After step (II) above, the process may further include step (VI) of removing metal particles larger than 20 μm using a magnet or metal detector. Furthermore, it is preferable to select materials containing 70% by mass or more of styrene monomer units from the recovered products. Examples of recovered products include pre-consumer materials such as factory-recovered products, post-consumer materials such as market-recovered products, long-term stock pellets, or off-spec pellets.

[0131] [Properties of recycled flame-retardant styrene resin compositions] <Flame-retardant> The flame retardancy of the recycled flame-retardant styrene resin composition of this embodiment is preferably within the UL94 standards in the vertical combustion test (UL94-V test), i.e., within the flame retardancy class of V-0 to V-2. Furthermore, in the horizontal combustion test (UL94-HB test), it is desirable that the combustion rate is 75 mm / min or less, which is within the HB standard, and is preferably 85 mm / min or less when considering standards such as the automotive flame retardancy standard (FMVSS302). In this disclosure, flame retardancy can be evaluated by the method described in the [Examples] section below.

[0132] <Thermal stability> In this embodiment, the thermal stability of the recycled flame-retardant styrene resin composition is preferably such that no molding defects, color changes, or burning occur during molding due to gas generation.

[0133] <Lightfastness> The lightfastness of the recycled flame-retardant styrene resin composition of this embodiment is preferably such that the color difference △E is 10 or less, and more preferably 5 or less. If it is greater than 10, it may not be usable outdoors due to reduced strength, and even indoors it may discolor, potentially impairing its design and recyclability. In this disclosure, the color difference △E is a value measured using a xenon lamp type weather meter in accordance with JIS K7103 and JIS K7105, by maintaining the temperature of the black panel at 63°C and measuring the color difference (△E) after 300 hours.

[0134] [Molded products] The recycled flame-retardant styrene resin composition of this embodiment can be used to produce molded products by the above-described melt-kneading molding machine, or by using the resulting pellets of the recycled flame-retardant styrene resin composition as a raw material, through injection molding, injection compression molding, extrusion molding, blow molding, press molding, vacuum molding, foam molding, and the like. Molded articles containing the recycled flame-retardant styrene resin composition of this embodiment are preferably suitable for use in injection molded articles (including injection compression), office automation equipment such as photocopiers, fax machines, televisions, radios, tape recorders, video decks, personal computers, printers, telephones, information terminals, refrigerators, and microwave ovens, as well as housings and various parts for home electrical appliances and electrical and electronic equipment, foamed insulation materials, insulating films, and the like. [Examples]

[0135] The embodiments of the present invention will be described in more detail below based on examples and comparative examples, but the present invention is not limited in any way by these embodiments.

[0136] "Measurement and Evaluation Methods" The physical properties of the resin compositions obtained in each example and comparative example were measured and evaluated based on the following methods.

[0137] (1) Evaluation of flame retardancy (i) Evaluation of combustion grade and burn time The flame retardancy of the test specimens (size: 127 mm x 12.7 mm, thickness: 0.8 mm) prepared using the method described below was evaluated in accordance with the UL94 vertical combustion test (UL94-V test) using a 50W test flame. The degree of combustion was evaluated by applying a gas burner flame to the above test specimens. The flame retardancy rating indicates the flame retardancy class classified by the UL94-V test. Five tests were conducted on each test specimen for evaluation. The general classification method is as follows: V-0: Total burning time of 5 sticks is 50 seconds or less, maximum burning time is 10 seconds or less, no drip cotton ignition. V-1: Total burning time of 5 sticks is 250 seconds or less, maximum burning time is 30 seconds or less, no drip cotton ignition. V-2: Total burning time of 5 sticks is 250 seconds or less, maximum burning time is 30 seconds or less, with drip cotton ignition. Not V: Not conforming to UL94 standards

[0138] (ii) Combustion rate Similar to the evaluation of flammability in (i) above, three test specimens (b) (size: 127 mm × 12.7 mm, thickness: 0.8 mm) prepared using the method described below were used to measure the combustion rate (mm / min) by UL94 horizontal combustion test.

[0139] (2) Evaluation of thermal stability Using an injection molding machine (Toshiba Machine Co., Ltd., EC60N), a 3mm thick plate was molded with the following settings: cylinder temperature 240°C, mold temperature 50°C, injection pressure (gauge pressure 40-60 MPa), injection speed (panel setting) 50%, injection time / cooling time = 5 sec / 100 sec, cooling time 100 seconds. The appearance and color changes of the 5th shot plate were visually compared with a 3mm thick plate produced using the method described below. The results are shown in Tables 1 and 2. In Tables 1 and 2, plates showing silver streaks are labeled "silver," and plates with overall or partial brown discoloration are labeled "burnt."

[0140] (3) Evaluation of lightfastness The 3 mm thick plates prepared by the methods described in Examples 1 to 12 below were evaluated in accordance with JIS K7103 and JIS K7105. Specifically, a xenon lamp weather meter [Atlas Corporation; Ci65] was used to maintain the temperature of the black panel at 63°C, and the color difference (ΔE) between the start of measurement and 300 hours after the start of measurement was evaluated. This ΔE was measured using a spectrophotometer [Nippon Denshoku Industries Co., Ltd.] under the following conditions. (a) Lamp: Halogen lamp; 12V, 50W [NARVA Corporation] (b) Wavelength of light: 400-700 nm (c) Light source: C light source 2 degree field of view (d) Measuring hole: 30mm in diameter (e) Measurement target: reflected light

[0141] The materials used in the examples and comparative examples are as follows.

[0142] <Component (A)> As the recycled styrene resin (A-1), high-impact polystyrene recovered from home appliances was used. It had an MFR of 5.6, a rubber-like polymer content of 7.5% by mass, and an average particle diameter of 1.6 μm. As the recycled styrene resin (A-2), polystyrene recovered from home appliances was used. It had an MFR of 2.3. Note that the high-impact polystyrene and polystyrene recovered from the above home appliances were recovered as styrene resins contained in the home appliances recovered by the home appliance recycling method, and those recovered from resin products labeled as polystyrene were used.

[0143] <Rubber-modified styrene resin (HIPS)> A rubber-modified styrene resin, which is a high-impact polystyrene (HIPS) with an MFR of 7.0, was used. The HIPS used polybutadiene as the rubber-like polymer, and the content of the rubber-like polymer was 8.6% by mass. The average particle diameter of the high-impact polystyrene (HIPS) was 1.5 μm.

[0144] <HIPS containing NOR type hindered amine compound (B) (NOR-HIPS-1)> A rubber-modified styrene resin, which is a polystyrene (HIPS) with an MFR of 8.2 containing 3% by mass of the NOR type hindered amine compound (B1) described later in the whole rubber-modified styrene resin, was used. The HIPS used polybutadiene as the rubber-like polymer, and the content of the rubber-like polymer was 8.5% by mass. The average particle diameter of the high-impact polystyrene (HIPS) was 1.5 μm. After adding 0.2 parts by mass of Irganox 1076 and Irgafos 168 to this HIPS and premixing, the obtained premix was mixed together, and melt extrusion (screw rotation speed was 150 rpm, discharge amount was 10 kg / hr) was performed in the range of 220 °C using a twin-screw extruder (manufactured by Toshiba Machine Co., Ltd., TEM-26SS) to produce pellets.

[0145] <HIPS containing NOR-type hindered amine compound (B1) (NOR-HIPS-2)> The pellets of the above NOR-HIPS-1 were left in an oven at 80 °C for 30 days to prepare samples equivalent to long-term inventory pellets.

[0146] <Component (B)> As the NOR-type hindered amine compound (B1) (also referred to as NOR-HALS-B1 in Tables 1 and 2), [Flamestab NOR116FF, NOR-type polymer type, manufactured by BASF] was used. As the NOR-type hindered amine compound (B2) (also referred to as NOR-HALS-B2 in Tables 1 and 2), [Adekastab LA-81 NOR-type, manufactured by ADEKA Corporation] was used.

[0147] <Component (C)> As the phosphinic acid compound (also referred to as C-1 in Tables 1 and 2), [HCA, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, manufactured by Sanko Co., Ltd.] was used. As the phosphate ester (also referred to as C-2 in Tables 1 and 2), [resorcinol bis-dixylenyl phosphate, manufactured by Daihachi Chemical Industry Co., Ltd., PX-200] was used. As the brominated flame retardant (also referred to as C-3 in Tables 1 and 2), [bis(pentabromophenyl)ethane, manufactured by Albemarle Corporation, Saytex 8010] was used.

[0148] <Additives> (Phenolic antioxidant) · Stearyl [3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] [Irganox 1076, manufactured by BASF] (Phosphorus antioxidant) · Tris(2,4-di-tert-butylphenyl)phosphite [Irgafos 168, manufactured by BASF]

[0149] [Examples 1 to 12] To 100 parts by mass of each component and components (A) and (B) in the composition ratios shown in Table 1, 0.2 parts by mass each of Irganox 1076 and Irgafos 168 were added and pre-mixed. The resulting pre-mixture was mixed together and melt-extruded using a twin-screw extruder (Toshiba Machine Co., Ltd., TEM-26SS) at a temperature of 180°C to 230°C (screw rotation speed 150 rpm, discharge volume 10 kg / hr) to produce a pellet-shaped recycled flame-retardant styrene resin composition. The pelletized recycled flame-retardant styrene resin composition obtained in this manner was molded using an injection molding machine (Toshiba Machine Co., Ltd., EC60N) at a cylinder temperature of 220°C, a mold temperature of 50°C, an injection pressure (gauge pressure of 40-60 MPa), an injection speed (panel setting) of 50%, and an injection time / cooling time of 5 sec / 20 sec to produce a 3 mm plate for evaluation of lightfastness. A comparative sample for evaluating lightfastness was also prepared using the above pelletized recycled flame-retardant styrene resin composition according to the method described in the section on thermal stability evaluation. The results of the lightfastness and thermal stability evaluations are shown in Table 1. Furthermore, using a flat plate mold with gates at both ends measuring 127 mm × 12.7 mm × 0.8 mm in thickness, combustion test specimens were prepared using the pelletized recycled flame-retardant styrene resin composition under the same conditions as the 3 mm plate, and flame retardancy was measured. The results are shown in Table 1. In addition, the evaluation results of the first burn time (seconds) of the first set of UL94-V tests for Examples 1 to 12 are shown in Table 1 below.

[0150] [Comparative Examples 1-10] Comparative Examples 1 to 10 were carried out in the same manner as Example 1, except that the composition was changed as shown in Table 1. The results of the measurement and evaluation of the physical properties of Comparative Examples 1 to 10 are shown in Table 2.

[0151] [Table 1]

[0152] [Table 2]

[0153] Examples 1 to 12, as shown in Table 1 above, exhibit high flame retardancy, good thermal stability, and good light resistance. Adding flame retardant (C) further reduces the combustion rate and improves flame retardancy. In particular, the use of phosphorus-based flame retardants further improves light resistance. Specifically, it is possible to restore the reduced thermal stability and light resistance of the recovered styrene resin (A).

[0154] On the other hand, as shown in Table 2, for Comparative Examples 1 to 4, the flame retardancy, thermal stability, and light resistance are insufficient without the inclusion of NOR-type hindered amine compounds (B) and flame retardants (C). Comparative Example 4 shows that the recovered styrene resin has inferior thermal stability and light resistance.

[0155] As shown in Table 2, while the flame retardancy of Comparative Examples 5-10 is improved by adding a flame retardant, the improvement in thermal stability and light resistance is insufficient. [Industrial applicability]

[0156] The recycled flame-retardant styrene resin composition of the present invention and molded articles containing the recycled flame-retardant styrene resin composition can be suitably used in computer components such as desktop and notebook computers, mobile phone components, electrical and electronic equipment, personal information terminals, home appliance components, automobile components, industrial materials, and building materials, including sheets, films, foams, etc.

Claims

[Claim 1] A recycled flame-retardant styrene resin composition comprising a recovered styrene resin (A) and a NOR-type hindered amine compound (B).

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