Regenerated resin composition, resin molded article, resin case, and electronic device

Abstract

The present disclosure addresses the problem of providing a regenerated resin composition, a resin molded article, a resin case, and an electronic device that are substantially free of harmful substances, have high impact strength, and have excellent flame retardancy. The present invention relates to a regenerated resin composition containing a PCR material containing a polycarbonate and a core-shell impact modifier, characterized in that the core-shell impact modifier contains a silicone rubber, and the content of a fluororesin in the regenerated resin composition is less than 1000 ppm.

Description

Technical Field

[0001] This disclosure relates to recycled resin compositions, resin molded articles, resin housings, and electronic devices. More specifically, it relates to recycled resin compositions, resin molded articles, resin housings, and electronic devices having high impact strength and excellent flame retardancy. Background Technology

[0002] In recent years, PFAS regulations on resin-molded products have been strengthened, as these products often contain harmful substances such as fluoropolymers like polytetrafluoroethylene (PTFE). Furthermore, these products are required to be as free of harmful substances as possible, such as fluoropolymers. Hereinafter, "polytetrafluoroethylene" will be abbreviated as "PTFE".

[0003] Among these requirements, flame retardancy is required for resin molded products, and the evaluation of this flame retardancy is based on a standard known as V-0, established by UL (Underwriters Laboratories) in the United States. Hereinafter, this standard will be abbreviated as "V-0 standard".

[0004] For resin molded products that are required to meet the V-0 standard, from the perspective of human health and environmental protection, flame retardants and anti-dripping agents are often used to ensure flame retardancy during the manufacturing of these resin molded products.

[0005] In anti-dripping agents, PTFE is generally used to ensure flame retardancy. However, the processed products of PTFE often contain harmful substances such as fluoropolymers in the aforementioned resin molded products. This is the current situation.

[0006] For example, for the housing of electronic devices requiring excellent flame retardancy and impact strength, the technology disclosed in Patent Document 1 is described. Furthermore, as in Patent Document 2, for resin compositions made from PCR materials containing polycarbonate, techniques are disclosed that implement treatments to prevent degradation from the initial performance stage, but these techniques leave room for improvement.

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent Document 1: Japanese Patent Application Publication No. 11-21441

[0010] Patent Document 2: Japanese Patent Application Publication No. 2000-103952 Summary of the Invention

[0011] The problem that the invention aims to solve

[0012] In the technology disclosed in Patent Document 1, flame retardancy and impact strength are improved by using a core-shell type impact modifier containing a flame retardant and silicone rubber in polycarbonate. Furthermore, the flame retardant uses a phosphorus-based flame retardant, and the core-shell type impact modifier containing silicone rubber uses a core-shell type impact modifier with an organosilicon-acrylic composite rubber that functions as both an impact modifier and a flame retardant auxiliary agent.

[0013] However, in the aforementioned technologies, manufacturing housings for electronic devices that meet V-0 standards requires anti-drip agents containing hazardous substances such as fluoropolymers like PTFE, which is the current reality. Therefore, alternative technologies to ensure flame retardancy are needed, but currently, there is a lack of such alternatives.

[0014] Furthermore, regarding the manufacture of resin molded products, etc., the concepts of low carbon footprint, biomassification, and recycling are also important. Alongside legal restrictions and promotional policies, technological development is booming, and in particular, the effective utilization of post-consumer recycled materials is crucial. Hereinafter, "post-consumer recycled materials" will also be referred to as "PCR materials." In this specification, used recycled materials that are recovered after being used in the market will be abbreviated as "PCR materials."

[0015] In particular, for products made using PCR materials, the initial performance of the products before they become PCR materials deteriorates significantly, thus limiting the applications of PCR materials.

[0016] In the technology disclosed in Patent Document 2, a treatment is performed to prevent degradation of initial performance in a resin composition made from a PCR material containing polycarbonate. Furthermore, it is described that the resin composition in this technology can withstand accelerated degradation tests and pulverization-remolding after the presence of virgin resin as a raw material. Hereinafter, "a resin composition made from a PCR material containing polycarbonate as a raw material" will also be referred to as "a PCR polycarbonate material resin composition".

[0017] However, in reality, the PCR polycarbonate material resin composition mentioned above has been found to deteriorate in initial performance, especially with a significant reduction in toughness, and cannot be considered to have practical performance.

[0018] In this instance, the technology to improve the performance of the aforementioned PCR polycarbonate material resin composition to a practical level is limited and insufficient to meet the large market demand.

[0019] In order to improve the performance of PCR polycarbonate material resin compositions to practical applications, the inclusion of well-known and highly effective halogen-based flame retardants was considered. However, since halogen-based flame retardants are bromine-based, they pose an environmentally unfriendly problem.

[0020] From the above, considering the harmful substances such as PTFE and halogenated flame retardants, it is preferable that the PCR polycarbonate resin composition does not contain them, from an environmental protection perspective. However, the raw materials used in this PCR polycarbonate resin composition are recycled products from the market. Therefore, it is not realistic to manufacture the PCR polycarbonate resin composition with zero content of PTFE and halogenated flame retardants, which are widely used in commercially available products.

[0021] Therefore, a PCR polycarbonate material resin composition that is substantially free of harmful substances such as PTFE and halogenated flame retardants, possesses high impact strength, and exhibits excellent flame retardancy is required. It should be noted that "substantially free of harmful substances" in this specification means that the amounts of fluoropolymers, bromine, and chlorine are each less than 1000 ppm.

[0022] This disclosure was made in view of the above-mentioned problems and situations, and its solution is to provide a recycled resin composition, resin molded article, resin housing and electronic device that is substantially free of harmful substances, has high impact strength and excellent flame retardancy.

[0023] Methods for solving problems

[0024] In order to solve the above-mentioned problems, the present inventors conducted research on the causes of the above-mentioned problems and found that the PCR polycarbonate material resin composition contains a core-shell type impact modifier containing silicone rubber, so that the content of fluoropolymer in the PCR polycarbonate material resin composition is less than 1000 ppm, thereby solving the above-mentioned problems and completing the present disclosure.

[0025] That is, the aforementioned problems covered by this disclosure are solved by the following means. It should be noted that in this specification, "resin composition made from PCR material containing polycarbonate as raw material", i.e., "PCR polycarbonate material resin composition", is also simply referred to as "regenerated resin composition".

[0026] 1. A recycled resin composition comprising: a PCR material containing polycarbonate and a core-shell type impact modifier, characterized in that,

[0027] The aforementioned core-shell type impact modifier contains silicone rubber.

[0028] The content of fluoropolymer in the above-mentioned recycled resin composition is less than 1000 ppm.

[0029] 2. The recycled resin composition according to claim 1, characterized in that the core of the core-shell type impact modifier is an organosilicon-acrylic composite rubber, and the shell is composed of a resin having structural units derived from methyl methacrylate.

[0030] 3. The regenerated resin composition according to claim 1, characterized in that the content of the polycarbonate-containing PCR material in the regenerated resin composition is in the range of 88% to 96% by mass, and the content of the core-shell type impact modifier is in the range of 4% to 12% by mass.

[0031] 4. The regenerated resin composition according to claim 1, characterized in that the total content of chlorine and bromine in the regenerated resin composition is less than 1000 ppm.

[0032] 5. A resin molded article, characterized in that it is composed of a recycled resin composition according to any one of claims 1 to 4.

[0033] 6. A resin housing, characterized in that it comprises the resin molded article as described in item 5.

[0034] 7. An electronic device, characterized in that it comprises the resin housing described in item 6.

[0035] The effects of the invention

[0036] Through the methods described above in this disclosure, it is possible to provide recycled resin compositions, resin molded articles, resin housings, and electronic devices that are substantially free of harmful substances, have high impact strength, and excellent flame retardancy.

[0037] The mechanism by which the effects of this disclosure are manifested or even acted is not yet clear, but speculations are made as follows.

[0038] The regenerated resin composition disclosed herein comprises: a PCR material containing polycarbonate and a core-shell type impact modifier, characterized in that the core-shell type impact modifier contains silicone rubber, and the content of fluororesin in the regenerated resin composition is less than 1000 ppm.

[0039] Polycarbonate-containing PCR materials are widely used as market recyclables, and their use as raw materials for manufacturing recycled resin compositions is an important consideration from an environmental perspective. Regarding the recycled resin compositions disclosed herein, even when using polycarbonate-containing PCR materials with a fluoropolymer content of less than 1000 ppm as raw materials, excellent flame retardancy is achieved.

[0040] In addition, by including a core-shell type impact modifier containing silicone rubber in the recycled resin composition, it has high impact strength. Detailed Implementation

[0041] The following provides a detailed description of this disclosure, its constituent elements, and the methods and schemes for implementing this disclosure. It should be noted that in this application, "~" is used to mean the lower and upper limits of the values ​​described before and after it.

[0042] It should be noted that the advantages and features provided by one or more embodiments of this disclosure can be fully understood from the following detailed description. Therefore, it is not intended to define the limits of this disclosure.

[0043] 1. Recycled resin composition

[0044] The regenerated resin composition disclosed herein is characterized by comprising: a PCR material containing polycarbonate, and a core-shell type impact modifier, wherein the core-shell type impact modifier contains silicone rubber and the fluoropolymer is less than 1000 ppm.

[0045] (1.1) Contains

[0046] (PCR materials containing polycarbonate)

[0047] The so-called "polycarbonate-containing PCR material" disclosed herein is the raw material for the recycled resin composition of this disclosure, which is market-recycled resin recovered from molded articles based on polycarbonate. It should be noted that, generally, this market-recycled resin includes resins other than polycarbonate; strictly speaking, the polycarbonate-containing PCR material also includes substances that are not resins.

[0048] There are no particular restrictions on the proportion of polycarbonate in the PCR materials disclosed herein, as long as polycarbonate is used as the main component.

[0049] In this specification, "virgin polycarbonate" refers to the polycarbonate material before it becomes a molded product, and is not polycarbonate derived from recycled resin. It should be noted that virgin polycarbonate is typically sold as granules consisting solely of virgin polycarbonate. It is also sold as granules of virgin polycarbonate resin compositions with added additives such as colorants, antioxidants, and flame retardants. These granules are then fed into a molding machine to produce resin molded products.

[0050] There are no particular restrictions on the proportion of polycarbonate in the virgin polycarbonate resin composition, as long as the polycarbonate is used as the main component.

[0051] While virgin polycarbonate is a resin with excellent initial impact resistance, it lacks flowability and is prone to hydrolysis, making it a material that deteriorates rapidly. Furthermore, virgin polycarbonate alone can exhibit a flame retardancy of around V-2, but to improve the flame retardancy to V-0, it is necessary to contain PTFE and flame retardants, which contain harmful substances.

[0052] However, in the recycled resin composition disclosed herein, even without virgin polycarbonate, the flame retardancy can be improved to V-0 by including a PCR material containing polycarbonate, even without the aforementioned PTFE and flame retardant. Furthermore, by including a core-shell type impact modifier containing silicone rubber in the recycled resin composition, the impact strength is improved.

[0053] Furthermore, without using PTFE or flame retardants containing harmful substances, the regenerated resin composition of this disclosure containing PCR material containing polycarbonate exhibits superior flame retardancy compared to resin compositions containing virgin polycarbonate.

[0054] The impact strength of PCR-based resin compositions and virgin polycarbonate-based resin compositions varies depending on the required grade of the resin composition and cannot be determined in a one-size-fits-all manner.

[0055] For example, in PCR-based resin compositions, the impact strength is increased compared to virgin polycarbonate-based resin compositions, so it can be adjusted to achieve the impact strength required for the aforementioned grade in a way that is practically problem-free.

[0056] In addition, in resin compositions based on virgin polycarbonate, especially when virgin polycarbonate with high impact strength is used, the impact strength may sometimes decrease if the aforementioned core-shell type impact modifier is added, but the decrease in impact strength is within a range that is not a problem in practical applications.

[0057] In the above-mentioned regenerated resin composition, the total content of the above-mentioned polycarbonate-containing PCR material and the above-mentioned core-shell type impact modifier is preferably 50% by mass or more, and the content ratio of the above-mentioned polycarbonate-containing PCR material and the above-mentioned core-shell type impact modifier is in the range of 88:12 to 96:4.

[0058] As a result, the impact strength is further improved, and the flame retardancy becomes even better.

[0059] (Core-shell type impact modifier)

[0060] Generally speaking, impact modifiers used in conjunction with flame retardants are, from the viewpoint of the dispersibility of the impact modifier during manufacturing, of the core-shell type.

[0061] There are no particular limitations on the core-shell type impact modifier, but core-shell type elastomers are preferred. One type can be used alone, or two or more can be used in combination. By using core-shell type elastomers, impact strength is further improved. The effects of external impacts such as bending and impacts during actual use are mitigated, resulting in good reliability over long-term use.

[0062] The elastomer can be a styrene-based elastomer. Examples of styrene-based elastomers include block copolymers of styrene with butadiene, isoprene, 1,3-pentadiene, etc. Modified forms and hydrides of these elastomers are also possible. More specifically, examples include SBS, SIS, SEBS, and SEPS.

[0063] The elastomer can also be an elastomer other than a styrene-based elastomer. Examples of styrene-based elastomers include polyester elastomers, polyolefin elastomers, diene elastomers, and acrylic elastomers. Other known elastomers include polyamide elastomers, polyurethane elastomers, fluoropolymer elastomers, and silicone elastomers.

[0064] The elastomer is generally a thermoplastic elastomer. Preferred elastomers are polyester-based elastomers or the aforementioned styrene-based elastomers.

[0065] A core-shell elastomer consists of an innermost layer (i.e., the core) and one or more outer layers (i.e., the shell) covering it. As a core-shell elastomer, a core-shell graft copolymer is preferred, in which a monomer component that can be graft copolymerized for the core is used as the shell.

[0066] Core-shell graft copolymers typically use a polymer component, referred to as the rubber component, as the core. In core-shell graft copolymers, it is preferable to graft copolymerize the polymer component constituting the core and a monomer component that can copolymerize with the polymer component as the shell.

[0067] Examples of polymer components that form the nucleus include, for instance, butadiene-based rubbers such as polybutadiene and styrene-butadiene copolymers; isoprene-based rubbers; acrylic rubbers such as polybutyl acrylate, poly(2-ethylhexyl acrylate), and butyl acrylate-2-ethylhexyl acrylate copolymers; silicone-based rubbers such as polysiloxane rubbers; butadiene-acrylic composite rubbers; silicone-acrylic composite rubbers such as IPN (Interpenetrating Polymer Network) type composite rubbers composed of polysiloxane rubbers and polyalkyl acrylate rubbers; ethylene-propylene copolymers, ethylene-butene copolymers, ethylene-octene copolymers, and other ethylene-α-olefin rubbers; ethylene-acrylic rubbers; and fluororubbers. These can be used individually or in combination of two or more.

[0068] Among these, considering mechanical properties and surface appearance, it is preferred to select one of butadiene rubber, acrylic rubber, silicone rubber, and silicone-acrylic composite rubber, with silicone-acrylic composite rubber being more preferred.

[0069] The core-shell type impact modifier disclosed herein contains silicone rubber, which reflects the flame retardancy and lubrication properties of organosilicon materials, and can be expected to improve the flame retardancy and moldability of the resin composition.

[0070] Monomers that form the shell and can be graft copolymerized with the polymer components of the core include, for example, aromatic vinyl compounds; cyanide vinyl compounds; (meth)acrylate compounds, such as (meth)acrylate compounds, (meth)acrylate compounds, glycidyl (meth)acrylate, and other (meth)acrylate compounds containing epoxy groups; maleimide compounds such as maleimide, N-methylmaleimide, and N-phenylmaleimide; α,β-unsaturated carboxylic acid compounds such as maleic acid, phthalic acid, and itaconic acid, and their anhydrides (e.g., maleic anhydride). These monomers can be used alone or in combination of two or more.

[0071] Among these, considering mechanical properties and surface appearance, aromatic vinyl compounds, acrylonitrile compounds, and (meth)acrylic acid compounds are preferred, and aromatic vinyl compounds and (meth)acrylic acid compounds are more preferred, wherein the latter are (meth)acrylic acid ester compounds.

[0072] Examples of aromatic vinyl compounds include styrene, α-methylstyrene, 1-vinylnaphthalene, 4-methylstyrene, 4-propylstyrene, 4-cyclohexylstyrene, and 4-dodecylstyrene. Other examples include 2-ethyl-4-benzylstyrene, 4-(phenylbutyl)styrene, and halostyrene. Among these, styrene or α-methylstyrene is more preferred.

[0073] Examples of (meth)acrylate compounds include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, cyclohexyl (meth)acrylate, and octyl (meth)acrylate. Among these, methyl (meth)acrylate and ethyl (meth)acrylate, which are readily available, are preferred, and methyl (meth)acrylate is more preferred. It should be noted that "(meth)acrylate" is a general term for both "acrylic acid" and "methacrylic acid".

[0074] The core of the core-shell elastomer is preferably a polymer component selected from at least one of butadiene rubber, acrylic rubber, silicone rubber, and silicone-acrylic composite rubber. Moreover, core-shell graft copolymers consisting of a shell formed by graft copolymerization of (meth)acrylate and other (meth)acrylate compounds and aromatic vinyl compounds around the core are particularly preferred.

[0075] The content of the polymer component of the core in the core-shell graft copolymer is preferably 40% by mass or more.

[0076] In addition, the total content of the (meth)acrylic acid-based compound component and the aromatic vinyl compound component in the shell of the core-shell graft copolymer is preferably 30% by mass or more. It should be noted that among the (meth)acrylic acid-based compounds, (meth)acrylate is particularly preferred.

[0077] In the shell, either the (meth)acrylic acid-based compound or the aromatic vinyl compound can be used alone, or they can be used in combination.

[0078] From the above, as the core of the core-shell impact modifier related to the present disclosure, an organosilicon-acrylic composite rubber is preferred, whereby the impact strength of the recycled resin composition is improved. In addition, as the shell of the core-shell impact modifier, a resin having a structural unit derived from methyl methacrylate is preferred.

[0079] Examples of the core-shell elastomer include methyl methacrylate-butadiene-styrene copolymer (MBS), methyl methacrylate-acrylonitrile-butadiene-styrene copolymer (MABS), methyl methacrylate-butadiene copolymer (MB), methyl methacrylate-acrylic rubber copolymer (MA), methyl methacrylate-acrylic rubber-styrene copolymer (MAS), methyl methacrylate-acrylic / butadiene rubber copolymer, methyl methacrylate-acrylic / butadiene rubber-styrene copolymer, methyl methacrylate-(organosilicon-acrylic composite rubber) copolymer, etc.

[0080] Regarding the content of the core-shell impact modifier in the recycled resin composition, from the viewpoint of the manifestation of the effects of the present disclosure, it is preferably within the range of 4 to 12% by mass.

[0081] (Hazardous substances)

[0082] In the recycled resin composition of the present disclosure, it is preferably free of hazardous substances. Specifically, the content of the fluororesin in the recycled resin composition is preferably less than 1000 ppm. In addition, the total content of chlorine and bromine in the recycled resin composition is preferably less than 1000 ppm.

[0083] The amount of hazardous substances contained in the recycled resin composition of the present disclosure depends on the amount used in the PCR materials recovered in the market. By limiting the types of recycled materials or performing screening based on inspections using a fluorescent X-ray analyzer, etc., certain control can be achieved.

[0084] (Others)

[0085] The recycled resin composition may contain flame retardants, other additives, etc., without impairing the effects of this disclosure, and various known substances can be used for these.

[0086] If the total content of the polycarbonate-containing PCR material and the core-shell type impact modifier in the recycled resin composition of this disclosure is 50% by mass or more, and the content ratio of the polycarbonate-containing PCR material and the core-shell type impact modifier is in the range of 88:12 to 96:4, the effect of this disclosure is further improved. Moreover, as a result, the recycled resin composition has sufficient impact strength as a housing component for electronic devices, and excellent flame retardancy.

[0087] (1.2) Analytical methods for the presence of substances

[0088] The contents of the regenerated resin composition can be analyzed by various known methods. Examples of known methods include wavelength dispersive X-ray spectrometry (WDX), energy dispersive X-ray spectrometry (EDS), infrared spectrometry (IR), and nuclear magnetic resonance spectrometry (NMR).

[0089] To clarify, regarding the core-shell type impact modifier containing the aforementioned silicone rubber, it is detected as a rubbery polymer with a composite rubber composed mainly of silicone rubber components during material analysis. Furthermore, whether a PCR material containing polycarbonate is used in the regenerated resin composition disclosed herein can be easily confirmed using published values ​​from manufacturers that produce materials actually used in practice.

[0090] 2. Resin molded products

[0091] The resin molded article disclosed herein is characterized by being molded using the aforementioned recycled resin composition. In this case, the resin molded article, formed using the aforementioned recycled resin composition, can be endowed with high impact strength and excellent flame retardancy.

[0092] The recycled resin composition disclosed herein contains polycarbonate as a thermoplastic resin. Thermoplastic resins can be molded into desired shapes using known injection molding machines, etc., and are easy to process. Therefore, by molding into suitable shapes and forms, they can also be used as housings or components in electronic devices, etc.

[0093] As for the molding method of the resin molded article involved in this disclosure, various known methods can be appropriately selected according to the shape and use of the molded article. For example, methods of melting and molding the above-mentioned recycled resin composition in various molding machines can be listed.

[0094] As a preferred method for homogenizing a recycled resin composition by adding additives to form a suitable molding material, melt mixing is an example. As a melt mixing method, for example, a method is to premix the resin, polysaccharide-containing nanoparticles, and other additives using various mixers such as tumblers and Henschel mixers, and then perform melt mixing using mixing equipment such as Banbury mixers, rollers, plastic deformation recorders, single-screw extruders, twin-screw extruders, and kneaders.

[0095] From a production efficiency perspective, an extruder is preferred, and a twin-screw extruder is even more preferred. By using an extruder to melt and mix materials, and then extruding the mixture into filaments, the mixture can be processed into granules.

[0096] It is preferable to thoroughly dry each material before premixing. There are no particular limitations on the drying temperature, but a range of 60–120°C is preferred. There are no particular limitations on the drying time, but a range of 2–6 hours is preferred. Furthermore, from the viewpoint of easier drying, drying under reduced pressure is preferred. The above drying can be performed after premixing.

[0097] There are no particular limitations on the melt mixing temperature, but it is preferable to select an appropriate temperature based on the type of resin used, specifically within the range of 150–280°C. The melt mixing temperature is, for example, equivalent to the barrel temperature in a mixing apparatus such as a twin-screw extruder. Furthermore, the barrel temperature, when multiple temperature settings are configured in the barrel of the mixing apparatus, refers to the temperature of the highest setting in the barrel section. There are no particular limitations on the mixing pressure, but it is preferably within the range of 1–20 MPa.

[0098] The discharge rate from the mixing unit varies significantly depending on the size of the mixing machine used and the composition of the materials being mixed. For example, the discharge rate is 100g to 1kg / hr for the smallest laboratory-grade equipment (rubber machine) and 200 to 500kg / hr for slightly larger ones.

[0099] Regarding the compound that is melted and mixed in a mixing apparatus using the above-described method, it is preferable to perform a cooling treatment after extrusion from the mixing apparatus. There are no particular limitations on the cooling treatment method; for example, methods such as water cooling by immersing the compound in water in the range of 0 to 60°C, cooling with a gas in the range of -40 to 60°C, and contacting with metal in the range of -40 to 60°C can be listed.

[0100] There are no particular limitations on the form and shape of the recycled resin composition disclosed herein. For example, it may be in the form of powder, granules, tablets (tablets), pellets, flakes, fibers, or other solid forms, or in the form of liquid.

[0101] As resin molded products, there are no particular limitations. Examples include components (electrical and electronic components, electrical components, exterior components, interior components, etc.) in the fields of home appliances and automobiles, various packaging materials, household goods, office supplies, piping, agricultural materials, etc.

[0102] 3. Resin housing and electronic equipment

[0103] The resin housing disclosed herein is characterized by comprising the aforementioned resin molded article. Furthermore, the electronic device disclosed herein is characterized by comprising the aforementioned resin molded article. That is, the aforementioned resin molded article can be used as a housing for housing the electronic device, or as a component, in the like. It should be noted that in this disclosure, "electronic device" refers to an electrical product employing electronic engineering technology.

[0104] There are no particular limitations on the articles contained in the resin housings disclosed herein, but electronic devices are preferred. Furthermore, the resin housings of this disclosure can be used even in housings that are preferably made of flame-retardant resins.

[0105] As electronic devices, there are no particular limitations. Examples include computers, scanners, copiers, printers, fax machines, multifunction printers (MFPs) that combine these functions, and digital printing systems for commercial printing.

[0106] Example

[0107] The following examples illustrate the present disclosure in detail, but the disclosure is not limited to these examples. It should be noted that the use of "parts" or "%" in the examples, unless otherwise specified, indicates "parts by mass" or "% by mass".

[0108] A. Preparation of the resin composition

[0109] (A.1) Resin composition [1]

[0110] As a raw material, the product of granular PCR material dried at 120°C for 2 hours was prepared and used as PCR material [1]. It should be noted that the PCR material [1] came from a CD containing polycarbonate.

[0111] The PCR material [1] and the core-shell type impact modifier "METABLEN SX-005" manufactured by Mitsubishi Chemical Corporation were dry-mixed and put into a twin-screw mixer for melt mixing at 240°C and 400 rpm. The weight ratio of PCR material [1] to core-shell type impact modifier was 96:4.

[0112] It should be noted that the above "METABLEN SX-005" refers to a core-shell type impact modifier with a core of silicone-acrylic composite rubber and a shell made of resin having structural units derived from methyl methacrylate.

[0113] Through the above, molten resin wire was produced [1].

[0114] The wire [1] was cooled and then placed in a granulator to produce a resin composition [1] as granules for the resin composition.

[0115] (A.2) Resin composition [2]

[0116] The raw materials and core-shell type impact modifier used the same substances as the resin composition [1]. They were dry-mixed and fed into a twin-screw mixer for melt mixing at 240°C and 400 rpm. However, the weight ratio of PCR material [1] to core-shell type impact modifier was 93:7.

[0117] Through the above, molten resin wire was produced[2].

[0118] The wire [2] was cooled and then placed in a granulator to produce a resin composition [2] as a granule for the resin composition.

[0119] (A.3) Resin composition [3]

[0120] The raw materials and core-shell type impact modifier used the same substances as the resin composition [1]. They were dry-mixed and fed into a twin-screw mixer for melt mixing at 240°C and 400 rpm. However, the weight ratio of PCR material [1] to core-shell type impact modifier was 88:12.

[0121] Through the above, molten resin wire was produced[3].

[0122] The wire [3] was cooled and then placed in a granulator to produce a resin composition [3] as a granule for the resin composition.

[0123] (A.4) Resin composition [4]

[0124] As a raw material, the product of drying granular polycarbonate-containing pure material at 120°C for 2 hours is prepared and used as pure material[1].

[0125] The pure material [1] and the core-shell type impact modifier "METABLEN SX-005" manufactured by Mitsubishi Chemical Corporation were dry-mixed and fed into a twin-screw mixer for melt mixing at 240°C and 400 rpm. The weight ratio of the pure material [1] to the core-shell type impact modifier was 96:4.

[0126] Using the above methods, molten resin wire was produced[4].

[0127] The wire [4] was cooled and then placed in a granulator to produce a resin composition [4] as a granule for the resin composition.

[0128] (A.5) Resin composition [5]

[0129] The raw materials and core-shell impact modifiers used the same substances as the resin composition [4], were dry-mixed, fed into a twin-screw mixer, and melt-mixed at 240°C and 400 rpm. However, the weight ratio of the pure material [1] to the core-shell impact modifier was 88:12.

[0130] Through the above, molten resin wire was produced[5].

[0131] The wire [5] was cooled and then placed in a granulator to produce a resin composition [5] as granules for the resin composition.

[0132] (A.6) Resin composition [6]

[0133] The PCR material [1] was fed into a twin-screw mixer and melt-mixed at 240°C and 400 rpm.

[0134] Using the above methods, molten resin wire was produced[6].

[0135] The wire [6] was cooled and then placed in a granulator to produce a resin composition [6] as granules for the resin composition.

[0136] (A.7) Resin composition [7]

[0137] The pure material [1] was fed into a twin-screw mixer and melt-mixed at 240°C and 400 rpm.

[0138] Through the above, molten resin wire was produced[7].

[0139] The wire [7] was cooled and then placed in a granulator to produce a resin composition [7] as granules for the resin composition.

[0140] B. Evaluation and determination of flame retardancy

[0141] Flame retardancy is evaluated by performing the UL 94V test. The UL 94 test is a combustion test for plastic materials used in equipment components, established by Underwriters Laboratories (UL). The UL 94V test evaluates flame retardancy by placing a test piece of a specified size vertically in contact with a burner flame for 10 seconds and assessing the afterflame time and drip rate.

[0142] Specifically, after drying each resin composition at 80°C for 4 hours, a rectangular test piece (short book type test piece) of 125mm×13mm×2.4mm was formed using an injection molding machine "J55ELII" manufactured by Nippon Steel Co., Ltd., at a barrel temperature of 280°C and a mold temperature of 80°C. The rectangular test pieces of the resin compositions[1] to [7] formed in this way were used as UL flammability test pieces[1] to [7].

[0143] The UL flammability test pieces of each resin composition were conditioned for 48 hours in a constant temperature chamber at 23°C and 50% humidity. Flammability was evaluated according to the UL94 test, and V-0, V-1, or V-2 were determined based on the flammability behavior of each UL flammability test piece.

[0144] C. Impact Strength Evaluation

[0145] For each resin composition, after pre-drying at 120°C for 2 hours, it is fed into an injection molding machine and a notched Charpy impact test piece of 80mm×10mm×4mm is made according to JIS-K7111-1 (ISO179-1). The impact test pieces made using resin compositions [1] to [7] are used as Charpy impact test pieces [1] to [7].

[0146] The impact strength of the Charpy impact test piece[1] to [7] was calculated by conducting a notched Charpy impact test and evaluated using the following evaluation criteria.

[0147] (Evaluation Criteria)

[0148] Qualified (no practical problems) Impact strength is 15kJ / m 2 above.

[0149] The impact strength is less than 15 kJ / m (which is unacceptable due to practical problems). 2 .

[0150] D. Detection of harmful substances

[0151] In each resin composition, fluorine (F), bromine (Br), and chlorine (Cl) were detected using wavelength dispersive X-ray diffraction (WDX) with Rigaku's ZSX Primus IV. It should be noted that since approximately 200 ppm can be detected in this WDX, it can be said that the levels of these elements are less than 1000 ppm if no substances below 1000 ppm are detected in this WDX.

[0152] E. Summary

[0153] Table I summarizes the results of the above evaluations for each resin composition, including the raw materials, impact modifiers, weight ratio of raw materials to impact modifiers, and the results of each evaluation.

[0154] Table 1

[0155] Table 1

[0156] *1: The weight ratio is the weight ratio of the raw material to the impact modifier.

[0157] In the table, "PC" represents polycarbonate.

[0158] In the table, "Si·Ac" represents organosilicon-acrylic acid compounds, and "MMA" represents methyl methacrylate.

[0159] In the table, "F" represents fluorine, "Br" represents bromine, and "Cl" represents chlorine.

[0160] From the results in Table I above, it can be seen that the resin composition of this disclosure using PCR material containing polycarbonate as raw material, i.e., the recycled resin composition, has superior flame retardancy compared to the resin composition using virgin polycarbonate as raw material.

[0161] Specifically, when the resin composition contains a core-shell type impact modifier including silicone rubber, it only meets the V-2 standard in the flame retardancy evaluation. In contrast, it is known that the resin composition of this disclosure, which is a recycled resin composition using PCR material containing polycarbonate as a raw material, meets the V-0 standard in the flame retardancy evaluation when it contains a core-shell type impact modifier including silicone rubber.

[0162] In addition, it was learned that by containing a core-shell type impact modifier containing silicone rubber in the recycled resin composition, it has impact strength that is practically problem-free.

[0163] The embodiments of this disclosure have been described in detail above. Although not illustrated, the disclosed embodiments are for illustrative purposes only and are not intended to be limiting. The scope of this disclosure should be interpreted through the language of the appended patent claims.

Claims

1. A regenerated resin composition comprising: a PCR material containing polycarbonate, and a nucleus... The recycled resin composition of the shell-type impact modifier is characterized in that, The core Shell-type impact modifiers contain silicone rubber. The content of fluoropolymer in the recycled resin composition is less than 1000 ppm.

2. The recycled resin composition according to claim 1, characterized in that, The core The core of the shell-type impact modifier is organosilicon. It is an acrylic composite rubber, and the shell is made of resin having structural units derived from methyl methacrylate.

3. The recycled resin composition according to claim 1, characterized in that, The polycarbonate-containing PCR material in the regenerated resin composition and the core The total content of the shell-type impact modifier is 50% by mass or more, and the PCR material containing polycarbonate is compatible with the core. The content ratio of shell-type impact modifier is in the range of 88:12 to 96:

4.

4. The recycled resin composition according to claim 1, characterized in that, The total content of chlorine and bromine in the regenerated resin composition is less than 1000 ppm.

5. A resin molded article, characterized in that, It comprises the recycled resin composition according to any one of claims 1 to 4.

6. A resin shell, characterized in that, It includes the resin molded article as described in claim 5.

7. An electronic device, characterized in that, It has the resin housing as described in claim 6.

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