Resin composition and resin molded article

Abstract

To provide a resin composition having good flame retardancy and fluidity.SOLUTION: The resin composition includes a polycarbonate resin, a metal salt of an organic sulfonic acid, and a phosphate ester, wherein the ratio of the z-average molecular weight to the weight-average molecular weight of the polycarbonate resin is 1.7 or more.SELECTED DRAWING: None

Description

[Technical Field]

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

[0002] Resin compositions containing polycarbonate resins have excellent mechanical and thermal properties and are therefore used in the automotive, office equipment, and electrical and electronics fields. Furthermore, high flame retardancy is strongly required for resin compositions used in office equipment and home appliances. Typically, halogen compounds are primarily used as flame retardants for resin compositions containing polycarbonate resins. Resin compositions containing halogen compounds as flame retardants exhibit relatively high flame retardancy, but they may cause environmental pollution in the event of a fire or during incineration, and they are likely to pose a problem from the perspective of recycling in the future.

[0003] In recent years, from the viewpoint of environmental conservation, there has been a demand for reducing waste from resin moldings. To address this, recycled materials such as waste from manufacturing processes and recovered used products are being used as raw materials for new products (see, for example, Patent Documents 1 and 2).

[0004] Patent Document 1 describes a polycarbonate resin composition containing a polycarbonate resin, a condensed phosphate ester-based flame retardant, a graft copolymer, and a fluoropolymer, and also describes that the polycarbonate resin may be a recycled material.

[0005] Patent Document 2 describes a flame-retardant resin composition containing an aromatic polycarbonate resin, a phosphate ester-based flame retardant, and an organic sulfonic acid-based flame retardant, and also describes that the aromatic polycarbonate resin may be a recycled material. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2022-93366 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-218181 Summary of the Invention [Problem to be solved by the invention]

[0007] Using recycled materials in new products, such as the polycarbonate resin composition described in Patent Document 1 and the flame-retardant resin composition described in Patent Document 2, can reduce the input of new resources and the energy required for crude oil extraction and the production of resin products from crude oil. However, when recycled materials are used for environmental conservation, problems arise, such as a decrease in molecular weight due to degradation and impurities remaining in the recycled material, which can lead to a decrease in physical properties such as fluidity and a decrease in flame retardancy. In particular, in resin compositions containing polycarbonate resin, a decrease in molecular weight reduces the melt tension of the resin, resulting in poor moldability and the resin may drip during combustion.

[0008] An object of the present invention is to provide a resin composition and a resin molded article having good flame retardancy and flowability. [Means for solving the problem]

[0009] A resin composition according to one embodiment of the present invention contains a polycarbonate resin, an organic sulfonic acid metal salt, and a phosphate ester, and the ratio of the z-average molecular weight to the weight-average molecular weight of the polycarbonate resin is 1.7 or more.

[0010] A resin molded article according to one embodiment of the present invention is molded using the resin composition of the present invention. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a resin composition and a resin molded article having good flame retardancy and flowability. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, the resin composition and resin molded product according to one embodiment of the present invention are not limited to the following embodiment. In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​written before and after "to" as the lower and upper limits. In the following explanation, the resin composition will be explained, followed by a method for producing a resin molded product and the resin molded product.

[0013] [Configuration of resin composition] The resin composition of the present embodiment contains a polycarbonate resin, an organic metal sulfonate, and a phosphate ester.

[0014] Polycarbonate resin is a polymer with a basic structure containing a carbonate bond, represented by -[-OXOC(=O)-]-, where X is a hydrocarbon group, but a heteroatom or heterobond may be introduced.

[0015] The type of polycarbonate resin is not particularly limited, but includes polycarbonate polymers obtained by reacting a dihydroxy compound with a carbonate precursor. In this case, a polyhydroxy compound or the like may be reacted in addition to the dihydroxy compound and carbonate precursor, or carbon dioxide may be used as a carbonate precursor and reacted with a cyclic ether. The polycarbonate resin may be a homopolymer consisting of one type of repeating unit, or a copolymer having two or more types of repeating units. The copolymer may be a random copolymer or a block copolymer.

[0016] The polycarbonate resin may be linear or branched, or may contain both linear and branched chains. The polycarbonate resin preferably contains a branched chain polycarbonate resin. When the polycarbonate resin contains a branched chain polycarbonate resin, the decomposition of the polycarbonate resin is promoted by the organic sulfonic acid metal salt at the crosslinked portion, and the formation of a carbonized layer progresses, thereby improving flame retardancy. In this embodiment, the polycarbonate resin is linear or contains both linear and branched chains.

[0017] Among the monomers used as raw materials for aromatic polycarbonate resins, examples of aromatic dihydroxy compounds include dihydroxybenzenes such as 1,2-dihydroxybenzene, 1,3-dihydroxybenzene, and 1,4-dihydroxybenzene; dihydroxybiphenyls such as 2,5-dihydroxybiphenyl, 2,2'-dihydroxybiphenyl, and 4,4'-dihydroxybiphenyl; 2,2'-dihydroxy-1,1'-binaphthyl, 1,2-dihydroxynaphthalene, 1,3-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, and 1 dihydroxynaphthalenes such as 2,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, and 2,7-dihydroxynaphthalene; dihydroxydiaryl ethers such as 2,2'-dihydroxydiphenyl ether, 3,3'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-3,3'-dimethyldiphenyl ether, 1,4-bis(3-hydroxyphenoxy)benzene, and 1,3-bis(4-hydroxyphenoxy)benzene;2,2-bis(4-hydroxyphenyl)propane, 1,1-bis(4-hydroxyphenyl)propane, 2,2-bis(3-methyl-4-hydroxyphenyl)propane, 2,2-bis(3-methoxy-4-hydroxyphenyl)propane, 2-(4-hydroxyphenyl)-2-(3-methoxy-4-hydroxyphenyl)propane, 1,1-bis(3-tert-butyl-4-hydroxyphenyl)propane, 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane, 2,2-bis(3-cyclohexyl) 2-(4-hydroxyphenyl)propane, 2-(4-hydroxyphenyl)-2-(3-cyclohexyl-4-hydroxyphenyl)propane, α,α'-bis(4-hydroxyphenyl)-1,4-diisopropylbenzene, 1,3-bis[2-(4-hydroxyphenyl)-2-propyl]benzene, bis(4-hydroxyphenyl)methane, bis(4-hydroxyphenyl)cyclohexylmethane, bis(4-hydroxyphenyl)phenylmethane, bis(4-hydroxyphenyl)(4-propenylphenyl) 1,1-bis(4-hydroxyphenyl)methane, bis(4-hydroxyphenyl)diphenylmethane, bis(4-hydroxyphenyl)naphthylmethane, 1,1-bis(4-hydroxyphenyl)ethane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, 1,1-bis(4-hydroxyphenyl)-1-naphthyleethane, 1,1-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)pentane, 1,1-bis(4-hydroxyphenyl)hexane, 2,2 - bis(hydroxyaryl)alkanes such as bis(4-hydroxyphenyl)hexane, 1,1-bis(4-hydroxyphenyl)octane, 2,2-bis(4-hydroxyphenyl)octane, 1,1-bis(4-hydroxyphenyl)hexane, 2,2-bis(4-hydroxyphenyl)hexane, 4,4-bis(4-hydroxyphenyl)heptane, 2,2-bis(4-hydroxyphenyl)nonane, 1,1-bis(4-hydroxyphenyl)decane, 1,1-bis(4-hydroxyphenyl)dodecane, etc.;1,1-bis(4-hydroxyphenyl)cyclopentane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)-3,3-dimethylcyclohexane, 1,1-bis(4-hydroxyphenyl)-3,4-dimethylcyclohexane, 1,1-bis(4-hydroxyphenyl)-3,5-dimethylcyclohexane, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 1,1-bis(4-hydroxy-3,5-dimethylphenyl)-3,3,5-trimethylcyclohexane, 1,1-bis(4-hydroxyphenyl)-3-propyl-5-methylcyclohexane, 1,1-bis(4-hydroxyphenyl)-3-tert-butyl-cyclohexane, 1,1-bis(4-hydroxyphenyl)-3-tert-butyl-cyclohexane, 1,1-bis(4-hydroxyphenyl)-3-tert-butyl-cyclohexane, Bis(hydroxyaryl)cycloalkanes such as 1,1-bis(4-hydroxyphenyl)-3-phenylcyclohexane and 1,1-bis(4-hydroxyphenyl)-4-phenylcyclohexane; cardo structure-containing bisphenols such as 9,9-bis(4-hydroxyphenyl)fluorene and 9,9-bis(4-hydroxy-3-methylphenyl)fluorene; dihydroxydiaryl sulfides such as 4,4'-dihydroxydiphenyl sulfide and 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfide; dihydroxydiaryl sulfoxides such as 4,4'-dihydroxydiphenyl sulfoxide and 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfoxide; dihydroxydiaryl sulfones such as 4,4'-dihydroxydiphenyl sulfone and 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfone;

[0018] Examples of monomers that can be used as raw materials for aliphatic polycarbonate resins include alkanediols such as ethane-1,2-diol, propane-1,2-diol, propane-1,3-diol, 2,2-dimethylpropane-1,3-diol, 2-methyl-2-propylpropane-1,3-diol, butane-1,4-diol, pentane-1,5-diol, hexane-1,6-diol, and decane-1,10-diol; cycloalkanediols such as cyclopentane-1,2-diol, cyclohexane-1,2-diol, cyclohexane-1,4-diol, 1,4-cyclohexanedimethanol, 4-(2-hydroxyethyl)cyclohexanol, and 2,2,4,4-tetramethyl-cyclobutane-1,3-diol; glycols such as ethylene glycol, 2,2'-oxydiethanol, triethylene glycol, propylene glycol, and spiroglycol; and 1,2-benzenedimethanol. Aralkyl diols such as 1,3-benzenedimethanol, 1,4-benzenedimethanol, 1,4-benzenediethanol, 1,3-bis(2-hydroxyethoxy)benzene, 1,4-bis(2-hydroxyethoxy)benzene, 2,3-bis(hydroxymethyl)naphthalene, 1,6-bis(hydroxyethoxy)naphthalene, 4,4'-biphenyldimethanol, 4,4'-biphenyldiethanol, 1,4-bis(2-hydroxyethoxy)biphenyl, bisphenol A bis(2-hydroxyethyl)ether, and bisphenol S bis(2-hydroxyethyl)ether; and cyclic ethers such as 1,2-epoxyethane, 1,2-epoxypropane, 1,2-epoxycyclopentane, 1,2-epoxycyclohexane, 1,4-epoxycyclohexane, 1-methyl-1,2-epoxycyclohexane, 2,3-epoxynorbornane, and 1,3-epoxypropane.

[0019] Among the monomers that are raw materials for aromatic polycarbonate resins, examples of carbonate precursors include carbonyl halides and carbonate esters.

[0020] Each monomer may be used alone or in combination of two or more types. The monomers may be used in any combination or in any ratio.

[0021] Examples of carbonyl halides include phosgene; and haloformates such as bischloroformates of dihydroxy compounds and monochloroformates of dihydroxy compounds.

[0022] Examples of carbonate esters include diaryl carbonates such as diphenyl carbonate and ditolyl carbonate; dialkyl carbonates such as dimethyl carbonate and diethyl carbonate; biscarbonates of dihydroxy compounds, monocarbonates of dihydroxy compounds, and carbonates of dihydroxy compounds such as cyclic carbonates.

[0023] The z-average molecular weight (Mz) relative to the weight-average molecular weight (Mw) of the polycarbonate resin is preferably 1.7 or more and 2.2 or less, and particularly preferably 1.8 or more and 2.2 or less. A z-average molecular weight (Mz) relative to the weight-average molecular weight (Mw) of 1.7 or more means that the molecular weight distribution is broader toward larger molecular weights. If the ratio of the z-average molecular weight (Mz) to the weight-average molecular weight (Mw) is less than 1.7, the fluidity of the polycarbonate resin decreases, and the dispersibility of the organic sulfonic acid metal salt in the resin composition decreases.

[0024] There is no particular limitation on the method for making the z-average molecular weight (Mz) of the polycarbonate resin to be 1.7 or more relative to the weight-average molecular weight (Mw). Examples of methods for making the z-average molecular weight (Mz) to be 1.7 or more relative to the weight-average molecular weight (Mw) include a method of mixing multiple types of polycarbonate resins with different sizes in a predetermined ratio.

[0025] The weight-average molecular weight (Mw) and z-average molecular weight (Mz) of the resin composition can be measured by gel permeation chromatography (GPC). Specifically, 5 mg of the resin composition and 10 g of tetrahydrofuran are dissolved in a glass bottle to obtain a sample. Next, the Mw and Mz of the sample are measured using an HLC-8420GPC (Tosoh Corporation), and the Mz / Mw ratio is calculated.

[0026] The ratio of the z-average molecular weight (Mz) to the number-average molecular weight (Mn) of the polycarbonate resin is preferably 3.0 or more and 4.0 or less, and particularly preferably 3.2 or more and 3.8 or less. A z-average molecular weight (Mz) to the number-average molecular weight (Mn) of 3.0 or more means that the molecular weight distribution is broad toward the lower molecular weight side. If the ratio of the z-average molecular weight (Mz) to the number-average molecular weight (Mn) is less than 3.0, the proportion of low-molecular-weight polycarbonate resin will be low, making it difficult to form a charred layer. This may result in poor flame retardancy.

[0027] There are no particular limitations on the method for making the ratio of the z-average molecular weight (Mz) to the number-average molecular weight (Mn) of the polycarbonate resin 3.0 or more. Examples of methods for making the ratio of the z-average molecular weight (Mz) to the number-average molecular weight (Mn) 3.0 or more include a method of mixing multiple types of polycarbonate resins with different sizes in a predetermined ratio.

[0028] The number-average molecular weight (Mn) and z-average molecular weight (Mz) of the resin composition can be measured by gel permeation chromatography (GPC). The z-average molecular weight (Mz) can be measured using the method described above. The number-average molecular weight (Mn) was measured by weighing 5 mg of a sample (resin composition) and adding it to 5 mL of THF. Ultrasonic waves were applied for 30 minutes, and the dissolved portion was used for measurement using a GPC device. The polystyrene-equivalent number-average molecular weight (Mn), weight-average molecular weight (Mw), and z-average molecular weight (Mz) were measured using an HLC-8320 GPC device (Tosoh Corporation). The columns used were one TSKguardcolumn SuperMP(HZ)-M guard column and two TSKgel SuperMultiporeHZ-M main columns, with chromatographic THF (tetrahydrofuran) manufactured by Wako Pure Chemical Industries, Ltd. as the eluent. The experimental conditions were a flow rate of 0.35 ml / min, a sample injection volume of 10 μl, a measurement temperature of 40°C, and an RI+UV detector. A calibration curve was created using 10 samples of "polystylene standard sample TSK standard" (Tosoh Corporation): A-500, F-1, F-10, F-80, F-380, A-2500, F-4, F-40, F-128, and F-700. The data collection interval for sample analysis was 300 ms.

[0029] Thus, it is preferable that the molecular weight distribution of the polycarbonate resin is broad. A broad molecular weight distribution of the polycarbonate resin is also advantageous in terms of using recycled materials, as described below.

[0030] Organic sulfonate metal salts are flame retardants. The inclusion of organic sulfonate metal salts in a resin composition promotes the formation of a char layer (carbonized layer) during combustion, improving the flame-retardant stability of the resin composition (shortening the burning time). It is believed that the char layer formed during combustion is firmly formed by the organic sulfonate metal salt, blocking external oxygen and thereby blocking the supply of oxygen necessary for sustained combustion. Furthermore, organic sulfonate metal salts act as a catalyst to promote the decomposition of polycarbonate resin. This generates carbon dioxide (a non-flammable gas) to suppress combustion, and simultaneously generates bubbles within the polycarbonate resin, suppressing the conduction of combustion heat.

[0031] Examples of metal organic sulfonates include metal salts of dodecylbenzenesulfonic acid, dodecylsulfonic acid, stearic acid sulfonic acid, dialkyl sulfosuccinic acid, polyoxyethylene polycyclic phenyl ether sulfate, and alkyl diphenyl ether disulfonic acid. Examples of metals in metal organic sulfonates include alkali metals such as sodium, lithium, potassium, rubidium, and cesium; magnesiums such as beryllium and magnesium; and alkaline earth metals such as calcium, strontium, and barium. One type of metal organic sulfonate may be used alone, or two or more types may be used in combination.

[0032] The content of the organic sulfonic acid metal salt is preferably in the range of 0.2 to 1.0% by mass, more preferably in the range of 0.2 to 0.5% by mass. If the content of the organic sulfonic acid metal salt is less than 0.2% by mass, the decomposition of the polycarbonate resin may not be promoted. If the content of the organic sulfonic acid metal salt is more than 1.0% by mass, the decomposition of the polycarbonate resin may be promoted too much, resulting in a decrease in flame retardancy.

[0033] The content of the organic sulfonic acid metal salt in the resin composition can be determined by IR and elemental analysis.

[0034] The phosphate ester is a flame retardant, and is preferably a compound represented by the following general formula (1):

[0035] [ka] (In the formula, R 1 , R 2 , R 3 and R 4 each represents an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 20 carbon atoms which may be substituted with an alkyl group; p, q, r, and s each represent 0 or 1; k represents an integer of 1 to 5; and X 1 represents an arylene group.

[0036] The compound represented by general formula (1) may be a mixture of compounds having different k numbers. In the case of compounds having different k numbers, k is the average value of the mixture. In the case of a mixture of compounds having different k numbers, the value (average value) of k is preferably in the range of 1 to 2, more preferably in the range of 1 to 1.5, particularly preferably in the range of 1 to 1.2, and even more preferably in the range of 1 to 1.15.

[0037] X 1 represents a divalent arylene group. 1 Examples of the dihydroxy group include divalent groups derived from dihydroxy compounds such as resorcinol, hydroquinone, bisphenol A, 2,2'-dihydroxybiphenyl, 2,3'-dihydroxybiphenyl, 2,4'-dihydroxybiphenyl, 3,3'-dihydroxybiphenyl, 3,4'-dihydroxybiphenyl, 4,4'-dihydroxybiphenyl, 1,2-dihydroxynaphthalene, 1,3-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, 1,8-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, and 2,7-dihydroxynaphthalene. Of these, divalent groups derived from resorcinol, bisphenol A, and 3,3'-dihydroxybiphenyl are particularly preferred.

[0038] In the general formula (1), p, q, r, and s each represent 0 or 1, and preferably 1. 1 , R 2 , R 3 and R 4 and respectively represent an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 20 carbon atoms which may be substituted with an alkyl group. Examples of the aryl group include a phenyl group, a cresyl group, a xylyl group, an isopropylphenyl group, a butylphenyl group, a tert-butylphenyl group, a di-tert-butylphenyl group, and a p-cumylphenyl group.

[0039] Examples of the phosphate ester represented by general formula (1) include phenyl resorcinol polyphosphate, cresyl resorcinol polyphosphate, phenyl cresyl resorcinol polyphosphate, xylyl resorcinol polyphosphate, phenyl-pt-butylphenyl resorcinol polyphosphate, phenyl isopropylphenyl resorcinol polyphosphate, cresyl xylyl resorcinol polyphosphate, and phenyl isopropylphenyl diisopropylphenyl resorcinol polyphosphate.

[0040] The phosphate ester may be used alone or in combination. The content of the phosphate ester is within the range of 1.0 to 10.0 mass%, and more preferably within the range of 3.0 to 8.0 mass%. If the content of the phosphate ester is less than 1.0 mass%, a carbonized layer may not be formed. If the content of the phosphate ester exceeds 10.0 mass%, plasticization of the resin composition may proceed, resulting in a decrease in impact strength and the risk of dripping during combustion.

[0041] The content of the phosphate ester in the resin composition can be determined by known IR and elemental analysis.

[0042] The resin composition may contain recycled materials. The recycled materials may be polycarbonate resin or other resins. Examples of other resins include polyethylene (PE), polypropylene (PP), polystyrene (PS), acrylonitrile-butadiene-styrene copolymer (ABS resin), acrylonitrile-styrene resin (AS resin), polyethylene terephthalate (PET), and polybutylene terephthalate (PBT).

[0043] The recycled material may be used alone or in combination of two or more types. The content of the recycled material is preferably within a range of 70 to 95% by mass.

[0044] In addition to the above components, the resin composition may contain additives such as a colorant, a lubricant, a compatibilizer, an antioxidant, an anti-drip agent, and an ultraviolet absorber. The additives may be used alone or in combination of two or more.

[0045] Examples of colorants include inorganic pigments and organic pigments. Examples of lubricants include metal salts of higher fatty acids and higher fatty acid amides. Examples of compatibilizers include random copolymer-based, graft copolymer-based, and block polymer-based compatibilizers. Examples of antioxidants include hindered phenol-based, sulfur-containing organic compound-based, and phosphorus-containing organic compound-based antioxidants. Examples of ultraviolet absorbers include benzotriazole-based, benzophenone-based, and salicylate-based ultraviolet absorbers.

[0046] The content of the additive is preferably 0.3% by mass or more, more preferably 0.5% by mass or more, from the viewpoint of exerting the effect of adding the additive, and is preferably 20% by mass or less, more preferably 15% by mass or less, from the viewpoint of not affecting melt-kneading.

[0047] [Method of manufacturing resin molded body] A resin molded article using the above-mentioned resin composition can be produced, for example, by the following method: The method for producing a resin molded article includes a step of obtaining a kneaded mixture and a step of obtaining a resin molded article by injection molding using the kneaded mixture.

[0048] In the step of obtaining a kneaded product, a polycarbonate resin, an organic sulfonic acid metal salt, and a phosphate ester are kneaded at a predetermined temperature to obtain a kneaded product. If necessary, recycled materials or other additives may be added. The ratio of the z-average molecular weight to the weight-average molecular weight of the polycarbonate resin is 1.7 or more.

[0049] The kneading temperature is not particularly limited as long as it is a temperature at which the resin composition can be melted. The kneading temperature is appropriately set depending on the resin composition. The kneading temperature is a temperature equal to or higher than the melting point. The kneading temperature is preferably within the range of 200 to 260°C.

[0050] The kneading time is not particularly limited as long as the resin composition is melted.

[0051] The order of kneading is not particularly limited. The polycarbonate resin, the organic sulfonic acid metal salt, and the phosphate ester may be added and kneaded simultaneously, or the polycarbonate resin may be melted and then the organic sulfonic acid metal salt and the phosphate ester may be added.

[0052] In the step of obtaining a resin molded body, the kneaded material is used to obtain a resin molded body. Specifically, for example, the resin composition is poured into a heated mold and cured. Finally, the molded body is obtained by releasing the resin composition from the mold.

[0053] [Resin molding] The resin molded article of the present embodiment is molded using the resin composition described above. The shape of the resin molded article is not particularly limited. The shape of the resin molded article is appropriately set depending on the intended use. Examples of the resin molded article include exterior materials for office equipment and interior materials for automobiles.

[0054] [Mechanism of action] Next, the reason why the resin composition and resin molded article of this embodiment exhibit good flame retardancy and good fluidity is presumed to be as follows. Resin compositions containing an organic sulfonic acid and a phosphate ester are known to have flame retardancy. Resin compositions containing only an organic sulfonic acid metal salt exhibit flame retardancy by forming a char layer as the polycarbonate resin decomposes. Resin compositions containing only an organic sulfonic acid metal salt have a high decomposition temperature, making it difficult to achieve UL94 V-1 level flame retardancy. However, resin compositions that further contain a large amount of a phosphate ester can achieve UL94 V-1 level flame retardancy and good fluidity. In this embodiment, by setting the ratio of the z-average molecular weight (Mz) to the weight-average molecular weight (Mw) to 1.7 or more, the organic sulfonic acid metal salt can be well dispersed in the resin composition. Furthermore, adding a phosphate ester to the resin composition is thought to further promote dispersion of the organic sulfonic acid metal salt in the resin composition, lower the decomposition temperature of the resin, promote the formation of a char layer, and improve flame retardancy. Increasing the ratio of the z-average molecular weight (Mz) to the number-average molecular weight (Mn) of the polycarbonate resin to be 3.0 or more is also thought to further promote the dispersion of the organic sulfonate metal salt in the resin composition, promote the formation of a carbonized layer, and contribute to improving flame retardancy.

[0055] [effect] As described above, in the resin composition and resin molded article according to the present embodiment, the ratio of the z-average molecular weight to the weight-average molecular weight of the polycarbonate resin is 1.7 or more, and therefore the flame retardancy and flowability are good. [Example]

[0056] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

[0057] 1. Preparation of resin molded body Example 1 Resin A (100% by weight polycarbonate resin, recycled polycarbonate resin derived from CDs and DVDs) (MW: 32,000), 0.3% by weight KSS-FR (arichem.LCC), an organic sulfonic acid metal salt, 4.0% by weight PX200 (Daihachi Chemical Industry Co., Ltd.), 0.3% by weight Polyflon FA500H (Daikin Industries, Ltd.), an anti-drip agent, and 0.2% by weight Irganox 1010 (BASF Japan Ltd.), a hindered phenolic antioxidant, were mixed in a twin-screw mixer TEX-25 (The Japan Steel Works, Ltd.) at 200°C and 200 rpm. The mixture was pre-dried at 80°C for 4 hours and then molded at 220°C using an injection molding machine JSW-AD110 (The Japan Steel Works, Ltd.) to obtain a resin molded body 1 of Example 1.

[0058] Examples 2 to 6, Comparative Examples 1 to 3 Resin molded articles 2 to 9 of Examples 2 to 6 and Comparative Examples 1 to 3 were produced in the same manner as Resin composition 1 of Example 1, except that the compositions were changed as shown in Table 1 below.

[0059] The polycarbonate resins in Table 1 used were: Resin B, a recycled polycarbonate resin (Mw: 40,000) derived from home appliances; Resin C, a recycled polycarbonate resin (Mw: 46,000) derived from water bottles; and Resin D, a resin derived from CD and a recycled polycarbonate resin derived from water bottles. NOVAREX (registered trademark) 7025R (Mitsubishi Engineering Plastics Corporation) and NOVAREX 7027I (Mitsubishi Engineering Plastics Corporation) were used. NOVAREX (registered trademark) 7025R and NOVAREX 7027I are virgin materials, Resin A and Resin C are recycled materials, and Resin B is a base material whose molecular weight has been reduced by melt-kneading.

[0060] The composition of each resin molded body is shown in Table 1.

[0061] [Table 1]

[0062] 2. Flame retardancy evaluation Flame retardancy was evaluated using the UL94V test. Specifically, the resin composition was dried at 80°C for 4 hours and then molded into 125mm x 13mm x 1.6mm rectangular test specimens using an injection molding machine (J55ELII, Japan Steel Works, Ltd.) at a cylinder temperature of 280°C and a mold temperature of 80°C. The molded test specimens (UL test specimens) were then conditioned for 48 hours in a temperature-controlled room at 23°C and 50% humidity. The UL94V test (flame resistance test for plastic materials for equipment components) was conducted in accordance with the UL94 test (flame resistance test for plastic materials for equipment components) established by Underwriters Laboratories (UL). The UL94V test is a method for evaluating flame retardancy based on the afterflame time and drip rate after a burner flame was applied to a test specimen of a specified size held vertically for 10 seconds. Each test specimen was then rated as V-0, V-1, V-2, or not-V based on its combustion behavior.

[0063] 3. Burn time evaluation The burning time was evaluated by measuring the afterflame time after contacting the five rectangular test pieces obtained in [2. Evaluation of flame retardancy] with a flame, and then adding up the total afterflame time of the five pieces. The evaluation criteria are as shown below, and a score of "○" or "△" on the following criteria was considered to be a pass. ○: Less than 30 seconds △: 30 seconds or more but less than 60 seconds ×: 60 seconds or more

[0064] 4. Liquidity Assessment To evaluate fluidity, the resin composition was dried at 80°C for 4 hours, and then the flow length was evaluated using an Archimedes spiral flow test piece (channel thickness 2 mm, channel width 10 mm) using an injection molding machine "ROBOSHOT_S-2000i 50BP" (FANUC Corporation) according to the company's evaluation criteria below. The conditions were an injection speed of 60 mm / s, a cylinder temperature of 280°C, a mold temperature of 80°C, and an injection pressure of 860 MPa. The longer the flow length, the better the fluidity. The evaluation criteria are as shown below, and a rating of "○" or "△" according to the following criteria was considered to be acceptable. ○:350mm or more △: 250mm or more and less than 350mm ×: Less than 250mm

[0065] 5. Impact strength evaluation Impact strength was evaluated by drying the resin composition at 80°C for 4 hours, and then molding 100mm x 10mm x 4mm rectangular test pieces using an injection molding machine J55ELII (manufactured by The Japan Steel Works, Ltd.) at a cylinder temperature of 260°C and a mold temperature of 40°C, and conducting an Izod impact test in accordance with JIS-K7110-1998. The evaluation criteria were as shown below, and a score of "○" or "△" was considered to be acceptable. ○: 32kJ / m 2 End △: 6kJ / m 2 More than 32kJ / m 2 less than ×:6kJ / m 2 less than

[0066] 6. Evaluation of bending strength Flexural strength was evaluated in accordance with ISO 178 by conditioning injection-molded test specimens (multipurpose test specimens) at 23°C ± 2°C and 50% ± 5% RH for at least 48 hours, and then measuring the flexural modulus using a Tensilon (A&D, RTI1310) at a support distance of 64 mm and a test speed of 2 mm / min. The measurement results are the average of three measurements. The evaluation criteria are as shown below, with a "Good" or "Poor" being considered a pass. ○: 2300MPa or more △: 2100 or more and less than 2300 MPa ×: Less than 2100 MPa

[0067] The evaluation results are shown in Table 2.

[0068] [Table 2]

[0069] 7. Evaluation As shown in Tables 1 and 2, Examples 1 to 6, in which the ratio of the z-average molecular weight to the weight-average molecular weight of the polycarbonate resin was 1.7 or higher, exhibited good flame retardancy and flowability. Examples 1, 2, and 5 also exhibited good flexural strength. This is thought to be because the organic sulfonic acid metal salt and phosphate ester, which are flame retardants, were in the preferred ranges. Furthermore, Example 4, which contained a large amount of phosphate ester and had a highly plasticized polycarbonate resin, exhibited slightly lower impact strength than Examples 1 to 3, 5, and 6.

[0070] On the other hand, in Comparative Example 1, in which the ratio of the z-average molecular weight to the weight-average molecular weight of the polycarbonate resin was less than 1.7, the flame retardancy and fluidity were poor. In Comparative Example 2, which did not contain an organic metal sulfonate, the flame retardancy and impact strength were poor. This is thought to be because the composition did not contain an organic metal sulfonate, which is a flame retardant, and therefore no char layer (carbonized layer) was formed during combustion. In Comparative Example 3, which did not contain a phosphate ester, the fluidity was also poor. This is thought to be because the composition did not contain an organic metal sulfonate, which is a flame retardant. [Industrial Applicability]

[0071] The resin composition and resin molded article according to the present invention are expected to contribute to the reuse of recovered materials, the expansion of effective utilization of resin materials, and further reduction of the burden on the environment.

Claims

1. The composition contains a polycarbonate resin, an organic sulfonic acid metal salt, and a phosphate ester, The ratio of the z-average molecular weight to the weight-average molecular weight of the polycarbonate resin is 1.7 or more. Resin composition.

2. The resin composition according to claim 1 , wherein the ratio of the z-average molecular weight to the number-average molecular weight of the polycarbonate resin is 3.0 or more.

3. The resin composition according to claim 1, wherein the content of the organic sulfonic acid metal salt is in the range of 0.2 to 1.0 mass %.

4. The resin composition according to claim 1, wherein the content of the phosphate ester is in the range of 1.0 to 10.0 mass%.

5. The resin composition according to claim 1 , wherein the polycarbonate resin is a linear or branched polycarbonate resin.

6. The resin composition of claim 1 , wherein the polycarbonate resin comprises recycled materials.

7. A resin molded article molded using the resin composition according to any one of claims 1 to 6.

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