Flame-retardant resin composition and molded product

Abstract

To provide a flame-retardant resin composition that balances flame retardancy and mechanical strength.SOLUTION: A flame-retardant resin composition contains 74-93 mass% of a styrene-based resin, a crystalline resin with a melting point of 250°C or higher, 4-15 mass% of a phosphorus-based flame retardant, and 0.3-3.0 mass% of a hindered amine-based photostabilizer.SELECTED DRAWING: None

Description

[Technical field]

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

[0002] Conventionally, a method of adding a halogen-containing flame retardant has been known as a method of making styrene-based resins flame-retardant. However, in recent years, since halogen-containing organic compounds have a negative impact on the environment, there has been a movement toward non-halogenated compounds, mainly in Europe. In addition, the demand for non-halogenated flame retardants has increased, and non-halogenated flame retardants for each resin have been developed. As a flame retardant when using styrene-based resins alone, non-halogenated flame retardants are known (see, for example, Patent Documents 1 and 2).

[0003] Patent Document 1 describes a flame-retardant styrene-based resin composition containing a rubber-modified styrene-based resin, a non-halogen type NOR type hindered amine-based compound, and a phosphorus-based flame retardant.

[0004] Patent Document 2 describes a flame-retardant styrene-based resin composition containing a styrene-based resin, a phosphate-based flame retardant, a non-halogen type hindered amine-based light stabilizer, and a zinc salt of a higher fatty acid. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2019-183084 [Patent Document 2] Unexamined Japanese Patent Publication No. 2014-95056 Summary of the Invention [Problem to be solved by the invention]

[0006] The flame-retardant styrene-based resin composition described in Patent Documents 1 and 2 contains a phosphorus-based flame retardant and a non-halogen type hindered amine-based light stabilizer. However, in a material in which a styrene-based resin composition is mixed with other resins to change the material properties, the variation in burning time increases when a flame retardant that extinguishes by dripping is used in combination. In particular, when using recycled resin to achieve V-2 in the UL flame retardancy test, the effect decreases and the variation increases, making it impossible to achieve V-2. On the other hand, increasing the amount of flame retardant added to the flame-retardant styrene-based resin composition may result in a decrease in mechanical properties.

[0007] An object of the present invention is to provide a flame-retardant resin composition and a molded article thereof which have both flame retardancy and mechanical strength. [Means for solving the problem]

[0008] A flame-retardant resin composition according to one embodiment of the present invention contains 74 to 93 mass % of a styrene-based resin, a crystalline resin having a melting point of 250°C or higher, 4 to 15 mass % of a phosphorus-based flame retardant, and 0.3 to 3.0 mass % of a hindered amine-based light stabilizer.

[0009] A molded article according to one embodiment of the present invention is formed using the flame-retardant resin composition of the present invention. Effect of the Invention

[0010] According to the present invention, it is possible to provide a flame-retardant resin composition that combines flame retardancy and mechanical strength. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, a flame-retardant resin composition and a molded article according to an embodiment of the present invention will be described in detail.

[0012] [Configuration of flame-retardant resin composition] The flame-retardant resin composition contains 74 to 93 mass % of a styrene-based resin, a crystalline resin having a melting point of 250°C or higher, 4 to 15 mass % of a phosphorus-based flame retardant, and 0.3 to 3.0 mass % of a hindered amine-based light stabilizer.

[0013] The decomposition temperature of the flame-retardant resin composition as determined by thermogravimetric analysis is preferably within the range of 390 to 410° C. If the decomposition temperature is less than 390° C., the viscosity during combustion is likely to decrease. On the other hand, if the decomposition temperature is more than 410° C., the viscosity during combustion is unlikely to decrease.

[0014] The decomposition temperature of the flame-retardant resin composition by thermogravimetric analysis can be measured, for example, by the following method: Using a thermogravimeter-differential thermal analyzer (TGDTA; Thermogravimeter-Differential Thermal Analyzer), the temperature is increased from room temperature to 600° C. at a rate of 20° C. / min. The temperature at which the weight loss is reduced by 5% from before the start of measurement is defined as the decomposition temperature.

[0015] The amount of the styrene-based resin, which is the amorphous resin in the flame-retardant resin composition, is within the range of 74 to 93 mass%, preferably within the range of 80 to 90 mass%. If the amount of the styrene-based resin is less than 74 mass% or more than 93 mass%, the amount of the flame retardant that can be added is relatively small, and flame retardancy cannot be ensured.

[0016] Examples of styrene-based resins include polystyrene resins, syndiotactic polystyrene resins, acrylonitrile-styrene copolymers (AS resins), and acrylonitrile-butadiene-styrene resins (ABS resins). Of the styrene-based resins, acrylonitrile-butadiene-styrene resins are preferred from the viewpoint of balance of mechanical properties.

[0017] The styrene-based resin is preferably a recycled resin. Here, the recycled resin means a resin component obtained by processing a recovered resin component into a form for reuse. In addition, among the styrene-based resins, a part of the resin may be a recycled resin, or the whole may be a recycled resin. Among the recycled resins, it is preferable that 90 mass% or more is a recycled styrene-based resin.

[0018] The styrene resin can be measured, for example, by the following method. The method for measuring the styrene resin is to first dissolve the flame-retardant resin composition in tetrahydrofuran and then filter it. Next, the weight of the recovered material is subtracted from the weight of the flame-retardant resin composition. The weight difference can then be regarded as the weight of the styrene resin.

[0019] The content of the crystalline resin in the flame-retardant resin composition is within the range of 0.5 to 3.0% by mass, and preferably within the range of 0.5 to 2.0% by mass. If the content of the crystalline resin is less than 0.5% by mass, dripping becomes difficult and the burning time becomes longer. If the content of the crystalline resin is more than 3.0% by mass, dripping becomes easy, but the fire does not go out when dripping, and the fire remains.

[0020] The melting point of the crystalline resin is 250°C or higher. The melting point of the crystalline resin is preferably 300°C or lower. The melting point of the crystalline resin is preferably 250°C or higher, and more preferably 270°C or lower. If the melting point of the crystalline resin is less than 250°C, it is easy to drip, but the drip speed is too fast, so the embers do not fall completely and tend to remain on the sample, resulting in a longer burning time.

[0021] The melting point of the crystalline resin can be measured, for example, by the following method. DSC measurement is performed by differential scanning calorimetry using a differential scanning calorimeter (DSC). The temperature is raised from room temperature to 300°C at a rate of 10°C / min, and the peak value corresponding to the melting point is taken as the melting point (°C).

[0022] Examples of crystalline resins include polyester resins, polyamide resins, PE (polyethylene), PP (polypropylene), PA (polyamide), POM (polyacetal, polyoxymethylene), PET (polyethylene terephthalate), PBT (polybutylene terephthalate), PPS (polyphenylene sulfide), PEEK (polyether ether ketone), LCP (liquid crystal polymer), and PTFE (polytetrafluoroethylene). From the viewpoint of compatibility with styrene-based resins, the crystalline resin is preferably a polyester resin or a polyamide resin.

[0023] The polyester resin includes a polymer or copolymer obtained by a condensation reaction of dicarboxylic acid (or an ester-forming derivative thereof) and diol (or an ester-forming derivative thereof) as main components, and a mixture thereof.

[0024] Examples of dicarboxylic acids include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, bis(p-carboxyphenyl)methane, anthracene dicarboxylic acid, 4,4'-diphenyl ether dicarboxylic acid, and 5-sodium sulfoisophthalic acid; aliphatic dicarboxylic acids such as adipic acid, sebacic acid, azelaic acid, and dodecanedioic acid; alicyclic dicarboxylic acids such as 1,3-cyclohexanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid; and ester-forming derivatives thereof.

[0025] Examples of the diol component include aliphatic glycols having 2 to 20 carbon atoms, i.e., ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, decamethylene glycol, cyclohexanedimethanol, cyclohexanediol, etc., or long-chain glycols having a molecular weight of 400 to 6,000, i.e., polyethylene glycol, poly-1,3-propylene glycol, polytetramethylene glycol, etc., and ester-forming derivatives thereof.

[0026] Examples of these polymers or copolymers include polybutylene terephthalate, polybutylene (terephthalate / isophthalate), polybutylene (terephthalate / adipate), polybutylene (terephthalate / sebacate), polybutylene (terephthalate / decanedicarboxylate), polybutylene naphthalate, polyethylene terephthalate, polyethylene (terephthalate / isophthalate), polyethylene (terephthalate / adipate), polyethylene (terephthalate / 5-sodium sulfoisophthalate), polybutylene (terephthalate / 5-sodium sulfoisophthalate), polyethylene naphthalate, and polycyclohexanedimethylene terephthalate. From the viewpoint of moldability of the polyester composition, the polymer or copolymer is preferably polybutylene terephthalate, polybutylene (terephthalate / adipate), polybutylene (terephthalate / decanedicarboxylate), polybutylene naphthalate, polyethylene terephthalate, polyethylene (terephthalate / adipate), polyethylene naphthalate, polycyclohexanedimethylene terephthalate, etc., with polyethylene terephthalate and polybutylene terephthalate being particularly preferred.

[0027] Polyamide resins are resins made of polymers with amide bonds, and are made primarily from amino acids, lactams, or diamines and dicarboxylic acids. Examples of raw materials include amino acids such as 6-aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, and para-aminomethylbenzoic acid, lactams such as ε-caprolactam and ω-laurolactam, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, 2-methylpentamethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2,2,4- / 2,4,4-trimethylhexamethylenediamine, 5-methylnonamethylenediamine, metaxylylenediamine, paraxylylenediamine, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, and 1-amino-3-aminomethylenediamine. Aliphatic, alicyclic, and aromatic diamines such as bis(3-methyl-4-aminocyclohexyl)methane, bis(3-methyl-3,5,5-trimethylcyclohexane, bis(4-aminocyclohexyl)methane, 2,2-bis(4-aminocyclohexyl)propane, bis(aminopropyl)piperazine, and aminoethylpiperazine, and aliphatic, alicyclic, and aromatic dicarboxylic acids such as adipic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, terephthalic acid, isophthalic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, 5-sodium sulfoisophthalic acid, hexahydroterephthalic acid, and hexahydroisophthalic acid. Also, polyamide homopolymers or copolymers derived from these raw materials can be used alone or in the form of a mixture.

[0028] Examples of polyamide resins include polycaproamide (polyamide 6), polyhexamethylene adipamide (polyamide 66), polypentamethylene adipamide (polyamide 56), polytetramethylene adipamide (polyamide 46), polyhexamethylene sebacamide (polyamide 610), polypentamethylene sebacamide (polyamide 510), polyhexamethylene dodecamide (polyamide 612), and polyundecane amide. (Polyamide 11), Polydodecanamide (Polyamide 12), Polycaproamide / Polyhexamethylene terephthalamide copolymer (Polyamide 6 / 6T), Polyhexamethylene adipamide / Polyhexamethylene terephthalamide copolymer (Polyamide 66 / 6T), Polyhexamethylene adipamide / Polyhexamethylene isophthalamide copolymer (Polyamide 66 / 6I), Polyhexamethylene adipamide / Polyhexamethylene isophthalamide / polycaproamide copolymer (polyamide 66 / 6I / 6), polyhexamethylene terephthalamide / polyhexamethylene isophthalamide copolymer (polyamide 6T / 6I), polyhexamethylene terephthalamide / polydodecanamide copolymer (polyamide 6T / 12), polyhexamethylene adipamide / polyhexamethylene terephthalamide / polyhexamethylene isophthalamide copolymer (polyamide 66 / 6T / 6I), polyxylylene adipamide (polyamide MXD6), polyhexamethylene terephthalamide / poly-2-methylpentamethylene terephthalamide copolymer (polyamide 6T / M5T), polyhexamethylene terephthalamide / polypentamethylene terephthalamide copolymer (polyamide 6T / 5T), and mixtures or copolymers thereof.

[0029] The polyamide resin is preferably a polyamide 6 resin, a polyamide 66 resin, a polyamide 610 resin, a polyamide 11 resin, a polyamide 12 resin, a polyamide 6 / 66 copolymer, or a polyamide 6 / 12 copolymer, and more preferably a polyamide 6 resin or a polyamide 610 resin.

[0030] The content of the crystalline resin can be measured, for example, by the following method: First, the flame-retardant resin composition (molded article) is measured with a Fourier transform infrared spectrometer (FT-IR), and the content of the crystalline resin can be calculated from the ratio of the peak intensity due to styrene to the peak intensity due to the crystalline resin.

[0031] The phosphorus-based flame retardant in the flame-retardant resin composition is in the range of 4 to 15% by mass, preferably in the range of 7 to 12% by mass. If the phosphorus-based flame retardant is less than 4% by mass, the flame retardant performance is reduced. If the phosphorus-based flame retardant is more than 15% by mass, the mechanical properties, particularly the impact strength, are reduced. If the phosphorus-based flame retardant is within the above range, a composition can be obtained that can provide a molded product excellent in flame retardancy, heat resistance, and mechanical strength such as bending strength and impact strength.

[0032] The phosphorus-based flame retardant may be a phosphorus compound having an aromatic ring in its structure, or may be a phosphorus compound having no aromatic ring. Examples of phosphorus compounds having an aromatic ring include phosphazene compounds having a skeleton represented by the general formula (1).

[0033] [ka]

[0034] In the formula, X represents an alkyl group, an aryl group, an alkoxy group, an aryloxy group, or an amino group.

[0035] Specifically, the phosphazene compound is represented by the general formula (2) or (3), and at least one of X's may contain an aromatic ring.

[0036] [ka]

[0037] In the formula, n is preferably an integer of 3 to 20. X represents an alkyl group, an aryl group, an alkoxy group, an aryloxy group or an amino group.

[0038] In the general formula (1), the -P=N- structure may be cyclic as shown in the general formula (2) or linear as shown in the general formula (3).

[0039] In the general formula (1), X may be the same or different.

[0040] The number of carbon atoms in the alkyl group is preferably 1 to 10, and more preferably 1 to 6. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-amyl group, and an isoamyl group.

[0041] The number of carbon atoms in the aryl group is preferably 6 to 11. The aryl group may be substituted with an alkyl group having 1 to 6 carbon atoms. Examples of the aryl group include a phenyl group, a 2-methylphenyl group, a 3-methylphenyl group, a 4-methylphenyl group, a 2,6-dimethylphenyl group, a 3,5-dimethylphenyl group, a 2,5-dimethylphenyl group, a 2,4-dimethylphenyl group, and a 3,4-dimethylphenyl group.

[0042] The number of carbon atoms in the alkoxy group is preferably 1 to 10, and more preferably 1 to 6. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, a sec-butoxy group, an isobutoxy group, and a tert-butoxy group.

[0043] The number of carbon atoms in the aryloxy group is preferably 1 to 10. Examples of the aryloxy group include a phenoxy group, a naphthoxy group, and an anthracenoxy group. The aryloxy group may have a substituent in the aryl portion. The substituent is preferably an alkyl group having 1 to 6 carbon atoms.

[0044] In the cyclic compound of general formula (2), n is preferably 3 or more and 20 or less. Also, a mixture of cyclic compounds having n of 3 or more and 20 or less may be used. In the case of a mixture, even if the cyclic compound having n of 3 is less than 50% by mass, it can be suitably used in the present invention, but if it is less than 50% by mass, the melting point is low and it is easy to aggregate at the feeder part in the process of kneading it into the resin. Preferably, the mixture contains 90% by mass or more of cyclic compounds having n of 3 and 4, and particularly preferably, it is 100% of cyclic compounds having n=3. That is, a cyclophosphazene oligomer represented by general formula (4) is preferred.

[0045] [ka]

[0046] In the general formula (4), X1 to X6 are preferably an alkoxy group, a fluorine atom, an aryloxy group or an alkoxy group, and more preferably a fluorine atom, a phenoxy group, an ethoxy group or a methoxy group.

[0047] Other examples of the phosphorus compound having an aromatic ring include phosphate ester compounds and condensed phosphate ester compounds. Other examples of the phosphorus compound having an aromatic ring include phosphate esters such as triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, dimethylphenyl phosphate, methyldiphenyl phosphate, ethyldiphenyl phosphate, and hydroxyphenyldiphenyl phosphate, and compounds modified with various substituents. Condensed phosphate ester compounds include, for example, compounds represented by the general formula (5).

[0048] [ka]

[0049] In the formula, Ra, Rb, Rc, and Rd each independently represent an aryl group, one or more hydrogen atoms of which may or may not be substituted, n represents a natural number, Xa represents an aromatic group derived from a divalent phenol, and j, k, l, and m each independently represent 0 or 1.

[0050] The phosphorus compound is most preferably a condensed phosphate ester compound. Examples of the phosphate ester compound include esters of phosphorous acid, phosphoric acid, phosphonous acid, and phosphonic acid.

[0051] Examples of the phosphite ester include triphenyl phosphite, tris(nonylphenyl)phosphite, tris(2,4-di-tert-butylphenyl)phosphite, distearyl pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, and bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite.

[0052] Examples of phosphate esters include triphenyl phosphate (TPP), tris(nonylphenyl) phosphate, tris(2,4-di-tert-butylphenyl) phosphate, distearyl pentaerythritol diphosphate, bis(2,6-di-t-butyl-4-methylphenyl)pentaerythritol diphosphate, bis(2,4-di-t-butylphenyl)pentaerythritol diphosphate, tributyl phosphate, and bisphenol A bis-diphenyl phosphate.

[0053] Examples of phosphonite esters include tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenylene phosphonite.

[0054] Examples of the phosphonate ester include dimethyl benzenephosphonate and benzene phosphonate.

[0055] The phosphate ester compound is preferably an ester of phosphorous acid, phosphoric acid, or phosphonic acid, and particularly preferably a phosphate ester.

[0056] Examples of the phosphazene compound having an aromatic ring represented by general formula (2) or general formula (3) include cyclic and chain-like alkylaryloxyphosphazenes such as (poly)tolyloxyphosphazene (e.g., o-tolyloxyphosphazene, m-tolyloxyphosphazene, p-tolyloxyphosphazene), (poly)xylyloxyphosphazene, and (poly)methylnaphthyloxyphosphazene, (poly)phenoxytolyloxyphosphazene (e.g., phenoxy o-tolyloxyphosphazene, phenoxy m-tolyloxyphosphazene, phenoxy p-tolyloxyphosphazene), (poly)phenoxyxylyloxyphosphazene, (poly)phenoxytolyloxyxylyloxyphosphazene, and (poly)phenoxymethylnaphthyloxyphosphazene.

[0057] Examples of commercially available phosphorus-based flame retardants include PX200, PX202, TPP, TCP, TXP, CDP, NDPP, PX-110, CR-733S, CR-741 (all manufactured by Daihachi Chemical Industry Co., Ltd.), and SPS100 (manufactured by Otsuka Chemical Co., Ltd.).

[0058] The content of the hindered amine light stabilizer in the flame-retardant resin composition is within the range of 0.3 to 3.0% by mass, and preferably within the range of 0.5 to 1.0% by mass. If the content of the hindered amine light stabilizer is less than 0.3% by mass, the time until dripping is prolonged and the fire is difficult to extinguish, resulting in a long burning time. If the content of the hindered amine light stabilizer is more than 3.0% by mass, dripping is easy to occur, but the fire is not extinguished when dripping, and the fire remains, resulting in a long burning time.

[0059] The hindered amine light stabilizer may be an NOR-type hindered amine compound in which the H of the imino group on the piperidine ring is substituted with an alkoxyl group (-OR (R represents a cycloalkyl group, an aralkyl group, or an aryl group)), an NH-type hindered amine compound in which the imino group (>NH) part on the piperidine ring remains as NH, or an NM-type hindered amine compound in which the H of the imino group on the piperidine ring is substituted with a methyl group.

[0060] Examples of commercially available NOR-type hindered amine compounds include Flamestab (registered trademark) NOR116FF, TINUVIN (registered trademark) NOR371, TINUVIN XT850FF, TINUVIN XT855FF, TINUVIN PA123 (all manufactured by BASF), LA-77Y, LA-81, and FP-T80 (all manufactured by ADEKA Corporation).

[0061] Examples of commercially available NH-type hindered amine compounds include TINUVIN 770DF (BASF), KEMISTAB 29, KEMISTAB 77, KEMISTAB 94 (all from Chemipro Chemical Co., Ltd.), Adeka STAB LA-52, Adeka STAB LA-57, Adeka STAB LA-68, and Adeka STAB LA-72 (all from ADECA).

[0062] Examples of commercially available NM type hindered amine compounds include TINUVIN 765 (BASF) and Adeka STAB LA-63 P (ADECA).

[0063] The hindered amine light stabilizer may be used alone or in combination of two or more kinds.

[0064] The flame-retardant resin composition may contain other components as long as they do not impair the above-mentioned functions. Examples of other components include inorganic fillers, antioxidants, heat stabilizers, lubricants, antistatic agents, and colorants. In addition, the flame-retardant resin composition of the present invention may further contain inorganic fillers such as glass fibers, glass powders, glass beads, glass flakes, alumina, alumina fibers, carbon fibers, graphite fibers, stainless steel fibers, whiskers, potassium titanate fibers, wollastonite, asbestos, hard clay, calcined clay, talc, kaolin, mica, calcium carbonate, magnesium carbonate, aluminum oxide, and minerals, antioxidants such as hindered phenols, sulfur-containing compounds, or phosphorus-containing organic compounds, heat stabilizers such as phenols and acrylates, benzotriazoles, The composition may contain one or more of the usual additives, such as ultraviolet absorbers such as benzophenones or salicylates; lubricants and plasticizers such as higher fatty acids, acid esters, acid amides, and higher alcohols; release agents such as montanic acid and its salts, esters, half esters, stearyl alcohol, stearamide, and ethylene wax; flame retardant assistants; color inhibitors such as phosphites and hypophosphites; neutralizing agents such as phosphoric acid, monosodium phosphate, maleic anhydride, and succinic anhydride; nucleating agents; antistatic agents such as amines, sulfonic acids, and polyethers; and colorants such as carbon black, pigments, and dyes.

[0065] When using recycled resin as a styrene-based resin, it is difficult to separate different materials in the manufacturing process of the recycled resin, so the recycled resin may contain different types of resin. Therefore, it is thought that the flame retardancy of a flame-retardant resin composition containing multiple types of resins varies because the ease of dripping during combustion changes. The viscosity of the crystalline resin contained in the flame-retardant resin composition changes significantly near the melting point. Therefore, in the UL flame retardancy test, the flame-retardant resin composition melts with the heat of combustion and the viscosity decreases. This makes it easier to drip, and the pilot flame falls and extinguishes the fire. In particular, a flame-retardant resin composition containing a crystalline resin with a high melting point is prone to drip because the viscosity changes with the rise in temperature during combustion. Conversely, a flame-retardant resin composition containing a crystalline resin with a low melting point is prone to drip, but the pilot flame is more likely to remain, making it difficult to extinguish the fire. On the other hand, in the case of non-crystalline resin, the viscosity changes with the rise in temperature, but the effect is small because the amount of change is small.

[0066] [Molded products] A molded article can be produced using the flame-retardant resin composition of the present invention. This molded article can provide a product having flame retardancy. When producing a molded article, the flame-retardant resin composition can be melted and molded in various molding machines. The molding method can be appropriately selected depending on the shape and application of the molded article. Examples of molding methods include injection molding, extrusion molding, compression molding, blow molding, calendar molding, and inflation molding. In addition, a sheet-like or film-like molded article obtained by extrusion molding, calendar molding, or the like can also be subjected to secondary molding such as vacuum molding or pressure molding.

[0067] The type of molded article molded from the flame-retardant resin composition of the present invention is not particularly limited. Examples of the types of molded articles include electric and electronic parts, electrical components, exterior parts, interior parts, etc. in the fields of home appliances and automobiles, as well as various packaging materials, household goods, office supplies, piping, and agricultural materials.

[0068] The present invention can provide an electronic device that uses a molded article as a part. The type of electronic device is not particularly limited. Examples of electronic devices include office automation equipment such as computers, scanners, copiers, printers, facsimile machines, and multifunction machines that combine the functions of these devices, called MFPs (Multi Function Peripherals), and digital printing systems for commercial printing. EXAMPLES

[0069] (Preparation of Flame Retardant Resin Composition 1) 3,735 g of a styrene-based resin H350 (Toyo Styrene Co., Ltd.), 500 g of a PET resin TRN-MTJ (Teijin Limited), 750 g of a phosphorus-based flame retardant PX-200 (Daihachi Chemical Industry Co., Ltd.), and 15 g of a hindered amine-based light stabilizer Flamestabb NOR116FF (BASF) were each weighed out, and then kneaded at a temperature of 200°C and a rotation speed of 200 rpm in a twin-screw kneader TEX-25 (Japan Steel Works, Ltd.) to obtain flame-retardant resin composition 1.

[0070] (Preparation of flame-retardant resin compositions 2 to 17) Flame-retardant resin compositions 2 to 17 were prepared in the same manner as in the preparation of flame-retardant resin composition 1, except that the materials and blending amounts shown in Tables 1 and 2 were used.

[0071] The materials shown in Tables 1 and 2 are as follows: As the styrene-based acrylonitrile-butadiene-styrene resin, Toyolac (registered trademark) 700 314 U (Toray Industries, Inc.) was used. GAR-011 (KINGFA) was used as the styrene-based acrylonitrile-butadiene-styrene resin. The recycled resin content in GAR-011 is 95%. Toyo Styrol HI H350 (Toyo Styrene Co., Ltd.) was used as the polystyrene resin, which is a styrene-based resin. TRN-MTJ (Teijin Ltd.) was used as the crystalline resin polyethylene terephthalate (PET). The melting point of TRN-MTJ was 254°C. Amilan (registered trademark) U310 (Toray Industries, Inc.) was used as the nylon resin, which is a crystalline resin. The melting point of Amilan U310 was 260°C. The crystalline resin polyethylene terephthalate (PET) used was KS710B-8S (Kuraray Co., Ltd.). The melting point of KS710B-8S was 233°C. As the crystalline resin polypropylene (PP), Prime Polypro (registered trademark) J105G (Prime Polymer Co., Ltd.) was used. The melting point of Prime Polypro J105G was 170°C. As the amorphous polycarbonate (PC) resin, Styron 301-10 (Sumika Polycarbonate Co., Ltd.) was used. PX-200 (Daihachi Chemical Industry Co., Ltd.) was used as an aromatic condensed phosphate ester, which is a phosphorus-based flame retardant. CR741 (Daihachi Chemical Industry Co., Ltd.) was used as an aromatic condensed phosphate ester, which is a phosphorus-based flame retardant. Tinuvin 770DF (BASF) was used as an NH-type hindered amine compound, which is a hindered amine-based light stabilizer. Tinuvin 765 (BASF) was used as the NM type hindered amine compound, which is a hindered amine-based light stabilizer. Flamestat NOR 116 FF (BASF) was used as a NOR type hindered amine compound, which is a hindered amine-based light stabilizer.

[0072] The category number, the flame-retardant resin composition number, the blending amount of each material, and the thermal decomposition temperature are shown in Tables 1 and 2. In addition, in Tables 1 and 2, the blending amount is shown when the entire flame-retardant resin composition is 100 mass %.

[0073] [Table 1]

[0074] [Table 2]

[0075] [evaluation] (Preparation of test specimens) Each of the prepared kneaded products was dried at 80° C. for 4 hours, and then molded at a molding temperature of 220° C. using an injection molding machine JSW-AD110 (manufactured by Japan Steel Works, Ltd.) to obtain each test piece.

[0076] (Flame retardancy evaluation) The flame retardancy of the flame-retardant resin composition was evaluated by carrying out a UL94V test. The evaluation criteria are as shown below, and a score of ◯ or △ on the following criteria was deemed to be acceptable. 〇: Extinguish within 10 seconds △: Fire extinguished within 10 to 30 seconds ×: Burned

[0077] (Impact strength evaluation) The flowability of the flame-retardant resin composition was evaluated in accordance with JIS K 7111-1. The evaluation criteria are as shown below, and the cases of ◯ and △ according to the following evaluation criteria were deemed to be passed. ○: 10kJ / m 2 End △: 5kJ / m 2 More than 10kJ / m 2 less than ×:5kJ / m 2 less than

[0078] (Evaluation of flexural modulus) The flexural modulus of the flame-retardant resin composition was evaluated in accordance with JIS K 7171. The evaluation criteria are as shown below, and the cases of ◯ and △ according to the following evaluation criteria were deemed to be acceptable. 〇: 2400MPa or more △: 2000MPa or more and less than 2400MPa ×: Less than 2000MPa

[0079] Table 3 shows the classification number, the flame-retardant resin composition number, and the evaluation results.

[0080] [Table 3]

[0081] As shown in Tables 1 to 3, the flame-retardant resin composition No. 10 (Comparative Example 1), which does not contain a crystalline resin, had poor impact strength and flexural modulus. The flame-retardant resin compositions No. 11 and No. 12 (Comparative Examples 2 and 3), which contain a crystalline resin with a melting point of less than 250°C, had poor flame retardancy. The flame-retardant resin composition No. 13 (Comparative Example 4), which does not contain a crystalline resin and contains an amorphous resin other than a styrene-based resin, had poor flame retardancy. In the flame-retardant resin composition No. 10 (Comparative Example 1), the amount of flame retardant is large, so the flame retardancy is good, but the mechanical strength (impact strength and flexural modulus) is reduced. In the flame-retardant resin composition No. 13 (Comparative Example 4), the amount of flame retardant is reduced, so the reduction in mechanical strength is good. On the other hand, the amount of flame retardant is small, and a crystalline resin is not added, so the drip time varies greatly, the burning time is long, and the flame retardancy is poor. Flame-retardant resin composition No. 14 (Comparative Example 5), which contains more than 15% by mass of phosphorus-based flame retardant, had poor impact strength and flexural modulus. Flame-retardant resin composition No. 15 (Comparative Example 6), which contains less than 4% by mass of phosphorus-based flame retardant, had poor flame retardancy. Flame-retardant resin composition No. 16 (Comparative Example 7), which contains less than 0.3% by mass of hindered amine-based light stabilizer, had poor flame retardancy. Flame-retardant resin composition No. 17 (Comparative Example 8), which contains more than 3.0% by mass of hindered amine-based light stabilizer, had poor flame retardancy.

[0082] As shown in Tables 1 to 3, flame retardant resin compositions No. 1 to 9 (Examples 1 to 9) containing 74 to 93 mass% of a styrene resin, a crystalline resin having a melting point of 250°C or higher, 4 to 15 mass% of a phosphorus-based flame retardant, and 0.3 to 3.0 mass% of a hindered amine-based light stabilizer were all good in flame retardancy, impact strength, and flexural modulus. In particular, flame retardant resin compositions No. 2 to 9 (Examples 2 to 9) containing an acrylonitrile-butadiene-styrene resin had a good flexural modulus compared to flame retardant resin composition No. 1 (Example 1). Flame retardant resin compositions No. 4 and 5 (Examples 4 and 5), in which the crystalline resin was a polyester resin or a polyamide resin, had a good impact strength compared to flame retardant resin composition No. 1 (Example 1). Furthermore, flame-retardant resin compositions Nos. 7 to 9 (Examples 7 to 9) in which the hindered amine light stabilizer was an NH-type hindered amine compound had better flame retardancy than flame-retardant resin compositions Nos. 1 to 6 (Examples 1 to 6).

[0083] (effect) As described above, the flame-retardant resin composition of the present embodiment contains 74 to 93 mass % of a styrene-based resin, a crystalline resin having a melting point of 250°C or higher, 4 to 15 mass % of a phosphorus-based flame retardant, and 0.3 to 3.0 mass % of a hindered amine-based light stabilizer, and therefore has good flame retardancy, impact strength, and flexural modulus. [Industrial Applicability]

[0084] According to the present invention, a molded article having good flame retardancy, impact strength and flexural modulus is provided.

Claims

1. 74 to 93% by mass of a styrene-based resin; A crystalline resin having a melting point of 250° C. or higher; 4 to 15 mass % of a phosphorus-based flame retardant; 0.3 to 3.0% by mass of a hindered amine light stabilizer; The flame-retardant resin composition has the following structure.

2. 2. The flame-retardant resin composition according to claim 1, wherein the styrene-based resin is an acrylonitrile-butadiene-styrene resin.

3. The flame-retardant resin composition according to claim 1 , wherein the styrene-based resin is a recycled resin.

4. The flame-retardant resin composition according to claim 1 , wherein the crystalline resin is a polyester resin or a polyamide resin.

5. The flame-retardant resin composition according to claim 1, wherein the content of the crystalline resin is 0.5 to 3.0 mass %.

6. The flame-retardant resin composition according to claim 1 , wherein the hindered amine light stabilizer is an NH-type hindered amine compound.

7. The flame-retardant resin composition according to claim 1, wherein the decomposition temperature of the flame-retardant resin composition by thermogravimetric analysis is within a range of 390 to 410°C.

8. A molded article formed using the flame-retardant resin composition according to any one of claims 1 to 7.

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