Resin composition comprising halogen-free composite flame retardant and molded article manufactured by molding same

Abstract

One embodiment of the present specification provides: a flame retardant resin composition comprising a composite flame retardant and a styrene-based resin, wherein the composite flame retardant is composited by adsorbing a phosphorus-based flame retardant on the surface of expanded graphite, and the expanded graphite has a foaming initiation temperature of 180 °C or higher; and a flame retardant resin molded article manufactured by molding said flame retardant resin composition.

Description

Resin composition containing halogen-free composite flame retardant and molded article manufactured by molding the same

[0001] The present specification relates to a flame-retardant resin composition including a composite flame retardant having excellent flame retardancy without using a halogenated flame retardant, and a molded article manufactured by molding the same.

[0002] Polymer resin products, widely used in everyday life, are generally vulnerable to heat. When a fire breaks out, the polymer chains in these resin products decompose due to a combustion source, generating flammable gases. These decomposition products then react with oxygen and combust, further decomposing the resin, resulting in a chain reaction that continues the combustion process. Polymer resins, in particular, have the problem of releasing large amounts of toxic gases in a fire, and thus, flame retardancy of resin products is a constant concern.

[0003] At this time, flame retardants used to make resin products flame-retardant are generally brominated flame retardants. However, due to environmental regulations, the use of some brominated flame retardants has been restricted, and resins containing brominated flame retardants are not used in the European market. In particular, unlike polycarbonate resins that demonstrate high flame retardancy using phosphorus-based flame retardants, it is difficult to achieve high flame retardancy in styrene resins without using brominated flame retardants.

[0004] Accordingly, products have been developed that blend styrene resins with flame-retardant resins such as polyphenyleneoxide (PPO) or polyphenyleneether (PPE). However, while PPO and PPE possess excellent mechanical properties and flame retardancy, they are not ductile and have poor flowability, making them unsuitable for injection molding. Consequently, utilizing the easy moldability of styrene resins to produce molded products of various shapes has been difficult.

[0005] To address these issues, the applicant of the present invention has proposed a composite flame retardant formed by adsorbing an organic flame retardant onto the surface of an inorganic flame retardant and a flame retardant resin composition comprising the composite flame retardant (Patent Document 1, Patent Publication No. 10-2021-0044982). However, Patent Document 1 required a large amount of composite flame retardant to achieve flame retardancy of grade V-1 or higher, resulting in deteriorated mechanical properties, making commercialization difficult.

[0006] The present specification is intended to solve the problems revealed in the above-mentioned prior art, and one of the several objects of the present specification is to provide a flame-retardant resin composition having excellent flame retardancy and injection moldability without using a halogenated flame retardant.

[0007] One of the several objects of the present invention is to provide a flame retardant resin molded article having excellent flame retardancy and mechanical properties.

[0008] According to one aspect, a flame retardant resin composition is provided, which comprises a composite flame retardant and a styrene-based resin, wherein the composite flame retardant is a phosphorus-based flame retardant adsorbed onto the surface of expanded graphite to form a complex, and the expanded graphite has a foaming initiation temperature of 180°C or higher.

[0009] In one embodiment, the composite flame retardant may include 50 to 80 wt% of the expanded graphite and 20 to 50 wt% of the phosphorus flame retardant.

[0010] In one embodiment, the particle size of the expanded graphite may be 50 to 300 mesh, and the foaming ratio may be 200 to 400 times.

[0011] In one embodiment, the phosphorus flame retardant may include one selected from the group consisting of triphenyl phosphate (TPP), resorcinol bis-(diphenyl phosphate) (RDP), tricresyl phosphate (TCP), ammonium polyphosphate (APP), lauryldiphenylphosphate (LDP), and combinations thereof.

[0012] In one embodiment, the styrenic resin may include one selected from the group consisting of polystyrene, polyalpha-methylstyrene, polyalpha-ethylstyrene, polyalpha-propylstyrene, polyalpha-butylstyrene, polychlorostyrene, polybromostyrene, high-impact polystyrene (HIPS), styrene-acrylonitrile (SAN) copolymer, styrene-butadiene (SB) copolymer, styrene-butadiene-styrene (SBS) copolymer, styrene-methylacrylate copolymer, styrene-methylmethacrylate copolymer, styrene-isobutylene-styrene (SiBS) copolymer, styrene-isoprene copolymer, and combinations thereof.

[0013] In one embodiment, 5 to 35 parts by weight of the composite flame retardant may be included for 100 parts by weight of the styrene resin.

[0014] According to another aspect, a flame-retardant resin molded product manufactured by molding the flame-retardant resin composition is provided.

[0015] In one embodiment, the molding temperature of the flame retardant resin composition may be lower than the foaming initiation temperature of the expanded graphite.

[0016] A flame retardant resin composition according to one aspect of the present specification can be applied to the manufacture of a molded product using a material having excellent injection moldability and flame retardancy.

[0017] In addition, a flame-retardant molded product according to another aspect of the present specification is formed by molding the flame-retardant resin composition through a molding method such as extrusion, and can have excellent flame retardancy and excellent mechanical properties.

[0018] It should be understood that the effects of one aspect of this specification are not limited to the effects described above, but include all effects that can be inferred from the detailed description or claims of this specification.

[0019] Figure 1 is a photograph taken with an optical microscope showing a composite flame retardant including a phosphorus flame retardant (TPP) and expanded graphite manufactured through Example 1 of the present invention dispersed in a polystyrene resin.

[0020] Below, aspects of this specification will be described with reference to the attached drawings. However, the contents of this specification may be implemented in various different forms and are therefore not limited to the embodiments described herein.

[0021] Throughout the specification, whenever a part is said to "include" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise stated.

[0022] When a range of numerical values ​​is stated herein, unless the specific range is otherwise specified, the values ​​have the precision of the significant figures provided according to the standard rules in chemistry for significant figures. For example, the number 10 includes the range of 5.0 to 14.9, and the number 10.0 includes the range of 9.50 to 10.49.

[0023] Flame retardant resin composition

[0024] A flame retardant resin composition according to one aspect of the present specification may include a composite flame retardant and a styrene-based resin.

[0025] The above composite flame retardant is a composite formed by adsorbing a phosphorus-based flame retardant onto the surface of expanded graphite, and is dispersed in a styrene-based resin to impart flame retardant performance to the resin composition. In particular, the composite flame retardant has a surface treated with a phosphorus-based flame retardant, which is a type of organic flame retardant, to improve dispersibility within the resin, and thus has the advantage of being able to impart excellent flame retardancy of grade V1 or higher by controlling the dosage.

[0026] The above expanded graphite promotes char formation in the flame-retardant resin composition, thereby forming a non-combustible layer on the surface of the combustor, thereby blocking heat transfer into the resin and physically preventing the supply of combustible materials to the combustion area, thereby providing an excellent flame-retardant effect.

[0027] The density of the above expanded graphite is 1~3g / cm 3 It can be. Preferably, the density of the expanded graphite is 1.5 to 2.5 g / cm 3 It can be. The density of the above expanded graphite is 1g / cm 3 If it is less than 3g / cm, the appearance of the flame-retardant resin molded product manufactured by molding the flame-retardant resin composition may become rough, and the density of the expanded graphite is less than 3g / cm. 3 If it is excessive, the moldability of the flame retardant resin composition may be reduced.

[0028] The expanded graphite may have a size of 50 to 300 mesh and a foaming ratio of 200 to 400 times. Preferably, the expanded graphite may have a size of 70 to 250 mesh and a foaming ratio of 250 to 350 times.

[0029] For example, the expanded graphite has a size of 50 mesh, 55 mesh, 60 mesh, 65 mesh, 70 mesh, 75 mesh, 80 mesh, 85 mesh, 90 mesh, 95 mesh, 100 mesh, 105 mesh, 110 mesh, 115 mesh, 120 mesh, 125 mesh, 130 mesh, 135 mesh, 140 mesh, 145 mesh, 150 mesh, 155 mesh, 160 mesh, 165 mesh, 170 mesh, 175 mesh, 180 mesh, 185 mesh, 190 mesh, 195 mesh, 200 mesh, 205 mesh, 210 mesh, 215 mesh, It may be 220 mesh, 225 mesh, 230 mesh, 235 mesh, 240 mesh, 245 mesh, 250 mesh, 255 mesh, 260 mesh, 265 mesh, 270 mesh, 275 mesh, 280 mesh, 285 mesh, 290 mesh, 295 mesh, 300 mesh, or a value between two of these values. At this time, if the size of the expanded graphite is less than 50 mesh, the elongation of the flame-retardant resin molded product manufactured by molding the flame-retardant resin composition may decrease, resulting in poor mechanical properties, and if it exceeds 300 mesh, the flame retardancy of the flame-retardant resin molded product manufactured by molding the flame-retardant resin composition may decrease.

[0030] For example, the expanded graphite has a foaming ratio of 200 times, 205 times, 210 times, 215 times, 220 times, 225 times, 230 times, 235 times, 240 times, 245 times, 250 times, 255 times, 260 times, 265 times, 270 times, 275 times, 280 times, 285 times, 290 times, 295 times, 300 times, 305 times, 310 times, 315 times, 320 times, 325 times, 330 times, 335 times, 340 times, 345 times, 350 times, 355 times, 360 times, 365 times, 370 times, 375 times, 380 times, 385 times, It can be 390 times, 395 times, 400 times, or a value between two of these values. At this time, if the foaming ratio is less than 200 times, the flame retardancy of the flame retardant resin molded product manufactured by molding the flame retardant resin composition may be reduced, and if it exceeds 400 times, the flame retardant resin composition may rapidly expand when molding.

[0031] When the above-mentioned expanded graphite is exposed to high-temperature heat, such as in a fire accident, it becomes non-combustible by forming a carbon layer through foaming. In Patent Document 1, when using general expanded graphite, the foaming initiation temperature was low at approximately 160°C, which was lower than the molding temperature of the flame-retardant resin composition. Therefore, the mechanical properties of the molded product manufactured by molding the flame-retardant resin composition by foaming the expanded graphite were significantly deteriorated.

[0032] In order to solve the above-mentioned problem, the expanded graphite included in the composite flame retardant of the present invention is characterized by a foaming initiation temperature of 180°C or higher. If the foaming initiation temperature of the expanded graphite is lower than 180°C, as mentioned above, when processing the flame retardant resin composition, the expanded graphite may already be foamed, making it difficult to properly secure flame retardant performance, and the mechanical properties of the molded product may also deteriorate.

[0033] The above-mentioned phosphorus flame retardant is a substance that can be adsorbed to the surface of expanded graphite and formed into a complex. When the compound is thermally decomposed to produce polymetaphosphoric acid, a layer is formed that protects the substance from heat and oxygen, and the formation of char is promoted to block oxygen, thereby imparting a flame retardant effect to the resin.

[0034] The phosphorus-based flame retardant may include one selected from the group consisting of triphenyl phosphate (TPP), resorcinol bis-(diphenyl phosphate) (RDP), tricresyl phosphate (TCP), ammonium polyphosphate (APP), lauryldiphenylphosphate (LDP), and combinations thereof. Preferably, the phosphorus-based flame retardant may be, but is not limited to, triphenyl phosphate (TPP).

[0035] The above composite flame retardant is a composite formed by adsorbing a phosphorus-based flame retardant onto the surface of expanded graphite, and is designed to solve the problem that the flame retardant is difficult to disperse in the flame retardant resin composition when extrusion molding is performed at a low temperature of 180°C or lower, since the melting point of a typical halogen-based flame retardant is 220°C or higher. When the above composite flame retardant is used, the molecular weight and melting point of the phosphorus-based flame retardant are lower than those of the halogen-based flame retardant, and the particles of the expanded graphite are large, so that the flame retardant is easily dispersed in the flame retardant resin composition, and even when the molding temperature is lowered to 180°C or lower, the moldability is excellent and the flame retardancy can be maintained.

[0036] The composite flame retardant may include 50 to 80 wt% of the expanded graphite and 20 to 50 wt% of the phosphorus-based flame retardant. If the weight ratio of the expanded graphite is less than the above range, the heat resistance of the flame retardant resin may be reduced, and if it exceeds the above range, the moldability of the flame retardant resin composition may be reduced. If the weight ratio of the phosphorus-based flame retardant is less than the above range, the dispersibility of the composite flame retardant in the resin may be reduced, and if it exceeds the above range, the impact strength of a flame retardant resin molded product manufactured by molding the flame retardant resin composition may be reduced.

[0037] The above styrenic resin is used as a base resin, and for example, the styrenic resin may be selected from the group consisting of polystyrene, polyalpha-methylstyrene, polyalpha-ethylstyrene, polyalpha-propylstyrene, polyalpha-butylstyrene, polychlorostyrene, polybromostyrene, high-impact polystyrene (HIPS), styrene-acrylonitrile (SAN) copolymer, styrene-butadiene (SB) copolymer, styrene-butadiene-styrene (SBS) copolymer, styrene-methylacrylate copolymer, styrene-methylmethacrylate copolymer, styrene-isobutylene-styrene (SiBS) copolymer, styrene-isoprene copolymer, and combinations thereof. Preferably, the styrenic resin may be a high-impact polystyrene (HIPS) resin, but is not limited thereto. When high-impact polystyrene (HIPS) resin is used, the flame-retardant resin composition has excellent flame retardancy and good moldability, and the mechanical properties of a molded product manufactured by molding the flame-retardant resin composition can be maintained excellently.

[0038] A flame-retardant resin composition according to one aspect of the present disclosure may contain 5 to 35 parts by weight of the composite flame retardant per 100 parts by weight of the styrene-based resin. In Patent Document 1, in order to achieve a flame retardancy of V-1 or higher, 40 parts by weight of the composite flame retardant had to be added per 100 parts by weight of the base resin. As a result, the mechanical properties of the flame-retardant resin molded product thus manufactured deteriorated, making it difficult to commercialize. However, after repeated experiments, the inventors of the present invention were able to confirm that the flame-retardant resin composition has flame retardancy equal to or greater than that of Patent Document 1 even when only 20 to 24 parts by weight of the composite flame retardant is added per 100 parts by weight of the styrene-based resin.

[0039] Preferably, the flame retardant resin composition may contain 10 to 30 parts by weight of the composite flame retardant per 100 parts by weight of the styrene resin. More preferably, the flame retardant resin composition may contain 15 to 25 parts by weight of the composite flame retardant per 100 parts by weight of the styrene resin. For example, for 100 parts by weight of the styrene resin, the composite flame retardant may be present in an amount of 5 parts by weight, 6 parts by weight, 7 parts by weight, 8 parts by weight, 9 parts by weight, 10 parts by weight, 11 parts by weight, 12 parts by weight, 13 parts by weight, 14 parts by weight, 15 parts by weight, 16 parts by weight, 17 parts by weight, 18 parts by weight, 19 parts by weight, 20 parts by weight, 21 parts by weight, 22 parts by weight, 23 parts by weight, 24 parts by weight, 25 parts by weight, 26 parts by weight, 27 parts by weight, 28 parts by weight, 29 parts by weight, 30 parts by weight, 31 parts by weight, 32 parts by weight, 33 parts by weight, 34 parts by weight, 35 parts by weight, or a value between two of these values. If the weight of the composite flame retardant is less than 5 parts by weight with respect to 100 parts by weight of the styrene resin, the flame retardancy of the flame retardant resin composition may be reduced, and if it is more than 35 parts by weight with respect to 100 parts by weight of the styrene resin, the mechanical properties of a flame retardant resin molded product manufactured by molding the flame retardant resin composition may be reduced.

[0040] A flame retardant resin composition according to one aspect of the present specification may further include a flame retardant auxiliary agent, a pigment, an antioxidant, an ultraviolet absorber, and an activator.

[0041] The above flame retardant auxiliary agent is a typical flame retardant auxiliary agent that can be included in the flame retardant resin composition, and is used together with the composite flame retardant agent to enhance the flame retardancy of the flame retardant resin. For example, the flame retardant auxiliary agent may include one selected from the group consisting of polytetrafluoroethylene (PTFE), melamine cyanurate, and combinations thereof. Preferably, the flame retardant auxiliary agent may be melamine cyanurate, which can provide flame retardancy superior to that of conventional flame retardants due to a synergistic effect with the composite flame retardant agent, but is not limited thereto.

[0042] The above pigment, antioxidant, ultraviolet absorber and activator are additives included in a typical flame-retardant resin composition, and the pigment adds color to the flame-retardant resin composition while enhancing chemical resistance, durability and weather resistance. For example, the pigments are Pigment Red 1, 2, 3, 9, 10, 17, 22, 23, 31, 38, 41, 48, 49, 88, 90, 97, 112, 119, 122, 123, 144, 149, 166, 168, 169, 170, 171, 177, 179, 180, 184, 185, 192, 200, 202, 209, 215, 216, 217, 220, 223, 224, 226, 227, 228, 240, 254; Pigment Orange 13, 31, 34, 36, 38, 43, 46, 48, 49, 51, 52, 55, 59, 60, 61, 62, 64, 65, 71; Pigment Yellow 1, 3, 12, 13, 14, 16, 17, 20, 24, 55, 60, 73, 81, 83, 86, 93, 95, 97, 98, 100, 109, 110, 113, 114, 117, 120, 125, 126, 127, 129, 137, 138, 139, 147, 148, 150, 151, 152, 153, 154, 166, 168, 175, 180, 185; Pigment Green 7, 10, 36; It may include one selected from the group consisting of Pigment Blue 15, 15:1, 15:2, 15:3, 15:4, 15:5, 15:6, 22, 24, 56, 60, 61, 62, 64; Pigment Violet 1, 19, 23, 27, 29, 30, 32, 37, 40, 50 and combinations thereof.

[0043] The above antioxidant acts as an antioxidant to prevent oxidation of the flame-retardant resin composition when it comes into contact with air, thereby allowing the flame-retardant function to be preserved for a long time.For example, the antioxidants include 2,6-di-tert-butyl-p-cresol, 2,6-diphenyl-4-octadecyloxyphenol, distearyl(3,5-di-tert-butyl-4-hydroxybenzyl)phosphonate, 1,6-hexamethylenebis[(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid amide], 4,4'-thiobis(6-tert-butyl-m-cresol), 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2,2'-methylenebis(4-ethyl-6-tert-butylphenol), 4,4'-butylidenebis(6-tert-butyl-m-cresol), 2,2'-ethylidenebis(4,6-di-tert-butylphenol), 2,2'-ethylidenebis(4-sec-butyl-6-tert-butylphenol), 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 1,3,5-tris(2,6-dimethyl-3-hydroxy-4-tert-butylbenzyl)isocyanurate, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate, trisnonylphenylphosphite, tris[2-tert-butyl-4-(3-tert-butyl-4-hydroxy-5-methylphenylthio)-5-methylphenyl]phosphite, 3,3'-thiodipropionic acid, alkyl(C12-14)thiopropionic acid, di(lauryl)-3,3'-thiodipropionate, 3,3'-thiobis propionic acid ditridecyl, di(myristyl)-3,3'-thiodipropionate, di(stearyl)-3,3'-thiodipropionate, di(octadecyl)-3,3'-thiodipropionate, lauryl stearylthiodipropionate tridecylphosphite, octyldiphenylphosphite, didecylmonophenylphosphite, bis(tridecyl)pentaerythritol diphosphite, bis(nonylphenyl)pentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, N-benzyl-α-phenylnitrone, N-ethyl-α-methylnitrone, N-octyl-α-heptylnitrone, N-lauryl-α-undecylnitrone, N-tetradecyl-α-tridecylnitrone, It may include one selected from the group consisting of N-hexadecyl-α-pentadecylnitrone and combinations thereof.

[0044] The above ultraviolet absorber plays a role in preventing the decomposition of a substance by ultraviolet rays. For example, the above ultraviolet absorber is a 2-hydroxybenzophenones such as 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, and 5,5'-methylenebis(2-hydroxy-4-methoxybenzophenone); 2-(2'-hydroxyphenyl)benzotriazoles such as 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-dicumylphenyl)benzotriazole, 2,2'-methylenebis(4-tert-octyl-6-(benzotriazolyl)phenol), 2-(2'-hydroxy-3'-tert-butyl-5'-carboxyphenyl)benzotriazole; Benzoates such as phenyl salicylate, resorcinol monobenzoate, 2,4-di-tert-butylphenyl-3,5-di-tert-butyl-4-hydroxybenzoate, 2,4-di-tert-amylphenyl-3,5-di-tert-butyl-4-hydroxybenzoate, and hexadecyl-3,5-di-tert-butyl-4-hydroxybenzoate; substituted oxanilides such as 2-ethyl-2'-ethoxyoxanilide and 2-ethoxy-4'-dodecyloxanilide; cyanoacrylates such as ethyl-α-cyano-β,β-diphenylacrylate and methyl-2-cyano-3-methyl-3-(p-methoxyphenyl)acrylate; It may be a triaryltriazine such as 2-(2-hydroxy-4-octoxyphenyl)-4,6-bis(2,4-di-tert-butylphenyl)-s-triazine, 2-(2-hydroxy-4-methoxyphenyl)-4,6-diphenyl-s-triazine, 2-(2-hydroxy-4-propoxy-5-methylphenyl)-4,6-bis(2,4-di-tert-butylphenyl)-s-triazine, and the like, and may be at least one selected from a group including all of the above compounds.

[0045] The above-mentioned lubricant serves to improve the compounding properties of styrene-based resins and the processability of flame-retardant resins. For example, the above-mentioned lubricant may be at least one selected from the group consisting of ethylene bis stearamide, oxidized polyethylene wax, magnesium stearate, and combinations thereof.

[0046] The above flame retardant resin composition may contain 1 to 10 parts by weight of the pigment, 1 to 10 parts by weight of the antioxidant, 1 to 10 parts by weight of the ultraviolet absorber, and 1 to 10 parts by weight of the lubricant, per 100 parts by weight of the styrene resin. If the additives are outside the above range, the additives may not perform their functions or the mechanical properties of the flame retardant resin may deteriorate.

[0047] Flame retardant resin molded products

[0048] A flame-retardant resin molded product according to another aspect of the present specification can be manufactured by molding the flame-retardant resin composition.

[0049] The above flame-retardant resin molded product is characterized by a flame retardancy of V-1 or higher measured according to the UL94 flame retardancy standard. In Patent Document 1, since the foaming initiation temperature of the expanded graphite is lower than 180°C, the flame retardancy of the flame-retardant resin is reduced or the mechanical properties are deteriorated. On the other hand, the flame-retardant resin molded product of the present invention uses a composite flame retardant including a styrene resin and expanded graphite having a foaming initiation temperature of 180°C or higher, thereby improving the flame retardancy and exhibiting excellent mechanical properties such as impact resistance, heat resistance, and moldability.

[0050] In the process of manufacturing the above flame-retardant resin molded product, the molding temperature of the flame-retardant resin composition may be lower than the foaming initiation temperature of the expanded graphite. Preferably, the molding temperature of the flame-retardant resin composition may be 2°C or lower than the foaming initiation temperature of the expanded graphite. More preferably, the molding temperature of the flame-retardant resin composition may be 5°C or lower than the foaming initiation temperature of the expanded graphite. Most preferably, the molding temperature of the flame-retardant resin composition may be 10°C or lower than the foaming initiation temperature of the expanded graphite. If the molded product is manufactured at a temperature higher than the foaming initiation temperature of the expanded graphite, the expanded graphite may foam at the molding temperature, making it difficult to properly secure the flame-retardant performance of the flame-retardant resin molded product.

[0051] The above flame-retardant resin molded product can be manufactured by mixing the flame-retardant resin composition and then extruding and injection-molding it. For example, the above flame-retardant resin molded product can be manufactured by first mixing the flame-retardant resin composition in a mixer or supermixer, then extruding it at 180°C or lower using a twin-screw extruder, cooling and solidifying it to obtain pellets, and then sufficiently drying the pellets using a dehumidifying dryer or a hot air dryer and then injection-molding them.

[0052] Hereinafter, the embodiments of this specification will be described in more detail. However, the experimental results below represent only representative experimental results among the above embodiments, and the scope and content of this specification cannot be interpreted as being reduced or limited by the embodiments, etc. The effects of each of the various implementation examples of this specification that are not explicitly presented below will be specifically described in the relevant sections.

[0053] Examples and Comparative Examples

[0054] A composite flame retardant was manufactured by coating a phosphorus flame retardant on expanded graphite having the properties described in Table 1 below, and the composition ratio of the flame retardant resin composition using the same is described in Table 2 below. The detailed manufacturing method of each example and comparative example is as follows.

[0055] Expanded graphite foaming initiation temperature (℃) Size (mesh) Foaming ratio MF1 174 100 300 MF2 180 200 300 MF3 206 80 300 MF5 207 200 300

[0056] HIPS resin: Based on 100 parts by weight (pt) of HI450W from Kumho Petrochemical Co., Ltd.

[0057] <Example 1>

[0058] Composite flame-retardant particles were manufactured by coating the surface of expanded graphite (MF2) with a phosphorus-based flame retardant (triphenyl phosphate, TPP) in a 5:5 ratio, and 20 pt of TPP / expanded graphite composite flame-retardant particles were sufficiently mixed with 100 pt of HIPS resin using a small tumbler mixer, extruded at an extrusion temperature of 170℃ using a twin-screw extruder with a diameter of 32 mm, and then cooled and solidified to form pellets. The pellet products manufactured in this way were dried in a circulating dryer maintained at a temperature of 60℃ for 4 hours, and test specimens were injection-molded at the same injection temperature as the extrusion temperature of a 160-ton injection molding machine and a mold temperature of 30℃ to evaluate the physical properties and flame retardancy.

[0059] <Example 2>

[0060] Compared to Example 1, a test specimen was manufactured in the same manner as Example 1, except that the molding temperature of the twin-screw extruder and the 160-ton injection molding machine was set to 180°C, and a phosphorus-based flame retardant (triphenyl phosphate, TPP) was coated on the surface of expanded graphite (MF5) at a ratio of 7:3 to manufacture composite flame retardant particles.

[0061] <Example 3>

[0062] Compared to Example 2, test specimens were manufactured in the same manner as in Example 2, except that the expanded graphite was changed to MF3.

[0063] <Example 4>

[0064] Compared to Example 3, a test specimen was manufactured in the same manner as in Example 3, except that 24 pt of TPP / expanded graphite composite flame-retardant particles were sufficiently mixed into 100 pt of the HIPS resin using a small tumbler mixer.

[0065] <Example 5>

[0066] Compared to Example 3, test specimens were manufactured in the same manner as in Example 3, except that the molding temperature of the twin-screw extruder and the 160-ton injection molding machine was set to 200°C.

[0067] <Comparative Example 1>

[0068] Compared to Example 1, a test specimen was manufactured in the same manner as Example 1, except that the molding temperature of the twin-screw extruder and the 160-ton injection molding machine was set to 180°C and the expanded graphite was changed to MF1.

[0069] <Comparative Example 2>

[0070] Compared to Comparative Example 1, a test specimen was manufactured in the same manner as Comparative Example 1, except that 30 pt of TPP / expanded graphite composite flame-retardant particles were sufficiently mixed with 100 pt of the HIPS resin using a small tumbler mixer, and the molding temperature of the twin-screw extruder and 160-ton injection molding machine was set to 200°C.

[0071] <Comparative Example 3>

[0072] Compared to Comparative Example 2, a test specimen was manufactured in the same manner as in Comparative Example 1, except that 40 pt of TPP / expanded graphite composite flame-retardant particles were sufficiently mixed into 100 pt of the HIPS resin using a small tumbler mixer.

[0073] Expanded graphite composite flame retardant content (pt) Molding temperature (℃) Example 1 MF 2 20 170 Example 2 MF 5 20 180 Example 3 MF 3 20 180 Example 4 MF 3 24 180 Example 5 MF 3 20 200 Comparative Example 1 MF 1 20 180 Comparative Example 2 MF 1 30 200 Comparative Example 3 MF 1 40 200

[0074] Experimental examples 1-3

[0075] Experimental Example 1: Physical Property Evaluation 1) Impact Strength (NI, kgf·cm / cm) Measurement

[0076] According to ASTM D256, measurements were made at 3.2 mm.

[0077] Experimental Example 2: Physical Property Evaluation 2) Heat Deflection Temperature (HDT) Measurement

[0078] It was measured under a load condition of 18.6 (kgf / ㎠) according to ASTM D648.

[0079] Experimental Example 3: Flame Retardancy Evaluation (Flame Retardancy Measurement)

[0080] The flame retardancy of the flame retardant resin specimens was measured according to the UL94 V (Vertical Burning Test) test method.

[0081] The results of measuring the impact strength (NI), heat distortion temperature (HDT), and flame retardancy of the above experimental examples 1 to 3 are shown in Table 3 below.

[0082] Impact strength (kgf·cm / cm) Heat distortion temperature ( o C) Flame retardancy (UL94) Example 16.269 V-1 Example 27.566 V-1 Example 3768 V-1 Example 4667 V-0 Example 56.269 V-1 Comparative Example 15.968 V-2 Comparative Example 24.763 V-1 Comparative Example 33.352 V-0

[0083] In the cases of Examples 1 to 5, since the foaming initiation temperature of the expanded graphite was 180°C or higher, even if the flame-retardant resin composition contained 20 to 24 parts by weight of the composite flame retardant relative to 100 parts by weight of the styrene-based resin, it was confirmed that the impact strength and heat distortion temperature of the molded product manufactured by extrusion-molding the flame-retardant resin composition were both high, and it was confirmed that the flame retardancy also recorded V-1 or higher. On the other hand, in the case of Comparative Example 1, since the foaming initiation temperature of the expanded graphite was less than 180°C, foaming of the expanded graphite had already occurred during extrusion-molding, and it was confirmed that it was difficult to secure flame retardancy performance of V-1 or higher even if 20 parts by weight of the composite flame retardant was added. In addition, in the case of Comparative Examples 2 and 3, it was possible to secure flame retardancy performance of V-1 or higher by adding 30 parts by weight or more of the composite flame retardant to 100 parts by weight of the styrene resin, but it was confirmed that the foamed expanded graphite affected the mechanical properties of the flame retardant resin molded product, and the impact strength and heat distortion temperature were lowered.

[0084] The description of this specification above is for illustrative purposes only, and those skilled in the art will readily appreciate that aspects of this specification can be readily modified into other specific forms without altering the technical concepts or essential features described herein. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. For example, each component described as a single entity may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined manner.

[0085] The scope of this specification is indicated by the claims set forth below, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included within the scope of this specification.

Claims

1. A resin composition comprising a composite flame retardant and a styrene resin, The above composite flame retardant is a composite formed by adsorbing a phosphorus flame retardant on the surface of expanded graphite. The above expanded graphite is a flame retardant resin composition having a foaming initiation temperature of 180°C or higher.

2. In paragraph 1, The above composite flame retardant is, 50 to 80 wt% of the above expanded graphite and, A flame retardant resin composition comprising 20 to 50 wt% of the above-mentioned flame retardant.

3. In paragraph 1, A flame retardant resin composition having a particle size of the expanded graphite of 50 to 300 mesh and a foaming ratio of 200 to 400 times.

4. In paragraph 1, A flame retardant resin composition comprising one selected from the group consisting of triphenyl phosphate (TPP), resorcinol bis-(diphenyl phosphate) (RDP), tricresyl phosphate (TCP), ammonium polyphosphate (APP), lauryldiphenylphosphate (LDP), and combinations thereof.

5. In paragraph 1, A flame retardant resin composition comprising one selected from the group consisting of polystyrene, polyalpha-methylstyrene, polyalpha-ethylstyrene, polyalpha-propylstyrene, polyalpha-butylstyrene, polychlorostyrene, polybromostyrene, high-impact polystyrene (HIPS), styrene-acrylonitrile (SAN) copolymer, styrene-butadiene (SB) copolymer, styrene-butadiene-styrene (SBS) copolymer, styrene-methylacrylate copolymer, styrene-methylmethacrylate copolymer, styrene-isobutylene-styrene (SiBS) copolymer, styrene-isoprene copolymer, and combinations thereof.

6. In paragraph 1, A flame retardant resin composition comprising 5 to 35 parts by weight of the composite flame retardant for 100 parts by weight of the styrene resin.

7. A flame-retardant resin molded product manufactured by molding the flame-retardant resin composition of any one of claims 1 to 6.

8. In paragraph 7, A flame-retardant resin molded product, characterized in that the molding temperature of the flame-retardant resin composition is lower than the foaming initiation temperature of the expanded graphite.

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