Thermoplastic resin composition and molded article produced therefrom

Abstract

The present invention provides a thermoplastic resin composition and a molded article produced therefrom, the composition comprising 100 parts by weight of a base resin containing (A) 70 to 95% by weight of a polyphenylene ether (PPE) resin and (B) 5 to 30% by weight of a polystyrene (PS) resin, (C) 1 to 5 parts by weight of a styrene-ethylene / propylene-styrene block copolymer (SEPS) having an average particle size of 0.05 to 0.15 μm, and (D) 0.1 to 2 parts by weight of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO).

Description

[Technical field]

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

[0002] Polyphenylene ether (PPE) resin has excellent heat resistance and mechanical strength, and has excellent dimensional stability of products during processing. However, polyphenylene ether resin has low fluidity and is difficult to process by itself, so it is usually blended with polystyrene resin, which has excellent usability, moldability and fluidity, and is widely used in automobile parts, etc.

[0003] Polyphenylene ether / polystyrene (PS) blend resins can be used in a variety of ways by adjusting the ratio of polyphenylene ether resin and polystyrene resin depending on the impact resistance / heat resistance required for the application, and impact resistance can be supplemented by using styrene-ethylene / butylene-styrene block copolymer (SEBS) as an impact reinforcement agent. In particular, polyphenylene ether / polystyrene blend resins have a low specific gravity among materials with high heat resistance, and have excellent appearance and metal deposition properties, so they can be used in applications where appearance properties are important, such as bezels and reflectors for automotive lighting.

[0004] However, when metal is deposited on a polyphenylene ether / polystyrene blend resin molded product, impact modifiers such as SEBS that can be contained in the polyphenylene ether / polystyrene blend resin may aggregate with each other, causing pinholes on the surface of the molded product, resulting in poor appearance.

[0005] Therefore, there is a need to develop a thermoplastic resin composition that can achieve a high appearance while maintaining excellent impact resistance and dimensional stability. Summary of the Invention [Problem to be solved by the invention]

[0006] Provided is a thermoplastic resin composition having excellent impact resistance, dimensional stability and appearance, and a molded article produced from the composition. [Means for solving the problem]

[0007] According to one embodiment, there is provided a thermoplastic resin composition comprising 100 parts by weight of a base resin including (A) 70 to 95% by weight of a polyphenylene ether (PPE) resin and (B) 5 to 30% by weight of a polystyrene (PS)-based resin, (C) 1 to 5 parts by weight of a styrene-ethylene / propylene-styrene block copolymer (SEPS) having an average particle size of 0.05 to 0.15 μm, and (D) 0.1 to 2 parts by weight of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO).

[0008] The (A) polyphenylene ether resin may include poly(2,6-dimethyl-1,4-phenylene) ether, poly(2,6-diethyl-1,4-phenylene) ether, poly(2,6-dipropyl-1,4-phenylene) ether, poly(2-methyl-6-ethyl-1,4-phenylene) ether, poly(2-methyl-6-propyl-1,4-phenylene) ether, poly(2-ethyl-6-propyl-1,4-phenylene) ether, poly(2,6-diphenyl-1,4-phenylene) ether, a copolymer of poly(2,6-dimethyl-1,4-phenylene) ether and poly(2,3,6-trimethyl-1,4-phenylene) ether, a copolymer of poly(2,6-dimethyl-1,4-phenylene) ether and poly(2,3,6-triethyl-1,4-phenylene) ether, or a combination thereof.

[0009] The (A) polyphenylene ether resin may have an intrinsic viscosity of 0.2 to 0.8 dl / g when measured in a chloroform solvent at 30°C.

[0010] The (B) polystyrene-based resin is produced by polymerizing a styrene-based monomer, and the styrene-based monomer may be one or more selected from styrene, α-methylstyrene, p-methylstyrene, pt-butylstyrene, 2,4-dimethylstyrene, and chlorostyrene.

[0011] The (C) styrene-ethylene / propylene-styrene block copolymer may have a weight average molecular weight of 10,000 to 200,000 g / mol.

[0012] The (C) styrene-ethylene / propylene-styrene block copolymer may have a soft segment content of 30 to 50% by weight.

[0013] The thermoplastic resin composition may further include at least one additive selected from a flame retardant, a nucleating agent, a coupling agent, a filler, a plasticizer, an impact modifier, a lubricant, an antibacterial agent, a release agent, a heat stabilizer, an antioxidant, an ultraviolet absorber, an antistatic agent, a pigment, and a dye.

[0014] Meanwhile, according to another embodiment, a molded article is provided which is manufactured from the thermoplastic resin composition described above.

[0015] The molded article may have an Izod impact strength of 2.5 kgf·cm / cm or more when measured according to ASTM D256 standard at a thickness of 1 / 8 inch.

[0016] The molded article may have a gloss of 110 GU or more, as measured at a reflection angle of 20° in accordance with ASTM D523.

[0017] The molded product is 1 cm 2 Hit: 0.1mm 2 The number of pinholes having an area of ​​10 or less may be 10 or less. Effect of the Invention

[0018] It is possible to provide a thermoplastic resin composition having excellent impact resistance, dimensional stability, and appearance properties, and a molded article produced from the same. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] The following detailed description of implementations of the present invention is given by way of example only and is not intended to limit the invention, which is defined solely by the claims that follow.

[0020] Unless otherwise specified in this specification, "copolymerization" means block copolymerization, random copolymerization, and graft copolymerization, and "copolymer" means block copolymer, random copolymer, and graft copolymer.

[0021] Unless otherwise specified in this specification, the average particle size of the block copolymer is the volume average diameter, and means the Z-average particle size measured using a dynamic light scattering analysis device.

[0022] Unless otherwise specified in this specification, the weight average molecular weight was measured by dissolving a powder sample in an appropriate solvent and then using an Agilent Technologies 1200 series Gel Permeation Chromatography (GPC) (Shodex polystyrene was used as the standard).

[0023] A thermoplastic resin composition according to one embodiment contains 100 parts by weight of a base resin containing (A) 70 to 95% by weight of a polyphenylene ether (PPE) resin and (B) 5 to 30% by weight of a polystyrene (PS)-based resin, (C) 1 to 5 parts by weight of a styrene-ethylene / propylene-styrene block copolymer (SEPS) having an average particle size of 0.05 to 0.15 μm, and (D) 0.1 to 2 parts by weight of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO).

[0024] Hereinafter, each component that can be contained in the thermoplastic resin composition will be specifically described.

[0025] (A) Polyphenylene ether resin The polyphenylene ether resin is a resin containing a polyphenylene ether polymer or a modified polyphenylene ether polymer in which a reactive monomer has reacted with a polyphenylene ether polymer, and two or more of the above polymers can be mixed and used.

[0026] The polyphenylene ether polymer may include one or more polyphenylene ether polymers selected from poly(2,6-dimethyl-1,4-phenylene) ether, poly(2,6-diethyl-1,4-phenylene) ether, poly(2,6-dipropyl-1,4-phenylene) ether, poly(2-methyl-6-ethyl-1,4-phenylene) ether, poly(2-methyl-6-propyl-1,4-phenylene) ether, poly(2-ethyl-6-propyl-1,4-phenylene) ether, poly(2,6-diphenyl-1,4-phenylene) ether, a copolymer of poly(2,6-dimethyl-1,4-phenylene) ether and poly(2,3,6-trimethyl-1,4-phenylene) ether, or a copolymer of poly(2,6-dimethyl-1,4-phenylene) ether and poly(2,3,6-trimethyl-1,4-phenylene) ether.

[0027] For example, poly(2,6-dimethyl-1,4-phenylene) ether or a copolymer of poly(2,6-dimethyl-1,4-phenylene) ether and poly(2,3,6-trimethyl-1,4-phenylene) ether can be used, for example, poly(2,6-dimethyl-1,4-phenylene) ether can be used.

[0028] The reactive monomer is a compound containing an unsaturated carboxylic acid or its anhydride group, or is modified with an unsaturated carboxylic acid or its anhydride group upon reaction, and serves to form a modified polyphenylene ether polymer by reacting with the polyphenylene ether polymer according to one embodiment of the present invention.

[0029] The reactive monomer may be selected from the group consisting of citric acid, citric anhydride, maleic anhydride, maleic acid, itaconic anhydride, fumaric acid, (meth)acrylic acid, (meth)acrylic acid esters, and combinations thereof.

[0030] The degree of polymerization of the polyphenylene ether resin according to one embodiment is not particularly limited, but the intrinsic viscosity measured in chloroform solvent at 30° C. is preferably 0.2 to 0.8 dl / g, and more preferably 0.3 to 0.6 dl / g.

[0031] When the intrinsic viscosity is within this range, the heat resistance and mechanical strength are excellent, and processing is easy.

[0032] The polyphenylene ether resin may be contained in an amount of 70 to 95% by weight, for example, 70 to 90% by weight, for example, 70 to 80% by weight, based on 100% by weight of the base resin. Within this range, the thermoplastic resin composition can have excellent impact resistance and size stability.

[0033] (B) Polystyrene resin In one embodiment, the (B) polystyrene-based resin can impart fluidity to the thermoplastic resin composition.

[0034] The (B) polystyrene-based resin can be produced by polymerizing a styrene-based monomer, and the styrene-based monomer can be one or more selected from styrene, α-methylstyrene, p-methylstyrene, pt-butylstyrene, 2,4-dimethylstyrene, and chlorostyrene.

[0035] In one embodiment, when different types of styrene-based monomers are copolymerized in the (B) polystyrene-based resin, the different types of styrene-based monomers may be copolymerized in a weight ratio of 1:99 to 99:1.

[0036] In one embodiment, the (B) polystyrene resin may be included in an amount of 5 to 30% by weight, for example, 10 to 30% by weight, for example, 20 to 30% by weight, based on 100% by weight of the base resin. When the amount is within the above range, the flowability of the thermoplastic resin composition including the (B) polystyrene resin may be excellent.

[0037] (C) Styrene-ethylene / propylene-styrene block copolymer The (C) styrene-ethylene / propylene-styrene block copolymer (SEPS) can improve the impact resistance and appearance properties of the thermoplastic resin composition.

[0038] In the past, impact resistance was improved by adding impact modifiers such as styrene-ethylene / butylene-styrene block copolymer (SEBS) to polyphenylene ether / polystyrene blend resins. However, there was a problem that the impact modifiers would aggregate together during metal deposition, causing pinholes on the surface of the molded product and deteriorating its appearance.

[0039] In the present invention, the above-mentioned problems are solved by using a styrene-ethylene / propylene-styrene block copolymer (SEPS) instead of the styrene-ethylene / butylene-styrene block copolymer (SEBS).

[0040] The (C) styrene-ethylene / propylene-styrene block copolymer may have an average particle size of 0.05 to 0.15 μm, for example, 0.05 to 0.10 μm, for example, 0.05 to 0.08 μm. The (C) styrene-ethylene / propylene-styrene block copolymer has a relatively small size within the average particle size range, and therefore can improve the gloss of the thermoplastic resin composition and the molded article produced therefrom.

[0041] The (C) styrene-ethylene / propylene-styrene block copolymer may have a weight average molecular weight of 10,000 to 200,000 g / mol.

[0042] The (C) styrene-ethylene / propylene-styrene block copolymer may have a soft segment content of 30 to 50% by weight, for example, 35 to 50% by weight, for example, 35 to 45% by weight. If the soft segment content is within the above range, the thermoplastic resin composition has good appearance properties.

[0043] In one embodiment, the (C) styrene-ethylene / propylene-styrene block copolymer may be included in an amount of 1 to 5 parts by weight, for example, 1 to 3 parts by weight, based on 100 parts by weight of the base resin. In this range, the appearance properties of the thermoplastic resin composition and molded articles produced therefrom are particularly good.

[0044] (D) 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide In one embodiment, (D) 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) can improve the heat resistance and appearance properties of the thermoplastic resin composition.

[0045] In one embodiment, the (D)DOPO may be included in an amount of 0.1 to 2 parts by weight, for example, 0.1 to 1.5 parts by weight, for example, 0.1 to 1.0 parts by weight, for example, 0.5 to 1.0 parts by weight, based on 100 parts by weight of the base resin. A thermoplastic resin composition including the above amount and a molded article produced therefrom may exhibit excellent heat resistance and appearance properties.

[0046] (E) Other additives In addition to the components (A) to (D), the thermoplastic resin composition according to one embodiment may further include one or more additives required for achieving a balance between various physical properties under conditions that allow other various physical properties to be excellently maintained during processing or use, or depending on the end use of the thermoplastic resin composition.

[0047] Specifically, the additives that can be used include flame retardants, nucleating agents, coupling agents, fillers, plasticizers, impact modifiers, lubricants, antibacterial agents, mold release agents, heat stabilizers, antioxidants, ultraviolet absorbers, antistatic agents, pigments, dyes, etc., which can be used alone or in combination of two or more kinds.

[0048] These additives may be appropriately contained within a range that does not impair the physical properties of the thermoplastic resin composition. Specifically, the additives may be contained in an amount of 20 parts by weight or less per 100 parts by weight of the base resin, but are not limited thereto.

[0049] The thermoplastic resin composition according to the present invention can be produced by a known method for producing a thermoplastic resin composition.

[0050] For example, the thermoplastic resin composition according to the present invention can be produced in the form of pellets by mixing the components of the present invention with other additives and then melt-kneading them in an extruder.

[0051] A molded article according to one embodiment of the present invention can be produced from the thermoplastic resin composition described above.

[0052] The molded article may have an Izod impact strength of 2.5 kgf·cm / cm or more when measured according to ASTM D256 standard at a thickness of 1 / 8 inch.

[0053] The molded article may have an Izod impact strength of 2.5 kgf·cm / cm or more when measured according to ASTM D256 standard at a thickness of 1 / 4 inch.

[0054] The molded article may have a gloss of 110 GU (gloss unit) or more, as measured at a reflection angle of 20° in accordance with ASTM D523.

[0055] The molded product is 1 cm 2 Hit: 0.1mm 2 The number of pinholes having an area of ​​10 or less may be 10 or less.

[0056] Hereinafter, preferred embodiments of the present invention will be described, however, the following embodiment is merely a preferred embodiment of the present invention and the present invention is not limited to the following embodiment.

[0057] Examples and Comparative Examples 1 to 5 The components shown in Table 1 below were mixed in a conventional mixer and extruded at a barrel temperature of about 230°C using a twin-screw extruder with L / D=29 and Φ=45 mm to produce a thermoplastic resin composition in the form of pellets.

[0058] The pellets were dried in a dehumidifying dryer at about 80℃ for about 4 hours before injection molding, and then specimens for evaluating physical properties and appearance were manufactured using a 6oz injection molding machine with a cylinder temperature of about 230℃ and a mold temperature of about 60℃. The measured physical properties are shown in Table 2 below.

[0059] [Table 1]

[0060] In Table 1, components (A) and (B) are expressed in weight percent, and components (C), (C1), (C2), (C3), and (D) are expressed in parts by weight based on 100 parts by weight of components (A) and (B), i.e., base resin.

[0061] (A) Polyphenylene ether resin Poly(2,6-dimethyl-1,4-phenylene) ether from China National Bluestar was used.

[0062] (B) Polystyrene resin Polystyrene (PS) resin from Kuraray was used.

[0063] (C) Styrene-ethylene / propylene-styrene block copolymer A styrene-ethylene / propylene-styrene block copolymer (SEPS) from Kuraray was used with an average particle size of about 0.08 μm and a soft segment content of about 35% by weight.

[0064] (C1) Styrene-ethylene / butylene-styrene block copolymer A styrene-ethylene / butylene-styrene block copolymer (SEBS) from Kraton Corp. was used having an average particle size of about 0.29 μm and a soft segment content of about 68% by weight.

[0065] (C2) Styrene-ethylene / butylene-styrene block copolymer A styrene-ethylene / butylene-styrene block copolymer (SEBS) from Kraton Corp. was used having an average particle size of about 0.24 μm and a soft segment content of about 67% by weight.

[0066] (C3) Styrene-ethylene / butylene-styrene block copolymer A styrene-ethylene / butylene-styrene block copolymer (SEBS) from Kraton Corp. was used having an average particle size of about 0.26 μm and a soft segment content of about 88% by weight.

[0067] (D) 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide 9,10-Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) from Shouguang Puer Chemical Company was used.

[0068] evaluation For the examples and comparative examples 1 to 5, the impact resistance, gloss and appearance characteristics were evaluated by the following evaluation methods, and the results are shown in Table 2 below.

[0069] 1. Impact resistance (unit: J / m) The notched Izod impact strength was measured at room temperature (23° C.) for each of the 1 / 8 inch and 1 / 4 inch thick test pieces according to the ASTM D256 standard.

[0070] 2. Glossiness (unit: GU) Based on ASTM D523, the gloss was measured at a reflection angle of 20° using a BYK gloss meter.

[0071] 3.Appearance characteristics Using an optical microscope, a unit of the specimen surface measuring 10cm x 10cm x 0.3cm (area 1cm 2 ) occurred per 0.1 mm 2 The number of pinholes in the above area was counted and the appearance characteristics were evaluated. The fewer the number of pinholes, the better the appearance characteristics were evaluated.

[0072] [Table 2]

[0073] From the results shown in Tables 1 and 2, it was confirmed that the thermoplastic resin compositions containing polyphenylene ether resin, polystyrene resin, styrene-ethylene / propylene-styrene block copolymer, and DOPO within the above-mentioned ranges, and the molded articles produced therefrom, have excellent impact resistance, gloss, and appearance properties.

[0074] Although the present invention has been described above through preferred embodiments, it will be readily understood by those skilled in the art to which the present invention pertains that the present invention is not limited thereto, and various modifications and variations are possible without departing from the concept and scope of the claims set forth below.

Claims

1. (A) 70 to 95% by weight of a polyphenylene ether (PPE) resin; and (B) per 100 parts by weight of a base resin containing 5 to 30% by weight of a polystyrene (PS)-based resin (C) 1 to 5 parts by weight of a styrene-ethylene / propylene-styrene block copolymer (SEPS) having an average particle size of 0.05 to 0.15 μm, and (D) A thermoplastic resin composition containing 0.1 to 2 parts by weight of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO).

2. The thermoplastic resin composition according to claim 1, wherein the polyphenylene ether resin (A) is selected from the group consisting of poly(2,6-dimethyl-1,4-phenylene) ether, poly(2,6-diethyl-1,4-phenylene) ether, poly(2,6-dipropyl-1,4-phenylene) ether, poly(2-methyl-6-ethyl-1,4-phenylene) ether, poly(2-methyl-6-propyl-1,4-phenylene) ether, poly(2-ethyl-6-propyl-1,4-phenylene) ether, poly(2,6-diphenyl-1,4-phenylene) ether, a copolymer of poly(2,6-dimethyl-1,4-phenylene) ether and poly(2,3,6-trimethyl-1,4-phenylene) ether, a copolymer of poly(2,6-dimethyl-1,4-phenylene) ether and poly(2,3,6-triethyl-1,4-phenylene) ether, and a combination thereof.

3. 2. The thermoplastic resin composition according to claim 1, wherein the polyphenylene ether resin (A) has an intrinsic viscosity of 0.2 to 0.8 dl / g when measured in chloroform at 30°C.

4. 2. The thermoplastic resin composition according to claim 1, wherein the (B) polystyrene-based resin is produced by polymerizing a styrene-based monomer, and the styrene-based monomer is one or more selected from the group consisting of styrene, α-methylstyrene, p-methylstyrene, p-t-butylstyrene, 2,4-dimethylstyrene, and chlorostyrene.

5. 2. The thermoplastic resin composition according to claim 1, wherein the styrene-ethylene / propylene-styrene block copolymer (C) has a weight average molecular weight of 10,000 to 200,000 g / mol.

6. 2. The thermoplastic resin composition according to claim 1, wherein the styrene-ethylene / propylene-styrene block copolymer (C) has a soft segment content of 30 to 50% by weight.

7. 2. The thermoplastic resin composition according to claim 1, further comprising at least one additive selected from the group consisting of a flame retardant, a nucleating agent, a coupling agent, a filler, a plasticizer, an impact modifier, a lubricant, an antibacterial agent, a mold release agent, a heat stabilizer, an antioxidant, an ultraviolet absorber, an antistatic agent, a pigment, and a dye.

8. A molded article produced from the thermoplastic resin composition of any one of claims 1 to 7.

9. 9. The molded article according to claim 8, which has an Izod impact strength of 2.5 kgf cm / cm or more when measured in accordance with ASTM D256 at a thickness of 1 / 8 inch.

10. 9. The molded article according to claim 8, having a gloss of 110 GU or more, measured at a reflection angle of 20° according to ASTM D523.

11. 1 cm ２ Hit: 0.1 mm ２ The molded product according to claim 8, wherein the number of pinholes having an area of 10 or less is 10 or less.