Thermoplastic resin composition, its method of manufacture and molded article containing same

Abstract

The present invention relates to a thermoplastic resin composition, a production method thereof, and a molded article containing the same. According to the present invention, there is an effect of providing a thermoplastic resin composition and a molded article thereof which have fluidity and weather resistance equal to or higher than those of conventional ASA resins, and which have excellent appearance quality by suppressing the occurrence of flow marks, as well as a molded article thereof.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0131044, filed on October 13, 2022, and all contents disclosed in the documents of this Korean patent application are incorporated herein by reference.

[0002] The present invention relates to a thermoplastic resin composition, a method for producing the same, and a molded article containing the same. More specifically, the present invention relates to a thermoplastic resin composition that has excellent fluidity and weather resistance and also suppresses the occurrence of flow marks, thereby achieving excellent appearance quality, a method for producing the same, and a molded article containing the same. [Background technology]

[0003] Acrylate-styrene-acrylonitrile graft copolymer (hereinafter referred to as "ASA resin") has weather resistance, aging resistance, chemical resistance, and processability, and is versatile in its applications, so it is widely used in the fields of automobiles, leisure goods, construction materials, gardening goods, and building materials.

[0004] Recently, there has been a significant increase in customer preference for molded products with excellent natural coloring properties in consideration of aesthetic design. However, conventional ASA resins have been prone to the occurrence of flow marks, one of the various appearance defects, when they are injection molded into the desired product shape. As a result, there is a growing demand for ASA resins that can eliminate this problem and achieve improved appearance quality.

[0005] Flow marks refer to striped defects in appearance that appear when the resin composition flows unevenly within a mold during molding.

[0006] Flow marks that appear during injection molding can be of irregular thickness, record-like, or wavy stripes like tiger stripes. In particular, with ASA injection molded products, gaps occur due to differences in the solidification speed within the resin composition as the molten resin cools on the surface of the mold, or when the fluidity of the resin composition is unstable, differences in transfer occur on the contact surface with the mold, resulting in the appearance of wavy stripes, with repeated stripes.

[0007] Generally, methods to improve the occurrence of flow marks include increasing the injection temperature and speed, but this method has the drawback of being difficult to apply because injection conditions are not standardized.In addition, methods to optimize the gate thickness and position have the drawback of being difficult to apply because mold designs are not standardized.

[0008] Another method is to add internal and external lubricants to ASA resin to improve the flow properties of the resin, but this method still has limitations because the improvement effect is not clear and low molecular weight substances such as lubricants volatilize during injection processing and over the long term can deposit inside the mold. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Korean Patent Publication No. 10-2022-0000554 Summary of the Invention [Problem to be solved by the invention]

[0010] In order to solve the above-mentioned problems of the conventional art, an object of the present invention is to provide a thermoplastic resin composition that has excellent flowability and weather resistance, and that prevents deterioration of surface properties that may occur during molding processing, thereby achieving excellent appearance quality.

[0011] Another object of the present invention is to provide a molded article produced from the thermoplastic resin composition.

[0012] The above and other objects of the present invention can all be achieved by the present invention described below. [Means for solving the problem]

[0013] In order to achieve the above object, the present invention provides I) a thermoplastic resin composition comprising 100 parts by weight of a base resin including (A-1) an acrylate-aromatic vinyl compound-vinyl cyanide compound graft copolymer containing an acrylate rubber having an average particle size of 400 to 600 nm, (A-2) an acrylate-aromatic vinyl compound-vinyl cyanide compound graft copolymer containing an acrylate rubber having an average particle size of 30 to 200 nm, (B) a heat-resistant resin having a weight-average molecular weight of 50,000 to 150,000 g / mol, and (C) an aromatic vinyl compound-vinyl cyanide compound copolymer having a weight-average molecular weight of 50,000 to 70,000 g / mol; and (D) 0.5 to 4 parts by weight of an aromatic vinyl compound-vinyl cyanide compound copolymer having a weight-average molecular weight of 1,000,000 to 10,000,000 g / mol.

[0014] II) In I), when the weight percentages of (A-1), (A-2), (B) and (C) are a, b, c and d, respectively, the following formula 1 can be satisfied.

[0015] [Formula 1] a≦d <b≦c (In the above formula, a is an integer of 5 to 20, b is an integer of 26 to 35, c is an integer of 35 to 60, and d is an integer of 6 to 25.)

[0016] III) In I) or II), the base resin may be contained in a weight ratio of (A-1):(A-2):(B):(C) of 1:2-3:4-5:1-2.

[0017] IV) In the above I) to III), the aromatic vinyl compound-vinyl cyan compound copolymer (D) may have an intrinsic viscosity (IV, 25° C.) of 10 dL / g or more.

[0018] V) In the above I) to IV), the aromatic vinyl compound-vinyl cyan compound copolymer (D) has a bulk density of 0.1 to 0.5 g / cm 3 may be.

[0019] VI) In the above I) to V), the aromatic vinyl compound-vinyl cyan compound copolymer (D) may have a weight average molecular weight of more than 1,000,000 g / mol.

[0020] VII) In the above I) to VI), the (D) aromatic vinyl compound-vinyl cyan compound copolymer may contain 50 to 90% by weight of an aromatic vinyl compound and 10 to 50% by weight of a vinyl cyan compound.

[0021] VIII) In I) to VII), the total amount of (A-1) and (A-2) may be 40% by weight or less, based on 100% by weight of the total content of all components constituting the base resin.

[0022] IX) In the above I) to VIII), the heat-resistant resin (B) may contain 60 to 80% by weight of an α-methylstyrene-based monomer and 20 to 40% by weight of a vinyl cyan compound.

[0023] X) In the above I) to IX), the (A-1) acrylate-aromatic vinyl compound-vinyl cyan compound graft copolymer may contain 40 to 60% by weight of acrylate rubber, 25 to 45% by weight of aromatic vinyl compound, and 5 to 20% by weight of vinyl cyan compound, based on a total of 100% by weight.

[0024] XI) In the above I) to X), the (A-2) acrylate-aromatic vinyl compound-vinyl cyan compound graft copolymer may contain 40 to 60% by weight of acrylate rubber, 25 to 45% by weight of aromatic vinyl compound, and 5 to 20% by weight of vinyl cyan compound, based on a total of 100% by weight.

[0025] XII) In the above I) to XI), the (C) aromatic vinyl compound-vinyl cyan compound copolymer may contain 50 to 90% by weight of an aromatic vinyl compound and 10 to 50% by weight of a vinyl cyan compound.

[0026] XIII) The present invention also provides (A-1) 5 to 20% by weight of an acrylate-aromatic vinyl compound-vinyl cyanide compound graft copolymer containing an acrylate rubber having an average particle size of 400 to 600 nm; (A-2) 20 to 40% by weight of an acrylate-aromatic vinyl compound-vinyl cyanide compound graft copolymer containing an acrylate rubber having an average particle size of 30 to 200 nm, (B) 30 to 60% by weight of a heat-resistant resin having a weight-average molecular weight of 50,000 to 150,000 g / mol, and (C) 100 parts by weight of a base resin containing 5 to 30% by weight of an aromatic vinyl compound-vinyl cyanide compound copolymer having a weight average molecular weight of 50,000 to 70,000 g / mol; (D) 0.5 to 4 parts by weight of an aromatic vinyl compound-vinyl cyanide compound copolymer having a weight average molecular weight of 1,000,000 to 10,000,000 g / mol; The thermoplastic resin composition is characterized in that the base resin is contained in a weight ratio of (A-1):(A-2):(B):(C) of 1:2-3:4-5:1-2.

[0027] XIV) In the above XIII), the thermoplastic resin composition can satisfy the condition of the following mathematical formula 3.

[0028] [Formula 3] 380≦flow index × die swell ratio × spiral × content of processing aids≦1400 (In Equation 3, the flow index is a value (unit: g / 10 min) measured for the thermoplastic resin composition at 220°C under a load of 10 kg in accordance with ASTM D1238, the die swell ratio is a value calculated using Equation 4 below, and the spiral is the length (unit: cm) of a test piece injected using a spiral mold (2.0T) under conditions of an injection temperature of 300°C, a mold temperature of 80°C, and a pressure of 500 kgf using an injection molding machine (Engel, Victory 80), and the content of the processing aid is the amount (parts by weight) of the (D) copolymer used based on 100 parts by weight of the total amount of the base resin and the aromatic vinyl compound-vinyl cyanide compound copolymer.)

[0029] [Formula 4] Die swell ratio = D ex / D0 (In the above formula 4, D0 is the diameter of the die, 2 mm, and D ex is the diameter (unit: mm) of an extruded test piece extruded at 220°C under a load of 10 kg using a fluidity tester (Melt Indexer, MI) with a die diameter of 2 mm (DO).

[0030] XV) In the above XIII) to XIV), the formula 3 can satisfy the range of 400 to 1300.

[0031] XVI) In the above XIII) to XV), the flow index may be 6.7 to 13.2 g / 10 min.

[0032] XVII) In the above XIII) to XVI), the die swell ratio may be 1.31 to 1.54.

[0033] XVIII) In the above XIII) to XVII), the spiral may be 21.1 to 24.4 cm.

[0034] The present invention also provides XIX) a composition comprising (A-1) 5 to 20% by weight of an acrylate-aromatic vinyl compound-vinyl cyanide compound graft copolymer containing an acrylate rubber having an average particle size of 400 to 600 nm, (A-2) 20 to 40% by weight of an acrylate-aromatic vinyl compound-vinyl cyanide compound graft copolymer containing an acrylate rubber having an average particle size of 30 to 200 nm, and (B) 30% by weight of a heat-resistant resin having a weight-average molecular weight of 50,000 to 150,000 g / mol. and (C) 5 to 30 weight % of an aromatic vinyl compound-vinyl cyanide copolymer having a weight average molecular weight of 50,000 to 70,000 g / mol; and (D) 0.5 to 4 weight % of an aromatic vinyl compound-vinyl cyanide copolymer having a weight average molecular weight of 1,000,000 to 10,000,000 g / mol; The present invention provides a method for producing a thermoplastic resin composition, wherein the base resin is contained in a weight ratio of (A-1):(A-2):(B):(C) of 1:2-3:4-5:1-2.

[0035] The present invention also provides XX) a molded article comprising the above-described thermoplastic resin composition. [Effects of the Invention]

[0036] According to the present invention, there is an effect of providing a thermoplastic resin composition which has fluidity and weather resistance equal to or better than conventional ASA resins, and which has excellent appearance quality by suppressing the occurrence of flow marks.

[0037] Therefore, the thermoplastic resin composition according to the present invention can be widely used in the field of automotive exterior parts, and specifically, can be used as a material for side mirror housings, radiator grilles, or pillars. [Brief explanation of the drawings]

[0038] [Figure 1]1 is a photograph taken to observe whether or not flow marks occur on the surfaces of injection test pieces each having a size of 40 mm x 200 mm, which were produced in Example 1 and Comparative Examples 1, 3, and 5. DETAILED DESCRIPTION OF THE INVENTION

[0039] The thermoplastic resin composition of the present invention, its production method, and molded articles containing the same will be described in detail below.

[0040] The inventors have confirmed that when two or more graft copolymers containing acrylate rubbers with different average particle sizes are combined with a heat-resistant resin, a low molecular weight SAN resin, and an ultra-high molecular weight SAN resin, etc., by adjusting the composition ratio, the combination produces a synergistic effect that results in excellent fluidity and weather resistance, as well as suppressing the occurrence of flow marks, thereby improving appearance quality. Based on this, they have continued their research and have completed the present invention.

[0041] The thermoplastic resin composition according to the present invention will be described in detail below.

[0042] The thermoplastic resin composition described herein comprises 100 parts by weight of a base resin including (A-1) an acrylate-aromatic vinyl compound-vinyl cyanide compound graft copolymer containing an acrylate rubber having an average particle size of 400 to 600 nm, (A-2) an acrylate-aromatic vinyl compound-vinyl cyanide compound graft copolymer containing an acrylate rubber having an average particle size of 30 to 200 nm, (B) a heat-resistant resin having a weight-average molecular weight of 50,000 to 150,000 g / mol, and (C) an aromatic vinyl compound-vinyl cyanide compound copolymer having a weight-average molecular weight of 50,000 to 70,000 g / mol; and (D) 0.5 to 4 parts by weight of an aromatic vinyl compound-vinyl cyanide compound copolymer having a weight-average molecular weight of 1,000,000 to 10,000,000 g / mol.

[0043] In this case, the ASA resin composition has the effect of providing fluidity and weather resistance equivalent to or better than conventional ASA resin compositions, and also suppressing the occurrence of flow marks, resulting in excellent appearance quality.

[0044] The thermoplastic resin composition of the present invention will be described in detail below, by constituent.

[0045] (A-1) Acrylate-aromatic vinyl compound-vinyl cyanide compound graft copolymer containing acrylate rubber having an average particle size of 400 to 600 nm The acrylate rubber of the (A-1) graft copolymer may have, for example, an average particle size of 420 to 550 nm, preferably 450 to 520 nm, and more preferably 450 to 500 nm. Within this range, the effect of excellent mechanical strength such as impact strength is achieved.

[0046] In this description, the average particle size can be measured using dynamic light scattering. Specifically, it is measured as an intensity value in Gaussian mode using a particle size analyzer (product name: Nicomp380, manufacturer: PSS). As a specific measurement example, a sample of 0.1 g of latex with a total solids content of 35-50 wt% is prepared by diluting it 1,000-5,000 times with distilled water. The measurement method is auto-dilution followed by measurement using a flow cell. The measurement mode is dynamic light scattering / intensity 300 kHz / intensity-weighted Gaussian analysis, with the following settings: temperature 23°C, measurement wavelength 632.8 nm, and channel width 10 μsec.

[0047] The (A-1) graft copolymer may be, for example, 5 to 20% by weight, preferably 7 to 20% by weight, and more preferably 7 to 15% by weight, based on the total weight of the base resin. Within this range, the resulting composition has the same or better fluidity and weather resistance as conventional ASA resin compositions, and also has an excellent die swell ratio, which suppresses the occurrence of flow marks and results in excellent appearance quality.

[0048] The (A-1) graft copolymer, for example, contains 40 to 60% by weight of an acrylate rubber, 25 to 45% by weight of an aromatic vinyl compound, and 5 to 20% by weight of a vinyl cyan compound, and preferably contains 45 to 55% by weight of an acrylate rubber, 30 to 40% by weight of an aromatic vinyl compound, and 10 to 15% by weight of a vinyl cyan compound. Within these ranges, the copolymer has the effect of exhibiting excellent mechanical strength, such as impact strength.

[0050] In the present description, the alkyl acrylate compound may be, for example, an alkyl acrylate having an alkyl group with 1 to 15 carbon atoms, preferably one or more selected from the group consisting of methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylbutyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, hexyl acrylate, heptyl acrylate, n-pentyl acrylate, and lauryl acrylate, more preferably an alkyl acrylate containing a chain alkyl group with 1 to 4 carbon atoms, and even more preferably butyl acrylate.

[0051] In this description, the aromatic vinyl compound may be, for example, one or more selected from the group consisting of styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, m-methylstyrene, ethylstyrene, isobutylstyrene, t-butylstyrene, o-bromostyrene, p-bromostyrene, m-bromostyrene, o-chlorostyrene, p-chlorostyrene, m-chlorostyrene, vinyltoluene, vinylxylene, fluorostyrene, and vinylnaphthalene, preferably one or more selected from the group consisting of styrene and α-methylstyrene, more preferably styrene, which has appropriate fluidity and therefore excellent processability and mechanical properties such as impact resistance.

[0052] In the present description, the vinyl cyanide compound may be, for example, one or more selected from the group consisting of acrylonitrile, methacrylonitrile, ethyl acrylonitrile, and isopropyl acrylonitrile, and is preferably acrylonitrile.

[0053] The (A-1) graft copolymer may be prepared by emulsion polymerization, for example, and in this case, it has the effect of being excellent in mechanical strength such as impact strength.

[0054] The emulsion polymerization is not particularly limited as long as it is an emulsion polymerization commonly performed in the technical field to which the present invention pertains, and a specific example thereof may be an emulsion graft polymerization method.

[0055] (A-2) Acrylate-aromatic vinyl compound-vinyl cyanide compound graft copolymer containing acrylate rubber having an average particle size of 30 to 200 nm The acrylate rubber of the (A-2) graft copolymer may have, for example, an average particle size of 30 to 200 nm, preferably 50 to 180 nm, more preferably 70 to 150 nm, and even more preferably 70 to 120 nm. Within this range, excellent impact strength and gloss can be imparted to the final produced thermoplastic resin composition.

[0056] The (A-2) graft copolymer may be, for example, 26 to 35% by weight, preferably 28 to 35% by weight, and more preferably 28 to 33% by weight, based on the total weight of the base resin. Within this range, the resulting composition has the same or better fluidity and weather resistance as conventional ASA resin compositions, and also has an excellent die swell ratio, which suppresses the occurrence of flow marks and results in excellent appearance quality.

[0057] The (A-2) graft copolymer, for example, contains 40 to 60% by weight of an acrylate rubber, 25 to 45% by weight of an aromatic vinyl compound, and 5 to 20% by weight of a vinyl cyan compound, and preferably contains 45 to 55% by weight of an acrylate rubber, 30 to 40% by weight of an aromatic vinyl compound, and 10 to 15% by weight of a vinyl cyan compound. Within these ranges, the graft copolymer has the effect of providing excellent gloss and impact strength.

[0058] The (A-2) graft copolymer may be produced by emulsion polymerization, for example, and in this case, it has the effect of providing excellent impact strength and gloss.

[0059] The emulsion polymerization is not particularly limited as long as it is an emulsion polymerization commonly performed in the technical field to which the present invention pertains, and a specific example thereof may be an emulsion graft polymerization method.

[0060] The weight ratio (A-1:A-2) of the graft copolymer (A-1) to the graft copolymer (A-2) may be preferably 1:2 or more, more preferably 1:2 to 3, and even more preferably 1:2.5 to 1:3. Within this range, there are advantages in that the fluidity and weather resistance are equal to or greater than the respective other components, and the occurrence of flow marks is suppressed, thereby improving the appearance quality.

[0061] In the present invention, the weight ratio of A to B means the weight ratio of A:B.

[0062] The total amount of the (A-1) graft copolymer and the (A-2) graft copolymer may be preferably 40% by weight or less, more preferably 10 to 40% by weight, and even more preferably 25 to 40% by weight, based on 100% by weight of the total content of all components constituting the base resin. Within this range, there are advantages in that the fluidity and weather resistance are equal to or better than the original, and the occurrence of flow marks is suppressed, thereby improving the appearance quality.

[0063] (B) a heat-resistant resin having a weight-average molecular weight of 50,000 to 150,000 g / mol The heat-resistant resin (B) preferably has a weight-average molecular weight of 50,000 to 150,000 g / mol, more preferably 70,000 to 140,000 g / mol, and even more preferably 90,000 to 130,000 g / mol. Within this range, the resin has the effect of providing excellent heat resistance.

[0064] In this description, unless otherwise specified, the weight average molecular weight can be measured using GPC (gel permeation chromatography, water breeze), and specifically, it can be measured as a relative value to a standard PS (standard polystyrene) sample through GPC using THF (tetrahydrofuran) as an eluent. In this case, as a specific measurement example, the solvent is THF, the column temperature is 40°C, the flow rate is 0.3 ml / min, the sample concentration is 20 mg / ml, the injection volume is 5 μL, the column model is 1×PLgel 10 μm MiniMix-B (250 × 4.6 mm) + 1×PLgel 10 μm MiniMix-B (250 × 4.6 mm) + 1×PLgel 10 μm MiniMix-B Guard (50 × 4.6 mm), the measuring equipment is an Agilent 1200 series system, the refractive index detector is an Agilent G1362 RID, the RI temperature is 35°C, the data is processed by Agilent ChemStation S / W, and the test method (Mn, Mw, and PDI) can be measured under the conditions of OECD TG 118.

[0065] The (B) heat-resistant resin may be, for example, 35 to 60% by weight, preferably 35 to 55% by weight, and more preferably 38 to 52% by weight, based on the total weight of the base resin. Within this range, the impact resistance, heat resistance, and hardness are maintained at the same levels, while the fluidity and die swell ratio are excellent, thereby preventing the occurrence of flow marks and improving the appearance quality.

[0066] In this description, the heat-resistant resin is not particularly limited as long as it is a polymer generally referred to as a heat-resistant resin in the technical field to which the present invention belongs. Specifically, it may refer to a polymer containing a monomer having a higher glass transition temperature (polymer basis) than a styrene monomer, i.e., a heat-resistant monomer.

[0067] For example, the heat-resistant resin (B) may contain at least one heat-resistant monomer selected from the group consisting of an α-methylstyrene-based monomer and a maleimide-based monomer, and preferably an α-methylstyrene-based monomer. In this case, the heat-resistant resin (B) has an excellent balance between heat resistance and physical properties.

[0068] The maleimide-based monomer may be, for example, at least one selected from the group consisting of maleimide and derivatives thereof, and preferably at least one selected from the group consisting of maleimide, N-methylmaleimide, N-ethylmaleimide, N-propylmaleimide, N-isopropylmaleimide, N-butylmaleimide, N-isobutylmaleimide, Nt-butylmaleimide, N-laurylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, N-(4-chlorophenyl)maleimide, 2-methyl-N-phenylmaleimide, N-(4-bromophenyl)maleimide, N-(4-nitrophenyl)maleimide, N-(4-hydroxyphenyl)maleimide, N-(4-methoxyphenyl)maleimide, N-(4-carboxyphenyl)maleimide, and N-benzylmaleimide.

[0069] The α-methylstyrene-based monomer may be, for example, at least one selected from the group consisting of α-methylstyrene and its derivatives, and in this case, it has the effect of being excellent in heat resistance.

[0070] In the present description, a derivative of a certain compound may preferably be a compound in which one or more of its hydrogen atoms have been substituted with a substituent such as an alkyl group having 1 to 10 carbon atoms, a halogen group, or the like.

[0071] The heat-resistant resin (B) preferably contains 60 to 80% by weight of an α-methylstyrene-based monomer and 20 to 40% by weight of a vinyl cyan compound, and more preferably contains 65 to 75% by weight of an α-methylstyrene-based monomer and 25 to 35% by weight of a vinyl cyan compound. In this case, the heat-resistant resin (B) has the effect of being excellent in heat resistance and mechanical properties.

[0072] The heat-resistant resin (B) may be, as a preferred example, an α-methylstyrene-vinyl cyanide copolymer, or as a more preferred example, an α-methylstyrene-acrylonitrile copolymer, which has the advantages of excellent heat resistance, suppressing the occurrence of flow marks, and providing excellent appearance quality.

[0073] The heat-resistant resin (B) preferably has a glass transition temperature of 110 to 150°C, more preferably 110 to 140°C, and within this range, it has the effect of providing excellent heat resistance.

[0074] In this description, the glass transition temperature (Tg) can be measured using a differential scanning calorimetry (DSC) in accordance with ASTM D 3418. As a specific example, the glass transition temperature (Tg) can be measured using a Q100 DSC manufactured by TA Instruments at a heating rate of 10°C / min.

[0075] The heat-resistant resin (B) may be produced by, for example, solution polymerization or bulk polymerization, which has the effect of providing excellent heat resistance and fluidity.

[0076] The solution polymerization and bulk polymerization are not particularly limited as long as they are solution polymerization and bulk polymerization methods commonly used in the technical field to which the present invention pertains.

[0077] (C) Aromatic vinyl compound-vinyl cyanide copolymer having a weight average molecular weight of 50,000 to 70,000 g / mol The weight-average molecular weight of the copolymer (C) is preferably 50,000 to 70,000 g / mol, more preferably 55,000 to 70,000 g / mol, and even more preferably 55,000 to 65,000 g / mol, and within this range, the occurrence of flow marks is suppressed, resulting in excellent appearance quality. If the weight-average molecular weight exceeds this range, the melt index decreases, and processability is poor, as can be seen from Comparative Example 7 described below.

[0078] The (C) copolymer may be, for example, 6 to 25% by weight, preferably 6 to 22% by weight, and more preferably 8 to 22% by weight, based on the total weight of the base resin. Within this range, the impact resistance, heat resistance, and hardness are maintained at the same levels, while the fluidity and die swell ratio are excellent, thereby preventing the occurrence of flow marks and improving the appearance quality.

[0079] The copolymer (C) may contain, for example, an aromatic vinyl compound and a vinyl cyan compound, which has the advantages of being excellent in impact resistance and suppressing the occurrence of flow marks.

[0080] As a preferred example, the aromatic vinyl compound-vinyl cyan compound copolymer may contain 50 to 90% by weight of an aromatic vinyl compound and 10 to 50% by weight of a vinyl cyan compound, more preferably 60 to 80% by weight of an aromatic vinyl compound and 20 to 40% by weight of a vinyl cyan compound, and even more preferably 70 to 75% by weight of an aromatic vinyl compound and 25 to 30% by weight of a vinyl cyan compound. In this case, the copolymer has excellent fluidity and die swell ratio, which has the advantage of suppressing the occurrence of flow marks.

[0081] The types of aromatic vinyl compounds and vinyl cyan compounds contained in the copolymer (C) may be within the same category as the types of aromatic vinyl compounds and vinyl cyan compounds contained in the graft copolymer (A-1) described herein.

[0082] The copolymer (C) may be produced by, for example, suspension polymerization, emulsion polymerization, solution polymerization, or bulk polymerization, and in this case, it has the effect of being excellent in heat resistance and fluidity.

[0083] The suspension polymerization, emulsion polymerization, solution polymerization, and bulk polymerization are not particularly limited as long as they are suspension polymerization, emulsion polymerization, solution polymerization, and bulk polymerization methods commonly used in the technical field to which the present invention pertains.

[0084] In this description, it is preferable to avoid the use of methacrylate-aromatic vinyl compound-vinyl cyanide compound copolymers other than the aforementioned (C) copolymer, since this allows for sufficient fluidity and weather resistance while eliminating flow marks that tend to occur on the surface of the injected product, but the present invention is not limited to this.

[0085] (D) Aromatic vinyl compound-vinyl cyanide copolymer having a weight average molecular weight of 1,000,000 to 10,000,000 g / mol The (D) copolymer may preferably have a weight average molecular weight of 3,000,000 to 8,000,000 g / mol, more preferably 4,000,000 to 7,000,000 g / mol, and even more preferably 4,000,000 to 5,000,000 g / mol. Within this range, the occurrence of flow marks is suppressed, resulting in excellent appearance quality.

[0086] The (D) copolymer may be, for example, 0.5 to 4 parts by weight, preferably 0.7 to 3.7 parts by weight, more preferably 0.9 to 3.5 parts by weight, even more preferably 0.9 to 3.2 parts by weight, and particularly preferably 1 to 3 parts by weight, based on 100 parts by weight of the base resin. Within this range, excellent fluidity is achieved, and the occurrence of flow marks is suppressed, resulting in excellent appearance quality.

[0087] The copolymer (D) may be, for example, a crosslinked aromatic vinyl compound-vinyl cyan compound copolymer, which has the advantages of being excellent in impact resistance and suppressing the occurrence of flow marks.

[0088] For example, the crosslinked aromatic vinyl compound-vinyl cyan compound copolymer may be a mixture of an aromatic vinyl compound and a vinyl cyan compound, and at least one polyfunctional compound selected from the group consisting of a polyfunctional mercaptan compound and a polyfunctional acrylic monomer. In this case, the crosslinked aromatic vinyl compound-vinyl cyan compound copolymer has the advantages of excellent impact resistance and suppressing the occurrence of flow marks.

[0089] As a preferred example, the crosslinked aromatic vinyl compound-vinyl cyan compound copolymer may contain 0.01 to 5 parts by weight of a polyfunctional mercaptan compound and 0.005 to 5 parts by weight of a polyfunctional acrylic monomer with respect to 100 parts by weight of a mixture containing 50 to 90% by weight of an aromatic vinyl compound and 10 to 50% by weight of a vinyl cyan compound, and more preferably 60 to 80% by weight of an aromatic vinyl compound and 20 to 40% by weight of a vinyl cyan compound with respect to 100 parts by weight of a mixture containing 0.01 to 5 parts by weight of a polyfunctional mercaptan compound and 0.005 to 5 parts by weight of a polyfunctional acrylic monomer. The composition may contain 0.5 to 3 parts by weight of a mercaptan compound and 0.05 to 3 parts by weight of a polyfunctional acrylic monomer, and more preferably, 0.5 to 3 parts by weight of a polyfunctional mercaptan compound and 0.05 to 3 parts by weight of a polyfunctional acrylic monomer per 100 parts by weight of a mixture containing 70 to 75% by weight of an aromatic vinyl compound and 20 to 30% by weight of a vinyl cyan compound. In this case, the composition has excellent fluidity and die swelling ratio, which has the advantage of suppressing the occurrence of flow marks.

[0090] In another preferred example, the copolymer (D) may contain 0.01 to 5 parts by weight of a polyfunctional mercaptan compound relative to 100 parts by weight of a mixture containing 50 to 90% by weight of an aromatic vinyl compound and 10 to 50% by weight of a vinyl cyan compound. In this case, the copolymer has excellent fluidity and die swell ratio, which is advantageous in that it suppresses the occurrence of flow marks.

[0091] In yet another preferred example, the copolymer (D) may contain 0.005 to 5 parts by weight of a polyfunctional acrylic monomer relative to 100 parts by weight of a mixture containing 50 to 90% by weight of an aromatic vinyl compound and 10 to 50% by weight of a vinyl cyan compound. In this case, there is an advantage that the fluidity and die swelling ratio are excellent, thereby suppressing the occurrence of flow marks.

[0092] The types of aromatic vinyl compounds and vinyl cyan compounds contained in the copolymer (D) may be within the same category as the types of aromatic vinyl compounds and vinyl cyan compounds contained in the graft copolymer (A-1) described herein.

[0093] The polyfunctional mercaptan compound may be, for example, one or more compounds selected from the group consisting of trimethylolpropane tris(3-mercaptopropionate), trimethylolpropane tris(3-mercaptoacetate), trimethylolpropane tris(4-mercaptobutanate), trimethylolpropane tris(5-mercaptopentanate), trimethylolpropane tris(6-mercaptohexanate), pentaerythritol tetrakis(2-mercaptoacetate), pentaerythritol tetrakis(3-mercaptopropionate), pentaerythritol tetrakis(4-mercaptobutanate), pentaerythritol tetrakis(5-mercaptopentanate), and pentaerythritol tetrakis(6-mercaptohexanate).

[0094] The polyfunctional acrylic monomer may be, for example, one or more selected from the group consisting of ethylene dimethacrylate, diethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, 1,3-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, and allyl acrylate.

[0095] The copolymer (D) may be produced by emulsion polymerization, bulk polymerization, or suspension polymerization, preferably emulsion polymerization, which has the advantage of producing a uniform ultra-high molecular weight resin.

[0096] thermoplastic resin composition For example, when the weight percentages of (A-1), (A-2), (B), and (C) are a, b, c, and d, respectively, the thermoplastic resin composition can satisfy the following mathematical formula 1. In this case, the thermoplastic resin composition has excellent fluidity and die swelling ratio, which has the advantage of suppressing the occurrence of flow marks.

[0097] [Formula 1] a≦d <b≦c

[0098] Here, a may be an integer of 5 to 20, an integer of 7 to 20, an integer of 7 to 15, or an integer of 7 to 12.

[0099] Here, b may be an integer from 26 to 35, an integer from 28 to 35, an integer from 26 to 32, or an integer from 28 to 32.

[0100] Here, c may be an integer of 35 to 60, an integer of 35 to 55, an integer of 38 to 55, or an integer of 38 to 52.

[0101] Here, d may be an integer of 6 to 25, an integer of 8 to 25, an integer of 6 to 20, an integer of 8 to 20, or an integer of 8 to 15.

[0102] As a specific example, the thermoplastic resin composition can satisfy the following mathematical formula 1-1. In this case, there is an effect that the thermoplastic resin composition has an excellent balance of physical properties and does not generate flow marks, resulting in excellent appearance quality.

[0103] [Formula 1-1] a <d<b<c

[0104] Here, a may be an integer of 5 to 20, an integer of 7 to 20, an integer of 7 to 15, or an integer of 7 to 12.

[0105] Here, b may be an integer from 26 to 35, an integer from 28 to 35, an integer from 26 to 32, or an integer from 28 to 32.

[0106] Here, c may be an integer of 35 to 60, an integer of 35 to 55, an integer of 38 to 55, or an integer of 38 to 52.

[0107] Here, d may be an integer of 6 to 25, an integer of 8 to 25, an integer of 6 to 20, an integer of 8 to 20, or an integer of 8 to 15.

[0108] For example, when the weights of (A-1), (A-2), (B) and (C) are a, b, c and d, respectively, the thermoplastic resin composition can satisfy the following formula 2. In this case, the thermoplastic resin composition has excellent fluidity and die swelling ratio, which has the advantage of suppressing the occurrence of flow marks.

[0109] [Formula 2] 0.3≦[(a+b) / (c+d)]<0.8

[0110] Here, a may be an integer of 5 to 20, an integer of 7 to 20, an integer of 7 to 15, or an integer of 7 to 12.

[0111] Here, b may be an integer from 26 to 35, an integer from 28 to 35, an integer from 26 to 32, or an integer from 28 to 32.

[0112] Here, c may be an integer of 35 to 60, an integer of 35 to 55, an integer of 38 to 55, or an integer of 38 to 52.

[0113] Here, d may be an integer of 6 to 25, an integer of 8 to 25, an integer of 6 to 20, an integer of 8 to 20, or an integer of 8 to 15.

[0114] As a specific example, the thermoplastic resin composition can satisfy the following mathematical formula 2-1. In this case, there is an effect that the balance of physical properties is excellent and no flow marks occur, resulting in excellent appearance quality.

[0115] [Formula 2-1] 0.3≦[(a+b) / (c+d)]≦0.75

[0116] Here, a may be an integer of 5 to 20, an integer of 7 to 20, an integer of 7 to 15, or an integer of 7 to 12.

[0117] Here, b may be an integer from 26 to 35, an integer from 28 to 35, an integer from 26 to 32, or an integer from 28 to 32.

[0118] Here, c may be an integer of 35 to 60, an integer of 35 to 55, an integer of 38 to 55, or an integer of 38 to 52.

[0119] Here, d may be an integer of 6 to 25, an integer of 8 to 25, an integer of 6 to 20, an integer of 8 to 20, or an integer of 8 to 15.

[0120] As a preferred example, the thermoplastic resin composition can satisfy the following formula 2-2. In this case, there is an effect that the balance of physical properties is excellent and no flow marks occur, resulting in excellent appearance quality.

[0121] [Formula 2-2] 0.3≦[(a+b) / (c+d)]≦0.7

[0122] Here, a may be an integer of 5 to 20, an integer of 7 to 20, an integer of 7 to 15, or an integer of 7 to 12.

[0123] Here, b may be an integer from 26 to 35, an integer from 28 to 35, an integer from 26 to 32, or an integer from 28 to 32.

[0124] Here, c may be an integer of 35 to 60, an integer of 35 to 55, an integer of 38 to 55, or an integer of 38 to 52.

[0125] Here, d may be an integer of 6 to 25, an integer of 8 to 25, an integer of 6 to 20, an integer of 8 to 20, or an integer of 8 to 15.

[0126] When the thermoplastic resin composition described herein simultaneously satisfies the above-mentioned formula 1 and formula 2, it is more preferable because it has the advantage that the fluidity and weather resistance are equal to or similar to those of conventional ASA resin compositions, and at the same time, it has an excellent die swelling ratio, thereby suppressing the occurrence of flow marks.

[0127] When the thermoplastic resin composition described herein satisfies the conditions of the following mathematical formula 3, it has the advantage that the fluidity and weather resistance are equivalent to or similar to those of conventional ASA resin compositions, and at the same time, it has an excellent die swelling ratio, thereby suppressing the occurrence of flow marks.

[0128] [Formula 3] 380≦flow index × die swell ratio × spiral × content of processing aids≦1400 (In Equation 3, the flow index is a value (unit: g / 10 min) measured on the thermoplastic resin composition at 220°C under a load of 10 kg, the die swell ratio is a value calculated using Equation 4 below, the spiral is the length (unit: cm) of a test piece injected using a spiral mold (2.0T) under conditions of an injection temperature of 300°C, a mold temperature of 80°C, and a pressure of 500 kgf using an injection molding machine (Engel, Victory 80), and the content of the processing aid is the amount (parts by weight) of the (D) copolymer used based on 100 parts by weight of the total amount of the base resin and the aromatic vinyl compound-vinyl cyanide compound copolymer.)

[0129] [Formula 4] Die swell ratio = D ex / D0 (In the above formula 4, D0 is the diameter of the die, 2 mm, and D ex is the diameter (unit: mm) of an extruded test piece extruded at 220°C under a load of 10 kg using a fluidity tester (Melt Indexer, MI) with a die diameter of 2 mm (DO).

[0130] The formula 3 preferably satisfies the range of 400 to 1300, and in this case, the effect of excellent fluidity and weather resistance, suppressing the occurrence of flow marks, and providing excellent appearance quality is achieved.

[0131] For example, the thermoplastic resin composition is extruded at 220°C under a load of 10 kg using a flowability tester (Melt Indexer, MI) with a die diameter (D0) of 2 mm. ex) and the die swell ratio calculated by the above formula 4 is 1.3 to 1.57, preferably 1.3 to 1.55, and more preferably 1.3 to 1.54. Within this range, the impact resistance and fluidity are excellent, and the occurrence of flow marks is suppressed, resulting in an excellent appearance quality.

[0132] For example, the thermoplastic resin composition is injected into a spiral mold (2.0T) using an injection molding machine (Engel, Victory 80) under conditions of an injection temperature of 300°C, a mold temperature of 80°C, and a pressure of 500 kgf, and the spiral length of the test piece is 21.1 cm or more, preferably 21.1 to 24.4 cm. Within this range, the thermoplastic resin composition has an excellent balance of physical properties and does not generate flow marks, resulting in excellent appearance quality.

[0133] For example, the thermoplastic resin composition has a flow index of 6.7 g / 10 min or more, preferably 6.7 to 13.2 g / 10 min, measured in accordance with ASTM D1238 at 220°C under 10 kg for 10 minutes. Within this range, the thermoplastic resin composition has an excellent balance of physical properties and does not generate flow marks, resulting in excellent appearance quality.

[0134] The thermoplastic resin composition has, for example, a Charpy impact strength of 9 kJ / m, measured at 23°C using a 4 mm thick test piece in accordance with ISO 179. 2 More than 10 kJ / m 2 More preferably, 10 to 15 kJ / m 2 , and more preferably 10.5 to 13 kJ / m 2 Within this range, there is an effect that the physical properties are well balanced and no flow marks occur, resulting in excellent appearance quality.

[0135] For example, the thermoplastic resin composition was injected into a test piece of 40 mm x 200 mm using an injection machine (Engel 120MT) under conditions of an injection temperature of 240°C, a holding pressure of 50 bar, and an injection speed of 80 mm / s, and no flow marks were observed on the surface. In this case, the thermoplastic resin composition had an excellent balance of all physical properties and improved appearance quality.

[0136] According to another embodiment of the present disclosure, the thermoplastic resin composition comprises (A-1) 5 to 20% by weight of an acrylate-aromatic vinyl compound-vinyl cyanide compound graft copolymer containing an acrylate rubber having an average particle size of 400 to 600 nm, (A-2) 20 to 40% by weight of an acrylate-aromatic vinyl compound-vinyl cyanide compound graft copolymer containing an acrylate rubber having an average particle size of 30 to 200 nm, (B) 30 to 60% by weight of a heat-resistant resin having a weight-average molecular weight of 50,000 to 150,000 g / mol, and (C) 30 to 60% by weight of a heat-resistant resin having a weight-average molecular weight of 50,000 to 150,000 g / mol. and (C) 5 to 30 weight % of an aromatic vinyl compound-vinyl cyan compound copolymer having a weight average molecular weight of 50,000 to 70,000 g / mol; and (D) 0.5 to 4 weight % of an aromatic vinyl compound-vinyl cyan compound copolymer having a weight average molecular weight of 1,000,000 to 10,000,000 g / mol; and the base resin may be contained in a weight ratio of (A-1):(A-2):(B):(C) of 1:2-3:4-5:1-2.

[0137] The thermoplastic resin composition may further contain, for example, 0.01 to 5 parts by weight, preferably 0.05 to 3 parts by weight, and more preferably 0.1 to 3 parts by weight, of one or more selected from the group consisting of lubricants, antioxidants, ultraviolet stabilizers, UV stabilizers, optical brighteners, chain extenders, pigments, dyes, antibacterial agents, processing aids, metal deactivators, smoke suppressants, inorganic fillers, glass fibers, antifriction agents, and anti-wear agents, based on 100 parts by weight of the base resin. In this case, the required physical properties are effectively achieved without deteriorating the inherent physical properties of the thermoplastic resin composition described herein.

[0138] Method for producing thermoplastic resin composition The method for producing the thermoplastic resin composition according to the present invention includes, for example, mixing (A-1) 5 to 20% by weight of an acrylate-aromatic vinyl compound-vinyl cyanide compound graft copolymer containing an acrylate rubber having an average particle size of 400 to 600 nm, (A-2) 20 to 40% by weight of an acrylate-aromatic vinyl compound-vinyl cyanide compound graft copolymer containing an acrylate rubber having an average particle size of 30 to 200 nm, (B) a heat-resistant resin having a weight-average molecular weight of 50,000 to 150,000 g / mol, and (C) a heat-resistant resin having a weight-average molecular weight of 100,000 to 150,000 g / mol. The method comprises the steps of kneading and extruding 100 parts by weight of a base resin containing 30-60% by weight of a resin, and (C) 5-30% by weight of an aromatic vinyl compound-vinyl cyanide copolymer having a weight-average molecular weight of 50,000-70,000 g / mol, and (D) 0.5-4 parts by weight of an aromatic vinyl compound-vinyl cyanide copolymer having a weight-average molecular weight of 1,000,000-10,000,000 g / mol, at 200-300°C and 100-500 rpm. In this case, the fluidity and weather resistance are equal to or better than those of conventional ASA resin compositions, and the die swelling ratio is excellent, which suppresses the occurrence of flow marks and results in excellent appearance quality.

[0139] The method for producing the thermoplastic resin composition shares all the technical features of the thermoplastic resin composition described above, and therefore, a description of the overlapping parts will be omitted.

[0140] The step of producing pellets using the extrusion kneader may be preferably carried out at 200-300°C and 25-75 phi, more preferably at 210-260°C and 20-70 phi, within which stable extrusion is possible and kneading effects are excellent. Here, the temperature is the temperature set in the cylinder, and phi means the outer diameter (unit: mm).

[0141] The extrusion kneader is not particularly limited as long as it is an extrusion kneader that is commonly used in the technical field to which the present invention pertains, and is preferably a twin-screw extrusion kneader.

[0142] Molded product As an example, the molded article described herein is characterized by containing the thermoplastic resin composition described herein. In this case, compared to conventional ASA resin compositions, the molded article has the effect of having fluidity and weather resistance equal to or greater than those of conventional ASA resin compositions, and also has the effect of suppressing the occurrence of flow marks, resulting in excellent appearance quality.

[0143] The method for producing a molded article described herein is characterized by including a step of injecting pellets produced by the method for producing a thermoplastic resin composition under conditions of an injection temperature of 200 to 300°C, an injection pressure of 60 to 100 bar, and a holding pressure of 30 to 65 bar. In this case, there is an advantage that an injection-molded article with high impact strength can be easily produced.

[0144] The injection temperature is preferably 220 to 280°C, more preferably 230 to 270°C, and within this range there is an advantage that injection molded articles requiring complex designs can be easily produced.

[0145] The injection pressure is preferably 70 to 90 bar, more preferably 75 to 85 bar, and within this range, there is an advantage that injection molded articles requiring complex designs can be easily produced.

[0146] The dwell pressure may be preferably 35 to 60 bar, more preferably 40 to 55 bar, and within this range there is an advantage that injection molded articles requiring complex designs can be easily produced.

[0147] The molded article can be used in automotive exterior applications such as side mirror housings, radiator grilles, or filters.

[0148] In describing the thermoplastic resin composition, its manufacturing method, and molded articles described herein, other conditions, equipment, etc. not explicitly described can be appropriately selected within the range commonly used in the art, and are not particularly limited.

[0149] Below, preferred examples are presented to help understand the present description, but the following examples are merely illustrative of the present description, and it will be apparent to those skilled in the art that various changes and modifications are possible within the scope and technical idea of ​​the present description, and it is natural that such changes and modifications also fall within the scope of the appended claims.

[0150] [Example] The materials used in the following examples and comparative examples are as follows. *(A-1) Graft copolymer: ASA graft copolymer containing 50% by weight of acrylate rubber with an average particle size of 400 to 600 nm, 13% by weight of acrylonitrile, and 37% by weight of styrene (LG Chemical's product name D927) *(A-2) Graft copolymer: ASA graft copolymer containing acrylate rubber with an average particle size of 30 to 200 nm (LG Chemical's product name D100) *(A-3) Graft copolymer: ASA graft copolymer containing 40% by weight of acrylate rubber with an average particle size of 300 to 600 nm, 15% by weight of acrylonitrile, and 45% by weight of styrene (LG Chemical's product name D928) *(B) Heat-resistant resin (α-methylstyrene 71% by weight, acrylonitrile 29% by weight, weight-average molecular weight 80,000 to 100,000 g / mol, bulk-polymerized heat-resistant SAN resin, LG Chem product name 200UH) *(C-1) Aromatic vinyl compound-vinyl cyanide copolymer (weight average molecular weight 60,000 g / mol, suspension polymerization branched SAN resin (long chain branched SAN), product name EMI-200 by Find Blend) *(C-2) Aromatic vinyl compound-vinyl cyanide copolymer (weight average molecular weight 80,000-120,000 g / mol, LG Chemical product name S95RF) *(D) Ultra-high molecular weight SAN resin (styrene 75% by weight, acrylonitrile 25% by weight, styrene-acrylonitrile copolymer with a weight-average molecular weight of 2,000,000 to 5,000,000 g / mol, product name ZB-869 from Zibo Huaxing Additives Co., Ltd.)

[0151] Examples 1 to 3 and Comparative Examples 1 to 8 The ingredients and contents listed in Tables 1 and 2 below were fed into a twin-screw extruder and kneaded and extruded at a cylinder temperature of 240°C to produce pellets. The flow index of the produced pellets was measured. As additives, 0.3 wt% each of a lubricant and a UV stabilizer was added.

[0152] Thereafter, the mixture was injected at an injection temperature of 250°C using an injection machine (Engel 120MT) to prepare test pieces for measuring physical properties.

[0153] [Test example] The properties of the test specimens prepared in Examples 1 to 3 and Comparative Examples 1 to 8 were measured by the following methods, and the results are shown in Tables 1 and 2 and FIG.

[0154] Measurement method *Flow index (g / 10 min): Measured in accordance with ASTM D1238 at 220°C and under 10 kg for 10 minutes.

[0155] *Charpy impact strength (kJ / m 2 ):Measured in accordance with ISO 179 on 4 mm thick test specimens at 23°C.

[0156] *Die swell ratio: The diameter (D) of the extruded sample extruded at 220°C and a load of 10 kg using a fluidity tester (Melt Indexer, MI) with a die diameter (D) of 2 mm. ex ) was measured and calculated using the following formula 4. [Formula 4] Die swell ratio = D ex / D0 (In the above formula 4, D ex is the diameter of the extruded sample (mm), and D0 is the diameter of the die (mm).

[0157] *Spiral (unit: cm): Using an injection molding machine (Engel, Victory 80), the length of the test piece injected using a spiral mold (1.5T) was measured under the conditions of an injection temperature of 250°C, a mold temperature of 60°C, and a pressure of 500 kgf.

[0158] *Presence or absence of flow marks: Using an injection molding machine (Engel 120MT), test pieces of 40mm x 200mm were injected under conditions of an injection temperature of 250°C, a holding pressure of 50 bar, and an injection speed of 90mm / s. The test pieces were visually inspected for the presence or absence of flow marks and evaluated as follows. Flow marks appear as V-shaped wave patterns. ×: No flow marks on the surface △: Fine flow marks appear on the surface ○: Flow marks appear on some parts of the surface ◎: A large number of flow marks occur on the surface

[0159] *Flow mark parameter: When the weight percentages of (A-1), (A-2), (B) and (C) are a, b, c and d, respectively, it is determined whether the following formula 1 is satisfied, and if it is satisfied, it is indicated by ○, and if it is not satisfied, it is indicated by ×. For reference, the ○ mark is related to the suppression of flow mark occurrence. [Formula 1] a≦d <b≦c

[0160] *Appearance quality parameter: The values ​​calculated by the following Equation 3 are shown in Tables 1 and 2. For reference, when the value is within the range of 380 to 1400, it is determined that the balance of physical properties and appearance quality are excellent. [Formula 3] 380≦flow index × die swell ratio × spiral × content of processing aids≦1400

[0161] [Table 1]

[0162] [Table 2] (In Tables 1 and 2, the contents of (A-1), (A-2), (A-3), (B), (C-1) and (C-2) are in weight percent based on the total weight of these, and the content of (D) is in parts by weight based on 100 parts by weight of the total weight of (A-1), (A-2), (A-3), (B), (C-1) and (C-2).)

[0163] As shown in Tables 1 and 2, it was confirmed that Examples 1 to 3 according to the present invention have the same or higher Charpy impact strength as Comparative Examples 1 to 9, have excellent flow index and die swell ratio, suppress the occurrence of flow marks, and simultaneously satisfy the appropriate ranges of the above-mentioned formulas 1 and 3.

[0164] Specifically, Comparative Example 1, which did not contain (C) SAN resin and (D) ultra-high molecular weight SAN resin, had a low flow index, which reduced processability, a low die swell ratio and spiral length, and a large number of flow marks, and did not satisfy the appropriate ranges of Equation 1 and Equation 3.

[0165] Furthermore, in Comparative Examples 2 and 3, which did not contain (D) ultra-high molecular weight SAN resin, the die swelling ratio was low, and flow marks occurred partially or in large quantities depending on the amount of (C) SAN resin used, and the appropriate range of Equation 3 was not satisfied.

[0166] In addition, in Comparative Examples 4 and 5, which did not contain (C) SAN resin, the flow index was low, resulting in poor processability and a slight decrease in spiral length. Depending on the amount of (D) ultra-high molecular weight SAN resin used, fine or partial flow marks occurred, and the appropriate ranges of Equation 1 and Equation 3 were not satisfied.

[0167] Furthermore, in Comparative Example 6, which contained SAN resin (C) outside the appropriate molecular weight range, the die swelling ratio was low, causing flow marks, and the appropriate range of Equation 3 was not satisfied.

[0168] In addition, Comparative Example 7, which contained graft copolymer (A) having a rubber with a medium diameter larger than that of the small diameter, had a low die swell ratio and a spiral length outside of 24.4 cm, resulting in poor injection moldability and not satisfying the appropriate range of Equation 3.

[0169] In addition, in Comparative Example 8, in which an excessive amount of (D) ultra-high molecular weight SAN resin was used, a spiral drop occurred, and the appropriate range of Equation 3 was not satisfied.

[0170] Figure 1 below shows the observation of the occurrence of flow marks on the test pieces injected from Example 1, Comparative Examples 1, 3 and 5, respectively. It was confirmed that Example 1 did not generate flow marks and had excellent appearance quality.

[0171] On the other hand, in Comparative Examples 1, 3, and 5, many wavy flow marks occurred on the test pieces, and the appearance quality was deteriorated.

[0172] Considering these results, by adjusting the die swelling ratio of a five-component thermoplastic resin composition containing a graft copolymer containing acrylate rubbers with different average particle sizes, a heat-resistant resin, and a thermoplastic copolymer in different molecular weight ranges, the synergistic effect of the combination of these components can be achieved, resulting in excellent fluidity and weather resistance, as well as suppressing the occurrence of flow marks and improving appearance quality, making it possible to confirm that the resin composition is suitable for use as an exterior material with excellent product reliability.

Claims

1. 100 parts by weight of a base resin comprising: (A-1) 5 to 20% by weight of an acrylate-aromatic vinyl compound-vinyl cyan compound graft copolymer containing an acrylate rubber having an average particle size of 400 to 600 nm; (A-2) 26 to 40% by weight of an acrylate-aromatic vinyl compound-vinyl cyan compound graft copolymer containing an acrylate rubber having an average particle size of 30 to 200 nm; (B) 30 to 60% by weight of a heat-resistant resin having a weight-average molecular weight of 50,000 to 150,000 g / mol; and (C) 6 to 25% by weight of a styrene-acrylonitrile copolymer having a weight-average molecular weight of 50,000 to 70,000 g / mol; (D) 0.5 to 4 parts by weight of an aromatic vinyl compound-vinyl cyan compound copolymer having a weight average molecular weight of 1,000,000 to 10,000,000 g / mol, When the weight percentages of (A-1), (A-2), (B) and (C) are a, b, c and d, respectively, the following formula 1 is satisfied: [Formula 1] a≦d<b≦c (In the above formula, a is an integer of 5 to 20, b is an integer of 26 to 40, c is an integer of 30 to 60, and d is an integer of 6 to 25.) Fulfilling The (A-1) acrylate-aromatic vinyl compound-vinyl cyan compound graft copolymer comprises 40 to 60% by weight of an acrylate rubber, 25 to 45% by weight of an aromatic vinyl compound, and 5 to 20% by weight of a vinyl cyan compound, based on a total of 100% by weight of the copolymers; The (A-2) acrylate-aromatic vinyl compound-vinyl cyan compound graft copolymer comprises 40 to 60% by weight of an acrylate rubber, 25 to 45% by weight of an aromatic vinyl compound, and 5 to 20% by weight of a vinyl cyan compound, based on a total of 100% by weight of the copolymers; the heat-resistant resin (B) is an aromatic vinyl compound-vinyl cyanide compound copolymer containing an α-methylstyrene monomer, The heat-resistant resin (B) has a glass transition temperature of 110 to 150°C as measured using a differential scanning calorimeter, The aromatic vinyl compound-vinyl cyan compound copolymer (D) has an intrinsic viscosity (IV, 25°C) of 10 dL / g or more and a bulk density of 0.1 to 0.5 g / cm ３ and a weight average molecular weight of greater than 1,000,000 g / mol; The thermoplastic resin composition is characterized in that it satisfies the condition of the following mathematical formula 3. [Formula 3] 380≦flow index×die swell ratio×spiral×content of processing aid≦1400 (In Equation 3, the flow index is a value (unit: g / 10 min) measured for the thermoplastic resin composition at 220°C under a load of 10 kg in accordance with ASTM D1238, the die swell ratio is a value calculated by the following Equation 4, the spiral is the length (unit: cm) of a test piece injected using a spiral mold (2.0T) under conditions of an injection temperature of 300°C, a mold temperature of 80°C, and a pressure of 500 kgf using an injection molding machine (Engel, Victory 80), and the content of the processing aid is the amount (parts by weight) of the (D) copolymer used based on 100 parts by weight of the total amount of the base resin and the aromatic vinyl compound-vinyl cyanide compound copolymer, The formula 3 satisfies the range of 400 to 1300, the flow index is 6.7 to 13.2 g / 10 min, the die swell ratio is 1.31 to 1.54, and the spiral is 21.1 to 24.4 cm. [Formula 4] Die swell ratio = D ｅｘ / D ０ (In the above formula 4, D ０ is the diameter of the die, 2 mm, and D ｅｘ is the diameter of the die, 2 mm (D ０ ) is the diameter (unit: mm) of an extruded test piece extruded at 220°C under a load of 10 kg using a fluidity tester (Melt Indexer, MI).

2. The thermoplastic resin composition according to claim 1, wherein the total amount of (A-1) and (A-2) is 40% by weight or less based on 100% by weight of the total content of all components constituting the base resin.

3. 2. The thermoplastic resin composition according to claim 1, wherein the heat-resistant resin (B) comprises 60 to 80% by weight of an α-methylstyrene-based monomer and 20 to 40% by weight of a vinyl cyan compound.

4. 2. The thermoplastic resin composition according to claim 1, wherein the aromatic vinyl compound-vinyl cyan compound copolymer (C) comprises 50 to 90% by weight of an aromatic vinyl compound and 10 to 50% by weight of a vinyl cyan compound.

5. (A-1) 5 to 20% by weight of an acrylate-aromatic vinyl compound-vinyl cyan compound graft copolymer containing an acrylate rubber having an average particle size of 400 to 600 nm, (A-2) 26 to 40% by weight of an acrylate-aromatic vinyl compound-vinyl cyan compound graft copolymer containing an acrylate rubber having an average particle size of 30 to 200 nm, (B) 30 to 60% by weight of a heat-resistant resin having a weight-average molecular weight of 50,000 to 150,000 g / mol, and (C) a weight-average molecular weight of 100,000 to 150,000 g / mol. 100 parts by weight of a base resin containing 6 to 25% by weight of a styrene-acrylonitrile copolymer having a molecular weight of 50,000 to 70,000 g / mol; and (D) 0.5 to 4 parts by weight of an aromatic vinyl compound-vinyl cyanide compound copolymer having a weight average molecular weight of 1,000,000 to 10,000,000 g / mol; kneading and extruding the mixture under conditions of 200 to 300°C and 100 to 500 rpm, When the weight percentages of (A-1), (A-2), (B) and (C) are a, b, c and d, respectively, the following formula 1 is satisfied: [Formula 1] a≦d<b≦c (In the above formula, a is an integer of 5 to 20, b is an integer of 26 to 40, c is an integer of 30 to 60, and d is an integer of 6 to 25.) Fulfilling The (A-1) acrylate-aromatic vinyl compound-vinyl cyan compound graft copolymer comprises 40 to 60% by weight of an acrylate rubber, 25 to 45% by weight of an aromatic vinyl compound, and 5 to 20% by weight of a vinyl cyan compound, based on a total of 100% by weight of the copolymers; The (A-2) acrylate-aromatic vinyl compound-vinyl cyan compound graft copolymer comprises 40 to 60% by weight of an acrylate rubber, 25 to 45% by weight of an aromatic vinyl compound, and 5 to 20% by weight of a vinyl cyan compound, based on a total of 100% by weight of the copolymers; the heat-resistant resin (B) is an aromatic vinyl compound-vinyl cyanide compound copolymer containing an α-methylstyrene monomer, The heat-resistant resin (B) has a glass transition temperature of 110 to 150°C as measured using a differential scanning calorimeter, The aromatic vinyl compound-vinyl cyan compound copolymer (D) has an intrinsic viscosity (IV, 25°C) of 10 dL / g or more and a bulk density of 0.1 to 0.5 g / cm ３ and a weight average molecular weight of greater than 1,000,000 g / mol; The thermoplastic resin composition satisfies the condition of the following mathematical formula 3. [Formula 3] 380≦flow index×die swell ratio×spiral×content of processing aid≦1400 (In Equation 3, the flow index is a value (unit: g / 10 min) measured for the thermoplastic resin composition at 220°C under a load of 10 kg in accordance with ASTM D1238, the die swell ratio is a value calculated by the following Equation 4, the spiral is the length (unit: cm) of a test piece injected using a spiral mold (2.0T) under conditions of an injection temperature of 300°C, a mold temperature of 80°C, and a pressure of 500 kgf using an injection molding machine (Engel, Victory 80), and the content of the processing aid is the amount (parts by weight) of the (D) copolymer used based on 100 parts by weight of the total amount of the base resin and the aromatic vinyl compound-vinyl cyanide compound copolymer, The formula 3 satisfies the range of 400 to 1300, the flow index is 6.7 to 13.2 g / 10 min, the die swell ratio is 1.31 to 1.54, and the spiral is 21.1 to 24.4 cm. [Formula 4] Die swell ratio = D ｅｘ / D ０ (In the above formula 4, D ０ is the diameter of the die, 2 mm, and D ｅｘ is the diameter of the die, 2 mm (D ０ The diameter (unit: mm) of an extruded test piece extruded at 220°C under a load of 10 kg using a fluidity tester (Melt Indexer, MI).

6. A molded article comprising the thermoplastic resin composition of claim 1.

Images