Resin composition

Abstract

The present invention relates to a resin composition that is excellent in heat resistance, transparency, and processability.

Description

[Technical Field]

[0001] The present invention claims the benefit of priority based on Korean Patent Application No. 10-2022-0136322, filed on October 21, 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 resin composition. [Background technology]

[0003] Acrylonitrile-butadiene-styrene (ABS) copolymer is produced by graft copolymerizing styrene and acrylonitrile onto a butadiene rubber-like polymer. ABS copolymers consistently possess rigidity, chemical resistance, impact resistance, and processability. They also boast excellent impact strength, mechanical properties, surface gloss, and secondary processing properties such as plating, printing, and painting. They also have the advantage of being able to be produced in a variety of colors. However, ABS resin alone is limited in its use in parts requiring heat resistance, such as the interior and exterior of automobiles, or in parts requiring transparency, such as transparent windows in washing machines, dust cups for vacuum cleaners, and transparent windows in office equipment.

[0004] To overcome these problems, methods for imparting transparency to plastic materials are known. First, a method using polycarbonate resin as a transparent plastic material is known. However, while polycarbonate resin has excellent transparency and room-temperature impact resistance, it suffers from problems with poor chemical resistance and low-temperature impact resistance. Its poor processability limits its application to large parts. Furthermore, U.S. Patent No. 3,787,522 and Japanese Patent Registration No. 1988-042940 disclose methods for imparting impact resistance to transparent polymethyl methacrylate resin. However, while polymethyl methacrylate resin has excellent transparency and processability, its extremely poor impact resistance limits its application to parts requiring impact resistance. Furthermore, European Patent Registration No. 0,703,252 discloses a method for imparting transparency to high-impact polystyrene (HIPS) resin. However, high-impact polystyrene resin suffers from problems with poor chemical resistance and scratch resistance.

[0005] Meanwhile, methods for producing ABS copolymers with excellent heat resistance have been developed, such as incorporating a heat-resistant monomer or adding inorganic materials to a resin composition containing an ABS copolymer. Common methods for incorporating a heat-resistant monomer include adding a maleimide monomer or alpha-methylstyrene monomer during the polymerization process, or blending a heat-resistant styrene resin containing the monomer with the ABS copolymer. However, maleimide monomers have a very fast polymerization rate, making it difficult to control the reaction temperature. Furthermore, due to the high heat of reaction, there is a limit to how much maleimide monomer can be added to the resin. As the maleimide monomer content in the resin increases, compatibility with the ABS copolymer and impact strength decrease. Furthermore, alpha-methylstyrene monomers have the disadvantage of requiring a long reaction time due to their very slow polymerization rate, and the resulting polymer has a low molecular weight and is prone to thermal decomposition. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] US3787522A [Patent Document 2] JP1988-042940B2 [Patent Document 3] EP0703252B2 Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide a resin composition that is excellent in heat resistance, transparency, and processability. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention provides a resin composition.

[0009] (1) The present invention provides a resin composition comprising a graft copolymer and a styrene-based copolymer, wherein the graft copolymer comprises a conjugated diene-based polymer, an alkyl(meth)acrylate-based monomer unit, and an aromatic vinyl-based monomer unit, and the styrene-based copolymer comprises an alkyl(meth)acrylate-based monomer unit, an aromatic vinyl-based monomer unit, and a maleimide-based monomer unit.

[0010] (2) The present invention provides the resin composition according to (1) above, wherein the graft copolymer has a refractive index of 1.515 or more and 1.520 or less.

[0011] (3) The present invention provides the resin composition according to (1) or (2) above, wherein the graft copolymer has a weight average molecular weight of 90,000 g / mol or more and 130,000 g / mol or less.

[0012] (4) The present invention provides the resin composition according to any one of (1) to (3) above, wherein the graft copolymer has a molecular weight distribution of 2.7 or less.

[0013] (5) The present invention provides the resin composition according to any one of (1) to (4) above, wherein the graft copolymer has a graft ratio of 44% or more.

[0014] (6) The present invention provides the resin composition according to any one of (1) to (5), wherein the graft copolymer contains 20% by weight to 70% by weight of a conjugated diene polymer, 25% by weight to 55% by weight of alkyl (meth)acrylate monomer units, 1% by weight to 15% by weight of aromatic vinyl monomer units, and 0% by weight to 5% by weight of vinyl cyanide monomer units.

[0015] (7) The present invention provides the resin composition according to any one of (1) to (6) above, wherein the graft copolymer contains a maleimide-based monomer unit.

[0016] (8) The present invention provides the resin composition according to (7) above, wherein the graft copolymer contains 20% by weight to 70% by weight of a conjugated diene polymer, 25% by weight to 55% by weight of alkyl (meth)acrylate monomer units, 0.1% by weight to 3% by weight of maleimide monomer units, 1% by weight to 15% by weight of aromatic vinyl monomer units, and 0% by weight to 5% by weight of vinyl cyanide monomer units.

[0017] (9) The present invention provides the resin composition according to any one of (1) to (8), wherein the styrene copolymer contains 50% by weight to 90% by weight of alkyl (meth)acrylate monomer units, 1% by weight to 20% by weight of aromatic vinyl monomer units, 1% by weight to 20% by weight of maleimide monomer units, and 0% by weight to 5% by weight of vinyl cyanide monomer units.

[0018] (10) The present invention provides the resin composition according to any one of (1) to (9), wherein the resin composition contains, relative to the total content of the graft copolymer and the styrene copolymer, 10% by weight to 40% by weight of a conjugated diene polymer, 40% by weight to 75% by weight of alkyl (meth)acrylate monomer units, 5% by weight to 15% by weight of maleimide monomer units, 5% by weight to 15% by weight of aromatic vinyl monomer units, and 0% by weight to 5% by weight of vinylcyan monomer units.

[0019] (11) The present invention provides the resin composition according to any one of (1) to (10), wherein the resin composition has a heat distortion temperature of 90.0°C or higher, as measured under a stress of 18.6 kgf using a test piece with a thickness of 6.4 mm according to the ASTM D648 method.

[0020] (12) The present invention provides the resin composition according to any one of (1) to (11), wherein the haze of a 3 mm thick test piece is measured according to the ASTM D1003 method, the test piece is stored in a low-temperature chamber at -40°C for 12 hours, and the haze is further measured. The haze change calculated by the following Equation 4 is 2.0 or less.

[0021] [Formula 4] △Haze = (haze of test piece after low-temperature storage) - (haze of test piece before low-temperature storage) [Effects of the Invention]

[0022] The resin composition of the present invention is excellent in all of heat resistance, transparency, and processability. DETAILED DESCRIPTION OF THE INVENTION

[0023] For better understanding of the present invention, the present invention will be described in more detail below.

[0024] The terms and words used in this specification should not be interpreted in a limited way to their ordinary or dictionary meanings, but should be interpreted in a way that is consistent with the technical idea of ​​the present invention, based on the principle that the inventors can appropriately define the concepts of terms in order to best explain their invention.

[0025] In the present invention, the term "monomer unit" refers to a component, structure, or substance itself resulting from a monomer, and as a specific example, it may refer to a repeating unit formed in a polymer when an input monomer participates in a polymerization reaction during polymerization of the polymer.

[0026] As used herein, the term "composition" includes mixtures of materials comprising the composition as well as reaction products and decomposition products formed from the materials of the composition.

[0027] The present invention provides a resin composition, which may be a transparent resin composition having excellent heat resistance, transparency, and processability.

[0028] According to one embodiment of the present invention, the resin composition includes a graft copolymer and a styrene-based copolymer. The graft copolymer may include a conjugated diene-based polymer, an alkyl(meth)acrylate-based monomer unit, and an aromatic vinyl-based monomer unit. The styrene-based copolymer may include an alkyl(meth)acrylate-based monomer unit, an aromatic vinyl-based monomer unit, and a maleimide-based monomer unit.

[0029] According to one embodiment of the present invention, the resin composition may be a resin composition containing a graft copolymer dispersed in a styrene-based copolymer matrix resin. By containing both the graft copolymer and the styrene-based copolymer in this manner, the transparent resin composition can improve heat resistance and processability while maintaining the impact strength provided by the graft copolymer.

[0030] According to one embodiment of the present invention, the graft copolymer may include a conjugated diene-based polymer, an alkyl (meth)acrylate-based monomer unit, and an aromatic vinyl-based monomer unit.

[0031] According to an embodiment of the present invention, the conjugated diene-based polymer is a polymer including conjugated diene-based monomer units polymerized with a conjugated diene-based monomer, and may be referred to as a rubber.

[0032] According to one embodiment of the present invention, the conjugated diene monomer may be at least one selected from the group consisting of 1,3-butadiene, 2,3-dimethyl-1,3-butadiene, piperylene, 3-butyl-1,3-octadiene, isoprene, and 2-phenyl-1,3-butadiene, and a more specific example thereof may be 1,3-butadiene.

[0033] According to an embodiment of the present invention, the conjugated diene-based polymer may be a conjugated diene-based copolymer obtained by polymerizing the conjugated diene-based monomer and a monomer copolymerizable with the conjugated diene-based monomer. Specific examples of the conjugated diene-based polymer include a butadiene polymer, a butadiene-styrene copolymer, and a butadiene-acrylonitrile copolymer.

[0034] According to one embodiment of the present invention, the conjugated diene-based polymer may be in the form of a conjugated diene-based polymer latex containing a conjugated diene-based polymer prepared by emulsion polymerization, and may be added during the preparation of the graft copolymer.

[0035] According to one embodiment of the present invention, the conjugated diene polymer may have an average particle size of 80 nm to 400 nm as measured by dynamic light scattering. Specific examples of the average particle size of the conjugated diene polymer include 80 nm or more, 100 nm or more, 150 nm or more, 200 nm or more, or 250 nm or more, and 400 nm or less, 350 nm or less, or 300 nm or less.

[0036] According to one embodiment of the present invention, the conjugated diene polymer latex may have a gel content of 60% by weight or more and 95% by weight or less. Specific examples of the gel content of the conjugated diene polymer latex include 60% by weight or more, 65% by weight or more, and 70% by weight or more, and 95% by weight or less, 90% by weight or less, 85% by weight or less, 80% by weight or less, and 75% by weight or less.

[0037] According to an embodiment of the present invention, the conjugated diene-based polymer latex may have a swelling index of 12 or more and 40 or less.

[0038] According to one embodiment of the present invention, the graft copolymer may include alkyl(meth)acrylate-based monomer units, maleimide-based monomer units, and aromatic vinyl-based monomer units graft polymerized onto the conjugated diene-based polymer. Thus, the graft copolymer may be a core-shell graft copolymer including a core including the conjugated diene-based polymer and a shell including alkyl(meth)acrylate-based monomer units, maleimide-based monomer units, and aromatic vinyl-based monomer units graft polymerized onto the conjugated diene-based polymer.

[0039] According to one embodiment of the present invention, the alkyl(meth)acrylate monomer unit provides transparency to the graft copolymer and improves compatibility with the styrene copolymer. The alkyl(meth)acrylate monomer forming the alkyl(meth)acrylate monomer unit may be an alkyl(meth)acrylate monomer having 1 to 12 carbon atoms. Specifically, the alkyl(meth)acrylate monomer may be one or more selected from the group consisting of methyl(meth)acrylate, ethyl(meth)acrylate, propyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, decyl(meth)acrylate, and lauryl(meth)acrylate, and more specifically, methyl methacrylate. Here, (meth)acrylate refers to both methacrylate and acrylate.

[0040] According to one embodiment of the present invention, the aromatic vinyl monomer unit is used to improve mechanical properties and compatibility with the styrene copolymer, and may be at least one selected from the group consisting of styrene, alpha-methylstyrene, alpha-ethylstyrene, and para-methylstyrene, and a specific example thereof may be styrene.

[0041] According to an embodiment of the present invention, the graft copolymer may further include a vinylcyan-based monomer unit graft-polymerized onto the conjugated diene-based polymer. The vinylcyan-based monomer unit is used to improve mechanical properties and compatibility with the styrene-based copolymer, and may be at least one selected from the group consisting of acrylonitrile, methacrylonitrile, and ethacrylonitrile, and a specific example thereof may be acrylonitrile.

[0042] According to one embodiment of the present invention, the graft copolymer may have a refractive index of 1.515 to 1.520. Specifically, the refractive index of the graft copolymer may be 1.515 to 1.516, 1.517 to 1.518, or 1.520 to 1.519, or 1.518. Within these ranges, the resin composition may have particularly excellent transparency. The refractive index may be calculated from the content of each component added during the preparation of the graft copolymer using Equation 1 below. The refractive index may also be measured using an Abbe refractometer. The refractive index may be adjusted by the content and content of the polymer and each monomer component added during polymerization of the graft copolymer. Specifically, to ensure the transparency of the graft copolymer, the refractive index of the conjugated diene-based polymer and the overall refractive index of the other components need to be similar, and therefore, the mixing ratio of each monomer is important. For example, the refractive index of each polymer and monomer component used in preparing the graft copolymer is about 1.518 for 1,3-butadiene, about 1.49 for methyl methacrylate, about 1.63 for N-phenylmaleimide, about 1.55 for styrene, and about 1.52 for acrylonitrile.

[0043] [Formula 1] Refractive index (RI) = ΣWti*RIi -Wti = weight fraction (%) of each component in the graft copolymer -RIi = refractive index of the homopolymer of each component of the graft copolymer

[0044] According to one embodiment of the present invention, the graft copolymer may have a weight-average molecular weight of 90,000 g / mol to 130,000 g / mol. The weight-average molecular weight of the graft copolymer is the weight-average molecular weight of the shell in a core-shell graft copolymer. Specifically, it may be the weight-average molecular weight of a free polymer containing each monomer unit contained in the shell, but not grafted to the core conjugated diene polymer. This can be measured by subjecting the graft copolymer to sol / gel separation, diluting the resulting sol in tetrahydrofuran, and then performing gel permeation chromatography. As a specific example, the weight average molecular weight of the graft copolymer may be 90,000 g / mol or more, 91,000 g / mol or more, 92,000 g / mol or more, 93,000 g / mol or more, 94,000 g / mol or more, 95,000 g / mol or more, 96,000 g / mol or more, 97,000 g / mol or more, 98,000 g / mol or more, 99,000 g / mol or more, 100,000 g / mol or more, 100,500 g / mol or more, 101,000 g / mol or more, 101,500 g / mol or more, or 102,000 g / mol or more, and may be 130,000 g / mol or less, 125,000 g / mol or less, 120,000 g / mol or less, or 115,000 g / mol or less. When the content is within this range, the resin composition has excellent mechanical properties and is even more compatible with the styrene copolymer.

[0045] According to one embodiment of the present invention, the graft copolymer may have a molecular weight distribution of 2.7 or less. Here, the molecular weight distribution is the ratio of the weight average molecular weight to the number average molecular weight, and means "weight average molecular weight (Mw) / number average molecular weight (Mn)." The molecular weight distribution of the graft copolymer may be 2.7 or less, 2.6 or less, 2.5 or less, 2.4 or less, or 2.3 or less, or 1.0 or more, 1.5 or more, 2.0 or more, or 2.1 or more. When the molecular weight distribution is within this range, the resin composition has excellent mechanical properties and is even more compatible with the styrene copolymer.

[0046] According to one embodiment of the present invention, the weight average molecular weight and molecular weight distribution of the graft copolymer can be controlled by using a molecular weight regulator during polymerization of the graft copolymer. The molecular weight regulator may be a mercaptan molecular weight regulator, specifically, at least one selected from the group consisting of 1-butyl mercaptan, n-decyl mercaptan, n-hexyl mercaptan, and n-octyl mercaptan, and more specifically, n-octyl mercaptan.

[0047] According to one embodiment of the present invention, the graft copolymer may have a graft ratio of 44% or more. The graft ratio of the graft copolymer may be calculated by adding a certain amount of dried copolymer powder from the graft copolymer latex to acetone, vibrating it in a vibrator (product name: SI-600R, manufacturer: Lab.companion) for 24 hours to dissolve the released graft copolymer, centrifuging it in a centrifuge at 14,000 rpm for 1 hour, and drying it in a vacuum dryer (product name: DRV320DB, manufacturer: ADVANTEC) at 140°C for 2 hours to obtain an insoluble fraction. Specifically, the graft ratio of the graft copolymer may be 44% or more, 45% or more, 46% or more, 47% or more, 48% or more, 49% or more, or 50% or more, and may be 80% or less, 75% or less, or 70% or less. Within these ranges, the resin composition exhibits excellent mechanical properties and excellent compatibility with the styrene-based copolymer.

[0048] [Formula 2] Grafting rate (%) = [(Y-(X*R)) / (X*R)]*100 Y: Weight of insoluble matter X: Weight of the graft copolymer added when the insoluble matter was obtained R: Fraction of conjugated diene polymer in the graft copolymer added when the insoluble fraction was obtained

[0049] According to one embodiment of the present invention, the graft copolymer may contain 20 to 70% by weight of a conjugated diene polymer and each of the monomer units to improve the mechanical properties of the graft copolymer and to improve heat resistance, transparency, and processability. Specifically, the graft copolymer may contain 20 to 70% by weight of a conjugated diene polymer, 25 to 55% by weight of an alkyl (meth)acrylate monomer unit, 0.1 to 3% by weight of a maleimide monomer unit, 1 to 15% by weight of an aromatic vinyl monomer unit, and 0 to 5% by weight of a vinyl cyanide monomer unit.

[0050] According to one embodiment of the present invention, the graft copolymer may contain 20% to 70% by weight of the conjugated diene polymer. Specifically, the graft copolymer may contain 20% by weight or more, 25% by weight or more, 30% by weight or more, 35% by weight or more, 40% by weight or more, 45% by weight or more, or 50% by weight or more of the conjugated diene polymer, or 70% by weight or less, 65% by weight or less, 60% by weight or less, 55% by weight or less, or 50% by weight or less. Within this range, the impact strength of the resin composition is ensured, and graft polymerization proceeds smoothly, resulting in excellent mechanical properties.

[0051] According to one embodiment of the present invention, the graft copolymer may contain 25% to 55% by weight of alkyl (meth)acrylate monomer units. Specific examples of the graft copolymer include 25% by weight or more, 30% by weight or more, or 35% by weight or more of alkyl (meth)acrylate monomer units, and 55% by weight or less, 50% by weight or less, 45% by weight or less, 40% by weight or less, or 35% by weight or less. Within these ranges, the resin composition has excellent transparency, excellent compatibility between the graft copolymer and the styrene copolymer, and excellent mechanical properties.

[0052] According to one embodiment of the present invention, the graft copolymer may contain 1% to 15% by weight of aromatic vinyl monomer units. Specific examples of the graft copolymer include 1% by weight or more, 5% by weight or more, 6% by weight or more, 7% by weight or more, 8% by weight or more, 9% by weight or more, or 10% by weight or more of aromatic vinyl monomer units, and 15% by weight or less, 14% by weight or less, 13% by weight or less, or 12% by weight or less. When the content is within this range, the resin composition has excellent transparency, excellent compatibility between the graft copolymer and the styrene copolymer, and excellent mechanical properties.

[0053] According to one embodiment of the present invention, the graft copolymer may contain 0 to 5 wt% of vinylcyan-based monomer units. Specifically, the graft copolymer may contain at least 0.0 wt%, 0.1 wt%, 0.5 wt%, 1 wt%, 1.5 wt%, or 2.0 wt% of vinylcyan-based monomer units, or at most 5.0 wt%, 4.5 wt%, 4.0 wt%, 3.5 wt%, 3.0 wt%, or 2.5 wt%. Within this range, the resin composition exhibits excellent transparency and color, minimizes the amount of coagulated material due to decreased latex stability, and exhibits excellent compatibility between the graft copolymer and the styrene-based copolymer, resulting in excellent mechanical properties.

[0054] According to one embodiment of the present invention, the graft copolymer may include a maleimide-based monomer unit. The maleimide-based monomer unit is intended to impart heat resistance to the graft copolymer and improve compatibility with the styrene-based copolymer. The maleimide-based monomer for forming the maleimide-based monomer unit may be one or more selected from the group consisting of N-phenylmaleimide, maleimide, N-methylmaleimide, N-ethylmaleimide, N-propylmaleimide, N-isopropylmaleimide, N-butylmaleimide, N-isobutylmaleimide, Nt-butylmaleimide, N-cyclohexylmaleimide, N-chloromaleimide, N-methylphenylmaleimide, N-bumolophenylmaleimide, N-naphthylmaleimide, N-laurylmaleimide, N-hydroxyphenylmaleimide, N-methoxyphenylmaleimide, N-carboxyphenylmaleimide, N-nitrophenylmaleimide, and N-benzylmaleimide, and a specific example thereof may be N-phenylmaleimide.

[0055] According to one embodiment of the present invention, when the graft copolymer contains maleimide-based monomer units, the graft copolymer may contain 0.1 wt% to 3 wt% of the maleimide-based monomer units. Maleimide-based monomers have a very fast polymerization rate, which makes it difficult to control the reaction temperature. Because they generate a high heat of reaction, it is preferable to adjust the content appropriately to minimize the amount of coagulation resulting from decreased latex stability and prevent discoloration of the resin composition. Specifically, the graft copolymer may contain 0.1 wt% or more, 0.5 wt% or more, or 1.0 wt% or more of the maleimide-based monomer units, or 3.0 wt% or less, 2.5 wt% or less, or 2.0 wt% or less. Within these ranges, the resin composition exhibits excellent heat resistance and transparency, excellent compatibility between the graft copolymer and the styrene-based copolymer, and excellent mechanical properties.

[0056] According to one embodiment of the present invention, the styrene-based copolymer is a matrix resin of the resin composition, and is referred to as a styrene-based copolymer in accordance with the name used to refer to a typical matrix resin, but may also be referred to as an acrylic copolymer in terms of the ratio between the monomers described below. The styrene-based copolymer may be a non-graft copolymer containing alkyl (meth)acrylate-based monomer units, aromatic vinyl-based monomer units, and maleimide-based monomer units, and as a specific example, may further contain vinylcyan-based monomer units as needed.

[0057] According to one embodiment of the present invention, the alkyl(meth)acrylate-based monomer unit, aromatic vinyl-based monomer unit, maleimide-based monomer unit, and vinylcyan-based monomer unit of the styrene-based copolymer may be selected from the same types of monomers as the alkyl(meth)acrylate-based monomer, aromatic vinyl-based monomer, maleimide-based monomer, and vinylcyan-based monomer of the graft copolymer, respectively, and may be the same as or different from each monomer of the graft copolymer.

[0058] According to one embodiment of the present invention, the styrene-based copolymer may have a refractive index of 1.515 to 1.520. Specifically, the refractive index of the styrene-based copolymer may be 1.515 or more, 1.516 or more, 1.517 or more, or 1.518 or more, or 1.520 or less, 1.519 or less, or 1.518 or less. Within these ranges, the transparency of the resin composition may be particularly excellent. The refractive index may be calculated from the content of each component added during the preparation of the styrene-based copolymer using Equation 5 below. The refractive index may also be measured using an Abbe refractometer. The refractive index may be adjusted depending on the polymer and each monomer component and content added during polymerization of the styrene-based copolymer. For example, the refractive indexes of the monomer components added during the preparation of the styrene-based copolymer are approximately 1.49 for methyl methacrylate, approximately 1.63 for N-phenylmaleimide, approximately 1.55 for styrene, and approximately 1.52 for acrylonitrile.

[0059] [Formula 5] Refractive index (RI) = ΣWti*RIi -Wti = weight fraction (%) of each component in styrene copolymer -RIi = refractive index of the homopolymer of each component of the styrene copolymer

[0060] According to one embodiment of the present invention, the styrene-based copolymer may have a weight-average molecular weight of 80,000 g / mol or more and 160,000 g / mol or less. The weight-average molecular weight of the styrene-based copolymer can be measured by gel permeation chromatography after dilution with tetrahydrofuran. Specific examples of the weight-average molecular weight of the styrene-based copolymer include 80,000 g / mol or more, 85,000 g / mol or more, 90,000 g / mol or more, 95,000 g / mol or more, or 100,000 g / mol or more, and 160,000 g / mol or less, 155,000 g / mol or less, 150,000 g / mol or less, or 140,000 g / mol or less. Within these ranges, the resin composition exhibits excellent mechanical properties and further excellent compatibility with the graft copolymer.

[0061] According to one embodiment of the present invention, the styrene-based copolymer may have a content of each monomer unit adjusted to improve the mechanical properties, heat resistance, transparency, and processability of the resin composition. Specifically, the styrene-based copolymer may contain 50% to 90% by weight of alkyl (meth)acrylate-based monomer units, 1% to 20% by weight of aromatic vinyl-based monomer units, 1% to 20% by weight of maleimide-based monomer units, and 0% to 5% by weight of vinyl cyanide-based monomer units.

[0062] According to one embodiment of the present invention, the styrene-based copolymer may contain 50% to 90% by weight of alkyl (meth)acrylate monomer units. Specific examples include 50% by weight or more, 55% by weight or more, 60% by weight or more, 65% by weight or more, 70% by weight or more, or 75% by weight or more of alkyl (meth)acrylate monomer units, and 90% by weight or less, 85% by weight or less, or 80% by weight or less. Within these ranges, the resin composition has excellent transparency, excellent compatibility between the graft copolymer and the styrene-based copolymer, and excellent mechanical properties.

[0063] According to one embodiment of the present invention, the styrene-based copolymer may contain 1 wt% to 20 wt% of aromatic vinyl-based monomer units. Specific examples of the styrene-based copolymer include 1 wt% or more, 2 wt% or more, 3 wt% or more, 4 wt% or more, 5 wt% or more, or 9 wt% or more of aromatic vinyl-based monomer units, and 20 wt% or less, 19 wt% or less, 18 wt% or less, 17 wt% or less, 16 wt% or less, or 15 wt% or less. Within these ranges, the resin composition has excellent transparency, excellent compatibility between the graft copolymer and the styrene-based copolymer, and excellent mechanical properties.

[0064] According to one embodiment of the present invention, the styrene-based copolymer may contain 1 wt% to 20 wt% of maleimide-based monomer units. Specific examples of the styrene-based copolymer include 1 wt% or more, 2 wt% or more, 3 wt% or more, 4 wt% or more, 5 wt% or more, 6 wt% or more, 7 wt% or more, or 7.5 wt% or more of maleimide-based monomer units, and 20 wt% or less, 19 wt% or less, 18 wt% or less, 17 wt% or less, or 15 wt% or less. Within these ranges, the resin composition exhibits excellent heat resistance and transparency, excellent compatibility between the graft copolymer and the styrene-based copolymer, and excellent mechanical properties.

[0065] According to one embodiment of the present invention, the styrene-based copolymer may contain 0 wt% to 5 wt% of vinylcyan-based monomer units. Specifically, the styrene-based copolymer may contain 0.0 wt% or more, 0.1 wt% or more, 0.5 wt% or more, 1 wt% or more, 1.5 wt% or more, or 2.0 wt% or more of vinylcyan-based monomer units, or 5.0 wt% or less, 4.5 wt% or less, 4.0 wt% or less, 3.5 wt% or less, or 3.0 wt% or less. Within this range, the resin composition exhibits excellent transparency and color, minimizes the content of coagulated materials due to decreased latex stability, and exhibits excellent compatibility between the graft copolymer and the styrene-based copolymer, resulting in excellent mechanical properties.

[0066] According to one embodiment of the present invention, the resin composition may contain 10% by weight or more and 40% by weight or less of the graft copolymer and 60% by weight or more and 90% by weight or less of the styrene copolymer. Specific examples of the resin composition include 10% by weight or more, 15% by weight or more, 20% by weight or more, 25% by weight or more, or 30% by weight or more of the graft copolymer, and 40% by weight or less, 35% by weight or less, or 30% by weight or less of the styrene copolymer, with the remainder being the remainder of the components other than the graft copolymer.

[0067] According to one embodiment of the present invention, the resin composition may contain, based on the total content of the graft copolymer and the styrene copolymer, 10% to 40% by weight of a conjugated diene polymer, 40% to 75% by weight of alkyl (meth)acrylate monomer units, 5% to 15% by weight of maleimide monomer units, 5% to 15% by weight of aromatic vinyl monomer units, and 0% to 5% by weight of vinyl cyanide monomer units. When the graft copolymer and the styrene copolymer are mixed and kneaded in the resin composition, it is difficult to distinguish them individually, even if the graft copolymer and the styrene copolymer each contain monomer units formed from the same type of monomer. The content of the conjugated diene polymer and each monomer unit refers to the content of the polymer and monomer unit in the resin composition including the graft copolymer and the styrene copolymer, not the content of the polymer and monomer unit in the graft copolymer and the styrene copolymer.

[0068] According to one embodiment of the present invention, the resin composition may contain 10% to 40% by weight of the conjugated diene polymer. Specific examples of the resin composition include 10% by weight or more, 11% by weight or more, 12% by weight or more, 13% by weight or more, 14% by weight or more, or 15% by weight or more of the conjugated diene polymer, and 40% by weight or less, 35% by weight or less, 30% by weight or less, 25% by weight or less, or 20% by weight or less. Within these ranges, the resin composition has sufficient impact strength and mechanical properties, and exhibits excellent transparency and processability.

[0069] According to one embodiment of the present invention, the resin composition may contain 40% to 75% by weight of alkyl (meth)acrylate monomer units. Specifically, the graft copolymer may contain 40% by weight or more, 45% by weight or more, 50% by weight or more, 55% by weight or more, or 60% by weight or more of alkyl (meth)acrylate monomer units, or 75% by weight or less, 70% by weight or less, or 65% by weight or less. Within these ranges, the transparency and mechanical properties of the resin composition are more excellent.

[0070] According to one embodiment of the present invention, the resin composition may contain 5 wt% to 15 wt% of maleimide-based monomer units. Specific examples include 5 wt% or more, 6 wt% or more, 7 wt% or more, 8 wt% or more, or 9 wt% or more of maleimide-based monomer units, and 15 wt% or less, 14 wt% or less, 13 wt% or less, 12 wt% or less, 11 wt% or less, or 10 wt% or less of maleimide-based monomer units. When the content is within this range, the resin composition has excellent heat resistance and transparency.

[0071] According to one embodiment of the present invention, the resin composition may contain 5 wt% to 15 wt% of aromatic vinyl-based monomer units. Specific examples of the resin composition include 5 wt% or more, 6 wt% or more, 7 wt% or more, 8 wt% or more, or 9 wt% or more of aromatic vinyl-based monomer units, and 15 wt% or less, 14 wt% or less, 13 wt% or less, 12 wt% or less, 11 wt% or less, or 10 wt% or less. Within these ranges, the resin composition has excellent transparency and mechanical properties.

[0072] According to one embodiment of the present invention, the resin composition may contain 0 to 5 wt% of vinylcyan-based monomer units. Specifically, the graft copolymer may contain 0.0 wt% or more, 0.1 wt% or more, 0.5 wt% or more, 1 wt% or more, 1.5 wt% or more, or 2.0 wt% or more of vinylcyan-based monomer units, or 5.0 wt% or less, 4.5 wt% or less, 4.0 wt% or less, 3.5 wt% or less, 3.0 wt% or less, or 2.5 wt% or less. Within these ranges, the resin composition exhibits excellent transparency and color.

[0073] According to one embodiment of the present invention, the resin composition may have a notched Izod impact strength, measured at room temperature (23°C) using a ¼-inch thick test specimen with a notch according to ASTM D256, of 5.0 kgf·cm / cm or more, 5.5 kgf·cm / cm or more, 6.0 kgf·cm / cm or more, 6.5 kgf·cm / cm or more, 7.0 kgf·cm / cm or more, 7.5 kgf·cm / cm or more, 8.0 kgf·cm / cm or more, or 8.5 kgf·cm / cm or more, and may have a notched Izod impact strength of 20.0 kgf·cm / cm or less, 18.0 kgf·cm / cm or less, or 15.0 kgf·cm / cm or less.

[0074] According to one embodiment of the present invention, the resin composition may have a heat distortion temperature of 90.0°C or higher, as measured under a stress of 18.6 kgf using a 6.4 mm thick test piece according to ASTM D648. Specific examples of the resin composition may have a heat distortion temperature of 90.0°C or higher, 91.0°C or higher, 92.0°C or higher, 93.0°C or higher, 94.0°C or higher, 95.0°C or higher, 95.7°C or higher, 96.0°C or higher, 97.0°C or higher, 98.0°C or higher, 99.0°C or higher, or 100.0°C or higher, or may have a heat distortion temperature of 110.0°C or lower, 108.0°C or lower, or 105.0°C or lower.

[0075] According to one embodiment of the present invention, the resin composition may have a Vicat softening temperature of 100.0°C or higher, as measured by ASTM D1525. As a specific example, the resin composition may have a Vicat softening temperature of 100.0°C or higher, 101.0°C or higher, 102.0°C or higher, 103.0°C or higher, 104.0°C or higher, 105.0°C or higher, 106.0°C or higher, 106.3°C or higher, 107.0°C or higher, 108.0°C or higher, 109.0°C or higher, or 110.0°C or higher, or may have a Vicat softening temperature of 120.0°C or lower, 118.0°C or lower, or 115.0°C or lower.

[0076] According to one embodiment of the present invention, the resin composition may have a haze change of 5.0 or less, as calculated by measuring the haze of a 3 mm thick test piece according to ASTM D1003, storing the test piece in a low-temperature chamber at -40°C for 12 hours, and then measuring the haze again using the following Equation 4: Specific examples of the resin composition may have a haze change of 5.0 or less, 4.5 or less, 4.0 or less, 3.5 or less, 3.0 or less, 2.5 or less, 2.0 or less, 1.9 or less, 1.8 or less, 1.7 or less, 1.6 or less, or 1.5 or less, or may be 0.0 or 0.1 or more.

[0077] [Formula 4] △Haze = (haze of test piece after low-temperature storage) - (haze of test piece before low-temperature storage)

[0078] Although the present invention may be embodied in various different forms, it is not intended to be limited to the embodiments set forth herein, and the present invention is not limited to the embodiments set forth herein.

[0079] Manufacturing example Production Example 1: Production of Graft Copolymer A A nitrogen-purged polymerization reactor was charged with 50 parts by weight (solids) of a conjugated diene polymer latex (emulsion polymerization, gel content 70% by weight, average particle size of conjugated diene polymer particles 330 nm), 100 parts by weight of ion-exchanged water, 1.0 part by weight of sodium oleate as an emulsifier, 37 parts by weight of methyl methacrylate, 2 parts by weight of N-phenylmaleimide, 11 parts by weight of styrene, 0.1 parts by weight of n-octyl mercaptan, 0.03 parts by weight of ethylenediaminetetraacetic acid, 0.1 parts by weight of sodium formaldehyde sulfoxylate, 0.0015 parts by weight of ferrous sulfide, and 0.2 parts by weight of t-butyl hydroperoxide, and the polymerization reaction was carried out continuously at 65°C for 3 hours. The internal temperature of the reactor was then raised to 70°C, and the reactor was aged for 1 hour and 30 minutes before the reaction was terminated to produce a graft copolymer latex containing the graft copolymer. The graft copolymer latex was then coagulated with an aqueous sulfuric acid solution, washed, dehydrated, and dried to obtain powdery graft copolymer A. The refractive index of the obtained graft copolymer A was 1.518, the weight-average molecular weight was 105,000 g / mol, the PDI was 2.1, the graft rate was 67%, and the coagulum content was 0.3 wt%.

[0080] Production Example 2: Production of Graft Copolymer B A polymerization reactor purged with nitrogen was continuously charged with 50 parts by weight (solids) of a conjugated diene polymer latex (emulsion polymerization, gel content 70% by weight, average particle size of conjugated diene polymer particles 330 nm), 100 parts by weight of ion-exchanged water, 1.0 part by weight of sodium oleate as an emulsifier, 36 parts by weight of methyl methacrylate, 2 parts by weight of N-phenylmaleimide, 10 parts by weight of styrene, 2 parts by weight of acrylonitrile, 0.1 parts by weight of n-octyl mercaptan, 0.03 parts by weight of ethylenediaminetetraacetic acid, 0.1 parts by weight of sodium formaldehyde sulfoxylate, 0.0015 parts by weight of ferrous sulfide, and 0.2 parts by weight of t-butyl hydroperoxide at 65°C for 3 hours, and the polymerization reaction was carried out. The internal temperature of the reactor was then raised to 70°C, and the reaction was terminated after aging for 1 hour and 30 minutes, producing a graft copolymer latex containing a graft copolymer. The graft copolymer latex was then coagulated with an aqueous sulfuric acid solution, washed, dehydrated, and dried to obtain powdery graft copolymer B. The refractive index of the obtained graft copolymer B was 1.518, the weight-average molecular weight was 114,000 g / mol, the PDI was 2.3, the graft rate was 69%, and the coagulum content was 0.3 wt%.

[0081] Production Example 3: Production of Graft Copolymer C A nitrogen-purged polymerization reactor was charged with 50 parts by weight (solids) of a conjugated diene polymer latex (emulsion polymerization, gel content 70% by weight, average particle size of conjugated diene polymer particles 330 nm), 100 parts by weight of ion-exchanged water, 1.0 part by weight of sodium oleate as an emulsifier, 37 parts by weight of methyl methacrylate, 1 part by weight of N-phenylmaleimide, 12 parts by weight of styrene, 0.1 parts by weight of n-octyl mercaptan, 0.03 parts by weight of ethylenediaminetetraacetic acid, 0.1 parts by weight of sodium formaldehyde sulfoxylate, 0.0015 parts by weight of ferrous sulfide, and 0.2 parts by weight of t-butyl hydroperoxide, and the polymerization reaction was carried out continuously at 65°C for 3 hours. The internal temperature of the reactor was then raised to 70°C, and the reaction was terminated after aging for 1 hour and 30 minutes to produce a graft copolymer latex containing a graft copolymer. The graft copolymer latex was then coagulated with an aqueous sulfuric acid solution, washed, dehydrated, and dried to obtain powdered graft copolymer C. The refractive index of the obtained graft copolymer C was 1.518, the weight-average molecular weight was 109,000 g / mol, the PDI was 2.2, the graft rate was 55%, and the coagulum content was 0.3 wt%.

[0082] Production Example 4: Production of Graft Copolymer D A nitrogen-purged polymerization reactor was charged with 50 parts by weight (solids) of a conjugated diene polymer latex (emulsion polymerization, gel content 70% by weight, average particle size of conjugated diene polymer particles 300 nm), 100 parts by weight of ion-exchanged water, 1.0 part by weight of sodium oleate as an emulsifier, 34 parts by weight of methyl methacrylate, 0.5 parts by weight of N-phenylmaleimide, 11.5 parts by weight of styrene, 4 parts by weight of acrylonitrile, 0.1 parts by weight of n-octyl mercaptan, 0.03 parts by weight of ethylenediaminetetraacetic acid, 0.1 parts by weight of sodium formaldehyde sulfoxylate, 0.0015 parts by weight of ferrous sulfide, and 0.2 parts by weight of t-butyl hydroperoxide at 65°C for 3 hours, and the polymerization reaction was carried out. The internal temperature of the reactor was then raised to 70°C, and the reactor was aged for 1 hour and 30 minutes, after which the reaction was terminated to produce a graft copolymer latex containing the graft copolymer. The graft copolymer latex was then coagulated with an aqueous sulfuric acid solution, washed, dehydrated, and dried to obtain powdery graft copolymer D. The refractive index of the obtained graft copolymer D was 1.518, the weight-average molecular weight was 102,000 g / mol, the PDI was 2.3, the graft rate was 50%, and the coagulum content was 0.1 wt%.

[0083] Production Example 5: Production of Graft Copolymer E A nitrogen-purged polymerization reactor was charged with 50 parts by weight (solids) of a conjugated diene polymer latex (emulsion polymerization, gel content 70% by weight, average particle size of conjugated diene polymer particles 300 nm), 100 parts by weight of ion-exchanged water, 1.0 part by weight of sodium oleate as an emulsifier, 34 parts by weight of methyl methacrylate, 12 parts by weight of styrene, 4 parts by weight of acrylonitrile, 0.4 parts by weight of t-dodecyl mercaptan, 0.03 parts by weight of ethylenediaminetetraacetic acid, 0.1 part by weight of sodium formaldehyde sulfoxylate, 0.0015 parts by weight of ferrous sulfide, and 0.2 parts by weight of t-butyl hydroperoxide, and the polymerization reaction was carried out continuously at 65°C for 3 hours. The internal temperature of the reactor was then raised to 70°C, and the reactor was aged for 1 hour and 30 minutes before the reaction was terminated to produce a graft copolymer latex containing the graft copolymer. The graft copolymer latex was then coagulated with an aqueous sulfuric acid solution, washed, dehydrated, and dried to obtain powdery graft copolymer E. The refractive index of the obtained graft copolymer E was 1.518, the weight-average molecular weight was 102,000 g / mol, the PDI was 3.3, the graft rate was 38%, and the coagulum content was 0.2 wt%.

[0084] Production Example 6: Production of styrene copolymer A A polymerization reactor equipped with a stirrer was charged with 75 parts by weight of methyl methacrylate, 9 parts by weight of styrene, 3 parts by weight of acrylonitrile, 3 parts by weight of N-phenylmaleimide, 64 parts by weight of ion-exchanged water, 0.02 parts by weight of 1,1-di(t-butylperoxy)cyclohexane, 0.02 parts by weight of dicumyl peroxide, and 1.3 parts by weight of tricalcium phosphate. The reactor stirring speed was set to 500 rpm, and the reactor temperature was raised to 90°C to initiate polymerization. Next, 86 parts by weight of ion-exchanged water was continuously added to the reactor at a constant rate from when the polymerization conversion rate reached 5% until the polymerization conversion rate reached 60%. Furthermore, polymerization was carried out by continuously adding 10 parts by weight of N-phenylmaleimide to the reactor at a constant rate from when the polymerization conversion rate reached 5% until the polymerization conversion rate reached 70%. At this time, continuous addition of ion-exchanged water was carried out for 100 minutes, and continuous addition of N-phenylmaleimide was carried out for 150 minutes. After the continuous addition of ion-exchanged water and N-phenylmaleimide was completed, polymerization was carried out for 90 minutes while maintaining the temperature of the reactor at 90°C, polymerization was carried out while raising the temperature of the reactor to 120°C for 20 minutes, and polymerization was carried out for 100 minutes while maintaining the temperature of the reactor at 120°C, after which polymerization was terminated. Formic acid was added to the obtained polymerization slurry to adjust the acid value of the slurry to 2.5, and the dispersant was removed. The slurry was then washed with water, dehydrated, and dried to obtain bead-shaped styrene copolymer A.

[0085] Production Example 7: Production of styrene copolymer B A polymerization reactor equipped with a stirrer was charged with 79 parts by weight of methyl methacrylate, 4 parts by weight of styrene, 5 parts by weight of N-phenylmaleimide, 64 parts by weight of ion-exchanged water, 0.02 parts by weight of 1,1-di(t-butylperoxy)cyclohexane, 0.02 parts by weight of dicumyl peroxide, and 1.3 parts by weight of tricalcium phosphate. The reactor was set to agitation at 500 rpm, and the temperature of the reactor was raised to 90°C to initiate polymerization. Next, 86 parts by weight of ion-exchanged water was continuously added to the reactor at a constant rate from when the polymerization conversion reached 5% until the polymerization conversion reached 60%. Polymerization was also carried out by continuously adding 12 parts by weight of N-phenylmaleimide to the reactor at a constant rate from when the polymerization conversion reached 5% until the polymerization conversion reached 70%. The continuous addition of ion-exchanged water was carried out for 100 minutes, and the continuous addition of N-phenylmaleimide was carried out for 150 minutes. After the continuous addition of ion-exchanged water and N-phenylmaleimide was completed, polymerization was carried out for 90 minutes while maintaining the temperature of the reactor at 90°C, polymerization was carried out for 20 minutes while increasing the temperature of the reactor to 120°C, and polymerization was then carried out for 100 minutes while maintaining the temperature of the reactor at 120°C, after which polymerization was terminated. Formic acid was added to the obtained polymerized slurry to adjust the acid value of the slurry to 2.5, and the dispersant was removed. The slurry was then washed with water, dehydrated, and dried to obtain a bead-like styrene copolymer B.

[0086] Production Example 8: Production of styrene copolymer C A polymerization reactor equipped with a stirrer was charged with 75 parts by weight of methyl methacrylate, 17.5 parts by weight of styrene, 2 parts by weight of N-phenylmaleimide, 64 parts by weight of ion-exchanged water, 0.02 parts by weight of 1,1-di(t-butylperoxy)cyclohexane, 0.02 parts by weight of dicumyl peroxide, and 1.3 parts by weight of tricalcium phosphate. The reactor was set to agitation at 500 rpm, and the temperature of the reactor was raised to 90°C to initiate polymerization. Next, 86 parts by weight of ion-exchanged water was continuously added to the reactor at a constant rate from when the polymerization conversion reached 5% until the polymerization conversion reached 60%. Polymerization was also carried out by continuously adding 5.5 parts by weight of N-phenylmaleimide to the reactor at a constant rate from when the polymerization conversion reached 5% until the polymerization conversion reached 70%. At this time, continuous addition of ion-exchanged water was carried out for 100 minutes, and continuous addition of N-phenylmaleimide was carried out for 150 minutes. After the continuous addition of ion-exchanged water and N-phenylmaleimide was completed, polymerization was carried out for 90 minutes while maintaining the temperature of the reactor at 90°C, polymerization was carried out while raising the temperature of the reactor to 120°C for 20 minutes, and polymerization was carried out for 100 minutes while maintaining the temperature of the reactor at 120°C, after which polymerization was terminated. Formic acid was added to the obtained polymerization slurry to adjust the acid value of the slurry to 2.5, and the dispersant was removed. After that, the slurry was washed with water, dehydrated, and dried to obtain a bead-shaped styrene copolymer C.

[0087] Production Example 9: Production of styrene copolymer D A continuous polymerization reactor was charged with a mixture of 64 parts by weight of methyl methacrylate, 26 parts by weight of styrene, 7 parts by weight of acrylonitrile, 3 parts by weight of methacrylic acid, 30 parts by weight of ethylbenzene, and 0.15 parts by weight of t-dodecyl mercaptan, while the raw materials were continuously added to the reactor so that the average residence time was 3 hours. The temperature of the reactor was maintained at 148°C. The polymerization solution continuously discharged from the reactor was heated in a preheating tank, and unreacted monomers were evaporated in a volatilization tank. Then, pellets of styrene copolymer D were obtained using a polymer transfer pump extruder while maintaining the temperature of the polymerization solution at 210°C.

[0088] Examples and Comparative Examples Each component was blended in the amounts shown in Table 1 and extruded at a cylinder temperature of 250°C using a twin-screw extruder to produce a transparent resin composition in the form of pellets.

[0089] In this case, the content of each component is based on 100 parts by weight of the total of the graft copolymer and the styrene copolymer.

[0090] [Table 1]

[0091] Experimental Example Experimental Example 1 The refractive index, weight average molecular weight, molecular weight distribution, graft rate, and coagulated matter content of the graft copolymers A to E produced in Production Examples 1 to 5 were measured by the following methods, and the results are shown in Table 2 below.

[0092] *Refractive index: Calculated from the content of each component added during the preparation of each graft copolymer in the above Preparation Examples using the following Equation 1.

[0093] [Formula 1] Refractive index (RI) = ΣWti*RIi -Wti = weight fraction (%) of each component in the graft copolymer -RIi = refractive index of the homopolymer of each component of the graft copolymer

[0094] *Weight-average molecular weight and molecular weight distribution: Each graft copolymer powder prepared in the above Preparation Examples was added to acetone and stirred for 24 hours. After that, the rubber component that does not dissolve in acetone (insoluble fraction) was separated from the copolymer component that does dissolve in acetone (soluble fraction) using a centrifuge. The weight-average molecular weight, number-average molecular weight, and molecular weight distribution of the separated acetone-soluble fraction were measured by gel permeation chromatography (GPC). Two PLgel Olexis columns and one PLgel mixed-C column (both manufactured by Polymer Laboratories) were used. All newly replaced columns were mixed-bed columns, and polystyrene was used as the GPC standard material. -Solvent: Tetrahydrofuran (Stabilized with BHT) -Flow rate: 1.0ml / min -Sample concentration: 2.0mg / ml -Injection volume: 100μl -Column temperature: 30℃ -Detector: Waters 2414 Refractive Index Detector -Data processing: Empower 3

[0095] *Graft rate (%): A certain amount of the dried copolymer powder prepared in each of the above Preparation Examples was added to acetone and shaken for 24 hours in a shaker (product name: SI-600R, manufacturer: Lab.companion) to dissolve the released graft copolymer. The solution was centrifuged at 14,000 rpm in a centrifuge for 1 hour and dried in a vacuum dryer (product name: DRV320DB, manufacturer: ADVANTEC) at 140°C for 2 hours to obtain an insoluble fraction, which was then calculated using the following formula 2.

[0096] [Formula 2] Grafting rate (%) = [(Y-(X*R)) / (X*R)]*100 Y: Weight of insoluble matter X: Weight of the graft copolymer added when the insoluble matter was obtained R: Fraction of conjugated diene polymer in the graft copolymer added when the insoluble fraction was obtained

[0097] *Coagulated matter content (wt%): Each graft copolymer latex prepared in the above Preparation Examples was passed through a 100 mesh screen, and the material that did not pass through the screen was dried in a hot air dryer at 80°C for 6 hours, and the weight of the solid coagulated matter was measured and calculated using the following Equation 3.

[0098] [Formula 3] Coagulated content (wt%) = [weight (g) of dried coagulated material separated by a mesh structure / weight (g) of total rubber and monomers used in polymerization] x 100

[0099] [Table 2]

[0100] Experimental Example 2 The pellets produced in Examples 1 to 6 and Comparative Examples 1 to 4 were injected into an injector at an injection temperature of 210°C to produce test pieces, and the impact strength, heat distortion temperature, Vicat softening temperature, and low-temperature whitening were measured by the following methods. The results are shown in Table 3 below.

[0101] *Impact strength (kgf·cm / cm): Following the ASTM D256 method, a notch was made in a 1 / 4 inch thick test piece, and the notched Izod impact strength was measured at room temperature (23°C) using an impact strength tester (Tinius Olsen).

[0102] *Heat distortion temperature (HDT, °C): Measured according to ASTM D648 method using a 6.4 mm thick test piece under a stress of 18.6 kgf.

[0103] *Vicat softening temperature (℃): Measured according to ASTM D1525 method using a test piece 10 mm wide and 3.2 mm thick under the conditions of a load of 50 N, maximum penetration of 1.0 mm, and 50℃ / hr.

[0104] *Low temperature whitening (ΔHaze): Haze of a 3 mm thick test piece was measured using a haze meter HZ-V3 according to ASTM D1003. The test piece was then stored in a low temperature chamber at -40°C for 12 hours, after which the haze was measured again, and the change in haze was calculated using the following equation 4.

[0105] [Formula 4] △Haze = (haze of test piece after low-temperature storage) - (haze of test piece before low-temperature storage)

[0106] [Table 3]

[0107] As shown in Table 3, the resin compositions of Examples 1 to 6 according to the present invention have a molecular weight distribution of 2.5 or less, a high graft ratio, and contain a graft copolymer containing maleimide-based monomer units, which results in excellent compatibility between the graft copolymer and the styrene-based copolymer matrix resin. As a result, it was confirmed that the resin compositions have excellent impact strength, heat resistance, and low-temperature whitening resistance.

[0108] In contrast, the resin compositions of Comparative Examples 1 to 3 were found to have extremely poor heat resistance, even though they contained the same graft copolymer as Examples 1 to 3, because the styrene copolymer matrix resin did not contain maleimide monomer units.

[0109] Moreover, it was confirmed that the resin composition of Comparative Example 4 was inferior in heat resistance and low-temperature whitening resistance because neither the graft copolymer nor the styrene copolymer contained maleimide monomer units.

Claims

1. including graft copolymers and styrene-based copolymers, the graft copolymer contains a conjugated diene polymer, an alkyl (meth)acrylate monomer unit, and an aromatic vinyl monomer unit; The styrene copolymer comprises an alkyl(meth)acrylate monomer unit, an aromatic vinyl monomer unit, and a maleimide monomer unit.

2. The resin composition according to claim 1 , wherein the graft copolymer has a refractive index of 1.515 or more and 1.520 or less.

3. The resin composition according to claim 1 , wherein the graft copolymer has a weight average molecular weight of 90,000 g / mol or more and 130,000 g / mol or less.

4. The resin composition according to claim 1 , wherein the graft copolymer has a molecular weight distribution of 2.7 or less.

5. The resin composition according to claim 1 , wherein the graft copolymer has a graft ratio of 44% or more.

6. The graft copolymer is 20% by weight to 70% by weight of a conjugated diene polymer, 25% by weight to 55% by weight of alkyl (meth)acrylate monomer units, 1% to 15% by weight of aromatic vinyl monomer units, and The resin composition according to claim 1, comprising 0 to 5% by weight of a vinylcyan-based monomer unit.

7. The resin composition according to claim 1 , wherein the graft copolymer contains a maleimide-based monomer unit.

8. The graft copolymer is 20% by weight to 70% by weight of a conjugated diene polymer, 25% by weight to 55% by weight of alkyl (meth)acrylate monomer units, 0.1% by weight to 3% by weight of maleimide-based monomer units, 1% to 15% by weight of aromatic vinyl monomer units, and The resin composition according to claim 7, comprising 0 to 5% by weight of a vinylcyan-based monomer unit.

9. The styrene copolymer is 50% by weight to 90% by weight of alkyl (meth)acrylate monomer units, 1% by weight to 20% by weight of aromatic vinyl monomer units, 1% to 20% by weight of maleimide-based monomer units, and The resin composition according to claim 1, comprising 0 to 5% by weight of a vinylcyan-based monomer unit.

10. The resin composition contains, based on the total content of the graft copolymer and the styrene-based copolymer, 10% by weight to 40% by weight of a conjugated diene polymer, 40% by weight to 75% by weight of alkyl (meth)acrylate monomer units, 5% by weight to 15% by weight of maleimide-based monomer units, 5% to 15% by weight of aromatic vinyl monomer units, and The resin composition according to claim 1, comprising 0 to 5% by weight of a vinylcyan-based monomer unit.

11. The resin composition according to claim 1, wherein the resin composition has a heat distortion temperature of 90.0°C or higher when measured under a stress of 18.6 kgf using a test piece having a thickness of 6.4 mm according to ASTM D648 method.

12. 2. The resin composition according to claim 1, wherein the haze of a 3 mm thick test piece is measured according to ASTM D1003, the test piece is stored in a low-temperature chamber at −40° C. for 12 hours, and the haze is further measured. The haze change calculated according to the following Equation 4 is 2.0 or less. [Formula 4] ΔHaze = (haze of test piece after low-temperature storage) - (haze of test piece before low-temperature storage)

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