Patent Description:
To use automobile exterior materials without painting, properties that can satisfy automobile reliability evaluation together with the excellent appearance quality of an injection-molded product are required. In particular, for application to radiator grills, resin flowability, and high level of heat resistance and impact strength are required to enable injection-molding of large products, and multi-axial impact strength characteristics related to major reliability evaluation are required. For this, it is necessary to mix an MMA-based resin for realizing deep black with a heat-resistant resin for realizing heat resistance. However, it is difficult to achieve the desired exterior quality of an injection-molded product and the uniform physical properties therein because the compatibility between the two resins is not good. When two resins with poor compatibility are mixed, goniochromism occurs and the deviation in properties increases. In particular, there is a problem in that the standard deviation value of multi-axial impact strength, which is a major reliability evaluation item for automobiles, increases.

Therefore, there is a need for the development of a thermoplastic resin composition that is capable of realizing deep black and injection-molding a large product while having heat resistance and impact resistance and improving the appearance quality of an injection-molded product.

<CIT> discloses a thermoplastic resin composition, comprising: <NUM> weight percent of a first graft copolymer which is formed by graft polymerization of a butyl acrylate rubber polymer having an average particle diameter of <NUM> with styrene and acrylonitrile; <NUM> weight percent of a second graft copolymer which is formed by graft polymerization of a butyl acrylate rubber polymer having an average particle diameter of <NUM> with styrene and acrylonitrile; <NUM> weight percent of a first styrene-based copolymer which comprises α-methyl styrene, acrylonitrile, and methyl methacrylate; and <NUM> weight percent of poly(methyl methacrylate) as a (meth)acrylic polymer.

<CIT> discloses a thermoplastic resin composition including an additive such as a lubricant, a heat stabilizer, or an ultraviolet stabilizer.

Therefore, the present invention has been made in view of the above problems, and it is one object of the present invention to provide a thermoplastic resin composition that has excellent impact resistance, heat resistance and fluidity, specifically can be used to injection-mold large products due to high average multi-axial impact strength and a low standard deviation of the multi-axial impact strength and can suppress the occurrence of goniochromism while realizing deep black to satisfy the appearance quality of an injection-molded product and automobile reliability evaluation; a method of preparing the thermoplastic resin composition; and a molded article manufactured using the same.

In accordance with an aspect of the present invention, the above and other objects can be accomplished by the provision of a thermoplastic resin composition, including: <NUM> to <NUM> % by weight of a graft copolymer (A-<NUM>) including an acrylate-based rubber having an average particle diameter of <NUM> to <NUM>, an aromatic vinyl compound, and a vinyl cyanide compound; <NUM> to <NUM> % by weight of a graft copolymer (A-<NUM>) including an acrylate-based rubber having an average particle diameter of <NUM> to <NUM>, an aromatic vinyl compound, and a vinyl cyanide compound; <NUM> to <NUM> % by weight of a copolymer (B) including a (meth)acrylic acid alkyl ester compound, an α-methyl styrene-based compound, and a vinyl cyanide compound, wherein the copolymer (B) comprises <NUM> to <NUM> % by weight of the (meth) acrylic acid alkyl ester compound, <NUM> to <NUM> % by weight of the α-methyl styrene-based compound, and <NUM> to <NUM> % by weight of the vinyl cyanide compound; and <NUM> to <NUM> % by weight of a polymethacrylate resin (C) (not containing α-methyl styrene), wherein the polymethacrylate resin (C) (not containing α-methyl styrene) is a methyl methacrylate-styrene-acrylonitrile copolymer, or a mixture of a methyl methacrylate-styrene-acrylonitrile copolymer and a polymethyl methacrylate resin; wherein the average multi-axial impact strength, which is obtained by measuring a maximum load energy <NUM> times at a speed of <NUM>/s according to ISO <NUM>-<NUM>, of a specimen having a thickness of <NUM> is <NUM> J/mm or more, and a standard deviation thereof is <NUM> or less.

In accordance with another aspect of the present invention, there is provided a thermoplastic resin composition, including: <NUM> to <NUM> % by weight of a graft copolymer (A-<NUM>) including an acrylate-based rubber having an average particle diameter of <NUM> to <NUM>, an aromatic vinyl compound, and a vinyl cyanide compound; <NUM> to <NUM> % by weight of a graft copolymer (A-<NUM>) including an acrylate-based rubber having an average particle diameter of <NUM> to <NUM>, an aromatic vinyl compound, and a vinyl cyanide compound; <NUM> to <NUM> % by weight of a copolymer (B) including a (meth)acrylic acid alkyl ester compound, an α-methyl styrene-based compound, and a vinyl cyanide compound, wherein the copolymer (B) comprises <NUM> to <NUM> % by weight of the (meth)acrylic acid alkyl ester compound, <NUM> to <NUM> % by weight of the α-methyl styrene-based compound, and <NUM> to <NUM> % by weight of the vinyl cyanide compound; and <NUM> to <NUM> % by weight of a polymethacrylate resin (C) (not containing α-methyl styrene), wherein the polymethacrylate resin (C) (not containing α-methyl styrene) is a methyl methacrylate-styrene-acrylonitrile copolymer, or a mixture of a methyl methacrylate-styrene-acrylonitrile copolymer and a polymethyl methacrylate resin, wherein the average multi-axial impact strength, which is obtained by measuring a maximum load energy <NUM> times at a speed of <NUM>/s according to ISO <NUM>-<NUM>, of a specimen having a thickness of <NUM> is <NUM> J/mm or more, a standard deviation thereof is <NUM> or less.

In accordance with still another aspect of the present invention, there is provided a thermoplastic resin composition, including: <NUM> to <NUM> % by weight of a graft copolymer (A-<NUM>) including an acrylate-based rubber having an average particle diameter of <NUM> to <NUM>, an aromatic vinyl compound, and a vinyl cyanide compound; <NUM> to <NUM> % by weight of a graft copolymer (A-<NUM>) including an acrylate-based rubber having an average particle diameter of <NUM> to <NUM>, an aromatic vinyl compound, and a vinyl cyanide compound; <NUM> to <NUM> % by weight of a copolymer (B) including a (meth)acrylic acid alkyl ester compound, an α-methyl styrene-based compound, and a vinyl cyanide compound, wherein the copolymer (B) comprises <NUM> to <NUM> % by weight of the (meth)acrylic acid alkyl ester compound, <NUM> to <NUM> % by weight of the α-methyl styrene-based compound, and <NUM> to <NUM> % by weight of the vinyl cyanide compound; and <NUM> to <NUM> % by weight of a polymethacrylate resin (C) (not containing α-methyl styrene), wherein the polymethacrylate resin (C) (not containing α-methyl styrene) is a methyl methacrylate-styrene-acrylonitrile copolymer, or a mixture of a methyl methacrylate-styrene-acrylonitrile copolymer and a polymethyl methacrylate resin, wherein the average multi-axial impact strength, which is obtained by measuring a maximum load energy <NUM> times at a speed of <NUM>/s according to ISO <NUM>-<NUM>, of a specimen having a thickness of <NUM> is <NUM> J/mm or more, a standard deviation thereof is <NUM> or less, and the polymethacrylate resin (C) (not containing α-methyl styrene) includes <NUM> % by weight or more of a methacrylate monomer.

In accordance with still another aspect of the present invention, there is provided a method of preparing a thermoplastic resin composition according to the invention, the method including: a step of mixing <NUM> to <NUM> % by weight of a graft copolymer (A-<NUM>) including an acrylate-based rubber having an average particle diameter of <NUM> to <NUM>, an aromatic vinyl compound, and a vinyl cyanide compound, <NUM> to <NUM> % by weight of a graft copolymer (A-<NUM>) including an acrylate-based rubber having an average particle diameter of <NUM> to <NUM>, an aromatic vinyl compound, and a vinyl cyanide compound, <NUM> to <NUM> % by weight of a copolymer (B) including a (meth)acrylic acid alkyl ester compound, an α-methyl styrene-based compound, and a vinyl cyanide compound, and <NUM> to <NUM> % by weight of a polymethacrylate resin (C) (not containing α-methyl styrene), and then preparing a thermoplastic resin composition at <NUM> to <NUM> using an extrusion kneader with a size of <NUM> to <NUM> pi, wherein the average multi-axial impact strength, which is obtained by measuring a maximum load energy <NUM> times using a specimen having a thickness of <NUM> at a speed of <NUM>/s according to ISO <NUM>-<NUM>, of the prepared thermoplastic resin composition is <NUM> J/mm or more, and a standard deviation of the average multi-axial impact strength is <NUM> or less.

In accordance with still another aspect of the present invention, there is provided a method of preparing a thermoplastic resin composition according to the invention, the method including: a step of mixing <NUM> to <NUM> % by weight of a graft copolymer (A-<NUM>) including an acrylate-based rubber having an average particle diameter of <NUM> to <NUM>, an aromatic vinyl compound, and a vinyl cyanide compound, <NUM> to <NUM> % by weight of a graft copolymer (A-<NUM>) including an acrylate-based rubber having an average particle diameter of <NUM> to <NUM>, an aromatic vinyl compound, and a vinyl cyanide compound, <NUM> to <NUM> % by weight of a copolymer (B) including a (meth) acrylic acid alkyl ester compound, an α-methyl styrene-based compound, and a vinyl cyanide compound, and <NUM> to <NUM> % by weight of a polymethacrylate resin (C) (not containing α-methyl styrene), and then preparing a thermoplastic resin composition at <NUM> to <NUM> using an extrusion kneader with a size of <NUM> to <NUM> pi, wherein an average multi-axial impact strength, which is obtained by measuring a maximum load energy <NUM> times using a specimen having a thickness of <NUM> at a speed of <NUM>/s according to ISO <NUM>-<NUM>, of the prepared thermoplastic resin composition is <NUM> J/mm or more, a standard deviation of the average multi-axial impact strength is <NUM> or less, and the copolymer (B) includes <NUM> to <NUM> % by weight of a (meth)acrylic acid alkyl ester compound, <NUM> to <NUM> % by weight of an α-methyl styrene-based compound, and <NUM> to <NUM> % by weight of a vinyl cyanide compound.

In accordance with still another aspect of the present invention, there is provided a method of preparing a thermoplastic resin composition according to the invention, the method including: a step of mixing <NUM> to <NUM> % by weight of a graft copolymer (A-<NUM>) including an acrylate-based rubber having an average particle diameter of <NUM> to <NUM>, an aromatic vinyl compound, and a vinyl cyanide compound, <NUM> to <NUM> % by weight of a graft copolymer (A-<NUM>) including an acrylate-based rubber having an average particle diameter of <NUM> to <NUM>, an aromatic vinyl compound, and a vinyl cyanide compound, <NUM> to <NUM> % by weight of a copolymer (B) including a (meth) acrylic acid alkyl ester compound, an α-methyl styrene-based compound, and a vinyl cyanide compound, and <NUM> to <NUM> % by weight of a polymethacrylate resin (C) (not containing α-methyl styrene), and then preparing a thermoplastic resin composition at <NUM> to <NUM> using an extrusion kneader with a size of <NUM> to <NUM> pi, wherein an average multi-axial impact strength, which is obtained by measuring a maximum load energy <NUM> times using a specimen having a thickness of <NUM> at a speed of <NUM>/s according to ISO <NUM>-<NUM>, of the prepared thermoplastic resin composition is <NUM> J/mm or more, a standard deviation of the average multi-axial impact strength is <NUM> or less, and the polymethacrylate resin (C) (not containing α-methyl styrene) includes <NUM> % by weight or more of a methacrylate monomer.

In accordance with yet another aspect of the present invention, there is provided a molded article including the thermoplastic resin composition.

As apparent from the above description, the present invention provides a thermoplastic resin composition that has excellent impact resistance, heat resistance and fluidity, specifically can be used to injection-mold large products due to high average multi-axial impact strength and a low standard deviation of the multi-axial impact strength and can suppress the occurrence of goniochromism while realizing deep black to satisfy the appearance quality of an injection-molded product and automobile reliability evaluation; a method of preparing the thermoplastic resin composition; and a molded article manufactured using the same.

Hereinafter, a thermoplastic resin composition of the present disclosure, a method of preparing the same, and a molded article manufactured using the same are described in detail.

The present inventors conducted studies to improve compatibility between a heat-resistant resin and an MMA-based resin. As a result, the present inventors confirmed that, when the contents of two kinds of ASA resins having different average particle diameters are adjected to predetermined contents and the contents of a copolymer, which includes a (meth)acrylic acid alkyl ester compound, an α-methyl styrene-based compound, and a vinyl cyanide compound, and a polymethacrylate resin (not containing α-methyl styrene) are adjusted to predetermined contents, goniochromism does not occur, deep black may be realized, multi-axial impact strength is increased, and a standard deviation of multi-axial impact strength is reduced. Based on these results, the present inventors conducted further studies to complete the present invention.

The thermoplastic resin composition of the present invention includes <NUM> to <NUM> % by weight of a graft copolymer (A-<NUM>) including an acrylate-based rubber having an average particle diameter of <NUM> to <NUM>, an aromatic vinyl compound, and a vinyl cyanide compound; <NUM> to <NUM> % by weight of a graft copolymer (A-<NUM>) including an acrylate-based rubber having an average particle diameter of <NUM> to <NUM>, an aromatic vinyl compound, and a vinyl cyanide compound; <NUM> to <NUM> % by weight of a copolymer (B) including a (meth)acrylic acid alkyl ester compound, an α-methyl styrene-based compound, and a vinyl cyanide compound, wherein the copolymer (B) comprises <NUM> to <NUM> % by weight of the (meth)acrylic acid alkyl ester compound, <NUM> to <NUM> % by weight of the α-methyl styrene-based compound, and <NUM> to <NUM> % by weight of the vinyl cyanide compound; and <NUM> to <NUM> % by weight of a polymethacrylate resin (C) (not containing α-methyl styrene), wherein the polymethacrylate resin (C) (not containing α-methyl styrene) is a methyl methacrylate-styrene-acrylonitrile copolymer, or a mixture of a methyl methacrylate-styrene-acrylonitrile copolymer and a polymethyl methacrylate resin, wherein the average multi-axial impact strength, which is obtained by measuring a maximum load energy <NUM> times at a speed of <NUM>/s according to ISO <NUM>-<NUM>, of a specimen having a thickness of <NUM> is <NUM> J/mm or more, and a standard deviation thereof is <NUM> or less. In this case, due to excellent impact resistance, heat resistance and fluidity, a large product can be injection-molded and deep black can be realized. Further, the occurrence of goniochromism is suppressed, thereby satisfying the appearance quality of an injection-molded product, and automobile reliability evaluation.

Hereinafter, each component of the thermoplastic resin composition of the present invention is described in detail.

The acrylate rubber of the graft copolymer may have, for example, average particle diameter of <NUM> to <NUM>, preferably <NUM> to <NUM>, more preferably <NUM> to <NUM>. Within these ranges, a finally produced thermoplastic resin composition may have excellent weather resistance, colorability, gloss, impact strength, and surface properties.

In this description, the average particle diameter may be measured by light scattering, and specifically, is measured as an intensity value using a particle size analyzer (trade name: Nicomp <NUM>, manufacturer: PSS) in a Gaussian mode. As a specific measurement example, a sample may be prepared by diluting <NUM> of latex (TSC: <NUM> to <NUM> wt%) <NUM>,<NUM> to <NUM>,<NUM>-fold with deionized water or distilled water, i.e., by appropriately diluting not to significantly deviate an intensity setpoint of <NUM>, and may be fed into a glass tube, and the average particle diameter may be measured using flow cells in an auto-dilution manner and in a mode of dynamic light scattering/intensity <NUM>/intensity-weight Gaussian analysis. At this time, temperature may be set to <NUM>, measurement wavelength may be set to <NUM>, and channel width may be set to <NUM>µsec.

The graft copolymer (A-<NUM>) is included in an amount of, <NUM> to <NUM> % by weight, preferably <NUM> to <NUM> % by weight, more preferably <NUM> to <NUM> % by weight. Within these ranges, impact resistance, heat resistance, and fluidity are excellent, specifically an average multi-axial impact strength is high and a standard deviation of the average multi-axial impact strength is reduced, thereby being capable of injection-molding a large product. Further, deep black can be realized, and the occurrence of goniochromism is suppressed, thereby satisfying the appearance quality of an injection-molded product, and automobile reliability evaluation.

In this disclosure, goniochromism refers to a phenomenon wherein a rainbow or pearlescent color appears on pellets or injection specimens due to poor compatibility between resins. When the phenomenon is expressed, the colorability of a dye or a pigment is lowered, so that the color of the exterior of an injection-molded product becomes non-uniform, and the blackness level (L) increases compared to coloring with pigment or dye, which makes it difficult to express deep black.

The graft copolymer (A-<NUM>) may include, for example, <NUM> to <NUM> % by weight of an acrylate-based rubber, <NUM> to <NUM> % by weight of an aromatic vinyl compound, and <NUM> to <NUM> % by weight of a vinyl cyanide compound. Within these ranges, impact resistance, multi-axial impact strength, and a standard deviation of the multi-axial impact strength are improved and the appearance quality of an injection-molded product are excellent.

As a preferred example, the graft copolymer (A-<NUM>) may include <NUM> to <NUM> % by weight of an acrylate-based rubber, <NUM> to <NUM> % by weight of an aromatic vinyl compound, and <NUM> to <NUM> % by weight of a vinyl cyanide compound. Within these ranges, multi-axial impact strength and a standard deviation thereof are improved, and the appearance quality of an injection-molded product is excellent.

In this disclosure, a polymer including a certain compound means a polymer prepared by polymerizing the compound, and a unit in the polymer is derived from the compound.

The graft copolymer (A-<NUM>) may be prepared, for example, by emulsion polymerization. In this case, impact resistance, chemical resistance, weather resistance, and colorability are excellent.

Emulsion graft polymerization methods commonly practiced in the art to which the present invention pertains may be used as the emulsion polymerization method of the present invention without particular limitation.

For example, the acrylate of the present invention may include one or more selected from the group consisting of alkyl acrylates containing an alkyl group having <NUM> to <NUM> carbon atoms, and is preferably an alkyl acrylate containing an alkyl group having <NUM> to <NUM> carbon atoms, more preferably butyl acrylate or ethylhexyl acrylate.

For example, the aromatic vinyl compound of the present invention may include one or more selected from the group consisting of styrene, α-methyl styrene, o-methyl styrene, ρ-methyl styrene, m-methyl styrene, ethyl styrene, isobutyl styrene, t-butyl styrene, o-bromo styrene, ρ-bromo styrene, m-bromo styrene, o-chlorostyrene, ρ-chlorostyrene, m-chlorostyrene, vinyltoluene, vinylxylene, fluorostyrene and vinylnaphthalene, and is preferably styrene.

For example, the vinyl cyanide compound of the present invention may include one or more selected from the group consisting of acrylonitrile, methacrylonitrile, ethylacrylonitrile, and isopropylacrylonitrile, and is preferably acrylonitrile.

The acrylate rubber of the graft copolymer may have an average particle diameter of, for example, <NUM> to <NUM>, preferably <NUM> to <NUM>, more preferably <NUM> to <NUM>. Within these ranges, a finally produced thermoplastic resin composition has excellent weather resistance, colorability, gloss, impact strength, and surface properties.

The graft copolymer (A-<NUM>) is included in an amount of <NUM> to <NUM> % by weight, preferably <NUM> to <NUM> % by weight, more preferably <NUM> to <NUM> % by weight. Within these ranges, impact resistance, heat resistance, and fluidity are excellent and, specifically, an average multi-axial impact strength is high and a standard deviation thereof is reduced, thereby being capable of injection-molding a large product, and suppressing the occurrence of goniochromism while realizing deep black. Accordingly, the appearance quality of an injection-molded product and automobile reliability evaluation are satisfied.

The graft copolymer (A-<NUM>) may include, for example, <NUM> to <NUM> % by weight of an acrylate-based rubber, <NUM> to <NUM> % by weight of an aromatic vinyl compound, and <NUM> to <NUM> % by weight of a vinyl cyanide compound. Within these ranges, deep black is excellently expressed, and a standard deviation of multi-axial impact strength is reduced, resulting in property stability.

As a preferred example, the graft copolymer (A-<NUM>) may include <NUM> to <NUM> % by weight of an acrylate-based rubber, <NUM> to <NUM> % by weight of an aromatic vinyl compound, and <NUM> to <NUM> % by weight of a vinyl cyanide compound. Within these ranges, deep black is excellently expressed, and a standard deviation of multi-axial impact strength is reduced, resulting in property stability.

The graft copolymer (A-<NUM>) may be prepared, for example, by emulsion polymerization. In this case, impact resistance, chemical resistance, weather resistance, and colorability are excellent.

Emulsion polymerization commonly practiced in the art to which the present invention pertains may be used in the present invention without particular limitation.

The graft copolymer (A-<NUM>) may be included, for example, in an amount the same or smaller than that of the graft copolymer (A-<NUM>). Preferably, a weight ratio between the graft copolymer (A-<NUM>) and the graft copolymer (A-<NUM>) may be <NUM> : <NUM> to <NUM> : <NUM>, more preferably <NUM> : <NUM> to <NUM>:<NUM>, even more preferably <NUM>: <NUM> to <NUM>: <NUM>, even more preferably <NUM>: <NUM> to <NUM>: <NUM>. Within these ranges, multi-axial impact strength and a standard deviation thereof are improved, so that a large injection- molded article can be manufactured, and deep black can be realized.

In this disclosure, the weight ratio of A to B refers to the weight ratio of A:B.

The copolymer (B) is included in an amount of <NUM> to <NUM> % by weight, preferably <NUM> to <NUM> % by weight, more preferably <NUM> to <NUM> % by weight, even more preferably <NUM> to <NUM> % by weight. Within these ranges, impact resistance, heat resistance, and fluidity are excellent, and specifically, an average multi-axial impact strength is excellent and a standard deviation of the average multi-axial impact strength is reduced, so that a large product can be injection-molded. In addition, the occurrence of goniochromism can be suppressed while realizing deep black, thereby satisfying the appearance quality of an injection-molded product and automobile reliability evaluation.

The copolymer (B) includes <NUM> to <NUM> % by weight of a (meth)acrylic acid alkyl ester compound, <NUM> to <NUM> % by weight of an α-methyl styrene-based compound, and <NUM> to <NUM> % by weight of a vinyl cyanide compound. Within these ranges, compatibility with a polymethacrylate resin (C) (not containing α-methyl styrene) described below is improved, so that goniochromism does not occur. Accordingly, the appearance quality of an injection-molded product is excellent.

The copolymer (B) may include preferably <NUM> to <NUM> % by weight of a (meth)acrylic acid alkyl ester compound, <NUM> to <NUM> % by weight of an α-methyl styrene-based compound, and <NUM> to <NUM> % by weight of a vinyl cyanide compound. Within these ranges, compatibility with the polymethacrylate resin (C) (not containing α-methyl styrene) described below is improved, so that goniochromism does not occur. Accordingly, the appearance of an injection-molded product is excellent.

The copolymer (B) may include more preferably <NUM> to <NUM> % by weight of a (meth)acrylic acid alkyl ester compound, <NUM> to <NUM> % by weight of an α-methyl styrene-based compound, and <NUM> to <NUM> % by weight of a vinyl cyanide compound. Within these ranges, compatibility with the polymethacrylate resin (C) (not containing α-methyl styrene) described below is improved, so that goniochromism does not occur. Accordingly, the appearance of an injection-molded product is excellent.

The weight-average molecular weight of the copolymer (B) may be, for example, <NUM>,<NUM> to <NUM>,<NUM>/mol, preferably <NUM>,<NUM> to <NUM>,<NUM>/mol, more preferably <NUM>,<NUM> to <NUM>,<NUM>/mol. Within these ranges, multi-axial impact strength is excellent, and injection moldability is secured.

In this description, unless otherwise defined, the weight average molecular weight may be measured using gel permeation chromatography (GPC, Waters Breeze). As a specific example, the weight average molecular weight may be measured using tetrahydrofuran (THF) as an eluate through gel permeation chromatography (GPC, Waters Breeze). In this case, weight average molecular weight is obtained as a relative value to a polystyrene standard (PS) specimen. As a specific measurement example, the weight average molecular weight may be measured under conditions of solvent: THF, column temperature: <NUM>, flow rate: <NUM>/min, sample concentration: <NUM>/ml, injection amount: <NUM>µl, column model: <NUM>× PLgel <NUM> MiniMix-B (<NUM> × <NUM>) + <NUM>× PLgel <NUM> MiniMix-B (<NUM> × <NUM>) + <NUM>× PLgel <NUM> MiniMix-B Guard (<NUM> × <NUM>), equipment name: Agilent <NUM> series system, refractive index detector: Agilent G1362 RID, RI temperature: <NUM>, data processing: Agilent ChemStation S/W, and test method (Mn, Mw and PDI): OECD TG <NUM>.

The (meth)acrylic acid alkyl ester polymer (B) may be, for example, one or more selected from the group consisting of (meth)acrylic acid methyl ester, (meth)acrylic acid ethyl ester, (meth)acrylic acid propyl ester, (meth)acrylic acid <NUM>-ethylhexylester, (meth)acrylic acid decyl ester and (meth)acrylic acid lauryl ester, preferably methyl methacrylate as a (meth)acrylic acid methyl ester.

For example, the α-methyl styrene compound may include one or more selected from the group consisting of α-methyl styrene and derivatives thereof. In this case, heat resistance may be excellent.

The derivatives of α-methyl styrene is preferably compounds in which one or more hydrogens of α-methyl styrene are substituted with a substituent such as an alkyl group having <NUM> to <NUM> carbon atoms and a halogen group, more preferably compounds in which one or more hydrogens in the aromatic ring of α-methyl styrene are substituted with a substituent such as an alkyl group having <NUM> to <NUM> carbon atoms and a halogen group.

The types of the vinyl cyanide compound included in the copolymer (B) may be the same as the types of the vinyl cyanide compound included in the graft copolymer (A-<NUM>).

The copolymer (B) may be prepared by, for example, solution polymerization, bulk polymerization, emulsion polymerization, or suspension polymerization, preferably bulk polymerization. Solution polymerization, bulk polymerization, emulsion polymerization, and suspension polymerization commonly practiced in the art to which the present invention pertains may be used in the present invention without particular limitation.

The polymethacrylate resin (C) (not containing α-methyl styrene) is included in an amount of <NUM> to <NUM> % by weight, preferably <NUM> to <NUM> % by weight, more preferably <NUM> to <NUM> % by weight, even more preferably <NUM> to <NUM> % by weight. Within these ranges, deep black is excellently expressed, and a melt flow index is excellent, so that a large product can be easily injection-molded.

The polymethacrylate resin (C) (not containing α-methyl styrene) includes preferably <NUM> % by weight or more, preferably <NUM> % by weight or more, most preferably <NUM> % by weight or more of a methacrylate monomer. Within these ranges, deep black is excellently expressed, and a melt flow index is excellent, so that a large product can be easily injection-molded.

The polymethacrylate resin (C) (not containing α-methyl styrene) is a methyl methacrylate-styrene-acrylonitrile copolymer, or a mixture of a polymethyl methacrylate resin and a methyl methacrylate-styrene-acrylonitrile copolymer. Within these ranges, deep black is excellently expressed, and a melt flow index is excellent, so that a large product can be easily injection-molded.

For example, when a mixture of a methyl methacrylate-styrene-acrylonitrile copolymer and a polymethyl methacrylate is used as the polymethacrylate resin (C) (not containing α-methyl styrene), the methyl methacrylate-styrene-acrylonitrile copolymer may be included in an amount the same as or larger than the amount of the polymethyl methacrylate resin. Preferably, the methyl methacrylate-styrene-acrylonitrile copolymer may be included in an amount larger than the amount of the polymethyl methacrylate. In this case, fluidity, multi-axial impact strength and a standard deviation of the multi-axial impact strength are excellent.

As a particular example, in <NUM> % by weight of the thermoplastic resin composition, the methyl methacrylate-styrene-acrylonitrile copolymer may be included in an amount of <NUM> to <NUM> % by weight and the polymethyl methacrylate may be included in an amount of <NUM> to <NUM> % by weight. Preferably, the methyl methacrylate-styrene-acrylonitrile copolymer may be used in an amount of <NUM> to <NUM> % by weight and the polymethyl methacrylate may be used in an amount of <NUM> to <NUM> % by weight. In this case, heat resistance, blackness, and multi-axial impact strength and a standard deviation of the multi-axial impact strength are excellent, and a melt flow index is excellent, so that a large product can be easily injection-molded.

The methyl methacrylate-styrene-acrylonitrile copolymer may include, for example, <NUM> to <NUM> % by weight of methyl methacrylate, <NUM> to <NUM> % by weight of styrene, and <NUM> to <NUM> % by weight of acrylonitrile, preferably <NUM> to <NUM> % by weight of methyl methacrylate, <NUM> to <NUM> % by weight of styrene, and <NUM> to <NUM> % by weight of acrylonitrile, more preferably <NUM> to <NUM> % by weight of methyl methacrylate, <NUM> to <NUM> % by weight of styrene, and <NUM> to <NUM> % by weight of acrylonitrile. Within these ranges, a melt flow index is improved, so that a large product can be easily injection-molded and properties are stabilized.

The weight-average molecular weight of the methyl methacrylate-styrene-acrylonitrile copolymer may be, for example, <NUM>,<NUM> to <NUM>,<NUM>/mol, preferably <NUM>,<NUM> to <NUM>,<NUM>/mol, more preferably <NUM>,<NUM>/mol to <NUM>,<NUM>/mol. Within these ranges, multi-axial impact strength is excellent, and injection moldability is secured.

The weight-average molecular weight of the polymethyl methacrylate resin may be, for example, <NUM>,<NUM> to <NUM>,<NUM>/mol, preferably <NUM>,<NUM> to <NUM>,<NUM>/mol, more preferably <NUM>,<NUM> to <NUM>,<NUM>/mol. Within these ranges, multi-axial impact strength is excellent, and injection moldability is secured.

The polymethyl methacrylate resin may include, for example, methyl methacrylate and methyl acrylate. Preferably, the methyl acrylate may be included in an amount of <NUM> to <NUM> % by weight, preferably <NUM> to <NUM> % by weight. Within these ranges, compatibility with the methyl methacrylate-styrene-acrylonitrile copolymer is excellent, so that colorability, a melt flow index, and mechanical properties are improved.

The polymethacrylate resin (C) may be prepared by, for example, solution polymerization, bulk polymerization, emulsion polymerization, or suspension polymerization. Solution polymerization, bulk polymerization, emulsion polymerization and suspension polymerization commonly practiced in the art to which the present invention pertains may be used in the present invention without particular limitation.

The present invention includes a combination of the copolymer (B) and the polymethacrylate resin (C), more preferably a combination of the copolymer (B) and the methyl methacrylate-styrene-acrylonitrile copolymer. Due to such combinations, the synergistic effect wherein mechanical properties, such as heat resistance, blackness, and impact strength, are excellent, and both multi-axial impact strength and a standard deviation thereof are excellent is expressed.

The thermoplastic resin composition may include, for example, one or more selected from the group consisting of a lubricant, a heat stabilizer, a UV stabilizer, and a slip additive. Within these ranges, the required physical properties of the thermoplastic resin composition of the present invention may be implemented without deterioration in the intrinsic physical properties thereof.

The lubricant may be included in an amount of, for example, <NUM> to <NUM> parts by weight, preferably <NUM> to <NUM> parts by weight, more preferably <NUM> to <NUM> parts by weight, based on <NUM> parts by weight in total of the thermoplastic resin composition. In this case, both impact strength and a melt flow index are excellent.

The lubricant may include, for example, one or more selected from the group consisting of an ester-based lubricant, a metal salt-based lubricant, a carboxylic acid-based lubricant, a hydrocarbon-based lubricant, and an amide-based lubricant, preferably an amide-based lubricant, more preferably a stearamide-based lubricant, even more preferably alkylene bis(stearamide) containing alkylene having <NUM> to <NUM> carbon atoms. In this case, the original effect of a lubricant may be well expressed without deterioration in the mechanical properties and thermal stability of a resin.

In this specification, the stearamide-based lubricant may include stearamide and a stearamide substituent in which one or more hydrogens thereof are substituted with other substituents.

Ester-based lubricants, metal salt-based lubricants, carboxylic acid-based lubricants, hydrocarbon-based lubricants, and amide-based lubricants commonly used in the art may be used in the present invention without particular limitation.

The heat stabilizer may be included in an amount of, for example, <NUM> to <NUM> parts by weight, preferably <NUM> to <NUM> parts by weight, based on <NUM> parts by weight in total of the thermoplastic resin composition. Within these ranges, heat resistance is improved.

The heat stabilizer, for example, may be one or more selected from the group consisting of a phenolic heat stabilizer, a phosphite heat stabilizer, and a thioether heat stabilizer. Preferably, the heat stabilizer is a phenolic heat stabilizer or a phosphite heat stabilizer.

The phenolic heat stabilizer, for example, may be one or more selected from the group consisting of tetrakis methylene <NUM>-(<NUM>,<NUM>-di-tert-butyl-<NUM>-hydroxyphenyl)propionate methane, <NUM>,<NUM>,<NUM>-tris-(<NUM>-t-butyl-<NUM>-hydroxy-<NUM>,<NUM>-dimethylbenzene)-<NUM>,<NUM>,<NUM>-triazine-<NUM>,<NUM>,<NUM>-(<NUM>,<NUM>,<NUM>)-trione, and <NUM>,<NUM>,<NUM>-tris-(<NUM>,<NUM>-di-t-butyl-<NUM>-hydroxybenzil)-s-triazine-<NUM>, <NUM>, <NUM>- (<NUM>, <NUM>, <NUM>) -trione.

The phosphite heat stabilizer may be, for example, trisnonylphenylphosphite, tris-(<NUM>,<NUM>-di-tert-butylphenyl)phosphite, bis(<NUM>,<NUM>-di-tert-butylphenyl)pentaerythritol diphosphite, or a mixture thereof.

The thioether heat stabilizer may be, for example, one or more selected from the group consisting of dilauryl thiodipropionate, dimyristyl thiodipropionate, lauryl stearyl thiodipropionate, distearyl thiodipropionate, dimethyl thiodipropionate, <NUM>-mercaptobenzimidazole, phenothiazine, octadecyl thioglycolate, butyl thioglycolate, octyl thioglycolate, and thiocresol.

The amount of the UV stabilizer may be, for example, <NUM> to <NUM> parts by weight, preferably <NUM> to <NUM> parts by weight, based on <NUM> parts by weight in total of the thermoplastic resin composition. In this case, weather resistance is improved.

The UV stabilizer may be, for example, a hindered amine UV stabilizer (hindered amine light stabilizer, HALS). Preferably, the UV stabilizer may be one or more selected from the group consisting of one or more selected from the group consisting of <NUM>,<NUM>-bis(<NUM>,<NUM>,<NUM>,<NUM>-tetramethyl-<NUM>-piperidyl)succinate, bis(<NUM>,<NUM>,<NUM>,<NUM>-tetramethyl-<NUM>-piperidyl)sebacate, bis(<NUM>,<NUM>,<NUM>,<NUM>,<NUM>-pentamethyl-<NUM>-piperidyl)sebacate, bis(<NUM>-octyloxy-<NUM>,<NUM>,<NUM>,<NUM>-tetramethyl-<NUM>-piperidyl)sebacate, bis(<NUM>,<NUM>,<NUM>,<NUM>,<NUM>-pentamethyl-<NUM>-piperidyl)-N-butyl-<NUM>,<NUM>-di-tert-butyl-<NUM>-hydroxybenzilmalonate, a condensation product of <NUM>-(<NUM>-hydroxyethyl)-<NUM>,<NUM>,<NUM>,<NUM>-tetramethyl-<NUM>-hydroxypiperidine and succinic acid, a linear or cyclic condensation product of N,N'-bis(<NUM>,<NUM>,<NUM>,<NUM>-tetramethyl-<NUM>-piperidyl)hexamethylene diamine and <NUM>-tert-octylamino-<NUM>,<NUM>-di-chloro-<NUM>,<NUM>,<NUM>-triazine, tris(<NUM>,<NUM>,<NUM>,<NUM>-tetramethyl-<NUM>-piperidyl)nitrilotriacetate, tetrakis(<NUM>,<NUM>,<NUM>,<NUM>-tetramethyl-<NUM>-piperidyl)-<NUM>,<NUM>,<NUM>,<NUM>-butane tetracarboxylate, <NUM>,<NUM>'-(<NUM>,<NUM>-ethanediyl)-bis(<NUM>,<NUM>,<NUM>,<NUM>-tetramethylpiperazinone), <NUM>-benzoyl-<NUM>,<NUM>,<NUM>,<NUM>-tetramethylpiperidine, <NUM>-stearyloxy-<NUM>,<NUM>,<NUM>,<NUM>-tetramethylpiperidine, a linear or cyclic condensation product of N,N'-bis(<NUM>,<NUM>,<NUM>,<NUM>-tetramethyl-<NUM>-piperidyl)hexamethylene diamine and <NUM>-morpholino-<NUM>,<NUM>-dichloro-<NUM>,<NUM>,<NUM>-triazine, a reaction product of <NUM>,<NUM>,<NUM>,<NUM>-tetramethyl-<NUM>-cycloundecyl-<NUM>-oxa-<NUM>,<NUM>-diaza-<NUM>-oxospiro-[<NUM>,<NUM>]decane and epichlorohydrin, and poly[[<NUM>-(<NUM>,<NUM>,<NUM>,<NUM>-tetramethylbutyl)amino]-<NUM>,<NUM>,<NUM>-triazine-<NUM>,<NUM>-diyl] [(<NUM>,<NUM>,<NUM>,<NUM>-tetramethyl-<NUM>-piperidinyl)imino]-<NUM>,<NUM>-hexanediyl[(<NUM>,<NUM>,<NUM>,<NUM>-tetramethyl-<NUM>-piperidinyl)imino].

The UV stabilizer may be more preferably bis(<NUM>,<NUM>,<NUM>,<NUM>-tetramethyl-<NUM>-piperidyl)sebacate, <NUM>-(<NUM>-benzotriazol-<NUM>-yl)-<NUM>-(-(<NUM>,<NUM>,<NUM>,<NUM>-tetramethylbutyl)phenol, poly[[<NUM>-(<NUM>,<NUM>,<NUM>,<NUM>-tetramethylbutyl)amino]-<NUM>,<NUM>,<NUM>-triazine-<NUM>,<NUM>-diyl] [(<NUM>,<NUM>,<NUM>,<NUM>-tetramethyl-<NUM>-piperidinyl)imino]-<NUM>,<NUM>-hexanediyl[(<NUM>,<NUM>,<NUM>,<NUM>-tetramethyl-<NUM>-piperidinyl)imino], or a mixture thereof, even more preferably bis(<NUM>,<NUM>,<NUM>,<NUM>-tetramethyl-<NUM>-piperidyl)sebacate(Bis(<NUM>,<NUM>,<NUM>,<NUM>-tetramethyl-<NUM>-piperidyl), poly[[<NUM>-(<NUM>,<NUM>,<NUM>,<NUM>-tetramethylbutyl)amino]-<NUM>,<NUM>,<NUM>-triazine-<NUM>,<NUM>-diyl] [(<NUM>,<NUM>,<NUM>,<NUM>-tetramethyl-<NUM>-piperidinyl)imino]-<NUM>,<NUM>-hexanediyl[(<NUM>,<NUM>,<NUM>,<NUM>-tetramethyl-<NUM>-piperidinyl), or a mixture thereof. In this case, weather resistance is greatly improved without compromising impact strength and fluidity.

The amount of the slip additive may be, for example, <NUM> to <NUM> parts by weight, preferably <NUM> to <NUM> parts by weight, based on <NUM> parts by weight in total of the thermoplastic resin composition. Within these ranges, friction resistance is improved.

In this disclosure, a lubricant is used to improve moldability (processability) upon injection molding, and a slip additive is used to improve surface properties of a completed product which has been subjected to injection molding.

The slip additive may be, for example, a polyester-modified siloxane. In this case, compatibility with a thermoplastic resin composition is excellent.

In particular, a main chain of the polyester-modified siloxane may be polydimethylsiloxane and an organic group of the polydimethylsiloxane may be substituted with polyester, so that polydimethylsiloxane is included as a main chain and polyester is included as a side chain. In this case, compatibility with a thermoplastic resin composition is further improved, so that friction resistance is further improved while highly maintaining the property balance of a composition.

The polyester-modified siloxane may be a polyester-modified siloxane at a terminal of which a hydroxyl group is present. In this case, compatibility with a thermoplastic resin composition is further improved so that friction resistance can be greatly improved while highly maintaining overall property balance.

The melting point of the polyester-modified siloxane may be, for example, <NUM> to <NUM>, preferably <NUM> to <NUM>, Within these ranges, compounding with the thermoplastic resin composition can be easily performed.

In this disclosure, the melting point may be measured using Differential Scanning Calorimeter (DSC) <NUM> manufactured by TA Instruments Co. As a particular measurement example, the melting point may be measured by a method of equilibrating DSC at <NUM>, and then increasing by <NUM> per minute to elevate up to <NUM>, and then decreasing by <NUM> per minute to lower up to -<NUM>, and then increasing by <NUM> per minute to elevate up to <NUM>. Here, the melting point is obtained by taking a top region of an endothermic curve during the second temperature rises.

The polyester-modified siloxane may have a pellet shape. In this case, compounding with a thermoplastic resin composition can be easily performed, resulting in productivity increase.

Based on <NUM> parts by weight of the thermoplastic resin composition, the thermoplastic resin composition may selectively include one or more selected from the group consisting of a dye, a pigment, a flame retardant, and an inorganic filler in an amount of <NUM> to <NUM> parts by weight, preferably <NUM> to <NUM> parts by weight, more preferably <NUM> to <NUM> parts by weight, even more preferably <NUM> to <NUM> parts by weight, as needed. Within these ranges, the required physical properties of the thermoplastic resin composition of the present invention may be implemented without deterioration in the intrinsic physical properties thereof.

An average multi-axial impact strength, which is obtained by measuring a maximum load energy <NUM> times at a speed of <NUM>/s according to ISO <NUM>-<NUM>, of the thermoplastic resin composition of the present invention is <NUM> J or more, more preferably <NUM> J or more, even more preferably <NUM> to <NUM> J, even more preferably <NUM> to <NUM> J. Here, a standard deviation of the average multi-axial impact strength is <NUM> or less, more preferably <NUM> or less, even more preferably <NUM> or less, even more preferably <NUM> to <NUM>. Within these ranges, major reliability evaluation required for automotive exterior materials is satisfied.

In addition, Charpy impact strength (<NUM>), which is measured using a notched specimen according to ISO <NUM>, of the thermoplastic resin composition may be preferably <NUM> kJ/m2 or more, more preferably <NUM> kJ/m2 to <NUM> kJ/m2, even more preferably <NUM> to <NUM> kJ/m2. Within these ranges, property balance is excellent, and impact strength required for a large injection-molded article is satisfied.

In addition, the melt flow index, which is measured under <NUM> at <NUM> according to ISO <NUM>, of the thermoplastic resin composition may be preferably <NUM>/<NUM> or more, more preferably <NUM> to <NUM>/<NUM>, even more preferably <NUM> to <NUM>/<NUM>. Within these ranges, flowability is excellent, so that a large product can be easily injection-molded.

The heat distortion temperature, which is measured at <NUM> MPa according to ISO <NUM>/Be, of the thermoplastic resin composition may be preferably <NUM> or more, more preferably <NUM> to <NUM>, even more preferably <NUM> to <NUM>. Within these ranges, overall property balance is excellent.

Based on <NUM> parts by weight of the thermoplastic resin composition, the thermoplastic resin composition preferably includes <NUM> parts by weight of BK56 (manufactured by Muilchemical) and <NUM> parts by weight of BK57 (manufactured by Muilchemical), as carbon black pigments. A specimen having a size of <NUM> × <NUM> × <NUM> is manufactured at an injection-molding temperature of <NUM> and a molding temperature of <NUM>. The blackness(L; pigment), which is measured in the SCI mode using a colormeter, of the specimen may be <NUM> or less, more preferably <NUM> to <NUM>, even more preferably <NUM> to <NUM>. Within these ranges, overall property balance is excellent, and deep black can be realized.

Based on <NUM> parts by weight of the thermoplastic resin composition, the thermoplastic resin composition preferably includes <NUM> parts by weight of BK39 (manufactured by Muilchemical), as a dye. A specimen having a size of <NUM> × <NUM> × <NUM> is manufactured at an injection-molding temperature of <NUM> and a molding temperature of <NUM>. The blackness(L; dye), which is measured in the SCI mode using a colormeter, of the specimen may be <NUM> or less, more preferably <NUM> to <NUM>, even more preferably <NUM> to <NUM>. Within these ranges, overall property balance is excellent, and deep black can be realized.

The tensile strength, which is measured according to ISO <NUM>, of the thermoplastic resin composition may be preferably <NUM> MPa or more, more preferably <NUM> MPa or more, even more preferably <NUM> to <NUM> MPa. Within these ranges, overall property balance is excellent.

For example, when a surface of a specimen injection-molded from the thermoplastic resin composition is visually observed, goniochromism is not be observed. In this case, excellent surface quality is provided.

Hereinafter, a method of preparing the thermoplastic resin composition of the present invention, and a molded article including the thermoplastic resin composition are described. In describing the method of preparing the thermoplastic resin composition of the present invention and the molded article including the thermoplastic resin composition, all contents regarding the above-described thermoplastic resin composition are included.

A method of preparing a thermoplastic resin composition of the present disclosure includes a step of mixing <NUM> to <NUM> % by weight of a graft copolymer (A-<NUM>) including an acrylate-based rubber having an average particle diameter of <NUM> to <NUM>, an aromatic vinyl compound, and a vinyl cyanide compound, <NUM> to <NUM> % by weight of a graft copolymer (A-<NUM>) including an acrylate-based rubber having an average particle diameter of <NUM> to <NUM>, an aromatic vinyl compound, and a vinyl cyanide compound, <NUM> to <NUM> % by weight of a copolymer (B) including a (meth)acrylic acid alkyl ester compound, an α-methyl styrene-based compound, and a vinyl cyanide compound and <NUM> to <NUM> % by weight of a polymethacrylate resin (C) (not containing α-methyl styrene), and then preparing a thermoplastic resin composition at <NUM> to <NUM> using an extrusion kneader with a size of <NUM> to <NUM> pi, wherein an average multi-axial impact strength, which is obtained by measuring a maximum, load energy <NUM> times at a speed of <NUM>/s according to ISO <NUM>-<NUM>, of the thermoplastic resin composition is <NUM> J/mm or more, and a standard deviation of the average multi-axial impact strength is <NUM> or less. In this case, impact resistance, heat resistance, and fluidity are excellent, so that a large product can be injection-molded. In addition, the occurrence of goniochromism can be suppressed while realizing deep black, so that the appearance quality of an injection-molded product, and automobile reliability evaluation are satisfied.

The kneading and the extrusion may be performed, for example, using a single-screw extruder, a twin-screw extruder, or a Banbury mixer. In this case, a composition is uniformly dispersed, so that excellent compatibility is provided.

The kneading and the extrusion may be performed at a barrel temperature of, for example, <NUM> to <NUM>, preferably <NUM> to <NUM>, more preferably <NUM> to <NUM>. In this case, a throughput per unit time is appropriate, melt-kneading may be sufficiently performed, and problems, such as thermal decomposition of resin components, can may be prevented.

The kneading and the extrusion may be performed, for example, under a condition of a screw rotation number of <NUM> to <NUM> rpm, <NUM> to <NUM> rpm, <NUM> to <NUM> rpm, or <NUM> to 310rpm, preferably <NUM> to <NUM> rpm. In this case, a throughput per unit time is appropriate, so that process efficiency is excellent and excessive cutting can be prevented.

A molded article of the present disclosure, for example, may include the thermoplastic resin composition of the present disclosure. In this case, impact resistance, heat resistance, and fluidity are excellent, so that a large product can be injection-molded, and the occurrence of goniochromism can be suppressed while realizing deep black can be realized. Accordingly, the appearance quality of an injection-molded product and automobile reliability evaluation are satisfied.

The molded article may be, for example, an automobile exterior material, specifically a large injection-molded article such as a radiator grill. Accordingly, the thermoplastic resin composition of the present disclosure can provide products having quality or higher quality required by the market.

Now, the present invention will be described in more detail with reference to the following preferred examples.

Pellets were manufactured by performing kneading and extrusion in an extruder (SM Twin screw extruder, 25Φ) at an extrusion temperature of <NUM>, a feed rate of <NUM>/hr, and a screw speed of <NUM> rpm according to the components and contents as summarized in Tables <NUM> to <NUM> below. The melt index of each of the manufactured pellets were measured. The manufactured pellets were used to produce injection-mold specimens using an injection machine (ENGEL 120MT) under conditions of an injection-molding temperature of <NUM>, a molding temperature of <NUM>, and an injection rate of <NUM>/min.

The properties of the pellets and injection-molded specimens manufactured according to Examples <NUM> to <NUM> and Comparative Examples <NUM> to <NUM> were measured according to the following methods. Results are summarized in Tables <NUM> to <NUM> below.

As a blackness (L) value is small, deep black is well expressed.

Based on <NUM> parts by weight of the thermoplastic resin composition, <NUM> parts by weight of BK56 (manufactured by Muilchemical) and <NUM> parts by weight of BK57 (manufactured by Muilchemical), as carbon black pigments, were kneaded and extruded to manufacture a pellet. Next, the pellet was injection-molded at an injection-molding temperature of <NUM> and a molding temperature of <NUM> to manufacture a pigment specimen having a size of <NUM> X <NUM> X <NUM>.

Based on based on <NUM> parts by weight of the thermoplastic resin composition, <NUM> parts by weight of BK39 (manufactured by Muilchemical), as a dye, were kneaded and extruded to manufacture a pellet. The pellet was injection-molded at an injection-molding temperature of <NUM> and a molding temperature of <NUM> to manufacture a dye specimen having a size of <NUM> X <NUM> X <NUM>.

Here, the NP color refers to the unique color of a resin that is not colored, meaning that no pigment or dye is applied.

As shown in Tables <NUM> to <NUM>, it was confirmed that the thermoplastic resin compositions (Examples <NUM> to <NUM>) according to the present invention exhibited excellent fluidity, heat resistance, and multi-axial impact strength and excellent standard deviation of the multi-axial impact strength and realized deep black without occurrence of goniochromism, compared to Comparative Examples <NUM> to <NUM>. It was confirmed that in the case of all of Comparative Examples <NUM> to <NUM>, an average multi-axial impact strength was less than <NUM> J, and a standard deviation exceeded <NUM>, which does not satisfy automobile reliability evaluation. Accordingly, it was confirmed that the compositions according to Comparative Examples <NUM> to <NUM> were insufficient for automobile applications. In particular, in the case of Comparative Examples <NUM>, <NUM> and <NUM> excluding the copolymer (B-<NUM>) or including the same in a small amount, goniochromism occurred. Specifically, in the case of Comparative Example <NUM> and <NUM>, a standard deviation of multi-axial impact strength was greatly increased.

In addition, in the case of Comparative Example <NUM> only including the ASA resin having an average particle diameter of <NUM>, Charpy impact strength was poor, and in the case of Comparative Examples <NUM> to <NUM> and <NUM> excluding the combination of the copolymer(B-<NUM>) and the copolymer (C-<NUM>), heat resistance was decreased.

Claim 1:
A thermoplastic resin composition, comprising:
<NUM> to <NUM> % by weight of a graft copolymer (A-<NUM>) comprising an acrylate-based rubber having an average particle diameter of <NUM> to <NUM>, an aromatic vinyl compound, and a vinyl cyanide compound;
<NUM> to <NUM> % by weight of a graft copolymer (A-<NUM>) comprising an acrylate-based rubber having an average particle diameter of <NUM> to <NUM>, an aromatic vinyl compound, and a vinyl cyanide compound;
<NUM> to <NUM> % by weight of a copolymer (B) comprising a (meth)acrylic acid alkyl ester compound, an α-methyl styrene-based compound, and a vinyl cyanide compound, wherein the copolymer (B) comprises <NUM> to <NUM> % by weight of the (meth)acrylic acid alkyl ester compound, <NUM> to <NUM> % by weight of the α-methyl styrene-based compound, and <NUM> to <NUM> % by weight of the vinyl cyanide compound; and
<NUM> to <NUM> % by weight of a polymethacrylate resin (C) (not containing α-methyl styrene), wherein the polymethacrylate resin (C) (not containing α-methyl styrene) is a methyl methacrylate-styrene-acrylonitrile copolymer, or a mixture of a methyl methacrylate-styrene-acrylonitrile copolymer and a polymethyl methacrylate resin;
wherein the average multi-axial impact strength, which is obtained by measuring a maximum load energy <NUM> times at a speed of <NUM>/s according to ISO <NUM>-<NUM>, of a specimen having a thickness of <NUM> is <NUM> J/mm or more, and a standard deviation thereof is <NUM> or less, wherein the average particle diameter is measured as disclosed in the specification.