Thermoplastic resin composition

Abstract

The present invention relates to a thermoplastic resin composition comprising: a diene-based graft polymer; a vinyl-based non-graft polymer containing an alkyl-substituted aromatic vinyl-based monomer unit and a vinyl cyanide-based monomer unit; a first maleimide-based non-graft polymer containing a maleimide-based monomer unit, an alkyl-unsubstituted aromatic vinyl-based monomer unit, and a vinyl cyanide-based monomer unit; and a second maleimide-based non-graft polymer containing a maleimide-based monomer unit and an alkyl-unsubstituted aromatic vinyl-based monomer unit, in which the first maleimide-based non-graft polymer has a lower glass transition temperature than the second maleimide-based non-graft polymer.

Description

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS]

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2022-0121698, filed on September 26, 2022, which is hereby incorporated by reference in its entirety. [Technical field]

[0003] The present invention relates to a thermoplastic resin composition. [Background Technology]

[0004] The diene graft polymer comprises a diene rubber polymer and a shell containing aromatic vinyl monomer units and vinyl cyanide monomer units grafted onto the diene rubber polymer. Compared with existing high-strength polystyrene, the diene graft polymer has higher impact resistance, chemical resistance, thermal stability, colorability, fatigue resistance, rigidity and processability. Due to these characteristics, diene rubber thermoplastic resin molded products produced from diene graft polymers are used as automotive interior and exterior materials, office supplies, and parts of various electrical and electronic products.

[0005] A diene-based thermoplastic resin composition comprising a diene-based graft polymer can be used as a material for a rear lampshade in an automotive component. The rear lampshade can be divided into a bulb-type housing and a combined housing. The bulb-type housing can be manufactured by directly depositing aluminum on the surface of the housing, and the combined housing can be manufactured by separately producing an internal component and then combining the component with the housing. However, due to the structural design characteristics of the rear lampshade, in a vehicle model with a large internal heat generation, the rear lampshade cannot withstand the heat generated. Therefore, a super heat-resistant thermoplastic resin composition with improved heat resistance is required. However, although the currently developed super heat-resistant thermoplastic resin composition has excellent heat resistance, it is not suitable for a bulb-type housing due to the high diffuse reflectivity of the aluminum deposition surface. In addition, due to the low melt flow index of the super heat-resistant thermoplastic resin composition, the processability is reduced, so the super heat-resistant thermoplastic resin composition is limited when used as a raw material for the rear lampshade.

[0006] [Prior art literature]

[0007] [Patent Document]

[0008] (Patent Document 1) KR10-2030120B [Summary of the invention]

[0009] [Technical issues]

[0010] The problem to be solved by the present invention is to provide a thermoplastic resin composition having improved processability, impact resistance, heat resistance and aluminum deposition surface properties.

[0011] [Technical solution]

[0012] 1) One aspect of the present invention provides a thermoplastic resin composition, which comprises: a diene grafted polymer; a vinyl non-grafted polymer containing an alkyl-substituted aromatic vinyl monomer unit and a vinyl cyanide monomer unit; a first maleimide non-grafted polymer containing a maleimide monomer unit, an alkyl-unsubstituted aromatic vinyl monomer unit and a vinyl cyanide monomer unit; and a second maleimide non-grafted polymer containing a maleimide monomer unit and an alkyl-unsubstituted aromatic vinyl monomer unit, wherein the first maleimide non-grafted polymer has a lower glass transition temperature than the second maleimide non-grafted polymer.

[0013] 2) According to 1), the present invention provides a thermoplastic resin composition, wherein the glass transition temperature of the first maleimide-based non-grafted polymer is 10 to 30° C. lower than the glass transition temperature of the second maleimide-based grafted polymer.

[0014] 3) According to 1) or 2), the present invention provides a thermoplastic resin composition, wherein the first maleimide-based non-grafted polymer has a glass transition temperature of 165 to 185°C.

[0015] 4) According to any one of 1) to 3), the present invention provides a thermoplastic resin composition, wherein the second maleimide-based non-grafted polymer has a glass transition temperature of 186 to 206°C.

[0016] 5) According to any one of 1) to 4), the present invention provides a thermoplastic resin composition, wherein the first maleimide non-grafted polymer is a terpolymer composed of maleimide monomer units, alkyl unsubstituted aromatic vinyl monomer units and vinyl cyanide monomer units.

[0017] 6) According to any one of 1) to 5), the present invention provides a thermoplastic resin composition comprising 7.5 to 16.5 wt% of a first maleimide-based non-grafted polymer.

[0018] 7) According to any one of 1) to 6), the present invention provides a thermoplastic resin composition, wherein the second maleimide-based non-grafted polymer is a binary copolymer composed of a maleimide-based monomer unit and an alkyl-unsubstituted aromatic vinyl-based monomer unit.

[0019] 8) According to any one of 1) to 7), the present invention provides a thermoplastic resin composition comprising 7.5 to 16.5 wt% of a second maleimide-based non-grafted polymer.

[0020] 9) According to any one of 1) to 8), the present invention provides a thermoplastic resin composition, wherein the diene graft polymer comprises a diene rubber polymer and a shell comprising an alkyl-substituted or alkyl-unsubstituted aromatic vinyl monomer unit and a vinyl cyanide monomer unit grafted onto the diene rubber polymer.

[0021] 10) According to any one of 1) to 9), the present invention provides a thermoplastic resin composition comprising 22.0 to 30.0 wt% of the diene-based graft polymer.

[0022] 11) According to any one of 1) to 10), the present invention provides a thermoplastic resin composition comprising a first diene-based graft polymer and a second diene-based graft polymer of a diene-based rubber polymer having different average particle sizes.

[0023] 12) According to 11), the present invention provides a thermoplastic resin composition, wherein the first diene graft polymer comprises a diene rubber polymer having an average particle size of 50 to 220 nm and a shell comprising alkyl-substituted or alkyl-unsubstituted aromatic vinyl monomer units and vinyl cyanide monomer units grafted onto the diene rubber polymer.

[0024] 13) According to 11) or 12), the present invention provides a thermoplastic resin composition, wherein the second diene grafted polymer comprises a diene rubber polymer having an average particle size of 250 to 500 nm and a shell containing alkyl-substituted or alkyl-unsubstituted aromatic vinyl monomer units and vinyl cyanide monomer units grafted onto the diene rubber polymer.

[0025] 14) According to any one of 11) to 13), the present invention provides a thermoplastic resin composition, wherein the weight ratio of the first diene graft polymer to the second diene graft polymer is 1:1.0 to 4.0.

[0026] 15) According to any one of 1) to 14), the present invention provides a thermoplastic resin composition comprising 45.0 to 53.0% by weight of the vinyl-based non-grafted polymer.

[0027] [Beneficial Effects]

[0028] The thermoplastic resin composition of the present invention has not only excellent processability, impact resistance, heat resistance and aluminum deposition surface properties, but also excellent tensile strength and stress. Therefore, the thermoplastic resin composition is suitable for automobile rear lamp housings that generate high temperature heat, and can be used for automobile exterior materials that generate high temperature heat. [Specific implementation method]

[0029] Hereinafter, the present invention will be described in more detail to help understanding of the present invention.

[0030] The terms and words in this specification and claims should not be construed as limited to their ordinary meanings or dictionary meanings, but should be construed with meanings and concepts consistent with the technical concept of the present invention based on the principle that the inventor can appropriately define the concepts of the terms in order to interpret his invention in the best manner.

[0031] In the present invention, the "diene rubber polymer" can be prepared by polymerizing a diene monomer, which can be one or more selected from the group consisting of 1,3-butadiene, isoprene, chloroprene and piperylene, preferably 1,3-butadiene.

[0032] In the present invention, the alkyl-substituted aromatic vinyl monomer may be one or more selected from the group consisting of α-methylstyrene, α-ethylstyrene, p-methylstyrene and 2,4-dimethylstyrene. The unit derived from the “alkyl-substituted aromatic vinyl monomer” may be an “alkyl-substituted aromatic vinyl monomer unit”.

[0033] In the present invention, the alkyl unsubstituted aromatic vinyl monomer may be one or more selected from the group consisting of styrene, p-fluorostyrene, p-chlorostyrene and p-bromostyrene. The unit derived from the "alkyl unsubstituted aromatic vinyl monomer" may be an "alkyl unsubstituted aromatic vinyl monomer unit".

[0034] In the present invention, the vinyl cyanide monomer may be one or more selected from the group consisting of acrylonitrile, methacrylonitrile, (Z)-3-phenylacrylonitrile and α-chloroacrylonitrile, preferably acrylonitrile. The unit derived from the “vinyl cyanide monomer” may be a “vinyl cyanide monomer unit”.

[0035] In the present invention, the maleimide monomer may be one or more selected from the group consisting of maleimide, N-methylmaleimide, N-ethylmaleimide, N-propylmaleimide, N-isopropylmaleimide, N-butylmaleimide, N-isobutylmaleimide, N-tert-butylmaleimide, N-laurylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, N-(4-chlorophenyl)maleimide, 2-methyl-N-phenylmaleimide, N-(4-bromophenyl)maleimide, N-(4-nitrophenyl)maleimide, N-(4-hydroxyphenyl)maleimide, N-(4-methoxyphenyl)maleimide, N-(4-carboxyphenyl)maleimide and N-benzylmaleimide, preferably N-phenylmaleimide. The unit derived from the “maleimide-based monomer” may be a “maleimide-based monomer unit”.

[0036] In the present invention, the weight average molecular weight can be measured as a relative value with respect to a standard polystyrene sample by gel permeation chromatography using tetrahydrofuran as an eluent.

[0037] In the present invention, the glass transition temperature can be measured by differential scanning calorimetry.

[0038] In the present invention, the average particle size can be measured by dynamic light scattering, specifically, using a Nicomp 380 instrument commercially available from ParticleSizing Systems. In the present invention, the average particle size may refer to the arithmetic mean particle size in the particle size distribution measured by dynamic light scattering, i.e., the average particle size based on the scattering intensity distribution.

[0039] 1. Thermoplastic resin composition

[0040] The thermoplastic resin composition according to an embodiment of the present invention includes: 1) a diene-based grafted polymer; 2) a vinyl-based non-grafted polymer containing an alkyl-substituted aromatic vinyl-based monomer unit and a vinyl cyan-based monomer unit; 3) a first maleimide-based non-grafted polymer containing a maleimide-based monomer unit, an alkyl-unsubstituted aromatic vinyl-based monomer unit, and a vinyl cyan-based monomer unit; and 4) a second maleimide-based non-grafted polymer containing a maleimide-based monomer unit and an alkyl-unsubstituted aromatic vinyl-based monomer unit, wherein the first maleimide-based non-grafted polymer has a lower glass transition temperature than the second maleimide-based non-grafted polymer.

[0041] The inventors have found that when a thermoplastic resin composition contains both a first maleimide non-grafted polymer having a lower glass transition temperature and a second maleimide non-grafted polymer having a higher glass transition temperature, the impact resistance, aluminum deposition surface properties and heat resistance of the thermoplastic resin composition are improved, so the thermoplastic resin composition is suitable for automobile rear lamp covers. Based on the above findings, the present invention has been completed.

[0042] Hereinafter, components of the thermoplastic resin composition according to an embodiment of the present invention will be described in detail.

[0043] 1) Diene graft polymer

[0044] The diene graft polymer is a component that improves the impact resistance, tensile strength and stress of the thermoplastic resin composition. The diene graft polymer may include a diene rubber polymer and a shell containing aromatic vinyl monomer units and vinyl cyanide monomer units grafted onto the diene rubber polymer. In addition, the shell may include aromatic vinyl monomer units and vinyl cyanide monomer units that are not grafted onto the diene rubber polymer.

[0045] The average particle size of the diene rubber polymer may be 50 to 500 nm, preferably 70 to 470 nm. When this condition is met, the impact resistance and surface properties of the diene graft polymer may be improved.

[0046] Based on the total weight of the thermoplastic resin composition, the content of the diene graft polymer may be 22.0 wt % to 30.0 wt %, preferably 24.0 wt % to 28.0 wt %. When this condition is met, excellent impact resistance, tensile force and stress can be imparted to the thermoplastic resin composition while minimizing the impact on the processability and heat resistance of the thermoplastic resin composition.

[0047] In order to improve impact resistance, tensile force and stress, and maximize surface smoothness, the diene-based graft polymer may include a first diene-based graft polymer and a second diene-based graft polymer of a diene-based rubber polymer having different average particle sizes.

[0048] The first diene graft polymer may include a diene rubber polymer having an average particle size of 50 to 220 nm, preferably 50 to 150 nm, more preferably 70 to 130 nm, and most preferably 90 to 110 nm, and a shell containing alkyl-substituted or alkyl-unsubstituted aromatic vinyl monomer units and vinyl cyanide monomer units grafted onto the diene rubber polymer. When the average particle size satisfies the above conditions, the thermoplastic resin composition may have excellent tensile force and stress, and the surface smoothness of the thermoplastic resin composition may be maximized, thereby achieving excellent aluminum deposition surface properties.

[0049] The second diene graft polymer may include a diene rubber polymer having an average particle size of 250 to 500 nm, preferably 250 to 400 nm, more preferably 250 to 350 nm, and most preferably 280 to 320 nm, and a shell containing alkyl-substituted or alkyl-unsubstituted aromatic vinyl monomer units and vinyl cyanide monomer units grafted onto the diene rubber polymer. When the average particle size satisfies the above conditions, the thermoplastic resin composition may have excellent impact resistance.

[0050] When the thermoplastic resin composition is used in fields requiring high tensile force, stress and surface smoothness, the thermoplastic resin composition may contain an excessive amount of the first diene rubber graft polymer. When the thermoplastic resin composition is used in fields requiring high impact strength, the thermoplastic resin composition may contain an excessive amount of the second diene graft polymer.

[0051] When the thermoplastic resin composition is used for a rear lamp cover of an automobile, the weight ratio of the first diene graft polymer to the second diene graft polymer may be 1:1.0 to 4.0, preferably 1:2.0 to 3.8, and more preferably 1:3.0 to 3.5. When this condition is met, the tensile force, stress and surface smoothness of the thermoplastic resin composition are improved, while the reduction in impact resistance is minimized, and therefore, a thermoplastic resin composition more suitable for a rear lamp cover of an automobile can be prepared.

[0052] The diene rubber graft polymer may be a graft polymer obtained by graft-polymerizing styrene and acrylonitrile onto a polybutadiene rubber polymer.

[0053] 2) Vinyl non-grafted polymers

[0054] The vinyl-based non-grafted polymer is a component that improves processability, chemical resistance, and heat resistance of the thermoplastic resin composition.

[0055] The vinyl non-grafted polymer contains an alkyl-substituted aromatic vinyl monomer unit and a vinyl cyanide monomer unit.

[0056] The vinyl-based non-grafted polymer may contain 67 to 75 wt%, preferably 69 to 73 wt% of an alkyl-substituted aromatic vinyl-based monomer unit. When this condition is satisfied, the heat resistance of the vinyl-based non-grafted polymer may be improved.

[0057] The vinyl-based non-grafted polymer may include 25 to 33 wt %, preferably 27 to 31 wt % of a vinyl cyanide-based monomer unit. When this condition is met, the chemical resistance of the vinyl-based non-grafted polymer may be improved.

[0058] The weight average molecular weight of the vinyl-based non-grafted polymer may be 80,000 to 120,000 g / mol, preferably 90,000 to 110,000 g / mol. When this condition is met, the processability and mechanical properties of the vinyl-based non-grafted polymer may be improved.

[0059] Based on the total weight of the thermoplastic resin composition, the content of the vinyl-based non-grafted polymer may be 45.0 wt % to 53.0 wt %, preferably 47.0 wt % to 51.0 wt %. When this condition is met, excellent processability, chemical resistance and heat resistance can be imparted to the thermoplastic resin composition.

[0060] 3) The first maleimide non-grafted polymer

[0061] The first maleimide-based non-grafted polymer is a component that improves impact resistance, tensile strength, processability, and aluminum deposition surface properties through a synergistic effect with the diene-based grafted polymer.

[0062] The first maleimide non-grafted polymer contains maleimide monomer units, alkyl unsubstituted aromatic vinyl monomer units and vinyl cyanide monomer units. Since the first maleimide non-grafted polymer contains alkyl unsubstituted aromatic vinyl monomer units and vinyl cyanide monomer units, the first maleimide non-grafted polymer has high compatibility with the diene grafted polymer and the vinyl non-grafted polymer. Therefore, the synergistic effect with the diene grafted polymer and the vinyl non-grafted polymer can improve impact resistance, tensile strength, processability and aluminum deposition surface properties.

[0063] The first maleimide-based non-grafted polymer has a lower glass transition temperature than the second maleimide-based non-grafted polymer described later. When this condition is met, the impact resistance and aluminum deposition surface properties are improved compared to the case where the first maleimide-based non-grafted polymer is not included, and the heat resistance is improved compared to the case where the second maleimide-based non-grafted polymer is not included.

[0064] The glass transition temperature of the first maleimide-based non-grafted polymer may be lower than the glass transition temperature of the second maleimide-based non-grafted polymer described later by 10 to 30° C., preferably lower by 15 to 25° C. When this condition is satisfied, the reduction in impact resistance and aluminum deposition surface properties of the thermoplastic resin composition due to the second maleimide-based non-grafted polymer can be minimized, and the reduction in heat resistance of the thermoplastic resin composition due to the first maleimide-based non-grafted polymer can be minimized.

[0065] The glass transition temperature of the first maleimide non-grafted polymer may be 165 to 185°C, preferably 170 to 180°C. When this condition is met, a relatively small amount of maleimide monomer units that improve heat resistance may be included, and a relatively excessive amount of alkyl unsubstituted aromatic vinyl monomer units and vinyl cyanide monomer units that improve compatibility with diene grafted polymers and vinyl non-grafted polymers may be included. Since the compatibility between the first maleimide non-grafted polymer, the diene grafted polymer and the vinyl non-grafted polymer is improved, the impact resistance and aluminum deposition surface properties may be further improved. In addition, the heat resistance of the thermoplastic resin composition may be improved, so the thermoplastic resin composition may be used for rear lamp covers of automobiles.

[0066] The weight average molecular weight of the first maleimide non-grafted polymer may be 125,000 to 155,000 g / mol, preferably 130,000 to 150,000 g / mol. When this condition is met, since the weight average molecular weight of the first maleimide non-grafted polymer is similar to that of the vinyl non-grafted polymer and the second maleimide non-grafted polymer, the compatibility with the vinyl non-grafted polymer and the second maleimide non-grafted polymer can be improved.

[0067] The first maleimide non-grafted polymer may be a terpolymer composed of maleimide monomer units, vinyl cyanide monomer units and alkyl unsubstituted aromatic vinyl monomer units. Specifically, the first maleimide non-grafted polymer may be N-phenylmaleimide / styrene / acrylonitrile polymer.

[0068] Based on the total weight of the thermoplastic resin composition, the content of the first maleimide-based non-grafted polymer may be 7.5 wt % to 16.5 wt %, preferably 10.0 wt % to 15.0 wt %. When this condition is met, the impact resistance and aluminum deposition surface properties of the thermoplastic resin composition are improved, and the reduction of tensile force and stress can be minimized.

[0069] 4) Second maleimide non-grafted polymer

[0070] The second maleimide-based non-grafted polymer is a component that improves the heat resistance of the thermoplastic resin composition.

[0071] The second maleimide non-grafted polymer contains maleimide monomer units and alkyl unsubstituted aromatic vinyl monomer units. Since the second maleimide non-grafted polymer contains maleimide monomer units and vinyl cyanide monomer units, the second maleimide non-grafted polymer has excellent compatibility with the first maleimide non-grafted polymer. Therefore, the heat resistance can be significantly improved by the synergistic effect between the first and second maleimide non-grafted polymers.

[0072] The glass transition temperature of the second maleimide-based non-grafted polymer may be 186 to 206° C., preferably 191 to 201° C. When this condition is satisfied, the heat resistance of the thermoplastic resin composition may be significantly improved.

[0073] The second maleimide non-grafted polymer may be a binary copolymer composed of a maleimide monomer unit and an alkyl unsubstituted aromatic vinyl monomer unit. Specifically, the second maleimide non-grafted polymer may be an N-phenylmaleimide / styrene polymer.

[0074] Based on the total weight of the thermoplastic resin composition, the content of the second maleimide-based non-grafted polymer may be 7.5 wt % to 16.5 wt %, preferably 10.0 wt % to 15.0 wt %. When this condition is met, the heat resistance of the thermoplastic resin composition is improved, and the reduction of processability, impact resistance, tensile force and stress can be minimized.

[0075] Hereinafter, the embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein.

[0076] Examples and Comparative Examples

[0077] The components used in the following Examples and Comparative Examples are described below.

[0078] First diene graft polymer: DP229M commercially available from LG Chem (comprising a polybutadiene rubber polymer having an average particle size of 100 nm and a shell containing styrene units and acrylonitrile units grafted onto the polybutadiene rubber polymer)

[0079] Second diene graft polymer: DP270E commercially available from LG Chem (comprising a polybutadiene rubber polymer having an average particle size of 300 nm and a shell containing styrene units and acrylonitrile units grafted onto the polybutadiene rubber polymer)

[0080] Vinyl-based non-grafted polymer: 200UH commercially available from LG Chem (α-methylstyrene / acrylonitrile non-grafted polymer, weight average molecular weight 100,000 g / mol, prepared by polymerization of 71 wt% α-methylstyrene and 29 wt% acrylonitrile)

[0081] SAN polymer: 95RF commercially available from LG Chem (styrene / acrylonitrile non-grafted polymer, weight average molecular weight 100,000 g / mol, prepared by polymerization of 71 wt % styrene and 29 wt % acrylonitrile)

[0082] First maleimide non-grafted polymer: IPX-02 commercially available from DENKA (N-phenylmaleimide / styrene / acrylonitrile non-grafted polymer, weight average molecular weight of 140,000 g / mol, glass transition temperature of 175°C)

[0083] First maleimide non-grafted polymer: IPX-02 commercially available from DENKA (N-phenylmaleimide / styrene / acrylonitrile terpolymer, weight average molecular weight of 140,000 g / mol, glass transition temperature of 175° C.)

[0084] Second maleimide non-grafted polymer: MS-NB (N-phenylmaleimide / styrene binary copolymer, weight average molecular weight of 140,000 g / mol, glass transition temperature of 196° C.) commercially available from DENKA

[0085] The above ingredients were mixed and stirred in the amounts shown in Table 1 and Table 2 below to prepare a thermoplastic resin composition.

[0086] Experimental Example 1

[0087] Each of the thermoplastic resin compositions of Examples and Comparative Examples was extruded to prepare pellets. The pellets were evaluated using the following method, and the results are shown in Tables 1 and 2 below.

[0088] (1) Melt flow index (g / 10 min): The melt flow index is measured under the conditions of 220° C. and 10 kg in accordance with ASTM D1238. In the present invention, when the melt flow index is 3.0 g / 10 min or more, the processability is judged to be excellent.

[0089] Experimental Example 2

[0090] Each thermoplastic resin composition of the examples and comparative examples was extruded and injection molded to prepare a sample. The samples were evaluated using the following methods, and the results are shown in Tables 1 and 2 below.

[0091] (2) Izod impact strength (kg·cm / cm, 1 / 4 inch): The Izod impact strength was measured in accordance with ASTM D 256. In the present invention, when the Izod impact strength is 9.0 kg·cm / cm or more, the impact resistance is judged to be excellent.

[0092] (3) Tensile strength (kg / cm 2 ) and tensile elongation (%): Tensile strength and tensile elongation are measured according to ASTM D638. In the present invention, when the tensile strength is 440kg / cm 2 When the tensile elongation is 40% or more, the tensile strength is judged to be excellent.

[0093] (4) Flexural strength (kg / cm 2 ): Flexural strength is measured according to ASTM D790. In the present invention, when the flexural strength is 650 kg / cm 2 When it is above, the stress is judged to be excellent.

[0094] (5) Heat deformation temperature (° C.): The heat deformation temperature was measured in accordance with ASTM D648 under unannealed conditions. In the present invention, when the heat deformation temperature is 109° C. or higher, the heat resistance is judged to be excellent.

[0095] Experimental Example 3

[0096] Each thermoplastic resin composition of the embodiment and the comparative example was extruded and injection molded into a 10 cm×10 cm sample, and Al was vacuum-deposited on the sample surface using a vacuum deposition device (a high vacuum deposition device manufactured by Daehan Vacuum Engineering Co., Ltd.). The physical properties of the samples formed with the Al film were measured by the following method, and the results are shown in Tables 1 and 2.

[0097] (6) Diffuse reflectance (%): Diffuse reflectance was measured using a surface gloss meter (reflectometer (TR-1100AD) manufactured by Tokyo Denshoku Co., Ltd.). Since diffuse reflectance is greatly affected by sensitivity, which varies depending on the gas and surface properties, the state of the vacuum deposited surface can be inferred from the diffuse reflectance. In the present invention, when the diffuse reflectance is 6.0% or less, the condition of the vacuum deposited surface is judged to be excellent.

[0098] Experimental Example 4

[0099] Each thermoplastic resin composition of the examples and comparative examples was extruded and injection molded into a sample of 10 cm×10 cm×3 cm. The physical properties of the sample were measured by the following methods. The results are shown in Tables 1 and 2.

[0100] (7) Whether cracks occur due to hammering: Use a rubber hammer to strike the same area of ​​the fixed sample 10 times to check whether cracks occur.

[0101] (8) Whether cracking occurs due to a falling ball: A falling ball device using a 5 kg ball is used to check whether cracking occurs. The falling ball device is a free fall test device that fixes a ball at a high place with a magnet, and then removes the magnetic force of the magnet to allow the ball to fall freely. The force applied to the sample is increased by raising the height of the ball at 10 cm intervals to check whether cracking occurs.

[0102] ×: No crack ○: Crack [Table 1]

[0103]

[0104] [Table 2]

[0105]

[0106] Referring to Table 1 and Table 2, the melt flow index, impact strength, tensile strength, tensile elongation, flexural strength, heat deformation temperature and diffuse reflectivity of Examples 1 to 6 are all suitable, and no cracking occurs due to hammering and ball dropping in Examples 1 to 6. These results show that Examples 1 to 6 have excellent processability, impact resistance, tensile force, stress, heat resistance and aluminum deposition surface properties.

[0107] Referring to Examples 1 to 3 in which the total amount of the first maleimide non-grafted polymer and the second maleimide non-grafted polymer is the same but the weight ratio of the first maleimide non-grafted polymer to the second maleimide non-grafted polymer is different, it is found that as the content of the first maleimide non-grafted polymer increases, the impact resistance, tensile force, stress and aluminum deposition surface properties are improved, and as the content of the second maleimide non-grafted polymer increases, the heat resistance is improved.

[0108] Referring to Examples 2, 4, and 5 in which the weight ratio of the first maleimide non-grafted polymer to the second maleimide non-grafted polymer is 1:1 but the total amount of the first maleimide non-grafted polymer and the second maleimide non-grafted polymer is different, it is found that as the total amount of the first and second maleimide non-grafted polymers increases, the tensile strength, bending strength, and heat deformation temperature increase, while as the total amount of the first and second maleimide non-grafted polymers decreases, the melt flow index increases and the diffuse reflectance decreases. These results show that as the total amount of the first and second maleimide non-grafted polymers increases, the tensile force, stress, and heat resistance are improved, and as the total amount of the first and second maleimide non-grafted polymers decreases, the processability and aluminum deposition surface properties are improved. In addition, in the case of Examples 2, 4, and 5, it can be seen that the heat deformation temperature is affected by the content of the second maleimide non-grafted polymer, rather than the content of the vinyl non-grafted polymer.

[0109] On the other hand, in the case of Comparative Example 1 containing a styrene / acrylonitrile non-grafted polymer instead of an α-methylstyrene / acrylonitrile non-grafted polymer, the tensile strength, tensile elongation and flexural strength were low, and the heat deformation temperature was low. These results show that the tensile force, stress and heat resistance of Comparative Example 1 were reduced.

[0110] In the case of Comparative Example 2 which does not include the first maleimide-based non-grafted polymer, the tensile strength is high, but the tensile elongation and heat deformation temperature are low, and cracking occurs due to hammering and ball dropping. These results show that the tensile force, heat resistance and impact resistance of Comparative Example 2 are reduced.

[0111] In the case of Comparative Example 3 which does not include the second maleimide-based non-grafted polymer, the melt flow index and impact strength are low, the tensile strength is high, but the tensile elongation is low, the diffuse reflectivity is high, and cracking occurs due to hammering and ball dropping. These results indicate that the processability, impact resistance, tensile force, and aluminum deposition surface properties of Comparative Example 3 are reduced.

Claims

1. A thermoplastic resin composition comprising: Diene graft polymers; Vinyl non-grafted polymers containing alkyl-substituted aromatic vinyl monomer units and vinyl cyanide monomer units; a first maleimide non-grafted polymer containing maleimide monomer units, alkyl unsubstituted aromatic vinyl monomer units and vinyl cyanide monomer units; and a second maleimide non-grafted polymer containing maleimide monomer units and alkyl unsubstituted aromatic vinyl monomer units, in, The first maleimide-based non-grafted polymer has a lower glass transition temperature than the second maleimide-based non-grafted polymer.

2. The thermoplastic resin composition according to claim 1, wherein The glass transition temperature of the first maleimide-based non-grafted polymer is 10 to 30° C. lower than the glass transition temperature of the second maleimide-based grafted polymer.

3. The thermoplastic resin composition according to claim 2, wherein The first maleimide-based non-grafted polymer has a glass transition temperature of 165 to 185°C.

4. The thermoplastic resin composition according to claim 2, wherein The second maleimide-based non-grafted polymer has a glass transition temperature of 186 to 206°C.

5. The thermoplastic resin composition according to claim 1, wherein The first maleimide non-grafted polymer is a terpolymer composed of a maleimide monomer unit, an alkyl unsubstituted aromatic vinyl monomer unit and a vinyl cyanide monomer unit. 6 . The thermoplastic resin composition of claim 1 , comprising 7.5 to 16.5 wt % of the first maleimide-based non-grafted polymer.

7. The thermoplastic resin composition according to claim 1, wherein The second maleimide-based non-grafted polymer is a binary copolymer composed of a maleimide-based monomer unit and an alkyl-unsubstituted aromatic vinyl-based monomer unit. 8 . The thermoplastic resin composition of claim 1 , comprising 7.5 to 16.5 wt % of the second maleimide-based non-grafted polymer.

9. The thermoplastic resin composition according to claim 1, wherein The diene-based graft polymer comprises a diene-based rubber polymer and a shell comprising an alkyl-substituted or alkyl-unsubstituted aromatic vinyl-based monomer unit and a vinyl cyanide-based monomer unit grafted onto the diene-based rubber polymer.

10. The thermoplastic resin composition according to claim 1, comprising 22.0 to 30.0 wt% of the diene-based graft polymer. 11 . The thermoplastic resin composition according to claim 1 , comprising a first diene-based graft polymer and a second diene-based graft polymer of a diene-based rubber polymer having different average particle sizes.

12. The thermoplastic resin composition according to claim 11, wherein The first diene-based graft polymer comprises a diene-based rubber polymer having an average particle size of 50 to 220 nm and a shell comprising an alkyl-substituted or alkyl-unsubstituted aromatic vinyl-based monomer unit and a vinyl cyanide-based monomer unit grafted onto the diene-based rubber polymer.

13. The thermoplastic resin composition according to claim 11, wherein The second diene-based graft polymer comprises a diene-based rubber polymer having an average particle size of 250 to 500 nm and a shell comprising an alkyl-substituted or alkyl-unsubstituted aromatic vinyl-based monomer unit and a vinyl cyanide-based monomer unit grafted onto the diene-based rubber polymer.

14. The thermoplastic resin composition according to claim 11, wherein The weight ratio of the first diene graft polymer to the second diene graft polymer is 1:1.0 to 4.

0.

15. The thermoplastic resin composition of claim 1, comprising 45.0 to 53.0 wt% of the vinyl-based non-grafted polymer.

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