Thermoplastic resin composition

Abstract

The present invention relates to a thermoplastic resin composition comprising a base resin including a diene-based graft polymer and a vinyl-based non-graft polymer containing vinyl aromatic monomer units and vinyl cyanide-based monomer units, and an additive including an olefin-based non-graft polymer containing olefin-based monomer units, (meth)acrylate-based monomer units and maleic acid-based monomer units.

Description

[Technical Field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0136421, filed on October 21, 2022, and all contents disclosed in the documents of this Korean patent application are incorporated herein by reference.

[0002] The present invention relates to a thermoplastic resin composition. [Background technology]

[0003] A diene graft polymer comprises a diene rubber polymer and a shell containing vinyl aromatic monomer units and vinyl cyanide monomer units grafted onto the diene rubber polymer. Compared to high-impact polystyrene, such diene graft polymers have superior physical properties, such as high impact resistance, chemical resistance, heat resistance, colorability, fatigue resistance, rigidity, and processability. Due to these properties, diene graft polymers have been used in automotive interior and exterior materials, office equipment, various electrical and electronic product components, toys, and the like.

[0004] However, despite these excellent physical properties, when a strong solvent is used to evaluate the chemical resistance of a diene-based graft polymer, cracks occur.

[0005] To solve these problems, studies have been conducted to adjust the rubber content of diene graft polymers or increase their size, but these methods have limited effectiveness in improving poor chemical resistance due to reduced fluidity of the diene graft polymers and increased residual stress in thermoplastic resin molded products. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] KR2011-0061303A Summary of the Invention [Problem to be solved by the invention]

[0007] The problem to be solved by the present invention is to provide a thermoplastic resin composition that is excellent in all of processability, impact resistance, heat resistance and chemical resistance. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems, 1) the present invention provides a thermoplastic resin composition comprising a base resin including a diene-based graft polymer and a vinyl-based non-graft polymer containing vinyl aromatic-based monomer units and vinyl cyanide-based monomer units, and an additive including an olefin-based non-graft polymer containing olefin-based monomer units, (meth)acrylate-based monomer units and maleic acid-based monomer units.

[0009] Further, 2) the present invention provides the thermoplastic resin composition in 1) above, which contains 0.5 to 5.0 parts by weight of the non-grafted olefin polymer per 100 parts by weight of the base resin.

[0010] Furthermore, 3) the present invention provides the thermoplastic resin composition according to 1) or 2), wherein the non-grafted olefin polymer is a terpolymer consisting of an olefin monomer unit, a (meth)acrylate monomer unit, and a maleic acid monomer unit.

[0011] Further, 4) the present invention provides the thermoplastic resin composition according to any one of the above 1) to 3), wherein the non-grafted olefin polymer is an ethylene / ethyl acrylate / maleic anhydride terpolymer.

[0012] Further, 5) the present invention provides a thermoplastic resin composition according to any one of 1) to 4), wherein the diene graft polymer comprises a diene rubber polymer and a shell containing vinyl aromatic monomer units and vinyl cyanide monomer units grafted to the diene rubber polymer.

[0013] Further, 6) the present invention provides a thermoplastic resin composition according to any one of 1) to 5) above, which comprises 10.0 to 40.0 parts by weight of the diene graft polymer per 100 parts by weight of the base resin.

[0014] Further, 7) the present invention provides a thermoplastic resin composition according to any one of 1) to 6), wherein the base resin comprises a non-grafted maleimide polymer containing maleimide monomer units, vinyl aromatic monomer units, and maleic acid monomer units.

[0015] Further, 8) the present invention provides the thermoplastic resin composition according to 7) above, which contains 10.0 to 50.0 parts by weight of the non-grafted maleimide polymer per 100 parts by weight of the base resin.

[0016] Furthermore, 9) the present invention provides the thermoplastic resin composition according to 7) or 8), wherein the non-grafted maleimide polymer is a terpolymer consisting of maleimide monomer units, vinyl aromatic monomer units, and maleic acid monomer units.

[0017] Further, 10) the present invention provides the thermoplastic resin composition according to any one of the above 7) to 9), wherein the non-grafted maleimide polymer is an N-phenylmaleimide / styrene / maleic anhydride polymer. [Effects of the Invention]

[0018] The thermoplastic resin composition according to one embodiment of the present invention is excellent in all of processability, impact resistance, heat resistance and chemical resistance. DETAILED DESCRIPTION OF THE INVENTION

[0019] The present invention will now be described in more detail to aid in understanding the present invention.

[0020] The terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted as having meanings and concepts that are consistent with the technical idea of ​​the present invention, based on the principle that inventors can appropriately define the concepts of terms in order to best explain their inventions.

[0021] In the present invention, the diene rubber polymer may be produced by polymerizing, specifically, crosslinking, a diene monomer or a monomer mixture containing a diene monomer as a main component. The diene monomer may be one or more of 1,3-butadiene, isoprene, chloroprene, and piperylene, among which 1,3-butadiene is preferred.

[0022] In the present invention, the vinyl aromatic monomer may be one or more of α-methylstyrene, α-ethylstyrene, p-methylstyrene, 2,4-dimethylstyrene, styrene, p-fluorostyrene, p-chlorostyrene, and p-bromostyrene, among which styrene is preferred. The unit derived from the vinyl aromatic monomer may be a vinyl aromatic monomer unit.

[0023] In the present invention, the vinyl cyanide-based monomer may be one or more of acrylonitrile, methacrylonitrile, (Z)-3-phenylacrylonitrile, and α-chloroacrylonitrile, among which acrylonitrile is preferred. The unit derived from the vinyl cyanide-based monomer may be a vinyl cyanide-based monomer unit.

[0024] In the present invention, the olefinic monomer may be one or more of ethylene, propylene, and butylene, among which ethylene is preferred. The unit derived from the olefinic monomer may be an olefinic monomer unit.

[0025] In the present invention, the (meth)acrylate monomer can refer to both an acrylate monomer and a methacrylate monomer. The (meth)acrylate monomer is a C1 to C 10 The unit derived from the (meth)acrylate monomer may be one or more of methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, heptyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and decyl (meth)acrylate, and among these, one or more of ethyl acrylate and butyl acrylate are preferred. The unit derived from the (meth)acrylate monomer may be a (meth)acrylate monomer unit.

[0026] In the present invention, the maleimide-based monomer may be one or more of maleimide, N-methylmaleimide, N-ethylmaleimide, N-propylmaleimide, N-isopropylmaleimide, N-butylmaleimide, N-isobutylmaleimide, Nt-butylmaleimide, N-laurylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, N-(4-chlorophenyl)maleimide, 2-methyl-N-phenylmaleimide, N-(4-bromophenyl)maleimide, N-(4-nitrophenyl)maleimide, N-(4-hydroxyphenyl)maleimide, N-(4-methoxyphenyl)maleimide, N-(4-carboxyphenyl)maleimide, and N-benzylmaleimide, among which N-phenylmaleimide is preferred. The unit derived from the maleimide-based monomer may be a maleimide-based monomer unit.

[0027] In the present invention, the maleic acid-based monomer may be one or more of maleic anhydride, maleic acid, maleic acid monoester, and maleic acid diester, among which maleic anhydride is preferred. The unit derived from the maleic acid-based monomer may be a maleic acid-based monomer unit.

[0028] In the present invention, the graft ratio of the diene graft polymer can be calculated by the following method.

[0029] First, 2 g of diene graft polymer powder is dissolved in 300 ml of acetone with stirring for 24 hours, and then separated using a centrifuge to obtain a precipitate. This precipitate is dried at 60 to 120°C to obtain a dried product. The weight of this dried product is then measured. The weight can be measured by substituting the weight of the dried product into the following formula.

[0030] Graft rate (%) = [(weight of diene graft polymer powder (2 g)) - (weight of dry material) - (weight of diene rubber polymer)] / (weight of diene rubber polymer) x 100

[0031] Weight of diene rubber polymer: Weight of diene rubber polymer theoretically contained in 2 g of diene graft polymer powder; or weight of diene rubber polymer measured by infrared spectroscopy of 2 g of diene graft polymer powder.

[0032] In the present invention, the weight average molecular weight of the shell of a diene-based graft polymer may refer to the weight average molecular weight of a polymer containing vinyl aromatic monomer units and vinyl cyanide monomer units grafted to a diene-based rubber polymer.

[0033] In the present invention, the weight average molecular weight of the shell of the diene graft polymer can be calculated by the following method.

[0034] The diene graft polymer can be dissolved in tetrahydrofuran (THF) solution (concentration: 1 wt%) and then filtered through a 1 μm filter. The material that passes through the 1 μm filter can be subjected to gel permeation chromatography to measure the shell weight average molecular weight relative to a standard polystyrene sample.

[0035] In the present invention, the weight average molecular weight can be measured as a relative value to that of a polystyrene standard sample by gel permeation chromatography using tetrahydrofuran as an eluent.

[0036] In the present invention, the glass transition temperature can be measured by differential scanning calorimetry.

[0037] In the present invention, the average particle size can be measured using a dynamic light scattering method, specifically, using a Nicomp 380 device manufactured by Particle Sizing Systems, Inc. In the present invention, the average particle size can refer to the arithmetic mean particle size in the particle size distribution measured by the dynamic light scattering method, i.e., the intensity distribution mean particle size.

[0038] 1.Thermoplastic resin composition A thermoplastic resin composition according to one embodiment of the present invention comprises: 1) a base resin comprising a diene-based graft polymer and a vinyl-based non-graft polymer comprising a vinyl aromatic-based monomer unit and a vinyl cyanide-based monomer unit; and 2) an additive comprising an olefin-based non-graft polymer comprising an olefin-based monomer unit, a (meth)acrylate-based monomer unit, and a maleic acid-based monomer unit.

[0039] The base resin may include a maleimide-based non-grafted polymer containing a maleimide-based monomer unit, a vinyl aromatic-based monomer unit, and a maleic acid-based monomer unit.

[0040] The components of the thermoplastic resin composition according to one embodiment of the present invention will be described in detail below.

[0041] 1) Base resin (1) Diene-based graft polymer The diene graft polymer is a component that improves the impact resistance, tensile strength and stress of the thermoplastic resin composition.

[0042] The diene graft polymer may include a diene rubber polymer and a shell including vinyl aromatic monomer units and vinyl cyanide monomer units grafted to the diene rubber polymer. The shell may also include vinyl aromatic monomer units and vinyl cyanide monomer units that are not grafted to the diene rubber polymer.

[0043] The diene rubber polymer may have an average particle size of 50 to 500 nm, preferably 70 to 470 nm. If the above conditions are satisfied, the impact resistance and surface properties of the diene graft polymer can all be improved.

[0044] The diene graft polymer may have a diene rubber polymer content of 40.0 to 80.0% by weight, preferably 50.0 to 70.0% by weight. When the above conditions are satisfied, the impact resistance of the diene graft polymer can be further improved.

[0045] The content of the vinyl aromatic monomer unit in the diene graft polymer may be 10.0 to 50.0% by weight, preferably 20.0 to 40.0% by weight. When the above conditions are satisfied, the processability of the diene graft polymer can be further improved.

[0046] The content of vinyl cyanide monomer units in the diene graft polymer may be 1.0 to 30.0% by weight, preferably 5.0 to 25.0% by weight. When the above conditions are satisfied, the chemical resistance of the diene graft polymer can be further improved.

[0047] The graft ratio of the diene graft polymer may be 10.0 to 50.0%, preferably 20.0 to 45.0%. When the above conditions are satisfied, excellent impact resistance and tensile strength can be achieved.

[0048] The weight average molecular weight of the shell of the diene graft polymer may be 50,000 to 130,000 g / mol, preferably 60,000 to 100,000 g / mol. When the above conditions are satisfied, excellent impact resistance and tensile strength can be achieved.

[0049] The content of the diene graft polymer may be 10.0 to 40.0 parts by weight, preferably 15.0 to 35.0 parts by weight, and more preferably 20.0 to 30.0 parts by weight, relative to 100 parts by weight of the base resin. When the above conditions are satisfied, the impact resistance, tensile strength, and stress of the thermoplastic resin composition can be further improved.

[0050] (2) Vinyl-based non-graft polymer The vinyl-based non-grafted polymer is a component that improves the processability of the thermoplastic resin composition.

[0051] The vinyl-based non-graft polymer may include a vinyl aromatic monomer unit and a vinyl cyanide monomer unit, and may preferably be a bipolymer consisting of a vinyl aromatic monomer unit and a vinyl cyanide monomer unit.

[0052] The vinyl-based non-graft polymer may contain vinyl aromatic monomer units and vinyl cyanide monomer units in a weight ratio of 90:10 to 60:40, preferably 85:15 to 65:35. By satisfying the above conditions, a vinyl-based non-graft polymer with improved processability and chemical resistance can be produced.

[0053] The vinyl-based non-graft polymer may be included as the remainder so that the total of the constituent elements of the base resin is 100 parts by weight.

[0054] (3) Maleimide-based non-graft polymer The maleimide-based non-grafted polymer is a component that improves the heat resistance of the thermoplastic resin composition.

[0055] The non-grafted maleimide polymer contains a maleimide monomer unit, a vinyl aromatic monomer unit, and a maleic acid monomer unit, and is preferably a terpolymer consisting of a maleimide monomer unit, a vinyl aromatic monomer unit, and a maleic acid monomer unit, and more preferably an N-phenylmaleimide / styrene / maleic anhydride terpolymer.

[0056] The non-grafted maleimide polymer may contain 40.0 to 60.0% by weight, preferably 45.0 to 55.0% by weight, of maleimide monomer units. When the above range is satisfied, heat resistance can be improved.

[0057] The non-grafted maleimide polymer may contain 35.0 to 55.0% by weight, preferably 40.0 to 50.0% by weight, of vinyl aromatic monomer units. When the above range is satisfied, impact resistance can be improved.

[0058] The non-grafted maleimide polymer may contain 0.01 to 10.0% by weight, preferably 0.50 to 7.0% by weight, of maleic acid monomer units. When the above range is satisfied, heat resistance can be improved.

[0059] The non-grafted maleimide polymer may have a glass transition temperature of 175 to 210° C., preferably 180 to 205° C., and more preferably 182 to 320° C. If the above conditions are satisfied, the heat resistance of the thermoplastic resin composition can be further improved.

[0060] The non-grafted maleimide polymer may have a weight average molecular weight of 75,000 to 150,000 g / mol, preferably 80,000 to 130,000 g / mol. When the above conditions are satisfied, the impact resistance, processability, and heat resistance of the thermoplastic resin composition can be improved.

[0061] The content of the non-grafted maleimide polymer may be 10.0 to 50.0 parts by weight, preferably 15.0 to 45.0 parts by weight, and more preferably 20.0 to 40.0 parts by weight, relative to 100 parts by weight of the base resin. When the above conditions are met, the deterioration of the impact resistance and processability of the thermoplastic resin composition can be minimized, and the heat resistance can be significantly improved.

[0062] 2) Additives (1) Olefin-based non-graft polymer The olefin-based non-grafted polymer is a component that improves the chemical resistance of the thermoplastic resin composition.

[0063] The non-grafted olefin polymer contains an olefin monomer unit, a (meth)acrylate monomer unit, and a maleic acid monomer unit, and is preferably a terpolymer consisting of an olefin monomer unit, a (meth)acrylate monomer unit, and a maleic acid monomer unit, and more preferably, the polymer is an ethylene / ethyl acrylate / maleic anhydride polymer.

[0064] The content of the olefinic monomer unit may be 60.0 to 80.0 wt %, preferably 65.0 to 75.0 wt %, based on the total weight of the non-grafted olefinic polymer. When the above conditions are satisfied, the chemical resistance of the thermoplastic resin composition can be improved.

[0065] The content of the (meth)acrylate monomer unit may be 19.0 to 39.0 wt %, preferably 24.0 to 34.0 wt %, based on the total weight of the non-grafted olefin polymer. When the above conditions are satisfied, the chemical resistance of the thermoplastic resin composition can be improved.

[0066] The content of the maleic acid-based monomer unit may be 0.1 to 5.0 wt %, preferably 0.1 to 3.0 wt %, based on the total weight of the non-grafted olefin polymer. When the above conditions are satisfied, the basic physical properties such as impact resistance of the thermoplastic resin composition can be maintained, and chemical resistance can be improved.

[0067] The content of the non-grafted olefin polymer may be 0.5 to 5.0 parts by weight, preferably 0.5 to 3.0 parts by weight, based on 100 parts by weight of the base resin. When the above conditions are met, the deterioration of impact resistance, processability, and heat resistance can be minimized, and chemical resistance can be improved.

[0068] While the present invention may be embodied in various different forms, it is to be understood that the invention is not limited to the specific embodiments set forth herein, and that the invention may be embodied in various different forms without departing from the spirit or scope of the present invention.

[0069] Examples and Comparative Examples The components used in the following examples and comparative examples are explained below. 1) Base resin (1) Diene-based graft polymer: 60.0 wt. % polybutadiene rubber polymer with an average particle size of 300 nm and a shell containing 30.0 wt. % styrene units and 10.0 wt. % acrylonitrile units grafted onto the polybutadiene rubber polymer. Shell weight-average molecular weight: 80,000 g / mol, graft ratio: 35%

[0070] (2) Vinyl-based non-graft polymer: a styrene / acrylonitrile bipolymer having a weight-average molecular weight of 130,000 g / mol and produced by polymerizing 73% by weight of styrene and 27% by weight of acrylonitrile.

[0071] (3) Maleimide-based non-graft polymer: N-phenylmaleimide / styrene / maleic anhydride terpolymer having a weight average molecular weight of 125,000 g / mol and a glass transition temperature of 185°C, prepared by polymerizing 52.0 wt% N-phenylmaleimide, 46.0 wt% styrene, and 2.0 wt% maleic anhydride.

[0072] 2) Additives (1) Olefin-based non-graft polymer: a terpolymer of ethylene / ethyl acrylate / maleic anhydride having a melting point of 79°C and produced by polymerizing 69.7% by weight of ethylene, 29% by weight of ethyl acrylate, and 1.3% by weight of maleic anhydride.

[0073] (2) Ethylene / methyl acrylate copolymer: melting point is 91°C, produced by polymerizing 76% by weight of ethylene and 24% by weight of methyl acrylate.

[0074] The above-mentioned components were mixed in the amounts shown in Tables 1 and 2 below and stirred to prepare thermoplastic resin compositions.

[0075] Experimental Example 1 The thermoplastic resin compositions of the Examples and Comparative Examples were extruded to produce pellets, and the pellets were evaluated by the methods described below. The results are shown in Tables 1 and 2 below.

[0076] (1) Melt Flow Index (g / 10 min): Measured according to ASTM D1238 under conditions of 220°C and 10 kg. In the present invention, a melt flow index of 4.0 g / 10 min or more was determined to be excellent in processability.

[0077] Experimental Example 2 The thermoplastic resin compositions of the examples and comparative examples were extruded and injected to prepare test pieces, which were then evaluated by the methods described below. The results are shown in Tables 1 to 4 below.

[0078] (2) Izod impact strength (kg·cm / cm, 1 / 4 inch): Measured according to ASTM D256. In the present invention, an Izod impact strength of 10.0 kg·cm / cm or more was determined to be excellent in impact resistance.

[0079] (3) Heat Deflection Temperature (°C): Measured under unanealed conditions in accordance with ASTM D648. In the present invention, a heat distortion temperature of 90.0°C or higher was determined to be excellent in heat resistance.

[0080] (4) Chemical resistance: A test piece (200 mm x 12.7 mm x 3.2 mm) was fixed to a curved jig with a stress of 1.1%, and 1 cc of thinner (T803 manufactured by NOROOBEE Chemical Co., Ltd.) was applied to it. The time until cracks appeared on the test piece was measured.

[0081] ○: No cracks occurred within 600 seconds after thinner application ×: If cracks occur within 600 seconds after thinner application

[0082] [Table 1]

[0083] [Table 2]

[0084] Referring to Tables 1 and 2, Example 1, which is a thermoplastic resin composition containing a diene graft polymer and a vinyl non-graft polymer as the base resin and an olefin non-graft polymer as the additive, was excellent in flow index, impact strength, and chemical resistance, and its heat distortion temperature was also at an appropriate level. Examples 2 to 6, which contain a diene graft polymer, a vinyl non-graft polymer, and a maleimide non-graft polymer as the base resin and an olefin non-graft polymer as the additive, were excellent in flow index, impact strength, and chemical resistance, and also had high heat distortion temperatures.

[0085] Furthermore, when Example 2 and Example 3 are compared, it is found that as the content of the non-grafted olefin polymer increases, the flow index and impact strength improve, but the heat distortion temperature decreases somewhat.

[0086] Furthermore, when Examples 1, 2 and 6 are compared, it is found that the non-grafted maleimide polymer increases the heat distortion temperature but decreases the flow index and impact strength.

[0087] Furthermore, when Examples 4 to 6 are compared, it is found that the content of the non-grafted olefin polymer affects the heat distortion temperature.

[0088] Furthermore, when Example 1 is compared with Comparative Example 1, Example 1 has significantly higher chemical resistance than Comparative Example 1, which does not contain an olefin-based non-grafted polymer.

[0089] Furthermore, when Examples 4 to 6 are compared with Comparative Example 2, Examples 4 to 6 are superior in impact strength and chemical resistance compared to Comparative Example 2, which does not contain an olefin-based non-grafted polymer, but the heat distortion temperature is somewhat lower.

[0090] Furthermore, when Example 5 is compared with Comparative Example 3, Example 5 has significantly better impact strength and chemical resistance than Comparative Example 3, which contains an ethylene / methyl acrylate copolymer instead of an olefin-based non-grafted polymer.

[0091] Furthermore, when Example 6 is compared with Comparative Example 4, Example 5 has significantly better impact strength and chemical resistance than Comparative Example 4, which contains an ethylene / methyl acrylate copolymer instead of an olefin-based non-grafted polymer.

Claims

1. a base resin including a diene-based graft polymer and a vinyl-based non-graft polymer including vinyl aromatic monomer units and vinyl cyanide monomer units; a thermoplastic resin composition comprising an additive including an olefin-based non-grafted polymer containing an olefin-based monomer unit, a (meth)acrylate-based monomer unit, and a maleic acid-based monomer unit;

2. For 100 parts by weight of the base resin, 2. The thermoplastic resin composition according to claim 1, comprising 0.5 to 5.0 parts by weight of the non-grafted olefin polymer.

3. 2. The thermoplastic resin composition according to claim 1, wherein the non-grafted olefin polymer is a terpolymer consisting of an olefin monomer unit, a (meth)acrylate monomer unit, and a maleic acid monomer unit.

4. 2. The thermoplastic resin composition according to claim 1, wherein the non-grafted olefin polymer is an ethylene / ethyl acrylate / maleic anhydride terpolymer.

5. 2. The thermoplastic resin composition according to claim 1, wherein the diene-based graft polymer comprises a diene-based rubber polymer and a shell containing vinyl aromatic-based monomer units and vinyl cyanide-based monomer units grafted to the diene-based rubber polymer.

6. 2. The thermoplastic resin composition according to claim 1, comprising 10.0 to 40.0 parts by weight of the diene graft polymer relative to 100 parts by weight of the base resin.

7. 2. The thermoplastic resin composition according to claim 1, wherein the base resin comprises a maleimide-based non-grafted polymer containing maleimide-based monomer units, vinyl aromatic-based monomer units, and maleic acid-based monomer units.

8. For 100 parts by weight of the base resin, The thermoplastic resin composition according to claim 7, comprising 10.0 to 50.0 parts by weight of the non-grafted maleimide polymer.

9. 8. The thermoplastic resin composition according to claim 7, wherein the non-grafted maleimide polymer is a terpolymer consisting of maleimide monomer units, vinyl aromatic monomer units, and maleic acid monomer units.

10. 8. The thermoplastic resin composition according to claim 7, wherein the non-grafted maleimide polymer is an N-phenylmaleimide / styrene / maleic anhydride polymer.

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