Thermoplastic resin composition

Abstract

This invention relates to a thermoplastic resin composition comprising a grafted polymer comprising a gel content of 0% to 10% by weight and a rubber polymer comprising aromatic vinyl monomer units and diene monomer units, and a shell comprising (meth)acrylate monomer units and aromatic vinyl monomer units grafted onto the rubber polymer; and a non-grafted polymer comprising (meth)acrylate monomer units and aromatic vinyl monomer units, wherein the refractive index difference between the grafted polymer and the non-grafted polymer is less than 0.0100.

Description

Technical Field

[0001] Cross-references to related applications

[0002] This application claims priority and benefit to Korean Patent Application No. 10-2021-0098174, filed on July 26, 2021, and Korean Patent Application No. 10-2022-0088183, filed on July 18, 2022, the disclosures of which are incorporated herein by reference in their entirety. Technical Field

[0004] This invention relates to a thermoplastic resin composition, and more specifically, to a thermoplastic resin composition capable of achieving excellent matte properties / transparency and impact resistance. Background Technology

[0005] As transparent resins, polycarbonate, polymethyl methacrylate (PMMA), polystyrene, and polyacrylonitrile-styrene are commonly used. In the case of polycarbonate, impact resistance and transparency are excellent, but it is difficult to manufacture complex products due to reduced processability, and it has poor chemical resistance. Furthermore, the use of polycarbonate is increasingly limited because bisphenol A is a raw material for it. Additionally, when ordinary PMMA is mixed with PMMA beads prepared through crosslinking polymerization, excellent transparency is exhibited, but impact resistance and chemical resistance are poor. Moreover, in the cases of polystyrene and polyacrylonitrile-styrene, both impact resistance and chemical resistance are poor.

[0006] To address the aforementioned issues, a diene-grafted polymer comprising (meth)acrylate monomer units and aromatic vinyl monomer units grafted onto diene-based rubber polymers is proposed.

[0007] However, with the progress of industry and the diversification of life in recent years, it is necessary to inject high functionality such as matte properties / transparency into complex structures, but it is difficult to achieve all of the above conditions for diene graft polymers.

[0008] [Related Technical Documents]

[0009] [Patent Literature]

[0010] (Patent Document 1) JP1995-025975B Summary of the Invention

[0011] Technical issues

[0012] The present invention aims to provide a thermoplastic resin composition that achieves excellent matte properties / transparency, impact resistance, and processability.

[0013] Technical solution

[0014] 1) One aspect of the present invention provides a thermoplastic resin composition comprising: a grafted polymer comprising a rubber polymer having a gel content of 0% to 10% by weight and comprising aromatic vinyl monomer units and diene monomer units, and a shell comprising (meth)acrylate monomer units and aromatic vinyl monomer units grafted onto the rubber polymer; and a non-grafted polymer comprising (meth)acrylate monomer units and aromatic vinyl monomer units, wherein the refractive index difference between the grafted polymer and the non-grafted polymer is less than 0.0100.

[0015] 2) According to 1), the present invention provides a thermoplastic resin composition wherein the gel content of the rubber polymer is from 0% by weight to 5% by weight.

[0016] 3) According to 1) or 2), the present invention provides a thermoplastic resin composition wherein the rubber polymer comprises the aromatic vinyl monomer units and the diene monomer units in a weight ratio of 10:90 to 35:65.

[0017] 4) According to any one of 1) to 3), the present invention provides a thermoplastic resin composition wherein the average particle size of the rubber polymer is 20 nm to 100 nm.

[0018] 5) According to any one of 1) to 4), the present invention provides a thermoplastic resin composition, wherein the graft polymer comprises: 30.0% to 65.0% by weight of the rubber polymer; 10.0% to 55.0% by weight of the (meth)acrylate monomer unit; and 5.0% to 40.0% by weight of the aromatic vinyl monomer unit.

[0019] 6) According to any one of 1) to 5), the present invention provides a thermoplastic resin composition, wherein the ungrafted polymer comprises: 39.0% to 65.0% by weight of the (meth)acrylate monomer unit; and 35.0% to 61.0% by weight of the aromatic vinyl monomer unit.

[0020] 7) According to any one of 1) to 6), the present invention provides a thermoplastic resin composition comprising: 10.0% to 70.0% by weight of the grafted polymer; and 30.0% to 90.0% by weight of the ungrafted polymer.

[0021] 8) According to any one of 1) to 7), the present invention provides a thermoplastic resin composition, wherein the shell of the grafted polymer comprises vinyl cyanide monomer units grafted to the rubber polymer, and the ungrafted polymer comprises vinyl cyanide monomer units.

[0022] 9) According to any one of 1) to 8), the present invention provides a thermoplastic resin composition wherein each of the grafted polymer and the ungrafted polymer has a refractive index of 1.5230 to 1.5420.

[0023] 10) According to any one of 1) to 9), the present invention provides a thermoplastic resin composition comprising: 5.0% to 35.0% by weight of a rubber polymer; 24.0% to 60.0% by weight of (meth)acrylate monomer units; and 19.0% to 47.0% by weight of aromatic vinyl monomer units.

[0024] Beneficial effects

[0025] The thermoplastic resin compositions according to the present invention can achieve excellent transparency, impact resistance, matte finish and processability. Attached Figure Description

[0026] Figure 1 Images comparing the sample prepared according to Example 3 and the sample prepared according to Comparative Example 4 are shown. Detailed Implementation

[0027] The terms and words used in this specification and claims should not be construed as limited to their common or dictionary meanings, and based on the principle that inventors may appropriately define the concepts of terms in order to best describe their inventions, the terms and words should be interpreted as having meanings and concepts consistent with the technical spirit of the invention.

[0028] In this invention, the gel content is calculated as follows: The rubber polymer latex is coagulated with a diluted acid or metal salt, washed, and dried in a vacuum oven at 60°C for 24 hours to obtain a rubber mass. The mass is then cut into 1g rubber sections, which are placed in 100g of toluene and stored in a dark room at 23°C for 48 hours to separate the sol and gel. The weights of the sol and gel are substituted into the following equation to calculate the gel content. In this case, although there is no particular limitation on the type of diluted acid, it is preferably one or more selected from hydrochloric acid, sulfuric acid, formic acid, etc. Furthermore, although there is no particular limitation on the type of metal salt, it is preferably one or more selected from magnesium sulfate, calcium chloride, aluminum sulfate, etc.

[0029] Gel content (wt%) = Gel weight / (Weight of rubber segment) × 100

[0030] In this invention, refractive index refers to the absolute refractive index of a material and is considered as the ratio of the velocity of electromagnetic radiation in free space to the velocity of radiation in the material, wherein the radiation can be visible light with wavelengths from 450 nm to 680 nm, specifically visible light with a wavelength of 589.3 nm. The refractive index can be measured by known methods, namely, using an Abbe refractometer.

[0031] In this invention, after the grafted and ungrafted polymers are spread to a thickness of 0.2 mm, the refractive index can be measured using an Abbe refractometer at 25°C with visible light at a wavelength of 589.3 nm.

[0032] In this invention, the average particle size can be measured by dynamic light scattering, specifically using a Nicomp380 instrument (commercially available from Particle Sizing Systems). In this invention, the average particle size can 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.

[0033] In this invention, the average particle size can be measured using a transmission electron microscope (TEM).

[0034] In this invention, the weights of the rubber polymer, diene monomer units, (meth)acrylate monomer units, aromatic vinyl monomer units, and vinyl cyanide monomer units contained in the thermoplastic resin composition can be measured by infrared (IR) spectroscopy. In this case, Nicolet can be used as the IR spectrometer. TM iS20 FTIR spectrometer (purchased from Thermo Scientific).

[0035] In this invention, polymerization conversion rate refers to the degree to which monomers polymerize to form polymers, and can be calculated using the following equation.

[0036] Polymerization conversion (%) = {(Total weight of monomers added before polymerization termination) - (Total weight of unreacted monomers at the time point when polymerization conversion is measured)} / (Total weight of monomers added before polymerization termination) × 100

[0037] In this invention, the diene monomer unit can be a unit derived from a diene monomer. The diene monomer can be selected from one or more of 1,3-butadiene, isoprene, chloroprene, and isoprene, preferably 1,3-butadiene.

[0038] In this invention, the aromatic vinyl monomer unit can be a unit derived from an aromatic vinyl monomer. The aromatic vinyl monomer can be selected from one or more of styrene, α-methylstyrene, α-ethylstyrene, and p-methylstyrene, preferably styrene.

[0039] In this invention, the (meth)acrylate monomer unit can be a unit derived from a (meth)acrylate monomer. The (meth)acrylate monomer can be a term encompassing both acrylate monomers and methacrylate monomers. The (meth)acrylate monomer can be C1 to C2. 10 Alkyl (meth)acrylate monomers, and the C1 to C1... 10 The alkyl (meth)acrylate monomers may be selected from 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, with methyl methacrylate being preferred.

[0040] In this invention, the vinyl cyanide monomer unit can be a unit derived from a vinyl cyanide monomer. The vinyl cyanide monomer can be selected from one or more of acrylonitrile, methacrylonitrile, phenylacrylonitrile, and α-chloroacrylonitrile, preferably acrylonitrile.

[0041] In this invention, the emulsifier may be selected from one or more of sodium dicyclohexyl sulfosuccinate, sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, sodium octadecyl sulfate, sodium oleyl sulfate, potassium dodecyl sulfate, potassium octadecyl sulfate, potassium oleate, sodium oleate, potassium rosinate, and sodium rosinate. Among those listed above, one or more of potassium oleate, sodium oleate, and potassium rosinate are preferred.

[0042] In this invention, the initiator may be selected from one or more of potassium persulfate, sodium persulfate, ammonium persulfate, cumene hydroperoxide, diisopropylbenzene hydroperoxide, azobisisobutyronitrile, tert-butyl hydroperoxide, p-menthane hydroperoxide, benzoyl peroxide, and 1,1-di(tert-butylperoxide)cyclohexane. Of those listed above, one or more of potassium persulfate, cumene hydroperoxide, and 1,1-di(tert-butylperoxide)cyclohexane are preferred.

[0043] In this invention, the molecular weight control agent may be selected from one or more of α-methylstyrene dimer, tert-dodecyl mercaptan, n-dodecyl mercaptan, tert-octyl mercaptan, n-octyl mercaptan, carbon tetrachloride, dichloromethane, dibromomethane, tetraethylthiuram disulfide, dipentylthiuram disulfide, and diisopropyl xanthate disulfide. Among those listed above, tert-dodecyl mercaptan is preferred.

[0044] In this invention, the redox catalyst may be selected from one or more of sodium formaldeh(V) sulfoxylate, sodium ethylenediaminetetraacetate, ferrous sulfate, glucose, tetrasodium pyrophosphate, anhydrous sodium pyrophosphate, and sodium sulfate. Among those listed above, one or more of ferrous sulfate, glucose, and tetrasodium pyrophosphate are preferred.

[0045] In this invention, the aqueous solvent can be ion-exchanged water or deionized water.

[0046] 1. Thermoplastic resin composition

[0047] A thermoplastic resin composition according to one aspect of the invention comprises: a grafted polymer comprising a rubber polymer having a gel content of 0% to 10% by weight and comprising aromatic vinyl monomer units and diene monomer units, and a shell comprising (meth)acrylate monomer units and aromatic vinyl monomer units grafted onto the rubber polymer; and a non-grafted polymer comprising (meth)acrylate monomer units and aromatic vinyl monomer units, wherein the refractive index difference between the grafted polymer and the non-grafted polymer is less than 0.0100.

[0048] The refractive indices of the grafted polymer and the ungrafted polymer included in the thermoplastic resin composition according to the present invention can differ by less than 0.0100, preferably less than 0.0050, more preferably less than 0.0035, even more preferably less than 0.0005, and most preferably 0. When the above conditions are met, the thermoplastic resin composition can achieve excellent transparency.

[0049] The thermoplastic resin composition according to the present invention may comprise 10% to 70% by weight of a grafted polymer and 30% to 90% by weight of a non-grafted polymer, preferably 15% to 65% by weight of a grafted polymer and 35% to 85% by weight of a non-grafted polymer, more preferably 15% to 35% by weight of a grafted polymer and 65% to 85% by weight of a non-grafted polymer. When the above conditions are met, the thermoplastic resin composition can achieve excellent impact resistance and processability.

[0050] The thermoplastic resin composition according to the invention may contain 5.0% to 35.0% by weight of a rubber polymer, preferably 10.0% to 30.0% by weight. When the above conditions are met, the thermoplastic resin composition can achieve excellent impact resistance.

[0051] The thermoplastic resin composition according to the invention may contain 24.0% to 60.0% by weight of (meth)acrylate monomer units, preferably 29.0% to 55.0% by weight. When the above conditions are met, the thermoplastic resin composition can achieve excellent transparency.

[0052] Furthermore, the thermoplastic resin composition according to the invention may contain 19.0% to 47.0% by weight of aromatic vinyl monomer units, preferably 23.0% to 42.0% by weight. When the above conditions are met, the thermoplastic resin composition can achieve excellent processability.

[0053] Furthermore, the thermoplastic resin composition according to the present invention may also contain vinyl cyanide monomer units to achieve excellent chemical resistance. In this case, the content of vinyl cyanide monomer units may be 10.0% by weight or less, preferably 5% by weight or less. When the above conditions are met, excellent chemical resistance can be achieved while minimizing yellowing caused by vinyl cyanide monomer units.

[0054] The grafted polymers and ungrafted polymers that are components of the present invention will be described in detail below.

[0055] 1) Grafted polymers

[0056] The grafted polymer comprises a rubber polymer having a gel content of 0% to 10% by weight and containing aromatic vinyl monomer units and diene monomer units; and a shell comprising (meth)acrylate monomer units and aromatic vinyl monomer units grafted onto the rubber polymer. Furthermore, the shell may contain (meth)acrylate monomer units and aromatic vinyl monomer units not grafted onto the rubber polymer. To improve the chemical resistance of the grafted polymer, the shell may also contain vinyl cyanide monomer units grafted onto or not grafted onto the rubber polymer.

[0057] The gel content of the rubber polymer can be from 0% to 10% by weight, preferably from 0% to 5% by weight, and more preferably from 0% to 1% by weight. When the above range is met, the thermoplastic resin composition can achieve excellent matte properties and impact resistance. However, above the above range, the thermoplastic resin composition may not achieve matte properties, and the impact resistance may degrade significantly.

[0058] Simultaneously, the gel content of the rubber polymer can be adjusted by the polymerization temperature and the final polymerization conversion rate. The rubber polymer satisfying the above gel content can be prepared by initiating and carrying out the polymerization of aromatic vinyl monomer units and diene monomer units at 0°C to 20°C, and terminating the polymerization when the polymerization conversion rate reaches 40% to 60%. Preferably, the rubber polymer satisfying the above gel content can be prepared by initiating and carrying out the polymerization of aromatic vinyl monomer units and diene monomer units at 5°C to 15°C, and terminating the polymerization when the polymerization conversion rate reaches 45% to 55%.

[0059] If either of the above polymerization temperature and polymerization termination point is not met, it may be difficult to prepare a rubber polymer that meets the above gel content.

[0060] The polymerization can be emulsion polymerization, and can be carried out in the presence of one or more selected from emulsifiers, initiators, molecular weight control agents, redox catalysts and aqueous solvents.

[0061] The amount of emulsifier can be from 1.0 to 10.0 parts by weight, preferably from 3.0 to 7.0 parts by weight, relative to 100 parts by weight of total monomers added during the preparation of the rubber polymer. When the above conditions are met, polymerization stability and latex stability can be improved, and adjustments can be made to ensure that the rubber polymer has a desired average particle size.

[0062] The amount of initiator can be 0.1 to 0.5 parts by weight, preferably 0.1 to 0.3 parts by weight, relative to 100 parts by weight of total monomers added during the preparation of the rubber polymer. When the above conditions are met, emulsion polymerization can be stably initiated and carried out.

[0063] The amount of the molecular weight control agent can be 0.1 to 1.7 parts by weight, preferably 0.3 to 1.5 parts by weight, and more preferably 0.5 to 1.3 parts by weight, relative to 100 parts by weight of total monomers added during the preparation of the rubber polymer. When the above conditions are met, the gel content of the rubber polymer can be finely adjusted. Increasing the content of the molecular weight control agent can decrease the gel content, and decreasing the content of the molecular weight control agent can increase the gel content.

[0064] The amount of redox catalyst can be from 0.010 parts by weight to 0.100 parts by weight, preferably from 0.030 parts by weight to 0.080 parts by weight, relative to 100 parts by weight of total monomers added during the preparation of rubber polymer.

[0065] Meanwhile, in the case of rubber polymers containing only diene monomer units, an excess of (meth)acrylate monomer units is required in the matrix portion to prevent or minimize the refractive index difference between the impact-modified portion and the matrix portion of the thermoplastic resin composition. However, due to the high unit cost of (meth)acrylate monomers, these units lead to degradation of the chemical resistance of the thermoplastic resin composition and increased manufacturing costs. Furthermore, rubber polymers cannot be prepared using only aromatic vinyl monomers.

[0066] However, since the rubber polymer contains not only diene monomer units but also aromatic vinyl monomer units, the refractive index of the rubber polymer can be increased, and correspondingly, a small amount of (meth)acrylate monomer units can be included in the matrix portion. Therefore, the thermoplastic resin composition according to the invention can minimize the chemical degradation and increased manufacturing cost caused by (meth)acrylate monomer units.

[0067] The rubber polymer may contain aromatic vinyl monomer units and diene monomer units in a weight ratio of 10:90 to 35:65, preferably 15:85 to 30:70. When the above conditions are met, impact resistance can be improved and the refractive index can be increased, thus reducing the amount of (meth)acrylate monomer units used and minimizing the chemical degradation and increased manufacturing costs caused by (meth)acrylate monomer units.

[0068] By including diene monomer units and aromatic vinyl monomer units in the above weight ratio, the rubber polymer can have a higher refractive index than a rubber polymer composed solely of diene monomers. As a specific example, the rubber polymer can have a refractive index of 1.5230 to 1.5420, preferably 1.5300 to 1.5400.

[0069] The average particle size of the rubber polymer can be from 20 nm to 100 nm, preferably from 20 nm to 80 nm. When the above range is met, excellent matte properties and impact resistance can be achieved.

[0070] The grafted polymer may contain 30.0% to 65.0% by weight of a rubber polymer, preferably 35.0% to 60.0% by weight. When the above range is met, excellent impact resistance can be achieved.

[0071] The graft polymer may contain 10.0% to 55.0% by weight of (meth)acrylate monomer units, preferably 15.0% to 50.0% by weight. When the above range is met, a certain level of transmittance is maintained, thus the graft polymer can achieve translucency.

[0072] The graft polymer may contain 5.0% to 40.0% by weight of aromatic vinyl monomer units, preferably 10.0% to 35.0% by weight. When the above range is met, excellent processability can be achieved.

[0073] The grafted polymer may further comprise vinyl cyanide monomer units, the content of which may be less than 7.0% by weight to achieve excellent chemical resistance and minimize yellowing. In this case, the content of the vinyl cyanide monomer units may refer to the content of vinyl cyanide monomer units grafted or ungrafted onto the rubber polymer.

[0074] The refractive index of the grafted polymer can be from 1.5230 to 1.5420, preferably from 1.5300 to 1.5400. When the above range is met, the refractive index is the same as or similar to that of the rubber polymer, thus improving the transparency of the grafted polymer.

[0075] 2) Non-grafted polymers

[0076] The ungrafted polymer comprises (meth)acrylate monomer units and aromatic vinyl monomer units. Furthermore, the ungrafted polymer may contain vinyl cyanide monomer units to achieve excellent chemical resistance.

[0077] The ungrafted polymer may contain 39.0% to 65.0% by weight of (meth)acrylate monomer units, preferably 40.0% to 60.0% by weight. When the above conditions are met, a thermoplastic resin composition achieving excellent transparency can be prepared.

[0078] The ungrafted polymer may contain 35.0% to 61.0% by weight of aromatic vinyl monomer units, preferably 40.0% to 60.0% by weight. When the above conditions are met, a thermoplastic resin composition achieving excellent processability can be prepared.

[0079] The ungrafted polymer may contain less than 12.0% by weight of vinyl cyanide monomer units. When the above conditions are met, a thermoplastic resin composition that achieves excellent chemical resistance while minimizing yellowing can be prepared.

[0080] The refractive index of the ungrafted polymer can be from 1.5230 to 1.5420, preferably from 1.5300 to 1.5400. When the above range is met, the refractive index is the same as or similar to that of the rubber polymer and the grafted polymer, thus an ungrafted polymer with improved transparency can be prepared.

[0081] The invention will be described in detail below with reference to embodiments that will enable those skilled in the art to readily implement it. However, the invention can be implemented in many different forms and is therefore not limited to the embodiments described herein.

[0082] Preparation Example 1

[0083] <Preparation of Rubber Polymers>

[0084] 200 parts by weight of deionized water, 20 parts by weight of styrene, 80 parts by weight of 1,3-butadiene, 2.0 parts by weight of potassium oleate, 3.0 parts by weight of potassium rosinate, 0.1 parts by weight of cumene hydroperoxide, 1.0 part by weight of tert-dodecyl mercaptan, 0.010 parts by weight of sodium pyrophosphate, 0.050 parts by weight of glucose, and 0.001 parts by weight of ferrous sulfate were added in batches to a nitrogen-purified polymerization reactor (autoclave) and polymerized at 10°C. When the polymerization conversion reached 50%, the polymerization was terminated to prepare a styrene / butadiene rubber polymer latex (gel content: 0 wt%, average particle size: 40 nm, refractive index: 1.5310).

[0085] <Preparation of Grafted Polymers>

[0086] A liquid mixture comprising 200 parts by weight of ion-exchanged water, 1.0 parts by weight of sodium oleate, 29.6 parts by weight of methyl methacrylate, 20.4 parts by weight of styrene, 0.6 parts by weight of tert-dodecyl mercaptan, 0.050 parts by weight of ethylenediaminetetraacetic acid, 0.100 parts by weight of sodium formaldehyde sulfoxylate, 0.001 parts by weight of ferrous sulfate, and 0.2 parts by weight of cumene hydroperoxide was prepared.

[0087] Fifty parts by weight (based on solids content) of styrene / butadiene rubber polymer latex were added to a reactor. Then, a liquid mixture was continuously added to the reactor at 60°C while polymerization continued for 5 hours. After the continuous addition of the liquid mixture was complete, aging was carried out at 60°C for 1 hour, and polymerization was terminated to prepare a grafted polymer latex. The entire amount of grafted polymer latex was added to an aqueous solution containing 2 parts by weight of calcium chloride, and the mixture was coagulated, aged, washed, dehydrated, and dried to prepare a grafted polymer powder (refractive index: 1.5310).

[0088] Preparation Example 2

[0089] <Preparation of Rubber Polymers>

[0090] 200 parts by weight of deionized water, 25 parts by weight of styrene, 75 parts by weight of 1,3-butadiene, 3.0 parts by weight of potassium oleate, 3.0 parts by weight of potassium rosinate, 0.1 parts by weight of cumene hydroperoxide, 0.8 parts by weight of tert-dodecyl mercaptan, 0.010 parts by weight of sodium pyrophosphate, 0.050 parts by weight of glucose, and 0.001 parts by weight of ferrous sulfate were added in batches to a nitrogen-purified polymerization reactor (autoclave) and polymerized at 10°C. When the polymerization conversion reached 60%, the polymerization was terminated to prepare a styrene / butadiene rubber polymer latex (gel content: 1 wt%, average particle size: 40 nm, refractive index: 1.5350).

[0091] <Preparation of Grafted Polymers>

[0092] A liquid mixture comprising 200 parts by weight of ion-exchanged water, 1.0 parts by weight of sodium oleate, 25.7 parts by weight of methyl methacrylate, 21.8 parts by weight of styrene, 2.5 parts by weight of acrylonitrile, 0.4 parts by weight of tert-dodecyl mercaptan, 0.050 parts by weight of ethylenediaminetetraacetic acid, 0.100 parts by weight of sodium formaldehyde sulfoxylate, 0.001 parts by weight of ferrous sulfate, and 0.2 parts by weight of cumene hydroperoxide was prepared.

[0093] Fifty parts by weight (based on solids content) of styrene / butadiene rubber polymer latex were added to a reactor. Then, a liquid mixture was continuously added to the reactor at 60°C while polymerization continued for 5 hours. After the continuous addition of the liquid mixture was complete, aging was carried out at 60°C for 1 hour, and polymerization was terminated to prepare a grafted polymer latex. The entire amount of grafted polymer latex was added to an aqueous solution containing 2 parts by weight of calcium chloride, and the mixture was coagulated, aged, washed, dehydrated, and dried to prepare a grafted polymer powder (refractive index: 1.5350).

[0094] Preparation Example 3

[0095] <Preparation of Rubber Polymers>

[0096] 200 parts by weight of deionized water, 25 parts by weight of styrene, 75 parts by weight of 1,3-butadiene, 3.0 parts by weight of potassium oleate, 3.0 parts by weight of potassium rosinate, 0.1 parts by weight of cumene hydroperoxide, 1.0 part by weight of tert-dodecyl mercaptan, 0.010 parts by weight of sodium pyrophosphate, 0.050 parts by weight of glucose, and 0.001 parts by weight of ferrous sulfate were added in batches to a nitrogen-purified polymerization reactor (autoclave) and polymerized at 15°C. When the polymerization conversion reached 60%, the polymerization was terminated to prepare a styrene / butadiene rubber polymer latex (gel content: 5 wt%, average particle size: 40 nm, refractive index: 1.5350).

[0097] <Preparation of Grafted Polymers>

[0098] Except for using the styrene / butadiene rubber polymer latex described above, the grafted polymer powder (refractive index: 1.5350) was prepared in the same manner as in Preparation Example 2.

[0099] Preparation Example 4

[0100] <Preparation of Rubber Polymers>

[0101] 200 parts by weight of deionized water, 25 parts by weight of styrene, 75 parts by weight of 1,3-butadiene, 2.0 parts by weight of potassium oleate, 1.5 parts by weight of potassium rosinate, 0.1 parts by weight of cumene hydroperoxide, 0.8 parts by weight of tert-dodecyl mercaptan, 0.010 parts by weight of sodium pyrophosphate, 0.050 parts by weight of glucose, and 0.001 parts by weight of ferrous sulfate were added in batches to a nitrogen-purified polymerization reactor (autoclave) and polymerized at 10°C. When the polymerization conversion reached 70%, the polymerization was terminated to prepare a styrene / butadiene rubber polymer latex, wherein 25% by weight of styrene and 75% by weight of butadiene were emulsion polymerized (gel content: 15% by weight, average particle size: 80 nm, refractive index: 1.5350).

[0102] <Preparation of Grafted Polymers>

[0103] Except for using the styrene / butadiene rubber polymer latex described above, the grafted polymer powder (refractive index: 1.5350) was prepared in the same manner as in Preparation Example 2.

[0104] Preparation Example 5

[0105] <Preparation of Rubber Polymers>

[0106] 200 parts by weight of deionized water, 25 parts by weight of styrene, 75 parts by weight of 1,3-butadiene, 1.0 part by weight of potassium oleate, 1.0 part by weight of potassium rosinate, 0.2 parts by weight of potassium persulfate, 0.3 parts by weight of tert-dodecyl mercaptan, 0.010 parts by weight of sodium pyrophosphate, 0.050 parts by weight of glucose, and 0.001 parts by weight of ferrous sulfate were added in batches to a nitrogen-purified polymerization reactor (autoclave) and polymerized at 70°C. When the polymerization conversion reached 93%, the polymerization was terminated to prepare a styrene / butadiene rubber polymer latex (gel content: 65 wt%, average particle size: 300 nm, refractive index: 1.5350).

[0107] <Preparation of Grafted Polymers>

[0108] Except for using the styrene / butadiene rubber polymer latex described above, the grafted polymer powder (refractive index: 1.5350) was prepared in the same manner as in Preparation Example 2.

[0109] Preparation Example 6

[0110] <Preparation of Rubber Polymers>

[0111] 200 parts by weight of deionized water, 25 parts by weight of styrene, 75 parts by weight of 1,3-butadiene, 2.0 parts by weight of potassium persulfate, 1.0 part by weight of potassium rosinate, 0.3 parts by weight of potassium persulfate, 0.3 parts by weight of tert-dodecyl mercaptan, 0.010 parts by weight of sodium pyrophosphate, 0.050 parts by weight of glucose, and 0.001 parts by weight of ferrous sulfate were added in batches to a nitrogen-purified polymerization reactor (autoclave) and polymerized at 70°C. When the polymerization conversion reached 99%, the polymerization was terminated to prepare a styrene / butadiene rubber polymer latex (gel content: 90 wt%, average particle size: 90 nm, refractive index: 1.5350).

[0112] <Preparation of Grafted Polymers>

[0113] Except for using the styrene / butadiene rubber polymer latex described above, the grafted polymer powder (refractive index: 1.5350) was prepared in the same manner as in Preparation Example 2.

[0114] Preparation Example 7

[0115] <Preparation of Rubber Polymers>

[0116] 200 parts by weight of deionized water, 25 parts by weight of styrene, 75 parts by weight of 1,3-butadiene, 2.0 parts by weight of potassium oleate, 3.0 parts by weight of potassium rosinate, 0.1 parts by weight of potassium persulfate, 0.8 parts by weight of tert-dodecyl mercaptan, 0.010 parts by weight of sodium pyrophosphate, 0.050 parts by weight of glucose, and 0.001 parts by weight of ferrous sulfate were added in batches to a nitrogen-purified polymerization reactor (autoclave) and polymerized at 10°C. When the polymerization conversion reached 65%, the polymerization was terminated to prepare a styrene / butadiene rubber polymer latex (gel content: 15% by weight, average particle size: 40 nm, refractive index: 1.5350).

[0117] <Preparation of Grafted Polymers>

[0118] Except for using the styrene / butadiene rubber polymer latex described above, the grafted polymer powder (refractive index: 1.5350) was prepared in the same manner as in Preparation Example 2.

[0119] Preparation Example 8

[0120] A liquid mixture comprising 51.4 parts by weight of methyl methacrylate, 43.6 parts by weight of styrene, 5.0 parts by weight of acrylonitrile, 3 parts by weight of toluene, 0.01 parts by weight of 1,1-di(tert-butylperoxide)cyclohexane, and 0.3 parts by weight of tert-dodecyl mercaptan was prepared.

[0121] Polymerization was carried out while the liquid mixture was continuously added to the reactor, with an average polymerization time of 3 hours. In this case, the reactor temperature was 148°C. The polymerization solution discharged from the reactor was heated in a preheating bath, and unreacted monomers were evaporated in a volatilization tank to prepare the polymer. The polymer was then fed into a polymer transfer pump extruder while maintaining a temperature of 210°C to prepare ungrafted polymer pellets (refractive index: 1.5315).

[0122] Preparation Example 9

[0123] A liquid mixture comprising 65.4 parts by weight of methyl methacrylate, 29.6 parts by weight of styrene, 5.0 parts by weight of acrylonitrile, 3 parts by weight of toluene, 0.01 parts by weight of 1,1-di(tert-butylperoxy)cyclohexane, and 0.3 parts by weight of tert-dodecyl mercaptan was prepared.

[0124] Polymerization was carried out while a liquid mixture was continuously added to the reactor, with an average polymerization time of 3 hours. In this case, the reactor temperature was 148°C. The polymerization solution discharged from the reactor was heated in a preheating bath, and unreacted monomers were evaporated in a volatilization tank to prepare the polymer. The polymer was then fed into a polymer transfer pump extruder while maintaining a temperature of 210°C to prepare ungrafted polymer pellets (refractive index: 1.5210).

[0125] Preparation Example 10

[0126] A liquid mixture comprising 70.4 parts by weight of methyl methacrylate, 24.6 parts by weight of styrene, 5.0 parts by weight of acrylonitrile, 3 parts by weight of toluene, 0.01 parts by weight of 1,1-di(tert-butylperoxide)cyclohexane, and 0.3 parts by weight of tert-dodecyl mercaptan was prepared.

[0127] Polymerization was carried out while the liquid mixture was continuously added to the reactor, with an average polymerization time of 3 hours. In this case, the reactor temperature was 148°C. The polymerization solution discharged from the reactor was heated in a preheating bath, and unreacted monomers were evaporated in a volatilization tank to prepare the polymer. The polymer was then fed into a polymer delivery pump extruder while maintaining a temperature of 210°C to prepare ungrafted polymer pellets (refractive index: 1.5160).

[0128] Examples 1 to 5 and Comparative Examples 1 to 5

[0129] The grafted polymer and non-grafted polymer of the preparation examples were mixed in the amounts described in Tables 1 and 2 below to prepare thermoplastic resin compositions.

[0130] Experimental Example 1

[0131] The physical properties of the rubber polymers prepared in the example were evaluated using the methods described below, and the results are shown in Tables 1 and 2 below.

[0132] 1) Gel content (wt%): The rubber polymer latex was coagulated with calcium chloride, washed, and dried in a vacuum oven at 60°C for 24 hours to obtain the rubber compound. The rubber compound was cut into 1g rubber segments, which were then placed in 100g of toluene and stored in a dark room at 23°C for 48 hours to separate the sol and gel. The gel content was calculated by substituting the weights of the sol and gel into the following equation.

[0133] Gel content (wt%) = Gel weight / Rubber segment weight × 100

[0134] 2) Average particle size (nm): Measured using a dynamic light scattering method with a Nicomp 380 instrument (commercially available from Particle Sizing Systems).

[0135] 3) Refractive index: After the rubber segment prepared in the gel content measurement was spread to a thickness of 0.2 mm, it was measured at 25 °C with visible light at a wavelength of 589.3 nm using an Abbe refractometer.

[0136] Experiment Example 2

[0137] The composition of the thermoplastic resin compositions of the examples and comparative examples was measured using the methods described below, and the results are shown in Tables 1 and 2 below.

[0138] 1) Content (wt%) of styrene / butadiene rubber polymer, methyl methacrylate monomer units, styrene monomer units, and acrylonitrile monomer units: using Nicolet TM The iS20 FTIR spectrometer (purchased from Thermo Scientific) calculates the content of rubber polymer and monomer units in thermoplastic resin compositions using infrared (IR) spectroscopy.

[0139] Experimental Example 3

[0140] 100 parts by weight of each thermoplastic resin composition of the Examples and Comparative Examples were mixed with 0.2 parts by weight of antioxidant and extruded to prepare granules. The granules were injection molded to prepare test specimens, and the physical properties of the specimens were evaluated by the following methods. The results are shown in Tables 1 and 2 below.

[0141] 1) Total Transmittance (%): The total transmittance of the specimen (thickness: 3 mm) was measured according to ASTM D1003. Excellent transparency was determined to be achieved when the total transmittance was above 70%.

[0142] 2) Gloss (45°): The gloss of the sample (thickness: 3 mm) was measured at 45° using a gloss meter (VG7000, purchased from Nippon Denshoku Industries Co., Ltd.). It was determined that a matte finish was achieved when the gloss value was below 40, and a better matte finish was exhibited when the gloss value was lower.

[0143] 3) Gloss (60°): The gloss of the sample (thickness: 3 mm) was measured at 60° using a gloss meter (VG7000, purchased from Nippon Denshoku Industries Co., Ltd.). It was determined that a matte finish was achieved when the gloss value was below 60, and a better matte finish was exhibited when the gloss value was lower.

[0144] 4) Impact strength (kgf·cm / cm): The impact strength of a notched cantilever beam specimen (1 / 4 inch) is measured at 23°C according to ASTM D256.

[0145] Experiment Example 4

[0146] The sample from Example 3 (right) and the sample from Comparative Example 4 (left) prepared in Experimental Example 3 were placed on a book and photographed. The results are as follows. Figure 1 As shown.

[0147] [Table 1]

[0148]

[0149]

[0150] [Table 2]

[0151]

[0152]

[0153]

[0154] Referring to Tables 1 and 2, Examples 1 to 5, wherein the gel content of the grafted polymer in the rubber polymer is 0% to 1% by weight, and the difference in refractive index between the grafted and non-grafted polymers is 0.0005 to 0.0100, exhibit high total transmittance and low gloss value, thereby achieving matte properties and transparency. Furthermore, they exhibit high impact strength values, thus achieving excellent impact resistance. On the other hand, Comparative Example 1, wherein the gel content of the grafted polymer in the rubber polymer is 0% by weight, and the difference in refractive index between the grafted and non-grafted polymers is 0.0150, exhibits a low gloss value, thus achieving matte properties, but does not achieve transparency due to its low total transmittance value.

[0155] Furthermore, in Comparative Example 2, the gel content of the grafted polymer in the rubber polymer was 15% by weight, and the refractive index difference between the grafted and ungrafted polymers was 0.0035, exhibiting a high total transmittance value, thus achieving transparency, but failing to achieve matte properties due to its high gloss value. Additionally, although the rubber polymer had a substantially larger average particle size compared to Examples 1 to 5, its impact resistance was not excellent.

[0156] Comparative Example 3, in which the gel content of the grafted polymer in the rubber polymer is 65% by weight, and the refractive index difference between the grafted and ungrafted polymers is 0.0035, exhibits a high total transmittance value, thus achieving transparency, but does not achieve matte properties due to the high gloss value. Furthermore, although the rubber polymer has a substantially larger average particle size compared to Examples 1 to 5, it exhibits the same level of impact resistance.

[0157] Comparative Example 4, in which the gel content of the grafted polymer in the rubber polymer is 90% by weight, and the difference in refractive index between the grafted and ungrafted polymers is 0.0035, exhibits a high total transmittance value, thus achieving transparency, but does not achieve matte properties due to its high gloss value. Furthermore, although the rubber polymer has a substantially larger average particle size compared to Examples 1 to 5, its impact resistance is not excellent.

[0158] Comparative Example 5, in which the gel content of the grafted polymer in the rubber polymer is 15% by weight, and the difference in refractive index between the grafted and ungrafted polymers is 0.0035, exhibits a high total transmittance value, thus achieving transparency, but does not achieve matte properties due to its high gloss value. Furthermore, although the rubber polymer has a substantially larger average particle size compared to Examples 1 to 5, its impact resistance is not excellent.

[0159] At the same time, refer to Figure 1As can be seen, the sample prepared according to Example 3 (right) achieved matte properties and transparency, while the sample prepared according to Comparative Example 4 (left) did not achieve matte properties and transparency due to its high gloss value.

Claims

1. A thermoplastic resin composition comprising: A grafted polymer comprising a rubber polymer having a gel content of 0% to 5% by weight and comprising aromatic vinyl monomer units and diene monomer units; and a shell comprising (meth)acrylate monomer units, aromatic vinyl monomer units, and vinyl cyanide monomer units grafted onto said rubber polymer; and Non-grafted polymers, comprising (meth)acrylate monomer units, aromatic vinyl monomer units, and vinyl cyanide monomer units. in, The refractive index difference between the grafted polymer and the ungrafted polymer is... Below 0.0100, The rubber polymer comprises the aromatic vinyl monomer units and the diene monomer units in a weight ratio of 10:90 to 35:

65. The method for calculating the gel content includes: The latex of the rubber polymer is coagulated with a diluted acid or metal salt, then washed and dried in a vacuum oven at 60°C for 24 hours to obtain a rubber compound, wherein the diluted acid includes one or more selected from hydrochloric acid, sulfuric acid or formic acid, and the metal salt includes one or more selected from magnesium sulfate, calcium chloride, aluminum sulfate. Cut the rubber compound with scissors to prepare a 1-gram rubber segment; The rubber segment was placed in 100 grams of toluene and stored in a dark room at 23°C for 48 hours to separate the sol and gel; and The gel content is calculated by substituting the weights of the sol and the gel into the following equation: <Equation 1> Gel content (weight %) = Gel weight / Rubber segment weight × 100.

2. The thermoplastic resin composition according to claim 1, wherein, The average particle size of the rubber polymer is 20 nm to 100 nm.

3. The thermoplastic resin composition according to claim 1, wherein, The graft polymer comprises: 30.0% to 65.0% by weight of the rubber polymer; 10.0% to 55.0% by weight of the (meth)acrylate monomer units; and 5.0% to 40.0% by weight of the aromatic vinyl monomer units.

4. The thermoplastic resin composition according to claim 1, wherein, The ungrafted polymer comprises: 39.0% to 65.0% by weight of the (meth)acrylate monomer units; and 35.0% to 61.0% by weight of the aromatic vinyl monomer units.

5. The thermoplastic resin composition according to claim 1, wherein, The thermoplastic resin composition comprises: 10.0% to 70.0% by weight of the grafted polymer; and 30.0% to 90.0% by weight of the ungrafted polymer.

6. The thermoplastic resin composition according to claim 1, wherein, Each of the grafted polymer and the ungrafted polymer has a refractive index of 1.5230 to 1.5420.

7. The thermoplastic resin composition according to claim 1, wherein, The thermoplastic resin composition comprises: 5.0% to 35.0% by weight of the rubber polymer; 24.0% to 60.0% by weight of the (meth)acrylate monomer units; and 19.0% to 47.0% by weight of the aromatic vinyl monomer units.

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