阅读说明：本技术 核-壳共聚物、其制备方法和包含其的热塑性树脂组合物 (Core-shell copolymer, method for preparing the same, and thermoplastic resin composition comprising the same ) 是由 李惠林 金伦皞 柳基现 于 2019-11-13 设计创作，主要内容包括：本发明涉及一种核-壳共聚物,更具体地,涉及一种核-壳共聚物、其制备方法和包含所述核-壳共聚物的热塑性树脂组合物,所述核-壳共聚物包括核和包围所述核的壳,其中,所述核包含具有1至8个碳原子的来自第一(甲基)丙烯酸烷基酯单体的重复单元和来自末端改性的聚二甲基硅氧烷交联剂的交联部分；并且所述末端改性的聚二甲基硅氧烷交联剂在该聚二甲基硅氧烷的两个末端包含来自第二(甲基)丙烯酸烷基酯单体的改性部分。(The present invention relates to a core-shell copolymer, more particularly, to a core-shell copolymer comprising a core and a shell surrounding the core, wherein the core comprises a repeating unit from a first alkyl (meth) acrylate monomer having 1 to 8 carbon atoms and a crosslinking moiety from a terminally modified polydimethylsiloxane crosslinking agent; and the terminally modified polydimethylsiloxane cross-linking agent comprises modified moieties from a second alkyl (meth) acrylate monomer at both ends of the polydimethylsiloxane.)

1. A core-shell copolymer comprising a core and a shell surrounding said core,

wherein the core comprises repeating units from a first alkyl (meth) acrylate monomer having 1 to 8 carbon atoms and a crosslinking moiety from a terminally modified polydimethylsiloxane crosslinker; and is

The terminally modified polydimethylsiloxane cross-linking agent comprises modified moieties from a second alkyl (meth) acrylate monomer at both ends of the polydimethylsiloxane.

2. The core-shell copolymer of claim 1, wherein the average particle size of the core is 150nm to 500 nm.

3. The core-shell copolymer of claim 1, wherein the average particle size of the core is 185nm to 260 nm.

4. The core-shell copolymer of claim 1, wherein the end-modified polydimethylsiloxane cross-linker comprises a compound represented by the following formula 1:

[ formula 1]

Wherein R is₁And R₂Each independently an alkylene group having 1 to 30 carbon atoms, R₃And R₄Each independently hydrogen or methyl, and n is from 5 to 400.

5. The core-shell copolymer of claim 4 wherein R₁And R₂Each independently an alkylene group having 1 to 8 carbon atoms, and n is 10 to 330.

6. The core-shell copolymer of claim 1, wherein the core comprises 70 to 95 parts by weight of repeating units from a first alkyl (meth) acrylate monomer having 1 to 8 carbon atoms and 0.01 to 5 parts by weight of cross-linking moieties from a terminally modified polydimethylsiloxane cross-linker, based on 100 parts by weight total of the core-shell copolymer.

7. The core-shell copolymer of claim 1, wherein the core comprises 83 to 88 parts by weight of repeating units from a first alkyl (meth) acrylate monomer having 1 to 8 carbon atoms and 0.1 to 2 parts by weight of cross-linking moieties from a terminally modified polydimethylsiloxane cross-linker, based on 100 parts by weight total of the core-shell copolymer.

8. The core-shell copolymer of claim 1, wherein the core comprises a seed.

9. The core-shell copolymer according to claim 8, wherein the seed is contained in an amount of 0.5 to 20 parts by weight, based on 100 parts by weight of the core-shell copolymer in total.

10. The core-shell copolymer of claim 1 wherein the shell comprises repeating units derived from a monomer selected from at least one of repeating units derived from a third alkyl (meth) acrylate monomer and repeating units derived from an aromatic vinyl monomer.

11. The core-shell copolymer of claim 1, wherein the core-shell copolymer comprises 70 to 95 parts by weight of the core and 5 to 30 parts by weight of the shell, based on 100 parts by weight of the core-shell copolymer in total.

12. A method of preparing a core-shell copolymer, the method comprising:

preparing a core by polymerizing a nucleating mixture comprising a first alkyl (meth) acrylate monomer having 1 to 8 carbon atoms and a terminally modified polydimethylsiloxane; and

the core-shell copolymer is prepared by polymerizing the shell-forming mixture in the presence of the prepared core,

wherein the terminally modified polydimethylsiloxane comprises modified moieties from a second alkyl (meth) acrylate monomer at both ends of the polydimethylsiloxane.

13. The method of claim 12, wherein the average particle size of the prepared core is 150nm to 500 nm.

14. A thermoplastic resin composition comprising the core-shell copolymer of any one of claims 1 to 11 and a polycarbonate resin.

15. The thermoplastic resin composition of claim 14, wherein said thermoplastic resin composition comprises 1 to 20 parts by weight of said core-shell copolymer, based on 100 parts by weight of said polycarbonate resin.

Technical Field

Cross Reference to Related Applications

This application claims the benefit of priority from korean patent application No.10-2018-0142092, filed on 16.11.2018 and korean patent application No.10-2019-0141838, filed on 7.11.2019, the disclosures of both of which are incorporated herein by reference in their entirety.

Background

Automobile exterior materials, cell phone cases, and the like are often exposed to cold environments and are easily exposed to light sources such as ultraviolet rays during use. In addition, these materials require high heat resistance in order to withstand burning sun, and high tensile strength.

In order to develop a thermoplastic resin composition having the above properties, products using a polycarbonate resin having high heat resistance, dimensional stability and tensile strength as a main resin have been developed.

However, the polycarbonate resin is low in low-temperature impact strength and room-temperature impact strength, and therefore is easily broken. In order to compensate for these problems, attempts have been made to improve the impact strength of polycarbonate resins using impact modifiers.

Examples of the impact modifier for improving the impact strength of the polycarbonate resin include acrylic rubber resins, butadiene-based rubber resins, silicone-based rubber resins, and the like. The impact modifier is applied according to the properties required for the thermoplastic resin.

However, when an acrylic rubber resin is used as an impact modifier to increase the impact strength of the polycarbonate resin, the polycarbonate resin has excellent weather resistance and coloring properties, but the glass transition temperature is low, thereby deteriorating the low-temperature impact strength.

In addition, when the butadiene-based rubber resin or the silicone-based rubber resin is applied, the polycarbonate resin has improved low-temperature impact strength. However, in the case of using the butadiene-based rubber resin, the polycarbonate resin is easily discolored due to external factors such as sunlight, heat and oxygen due to unsaturated bonds in the butadiene rubber, and in the case of using the silicone-based rubber resin, its coloration is reduced when applied to a polycarbonate resin having a high refractive index due to a low refractive index of the silicone-based resin itself.

Therefore, research is continuously required to develop an impact modifier having excellent low-temperature impact strength and room-temperature impact strength, as well as excellent colorability when applied to polycarbonate resins.

Disclosure of Invention

Technical problem

It is an object of the present invention to improve impact strength without reducing coloring properties of a molded article molded from a thermoplastic resin composition comprising an impact modifier.

That is, it is an object of the present invention to provide a core-shell copolymer having improved impact strength without decreasing the coloring property of a molded article molded by using a thermoplastic resin composition comprising the core-shell copolymer, as an impact modifier, wherein a silicone-based polymer end-modified with a double bond-containing monomer is used as a crosslinking agent of the core.

Technical scheme

In one general aspect, there is provided a core-shell copolymer comprising a core and a shell surrounding the core, wherein the core comprises repeat units from a first alkyl (meth) acrylate monomer having 1 to 8 carbon atoms and a crosslinking moiety from a terminally modified polydimethylsiloxane crosslinker; and the terminally modified polydimethylsiloxane cross-linking agent comprises modified moieties from a second alkyl (meth) acrylate monomer at both ends of the polydimethylsiloxane.

In another general aspect, there is provided a method of preparing a core-shell copolymer, comprising: preparing a core by polymerizing a nucleating mixture comprising a first alkyl (meth) acrylate monomer having 1 to 8 carbon atoms and a terminally modified polydimethylsiloxane; and preparing a core-shell copolymer by polymerizing the shell-forming mixture in the presence of the prepared core, wherein the end-modified polydimethylsiloxane includes modified moieties from the second alkyl (meth) acrylate monomer at both ends of the polydimethylsiloxane.

In another general aspect, there is provided a thermoplastic resin composition comprising the core-shell copolymer and a polycarbonate resin.

Advantageous effects

In the present invention, when the core-shell copolymer is used as the impact modifier, a molded article molded from the thermoplastic resin composition comprising the core-shell copolymer has excellent impact strength, in particular, excellent low-temperature impact strength, without reducing colorability.

Detailed Description

The terms and words used in the detailed description and claims should not be construed as limited to conventional or dictionary meanings, but should be construed to have meanings and concepts consistent with the technical idea of the present invention on the basis of the principle that the inventor can appropriately define the concept of the term to describe their own invention in the best way.

The term "repeat unit from a monomer" as used herein may refer to a component from a monomer, its structure, or the substance itself. Specific examples thereof may refer to a repeating unit in which a monomer to be added participates in polymerization reaction during polymerization of a polymer and is formed in the polymer.

The term "crosslinking moiety derived from a crosslinking agent" as used herein may refer to a component derived from a compound used as a crosslinking agent, its structure, or the substance itself, and may refer to a crosslinking moiety that performs a crosslinking action in or between polymers formed by the action and reaction of a crosslinking agent.

The term "seed" as used herein may refer to a polymer component or copolymer component that is first polymerized prior to polymerization of the core during preparation to complement the mechanical physical properties of the core-shell copolymer, facilitate polymerization of the core, and adjust the average particle size of the core.

The term "core" as used herein may refer to a polymer component or copolymer component in which a nucleating monomer polymerizes to form a core or core layer of a core-shell copolymer. Further, the term "core" may refer to a polymer or copolymer component in which a nucleating monomer is formed on a seed to form a core or core layer exhibiting a form in which the core surrounds the seed.

The term "shell" as used herein may refer to a polymer component or copolymer component in which a shell-forming monomer is graft polymerized on the core of a core-shell copolymer to form a shell or shell layer of the core-shell copolymer in a form in which the shell surrounds the core.

Hereinafter, the present invention will be described in more detail to help understanding the technical idea of the present invention.

< core-Shell copolymer >

The core-shell copolymer according to the present invention may comprise a core and a shell surrounding the core.

The core may comprise repeating units from a first alkyl (meth) acrylate monomer having 1 to 8 carbon atoms and a crosslinking moiety from a terminally modified polydimethylsiloxane crosslinker.

The first alkyl (meth) acrylate monomer is a component that improves the room-temperature impact strength of the polycarbonate resin, and may be an alkyl (meth) acrylate monomer including an alkyl group having 1 to 8 carbon atoms. In this case, the alkyl group having 1 to 8 carbon atoms may refer to both a straight chain alkyl group having 1 to 8 carbon atoms and a branched chain alkyl group having 3 to 8 carbon atoms. Specific examples of the alkyl (meth) acrylate monomer may include: methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, or 2-ethylhexyl (meth) acrylate. Here, the first alkyl (meth) acrylate monomer may refer to an alkyl acrylate or an alkyl methacrylate.

The content of the repeating unit from the first alkyl (meth) acrylate monomer may be 70 to 95 parts by weight, 80 to 92 parts by weight, or 83 to 88 parts by weight, based on 100 parts by weight of the core-shell copolymer in total. Within the above range, molded articles molded by using the thermoplastic resin composition comprising the core-shell copolymer according to the present invention as an impact modifier have excellent colorability and impact strength.

The terminally modified polydimethylsiloxane crosslinker is a component for crosslinking repeating units from a first alkyl (meth) acrylate monomer, and may include modified moieties from a second alkyl (meth) acrylate monomer at both ends of the polydimethylsiloxane.

Specifically, the terminal-modified polydimethylsiloxane cross-linking agent may include a compound represented by the following formula 1:

[ formula 1]

Wherein R is₁And R₂Each independently is an alkylene group having 1 to 30 carbon atoms, an alkylene group having 1 to 20 carbon atoms, or an alkylene group having 1 to 8 carbon atoms, R₃And R₄Each independently hydrogen or methyl, and n is 5 to 400, 5 to 360, or 10 to 330.

Meanwhile, in the case of a core-shell copolymer prepared by using an acrylic resin (e.g., ethylene glycol dimethacrylate) including double bonds at both terminals as a crosslinking agent, low-temperature impact strength is poor because the acrylic resin itself has a glass transition temperature of about-40 ℃ to-50 ℃. However, since the core-shell copolymer of the present invention has end-modified polydimethylsiloxane comprising modified moieties derived from alkyl (meth) acrylate at both ends of polydimethylsiloxane as a crosslinking agent, and the polydimethylsiloxane itself has a glass transition temperature of-100 ℃ to-120 ℃, molded articles molded by using the thermoplastic resin composition comprising the core-shell copolymer according to the present invention as an impact modifier have excellent colorability and impact strength.

The content of the crosslinking moiety from the end-modified polydimethylsiloxane crosslinker may be 0.01 to 5 parts by weight, 0.01 to 2 parts by weight, or 0.1 to 2 parts by weight, based on 100 parts by weight of the core-shell copolymer in total. Within the above range, molded articles molded by using the thermoplastic resin composition comprising the core-shell copolymer according to the present invention as an impact modifier have excellent colorability and impact strength.

The core may be a component for easily grafting the shell to the core, and may further include a repeating unit from a first crosslinkable monomer along with a repeating unit from a first alkyl (meth) acrylate monomer having 1 to 8 carbon atoms and a crosslinking moiety from a terminally modified polydimethylsiloxane crosslinker.

Specific examples of the first crosslinkable monomer may include at least one selected from the group consisting of: (meth) acrylic crosslinkable monomers such as ethylene glycol di (meth) acrylate, 1, 6-hexanediol di (meth) acrylate, allyl (meth) acrylate, trimethylolpropane tri (meth) acrylate, and pentaerythritol tetra (meth) acrylate; and vinyl-based crosslinkable monomers such as divinylbenzene, divinylnaphthalene, and diallyl phthalate.

When the core includes the repeating unit from the first crosslinkable monomer, the content of the repeating unit from the first crosslinkable monomer may be 0.01 to 5 parts by weight, 0.01 to 2 parts by weight, or 0.1 to 2 parts by weight, based on 100 parts by weight of the core-shell copolymer in total. Within the above range, the shell can be easily grafted to the core, and a molded article molded by using the thermoplastic resin composition comprising the core-shell copolymer according to the present invention as an impact modifier has excellent colorability and impact strength.

Meanwhile, the core may include a seed including a repeating unit from a fourth alkyl (meth) acrylate monomer having 1 to 8 carbon atoms to adjust the average particle diameter of the core. As a specific example, the core may include a core surrounding the seed.

The seed may further include a repeating unit from the second crosslinkable monomer along with a repeating unit from the fourth alkyl (meth) acrylate monomer having 1 to 8 carbon atoms to easily form a core on the seed. The repeating unit from the fourth alkyl (meth) acrylate monomer and the repeating unit from the second crosslinkable monomer included in the seed may be the same as the types of the respective monomers, specifically, the first alkyl (meth) acrylate and the first crosslinkable monomer used to form the repeating unit from the monomer included in the above-described core.

When the core includes the seed, the content of the seed may be 0.5 to 20 parts by weight, 5 to 18 parts by weight, or 5.8 to 15.5 parts by weight, based on 100 parts by weight of the core-shell copolymer in total. Within the above range, the average particle diameter of the core can be easily adjusted.

In addition, when the core includes a seed, the content of the repeating unit from the first alkyl (meth) acrylate monomer included in the core may include the content of the repeating unit from the fourth alkyl (meth) acrylate monomer included in the seed, and the content of the repeating unit from the first crosslinkable monomer included in the core may include the content of the repeating unit from the second crosslinkable monomer included in the seed.

As a specific example, the content of the repeating unit from the fourth alkyl (meth) acrylate monomer may be 90 to 99.5 parts by weight, 92 to 98 parts by weight, or 93 to 96 parts by weight, based on a total of 100 parts by weight of the seed. Within the above range, the impact strength is excellent and the compatibility with the core is excellent.

In addition, the content of the repeating unit from the second crosslinkable monomer may be 0.5 to 10 parts by weight, 2 to 8 parts by weight, or 4 to 7 parts by weight, based on the total weight of the seed. Within the above range, the core of the large-diameter particle can be easily prepared.

The average particle size of the core according to the invention may be from 150nm to 500nm, from 150nm to 300nm or from 185nm to 260 nm. Within the above range, molded articles molded by using the thermoplastic resin composition comprising the core-shell copolymer according to the present invention as an impact modifier have excellent gloss, colorability and impact strength.

The shell may be formed by graft-polymerizing at least one repeating unit derived from a monomer selected from repeating units derived from a third alkyl (meth) acrylate monomer and repeating units derived from an aromatic vinyl monomer on the core. As a specific example, the shell of the present invention may comprise a repeating unit from a third alkyl (meth) acrylate monomer or a repeating unit from an aromatic vinyl monomer, or a repeating unit from a third alkyl (meth) acrylate monomer and a repeating unit from an aromatic vinyl monomer.

The third alkyl (meth) acrylate monomer is a component that imparts compatibility between the polycarbonate resin and the core, and may be an alkyl (meth) acrylate monomer including an alkyl group having 1 to 8 carbon atoms. In this case, the alkyl group having 1 to 8 carbon atoms may refer to both a straight chain alkyl group having 1 to 8 carbon atoms and a branched chain alkyl group having 3 to 8 carbon atoms. Specific examples of the alkyl (meth) acrylate monomer may include: methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, or 2-ethylhexyl (meth) acrylate. Here, the third alkyl (meth) acrylate monomer may refer to an alkyl acrylate or an alkyl methacrylate, and the third alkyl (meth) acrylate monomer may be the same as or different from the first alkyl (meth) acrylate monomer or the second alkyl (meth) acrylate monomer.

The aromatic vinyl monomer imparts compatibility between the thermoplastic resin and the core, and has a high refractive index. Therefore, when a core-shell copolymer including an aromatic vinyl monomer is used as the impact modifier, as a component for improving the coloring property of the thermoplastic resin, styrene, α -methylstyrene, 3-methylstyrene, 4-propylstyrene, isopropenylnaphthalene, 1-vinylnaphthalene, styrene substituted with an alkyl group having 1 to 3 carbon atoms, 4-cyclohexylstyrene, 4- (p-methylphenyl) styrene, halogen-substituted styrene, or a combination thereof may be used.

The content of at least one repeating unit derived from a monomer selected from the group consisting of a repeating unit derived from a third alkyl (meth) acrylate monomer and a repeating unit derived from an aromatic vinyl monomer may be 5 to 30 parts by weight, 10 to 25 parts by weight, or 10 to 20 parts by weight, based on 100 parts by weight of the core-shell copolymer in total. Within the above range, molded articles molded by using the thermoplastic resin composition comprising the core-shell copolymer according to the present invention as an impact modifier have excellent colorability and impact strength.

That is, the core-shell copolymer of the present invention may include 70 to 95 parts by weight, 80 to 90 parts by weight, or 85 to 90 parts by weight of the core, and 5 to 30 parts by weight, 10 to 25 parts by weight, or 10 to 20 parts by weight of the shell, based on 100 parts by weight of the core-shell copolymer in total. Within the above range, molded articles molded by using the thermoplastic resin composition comprising the core-shell copolymer according to the present invention as an impact modifier have excellent colorability and impact strength.

< preparation of core-Shell copolymer >

The method for preparing the core-shell copolymer according to the present invention may comprise: preparing a core by polymerizing a nucleating mixture comprising a first alkyl (meth) acrylate monomer having 1 to 8 carbon atoms and a terminally modified polydimethylsiloxane; and preparing a core-shell copolymer by polymerizing the shell-forming mixture in the presence of the prepared core, wherein the end-modified polydimethylsiloxane includes modified moieties from the second alkyl (meth) acrylate monomer at both ends of the polydimethylsiloxane. The average particle diameter of the prepared core may be 150nm to 500 nm.

The preparation method of the core-shell copolymer may include stepwise preparation of the core and the shell by separately preparing the core and preparing the core-shell copolymer, and then polymerizing the core and the shell. The core of the core-shell copolymer may be polymerized by preparing the core, and then the shell may be polymerized on the core by preparing the core-shell copolymer.

The preparation of the core may be the preparation of the core-shell copolymer, and the type and content of each monomer in the nucleating mixture added in the preparation of the core may be the same as those described above for forming the repeating units derived from the monomers contained in the core.

Meanwhile, the preparation of the core may include: preparing seeds; and preparing a core by polymerizing a nucleating mixture comprising a first alkyl (meth) acrylate monomer having 1 to 8 carbon atoms and a terminally modified polydimethylsiloxane in the presence of the prepared seed.

The seed is prepared in order to facilitate polymerization of the core and to adjust the average particle diameter of the core when polymerizing the core-shell copolymer, and may be performed by radical polymerization in the presence of a fourth alkyl (meth) acrylate monomer having 1 to 8 carbon atoms and a second crosslinkable monomer, and may be performed by emulsion polymerization. Further, the polymerization may be performed by further using additives such as an initiator, an emulsifier, a molecular weight regulator, an activator, a redox catalyst, and ion-exchanged water.

In addition, the preparation of the seeds may be carried out at a temperature of 45 ℃ to 65 ℃, 48 ℃ to 62 ℃, or 50 ℃ to 60 ℃.

The fourth alkyl (meth) acrylate monomer and the second crosslinkable monomer included in the seed may be the same as the types of the respective monomers, specifically, the first alkyl (meth) acrylate and the first crosslinkable monomer described above for forming the repeating unit from the monomers included in the core.

In addition, the preparation of the core-shell copolymer may be the preparation of the shell of the core-shell copolymer, and the types and contents of the respective monomers in the shell-forming mixture added in the preparation of the core-shell copolymer may be the same as those of the respective monomers described above for forming the respective repeating units derived from the monomers contained on the shell.

Polymerization in the preparation of the seed, the preparation of the core, and the preparation of the core-shell copolymer may be performed by using methods such as emulsion polymerization, bulk polymerization, suspension polymerization, and solution polymerization, and may be further performed using additives such as an initiator, an emulsifier, a molecular weight regulator, an activator, a redox catalyst, and ion-exchanged water.

The initiator may be, for example, but is not limited to: inorganic peroxides such as sodium persulfate, potassium persulfate, ammonium persulfate, potassium perphosphate, and hydrogen peroxide; organic peroxides such as t-butyl hydroperoxide, cumene hydroperoxide, p-menthane hydroperoxide, di-t-butyl peroxide, t-butyl cumyl peroxide, acetyl peroxide, isobutyl peroxide, octanoyl peroxide, dibenzoyl peroxide, 3,5, 5-trimethylhexanol peroxide and t-butyl peroxyisobutyrate; and nitrogen compounds such as azobisisobutyronitrile, azobis-2, 4-dimethylvaleronitrile, azobiscyclohexanecarbonitrile, and methyl azobisisobutyrate. The initiator may be used in an amount of 0.03 parts by weight to 0.2 parts by weight, based on 100 parts by weight of the total seed or 100 parts by weight of the total core-shell copolymer.

The emulsifier may be at least one selected from the group consisting of an anionic emulsifier, a cationic emulsifier and a nonionic emulsifier. For example, the emulsifier may be at least one selected from the group consisting of, but not limited to: anionic emulsifiers widely used in emulsion polymerization, such as sulfonates, carboxylates, succinates, sulfosuccinates and their metal salts, for example, alkylbenzenesulfonic acid, sodium alkylbenzenesulfonate, alkylsulfonic acid, sodium alkylsulfonate, sodium polyoxyethylene nonylphenyl ether sulfonate, sodium stearate, sodium lauryl sulfate, sodium dodecylbenzenesulfonate, sodium lauryl sulfate, sodium dodecylsulfosuccinate, potassium oleate and abietate; cationic emulsifiers in which amine halides, alkyl tetraammonium salts, alkyl pyridinium salts, and the like are bonded as functional groups of higher aliphatic hydrocarbons; and nonionic emulsifiers such as polyvinyl alcohol and nonylphenylpolyoxyethylene. The emulsifier may be used in an amount of 0.1 parts by weight to 5 parts by weight, based on 100 parts by weight of the total seed or 100 parts by weight of the total core-shell copolymer.

The molecular weight regulator may be, for example, but is not limited to: mercaptans such as alpha-methylstyrene dimer, tert-dodecyl mercaptan, n-dodecyl mercaptan and octyl mercaptan; halogenated hydrocarbons such as carbon tetrachloride, methylene chloride and methylene bromide; and sulfur-containing compounds such as tetraethylthiuram disulfide, dipentamethylenethiuram disulfide, and diisopropyl xanthogen disulfide. The molecular weight regulator may be used in an amount of 0.1 to 3 parts by weight, based on 100 parts by weight of the total seed or 100 parts by weight of the total core-shell copolymer.

The activator may be, for example, at least one selected from the group consisting of, but not limited to: sodium hydrosulfite, sodium formaldehyde sulfoxylate, sodium ethylene diamine tetracetate, ferrous sulfate, lactose, glucose, sodium linoleate and sodium sulfate. The activator may be used in an amount of 0.01 to 0.15 parts by weight, based on 100 parts by weight of the total seed or 100 parts by weight of the total core-shell copolymer.

The redox catalyst may be, for example, but is not limited to: sodium formaldehyde sulfoxylate, ferrous sulfate, disodium ethylene diamine tetraacetate, copper sulfate and the like. The redox catalyst may be used in an amount of 0.01 parts by weight to 0.1 parts by weight, based on 100 parts by weight of the total seed or 100 parts by weight of the total core-shell copolymer.

In addition, the core and core-shell copolymers prepared in the preparation of the core and the preparation of the core-shell copolymer may be obtained in the form of a core latex and a core-shell copolymer latex, in which the core and the core-shell copolymer are dispersed in a solvent, respectively. In order to obtain the core-shell copolymer in the form of powder from the core-shell copolymer, processes such as agglomeration, aging, dehydration and drying may be performed.

< thermoplastic resin composition >

The thermoplastic resin composition according to the present invention may include the core-shell copolymer as an impact modifier, and may include a polycarbonate resin. That is, the thermoplastic resin composition may be a polycarbonate resin composition.

The thermoplastic resin composition may include the core-shell copolymer in an amount of 1 to 20 parts by weight, 1 to 15 parts by weight, or 1 to 10 parts by weight, based on 100 parts by weight of the polycarbonate resin. Within the above range, molded articles molded from the thermoplastic resin composition have excellent colorability and impact strength.

The thermoplastic resin composition according to the present invention may further contain, in addition to the core-shell copolymer and the polycarbonate resin, additives such as flame retardants, lubricants, antioxidants, light stabilizers, reaction catalysts, mold release agents, pigments, antistatic agents, conductivity imparting agents, EMI shielding agents, magnetizing agents, crosslinking agents, antibacterial agents, processing aids, metal deactivators, smoke suppressors, fluorine-based drip retardants, inorganic fillers, glass fibers, friction-reducing and abrasion-resisting agents, and coupling agents, as necessary, within a range that does not deteriorate physical properties.

The method of melt kneading and processing the thermoplastic resin composition is not particularly limited. However, as an example, the thermoplastic resin composition is first mixed in a super mixer and then melt-kneaded by using one of conventional mixing devices such as a twin-screw extruder, a single-screw extruder, a roll mill, a kneader or a banbury mixer to obtain pellets by using a pelletizer. Thereafter, the resulting pellets may be sufficiently dried with a dehumidifying dryer or a hot air dryer, and then subjected to injection processing to obtain a final molded article.

Hereinafter, the present invention will be described in detail with reference to the following examples. However, the following examples describe the invention by way of example only. It will be apparent to those skilled in the art that various changes and modifications may be made within the scope and spirit of the present invention, and the present invention is not limited thereto.