Patent Description:
Acrylonitrile-butadiene-styrene resins (hereinafter referred to as "ABS resins") based on conjugated diene rubber have excellent processability, mechanical properties, and appearance properties, and thus have been widely used in electric and electronic products, automobiles, small toys, furniture, and construction materials. However, since ABS resins are based on butadiene rubber containing an unsaturated bond that is chemically unstable, ABS resins have very poor weather resistance due to aging of the rubber polymer by ultraviolet light. Thus, ABS resins are not suitable as outdoor materials. To solve these problems, a method of painting an ABS resin has been proposed. However, painting causes environmental pollution. In addition, painted products are difficult to recycle, and the durability thereof is degraded.

To overcome these problems of ABS resins, acrylic copolymers typified by acrylate-styrene-acrylonitrile graft copolymers (hereinafter referred to as "ASA resins") not containing an ethylenically unsaturated bond have been used. ASA resins have excellent physical properties, such as processability, impact resistance, chemical resistance, and weather resistance, and thus have been used in various fields, such as materials for buildings, interior and exterior materials for automobiles and motorcycles, electric and electronic products, ships, leisure goods, and gardening goods. In addition, there is increasing demand for ASA resins. However, in terms of appearance properties, such as colorability, ASA resins are inferior to painted ABS resins. In addition, the level of weather resistance demanded by the market is increasing. However, ASA resins are insufficient to meet this demand.

In addition, as the importance of aesthetics increases in the market, research is being conducted to realize a luxurious appearance and excellent colorability and weather resistance by finishing the outer surfaces of substrates, such as ABS, PVC, and steel sheets, with thermoplastic resins. Such a finishing material is mainly manufactured in the form of a film and then processed into a final product through a process such as bending or folding according to the shape of a substrate to which the finishing material is applied. However, due to the characteristics of a thermoplastic ASA resin, when the above-described finishing treatment is performed at room temperature, whitening occurs, thereby losing the original color of the resin and deteriorating aesthetics.

According to analysis results, whitening is caused by voids due to cracks occurring inside a thermoplastic resin during bending. To solve this problem, a method of improving whitening properties through adjusting a rubber content in a thermoplastic resin or softening of a thermoplastic resin by mixing the thermoplastic resin and an elastomer have been proposed. However, when these methods are applied, occurrence of whitening may be suppressed to some extent, but mechanical properties, colorability, and surface gloss are deteriorated. To date, development of a thermoplastic resin composition in which all of these properties are excellent and having satisfactory non-whitening properties is insufficient.

<CIT> discloses an acrylic impact modifier having a core-shell structure, the acrylic impact modifier comprising a rubber core which comprises an alkyl acrylate monomer, and, on the rubber core, a graft copolymer shell which comprises an alkyl methacrylate monomer and the alkylacrylate monomer; and a resin composition comprising a polymethylmethacrylate resin as a matrix resin.

<CIT> discloses a molding composition comprising a matrix composed of a thermoplastic polymer and a melting agent dispersed in the matrix, wherein the melting agent is a (meth)acrylate copolymer prepared from the monomers of methylmethacrylate, C<NUM>-C<NUM> alkylacrylate, a crosslinker monomer and/or graft-linking agent having two or more free radical polymerizable ethylenically unsaturated radicals and at least one other free-radically polymerizable ethylenically unsatured monomer free radical polymerizable.

Therefore, the present invention has been made in view of the above problems, and it is one object of the present invention to provide a thermoplastic resin having excellent impact strength, gloss, weather resistance, colorability, and fluidity and being capable of preventing occurrence of whitening when bent or struck due to excellent non-whitening properties thereof; and a method of preparing the thermoplastic resin. In addition, it is another object of the present invention to provide a molded article manufactured using the thermoplastic resin.

In accordance with one aspect of the present invention, provided is a thermoplastic resin including an alkyl acrylate-alkyl methacrylate graft copolymer (A), or an alkyl acrylate-alkyl methacrylate graft copolymer (A) and a matrix resin (B) including one or more selected from the group consisting of an aromatic vinyl compound, a vinyl cyanide compound, an alkyl methacrylate, and an alkyl acrylate, wherein the total content of the alkyl acrylate is <NUM> to <NUM> % by weight, and the butyl acrylate coverage value (X) as calculated by Equation <NUM> below is <NUM> or more:.

<MAT>
wherein, G represents the total gel content (%) of the thermoplastic resin, and Y represents the content (% by weight) of butyl acrylate in the gel of the thermoplastic resin.

Provided is a thermoplastic resin including an alkyl acrylate-alkyl methacrylate graft copolymer (A), or an alkyl acrylate-alkyl methacrylate graft copolymer (A) and a matrix resin (B) including one or more selected from the group consisting of an aromatic vinyl compound, a vinyl cyanide compound, an alkyl methacrylate, and an alkyl acrylate, wherein the total content of the alkyl acrylate is <NUM> to <NUM> % by weight, and the elution amount of butyl acrylate in acetone is <NUM> % by weight or more.

Provided is a thermoplastic resin including an alkyl acrylate-alkyl methacrylate graft copolymer (A), or an alkyl acrylate-alkyl methacrylate graft copolymer (A) and a matrix resin (B) including one or more selected from the group consisting of an aromatic vinyl compound, a vinyl cyanide compound, an alkyl methacrylate, and an alkyl acrylate, wherein the total content of the alkyl acrylate is <NUM> to <NUM> % by weight, and the copolymer (A) includes <NUM> to <NUM> % by weight of alkyl acrylate rubber (a-<NUM>) having a DLS average particle diameter of <NUM> to <NUM> or a TEM average particle diameter of <NUM> to <NUM> and <NUM> to <NUM> % by weight of an alkyl acrylate-alkyl methacrylate copolymer (a-<NUM>) based on <NUM> % by weight in total of the copolymer (A).

Preferably, the thermoplastic resin may include <NUM> to <NUM> % by weight of the alkyl acrylate-alkyl methacrylate graft copolymer (A) and <NUM> to <NUM> % by weight of the matrix resin (B) including one or more selected from the group consisting of an aromatic vinyl compound, a vinyl cyanide compound, an alkyl methacrylate, and an alkyl acrylate.

Preferably, when the thermoplastic resin is eluted using acetone, an elution amount of butyl acrylate may be <NUM> % by weight or more.

Preferably, based on <NUM> % by weight in total of the copolymer (A), the copolymer (A) may include <NUM> to <NUM> % by weight of alkyl acrylate rubber (a-<NUM>) having a DLS average particle diameter of <NUM> to <NUM> or a TEM average particle diameter of <NUM> to <NUM> and <NUM> to <NUM> % by weight of an alkyl acrylate-alkyl methacrylate copolymer (a-<NUM>).

Preferably, the copolymer (A) may have a grafting degree of <NUM> to <NUM> %, and the copolymer (a-<NUM>) may have a weight average molecular weight of <NUM>,<NUM> to <NUM>,<NUM>/mol.

Preferably, the thermoplastic resin, the rubber (a-<NUM>), or both the thermoplastic resin and the rubber (a-<NUM>) may have a glass transition temperature of -<NUM> to -<NUM>.

Preferably, the rubber (a-<NUM>) may further include an alkyl methacrylate. In this case, based on <NUM> % by weight in total of the rubber (a-<NUM>), the alkyl methacrylate may be included in an amount of <NUM> to <NUM> % by weight.

Preferably, based on <NUM> % by weight in total of the copolymer (a-<NUM>), the copolymer (a-<NUM>) may be a copolymer including <NUM> to <NUM> % by weight of an alkyl methacrylate and <NUM> to <NUM> % by weight of an alkyl acrylate.

Preferably, the copolymer (A) may have a grafting frequency of <NUM> to <NUM> % as calculated by Equation <NUM> below.

Preferably, the matrix resin (B) may include one or more selected from the group consisting of an aromatic vinyl compound-vinyl cyanide compound copolymer, an aromatic vinyl compound-vinyl cyanide compound-alkyl methacrylate copolymer, an alkyl methacrylate polymer, and an alkyl methacrylate-alkyl acrylate copolymer, and may further include an aromatic vinyl compound-vinyl cyanide compound-alkyl acrylate copolymer.

Preferably, when the thermoplastic resin is extruded to obtain a film having a thickness of <NUM>, and a <NUM> weight is vertically dropped onto the film from a height of <NUM> at a temperature of <NUM> using a Gardner impact tester, the difference in haze values measured before and after impact according to ASTM D1003-<NUM> for an area hit by the weight may be <NUM> or less.

In accordance with still another aspect of the present invention, provided is a method of preparing a thermoplastic resin, the method including a step of kneading and extruding an alkyl acrylate-alkyl methacrylate graft copolymer (A), or an alkyl acrylate-alkyl methacrylate graft copolymer (A) and a matrix resin (B) including one or more selected from the group consisting of an aromatic vinyl compound, a vinyl cyanide compound, an alkyl methacrylate, and an alkyl acrylate, wherein the total content of the alkyl acrylate included in the thermoplastic resin is <NUM> to <NUM> % by weight, and the butyl acrylate coverage value (X) of the thermoplastic resin as calculated by Equation <NUM> below is <NUM> or more:.

<MAT>
wherein G represents the total gel content (%) of the thermoplastic resin, and Y represents the content (% by weight) of butyl acrylate in the gel of the thermoplastic resin.

Preferably, the graft copolymer (A) may be prepared by a method including a step of emulsion-polymerizing <NUM> parts by weight in total of a monomer mixture including <NUM> to <NUM> % by weight of alkyl acrylate rubber having a DLS average particle diameter of <NUM> to <NUM> or a TEM average particle diameter of <NUM> to <NUM> and <NUM> to <NUM> % by weight of an alkyl acrylate compound and an alkyl methacrylate compound.

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

Preferably, the molded article may be a finishing material.

According to the present invention, by adjusting the particle diameter and content of rubber included in the resin, grafting degree, molecular weight, and the gel content of the resin, a thermoplastic resin having excellent impact strength, weather resistance, gloss, colorability, and fluidity and being capable of preventing occurrence of whitening when bent or struck due to excellent non-whitening properties; and a method of preparing the thermoplastic resin can be provided.

Hereinafter, a thermoplastic resin of the present invention will be described in detail.

The present inventors conducted studies to develop an ASA resin capable of providing a finishing material having a luxurious appearance. As a result of such study, the present inventors confirmed that, when formation of voids due to cracking was minimized by reducing the distance between rubber particles and increasing grafting degree to a predetermined range, non-whitening properties were significantly improved. Based on these results, the present inventors conducted further studies to complete the present invention.

In this description, a resin does not mean only a single (co)polymer, and may include two or more (co)polymers as main components.

In this description, the composition ratio of a (co)polymer may mean the content of units constituting the (co) polymer, or may mean the content of units fed during polymerization of the (co)polymer.

A thermoplastic resin of the present invention includes an alkyl acrylate-alkyl methacrylate graft copolymer (A), or an alkyl acrylate-alkyl methacrylate graft copolymer (A) and a matrix resin (B) including one or more selected from the group consisting of an aromatic vinyl compound, a vinyl cyanide compound, an alkyl methacrylate, and an alkyl acrylate, wherein the total content of the alkyl acrylate is <NUM> to <NUM> % by weight, and the butyl acrylate coverage value (X) as calculated by Equation <NUM> below is <NUM> or more. In this case, impact resistance, weather resistance, and molding processability may be excellent. In addition, whitening does not occur when bent or struck. That is, non-whitening properties may be excellent.

In Equation <NUM>, G represents the total gel content (%) of the thermoplastic resin, and Y represents the content (% by weight) of butyl acrylate in the gel of the thermoplastic resin.

As another example, the thermoplastic resin of the present invention includes <NUM> to <NUM> % by weight of an alkyl acrylate-alkyl methacrylate graft copolymer (A) and <NUM> to <NUM> % by weight of a matrix resin (B) including one or more selected from the group consisting of an aromatic vinyl compound, a vinyl cyanide compound, an alkyl methacrylate, and an alkyl acrylate, wherein an X value as calculated by Equation <NUM> below is <NUM> % or more. In this case, impact resistance, weather resistance, and molding processability may be excellent, and due to excellent non-whitening properties, whitening does not occur upon bending.

In addition, as another example, the thermoplastic resin includes an alkyl acrylate-alkyl methacrylate graft copolymer (A), or an alkyl acrylate-alkyl methacrylate graft copolymer (A) and a matrix resin (B) including one or more selected from the group consisting of an aromatic vinyl compound, a vinyl cyanide compound, an alkyl methacrylate, and an alkyl acrylate, wherein the total content of the alkyl acrylate is <NUM> to <NUM> % by weight, and the elution amount of butyl acrylate using acetone is <NUM> % by weight or more. In this case, impact resistance, weather resistance, and molding processability may be excellent, and due to excellent non-whitening properties, whitening does not occur upon bending.

In addition, the thermoplastic resin of the present invention includes an alkyl acrylate-alkyl methacrylate graft copolymer (A), or an alkyl acrylate-alkyl methacrylate graft copolymer (A) and a matrix resin (B) including one or more selected from the group consisting of an aromatic vinyl compound, a vinyl cyanide compound, an alkyl methacrylate, and an alkyl acrylate, wherein the total content of the alkyl acrylate is <NUM> to <NUM> % by weight, and the copolymer (A) includes <NUM> to <NUM> % by weight of alkyl acrylate rubber (a-<NUM>) having a DLS average particle diameter of <NUM> to <NUM> or a TEM average particle diameter of <NUM> to <NUM> and <NUM> to <NUM> % by weight of an alkyl acrylate-alkyl methacrylate copolymer (a-<NUM>) based on <NUM> % by weight in total of the copolymer (A). In this case, impact resistance, weather resistance, and molding processability may be excellent, and due to excellent non-whitening properties, whitening does not occur upon bending.

In this description, when measuring gel content, <NUM> of acetone is added to <NUM> of dry powder of a thermoplastic resin, agitation is performed at <NUM> rpm and room temperature for <NUM> hours using a shaker (SKC-<NUM>, Lab Companion Co. ), centrifugation is performed at <NUM>,<NUM> rpm and <NUM> for <NUM> hours using a centrifuge (Supra R30, Hanil Science Co. ) to separate only insoluble matter that is not dissolved in acetone, and the separated insoluble matter is dried via forced circulation at <NUM> for <NUM> hours using a forced convection oven (OF-12GW, Lab Companion Co. Then, the weight of the dried insoluble matter is measured, and gel content is calculated by Equation <NUM> below.

In this description, when measuring grafting degree, <NUM> of acetone is added to <NUM> of dry powder of a graft polymer, agitation is performed at <NUM> rpm and room temperature for <NUM> hours using a shaker (SKC-<NUM>, Lab Companion Co. ), centrifugation is performed at <NUM>,<NUM> rpm and <NUM> for <NUM> hours using a centrifuge (Supra R30, Hanil Science Co. ) to separate only insoluble matter that is not dissolved in acetone, and the separated insoluble matter is dried via forced circulation at <NUM> for <NUM> hours using a forced convection oven (OF-12GW, Lab Companion Co. Then, the weight of the dried insoluble matter is measured, and grafting degree is calculated by Equation <NUM> below.

In Equation <NUM>, the weight of grafted monomers is a value obtained by subtracting the weight (g) of rubber from the weight of insoluble matter (gel) obtained by dissolving a graft copolymer in acetone and performing centrifugation, and the weight (g) of rubber is the weight of rubber components theoretically included in the graft copolymer powder.

In this description, DLS average particle diameter may be measured by dynamic light scattering, and specifically, may be measured as an intensity value using a sample in the form of latex and using a particle size analyzer (Nicomp CW380, PPS Co. ) in a Gaussian mode. As a specific example, <NUM> of latex having a solids content of <NUM> to <NUM> % by weight is diluted with <NUM> of deionized water to prepare a sample, and the DLS average particle diameter of the sample may be measured at <NUM> using a particle size analyzer (Nicomp CW380, PPS Co. ) in a measurement method using auto-dilution and flow cells, and in a measurement mode of dynamic light scattering/intensity <NUM>/intensity-weight Gaussian analysis.

In this description, TEM average particle diameter may be measured using a transmission electron microscope (TEM). Specifically, the TEM average particle diameter refers to a value obtained by numerically measuring particle size on a high magnification image of a TEM and averaging the measurement results. In this case, a specific measurement example is as follows:.

Here, the average value of the largest diameters of each of particles in the top <NUM> % of a particle diameter distribution may mean an arithmetic mean value of the top <NUM> % of the largest diameters of each of <NUM> or more particles randomly selected from a TEM image.

Hereinafter, each component constituting the thermoplastic resin of the present invention will be described in detail.

The copolymer (A) includes an alkyl acrylate and an alkyl methacrylate, and is included in an amount of <NUM> to <NUM> % by weight based on <NUM> % by weight in total of the thermoplastic resin.

For example, based on <NUM> % by weight in total of the copolymer (A), the copolymer (A) may include <NUM> to <NUM> % by weight, preferably <NUM> to <NUM> % by weight, more preferably <NUM> to <NUM> % by weight of alkyl acrylate rubber (a-<NUM>) having a DLS average particle diameter of <NUM> to <NUM> or a TEM average particle diameter of <NUM> to <NUM> and <NUM> to <NUM> % by weight, preferably <NUM> to <NUM> % by weight, more preferably <NUM> to <NUM> % by weight of an alkyl acrylate-alkyl methacrylate copolymer (a-<NUM>). Within this range, gloss, non-whitening properties, and impact resistance may be excellent. The rubber (a-<NUM>) preferably has a DLS average particle diameter of <NUM> to <NUM>, more preferably <NUM> to <NUM> and a TEM average particle diameter of <NUM> to <NUM>, more preferably <NUM> to <NUM>. Within this range, colorability and weather resistance may be excellent without reducing mechanical strength.

In this description, the graft copolymer (A) including the alkyl acrylate rubber (a-<NUM>) and the alkyl acrylate-alkyl methacrylate copolymer (a-<NUM>) means a graft copolymer (A) including the alkyl acrylate rubber (a-<NUM>) and the alkyl acrylate-alkyl methacrylate copolymer (a-<NUM>) surrounding the alkyl acrylate rubber (a-<NUM>). In addition, the graft copolymer (A) may be represented as a graft copolymer (A) prepared by graft-polymerizing an alkyl acrylate and an alkyl methacrylate onto the alkyl acrylate rubber (a-<NUM>).

For example, the copolymer (A) may have a grafting degree of <NUM> to <NUM> %, and the copolymer (a-<NUM>) may have a weight average molecular weight of <NUM>,<NUM> to <NUM>,<NUM>/mol. Within these ranges, molding processability and non-whitening properties may be excellent. The copolymer (A) preferably has a grafting degree of <NUM> to <NUM> %, more preferably <NUM> to <NUM> %, still more preferably <NUM> to <NUM> %. Within this range, non-whitening properties may be excellent without deterioration in impact resistance and molding processability. The copolymer (a-<NUM>) preferably has a weight average molecular weight of <NUM>,<NUM> to <NUM>,<NUM>/mol, more preferably <NUM>,<NUM> to <NUM>,<NUM>/mol. Within this range, molding processability and non-whitening properties may be excellent without reducing impact resistance.

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

For example, the rubber (a-<NUM>) may have a glass transition temperature of -<NUM> to -<NUM>, preferably -<NUM> to - <NUM>. Within this range, impact strength may be excellent without deterioration in other physical properties.

In this description, glass transition temperature may be measured at a temperature increase rate of <NUM>/min using a differential scanning calorimeter (DSC, Q100, TA Instruments Co. ) according to ASTM D <NUM>.

For example, the copolymer (A) may have a grafting frequency (%) of <NUM> to <NUM> %, preferably <NUM> to <NUM> %, more preferably <NUM> to <NUM> %, still more preferably <NUM> to <NUM> % as measured by Equation <NUM> below. Within this range, the rubber (a-<NUM>) may be evenly surrounded by the copolymer (a-<NUM>), thereby further improving non-whitening properties.

In Equation <NUM>, the grafting degree is the grafting degree of the copolymer (A), and the parts excluding rubber refer to parts excluding the rubber (a-<NUM>) included in the copolymer (A), i.e., the copolymer (a-<NUM>).

For example, the rubber (a-<NUM>) may further include an alkyl methacrylate. In this case, chemical resistance and impact resistance may be further improved. For example, based on <NUM> % by weight in total of the rubber (a-<NUM>), the content of the alkyl methacrylate included in the rubber (a-<NUM>) may be <NUM> to <NUM> % by weight, preferably <NUM> to <NUM> % by weight, more preferably <NUM> to <NUM> % by weight, still more preferably <NUM> to <NUM> % by weight. Within this range, the desired effects may be sufficiently obtained without deterioration in other physical properties.

For example, the alkyl acrylate rubber may be prepared by emulsion- polymerizing an alkyl acrylate-based compound. As a specific example, the alkyl acrylate rubber may be prepared by mixing an acrylate-based compound, an emulsifier, an initiator, a grafting agent, a crosslinking agent, an electrolyte, and a solvent and emulsion-polymerizing the mixture. In this case, grafting efficiency may increase, thereby improving physical properties such as impact resistance.

For example, based on <NUM> % by weight in total of the copolymer (a-<NUM>), the copolymer (a-<NUM>) may include <NUM> to <NUM> % by weight of an alkyl methacrylate and <NUM> to <NUM> % by weight of an alkyl acrylate, preferably <NUM> to <NUM> % by weight of an alkyl methacrylate and <NUM> to <NUM> % by weight of an alkyl acrylate, more preferably <NUM> to <NUM> % by weight of an alkyl methacrylate and <NUM> to <NUM> % by weight of an alkyl acrylate. Within this range, impact strength and weather resistance may be further improved.

For example, the rubber (a-<NUM>) may include a rubber seed.

For example, the rubber seed may be prepared by polymerizing an alkyl acrylate and optionally an alkyl methacrylate. When the alkyl methacrylate is included, based on <NUM> % by weight of the rubber seed, the alkyl methacrylate may be included in an amount of <NUM> to <NUM> % by weight, preferably <NUM> to <NUM> % by weight, more preferably <NUM> to <NUM> % by weight. Within this range, impact strength, weather resistance, and physical property balance may be excellent.

As a specific example, based on <NUM> parts by weight of units constituting the copolymer (A), the rubber seed may be prepared by adding <NUM> to <NUM> parts by weight of a crosslinking agent, <NUM> to <NUM> parts by weight of an initiator, and <NUM> to <NUM> parts by weight of an emulsifier to an alkyl acrylate and performing polymerization. Within this range, a polymer having an even size may be prepared within a short time, and physical properties such as weather resistance and impact strength may be further improved.

As another specific example, based on <NUM> parts by weight of units constituting the copolymer (A), the rubber seed may be prepared by adding <NUM> to <NUM> part by weight of a crosslinking agent, <NUM> to <NUM> part by weight of an initiator, and <NUM> to <NUM> parts by weight of an emulsifier to monomers including an alkyl acrylate and an alkyl methacrylate and performing polymerization. Within this range, a polymer having an even size may be prepared within a short time, and physical properties such as weather resistance and impact strength may be further improved.

For example, based on <NUM> parts by weight of units constituting the copolymer (A), the copolymer (A) may be prepared by a method including a step (A-<NUM>) of preparing a rubber seed by polymerizing a mixture including <NUM> to <NUM> parts by weight of an alkyl acrylate and optionally an alkyl methacrylate, <NUM> to <NUM> part by weight of an electrolyte, <NUM> to <NUM> parts by weight of a crosslinking agent, <NUM> to <NUM> parts by weight of an initiator, and <NUM> to <NUM> parts by weight of an emulsifier; a step (A-<NUM>) of preparing a rubber core by polymerizing a mixture including <NUM> to <NUM> parts by weight of an alkyl acrylate and optionally an alkyl methacrylate, <NUM> to <NUM> part by weight of a crosslinking agent, <NUM> to <NUM> parts by weight of an initiator, and <NUM> to <NUM> parts by weight of an emulsifier in the presence of the rubber seed; and a step (A-<NUM>) of preparing a graft shell by mixing <NUM> to <NUM> parts by weight of an alkyl acrylate and an alkyl methacrylate, <NUM> to <NUM> parts by weight of a crosslinking agent, <NUM> to <NUM> parts by weight of an initiator, <NUM> to <NUM> parts by weight of an emulsifier, and <NUM> to <NUM> part by weight of an activator in the presence of the rubber core. In this case, the physical property balance of impact resistance, weather resistance, molding processability, and non-whitening properties may be excellent.

In this description, for example, the alkyl acrylate compound may be an alkyl acrylate containing an alkyl group having <NUM> to <NUM> carbon atoms, and as a specific example, may include one or more selected from the group consisting of methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, <NUM>-ethylbutyl acrylate, octyl acrylate, <NUM>-ethylhexyl acrylate, hexyl acrylate, heptyl acrylate, n-pentyl acrylate, and lauryl acrylate. As another example, the alkyl acrylate compound preferably is an alkyl acrylate containing a chain alkyl group having <NUM> to <NUM> carbon atoms, more preferably butyl acrylate.

In this description, for example, the alkyl methacrylate may be an alkyl methacrylate containing an alkyl group having <NUM> to <NUM> carbon atoms. As a specific example, the alkyl methacrylate may include one or more selected from the group consisting of methyl methacrylate, ethyl methacrylate, butyl methacrylate, <NUM>-ethylbutyl methacrylate, <NUM>-ethylhexyl methacrylate, and lauryl methacrylate, preferably an alkyl methacrylate containing a chain alkyl group having <NUM> to <NUM> carbon atoms, more preferably methyl methacrylate.

In this description, unless otherwise defined, crosslinking agents commonly used in the art to which the present invention pertains may be used in the present invention without particular limitation. For example, one or more compounds including an unsaturated vinyl group and being capable of serving as a crosslinking agent or one or more compounds including two or more unsaturated vinyl groups having different reactivities may be used as the crosslinking agent of the present invention. As a specific example, the crosslinking agent of the present invention may include one or more selected from the group consisting of polyethyleneglycol diacrylate, polyethyleneglycol dimethacrylate, polypropyleneglycol diacrylate, polypropyleneglycol dimethacrylate, ethyleneglycol diacrylate, ethyleneglycol dimethacrylate, divinylbenzene, diethyleneglycol dimethacrylate, triethyleneglycol dimethacrylate, <NUM>,<NUM>-butanediol dimethacrylate, hexanediol propoxylate diacrylate, neopentylglycol dimethacrylate, neopentylglycol ethoxylate diacrylate, neopentylglycol propoxylate diacrylate, trimethylolpropane trimethacrylate, trimethylolmethane triacrylate, trimethylolpropane ethoxylate triacrylate, trimethylolpropane propoxylate triacrylate, pentaerythritol ethoxylate triacrylate, pentaerythritol propoxylate triacrylate, vinyltrimethoxysilane, allyl methacrylate, triallyl isocyanurate, triallyl amine, and diallyl amine, without being limited thereto.

In this description, for example, a mixture containing one or more selected from the group consisting of KCl, NaCl, KHCO<NUM>, NaHCO<NUM>, K<NUM>CO<NUM>, Na<NUM>CO<NUM>, KHSO<NUM>, NaHSO<NUM>, K<NUM>P<NUM>O<NUM>, Na<NUM>P<NUM>O<NUM>, K<NUM>PO<NUM>, Na<NUM>PO<NUM>, K<NUM>HPO<NUM>, Na<NUM>HPO<NUM>, KOH, NaOH, and Na<NUM>S<NUM>O<NUM> may be used as the electrolyte, without being limited thereto.

In this description, initiators commonly used in the art to which the present invention pertains may be used in the present invention without particular limitation. For example, radical initiators such as water-soluble initiators and fat-soluble initiators may be used, and a mixture containing one or more of the radical initiators may be used.

The water-soluble initiator may include one or more selected from the group consisting of inorganic peroxides including sodium persulfate, potassium persulfate, ammonium persulfate, potassium superphosphate, and hydrogen peroxide, without being limited thereto.

The fat-soluble initiator may include one or more selected from the group consisting of dialkyl peroxides, diacyl peroxides, diperoxyketals, hydroperoxides, peroxyesters, peroxydicarbonates, and azo compounds.

As a more specific example, the fat-soluble initiator may include one or more selected from the group consisting of organic peroxides such as cumene hydroperoxide, p-menthane hydroperoxide, di-t-butyl peroxide, dicumyl peroxide, t-butylcumyl peroxide, di-t-amyl peroxide, <NUM>,<NUM>-dimethyl-<NUM>,<NUM>-di(t-butylperoxy)-hexane, <NUM>,<NUM>-di(t-butylperoxy)-<NUM>,<NUM>,<NUM>-trimethylcyclohexane, <NUM>,<NUM>-di(t-butylperoxy)-cyclohexane, <NUM>,<NUM>-di(t-amylperoxy)-cyclohexane, ethyl <NUM>,<NUM>-di(t-amylperoxy)-butyrate, diisopropylbenzene mono-hydroperoxide, t-amyl hydroperoxide, t-butyl hydroperoxide, t-butyl peroxyneodecanoate, t-butyl peroxypivalate, di-(<NUM>,<NUM>,<NUM>-trimethylhexanoyl)-peroxide, t-butyl peroxy-<NUM>-ethylhexanoate, t-butyl peroxy-<NUM>,<NUM>,<NUM>-trimethylhexanoate, t-amyl peroxy neodecanoate, t-amyl peroxypivalate, t-amyl peroxy-<NUM>-ethylhexanoate, t-butyl peroxyacetate, t-butyl peroxybenzoate, t-amyl peroxy <NUM>-ethylhexyl carbonate, t-butyl peroxy <NUM>-ethylhexyl carbonate, t-butyl peroxy isopropyl monocarbonate, t-butyl peroxy maleic acid, cumyl peroxyneodecanoate, <NUM>,<NUM>,<NUM>,<NUM>,-tetramethylbutyl peroxy neodecanoate, <NUM>,<NUM>,<NUM>,<NUM>,-tetramethylbutyl peroxy <NUM>-ethylhexanoate, di-<NUM>-ethylhexyl peroxydicarbonate, <NUM>-hydroxy-<NUM>,<NUM>-dimethylbutylperoxy neodecanoate, acetyl peroxide, isobutyl peroxide, octanoyl peroxide, dibenzoyl peroxide, dilauroyl peroxide, <NUM>,<NUM>,<NUM>-trimethylhexanoyl peroxide, and t-butyl peroxy isobutyrate; azobisisobutyronitrile; azobismethylbutyronitrile; azobis-<NUM>-methoxy-<NUM>,<NUM>-dimethylvaleronitrile; azobis-<NUM>,<NUM>-dimethylvaleronitrile; azobis cyclohexanecarbonitrile; and azobis isobutyric acid methyl, without being limited thereto.

In the step of preparing a rubber seed, the step of preparing a rubber core, and the step of preparing a copolymer shell (graft shell), in addition to the initiator, an oxidation-reduction catalyst may be optionally used to further accelerate initiation reaction. For example, the oxidation-reduction catalyst may include one or more selected from the group consisting of sodium pyrophosphate, dextrose, ferrous sulfide, sodium sulfite, sodium formaldehyde sulfoxylate, sodium ethylenediaminetetraacetate, sulfonato acetic acid metal salt, and sulfinato acetic acid metal salt without being limited thereto.

In at least one step of the step of preparing a rubber seed, the step of preparing a rubber core, and the step of preparing a copolymer shell (graft shell), in addition to the polymerization initiator, an activator is preferably used to promote initiation reaction of peroxides. The activator preferably includes one or more selected from the group consisting of sodium formaldehyde sulfoxylate, sodium ethylenediamine tetraacetate, ferrous sulfate, dextrose, sodium pyrrolate, sodium sulfite, sulfonato acetic acid metal salt, and sulfinato acetic acid metal salt.

Based on <NUM> parts by weight in total of monomers added when preparing the copolymer (A), the activator may be added in an amount of <NUM> to <NUM> parts by weight or <NUM> to <NUM> part by weight. Within this range, high polymerization rate may be ensured.

In the step of preparing a seed and the step of preparing a core, as a method of feeding monomers, batch feed or continuous feed may be used alone, or two methods may be used in combination.

In this description, "continuous feed" means that components are not fed batchwise. For example, according to continuous feed, components may be fed for <NUM> minutes or more, <NUM> minutes or more, <NUM> hour or more, preferably <NUM> hours or more within a polymerization time range in drop by drop, little by little, step by step, or continuous flow.

In this description, emulsifiers commonly used in the art to which the present invention pertains may be used in the present invention without particular limitation. For example, the emulsifier of the present invention may include one or more selected from the group consisting of low-molecular weight carboxylates having <NUM> or fewer carbon atoms or <NUM> to <NUM> carbon atoms, such as rosin acid salt, lauric acid salt, oleic acid salt, and stearic acid salt; alkyl sulfosuccinates having <NUM> or fewer carbon atoms or <NUM> to <NUM> carbon atoms or derivatives thereof; alkyl sulfates or sulfonates having <NUM> or fewer carbon atoms or <NUM> to <NUM> carbon atoms; polyfunctional carboxylic acids having <NUM> to <NUM>, <NUM> to <NUM>, or <NUM> to <NUM> carbon atoms and having two or more carboxy groups, preferably <NUM> to <NUM> carboxy groups, or salts thereof; and one or more phosphoric acid salts selected from the group consisting of mono alkyl ether phosphates and dialkyl ether phosphates.

As another example, the emulsifier may include one or more selected from the group consisting of reactive emulsifiers selected from the group consisting of sulfoethyl methacrylate, <NUM>-acrylamido-<NUM>-methylpropane sulfonic acid, sodium styrene sulfonate, sodium dodecyl allyl sulfosuccinate, a copolymer of styrene and sodium dodecyl allyl sulfosuccinate, polyoxyethylene alkylphenyl ether ammonium sulfates, C16-<NUM> alkenyl succinic acid di-potassium salt, and sodium methallyl sulfonate; and non-reactive emulsifiers selected from the group consisting of alkyl aryl sulfonate, alkali methyl alkyl sulfate, sulfonated alkyl esters, fatty acid soap, and alkali salts of rosin acid.

As another example, as the emulsifier, the derivatives of C12 to C18 alkyl sulfosuccinate metal salts, C12 to C20 alkyl sulfate esters, or the derivatives of sulfonic acid metal salts may be used. For example, the derivatives of C12 to C18 alkyl sulfosuccinate metal salts may include sodium or potassium salts of dicyclohexyl sulfonate, dihexyl sulfosuccinate, and dioctyl sulfosuccinate, and the C12 to C20 alkyl sulfate esters or the sulfonic acid metal salts may include alkyl sulfate metal salts such as sodium lauric sulfate, sodium dodecyl sulfate, sodium dodecyl benzene sulfate, sodium octadecyl sulfate, sodium oleic sulfate, potassium dodecyl sulfate, and potassium octadecyl sulfate. The emulsifiers may be used alone or in combination thereof.

In this description, a derivative of a compound refers to a substance obtained by substituting at least one of hydrogen and a functional group of the compound with another type of group such as an alkyl group or a halogen group.

In this description, when preparing the copolymer (A), a molecular weight modifier may be optionally included, and then emulsion polymerization may be performed. Based on <NUM> parts by weight of units constituting the copolymer (A), the molecular weight modifier may be included in an amount of <NUM> to <NUM> parts by weight, <NUM> to <NUM> parts by weight, or <NUM> to <NUM> part by weight. Within this range, a polymer having a desired molecular weight may be easily prepared.

For example, the molecular weight modifier may include one or more selected from the group consisting of mercaptans such as α-methyl styrene dimer, t-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 tetra ethyl thiuram disulfide, dipentamethylene thiuram disulfide, and diisopropylxanthogen disulfide, and preferably includes mercaptan compounds such as tert-dodecylmercaptan, without being limited thereto.

When emulsion polymerization is performed, polymerization temperature is not particularly limited. In general, emulsion polymerization may be performed at <NUM> to <NUM>, preferably <NUM> to <NUM>.

For example, the copolymer latex (A) prepared in the above step may have a coagulum content of <NUM> % or less, preferably <NUM> % or less, still more preferably <NUM> % or less. Within this range, the productivity of a resin may be increased, and mechanical strength and appearance properties may be improved.

In this description, the weight of coagulum produced in a reactor, the weight of total rubber, and the weight of monomers are measured, and coagulum content (%) is calculated by Equation <NUM> below.

For example, the latex of the copolymer (A) may be prepared in the form of powder through a conventional process including coagulation, washing, and drying. As a specific example, a metal salt or an acid is added, coagulation is performed at <NUM> to <NUM>, and aging, dehydration, washing, and drying are performed to prepare the latex of the copolymer (A) in powder form, but the present invention is not limited thereto.

Other conditions not specified in the method for preparing the above-described copolymer (A), i.e., polymerization conversion rate, reaction pressure, reaction time, gel content, etc., are not particularly limited when the conditions are within the ranges commonly used in the technical field to which the present invention pertains. The above conditions may be appropriately selected and used when necessary.

In this description, unless defined otherwise, "%" means "% by weight".

Based on <NUM> % by weight in total of the thermoplastic resin of the present invention, the thermoplastic resin includes <NUM> to <NUM> % by weight of a matrix resin including one or more selected from the group consisting of an aromatic vinyl compound, a vinyl cyanide compound, an alkyl methacrylate, and an alkyl acrylate. When the matrix resin (B) is included in the thermoplastic resin, mechanical properties and molding processability may be further improved.

The matrix resin (B) is a hard matrix capable of being melt-kneaded with the dry powder (DP) of the copolymer (A), and includes a hard polymer-forming monomer having a glass transition temperature of <NUM> or higher. Specifically, the matrix resin (B) is preferably a compound including an aromatic vinyl compound, a vinyl cyanide compound, methyl methacrylate, and an alkyl acrylate or units derived therefrom, or is preferably prepared by mixing one or more compounds including an aromatic vinyl compound, a vinyl cyanide compound, methyl methacrylate, and an alkyl acrylate or units derived therefrom. The matrix resin (B) preferably has a glass transition temperature of <NUM> to <NUM>, more preferably <NUM> to <NUM>. Within this range, molding processability may be further improved.

For example, the matrix resin (B) may include one or more selected from the group consisting of an aromatic vinyl compound-vinyl cyanide compound copolymer, an aromatic vinyl compound-vinyl cyanide compound-alkyl methacrylate copolymer, an alkyl methacrylate polymer, and an alkyl methacrylate-alkyl acrylate copolymer, and may further include an aromatic vinyl compound-vinyl cyanide compound-alkyl acrylate copolymer. In this case, physical property balance between molding processability and other physical properties may be excellent.

The alkyl methacrylate-alkyl acrylate copolymer that may be included in the matrix resin (B) is different from the graft copolymer (A).

For example, the aromatic vinyl compound included in the matrix resin may include one or more selected from the group consisting of styrene, α-methyl styrene, o-methyl styrene, p-methyl styrene, m-methyl styrene, ethyl styrene, isobutyl styrene, t-butyl styrene, o-bromo styrene, p-bromo styrene, m-bromo styrene, o-chloro styrene, p-chloro styrene, m-chloro styrene, vinyltoluene, vinylxylene, fluorostyrene, and vinylnaphthalene, preferably includes one or more selected from the group consisting of styrene and α-methyl styrene. In this case, processability may be excellent due to proper fluidity, and mechanical properties such as impact resistance may be excellent.

For example, the vinyl cyanide compound included in the matrix resin may include one or more selected from the group consisting of acrylonitrile, methylacrylonitrile, ethylacrylonitrile, and isopropylacrylonitrile, preferably acrylonitrile.

Each of the alkyl methacrylate and the alkyl acrylate included in the matrix resin may be appropriately selected within the same range as mentioned in the copolymer (A).

The alkyl methacrylate included in the matrix resin is preferably methyl methacrylate.

The alkyl acrylate included in the matrix resin preferably includes one or more selected from the group consisting of methyl acrylate and ethyl acrylate.

The matrix resin (B) may be prepared by a commonly known method. When preparing the matrix resin (B), one or more of an initiator, a crosslinking agent, and a molecular weight modifier may be included when necessary. The matrix resin (B) may be prepared by suspension polymerization, emulsion polymerization, bulk polymerization, or solution polymerization.

Materials required for reaction such as solvents and emulsifiers or conditions such as polymerization temperature and polymerization time, which are to be added or changed according to polymerization methods, may be appropriately selected without particular limitation when the materials and the conditions are generally applicable depending on a polymerization method selected for the preparation of a matrix resin.

As another example, a commercially available matrix resin may be used as the matrix resin (B).

Based on <NUM> % by weight in total of the thermoplastic resin of the present invention, the thermoplastic resin may include <NUM> to <NUM> % by weight of the copolymer (A) and <NUM> to <NUM> % by weight of the matrix resin (B), preferably <NUM> to <NUM> % by weight of the copolymer (A) and <NUM> to <NUM> % by weight of the matrix resin (B), more preferably <NUM> to <NUM> % by weight of the copolymer (A) and <NUM> to <NUM> % by weight of the matrix resin (B). Within this range, impact resistance, fluidity, and non-whitening properties may be excellent.

The total content of the alkyl acrylate included in <NUM> % by weight in total of the thermoplastic resin is <NUM> to <NUM> % by weight, preferably <NUM> to <NUM> % by weight, more preferably <NUM> to <NUM> % by weight. Within this range, impact strength and non-whitening properties may be excellent without deterioration in weather resistance.

In this description, the total content of the alkyl acrylate included in <NUM> % by weight in total of the thermoplastic resin means the sum of the total weight of alkyl acrylate compounds respectively included in the copolymer (A) and the matrix resin (B). For example, the total content of the alkyl acrylate may be calculated by summing the weights (parts by weight) of alkyl acrylate compounds fed when preparing the thermoplastic resin. As another example, the total content of the alkyl acrylate may be quantitatively determined by subjecting the thermoplastic resin to nuclear magnetic resonance (NMR) analysis or Fourier transform infrared spectroscopy (FT-IR) analysis.

In this description, NMR analysis means analysis by <NUM>H NMR unless otherwise specified.

In this description, NMR analysis may be performed according to a method commonly practiced in the art, and a specific measurement example is as follows.

In this description, FT-IR analysis may be performed according to a method commonly practiced in the art, and a specific measurement example is as follows.

The thermoplastic resin has a butyl acrylate coverage value (X) of <NUM> % or more, preferably <NUM> to <NUM> %, more preferably <NUM> to <NUM> % as measured by Equation <NUM> below through the limited composition as described above. Within this range, non-whitening properties may be further improved.

In Equation <NUM>, the content of butyl acrylate in the gel of the thermoplastic resin represents the content (based on <NUM> % by weight in total of the fed thermoplastic resin) of butyl acrylate in insoluble matter (gel) obtained in the process of determining gel content. Here, the gel content represents the content (% by weight) of the insoluble matter based on <NUM> % by weight in total of the thermoplastic resin.

The thermoplastic resin may include one or more types of alkyl acrylate compounds. By limiting the difference between a total gel content and the content of butyl acrylate in the gel with respect to the content of butyl acrylate in the gel of the thermoplastic resin to a specific range, a thermoplastic resin having excellent mechanical properties, such as impact resistance, molding processability, gloss, and non-whitening properties may be provided.

When elution of the thermoplastic resin is performed using acetone, the elution amount of butyl acrylate is preferably <NUM> % by weight or more, more preferably <NUM> % by weight or more, as a preferred example, <NUM> to <NUM> % by weight, as a more preferred example, <NUM> to <NUM> % by weight. Within this range, non-whitening properties may be excellent.

In this description, when measuring the elution amount of an alkyl acrylate using acetone, <NUM> of acetone is added to <NUM> of dry powder of a thermoplastic resin, agitation is performed at <NUM> rpm and room temperature for <NUM> hours using a shaker (SKC-<NUM>, Lab Companion Co. ), centrifugation is performed at <NUM>,<NUM> rpm and <NUM> for <NUM> hours using a centrifuge (Supra R30, Hanil Science Co. ) to obtain an acetone solution from which insoluble matter is separated, and the obtained acetone solution is dried via forced circulation at <NUM> for <NUM> hours using a forced convection oven (OF-12GW, Lab Companion Co. ) to obtain a resin sol. Then, NMR analysis or FT-IR analysis is performed on the resin sol to quantitatively determine the elution amount of an alkyl acrylate.

For example, the thermoplastic resin, the rubber (a-<NUM>), or both of them may have a glass transition temperature of -<NUM> to -<NUM>, preferably -<NUM> to -<NUM>. Within this range, impact strength may be excellent without deterioration in other physical properties.

The thermoplastic resin of the present invention has excellent whitening resistance when bent or folded. For example, when the thermoplastic resin is extruded into a film having dimensions of <NUM> × <NUM> × <NUM> in width, length, and thickness, and the film is bent at <NUM>° at a temperature of <NUM>, whitening does not occur, indicating that the thermoplastic resin has excellent non-whitening properties.

In addition, the thermoplastic resin of the present invention has excellent whitening resistance against external impact (hit). For example, when the thermoplastic resin is extruded into a film having a thickness of <NUM> and a weight having a weight of <NUM> is vertically dropped onto the film from a height of <NUM> at a temperature of <NUM> using a Gardner impact tester, a difference in haze values measured before and after impact according to ASTM D1003-<NUM> for an area hit by the weight may be <NUM> or less, preferably <NUM> or less, more preferably <NUM> or less. In this case, upon bending or when external impact is applied, whitening is significantly reduced, and thus problems such as inhibition of expression of intrinsic color due to whitening, deterioration of appearance, and reduction of luxuriousness may be prevented, thereby providing a molded article having excellent appearance.

In this description, specifically, when a difference in haze values before and after impact is measured, impact is applied to the middle portion of a film having dimensions of <NUM> × <NUM> × <NUM> in width, length, and thickness using a weight (Falling Weight <NUM>, Cat. No. <NUM>) and using a Gardner impact tester (Impact Tester <NUM>, BYK Gardner Co. ), haze values before and after impact are measured for the middle portion of the film, and a difference in haze values before and after impact is calculated based the measured values.

In this description, haze may be measured using a known method for measuring transparency in the related field, and specifically, may be measured according to ASTM D1003. As a specific example, the haze value of a film extruded at an extrusion temperature of <NUM> may be measured at <NUM> using a haze meter (model name: HM-<NUM>, MURAKAMI Co. ) according to ASTM D1003.

For example, the thermoplastic resin may have a gloss of <NUM> or more, preferably <NUM> to <NUM>, more preferably <NUM> to <NUM>, still more preferably <NUM> to <NUM> as measured at an incidence angle of <NUM>° according to ASTM D528. Within this range, gloss may be excellent without deterioration in other physical properties, thereby providing a molded article having excellent appearance.

For example, the thermoplastic resin may have a melt flow index (MI) of <NUM>/<NUM> or more, preferably <NUM> to <NUM>/<NUM>, more preferably <NUM> to <NUM>/<NUM>, still more preferably <NUM> to <NUM>/<NUM> as measured according to ASTM D1238. Within this range, molding processability may be excellent without deterioration in other physical properties.

In this description, melt flow index may be measured at a temperature of <NUM> for a reference time of <NUM> minutes under a load of <NUM> according to ASTM D1238. As a specific example, a specimen is heated to <NUM> using a melt indexer (GOETTFERT Co. ), the specimen is placed in the cylinder of the melt indexer, and a load of <NUM> is applied with a piston. At this time, the weight (g) of a resin melted and flowing out for <NUM> minutes is measured, and a melt flow index is calculated based on the measured value.

A method of preparing the thermoplastic resin of the present invention includes a step of kneading and extruding <NUM> to <NUM> parts by weight of an alkyl acrylate-alkyl methacrylate graft copolymer (A) and <NUM> to <NUM> parts by weight of a matrix resin (B) including one or more selected from the group consisting of an aromatic vinyl compound, a vinyl cyanide compound, an alkyl methacrylate, and an alkyl acrylate, wherein the thermoplastic resin has an X value of <NUM> % or more as measured by Equation <NUM> below. In this case, molding processability, gloss, and non-whitening properties may be excellent while maintaining mechanical properties equal to those of conventional ASA based resins, thereby providing excellent appearance.

The copolymer (A) used in the preparation of the thermoplastic resin may be prepared by the method of preparing the copolymer (A). In this case, grafting degree, grafting frequency, and molecular weight may be properly adjusted, and thus molding processability and non-whitening properties may be excellent.

When the thermoplastic resin of the present invention is prepared, in the step of kneading and extruding, when necessary, one or more selected from the group consisting of a lubricant, a heat stabilizer, a light stabilizer, an antioxidant, a UV stabilizer, a dye, a pigment, a colorant, a release agent, an antistatic agent, an antibacterial agent, a processing aid, a compatibilizer, a metal deactivator, a flame retardant, a smoke suppressant, an anti-dripping agent, a foaming agent, a plasticizer, a reinforcing agent, a filler, a matting agent, an antifriction agent, and an anti-wear agent may be further included in an amount of <NUM> to <NUM> parts by weight, <NUM> to <NUM> parts by weight, <NUM> to <NUM> parts by weight, or <NUM> to <NUM> part by weight based on <NUM> parts by weight in sum of the copolymer (A) and the matrix resin (B). Within this range, required physical properties may be implemented without deterioration in the intrinsic physical properties of ASA-based resins.

For example, the lubricant may include one or more selected from ethylene bis stearamide, polyethylene oxide wax, magnesium stearate, calcium stearamide, and stearic acid, without being limited thereto.

For example, the antioxidant may include phenolic antioxidants, and phosphorus antioxidants without being limited thereto.

For example, the light stabilizer may include HALS-based light stabilizers, benzophenone-based light stabilizers, and benzotriazole-based light stabilizers without being limited thereto.

For example, the antistatic agent may include one or more of anionic surfactants, and nonionic surfactants without being limited thereto.

For example, the release agent may include one or more selected from glyceryl stearate, and polyethylene tetra stearate without being limited thereto.

A molded article of the present invention includes the thermoplastic resin of the present invention having excellent non-whitening properties. In this case, weather resistance, impact resistance, molding processability, gloss, and whitening resistance may be excellent, thereby providing excellent appearance. Thus, the molded article may be applied to film or sheet products.

For example, the molded article may be a finishing material. In this case, non-whitening properties may be excellent, and thus appearance may be excellent.

<NUM> parts by weight of distilled water, <NUM> parts by weight of butyl acrylate, <NUM> part by weight of sodium dodecyl sulfate, <NUM> parts by weight of ethylene glycol dimethacrylate, <NUM> parts by weight of allyl methacrylate, <NUM> parts by weight of sodium hydrogen carbonate, and <NUM> parts by weight of distilled water were fed into a nitrogen-substituted reactor batchwise, temperature was raised to <NUM>, and then <NUM> parts by weight of potassium persulfate was added thereto to initiate reaction. Then, polymerization was performed for <NUM> hour.

<NUM> parts by weight of butyl acrylate, <NUM> part by weight of sodium dodecyl sulfate, <NUM> parts by weight of ethylene glycol dimethacrylate, <NUM> parts by weight of allyl methacrylate, <NUM> parts by weight of distilled water, and <NUM> parts by weight of potassium persulfate were mixed with the rubber seed, and the mixture was continuously fed into a reactor at <NUM> for <NUM> hours. After feeding, polymerization was further performed for <NUM> hour. After completion of the reaction, the average particle size of the obtained rubber polymer was <NUM>.

A mixture prepared by homogeneously mixing <NUM> parts by weight of distilled water, <NUM> parts by weight of methyl methacrylate, <NUM> parts by weight of butyl acrylate, <NUM> part by weight of sodium dodecylbenzene sulfonate, <NUM> parts by weight of tert-dodecyl mercaptan, and <NUM> parts by weight of t-butyl hydroperoxide as an initiator and a mixed solution containing <NUM> parts by weight of sodium ethylenediaminetetraacetate as an activator, <NUM> parts by weight of sodium formaldehyde sulfoxylate, and <NUM> parts by weight of ferrous sulfide were each continuously fed into the reactor containing the rubber core at <NUM> for <NUM> hours to perform polymerization. After completion of the continuous feed, polymerization was further performed at <NUM> for <NUM> hour, and temperature was cooled to <NUM> to terminate and prepare graft copolymer latex.

After completion of the reaction, the grafting degree of the obtained graft copolymer was <NUM> %, the weight average molecular weight of the shell was <NUM>,<NUM>/mol, and grafting frequency was <NUM> %.

<NUM> part by weight of an aqueous calcium chloride solution was added to the prepared acrylate graft copolymer latex, coagulation was performed at <NUM> to <NUM> under atmospheric pressure, aging was performed at <NUM> to <NUM>, dehydration and washing were performed, and then hot-blast drying was performed at <NUM> for <NUM> hours to obtain graft copolymer powder.

<NUM> parts by weight of the graft copolymer powder, <NUM> parts by weight of methyl methacrylate (BA611, LGMMA Co. ) as a matrix resin, <NUM> parts by weight of a lubricant, <NUM> part by weight of an antioxidant, and <NUM> parts by weight of a UV stabilizer were mixed. When preparing a specimen for evaluating colorability and a specimen for evaluating weather resistance, based on <NUM> parts by weight in sum of the graft copolymer and the matrix resin, <NUM> part by weight of a black colorant was additionally added. The mixture was extrusion-kneaded at a cylinder temperature of <NUM> using a <NUM> pi extrusion kneader to prepare pellets. The prepared pellets were injected at a barrel temperature of <NUM> using an injection machine to prepare a specimen for measuring physical properties, such as impact strength.

The content of butyl acrylate (BA) in the prepared thermoplastic resin was <NUM> % (wt%), the glass transition temperature of rubber was -<NUM>, a BA coverage value of <NUM> % was observed, and a BA elution amount in a resin sol of <NUM> % was observed.

The thermoplastic resin pellets were introduced into a <NUM> pi single extrusion kneader equipped with a T-die at a cylinder temperature of <NUM> to prepare a film having a thickness of <NUM>.

The same procedure as in Example <NUM> was performed except that <NUM> parts by weight of butyl acrylate was used when preparing a rubber core, and <NUM> parts by weight of methyl methacrylate and <NUM> parts by weight of butyl acrylate were used when preparing a copolymer shell.

The grafting degree of the obtained graft copolymer was <NUM> %, the weight average molecular weight of a shell was <NUM>,<NUM>, and grafting frequency was <NUM> %.

The BA content of the prepared thermoplastic resin was <NUM> %, a BA coverage value was <NUM> %, and a BA elution amount in a resin sol was <NUM> %.

The BA content of the prepared thermoplastic resin was <NUM> %, an alkyl acrylate coverage value was <NUM> %, and a BA elution amount in a resin sol was <NUM> %.

The same procedure as in Example <NUM> was performed except that <NUM> parts by weight of sodium dodecyl sulfate was used when preparing a rubber seed.

The average particle diameter of the obtained rubber polymer was <NUM>, the grafting degree of a graft copolymer was <NUM> %, the weight average molecular weight of a shell was <NUM>,<NUM>, and grafting frequency was <NUM> %.

The same procedure as in Example <NUM> was performed except that <NUM> parts by weight of butyl acrylate and <NUM> parts by weight of methyl methacrylate were used when preparing a rubber core, and <NUM> parts by weight of sodium dodecyl sulfate, <NUM> parts by weight of butyl acrylate, and <NUM> parts by weight of methyl methacrylate were used when preparing a rubber seed.

The BA content of the prepared thermoplastic resin was <NUM> %, rubber glass transition temperature was -<NUM>, a BA coverage value was <NUM> %, and a BA elution amount in a resin sol was <NUM> %.

The same procedure as in Example <NUM> was performed except that <NUM> parts by weight of methyl methacrylate and <NUM> parts by weight of butyl acrylate were used when preparing a copolymer shell.

The BA content of a resin was <NUM> %, a BA coverage value was <NUM> %, and a BA elution amount in a resin sol was <NUM> %.

The BA content of a resin was <NUM> %, the glass transition temperature of rubber was -<NUM>, a BA coverage value was <NUM> %, and a BA elution amount in a resin sol was <NUM> %.

The same procedure as in Example <NUM> was performed except that <NUM> parts by weight of the graft copolymer was used without using a matrix resin when preparing a thermoplastic resin.

The same procedure as in Example <NUM> was performed except that <NUM> parts by weight of a styrene-acrylonitrile resin (S85RF, LG Chemical Co. ) as a matrix resin was used when preparing a thermoplastic resin.

The BA coverage value of a resin was <NUM> %, and a BA elution amount in a resin sol was <NUM> %.

The same procedure as in Example <NUM> was performed except that <NUM> parts by weight of a styrene-acrylonitrile-methyl methacrylate copolymer (XT500, LG Chemical Co. ) as a matrix resin was used when preparing a thermoplastic resin.

The same procedure as in Example <NUM> was performed to prepare a graft copolymer except that <NUM> parts by weight of butyl acrylate and <NUM> parts by weight of methyl methacrylate were used when preparing a rubber seed, <NUM> parts by weight of butyl acrylate and <NUM> parts by weight of methyl methacrylate were used when preparing a rubber core, and <NUM> parts by weight of methyl methacrylate and <NUM> parts by weight of butyl acrylate were used when preparing a copolymer shell.

The same procedure as in Example <NUM> was performed to prepare a thermoplastic resin except that <NUM> parts by weight of the prepared graft copolymer and <NUM> parts by weight of an (alpha-methylstyrene)-styrene-acrylonitrile copolymer (S99UH, LG Chemical Co. ) as a matrix resin were used.

The same procedure as in Example <NUM> was performed except that <NUM> parts by weight of the prepared graft copolymer, and as a matrix resin, <NUM> parts by weight of a methyl methacrylate resin (BA611, LGMMA Co. ) and <NUM> parts by weight of an alkyl acrylate-aromatic vinyl compound-vinyl cyanide compound copolymer (SA927, LG Chemical Co. ) were used when preparing a thermoplastic resin.

The same procedure as in Example <NUM> was performed except that <NUM> parts by weight of butyl acrylate was used when preparing a rubber core, and <NUM> parts by weight of methyl methacrylate was used when preparing a copolymer shell.

The same procedure as in Example <NUM> was performed except that <NUM> parts by weight of sodium dodecyl sulfate, <NUM> parts by weight of butyl acrylate, and <NUM> parts by weight of methyl methacrylate were used when preparing a rubber seed, <NUM> parts by weight of butyl acrylate and <NUM> parts by weight of methyl methacrylate were used when preparing a rubber core, and <NUM> parts by weight of methyl methacrylate was used when preparing a shell.

The same procedure as in Example <NUM> was performed except that <NUM> parts by weight of methyl methacrylate and <NUM> parts by weight of butyl acrylate were used when preparing a shell.

The same procedure as in Example <NUM> was performed except that <NUM> parts by weight of the graft copolymer powder and <NUM> parts by weight of the matrix resin were used when preparing a thermoplastic resin.

The grafting frequency of the obtained graft copolymer was <NUM> %.

The same procedure as in Comparative Example <NUM> was performed except that <NUM> parts by weight of the graft copolymer powder and <NUM> parts by weight of the matrix resin were used when preparing a thermoplastic resin.

The same procedure as in Comparative Example <NUM> was performed except that <NUM> parts by weight of methyl methacrylate and <NUM> parts by weight of butyl acrylate were used when preparing a shell, and <NUM> parts by weight of the graft copolymer powder and <NUM> parts by weight of the matrix resin were used when preparing a thermoplastic resin.

The same procedure as in Example <NUM> was performed except that <NUM> parts by weight of sodium dodecyl sulfate was used when preparing a rubber seed, and <NUM> parts by weight of methyl methacrylate was used when preparing a shell.

The physical properties of the specimens and the films prepared in Examples <NUM> to <NUM>, Comparative Examples <NUM> to <NUM>, and Reference Example <NUM> were measured according to the following methods, and the results are shown in Tables <NUM> and <NUM> below.

In Equation <NUM>, the weight (g) of grafted monomers is a value obtained by subtracting the weight (g) of rubber from the weight of insoluble matter (gel) obtained by dissolving a graft copolymer in acetone and performing centrifugation, and the weight (g) of rubber is the amount (parts by weight) of rubber components theoretically included in the graft copolymer powder. Here, the parts by weight of the rubber means the total sum of parts by weights of unit components fed when preparing a rubber seed and a core.

In Equation <NUM>, G represents the total gel content (%) of the thermoplastic resin, and Y represents the content (% by weight) of butyl acrylate in the gel. Here, the content (% by weight) of butyl acrylate in the gel was quantitatively measured by <NUM>NMR analysis or FT-IR analysis.

In addition, a film having dimensions of <NUM> × <NUM> × <NUM> in width, length, and thickness was prepared. Then, a <NUM> weight (Cat No. <NUM>, Falling Weight <NUM>) was vertically dropped onto the film from a height of <NUM> at a temperature of <NUM> using a Gardner impact tester (Impact Tester <NUM>, BYK Gardner Co. ), haze values before and after impact were measured for the middle portion of the film hit by the weight according to ASTM D1003-<NUM>, and a difference in haze values was calculated by Equation <NUM> below (dropping-caused whitening).

Referring to Tables <NUM> and <NUM>, in the case of bending-caused whitening, when whitening occurs, it is marked as "○". When whitening does not occur (non-whitening), it is marked as "X". In the case of dropping-caused whitening, the haze difference values calculated by Equation <NUM> are shown.

In this case, haze was measured at a temperature of <NUM> using a haze meter (model name: HM-<NUM>, MURAKAMI Co. ) according to ASTM D1003-<NUM>.

Referring to Tables <NUM> and <NUM>, in the case of thermoplastic resins (Examples <NUM> to <NUM>) according to the present invention, the balance between melt flow index and impact strength is properly maintained, and gloss, weather resistance, and colorability are excellent. In particularly, bending-caused whitening is not observed, and a difference in haze values before and after impact caused by dropping is <NUM> or less, indicating that the thermoplastic resins according to the present invention have excellent non-whitening properties. On the other hand, in the case of thermoplastic resins (Comparative Examples <NUM> to <NUM>) outside the range of the present invention, the balance between melt flow index and impact strength is not properly maintained, and gloss, weather resistance, and colorability are deteriorated. In addition, whitening is observed upon bending, and a difference in haze values before and after impact caused by dropping is greater than <NUM>, indicating that the thermoplastic resins of Comparative Examples <NUM> to <NUM> have poor non-whitening properties.

<FIG> includes images taken after bending, in the Md and Td directions, films manufactured in an example (left image) and a comparative example (right image) to check whether whitening occurs. As shown in <FIG>, in the case of the example according to the present invention, whitening does not occur at the bent portion, indicating that the example according to the present invention has non-whitening properties. However, in the case of the comparative example outside the scope of the present invention, whitening occurs clearly at the bent portion.

Claim 1:
A thermoplastic resin, comprising:
an alkyl acrylate-alkyl methacrylate graft copolymer (A), or an alkyl acrylate-alkyl methacrylate graft copolymer (A) and a matrix resin (B) comprising one or more selected from the group consisting of an aromatic vinyl compound, a vinyl cyanide compound, an alkyl methacrylate, and an alkyl acrylate,
wherein the total content of the alkyl acrylate is <NUM> to <NUM> % by weight, and
the butyl acrylate coverage value (X) as calculated by Equation <NUM> below is <NUM> or more: <MAT>
wherein G represents the total gel content (%) of the thermoplastic resin, and Y represents the content (% by weight) of butyl acrylate in the gel of the thermoplastic resin, wherein the total gel content, the total content of alkyl acrylate and the butyl acrylate coverage value are measured as disclosed in the specification.