Thermoplastic resin composition and molded article formed therefrom

Abstract

A thermoplastic resin composition of the present invention comprises: about 100 parts by weight of a polycarbonate resin; about 3 to about 17 parts by weight of a polyalkyl (meth)acrylate resin; about 5 to about 32 parts by weight of a biphenyl group-containing (meth)acrylic copolymer resin including a unit derived from a monomer represented by chemical formula 1; and about 2 to about 7 parts by weight of a rubber-modified vinyl-based graft copolymer in which a monomer mixture including an alkyl (meth) acrylic monomer and an aromatic vinyl-based monomer is graft-polymerized to a rubber polymer, wherein a weight ratio of the biphenyl group-containing (meth) acrylic copolymer resin to the rubber-modified vinyl-based graft copolymer is about 1: 0.1 to about 1: 0.7. The thermoplastic resin composition exhibits excellent impact resistance, chemical resistance, hardness, appearance characteristics, and a balance of these physical properties.

Description

Thermoplastic resin composition and molded article formed therefrom

[0001] The present invention relates to a thermoplastic resin composition and a molded article formed therefrom. More specifically, the present invention relates to a thermoplastic resin composition having excellent impact resistance, chemical resistance, hardness, appearance characteristics, and a balance of these physical properties, and a molded article formed therefrom.

[0002]

[0003] Polycarbonate resin belongs to the category of engineering plastics and is applied to materials requiring physical durability due to its excellent transparency, impact resistance, thermal stability, dimensional stability, weather resistance, chemical resistance, and electrical properties. Additionally, polymethyl (meth)acrylate resin is a thermoplastic polymer characterized by excellent transparency and hardness, and is notably distinguished by its superior chemical resistance.

[0004] However, when polycarbonate resin and polymethyl (meth)acrylate resin are mixed and applied, transparency and other properties may be reduced, and if the amount of polycarbonate resin is large, delamination may occur in which the polymethyl (meth)acrylate resin clumps together on the surface of the polycarbonate resin. Consequently, there is a risk of deterioration in appearance characteristics and impact resistance. In addition, if a modified polyacrylate-based resin is applied to prevent phase separation, many of the advantages of polymethyl (meth)acrylate resin are lost, and there is a risk of reduced chemical resistance.

[0005] Therefore, there is a need to develop polycarbonate resin and polymethyl (meth)acrylate resin-based thermoplastic resin compositions that exhibit excellent impact resistance, chemical resistance, hardness, appearance characteristics, and a balance of these physical properties.

[0006] The background technology of the present invention is disclosed in Korean Patent Publication No. 10-2016-0144944, etc.

[0007]

[0008] The objective of the present invention is to provide a thermoplastic resin composition having excellent impact resistance, chemical resistance, hardness, appearance characteristics, and a balance of these physical properties.

[0009] Another objective of the present invention is to provide a molded article formed from the thermoplastic resin composition.

[0010] The above and other objectives of the present invention can all be achieved by the present invention described below.

[0011]

[0012] 1. One aspect of the present invention relates to a thermoplastic resin composition. The thermoplastic resin composition comprises about 100 parts by weight of a polycarbonate resin; about 3 to about 17 parts by weight of a polyalkyl (meth)acrylate resin; about 5 to about 32 parts by weight of a biphenyl group-containing (meth)acrylic copolymer resin comprising a unit derived from a monomer represented by the following chemical formula 1; and about 2 to about 7 parts by weight of a rubber-modified vinyl graft copolymer in which a monomer mixture comprising an alkyl (meth)acrylic monomer and an aromatic vinyl monomer is graft-polymerized into a rubbery polymer; wherein the weight ratio of the biphenyl group-containing (meth)acrylic copolymer resin and the rubber-modified vinyl graft copolymer is about 1:0.1 to about 1:0.7:

[0013] [Chemical Formula 1]

[0014]

[0015] In the above chemical formula 1, R1 is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and n is an integer from 0 to 10.

[0016] 2. In the above 1 embodiment, the polycarbonate resin may have a weight-average molecular weight of about 10,000 to about 200,000 g / mol.

[0017] 3. In the above 1 or 2 embodiments, the polyalkyl (meth)acrylate resin may include one or more of polymethyl (meth)acrylate resin, polyethyl (meth)acrylate resin, polypropyl (meth)acrylate resin, methyl (meth)acrylate, and copolymers of alkyl (meth)acrylate having 2 to 10 carbon atoms.

[0018] 4. In the above 1 to 3 embodiments, the polyalkyl (meth)acrylate resin may have a weight-average molecular weight of about 50,000 to about 130,000 g / mol.

[0019] 5. In the above 1 to 4 embodiments, the biphenyl group-containing (meth)acrylic copolymer resin may be a polymer of a monomer mixture comprising about 10 to about 40 weight% of a monomer represented by Formula 1 and about 60 to about 90 weight% of an alkyl (meth)acrylic monomer.

[0020] 6. In the above 1 to 5 embodiments, the biphenyl group-containing (meth)acrylic copolymer resin may have a weight-average molecular weight of about 5,000 to about 25,000 g / mol.

[0021] 7. In the above 1 to 6 embodiments, the rubber-modified vinyl graft copolymer may comprise about 10 to about 70 weight% of a rubbery polymer and about 30 to about 90 weight% of a monomer mixture comprising an alkyl (meth)acrylic monomer and an aromatic vinyl monomer.

[0022] 8. In the above 1 to 7 embodiments, the weight ratio of the polyalkyl (meth)acrylate resin and the biphenyl group-containing (meth)acrylic copolymer resin may be about 1:1 to about 1:7.

[0023] 9. In the above 1 to 8 embodiments, the thermoplastic resin composition may have a notched Izod impact strength of about 50 to about 90 kgf·cm / cm of a 1 / 8" thick specimen measured according to ASTM D256.

[0024] 10. In the above 1 to 9 embodiments, when the thermoplastic resin composition is applied and wrapped with 0.5 ml of liquid extracted from a sterilizing wet wipe (manufacturer: PDI Healthcare, product name: Sani-cloth AFIII) on a 1 / 8" thick Type I tensile specimen made according to ASTM D638 standards, and then left on a 1% strain curvature jig, the time at which cracks occur on the surface of the specimen may be about 60 minutes or more.

[0025] 11. In the above 1 to 10 embodiments, the thermoplastic resin composition may have a pencil hardness of HB or higher on a 1 mm thick specimen measured according to JIS K5401, and a scratch width of about 230 to about 295 μm according to a Ball-type Scratch Profile (BSP) test.

[0026] 12. In the above 1 to 11 embodiments, the thermoplastic resin composition may have a phase separation area (opaque area) of an injection molded specimen of size 5 cm × 9 cm × 2 cm of about 25% or less.

[0027] 13. Another aspect of the present invention relates to a molded article. The molded article is characterized by being formed from a thermoplastic resin composition according to any one of 1 to 12.

[0028]

[0029] The present invention has the effect of providing a thermoplastic resin composition having excellent impact resistance, chemical resistance, hardness, appearance characteristics, and a balance of these physical properties, and a molded article formed therefrom.

[0030]

[0031] The present invention will be described in detail below.

[0032] The thermoplastic resin composition according to the present invention comprises (A) a polycarbonate resin; (B) a polyalkyl (meth)acrylate resin; (C) a biphenyl group-containing (meth)acrylic copolymer resin; and (D) a rubber-modified vinyl graft copolymer.

[0033] In this specification, "a to b" indicating a numerical range is defined as "≥a and ≤b".

[0034]

[0035] (A) Polycarbonate resin

[0036] A polycarbonate resin according to one embodiment of the present invention can be applied together with polyalkyl (meth)acrylate resins, biphenyl group-containing (meth)acrylic copolymer resins, rubber-modified vinyl graft copolymers, etc., to improve the impact resistance, chemical resistance, hardness, appearance characteristics, and balance of physical properties of a thermoplastic resin composition, and a polycarbonate resin used in a conventional thermoplastic resin composition can be used. For example, an aromatic polycarbonate resin prepared by reacting diphenols (aromatic diol compounds) with precursors such as phosgene, halogen formate, and carbonate diester can be used.

[0037] In a specific example, the above diphenols may be exemplified as 4,4'-biphenol, 2,2-bis(4-hydroxyphenyl)propane, 2,4-bis(4-hydroxyphenyl)-2-methylbutane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 2,2-bis(3-chloro-4-hydroxyphenyl)propane, 2,2-bis(3,5-dichloro-4-hydroxyphenyl)propane, etc., but are not limited thereto. For example, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(3,5-dichloro-4-hydroxyphenyl)propane, or 1,1-bis(4-hydroxyphenyl)cyclohexane may be used, and specifically, 2,2-bis(4-hydroxyphenyl)propane called bisphenol-A may be used.

[0038] In a specific example, the polycarbonate resin may be used having branched chains, and for example, a branched polycarbonate resin may be used by adding about 0.05 to about 2 mol% of a trivalent or higher polyfunctional compound, specifically a compound having a trivalent or higher phenolic group, to the total amount of diphenols used in polymerization.

[0039] In a specific example, the polycarbonate resin may be used in the form of a homopolycarbonate resin, a copolycarbonate resin, or a blend thereof. Additionally, the polycarbonate resin may be partially or entirely replaced with an aromatic polyester-carbonate resin obtained by polymerizing in the presence of an ester precursor, such as a difunctional carboxylic acid.

[0040] In a specific example, the polycarbonate resin may have a weight-average molecular weight (Mw) measured by gel permeation chromatography (GPC) of about 10,000 to about 200,000 g / mol, for example, about 15,000 to about 100,000 g / mol. Within this range, the fluidity (processability), impact resistance, and appearance characteristics of the thermoplastic resin composition may be excellent.

[0041]

[0042] (B) Polyalkyl (meth)acrylate resin

[0043] A polyalkyl (meth)acrylate resin according to one embodiment of the present invention can be applied together with a polycarbonate resin, a biphenyl group-containing (meth)acrylate copolymer resin, and a rubber-modified vinyl graft copolymer to improve the impact resistance, chemical resistance, hardness, appearance characteristics, and the balance of these physical properties of a thermoplastic resin composition, and a polyalkyl (meth)acrylate resin used in a conventional thermoplastic resin composition can be used.

[0044] In a specific example, the polyalkyl (meth)acrylate resin may be a polymer of monomers comprising one or more of alkyl (meth)acrylates having 1 to 10 carbon atoms polymerized by a known polymerization method, for example, polymethyl (meth)acrylate resin, polyethyl (meth)acrylate resin, polypropyl (meth)acrylate resin, copolymer of methyl (meth)acrylate and alkyl (meth)acrylates having 2 to 10 carbon atoms, and specifically may be polymethyl methacrylate (PMMA) resin.

[0045] In a specific example, the polyalkyl (meth)acrylate resin may have a weight-average molecular weight of about 50,000 to about 130,000 g / mol, for example, about 60,000 to about 120,000 g / mol, as measured by gel permeation chromatography (GPC). Within this range, the impact resistance, chemical resistance, transparency, etc. of the thermoplastic resin composition may be excellent.

[0046] In a specific example, the polyalkyl (meth)acrylate resin may be included in an amount of about 3 to about 17 parts by weight, for example, about 3.5 to about 15 parts by weight, with respect to about 100 parts by weight of the polycarbonate resin. If the content of the polyalkyl (meth)acrylate resin is less than about 3 parts by weight with respect to about 100 parts by weight of the polycarbonate resin, there is a risk that the impact resistance, chemical resistance, etc. of the thermoplastic resin composition will be reduced, and if it exceeds about 17 parts by weight, there is a risk that the chemical resistance, appearance characteristics, etc. of the thermoplastic resin composition will be reduced.

[0047]

[0048] (C) Biphenyl group-containing (meth)acrylic copolymer resin

[0049] A biphenyl group-containing (meth)acrylic copolymer resin according to one embodiment of the present invention can be applied together with polycarbonate resin, polyalkyl (meth)acrylate resin and rubber-modified vinyl graft copolymer, etc., to improve the impact resistance, chemical resistance, hardness, appearance characteristics, and balance of physical properties of a thermoplastic resin composition, and a biphenyl group-containing (meth)acrylic copolymer resin containing a unit derived from a monomer represented by the following chemical formula 1 can be used.

[0050] [Chemical Formula 1]

[0051]

[0052] In the above chemical formula 1, R1 is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and n is an integer from 0 to 10.

[0053] In a specific example, the biphenyl group-containing (meth)acrylic copolymer resin may be a polymer of a monomer mixture comprising about 10 to about 40 weight%, for example, about 20 to about 35 weight%, of a monomer represented by Formula 1, and about 60 to about 90 weight%, for example, about 65 to about 85 weight%, of an alkyl (meth)acrylic monomer. Within the above range, the compatibility, impact resistance, transparency, etc., of the thermoplastic resin composition may be excellent.

[0054] In a specific example, the biphenyl group-containing (meth)acrylic copolymer resin may have a weight-average molecular weight of about 5,000 to about 25,000 g / mol, for example, about 10,000 to about 20,000 g / mol, as measured by gel permeation chromatography (GPC). Within this range, the impact resistance, chemical resistance, hardness, etc. of the thermoplastic resin composition may be excellent.

[0055] In a specific example, the biphenyl group-containing (meth)acrylic copolymer resin may be included in an amount of about 5 to about 32 parts by weight, for example, about 7 to about 30 parts by weight, per about 100 parts by weight of the polycarbonate resin. If the content of the biphenyl group-containing (meth)acrylic copolymer resin is less than about 5 parts by weight per about 100 parts by weight of the polycarbonate resin, there is a risk that the chemical resistance, hardness, appearance characteristics, etc. of the thermoplastic resin composition will be reduced, and if it exceeds about 32 parts by weight, there is a risk that the impact resistance, chemical resistance, etc. of the thermoplastic resin composition will be reduced.

[0056] In a specific example, the weight ratio (B:C) of the polyalkyl (meth)acrylate resin (B) and the biphenyl group-containing (meth)acrylic copolymer resin (C) may be about 1:1 to about 1:7, for example, about 1:1.2 to about 1:5. Within this range, the impact resistance, chemical resistance, hardness, appearance characteristics, etc. of the thermoplastic resin composition may be superior.

[0057]

[0058] (D) Rubber-modified vinyl graft copolymer

[0059] A rubber-modified vinyl graft copolymer according to one embodiment of the present invention can be applied together with a polycarbonate resin, a polyalkyl (meth)acrylate resin, a biphenyl group-containing (meth)acrylate copolymer resin, etc., to improve the impact resistance, chemical resistance, hardness, appearance characteristics, and the balance of physical properties thereof of a thermoplastic resin composition. A rubber-modified vinyl graft copolymer in which a monomer mixture containing an alkyl (meth)acrylate monomer and an aromatic vinyl monomer is graft-polymerized into a rubbery polymer can be used. For example, the rubber-modified vinyl graft copolymer can be obtained by graft-polymerizing a monomer mixture containing an alkyl (meth)acrylate monomer and an aromatic vinyl monomer into a rubbery polymer, and if necessary, a vinyl cyanide monomer and a monomer that imparts processability and heat resistance can be further included in the monomer mixture and graft-polymerized. The above polymerization can be carried out by known polymerization methods such as bulk polymerization, emulsion polymerization, and suspension polymerization.

[0060] In a specific example, the rubbery polymer may be exemplified by diene-based rubbers such as polybutadiene, poly(styrene-butadiene), and poly(acrylonitrile-butadiene), saturated rubber obtained by hydrogenating the diene-based rubber, acrylic rubbers such as isoprene rubber and polybutylacrylic acid, and ethylene-propylene-diene monomer terpolymer (EPDM). These may be used alone or in a mixture of two or more types. For example, diene-based rubber may be used, and specifically, butadiene-based rubber may be used.

[0061] In a specific example, the average particle size (Z-mean) of the rubbery polymer (rubber particles) may be about 0.1 to about 0.5 μm, for example, about 0.2 to about 0.4 μm. Within this range, the impact resistance, chemical resistance, etc. of the thermoplastic resin composition may be excellent. Here, the average particle size (z-mean) of the rubbery polymer (rubber particles) can be measured using a light scattering method in the latex state. Specifically, the rubbery polymer latex is filtered through a mesh to remove coagulated material generated during the polymerization of the rubbery polymer, a solution of 0.5 g of latex and 30 ml of distilled water is poured into a 1,000 ml flask and filled with distilled water to prepare a sample, then 10 ml of the sample is transferred to a quartz cell, and the average particle size of the rubbery polymer can be measured using a light scattering particle size analyzer (Malvern, nano-zs).

[0062] In a specific example, the content of the rubbery polymer may be about 10 to about 70 weight%, for example, about 15 to about 65 weight%, of the total 100 weight% of the rubber-modified vinyl graft copolymer, and the content of the monomer mixture (including alkyl (meth)acrylate and aromatic vinyl monomer) may be about 30 to about 90 weight%, for example, about 35 to about 85 weight%, of the total 100 weight% of the rubber-modified vinyl graft copolymer. Within the above range, the impact resistance, chemical resistance, etc. of the thermoplastic resin composition may be excellent.

[0063] In a specific example, the alkyl (meth)acrylate can be graft copolymerized into the rubbery copolymer or copolymerized with an aromatic vinyl monomer, etc., and may use alkyl (meth)acrylates having 1 to 10 carbon atoms, such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, etc., and for example, methyl (meth)acrylate, etc. may be used. The content of the alkyl (meth)acrylate may be about 30 to about 90 weight%, for example, about 35 to about 85 weight%, of 100 weight% of the monomer mixture. Within this range, the impact resistance, chemical resistance, etc. of the thermoplastic resin composition may be excellent.

[0064] In a specific example, the aromatic vinyl monomer can be graft copolymerized into a rubbery copolymer, and examples include styrene, α-methylstyrene, β-methylstyrene, p-methylstyrene, pt-butylstyrene, ethylstyrene, vinylxylene, monochlorostyrene, dichlorostyrene, dibromostyrene, vinylnaphthalene, etc. These may be used alone or in a mixture of two or more types. The content of the aromatic vinyl monomer may be about 10 to about 70 weight%, for example, about 15 to about 65 weight%, of 100 weight% of the monomer mixture. Within this range, the impact resistance, chemical resistance, etc. of the thermoplastic resin composition may be excellent.

[0065] In a specific example, the vinyl cyanide monomer is copolymerizable with the aromatic vinyl monomer, and examples include, but are not limited to, acrylonitrile, methacrylonitrile, ethacrylonitrile, phenylacrylonitrile, α-chloroacrylonitrile, fumaronitrile. These may be used alone or in a mixture of two or more. For example, acrylonitrile, methacrylonitrile, etc. may be used. When the vinyl cyanide monomer is applied, its content may be about 15% by weight or less, for example, about 0.1 to about 10% by weight, of the monomer mixture. Within this range, the impact resistance, chemical resistance, etc. of the thermoplastic resin composition may be excellent.

[0066] In a specific example, examples of monomers for imparting processability and heat resistance include (meth)acrylic acid, maleic anhydride, N-substituted maleimide, etc. When applying the monomer for imparting processability and heat resistance, the content thereof may be about 15% by weight or less, for example, about 0.1 to about 10% by weight, of 100% by weight of the monomer mixture. Within this range, processability and heat resistance, etc., can be imparted to the thermoplastic resin composition without degrading other physical properties.

[0067] In a specific example, the rubber-modified vinyl-based graft copolymer may be exemplified as a methyl methacrylate-butadiene-styrene graft copolymer (g-MBS). Here, the g-MBS may consist of a rubbery polymer (core) of polybutadiene (PBD) and a methyl methacrylate-styrene copolymer shell graft-polymerized onto the core, but is not limited thereto.

[0068] In a specific example, the rubber-modified vinyl graft copolymer may be included in an amount of about 2 to about 7 parts by weight, for example, about 2.3 to about 6 parts by weight, per about 100 parts by weight of the polycarbonate resin. If the content of the rubber-modified vinyl graft copolymer is less than about 2 parts by weight per about 100 parts by weight of the polycarbonate resin, there is a risk that the chemical resistance, impact resistance, etc. of the thermoplastic resin composition will be reduced, and if it exceeds about 7 parts by weight, there is a risk that the chemical resistance, hardness, appearance characteristics, etc. of the thermoplastic resin composition will be reduced.

[0069] In a specific example, the weight ratio (B:D) of the polyalkyl (meth)acrylate resin (B) and the rubber-modified vinyl graft copolymer (D) may be about 1:0.1 to about 1:1.5, for example, about 1:0.2 to about 1:1.2. Within this range, the impact resistance, chemical resistance, etc. of the thermoplastic resin composition may be superior.

[0070] In a specific example, the weight ratio (C:D) of the biphenyl group-containing (meth)acrylic copolymer resin (C) and the rubber-modified vinyl graft copolymer (D) may be about 1:0.1 to about 1:0.7, for example, about 1:0.13 to about 1:0.6. If the weight ratio of the biphenyl group-containing (meth)acrylic copolymer resin and the rubber-modified vinyl graft copolymer is less than about 1:0.1, there is a risk that the impact resistance, chemical resistance, etc. of the thermoplastic resin composition may be reduced, and if it exceeds about 1:0.7, there is a risk that the impact resistance, chemical resistance, hardness, appearance characteristics, etc. of the thermoplastic resin composition may be reduced.

[0071]

[0072] A thermoplastic resin composition according to one embodiment of the present invention may further include additives included in conventional thermoplastic resin compositions. Examples of such additives include, but are not limited to, flame retardants, anti-dropping agents, inorganic fillers, lubricants, nucleating agents, phosphorus-based stabilizers, release agents, pigments, dyes, and mixtures thereof. When using such additives, the content thereof may be about 0.001 to about 40 parts by weight, for example, about 0.1 to about 10 parts by weight, per about 100 parts by weight of the polycarbonate resin.

[0073]

[0074] A thermoplastic resin composition according to one embodiment of the present invention may be in the form of pellets produced by mixing the above components and melt-extruding them using a conventional twin-screw extruder at about 200 to about 300°C, for example, about 220 to about 280°C.

[0075] In a specific example, the thermoplastic resin composition may have a notched Izod impact strength of about 50 to about 90 kgf·cm / cm, for example, about 55 to about 80 kgf·cm / cm, of a 1 / 8" thick specimen measured according to ASTM D256.

[0076] In a specific example, when the thermoplastic resin composition is applied and wrapped with 0.5 ml of liquid extracted from a sterilizing wet wipe (manufacturer: PDI Healthcare, product name: Sani-cloth AFIII) on a 1 / 8" thick Type I tensile specimen made according to ASTM D638 standards, and then left on a 1% strain curvature jig, the time at which cracks occur on the surface of the specimen may be about 60 minutes or more.

[0077] In a specific example, the thermoplastic resin composition may have a pencil hardness of HB or higher on a 1 mm thick specimen measured according to JIS K5401, and a scratch width of about 230 to about 295 μm by a BSP (Ball-type Scratch Profile) test, for example, about 240 to about 290 μm.

[0078] In a specific example, the thermoplastic resin composition may have a phase separation area of ​​about 25% or less, for example, about 20% or less, of an injection molded specimen with dimensions of 5 cm × 9 cm × 2 cm. Here, the phase separation area refers to the area where the polyalkyl (meth)acrylate resin has phase separated and become opaque.

[0079]

[0080] The molded article according to the present invention is formed from the thermoplastic resin composition. The thermoplastic resin composition may be manufactured in the form of pellets, and the manufactured pellets may be produced into various molded articles (products) through various molding methods such as injection molding, extrusion molding, vacuum molding, and casting molding. Such molding methods are well known to those skilled in the art to which the present invention belongs. The molded article has excellent impact resistance, chemical resistance, hardness, appearance characteristics, and a balance of these physical properties, and is useful as an interior / exterior material for electrical / electronic products, an interior / exterior material for automobiles, and an exterior material for buildings.

[0081]

[0082] The present invention is to be explained more specifically through the following examples, but these examples are for illustrative purposes only and should not be interpreted as limiting the invention.

[0083]

[0084] Examples

[0085] The specifications of each component used in the examples and comparative examples below are as follows.

[0086] (A) Polycarbonate resin

[0087] Bisphenol-A type polycarbonate resin (weight-average molecular weight (Mw): approximately 22,000 g / mol) was used.

[0088] (B) Polyalkyl (meth)acrylate resin

[0089] Polymethyl methacrylate resin (Manufacturer: ASAHI KASEI, Product Name: Del Powder 720V) was used.

[0090] (C) Biphenyl group-containing (meth)acrylic copolymer resin

[0091] A polymer of 30 wt% biphenylmethylacrylate and 70 wt% methyl methacrylate (weight-average molecular weight (Mw): approximately 15,000 g / mol) was used.

[0092] (D) Rubber-modified vinyl graft copolymer

[0093] A core-shell type graft copolymer (g-MBS) was used, prepared by graft copolymerizing 45 wt% of styrene, methyl methacrylate, and styrene (methyl methacrylate / styrene: 70 wt% / 30 wt%) with 55 wt% of butadiene rubber having an average particle size of about 0.28 μm.

[0094]

[0095] Examples 1 to 9 and Comparative Examples 1 to 8

[0096] Each of the above components was added in the amounts listed in Tables 1, 2, 3, and 4 below, and pellets were prepared by extrusion at approximately 260°C. A twin-screw extruder with L / D=36 and a diameter of 45 mm was used for extrusion. The prepared pellets were dried at approximately 100°C for at least 6 hours, and then injection molded in an injection molding machine (molding temperature: approximately 290°C, mold temperature: approximately 80°C) to produce specimens. The physical properties of the prepared specimens were evaluated by the following method, and the results are shown in Tables 1, 2, 3, and 4 below.

[0097]

[0098] Methods for measuring physical properties

[0099] (1) Notched Izod impact strength (unit: kgf·cm / cm): The notched Izod impact strength of a 1 / 8" thick specimen was measured according to ASTM D256.

[0100] (2) Chemical resistance evaluation: 0.5 ml of liquid extracted from antibacterial wipes (manufacturer: PDI Healthcare, product name: Sani-cloth AFIII) was applied to and wrapped onto a 1 / 8" thick Type I tensile specimen made according to ASTM D638 standards, and then left on a 1% strain curvature jig and the time it took for a crack to form on the surface of the specimen was measured.

[0101] (3) Pencil hardness: According to JIS K5401, the pencil hardness of a 1 mm thick specimen was measured.

[0102] (4) Scratch width (unit: μm): Measured according to the BSP (Ball-type Scratch Profile) test method. A spherical metal tip with a diameter of 0.7 mm was used to apply a scratch of 10 to 20 mm in length to a specimen surface measuring 90 mm × 50 mm × 1 mm with a load of 1 kg and a scratch speed of 75 mm / min. The scratch width, which is a measure of scratch resistance, was measured by scanning the surface of the applied scratch using a metal stylus tip with a diameter of 2 μm with an Ambios contact surface profile analyzer (XP-1).

[0103] (5) Appearance evaluation: After injecting a specimen of size 5 cm × 9 cm × 2 cm, the phase separation area (unit: %) of the injection specimen was visually inspected. Here, the phase separation area refers to the area where the polyalkyl (meth)acrylate resin has separated into phases and become opaque.

[0104]

[0105] Example 1 2345(A) (parts by weight) 100 100 100 100 100(B) (parts by weight) 3.7 5.9 8.5 5.9 5.9(C) (parts by weight) 11.8 11.8 11.8 7.4 28.6(D) (parts by weight) 4.2 4.2 4.2 4.2 4.2 Notch Izod Impact Strength (kgf·cm / cm) 60 60 60 60 60 Time to Crack (min) 70 70 70 70 70 Pencil Hardness HB HB HB HB F Scratch Width (㎛) 280 280 275 290 268 Phase Separation Area (%) 00 0 50

[0106]

[0107] Example 6789(A) (parts by weight) 100 100 100 100(B) (parts by weight) 5.9 5.9 3.7 14.3(C) (parts by weight) 11.8 11.8 7.4 28.6(D) (parts by weight) 2.4 5.9 3.7 4.3 Notch Izod Impact Strength (kgf·cm / cm) 60 70 70 60 Crack Initiation Time (min) 70 80 70 90 Pencil Hardness HB HB HBH Scratch Width (㎛) 280 285 290 250 Phase Separation Area (%) 00 0 10

[0108]

[0109] Comparative Example 1234(A) (parts by weight) 100 100 100 100(B) (parts by weight) 21 85.9 5.9(C) (parts by weight) 11.8 11.8 335(D) (parts by weight) 4.2 4.2 4.2 4.2 Notch Izod Impact Strength (kgf·cm / cm) 30 50 50 30 Crack Initiation Time (min) 20 50 20 50 Pencil Hardness HB HBB F Scratch Width (㎛) 29 28 30 0 270 Phase Separation Area (%) 10 60 500

[0110]

[0111] Comparative Example 5678(A) (parts by weight) 100 100 100 100(B) (parts by weight) 5.9 5.9 5.9 5.9(C) (parts by weight) 11.8 11.8 28.6 7.4(D) (parts by weight) 110 2.4 5.9(C):(D) (weight ratio) 1:0.0 8 1:0.8 5 1:0.0 8 1:0.8 Notch Izod Impact Strength (kgf·cm / cm) 10 60 40 30 Crack Initiation Time (min) 10 50 30 20 Pencil Hardness HBB HBB Scratch Width (㎛) 29 30 0 28 30 0 Phase Separation Area (%) 55 30

[0112]

[0113] From the above results, it can be seen that the thermoplastic resin composition of the present invention exhibits excellent impact resistance (notched Izod impact strength), chemical resistance (time to crack), hardness (pencil hardness, scratch width), appearance characteristics (phase separation area), and the balance of these physical properties.

[0114] On the other hand, in Comparative Example 1, in which a small amount of polyalkyl (meth)acrylate resin was applied, it was found that impact resistance and chemical resistance were reduced, and in Comparative Example 2, in which an excessive amount of polyalkyl (meth)acrylate resin was applied, it was found that chemical resistance and appearance characteristics were reduced. In Comparative Example 3, in which a small amount of biphenyl group-containing (meth)acrylic copolymer resin was applied, it was found that chemical resistance, hardness, and appearance characteristics were reduced, and in Comparative Example 4, in which an excessive amount of biphenyl group-containing (meth)acrylic copolymer resin was applied, it was found that impact resistance and chemical resistance were reduced. In Comparative Example 5, in which a small amount of rubber-modified vinyl graft copolymer was applied, it was found that impact resistance and chemical resistance were reduced, and in Comparative Example 6, in which an excessive amount of rubber-modified vinyl graft copolymer was applied, it was found that chemical resistance and hardness were reduced.

[0115] In addition, even if the content of the polyalkyl (meth)acrylate resin and the biphenyl group-containing (meth)acrylic copolymer resin is included within the range of the present invention, in the case of Comparative Example 7, where the weight ratio of the polyalkyl (meth)acrylate resin and the biphenyl group-containing (meth)acrylic copolymer resin is less than the range of the present invention, it can be seen that impact resistance, chemical resistance, etc. are reduced, and in the case of Comparative Example 8, where the weight ratio of the polyalkyl (meth)acrylate resin and the biphenyl group-containing (meth)acrylic copolymer resin exceeds the range of the present invention, it can be seen that impact resistance, chemical resistance, hardness, appearance characteristics, etc. are reduced.

[0116]

[0117] The present invention has been described above with reference to embodiments. Those skilled in the art will understand that the present invention may be embodied in modified forms without departing from the essential characteristics of the invention. Therefore, the disclosed embodiments should be considered in an illustrative rather than a restrictive sense. The scope of the invention is defined by the claims, not by the foregoing description, and all variations within the scope of equivalents should be interpreted as being included in the invention.

Claims

1. 100 parts by weight of polycarbonate resin; 3 to 17 parts by weight of polyalkyl (meth)acrylate resin; 5 to 32 parts by weight of a biphenyl group-containing (meth)acrylic copolymer resin comprising a unit derived from a monomer represented by the following chemical formula 1; and 2 to 7 parts by weight of a rubber-modified vinyl graft copolymer in which a monomer mixture comprising an alkyl (meth)acrylic monomer and an aromatic vinyl monomer is graft-polymerized onto a rubbery polymer; and A thermoplastic resin composition characterized in that the weight ratio of the above-mentioned biphenyl group-containing (meth)acrylic copolymer resin and the above-mentioned rubber-modified vinyl graft copolymer is 1:0.1 to 1:0.7: [Chemical Formula 1] In the above chemical formula 1, R1 is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and n is an integer from 0 to 10.

2. A thermoplastic resin composition according to claim 1, characterized in that the polycarbonate resin has a weight-average molecular weight of 10,000 to 200,000 g / mol.

3. A thermoplastic resin composition according to claim 1, wherein the polyalkyl (meth)acrylate resin comprises one or more of polymethyl (meth)acrylate resin, polyethyl (meth)acrylate resin, polypropyl (meth)acrylate resin, methyl (meth)acrylate, and copolymers of alkyl (meth)acrylates having 2 to 10 carbon atoms.

4. A thermoplastic resin composition according to claim 1, characterized in that the polyalkyl (meth)acrylate resin has a weight-average molecular weight of 50,000 to 130,000 g / mol.

5. A thermoplastic resin composition according to claim 1, wherein the biphenyl group-containing (meth)acrylic copolymer resin comprises 10 to 40 weight% of a monomer represented by Formula 1 and 60 to 90 weight% of an alkyl (meth)acrylic monomer.

6. A thermoplastic resin composition according to claim 1, characterized in that the biphenyl group-containing (meth)acrylic copolymer resin has a weight-average molecular weight of 5,000 to 25,000 g / mol.

7. A thermoplastic resin composition according to claim 1, wherein the rubber-modified vinyl graft copolymer comprises 10 to 70 weight% of a rubbery polymer and 30 to 90 weight% of a monomer mixture comprising an alkyl (meth)acrylic monomer and an aromatic vinyl monomer.

8. A thermoplastic resin composition according to claim 1, characterized in that the weight ratio of the polyalkyl (meth)acrylate resin and the biphenyl group-containing (meth)acrylic copolymer resin is 1:1 to 1:

7.

9. The thermoplastic resin composition according to claim 1, characterized in that the notched Izod impact strength of a 1 / 8" thick specimen measured according to ASTM D256 is 50 to 90 kgf·cm / cm.

10. The thermoplastic resin composition according to claim 1, characterized in that when 0.5 ml of liquid extracted from a sterilizing wet wipe is applied and wrapped onto a 1 / 8" thick Type I tensile specimen manufactured according to ASTM D638 standards, and then left in a 1% strain curvature jig, the time at which cracks occur on the surface of the specimen is 60 minutes or more.

11. The thermoplastic resin composition according to claim 1, characterized in that the pencil hardness of a 1 mm thick specimen measured according to JIS K5401 is HB or higher, and the scratch width by a BSP (Ball-type Scratch Profile) test is 230 to 295 μm.

12. The thermoplastic resin composition according to claim 1, characterized in that the phase separation area (opaque area) of an injection molded specimen of size 5 cm × 9 cm × 2 cm is 25% or less.

13. A molded article characterized by being formed from a thermoplastic resin composition according to any one of claims 1 to 12.

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