WO2019078479A1 - Thermoplastic resin composition and molded product formed therefrom - Google Patents

Abstract

A thermoplastic resin composition of the present invention comprises: (A) a rubber-modified vinyl-based graft copolymer; (B) a first aromatic vinyl-cyanovinyl-based copolymer having a weight average molecular weight of approximately 100,000-500,000 g/mol; (C) a second aromatic vinyl-cyanovinyl-based copolymer having a weight average molecular weight of approximately 4,000,000 g/mol or more; and (D) zinc oxide, wherein the weight ratio of (C) and (D) is approximately 1 : approximately 0.5 to approximately 1 : approximately 5.

Description

Thermoplastic resin composition and molded article formed therefrom

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 excellent in antibacterial properties, vacuum formability, mechanical strength and the like, and a molded article formed therefrom.

Rubber-modified aromatic vinyl-based copolymer resins such as ABS (acrylonitrile-butadiene-styrene copolymer) resins have been mainly used as refrigerating machine resins. Unlike general ABS processing, extruded ABS used for refrigerators, in particular, includes an additional step of vacuum forming, which requires excellent processability. Further, since the refrigerator material is used for storing foods, it is necessary to impart antimicrobial properties.

Thus, a method of adding an antimicrobial agent to impart antimicrobial properties has been proposed. Organic antimicrobial agents are relatively inexpensive and have good antimicrobial activity in a small amount. However, they sometimes have human toxicity and may be effective only for certain bacteria. have. Further, it may cause discoloration after processing, and there is a disadvantage that the antimicrobial persistence is short due to the elution problem.

The inorganic antimicrobial agent is an antimicrobial agent containing a metal component such as silver (Ag) and copper (Cu) and is excellent in thermal stability and is widely used for producing an antimicrobial thermoplastic resin composition (antibacterial resin). However, Excessive use is required and there are disadvantages such as relatively high price, uniform dispersion problem during processing, discoloration due to metal components, and there are many restrictions in use. In particular, inorganic antibacterial agents may affect vacuum formability, and it is necessary to develop a product that satisfies all of antimicrobial activity, vacuum formability, and mechanical strength in accordance with the recent trend of large capacity and thinning of products.

The background art of the present invention is disclosed in Korean Patent Publication No. 10-2009-0073453.

It is an object of the present invention to provide a thermoplastic resin composition having excellent antibacterial properties, vacuum formability and mechanical strength, and a molded article formed from the thermoplastic resin composition.

Another object of the present invention is to provide a thermoplastic resin composition having excellent low-temperature characteristics and a molded article formed therefrom.

The above and other objects of the present invention can be achieved by the present invention described below.

One aspect of the present invention relates to a thermoplastic resin composition. Wherein the thermoplastic resin composition comprises (A) a rubber-modified vinyl-based graft copolymer; (B) a first aromatic vinyl-cyanide vinyl copolymer having a weight average molecular weight of about 100,000 to about 500,000 g / mol; (C) a second aromatic vinyl-cyanide vinyl copolymer having a weight average molecular weight of about 4,000,000 g / mol or more; And (D) zinc oxide, wherein the weight ratio of (C) to (D) is about 1: about 0.5 to about 1: about 5.

In an embodiment, the thermoplastic resin composition comprises about 10 to about 70% by weight of the rubber-modified vinyl graft copolymer (A) and about 30 to about 90% by weight of the first aromatic vinyl-cyanide vinyl copolymer (B) About 100 parts by weight of a base resin; About 1 to about 10 parts by weight of the second aromatic vinyl-cyanide vinyl copolymer (C); And about 2 to about 10 parts by weight of (D) zinc oxide.

In a specific example, the rubber-modified vinyl-based graft copolymer (A) may be one obtained by graft-polymerizing a monomer mixture containing an aromatic vinyl monomer and a vinyl cyan monomer in a diene rubber-like polymer.

In embodiments, the diene-based rubbery polymer may have an average particle size of from about 0.1 to about 0.4 micrometers.

In an embodiment, the second aromatic vinyl-cyanide vinyl copolymer (C) may have a weight average molecular weight of about 4,000,000 to about 10,000,000 g / mol.

In an embodiment, the zinc oxide (D) has a size ratio (B / A) of peak A in the region of 370 to 390 nm and peak B in the region of 450 to 600 nm in the range of about 0.01 to about 10 < / RTI >

In an embodiment, the zinc oxide (D) has a size ratio (B / A) of peak A in the region of 370 to 390 nm and peak B in the region of 450 to 600 nm in the range of about 0.01 to about 1 < / RTI >

In an embodiment, (D) zinc oxide may have a BET surface area of less than about 15 m ² / g.

In an embodiment, the zinc oxide (D) has a peak position 2θ value in the range of 35 to 37 ° in X-ray diffraction (XRD) analysis, and the size the crystallite size value can be from about 1,000 to about 2,000 A:

[Formula 4]

Microcrystalline size (D) =

In the formula 4, K is a shape factor,? Is an X-ray wavelength,? Is an FWHM value (degree) of an X-ray diffraction peak,? Is a peak position value (peak position degree).

In an embodiment, the (D) zinc oxide may have an average particle size (D50) of from about 0.5 to about 3 microns.

In a specific example, the thermoplastic resin composition may satisfy the following formulas 1 and 2:

[Formula 1]

6 Kg / cm ² ≤ TS ₁₅₀ ≤ 20 Kg / cm ²

In the above formula (1), TS ₁₅₀ is a tensile strength measured at a rate of 150 mm / min after being maintained at 150 캜 for 3 minutes in accordance with ASTM D638.

[Formula 2]

485 Kg / cm ² ≤ TS ₂₃ ≤ 600 Kg / cm ²

In the formula 2, TS ₂₃ is a tensile strength measured at a rate of 5 mm / min at 23 캜 according to ASTM D638.

In the specific example, the thermoplastic resin composition was prepared by inoculating Staphylococcus aureus and E. coli into a 5 cm x 5 cm size specimen according to JIS Z 2801 Antibacterial Evaluation Method, and measuring the antibacterial activity value against Staphylococcus aureus About 2 to about 5, and the antimicrobial activity value for E. coli may be about 2 to about 5. [

[Formula 3]

Antibacterial activity = log (M1 / M2)

In the formula (3), M1 is the number of bacteria after culture for 24 hours at 35 ° C and RH 90% for blank specimens, M2 is the number of bacteria after incubation for 24 hours at 35 ° C and RH 90% It is the number of bacteria.

In a specific example, the thermoplastic resin composition has a detection area value of a volatile organic compound collected at 120 ° C for 300 minutes using a HS-SPME GC / MS (headspace solid-phase microextraction coupled gas chromatography / mass spectrometry) 200 to about 500 area / g.

In an embodiment, the thermoplastic resin composition may have a residual volatile content of about 800 to about 1,200 ppm measured at 250 ° C using GC / MS (gas chromatography / mass spectrometry).

Another aspect of the present invention relates to a molded article formed from the thermoplastic resin composition.

In a specific example, the molded article is vacuum molded and may be a refrigerator interior component.

INDUSTRIAL APPLICABILITY The present invention has the effect of providing a thermoplastic resin composition excellent in antibacterial properties, vacuum formability and mechanical strength, excellent in low-temperature characteristics, and a molded article formed therefrom.

Hereinafter, the present invention will be described in detail.

The thermoplastic resin composition according to the present invention comprises (A) a rubber-modified vinyl-based graft copolymer; (B) a first aromatic vinyl-cyanide vinyl copolymer having a weight average molecular weight of about 100,000 to about 500,000 g / mol; (C) a second aromatic vinyl-cyanide vinyl copolymer having a weight average molecular weight of about 4,000,000 g / mol or more; And (D) zinc oxide.

(A) Rubber degeneration Vinyl-based Graft  Copolymer

The rubber-modified vinyl-based graft copolymer according to one embodiment of the present invention is capable of improving the impact resistance and the like of the thermoplastic resin composition, and is obtained by adding a monomer mixture comprising an aromatic vinyl monomer and a vinyl cyanide monomer to a diene rubber- May be graft-polymerized. For example, the rubber-modified vinyl-based graft copolymer can be obtained by graft copolymerizing a monomer mixture containing an aromatic vinyl monomer and a vinyl cyan monomer to a diene rubber-like polymer, and if necessary, Graft polymerization may be further carried out by further including a monomer which imparts processability and heat resistance. The polymerization may be carried out by a known polymerization method such as emulsion polymerization or suspension polymerization.

Examples of the diene-based rubbery polymer include, but are not limited to, polybutadiene, poly (styrene-butadiene), poly (acrylonitrile-butadiene), and the like. These may be used alone or in combination of two or more. For example, a butadiene rubber such as polybutadiene can be used.

In embodiments, the average particle size (Z-average) of the diene-based rubbery polymer (rubber particles) may be from about 0.1 to about 0.4 microns, for example, from about 0.2 to about 0.4 microns. The impact resistance and appearance of the thermoplastic resin composition may be excellent in the above range.

In embodiments, the content of the diene-based rubbery polymer may be from about 20 to about 65 weight percent, such as from about 30 to about 60 weight percent, based on 100 weight percent of the total rubber modified vinyl based graft copolymer, (Including aromatic vinyl monomer and vinyl cyanide monomer) may be about 35 to about 80 wt%, for example about 40 to about 70 wt%, of 100 wt% of the entire rubber-modified vinyl-based graft copolymer. The impact resistance and fluidity of the thermoplastic resin composition can be excellent in the above range.

In an embodiment, the aromatic vinyl-based monomer may be graft-copolymerized with the diene-based rubbery polymer, and examples thereof include styrene,? -Methylstyrene,? -Methylstyrene, p-methylstyrene, pt-butylstyrene, Xylene, monochlorostyrene, dichlorostyrene, dibromostyrene, vinylnaphthalene, and the like, but the present invention is not limited thereto. These may be used alone or in combination of two or more. The content of the aromatic vinyl-based monomer may be about 50 to about 90% by weight, for example about 60 to about 80% by weight, based on 100% by weight of the monomer mixture. The impact resistance and fluidity of the thermoplastic resin composition can be excellent in the above range.

In the specific examples, the vinyl cyanide monomer is copolymerizable with the aromatic vinyl system, and examples thereof include acrylonitrile, methacrylonitrile, ethacrylonitrile, phenyl acrylonitrile,? -Chloroacrylonitrile, But is not limited thereto. These may be used alone or in combination of two or more. For example, acrylonitrile, methacrylonitrile and the like can be used. The content of the vinyl cyanide monomer may be about 10 to about 50 wt%, for example about 20 to about 40 wt%, of 100 wt% of the monomer mixture. The impact resistance and fluidity of the thermoplastic resin composition can be excellent in the above range.

In the specific examples, examples of the monomer for imparting the above processability and heat resistance include, but are not limited to, (meth) acrylic acid, maleic anhydride, N-substituted maleimide and the like. When the monomer for imparting processability and heat resistance is used, the content thereof may be about 15% by weight or less, for example, about 0.1 to about 10% by weight, based on 100% by weight of the monomer mixture. Within the above range, the thermoplastic resin composition can be imparted with processability and heat resistance without deteriorating other physical properties.

In an embodiment, the rubber-modified vinyl-based graft copolymer may be an acrylonitrile-butadiene-styrene graft copolymer (g-ABS), but is not limited thereto.

In an embodiment, the rubber-modified vinyl-based graft copolymer comprises about 10 to about 70 weight percent, for example about 15 to about 65 weight percent, and about 20 weight percent, based on 100 weight percent of the base resin of (A) To about 60 wt%, from about 20 wt% to about 55 wt%, and from about 25 wt% to about 50 wt%. Within the above range, the thermoplastic resin composition may have excellent chemical resistance, rigidity, impact resistance, fluidity, and physical properties thereof.

(B) a first aromatic vinyl-cyanide Vinyl-based  Copolymer

The first aromatic vinyl-cyanide vinyl copolymer of the present invention can improve the chemical resistance, fluidity and the like of the thermoplastic resin composition and has a weight average molecular weight of about 100,000 to about 500,000 g / mol, for example, about 200,000 to about 500,000 g / About 400,000 g / mol, and the content of the repeating units derived from the vinyl cyanide monomer is about 25 to about 31% by weight, based on the total weight of the cyanide-based monomer and the vinyl cyanide-based monomer. For example, the first aromatic vinyl-cyanide vinyl copolymer is a copolymer comprising a repeating unit derived from an aromatic vinyl monomer and a repeating unit derived from a vinyl cyan monomer, wherein the weight average molecular weight range and the repeating unit And the monomer mixture is reacted according to a known polymerization method so as to have a unit range. Further, if necessary, a first aromatic vinyl-cyanide vinyl copolymer further containing a monomer for imparting processability and heat resistance to the monomer mixture and further containing a repeating unit derived from a monomer giving workability and heat resistance is obtained .

In an embodiment, the aromatic vinyl-based monomer is a monomer capable of forming a repeating unit derived from an aromatic vinyl-based monomer by being polymerized with a vinyl cyanide monomer or the like, and examples thereof include styrene,? -Methylstyrene,? -Methylstyrene, but are not limited to, pt-butylstyrene, ethylstyrene, vinylxylene, monochlorostyrene, dichlorostyrene, dibromostyrene, and vinylnaphthalene. These may be used alone or in combination of two or more. The content of the aromatic vinyl monomer (the repeating unit derived from the aromatic vinyl monomer) is about 69 to about 75% by weight of 100% by weight of the monomer mixture (first aromatic vinyl-cyanide vinyl copolymer), for example, about 70 to about 74% by weight. Within the above range, the thermoplastic resin composition may have excellent chemical resistance and fluidity.

In an embodiment, the vinyl cyanide monomer may be a polymer which is capable of forming a repeating unit derived from a vinyl cyanide monomer by being polymerized with an aromatic vinyl-based monomer or the like. The vinyl monomer may be acrylonitrile, methacrylonitrile, ethacrylonitrile, Nitrile,? -Chloroacrylonitrile, fumaronitrile, and the like, but are not limited thereto. These may be used alone or in combination of two or more. For example, acrylonitrile, methacrylonitrile and the like can be used. The content of the vinyl cyanide monomer (the repeating unit derived from the vinyl cyanide monomer) is about 25 to about 31% by weight of 100% by weight of the monomer mixture (first aromatic vinyl-cyanide vinyl copolymer) 26 to about 30% by weight. The above range is excellent in chemical resistance and fluidity.

In the specific examples, examples of the monomer for imparting the above processability and heat resistance include, but are not limited to, (meth) acrylic acid, maleic anhydride, N-substituted maleimide and the like. When the monomer for imparting processability and heat resistance is used, the content thereof may be about 15% by weight or less, for example, about 0.1 to about 10% by weight, based on 100% by weight of the monomer mixture. Within the above range, the thermoplastic resin composition can be imparted with processability and heat resistance without deteriorating other physical properties.

In an embodiment, the first aromatic vinyl-cyanide vinyl copolymer has a weight average molecular weight, as measured by gel permeation chromatography (GPC), of from about 100,000 to about 500,000 g / mol, in embodiments from about 200,000 to about 400,000 g / mol, about 250,000 to about 350,000 g / mol. When the weight average molecular weight of the first aromatic vinyl-cyanide vinyl copolymer is less than about 100,000 g / mol, the impact resistance and the like of the thermoplastic resin composition may deteriorate. When the weight average molecular weight of the first aromatic vinyl-cyanide vinyl copolymer exceeds about 500,000 g / mol, There is a possibility that the fluidity and the like of the composition is lowered.

In an embodiment, the first aromatic vinyl-cyanide vinyl copolymer comprises about 30 to about 90% by weight, for example about 35 to about 85% by weight, based on 100% by weight of the base resin of (A) + (B) From about 40 to about 80 weight percent, from about 45 to about 80 weight percent, from about 50 weight percent to about 75 weight percent. Within the above range, the thermoplastic resin composition may have excellent chemical resistance, rigidity, impact resistance, fluidity, and physical properties thereof.

(C) Second aromatic vinyl-cyanide Vinyl-based  Copolymer

The second aromatic vinyl-cyanide vinyl copolymer of the present invention can impart a high temperature tensile strength of the thermoplastic resin.

The second aromatic vinyl-cyanide vinyl copolymer is a copolymer comprising a repeating unit derived from an aromatic vinyl monomer and a repeating unit derived from a vinyl cyan monomer.

The second aromatic vinyl-cyanide vinyl copolymer may be produced by cross-linking a monomer mixture comprising an aromatic vinyl monomer and a vinyl cyanide monomer.

In an embodiment, the aromatic vinyl-based monomer is a monomer capable of forming a repeating unit derived from an aromatic vinyl-based monomer by being polymerized with a vinyl cyanide monomer or the like, and examples thereof include styrene,? -Methylstyrene,? -Methylstyrene, but are not limited to, pt-butylstyrene, ethylstyrene, vinylxylene, monochlorostyrene, dichlorostyrene, dibromostyrene, and vinylnaphthalene. These may be used alone or in combination of two or more. The content of the aromatic vinyl monomer (repeating unit derived from an aromatic vinyl monomer) is about 60 to about 85 wt%, for example, about 100 to about 85 wt% of the monomer mixture (second aromatic vinyl-cyanide vinyl copolymer) By weight to about 80% by weight. Within the above range, the thermoplastic resin composition may have excellent chemical resistance and fluidity.

In an embodiment, the vinyl cyanide monomer may be a polymer which is capable of forming a repeating unit derived from a vinyl cyanide monomer by being polymerized with an aromatic vinyl-based monomer or the like. The vinyl monomer may be acrylonitrile, methacrylonitrile, ethacrylonitrile, Nitrile,? -Chloroacrylonitrile, fumaronitrile, and the like, but are not limited thereto. These may be used alone or in combination of two or more. For example, acrylonitrile, methacrylonitrile and the like can be used. The content of the vinyl cyanide monomer (the repeating unit derived from the vinyl cyanide monomer) is about 15 to about 40 wt% of 100 wt% of the monomer mixture (second aromatic vinyl-cyanide vinyl copolymer) 20 to about 35% by weight. Within the above range, the thermoplastic resin composition may have better chemical resistance and fluidity.

In the specific examples, examples of the monomer for imparting the above processability and heat resistance include, but are not limited to, (meth) acrylic acid, maleic anhydride, N-substituted maleimide and the like. When the monomer for imparting processability and heat resistance is used, the content thereof may be about 15% by weight or less, for example, about 0.1 to about 10% by weight, based on 100% by weight of the monomer mixture. Within the above range, the thermoplastic resin composition can be imparted with processability and heat resistance without deteriorating other physical properties.

In an embodiment, the second aromatic vinyl-cyanide vinyl copolymer has a weight average molecular weight, as measured by gel permeation chromatography (GPC), of at least about 4,000,000 g / mol, such as from about 4,000,000 to about 10,000,000 g / mol. When the weight average molecular weight of the second aromatic vinyl-cyanide vinyl copolymer is less than about 4,000,000 g / mol, sufficient high temperature tensile strength can not be obtained.

In an embodiment, the second aromatic vinyl-cyanide vinyl copolymer comprises about 1 to about 10 parts by weight, for example about 1 to about 5 parts by weight, based on about 100 parts by weight of the base resin of (A) + (B) ≪ / RTI > The high temperature tensile strength, chemical resistance, rigidity, impact resistance, fluidity and balance of physical properties of the thermoplastic resin composition in the above range can be excellent.

In embodiments, the weight ratio of (B) to (C) is about 90: about 1 to about 3: about 1, such as about 75: about 1 to about 30: about 1, 35: can be about 1. Within the above range, fluidity and processability and high temperature tensile strength efficiency can be excellent.

(D) zinc oxide

The zinc oxide used in the present invention is obtained by melting zinc in a metal form and then heating it to a temperature of about 850 to about 1,000 ° C, for example, about 900 to about 950 ° C, Deg.] C, and if necessary, heat treatment is performed at about 400 to about 900 DEG C, for example, about 500 to about 800 DEG C for about 30 minutes to about 150 minutes while injecting nitrogen / hydrogen gas into the reactor , And cooling to room temperature (20 to 30 占 폚).

(B / A) of peak A in the region of 370 to 390 nm and peak B in the region of 450 to 600 nm is in the range of about 0.01 to about 10, From about 0.01 to about 2, from about 0.01 to about 1, from about 0.01 to about 0.5, from about 0.1 to about 0.3, a BET surface area of less than about 15 m ² / g, less than about 10 m ² / g, To about 7 m ² / g may be used. The discoloration resistance, low brittleness and high temperature tensile strength can be secured together with excellent antimicrobial activity in the above-mentioned size ratio (B / A). Also, it can have low embrittlement at a BET surface area of about 15 m ² / g or less.

In an embodiment, the zinc oxide may have various shapes and may include, for example, spheres, plates, rods, combinations thereof, and the like.

The zinc oxide may have a mean particle size of from about 0.5 to about 3 microns, for example, about 1 micron, of a single particle (the particles do not form secondary particles) measured using a Beckman coulter LS 13 320 Particle size analyzer particle size analyzer To about 3 [mu] m. Within the above range, the thermoplastic resin composition may have excellent discoloration resistance, low embrittleness and the like.

The zinc oxide has a peak position 2θ value in the range of 35 to 37 ° and a crystallite size value according to the following formula (4) is about the same as that in the X-ray diffraction (XRD) 500 to about 2,000 A, e.g., from about 1,000 to about 2,000 A, from about 1,200 to about 1,800 A. Within the above range, the thermoplastic resin composition may have excellent initial color, weather resistance, antimicrobial properties, and the like.

[Formula 4]

Microcrystalline size (D) =

In the formula 4, K is a shape factor,? Is an X-ray wavelength,? Is an FWHM value (degree) of an X-ray diffraction peak,? Is a peak position value (peak position degree).

In an embodiment, the zinc oxide may be included in an amount of about 2 to about 10 parts by weight, for example about 1 to about 5 parts by weight, relative to about 100 parts by weight of the base resin composed of (A) + (B). In the above range, impact resistance, low embrittleness and antimicrobial property can be excellent.

The weight ratio of the second aromatic vinyl-cyanide vinyl copolymer (C) to the zinc oxide (D) may be about 1: about 0.5 to about 1: about 5. For example, from about 1: about 1 to about 1: about 3. When the weight ratio is more than about 1: about 5, there is a possibility that the physical property balance is lowered. When the weight ratio is less than about 1: about 0.5, there is a possibility that the antibacterial activity value is lowered.

The thermoplastic resin composition according to one embodiment of the present invention may contain a flame retardant, an antioxidant, a lubricant, a releasing agent, a nucleating agent, an antistatic agent, a stabilizer, a colorant, a combination thereof or the like in addition to the above- Based on the total weight of the composition. When the additive is used, the content thereof may be about 20 parts by weight or less, for example, about 0.1 to about 10 parts by weight, based on 100 parts by weight of the base resin, but is not limited thereto.

The thermoplastic resin composition according to one embodiment of the present invention can satisfy the following formulas (1) and (2).

[Formula 1]

6 Kg / cm ² ≤ TS ₁₅₀ ≤ 20 Kg / cm ²

In the above formula (1), TS ₁₅₀ is a tensile strength measured at a rate of 150 mm / min after holding at 150 캜 for 3 minutes in accordance with ASTM D638.

[Formula 2]

485 Kg / cm ² ≤ TS ₂₃ ≤ 600 Kg / cm ²

In the formula 2, TS ₂₃ is a tensile strength measured at a rate of 5 mm / min at 23 캜 according to ASTM D638.

The thermoplastic resin composition had a notched Izod impact strength of about 20 to about 40 kgf · cm / cm measured at 23 ° C for a 1/4 "thick specimen measured according to ASTM D256, The low temperature impact strength may be from about 7 to about 15 kgf / cm / cm.

In the specific example, the thermoplastic resin composition was prepared by inoculating Staphylococcus aureus and E. coli into a 5 cm x 5 cm size specimen according to JIS Z 2801 Antibacterial Evaluation Method, and measuring the antibacterial activity value against Staphylococcus aureus About 2 to about 5, and the antimicrobial activity value for E. coli may be about 2 to about 5. [

[Formula 3]

Antibacterial activity = log (M1 / M2)

In the formula (3), M1 is the number of bacteria after culture for 24 hours at 35 ° C and RH 90% for blank specimens, M2 is the number of bacteria after incubation for 24 hours at 35 ° C and RH 90% It is the number of bacteria.

 In a specific example, the thermoplastic resin composition has a detection area value of a volatile organic compound collected at 120 ° C for 300 minutes using a HS-SPME GC / MS (headspace solid-phase microextraction coupled gas chromatography / mass spectrometry) G, for example, from about 200 to about 460 area / g, from about 250 to about 450 area / g, and from about 300 to about 400 area / g.

In an embodiment, the thermoplastic resin composition has a residual volatile component content of from about 800 to about 1,200 ppm, for example, from about 900 to about 1,100, measured by GC / MS (gas chromatography / mass spectrometry) ppm, from about 950 to about 1,080 ppm.

The molded article according to the present invention is formed from the thermoplastic resin composition. The thermoplastic resin composition of the present invention can be produced by a known method for producing a thermoplastic resin composition. For example, after mixing the above components and other additives as necessary, they may be melt-extruded in an extruder to produce pellets. The produced pellets can be manufactured 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 of ordinary skill in the art to which the present invention pertains. The molded article can be used in the fields of interior / exterior materials such as electric / electronic products, automobile parts, and the like. Particularly, the molded article can be vacuum-molded, and can be usefully applied to refrigerator interior parts and the like.

Hereinafter, the present invention will be described in more detail by way of examples, but these examples are for illustrative purposes only and should not be construed as limiting the present invention.

Example

The specifications of each component used in the following examples and comparative examples are as follows.

(A) a rubber-modified vinyl-based graft copolymer

Acrylonitrile-butadiene-styrene graft copolymer prepared by graft copolymerizing styrene and 42% by weight of acrylonitrile (styrene / acrylonitrile: 75% by weight / 25% by weight) in 58% by weight of polybutadiene rubber having an average particle diameter of 0.3 μm (G-ABS) was used.

(B) a first aromatic vinyl-cyanide vinyl copolymer

A resin (weight average molecular weight: 250,000 g / mol) prepared by polymerizing 71% by weight of styrene and 29% by weight of acrylonitrile was used.

(C) a second aromatic vinyl-cyanide vinyl copolymer

(Zibo Huaxing Additives Co., Ltd.), a bead-like copolymer containing 72.5% by weight of (C1) styrene monomer and 27.5% by weight of acrylonitrile monomer was used. The weight average molecular weight of the second aromatic vinyl-cyanide vinyl copolymer was 5,100,000.

(C2) A bead-like copolymer ZB-869 (Zibo Huaxing Additives Co., Ltd.) containing 72.5% by weight of styrene monomer and 27.5% by weight of acrylonitrile monomer was used. The weight average molecular weight of the second aromatic vinyl-cyanide vinyl copolymer was 3,000,000.

(D) zinc oxide

(D1) After dissolving zinc in the form of metal, it was heated to 900 DEG C and vaporized. Then, oxygen gas was introduced and cooled to room temperature (25 DEG C) to obtain a primary intermediate. Next, the primary intermediate product was heat-treated at 700 ° C. for 30 to 150 minutes and then cooled to room temperature (25 ° C.) to obtain a product having a purity of 99% or more, a particle size (D50) ) Was used as the zinc oxide.

(D2) zinc oxide (manufacturer: Ristec Biz, product name: RZ-950) was used.

(D3) zinc oxide (manufacturer: Ristec Beads, product name: RZ-950) was additionally subjected to heat treatment at 700 ° C for 90 minutes and then cooled to room temperature (25 ° C).

The ratio of the peak A in the region of 370 to 390 nm and the peak B of the region of 450 to 600 nm in the range of 370 to 390 nm (in terms of the average particle size, the BET surface area, the purity and the photo luminescence) of the zinc oxide (D1, D2 and D3) B / A) and the crystallite size were measured according to the following physical properties of zinc oxide, and the results are shown in Table 1 below.

	(D1)	(D2)	(D3)
Average particle size (占 퐉)	1.2	1.1	1.2
Purity (%)	99	97	99
BET surface area (m 2 / g)	4	15	14.9
PL size ratio (B / A)	0.28	9.8	1.61
The crystallite size (A)	1417	503	519

Zinc oxide  How to measure property

(1) Average particle size (unit: 占 퐉): The average particle size (volume average) was measured using a particle size analyzer (Beckman Coulter Laser Diffraction Particle Size Analyzer LS I3 320 instrument).

(2) Purity (unit:%): Purity was measured using TGA thermal analysis at a temperature of 800 ° C.

(3) BET surface area (unit: m ² / g): The BET surface area was measured with a BET analyzer (Micromeritics Surface Area and Porosity Analyzer ASAP 2020 instrument) using a nitrogen gas adsorption method.

(4) PL size ratio (B / A): According to the photoluminescence measurement method, the spectrum emitted from a He-Cd laser (KIMMON company, 30 mW) having a wavelength of 325 nm at room temperature is measured by a CCD detector The temperature of the CCD detector was maintained at -70 ℃. (B / A) of the peak A in the 370 to 390 nm region and the peak B in the 450 to 600 nm region was measured. The injection specimen was subjected to PL analysis by injecting a laser into the specimen without any additional treatment. The zinc oxide powder was placed in a pelletizer having a diameter of 6 mm and pressed to form a flat specimen. Respectively.

(5) Crystallite size (unit: Å): A high resolution X-ray diffractometer (manufacturer: X'pert, device name: PRO-MRD) position 2? value is in the range of 35 to 37 and applied to Scherrer's equation (Equation 4 below) based on the measured FWHM value (full width at half maximum of diffraction peak). In this case, both the powder shape and the injection specimen can be measured. For the more accurate analysis, the injection specimen was subjected to heat treatment at 600 ° C. and air for 2 hours to remove the polymer resin, and then XRD analysis was carried out.

[Formula 4]

Microcrystalline size (D) =

In Equation 4, K is a shape factor,? Is an X-ray wavelength,? Is a FWHM value, and? Is a peak position degree.

Example  1 to 4 and Comparative Example  1 to 4

The above components were mixed and then added to a twin screw type extruder having an L / D of 35 and a diameter of 45 mm according to the composition and content of the following Table 2, and melted and extruded at 230 ° C to prepare pellets . The prepared pellets were dried at 80 ° C. for 4 hours or more, and then injection molded at an injection temperature of 230 ° C. and a mold temperature of 60 ° C. to prepare specimens. The properties of the prepared specimens were evaluated by the physical properties of the following specimens, and the results are shown in Table 2 below.

Method of measuring physical properties of specimen

(1) Impact Strength (Unit: kgf · cm / cm): A notch was formed in a 1/4 "thick specimen according to ASTM D256 to measure the notched Izod impact strength at 23 ° C and -30 ° C, respectively.

(2) Tensile strength (unit: Kg / cm ² ): TS ₁₅₀ is a tensile strength measured at a speed of 150 mm / min after holding at 150 ° C for 3 minutes in accordance with ASTM D638. TS ₂₃ is 23 Lt; 0 > C at a rate of 5 mm / min.

(3) Antibacterial activity value: Staphylococcus aureus and E. coli were inoculated on a 5 cm x 5 cm size specimen according to JIS Z 2801 antibacterial evaluation method, and antibacterial activity values were determined according to the following formula 3.

[Formula 3]

Antibacterial activity = log (M1 / M2)

In the formula (3), M1 is the number of bacteria after culture for 24 hours at 35 ° C and RH 90% for blank specimens, M2 is the number of bacteria after incubation for 24 hours at 35 ° C and RH 90% It is the number of bacteria.

 (4) R-SM GC / MS Low embrittlement evaluation: (Residual volatile component (RTVM) content, unit: ppm) Using GC / MS (gas chromatography / mass spectrometry) Respectively. The measurement conditions and the pretreatment method are as follows.

- Measuring conditions

- Pretreatment method

1) In a 20 mL vial, add 0.2 to 0.3 g of the sample to be measured.

2) Add 9 mL of NMP and dissolve for 10 hours or longer using a shaker.

3) Add 1 mL of internal standard solution and stir, then filter with 0.45 ㎛ filter.

(5) HS-SPME GC / MS Low embrittlement evaluation: (TVOC detection area value, unit area / g) HS-SPME GC / MS (headspace solid-phase microextraction coupled to gas chromatography / mass spectrometry) , The detection area value of the volatile organic compound collected at 120 캜 for 300 minutes was measured. The measurement conditions and the pretreatment method are as follows.

- Measuring conditions

- Pretreatment method

1) Place the sample in an HSS vial (Powder 20 mg, Pellet 2 g).

2) Set the Headspace Sampler condition as above.

(6) Evaluation of fluidity (vacuum formability): The pellets prepared in Examples and Comparative Examples were dried at 80 DEG C for 4 hours or more, and then injection-molded in an extruder at an injection temperature of 230 DEG C and a mold temperature of 60 DEG C to obtain 6X6 15 cm) 2T specimen was prepared. The prepared specimen was placed in a vacuum molding machine (manufactured by Dongjin Industrial Co., Ltd.), and the temperature was set to 500 ° C, pre-heating time 25 sec and vacuum pressure 10% as a reference condition. When the specimen was bubbled under the above reference conditions, water was filled in the bubbled portion and the volume of the charged water was measured to determine the fluidity (vacuum moldability). If the volume of water injected into the bubbled specimen is more than 1000 ml, the level is evaluated as Level 1, 950 ml or more if less than 1000 ml, Level 3 if less than 950 ml or Level 4 if less than 900 ml.

(Unit: parts by weight)		Example 1	Example 2	Example 3	Example 4
Basic resin	(A) g-ABS	25	25	25	25
	(B) General SAN	75	75	75	75
(C) Ultrahigh molecular weight SAN	(C1)	2	2	2	2
	(C2)	-	-	-	-
(D) zinc oxide	(D1)	2	-	-	4
	(D2)	-	2	-	-
	(D3)	-	-	2	-
Antimicrobial activity value	Staphylococcus aureus	3.6	3.2	3.1	3.6
	Escherichia coli	3.5	3.0	3.0	3.6
Impact strength	23 ℃	25	24	24	25
	-30 ° C	9	8	8	9
The tensile strength	150 ℃	6.6	6.2	6.3	6.5
	23 ℃	491	488	486	490
Low embrittlement	R-SM GC / MS (ppm)	992	1031	1079	994
	HS-SPME GC / MS (area / g)	326	412	451	336
Flowability (Vacuum formability) * Level		One	One	2	One

* The lower the number, the better the liquidity

(Unit: parts by weight)		Comparative Example 1	Comparative Example 2	Comparative Example 3	Comparative Example 4
Basic resin	(A) g-ABS	25	25	25	25
	(B) General SAN	75	75	75	75
(C) Ultrahigh molecular weight SAN	(C1)	15	2	-	-
	(C2)	-	-	2	-
(D) zinc oxide	(D1)	One	-	2	2
	(D2)	-	-	-	-
	(D3)	-	-	-	-
	(D4)	-	-	-	-
CaO		-	2	-	-
Antimicrobial activity value	Staphylococcus aureus	1.8	1.8	3.2	2.1
	Escherichia coli	1.7	1.6	3.6	2.8
Impact strength	23 ℃	30	22	22	21
	-30 ° C	10	7	6	7
The tensile strength	150 ℃	7.1	5.7	4.8	5.1
	23 ℃	492	482	487	480
Low embrittlement	R-SM GC / MS (ppm)	1392	1259	1069	1028
	HS-SPME GC / MS (area / g)	594	511	429	384
Flowability (Vacuum formability) * Level		4	One	2	3

* The lower the number, the better the liquidity

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (16)

1. (A) a rubber-modified vinyl-based graft copolymer;

   (B) a first aromatic vinyl-cyanide vinyl copolymer having a weight average molecular weight of about 100,000 to about 500,000 g / mol;

   (C) a second aromatic vinyl-cyanide vinyl copolymer having a weight average molecular weight of about 4,000,000 g / mol or more; And

   (D) zinc oxide; ≪ / RTI >

   Wherein the weight ratio of (C) to (D) is about 1: about 0.5 to about 1: about 5.
2. The thermoplastic resin composition according to claim 1, wherein the thermoplastic resin composition comprises about 10 to about 70% by weight of the rubber-modified vinyl graft copolymer (A) and about 30 to about 90% by weight of the first aromatic vinyl-cyanide vinyl copolymer (B) About 100 parts by weight of a base resin containing% by weight; About 1 to about 10 parts by weight of the second aromatic vinyl-cyanide vinyl copolymer (C); And about 2 to about 10 parts by weight of (D) zinc oxide.
3. The thermoplastic resin composition according to claim 1, wherein the rubber-modified vinyl-based graft copolymer (A) is obtained by graft-polymerizing a monomer mixture comprising an aromatic vinyl monomer and a vinyl cyan monomer in a diene rubber- .
4. The thermoplastic resin composition according to claim 3, wherein the diene-based rubbery polymer has an average particle diameter of about 0.1 to about 0.4 탆.
5. The thermoplastic resin composition according to claim 1, wherein the second aromatic vinyl-cyanide vinyl copolymer (C) has a weight average molecular weight of about 4,000,000 to about 10,000,000 g / mol.
6. The method of claim 1, wherein the zinc oxide (D) has a size ratio (B / A) of a peak A in a range of 370 to 390 nm and a peak B in a range of 450 to 600 nm of about 0.01 To about 10 carbon atoms.
7. The method of claim 1, wherein the zinc oxide (D) has a size ratio (B / A) of a peak A in a range of 370 to 390 nm and a peak B in a range of 450 to 600 nm of about 0.01 ≪ / RTI > to about < RTI ID = 0.0 > 1. < / RTI >
8. The thermoplastic resin composition according to claim 1, wherein the zinc oxide (D) has a BET surface area of about 15 m ² / g or less.
9. 2. The method according to claim 1, wherein the zinc oxide (D) has a peak position 2θ value in the range of 35 to 37 ° in X-ray diffraction (XRD) analysis, Wherein the crystallite size value of the thermoplastic resin composition is from about 1,000 to about 2,000 ANGSTROM.

   [Formula 4]

   Microcrystalline size (D) =

   

   In the formula 4, K is a shape factor,? Is an X-ray wavelength,? Is an FWHM value (degree) of an X-ray diffraction peak,? Is a peak position value (peak position degree).
10. The thermoplastic resin composition according to claim 1, wherein (D) zinc oxide has an average particle size (D50) of about 0.5 to about 3 탆.
11. The thermoplastic resin composition according to claim 1, wherein the thermoplastic resin composition satisfies the following formulas 1 and 2:

    [Formula 1]

    6 Kg / cm ² ≤ TS ₁₅₀ ≤ 20 Kg / cm ²

    TS ₁₅₀ in the formula (1) is a tensile strength measured at 150 mm / min after maintained at 150 캜 for 3 minutes in accordance with ASTM D638;

    [Formula 2]

    485 Kg / cm ² ≤ TS ₂₃ ≤ 600 Kg / cm ²

    In the formula 2, TS ₂₃ is a tensile strength measured at a rate of 5 mm / min at 23 캜 according to ASTM D638.
12. The thermoplastic resin composition according to claim 1, wherein the thermoplastic resin composition is prepared by inoculating Staphylococcus aureus and Escherichia coli into a 5 cm x 5 cm size specimen according to JIS Z 2801 Antibacterial Evaluation Method, An active value of about 2 to about 5, and an antibacterial activity value for E. coli of about 2 to about 5. The thermoplastic resin composition of claim 1,

    [Formula 3]

    Antibacterial activity = log (M1 / M2)

    In the formula (3), M1 is the number of bacteria after culture for 24 hours at 35 ° C and RH 90% for blank specimens, M2 is the number of bacteria after incubation for 24 hours at 35 ° C and RH 90% It is the number of bacteria.
13. The thermoplastic resin composition according to claim 1, wherein the thermoplastic resin composition has a detection area value of the volatile organic compound collected at 120 ° C for 300 minutes using HS-SPME GC / MS of about 200 to about 500 area / g Thermoplastic resin composition.
14. The thermoplastic resin composition according to claim 1, wherein the thermoplastic resin composition has a residual volatile component content of about 800 to about 1,200 ppm measured by GC / MS at 250 ° C.
15. A molded article formed from the thermoplastic resin composition according to any one of claims 1 to 14.
16. 16. A molded article according to claim 15, wherein the molded article is a vacuum molded article and is an in-refrigerator component of a refrigerator.