KR102013026B1 - Thermoplastic resin composition - Google Patents

Abstract

The thermoplastic resin composition of the present invention is a thermoplastic resin; And zinc oxide; wherein the zinc oxide has a yellowness (YELLOW INDEX) according to ASTM D1925 standard of 1.0 or less.

Description

Thermoplastic composition {THERMOPLASTIC RESIN COMPOSITION}

The present invention relates to a thermoplastic resin composition. More specifically, the present invention relates to a thermoplastic resin composition excellent in discoloration resistance and antibacterial properties.

Thermoplastic resins are widely used in a variety of applications, such as automobiles, electronics, office equipment, home appliances, toys, stationery.

Recently, as the interest in the health and hygiene of the individual and the level of income increase, the demand for thermoplastic resin products containing antibacterial hygiene function is increasing. Accordingly, an increasing number of thermoplastic resin products that have been treated with antimicrobial to remove or inhibit bacteria from surfaces of household goods and electronic products, and the development of a stable and reliable functional antimicrobial material (antimicrobial thermoplastic resin composition) is very important. It is a task.

In order to prepare such an antimicrobial thermoplastic resin composition, addition of an antimicrobial agent is necessary, and the antimicrobial agent may be divided into an organic antimicrobial agent and an inorganic antimicrobial agent.

Organic antimicrobial agents are relatively inexpensive and have a good antimicrobial effect even with a small amount. However, they are sometimes toxic to humans and may only be effective against specific bacteria. have. In addition, there may be a cause of discoloration after processing, there is a shortage of antimicrobial persistence due to elution problem, the range of organic antimicrobial agent that can be applied to the antimicrobial thermoplastic resin composition is extremely limited.

Inorganic antibacterial agent is an antimicrobial agent containing metal components such as silver (Ag) and copper (Cu) and has excellent thermal stability and is widely used in the production of antimicrobial thermoplastic resin compositions (antimicrobial resins). Excessive input is required, and there are disadvantages such as relatively high price, uniform dispersion problem during processing and discoloration due to metal components, and thus there are many restrictions on use.

Therefore, there is a need for the development of a thermoplastic resin composition that is excellent in weather resistance (color resistance), antibacterial and antimicrobial persistence, and can implement antifungal properties.

Background art of the present invention is disclosed in Republic of Korea Patent No. 10-0696385.

An object of the present invention is to provide a thermoplastic resin composition excellent in both discoloration resistance and antibacterial properties.

Another object of the present invention is to provide a molded article formed from the thermoplastic resin composition.

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. The thermoplastic resin composition is a thermoplastic resin; And zinc oxide; wherein the zinc oxide has a yellowness (YELLOW INDEX) according to ASTM D1925 standard of 1.0 or less.

In one embodiment, the thermoplastic resin may include at least one of rubber-modified aromatic vinyl resins, aromatic vinyl resins, polyolefin resins, polycarbonate resins, polyalkyl (meth) acrylate resins, polyester resins, and polyamide resins. Can be.

In an embodiment, the thermoplastic resin may include 10 to 40 wt% of the rubber-modified vinyl graft copolymer and 60 to 90 wt% of the aromatic vinyl copolymer copolymer resin.

In embodiments, the zinc oxide has a size ratio (B / A) of peak A in the 370 to 390 nm region and peak B in the 450 to 600 nm region when measured by photo luminescence, and has a BET surface area. It may be 10 m ² / g or less.

In embodiments, the zinc oxide may have an average particle size (D50) of 1 to 5 ㎛.

In embodiments, the zinc oxide has a peak position 2θ of 35 to 37 ° in X-ray diffraction (XRD) analysis, and has a crystallite size represented by Equation 1 below (crystallite) size) can range from 1,000 to 2,000 mm 3:

[Equation 1]

Microcrystal size (D) =

In Equation 1, K is a shape factor, λ is an X-ray wavelength, β is an FWHM value of an X-ray diffraction peak, and θ is a peak position value. (peak position degree).

In one embodiment, the zinc oxide is non-halogen-containing zinc oxide prepared by vaporizing zinc at 850 to 1,000 ℃, injecting and cooling with oxygen gas, then pre-heating and cooling at 700 to 800 ℃ Can be.

In embodiments, the zinc oxide may be further post-heat treatment of the non-halogen-containing zinc oxide at 200 to 400 ℃.

In one embodiment, the thermoplastic resin composition may include 0.5 to 30 parts by weight of the zinc oxide based on 100 parts by weight of the thermoplastic resin.

In an embodiment, the thermoplastic resin composition is inoculated with Staphylococcus aureus and Escherichia coli on a 5 cm × 5 cm size specimen, based on JIS Z 2801 antimicrobial evaluation method, and the antibacterial activity value against Staphylococcus aureus calculated according to Equation 2 is 2.0 to 7.0, and the antimicrobial activity against E. coli may be 2.0 to 7.5.

[Equation 2]

Antimicrobial activity = log (M1 / M2)

In Equation 2, M1 is the number of bacteria after 24 hours incubation at 90 ° C, RH 90% conditions for the blank (blank) specimens, M2 after 35 hours at 35 ° C, RH 90% conditions for the thermoplastic resin composition specimens after 24 hours Bacteria count.

In a specific example, the thermoplastic resin composition has a yellowness change (ΔYI) represented by the following Equation 3 of 0.1 or less.

[Equation 3]

Yellowness change of the thermoplastic resin (△ YI) = │ (Y ₁ -Y ₀ ) │

In Equation 3, Y ₁ is the yellowness measured by ASTM D1925 standard after 10 minutes at 250 ° C., and Y ₀ is the initial yellowness before retention.

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

This invention has the effect of providing the thermoplastic resin composition excellent in both discoloration resistance and antibacterial property.

(A) thermoplastic resin

The thermoplastic resin of the present invention may be a thermoplastic resin used in a conventional thermoplastic resin composition. For example, rubber-modified aromatic vinyl resins, aromatic vinyl resins, polyolefin resins, polycarbonate resins, polyalkyl (meth) acrylate resins, polyester resins, polyamide resins, combinations thereof and the like can be used. Specifically, it may be a rubber modified aromatic vinyl resin containing (A1) rubber modified vinyl graft copolymer and (A2) aromatic vinyl copolymer resin.

(A1) rubber modified aromatic vinyl graft copolymer

The rubber-modified aromatic vinyl graft copolymer according to one embodiment of the present invention may be a graft copolymer of an aromatic vinyl monomer and a monomer copolymerizable with the aromatic vinyl monomer in a rubbery polymer.

In an embodiment, the rubber-modified vinyl graft copolymer may be polymerized by adding an aromatic vinyl monomer and a monomer copolymerizable with the aromatic vinyl monomer to a rubbery polymer, and the polymerization may be emulsion polymerization, suspension polymerization, or bulk formation. It can be performed by a known polymerization method such as polymerization.

In an embodiment, the rubbery polymers include diene rubbers such as polybutadiene, poly (styrene-butadiene), poly (acrylonitrile-butadiene), and saturated rubbers hydrogenated to the diene rubber, isoprene rubber, and polybutylacrylic acid. Acrylic rubber, ethylene-propylene-diene monomer terpolymer (EPDM), etc. can be illustrated. These can be applied individually or in mixture of 2 or more types. For example, a diene rubber can be used and specifically, a butadiene rubber can be used. The content of the rubbery polymer may be 5 to 65% by weight, for example, 10 to 60% by weight, specifically 20 to 50% by weight, based on the total weight (100% by weight) of the rubber-modified aromatic vinyl graft copolymer. Impact resistance, mechanical properties and the like of the thermoplastic resin composition may be excellent in the above range. In addition, the average particle size (Z-average) of the rubbery polymer (rubber particles) may be 0.05 to 6 μm, for example 0.15 to 4 μm, specifically 0.25 to 3.5 μm. In the above range, the impact resistance, appearance, and the like of the thermoplastic resin composition may be excellent.

In an embodiment, the aromatic vinyl monomer may be graft copolymerized to the rubbery copolymer, for example, styrene, α-methylstyrene, β-methylstyrene, p-methylstyrene, pt-butylstyrene, ethyl Styrene, vinyl xylene, monochlorostyrene, dichlorostyrene, dibromostyrene, vinyl naphthalene, etc. may be used, but is not limited thereto. These can be applied individually or in mixture of 2 or more types. The content of the aromatic vinyl monomer may be 15 to 94% by weight, for example 20 to 80% by weight, specifically 30 to 60% by weight, based on the total weight (100% by weight) of the rubber-modified aromatic vinyl graft copolymer. . In the above range, the fatigue resistance of the thermoplastic resin composition may be excellent in impact resistance, mechanical properties, and the like.

In a specific embodiment, as the monomer copolymerizable with the aromatic vinyl monomer, for example, acrylonitrile, methacrylonitrile, ethacrylonitrile, phenylacrylonitrile, α-chloroacrylonitrile, fumaronitrile, and the like. Vinyl cyanide compounds, (meth) acrylic acid and alkyl esters thereof, maleic anhydride, N-substituted maleimides, and the like can be used, and they can be used alone or in combination of two or more thereof. Specifically, acrylonitrile, methyl (meth) acrylate, a combination thereof, and the like can be used. The content of the copolymerizable monomer with the aromatic vinyl monomer may be 1 to 50% by weight, for example, 5 to 45% by weight, specifically 10 to 30% by weight, based on 100% by weight of the total rubber-modified vinyl graft copolymer. . In the above range, the thermoplastic resin composition may have excellent impact resistance, fluidity, appearance characteristics, and the like.

In one embodiment, the rubber-modified vinyl graft copolymer is a copolymer in which a styrene monomer, which is an aromatic vinyl compound, and an acrylonitrile monomer, which is a vinyl cyanide compound, are grafted to a butadiene rubber polymer (butadiene). A styrene monomer, which is an aromatic vinyl compound, and a copolymer (g-MBS) grafted with methyl methacrylate as a monomer copolymerizable with the rubbery polymer may be exemplified, but is not limited thereto.

In embodiments, the rubber modified aromatic vinyl graft copolymer may be included in 10 to 40% by weight, for example 15 to 30% by weight of 100% by weight of the total thermoplastic resin. Impact resistance, fluidity (molding processability) and the like of the thermoplastic resin composition in the above range may be excellent.

(A2) aromatic vinyl copolymer resin

The aromatic vinyl copolymer resin according to one embodiment of the present invention may be an aromatic vinyl copolymer resin used in a conventional rubber-modified vinyl copolymer resin. For example, the aromatic vinyl copolymer resin may be a polymer of a monomer mixture including a monomer copolymerizable with the aromatic vinyl monomer such as an aromatic vinyl monomer and a vinyl cyanide monomer.

In an embodiment, the aromatic vinyl copolymer resin may be obtained by mixing an aromatic vinyl monomer and a monomer copolymerizable with an aromatic vinyl monomer, and then polymerizing them, and the polymerization may be emulsion polymerization, suspension polymerization, bulk polymerization, or the like. It can be carried out by a known polymerization method of.

In embodiments, the aromatic vinyl monomers include styrene, α-methylstyrene, β-methylstyrene, p-methylstyrene, pt-butylstyrene, ethyl styrene, vinyl xylene, monochlorostyrene, dichlorostyrene, dibromostyrene Vinyl naphthalene may be used, but is not limited thereto. These can be applied individually or in mixture of 2 or more types. The content of the aromatic vinyl monomer may be 20 to 90% by weight, for example 30 to 80% by weight, of 100% by weight of the total aromatic vinyl copolymer resin. In the above range, the impact resistance, fluidity, and the like of the thermoplastic resin composition may be excellent.

In a specific embodiment, as the monomer copolymerizable with the aromatic vinyl monomer, for example, acrylonitrile, methacrylonitrile, ethacrylonitrile, phenylacrylonitrile, α-chloroacrylonitrile, fumaronitrile, and the like. Vinyl cyanide monomers and the like can be used, and can be used alone or in combination of two or more. The content of the monomer copolymerizable with the aromatic vinyl monomer may be 10 to 80% by weight, for example 20 to 70% by weight, based on 100% by weight of the total aromatic vinyl copolymer resin. In the above range, the impact resistance, fluidity, and the like of the thermoplastic resin composition may be excellent.

In embodiments, the aromatic vinyl copolymer resin may have a weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) of 10,000 to 300,000 g / mol, for example, 15,000 to 150,000 g / mol. In the above range, the mechanical strength, moldability, and the like of the thermoplastic resin composition may be excellent.

In embodiments, the aromatic vinyl copolymer resin may be included in 60 to 90% by weight, for example 70 to 85% by weight of 100% by weight of the total thermoplastic resin. Impact resistance, fluidity (molding processability) and the like of the thermoplastic resin composition in the above range may be excellent.

(B) zinc oxide

Zinc oxide used in the present invention is characterized in that the yellowness (YELLOW INDEX) according to the ASTM D1925 standard is 1.0 or less. In embodiments, the yellowness of the zinc oxide may be 0.9 or less, preferably 0.1 to 0.8. When the yellowness exceeds 1.0, discoloration resistance and antibacterial properties aimed at in the present invention cannot be obtained.

In one embodiment, the zinc oxide is non-halogen-containing zinc oxide prepared by vaporizing zinc at 850 to 1,000 ℃, injecting and cooling with oxygen gas, then pre-heating and cooling at 700 to 800 ℃ Can be.

For example, the non-halogen-containing zinc oxide is dissolved in zinc in the form of metal, vaporized by heating to 850 to 1,000 ° C., for example, 900 to 950 ° C., and then injected with oxygen gas and cooled to 20 to 30 ° C. Next, if necessary, while injecting nitrogen / hydrogen gas into the reactor, after the heat treatment for 30 minutes to 150 minutes at 700 to 800 ℃, it can be prepared by cooling to room temperature (20 to 30 ℃).

The zinc oxide may be a further post-heat treatment of the non-halogen-containing zinc oxide at 200 to 400 ℃. In this case, it is advantageous to control the yellowness of the zinc oxide to 1.0 or less, it can be implemented to the extent that the discoloration resistance and antibacterial properties of the thermoplastic resin including the same to the desired degree.

For example, the non-halogen-containing zinc oxide may be used after the post-heat treatment for 2 hours at a temperature of 200 to 400 ℃.

In embodiments, the zinc oxide 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, for example, when measuring photo luminescence. 0.01 to 0.5, preferably 0.1 to 0.3, the BET surface area may be 10 m ² / g or less, for example 1 to 7 m ² / g. It can be implemented to the extent that the discoloration resistance and antibacterial properties of the thermoplastic resin within the above range.

In embodiments, the zinc oxide has a peak position 2θ of 35 to 37 ° when analyzed by X-ray diffraction (XRD), and crystallite size according to Equation 1 below. ) Value can be 1,000 to 2,000 Hz, for example, 1,200 to 1,800 Hz. In the above range, the initial color of the thermoplastic resin composition, mechanical properties, weather resistance, antibacterial and the like can be excellent.

[Equation 1]

Microcrystal size (D) =

In Equation 1, K is a shape factor, λ is an X-ray wavelength, β is an FWHM value of an X-ray diffraction peak, and θ is a peak position value. (peak position degree).

In embodiments, the zinc oxide may have an average particle size (D50) of 1 to 5 μm, for example 1.5 to 3 μm, measured using a Beckman coulter LS 13 320 Particle size analyzer particle size analyzer, and has a purity of 99%. It may be abnormal. Mechanical properties of the thermoplastic resin composition, discoloration resistance and the like in the above range may be excellent.

In an embodiment, the zinc oxide may be included in an amount of 0.5 to 30 parts by weight, for example, 0.5 to 20 parts by weight, specifically 1 to 10 parts by weight, based on 100 parts by weight of the thermoplastic resin. It is excellent in weather resistance, antibacterial properties, mechanical properties and discoloration resistance in the above range.

The thermoplastic resin composition according to one embodiment of the present invention may further include an additive included in a conventional thermoplastic resin composition. The additives may include, but are not limited to, flame retardants, fillers, antioxidants, anti drip agents, lubricants, mold release agents, nucleating agents, antistatic agents, stabilizers, pigments, dyes, mixtures thereof, and the like. When using the additive, the content may be 0.001 to 40 parts by weight, for example 0.1 to 10 parts by weight, based on 100 parts by weight of the thermoplastic resin.

The thermoplastic resin composition according to an embodiment of the present invention may be in the form of pellets which are mixed with the above components and melt-extruded at 200 to 280 ° C, for example, 220 to 250 ° C, using a conventional twin screw extruder.

The thermoplastic resin composition has an antimicrobial effect against various bacteria such as Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, Salmonella, Pneumococcus, and MRSA (Methicillin-Resistant Staphylococcus Aureus).

In an embodiment, the thermoplastic resin composition is inoculated with Staphylococcus aureus and Escherichia coli on a 5 cm × 5 cm size specimen, based on JIS Z 2801 antimicrobial evaluation method, and the antibacterial activity value against Staphylococcus aureus calculated according to Equation 2 is 2.0 to 7.0, for example 3 to 7.0, specifically 4 to 6.5, and the antimicrobial activity against E. coli may be 2.0 to 7.5, for example 4 to 7.0, specifically 5 to 6.5:

[Equation 2]

Antimicrobial activity = log (M1 / M2)

In Equation 2, M1 is the number of bacteria after 24 hours incubation at 90 ° C, RH 90% conditions for the blank (blank) specimens, M2 after 35 hours at 35 ° C, RH 90% conditions for the thermoplastic resin composition specimens after 24 hours Bacteria count.

In an embodiment, the thermoplastic resin composition may have a yellowness change (ΔYI) of 0.1 or less, preferably 0 to 0.08.

[Equation 3]

Yellowness change of the thermoplastic resin (△ YI) = │ (Y ₁ -Y ₀ ) │

In Equation 3, Y ₁ is yellowness according to ASTM D1925 standard after 10 minutes at 250 ° C., and Y ₀ is the initial yellowness before retention.

The molded article according to the present invention is formed from the thermoplastic resin composition. The antimicrobial thermoplastic resin composition may be prepared in pellet form, and the prepared pellet may 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 by those skilled in the art. The molded article is excellent in weather resistance, deodorization, antibacterial, impact resistance, fluidity (molding processability), the balance of physical properties thereof, etc., it is useful as antibacterial function products, exterior materials and the like frequently in contact with the body.

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

Example

(A) thermoplastic resin

(A1) rubber modified aromatic vinyl graft copolymer

55% by weight of styrene and acrylonitrile (weight ratio: 75/25) were grafted into graft copolymerized g-ABS (45% by weight polybutadiene rubber (PBR) having a Z-average of 310 nm of 45 nm by weight) prepared from Lotte Advanced Materials. Copolymerized g-ABS) was used.

(A2) aromatic vinyl copolymer resin

SAN resin (weight average molecular weight: 150,000 g / mol) polymerized with 80% by weight of styrene and 20% by weight of acrylonitrile prepared from Lotte Advanced Materials was used.

(B) zinc oxide

(B1) After dissolving zinc in the form of metal, the mixture was heated to 900 ° C. to vaporize, and then injected with oxygen gas, cooled to room temperature (25 ° C.) to obtain a primary intermediate. Next, the primary intermediate was subjected to an electrothermal treatment at 700 ° C. for 30 to 150 minutes, and then cooled to room temperature (25 ° C.) to have a purity of 99% or more and a particle size (D50) of 1.0 μm, and halogen (Cl, The prepared dry zinc oxide containing no Br) was used, and no additional heat treatment was performed.

(B2) ~ (B8) The zinc oxide of (B1) was subjected to a post-heat treatment for 2 hours in air at the temperature of Table 1 below.

(B9) The wet zinc oxide (manufacturer: Listek beads, product name: RZ-950) containing 1700 ppm of halogen (Cl) was subjected to heat treatment at a temperature (200 ° C.) shown in Table 1 below.

Zinc oxide (B1) (B2) (B3) (B4) (B5) (B6) (B7) (B8) (B9) Post heat treatment temperature - 100 200 300 400 500 600 700 200 Yellowness of Zinc Oxide (YI) 1.7 1.2 0.6 0.7 0.9 1.4 1.7 1.9 2.5 halogen
The presence or absence radish radish radish radish radish radish radish radish U Average particle size (μm) 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 BET surface area (m ² / g) 4.0 4.3 4.5 4.1 4.2 4.0 4.3 4.4 15 Purity (%) 99 99 99 99 99 99 99 99 98 PL size ratio (B / A) 0.28 0.28 0.25 0.24 0.24 0.24 0.23 0.21 4.7 Microcrystalline Size 1417 1300 1287 1320 1392 1406 1365 1221 523

Example  1-3 and Comparative example  1-6: Preparation of a thermoplastic resin composition

Each of the components was added in an amount as described in Tables 2 and 3, and then extruded at 230 ° C. to prepare pellets. Extrusion was performed using a twin screw extruder with a diameter of L / D = 36 and 45 mm, and the pellets were dried at 80 ° C. for at least 4 hours, and then injected into a 6 Oz injection machine (molding temperature 250 ° C., mold temperature: 60 ° C.). Was prepared. The physical properties of the prepared specimens were evaluated by the following method, and the results are shown in Table 2 below.

Property evaluation method

(1) Yellowness (YI): It was measured with a spectrophotometer instrument (KONICA MINOLTA, CM-3600d) according to ASTM D1925.

(2) Antibacterial activity value: In accordance with JIS Z 2801 antimicrobial evaluation method, 5 cm × 5 cm size specimen was inoculated with Staphylococcus aureus and E. coli, and the antibacterial activity value was determined according to the following formula (2).

[Equation 2]

Antimicrobial activity = log (M1 / M2)

(In Formula 2, M1 is the number of bacteria after 24 hours incubation at 35 ℃, RH 90% conditions for the blank specimen, M2 is 24 hours incubation at 35 ℃, RH 90% conditions for the thermoplastic resin composition specimens Germ count after)

(3) Yellowness change of the thermoplastic resin (ΔYI): The initial yellowness (Y ₀ ) of the thermoplastic resin was measured by a spectrophotometer instrument (KONICA MINOLTA, CM-3600d) according to ASTM D1925. The yellowness (Y ₁ ) was measured by ASTM D1925 standard after the resin was left at 250 ° C. for 10 minutes. In addition, the yellowness change (ΔYI) of zinc oxide was determined by the following Equation 3 using the measured value.

[Equation 3]

Yellowness change of the thermoplastic resin (△ YI) = │ (Y ₁ -Y ₀ ) │

In Equation 3, Y ₁ is yellowness according to ASTM D1925 standard after 10 minutes at 250 ° C., and Y ₀ is the initial yellowness before retention.

Example 1 Example 2 Example 3 (A) curable resin g-ABS 28 28 28 SAN 72 72 72 (B)
Zinc oxide (B3) 2 - - (B4) - 2 - (B5) - - 2 Antimicrobial activity yellow
Grape
coccus 4.6 4.6 4.6 Escherichia coli 6.1 6.3 6.3 Of thermoplastic resin
Yellowness change (△ YI) 0.02 0.05 0.09

Comparative example One 2 3 4 5 6 7 (A) curable resin g-ABS 28 28 28 28 28 28 28 SAN 72 72 72 72 72 72 72 (B)
Zinc oxide (B1) - 2 - - - - - (B2) - - 2 - - - - (B6) - - - 2 - - - (B7) - - - - 2 - - (B8) - - - - - 2 - (B9) - - - - - - 2 Antimicrobial activity yellow
Grape
coccus 0.1 4.2 4.6 4.6 4.6 4.6 4.6 Escherichia coli 0.2 5.1 6.0 6.1 6.1 6.1 6.1 Of thermoplastic resin
Yellowness change (△ YI) 0.03 1.25 1.2 1.4 1.6 1.4 2.7

As can be seen from the above results, in Comparative Example 1, the antimicrobial activity was low and unsuitable. In addition, in Comparative Examples 2 to 6, even if zinc oxide is applied, when the yellowness of zinc oxide is out of the range of the present invention, antibacterial activity could be ensured, but discoloration resistance was remarkably decreased. In particular, in Comparative Example 7, it was confirmed that a large decrease in yellowness occurred.

On the other hand, the thermoplastic resin composition of Examples 1 to 3 of the present invention had a low yellowness change value and was excellent in discoloration resistance, and at the same time, high antibacterial activity against Staphylococcus aureus and E. coli was confirmed to implement excellent antimicrobial activity.

Simple modifications and variations of the present invention can be easily made by those skilled in the art, and all such modifications or changes can be seen to be included in the scope of the present invention.

Claims (12)

To 100 parts by weight of a thermoplastic resin comprising 10 to 40% by weight of a rubber-modified vinyl graft copolymer and 60 to 90% by weight of an aromatic vinyl copolymer resin,
0.5 to 10 parts by weight of zinc oxide,
The zinc oxide is a thermoplastic resin composition having a yellowness (YELLOW INDEX) of 1.0 or less according to ASTM D1925 standard,
The thermoplastic resin composition is a thermoplastic resin composition having a yellowness change (ΔYI) of 0.1 or less according to Formula 3 below:
[Equation 3]
Yellowness change of the thermoplastic resin (△ YI) = │ (Y ₁ -Y ₀ ) │
In Equation 3, Y ₁ is the yellowness measured by ASTM D1925 standard after the thermoplastic resin is held at 250 ° C. for 10 minutes, and Y ₀ is the initial yellowness before retention.
delete delete The method according to claim 1, wherein the zinc oxide has a size ratio (B / A) of peak A in the 370 to 390 nm region and peak B in the 450 to 600 nm region, when measuring photo luminescence. A thermoplastic resin composition having a BET surface area of 10 m ² / g or less.
The thermoplastic resin composition of claim 1, wherein the zinc oxide has an average particle size (D50) of 1 to 5 μm.
The method of claim 1, wherein the zinc oxide has a peak position 2θ value of 35 to 37 ° in X-ray diffraction (XRD) analysis, and the size of the microcrystals Crystallite size) is a thermoplastic resin composition characterized in that the value of 1,000 to 2,000 mm 3:
[Equation 1]
Microcrystal size (D) =

In Equation 1, K is a shape factor, λ is an X-ray wavelength, β is an FWHM value of an X-ray diffraction peak, and θ is a peak position value. (peak position degree).
The thermoplastic oxide of claim 6, wherein the zinc oxide is a non-halogen-containing zinc oxide prepared by vaporizing zinc at 850 to 1,000 ° C., injecting and cooling oxygen gas, and then preheating and cooling at 700 to 800 ° C. 8. Resin composition.
The method of claim 7, wherein
The zinc oxide is a thermoplastic resin composition further post-heat treatment of the non-halogen-containing zinc oxide at 200 to 400 ℃.
delete According to claim 1, wherein the thermoplastic resin composition is inoculated with Staphylococcus aureus and E. coli in 5 cm × 5 cm size specimens based on the antimicrobial evaluation method, and antibacterial against Staphylococcus aureus calculated according to the following formula 3 A thermoplastic resin composition having an activity value of 2.0 to 7.0 and an antibacterial activity value of E. coli at 2.0 to 7.5:
[Equation 2]
Antimicrobial activity = log (M1 / M2)
(In Formula 2, M1 is the number of bacteria after 24 hours incubation at 35 ℃, RH 90% conditions for the blank specimen, M2 is 24 hours incubation at 35 ℃, RH 90% conditions for the thermoplastic resin composition specimens After bacteria.)
delete A molded article formed from the thermoplastic resin composition according to any one of claims 1, 4 to 8 and 10.