Thermoplastic resin composition and molded article produced therefrom

Abstract

The thermoplastic resin composition of the present invention includes: about 100 parts by weight of a rubber-modified aromatic vinyl-based copolymer resin; about 4 to 23 parts by weight of a polyether ester amide block copolymer; about 0.03 to 1 parts by weight of a silver (Ag)-based compound; and about 0.05 to 4 parts by weight of zinc oxide, wherein the zinc oxide is composed of primary particles having an average particle diameter (D50) of about 1 to 50 nm and secondary particles having an average particle diameter (D50) of about 0.1 to 10 µm. The thermoplastic resin composition has excellent antibacterial properties, transparency, antistatic properties, and impact resistance, etc.

Description

Technical Field

[0001] This invention relates to thermoplastic resin compositions and molding articles thereof. More specifically, this invention relates to thermoplastic resin compositions and molding articles thereof that have good properties in terms of antibacterial properties, transparency, antistatic properties, and impact resistance. Background Technology

[0002] Recently, with increasing public awareness of personal health and hygiene, as well as rising income levels, the demand for thermoplastic resin products with antibacterial and hygienic properties has also been increasing. Therefore, there is a growing need for thermoplastic resin products that have undergone antibacterial treatment to remove or inhibit bacterial growth on the surfaces of household goods and electronic products. Thus, developing functional antibacterial materials (antibacterial thermoplastic resin compositions) with stability and reliability is a significant challenge.

[0003] This antibacterial thermoplastic resin composition requires an antibacterial agent. Antibacterial agents can be divided into organic antibacterial agents and inorganic antibacterial agents.

[0004] While small amounts of organic antimicrobial agents offer advantages such as relative inexpensiveness and good antimicrobial efficacy, they are sometimes toxic to humans, effective only against certain bacteria, and there are concerns that their antimicrobial efficacy may be lost through decomposition during high-temperature processing. Furthermore, organic antimicrobial agents can cause discoloration after processing and exhibit short antimicrobial durability due to elution. Therefore, the range of antimicrobial agents suitable for antimicrobial thermoplastic resin compositions is very limited.

[0005] Inorganic antibacterial agents contain metallic components, such as silver (Ag) and copper (Cu), and exhibit good thermal stability, thus they are frequently used to prepare antibacterial thermoplastic resin compositions (antibacterial resins). However, compared to organic antibacterial agents, inorganic antibacterial agents have insufficient antibacterial properties, requiring them to be added in excessive amounts. Furthermore, their applications are severely limited due to drawbacks such as relatively high price, problems with uniform distribution during processing, and discoloration caused by the metallic components.

[0006] Therefore, it is necessary to develop thermoplastic resin compositions with good properties in terms of antibacterial properties, transparency, antistatic properties and impact resistance.

[0007] The background technology of this invention is disclosed in Korean Patent Registration No. 10-0696385, etc. Summary of the Invention

[0008] Technical issues

[0009] One object of the present invention is to provide a thermoplastic resin composition having good properties in terms of antibacterial properties, transparency, antistatic properties and impact resistance.

[0010] Another object of the present invention is to provide a molded article formed from the thermoplastic resin composition described above.

[0011] The above and other objects of the present invention will become apparent from the following detailed description of the embodiments.

[0012] Technical solution

[0013] 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 rubber-modified aromatic vinyl copolymer resin; about 4 parts by weight to about 23 parts by weight of a polyether-ester-amide block copolymer; about 0.03 parts by weight to about 1 part by weight of a silver (Ag) compound; and about 0.05 parts by weight to about 4 parts by weight of zinc oxide, wherein the zinc oxide comprises primary particles and secondary particles, the primary particles having an average particle size (D50) of about 1 nm to about 50 nm, and the secondary particles having an average particle size (D50) of about 0.1 μm to about 10 μm.

[0014] 2. In embodiment 1, the weight ratio of the polyether-ester-amide block copolymer to the sum of the silver compound and zinc oxide (polyether-ester-amide block copolymer: silver compound + zinc oxide) can be in the range of about 1:0.01 to about 1:0.5.

[0015] 3. In embodiment 1 or 2, the weight ratio of silver compound to zinc oxide (silver compound: zinc oxide) may be in the range of about 1:0.5 to about 1:60.

[0016] 4. In embodiments 1 to 3, the rubber-modified aromatic vinyl copolymer resin may include about 5 wt% to about 50 wt% of rubber-modified vinyl graft copolymer and about 50 wt% to about 95 wt% of aromatic vinyl copolymer resin.

[0017] 5. In embodiments 1 to 4, a rubber-modified vinyl graft copolymer can be obtained by graft polymerization of (meth)acrylate, aromatic vinyl monomer and vinyl cyanide monomer onto a rubber polymer.

[0018] 6. In embodiments 1 to 5, aromatic vinyl copolymer resins can be obtained by polymerization of (meth)acrylate alkyl esters, aromatic vinyl monomers and vinyl cyanide monomers.

[0019] 7. In embodiments 1 to 6, the polyether-ester-amide block copolymer may be a block copolymer comprising the following reaction mixtures: aminocarboxylic acid, lactam, or diamine-dicarboxylic acid salt having 6 or more carbon atoms; polyalkylene glycol; and dicarboxylic acid having 4 to 20 carbon atoms.

[0020] 8. In embodiments 1 to 7, the silver compound may include at least one of metallic silver, silver oxide, silver halide and a silver ion-containing carrier.

[0021] 9. In embodiments 1 to 8, 5cm × 5cm samples were inoculated with Staphylococcus aureus and Escherichia coli respectively according to JIS Z 2801, and after culturing for 24 hours at 35°C and 90% RH (relative humidity), the thermoplastic resin composition exhibited antibacterial activity of about 2 to about 7 against each of Staphylococcus aureus and Escherichia coli, as calculated according to Formula 1.

[0022] [Formula 1]

[0023] Antibacterial activity = log(M1 / M2)

[0024] Where M1 represents the number of bacteria measured on a blank sample after 24 hours of incubation, and M2 represents the number of bacteria measured on each of the samples of the thermoplastic resin composition after 24 hours of incubation.

[0025] 10. In embodiments 1 to 9, when measured on a 0.1 mm thick sample according to ASTM D1003, the thermoplastic resin composition may have a haze of about 1% to about 13% and a light transmittance of about 82% to about 95%.

[0026] 11. In embodiments 1 to 10, when measured on a 3.2 mm thick injection-molded sample according to ASTM D257, the thermoplastic resin composition may have approximately 1 × 10⁻⁶. 8 Approximately 5×10 12 Surface resistance in Ω / sq.

[0027] 12. In embodiments 1 to 11, when measured on a 1 / 8" thick sample according to ASTM D256, the thermoplastic resin composition may have a notched cantilever beam impact strength of about 5 kgf·cm / cm to about 20 kgf·cm / cm.

[0028] 13. Another aspect of the invention relates to a molded article. The molded article is formed from a thermoplastic resin composition according to any one of embodiments 1 to 12.

[0029] 14. In embodiment 13, the molded article may be an antimicrobial film having a thickness of about 0.1 mm to about 3 mm.

[0030] Beneficial effects

[0031] This invention provides a thermoplastic resin composition with good properties in terms of antibacterial properties, transparency, antistatic properties and impact resistance. Detailed Implementation

[0032] Exemplary embodiments of the present invention will be described in detail below.

[0033] The thermoplastic resin composition according to the present invention comprises: (A) a rubber-modified aromatic vinyl copolymer resin; (B) a polyether-ester-amide block copolymer; (C) a silver (Ag) compound; and (D) zinc oxide.

[0034] As used in this article, in order to indicate a specific numerical range, "a to b" is limited to "≥a and ≤b".

[0035] (A) Rubber-modified aromatic vinyl copolymer resin

[0036] The rubber-modified aromatic vinyl copolymer resin according to the present invention may be selected from any rubber-modified aromatic vinyl copolymer resin used in typical transparent thermoplastic resin compositions, and may include, for example, (A1) rubber-modified vinyl graft copolymers and (A2) aromatic vinyl copolymer resins.

[0037] (A1) Rubber-modified vinyl graft copolymer

[0038] According to one embodiment of the invention, a rubber-modified vinyl graft copolymer is used to improve the transparency, impact resistance, and flowability of thermoplastic resin compositions, and can be obtained by graft polymerization of (meth)acrylate, aromatic vinyl monomers, and vinyl cyanide monomers onto a rubber polymer. For example, a rubber-modified vinyl graft copolymer can be obtained by graft polymerization of a monomer mixture comprising (meth)acrylate, aromatic vinyl monomers, and vinyl cyanide monomers onto a rubber polymer, wherein, if desired, the monomer mixture may further comprise monomers for imparting processing properties and heat resistance. Here, polymerization can be carried out by any suitable polymerization method known in the art (e.g., emulsion polymerization, suspension polymerization, and bulk polymerization).

[0039] In some embodiments, the rubber polymer may include: diene rubbers, such as polybutadiene, poly(styrene-butadiene), and poly(acrylonitrile-butadiene); saturated rubbers obtained by adding hydrogen to diene rubbers; isoprene rubbers; acrylic rubbers, such as poly(butyl acrylate); and ethylene-propylene-diene terpolymers (EPDM). These may be used alone or as mixtures thereof. For example, the rubber polymer may include diene rubbers, particularly butadiene rubber.

[0040] In some embodiments, the rubber polymer (rubber particles) may have an average (z-average) particle size of about 0.1 to about 0.5 μm, for example, about 0.2 to about 0.4 μm. Within this range, the thermoplastic resin composition can exhibit good properties in terms of impact resistance and flowability without degrading transparency. Here, the average (z-average) particle size of the rubber polymer (rubber particles) can be measured in the latex state by light scattering. Specifically, the rubber polymer latex is filtered through a mesh sieve to remove agglomerates formed during the polymerization of the rubber polymer. Then, a mixture of 0.5 g of latex and 30 ml of distilled water is placed in a 1,000 ml flask, which is then 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 rubber polymer is measured using a light scattering particle size analyzer (Malvern Co., Ltd., Nano-zs).

[0041] In some embodiments, based on 100 wt% of the rubber-modified vinyl graft copolymer, the amount of the rubber polymer present may be from about 5 wt% to about 65 wt%, for example, from about 10 wt% to about 60 wt%, and based on 100 wt% of the rubber-modified vinyl graft copolymer, the amount of the monomer mixture (including alkyl (meth)acrylate, aromatic vinyl monomers, and vinyl cyanide monomers) present may be from about 35 wt% to about 95 wt%, for example, from about 40 wt% to about 90 wt%. Within this range, the thermoplastic resin composition may have good properties in terms of impact resistance, transparency, and flowability.

[0042] In some embodiments, the (meth)acrylate alkyl ester may be graft copolymerized with a rubber polymer or with an aromatic vinyl monomer, and may include, for example, (meth)acrylate C1 to C1444567 ... 10 Alkyl esters, such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, and butyl (meth)acrylate, especially methyl (meth)acrylate. Based on a 100 wt% monomer mixture, the amount of alkyl (meth)acrylate present can be from about 55 wt% to about 85 wt%, for example, from about 60 wt% to about 80 wt%. Within this range, the thermoplastic resin composition can exhibit good properties in terms of impact resistance, transparency, and flowability.

[0043] In some embodiments, aromatic vinyl monomers may be graft copolymerized with the rubber polymer and may include, for example, styrene, α-methylstyrene, β-methylstyrene, p-methylstyrene, p-tert-butylstyrene, ethylstyrene, vinylxylene, monochlorostyrene, dichlorostyrene, dibromostyrene, and vinylnaphthalene. These may be used alone or as mixtures thereof. Based on a 100 wt% monomer mixture, the amount of aromatic vinyl monomer present may be from about 10 wt% to about 40 wt%, for example, from about 15 wt% to about 35 wt%. Within this range, the thermoplastic resin composition may exhibit good properties in terms of impact resistance, transparency, heat resistance, and flowability.

[0044] In some embodiments, the vinyl cyanide monomer is a monomer copolymerized with an aromatic vinyl monomer, and may include, for example, acrylonitrile, methacrylonitrile, ethyl acrylonitrile, phenyl acrylonitrile, α-chloroacrylonitrile, and fumaric acid, but is not limited thereto. These may be used alone or as mixtures thereof. For example, the vinyl cyanide monomer may be acrylonitrile and methacrylonitrile, etc. Based on a 100 wt% monomer mixture, the amount of vinyl cyanide monomer present may be from about 1 wt% to about 30 wt%, for example, from about 5 wt% to about 25 wt%. Within this range, the thermoplastic resin composition may have good properties in terms of impact resistance, transparency, and flowability.

[0045] In some embodiments, monomers used to impart processability and heat resistance may include, for example, (meth)acrylic acid, maleic anhydride, and N-substituted maleimides. Based on a 100 wt% monomer mixture, the amount of monomers used to impart processability and heat resistance may be about 15 wt% or less, for example, about 0.1 wt% to about 10 wt%. Within this range, monomers used to impart processability and heat resistance can impart processability and heat resistance to the thermoplastic resin composition without degrading other properties.

[0046] In some embodiments, the rubber-modified vinyl graft copolymer may include, for example, methyl methacrylate-acrylonitrile-butadiene-styrene graft copolymer (g-MABS). Here, g-MABS may include polybutadiene (PBD) constituting the rubber polymer (core) and a methyl methacrylate-acrylonitrile-styrene copolymer shell grafted to the core, wherein the shell may include, but is not limited to, an inner shell comprising an acrylonitrile-styrene resin and an outer shell comprising poly(methyl methacrylate).

[0047] In some embodiments, based on 100 wt% of a rubber-modified aromatic vinyl copolymer resin, the amount of the rubber-modified vinyl graft copolymer may be from about 5 wt% to about 50 wt%, for example, from about 10 wt% to about 45 wt%. Within this range, the thermoplastic resin composition can exhibit good properties in terms of transparency, impact resistance, flowability, and the balance between them.

[0048] (A2) Aromatic vinyl copolymer resin

[0049] According to one embodiment of the present invention, an aromatic vinyl copolymer resin is used to improve the impact resistance and transparency of thermoplastic resin compositions, and may be a polymer comprising a monomer mixture including alkyl (meth)acrylates, aromatic vinyl monomers, and vinyl cyanide monomers. For example, the aromatic vinyl copolymer resin can be obtained by polymerization of the monomer mixture using polymerization methods known to those skilled in the art. Additionally, if desired, the monomer mixture may further include monomers for imparting processing properties and heat resistance.

[0050] In some embodiments, the (meth)acrylate alkyl ester may be graft copolymerized with a rubber polymer or with an aromatic vinyl monomer, and may include, for example, (meth)acrylate C1 to C1444567 ... 10 Alkyl esters, such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, and butyl (meth)acrylate, especially methyl (meth)acrylate. Based on a 100 wt% monomer mixture, the amount of alkyl (meth)acrylate present can be from about 55 wt% to about 85 wt%, for example, from about 60 wt% to about 80 wt%. Within this range, the thermoplastic resin composition can exhibit good properties in terms of impact resistance, transparency, and flowability.

[0051] In some embodiments, the aromatic vinyl monomers may include, for example, styrene, α-methylstyrene, β-methylstyrene, p-methylstyrene, p-tert-butylstyrene, ethylstyrene, vinylxylene, monochlorostyrene, dichlorostyrene, dibromostyrene, and vinylnaphthalene. These may be used alone or as mixtures thereof. Based on a 100 wt% monomer mixture, the amount of aromatic vinyl monomer present may be from about 10 wt% to about 40 wt%, for example, from about 15 wt% to about 35 wt%. Within this range, the thermoplastic resin composition may exhibit good properties in terms of impact resistance, transparency, and flowability.

[0052] In some embodiments, the vinyl cyanide monomer may be copolymerized with aromatic vinyl monomers, and may include, for example, acrylonitrile, methacrylonitrile, ethyl acrylonitrile, phenyl acrylonitrile, α-chloroacrylonitrile, and fumaric acid. These may be used alone or as mixtures thereof. Based on a 100 wt% monomer mixture, the amount of vinyl cyanide present may be from about 1 wt% to about 30 wt%, for example, from about 5 wt% to about 25 wt%. Within this range, the thermoplastic resin composition may exhibit good properties in terms of impact resistance, transparency, and flowability.

[0053] In some embodiments, monomers used to impart processability and heat resistance may include, for example, (meth)acrylic acid, maleic anhydride, and N-substituted maleimides, but are not limited thereto. Based on a 100 wt% monomer mixture, the amount of monomers used to impart processability and heat resistance may be about 15 wt% or less, for example, about 0.1 wt% to about 10 wt%. Within this range, monomers used to impart processability and heat resistance can impart processability and heat resistance to the thermoplastic resin composition without degrading other properties.

[0054] In some embodiments, the aromatic vinyl copolymer resin may have a weight-average molecular weight of about 50,000 g / mol to about 200,000 g / mol, for example, about 100,000 g / mol to about 180,000 g / mol, when measured by GPC (gel permeation chromatography). Within this range, the thermoplastic resin composition may have good properties in terms of impact resistance and processing performance (flowability).

[0055] In some embodiments, the amount of aromatic vinyl copolymer resin present, based on 100 wt% of the base resin, may be from about 50 wt% to about 95 wt%, for example, from about 55 wt% to about 90 wt%. Within this range, the thermoplastic resin composition can exhibit good properties in terms of transparency, impact resistance, flowability, and the balance between them.

[0056] In some embodiments, the rubber-modified aromatic vinyl copolymer resin (base resin) may include, for example, a methyl methacrylate-acrylonitrile-butadiene-styrene copolymer resin (MABS resin), which is a mixture of methyl methacrylate-acrylonitrile-butadiene-styrene graft copolymer (g-MABS) and methyl methacrylate-styrene-acrylonitrile copolymer resin (MSAN), but is not limited thereto. Here, the MABS resin may have a structure in which g-MABS is dispersed in MSAN.

[0057] (B) Polyether-ester-amide block copolymer

[0058] According to one embodiment of the invention, a polyether-ester-amide block copolymer, together with silver compounds and zinc oxide in a rubber-modified aromatic vinyl copolymer resin, is used to maintain the transparency of a thermoplastic resin composition while improving the antibacterial and antistatic properties of the thermoplastic resin composition, and may include a polyether-ester-amide block copolymer used as an antistatic agent, for example, a block copolymer comprising a reaction mixture of: aminocarboxylic acid, lactam, or diamine-dicarboxylic acid having 6 or more carbon atoms; polyalkylene glycol; and dicarboxylic acid having 4 to 20 carbon atoms.

[0059] In some embodiments, aminocarboxylic acids, lactams, or diamine-dicarboxylic acids having six or more carbon atoms may include aminocarboxylic acids such as ω-aminohexanoic acid, ω-aminoheptanoic acid, ω-aminooctanoic acid, ω-aminononanoic acid, ω-aminodecanoic acid, 1,1-aminoundecanoic acid, and 1,2-aminododecanoic acid; lactams such as caprolactam, heptanolactam, octolactam, and dodecanoic acid; and salts of diamines and dicarboxylic acids, such as salts of hexamethylenediamine-adipic acid and hexamethylenediamine-isophthalic acid. For example, salts of 1,2-aminododecanoic acid, caprolactam, and hexamethylenediamine-adipic acid may be used.

[0060] In some embodiments, polyalkylene glycols may include polyethylene glycol, poly(1,2-diol and 1,3-propanediol), polytetramethylene glycol, polyhexamethylene glycol, block copolymers or random copolymers of ethylene glycol and propylene glycol, and copolymers of ethylene glycol and tetrahydrofuran, etc. For example, polyethylene glycol and copolymers of ethylene glycol and propylene glycol can be used.

[0061] In some embodiments, dicarboxylic acids having 4 to 20 carbon atoms may include terephthalic acid, 1,4-cyclohexanoic acid, sebacic acid, adipic acid, and lauryl carboxylic acid, etc.

[0062] In some embodiments, the bond between an aminocarboxylic acid, a lactam, or a diamine-dicarboxylate having six or more carbon atoms and the polyalkylene glycol may be an ester bond; the bond between an aminocarboxylic acid, a lactam, or a diamine-dicarboxylate having six or more carbon atoms and a dicarboxylic acid having four to 20 carbon atoms may be an amide bond; and the bond between the polyalkylene glycol and the dicarboxylic acid having four to 20 carbon atoms may be an ester bond.

[0063] In some embodiments, polyether-ester-amide block copolymers can be prepared by methods well known in the art, for example, by methods disclosed in JP Patent Publication No. S56-045419 or JP Unexamined Patent Publication No. S55-133424.

[0064] In some embodiments, the polyether-ester-amide block copolymer may comprise about 10 wt% to about 95 wt% of polyether-ester blocks. Within this range, the thermoplastic resin composition may have good antistatic properties and heat resistance, etc.

[0065] In some embodiments, when measured at 25°C using a refractometer (manufacturer: ATAGO, model: Abbe refractometer DR-A1) on a 2.5 mm thick sample, the polyether-ester-amide block copolymer can have a refractive index of about 1.49 to about 1.52, for example, about 1.50 to about 1.51. The difference between the refractive index of the polyether-ester-amide block copolymer and the rubber-modified aromatic vinyl copolymer resin is about 0.01 or less, for example, about 0.005 or less, particularly about 0.001 to about 0.002. Within this range, the thermoplastic resin composition (molded article) can exhibit suitable transparency.

[0066] In some embodiments, the amount of polyether-ester-amide block copolymer present relative to about 100 parts by weight of rubber-modified aromatic vinyl copolymer resin may be from about 4 parts by weight to about 23 parts by weight, for example, from about 5 parts by weight to about 20 parts by weight. If the content of polyether-ester-amide block copolymer is less than about 4 parts by weight relative to about 100 parts by weight of rubber-modified aromatic vinyl copolymer resin, the thermoplastic resin composition may suffer deterioration in antibacterial properties, antistatic properties, and impact resistance, etc., and if the content of polyether-ester-amide block copolymer exceeds about 23 parts by weight, the thermoplastic resin composition (molded article) may suffer deterioration in transparency and heat resistance, etc.

[0067] (C) Silver (Ag) compounds

[0068] According to one embodiment of the invention, a silver compound can improve the antibacterial properties and transparency of thermoplastic resin compositions, even when added in small amounts, together with polyether-ester-amide block copolymers and zinc oxide. The silver compound can be selected from any silver-containing compound without limitation. For example, the silver compound may include metallic silver, silver oxide, silver halide, silver ion-containing supports, and combinations thereof. In particular, silver ion-containing supports can be used as silver compounds. Supports may include zeolites, silica gel, calcium phosphate, zirconium phosphate, sodium zirconium phosphate, and sodium zirconium hydrogen phosphate, etc. The support preferably has a porous structure. Because a porous support can contain a silver component, the support can increase the silver component content while improving the durability (retention properties) of the silver component. Specifically, the silver compound may be sodium zirconium hydrogen phosphate.

[0069] In some embodiments, when measured by a particle size analyzer (laser diffraction particle size analyzer LS I3 320, Beckman Coulter Co., Ltd.), the silver compound may have an average particle size (D50) of about 1.5 μm or smaller, for example, about 0.1 μm to about 1 μm.

[0070] In some embodiments, the amount of silver compound present relative to about 100 parts by weight of the rubber-modified aromatic vinyl copolymer resin may be from about 0.03 parts by weight to about 1 part by weight, for example, from about 0.05 parts by weight to about 0.7 parts by weight. If the content of silver compound is less than about 0.03 parts by weight relative to about 100 parts by weight of the rubber-modified aromatic vinyl copolymer resin, the thermoplastic resin composition may suffer from deterioration in antibacterial properties, etc., and if the content of silver compound exceeds about 1 part by weight, the thermoplastic resin composition may suffer from deterioration in transparency and impact resistance, etc.

[0071] (D) Zinc oxide

[0072] The zinc oxide according to the present invention, together with polyether-ester-amide block copolymers and silver compounds, is used to improve the antibacterial properties, transparency, and antistatic properties of thermoplastic resin compositions, even when added in small amounts. The zinc oxide according to the present invention consists of primary particles (single particles) and secondary particles formed by the aggregation of the primary particles. When measured using a particle size analyzer (laser diffraction particle size analyzer LS I3 320, Beckman Coulter Co., Ltd.), the primary particles may have an average particle size (D50) of about 1 nm to about 50 nm, for example, about 1 nm to about 30 nm, and the secondary particles may have an average particle size (D50) of about 0.1 μm to about 10 μm, for example, about 0.5 μm to about 5 μm. If the average particle size of the primary zinc oxide particles is less than about 1 nm, the thermoplastic resin composition may suffer from deterioration of antibacterial properties, etc., and if the average particle size of the primary zinc oxide particles exceeds about 50 nm, the thermoplastic resin composition may suffer from deterioration of transparency, etc. Furthermore, if the average particle size of the secondary zinc oxide particles is less than about 0.1 μm, the thermoplastic resin composition may suffer from deterioration in antibacterial properties, etc., and if the average particle size of the secondary zinc oxide particles exceeds about 10 μm, the thermoplastic resin composition may suffer from deterioration in transparency and mechanical properties, etc.

[0073] In some embodiments, the amount of zinc oxide present relative to about 100 parts by weight of the rubber-modified aromatic vinyl copolymer resin may be from about 0.05 parts by weight to about 4 parts by weight, for example, from about 0.1 parts by weight to about 3 parts by weight. If the zinc oxide content is less than about 0.05 parts by weight relative to about 100 parts by weight of the rubber-modified aromatic vinyl copolymer resin, the thermoplastic resin composition may suffer from deterioration in antibacterial properties, etc., and if the zinc oxide content exceeds about 4 parts by weight, the thermoplastic resin composition may suffer from deterioration in transparency and impact resistance, etc.

[0074] In some embodiments, the weight ratio of the polyether-ester-amide block copolymer to the sum of the silver compound and zinc oxide (polyether-ester-amide block copolymer: silver compound + zinc oxide) can be in the range of about 1:0.01 to about 1:0.5, for example, from about 1:0.01 to about 1:0.25. Within this range, the thermoplastic resin composition may exhibit better properties in terms of antibacterial properties, transparency, and antistatic properties.

[0075] In some embodiments, the weight ratio of the silver compound to zinc oxide (silver compound:zinc oxide) can be in the range of about 1:0.5 to about 1:60, for example, about 1:0.6 to about 1:30. Within this range, the thermoplastic resin composition can exhibit better properties in terms of antibacterial properties and transparency.

[0076] The thermoplastic resin composition according to one embodiment of the invention may further include additives typically used in thermoplastic resin compositions. Examples of additives may include, but are not limited to, flame retardants, fillers, antioxidants, anti-dripping agents, lubricants, release agents, nucleating agents, stabilizers, pigments, dyes, and mixtures thereof. The amount of additive present relative to about 100 parts by weight of the rubber-modified aromatic vinyl copolymer resin may be from about 0.001 parts by weight to about 40 parts by weight, for example, from about 0.1 parts by weight to about 10 parts by weight.

[0077] According to one embodiment of the invention, a thermoplastic resin composition can be prepared into pellet form by mixing the aforementioned components and then melt-extruding them in a typical twin-screw extruder at about 200°C to about 280°C, for example, about 220°C to about 250°C.

[0078] In some embodiments, the thermoplastic resin composition exhibits antibacterial activity against various bacteria (such as Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, Salmonella, pneumonia, and MRSA (methicillin-resistant Staphylococcus aureus)). After inoculating 5cm × 5cm samples with Staphylococcus aureus and Escherichia coli according to JIS Z 2801 and culturing for 24 hours at 35°C and 90% RH, the thermoplastic resin composition, when calculated according to Formula 1, exhibits antibacterial activity of about 2 to about 7, for example, about 3 to about 6.5, against each of Staphylococcus aureus and Escherichia coli.

[0079] [Formula 1]

[0080] Antibacterial activity = log(M1 / M2)

[0081] Where M1 represents the number of bacteria measured on a blank sample after 24 hours of incubation, and M2 represents the number of bacteria measured on each of the samples of the thermoplastic resin composition after 24 hours of incubation.

[0082] Here, "blank sample" refers to a control sample used for comparison with the test sample (a sample of the thermoplastic resin composition). Specifically, the blank sample is prepared by inoculating an empty petri dish with bacteria suitable for checking normal bacterial growth, followed by incubation for 24 hours under the same conditions as the test sample. The antimicrobial performance of the test sample is evaluated based on a comparison of the number of cultured bacteria between the blank sample and the test sample. Here, the "number of cultured bacteria" can be determined by the following procedure: each sample is inoculated with bacteria, then incubated for 24 hours, and then the inoculation solution is recovered and diluted, after which the bacteria grow into colonies on the petri dish. When the colony population is too large to be counted, the number of cultured bacteria can be determined by dividing the colony into multiple sectors, measuring the colony size of one sector, and converting the measurement into a total colony.

[0083] In some embodiments, when measured on a 1 mm thick sample according to ASTM D1003, the thermoplastic resin composition may have a haze of about 1% to about 13%, for example, about 1% to 10%, and a light transmittance of about 82% to about 95%, for example, about 85% to 92%.

[0084] In some embodiments, when measured on a 3.2 mm thick injection-molded sample according to ASTM D257, the thermoplastic resin composition may have approximately 1 × 10⁻⁶. 8 Approximately 5×10 12 Ω / sq, for example, about 1×10 8 To approximately 1×10 11 Surface resistance in Ω / sq.

[0085] In some embodiments, when measured on a 1 / 8" thick sample according to ASTM D256, the thermoplastic resin composition may have a notched cantilever beam impact strength of about 5 kgf·cm / cm to about 20 kgf·cm / cm, for example, about 6 kgf·cm / cm to about 150 kgf·cm / cm.

[0086] The molded articles according to the present invention are formed from the above-described thermoplastic resin composition. The antibacterial thermoplastic resin composition can be prepared in the form of small balls. The prepared small balls can be molded into various molded articles (molded products) by various molding methods, such as injection molding, extrusion, vacuum molding, and casting. These molding methods are well known to those skilled in the art.

[0087] In some embodiments, the molded article has good properties in terms of antibacterial properties, transparency, antistatic properties, impact resistance, and the balance between them, and is therefore used as an antibacterial film that can be frequently in contact with the body.

[0088] In some embodiments, the antimicrobial film may have a thickness of about 0.1 mm to about 3 mm, for example, about 0.2 mm to about 2 mm. Within this range, the antimicrobial film may exhibit good properties in terms of transparency, antimicrobial properties, antistatic properties, and mechanical properties.

[0089] Inventive Method

[0090] The invention will now be described in more detail with reference to some embodiments. It should be understood that these embodiments are provided for illustrative purposes only and are in no way intended to limit the invention.

[0091] Example

[0092] Details of the components used in the examples and comparative examples are as follows:

[0093] (A) Rubber-modified aromatic vinyl copolymer resin

[0094] The rubber-modified aromatic vinyl copolymer resin (A) is used, comprising 30 wt% (A1) rubber-modified vinyl graft copolymer and 70 wt% (A2) aromatic vinyl copolymer resin.

[0095] (A1) Rubber-modified vinyl graft copolymer

[0096] The core-shell graft copolymer (g-MABS) is used, which is obtained by graft copolymerizing 45 wt% styrene, acrylonitrile and methyl methacrylate (styrene / acrylonitrile / methyl methacrylate: 20 wt% / 10 wt% / 70 wt%) into 55 wt% butadiene rubber particles with an average (Z average) particle size of 0.28 μm.

[0097] (A2) Aromatic vinyl copolymer resin

[0098] The resin (weight average molecular weight: 160,000 g / mol) was obtained by polymerization of 70 wt% methyl methacrylate, 20 wt% styrene and 10 wt% acrylonitrile.

[0099] (B) Block copolymers

[0100] (B1) Polyamide-6-polyethylene oxide block copolymer (PA6-b-PEO, manufacturer: Sanyo Chemical Co., Ltd., product name: PELECTRON AS, refractive index: 1.51) is used.

[0101] (B2) Use polypropylene-ethylene oxide block copolymer (PP-b-PEO, manufacturer: Sanyo Chemical Co., Ltd., product name: PELECTRON PVL, refractive index: 1.50).

[0102] (C) Silver (Ag) compounds

[0103] Sodium zirconium hydrogen phosphate (manufacturer: Toa Gosei Co., Ltd., product name: Novaron AGZ030).

[0104] (D) Zinc oxide

[0105] (D1) Zinc oxide (manufacturer: SH SH Energy & Chemical, product name: ANYZON) is used, consisting of primary particles with an average particle size (D50) of 10 nm and secondary particles with an average particle size (D50) of 1.7 μm.

[0106] (D2) Zinc oxide (manufacturer: PJChemTech, product name: KS-1) is used, which consists of uniform particles and has an average particle size of 1 μm (D50).

[0107] Examples 1 to 7 and Comparative Examples 1 to 8

[0108] The aforementioned components were mixed in the amounts listed in Tables 1 and 2, and then extruded at 230°C to prepare a thermoplastic resin composition in the form of microspheres. Here, extrusion was performed using a twin-screw extruder (L / D: 36, diameter: 45 mm). The prepared microspheres were dried at 80°C for 2 hours or longer, and then injection molded using a 6-ounce injection molding machine (molding temperature: 230°C, mold temperature: 60°C) to prepare samples. The following properties of the prepared samples were evaluated. The results are shown in Tables 1 and 2.

[0109] Feature evaluation

[0110] (1) Antibacterial activity: Staphylococcus aureus and Escherichia coli were inoculated into 5cm×5cm samples according to JIS Z 2801 and cultured at 35℃ and 90%RH for 24 hours. The antibacterial activity was then calculated according to Formula 1.

[0111] [Formula 1]

[0112] Antibacterial activity = log(M1 / M2),

[0113] Where M1 represents the number of bacteria measured on a blank sample after 24 hours of incubation, and M2 represents the number of bacteria measured on each sample after 24 hours of incubation.

[0114] (2) Haze and transmittance (unit: %): Haze and transmittance were measured on a 1 mm thick sample using a haze meter NDH 2000 (Nippon Denshoku Co., Ltd.) according to ASTM D1003.

[0115] (3) Surface resistance (unit: Ω / sq): Surface resistance was measured on an injection-molded sample with dimensions of 10 mm × 10 mm × 3.2 mm using a surface resistance meter (manufacturer: Mitsubishi Chemical Co., Ltd., model: Hiresta-UP (MCP-HT450)) in accordance with ASTM D257.

[0116] (4) Notched cantilever beam impact strength (unit: kgf·cm / cm): The notched cantilever beam impact strength was measured on a 1 / 8" thick sample according to ASTM D256.

[0117] Table 1

[0118]

[0119]

[0120] Table 2

[0121]

[0122] The results show that the thermoplastic resin composition according to the present invention has good properties in terms of antibacterial properties, transparency, antistatic properties and impact resistance.

[0123] Conversely, it can be seen that the resin composition of Comparative Example 1, prepared using an insufficient amount of polyether-ester-amide block copolymer, suffers from deterioration in antibacterial properties, antistatic properties, and impact resistance; while the resin composition of Comparative Example 2, prepared using an excessive amount of polyether-ester-amide block copolymer, suffers from deterioration in transparency, etc. Furthermore, it can be seen that the resin composition of Comparative Example 3, prepared using polypropylene-polyethylene oxide block copolymer (B2) instead of the polyether-ester-amide block copolymer according to the present invention, suffers from deterioration in impact resistance, etc., and exhibits poorer transparency, etc., compared to the resin compositions of the examples. It can be seen that the resin composition of Comparative Example 4, prepared using an insufficient amount of silver compound, suffers from deterioration in antibacterial properties, etc.; the resin composition of Comparative Example 5, prepared using an excessive amount of silver compound, suffers from deterioration in transparency, etc.; the resin composition of Comparative Example 6, prepared using an insufficient amount of zinc oxide, suffers from deterioration in antibacterial properties, etc.; and the resin composition of Comparative Example 7, prepared using an excessive amount of zinc oxide, suffers from deterioration in transparency and impact resistance, etc. Furthermore, it can be seen that the resin composition of Comparative Example 8, prepared by using zinc oxide (D2) instead of zinc oxide according to the present invention, suffers from deterioration in antibacterial properties and transparency, etc.

[0124] The present invention has been described above with reference to exemplary embodiments. It should be understood that various modifications, alterations, variations, and equivalent embodiments can be made by those skilled in the art without departing from the spirit and scope of the invention.

Claims

1. A thermoplastic resin composition comprising: 100 parts by weight of rubber-modified aromatic vinyl copolymer resin; 4 to 23 parts by weight of polyether-ester-amide block copolymer; 0.03 parts by weight to 1 part by weight of silver (Ag) compound; and 0.05 parts by weight to 4 parts by weight of zinc oxide, The zinc oxide comprises primary particles and secondary particles, the primary particles having an average particle size D50 of 1 nm to 50 nm, and the secondary particles having an average particle size D50 of 0.1 μm to 10 μm. The weight ratio of the polyether-ester-amide block copolymer to the sum of the silver compound and the zinc oxide (polyether-ester-amide block copolymer: silver compound + zinc oxide) is in the range of 1:0.01 to 1:0.

5. The rubber-modified aromatic vinyl copolymer resin comprises 5 wt% to 50 wt% of a rubber-modified vinyl graft copolymer and 50 wt% to 95 wt% of an aromatic vinyl copolymer resin. The rubber-modified vinyl graft copolymer is obtained by graft polymerization of (meth)acrylate, aromatic vinyl monomers, and vinyl cyanide monomers onto a rubber polymer, wherein the amount of (meth)acrylate present is 55 wt% to 85 wt% based on a 100 wt% monomer mixture. The aromatic vinyl copolymer resin is obtained by polymerization of alkyl (meth)acrylate, aromatic vinyl monomer and vinyl cyanide monomer, and the amount of alkyl (meth)acrylate present is 55 wt% to 85 wt% based on 100 wt% of monomer mixture.

2. The thermoplastic resin composition according to claim 1, wherein the weight ratio of the silver compound to the zinc oxide (silver compound:zinc oxide) is in the range of 1:0.5 to 1:

60.

3. The thermoplastic resin composition according to claim 1 or 2, wherein the polyether-ester-amide block copolymer is a block copolymer comprising a reaction mixture of: aminocarboxylic acid, lactam, or diamine-dicarboxylic acid having 6 or more carbon atoms; polyalkylene glycol; and dicarboxylic acid having 4 to 20 carbon atoms.

4. The thermoplastic resin composition according to claim 1 or 2, wherein the silver compound comprises at least one of silver oxide, silver halide, and a silver ion-containing carrier.

5. The thermoplastic resin composition according to claim 1 or 2, wherein, According to JIS Z 2801, 5 cm × 5 cm samples were inoculated with Staphylococcus aureus and Escherichia coli, respectively, and incubated for 24 hours at 35°C and 90% RH. When calculated according to Formula 1, the thermoplastic resin composition exhibited antibacterial activity of 2 to 7 against each of Staphylococcus aureus and Escherichia coli. [Formula 1] Antibacterial activity = log(M1 / M2) Where M1 represents the number of bacteria measured on a blank sample after 24 hours of incubation, and M2 represents the number of bacteria measured on each of the samples of the thermoplastic resin composition after 24 hours of incubation.

6. The thermoplastic resin composition according to claim 1 or 2, wherein, When measured on a 0.1 mm thick sample according to ASTM D1003, the thermoplastic resin composition has a haze of 1% to 13% and a light transmittance of 82% to 95%.

7. The thermoplastic resin composition according to claim 1 or 2, wherein, When measured according to ASTM D257 on a 3.2 mm thick injection-molded sample, the thermoplastic resin composition has a density of 1 × 10⁻⁶. 8 Up to 5 × 10 12 Surface resistance in Ω / sq.

8. The thermoplastic resin composition according to claim 1 or 2, wherein, When measured on a 1 / 8-inch thick sample according to ASTM D256, the thermoplastic resin composition has a notched cantilever beam impact strength of 5 kgf·cm / cm to 20 kgf·cm / cm.

9. A molded article formed from a thermoplastic resin composition according to any one of claims 1 to 8.

10. The molding article according to claim 9, wherein the molding article is an antimicrobial film having a thickness of 0.1 mm to 3 mm.

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