Antibacterial SAN resin, method for producing the same, and antibacterial ABS resin composition containing the same

Abstract

The present invention relates to an antibacterial SAN resin, a manufacturing method thereof, and an antibacterial ABS resin composition containing the same, and provides an antibacterial SAN resin that can exhibit sustained antibacterial properties since there is no leakage of antibacterial substances, a manufacturing method thereof, and an antibacterial ABS resin composition containing the same.

Description

Technical Field

[0001] Cross-reference to related applications (etc.) This application claims the benefit of priority based on Korean Patent Application No. 10-2021-0098134 filed on July 26, 2021 and Korean Patent Application No. 10-2022-0079972 filed on June 29, 2022, and all the contents disclosed in the documents of the Korean patent applications are incorporated herein by reference in their entirety.

[0002] The present invention relates to an antibacterial SAN resin exhibiting sustainable antibacterial properties, a method for producing the same, and an antibacterial ABS resin composition containing the same.

Background Art

[0003] SAN resin (Styrene-Acrylonitrile Resin) is a general term for a copolymer containing repeating units derived from styrene-based monomers and repeating units derived from acrylonitrile-based monomers. Such SAN resins are excellent in heat resistance, chemical resistance, and mechanical strength while having excellent fluidity, and are widely used in electrical and electronic applications, household applications, office applications, automotive parts, medical equipment systems, etc.

[0004] In particular, SAN resins can be mixed with ABS resins (acrylonitrile butadiene styrene resins) and used to manufacture articles closely related to daily life such as interior / exterior automotive materials, household appliances such as refrigerators and vacuum cleaners, and toys, where there is a high demand for antibacterial properties.

[0005] Therefore, attempts have been made to introduce various bacteria growth inhibitory components, deodorants, or antibacterial agents into SAN resins and the like. Specifically, as antibacterial agents, there are organic and inorganic antibacterial agents. Organic antibacterial agents are relatively inexpensive and economical, and have excellent immediate antibacterial effects, but have the demerits of low antibacterial persistence, low human body safety, and low thermal stability. In addition, inorganic antibacterial agents not only have a high unit price, but also have low immediate antibacterial effects, and may oxidize and cause discoloration of articles when exposed to air, light, moisture, etc., and there is a problem of rapidly reducing the physical properties of the composition during injection.

[0006] As a result, there has been a continuous demand for the development of SAN resin-related technologies that can suppress the growth of excellent bacteria without degrading the basic physical properties of SAN resin by introducing antibacterial agents and the like that suppress the growth of bacteria into SAN resin.

Summary of the Invention

Problems to be Solved by the Invention

[0007] Therefore, the present invention aims to provide an antibacterial SAN resin that is not harmful due to no outflow of antibacterial substances and can exhibit continuous antibacterial properties, a method for producing the same, and an antibacterial ABS resin composition containing the same.

Means for Solving the Problems

[0008] According to one embodiment of the present invention, Provided is an antibacterial SAN resin containing a repeating unit derived from a monomer represented by the following Chemical Formula 1, a repeating unit derived from a styrene-based monomer, and a repeating unit derived from an acrylonitrile-based monomer.

Chem.

[0009] According to still another embodiment of the present invention, Provided is a method for producing an antibacterial SAN resin, which includes a step of polymerizing a monomer represented by the following Chemical Formula 1, a styrene-based monomer, and an acrylonitrile-based monomer at a temperature of 60°C to 90°C for 3 hours to 8 hours in the presence of a polymerization initiator.

[0010] Furthermore, according to still another embodiment of the present invention, provided is an antibacterial ABS resin composition including the aforementioned antibacterial SAN resin and an ABS resin.

Effects of the Invention

[0011] The antibacterial SAN resin of the present invention can continuously exhibit antibacterial properties of suppressing the growth of bacteria without elution of an antibacterial agent.

[0012] Specifically, the antibacterial SAN resin is not one in which a polymerizable antibacterial monomer having a specific structure is separately mixed, but is produced by copolymerization with a styrene-based monomer and an acrylonitrile-based monomer. Therefore, even after a lapse of time, an antibacterial substance does not flow out, so it is not harmful and can continuously exhibit excellent antibacterial properties against at least one of Gram-positive bacteria and Gram-negative bacteria.

[0013] Therefore, the antibacterial SAN resin can be preferably used by being mixed with an ABS resin in various industrial products and daily necessities that require durability and thermal stability.

Brief Description of the Drawings

[0014]

Figure 1

DETAILED DESCRIPTION OF THE INVENTION

[0015] The terms used in this specification are used merely to explain exemplary embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as "including," "comprising," or "having" are intended to specify the presence of implemented features, steps, components, or combinations thereof, and should be understood not to preclude the presence or addition of one or more other features, steps, components, or combinations thereof in advance.

[0016] Also, in the present invention, when each layer or element is referred to as being "formed on" or "on" each layer or element, it means that each layer or element is formed directly on each layer or element, or that other layers or elements can be additionally formed between the layers, on the object, or on the substrate.

[0017] Since the present invention can be subjected to various modifications and can have various forms, specific embodiments are illustrated and described in detail below. However, this is not intended to limit the present invention to specific disclosed forms, and should be understood to include all modifications, equivalents, or alternatives included in the spirit and technical scope of the present invention.

[0018] Also, the technical terms used in this specification are merely for referring to specific embodiments and are not intended to limit the present invention. And the singular forms used herein include the plural forms unless the context clearly indicates the contrary meaning.

[0019] On the other hand, the term "(meth)acrylate" used in this specification includes both acrylate and methacrylate.

[0020] In addition, in the present specification, the alkyl group may be linear or branched, and the number of carbon atoms is not particularly limited, but is preferably 1 to 10. According to one embodiment, the number of carbon atoms of the alkyl group is 1 to 6. Specific examples of the alkyl group include methyl, ethyl, propyl, n-propyl, isopropyl, butyl, n-butyl, isobutyl, tert-butyl, sec-butyl, 1-methyl-butyl, 1-ethylbutyl, pentyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, 1-ethyl-propyl, 1,1-dimethylpropyl, hexyl, n-hexyl, 1-methylpentyl, 2-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, heptyl, n-heptyl, isohexyl, 1-methylhexyl, 2-methylhexyl, 3-methylhexyl, 4-methylhexyl, 5-methylhexyl, cyclopentylmethyl, cyclohexylmethyl, octyl, n-octyl, tert-octyl, 1-methylheptyl, 2-ethylhexyl, 2,4,4-trimethyl-1-pentyl, 2,4,4-trimethyl-2-pentyl, 2-propylpentyl, n-nonyl, 2,2-dimethylheptyl, etc., but are not limited thereto.

[0021] In addition, in the present specification, the alkoxy group may be linear or branched, and the number of carbon atoms is not particularly limited, but is preferably 1 to 10. According to one embodiment, the number of carbon atoms of the alkoxy group is 1 to 6. Specific examples of the alkoxy group include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, etc., but are not limited thereto.

[0022] Conventionally, in order to ensure antibacterial and deodorizing properties in plastics such as SAN resin, a metal compound having an antibacterial function or an organic compound containing a cation or an alcohol functional group has been introduced in the form of an additive. However, in this case, there are problems such as a decrease in the safety of SAN resin, or the persistence of antibacterial properties and the outflow of antibacterial substances.

[0023] As an example, attempts have been made to mix an antibacterial agent component containing antibacterial metal ions such as silver, copper, and zinc into a plastic resin. Such antibacterial metal ion-containing components can exhibit antibacterial properties by destroying the cell walls of microorganisms such as bacteria, but they are classified as biocide substances that can kill even beneficial microorganisms in the human body. Also, when the antibacterial agent component is to be mixed after the production of the plastic resin, there has been a problem that over time, the antibacterial agent elutes from the final article and the antibacterial property does not persist. Moreover, since the eluting antibacterial agent has an adverse effect on the human body, the plastic resin exhibiting antibacterial properties produced as described above also has the demerit of reducing human body safety.

[0024] Also, it has been confirmed that there are more than 5,000 diverse types of bacteria. Specifically, bacteria are spherical, rod-shaped, spiral-shaped, etc., with diverse cell shapes, and the degree of oxygen requirement also varies from bacterium to bacterium, and they are classified into aerobic bacteria, facultative bacteria, and anaerobic bacteria. Therefore, it has not been easy for a single type of antibacterial agent to have a physical / chemical mechanism capable of damaging the cell membranes / cell walls of diverse bacteria or modifying proteins.

[0025] However, when producing SAN resin by polymerizing a monomer containing a carboxy group having a specific structure together with styrene-based monomers and acrylonitrile-based monomers, etc., it has been confirmed that it can exhibit antibacterial properties against at least one of Gram-positive bacteria and Gram-negative bacteria, and since the antibacterial substance does not elute, it is excellent in human body safety and the antibacterial effect can be sustained, thus completing the present invention.

[0026] More specifically, when the polymerizable antibacterial monomer represented by Chemical Formula 1 comes into contact with bacteria, an acidic condition is formed by the dissociation of the carboxy group (COOH) substituted on the A ring. Under such acidic conditions, bacteria are affected by the structure and function of the cell membrane, and thus the growth of bacteria may be reduced. Therefore, the SAN resin containing the copolymer formed by the polymerizable antibacterial monomer represented by Chemical Formula 1 can exhibit antibacterial properties against at least one of Gram-positive bacteria and Gram-negative bacteria.

[0027] Hereinafter, the SAN resin, a method for producing the same, and an ABS resin composition containing the same will be described in more detail with reference to specific embodiments of the invention.

[0028] SAN resin The SAN resin according to one embodiment is characterized by including a repeating unit derived from a monomer represented by the following Chemical Formula 1, a repeating unit derived from a styrene monomer, and a repeating unit derived from an acrylonitrile monomer.

Chemical formula

[0029] More specifically, the SAN resin is a copolymer produced by copolymerizing the monomer represented by Chemical Formula 1, a styrene-based monomer, and an acrylonitrile-based monomer, and has a one-dimensional linear polymer form having a structure in which repeating units are arranged in a long chain. Further, the SAN resin may be an alternating copolymer in which the repeating units derived from the monomer represented by Chemical Formula 1, the repeating units derived from the styrene-based monomer, and the repeating units derived from the acrylonitrile-based monomer are regularly arranged alternately, or a random copolymer in which the repeating units are randomly arranged.

[0030] At this time, the antibacterial property of the SAN resin is exhibited by the carboxy group contained in the repeating unit derived from the monomer represented by Chemical Formula 1, as described above. Since the monomer represented by Chemical Formula 1 does not exist as a separate compound in the SAN resin but exists as a repeating unit constituting the main chain, it does not flow out even over time, so that the antibacterial property of the SAN resin can be continuously maintained.

[0031] Furthermore, the repeating unit derived from the monomer represented by Chemical Formula 1 may be contained in the antibacterial SAN resin in an amount of 0.01 to 0.7 mol based on 1 mol of the antibacterial SAN resin. When the repeating unit derived from the monomer represented by Chemical Formula 1 is contained in an excessively low amount, it is difficult to exhibit a sufficient antibacterial effect. When the repeating unit derived from the monomer represented by Chemical Formula 1 is contained in an excessively high amount, the glass transition temperature of the SAN resin may increase and the processability may decrease.

[0032] Specifically, the repeating unit derived from the monomer represented by Chemical Formula 1 may be contained in an amount of 0.02 mol or more, 0.03 mol or more, 0.04 mol or more, or 0.05 mol or more, and 0.65 mol or less, 0.6 mol or less, 0.55 mol or less, 0.5 mol or less, or 0.45 mol or less based on 1 mol of the antibacterial SAN resin.

[0033] Also, in the chemical formula 1, A may be an unsubstituted or aromatic ring having 6 to 60 carbon atoms substituted with one or more substituents selected from alkyl, hydroxy, and carboxy groups having 1 to 4 carbon atoms.

[0034] In one embodiment, R1 to R3 may each independently be hydrogen or methyl.

[0035] Also, in one embodiment, A may be an unsubstituted or aromatic ring having 6 to 10 carbon atoms substituted with one or more, for example, 1 to 5 substituents selected from alkyl, hydroxy, and carboxy groups having 1 to 4 carbon atoms.

[0036] Specifically, A may be an unsubstituted or benzene ring substituted with one or more, for example, 1 to 5 substituents selected from alkyl, hydroxy, and carboxy groups having 1 to 4 carbon atoms.

[0037] As an example, the polymerizable antibacterial monomer may be any one selected from the following.

Chemical formula

[0038] On the other hand, the styrene monomer may be one or more selected from styrene, α-methylstyrene, β-methylstyrene, p-methylstyrene, p-tert-butylstyrene, o-bromostyrene, o-chlorostyrene, m-bromostyrene, m-chlorostyrene, p-bromostyrene, and p-chlorostyrene. The repeating unit derived from such a styrene monomer can play a role in increasing the polymerization conversion rate during polymerization while enhancing the heat resistance of the SAN resin.

[0039] Further, the acrylonitrile monomer may be one or more selected from acrylonitrile, methacrylonitrile, and ethacrylonitrile. The repeating units derived from such acrylonitrile monomers can play a role in enhancing the strength, heat resistance, and crack resistance of the SAN resin.

[0040] At this time, the repeating units derived from the styrene monomer and the repeating units derived from the acrylonitrile monomer in the antibacterial SAN resin may be contained in a molar ratio of 5:5 to 9:1. When the molar ratio of the repeating units derived from the styrene monomer and the repeating units derived from the acrylonitrile monomer in the SAN resin is less than 5:5, the repeating units derived from the acrylonitrile monomer are excessively contained relative to the repeating units derived from the styrene monomer, and a gel polymer that is insoluble in a solvent can be formed. However, since such a gel polymer is very weak to heat, it may appear as a red or black foreign matter during heating, and there may be a problem of damaging the outer shape of the product. Further, when the molar ratio of the repeating units derived from the styrene monomer and the repeating units derived from the acrylonitrile monomer in the SAN resin exceeds 9:1, the content of the repeating units derived from the acrylonitrile monomer is excessively low, not only the polymerization conversion rate and the molecular weight decrease, but also the content of the repeating units derived from the styrene monomer is excessively high, and there may be a problem of a decrease in heat resistance.

[0041] Specifically, the repeating units derived from the styrene monomer and the repeating units derived from the acrylonitrile monomer in the antibacterial SAN resin may be contained in a molar ratio of 5.2:4.8 or more, 5.3:4.7 or more, 5.4:4.6 or more, 5.5:4.5 or more, 5.6:4.4 or more, 5.7:4.3 or more, 5.8:4.2 or more, or 5.9:4.1 or more, and 8:2 or less, 7:3 or less, 6.5:3.5 or less, or 6:4 or less.

[0042] On the one hand, when styrene is used as the styrenic monomer and acrylonitrile is used as the acrylonitrile-based monomer, the antibacterial SAN resin may be represented as shown in the following Chemical Formula 2. [Chemical Formula] In Chemical Formula 2, A is as defined in Chemical Formula 1, x + y is a real number from 0.3 to 0.99, z is a real number from 0.01 to 0.7, x + y + z = 1.

[0043] In other words, in Chemical Formula 2, x, y, and z respectively represent the number of moles of the repeating unit derived from styrene, the repeating unit derived from acrylonitrile, and the repeating unit derived from the monomer represented by Chemical Formula 1.

[0044] In addition, the SAN resin can exhibit antibacterial properties against at least one of Gram-negative bacteria and Gram-positive bacteria as described above. More specifically, the SAN resin can exhibit antibacterial properties against one or more types of bacteria classified as Gram-positive bacteria. Alternatively, the SAN resin can exhibit antibacterial properties against one or more types of bacteria classified as Gram-negative bacteria. Alternatively, the SAN resin can exhibit antibacterial properties against one or more types of bacteria classified as Gram-negative bacteria and one or more types of bacteria classified as Gram-positive bacteria

[0045] In addition, Gram-positive bacteria are a general term for bacteria that are stained purple when stained by the Gram staining method. The cell wall of Gram-positive bacteria is composed of multiple layers of peptidoglycan. After staining with a basic dye such as crystal violet, it will not be decolorized even after treatment with ethanol and will show a purple color. Bacteria classified as such Gram-positive bacteria include Enterococcus faecalis, Staphylococcus aureus, Streptococcus pneumoniae, Enterococcus faecium, or Lactobacillus lactis, etc.

[0046] In addition, Gram-negative bacteria are a general term for bacteria that are stained red when stained by the Gram staining method. Instead of having a cell wall with a relatively small amount of peptidoglycan compared to Gram-positive bacteria, they have an outer membrane composed of lipopolysaccharides, lipoproteins, and other complex polymer substances. As a result, after staining with a basic dye such as crystal violet, decolorization occurs when treated with ethanol, and when counterstained with a red dye such as safranin, it will show a red color. Bacteria classified as such Gram-negative bacteria include Proteus mirabilis, Escherichia coli, Salmonella typhi, Pseudomonas aeruginosa, or Vibrio cholerae, etc.

[0047] Therefore, since the above-mentioned Gram-positive bacteria and Gram-negative bacteria not only induce various diseases upon contact but may also cause secondary infections in critically ill patients with weakened immunity, it is preferable to show antibacterial properties against both the Gram-positive bacteria and Gram-negative bacteria using a single antibacterial agent.

[0048] Preferably, the SAN resin can exhibit antibacterial properties against both the Gram-negative bacteria and the Gram-positive bacteria. At this time, the Gram-negative bacteria against which the SAN resin exhibits antibacterial properties may be Proteus mirabilis or Escherichia coli, and the Gram-positive bacteria may be Enterococcus faecalis or Staphylococcus aureus, but are not limited thereto.

[0049] Here, the antibacterial property evaluation of the SAN resin can be measured based on JIS Z 2801 (Measurement of Antibacterial Activity on Plastics and Non-porous Surfaces) or ASTM E2149 (Determining the Antimicrobial Activity of Immobilized Antimicrobial Agents Under Dynamic Contact Conditions; Shake Flask Method).

[0050] More specifically, based on the ASTM E2149 standard, the bacteriostatic rate measured by the following mathematical formula 1 of the SAN resin may be 38% or more, 50% or more, 60% or more, 70% or more, 80% or more, 90% or more, 95% or more, 96% or more, 97% or more, 98% or more, 98.1% or more, 99% or more, 99.3% or more, or 99.9% or more, and 100% or less. [Mathematical formula 1] Bacteriostatic rate (%) = [1 - (number of bacteria in the test group / number of bacteria in the control group)] × 100

[0051] The method for measuring the bacteriostatic rate will be described in more detail in the experimental examples described later.

[0052] Further, the SAN resin may have a weight average molecular weight of 20,000 to 100,000 g / mol. When the weight average molecular weight of the SAN resin is less than 20,000 g / mol, not only can there be a problem that it exists in the form of monomers rather than polymers and is easily eluted and absorbed by the human body due to its low molecular weight, but also cracks may occur in the resin, making processing difficult. When the weight average molecular weight of the SAN resin exceeds 100,000 g / mol, the strength and chemical resistance decrease, and molding defects may occur during injection molding.

[0053] More specifically, the weight average molecular weight (Mw, g / mol) of the SAN resin may be 20,000 or more, 25,000 or more, 25,187 or more, 30,000 or more, 31,468 or more, 40,000 or more, 50,000 or more, or 60,000 or more, and 95,000 or less, 93,000 or less, 91,000 or less, 90,403 or less, 85,000 or less, 80,000 or less, 78,568 or less, or 75,000 or less.

[0054] At this time, the weight average molecular weight (Mw) of the SAN resin can be measured using gel permeation chromatography (GPC) with polystyrene (PS) as the calibration standard sample. More specifically, after diluting the SAN resin to a concentration of 2 mg / mL in a tetrahydrofuran (THF) solvent, the weight average molecular weight can be measured through an RI detector at a flow rate of 1.0 mL / min using an Agilent 1200 series GPC instrument of Agilent Technologies. For a more specific measurement method, refer to the experimental examples described later.

[0055] Further, the SAN resin may have a glass transition temperature (Tg) of 90°C to 160°C. The SAN resin having a glass transition temperature within the above range is excellent in the balance between heat resistance and strength. At this time, the glass transition temperature of the SAN resin can be measured using a DSC (Differential Scanning Calorimeters) manufactured by TA Instruments.

[0056] Further, the SAN resin may have a bulk density of 0.6 to 0.7 g / cc. The SAN resin having a bulk density within the above range has the merit of being easy to store and transport. At this time, the bulk density of the SAN resin can be measured by filling a 100 cc cup with powdery SAN resin and then dividing the weight (g) by 100.

[0057] Manufacturing method of SAN resin On the other hand, the SAN resin may be manufactured by including a step of polymerizing the monomer represented by the chemical formula 1, a styrene-based monomer, and an acrylonitrile-based monomer at a temperature of 60°C to 90°C for 3 hours to 8 hours in the presence of a polymerization initiator. More specifically, the SAN resin may be manufactured by polymerizing the three kinds of monomers within a temperature range of 60°C or higher, or 70°C or higher, and 90°C or lower, or 80°C or lower, and within a time range of 3 hours or longer, or 3 hours and 30 minutes or longer, and 8 hours or shorter, 7 hours or shorter, 6 hours or shorter, 5 hours or shorter, or 4 hours or shorter.

[0058] More specifically, the copolymerization may be carried out by a method such as emulsion polymerization, suspension polymerization, or bulk polymerization, and a polymerization method suitable for the final use may be selected.

[0059] In addition, an azo initiator can be used as a polymerization initiator for polymerization stability and promoting the polymerization reaction. For example, as azo initiators, there are azobisisobutyronitrile (AIBN), 2-azobis-(2-amidinopropane) dihydrochloride, 2,2-azobis-(N,N-dimethylene)isobutyramidine dihydrochloride, 2-(carbamoylazo)isobutylonitril, 2,2-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride, 4,4-azobis-(4-cyanovaleric acid), and the like.

[0060] The polymerization initiator may be used in an amount of 0.01 to 5 parts by weight based on 100 parts by weight in total of the monomers. If the content of such a polymerization initiator is less than 0.01 part by weight, the effect of adding the polymerization initiator is negligible. If the content of the polymerization initiator exceeds 5 parts by weight, the molecular weight of the SAN resin may be small and the physical properties may deteriorate. More specifically, the polymerization initiator may be used in an amount of 0.05 part by weight or more, or 0.1 part by weight or more, 0.5 part by weight or more, or 1.2 part by weight or more, and 4 parts by weight or less, 2 parts by weight or less, or 1.85 part by weight or less based on 100 parts by weight in total of the monomers.

[0061] In addition, the monomers and the polymerization initiator may be prepared in the form of a solution dissolved in a solvent.

[0062] The solvent used at this time can be used without being limited to its composition as long as it can dissolve the aforementioned components. For example, water, ethanol, ethylene glycol, diethylene glycol, triethylene glycol, 1,4-butanediol, propylene glycol, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, methyl ethyl ketone, acetone, methyl amyl ketone, cyclohexanone, cyclopentanone, diethylene glycol monomethyl ether, diethylene glycol ethyl ether, toluene, xylene, butyrolactone, carbitol, methyl cellosolve acetate, N,N-dimethylformamide, and N,N-dimethylacetamide, etc., may be used in combination of one or more selected therefrom.

[0063] Also, a molecular weight regulator such as a mercaptan compound may be additionally used during polymerization, and when performing the polymerization reaction by emulsion polymerization, an emulsifier such as a potassium fatty acid salt may be used.

[0064] And the polymerization can be carried out until, for example, the polymerization conversion rate is 50% or more, more specifically 50 to 90%. For example, the polymerization can be carried out until the polymerization conversion rate is 60% or more, 70% or more, or 80% or more, and 90% or less, or 85% or less. When the polymerization is carried out within the aforementioned polymerization conversion rate range, the process is easy and excellent productivity can be exhibited.

[0065] Also, after the polymerization step, a step of extracting and vacuum drying the polymer can be carried out to finally obtain the desired SAN resin. In particular, by volatilizing the unreacted monomers and solvents remaining after the polymerization reaction through the vacuum drying step, the transparency of the final SAN resin can be improved and the heat resistance can be enhanced.

[0066] ABS resin composition On the other hand, as another embodiment, an antibacterial ABS resin composition containing the aforementioned antibacterial SAN resin and an ABS resin is provided.

[0067] The ABS resin may, for example, be a copolymer of an acrylonitrile monomer, a conjugated diene monomer, and a vinyl aromatic monomer.

[0068] Here, the acrylonitrile monomer is as described above.

[0069] Also, the conjugated diene monomer may be one or more selected from 1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 2-ethyl-1,3-butadiene, 1,3-pentadiene, and isoprene.

[0070] Also, the vinyl aromatic monomer may be one or more selected from styrene, α-methylstyrene, β-methylstyrene, p-t-butylstyrene, chlorostyrene, vinyl benzoic acid, methyl vinyl benzoate, vinyl naphthalene, chloromethylstyrene, hydroxymethylstyrene, and divinylbenzene.

[0071] More specifically, the ABS resin may be a graft copolymer in which a vinyl aromatic monomer and an acrylonitrile monomer are grafted onto a rubbery polymer obtained by polymerizing a conjugated diene monomer. Here, the content of the rubbery polymer is preferably 30 to 75% by weight based on the total weight of the graft copolymer. Within this range, not only is the graft ratio high, but the impact strength and chemical resistance of the finally produced molded article are also excellent. Also, in terms of increasing the graft ratio with the rubbery polymer, the content of the vinyl aromatic monomer is preferably 20 to 65% by weight based on the total weight of the graft copolymer resin, and the content of the acrylonitrile monomer is preferably 5 to 30% by weight based on the total weight of the graft copolymer resin.

[0072] Also, the ABS resin composition may contain 60 to 90% by weight of the antibacterial SAN resin and 10 to 40% by weight of the ABS resin.

[0073] Further, the ABS resin composition may further contain antioxidants such as hindered phenol-based antioxidants and phosphorus-based antioxidants.

[0074] On the other hand, as another embodiment, a molded article made of the above-described ABS resin composition is provided. The molded article may be, for example, one or more selected from automotive interior / exterior materials, home appliance housings, toys, food containers, and medical articles.

[0075] Hereinafter, preferred embodiments are presented for the understanding of the invention. However, the following examples are only for illustrating the invention and do not limit the invention only to these.

Example

[0076] Production Example 1: Production of Polymerizable Antibacterial Monomer 1-1 3-(Acryloyloxy)benzoic Acid (1-13-(acryloyloxy)benzoic acid; A-BA))

Chemical formula

[0077] Production Example 2: Production of Polymerizable Antibacterial Monomer 1-2 2-(Acryloyloxy)benzoic Acid (2-A-BA)

Chemical Structure

[0078] Example - Production of SAN Resin Example 1 [Chemical] 4.878 g of styrene, 1.657 g of acrylonitrile, 15 g of the polymerizable antibacterial monomer 1-1 produced in Production Example 1, and 0.26 g of azobisisobutyronitrile (AIBN) as a polymerization initiator were dissolved in 35.89 mL of N,N-dimethylformamide (DMF) as a solvent. Then, polymerization was carried out using a magnetic bar at 80 °C and under air conditions for 4 hours, and the reaction was terminated when the polymerization conversion rate reached 80%. Thereafter, the solution after the reaction was cooled to room temperature, precipitated in a sufficient amount of water, and then vacuum-dried to obtain a solid powder copolymer SAN-co-(A-BA) resin.

[0079] The produced SAN-co-(A-BA) resin had a weight-average molecular weight of 90,403 g / mol, and the molar ratio (x:y:z) of the repeating units derived from styrene, the repeating units derived from acrylonitrile, and the repeating units derived from the polymerizable antibacterial monomer was 0.3:0.2:0.5.

[0080] At this time, the weight-average molecular weight of the SAN-co-(A-BA) resin was measured using GPC (instrument name: Agilent 1200 series GPC, manufactured by Agilent Technologies) by dissolving the copolymer produced in tetrahydrofuran (THF). Specifically, the sample preparation method and measurement conditions for measuring the weight-average molecular weight are as follows.

[0081] (1) Sample preparation 1000 mL of THF (stabilized with BHT) was filtered through a solvent clarification system to prepare mobile bed A. Then, the sample to be measured was diluted to a concentration of 2 mg / mL in THF (stabilized with BHT), dissolved at a temperature of 50 °C for 6 hours, and then filtered through a PVDF filter (pore size: 0.45 μm) to prepare a sample solution.

[0082] (2) GPC measurement conditions - Fixed bed: 3 x Agilent PLgel MIXED-C, 7.5 x 300 mm, 5 μm - Moving bed A: THF (stabilized with BHT) = 100 (w / v, %) - Flow rate: 1.0 mL / min - Fixed bed temperature: 40 °C - Injection volume: 100 μl (0.45 μm filter) - Analysis time: 35 minutes - Standard: Polystyrene

[0083] Example 2 [Chemical formula] 61.36 g of styrene, 20.84 g of acrylonitrile, 10 g of the polymerizable antibacterial monomer 1-1 produced in Production Example 1, and 1.70 g of azobisisobutyronitrile (AIBN) as a polymerization initiator were dissolved in 153.66 mL of N,N-dimethylformamide (DMF) as a solvent, and then polymerization was carried out using a magnetic bar at 80 °C and under air conditions for 4 hours. The reaction was terminated when the polymerization conversion rate reached 80%. Thereafter, the reacted solution was cooled to room temperature, precipitated in a sufficient amount of water, and then vacuum dried to obtain a solid powder copolymer SAN-co-(A-BA) resin.

[0084] The weight average molecular weight of the produced SAN-co-(A-BA) resin was 31,468 g / mol when measured according to the method described in Example 1, and the molar ratio (x:y:z) of the repeating units derived from styrene, the repeating units derived from acrylonitrile, and the repeating units derived from the polymerizable antibacterial monomer was 0.57:0.38:0.05.

[0085] Example 3 [Chemical formula] 4.878 g of styrene, 1.657 g of acrylonitrile, 15 g of the polymerizable antibacterial monomer 1-2 produced in Production Example 2, and 0.26 g of azobisisobutyronitrile (AIBN) as a polymerization initiator were dissolved in 35.89 mL of N,N-dimethylformamide (DMF) as a solvent. Then, polymerization was carried out using a magnetic bar at 80 °C and under air conditions for 4 hours, and the reaction was terminated when the polymerization conversion rate reached 80%. Thereafter, the solution after the reaction was cooled to room temperature, precipitated in a sufficient amount of water, and then vacuum dried to obtain a solid powder copolymer SAN-co-(2-A-BA) resin.

[0086] When the weight average molecular weight of the produced SAN-co-(2-A-BA) resin was measured as described in the method of Example 1, it was 78,568 g / mol, and the molar ratio (x:y:z) of the repeating unit derived from styrene, the repeating unit derived from acrylonitrile, and the repeating unit derived from the polymerizable antibacterial monomer was 0.32:0.23:0.45.

[0087] Example 4

Chemical formula

[0088] The weight-average molecular weight of the produced SAN-co-(2-A-BA) resin was 25,187 g / mol when measured as per the method described in Example 1, and the molar ratio (x:y:z) of the repeating units derived from styrene, the repeating units derived from acrylonitrile, and the repeating units derived from the polymerizable antibacterial monomer was 0.58:0.39:0.03.

[0089] Comparative Example 1

Chemical formula

[0090] The weight-average molecular weight of the produced SAN resin was 37,266 g / mol when measured as per the method described in Example 1, and the molar ratio (x:y) of the repeating units derived from styrene and the repeating units derived from acrylonitrile was 0.6:0.4.

[0091] Comparative Example 2 For comparison of the antibacterial properties with the SAN resin produced in the examples, ABS HF380 (manufactured by LG Chem), a commercialized ABS resin, was used in Comparative Example 2.

[0092] Comparative Example 3

Chemical formula

[0093] The weight-average molecular weight of the produced SAN-co-(4-VBA) resin was 147,822 g / mol when measured according to the method described in Example 1, and the molar ratio (x:y:z) of the repeating unit derived from styrene, the repeating unit derived from acrylonitrile, and the repeating unit derived from the polymerizable antibacterial monomer was 0.3:0.2:0.5.

[0094] Experimental Example 1 The antibacterial properties of each of the SAN resins produced in the above Examples and Comparative Examples against Escherichia coli (E. coli, ATCC25922) were measured by the following method based on ASTM E2149 (Shake Flask Method).

[0095] Specifically, after the bacteria were allowed to contact the sample to be tested for a certain period of time, they were recovered and cultured in a medium, and then the bacteriostatic rate was calculated by comparing the colony forming unit (CFU) with the control group (Control; SAN resin of Comparative Example 1). The medium required for the antibacterial test, the method for producing the test group, and the detailed method of the antibacterial test are as follows.

[0096] [Medium Production] In the case of a liquid medium, 8 g of NB broth and 1 L of distilled water were placed in a 2 L container, dissolved sufficiently, and then sterilized in a high-temperature and high-pressure sterilizer at a steam pressure of 103 kPA and (120 ± 2) °C for 20 minutes.

[0097] In the case of a solid medium, 8 g of NB broth, 25 g of agar powder, and 1 L of distilled water were placed in a 2 L container and stirred with a spoon or heated to dissolve. Since the agar powder attached to the wall did not dissolve even at the high temperature during the sterilization process, care was taken not to dissolve it by shaking. Then, it was sterilized under the same conditions as the liquid medium. Since NB broth solidifies at 40 °C, after sterilization, when the temperature dropped to 60 °C, the solution was poured into 90 mm diameter Petri dishes in 25 mL portions and solidified.

[0098] [Test group culture] (1) A part of the stored strain was transplanted into 10 mL of liquid medium using a loop and suspension-cultured at (37 ± 1) °C for 18 to 24 hours using a shaking incubator. (2) The bacteria cultured in liquid form were centrifuged at 2000 rpm for 3 minutes to separate only the bacteria from the medium, and then diluted with 1X PBS so that the OD value (optical density) was 1 at a wavelength of 600 nm. The CFU value of Escherichia coli at OD 600nm = 0.45 was 2*10 8 CFU / mL.

[0099] [Bacteriostatic rate measurement] (1) 0.5 g of a powdered or liquid antibacterial sample and 25 mL of bacteria with a CFU concentration of 10 5 (1X PBS 25 mL, 250 μL of bacteria with an OD 600nm = 0.45 value) were added to a 50 mL conical tube. As a control test piece, the remaining (bacteria, PBS) excluding the antibacterial sample was prepared in a 50 mL conical tube. (2) The prepared samples were suspension-cultured at (37 ± 1) °C for 18 to 24 hours using a shaking incubator. (3) The samples after the bacterial culture were diluted 1-fold, 10-fold, and 100-fold, inoculated into the agar solid medium in 100 μL portions each, and then spread using a spreader or glass beads until absorbed by the medium. (4) The solid medium was statically cultured at (37 ± 1) °C for 24 to 48 hours. (5) Among the 1-fold, 10-fold, and 100-fold diluted samples, the colonies on the Petri dish with 30 - 300 bacterial colonies were counted and recorded. Then, the bacteriostatic rate (%) was determined by calculating, using the following Mathematical Formula 1, the percentage decrease in the number of CFU of the sample relative to the control group. After conducting the test three times repeatedly, the obtained average value was shown in Table 1 below. [Mathematical Formula 1] Bacteriostatic rate (%) = [1 - (number of bacteria in the test group / number of bacteria in the control group)] × 100 In the above Mathematical Formula 1, The number of bacteria in the test group is the number of antibacterial test bacteria in the resin of each example and comparative example The number of bacteria in the control group is the number of bacteria after the antibacterial test with the resin of Comparative Example 1

[0100]

Table 1

[0101] Referring to Table 1 above, it can be confirmed that the SAN-co-(A-BA) and SAN-co-(2-A-BA) resins of the examples exhibit excellent antibacterial properties against Escherichia coli, which is one of the Gram-negative bacteria, compared to the resins of the comparative examples that do not contain repeating units derived from the polymerizable antibacterial monomer represented by Chemical Formula 1.

[0102] In particular, in the case of the SAN-co-(4-VBA) resin of Comparative Example 3 produced using 4-vinylbenzoic acid instead of the polymerizable antibacterial monomers produced in Production Examples 1 and 2, it can be seen that it exhibits significantly lower antibacterial properties compared to the resins of the examples.

[0103] Thus, it can be understood that when the SAN resin further contains repeating units derived from the polymerizable antibacterial monomer represented by Chemical Formula 1 in addition to repeating units derived from styrene-based monomers and repeating units derived from acrylonitrile-based monomers, it is excellent in antibacterial properties compared to the case where it further contains repeating units derived from monomers having other carboxy groups such as 4-vinylbenzoic acid.

Claims

1. It contains a repeating unit derived from a monomer represented by the following Chemical Formula 1, a repeating unit derived from a styrene monomer, and a repeating unit derived from an acrylonitrile monomer, with a weight average molecular weight of 25,000 to 95,000 g / mol, an antibacterial SAN resin. 【Chemical 1】 In the above Chemical Formula 1, R １ or R ３ is each independently hydrogen or alkyl having 1 to 4 carbon atoms, A is an aromatic ring having 6 to 60 carbon atoms which is unsubstituted or substituted with one or more substituents selected from alkyl having 1 to 10 carbon atoms, alkoxy having 1 to 10 carbon atoms, deuterium, halogen, hydroxy, and carboxy groups.

2. The repeating unit derived from the monomer represented by the above Chemical Formula 1 is contained in an amount of 0.01 to 0.7 mol based on 1 mol of the antibacterial SAN resin, The antibacterial SAN resin according to Claim 1.

3. In the above Chemical Formula 1, A is a benzene ring which is unsubstituted or substituted with one or more substituents selected from alkyl having 1 to 4 carbon atoms, hydroxy, and carboxy groups, The antibacterial SAN resin according to Claim 1.

4. The monomer represented by the above Chemical Formula 1 is any one selected from the following, The antibacterial SAN resin according to Claim 1. [Chemical 2]

5. The styrene monomer is one or more selected from styrene, α-methylstyrene, β-methylstyrene, p-methylstyrene, p-tert-butylstyrene, o-bromostyrene, o-chlorostyrene, m-bromostyrene, m-chlorostyrene, p-bromostyrene, and p-chlorostyrene, The antibacterial SAN resin according to Claim 1.

6. The acrylonitrile monomer is one or more selected from acrylonitrile, methacrylonitrile, and ethacrylonitrile, The antibacterial SAN resin according to Claim 1.

7. The repeating unit derived from the styrene monomer and the repeating unit derived from the acrylonitrile monomer are contained in a molar ratio of 5:5 to 9:1, The antibacterial SAN resin according to Claim 1.

8. The antibacterial SAN resin exhibits antibacterial properties against at least one of Gram-negative bacteria and Gram-positive bacteria, The antibacterial SAN resin according to Claim 1.

9. The Gram-negative bacteria are Proteus mirabilis or Escherichia coli, The Gram-positive bacterium is Enterococcus faecalis or Staphylococcus aureus. The antibacterial SAN resin according to claim 8.

10. In the presence of a polymerization initiator, a monomer represented by the following Chemical Formula 1, a styrene monomer, and an acrylonitrile monomer are polymerized at a temperature of 60°C to 90°C for 3 hours to 8 hours, including the step of polymerization. A method for producing an antibacterial SAN resin. 【Chemical Formula 3】 In the Chemical Formula 1, R １ or R ３ is, independently of one another, hydrogen or alkyl having 1 to 4 carbon atoms, A is an aromatic ring having 6 to 60 carbon atoms which is unsubstituted or substituted with one or more substituents selected from alkyl having 1 to 10 carbon atoms, alkoxy having 1 to 10 carbon atoms, deuterium, halogen, hydroxy, and carboxy groups.

11. The polymerization is carried out until the polymerization conversion rate reaches 50 to 90%. The method for producing an antibacterial SAN resin according to claim 10.

12. The antibacterial SAN resin according to any one of claims 1 to 9, and an ABS resin, An antibacterial ABS resin composition.

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