Hybrid antibacterial agent and method for producing the same, and antibacterial resin and method for producing the same

Abstract

To maintain deodorizing performance, while achieving superior heat resistance and compatibility with resins, and enabling long-term persistence of antibacterial effect.SOLUTION: The hybrid antibacterial agent comprises a low-crystallinity silica-zinc-aluminum composite represented by the chemical formula aSiO2 bZnO Al2O3 (where a=0.08-80 and b=0.5-65), and a quaternary ammonium compound supported on the silica-zinc-aluminum composite.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a hybrid antibacterial agent that combines inorganic and organic antibacterial agents and a method for producing the same, as well as an antibacterial resin that contains the hybrid antibacterial agent and a method for producing the same. [Background technology]

[0002] Silica zinc aluminum composite compounds are porous compounds in which silica (Si), zinc (Zn), and aluminum (Al) are composited, and are known to exhibit deodorizing properties as well as antibacterial properties derived from zinc. For example, Patent Document 1 describes a silica zinc aluminum composite compound represented by mSiO2·nZnO·Al2O3 (wherein m is 0.08 to 80 and n is 0.5 to 65) and containing 100m 2 / g or more and a BET specific surface area of ​​0.2 to 1.0 cm 3 This patent discloses an antibacterial agent comprising low-crystalline silica-zinc-aluminum composite particles having a pore volume of 10 ...

[0003] On the other hand, organic antibacterial agents have high antibacterial performance but have the disadvantage of low heat resistance. For example, when blended with a resin, if the organic antibacterial agent is heated to the melting temperature of the resin and kneaded, the organic antibacterial agent is denatured and its antibacterial activity is reduced. For this reason, organic antibacterial agents are not suitable for use as resin additives. To overcome the disadvantages of inorganic and organic antibacterial agents alone, antibacterial agents that combine the two are known.

[0004] Patent Document 2 discloses an antibacterial agent consisting of a complex composed of a long-chain alkyl quaternary ammonium compound and a honeycomb-like network of silica walls surrounding the quaternary ammonium compound, with an X-ray diffraction peak at a diffraction angle of 2.2 to 4.4° (Cu-α). The strong antibacterial quaternary ammonium compound compensates for the weak antibacterial activity of inorganic antibacterial agents. The antibacterial agent in Patent Document 2 sustains its antibacterial activity by gradually releasing the active ingredient, quaternary ammonium, (Figure 13 of Patent Document 2). This sustained release is due to physical, rather than ionic, adsorption of the quaternary ammonium compound onto the silica, resulting in weak retention of the quaternary ammonium compound and sustained release. However, depending on the conditions of use, this sustained-release antibacterial agent may dissolve most of the active ingredient early, potentially resulting in a loss of antibacterial activity.

[0005] Patent Document 3 discloses an antibacterial composition comprising an amorphous composite in which antibacterial quaternary ammonium ions are complexed with silicon dioxide and zinc oxide. Patent Document 4 discloses an antibacterial composition comprising amorphous silicon dioxide complexed with antibacterial quaternary ammonium ions. However, in the antibacterial agents of Patent Documents 3 and 4, the quaternary ammonium ions in the reaction system are incorporated into the gel skeleton in the form of ions or silicates to form a complex (paragraphs 0010 of Patent Documents 3 and 4). For this reason, it is presumed that the quaternary ammonium is encapsulated within the inorganic support without ion adsorption. The outer surface of the inorganic support is hardly coated with the quaternary ammonium, and the antibacterial agents of Patent Documents 3 and 4 cannot be expected to improve compatibility with resins or solvents.

[0006] If the compatibility between the antibacterial agent and the resin is poor, large aggregates of the powdery or granular antibacterial agent will occur when the resin is melt-kneaded after adding the antibacterial agent, which will clog the filter (screen mesh) used to remove foreign matter, increasing the internal pressure of the molding machine and placing a heavy burden on the equipment.

[0007] Patent Document 5 discloses an antibacterial and antifungal aluminum silicate containing a compound containing a quaternary ammonium ion. The stable release of the compound in a sustained release manner provides sustained antibacterial, antifungal, antiseptic, and antialgal effects (Patent Document 5, paragraph 0049). Specifically, the antibacterial and antifungal aluminum silicate of Patent Document 5 is a sustained-release antibacterial agent that utilizes the amorphous aluminum silicate carrier (paragraph 0040) that exhibits no or weak structural adsorption to quaternary ammonium ions. Therefore, similar to Patent Document 2, if most of the active ingredient is released prematurely, the antibacterial effect cannot be exerted thereafter. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2016-108286 A [Patent Document 2] JP 2001-26504 A [Patent Document 3] Japanese Patent Application Publication No. 9-110607 [Patent Document 4] Japanese Patent Application Publication No. 10-25206 [Patent Document 5] JP 2011-148754 A Summary of the Invention [Problem to be solved by the invention]

[0009] Therefore, an object of the present invention is to provide a hybrid antibacterial agent having excellent heat resistance, whiteness, and resin compatibility, a method for producing the same, an antibacterial resin using the hybrid antibacterial agent, and a method for producing the same, as well as a hybrid antibacterial agent and a method for producing the same, which maintain antibacterial function for a long period of time, and an antibacterial resin and a method for producing the same. [Means for solving the problem]

[0010] The hybrid antibacterial agent of the present invention is composed of a low-crystalline silica-zinc-aluminum complex represented by the chemical formula: aSiO2·bZnO·Al2O3 (wherein a = 0.08 to 80, b = 0.5 to 65) and a quaternary ammonium compound supported on the silica-zinc-aluminum complex.

[0011] The hybrid antibacterial agent of the present invention exhibits higher heat resistance than a silica-zinc-aluminum composite (inorganic support) alone, or than an antibacterial agent composed of, for example, amorphous silicon dioxide and a quaternary amine compound. That is, it maintains high antibacterial activity and whiteness even after heat treatment. Furthermore, the hybrid antibacterial agent of the present invention has higher resin compatibility than a silica-zinc-aluminum composite alone. Therefore, the hybrid antibacterial agent of the present invention is ideal for use as a resin additive at high temperatures. Furthermore, in the present invention, the quaternary amine compound is firmly supported on the silica-zinc-aluminum composite by ion exchange adsorption rather than physical adsorption. Therefore, the quaternary amine compound is hardly eluted even under environments where strong external factors (fluid, friction, heat, light, etc.) are applied, and the antibacterial activity can be effectively maintained for a longer period of time than conventional sustained-release antibacterial agents.

[0012] In an embodiment of the hybrid antibacterial agent according to the present invention, the silica zinc aluminum complex is supported with 0.5 to 30% by weight of a quaternary ammonium compound. In thermogravimetric analysis, substantial weight loss occurs at temperatures above 200°C. The hybrid antimicrobial agent, when heated at a temperature at which no substantial weight loss occurs, has a whiteness index of 85 or greater. In X-ray diffraction (XRD) analysis, it does not have a diffraction peak in the region of interplanar spacing of 6.40 to 8.40 Å, but has a diffraction peak in the region of interplanar spacing of 2.56 to 2.71 Å. The quaternary ammonium compound is one or more selected from alkyldimethylbenzylammonium chloride (benzalkonium chloride), or N,N'-hexamethylenebis(4-carbamoyl-1-decylpyridinium acetate) (dimer 38A).

[0013] The antibacterial resin of the present invention is an antibacterial resin obtained by blending the hybrid antibacterial agent with a thermoplastic resin, and the hybrid antibacterial agent has higher compatibility with the thermoplastic resin than a silica-zinc-aluminum composite. Because the antibacterial resin of the present invention contains the hybrid antibacterial agent with high whiteness, it does not adversely affect the color tone after processing, and can form resin molded articles and resin films with excellent design.

[0014] The method for producing the hybrid antibacterial agent of the present invention includes the steps of: mixing sodium silicate, zinc sulfate, and sodium aluminate in the presence of water to produce a low-crystalline silica-zinc-aluminum complex represented by the chemical formula aSiO2·bZnO·Al2O3 (wherein a = 0.08 to 80, b = 0.5 to 65); and adding a quaternary ammonium compound to the produced silica-zinc-aluminum complex, followed by stirring, filtering, and drying to support the quaternary ammonium compound on the silica-zinc-aluminum complex.

[0015] In an embodiment of the method for producing a hybrid antibacterial agent according to the present invention, the step of producing a silica zinc aluminum complex comprises mixing sodium silicate, zinc sulfate, and sodium aluminate in the presence of water and filtering the resulting precipitate, and the step of supporting a quaternary ammonium compound on the silica zinc aluminum complex comprises adding a quaternary ammonium compound to a slurry in which the produced silica zinc aluminum complex is dispersed in water. After the step of filtering the resulting precipitate, the method further includes a step of drying the precipitate and pulverizing the resulting dry cake.

[0016] The method for producing an antibacterial resin of the present invention includes the steps of adding the hybrid antibacterial agent obtained by the above-mentioned production method to a thermoplastic resin raw material and kneading the mixture under heat, and contacting the thermoplastic resin raw material with a quaternary ammonium compound by kneading to disperse the hybrid antibacterial agent in the thermoplastic resin with good compatibility without generating agglomerates.In the method for producing an antibacterial resin of the present invention, the hybrid antibacterial agent of the present invention, which has excellent compatibility with the resin, is used, so agglomerations are less likely to occur during resin melt-kneading, there is no clogging of the foreign matter removal filter, and pressure increases inside the molding machine can be suppressed. [Effects of the Invention]

[0017] The hybrid antibacterial agent of the present invention has excellent heat resistance and maintains high antibacterial activity and whiteness even after heat treatment, allowing for the formation of high-quality resin processed products. It also has good resin compatibility, reducing the equipment load on resin molding machines and reducing the effort and cost of equipment maintenance. Furthermore, the antibacterial component, the quaternary ammonium compound, is not easily eluted, allowing for sustained antibacterial activity. This makes the agent ideal for applications where elution of the antibacterial component is undesirable, applications in locations where maintenance is difficult, and applications in environments subject to strong external forces. [Brief explanation of the drawings]

[0018] [Figure 1] Graph showing X-ray diffraction patterns of the hybrid antibacterial agent of the present invention [Figure 2A] Graph showing the results of thermogravimetry for the hybrid antibacterial agent of the present invention. [Figure 2B] Graph showing the results of differential thermal analysis of the hybrid antibacterial agent of the present invention. [Figure 2C] Graph showing the results of thermogravimetry for the hybrid antibacterial agent of the present invention. [Figure 2D] Graph showing the results of differential thermal analysis of the hybrid antibacterial agent of the present invention. [Figure 2E] Graph showing the results of thermogravimetry for the hybrid antibacterial agent of the present invention. [Figure 2F] Graph showing the results of differential thermal analysis of the hybrid antibacterial agent of the present invention. [Figure 3] Graph showing the results of deodorizing tests on ammonia (A) and hydrogen sulfide (B) for the hybrid antibacterial agent of the present invention. [Figure 4] Graph showing the change in pressure inside a molding machine due to the addition of the hybrid antibacterial agent of the present invention DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, embodiments of the hybrid antibacterial agent and its manufacturing method, and the antibacterial resin and its manufacturing method according to the present invention will be described. The following embodiments are merely examples and should not be construed as limiting the present invention.

[0020] The hybrid antibacterial agent of the present invention is composed of a low-crystalline silica-zinc-aluminum complex (inorganic support) represented by the chemical formula aSiO2·bZnO·Al2O3 (where a = 0.08 to 80, b = 0.5 to 65) and a quaternary ammonium compound (antibacterial component) supported on the silica-zinc-aluminum complex, and has excellent deodorizing properties, heat resistance, resin compatibility, whiteness, antibacterial activity, and antibacterial durability. The hybrid antibacterial agent of the present invention can be incorporated into materials and used in applications such as home appliances, kitchen utensils, toiletries, toys, paper products, leather products, stationery, building materials, housing supplies, and packaging.

[0021] The low-crystalline silica-zinc-aluminum composite of the inorganic support is crystallized to a low level. The low crystallinity is due to the complexation of the SiO2, ZnO, and Al2O3 components, and its structure can be confirmed by X-ray diffraction (XRD) analysis. Figure 1 is a graph showing the X-ray diffraction patterns of the hybrid antibacterial agent of the present invention and the silica-zinc-aluminum composite alone, measured using an X-ray diffractometer (Rigaku Ultima 4) against the diffraction peak of natural flypontite (zinc aluminophyllosilicate) according to the 1974 ASTM card.

[0022] Flypontite has a basic skeleton consisting of a two-layer structure consisting of SiO4-AlO4 tetrahedral layers and ZnO6-AlO6 octahedral layers. As shown in Figure 1, the intensity (vertical axis in Figure 1) of the diffraction peak (diffraction peak with plane index

[0001] ) is maximum at a plane spacing of 7.0 Å (2θ (horizontal axis in Figure 1) = 12.6°), which indicates the regular stacking of the basic two-layer structure in the C-axis direction. It also has diffraction peaks at plane spacings of 3.52 Å (2θ = 25.3°) and 2.63 Å (2θ = 34.0°). On the other hand, in the diffraction patterns shown in Figure 1 for the hybrid antibacterial agent (Examples 1 and 6 described below) and the silica-zinc-aluminum composite alone (Comparative Example 1 described below), there is no diffraction peak in the region of 6.40 to 8.40 Å (2θ = 13.8 to 10.5°), which corresponds to a 7.0 Å interplanar spacing diffraction peak, but there is a loose diffraction peak in the region of 2.56 to 2.71 Å (2θ = 35.0 to 33.0), which corresponds to a 2.63 Å interplanar spacing. This indicates that the hybrid antibacterial agent and the silica-zinc-aluminum composite alone of the present invention are similar to flypontite, but are less crystallized without stacking in the C-axis direction of the basic two-layer structure, and have a loose crystalline structure like a layered clay mineral.

[0023] Furthermore, the hybrid antibacterial agent of the present invention (Example 1) exhibits a diffraction peak at a lattice spacing of 8.58 to 9.30 Å (2θ (horizontal axis in FIG. 1) = 10.3 to 9.5°), a region where no diffraction peak is present in flypontite and the silica-zinc-aluminum composite alone (Comparative Example 1) and conventional antibacterial agents (FIG. 4 in Patent Document 2, FIG. 1 in Patent Document 3, and FIG. 1 in Patent Document 4). This structure is thought to be a result of the hybrid antibacterial agent of the present invention supporting a quaternary ammonium compound (benzalkonium chloride in this embodiment) and changing the structure of the silica-zinc-aluminum composite. Specifically, it is thought to be a structure in which the quaternary ammonium compound is encapsulated in the silica-zinc-aluminum composite and ion-adsorbed. However, in the hybrid antibacterial agent of the present invention (Example 6), as shown in FIG. 1, no diffraction peak is observed at 8.58 to 9.30 Å (2θ = 10.3 to 9.5°), and therefore this diffraction peak cannot be said to be a characteristic common to the entire range of the present invention. Regardless of the presence or absence of a diffraction peak between 8.58 and 9.30 Å, in the hybrid antibacterial agent of the present invention, the quaternary amine compound is firmly supported on the silica zinc aluminum composite and is difficult to elute, allowing the antibacterial activity to be maintained for a long period of time.

[0024] The quaternary ammonium compound of the antibacterial component is one or more amine-based quaternary ammonium compounds selected from alkyldimethylbenzylammonium chloride (benzalkonium chloride), benzethonium chloride, decyltrimethylammonium chloride, dodecyltrimethylammonium chloride, tridodecylmethylammonium chloride, tetradecyltrimethylammonium chloride, hexadecyltrimethylammonium chloride, octadecyltrimethylammonium chloride, didecyldimethylammonium chloride, hexadecyldimethylbenzylammonium chloride, hexadecyltrimethylammonium bromide, or any derivative thereof. The quaternary ammonium compound is one or more pyridine-based quaternary ammonium compounds selected from N,N'-hexamethylenebis(4-carbamoyl-1-decylpyridinium acetate) (dimer 38A), N,N'-hexamethylenebis(4-carbamoyl-1-decylpyridinium bromide) (dimer 38), 4,4'-(tetramethylenedicarbonyldiamino)bis(1-decylpyridinium acetate) (dimer 136A), 4,4'-(tetramethylenedicarbonyldiamino)bis(1-decylpyridinium bromide) (dimer 136), or any derivative thereof.

[0025] In particular, alkyldimethylbenzylammonium chloride (benzalkonium chloride) shown in the following chemical formula 1 (wherein R = -CH) is used as a quaternary ammonium compound because of its easy availability and simple structure. 17 ~-C 18 H 37 In the present invention, it is preferred to use N,N'-hexamethylenebis(4-carbamoyl-1-decylpyridinium acetate) (dimer 38A) shown in Chemical Formula 2. [ka] [ka]

[0026] In the hybrid antibacterial agent of the present invention, the quaternary ammonium compound is supported in an amount of 0.5 to 30% by weight relative to the silica-zinc-aluminum composite. If the amount is less than 0.5% by weight, the amount of active ingredient is small and sufficient antibacterial activity is not obtained. If the amount exceeds 30% by weight, the heat resistance of the hybrid antibacterial agent decreases, and the maximum support rate that can be supported on the silica-zinc-aluminum composite is exceeded, making it impossible to support any more quaternary ammonium compound in terms of volume. Preferably, the support rate of the quaternary ammonium compound relative to the silica-zinc-aluminum composite is 0.9 to 27% by weight.

[0027] The antibacterial properties of the present invention are primarily due to the antibacterial activity of the hybrid antibacterial agent itself. Specifically, this is due to the antibacterial activity of the supported quaternary ammonium compound and the antibacterial activity derived from the zinc in the silica-zinc-aluminum composite particles as an inorganic support. A small amount of elution from the quaternary ammonium compound also contributes to the antibacterial activity. However, as described below, the amount of elution is extremely small in the present invention compared to conventional sustained-release antibacterial agents. Therefore, the hybrid antibacterial agent of the present invention retains its active ingredient and maintains its antibacterial activity for a long period of time, making it ideal for applications where elution is undesirable (e.g., continuous adsorption treatment) or where maintenance is difficult (e.g., incorporation into resin materials at high altitudes). The antibacterial properties include, for example, antibacterial activity against bacteria, fungi, protozoa, viruses, etc., and bacterial growth inhibition.

[0028] Regarding heat resistance, the hybrid antibacterial agent of the present invention undergoes substantial weight loss at temperatures of 200°C or higher, 220°C or higher, or 240°C or higher in thermogravimetry. In other words, up to temperatures of 200°C, 220°C, or 240°C, no weight loss occurs, the hybrid antibacterial agent does not denature, and heat resistance is maintained. For this reason, the hybrid antibacterial agent of the present invention is ideal for applications such as the production of antibacterial resins to be added to resins at temperatures of 200°C or lower, 220°C or lower, or 240°C or lower. This is thought to be because the bond between the silica-zinc-aluminum complex and the quaternary ammonium compound is ionic adsorption rather than physical adsorption, which increases the thermal decomposition onset temperature of the hybrid antibacterial agent.

[0029] Regarding whiteness, the hybrid antibacterial agent of the present invention, when heated at a temperature at which no substantial weight loss occurs, has a whiteness of 85 or more or 90 or more. For example, when the hybrid antibacterial agent of the present invention is heat-treated for 1 hour at approximately 200°C, a temperature at which no substantial weight loss occurs, the whiteness value remains almost the same as before the heat treatment, and the appearance remains white without developing burnt colors such as brown or black. Therefore, when the hybrid antibacterial agent is mixed with other materials under heating, the color and design of the final product are not impaired.

[0030] The antibacterial resin of the present invention using the hybrid antibacterial agent will be described in detail below. The antibacterial resin of the present invention is obtained by blending the hybrid antibacterial agent with a thermoplastic resin. The thermoplastic resin has higher compatibility with quaternary ammonium compounds than the silica-zinc-aluminum composite used as an inorganic support. The quaternary ammonium compound, which has high compatibility with the resin, is mainly coated on the outer surface of the hybrid antibacterial agent, so the thermoplastic resin and the hybrid antibacterial agent are easily mixed, and aggregation and clumping due to poor mixing are unlikely to occur.

[0031] The resin raw material applicable to the antibacterial resin of the present invention is not limited as long as it is a thermoplastic resin, and examples thereof include polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), polystyrene (PS), polyvinyl acetate (PVAC), polyvinyl alcohol (PVAL), polyvinyl butyral (PVB), polyurethane (PUR), polytetrafluoroethylene (PTFE), acrylonitrile butadiene styrene copolymer resin (ABS), acrylonitrile styrene copolymer resin (AS), acrylic resin (PMMA), polyamide (PA), nylon 6 (PA6), nylon 7 (PA7), nylon 8 (PA8), nylon 9 (PA9), nylon 10 (PA10), nylon 11 (PA11), nylon 12 (PA12), nylon 13 (PA13), nylon 14 (PA14), nylon 15 (PA15), nylon 16 (PA16), nylon 17 (PA17), nylon 18 (PA18), nylon 19 (PA19), nylon 20 (PA19), nylon 21 (PA19), nylon 22 (PA19), nylon 23 (PA19), nylon 24 (PA19), nylon 25 (PA19), nylon 26 (PA19), nylon 27 (PA19), nylon 28 (PA19), nylon 29 (PA19), nylon 30 (PA19), nylon 31 (PA19), nylon 32 (PA19), nylon 33 (PA19), nylon 34 (PA19), nylon 35 (PA19), nylon 36 (PA19), nylon 37 (PA19), nylon 38 (PA19), nylon 40 (PA19), nylon 41 (PA19), nylon 42 (PA19), nylon 43 (PA19), nylon 44 (PA19), nylon 45 (PA19), nylon 46 (PA19), nylon 47 (PA19), nylon The antibacterial resin of the present invention is preferably one or more selected from the group consisting of polyolefin 66 (PA66), polyacetal (POM), polycarbonate (PC), polyphenylene ether (PPE), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), cyclic polyolefin (COP), polyphenylene sulfide (PPS), polytetrafluoroethylene (PTFE), polysulfone (PSF), polyethersulfone (PES), amorphous polyarylate (PAR), liquid crystal polymer (LCP), polyetheretherketone (PEEK), polyimide (PI), polyamideimide (PAI), and derivatives thereof. The raw material of the antibacterial resin of the present invention is preferably a polyolefin resin, more preferably polypropylene (PP) or polyethylene (PE).

[0032] The method for producing the hybrid antibacterial agent according to the present invention will now be described in detail. First, sodium silicate (Na2SiO3), zinc sulfate (ZnSO4), and sodium aluminate (NaAlO2) are dispersed in water in separate containers to prepare individual slurries. The prepared sodium silicate, zinc sulfate, and sodium aluminate slurries are mixed by simultaneous addition in the presence of water, and a metathesis reaction is carried out at a temperature of 50°C or less to prevent crystallization. The water content is adjusted to a pH of 6.0 to 9.5, and the resulting precipitate is filtered, washed with water, dried, and pulverized to obtain a low-crystalline silica-zinc-aluminum composite with the chemical formula: aSiO2·bZnO·Al2O3 (where a = 0.08 to 80, b = 0.5 to 65). The resulting silica-zinc-aluminum composite particles have a BET specific surface area of ​​100 m 2 / g or more, especially 200-350m 2 / g, and the pore volume of pores with a diameter of 1.7 to 300 nm is 0.2 to 1.0 cm 3 / g, especially 0.3-0.8cm 3 / g.

[0033] Alternatively, the silica zinc aluminum composite may be obtained from the precipitate produced by the reaction in a pre-filtered state (referred to as the "reaction liquid") without undergoing any of the steps of filtration, water washing, drying, and pulverization. Alternatively, the silica zinc aluminum composite may be obtained from the precipitate produced by the reaction in an unpulverized state by filtering, washing with water, and drying. Alternatively, the silica zinc aluminum composite may be obtained from the precipitate produced by the reaction in an unpulverized state by filtering and washing with water (without drying), or by filtering (without washing with water and drying). In other words, any of the silica zinc aluminum composites produced by the reaction before filtration, after filtration, after water washing, after drying, and after pulverization can be applied to the hybrid antibacterial agent and its production method of the present invention.

[0034] The silica-zinc-aluminum composite itself exhibits antibacterial properties due to the ZnO component, but to further enhance its antibacterial properties, a quaternary ammonium compound is supported on it. Specifically, an appropriate amount of a quaternary ammonium compound is added to the resulting reaction solution. Alternatively, the reaction solution is filtered, washed with water, and dried to obtain a slurry in which a crushed or uncrushed silica-zinc-aluminum composite is dispersed in water, and an appropriate amount of a quaternary ammonium compound is added to the slurry. The resulting slurry is then stirred, filtered, washed with water, and dried to support the quaternary ammonium compound on the silica-zinc-aluminum composite. This results in a hybrid antibacterial agent in which 0.5 to 30 wt %, preferably 0.9 to 27.0 wt %, of the quaternary ammonium compound is supported on the silica-zinc-aluminum composite.

[0035] The method for producing the antibacterial resin according to the present invention will now be described. A thermoplastic resin raw material, a hybrid antibacterial agent, and an appropriate antiblocking agent (AB agent) are mixed and kneaded in a molding machine while heating to a temperature above the melting point of the thermoplastic resin and below the thermal decomposition point of the hybrid antibacterial agent (40°C to 200°C, 220°C, or 240°C). Kneading allows the thermoplastic resin and the quaternary ammonium compound supported on the hybrid antibacterial agent to smoothly and affinitively contact each other, resulting in a highly compatible mixture with almost no formation of aggregates. This results in an antibacterial resin in which the hybrid antibacterial agent is dispersed and blended within the molten thermoplastic resin. In the present invention, because aggregates are less likely to form, foreign matter removal filters do not clog and pressure increases are suppressed, reducing the frequency of equipment maintenance. [Example]

[0036] Examples (the present invention) and comparative examples (prior art) will be compared and explained below.

[0037] [Examples 1 to 8: Hybrid antibacterial agent of the present invention] Solution A was prepared by dissolving 600 g of No. 3 sodium silicate (SiO2: 22.9%, Na2O: 7.3%) in water to a total volume of 1 L, and 100 g of zinc oxide and 100 cm3 of 75% sulfuric acid were used. 3Solution B, which was prepared by dissolving 105 g of sodium aluminate (Al2O3: 23.8%, Na2O: 19.2%) in water to a total volume of 1 L, and solution C, which was prepared by dissolving 33 g of 49% sodium hydroxide in water to a total volume of 0.5 L, were simultaneously poured into a vessel containing 2 L of water. The liquid temperature was maintained at approximately 35°C while stirring, and 6.4 g of 49% sodium hydroxide was added. After further stirring and aging for 20 hours, the precipitate was filtered, washed with water, and dried at 140°C. The resulting dried cake was pulverized to produce low-crystalline silica-zinc-aluminum composite particles with the chemical formula: aSiO2·bZnO·Al2O3 (where a = 0.08-80, b = 0.5-65).

[0038] The resulting silica-zinc-aluminum complex was dispersed in water to form a slurry, to which commercially available benzalkonium chloride (BAC) as a quaternary ammonium compound was added in an amount of 10% by weight relative to the silica-zinc-aluminum complex, to prepare a slurry containing the hybrid antibacterial agent of the present invention. The resulting slurry was stirred, filtered, washed with water, and dried to produce the hybrid antibacterial agent of the present invention (Example 1). Using a similar method, hybrid antibacterial agents of the present invention were produced by adding 30% and 1% by weight of benzalkonium chloride relative to the silica-zinc-aluminum complex (Examples 2 and 3), respectively. Furthermore, using a similar method, commercially available dimer 38A was added in an amount of 10% by weight relative to the silica-zinc-aluminum complex to produce the hybrid antibacterial agent of the present invention (Example 4).

[0039] The process was the same as in Examples 1 to 4, but the 20-hour aging process was omitted, resulting in a low-crystalline silica-zinc-aluminum composite represented by the above chemical formula as a reaction solution before filtration. Subsequently, commercially available benzalkonium chloride (BAC) as a quaternary ammonium compound was added to the silica-zinc-aluminum composite (solid content concentration 5.7%) of the reaction solution, at 25 wt % and 100 wt % relative to the solid content of the silica-zinc-aluminum composite, to prepare slurries containing the hybrid antibacterial agent of the present invention. The process was then repeated in the same manner as in Example 1, producing the hybrid antibacterial agents of the present invention (Examples 5 and 6).

[0040] After aging for 20 hours, the precipitate was filtered, washed with water, and dried at 140°C in the same manner as in Examples 1 to 4, except that the pulverization step was omitted to produce a low-crystalline silica-zinc-aluminum composite represented by the above chemical formula in an unpulverized state. The unpulverized silica-zinc-aluminum composite was then dispersed in water to form a slurry, to which commercially available benzalkonium chloride (BAC) as a quaternary ammonium compound was added in amounts of 9% by weight and 30% by weight, respectively, based on the solid content of the silica-zinc-aluminum composite, to prepare slurries containing the hybrid antibacterial agent of the present invention. The hybrid antibacterial agents of the present invention were then produced in the same manner as in Example 1 (Examples 7 and 8).

[0041] Comparative Examples 1 to 9: Antibacterial Agents of the Prior Art The resulting silica zinc aluminum composite was used as a conventional antibacterial agent (Comparative Example 1). To a slurry of commercially available amorphous silicon dioxide (wet silica) dispersed in water, commercially available benzalkonium chloride (BAC) as a quaternary ammonium compound was added in an amount of 10% by weight relative to the amorphous silicon dioxide, followed by stirring, filtration, washing with water, and drying to produce a conventional antibacterial agent in which benzalkonium chloride (BAC) was supported on amorphous silicon dioxide (Comparative Example 2).Furthermore, commercially available amorphous silicon dioxide was added to an aqueous benzalkonium chloride solution, and the mixture was heated and mixed at 130°C to produce a conventional antibacterial agent with the same benzalkonium chloride support rate as Example 2 (Comparative Example 3). Commercially available amorphous silicon dioxide alone was used as the antibacterial agent of the prior art (Comparative Example 4). Commercially available benzalkonium chloride alone was used as the antibacterial agent of the prior art (Comparative Example 5).

[0042] For comparison, the prior art antibacterial agents described in Patent Documents 5 and 2 are shown as Comparative Examples 6 and 7, respectively. Comparative Example 6 is a prior art antibacterial agent produced by adding 5 g of aluminum silicate (Kyowa Chemical Industry Co., Ltd., Kyoward 700SEN, particle size distribution 150-350 μm (80.0%)) to a solution prepared by dissolving 2 g of quaternary ammonium dimer in 20 mL of water and stirring at 60°C. The solution was then stirred at 60°C for 30 minutes, followed by cooling, filtration, washing with water, vacuum drying, and pulverization. Comparative Example 7 is a prior art antibacterial agent produced by sequentially adding 54 g of sodium silicate (SiO2 = 23%, Na2O = 7%), 6 g of sodium hydroxide, and 21.3 g of a 50% aqueous solution of benzalkonium chloride to 600 g of ion-exchanged water, mixing at 70°C for 3 hours, adjusting the pH to 8.0, mixing at 70°C for 3 hours, filtering, washing with water, and drying at 60°C for 2 days.

[0043] The silica zinc aluminum composite alone in the reaction solution produced by the production method of Examples 5 and 6 was used as the antibacterial agent of the prior art (Comparative Example 8). The unground silica zinc aluminum composite alone produced by the manufacturing method of Examples 7 and 8 was used as the antibacterial agent of the prior art (Comparative Example 9).

[0044] [Test 1: Measurement of average particle size and bulk density] The average particle size [μm] of each of the antibacterial agents of Examples 1 to 8 and Comparative Examples 1 to 4 and 9 was measured by laser diffraction and scattering using a Mastersizer 3000 manufactured by Malvern. Water was used as the dispersion medium, and the particle refractive index was 1.50, the dispersion medium refractive index was 1.33, and the light scattering model was analyzed using Mie theory. Bulk density [g / cm 3 ] was measured in accordance with JIS K 6220-1 7.8.2:2015.

[0045] [Test 2: Measurement of Quaternary Ammonium Compound Support Rate] For each of the antibacterial agents in Examples 1 to 8 and Comparative Examples 2 and 3, the loading rate [wt %] of benzalkonium chloride (BAC) or dimer 38A relative to the inorganic support was determined from the weight loss measured using a differential thermal-thermogravimetric analyzer (Rigaku Corporation Thermo plus EV02).

[0046] [Test 3: Cation adsorption test] To confirm whether the quaternary ammonium compound loading rate was the highest in Examples 2, 6, and 8, the methylene blue adsorption amount was determined and the cation adsorption ability was evaluated for Comparative Example 1 (silica zinc aluminum composite alone) and Comparative Example 8 (silica zinc aluminum composite alone in the reaction solution). The methylene blue adsorption amount was defined as the number of mmoles of methylene blue that can be adsorbed by 1 g of sample from a 6.25 mmol / L methylene blue aqueous solution, and was measured and calculated using the following method. First, methylene blue trihydrate (special grade reagent, Wako Pure Chemical Industries, Ltd.) was dissolved in water to obtain a 6.25 mmol / L methylene blue solution. 20 mL of this 6.25 mmol / L methylene blue solution was weighed into a 50 mL centrifuge tube, and 0.10 g of the antibacterial agent from Comparative Example 1 was added. The solution was then shaken for 7.5 hours using a shaker (Yamato Scientific SA300, shaking speed 5). After shaking, the solution was allowed to stand for at least 12 hours. Next, the solution was centrifuged at a centrifugal acceleration of 3000 rpm for 15 minutes using a KUBOTA 5200. 1.0 mL of the supernatant was then sampled and diluted 200-fold with ion-exchanged water. The absorbance of the solution at 667 nm wavelength was measured using a spectrophotometer (JASCO V-630). The amount of methylene blue remaining in the sample solution was calculated using a calibration curve showing the relationship between the methylene blue content in the methylene blue solution and the absorbance of 667 nm light. This value was subtracted from the amount of methylene blue added to the sample to determine the amount of methylene blue adsorbed.

[0047] [Test 3-2: Composition analysis (XRF measurement)] For each of the antibacterial agents of Examples 1 and 5 to 8 and Comparative Example 1, the intensities of the chlorine (Cl) and sulfur (S) components were measured using an X-ray fluorescence (XRF) analyzer (Rigaku Corporation ZSXprimus II).

[0048] [Test 4: Antibacterial test] In accordance with the "Test Method for Evaluating the Antibacterial Activity of Antibacterial Agents: Minimum Inhibitory Concentration Measurement Method I (2018 Edition)" established by the Society of International Studies on Antibacterial Products (SIAA), the antibacterial agent of Example 1 was added to a bacterial solution of Escherichia coli and Staphylococcus aureus prepared to an arbitrary bacterial concentration, and after 24 hours of incubation, the minimum added concentration [ppm] at which no bacterial growth was confirmed was evaluated as the minimum inhibitory concentration (MIC). The antibacterial agents of Examples 3 to 6 and 8 and Comparative Examples 1 to 5 and 9 were also evaluated using the same method. The smaller the MIC value, the stronger the antibacterial activity, and according to the SIAA standard, an MIC of 800 ppm or less is considered to be antibacterial.

[0049] [Test 5: Sustained release test] A slurry prepared by dispersing 5 g of the antibacterial agent of Example 1 in 95 mL of ion-exchanged water was stirred for 24 hours and then filtered. The concentration [ppm] of the quaternary ammonium compound (benzalkonium chloride) in the filtrate was measured using a spectrophotometer (JASCO Corporation V-630) to determine the quaternary ammonium compound elution rate [%]. Another slurry of Example 1 obtained in the same manner as above was stirred for one week and then measured to determine the quaternary ammonium compound elution rate [%]. Comparative Examples 6 and 7 were used for comparison.

[0050] [Test 6: Heat resistance test] The temperature at which Example 1 (hybrid antibacterial agent) lost weight relative to Comparative Example 1 (silica-zinc-aluminum composite alone) was measured using a differential thermal-thermogravimetric analyzer (Rigaku Thermoplus EV02). Similarly, the temperature at which Comparative Example 3 (amorphous silicon dioxide + benzalkonium chloride) lost weight relative to Comparative Example 4 (amorphous silicon dioxide alone), the temperature at which Examples 5 and 6 (hybrid antibacterial agents produced from a reaction solution) lost weight relative to Comparative Example 1, and the temperature at which Examples 7 and 8 (hybrid antibacterial agents produced from an unpulverized silica-zinc-aluminum composite) lost weight relative to Comparative Example 9 (unpulverized silica-zinc-aluminum composite alone) were all measured. The temperature at which the weight lost is the temperature at which the chemical or physical properties change and represents the heat resistance temperature of the antibacterial agent.

[0051] [Test 7: Whiteness test] The whiteness of each of the antibacterial agents in Examples 1 and 5 to 8 and Comparative Examples 1 to 4 and 9 was measured using a spectrophotometer / color difference meter (PF7000(Q-57) manufactured by Nippon Denshoku Industries Co., Ltd.) Furthermore, the whiteness of each of the antibacterial agents in Examples 1 and 5 to 8 and Comparative Examples 1 to 4 and 9 was measured in the same manner after heating for 1 hour at approximately 200°C, which is the temperature at which the resin is added.

[0052] [Test 8: Deodorizing Test] Ammonia gas was injected with a syringe into a 1.8 L sealed container containing 0.01 g of the antibacterial agent of Example 1, and the ammonia concentration was measured using a detector tube (Gastec No. 3La, Corp.) at 30 minutes, 1 hour, 2 hours, and 18 hours after the time of injection. The ammonia concentration was similarly measured at each time after the time of injection for the antibacterial agent of Comparative Example 1, each of the antibacterial agents obtained by heating Example 1 and Comparative Example 1 at about 200°C for 1 hour (Example 1' and Comparative Example 1'), and a blank containing no antibacterial agent.

[0053] Hydrogen sulfide gas was injected with a syringe into a 1.8 L sealed container containing 0.01 g of the antibacterial agent of Example 1, and the hydrogen sulfide concentration was measured using a detector tube (Gastec No. 4LL, Corp.) at 30 minutes, 1 hour, 2 hours, and 3 hours after the time of injection. The hydrogen sulfide concentration was similarly measured at each time after the time of injection for the antibacterial agent of Comparative Example 1, each of the antibacterial agents obtained by heating Example 1 and Comparative Example 1 at about 200°C for 1 hour (Example 1' and Comparative Example 1'), and a blank containing no antibacterial agent.

[0054] [Test 9: Resin addition behavior test / transparency test] The behavior of the resin during addition was evaluated by monitoring the change in the internal pressure of the molding machine over time during masterbatch (MB) production. 3% by weight of the antibacterial agent of Example 1 was continuously added to polypropylene for injection molding (Novatec® PP injection molding grade MA3, Japan Polypropylene Corporation), and the mixture was kneaded in a molding machine at a temperature of approximately 185°C. The change in the internal pressure [MPa] of the molding machine over time, which corresponds to the degree of clogging of the screen mesh, was measured (Example 1A). Using a similar method, 3% by weight of the antibacterial agent of Comparative Example 1 was continuously added, and the change in the internal pressure [MPa] over time was measured (Comparative Example 1A). Furthermore, the MB obtained in Example 1A and Comparative Example 1A were continuously added to polypropylene for injection molding so that the antibacterial agent content was 2% by weight, and the transparency of each of the obtained injection-molded products was measured using a measuring device (BYK Haze-gard plus 4725) (a smaller value indicates higher transparency).

[0055] The behavior of the resin during addition was evaluated by measuring the change over time in the internal pressure of the molding machine during masterbatch (MB) production. 3% by weight of the antibacterial agent of Example 1 was continuously added to polypropylene for film formation (Japan Polypropylene Corporation, Novatec® PP Cast Film Grade FW4BA), and the mixture was kneaded in a molding machine at temperatures of 210 to 230°C. The change over time in the internal pressure [MPa] of the molding machine, which corresponds to the degree of clogging of the screen mesh, was measured (Example 1B). Using a similar method, 3% by weight of the antibacterial agent of Comparative Example 1 was continuously added, and the change over time in the internal pressure [MPa] was measured (Comparative Example 1B). Furthermore, the MB obtained in Example 1B and Comparative Example 1B were continuously added to polypropylene for film formation so that the antibacterial agent content was 0.2 wt %, and the transparency of each of the obtained films was measured using a measuring device (BYK Haze-gard plus 4725) (a smaller value indicates higher transparency).

[0056] [Test results and discussion] The results of Test 1 (average particle size and bulk density measurement), Test 2 (quaternary ammonium compound loading measurement), Test 3 (cation adsorption capacity test), Test 3-2 (composition analysis), Test 4 (antibacterial test), and Test 7 (whiteness test) are shown in Table 1.

[0057] [Table 1]

[0058] The results of Test 2 (Quaternary Ammonium Compound Loading Measurement) in Table 1 show that the BAC (benzalkonium chloride) loading rate and loading rate were 10 wt% and 8.0 wt% for Example 1, and 30 wt% and 8.7 wt% (=87 mg / g = 0.3 mmol / g) for Example 2. Meanwhile, the results of Test 3 (Cation Adsorption Capacity Test) in Table 1 show that the methylene blue adsorption amount for Comparative Example 1 (silica-zinc-aluminum composite alone) was 98 mg / g (=0.3 mmol / g), and the number of moles per unit mass was consistent with Example 2. Therefore, it was confirmed that in Example 2 (and Examples 1, 3, and 4), BAC adsorption was an ion exchange process, similar to methylene blue. It was also found that 8.7 wt% was the maximum loading rate for BAC on the silica-zinc-aluminum composite.

[0059] Furthermore, the results of Test 2 in Table 1 show that the BAC loading rate and loading rate for Example 5 were 25 wt% and 16.9 wt%, respectively, while those for Example 6 were 100 wt% and 27.0 wt% (=270 mg / g=0.9 mmol / g). Meanwhile, the results of Test 3 in Table 1 show that the methylene blue adsorption amount for Comparative Example 8 (silica-zinc-aluminum composite of reaction solution) was 240 mg / g (=0.8 mmol / g), and the number of moles per unit mass was approximately the same as that for Example 6. Therefore, in Example 6 (and Example 5), it was confirmed that BAC adsorption was an ion exchange process, similar to methylene blue. Furthermore, it was found that 27.0 wt% was approximately the maximum loading rate for BAC on the silica-zinc-aluminum composite.

[0060] Furthermore, the results of Test 2 in Table 1 show that the BAC loading rate and loading rate were 9 wt% and 6.7 wt% in Example 7, respectively, and 30 wt% and 12.0 wt% (=120 mg / g = 0.4 mmol / g) in Example 8. Meanwhile, the results of Test 3 in Table 1 show that the methylene blue adsorption amount for Comparative Example 1 (silica-zinc-aluminum composite alone) was 98 mg / g (=0.3 mmol / g), and the number of moles per unit mass was approximately the same as in Example 8. Therefore, in Example 8 (and Example 7), it was confirmed that BAC adsorption was an ion exchange process, similar to methylene blue. It was also found that 12.0 wt% was approximately the maximum loading rate of BAC for the silica-zinc-aluminum composite.

[0061] As described above, the relationship between the loading rate in Example 6 and the methylene blue adsorption amount in Comparative Example 8 was 0.9 mmol / g and 0.8 mmol / g, respectively. Furthermore, the relationship between the loading rate in Example 8 and the methylene blue adsorption amount in Comparative Example 1 was 0.4 mmol / g and 0.3 mmol / g, respectively. While there was no significant deviation between the two, Examples 6 and 8 showed slightly larger values. This is thought to be due to some BAC being physically adsorbed beyond the upper limit of ion exchange. Specifically, when BAC is ion-exchanged, the chlorine (Cl) in the BAC is released by washing with water. However, in the case of physical adsorption, Cl remains even after washing with water. Therefore, physical adsorption can be confirmed by detecting Cl in the hybrid antibacterial agent. According to the results of Table 1, Test 3-2 (Composition Analysis (XRF Measurement)), Cl was not detected in Example 1, but the Cl intensity was 1.3 and 4.1 in Examples 6 and 8, respectively. Therefore, in Example 1, the entire amount of BAC was supported without exceeding the upper limit of ion exchange, whereas in Examples 6 and 8, the upper limit of ion exchange was exceeded and some BAC remained due to physical adsorption, resulting in slightly higher values ​​in Examples 6 and 8. Furthermore, the reason why the support rate in Example 6 is slightly higher than that in Comparative Example 8 is thought to be that sulfur (S) components in the reaction solution reacted with BAC and precipitated, contributing to an increase in the amount of BAC supported. In fact, according to the results of Test 3-2 in Table 1, the S intensity in Example 1 was 6.7, while the S intensities in Examples 5 and 6 (hybrid antibacterial agents produced from the reaction solution) were 21.9 and 32.6, respectively. This confirmed the reason why the support rate in Example 6 was slightly higher.

[0062] The results of Test 4 (antibacterial test) in Table 1 show that before heating, the MIC (minimum inhibitory concentration) for Escherichia coli and Staphylococcus aureus was 800 ppm and 400 ppm for Comparative Example 1, while it was 100 ppm and 5 ppm for Example 1. Therefore, the antibacterial properties of Example 1 far exceeded those of Comparative Example 1, which has antibacterial properties derived from zinc. Furthermore, after heating at approximately 200°C, which is the target temperature for adding resin, the MIC for Escherichia coli and Staphylococcus aureus was 800 ppm and 400 ppm for Comparative Example 1, while it was 200 ppm and 5 ppm for Example 1. Therefore, it was confirmed that the hybrid antibacterial agent of Example 1 maintained high antibacterial function even after heat treatment.

[0063] In Example 3, with a BAC loading rate of 0.9 wt%, the MICs for E. coli and S. aureus were 400 ppm and 50 ppm before heating, respectively, and the MIC for S. aureus was 50 ppm after heating. Therefore, it was confirmed that sufficient antibacterial activity was achieved even with a small amount of BAC loaded. According to the SIAA standard, an MIC of 800 ppm or less is considered to be antibacterial, so in the present invention, it is expected that sufficient antibacterial function can be achieved even with an even smaller loading rate, for example, approximately 0.5 wt%. Furthermore, in Example 4, which used dimer 38A, the MICs for E. coli and S. aureus were 50 ppm or less and 5 ppm before heating, respectively, confirming that dimer 38A can be applied to the present invention as an antibacterial component, just like BAC. Regarding Comparative Example 3, the antibacterial activity was as good as in Example 1, but as described below, poor whiteness results were obtained after heating.

[0064] Example 5 (BAC loading rate 16.9% by weight) produced from the reaction solution had MICs of 50 ppm and 1.25 ppm against Escherichia coli and Staphylococcus aureus before heating, and 50 ppm and 1.25 ppm after heating. Example 6 (BAC loading rate 27.0% by weight) produced from the reaction solution had MICs of 25 ppm and 0.63 ppm against Escherichia coli and Staphylococcus aureus before heating, and 25 ppm and 1.25 ppm after heating. Therefore, it was confirmed that the hybrid antibacterial agents of Examples 5 and 6 exhibited extremely high antibacterial functions before and after heat treatment.

[0065] Furthermore, the results of Test 4 in Table 1 show that before heating, the MICs of Escherichia coli and Staphylococcus aureus were 800 ppm and 800 ppm for Comparative Example 9 (unground silica-zinc-aluminum composite alone), while those of Example 8 (Comparative Example 9 + BAC) were 50 ppm and 1.25 ppm. Therefore, the antibacterial properties of Example 8 far exceeded those of Comparative Example 9, which possesses antibacterial properties derived from zinc. Furthermore, after heating at approximately 200°C, which is the target temperature for resin addition, the MICs of Escherichia coli and Staphylococcus aureus were 800 ppm and 800 ppm for Comparative Example 9, while those of Example 8 were 50 ppm and 1.25 ppm. Therefore, it was confirmed that Example 8 maintained extremely high antibacterial function even after treatment at 200°C for the purpose of resin addition.

[0066] The results of Test 5 (sustained release test) are shown in Table 2. [Table 2]

[0067] As shown in Table 2, the elution rates of the quaternary ammonium compound were 22.1 wt % and 12.0 wt % for Comparative Examples 6 and 7, and 0.9 wt % and 0.6 wt % for Example 1. The antibacterial agents of Comparative Examples 6 and 7 exert their antibacterial properties by sustained release of the quaternary ammonium compound, whereas Example 1 exhibited a sufficient antibacterial effect, as shown in the results of Test 4 above (Table 1). This indicates that the antibacterial mechanism of Example 1 differs from that of Comparative Examples 6 and 7, and that the antibacterial function is primarily exerted by the hybrid antibacterial agent itself. Therefore, the hybrid antibacterial agent of the present invention is expected to be usable for a longer period of time, even in environments where external forces are applied, than the sustained-release antibacterial agents (Comparative Examples 6 and 7).

[0068] Regarding the results of Test 6 (heat resistance test), Figures 2A, 2C, and 2E show the weight change rate (TG) [%] due to heating on the vertical axis, while Figures 2B, 2D, and 2F show the results of differential thermal analysis (DTA) [μv] on the vertical axis. Figure 2A shows that Example 1 (hybrid antibacterial agent) lost weight at approximately 240°C compared to Comparative Example 1 (silica-zinc-aluminum composite alone), Comparative Example 3 (amorphous silicon dioxide + benzalkonium chloride) lost weight at approximately 180°C compared to Comparative Example 4 (amorphous silicon dioxide alone), and Comparative Example 5 (blank containing only BAC) lost weight at 170-180°C. Therefore, the starting temperature for weight loss, i.e., the heat resistance temperature, was almost the same for Comparative Example 3 and the blank, but Example 1 showed a significant increase of 60-70°C compared to the blank. It is believed that the heat resistance temperature was significantly improved in Example 1 (and Examples 5-8) due to ion adsorption, compared to physical adsorption in Comparative Example 3.

[0069] 2C, compared to Comparative Example 1 (silica zinc aluminum composite alone), Examples 5 and 6 (hybrid antibacterial agents produced from reaction solutions) lost weight at approximately 220°C and 200°C, respectively, and Comparative Example 5 (blank containing only BAC) lost weight at 170 to 180°C. Therefore, the starting temperature for weight loss, i.e., the heat resistance temperature, increased by 40 to 50°C in Example 5 and 20 to 30°C in Example 6 compared to the blank.

[0070] 2E, compared to Comparative Example 9 (unground silica-zinc-aluminum composite alone), Examples 7 and 8 (hybrid antibacterial agent of Comparative Example 9 + BAC) each lost weight at approximately 220°C, and Comparative Example 5 (blank with BAC only) lost weight at 170 to 180°C. Therefore, the starting temperature for weight loss, i.e., the heat resistance temperature, was higher by 40 to 50°C in Examples 7 and 8 compared to the blank.

[0071] The results of Test 7 (whiteness test) are shown in Table 1. The loss in whiteness (= whiteness before heating - whiteness after heating) was 11.3 and 21.4 for Comparative Examples 2 and 3, respectively, while it was 2.2 for Example 1, revealing a significant difference. That is, upon heating at approximately 200°C, the BAC in Comparative Examples 2 and 3 of the prior art was scorched, resulting in a significant decrease in whiteness (particularly in Comparative Example 3, which supported 8.7 wt% BAC, a very significant decrease in whiteness occurred), whereas in Example 1 of the present invention, the BAC ions adsorbed on the inorganic support were hardly scorched, and the whiteness was maintained at the same level as before heating.

[0072] The loss in whiteness was 11.3 and 21.4 in Comparative Examples 2 and 3, while it was 1.6, 2.0, 3.5, and 4.7 in Examples 5 to 8, showing a significant difference. That is, by heating at about 200°C, the BAC in Comparative Examples 2 and 3 of the prior art was scorched and the whiteness was significantly reduced, but in Examples 5 to 8 of the present invention, the BAC ions adsorbed on the inorganic support were hardly scorched and the whiteness was maintained at the same level as before heating.

[0073] The whiteness after heating was 92.2 for Example 1 (pulverized silica zinc aluminum composite + BAC), while it was 86.9 and 85.0 for Examples 7 and 8 (unpulverized silica zinc aluminum composite + BAC). This is thought to be due to the larger particle size of Examples 7 and 8 (average particle size 20.5 μm and 21.0 μm) compared to Example 1 (average particle size 4.5 μm). On the other hand, in Examples 5 and 6, which used undried and unfiltered reaction liquid in a different state from Examples 7 and 8, the whiteness after heating was 90 or more (90.7 and 90.4), similar to Example 1.

[0074] Regarding the results of Test 8 (deodorizing property test), Figure 3A shows the measurement results of the ammonia concentration [ppm], and Figure 3B shows the measurement results of the hydrogen sulfide concentration [ppm]. As can be seen from Figures 3A and 3B, the ammonia and hydrogen sulfide concentrations decreased over time in almost the same way in Comparative Example 1 before BAC loading and in Example 1 after loading. Furthermore, after heating at approximately 200°C, the ammonia and hydrogen sulfide concentrations decreased over time in almost the same way in Comparative Example 1' before BAC loading and in Example 1' after loading. Therefore, it was confirmed that the deodorizing performance derived from the inorganic support, the silica zinc aluminum composite (Comparative Example 1), was not lost and was maintained even after BAC loading and heating at approximately 200°C.

[0075] The results of Test 9 (resin addition behavior test / transparency test) are shown in Table 3 and Figure 4. [Table 3]

[0076] As shown in Table 3 and Figure 4, the internal pressure after 45 minutes was 14.1 MPa and 12.2 MPa for Comparative Examples 1A and 1B, and 6.1 MPa and 5.0 MPa for Examples 1A and 1B. Compared to Comparative Examples 1A and 1B, in which a silica-zinc-aluminum composite alone was added to the resin, Examples 1A and 1B, in which a BAC-supported hybrid antibacterial agent was added to the resin, were able to significantly reduce the pressure rise, regardless of whether the added resin was PP for injection molding or PP for film formation. This is because the supported BAC has good compatibility with thermoplastic resins, reducing the occurrence of aggregates.

[0077] The transparency test results in Table 3 show that for injection-molded products, the value for Comparative Example 1A was 92.4, while that for BAC-supported Example 1A was 90.0, maintaining transparency without a significant decrease in value. For films, the value for Comparative Example 1B was 2.14, while that for BAC-supported Example 1B was 1.93, maintaining transparency without a significant decrease in value. Therefore, the hybrid antibacterial agent of the present invention carrying BAC does not impair the transparency of processed products (injection-molded products and resin films) and is suitable for use as a resin additive.

[0078] [Conclusion] From the results of Tests 2, 3 and 4, it was confirmed that the loading rate of the quaternary ammonium compound in the silica zinc aluminum composite, i.e., the range of loading rate at which antibacterial function can be exerted, is 0.5 to 27.0 wt% (0.5 to 30 wt% rounded to the second significant digit) in Examples 1 to 8, and preferably 0.9 to 27.0 wt% (0.9 to 30 wt% rounded to the second significant digit). The results of Test 4 confirmed that the hybrid antibacterial agents of the present invention (Examples 1, 3, 5, 6, and 8) were able to maintain high antibacterial activity even after heat treatment. In particular, Examples 5, 6, and 8 maintained extremely high antibacterial activity. From the results of Tests 4 and 5, it was confirmed that the hybrid antibacterial agent of the present invention (Example 1) was able to maintain high antibacterial activity, although the elution of the quaternary ammonium compound was slight. From the results of Test 6, it was confirmed that the heat resistance temperature of the hybrid antibacterial agent of the present invention was approximately 240°C in Example 1, approximately 220°C in Examples 5, 7 and 8, and approximately 200°C in Example 6. From the results of Test 7, it was confirmed that the whiteness of the hybrid antibacterial agents of the present invention (Examples 1 and 5 to 8) remained almost unchanged even after heat treatment, and that the white color could be maintained. The results of Test 8 confirmed that the hybrid antibacterial agent of the present invention (Example 1) has a high deodorizing ability for ammonia and hydrogen sulfide, and that even after heat treatment (Example 1') it still has almost the same deodorizing ability as before heating. From the results of Test 9, it was confirmed that the hybrid antibacterial agent of the present invention (Example 1) has good compatibility with resins and can suppress an increase in the internal pressure of the molding machine. The results of Test 9 confirmed that both the injection-molded articles and films using the antibacterial resins of the present invention (Examples 1A and 1B) had high transparency. [Industrial Applicability]

[0079] By adding the hybrid antibacterial agent of the present invention to resins, fibers, cloth, civil engineering and construction materials, interior materials, paints, fertilizers, soil, etc., the hybrid antibacterial agent and antibacterial resin of the present invention can be widely used in industrial fields such as apparel, medicine, hygiene, construction, housing, pet supplies, automobiles, railways, space, and agriculture.

Claims

1. Chemical formula: aSiO ２ bZnO Al ２ O ３ A hybrid antibacterial agent characterized by comprising a low-crystalline silica zinc aluminum complex represented by the formula (wherein a = 0.08 to 80, b = 0.5 to 65) and a quaternary ammonium compound supported on the silica zinc aluminum complex.

2. 2. The hybrid antibacterial agent according to claim 1, wherein the silica zinc aluminum complex is supported with 0.5 to 30% by weight of a quaternary ammonium compound.

3. 2. The hybrid antibacterial agent according to claim 1, which undergoes substantial weight loss at temperatures of 200°C or higher in thermogravimetric analysis.

4. 2. The hybrid antibacterial agent according to claim 1, wherein the hybrid antibacterial agent has a whiteness index of 85 or more when heated at a temperature at which no substantial weight loss occurs.

5. 2. The hybrid antibacterial agent according to claim 1, which does not have a diffraction peak in the region of interplanar spacing of 6.40 to 8.40 Å but has a diffraction peak in the region of interplanar spacing of 2.56 to 2.71 Å in X-ray diffraction (XRD) analysis.

6. The hybrid antibacterial agent according to claim 1, wherein the quaternary ammonium compound is one or more selected from alkyldimethylbenzylammonium chloride (benzalkonium chloride) and N,N'-hexamethylenebis(4-carbamoyl-1-decylpyridinium acetate) (dimer 38A).

7. An antibacterial resin obtained by blending the hybrid antibacterial agent according to claim 1 into a thermoplastic resin, The hybrid antibacterial agent is an antibacterial resin characterized by having higher compatibility with thermoplastic resins than silica-zinc-aluminum composites.

8. Sodium silicate, zinc sulfate, and sodium aluminate are mixed in the presence of water to form a compound having the chemical formula: SiO ２ bZnO Al ２ O ３ (wherein a=0.08-80, b=0.5-65) and a step of adding a quaternary ammonium compound to the produced silica zinc aluminum complex, stirring, filtering, and drying the resulting mixture to support the quaternary ammonium compound on the silica zinc aluminum complex.

9. The step of producing the silica zinc aluminum composite includes mixing sodium silicate, zinc sulfate, and sodium aluminate in the presence of water and filtering the resulting precipitate; 9. The method for producing a hybrid antibacterial agent according to claim 8, wherein the step of supporting a quaternary ammonium compound on the silica zinc aluminum complex comprises a step of adding a quaternary ammonium compound to a slurry in which the produced silica zinc aluminum complex is dispersed in water.

10. The method for producing the hybrid antibacterial agent according to claim 9, further comprising the step of filtering the precipitate and then pulverizing the dried cake obtained by drying the precipitate.

11. A step of adding the hybrid antibacterial agent obtained by the production method according to claim 8 to a thermoplastic resin raw material, and kneading the mixture by heating; and a step of contacting a thermoplastic resin raw material with a quaternary ammonium compound by kneading to disperse and blend the hybrid antibacterial agent in the thermoplastic resin with good compatibility without generating agglomerates.

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