WO2016147889A1 - Antibacterial glass and resin molded product using same - Google Patents

Abstract

The present invention addresses the technical problem of realizing a cheap antibacterial glass having highly persistent antibacterial properties without causing any trouble regarding appearance when the antibacterial glass is formed into a resin molded product, and a resin molded product using the antibacterial glass. In order to solve the problem, the antibacterial glass of the present invention is characterized by containing, as the glass composition in mass%, ZnO by less than 40-54%, B₂O₃ by less than 40-50%, SiO₂ by 0.1-5%, Al₂O₃ by 0.1-2%, and Ag₂O by 0.05-0.9%, but not containing a substantial amount of an alkaline component.

Description

Antibacterial glass and resin molded product using the same

The present invention relates to antibacterial glass and a resin molded product using the same.

Resin molded products such as toothbrushes, soap holders, troughs, washstands, and bathtubs are used for a long time under high humidity conditions, so bacteria and sputum are prone to multiply.

In order to suppress the growth of bacteria and sputum, the resin is conventionally filled with an antibacterial agent, which is used as a resin molded product.

In addition, antibacterial agents that use Ag ions with high antibacterial properties are often used. For example, zeolite powder supporting Ag ions, water-soluble glass powder containing Ag ₂ O in the glass composition, and the like are known. It has been.

However, conventional antibacterial agents containing Ag ions are expensive. Furthermore, when Ag ₂ O is introduced into the glass composition, the glass tends to discolor due to the action of ultraviolet rays, heat or the like due to long-term use. This tendency is easily manifested when the resin molded product is white.

Therefore, a glass containing a large amount of ZnO in the glass composition has been proposed as an antibacterial agent. For example, Patent Document 1 discloses ZnO—B ₂ O ₃ —Na ₂ O glass powder as an antibacterial agent. ZnO—B ₂ O ₃ —Na ₂ O-based glass is inexpensive and has the feature that it does not discolor due to the action of ultraviolet rays or heat.

Japanese Patent Application Laid-Open No. 7-257938

However, the resin molded product containing ZnO—B ₂ O ₃ —Na ₂ O-based glass powder loses the gloss of the resin over time and becomes cloudy or has a rough feeling. Invite the problem.

In addition, ZnO—B ₂ O ₃ —Na ₂ O-based glass powder has insufficient antibacterial durability, in particular, antibacterial durability after being immersed in warm water, and has not yet satisfied market needs.

The present invention has been made in view of the above circumstances, does not cause a problem in appearance when it is a resin molded product, is inexpensive, and has high antimicrobial durability, and resin molding using the same It is to create a product.

As a result of various experiments, the present inventor solved the above technical problem by introducing a small amount of Ag ₂ O into the ZnO—B ₂ O ₃ glass and reducing the content of the alkali component. The present invention is found and proposed as the present invention. That is, the antibacterial glass of the present invention has a glass composition in terms of mass%, ZnO 40-54%, B ₂ O ₃ 40-50%, SiO ₂ 0.1-5%, Al ₂ O ₃ 0 0.1-2%, Ag ₂ O 0.05-0.9%, and substantially free of alkali components. Here, “substantially no alkali component” means that the content of alkali components (Li ₂ O, Na ₂ O, K ₂ O) in the glass composition is less than 1% by mass. In addition, content of an alkali component becomes like this. Preferably it is less than 0.5 mass%, More preferably, it is less than 0.1 mass%.

The antibacterial glass of the present invention contains 40% by mass or more of ZnO and 0.05 to 0.9% by mass of Ag ₂ O in the glass composition. Thereby, after suppressing an increase in cost, antibacterial property can be improved. Furthermore, since the content of Ag ₂ O is small, problems such as discoloration due to ultraviolet irradiation hardly occur.

In addition, the antibacterial glass of the present invention contains 40% by mass or more of B ₂ O ₃ and 0.1 to 5% by mass of SiO ₂ in the glass composition. Thereby, antimicrobial persistence can be improved.

Further, the antimicrobial glass of the present invention include _Al 2 _{O 3} 0.1 wt% in the glass composition. Thereby, Ag can be stably held in an ion state in the glass. As a result, even if the content of Ag ₂ O is small, the antibacterial action of Ag ions can be exhibited effectively.

Furthermore, the antibacterial glass of the present invention contains substantially no alkali component in the glass composition. Thereby, with the passage of time, the gloss of the resin is lost, and it becomes difficult to cause an appearance problem that the resin becomes cloudy or has a rough feeling.

Second, the antibacterial glass of the present invention has a glass composition in terms of mass%, ZnO 40 to 54%, B ₂ O ₃ 40 to 50%, SiO ₂ 0.1 to 2%, MgO 1 to 5%. Al ₂ O ₃ 0.1 to 2%, Ag ₂ O 0.1 to 0.9%, P ₂ O ₅ 0 to 5%, and substantially no alkali component are preferably contained.

Third, the antibacterial glass of the present invention is preferably in the form of powder.

Fourth, the antimicrobial glass of the present invention preferably has an average particle diameter _{D 50} is 0.5 ~ 25 [mu] m. Here, the “average particle diameter D ₅₀ ” refers to a value measured with a laser diffractometer, and in the volume-based cumulative particle size distribution curve measured by the laser diffraction method, the accumulated amount is accumulated from the smaller particle. The particle diameter is 50%.

Fifth, the resin molded product of the present invention is a resin molded product containing antibacterial glass, and the antibacterial glass is preferably the above-mentioned antibacterial glass.

Sixth, the resin molded article of the present invention preferably has an antibacterial glass content of 0.01 to 20% by mass.

The antibacterial glass of the present invention does not cause a problem in appearance when it is a resin molded product, is inexpensive, and has a high antibacterial sustainability. For this reason, it is suitable as an antibacterial agent to be filled in a resin molded product, and particularly suitable as an antibacterial agent to be filled in a resin molded product such as a toothbrush, a soap dish, a tub, a wash basin, and a bathtub.

The antibacterial glass of the present invention has a glass composition in terms of mass%, ZnO 40-54%, B ₂ O ₃ 40-50%, SiO ₂ 0.1-5%, Al ₂ O ₃ 0.1 It is characterized by containing ˜2%, Ag ₂ O 0.05-0.9%, and substantially free of alkali components. The reason for limiting the content range of each component as described above will be described below. In addition, in description of the containing range of each component,% display means the mass%.

ZnO is a main factor that imparts antibacterial properties, and is a component that imparts antibacterial properties as Zn ions. The content of ZnO is 40 to less than 54%, preferably 42 to 54%. When there is too little content of ZnO, antibacterial property will fall easily. When the content of ZnO is too small, in order to enhance the antibacterial activity has to introduce the Ag 2 _O in a large amount, the raw material cost is likely to rise. On the other hand, when there is too much content of ZnO, vitrification will become difficult.

B ₂ O ₃ is a glass-forming component and a component that can adjust antimicrobial persistence. The content of B ₂ O ₃ is 40 to less than 50%, preferably 40 to 49%. When the content of B ₂ O ₃ is too small, vitrification becomes difficult and water resistance becomes too high, and the elution amount of Zn ions and Ag ions decreases, so that the antibacterial durability tends to decrease. On the other hand, if the content of B ₂ O ₃ is too large, the water resistance is excessively decreased, and the elution amount of Zn ions and Ag ions becomes excessive, so that the antibacterial durability is likely to decrease.

SiO ₂ is a component that can adjust the antibacterial persistence and is essential. The content of SiO ₂ is 0.1 to 5%, preferably 0.1 to 2%. When the content of SiO ₂ is too small, the water resistance is lowered, because the amount of elution of Zn ions and Ag ions becomes excessive, antimicrobial persistence is liable to decrease. On the other hand, when the content of SiO ₂ is too large, the water resistance becomes too high, and the elution amount of Zn ions and Ag ions decreases, so that the antibacterial durability tends to be lowered.

Al ₂ O ₃ is a component that assists in vitrification, and is a component that stably keeps the Ag component in an ionic state in the glass. Al exists in the glass in an oxygen tetracoordinate like Si. Al is a trivalent cation in the glass and has one valence less than that of Si, so it has a negative ion (-1) charge due to the charge balance with oxygen ions. Existing. On the other hand, Ag ions are monovalent cations and are stably supported on the Al sites of monovalent negative ions in a state of charge compensation. In addition, although Ag ion has high antibacterial property in an ionic state, since it is very reducible, it has a property which takes an electron from the periphery and changes easily from an ionic state to a metallic state. And although Ag ion has high antibacterial property in an ion state, when it changes to a metal state, antibacterial property will fall remarkably. When the content of Al ₂ O ₃ is too small, it becomes difficult to enjoy the effect of the above. On the other hand, when the content of Al ₂ O ₃ is too large, water resistance becomes too high, because the amount of elution of Zn ions and Ag ions is reduced, the antimicrobial persistence is liable to decrease. Therefore, the content of Al ₂ O ₃ is 0.1 to 2%. Further, the content of _Al 2 _{O 3} is preferably greater than the content of Ag ₂ O.

Ag ₂ O is a component that enhances antibacterial properties. The content of Ag ₂ O is 0.05 to 0.9%, preferably 0.1 to 0.9%, more preferably 0.3 to 0.8%. When the content of Ag 2 _O is too small, it becomes difficult to enjoy the effect of the above. On the other hand, when the content of Ag 2 _O is too large, it tends to occur problems such as discoloration due to irradiation of ultraviolet rays, also the raw material cost is likely to rise.

As described above, the alkali component is a component that causes an appearance problem in the resin molded product. Therefore, in this invention, an alkali component is not contained substantially. The alkali component may adversely affect the curing characteristics of the resin.

The antibacterial glass of the present invention may contain the following components in addition to the above components.

MgO is a component that lowers the viscosity of the glass while maintaining water resistance, and is essential. The content of MgO is preferably 0 to 10%, more preferably 1 to 5%. When there is too little content of MgO, it will become difficult to receive said effect. When there is too much content of MgO, vitrification will become difficult.

P ₂ O ₅ is a glass forming component and a component capable of adjusting antibacterial persistence. The content of P ₂ O ₅ is preferably 0 to 25%, more preferably 0 to 5%, and still more preferably 0 to 1%. When the content of P ₂ O ₅ is too large, the water resistance is lowered, because the amount of elution of Zn ions and Ag ions becomes excessive, antimicrobial persistence is liable to decrease.

The antibacterial glass of the present invention may contain other components in addition to the above components. For example, CaO, SrO, BaO, ZrO ₂ , TiO ₂ , CeO _{2 and the} like may be combined or individually, preferably up to 5%. In particular, it may be introduced up to 1%.

The shape of the antibacterial glass of the present invention is not particularly limited. For example, the shape can be a powder shape, a fiber shape, a flake shape, or the like. Among these, a powder shape, that is, a glass powder is particularly preferable. When the glass powder is used, the specific surface area is increased, so that high antibacterial properties can be obtained.

The average particle diameter _{D 50} of the glass powder is preferably 0.5 ~ 25 [mu] m, more preferably 2 ~ 20 [mu] m, more preferably 5 ~ 15 [mu] m. When the average particle diameter D ₅₀ of the glass powder is too small, the glass powder particles are aggregated, hardly kneaded with a resin or the like. Moreover, when it is set as a resin molded product, it may flow out into warm water or the like and may not contribute to the antibacterial properties of the resin molded product. On the other hand, when the average particle diameter D ₅₀ of the glass powder is too large, the amount of elution of Zn ions and Ag ions per unit mass is reduced, the antimicrobial persistence is liable to decrease.

The resin molded product of the present invention is a resin molded product containing antibacterial glass, and the antibacterial glass is preferably the above antibacterial glass. In the resin molded product of the present invention, the content of the antibacterial glass is preferably 0.01 to 20% by mass, more preferably 0.05 to 5% by mass. When there is too little content of antibacterial glass, it will become difficult to provide sufficient antibacterial property to a resin molded product. On the other hand, when there is too much content of antibacterial glass, it will become difficult to disperse | distribute uniformly in resin, and it will become difficult to perform masterbatch shaping | molding. Furthermore, even if the antibacterial glass is added excessively, the antibacterial property does not increase so much, which is disadvantageous in terms of cost.

As the resin, a thermoplastic resin, a thermosetting resin, or the like can be used. For example, polyolefin resin, polycarbonate resin, ABS resin, AS resin, polyamide resin, polyurethane resin, polyvinyl alcohol resin, polyester resin, polyethylene terephthalate resin, polyethylene oxide resin, polyphenyl sulfide resin, acrylic resin, melamine resin , Phenolic resin, epoxy resin, urea resin, polyimide resin, aliphatic nylon resin, polyvinyl chloride resin, polyvinylidene chloride resin, vinyl acetate resin, fluorine resin, silicone resin, main engineering It can be used for plastics and the like and composites thereof. It can also be applied to resins reinforced with glass fibers, boron fibers, and carbon fibers.

When antibacterial glass is filled into a thermoplastic resin or a thermosetting resin, the antibacterial glass surface can be made oleophilic by silane coupling treatment or the like in order to enhance the dispersibility of the antibacterial glass. Thereby, even if there is little content of antimicrobial glass, antimicrobial property can be provided to a thermoplastic resin etc. Examples of the silane coupling agent include amino silane, epoxy silane, methacryl silane, ureido silane, and isocyanate silane.

The resin molded article of the present invention may contain various additives (colloidal silica, zinc oxide, alumina, white carbon, tin oxide, titanium oxide, silicon oxide, etc.) in addition to the antibacterial glass.

Hereinafter, the present invention will be described based on examples. The following examples are merely illustrative. The present invention is not limited to the following examples.

Table 1 shows an example (sample No. 1 to 3) and a comparative example (sample No. 4) of the present invention.

 

Each sample was prepared as follows. First, glass raw materials were prepared so as to have the glass composition in the table, mixed well, then placed in a platinum-rhodium alloy crucible and melted at 1100 to 1350 ° C. for 3 hours. After melting, it was formed into a film having a thickness of about 0.7 mm. The obtained glass film was pulverized by a ball mill and passed through a sieve having an opening of 75 microns to obtain a glass powder having the particle size shown in the table. The particle size of the glass powder is a value measured with a laser diffraction measuring device manufactured by Shimadzu Corporation.

The amount of silver ions and zinc ions eluted in pure water was evaluated as follows. 3 g of the above glass powder was placed in 30 g of pure water and held at 50 ° C. for 16 hours, and then the glass powder was collected by filtration and dried at 120 ° C. for 2 hours. Next, 0.4 g of glass powder treated with pure water was again put into 40 g of pure water and shaken in a thermostatic bath set at 35 ° C. for 24 hours. Finally, the aqueous solution was collected by filtration, and the elution amounts of silver ions and zinc ions in the aqueous solution were evaluated by ICP emission analysis. In addition, about the glass powder which was not processed with the pure water of 50 degreeC, the elution amount of the silver ion and zinc ion in aqueous solution was evaluated by the same method.

As can be seen from Table 1, sample no. The elution amounts of 1 to 3 silver ions and zinc ions were 1 ppm / m ² or more after the treatment with pure water at 50 ° C., similarly to the case before the treatment with pure water at 50 ° C. On the other hand, sample No. When No. 4 was treated with pure water at 50 ° C., the elution amount of silver ions and zinc ions was greatly reduced.

The antibacterial properties were evaluated as follows. In other words, in accordance with the test method “antibacterial activity evaluation test method minimum growth inhibitory concentration measurement method I (1998 revised edition) MIC measurement method by liquid medium dilution method” established by the Antibacterial Product Technology Council, antibacterial properties are exhibited as MIC values. evaluated. The results are shown in Table 1.

As can be seen from Table 1, when the test bacteria is Escherichia coli, sample No. In Nos. 1 to 4, the MIC value was 200 (μg / ml) or less, which satisfied the standard value 800 (μg / ml) or less as an antibacterial agent shown by the Antibacterial Product Technical Council.

Next, the antibacterial sustainability and appearance quality when the resin was actually kneaded and filled into a resin molded product were evaluated. Specifically, glass powder (0.2% by mass) and polypropylene resin according to each sample were mixed and formed into a plate shape of about 50 × 50 × 2 mm, and the antibacterial durability and appearance quality were evaluated. The results are shown in Table 1.

The antibacterial sustainability test was carried out by the Antibacterial Product Technology Council, “Antibacterial power test method for antibacterial processed products I (1998 version) film adhesion method: JISZ2801”. Specifically, the above-mentioned resin molded product was immersed in warm water at 50 ° C. for 16 hours, and the above antibacterial test was conducted. In this test method, when the test bacterium is Escherichia coli, if the antibacterial activity value is 2.0 or more, it is evaluated as “antibacterial”. Thereafter, the appearance of the resin molded product was visually observed.

As can be seen from Table 1, sample no. Nos. 1 to 3 had an antibacterial activity value of 2 or more even after being immersed in warm water, and had good antibacterial persistence. Moreover, the color tone of the resin molded product after being immersed in warm water maintained the same milky white color as before being immersed in warm water, and yellowing by Ag colloid was not recognized. On the other hand, sample No. No. 4 had an antibacterial activity value of less than 2 after being immersed in warm water, and its antibacterial persistence was low.

The antibacterial glass of the present invention is suitable as an antibacterial agent to be filled into a resin molded product, and particularly suitable as an antibacterial agent to be filled into a resin molded product such as a toothbrush, a soap bowl, a tub, a wash basin, and a bathtub. In addition to this, the antibacterial glass of the present invention can be applied to antibacterial applications such as antibacterial glazes such as glass articles and ceramic articles, and antibacterial paints such as metal articles.

Claims (6)

1. As a glass composition, ZnO 40 to less than 54%, B ₂ O ₃ 40 to less than 50%, SiO ₂ 0.1 to 5%, Al ₂ O ₃ 0.1 to 2%, Ag ₂ O 0 in mass%. An antibacterial glass characterized by containing 0.05 to 0.9% and substantially free of alkali components.
2. As a glass composition, ZnO 40-54%, B ₂ O ₃ 40-50%, SiO ₂ 0.1-2%, MgO 1-5%, Al ₂ O ₃ 0.1-2% in mass%. The antibacterial glass according to claim 1, comprising 0.1 to 0.9% of Ag ₂ O, 0 to 5% of P ₂ O ₅ and substantially free of an alkali component.
3. The antibacterial glass according to claim 1 or 2, which is in a powder form.
4. 4. The antibacterial glass according to claim 3, wherein the average particle diameter D ₅₀ is 0.5 to 25 μm.
5. A resin molded product containing antibacterial glass,
   A resin molded product, wherein the antibacterial glass is the antibacterial glass according to any one of claims 1 to 4.
6. The resin molded product according to claim 6, wherein the content of the antibacterial glass is 0.01 to 20% by mass.