JPH06329511A - Antifungal material, antifungal composite and their production - Google Patents

Abstract

PURPOSE:To provide an antifungal composite having stable antifungal activity and hardly contributing to environmental pollution. CONSTITUTION:The objective antifungal composite made up of (A) a porous carrier and (B) a silver compound carried on the carrier A and characterized, in its X-ray diffraction pattern, by having the diffraction spectrum of Ag2O and also diffraction intensities at diffraction angles 2theta (i.e., 10.3 deg., 11.2 deg., 11.9 deg., and 12.3 deg.).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antibacterial material, an antibacterial composite and a method for producing the same.

[0002]

2. Description of the Related Art In recent years, contamination of synthetic resin products with fungi and mold has become a problem in places where water is used in kitchens and in humid environments. In addition, the caulking material used as a building material also has a problem that fungi and mold propagate on the surface. As a countermeasure against these, for example, a method of mixing an antibacterial and antifungal material in a synthetic resin and eluting it into the surface of the synthetic resin to sterilize and kill the surface of the resin is adopted. Organic materials such as thiabendazole are known as antibacterial and antifungal materials of this type. Further, among plant extracts, terpene compounds and the like are known as substances having an antibacterial effect.

[0003]

However, since the former organic antibacterial and antifungal material has volatility, inclusion of this in a synthetic resin has a disadvantage of contaminating the surrounding environment of the synthetic resin product. In addition, since the antibacterial and antifungal material is contained in the water contacted with the synthetic resin product, there is a problem that it causes pollution of drainage environment and further affects activated sludge during sewage treatment. In addition, since the latter plant extract is mostly an aromatic substance and has volatility, even if an attempt is made to mix these substances into the resin, it will evaporate due to the heating during the molding of the resin, so that it is impossible to mix them. There is.

In view of the above problems, it is an object of the present invention to provide an antibacterial material and an antibacterial composite which are unlikely to cause environmental pollution even when dissolved in water. Another object of the present invention is to provide an antibacterial composite which does not easily volatilize and has a stable antibacterial effect, and a method for producing the same.

[0005]

The antibacterial material of the present invention contains a water-soluble silver compound, has an Ag ₂ O diffraction line and a diffraction angle of 2θ in an X-ray diffraction image by Cu Kα ray.
10.3 °, 11.2 °, 11.9 ° and 12.3 °
It is characterized by having a diffraction intensity at °. Further, the antibacterial composite of the present invention includes a porous carrier and a silver compound supported on the porous carrier, and the silver compound has an Ag ₂ O diffraction line in an X-ray diffraction image by Cu Kα ray. , 10.3 ° of diffraction angle 2θ, 11.2 °, 1
It is characterized by having diffraction intensities at 1.9 ° and 12.3 °. Here, the porous carrier, silica gel, alumina, zeolite, zirconia,
Although inorganic oxides such as montmorillonite are used, silica gel is preferable.

Further, the antibacterial composite of the present invention is characterized in that it has a porous outer shell coating layer made of silicon oxide on the surface of the carrier carrying the silver compound. Further, the present invention comprises a silicon oxide on the surface of the carrier by a sol-gel method in which an alcohol solution of an alkoxysilane is deposited on the carrier carrying the silver compound and then water is added to hydrolyze the alkoxysilane. A method for producing an antibacterial composite forming an outer shell coating layer.

[0007]

The silver compound which acts as an antibacterial material of the present invention is difficult to obtain as a solid by itself, but as described below, it is prepared as a water-soluble compound, and its aqueous solution has a porosity such as silica gel. By impregnating into the carrier and drying it, the carrier can be immobilized in a state of being supported on the carrier. In the present invention, the silver compound and the carrier carrying the silver compound are thus referred to as an antibacterial composite.

The silver compound thus supported on the carrier is C
It can be identified by an X-ray diffraction image using Kα ray of u.
it can. Figure 1 shows this X-ray diffraction image.
(Ag 2O) diffraction line (marked with ●) along with JCPDS
(Joint Committee on Power
 Diffraction Standards)
Diffraction image that is not recognized in the image, that is, 1 with a diffraction angle of 2θ
0.3 °, 11.2 °, 11.9 ° and 12.3 °
(Hereinafter, these values of 2θ are set to P₁, P₂, P₃And P_Four
Express with. ) Clearly has a diffraction intensity
It In addition, the circles indicate sodium sulfate (Na₂SO_Four) Diffraction
Shows a line. In the step of supporting the silver compound on a carrier,
Then, when the drying temperature is raised,
X-ray diffraction intensity is no longer recognized.

FIG. 1 shows an X-ray diffraction image of the antibacterial composite obtained at a drying temperature of 100 ° C. or lower. 2 is 2
The X-ray diffraction images of the product dried by heating at 40 ° C. for 10 minutes, FIG. 3 shows the product dried by heating at 240 ° C. for 30 minutes, and FIG. 4 shows the product dried by heating at 500 ° C. for 5 minutes. When the heating temperature exceeds 200 ° C., Ag ₂ O and P _{1 to} P ₄
The X-ray diffraction intensity at is gradually reduced. And 50
If heated at 0 ° C, the silver compound sublimes.
No diffraction intensity other than a ₂ SO ₄ is observed.

In addition to the X-ray diffraction image shown in FIG. ₁ , P ₁ to P ₁ have an antibacterial effect as will be described later, as shown in FIG.
Although the diffraction intensities at P ₄ are small and they are almost equal, clear diffraction intensities are observed at P _{1 to} P ₄ . Those showing X-ray diffraction images as shown in FIGS. 3 and 4 have no antibacterial effect. Although it is not clear how the silver compound of the present invention is carried on the carrier, it dissolves in water and exerts an antibacterial effect. It is not clear whether the compound dissolved from the antibacterial complex is the same as the compound in the solution in which the carrier was first impregnated,
All of them are silver compounds, and even if chlorine ion is added, silver chloride does not become cloudy, so it exhibits an antibacterial effect even in the kitchen where tap water is used.

Since the antibacterial material of the present invention is a silver compound, it is weak against light and high temperature. Therefore, the antibacterial composite of the present invention is preferably packaged in a moisture-proof, vacuum pack and stored in a cool and dark place. In order to further improve the storage stability of the antibacterial composite and adjust the durability of the antibacterial effect, it is preferable to form a porous outer shell coating layer on the outer surface. The area, thickness, porosity and the like of the coating layer control the elution process of the silver compound supported on the carrier.

As a method of forming this coating layer, there is a method of forming a coating layer of silicon oxide by a sol-gel method in which water is added to an alkoxysilane alcohol solution to cause hydrolysis. As the alkoxysilane and alcohol, those having an alkyl group having 1 to 4 carbon atoms are used.
By forming the outer shell coating layer, the antibacterial material has a sustained release property and the thermal stability is improved. Further, even when used in an atmosphere with a high chlorine concentration, the color does not change, and the antibacterial effect does not deteriorate.

Next, an example of a method for preparing the water-soluble silver compound with which the carrier is impregnated will be described. First, silver acetate (CH ₃ COOA
g) is dissolved in water. Since silver acetate has a low solubility, it dissolves about 7.7 g / l, which is close to the solubility. Since silver acetate decomposes when the water temperature is raised, the temperature is set to 60 ° C or lower. Sodium sulfite heptahydrate (Na ₂ S
O ₃ · 7H ₂ O) is added. At first, it becomes cloudy, but when the amount of sodium sulfite is increased, the cloudiness disappears and the liquid becomes transparent. The molar ratio of silver acetate to sodium sulfite when it becomes transparent is about 1: 3. After dissolving sodium sulfite so as to be slightly in excess of the above ratio, sodium thiosulfate pentahydrate (Na ₂ S ₂ O ₃ .5H ₂ O) is dissolved. At this time, the temperature of the aqueous solution is preferably room temperature to 40 ° C. The amount of sodium thiosulfate is about 2 per mol of silver acetate in a molar ratio.

[0014]

EXAMPLES Next, examples of the present invention will be described. Example 1 First, 0.232 g of silver acetate is dissolved in 30 ml of pure water at room temperature. To this aqueous solution of silver acetate, 1.0 g of sodium sulfite heptahydrate is added and completely dissolved. Next, 0.67 g of sodium thiosulfate pentahydrate is added and dissolved. To 30 ml of the aqueous solution of the silver compound produced as described above, 5 g of sufficiently dried silica gel having a particle size of about 30 μm is added, and the aqueous solution is sufficiently adsorbed on the silica gel.

Next, the silica gel was dried at 40 ° C. under reduced pressure for 2 hours.
Dry for an hour. The antibacterial composite thus obtained is designated as A. [Example 2] An antibacterial composite A of Example 1 was added to a mixed solution of ethyl alcohol and tetraethoxysilane at a volume ratio of 1: 1.
Was added at a rate of 0.5 g / ml and mixed well, and then pure water was added thereto in an amount of 0.2 per 1 ml of the tetraethoxysilane.
The tetraethoxysilane is hydrolyzed by dropping at a rate of ml to form a shell coating layer of silicon oxide on the surface of the composite. The coating layer absorbs moisture in the air to further promote the hydrolysis reaction.
Further, when heated at a temperature lower than 60 ° C., the reaction proceeds rapidly. The antibacterial composite obtained as described above is designated as B.

[Comparative Example 1] The aqueous solution to be adsorbed on silica gel contains sodium sulfite and sodium thiosulfate, and the same treatment as in Example 2 is performed except that silver acetate is not added. [Comparative Example 2] The same treatment as in Example 2 was performed, except that the aqueous solution adsorbed on the silica gel was an aqueous solution in which only silver acetate was dissolved.

After dispersing 1 g of each sample described above in 100 ml of pure water, NO. After filtering with a filter paper of No. 5, 0.1 g of sodium chloride was added to this filtrate, and a test for checking the presence or absence of white turbidity was conducted. As a result, white turbidity was observed only in the filtrate of Comparative Example 2. Next, an unsaturated polyester resin molding was prepared by adding the above-mentioned respective samples at a ratio of 5 parts by weight to 100 parts by weight of the resin, and the following antibacterial and antifungal test was conducted.

The antifungal test was based on the halo test method by the fungicide resistance test (JIS Z 2911) for the textile products of the Japanese Industrial Standards. The mold used is Cladosporium Cladosporioides.
rium cladosporioides), ketomium globosum (Chaetomium globo)
sum), Penicillium citrinum (Penicil)
ium citrinum) and Aspergillus
Niger (Asperigillus niger) and evaluated 14 days later. In addition, the antibacterial test was conducted using Escherichia col
i), Staphylococcus aureus (Staphy)
lococcus aureus) and Bacillus subtilis were used, and the halo test method was followed. The evaluation was carried out after 7 days.
The test results are shown in Table 1. In addition, Comparative Example 3 is a molded product of only resin.

[0019]

[Table 1]

[0020]

As described above, according to the present invention, it is possible to obtain an antibacterial material and an antibacterial composite which are unlikely to cause environmental pollution even when they are dissolved in water. Further, according to the present invention,
It is possible to obtain an antibacterial composite which does not easily volatilize and exhibits a stable antibacterial effect.

[Brief description of drawings]

FIG. 1 shows an X-ray diffraction pattern of an antibacterial composite in one example of the present invention.

FIG. 2 shows an X-ray diffraction pattern of the composite heated at 240 ° C. for 10 minutes.

FIG. 3 shows an X-ray diffraction pattern of the composite which was heated at 240 ° C. for 30 minutes.

FIG. 4 X of the same complex heated at 500 ° C. for 5 minutes
A line diffraction pattern is shown.

Claims (6)

[Claims] 1. An X containing Cu compound containing a silver compound
An antibacterial material having a diffraction line of Ag ₂ O and a diffraction intensity at 10.3 °, 11.2 °, 11.9 ° and 12.3 ° of a diffraction angle 2θ in a line diffraction image. 2. A porous carrier and a silver compound supported on the porous carrier, wherein the silver compound has a diffraction line of Ag ₂ O and an diffraction angle of 2θ of 10. in an X-ray diffraction image by Kα line of Cu. 3 °, 11.2 °, 11.9 ° and 1
An antibacterial composite having a diffraction intensity at 2.3 °. 3. The carrier is an inorganic oxide.
The antibacterial composite described. 4. The antibacterial composite according to claim 3, wherein the inorganic oxide is silica gel. 5. The antibacterial composite according to claim 2, which has an outer shell coating layer made of silicon oxide on the outer surface. 6. An outer shell coating layer is formed on the surface of the carrier by depositing an alcohol solution of an alkoxysilane on the carrier carrying the silver compound and then adding water to hydrolyze the alkoxysilane. The method for producing an antibacterial composite according to claim 5, characterized in that