JPH0610126B2 - Antibacterial agent - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Object of the invention [Industrial field of application] The present invention relates to an antibacterial material containing a special phosphate compound having a silver ion as an active ingredient, and various binders. As an antibacterial composition mixed with or as a fiber, film,
It can be used as an antibacterial molded product by supporting it on various carriers such as paper and plastic.

[Prior Art] It has long been known that silver ions have antibacterial properties, and they are widely used as disinfectants and disinfectants in the form of, for example, an aqueous solution of silver nitrate. However, since silver ions are harmful to the human body, there are various restrictions on the method of use, storage, disposal, etc., and their applications have also been limited.

In order to exert antifungal and antibacterial properties, it has become clear recently that it is sufficient to act a slight amount of silver ions on the object to be applied, and the carrier carries silver ions for elution during use. Various antibacterial agents having antifungal and antibacterial properties have been proposed.

One of them is an antibacterial agent in which silver ion is supported on an ion exchange resin or a chelate resin, but these antibacterial agents are unstable to heat and light exposure and lack long-term stability. There is.

As other antibacterial agents, there are antibacterial agents in which adsorbent activated carbon and clay minerals are loaded with silver ions.When activated carbon is used as a carrier, a soluble silver salt is physically adsorbed or absorbed. Since they are attached, the silver ions are rapidly eluted when they are brought into contact with water, and it is difficult to elute a minute amount of silver ions on a regular basis for a long time. In addition, when a clay mineral such as montmorillonite or zeolite is used as a carrier, and an alkali metal ion such as sodium ion in the clay mineral is ion-exchanged with silver ion, the silver ion is eluted from the carrier by ion exchange equilibrium. When the concentration of silver ions in the liquid to be contacted is extremely low, the liquid is rapidly eluted, and it is also difficult to maintain the elution of silver ions in an extremely small amount for a long time.

[Problems to be Solved by the Invention] An object of the present invention is to provide a material that maximizes antifungal and antibacterial properties by silver ions. That is, the present invention uses a very small amount of silver ions to exhibit antifungal and antibacterial properties for a long period of time, so that it is chemically and physically stable and has a very small amount of silver necessary for antifungal and antibacterial. An object of the present invention is to provide a material capable of sustaining elution of ions for a long time.

(B) Structure of the Invention [Means for Solving the Problems] The inventors of the present invention have conducted extensive studies to solve the above problems, and as a result, found that a special phosphate compound having silver ions was
It was found that it has extremely excellent chemical and physical stability and can elute a very small amount of silver ion,
The present invention has been completed.

That is, the present invention provides the general formula Ag _x H _y AzM ₂ (PO ₄ ) ₃ (A is an alkali metal, M is Zr, Ti or Sn, x, y).
And z are each positive numbers less than 1 and x + y + z =
It is 1. ) Relates to an antibacterial agent containing a compound represented by

Hereinafter, the compound used in the present invention and the method of using the same will be described.

O Phosphate compound The compound used in the present invention is represented by the following general formula [I] Ag _x H _y AzM ₂ (PO ₄ ) ₃ [I] (A is an alkali metal, M is Zr, Ti or Sn x, y. And z are each positive numbers less than 1 and x + y
+ Z = 1. ) Is a compound represented by. This is a compound that belongs to the space group R3c and in which each constituent ion forms a three-dimensional network.

A in the above formula is an alkali metal, specifically L
i is a metal such as Na and K, and M is Zr, Ti or S
n.

The following are specific examples of the above phosphate compound.

Ag _0.01 H _0.95 Li _0.04 Zr ₂ (PO ₄ ) ₃ Ag _0.05 H _0.85 Li _0.10 Zr ₂ (PO ₄ ) ₃ Ag _0.10 H _0.80 Li _0.10 Ti ₂ (PO ₄ ) ₃ Ag _0.10 H _0.85 Li _0.05 Zr ₂ (PO ₄ ) ₃ Ag _0.20 H _0.75 Na _0.05 Ti ₂ (PO ₄ ) ₃ Ag _0.30 H _0.45 Na _0.25 Zr ₂ (PO ₄ ) ₃ Mg _0.35 H _0.60 Na _0.05 Sn ₂ (PO ₄ ) ₃ Ag _0.50 H _0.45 K _0.05 Sn ₂ ( PO ₄ ) ₃ Ag _0.50 H _0.40 Li _0.10 Ti ₂ (PO ₄ ) ₃ Ag _0.70 H _0.25 K _0.05 Ti ₂ (PO ₄ ) ₃ Ag _0.92 H _0.05 Li _0.03 Zr ₂ (PO ₄ ) _{3 The} above phosphate compounds Is obtained as follows, for example.

That is, a compound containing an alkali metal such as lithium carbonate (Li ₂ CO ₃ ) or sodium carbonate (Na ₂ CO ₃ ), Z such as zirconium oxide (ZrO ₂ ) or titanium oxide (TiO ₂ ).
A mixture of a compound containing r, Ti or Sn and a compound containing a phosphate group such as ammonium dihydrogen phosphate (NH ₄ H ₂ PO ₄ ) in a molar ratio of about 1: 4: 6. ,
By firing at 1100 to 1400 ° C, the general formula A
After obtaining a compound represented by M ₂ (PO ₄ ) ₃ (A and M are the same as above), the resulting compound was treated with nitric acid at room temperature to 100 ° C.,
By immersion in an aqueous mineral acid such as sulfuric acid and hydrochloric acid, to obtain the general formula _{H (1-z) A z} M 2 (PO 4) 3 compound represented by the [II]. Further, by immersing this in an aqueous solution containing silver ions at an appropriate concentration, the general formula Ag _x H _y
A compound [I] represented by AzM ₂ (PO ₄ ) ₃ is obtained.

Generally, the larger the values of x and y in the compound [I], the higher the antifungal and antibacterial properties can be exhibited. Therefore, the value of z in the compound [I] is preferably small.
A value less than 0.3 is preferable. Further, the lower limit is preferably set to 0.05 or more from the viewpoint of ease of ion exchange reaction between alkali ions and H ions.

Even if the value of x is extremely small, it is possible to exert antifungal and antibacterial properties, but if it is less than 0.001, it may be difficult to exert antifungal and antibacterial properties for a long time, and it is economical. Considering the sex, 0.01 or more and 0.5
The following values are preferable.

Further, the value of x can be appropriately adjusted by adjusting the concentration of silver in the aqueous solution or the time or temperature for immersing the compound [II] in the aqueous solution, depending on the required properties and use conditions. it can.

Incidentally, since the value of y is equal to (1-x-z), if the values of x and z are set in a preferable range as described above, the preferable value of y is larger than 0.2 and is 0.94 or less. It is decided by oneself.

This compound is stable to heat and light exposure and
Even after heating at 0 ° C., the structure and composition did not change at all, and no color change was caused by irradiation with ultraviolet rays. Therefore, unlike the conventional organic antibacterial agents, there are no restrictions on the processing temperature for obtaining various molded products, such as the heating temperature or the light shielding conditions.

The usage form of this compound is not particularly limited, and can be appropriately mixed with other components or combined with other materials depending on the application. For example, it can be used in various forms such as powders, powder-containing dispersions, powder-containing particles, powder-containing paints, powder-containing fibers, powder-containing papers, powder-containing films and powder-containing aerosols. It can also be used in combination with various additives or materials such as odorants, flame retardants, anticorrosion, fertilizers and building materials.

The antibacterial agent of the present invention generally exhibits antifungal and antibacterial properties for fungi and fungi on which silver ions effectively act, and can be effectively used for the following uses, for example. .

Work clothes, medical clothes, medical bedding, sports clothes, bandages,
Fibers such as fish nets, curtains, carpets, underwear, and air filters; papers such as wallpaper; films for food packaging films, medical films, synthetic leather, etc .; sterilizer wall paints, antiseptic paints, antifungal paints, etc. Paints; Powders such as agricultural soil;
Liquid composition such as shampoo.

[Action] The antibacterial agent of the present invention exerts antifungal and antibacterial properties by the combined action involving silver ions and H ions as described below.

First, when the compound [I] comes into contact with water, a very small amount of silver ion is ionized and eluted. The ion concentration necessary for exhibiting antifungal and antibacterial properties varies depending on the target fungus, type of bacteria and environment, but is several μg / to several hundred μg /
It is said that the range. In the antibacterial agent of the present invention,
This elution amount can be easily controlled by determining the values of x and y in the general formula. It is considered that this is because the bond between the silver atom and the oxygen atom in the compound has a strong covalent property, so that the elution can be made extremely small.

In addition, the H ion in the compound [I] exists due to an ionic bond with an oxygen atom in the compound, and can be easily liberated by contact with water until ionic equilibrium is reached. As a result, the liquid property becomes acidic. And is effective in suppressing the generation of fungi and bacteria that are sensitive to acid.

The above composite action is an action not found in clay minerals such as zeolite.

Reference Examples, Examples and Comparative Examples Reference Example Lithium carbonate (Li ₂ CO ₃ ), zirconium oxide (ZrO ₂ ) and diammonium hydrogen phosphate (NH ₄ H ₂ PO ₄ ) in a molar ratio of 1: 4: 6. After mixing and mixing well,
It was calcined at 00 ° C. to obtain a compound having a composition formula of LiZr ₂ (PO ₄ ) ₃ .

After crushing this compound, it was immersed in 2N hydrochloric acid at 80 ° C. to obtain a compound represented by the following formula.

T _0.9 Li _0.1 Zr ₂ (PO ₄ ) ₃ (hereinafter abbreviated as HZP) Further, the following compound was obtained in the same manner as above except that titanium oxide and tin oxide were used instead of zirconium oxide.

H _0.8 Li _0.2 (PO ₄ ) ₃ (hereinafter abbreviated as HTP) H _0.9 Li _0.1 Sn ₂ (PO ₄ ) ₃ (hereinafter abbreviated as HSP) These compounds were added to a 1/100 N AgNO ₃ aqueous solution and stirred at room temperature. Was varied and stirred. After filtering these slurries, A
The residue was washed with pure water until g ions were not detected.

By analyzing the Ag ion concentration in the filtrate, the composition formula and Ag weight% in terms of solid were obtained, and the results are shown in the first section below.
Shown in the table.

After the washing was completed, the residue was wet pulverized with water as a liquid medium, and the pulverized product was classified using a sieve to collect fine particles of 1.0 μm or less. Further, the fine particles were dried at 110 ° C. overnight to obtain an antibacterial agent.

<Method of evaluating antibacterial property> Evaluation of antibacterial activity of the antibacterial agent obtained as described above is as follows.
The following method was used.

That is, these antibacterial agents were mixed with a resin and a resin composition described later to prepare a molded body, which was used as a test disk having a diameter of 20 mm or a thread-shaped molded body to fabricate a test piece.

The following were used as test bacteria. That is, as bacteria, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus subtilis are used, as yeasts, Cadeida yeast and Saccharomyces yeast, and as molds, black koji mold, gliocladius, aureobasidium and clad. Sheporium was used.

As a medium, for bacteria, Mueller Hinton (Mu
Liller-Hinton) medium and Sabouraud medium in yeast and mold.

When the above-mentioned test bacteria were suspended in physiological saline at a concentration of 10 ⁸ / ml, 0.1 ml was dispersed in the above medium with a conradi stick, and when the antibacterial activity was judged, a test disk was stuck on the test bacteria, and in the case of bacteria After culturing at 37 ° C for 18 hours, or for yeast and mold for 1 week at 30 ° C,
Whether or not the inhibition zone was formed was observed, and when the inhibition zone was formed, it was judged to have antibacterial activity.

Examples 1 to 6 and Comparative Examples 1 to 4 Polyethylene terephthalate having an intrinsic viscosity [η] of 0.640 obtained by measuring the antibacterial agents of Samples 1 to 6 obtained in Reference Examples in a phenol / ethane tetrachloride (6: 4) mixed solvent. Chip 1
Two parts each were added to 00 parts, and the mixture was melt-mixed and injected at 270 ° C. to prepare a molded body having a diameter of 20 mm and a thickness of 3 mm. These molded products were evaluated for antibacterial activity according to the above antibacterial evaluation method (Examples 1 to 6).

In addition, the HZP used in the reference example is not loaded with Ag.
(Sample No. is P1), HTP (Sample N)
o. Is P2) and HSP (Sample No. is P3)
And a HZ produced by the same method using
The molded articles produced without adding P, HTP and HSP were similarly evaluated for antibacterial activity (Comparative Examples 1 to 4).
The results are shown in Table 2 below. From Table 2, it can be seen that the molded product containing the antibacterial agent of the present invention has excellent antibacterial properties.

Examples 7 to 12 and Comparative Example 5 70% by weight of emulsion containing 43% of acrylic resin (hereinafter,% means wt%), titanium dioxide 10%, 4%
Aqueous solution containing 10% hydroxylethyl cellulose
%, 25% demole EP aqueous solution (made by Kao Soap) 8% and water 2% 100 g acrylic resin emulsion paint
The antibacterial agents of Samples 1 to 6 obtained in Reference Example were added as shown in Table 3 and stirred (Examples 7 to 12).
In addition, a non-added paint was prepared (Comparative Example 5).

Using each paint obtained by adding the antibacterial agent in the ratio shown in Table 3, coat it twice on an aluminum plate with a length of 150 mm, a width of 70 mm and a thickness of 2 mm, and apply it at room temperature. A test piece was prepared by leaving it for 48 hours.

A test disk having a diameter of 20 mm was cut out from this test piece, and the antibacterial activity was evaluated in the same manner as in Examples 1 to 6, and the results are shown in Table 2 above.

The paint of each Example and the paint of Comparative Example 5 had discoloration,
There was no difference in the properties of paints such as paint and coating film appearance, drying property and hardening property.

Thereby, the coating composition containing the antibacterial agent of the present invention,
It can be seen that it has excellent antibacterial properties.

Examples 13 to 18 The test pieces prepared in Examples 7 to 12 are JIS-A1415.
According to the above, after processing for 500 hours using an accelerated exposure test device, a test disk having a diameter of 20 mm was cut out from each test piece,
The antibacterial activity was evaluated in the same manner as in Examples 1 to 6. The results were exactly the same as in Examples 7-12.

From this, it can be seen that the antibacterial composition containing the antibacterial agent of the present invention exhibits antibacterial properties for an extremely long period of time.

Examples 19 to 24 The antibacterial agents of Samples 1 to 6 prepared in Reference Example were added to and mixed with 6 nylon dry chips having a relative viscosity [η] of 2.3 measured with 95% sulfuric acid so as to have a concentration of 2% each. After melt-spinning by a conventional method, drawing was carried out to obtain 6 kinds of drawn yarns of 120 denier / 4 filament. Next, the drawn yarn was cylindrically knitted and refined, and then a test piece having a diameter of 20 mm was cut out, and the antibacterial activity was evaluated in the same manner as in Examples 1 to 6. As a result, as shown in Table 2, a stop band was formed in each case.

Examples 25 to 30 and Comparative Examples 6 to 8 Using the antibacterial agents of Samples 1 to 6 produced in Reference Examples, drawn yarns obtained in the same manner as in Examples 19 to 24 are tubular knitted and scoured to give a tubular knitted fabric. Was obtained (Examples 25 to 30).

Next, silver particles, silver-supported activated carbon and A-type zeolite (composition
0.94Na ₂ O ・ Al ₂ O ₃・ 1.92SiO ₂・ xH ₂ O, average particle size 1.1μ
m) 500 ml of a 1/10 M silver nitrate aqueous solution was added per 250 g and the mixture was stirred at room temperature for 3 hours, and three types of powder such as silver-type zeolite were pulverized and classified. The average particle size obtained is 1.0 each
It was a fine powder of μm, 1.1 μm, and 1.1 μm.

Using these fine powders, tubular knit fabrics were obtained in the same manner as in Examples 25 to 30 (Comparative Examples 6, 7, and 8).

The tubular knitted fabric obtained as described above was left outdoors for 2 years without direct sunlight and poor air permeability, and the state was observed.
The results are shown in Table 4.

Furthermore, the tubular knitted fabrics obtained in Examples 25 to 30 and Comparative Example 8 were washed according to JIS-0217 (method 105), and after this washing was repeated 100 times, a test piece was cut out from the tubular knitted fabric, The antibacterial activity was evaluated in the same manner as in Examples 1 to 6. As a result, in the tubular knitted pieces obtained in Examples 25 to 30, the inhibition zone was formed, but in the tubular knitted pieces obtained in Comparative Example 8,
No zone of inhibition was formed.

From the above results, it can be seen that the molded product containing the antibacterial agent according to the present invention retains the antibacterial activity for a very long period of time.

(C) Effect of the Invention The antibacterial agent of the present invention is chemically and physically stable, and can elute a minute amount of silver ions necessary for antifungal and antibacterial for a long time. It is extremely useful as a material exhibiting antifungal and antibacterial properties for a long time by using silver ions.

Claims (1)

[Claims] 1. A general formula Ag _x H _y AzM ₂ (PO ₄ ) ₃ (A is an alkali metal, M is Zr, Ti or Sn, x, y.
And z are each positive numbers less than 1 and x + y + z =
It is 1. ) An antibacterial agent containing a compound represented by