JPH0578218A - Germicidal and rust proof composition and mixture containing the same composition - Google Patents

Abstract

PURPOSE:To provide a composition composed of a germicidal powder and a natural organic polymer or a synthetic organic polymer and applicable to wide fields as an antibacterial agent, an antifugnal agent, a rust proof agent and an anti-alga agent. CONSTITUTION:A germicidal metal ion is adsorbed and supported on a calcium carbide powder or a hydroxyapatite powder (calcium phosphate) and the resultant ion-supporting powder is blended with a zinc oxide whisker having a single crystal three-dimensional structure to obtain a germicidal powder exhibiting a remarkably improved germicidal effect. The obtained germicidal powder remarkably improved in germicidal effect is blended with a natural organic polymer or a synthetic organic polymer and a ceramic powder and the resultant mixture is formed.

Description

Detailed Description of the Invention

[0001]

INDUSTRIAL APPLICABILITY The present invention provides an antibacterial effect by blending zinc oxide whiskers having a single crystal three-dimensional structure with ion-carrying particle powder in which antibacterial metal ions are adsorbed and supported on calcium carbonate particle powder or hydroxyapatite particle powder. Of the antibacterial particle powder, the antibacterial natural organic polymer composition mainly composed of the antibacterial particle powder and the natural organic polymer, and the antibacterial synthetic polymer composition mainly composed of the antibacterial particle powder and the synthetic organic polymer, The present invention relates to an antibacterial ceramic composition mainly composed of antibacterial particle powder and ceramics.

[0002]

2. Description of the Related Art Generally, it is well known that silver, copper, zinc and the like have antibacterial properties as a trace metal action. For example, soluble silver nitrate AgNO ₃ is diluted with water to be used as a newborn eye drop in a liquid form. , Copper is used as a drug that uses copper ions such as copper complex compounds, or is malleable,
Due to its high ductility, it has been widely used as an interwoven woven antibacterial filter for ultrafine fibers, and as an inner material for shoes by making use of the characteristics of antibacterial and deodorant effect by coating a non-woven fabric with copper-based amorphous alloy. Zinc is considered to play an important role in the metabolism of proteins, sugars and lipids, but it is widely used as a compound such as zinc white in pharmaceuticals and cosmetics.

Recently, a synthetic zeolite or a natural zeolite is chemically adsorbed by the ion exchange reaction to chemically adsorb the antibacterial metal and kneaded with a synthetic resin to provide an antibacterial synthetic resin (for example, JP-A-59-133236). Also, an antibacterial composition in which silver chloride is attached to an oxide support such as Ti, Mg, Al is described.

By the way, in recent years, various kinds of damages to buildings, industrial products, electric products, and organic polymers due to harmful microorganisms such as mold, algae, and bacteria have been increasing. Originally, plastics are known to have antibacterial properties against microorganisms such as molds and bacteria except some plastics (eg, melamine, polyvinyl acetate, viscose rayon), but actually suitable products In order to obtain
Auxiliary agents or additives such as plasticizers and lubricants must be added. Some of the blended auxiliaries, additives, etc.
So-called microbial deterioration occurs, such as contamination or discoloration by harmful microorganisms such as mold and bacteria.

Many proposals have been made to prevent these problems. For example, various titanium oxides have been attempted to be supported by a surface plating method or a vapor deposition method (for example, JP-A-63-64392). Publication).

[0006]

However, the water-soluble state containing the metal component is inconvenient in terms of handling and management, and there is a drawback that the application must be limited.

Further, it is expected that a method of supplementing the above-mentioned drawbacks by holding fine metal particles of silver, copper, zinc or the like in a synthetic organic polymer or fiber, and utilizing it in a wide range of fields, will actually impart antibacterial properties. It has a poor affinity with synthetic organic polymers, and it is difficult to obtain a favorable color tone. In addition, the weaving of various fibers and the like in the form of ultrafine wires by utilizing the great malleability and ductility of silver or copper has a bad influence on the physical properties because the Young's modulus of the organic polymer and the metal is significantly different. There is a danger, and there is the problem that the cost will increase. Therefore, the present invention is intended to solve the above problems and to provide antibacterial powder particles, a natural organic polymer composition, a synthetic organic polymer composition and a ceramic composition which can be used in a wide range of fields. ..

[0008]

In order to achieve the above object, the antibacterial composition of the present invention comprises an ion-supporting particle powder obtained by adsorbing and carrying antibacterial metal ions on calcium carbonate particles or hydroxyapatite particles. By mixing zinc oxide whiskers having a crystalline three-dimensional structure, antibacterial powder particles having an enhanced antibacterial effect are mixed with a natural organic polymer or a synthetic organic polymer and a ceramic powder, and molded.

[0009]

[Function] Since the zinc oxide whiskers to be mixed with the ion-supporting particle powder are single crystal tetrapot-shaped particle powders and have a unique shape of growing in four directions, which is not found in other crystals, the conventional multi-particle powders can be used. It is more active than crystalline zinc oxide powder and has fast-acting and stable and long-lasting antibacterial effect.

[0010]

EXAMPLE This example will be described below.

The present inventors have developed a zinc oxide whisker in the form of a single crystal tetrapot (three-dimensional structure), and the whisker fiber length is from 2 μm to 3 μm to several tens.
A manufacturing technology that can be arbitrarily adjusted to 0 μm has also been established, with a specific gravity of 5.78 (air permeation method) and a sublimation temperature of about 1720.
℃, tensile strength 270-280kgf / cm ² , bending strength 440
kgf / cm ² , flexural modulus 20000-21000 kgf / cm ²
Since it has properties such as, it can be used in a wide range of fields such as reinforcement of synthetic organic polymers, improvement of creep properties, or increase of vibration damping by combining with synthetic organic polymers. I got the materials. (Table 1)
Is a comparison of the physical properties of the glass fiber usually used as a reinforcing material and the zinc oxide whiskers.

[0012]

[Table 1]

When the present inventors compared the presently commercially available zinc oxide (zinc white) with the above-mentioned newly developed zinc oxide whiskers in terms of particle powder shape, the present inventors found that there was no zinc oxide (zinc white) commercially available. Zinc oxide whiskers are in the form of single crystal tetrapots, whereas they are in the form of regular fine powders.We focused on the large difference in shape and activity, and conducted various studies on antibacterial properties (for simplicity, Crystal tetrapod-shaped zinc oxide whiskers are described as zinc oxide whiskers.) That is, the present invention is characterized by mainly mixing zinc oxide whiskers with calcium carbonate particle powder or hydroxyapatite (calcium phosphate) particle powder carrying one or more kinds of silver ion, copper ion and zinc ion. An antibacterial natural organic polymer obtained by combining the antibacterial particle powder with a natural organic polymer, an antibacterial synthetic organic polymer obtained by combining the antibacterial particle powder with a synthetic organic polymer, and the antibacterial particle powder. In providing an antibacterial ceramic composition composited with ceramics, among the antibacterial particle powders, calcium carbonate particle powder and hydroxyapatite particle powder which are base materials for adsorbing and supporting the metal ions are , Various particle powders are commercially available, but regarding the calcium carbonate particle powder, The specific surface area 0.3~40m
² / g (BET method) is sufficient, and a water suspension pH of 7.0 to
9.5, Ket white liquid meter 5.0 to 9.8, and particle size 0.
It may be in the range of 1 to 8 μm. In particular, in order to quickly enable the physical adsorption supporting process, 30-40 m ² / g
It is preferable to have a specific surface area of
9.5 is preferable. On the other hand, the hydroxyapatite particle powder is represented by the structural formula of Ca ₁₀ (PO ₄ ) ₆ (OH) ₂ ,
It is a group of phosphate minerals that are commonly produced as apatite.

The hydroxyapatite particle powder used in the present invention may have a particle size of 100 to 350 mesh and a specific surface area in the range of 60 m ² / g to submicron fine particle powder, but is preferably 60 m ² / g. Further, the water suspension PH is preferably 7 to 9.5.

Conventionally, as a method for supporting a metal ion of silver, copper or zinc, for example, in the case of supporting it on zeolite, a metal ion supporting method (also called chemisorption) utilizing the ion exchange ability of zeolite, and various oxidations are carried out. A plating method, a vapor deposition method, or the like for depositing silver or copper on the surface of titanium particle powder has been tried, but in the present invention, immersion of calcium carbonate particle powder or hydroxyapatite particle powder in an aqueous solution of the metal component by immersion adsorption Method (also called physical adsorption).

Therefore, particular attention must be paid to the specific surface area of the substrate. Usually, when supporting silver, copper or zinc, a solution of a water-soluble metal salt such as silver nitrate AgNO ₃ , copper sulfate CuSO ₄ or zinc sulfate ZnSO ₄ is used, but be careful not to make this concentration excessive. There must be. For example, when the silver ion is immersed and supported on the calcium carbonate particle powder by immersion, if the silver ion concentration is excessive, the silver ion precipitates as a silver oxide in the solid phase (porosity) of calcium carbonate.

For this reason, the porosity of the calcium carbonate particle powder is reduced, and the presence of silver oxide may reduce the desired adsorption force. This is common to hydroxyapatite particles.

In order to prevent such excess silver from precipitating on the calcium carbonate particle powder or the hydroxyapatite particle powder, the concentration of the silver aqueous solution should be kept as dilute as possible, for example, the concentration of silver nitrate AgNO ₃ . Must be kept in a diluted state in the range of 0.1 to 0.5 mol / l.

Next, when copper ions as defined in the present invention are adsorbed and supported on the calcium carbonate particle powder or hydroxyapatite particle powder as the base material, the same state as described above occurs (hereinafter, for the sake of simplicity, calcium carbonate is used). The particle powder is used as the base material A and the hydroxyapatite particle powder is used as the base material B).

For example, when a 1 mol / l copper sulfate CuSO ₄ solution is used, a precipitate of basic carbonate CuCO ₃ .Cu (OH) ₂ is deposited in the solid phase of the base material A and the base material B. The porosity of the base material A and the base material B may be reduced, and the target adsorption force may be reduced.

In order to prevent such excessive copper precipitation, it is desirable to keep the concentration of the water-soluble copper sulfate used in a more dilute state, for example, 0.05 mol / l or less. In the present invention, the adsorbing and supporting treatment of the metallic component of silver or copper on the base materials A and B can be carried out by the following method. For example, it is a method of immersing the base material A or the base material B in an aqueous metal ion solution containing the metal component, and stirring the solution for a predetermined time to adsorb and carry the metal ions, that is, silver ions and copper ions. It has been found that when A or the base material B is wetted in advance, it is possible to suppress the oxidative precipitation of the metal adsorbed and supported in the pores of the base material A or the base material B. .. This phenomenon seems to be closely related to that the pH of the aqueous suspension PH of the base material is 7.0 to 9.5. If the metal oxide precipitates in the aqueous solution of metal ions, ammonia water may be added to form complex ions for use, and the ammonia water may be added until the metal oxide is dissolved. The proportion of silver, copper or zinc in the A or B base material is 30% by weight or less for silver Ag, preferably 0.01 to 3%
The range is. Copper Cu and zinc Zn are 35% by weight or less, preferably 0.01 to 3.0%.

If the amount is less than 0.01%, the antibacterial and anticorrosive effects aimed at by the present invention cannot be sufficiently obtained.
This is because if the amount is too much, such as 3% or more, the antibacterial / rust-preventing effect does not change, which is disadvantageous in terms of cost.

(Example 1) 15 g of silver was dissolved in 400 g of a 10% nitric acid solution to prepare a silver nitrate solution, water was added to make 1 liter of a water-soluble metal salt solution, and an 8.5% aqueous ammonia solution was added. , A complex ionized silver nitrate complex ion solution is prepared and heated and cooled, for example, in a container equipped with a high temperature oil circulation tank, a particle diameter of 0.5 μm, a specific surface area of 40 m ² / g, and a water suspension of pH 7.0, 1 kg of calcium carbonate. Throw in 11
It is kept at 0 ° C., and is sufficiently adsorbed and supported while being well stirred.
At this time, water and ammonia in the solution are completely vaporized, and silver is uniformly supported on the surface of the calcium carbonate particles. Furthermore, particle size 150 mesh, specific surface area 60 m ² /
g, 1 kg of hydroxyapatite with pH 7.0 in water suspension, and natural organic polymer (molecular weight 500
(00) together with the above-mentioned silver-calcium carbonate powder and zinc oxide whiskers while being heated and maintained at 110 ° C., each raw material was stirred with a crusher until sufficiently dispersed, and then extruded into a white sphere of about 2.5φ. Molded with a molding machine 80-1
When dried at 00 ° C. for about 4 hours, white spheres are obtained, which are the antibacterial, mildew-proof, rust-proof and algae-proofing agent of the present invention. The shape and color can be freely selected in the manufacturing process, and the function is not impaired with general color pigments.

Comparative Example 1 Here, in order to evaluate the degree of influence of zinc oxide whiskers on antibacterial and other effects,
The amount of zinc oxide whiskers added was changed so that the weight ratio was 0% to 30%.

The composition is shown in (Table 2).

[0026]

[Table 2]

The amount of expensive silver supported is 0.01 to 3% when it is used in combination with zinc oxide whiskers, and the cost performance becomes worse when the amount is more than this range. Therefore 1.5%
I decided to evaluate it at a certain level.

Although calcium carbonate and hydroxyapatite do not have antibacterial and antifungal effects by themselves, they have a sufficiently large specific surface area and are relatively easy to support silver, especially hydroxyapatite. Is insoluble in water and is ideal for immersion in water.
The more desirable property is that even if this product is no longer needed and it is discarded, the raw materials used in this product do not require any special treatment and can be treated as general industrial waste.

Calcium carbonate is cheaper in price than hydroxyapatite and is excellent in cost performance, and is widely used as a composite material in general resins. In addition, if the calcium carbonate is increased above this ratio, the water may become cloudy and the molded shape may collapse when immersed in water for a long time. From the above viewpoints, we decided to change the content of zinc oxide whiskers in calcium carbonate, hydroxyapatite, binder, etc.

(Example 2) In Example 1, calcium carbonate was used as a carrier for silver metal ions, whereas in Example 2, hydroxyapatite was used as a carrier.
White spheres having the same effects, that is, antibacterial, antifungal, rustproof and algaeproof properties can be obtained by the same operation as in Example 1.

(Comparative Example 2) In the same manner as in Comparative Example 1, the effect was evaluated by changing the proportion of zinc oxide whiskers added so that the weight ratio was 0 to 30%.

The composition is shown in (Table 3). However, even if calcium carbonate in (Table 3) is replaced with hydroxyapatite, the effect does not change at all.

[0033]

[Table 3]

(Example 3) In Example 1, calcium carbonate was used as a carrier, and in Example 2, hydroxyapatite was used as a carrier. This embodiment is a composite of the first or second embodiment and a synthetic resin (plastic). That is,
Silver nitrate solution is made by dissolving 15 g of silver in 400 g of 10% nitric acid solution, water is added to make 1 liter of water-soluble metal salt solution, and 8.5% ammonia aqueous solution is added to make complex ionized silver nitrate complex ion solution. 0.5 μm in a container equipped with a high temperature oil circulation tank that can be heated and cooled.
m, a specific surface area of 40 m ² / g, and 1 kg of calcium carbonate having an aqueous suspension pH of 7.0 and charged at 110 ° C., and sufficiently adsorbed and supported while stirring well. Put this in the dryer 80
C. to 100.degree. C. is held for about 2 hours and dried to vaporize water and ammonia. In the process of pelletizing with a resin extruder (extruder) as a means to combine the obtained antibacterial powder with a synthetic resin, the antibacterial powder and the resin are first mixed to form an initial composite resin, and injection molding is performed. There are a method of compounding with zinc oxide whiskers at the step, a method of simultaneously compounding the above three kinds of materials at the time of extruding step for making pellets, a method of dividing the extruding step into two steps and compounding two kinds each. This makes it possible to obtain an injection-moldable antibacterial resin.

The former compounding with zinc oxide whiskers at the time of injection molding is considered to be more effective, but Example 3
Then, choose polypropylene as the plastic, and weigh each powder 1 powder, zinc oxide whiskers 1, polypropylene 8
The composite pellets were obtained at the ratio of.

(Comparative Example 3) In this example, based on Example 3,
The effects were evaluated by adding the addition amounts of zinc oxide whiskers and carrier powder. The composition is shown in (Table 4).

[0037]

[Table 4]

(Comparative Example 4) In this example, the resin material is changed by using the method of Example 3. However, the amount of zinc oxide whiskers added was 20% and the amount of powder added was 10%.
Table 5 shows the composition of the resin.

[0039]

[Table 5]

The materials of the synthetic resin are as follows.
The effects of antibacterial, mildewproof, rustproof, algaeproof, etc. are the same as polypropylene.

1. Acrylic 2. Polystyrene 3. ABS 4. Polycarbonate 5. polyethylene
6. Nylon 7. POM 8. Polyamide imide
9. Polyacetal (Example 4) In Examples 1, 2, and 3, calcium carbonate or hydroxyapatite and a synthetic resin were used as a carrier for silver metal ions.

In this example, a ceramic powder such as acid clay,
It is a carrier such as Doshisen (name of raw material for ceramics). In the same manner as in Example 3, calcium carbonate was replaced with ceramic powder to be adsorbed and supported, and molded to form a white spherical body having a diameter of about 3φ to 10φ. Kitchen products such as pots can be made from this white sphere. After leaving it at room temperature for about 2 weeks to dry, it is put in a baking pot, and the baking is completed in about 2 hours at a maximum temperature of 1100 ° C. through the same steps as the baking of ceramics. However, raising and lowering the temperature gradually takes about 7 days each.

Comparative Example 5 The compositions of silver-ceramic powder and zinc oxide whiskers are shown in (Table 6).

[0044]

[Table 6]

(Antibacterial and antifungal effect) Examples 1, 2, 3, 4
Antibacterial powders and antibacterial compositions A, B, C, D to P, Q, R obtained in Comparative Examples 1, 2, 3, 4, and 5 except N
An antibacterial and antifungal test was conducted on 5 types. The molds used in the test were the first group Aspergillus Niger and the second group Penisillium Citrinum according to JIS 2911 “Mold resistance test method”.
Blue mold, 4th group Cladosporium Cladosporiodes, 5th group Ketotomium Globosum, and 5 fungi Candida Albicans
It is a seed. The test method is Sabouraud-Agar (Sabouraud
-Agar medium) is poured into a petri dish, and the antibacterial composition is evenly and thinly arranged on the surface. After uniformly applying the test bacteria on the entire surface, place it in a weather meter at a temperature of 28 ° C and a humidity of 70 to 75
After setting the condition to%, it was left to stand for 150 hours and the state of reproduction of test bacteria was examined. The results are shown in (Table 7) and (Table 8).

[0046]

[Table 7]

[0047]

[Table 8]

ABCD ... PQR in (Tables 7 and 8) is
It corresponds to the samples of Examples 1 to 4 and Comparative Examples 1 to 5. In the table, + means that there is an antibacterial effect, and-means that there is no antibacterial effect.

(Rust prevention effect) A beaker containing 500 ml of tap water was prepared, and 15 kinds of samples A to R except N were added so that the weight ratio was 0.4%. Insert the steel wire in the same manner as 20 cm so that it is fully immersed in water. Steel wire rusts and brown iron rust floats or precipitates in water depending on the number of days. The steel wire left at room temperature for 50 days is taken out of water and the weight before and after the test is measured. The results of comparing the rates of rusting with the percentage of reduction in the weight of steel wire are shown in (Table 9).

[0050]

[Table 9]

Those having a zinc oxide whisker content of more than 20% exhibited a very excellent rust preventive effect,
In particular, by putting it in a water circulation type cooling circuit such as a cooling tower, there is no clogging of the cooling circuit due to iron rust, and it can always be used in a clean state. Regarding the durability of the effect,
Since it consumes very little and melts into water, it is much more durable and cost effective and ecologically advantageous as compared with other methods such as continuous dropping method and dissolution method.

(Algae proof effect) 5 as in the test for rust proof effect
Green algae (Sayamidori Dedogonial) in a 00 ml beaker
es) is added to the water in the pond, and samples AB to QR are set to 0.4.
%, The difference due to the content of zinc oxide whiskers, and the difference between the non-addition were observed. Although the algae differed depending on the difference in the content, they settled with the passage of days and became almost completely transparent water except the bottom. As an application of this effect, two cooling towers exposed to direct sunlight were selected, and one of them puts 0.4% of the sample into its holding water tank. One cooling tower was left untouched. Similarly, before the addition, the cooling water circuit was thoroughly washed and the generation of two algae was observed. Natural algae gradually develop algae, and once a week has passed, once a week,
The algae were so dense that a sufficient amount of water could not be secured unless the algae were removed by hand. The sample added has the advantage that it does not generate algae and exhibits stable performance without impairing the cooling performance. Furthermore, when it is put into a goldfish aquarium, there is no stain on the glass wall surface and no stain on the water itself.

[0053]

As described above, it has been confirmed that the synergistic effect of metal ions and zinc oxide whiskers exhibits excellent antibacterial, antifungal and antialgal effects. In addition, zinc leaching into water is 0.25 mg / l, which is 1/20 of the emission standard, and similarly, silver is 0.01 ml / l, confirming that it is an environmentally safe material. Was done. This safety expands the range of use,
It has a high industrial value.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Minoru Yoshinaka 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (5)

[Claims] 1. An ion having antibacterial properties, which comprises one or more metal ions selected from the group consisting of silver, copper and zinc, and calcium carbonate, calcium phosphate and ceramic materials which adsorb and carry the metal ions. An antibacterial / rust-preventive composition comprising a carrier having at least one carrier selected from the group consisting of the following, and a zinc oxide whisker having a three-dimensional structure in the form of a single crystal tetrapot. 2. The antibacterial / rust-preventing composition according to claim 1, which contains 3% by weight of a metal capable of eluting metal ions as an upper limit. 3. The antibacterial / rust preventive composition according to claim 1, which contains zinc oxide whiskers in an amount of 10 or more and 30% by weight or less. 4. A mixture obtained by mixing the antibacterial / rust-preventing composition according to claim 1, 2 or 3 with a resin or a resinous material to form a small particle. 5. The mixture according to claim 4, which is in the form of pellets.