JP2987262B2 - Antimicrobial agent and antimicrobial resin or rubber composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a novel antimicrobial agent and an antimicrobial resin or rubber composition. More specifically, it is non-toxic or extremely non-toxic in itself,
An antimicrobial agent that is a fine particle having high heat resistance and weather resistance, and has a characteristic of being excellent in dispersibility in resin, rubber and paint, and further improving the thermal stability thereof when blended in resin, rubber and paint, Specifically, the present invention relates to an antibacterial agent, an antifungal agent, and an antimicrobial resin or rubber composition containing the antimicrobial agent.

[0002]

2. Description of the Related Art Climate climates with high humidity and temperature, such as Japan, are suitable for the propagation of microorganisms. For this reason, microorganisms (bacteria, mold, etc.) propagate in drinking water, foods, and the like, and often bring serious danger to human life. In addition, food, cosmetics, plastic products, wallpaper, interior and exterior products for automobiles, building materials, electric wires, cables, synthetic leather, sealants,
Microorganisms propagate on rubber hoses, flooring materials, wood, paint, etc.
Discoloration, odor, strength deterioration, etc. may occur. For example,
If it is an electric wire, it may lead to electric leakage, which may cause a fire, an electric shock or the like. Damage such as damage to cultural properties caused by microorganisms, cancer caused by molds bred on plastics, development of allergic pneumonia, occurrence of large numbers of mites feeding on breeding bacteria, athlete's foot caused by Trichophyton parasite, and development of stubborn disease Bring.

[0003] The need to prevent the above-mentioned microbial disaster has been increasing more and more in recent years, and various antimicrobial agents are commercially available. These antimicrobial agents include chlorine, bromine,
Halogen compounds containing iodine; inorganic compounds such as copper arsenite, cuprous oxide, silver nitrate, glass containing silver and copper;
Nitrogen compounds such as amines and triazines; arsenic, copper, mercury,
Organometallic compounds such as tin and zinc; organic sulfur compounds such as isothiazolone, pyrithione and thiocyanate; quaternary ammonium compounds such as alkyldimethylbenzylammonium compounds; chlorinated phenols, bisphenols, O-
It is classified into phenol compounds such as phenylphenol.

[0004]

The existing antimicrobial agents include:
Many are highly toxic, and have not only safety for the human body but also environmental pollution. Moreover, it is expensive for its effect. For example, a high effect cannot be obtained unless an expensive metal such as silver is used. In addition, the addition of existing antimicrobial agents often results in deterioration of heat resistance of products, deterioration of product appearance and mechanical strength due to poor dispersion in resins, rubbers, and paints, and the like.

The present invention provides a novel antimicrobial agent which is nontoxic or nearly nontoxic in itself, yet has a high antimicrobial effect, and is insoluble or hardly soluble in water or organic solvents and does not pose a problem of environmental pollution. The purpose is to provide microbial agents. Furthermore, the present invention itself is stable against heat and ultraviolet rays, and is well dispersed in resins, rubbers and paints, so that it has excellent workability, appearance of molded products, mechanical strength, and existing copper and zinc. Provided are an antimicrobial agent which does not have a drawback such as remarkably lowering the thermal stability of a resin contained in an antimicrobial agent, for example, a halogen-containing resin such as vinyl chloride, and a resin or rubber composition containing the antimicrobial agent. With the goal.

[0006]

SUMMARY OF THE INVENTION The present invention relates to compounds of formula ^{_{(1) (M 1 2+)}} 1-x (M 2 2+) x O (1) [ in the formula, the M ₁ is Mg and / or Ca , M ₂ represents Cu and / or Zn, and x is 0.0001 ≦ x ≦ 0.0.
5, preferably 0.0005 ≤ x ≤ 0.4, more preferably 0.001 ≤ x ≤ 0.3]. Provided as an active ingredient is a composite metal oxide having the following formula:

Further, the present invention relates to 100 parts by weight of a resin or rubber and 0.001 to 50 parts by weight, preferably 0.00
An antimicrobial resin or rubber composition comprising 1 to 15 parts by weight, more preferably 0.01 to 5 parts by weight, of the above antimicrobial agent is provided.

The present inventor has focused on zinc ions and copper ions which are relatively inexpensive and which are nontoxic or have relatively low toxicity, and discuss the cause of the low antimicrobial effect of existing antimicrobial agents containing these metals. The examination was repeated. As a result, it was presumed that these antimicrobial agents had low solubility in water, that is, were caused by poor solubility. As a result, the present inventor has determined that the formula (2) (M ₁ ²⁺ ) _1-x (M ₂ ²⁺ ) _x (OH) ₂ (2) [wherein M ₁ , M ₂ and x represent the formula (1) In the composite metal hydroxide represented by the formula, the copper ion and the zinc ion show moderate solubility in water. Have been found to be effective (Japanese Patent Application No. 3-3375).
94). It has also been found that this compound, when incorporated into a resin or rubber, not only does not deteriorate the heat resistance and weather resistance of the resin or rubber, but rather improves these properties.

As a result of further research, the composite metal oxide of the formula (1) obtained by calcining the composite metal hydroxide of the formula (2) is more effective as an antimicrobial agent than the compound of the formula (2). Was found to show the work of. It has also been found that a resin or rubber containing the composite metal oxide of the formula (1) exhibits properties such as heat resistance and weather resistance which are more improved than those of the compound of the formula (2).

Although such characteristics are not known in detail, they are presumed to be exhibited for the following reasons. Copper and / or zinc form a solid solution in magnesium oxide or calcium oxide and are dispersed in the form of atoms in the crystal of magnesium oxide or calcium oxide, and crystallization of cupric oxide or zinc oxide is suppressed. Is done. For this reason, it is extremely active, and since calcium oxide or magnesium oxide shows appropriate solubility in water,
Releases copper and / or zinc ions easily and over time. By moderate solubility is meant solubility that is much more soluble than cupric oxide and zinc oxide, but not so soluble in water as cupric nitrate and zinc nitrate. The magnesium oxide or calcium oxide, cupric oxide and zinc oxide, particularly cupric oxide
It is presumed that the resin and rubber of the present invention exhibit a function of preventing the heat and weather resistance of the halogen-containing resin such as vinyl chloride from deteriorating, but rather improving it.

Since the former is diluted with magnesium oxide or calcium oxide which is less expensive than zinc oxide and cupric oxide, it is easy to use in terms of cost. Compounds of formula (1) containing zinc are not only non-toxic,
While having excellent whiteness, hiding properties and UV resistance,
It has the advantage that resin and rubber can be colored freely. Even when the compound of the formula (1) contains copper, its color is diluted with magnesium oxide and / or calcium oxide. It also has the advantage of being significantly lower than compounds.

The compound of the present invention represented by the formula (1) is a novel compound found by the present inventors, and is disclosed in Japanese Patent Application No. Hei.
No. 6813, Japanese Patent Application No. 3-124758, Japanese Patent Application No. 3-1
Hexagonal plate-like or fibrous composite metal hydroxides disclosed in U.S. Pat.
Obtained by sintering at 3 00 ° C. or higher. This compound is obtained by ^adding copper ion (Cu ²⁺ ) and / or zinc ion (Z
n ²⁺ ) is a compound having the same crystal structure as magnesium oxide or calcium oxide, in which n ²⁺ ) is dissolved. It shows almost the same diffraction pattern as magnesium oxide or calcium oxide when subjected to powder X-ray diffraction.

In the formula (1), when the value of x exceeds 0.5, cupric oxide and / or zinc oxide are mixed in the solid solution of the formula (1), and the above-mentioned advantage of the solid solution of the formula (1) is not satisfied. There is a tendency that it is not sufficiently exhibited. When the value of x is less than 0.0001, the concentration of copper and / or zinc, which is an active ingredient for antimicrobial action, becomes too low, so that excellent antimicrobial action tends to be unable to be exhibited. Therefore, the range of x of the antimicrobial agent of the present invention is 0.0001 ≦ x ≦ 0.5, preferably 0.0005 ≦ x ≦ 0.4, more preferably 0.001 ≦ x ≦ 0.2. . In the present invention, the by-produced cupric oxide and / or zinc oxide is represented by the formula (1)
Can be applied as an antimicrobial agent even when mixed with the composite metal oxide.

The method for producing an antimicrobial agent of the present invention comprises the steps of: preparing an aqueous solution containing magnesium ions and / or calcium ions and copper ions (Cu ²⁺ ) and / or zinc ions (Zn ²⁺ ); Alkaline substance of approximately equivalent or less with respect to the total equivalent is added, reacted under stirring, and if necessary, the reaction product is further subjected to hydrothermal treatment at about 100 to 200 ° C. using an autoclave, followed by washing with water, dehydration,
dry. Then, after baking at about 300 to 1200 ° C., preferably about 400 to 900 ° C. for about 0.1 to 10 hours, it is manufactured by appropriately selecting and employing conventional means such as pulverization, surface treatment, and classification. In order to further increase the dispersibility and affinity of the antimicrobial agent in the resin and rubber, an anionic surfactant, aluminum, a titanate coupling agent, a fatty acid ester of a polyhydric alcohol, etc., are used in a conventional method. The surface treatment may be applied to the antimicrobial agent.

The antimicrobial agent of the present invention includes drinking water, food, resin, rubber, wallpaper, bathroom interior materials, electric wires, flooring materials, cement,
Shower curtains, urethane foam, veils, vinyl sheets, agricultural films, synthetic leather, sealants, building materials, furniture, textiles such as cloth, tents, socks, non-woven fabrics,
It is used in paints such as ship bottom paints, adhesives, wood, bamboo materials, cosmetics, oral products such as toothpastes, toothbrushes, pools, cooling towers, and various other fields that may be adversely affected by microorganisms. The antimicrobial agent of the present invention comprises
Usually, it is appropriately mixed and used in the range of 0.001 to 50 parts by weight with respect to 00 parts by weight, but the amount is appropriately selected depending on the use. The antimicrobial agent of the present invention has an average secondary particle size of about 0.5.
It can be 1 to 2 μm, and is excellent in dispersibility in resin, rubber, and paint.

Examples of the resin and rubber used in the present invention are as follows. For example, polyvinyl chloride, polyvinylidene chloride, polyethylene, copolymers of ethylene and other α-olefins, copolymers of ethylene and vinyl acetate, ethyl acrylate or methyl acrylate, polypropylene, propylene and other α-olefins Copolymer with olefin, polybutene-1, polystyrene, styrene and acrylonitrile, ethylene and propylene, copolymer with ethylene and propylene diene rubber or butadiene, vinyl acetate, polyacrylate, polymethacrylate, polyurethane, polyester, polyether, Thermoplastic resins such as polyamides, phenolic resins, melamine resins, epoxy resins, unsaturated polyester resins, thermosetting resins such as alkyd resins, EPDM, SBR, NBR, butyl rubber,
Rubbers such as isoprene rubber and chlorosulfonated polyethylene can be exemplified, but not limited thereto.
Hereinafter, the present invention will be described in more detail by way of examples.

EXAMPLE 1 A mixed aqueous solution of magnesium nitrate and cupric nitrate (Mg ²⁺ =
1.05 mol / l, Cu ²⁺ = 0.05 mol / l, 25 ° C.) 2 liters were placed in a 5 liter stainless-steel cylindrical reaction vessel, and 1.0 mol / l of synthetic Ca was stirred. (OH) ₂ 2 liters (25 ° C.) was added and reacted. Thereafter, the reaction product was heated and aged at 100 ° C. for the first time, then filtered, washed with water, dried and pulverized. 450 this thing
Calcination was carried out at a temperature of 1 ° C. for 1 hour using a siliconite furnace.

The chemical composition was Mg _0.95 Cu _0.05 O.
The X-ray diffraction pattern of the fired product did not show the presence of cupric oxide, and was only that corresponding to magnesium oxide. Therefore, it was confirmed that cupric oxide was dissolved in magnesium oxide. The chemical composition of this product was measured by a chelate titration method, and the average secondary particle diameter was measured by a microtrack method after a dispersion treatment using an ultrasonic method using ethanol as a solvent. In the antibacterial test, the minimum growth inhibitory concentration was defined as the minimum concentration at which the growth of the bacteria was inhibited after the bacterial solution for inoculation adjusted to an arbitrary concentration was spread on an agar plate medium and cultured. The lower the concentration, the higher the antibacterial property. Table 1 shows the measurement results.

Example 2 A mixed aqueous solution of magnesium nitrate and zinc nitrate (Mg ²⁺ =
1.1 mol / l, Zn ²⁺ = 0.02 mol / l, 20 ° C.) 2 liters were placed in a 5 liter stainless steel cylindrical reaction vessel, and 1.0 mol / l of synthetic Ca was stirred. (OH) ₂ 2 liters (20 ° C.) was added to the whole mixture and reacted. Thereafter, the reaction product was heated and aged at 120 ° C. for 2 hours, and then filtered, washed with water, dried and pulverized. 500 this thing
Calcination was carried out at a temperature of 1 ° C. for 1 hour using a siliconite furnace.

The chemical composition was Mg _0.98 Zn _0.02 O. The X-ray diffraction pattern of the fired product was only that corresponding to magnesium oxide. Therefore, it was confirmed that zinc oxide was dissolved in magnesium oxide. Table 1 shows the measurement results.

Example 3 A mixed aqueous solution of calcium nitrate and copper nitrate (Ca ²⁺ = 0.
85 mol / L, Cu ²⁺ = 0.15 mol / L, 30 ° C.) 2 L and 2.0 mol / L of N
2 liters of an aOH aqueous solution (30 ° C.) were flowed at a flow rate of 50 ml / min.
The reaction was continuously supplied to a 5 liter reaction tank containing 0 ml of water. Filter the reaction mixture, wash with water,
After dehydration, drying and pulverization, 550 ° C using a siliconit furnace
For 1 hour.

The chemical composition was Ca _0.82 Cu _0.18 O. The X-ray diffraction pattern of this product was only CaO. Therefore, it was confirmed that CuO was dissolved in CaO. Table 1 shows the measurement results of this product.

Example 4 4 L of a 1.0 mol / L slurry of Ca (OH) ₂ synthesized at 20 ° C. from NaOH and Ca (NO ₃ ) ₂
Was placed in a reaction vessel having a capacity of 5 liters, and 240 ml of a 1.0 mol / l aqueous solution of zinc nitrate (20 ° C.) was added and reacted under stirring. The reaction product is filtered, washed with water, dried,
After the pulverization, the mixture was fired at 600 ° C. for 1 hour using a siliconit furnace.

The chemical composition is Ca _0.94 Zn _0.06 O
Met. The X-ray diffraction pattern of this product was only CaO. Therefore, it was confirmed that ZnO was dissolved in CaO. Table 1 shows the measurement results of this product.

[0025] Example 5 Synthesis Ca (OH) ₂ of 1.0 mol / liter of slurry 2
Liter (20 ° C.) into a 5 liter reactor,
Under stirring, 2 liters of a mixed aqueous solution of magnesium nitrate and cupric nitrate (Mg ²⁺ = 0.08 mol / l, Cu ²⁺ = 0.10 mol / l, 20 ° C.) was added and reacted.
The reaction product was filtered, washed with water, dried and pulverized, and then calcined at 600 ° C. for 1 hour using a siliconite furnace.

The chemical composition was Ca _0.82 Mg _0.08 Cu _0.10 O. The X-ray diffraction pattern of this product was only CaO. Therefore, it was confirmed that both MgO and CuO were dissolved in CaO. Table 1 shows the measurement results of this product.

Example 6 31 g of magnesium oxide powder was added to 5 liters of a 3.0 mol / l aqueous solution of magnesium chloride with stirring, and the mixture was reacted at 40 ° C. for 7 hours. In this system,
35 ml of a 1.0 mol / l zinc chloride aqueous solution was added thereto, and the mixture was reacted for about 30 minutes, filtered, washed with water, and the obtained cake was heated to 90 ° C. and a 5 mol / l aqueous sodium hydroxide solution was added. The solution was added to 500 ml with stirring and reacted for about 20 minutes. After the reaction, filtration,
Washed, dried and sieved. This was fired at 500 ° C. for 1 hour in an air atmosphere using an electric furnace.

The chemical composition was Mg _0.96 Zn _0.04 O.
Observation of the fired product by a scanning electron microscope revealed a fibrous outer shape having a minor axis of about 0.2 to 0.3 μm and a major axis of about 20 to 60 μm. The powder X-ray diffraction pattern was almost the same as that of magnesium oxide, and no zinc oxide was detected.
Table 1 shows the measurement results of this product.

[0029] Comparative Example 1 Synthesis Ca (OH) ₂ of 1.0 mol / liter of slurry 2
Liter (20 ° C.) into a 5 liter reactor,
Under stirring, 2 liters of a 0.6 mol / liter aqueous solution of cupric nitrate (20 ° C.) was added and reacted. The reaction product was filtered, washed with water, dried and pulverized, and then subjected to 60
It was baked at 0 ° C. for 1 hour.

The chemical composition was Ca _0.4 Cu _0.6 O. The X-ray diffraction pattern of this product showed two of CaO and CuO. Therefore, it was confirmed that CuO not dissolved in CaO was present. Table 1 shows the measurement results of this product.

Comparative Examples 2 and 3 Table 1 shows the measurement results of commercially available reagent grade 1 CuO (Comparative Example 2) and ZnO (French method, special name, Comparative Example 3).

Table 1 Average secondary particle size Antibacterial activity (%)Example (Μm) E. coli Staphylococcus aureus  1 1.10 0.05 0.05 2 0.34 0.125 0.13 0.72 0.025 0.025 4 1.20 0.125 0.15 0.87 0.05 0.05 6 Minor diameter 0.2 ■ 0.3 0.125 0.1 Long diameter 20 ■ 60Comparative example 1 3.40 1.0 or more 1.0 or more 2-1.0 or more 1.0 or more 3 0.50 1.0 or more 1.0 or more Note: Antibacterial activity indicates minimum growth inhibitory concentration.

Examples 7 and 8 and Comparative Examples 4 and 5 In order to prepare a sheet of soft vinyl chloride, the following compounding ratio: 100 parts by weight of polyvinyl chloride (average degree of polymerization: 1300) 100 parts by weight of dioctyl phthalate 50 parts by weight of Ba / Zn composite heat Stabilizer 2 parts by weight Epoxidized soybean oil 2 parts by weight Antifungal agent 1 part by weight After uniformly mixing the composition, the mixture was melt-kneaded at 170 ° C. for 3 minutes using a roll. Then, using a press molding machine,
A sheet having a thickness of 1 mm was prepared at 70 ° C. for 2 minutes at 200 kg / cm ² . Blue mold was sprinkled on this sheet, and the growth state of the mold was observed thereafter. On the other hand, the time until the sheet was placed in an oven at 190 ° C. and turned black was measured. Since vinyl chloride blackens when thermally degraded, the longer the time until blackening is, the better the thermal stability is. Table 2 shows the measurement results. As an antifungal agent, Example 7 used the antimicrobial agent obtained in Example 1, Example 8 used the antimicrobial agent obtained in Example 4, Comparative Example 4 used CuO of Comparative Example 2, In Example 5, the ZnO of Comparative Example 3 was used.

Table 2 Results of Evaluation of Thermal Stability and Antifungal Property (Days of Culture) Time (minutes) 714 21 28 Example 7 70 00 00 Example 8 800 0 0 1 Comparative Example 4 5 2 3 4 4 Comparison Example 5 10 3 4 4 4 Note: Evaluation method 0; no mold growth is observed 1; mold growth is slightly observed 2; mold growth is slightly observed 3; moderate growth is observed 4: Mold growth is severely recognized.

[0035]

According to the present invention, there is provided a novel antimicrobial agent obtained by dissolving cupric oxide and / or zinc oxide in calcium oxide and / or magnesium oxide. Since the antimicrobial agent of the present invention releases copper ions and / or zinc ions with solubility in water close to calcium oxide or magnesium oxide, the antimicrobial agent is superior to poorly soluble cupric oxide or zinc oxide. Demonstrate the nature. Furthermore, excellent dispersibility in resin, rubber, paint,
It has excellent characteristics of improving heat resistance and weather resistance without impairing those characteristics.

Claims (2)

(57) [Claims] 1. Formula (1) (M ₁ ²⁺ ) _1-x (M ₂ ²⁺ ) _x O (1) wherein M ₁ is Mg and / or Ca, M ₂ is Cu and / or Represents Zn, x is 0.0001 ≦ x ≦ 0.5
An antimicrobial agent comprising the composite metal oxide of the above as an active ingredient. 2. 100 parts by weight of resin or rubber and 0.0
An antimicrobial resin or rubber composition comprising 01 to 50 parts by weight of the antimicrobial agent according to claim 1.