JPH09206680A - Method for coating zeolite provided with antibacterial and mildew-proofing properties - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a zelite film of antibacterial and mildew-proofing properties on the surface of a base or a molded product by a simple method. SOLUTION: A sol-gel bath is prepared by adding alcoxyde of antibacterial metal or β-diketonate into a solution prepared by dissolved aluminum alcoxyde, alcoxysilane, alcoxyde of alkaline metal or alkaline earth metal, a stabilizer and water into an organic solvent, and a base or a molded product is coated by using the sol-gel bath and also using immersion, coating, spraying methods or the like, and dried and then burnt. As the antibacterial metal, one kind or two kinds or more selected out of Ag, Cu, Zn, Sn, Pb, Co and Bi are used. It is preferable that the antibacterial metal of the ratio of 0.1-45% is carried on a zeolite film. Therefore, the zeolite film of antibacterial properties and mildew resistance is manufactured in one process.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a zeolite layer having antibacterial / antifungal properties on a metal surface or the like by a sol-gel method.

[0002]

2. Description of the Related Art An antibacterial agent in which a metal ion having antibacterial and antifungal properties is carried on zeolite powder by an ion exchange method is known. Powder antibacterial agent is dispersed in the resin because it is used as a film-like antibacterial agent that is easy to handle, but the antibacterial agent is only partially exposed on the surface, and the entire surface is coated from the viewpoint of antibacterial and antifungal effects Is desired. As a means for covering the entire surface, it is conceivable to carry a metal ion having antibacterial and antifungal properties by ion exchange after forming the zeolite membrane. The zeolite membrane is formed by a hydrothermal synthesis method. For example, when an aqueous gel mixture containing colloidal silica, aluminum nitrate, sodium hydroxide, a crystallization modifier, etc. is brought into contact with an appropriate substrate and subjected to hydrothermal treatment, a zeolite film is formed on the substrate surface (Nippon Kagaku Magazine 1992). Year No. 8 877-88
Page 0). When this zeolite membrane is loaded with metal ions having antibacterial / antifungal properties, the appropriate p
Generally, a method of immersing in a metal salt solution of silver nitrate, zinc nitrate, copper nitrate or the like adjusted to H and performing ion exchange is used.

[0003]

[Problems to be Solved by the Invention] In conventional hydrothermal synthesis,
The hydrolysis of the solution does not occur at room temperature and atmospheric pressure, and a zeolite solid cannot be formed. Therefore, high-temperature heating in the autoclave is required, but the use of the autoclave makes the manufacturing process batch type, which is not suitable for continuous manufacturing.
Further, since the antibacterial metal ions are supported by ion exchange after the zeolite film is formed, two steps of forming the zeolite film and supporting the antibacterial metal ions are required, resulting in an increase in manufacturing cost. The present invention has been devised to solve such a problem, and by using a sol-gel bath containing an antibacterial metal, continuous production is possible,
The purpose is to form a zeolite membrane with antibacterial and antifungal properties in one step.

[0004]

In order to achieve the object, the zeolite coating method of the present invention dissolves an aluminum alkoxide, an alkoxysilane, an alkali metal or alkaline earth metal alkoxide, a stabilizer and water in an organic solvent. An antibacterial metal alkoxide or β-diketonate is added to the prepared solution to prepare a sol-gel bath, the substrate or molded article is coated with the sol-gel bath by dipping, coating, spraying, etc., dried, and then baked. It is characterized by doing. Antibacterial metals include Ag, Cu, Zn, S
One or more selected from n, Pb, Co and Bi are used. The antibacterial metal is 0.1 to 0.1% in the zeolite film.
It is preferable to support it at a ratio of 45%.

When forming a zeolite membrane, high temperature heating using an autoclave does not allow continuous production. The present inventors have developed, as a zeolite coating method for solving this drawback, a coating method using a solution in which an aluminum alkoxide, an alkoxysilane, an alkoxide or a hydroxide of an alkali metal or an alkaline earth metal are dissolved in an organic solvent. did. But even with this method,
An ion exchange step is required after formation of the zeolite membrane.
Therefore, as a result of further research, Ag, Cu, Zn, S
One or more of alkoxides or β-diketonates of antibacterial metals such as n, Pb, Co, Bi, etc. are added to the above-mentioned solution to prepare a sol-gel bath, and the sol-gel bath is used to prepare a substrate or molded article. It was found that a zeolite membrane in which antibacterial metal ions are supported can be formed by one step by coating by a method such as dipping, coating, spraying, etc., and then drying and firing.

[0006]

[Embodiment] When a sol-gel bath is coated on a substrate or a molded article by dipping, coating, spraying or the like, aluminum alkoxides, alkoxysilanes, alkali metal or alkaline earth metal alkoxides and antibacterial metal alkoxides or β-diketonates are hydrolyzed. Hydroxide adheres. When the substrate or molded product is heated, the synthetic reaction proceeds,
A zeolite film having antibacterial / antifungal properties is formed on the surface of the substrate or the molded product. Examples of the antibacterial metal salt added to the sol-gel bath include methoxysilver, ethoxysilver, silver acetylacetonate, dimethoxyzinc, diethoxyzinc, zinc acetylacetonate, dimethoxycopper, diethoxycopper and copper acetylacetonate. The amount of the antibacterial metal element supported in the zeolite membrane is controlled by the concentration of the antibacterial metal alkoxide or acetylacetonate in the solution. The supported amount in zeolite is preferably 0.1 to 45%. If the supported amount is less than 0.1%, the required antibacterial and antifungal effects are hardly exhibited. On the contrary, if the supported amount exceeds 45%, the sol-gel bath becomes unstable and it becomes difficult to form a zeolite membrane.

[0007]

【Example】

Example 1: Aluminum isopropoxide, tetraethyl orthosilicate, sodium methoxide, triisopropanolamine and water were dissolved in butyl cellosolve, silver methoxide was added, and the mixture was stirred for 24 hours to prepare a sol-gel bath. The composition of the prepared sol-gel bath is shown in Table 1. All the baths were transparent and were stable even when left to stir for 100 hours. Using these sol-gel baths, a stainless steel plate SUS430 having a plate thickness of 0.5 mm was coated as a substrate by a pulling method, dried at room temperature for 2 minutes, and then dried at 380 ° C. for 2 minutes.
Bake for minutes. The formed zeolite film was uniform and dense and was a transparent film. Structural analysis of this coating by X-ray diffraction revealed that silver zeolite crystals were formed.

[0008]

Example 2 A sol-gel bath was prepared in the same manner as in Example 1 except that copper acetylacetonate was added instead of silver methoxide. Table 2 shows the composition of the sol-gel bath in this example. All the sol-gel baths were transparent baths, and the zeolite coating formed from these sol-gel baths under the same conditions as in Example 1 was transparent, uniform, and dense. In addition, structural analysis revealed that copper zeolite crystals were formed.

[0010]

Example 3 A sol-gel bath was prepared in the same manner as in Example 1 except that zinc acetylacetonate was added instead of silver methoxide. The composition of the sol-gel bath in this example is shown in Table 3. All the sol-gel baths were transparent baths, and the zeolite coating formed from these sol-gel baths under the same conditions as in Example 1 was transparent, uniform, and dense. In addition, structural analysis revealed that zinc zeolite crystals were formed.

[0012]

Example 4 A 50 mm × 50 mm test piece was cut out from the antibacterial zeolite-coated steel sheet prepared in the same manner as in Examples 1 to 3, and the antibacterial activity was investigated by the sprinkling method using Escherichia coli and Staphylococcus aureus as test bacteria. did. In the antibacterial test, 1 ml of the bacterial solution adjusted to a concentration of 10 ⁵ cells / ml was dropped on the test piece and incubated at 37 ° C. for 24 hours, and then the bacteria were washed out with a phosphate buffer. The number of bacteria was measured for the washed bacterial solution. As shown in Table 5 showing the observation result, A
It can be seen that good antibacterial properties are obtained in any zeolite film supporting any of g, Cu and Zn. Among them, a remarkable antibacterial property was shown at a supported amount of 0.1% or more.

[0014]

Example 5: The same sample as in Example 4 was examined for antifungal properties. In the fungicide resistance test, 5 kinds of mixed spore suspensions were sprayed on a 50 mm x 50 mm test piece cut out from a zeolite-coated steel plate, followed by culturing for 28 days at a temperature of 28 ° C and a relative humidity of 97%, and then a mold surface The growth state of was observed visually. As can be seen from Table 5 showing the observation results, it was found that good antifungal properties were obtained in any of the zeolite films supporting any of Ag, Cu and Zn. Among them, the growth of fungi was almost suppressed when the loading amount was 0.1% or more.

[0016]

In the above examples, the zeolite layer supporting Ag, Cu and Zn was described. However, when other antibacterial metals such as Sn, Pb, Co and Bi were carried, the same excellent antibacterial and antifungal effects were obtained.

[0018]

As described above, according to the present invention, a zeolite coating having an antibacterial / antifungal action is formed in one step by performing zeolite coating using a sol-gel bath containing an antibacterial metal. . Since the obtained zeolite film has excellent antibacterial and antifungal properties, it is used in a wide range of fields such as medical instruments, kitchen products, building materials, and accessories.

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location C23C 18/02 C23C 18/02 26/00 26/00 C

Claims (3)

[Claims] 1. An organic alkoxide in an organic solvent,
A sol-gel bath is prepared by adding an antibacterial metal alkoxide or β-diketonate to a solution in which an alkoxysilane, an alkali metal or alkaline earth metal alkoxide, a stabilizer and water are dissolved, and a substrate using the sol-gel bath Alternatively, a zeolite coating method having antibacterial and antifungal properties, which is characterized in that a molded product is coated by a method such as dipping, coating, or spraying, dried, and then fired. 2. The antibacterial metal according to claim 1, wherein Ag, Cu,
A zeolite coating method comprising one or more selected from Zn, Sn, Pb, Co and Bi. 3. A zeolite coating method in which the zeolite coating carries 0.1 to 45% of the antibacterial metal according to claim 1 or 2.